• Korea journal of population studies
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• v.28 no.2
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• pp.1-32
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• 2005

The optimum population of a society or country can be defined as 'the population growth path that maximizes the welfare level of the society over the whole generations of both the present and the future, under the paths allowed by its endowments of production factors such as technology, capital and labor'. Thus, the optimum size or growth rate of population depends on: (i) the social welfare function, (ii) the production function, and (iii)demographic economic interrelationship which defines how the national income is disposed into consumption(birth and education of children included) and savings on the one hand and how the demographic and economic change induced thereby, in turn, affect production capacities on the other. The optimum population growth path can, then, be derived in the process of dynamic optimization of (i) under the constraints of (ii) and (iii), which will give us the optimum population growth rate defined as a function of parameters thereof. This paper estimates the optimum population growth rate of Korea by: specifying (i), (ii), and (iii) based on the recent development of economic theories, solving the dynamic optimization problem and inserting empirical estimates in Korea as the parametric values. The result shows that the optimum path of population growth in Korea is around TFR=1.81, which is affected most sensitively, in terms of the size of the partial elasticity around the optimum path, by the cost of children, share of capital income, consumption rate, time preference, population elasticity of utility function, etc. According to a survey implemented as a follow up study, there are quite a significant variations in the perceived cost of children, time preference rate, population elasticity of utility across different socio-economic classes in Korea, which implied that, compared to their counterparts, older generation and more highly educated classes prefer higher growth path for the population of Korea.

• Journal of Preventive Medicine and Public Health
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• v.9 no.1
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• pp.11-24
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• 1976

This study was a part of large scale of a prospective study on attitudes of professional students in medicine, nursing and teaching toward population related issues in Korea. The study was first conducted in May 1974 and then in May 1975 for the 1974 class cohot using a questionaire consisted of attitude scales and other items developed by Lee. The purpose of stuay was twohold, namely, to determine the difference in students among specializations on one hand and between the first and second years in the 1974 class cohot regarding tile subject matter. A one-way analysis of variance was used for attitude scale, and absolute and relative frequency were computed for the analysis of non-attitude scale items by employing Fishers' Ratio and Duncan's multiple range test at 5% level and chi square test at 5% level as significance tests. The hypothesis 'students in health profession are more likely to have positive attitudes toward population related issues progressively as class year advances than students in teaching profession' was tested and the following results were obtained: 1) Nursing students were more likely to display favarable attitudes toward family planning than medical or teaching students although the class cohot showed slightly negative improvement in the second year. Medical and teaching students apperaed to have slightly improved attitudes in the second year. 2) Respondents in general perceived national family planning program as a means of population control and this tendency was more true among nursing students as the class year advances than two other professional groups of students. Students in teaching profession appeared to perceive it more as a means to improve individual family welfare while health students were likely to see as to improve maternal and child health. This tendency was progressively improved as the class year advanced. 3) The majority of students regardless of their respective specializations believed that family planning program should be directed toward the improvement of individual family welfare. No progressive changes in the class cohot were observed. 4) About the plan to use contraceptives in future, no singnificant differences were observes among different specializations nor in different class years. However, the majority was confirmed to have a plan to use contracepives in future. An increasing proportion of the undecided category was observed, as class year advanced among health students. 5) Students in health profession were found to be more favorable about 'more leisure opportunities' as motive for limiting number of children whereas education students indicated the reasons as 'facilitate ambitions' and 'economic base' The progressive changes toward positive direction in both groups were observed as the class years advanced. 6) Attitudes toward induced abortions of the health students were observed to be positively related to class years while an inverse relationship was found in teaching students who showed much less favor in the subject matter than health students. This phenomenon may be due to the different exposure to learning environments unique to respective specializations. 7) Health students were found to have more favorable attitudes toward population education in general than the teaching students. The teaching students appeared to have changed more to the negative direction when they became the second year while no such development was observed in health students. The teaching students seemed to hold a very conservative position with regard to sex education in schools. 8) About the equality of sexes, the nursing group was found to be most favorable while the reverse was true in the teaching group. A change in the negative direction as the class year advanced was found in the teaching group. 9) About questions related to fertility values-the 10 percent of respondents regardless of specialization indicated that they would maintain their single status in future, however no change was observed in the second year. The desired number of children was found to be two by the majority of students in nursing, medicine and teaching in order of high proportion. No changes in a different class year were observed. The childless marriage was seen by nursing students as a problem more than other students, but a slight change in positive direction was found when the nursing students became the second year. In summing, as data supported in the above, students in health profession demonstrated more favorable attitudes toward population related issues than the teaching students and this tendency became more apparent in the second year. It was noticed that health students were more conscious about the health aspect of population and family planning program while the teaching students gave more attention to the socioeconomic aspect. The sex variable seemed to have operated in the item related to the equality of sexes. In conclusion, as data presented in the above, the hypothesis of this study was accepted except in the few items. It should be noted that the limitation of this study is the short duration of the observation in measuring the possible attitude changes. It should include curriculum analysis for the respective specializations in order to indentify the area of curriculum impact on students in future study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1467-1474
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• 2012

