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Ecological Evaluation Using Seaweed Distribution Characteristics along the Coast of Jeju Island (제주도 연안의 해조류 분포 특성을 이용한 생태학적 평가)

  • Sung-Hwan Cho;Young-Seok Noh;Seung-Hwan Won;Soo-Kang Kim;Sang-Mok Jung
    • Korean Journal of Environment and Ecology
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    • v.36 no.6
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    • pp.627-638
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    • 2022
  • This study was conducted at a village fishing farm on 4 peaks on the main island of Jeju Island and 2 peaks on an inhabited island to compare the distribution characteristics of seaweeds along the coast of Jeju Island from May to December 2018. A total of 101 species of seaweeds were surveyed, including 13 species (12.9%) of green algae, 24 species (23.8%) of Phaeophyta, and 64 species (63.4%) of Rhodophyta. The largest number of seaweeds appeared in May and the fewest in October, showing typical features of a temperate sea area. The number of seaweed species that appeared was 66 and 65 species at the water depths of 5 m and 8 m, respectively, and the largest was 74 species at 12 m. The number of seaweeds that appeared by area was the largest at 66 species on Udo Island, an eastern island near Jeju Island, and the lowest at 27 species in Pyoseon-ri, an eastern part of Jeju Island. The important values of emerging species were high in the order of, Ecklonia cavaand Corallina crassissima at 21.1% and 20.3%, respectively, Corallina aberransat 9.2%, Amphora ephedraeaat 6.2%, and Sargassum macrocarpumat 4.4%. Among seaweeds, an average of 11.2 species of coralline algae appeared, and the mean importance value was 32.6% in the sear area. The lowest importance value was 14.7% on Udo Island, and the highest was 41.0% in Pyoseon-ri. The mean ecological evaluation index (EEI) of seaweed colonies ranged from 2.1 to 10. It was the lowest at the water depth of 12 m in Pyoseon-ri in May and June and was 7.3 or higher in other areas, indicating good condition. This study rated the standardized ecological grade I for the water depth of 12 m on Udo Island and grade II for the water depths of 5 m and 8 m in Sagye-ri and on Chujado Island. Grade III was the water depth of 5 m and 12 m in Pyoseon-ri and Guideok 2-ri and the water depth of 5 m and 8 m in Pyeongdae-ri, and grade IV was the water depth of 8 m in Guideok 2-ri.

Studies on the Maturation of the Follicular Oocytes by Xenoplastical Transplantation in the Anterior Chamber of the Eye (異種動物의 眼前房에 이식된 濾胞卵子의 成熟에 관한 연구)

  • Cho, Wan Kyoo
    • The Korean Journal of Zoology
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    • v.13 no.3
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    • pp.68-74
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    • 1970
  • In the previous studies, the present author found that high proportion of the follicular oocytes from mouse and rabbit ovaries are able to resume their maturation division in the anterior chamber of the eye in which they have been incubated by auto- or homoplastic transplantation. Especially in the case of the homoplastic transplantation, it was known that no trouble has been detected in the process of resumption of the oval maturation in particular connection with the antigen-antibody reaction between donor and recipient. These findings provide a possibility that the follicular oocytes from various animals would be matured in the eye even after the xenoplastic transplantation. Under such an assumption, the present studies were performed to examine the behavior of the follicular oocytes in the eye chamber of the animals of different species. For the donor of the follicular oocytes, domestic rabbits, albino rats of Sprague-Dowley strain, and albino mice of A-strain bred in our laboratory were used. The oocytes obtained from the ovarian follicules were introduced to the anterior chamber of the eye of different species of animals, with an exception of rabbit in which only the female animals were used as a recipient. The procedures of collection of ova, introduction to the eye, harvest from the eye ball, fixation, and staining were the same as mentioned in the previous reports (Cho, 1967b; Cho and Kim, 1968). The conclusions obtained are summarized as below. 1. The rabbit follicular oocytes are able to mature in the eye chambers of both male mouse and rat, although the proportion of the maturation is lower than when they are incubated autoplastically in the eye. When the ova were incubated in the male mouse eye for 24 hours, 21 per cent of them showed chromosomes at metaphase I and II, whereas the rate was 32 per cent when they were incubated in the eye of the male rat. These are apparently low comparing to the rate of 52 per cent of autoplastic transplantation. 2. When rat follicular oocytes were transferred into the mouse eye chamber and recovered after 24 hours, 43 per cent of them produced the mataphase I and II chromosomes. This proportion was higher than the result of the homoplastic transplantation which yielded 23 per cent of the ova on maturation. 3. The most striking result was found in the experiment with mouse follicular oocytes. Seventy-six per cent of the oocytes resumed their maturation division within 24 hours after they were transferred into the male rat eye chamber, and this figure was significantly high compared to the result o 55 per cent obtained by the homoplastic transplantation. In the rat eye, the induction of the degenerative ova also was low (19%). On the other hand, the proportion of the oval maturation decreased to 45 per cent, while that of degeneration increased 33 per cent when they were incubated in the eye of the female rabbit. 4. It was apparent from the present experiments that the follicular oocytes can reveal their activation to maturation in the eye chamber which contains aqueous humor which is known to be composed of low protein content and of very little gamma-globulin which acts as an antibody(Oser, 1965), and that it shows higher osmolarity than blood serum(Levene, 1958). Taking these properities into consideration the humor may provide unfavourable environment to the cells and tissues incubated in. However, it could be noteworthy finding that only the follicular oocytes in the eye of the different species can grow in healthy condition although the maturation rates are varied with the animal species. The fact that the rabbit follicular oocytes show the lower proportion in maturation may be due to the greater amount of the yolk granules in the egg cytoplasm than those in the mouse and rat oocytes. That the mouse oocytes incubated in the eye of the rat mouse and rat oocytes. That the mouse oocytes incubated in the eye of the rat resumed their maturation process in greater proportion would e explained by the fact that the rat eye chamber particularly provides the better environment to the mouse oocytes than the eye chamber of mouse does.

