• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.241-247
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• 2001

Boundary line method was adopted to analyze the relationships between rice yield and meteorological conditions during rice growing period. Boundary lines of yield responses to mean temperature($T_a$) and sunshine hour( $S_{h}$) and diurnal temperature range($T_r$) were well-fitted to hyperbolic functions of f($T_a$) =$$\beta$_{0t}$(1-EXP(-$$\beta$_{1t}$ $\times$ ($T_a$) ) and f( $S_{h}$)=$$\beta$_{0t}$((1-EXP($$\beta$_{1t}$$\times$ $S_{h}$)), to quadratic function of f($T_r$) =$\beta$$_{0r}$(1-($T_r$ 1r)$^2$), respectively. to take into account to, the sterility caused by low temperature during reproductive stage, cooling degree days [$T_c$ =$\Sigma$(20-$T_a$] for 30 days before heading were calculated. Boundary lines of yield responses to $T_c$ were fitted well to exponential function of f($T_c$) )=$\beta$$_{0c}$exp(-$$\beta$_{1c}$$\times$$T_c$ ). Excluding the constants of $\beta$$_{0s}$ from the boundary line functions, formed are the relative function values in the range of 0 to 1. And these were used as yield indices of the meteorological elements which indicate the degree of influence on rice yield. Assuming that the meteorological elements act multiplicatively and independently from each other, meteorological yield index (MIY) was calculated by the geometric mean of indices for each meteorological elements. MIY in each growth period showed good linear relationship with rice yield. The MIY's during 31 to 45 days after transplanting(DAT) in vegetative stage, during 30 to 16 days before heading (DBH) in reproductive stage and during 20 days after heading (DAH) in ripening stage showed greater explainablity for yield variation in each growth stage. MIY for the whole growth period was calculated by the following three methods of geometric mean of the indices for vegetative stage (MIVG), reproductive stage (HIRG) and ripening stage (HIRS). MI $Y_{I}$ was calculated by the geometric mean of meteorological indices showing the highest determination coefficient n each growth stage of rice. That is, (equation omitted) was calculated by the geometric mean of all the MIY's for all the growth periods devided into 15 to 20 days intervals from transplanting to 40 DAH. MI $Y_{III}$ was calculated by the geometric mean of MIY's for 45 days of vegetative stage (MIV $G_{0-45}$ ), 30 days of reproductive stage (MIR $G_{30-0}$) and 40 days of ripening stage (MIR $S_{0-40}$). MI $Y_{I}$, MI $Y_{II}$ and MI $Y_{III}$ showed good linear relationships with grain yield, the coefficients of determination being 0.651, 0.670 and 0.613, respectively.and 0.613, respectively.

• Korean Journal of Psychosomatic Medicine
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• v.10 no.1
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• pp.8-17
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• 2002

Objective : Increasing in frequency and success of hematopoietic stem cell transplantation and improved survival rates have led to growing concerns regarding the psychosocial aspects of hematopoietic stem cell transplantation recipients. In this study, we have examined the stress coping strategies and related psychiatric symptom in the hematopoietic stem cell transplantation recipients. Methods : In this study, we examined the psychological stress symptoms of hematopoietic stem cell transplantation recipients and differences of psychosocial variables between active coping group and passive coping group. Twenty nine recipients of hematopoietic stem cell transplantation were recruited prospectively and assessed at 2 weeks pretranplant and at 1-2 days posttranplant. Thirty normal controls were recruited. Assessments included a psychiatric interview, a variety of standardized questionnaires (Ways of Coping Questionnaires, Perceived Stress Scale, Hospital Depression and Anxiety Scale, Short-Form 36 Health Survey). Results : Hematopoietic stem cell transplantation patients showed higher degree of depression (p<0.001) and anxiety (p=0.011) symptoms than normal control group. However, no differences of depression and anxiety symptoms between pretransplant and posttransplant status were showed. And, passive coping group showed higher degree of depression (p=0.046) and anxiety symptoms (p<0.001) than active coping group. Conclusions : Our results suggested that many hematopoietic stem cell transplantation recipients would exhibit severe to moderate symptoms of anxiety and depression. Also, it seemed likely that passive coping style might influence the development of negative affect such as anxiety and depression. The implications of these findings were discussed in terms of the need to monitor the coping strategies and apply the appropriate psychiatric intervention. And, further prospective studies about long-term survival and psychological adaptive functions of hematopoietic stem cell transplantation patients are recommended.