The purpose of study was to introduce menus consisting of traditional local foods consumed in Busan, Korea. Five different types of formal meal menus with three side dishes and five different types of informal meal menus of which the main dish was not cooked rice were developed. Scores for the menu evaluations of formal and informal meals were higher than 7.9 (mean score of 6 category) on a 9.0 scale, suggesting that the menus were well constituted in terms of 'repeated use of ingredients and cooking methods', 'balance between main and side dishes', 'frequency of usage of local products', 'nutritional balance', 'variety of dishes', and 'popularization'. Nutritional values of menus were compared with those of the KDRI for men aged 30~49 years old. All ten menus reflected a low calorie, high protein, and high fiber diet. Mineral contents (Ca, Fe, Zn, K, and Na) of the above 10 menus were higher than those of the KDRI. On the other hand, vitamin contents slightly differed according to meal type due to limited fresh vegetable usage in the winter season. Vitamin A, B ($B_1$, $B_2$, niacin, $B_6$), C, folic acid, and E contents in the five informal menus were found to be proper or greater than those of the KDRI. However, for the formal meal menus, all vitamin contents except that of vitamin A in menu type I was lower than that of the KDRI. Content of vitamin C in menu type V was approximately 50% of that of the KDRI. The most preferred formal menu was consisted of Ogokbap, Boreumjijimi, Dongchimi, Namul (nine varieties), Gaksaeksanjeok (Shark/Daegu/Gunso), and Gimgui. And that for informal menu was consisted of Honghapjuk, Baechu kimchi, Dongchimi, Miyeokseolchi, Kodari jorim, and Neulgeun hobakjeon. Suggestions for providing more fresh vegetables or fruits for certain types of meals (formal meal type V) were offered. Additionally, pre-preparation of sea products were required to reduce Na contents.

• The Korean Journal of Physiology
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• v.7 no.2
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• pp.1-8
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• 1973

Though it has been reported by Clements et al. and Avery et al. that the activity of the pulmonary surfactant can be altered by the temperature changes, a conclusive evidence of the effects of temperature on the surfactant system of the lung is yet to come. In the present study, an attempt was made to observe possible effects of a few different degrees of temperature on the activity of the pulmonary surfactant of the rabbit in vivo and in vitro. The rabbit was sacrificed by blood shedding and both lungs were completely removed. The lung washings, obtained by gently lavaging the left lung with saline, was placed at 1) 4C for 1, 5, 10, 15, 30 and 40 days, and 2) 20C for 1, 2, 3, 4, 5 and 7 days for in vitro experiment. For in vivo experiment, the rabbit was placed at 4C for 4, 8, 12 and 24 hours, and the lung lavage was prepared as described above in the in vitro experiment. Tension-area (T-A) diagram of the lung lavage was recorded automatically by a modified. Langmuir-Wilhelmy balance with a synchronized recording system. The surface tensions thus obtained were compared with those of the normal rabbit, and the results are summarized as follows: 1. The maximal surface tension, minimal surface tension and stability index of the normal rabbit lung lavage were $52.5{\pm}2.3\;dynes/cm,\;4.9{\pm}2.3\;dynes/cm$ and 1.65, respectively. 2. In the group where the lung lavage was placed at 4C in vitro, the maximal and minimal surface tensions, and stability index did not show any noticeable changes comparing with the normal values up to 30 days. On the 40th day of the experiment, a tendency of a slight increase in the surface tensions was observed but the change was not significant. 3. When the lung lavage was placed at 20 C in vitro, the maximal surface tension did not show any appreciable change comparing with the normal except on the 7 th day with a slight increase. The minimal surface tension showed an increased value from the 2nd day, and on the 5 th and 7 th experimental day, markedly increased value was observed. The stability index, on the other hand. showed a marked decrease throughout the entire experiment with the value of 0.71 and 0.53 on the 5th and 7 th day, respectively. 4. In the group where the rabbit was placed at 4 C in vivo, the maximal surface tensions and stability index of the lung lavage showed little change from the normal. The minimal surface tension at 12 experimental hour showed a slight increase, but it returned to the normal value at 24 hour.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.29-46
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• 2004