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Metabolic Discrimination of Papaya (Carica papaya L.) Leaves Depending on Growth Temperature Using Multivariate Analysis of FT-IR Spectroscopy Data (FT-IR 스펙트럼 다변량통계분석을 이용한 파파야(Carica papaya L.)의 생육온도 변화에 따른 대사체 수준 식별)

  • Jung, Young Bin;Kim, Chun Hwan;Lim, Chan Kyu;Kim, Sung Chel;Song, Kwan Jeong;Song, Seung Yeob
    • Journal of the Korean Society of International Agriculture
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    • v.31 no.4
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    • pp.378-383
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    • 2019
  • To determine whether FT-IR spectral analysis based on multivariate analysis for whole cell extracts can be used to discriminate papaya at metabolic level. FT-IR spectral data from leaves were analyzed by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA) and hierarchical clustering analysis (HCA). FT-IR spectra confirmed typical spectral differences between the frequency regions of 1,700-1,500, 1,500-1,300 and 1,100-950 cm-1, respectively. These spectral regions were reflecting the quantitative and qualitative variations of amide I, II from amino acids and proteins (1,700-1,500 cm-1), phosphodiester groups from nucleic acid and phospholipid (1,500-1,300 cm-1) and carbohydrate compounds (1,100-950 cm-1). The result of PCA analysis showed that papaya leaves could be separated into clusters depending on different growth temperature. In this case, showed discrimination confirmed according to metabolite content of growth condition from papaya. And PLS-DA analysis also showed more clear discrimination pattern than PCA result. Furthermore, these metabolic discrimination systems could be applied for rapid selection and classification of useful papaya cultivars.

The embryological studies on the interspecific hybrid of ginseng plant (Panax ginseng x P. Quiuquefolium) with special references to the seed abortion (인삼의 종간잡종 Panax ginseng x P Quinquefoilium의 발생학적 연구 특히 결실불능의 원인에 관하여)

  • Jong-Kyu Hwang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.5 no.1
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    • pp.69-86
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    • 1969
  • On the growing of the interspecific hybrid ginseng plant, the phenomena of hybrid vigoures are observed in the root, stem, and leaf, but it can not produce seeds favorably since the ovary is abortive in most cases in interspecific hybrid plants. The present investigation was undertaken in an attempt to elucidate the embryological dses of the seed failure in the interspecific hybrid of ginseng (Panax Ginseng ${\times}$ P. Quinque folium). And the results obtained may be summarized as follows. 1). The vegetative growth of the interspecific hybrid ginseng plant is normal or rather vigorous, but the generative growth is extremely obstructed. 2). Even though the generative growth is interrupted the normal development of ovary tissue of flower can be shown until the stage prior to meiosis. 3). The division of the male gameto-genetic cell and the female gameto-genetic cell are exceedingly irregular and some of them are constricted prior to meiosis. 4). At meiosis in the microspore mother cell of the interspecific hybrid, abnormal division is observed in that the univalent chromosome and chromosome bridge occure. And in most cases, metaphasic configuration is principally presented as 23 II+2I, though rarely 22II+4I is also found. 5). Through the process of microspore and pollen formation of F1, the various developmental phases occur even in an anther loclus. 6). Macro, micro and empty pollen grains occur and the functional pollen is very rare. 7). After the megaspore mother cell stage, the rate of ovule development is, on the whole, delayed but the ovary wall enlargement is nearly normal. 8). Degenerating phenomena of ovules occur from the megaspore mother cell stage to 8-nucleate embryo sac stage, and their beginning time of constricting shape is variously different. 9). The megaspore arrangement in the parent is principally of the linear type, though rarely the intermediate type is also observed, whereas various types, viz, linear, intermediate, Tshape, and I shape can be observed in hybrid. 10). After meiosis, three or five megaspore are some times counted. 11). Charazal end megaspore is generally functional in the parents, whereas, in F1, very rarely one of the center megaspores (the second of the third megaspore) grows as an embryo sac mother cell. 12). In accordance with the extent of irregularity or abnormality in meiosis, division of embryo sac nuclei and embryo sac formation cause more nucellus tissue to remain within th, embryo sac. 13). Even if one reached the stage of embryo sac formation, the embryo sac nuclei are always precarious and they can not be disposed to theil proper, respective position. 14). Within the embryo sac, which is lacking the endospermcell, the 4-celled proembryo, linear arrangement, is observed. 15). Through the above respects, the cause of sterile or seed failure of interspecific hybrid would be presumably as follows, By interspecific crossing gene reassortments takes place and the gene system influences the metabolism by the interference of certain enzyme as media. In the F1 plant, the quantity and quality of chemicals produced by the enzyme system and reaction system are entirely different from the case of the parents. Generally, in order to grow, form, and develop naw parts it is necessary to change the materials and energy with reasonable balance, whereas in the F1 plant the metabolic process becomes abnormal or irregular because of the breakdown of the balancing. Thus the changing of the gene-reaction system causes the alteration of the environmental condition of the gameto-genetic cells in the anther and ovule; the produced chemicals cause changes of oxidatio-reduction potential, PH value, protein denaturation and the polarity, etc. Then, the abnormal tissue growing in the ovule and emdryo sac, inhibition of normal development and storage of some chemicals, especially inhibitor, finally lead to sterility or seed failure. Inconclusion, we may presume that the first cause of sterile or seed abortion in interspecific hybrids is the gene reassortment, and the second is the irregularity of the metabolic system, storage of chemicals, especially inhibitor, the growth of abnormal tissue and the change of the polarity etc, and they finally lead to sexual defect, sterility and seed failure.

