• Korea journal of population studies
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• v.19 no.1
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• pp.139-159
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• 1996

This study comparatively examines a causal model of employee attatchment which focuses on employee's organizational commitment and intent to stay with an organization. This study is based on two separate studies of employee attachment among teachers : the U.S. case of the Chicago Public Schools (CPS) and the South Korean case of the Seoul Educational District (SED). The main purpose of this study is to replicate in Korea the CPS study. A revised model based on the unique characteristics of Korean teachers is also developed and estimated. The Price Mueller model of employee attachment provides the basic theoretical framework for this study. It includes five general classes of variables : 1) employee responses to work variables : job satisfaction, commitment, and intent to stay; 2) psychological stress variables: role ambiguity, role conflict, work overload, and quality of students; 3) social structural variables: autonomy, routinization, distributive justice, and legitimacy; 4) economic structural variables: pay, job security, promotional opportunities, and job opportunities; and 5) work orientation variables : career commitment, normative commitment, work motivation, affectivity, work values, and met expectations. The data was collected through questionnaire survey and a sample of 649 secondary school teachers in Seoul, South Korea, was included in the final analysis. Covariance structure analysis (LISREL) was used to estimate the causal model. The results indicate that the endogenous variables of job satisfaction and commitment play a considerably less important role than in the U.S. model in mediating the effects of the exogenous variables on intent to stay, and the model fails to explain the majority of the variance in intent to stay. In addition, the new variables added to the revised Korean model do not bave significant effects on intent to stay. The structural characteristics of the employment relationship and labor markets associated with Korean teachers forced mobility and closed external markets - are largely accountable for the major differences between the Korean and the U.S. cases. The study suggests that conceptual and empirical work on what produces employee attachment under these structural constraints needs to receive more attention in future studies.

• Journal of Korean Academy of Nursing
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• v.7 no.2
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• pp.60-82
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• 1977

The purpose of this study is first, to analyse the present nursing education and the curriculum in Korea in view of the changes and the new tendency of nursing education and second, to compare our curriculum with that of America, where nursing activities are actively earring on and, third, to try to find out what we should reconsider and improve in our nursing education. The object of this study is the educational program and the curriculum from 1973 to 1976 by selecting each five from colleges and department of nursing in Korea and America. The results of the study were as fellows : . 1. The aim of nursing education puts impassion the role of leader, knowledge and technology of nursing, welfare of society and service of community in both the America and Korea. In Korea nursing is mainly restricted to the treatment of diseases, while in the America the items of the aim of nursing are mainly extended to the capacity for Self- realization of nurse, in Korea they are restricted to the treatment of diseases. 2. In Korea the rate of credit of the curriculum of nursing education is the highest in professional education, next in general education, next in supporting science and educational subject, while in America the rate of the credit is the highest in general education, next professional education and then supporting Science and educational subject isn′t included in the curriculum. 3. In both Korea and America the role of the animal credit allotment in general education, is the highest in the first year and the rate in supporting science is the highest in the second year. In Korea professional subjects are concentrated in the third year while in America there is a tendency that they are increasing in number in the grade order. 4. There is a tendency that the rate of the credit allotment of the main professional subjects in curriculum is higher in Korea than in America : that is, in Korea the rate of the allotment of the credit is the highest in medical - surgical nursing, next maternal - child nursing, next community - health nursing and the psychiatric nursing and there in a great difference in the rate of the allotment of each credit. While in America the rate of the allotment of the credit is the highest in community - health nursing, next in medical- surgical nursing, next in maternal - child nursing, and then in psychiatric nursing and there is little difference in the rate of tile allotment of each credit. 5. From general education, supporting science and professional education, they have considered the continuity and sequence in the structure of nursing curriculum of Korea and America. While in Korea we have partly made integration in tile content of the subjects. Most of the school in America, they have made integration in the content of subjects especially in all subjects, but in Korea we haven't made it in all subjects. 6. In the system and form of nursing education Problem solving method, Dialectical method and operational method are introduced in some America schools and in others there is a tendency that the whole nursing education has the system based on Preventive frame - work or Health -illness frame work ; while only one college has an attempt for Health - Illness continue in Korea. 7. In Korea nursing education, as the importance of health- nursing and team nursing, the aim which is also comparatively emphasized is about health management and service of collective community. The subject pertaining to the aim is the studies of community health nursing, which are more in number in America. 8. When we consider the association between the social, general aims ?f the nursing education and the formation of the curriculum in Korean nursing school the courses of study concerning "the role of leadership and cooperative personal relation": "nursing care for the group": dynamic nursing care": and "the system of the public health nursing associated with the understanding of the regional community" are insufficient as compared with those of America. Especially, the lack of the behavioral science including the nursing care connected with the care for the group, the basic science on the clinical and developmental psychology, anthropology in known to be a prominent issue.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.97-106
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• 2000