It is important to identify geometries of fracture that act as a conduit of fluid flow for characterization of ground water flow in fractured rock. Fracture geometries control hydraulic conductivity and stream lines in a rock mass. However, we have difficulties to acquire whole geometric data of fractures in a field scale because of discontinuous distribution of outcrops and impossibility of continuous collecting of subsurface data. Therefore, it is needed to develop a method to describe whole feature of a target fracture geometry. This study suggests a new approach to develop a method to characterize on the whole feature of a target fracture geometry based on the Fourier transform. After sampling of specimens along a target fracture from borehole cores, effective frequencies among roughness components were selected by the Fourier transform on each specimen. Then, the selected effective frequencies were averaged on each frequency. Because the averaged spectrum includes all the frequency profiles of each specimen, it shows the representative components of the fracture roughness of the target fracture. The inverse Fourier transform is conducted to reconstruct an averaged whole roughness feature after low pass filtering. The reconstructed roughness feature also shows the representative roughness of the target subsurface fracture including the geometrical characteristics of each specimen. It also means that overall roughness feature by scaling up of a fracture. In order to identify the characteristics of permeability coefficients along the target fracture, fracture models were constructed based on the reconstructed roughness feature. The computation of permeability coefficient was performed by the homogenization analysis that can calculate accurate permeability coefficients with full consideration of fracture geometry. The results show a range between $10^{-4}{\;}and{\;}10^{-3}{\;}cm/sec$, indicating reasonable values of permeability coefficient along a large fracture. This approach will be effectively applied to the analysis of permeability characteristics along a large fracture as well as identification of the whole feature of a fracture in a field scale.

• Economic and Environmental Geology
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• v.35 no.3
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• pp.257-271
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• 2002

One of the main interests in relation to heavily contaminated gully-pot sediment in urban area is the short term mobility of heavy metals, which depends on the pH of acidic rainwater and on the buffering effects of carbonate minerals. The buffering effects of carbonates are determined by titration (acid addition). Leaching experiments are carried out in solutions with variable initial HN03 contents for 24h. The gully-pot sediment appears to be predominantly buffered by calcite and dolomite. In case of sediment samples, which highly contain carbonates, pH decreases more slowly with increasing acidity. On the other hand, for the sediment samples, which less contain carbonate minerals, pH rapidly drops until it reaches about 2 then it decreases slowly. The leaching reactions are delayed until more acid is added to compensate for the buffering effects of carbonates. The Zn, Cu, Pb and Mn concentrations of leachate rapidly increase with decreased pH, while Cd, Co, Ni, Cr and Fe dissolutions are very slow and limited. The solubility of heavy metals depends not only on thc pH values of leachatc but also on the speciation in which metals are associated with sediment particles. In slightly to moderately acid conditions, Zn, Cd, Co, Ni and Cu dissolutions become increasingly important. As deduced from leaching runs, the relative mobility of heavy metals at pH of 5 is found to be: Zn > Cd > Co > Ni > Cu » Pb > Cr, suggesting that moderately acid rainwater leach Zn, Cd, Co, Ni and Cu from thc contaminated gully-pot sediment, while Pb and Cr would remain fixed. The buffering effects of Ca- and Mg-carbonates play an important role in delaying as well as limiting the leaching reactions of heavy metals from highly contaminated gully-pot sediment. The extent of such a secondary environmental pollution will thus depends on how well the metals in sediment can be leached by somewhat acidic rain water. Changes in the physicochemical environments may result in the severe environmental pollution of heavy metals. These results are to be taken into account in the management of contaminated sediments during rainstorms.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.19-26
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• 2000