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A Study on Maternity Aids Utilization in the Maternal and Child Health and Family Planning (농촌(農村)에 있어서 분만개조요원(分娩介助要員)의 봉사(奉仕)에 의(依)한 모자보건(母子保健)rhk 가족계획(家族計劃)에 관(關) 연구(硏究))

  • Yeh, Min-Hae;Lee, Sung Kwan
    • Journal of Preventive Medicine and Public Health
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    • v.5 no.1
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    • pp.57-95
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    • 1972
  • This study was conducted to assess the effectiveness of service by maternity aids concerning maternal and child health in improving simultaneously infant mortality, contraception and vital registration among expectant mothers in rural Korea, where there is less apportunity for maternal and child health care. It is unrealistic to expect to solve this problem in rural Korea through professional persons considering the situation of medical facilities and the socioeconomic condition of residents. So, we intended to adopt a system of services by maternity aids who were educated formally among indigenous women. After the women were trained in maternal and child health, contraception, and registration for a short period, they were assigned as a maternity aids to each village to help with various activities concerning maternal and child health, for example, registration of pregnant women, home visiting to check for complications, supplying of delivery kits, attendance at delivery, persuasion of contraception, and invitation for registration and so on. Mean-while, four researchers called on the maternity aids to collect materials concerning vital events, maternal child health, contraception and registration, and to give further instruction and supervision as the program proceeded. A. Changes of women's attitude by services of maternity aid. Now, we examined to what extent' such a service system to expectant mothers affected a change in attitude of women residing in the study area as compared to women of the control area. 1) In the birth and death places, there were no changes between last and present infants, in study or control area. 2) In regard to attendants at delivery, there were no changes except for a small percentage of attendance (8%) by maternity aid in study area. But, I expect that more maternity sids could be used as attendants at delivery if they would be trained further and if there was more explanation to the residents about such a service. 3) Considering the rate of utilization of sterilized delivery kit, I am sure that more than 90 percent would be used if the delivery kit were supplied in the proper time. There were significant differences in rates between the study and the control areas. 4) Taking into consideration the utilization rate of the clinic for prenatal care and well baby care, if suck facilities were installed, it would probably be well utilized. 5) In the contraception, the rate of approval was as high as 89 percent in study area as compared to 82 percent in the control area. 6) Considering the rate of pre-and post-partum acceptance on contraception were as much as 70 percent or more, if motivation to use contraception was given to them adequately, the government could reach the goals for family planning as planned. 7) In the vital registration, the rate of birth registration in the study area was some what improved compared to that of the control area, while the rate of death registration was not changed at all. Taking into account the fact that the rate of confirmation of vital events by maternity aids was remarkably high, if the registration system changed to a 'notification' system instead of formal registration ststem, it would be improved significantly compared to present system. B. Effect of the project Thus, with changes in the residents' attitude, was there a reduction in the infant death rate? 1) It is very difficult problem to compare the mortality of infants between last and present infants, because many women don't want to answer accurately about their dead children especially the infants that died within a few days after birth. In this study the data of present death comes from the maternity aides who followed up every pregnancy they had recorded to see what had happened. They seem to have very reliable information on what happened in first few weeks with follow up visitits to check out later changes. From these calculaton, when we compared the rate of infant death between last and present infant, there was remarkable reduction of death rate for present infant compare to that of last children, namely, the former was 30, while the latter 42. The figure is the lowest rate that I have ever heard. As the quality of data we could assess by comparing the causes of death. In the current death rate by communicable disease was much lower compare to the last child especially, tetanus cases and pneumonia. 2) Next, how many respondents used contraception after birth because of frequent contact with the maternity aid. In the registered cases, the respondents showed a tendency to practice contraception at an earlier age and with a small number of children. In a comparison of the rate of contraception between the study and the control area, the rate in the former was significantly higher than that of the latter. What is more, the proportion favoring smaller numbers of children and younger women rose in the study area as compared to the control area. 3) Regarding vital registration, though the rate of registration was gradually improved by efforts of maternity aid, it would be better to change the registration system. 4) In the crude birth rate, the rate in the study area was 22.2 while in the control area was 26.5. Natural increase rate showed 15.4 in the study area, while control area was 19.1. 5) In assessment of the efficiency of the maternity aids judging by the cost-effect viewpoint, the workers in the Medium area seemed to be more efficiency than those of other areas.

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The Experimental Study for Myocardial Preservation Effect of Ischemic Preconditioning (허혈성 전조건화 유발이 심근보호에 미치는 영향에 관한 실험적 연구)

  • 이종국;박일환;이상헌
    • Journal of Chest Surgery
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    • v.37 no.2
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    • pp.119-130
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    • 2004
  • Decrease in cardiac function after open heart surgery is due to an ischemia induced myocardial damage during surgery, and ischemic preconditioning, a condition in which the myocardial damage does not accumulate after repeated episodes of ischemia but protects itself from damage after prolonged ischemia due to myocytes tolerating the ischemia, is known to diminish myocardial damage, which also helps the recovery of myocardium after reperfusion, and decreases incidences of arrythmia. Our study is performed to display the ischemic preconditioning and show the myocardial protective effect by applying cardioplegic solution to the heart removed from rat. Material and Method: Sprague-Dawley male rats were used, They were fixed on a modified isolated working heart model after cannulation. The reperfusion process was according to non-working and working heart methods and the working method was executed for 20 minutes in which the heart rate, aortic pressure, aortic flow and coronary flow were measured and recorded. The control group is the group which the extracted heart was fixed on the isolated working heart model, recovered by reperfusion 60 minutes after infusion and preserved in the cardioplegic solution 20 minutes after the working heart perfusion and aortic cross clamp, The thesis groups were divided into group I, which ischemic hearts that were hypoxia induced were perfused by cardioplegic solution and preserved for 60 minutes; group II, the cardioplegic solution was infused 45 seconds (II-1), 1 minutes (II-2), 3 minutes (II-3), after the ischemia induction, 20 minutes after working heart perfusion and aortic cross clamp; and group III, hearts were executed on working heart perfusion for 20 minutes and aortic cross clamp was performed for 45 seconds (III-1), 1minute (III-2), 3 minutes (III-3), reperfused for 2 minutes to recover the heart, and then aortic cross clamping was repeated for reperfusion, all the groups were compared based on hemodynamic performance after reperfusion of the heart after preservation for 60 minutes. Result: The recovery time until spontaneous heart beat was longer in groups I, II-3, III-2 and III-3 to control group (p<0.01). Group III-1 (p<0.05) had better results in terms of recovery in number of heart rates compared to control group, and recovered better compared to II-1 (p<0.05). The recovery of aortic blood pressure favored group III-1 (p<0.05) and had better outcomes compared with II-1 (p<0.01). Group III-1 also showed best results in terms of cardiac output (p<0.05) and group III-2 was better compared to II-2 (p<0.05). Group I (p<0.01) and II-3 (p<0.05) showed more cardiac edema than control group. Conclusion: When the effects of other organs are dismissed, protecting the heart by infusion of cardioplegic solution after enforcing ischemia for a short period of time before the onset of abnormal heart beats for preconditioning has a better recovery effect in the cardioplegic group with preconditioning compared to the cardioplegic solution itself. we believe that further study is needed to find a more effective method of preconditioning.