In these respects the purpose of this research is manufacturing Co-W-P alloy thin film on the corning glass 2948 by electroless plating method using $NaH_2PO_2H_2O$ (sodium hypophosphite) as a reductant, and analyzing deposition rate, alloy composition, microstructure, and magnetic characteristics at various pH's and temperatures. For Co-P alloy thin film, the reductive deposition reaction occurred only in basic condition, not in acidic condition. The deposition rate increased as the pH and temperature increased, and the optimum condition was found at the pH of 10 and the temperature of 8$0^{\circ}C$. Also magnetic characteristics was found to be most excellent at the pH of 9 and the temperature of 7$0^{\circ}C$, resulting in the coercive force of 870Oe and the squareness of 0.78. At this condition, the contents of P was 2.54% and the thickness of the film was 0.216$\mu\textrm{m}$. For crystal orientation, we could not observe fcc for $\beta$-Co. On the other hand, (1010), (0002), (1011) orientation of hcp for $\alpha$-Co was observed. We could confirm the formation of longitudinal magnetization from dominant (1010) and (1011) orientation of Co-P alloy. For Co-W-P alloy thin film, coercive force was 500Oe and squareness was 0.6. For crystal orientation, (0002) orientation of $\alpha$-Co was dominatly found. Then we could confirm the formation of perpendicular magnetization. The content of P was constant at 0.8$\pm$0.2% and the content of W increased as the concentration of Na$_2$WO$_4$increased. When the concentration of Na$_2$WO$_4$was 0.1mol/L, the composition of W was 20%. We observed the changes of magnetic characteristics and microstructure of thin film depositions of Co-W-P by the heat treatment. For heat treatment, the temperature was increased step by step to 10$0^{\circ}C$, 20$0^{\circ}C$, 30$0^{\circ}C$, and 40$0^{\circ}C$ and it took 1 hour at each step in the reductive condition of hydrogen gas. By the heat treatment, flatness of surface was improved, but there were no changes on the magnetic characteristics and the microstructures.

• Journal of the Korean earth science society
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• v.28 no.1
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• pp.64-74
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• 2007

The marine seismic prospecting using a research vessel in the shallow sea near the coastal area has certain limits according to the water depth and survey environment. Also, for the electrical resistivity survey at seashore area, one may need a specially designed high-voltage source to penetrate the very conductive surface layer. Therefore, we have conducted a feasibility study on the application of magnetotelluric method (MT), a passive geophysical method, on investigating of shallow marine environment geology. Our study involves both theoretical modeling and field survey at the tidal flat area which represent the very shallow marine environment. We have applied the audio-frequency magnetotelluric (AMT) method to the intertidal deposits of Gunhung Bay, west coast of Korea, and analysed the field data both qualitatively and quantitatively to investigate the morphology and sedimentary stratigraphy of the tidal flat. The inversion of AMT data well reveals the upper sedimentary layer of Holocene intertidal sediments having a range of 13-20 m thickness and the erosional patterns at the unconformable contact boundary. However, the AMT inversion results tend to overestimate the depth of basement (30-50 m) when compared with the seismic section (27-33 m). Since MT responses are not significantly sensitive to the resistivity of middle layer or the depth of basement, the AMT inversion result for basement may have to be adjusted using the comparison with other geophysical information like seismic section or logging data if possible. But, the AMT method can be an effective alternative choice for investigating the seashore area to get important basic informations such as the depositional environment of the tidal flat, sea-water intrusion and the basement structure near the sea shore.

• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.91-102
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• 1985

Growth and biomass production of natural stands of Quercus variabilis in relation to tree density were studied to obtain basic guide lines for future tending operation. Two natural stands of Quercus variabilis located at 900m (A stand: 6,600trees/ha, $15.84m^2/ha$, $\frac{19}{17-20}$) and 800m (B stand: 4,300trees/ha, $16.65m^2/ha$, $\frac{20}{17-21}$) elevation in Sancheong, Kyongnam Province were selected for the comparative study and following results were obtained through a sample plot method. After diameter of individual trees in the sample plots was measured, twelve average trees from each diameter class were cut felled to measure dry weight of $W_S$, $W_B$, $W_L$, $W_{Ba}$, and standing biomass and biomass production rates by a allometrior regressions related to $D^2H$. Vertical distribution of leaves along the stems indicated that photosynthesis was carried out 2.2m above the ground in Stand A and 1.2m in Stand B. Maximum photosynthesis was located 4.2m and 6.2m above the ground in Stand A and B, respectively. Leaf area index was 4.25ha/ha for Stand A, and 3.89ha/ha for Stand B. Above-ground standing biomass was 49.51 ton/ha for Stand A and 59.20 ton/ha and net annual production was 6.75 ton/ha/yr. for Stand A and 8.99 ton/ha/yr. for Stand B. The ratio of net annual production to standing biomass was 17.5% for Stand A and 16.7% for Stand B. Net assimilation rate was 2.75kg/kg/yr. for Stand A and 3.58kg/kg/yr. for Stand B. Stem wood production rate was 1.46kg/kg/yr. for Stand A and 2.09kg/kg/yr. for Stand B. Bark production rate was 0.60 kg/kg/yr. for Stand A and 0.34kg/kg/yr. for Stand B. Above data indicated that Stand B utilized growing spaces and sites more efficiently than Stand A. It is concluded chat productivity of natural stands of Quercus variabilis can be enhanced through optimization of basal areas and number of tree per hectare and that sound management of natural oak stands should be based on systematic sampling of the area for periodic productivity estimation.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.131-144
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• 1995

To determine the structure of chromosome and to identify the sex chromosome of Ginkgo biloba and G. biloba var. fastigiata, the samples were obtained from root tips of trees growing in seven different provinences. The results are as follows. The basic number of somatic chromosomes was 2n=24. The range of a relative length of long chromosome was between $14.88{\sim}11.18{\mu}m$ and that of short chromosome was $8.11{\sim}6.24{\mu}m$. The chromosome sets were composed with one long pairs of m type and 11 short pairs of sm or st type. These short pairs showed the continuous descending in length. There was a satellite on the short arm of the Longest chromosome pair, and were satellites of the one or both long arm of 7th or 8th chromosome pair which were sm or st type, or the shortest st type chromosome pair. Sometimes, a satellite on the short arm of the longest chromosome pairs of Ginkgo biloba was double satellite, but that of G. biloba var. fastigiata was not. Karyotype was $2n=24=2^{2s}A^m+2B^{st\;or\;sm}+2C^{st}+2D^{st}+2E^{st}+2F^{st\;or\;sm}+2G^{sm}+2^{2s}H^{sm}\;or\;(^{1s}H^{sm}+H^{sm})+2I^{st}+2J^{st}+2K^{st}+2^{2s}L^{st}\;or\;(^{1s}L^{st}+L^{st})$. The male and female trees were not apparently distinguished by the chromsome structures. However the differences between the satellites could be used to identify the male and females. The male tree has double satellite on short arm of a longest chromosome pairs and females' has not. Also female trees have a satellite on a short chromosome more frequently than male trees.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.144-152
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• 2010

This study was conducted to analyze the growth characteristics and aboveground carbon storage for old growth Zelkova serrata artificial forests (site1: age class IX, site2: age class VIII) in Gwangneung Experimental Forest. The trees were classified by crown classes for analyzing forest stand structure. The growth characteristics were analized through ringwidth increment by crown classes and stem analysis of dominant trees. There were a wide range of DBH (site1: 8~62 cm, site2: 14~40 cm) and height (site1: 8~26 m, site2: 12~26 m) distributions and revealed different growth characteristics by crown classes in both sites. The mean annual increment (MAI) of ringwidth for the last 5 years of dominant trees for site1 (3.3 mm) was higher than MAI of ringwidth of total growth period (2.3 mm) and MAI of ringwidth for the last 5 years of dominant trees for site2 (2.2 mm) was equal to MAI of ringwidth of total growth period (2.2 mm). Also, the growth increment of ringwidth by crown classes had significant differences between dominant tree and the others crown classes (p<0.01) in both sites. As a results of stem analysis of dominant trees in both sites, there were similar to their volume between site1 (1.106 $m^3$) and site2 (1.035 $m^3$). In spite of old age, the annual increment of volume has been increasing steadily until recent year. Meanwhile, total aboveground carbon storage of site1 (65.6 Mg C $ha^{-1}$) was higher than that of site2 (56.1 Mg C $ha^{-1}$). The proportion of dominant and co-dominant trees to total aboveground carbon storage was more than 90% and the greatest individual aboveground carbon storage by crown classes was dominant tree in all both sites. However, individual aboveground carbon storage of dominant tree in site1 had 0.054 Mg C $tree^{-1}$ more than site2 owing to the differences from average DBH of dominant trees by sites. We think that these results will contribute to the forest practice for Zelkova serrata artificial forests as a basic information.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.333-340
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• 2015