In order to select potent bioactive isolates, 70 Fusarium isolates obtained from soil and 21 plant species were screened by antifungal, insecticidal, herbicidal, and duckweed bioassays after culturing in potato dextrose broth and rice solid media. Eight (11.4%) of the 70 liquid broth cultures showed disease-controlling activities more than 80% against at least one of the 6 plant diseases tested. Fusarium sp. FO-68 isolate exhibited the most potent antifungal activity; it controlled rice blast, wheat leaf rust, and barley powdery mildew with control values more than 95%. Out of 70 solid cultures, 21 (30.0%) controlled at least one plant disease more than 80% and F. equiseti FO-68 isolate showed disease-controlling activities more than 95% against 3 plant diseases such as rice blast, tomato late blight, and wheat leaf rust. As for tile insecticidal activities, 2 liquid and 1 solid cultures showed potent insecticidal activities against pest insects more than 80%, Liquid cultures of F. oxysporum FO-61 and Fusarium sp. FO-80 isolates exhibited insecticidal activities more than 80% against green peach aphid and diamondback moth, respectively. The solid culture of Fusarium sp. FO-510 isolate had 80% insecticidal activity against green peach aphid. However, none of liquid and solid cultures of the 70 Fusarium isolates showed potent herbicidal activities against 10 upland weeds. As the results of duckweed assay, 3 liquid cultures showed 70% growth inhibitory activity at concentrations less than 1.25% of culture supernatants and 9 solid cultures had a potent inhibitory activity against duckweed growth. On the other hand, there was a significant correlation between antifungal activities and herbicidal activities against duckweed of both liquid and solid cultures of tile 70 Fusarium isolates.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.4
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• pp.218-234
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• 2004

Recent warm winters were evaluated for a possible shifting of the northern limit for winter barley cultivation in Korea. Therefore, safe zones for winter barley cultivation were reclassified based on the average and minimum January air temperature in recent years. The results are as follows: By analysis of mean values of January average air temperatures for 30 years (1971-2000), the northern limits for safe cultivation of hulled, naked, and malting barley were Ganghwa - Icheon - Chungju - Chunyang - Goseong, Cheonan - Geumsan - Mungyeong - Andong - Sokcho, and Gwangju - Jangheung - Sancheong - Pohang - Uljin lines, respectively. Meanwhile, based on the January average air temperature of 14 years (1987-2000) with warmer winters, the safe cultivation zone of winter barley shifted northward of the normal (1971-2000). So, the northern limits for hulled, naked, and malting barley were Pocheon - Chuncheon - Wonju - Yangpyeong - Chunyang, Ganghwa - Icheon - Chungju - Uiseong - Goseong, and Gunsan - Suncheon - Jinju - Miryang - Yeongdeok - Uljin lines, respectively. Winter barley cultivars with the strongest tolerance to low temperature can be grown up to the adjacent areas of Taebaek Mountains (that is, Inje, Hongcheon, Jecheon, and Taebaek areas). Based on January mean air temperatures of 10-year return period for 30 years (1971-2000), the northern limits for hulled and naked barley were Boryeong - Namwon - Geochang - Gumi - Goseong and Seocheon - Jeongeup - Hapcheon - Yeongdeok - Sokcho lines, respectively. It ~ppears that malting barley can be cultivated only at southern coastal areas (that is, Busan, Tongyeong, Yeosu, and Wando areas). On the other hand, based on the weather conditions of 14 years (1987-2000) with warmer winters, the northern limits for hulled, naked, and malting barley were Ganghwa - Icheon - Yeongju - Goseong, Seosan - Namwon - Mungyeong - Andong - Sokcho, and Gwangju - Jangheung - Sacheon - Ulsan - Uljin lines, respectively. The northern limit for winter barley cultivars including Olbori with the strongest tolerance to low temperature was the Ganghwa - Wonju - Chungju - Chunyang - Goseong line.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.465-471
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• 2008