Studies on the Derivation of the Instantaneous Unit Hydrograph for Small Watersheds of Main River Systems in Korea (한국주요빙계의 소유역에 대한 순간단위권 유도에 관한 연구 (I))

  • 이순혁
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.19 no.1
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    • pp.4296-4311
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    • 1977
  • This study was conducted to derive an Instantaneous Unit Hydrograph for the accurate and reliable unitgraph which can be used to the estimation and control of flood for the development of agricultural water resources and rational design of hydraulic structures. Eight small watersheds were selected as studying basins from Han, Geum, Nakdong, Yeongsan and Inchon River systems which may be considered as a main river systems in Korea. The area of small watersheds are within the range of 85 to 470$\textrm{km}^2$. It is to derive an accurate Instantaneous Unit Hydrograph under the condition of having a short duration of heavy rain and uniform rainfall intensity with the basic and reliable data of rainfall records, pluviographs, records of river stages and of the main river systems mentioned above. Investigation was carried out for the relations between measurable unitgraph and watershed characteristics such as watershed area, A, river length L, and centroid distance of the watershed area, Lca. Especially, this study laid emphasis on the derivation and application of Instantaneous Unit Hydrograph (IUH) by applying Nash's conceptual model and by using an electronic computer. I U H by Nash's conceptual model and I U H by flood routing which can be applied to the ungaged small watersheds were derived and compared with each other to the observed unitgraph. 1 U H for each small watersheds can be solved by using an electronic computer. The results summarized for these studies are as follows; 1. Distribution of uniform rainfall intensity appears in the analysis for the temporal rainfall pattern of selected heavy rainfall event. 2. Mean value of recession constants, Kl, is 0.931 in all watersheds observed. 3. Time to peak discharge, Tp, occurs at the position of 0.02 Tb, base length of hlrdrograph with an indication of lower value than that in larger watersheds. 4. Peak discharge, Qp, in relation to the watershed area, A, and effective rainfall, R, is found to be {{{{ { Q}_{ p} = { 0.895} over { { A}^{0.145 } } }}}} AR having high significance of correlation coefficient, 0.927, between peak discharge, Qp, and effective rainfall, R. Design chart for the peak discharge (refer to Fig. 15) with watershed area and effective rainfall was established by the author. 5. The mean slopes of main streams within the range of 1.46 meters per kilometer to 13.6 meter per kilometer. These indicate higher slopes in the small watersheds than those in larger watersheds. Lengths of main streams are within the range of 9.4 kilometer to 41.75 kilometer, which can be regarded as a short distance. It is remarkable thing that the time of flood concentration was more rapid in the small watersheds than that in the other larger watersheds. 6. Length of main stream, L, in relation to the watershed area, A, is found to be L=2.044A0.48 having a high significance of correlation coefficient, 0.968. 7. Watershed lag, Lg, in hrs in relation to the watershed area, A, and length of main stream, L, was derived as Lg=3.228 A0.904 L-1.293 with a high significance. On the other hand, It was found that watershed lag, Lg, could also be expressed as {{{{Lg=0.247 { ( { LLca} over { SQRT { S} } )}^{ 0.604} }}}} in connection with the product of main stream length and the centroid length of the basin of the watershed area, LLca which could be expressed as a measure of the shape and the size of the watershed with the slopes except watershed area, A. But the latter showed a lower correlation than that of the former in the significance test. Therefore, it can be concluded that watershed lag, Lg, is more closely related with the such watersheds characteristics as watershed area and length of main stream in the small watersheds. Empirical formula for the peak discharge per unit area, qp, ㎥/sec/$\textrm{km}^2$, was derived as qp=10-0.389-0.0424Lg with a high significance, r=0.91. This indicates that the peak discharge per unit area of the unitgraph is in inverse proportion to the watershed lag time. 8. The base length of the unitgraph, Tb, in connection with the watershed lag, Lg, was extra.essed as {{{{ { T}_{ b} =1.14+0.564( { Lg} over {24 } )}}}} which has defined with a high significance. 9. For the derivation of IUH by applying linear conceptual model, the storage constant, K, with the length of main stream, L, and slopes, S, was adopted as {{{{K=0.1197( {L } over { SQRT {S } } )}}}} with a highly significant correlation coefficient, 0.90. Gamma function argument, N, derived with such watershed characteristics as watershed area, A, river length, L, centroid distance of the basin of the watershed area, Lca, and slopes, S, was found to be N=49.2 A1.481L-2.202 Lca-1.297 S-0.112 with a high significance having the F value, 4.83, through analysis of variance. 10. According to the linear conceptual model, Formular established in relation to the time distribution, Peak discharge and time to peak discharge for instantaneous Unit Hydrograph when unit effective rainfall of unitgraph and dimension of watershed area are applied as 10mm, and $\textrm{km}^2$ respectively are as follows; Time distribution of IUH {{{{u(0, t)= { 2.78A} over {K GAMMA (N) } { e}^{-t/k } { (t.K)}^{N-1 } }}}} (㎥/sec) Peak discharge of IUH {{{{ {u(0, t) }_{max } = { 2.78A} over {K GAMMA (N) } { e}^{-(N-1) } { (N-1)}^{N-1 } }}}} (㎥/sec) Time to peak discharge of IUH tp=(N-1)K (hrs) 11. Through mathematical analysis in the recession curve of Hydrograph, It was confirmed that empirical formula of Gamma function argument, N, had connection with recession constant, Kl, peak discharge, QP, and time to peak discharge, tp, as {{{{{ K'} over { { t}_{ p} } = { 1} over {N-1 } - { ln { t} over { { t}_{p } } } over {ln { Q} over { { Q}_{p } } } }}}} where {{{{K'= { 1} over { { lnK}_{1 } } }}}} 12. Linking the two, empirical formulars for storage constant, K, and Gamma function argument, N, into closer relations with each other, derivation of unit hydrograph for the ungaged small watersheds can be established by having formulars for the time distribution and peak discharge of IUH as follows. Time distribution of IUH u(0, t)=23.2 A L-1S1/2 F(N, K, t) (㎥/sec) where {{{{F(N, K, t)= { { e}^{-t/k } { (t/K)}^{N-1 } } over { GAMMA (N) } }}}} Peak discharge of IUH) u(0, t)max=23.2 A L-1S1/2 F(N) (㎥/sec) where {{{{F(N)= { { e}^{-(N-1) } { (N-1)}^{N-1 } } over { GAMMA (N) } }}}} 13. The base length of the Time-Area Diagram for the IUH was given by {{{{C=0.778 { ( { LLca} over { SQRT { S} } )}^{0.423 } }}}} with correlation coefficient, 0.85, which has an indication of the relations to the length of main stream, L, centroid distance of the basin of the watershed area, Lca, and slopes, S. 14. Relative errors in the peak discharge of the IUH by using linear conceptual model and IUH by routing showed to be 2.5 and 16.9 percent respectively to the peak of observed unitgraph. Therefore, it confirmed that the accuracy of IUH using linear conceptual model was approaching more closely to the observed unitgraph than that of the flood routing in the small watersheds.