Because soils in reclaimed lands nearby coastal areas have much higher salinity and moisture content than soils in inland area, parts of greenhouses embedded in such soils are exposed to highly corrosive environments. Owing to the accelerated corrosion of galvanized steel pipes for substrucrture and structure of greenhouses in saline environments, repair and reinforcement technologies and efficient maintenance and management for the construction materials in such facilities are required. In this study, we measured the corrosion rates of the parts used for greenhouse construction that are exposed to the saline environment to obtain a basic database for the establishment of maintenance and reinforcement standards for greenhouse construction in reclaimed lands with soils with high salinity. All the test pipes were exposed to soil and water environments with 0, 0.1, 0.3, and 0.5% salinity during the observation period of 480 days. At the end of the observation period, salinity-dependent differences of corrosion rate between black-surface corrosion and relatively regular corrosion were clearly manifested in a visual assessment. For the soils in rice paddies, the corrosion growth rate increased with salinity (0.008, 0.027, 0.036, and $0.043mm{\cdot}yr^{-1}$ at 0, 0.1, 0.3, and 0.5% salinity, respectively). The results for the soils in agricultural fields are 0.0002, 0.039, 0.040, and $0.039mm{\cdot}yr^{-1}$ at 0, 0.1, 0.3, and 0.5% salinity, respectively. The higher corrosion rate of rice-paddy soil was associated with the relatively high proportion of fine particles in it, reflecting the general tendency of soils with evenly distributed fine particles. Hence, it was concluded that thorough measures should be taken to counteract pipe corrosion, given that besides high salinity, the soils in reclaimed lands are expected to have a higher proportion of fine particles than those in inland rice paddies and agricultural fields.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.301-309
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• 2017

This study was conducted to provide basic data needed to calculate the crop loads for the greenhouse design. Four countries' crop loads for greenhouse structures were compared and the crop loads were measured directly and analyzed for various greenhouse crops, including tomato, strawberry, cucumber, and eggplant. According to the analysis results of four country's standards for the design crop loads, it was judged that the new design crop loads suit for greenhouse crops in our country should be suggested because our standards just used the design crop loads of other countries. The maximum crop loads per plant of tomato, cucumber, eggplant, and strawberry were 3.9, 0.75, 1.9 and $2.1kgf{\cdot}plant^{-1}$, respectively. The crop load per unit area of tomato was $8.5kgf{\cdot}m^{-2}$, which was much greater than the cucumber and eggplant's crop load of 2.1 and $2.4kgf{\cdot}m^{-2}$ respectively. The crop loads of tomato and cucumber, suggested by the greenhouse structure design standard of Korea, is $15kgf{\cdot}m^{-2}$, which is far greater than the values suggested by this research. It was judged that this was because our standard just used the Dutch standard, our crop load standard should be reviewed considering this difference. The crop load of strawberry, including the growing bed, was $21.0kgf{\cdot}m^{-2}$, which was much greater than the crop load in the Dutch standard.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.279-287
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• 2020

Recently, interest in radiation protection is increasing because of the occurrence of accidents related to exposure dose. So, the nuclear safety act provides to install the shields to avoid exceeding the dose limit. In particular, when the worker conducts the non-destructive testing (NDT) without the fixed shielding structure, we should monitor the access to the workplace based on a constant dose rate. However, when we apply for permits for NDT work in these work environments, the consideration factors to the estimation of the distance and exposure dose are not legally specified. Therefore, we developed the excel model that automatically calculates the distance, exposure dose, and cost if we input the factors. We applied the assumption data to this model. As a result of the application, the distance change rate was low when the thickness of the lead blanket and collimator is above 25 mm, 21.5 mm, respectively. However, we didn't consider the scattering and build-up factor. And, we assumed the shape of the lead blanket and collimator. Therefore, if we make up for these limitations and use the actual data, we expect that we can build a database on the distance and exposure dose.