Physicochemical characteristics of black garlic were analyzed. Colorimetry measurement showed that the black garlic, compared with fresh and steamed garlics, was the highest in a value and the lowest in L and b values. Crude lipid, crude protein, and total sugars were the highest in black garlic, which was followed by steamed and fresh garlic. On the other hand, moisture content was the lowest in the black garlic and the highest in the fresh garlic. The pH of garlics was ca. 6.8, 6.5, and 4.4 in fresh, steamed, and black garlic, respectively, which indicated that garlics tended to be acidified with the thermal processing. Total pyruvate and total thiosulfinates were the lowest in steamed garlic ($77{\mu}mol$/g and 0.07 OD/g for each) and the highest in black garlic ($278{\mu}mol$/g and 0.77 OD/g). Arabinose and galactose were detected only in black garlic and their contents were 1.6 and 13 mg/100 g, respectively. Free sugars such as glucose, sucrose and fructose were the highest in the order of fresh, steamed, and black garlic. Potassium was a predominant mineral in all garlics, constituting 76% of total minerals. Glutamic acid, arginine, and aspartic acid were the major composition amino acids in all garlics, regardless of processing conditions. 15 kinds of free amino acids were detected in fresh and steamed garlic, while five more free amino acids, O-phosphoethanolamine, and urea were additionally detected in black garlic.

• Korean Journal of Poultry Science
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• v.7 no.2
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• pp.37-46
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• 1980

Hand deboned and mechanically deboned chicken meat were produced from domestic broilers and spent layers. Meat yield, chemical composition, functional characteristics, stability during storage, and microbiological properties were investigated Chicken patties and frankfurters were also manufactured by varying the relative proportion of MDCM to HDCM as raw materials, ana their palatability, shelf-life and textural properties were evaluated. The obtained results were as follows: 1) 35% of carcass wt was recovered as HDCM and 45% as MDCM, total meat yield reaching 80% of carcass wt. 2) Moisture, protein, fat, ash and Ca content of MDCM were 65, 12, 20, 1.7 and 0.2-0.4%,respectively. MDCM was higher in fat, ash and Ca, but significantly lower in moisture and protein. Total pigment content of MDCM was 2.5 times higher than that of HDCD such high content being attributed to the increased inclusion of hemoglobin. 3) The emulsifying capacity (ES) of MOCM per g meat was only 70% that of HDCM. but when ES was expressed on unit g of protein basis MDCM showed even higher ES than HDCM primarily due to tile higher proportion of salt soluble protein fraction. 4) Since the TBA values of MDCM increased rapidly after 4 weeks of frozen storage at -20$^{\circ}C$, the maximum possible storage period of MDCM is estimated to be about 4 weeks. 5) Total microbial counts of MDCM was approximately 1.8${\times}$10$\^$6/g/, showing no great difference from HDCM or red meat. 6) Chicken patty containing MDCM showed gradual increase in TBA value during frozen storage, but its storage up to 8 weeks presented no problems in flavor stability. 7) Color score an4 total palatability of chicken Patty were best for the product containing 30% MDCM. It was also concluded that MDCM can be included in the patties up to 50% of total meat with good results, but more than 70% was not recommended 8) The formulation of MDCM up to 50% in frankfurter gave quite satisfactory acceptability and textural properties comparable to frankfurter made of 100% MDCM, but the inclusion of more than 70% MDCM was not recommended 9) The TBA value of frankfurter containing MDCM did not increase to any great extent until 4 weeks of storage at 4$^{\circ}C$, indicating no unique problems in flavor instability compared to regular frankfurter. 10) It was concluded that processed meat products such as patties and frankfurters containing MDCM up to 30-50% of total meat ingredients gave satisfactory results in color, texture and palatability, comparable to regular products.