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The Effects of Online Service Quality on Consumer Satisfaction and Loyalty Intention -About Booking and Issuing Air Tickets on Website- (온라인 서비스 품질이 고객만족 및 충성의도에 미치는 영향 -항공권 예약.발권 웹사이트를 중심으로-)

  • Park, Jong-Gee;Ko, Do-Eun;Lee, Seung-Chang
    • Journal of Distribution Research
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    • v.15 no.3
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    • pp.71-110
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    • 2010
  • 1. Introduction Today Internet is recognized as an important way for the transaction of products and services. According to the data surveyed by the National Statistical Office, the on-line transaction in 2007 for a year, 15.7656 trillion, shows a 17.1%(2.3060 trillion won) increase over last year, of these, the amount of B2C has been increased 12.0%(10.2258 trillion won). Like this, because the entry barrier of on-line market of Korea is low, many retailers could easily enter into the market. So the bigger its scale is, but on the other hand, the tougher its competition is. Particularly due to the Internet and innovation of IT, the existing market has been changed into the perfect competitive market(Srinivasan, Rolph & Kishore, 2002). In the early years of on-line business, they think that the main reason for success is a moderate price, they are awakened to its importance of on-line service quality with tough competition. If it's not sure whether customers can be provided with what they want, they can use the Web sites, perhaps they can trust their products that had been already bought or not, they have a doubt its viability(Parasuraman, Zeithaml & Malhotra, 2005). Customers can directly reserve and issue their air tickets irrespective of place and time at the Web sites of travel agencies or airlines, but its empirical studies about these Web sites for reserving and issuing air tickets are insufficient. Therefore this study goes on for following specific objects. First object is to measure service quality and service recovery of Web sites for reserving and issuing air tickets. Second is to look into whether above on-line service quality and on-line service recovery have an impact on overall service quality. Third is to seek for the relation with overall service quality and customer satisfaction, then this customer satisfaction and loyalty intention. 2. Theoretical Background 2.1 On-line Service Quality Barnes & Vidgen(2000; 2001a; 2001b; 2002) had invented the tool to measure Web sites' quality four times(called WebQual). The WebQual 1.0, Step one invented a measuring item for information quality based on QFD, and this had been verified by students of UK business school. The Web Qual 2.0, Step two invented for interaction quality, and had been judged by customers of on-line bookshop. The WebQual 3.0, Step three invented by consolidating the WebQual 1.0 for information quality and the WebQual2.0 for interactionquality. It includes 3-quality-dimension, information quality, interaction quality, site design, and had been assessed and confirmed by auction sites(e-bay, Amazon, QXL). Furtheron, through the former empirical studies, the authors changed sites quality into usability by judging that usability is a concept how customers interact with or perceive Web sites and It is used widely for accessing Web sites. By this process, WebQual 4.0 was invented, and is consist of 3-quality-dimension; information quality, interaction quality, usability, 22 items. However, because WebQual 4.0 is focusing on technical part, it's usable at the Website's design part, on the other hand, it's not usable at the Web site's pleasant experience part. Parasuraman, Zeithaml & Malhorta(2002; 2005) had invented the measure for measuring on-line service quality in 2002 and 2005. The study in 2002 divided on-line service quality into 5 dimensions. But these were not well-organized, so there needed to be studied again totally. So Parasuraman, Zeithaml & Malhorta(2005) re-worked out the study about on-line service quality measure base on 2002's study and invented E-S-QUAL. After they invented preliminary measure for on-line service quality, they made up a question for customers who had purchased at amazon.com and walmart.com and reassessed this measure. And they perfected an invention of E-S-QUAL consists of 4 dimensions, 22 items of efficiency, system availability, fulfillment, privacy. Efficiency measures assess to sites and usability and others, system availability measures accurate technical function of sites and others, fulfillment measures promptness of delivering products and sufficient goods and others and privacy measures the degree of protection of data about their customers and so on. 2.2 Service Recovery Service industries tend to minimize the losses by coping with service failure promptly. This responses of service providers to service failure mean service recovery(Kelly & Davis, 1994). Bitner(1990) went on his study from customers' view about service providers' behavior for customers to recognize their satisfaction/dissatisfaction at service point. According to them, to manage service failure successfully, exact recognition of service problem, an apology, sufficient description about service failure and some tangible compensation are important. Parasuraman, Zeithaml & Malhorta(2005) approached the service recovery from how to measure, rather than how to manage, and moved to on-line market not to off-line, then invented E-RecS-QUAL which is a measuring tool about on-line service recovery. 2.3 Customer Satisfaction The definition of customer satisfaction can be divided into two points of view. First, they approached customer satisfaction from outcome of comsumer. Howard & Sheth(1969) defined satisfaction as 'a cognitive condition feeling being rewarded properly or improperly for their sacrifice.' and Westbrook & Reilly(1983) also defined customer satisfaction/dissatisfaction as 'a psychological reaction to the behavior pattern of shopping and purchasing, the display condition of retail store, outcome of purchased goods and service as well as whole market.' Second, they approached customer satisfaction from process. Engel & Blackwell(1982) defined satisfaction as 'an assessment of a consistency in chosen alternative proposal and their belief they had with them.' Tse & Wilton(1988) defined customer satisfaction as 'a customers' reaction to discordance between advance expectation and ex post facto outcome.' That is, this point of view that customer satisfaction is process is the important factor that comparing and assessing process what they expect and outcome of consumer. Unlike outcome-oriented approach, process-oriented approach has many advantages. As process-oriented approach deals with customers' whole expenditure experience, it checks up main process by measuring one by one each factor which is essential role at each step. And this approach enables us to check perceptual/psychological process formed customer satisfaction. Because of these advantages, now many studies are adopting this process-oriented approach(Yi, 1995). 2.4 Loyalty Intention Loyalty has been studied by dividing into behavioral approaches, attitudinal approaches and complex approaches(Dekimpe et al., 1997). In the early years of study, they defined loyalty focusing on behavioral concept, behavioral approaches regard customer loyalty as "a tendency to purchase periodically within a certain period of time at specific retail store." But the loyalty of behavioral approaches focuses on only outcome of customer behavior, so there are someone to point the limits that customers' decision-making situation or process were neglected(Enis & Paul, 1970; Raj, 1982; Lee, 2002). So the attitudinal approaches were suggested. The attitudinal approaches consider loyalty contains all the cognitive, emotional, voluntary factors(Oliver, 1997), define the customer loyalty as "friendly behaviors for specific retail stores." However these attitudinal approaches can explain that how the customer loyalty form and change, but cannot say positively whether it is moved to real purchasing in the future or not. This is a kind of shortcoming(Oh, 1995). 3. Research Design 3.1 Research Model Based on the objects of this study, the research model derived is