• KDI Journal of Economic Policy
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• v.12 no.4
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• pp.21-46
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• 1990

This paper, a sequel to Yoo and Lee (1990), attempts to investigate the interindustry determinants of technical efficiency in Korea's manufacturing industries, and also to conduct an exploratory analysis on the stability of technical efficiency over time. The hypotheses set forth in this paper are most found in the existing literature on technical efficiency. They are, however, revised and shed a new light upon, whenever possible, to accommodate any Korea-specific conditions. The set of regressors used in the cross-sectional analysis are chosen and the hypotheses are posed in such a way that our result can be made comparable to those of similar studies conducted for the U.S. and Japan by Caves and Barton (1990) and Uekusa and Torii (1987), respectively. It is interesting to observe a certain degree of similarity as well as differentiation between the cross-section evidence on Korea's manufacturing industries and that on the U.S. and Japanese industries. As for the similarities, we can find positive and significant effects on technical efficiency of relative size of production and the extent of specialization in production, and negative and significant effect of the variations in capital-labor ratio within industries. The curvature influence of concentration ratio on technical efficiency is also confirmed in the Korean case. There are differences, too. We cannot find any significant effects of capital vintage, R&D and foreign competition on technical efficiency, all of which were shown to be robust determinants of technical efficiency in the U.S. case. We note, however, that the variables measuring capital vintage effect, R&D and the degree of foreign competition in Korean markets are suspected to suffer from serious measurement errors incurred in data collection and/or conversion of industrial classification system into the KSIC (Korea Standard Industrial Classification) system. Thus, we are reluctant to accept the findings on the effects of these variables as definitive conclusions on Korea's industrial organization. Another finding that interests us is that the cross-industry evidence becomes consistently strong when we use the efficiency estimates based on gross output instead of value added, which provides us with an ex post empirical criterion to choose an output measure between the two in estimating the production frontier. We also conduct exploratory analyses on the stability of the estimates of technical efficiency in Korea's manufacturing industries. Though the method of testing stability employed in this paper is never a complete one, we cannot find strong evidence that our efficiency estimates are stable over time. The outcome is both surprising and disappointing. We can also show that the instability of technical efficiency over time is partly explained by the way we constructed our measures of technical efficiency. To the extent that our efficiency estimates depend on the shape of the empirical distribution of plants in the input-output space, any movements of the production frontier over time are not reflected in the estimates, and possibilities exist of associating a higher level of technical efficiency with a downward movement of the production frontier over time, and so on. Thus, we find that efficiency measures that take into account not only the distributional changes, but also the shifts of the production frontier over time, increase the extent of stability, and are more appropriate for use in a dynamic context. The remaining portion of the instability of technical efficiency over time is not explained satisfactorily in this paper, and future research should address this question.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.3
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• pp.157-180
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• 2012

The purposes of this study are to design and apply an experienced-based reading program using picture books for the struggling readers to improve their reading ability; and to analyze and verify how this program influences their self-esteem. The final objects of this study are 53 struggling readers who are 1-4th graders in 8 elementary schools. For this, the specific goals are set up as follows: First, an experience-based reading program using ADDIE teaching design model and Kolb's experience learning cycle are planned and developed to improve reading abilities and self-esteem of the struggling readers. Second, it also aimed to clarify how the experience-based reading program using picture books influence the struggling readers' self-esteem in affective ones. As a result, this experience-based reading program using picture books is effective on improving the struggling readers' self-esteem, generally. Although the degree of improvement is different from each of the subordinate factors, the overall scores of self-esteem are raised. This study suggests that an experience-based reading program using picture books is appropriate for improving the affective characteristics of the struggling readers. And it is also needed to produce a research manual to get the same test condition that prescribes the methods of pre-test and post-test.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.147-158
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• 2010

Studies on the distribution of traffic demands have been proceeding by providing traffic information for reducing greenhouse gases and reinforcing the road's competitiveness in the transport section, however, since it is preferentially required the extensive studies on the driver's behavior changing routes and its influence factors, this study has been developed a discriminant model for changing routes considering driving conditions including traffic conditions of roads and driver's preferences for information media. It is divided into three groups depending on driving conditions in group classification with the CART analysis, which is statistically meaningful. And, elements of the driving conditions and the preferred media affecting the change of paths are classified into statistical meaningful groups through the CHAID analysis, and the major factors affecting the change of paths are examined. Finally, the extent that driving conditions and preferred media affect a route change is examined through a discriminant analysis, and it is developed a discriminant model equation to predict a route change. As a result of building the discriminant model equation, it is shown that driving conditions affect a route change much more, the entire discriminant hit ratio is derived as 64.2%, and this discriminant equation shows high discriminant ability more than a certain degree.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.284-295
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• 2017