    . 3.2 Hypotheses 3.2.1 The Hypothesis of On-line Service Quality and Overall Service Quality The relation between on-line service quality and overall service quality I-1. Efficiency of on-line service quality may have a significant effect on overall service quality. I-2. System availability of on-line service quality may have a significant effect on overall service quality. I-3. Fulfillment of on-line service quality may have a significant effect on overall service quality. I-4. Privacy of on-line service quality may have a significant effect on overall service quality. 3.2.2 The Hypothesis of On-line Service Recovery and Overall Service Quality The relation between on-line service recovery and overall service quality II-1. Responsiveness of on-line service recovery may have a significant effect on overall service quality. II-2. Compensation of on-line service recovery may have a significant effect on overall service quality. II-3. Contact of on-line service recovery may have a significant effect on overall service quality. 3.2.3 The Hypothesis of Overall Service Quality and Customer Satisfaction The relation between overall service quality and customer satisfaction III-1. Overall service quality may have a significant effect on customer satisfaction. 3.2.4 The Hypothesis of Customer Satisfaction and Loyalty Intention The relation between customer satisfaction and loyalty intention IV-1. Customer satisfaction may have a significant effect on loyalty intention. 3.2.5 The Hypothesis of a Mediation Variable Wolfinbarger & Gilly(2003) and Parasuraman, Zeithaml & Malhotra(2005) had made clear that each dimension of service quality has a significant effect on overall service quality. Add to this, the authors analyzed empirically that each dimension of on-line service quality has a positive effect on customer satisfaction. With that viewpoint, this study would examine if overall service quality mediates between on-line service quality and each dimension of customer satisfaction, keeping on looking into the relation between on-line service quality and overall service quality, overall service quality and customer satisfaction. And as this study understands that each dimension of on-line service recovery also has an effect on overall service quality, this would examine if overall service quality also mediates between on-line service recovery and each dimension of customer satisfaction. Therefore these hypotheses followed are set up to examine if overall service quality plays its role as the mediation variable. The relation between on-line service quality and customer satisfaction V-1. Overall service quality may mediate the effects of efficiency of on-line service quality on customer satisfaction. V-2. Overall service quality may mediate the effects of system availability of on-line service quality on customer satisfaction. V-3. Overall service quality may mediate the effects of fulfillment of on-line service quality on customer satisfaction. V-4. Overall service quality may mediate the effects of privacy of on-line service quality on customer satisfaction. The relation between on-line service recovery and customer satisfaction VI-1. Overall service quality may mediate the effects of responsiveness of on-line service recovery on customer satisfaction. VI-2. Overall service quality may mediate the effects of compensation of on-line service recovery on customer satisfaction. VI-3. Overall service quality may mediate the effects of contact of on-line service recovery on customer satisfaction. 4. Empirical Analysis 4.1 Research design and the characters of data This empirical study aimed at customers who ever purchased air ticket at the Web sites for reservation and issue. Total 430 questionnaires were distributed, and 400 were collected. After surveying with the final questionnaire, the frequency test was performed about variables of sex, age which is demographic factors for analyzing general characters of sample data. Sex of data is consist of 146 of male(42.7%) and 196 of female(57.3%), so portion of female is a little higher. Age is composed of 11 of 10s(3.2%), 199 of 20s(58.2%), 105 of 30s(30.7%), 22 of 40s(6.4%), 5 of 50s(1.5%). The reason that portions of 20s and 30s are higher can be supposed that they use the Internet frequently and purchase air ticket directly. 4.2 Assessment of measuring scales This study used the internal consistency analysis to measure reliability, and then used the Cronbach'$\alpha$ to assess this. As a result of reliability test, Cronbach'$\alpha$ value of every component shows more than 0.6, it is found that reliance of the measured variables are ensured. After reliability test, the explorative factor analysis was performed. the factor sampling was performed by the Principal Component Analysis(PCA), the factor rotation was performed by the Varimax which is good for verifying mutual independence between factors. By the result of the initial factor analysis, items blocking construct validity were removed, and the result of the final factor analysis performed for verifying construct validity is followed above. 4.3 Hypothesis Testing 4.3.1 Hypothesis Testing by the Regression Analysis(SPSS) 4.3.2 Analysis of Mediation Effect To verify mediation effect of overall service quality of and , this study used the phased analysis method proposed by Baron & Kenny(1986) generally used. As shows, Step 1 and Step 2 are significant, and mediation variable has a significant effect on dependent variables and so does independent variables at Step 3, too. And there needs to prove the partial mediation effect, independent variable's estimate ability at Step 3(Standardized coefficient $\beta$eta : efficiency=.164, system availability=.074, fulfillment=.108, privacy=.107) is smaller than its estimate ability at Step 2(Standardized coefficient $\beta$eta : efficiency=.409, system availability=.227, fulfillment=.386, privacy=.237), so it was proved that overall service quality played a role as the partial mediation between on-line service quality and satisfaction. As
    shows, Step 1 and Step 2 are significant, and mediation variable has a significant effect on dependent variables and so does independent variables at Step 3, too. And there needs to prove the partial mediation effect, independent variable's estimate ability at Step 3(Standardized coefficient $\beta$eta : responsiveness=.164, compensation=.117, contact=.113) is smaller than its estimate ability at Step 2(Standardized coefficient $\beta$eta : responsiveness=.409, compensation=.386, contact=.237), so it was proved that overall service quality played a role as the partial mediation between on-line service recovery and satisfaction. Verified results on the basis of empirical analysis are followed. First, as the result of , it shows that all were chosen, so on-line service quality has a positive effect on overall service quality. Especially fulfillment of overall service quality has the most effect, and then efficiency, system availability, privacy in order. Second, as the result of , it shows that all were chosen, so on-line service recovery has a positive effect on overall service quality. Especially responsiveness of overall service quality has the most effect, and then contact, compensation in order. Third, as the result of and , it shows that and all were chosen, so overall service quality has a positive effect on customer satisfaction, customer satisfaction has a positive effect on loyalty intention. Fourth, as the result of and , it shows that and all were chosen, so overall service quality plays a role as the partial mediation between on-line service quality and customer satisfaction, on-line service recovery and customer satisfaction. 5. Conclusion This study measured and analyzed service quality and service recovery of the Web sites that customers made a reservation and issued their air tickets, and by improving customer satisfaction through the result, this study put its final goal to grope how to keep loyalty customers. On the basis of the result of empirical analysis, suggestion points of this study are followed. First, this study regarded E-S-QUAL that measures on-line service quality and E-RecS-QUAL that measures on-line service recovery as variables, so it overcame the limit of existing studies that used modified SERVQUAL to measure service quality of the Web sites. Second, it shows that fulfillment and efficiency of on-line service quality have the most significant effect on overall service quality. Therefore the Web sites of reserving and issuing air tickets should try harder to elevate efficiency and fulfillment. Third, privacy of on-line service quality has the least significant effect on overall service quality, but this may be caused by un-assurance of customers whether the Web sites protect safely their confidential information or not. So they need to notify customers of this fact clearly. Fourth, there are many cases that customers don't recognize the importance of on-line service recovery, but if they would think that On-line service recovery has an effect on customer satisfaction and loyalty intention, as its importance is very significant they should prepare for that. Fifth, because overall service quality has a positive effect on customer satisfaction and loyalty intention, they should try harder to elevate service quality and service recovery of the Web sites of reserving and issuing air tickets to maximize customer satisfaction and to secure loyalty customers. Sixth, it is found that overall service quality plays a role as the partial mediation, but now there are rarely existing studies about this, so there need to be more studies about this.

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  • Studies on the Effects of Several Factors on Soil Erosion (토양침식(土壤侵蝕)에 작용(作用)하는 몇가지 요인(要因)의 영향(影響)에 관(關)한 연구(硏究))

    • Woo, Bo Myeong
      • Journal of Korean Society of Forest Science
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      • v.29 no.1
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      • pp.54-101
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      • 1976
    • This study was conducted on the major factors affecting soil erosion and surface run-off. In order to investigate the processes and mechanisms of soil erosion on denuded forest-land in Korea, and to systematize the magnitudes of influences and interactions between individual factors, the five major factors adopted in these experiments are soil textures (coarse sand and clay loam), slope steepness ($10^{\circ}$, $20^{\circ}$, $30^{\circ}$ and $40^{\circ}$), rainfall intensities (50, 75 and 100mm/hr), slope mulching methods (bare, coarse straw-mat mulching, grass mulching and anti-erosion liquid mulching) and vegetation densities (sparse, moderate and dense). The processes and mechanisms of soil erosion, and the effects of mulchings on soil erosion as well as surface run-off rates were studied algebraically with four parts of laboratory experiments under the simulated rainfall and another part of field experiment under the natural rainfall. The results in this study are summarized as follows: 1. Experiment factors and surface run-off rates The surface run-off rates under the natural rainfall were resulted about 24.7~28.7% from the bare slopes, about 14.0~16.4% from the straw-mat mulched slopes, about 7.9~9.1% from the liquid mulched slopes, and about 5.6~7.2% from the grass mulched slopes respectively. The surface run-off rates under the simulated rainfall differed greatly according to the rainfall intensity and the mulching method. 2. Magnitudes of influences and interactions of the individual factor on the surface run-off rates. The experimental analyses on the major factors(soils, slopes, rainfalls, mulchings and vegetations) affecting the rates of surface run-off, show that the mean differences of surface run-off rate are significant at 5% level between the soil texture factors, among the slope steepness factors, among the rainfall intensity factors, among the mulching method factors, and among the vegetation density factors respectively. The interactions among the individual factor have a great influence(significant at 1% level) upon the rate of surface run-off, except for the interactions of the factors between soils and slopes; between slopes and vegetations; among soils, slopes and rainfalls; and among soils, slopes and mulchings respectively. On the bare slopes under the simulated rainfall, the magnitude of influences of three factors(soils, slopes and rainfalls) affecting the rate of surface run-off is in the order of the factor of rainfalls, soils and slopes. The magnitude of influences of three factors (soils, rainfalls and mulchings) affecting the rate of surface run-off, on the mulched slopes under the simulated rainfall is in the order of the factor of mulchings, rainfalls and soils and that of influences of the factor of soils, slopes and mulchings is in the order of the factor of mulchings, soils and slopes. On the vegetation growing slopes under the simulated rainfall, the magnitude of influences of three factors (soils, slopes and vegetations) affecting the rate of surface run-off is in the order of the factor of vegetations, soils and slopes. In the same condition of treatments on the field experiment under the natural rainfall, the order of magnitude of influences affecting the rate of surface run-off is the factor of mulchings, soils and slopes. 3. Experiment factors and soil losses The soil losses of the experiment plots differed according to the factors of soil texture, slope steepness, rainfall intensity and mulching method. The soil losses from the coarse soil were increased about 1.1~1.3 times as compared with that of fine soil under the natural rainfall, while the soil losses from the fine soil were increased about 1.2~1.3 times compared with that of coarse soil under the simulated rainfall. The equation of $E=aS^b$ (a, b are constant) between the slope steepness (log S) and soil losses (log E) under the simulated rainfall were developed. The equation of $E=aI^b$ (a, b are constant) between the rainfall intensity (log I) and soil losses (log E) were developed, and b values have a decreasing tendency according to the increase of the slope steepness and rainfall intensity. The soil losses under the natural rainfall were appeared about 38~41% from the coarse straw-mat mulched slopes, about 20~22% from the liquid mulched slopes, about 14~15% from the grass mulched slopes as compared with that of the bare slopes respectively. The soil loss from the vegetation plots showed about 7.1~16.4 times from the sparse plot, about 10.0~17.9 times from the moderate plot and about 11.1~28.1 times from the dense plot as compared with that of the bare slopes. 4. Magnitudes of influences and interactions of the individual factor on the soil erosion. The experimental analyses on the major factors(soils, slopes, rainfalls, mulchings and vegetations) affecting the soil erosion, show that the mean differences of soil losses are highly significant between the soil texture factors, among the slope steepness factors, among the rainfall intensity factors, among the mulching method factors and among the vegetation density factors respectively. The interactions among the individual factor have mostly great influences upon the soil erosion. The magnitude of influences of three factors (soils, slopes and rainfalls) affecting the soil erosion on the bare slopes under the simulated rainfall is in order of the factor of rainfalls, soils and slopes. On the mulched slopes under the simulated rainfall, the magnitude order of influences of three factors(soils, rainfalls and mulchings) affecting the soil erosion is the factor of mulchings, rainfalls and soils, and the order of influences of factor of soils, slopes and mulchings is the factor of mulchings, soils and slopes. On the vegetation growing slopes under the simulated rainfall, the magnitude of influences of three factors (soils, slopes and vegetations) affecting the soil erosion is in the order of the factor of slopes. vegetations and soils. In the same condition of treatments on the field experiment under the natural rainfall, the order of magnitude of influences of three factors (soils, slopes and mulchings) affecting the soil erosion is the factor of mulchings, of slopes and of soils.

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    Studies on Dairy Farming Status, Reproductive Efficiencies and Disorders in New Zealand (I) A Survey on Dairy Farming Status and Milk Yield in Palmerston North Area (뉴질랜드 (Palmerston North) 의 낙농 현황과 번식 및 번식장해에 관한 연구(I) Palmerston North 지역의 낙농 현황과 우유 생산량에 관한 조사 연구)

    • 김중계;맥도날드
      • Korean Journal of Animal Reproduction
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      • v.24 no.1
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      • pp.1-18
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      • 2000
    • Eighty dairy farms in Palmers ton North area in New Zealand were surveyed on 1) general characteristics (10 Questions), 2) milk yield and feed supplementary (7 questions), 3) reproductive efficiencies (12 questions) and 4) reproductive disorders (12 questions) by mail questions from February to July, 1998. Among those 4 items from 38 dairy farms (47.5%), especially in items 1) and 2), overall dairy farming situation, supplementary feeding and milk yields were surveyed and analyzed for Korean dairy farmers (especially in Cheju island) to have better understanding or higher economical gains. The results were as follows. 1. In dairy experience, 21 (45%) among 38 dairy farms surveyed were answered that farming less than 15 years, 15~19 year, 20~25 years and over 26 years experience were 3 (7.9%), 7 (18.4%), 6 (15.8%) and 5 (13.2%) which generally showed longer experience compare to Korean dairy farming situation. In survey of labour input and business goal of dairy farming, self-managing farms, sharemilkers, unpaid family manpowering farms, manager running farms, farms with hired worker, farms with part time helper and other type was 21 (55.3%), 10 (26.3%), 2 (3.5%), 3 (5.3%), 18 (31.6%), 2 (3.5%), and 1 (1.8%), respectively. 2. Analyzing pasture and tillable land, pasture according to feeding scale (200, 300 and 400 heads) were 56, 90 and 165.3 ha, and tillable lands were 51, 78 and 165 ha which showed some differences among feeding scale. In recording methods in 38 farms replied, 36 (95%) dairy handbook and 23 (70%) dual methods taking farms were higher than that of 10 (26.3%) computer and 15(39.5%) well-recorder methods. 3. Dairy waste processing facilities in environmental field were almost perfect except of metropolitan area, and so no problem was developed in its control so far. Hence, 26 farm (68.4%) of pond system was higher rather than those in 8 (21.2%) of using as organic manure after storing feces of dairy cattle, 1(2.6%) bunker system and 3 (7.9%) other type farms. 4. In milking facilities, 33 farms (86.9%) of Harringbone types were higher than those in 3 (7.9%) of Walkthrough types, 1 (2.6%) of Rotary system and other types. Although the construction facilities was not enough, this system show the world-leveled dairy country to attempted to elevate economic gains using the advantage of climatic condition. 5. In milking day and yearly yield per head, average 275 milking days and 87 drying days were longer than that of 228 average milking days in New Zealand. Annual total milk yield per head and milk solid (ms) was 3,990 kg and approximately 319 kg. Dairy milk solid (ms) per head, milk yield, fat percentage was 1.2 kg, 15.5 kg and average 4.83% which was much higher than in other country, and milk protein was average 3.75%. 6. In coclusion, Palmerstone North has been a center of dairy farming in New Zealand for the last 21 years. Their dairy farming history is 6~9 year longer than ours and the average number of milking cows per farm is 355, which is much greater than that (35) of Korea. They do not have dairy barn, but only milking parlors. Cows are taken care of by family 0.5 persons), are on a planned calving schedule in spring (93%) and milked for 240~280 days a year, avoiding winter. Cows are dried according to milk yield and body condition score. This management system is quite different from that of Korean dairy farms. Cows are not fed concentrates, relying entirely on pasture forages and the average milk yield per cow is 3,500 kg, which is about 1/2 milk yield of Korean dairy farms. They were bred to produce high fat milk with an average of 4.5%. Their milk production cost is the lowest in the world and the country's economy relies heavily on milk production. We Korean farmers may try to increase farming size, decreasing labor and management costs.

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