This study examined the degree of nurses' image, professional self-concept, and organizational commitment of nursing students to clarify the relationship among these variables. A descriptive research design was used. The participants were 238 nursing students in J city who were surveyed between September 7 and 10, 2016. The data were analyzed using the SPSS WIN 21.0 program, which determined the frequency, percentage, mean, standard deviation, t-test, One-way ANOVA, Scheffe's test, Pearson correlation coefficient, and Stepwise multiple regression analysis. The nurses' image, professional self-concept, and organizational commitment of nursing students showed an average of 4.01, 3.40, and 3.77 points, respectively, based on a five-point scale. There was a statistically significant positive correlation between the nurses' image, professional self-concept and organizational commitment. In addition, there was a positive correlation between the professional self-concept and organizational commitment for nursing students. Two factors explained 56.3% of the organizational commitment of the nursing students. The relative influence affecting the organizational commitment Nurse image, and professional self-concept were found. The nurse image was confirmed to be the largest predictor of organizational commitment.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.135-142
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• 2008

The primary innovation in the new footwear is a heel lift of $20^{\circ}$ which is proposed to improve posture and balance as well as increase shock absorption. The purpose of this research was to compare the movement, forces and muscle activity between the new shoes and standard athletic footwear during standing and walking. Nine healthy subjects participated in this study. Data were collected at two times: 1) when the subjects first wore the new walking shoes and 2) after the subjects wore the shoes for 6 hours a day for two weeks. 1. During standing. the movement of the center of pressure is increased approximately 60% when wearing the new walking shoes compared to a control shoe. 2. During walking. the ankle is approximately $14^{\circ}$ more dorsiflexed during landing due to the 200heel lift in the new walking shoes. The knee compensates slightly by flexing approximately $2^{\circ}$ more. 3. As a result of the changes in the walking movement, the ground reaction forces are applied more quickly, although the peak magnitudes do rut change. 4. The resultant joint moments at the ankle and knee joints decrease from 21-60% with the largest reductions occurring during landing. In conclusion, the new footwear change the movement, showing a more upright stance. Also, the new footwear reduce joint loading at the joint during the landing and weight acceptance phase of walking. However, the influence of the new footwear is immediate and does rut change after wearing the shoes for two weeks.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.176-183
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• 2016

This study relates to a polymer electrolyte membrane for improved performance fuel cell, were researched with respect to properties required for driving a fuel cell. The bis(4-fluorophenyl)phenyl phosphine oxide was sulfonated using fuming sulfuric acid. Synthetic hydrophilic oligomer and the hydrophobic oligomer and the block copolymers were prepared via aromatic nucleophilic substitution polycondensation. A block copolymer structure and degree of sulfonation was analyzed by $^1H$-NMR and gel permeation chromatography(GPC) analysis. Thermal stability was confirmed by thermogravimetric analysis(TGA), block copolymer was stable at high temperature(>$200^{\circ}C$), The ion conductivity was measured in order to demonstrate the performance of fuel cell. Synthesis membrane was the increase of temperature was improved conductivity up to 58 mS/cm due to the influence of the developed ion clusters. The phase separation of the polymer was observed to make AFM analysis.

• Science of Emotion and Sensibility
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• v.5 no.1
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• pp.71-78
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• 2002

Driving involves a series of complicated precesses requiring various human capacities, such as perception, will decision, and athletic functions. Consequently, it induces a high degree of continuous concentration of mind and tension from external stimulation, bringing fatigue to the driver, and driver fatigue is counted as one of the major causes of traffic accidents. Nevertheless, because of the complicated urban lives, traffic congestion, job characteristics, and so on, the drivers have to spend a longer time inside a vehicle, and the fatigue and stress thereof is almost unavoidable. We haute, therefore, turned our attention to the reduction in the fatigue during driving by supplying oxygen, and investigated in this research the drivers subjective fatigue evaluations and reaction time when oxygen is supplied in different rates. As a result, we have found that the subjective fatigue feeling is highest at low-rate O/Sub 2/ supply (18%), and fatigue feeling was comparatively reduced at high-rate O/Sub 2/ (30%). The sleepiness also showed the tendency to be reduced at high-rate O/Sub 2/ supply in the case of driving for 1 hour or more. The time for reaction to braking after the sign for urgent stop is given tends to show more substantial reduction at high-rate O/Sub 2/ supply than at low-rate O/Sub 2/ supply after 2 hours driving. It can, therefore, be deduced from the aforesaid results that the subjective responses and behavioral reactions tend to show reduced fatigue at the condition of high-rate O/Sub 2/ supply. Hence, it was suggested that drivers felt subjective fatigue while driving at low-rate O/Sub 2/ and the subjective fatigue and reaction time were reduced at high-rate O/Sub 2/. These findings suggest that the oxygen supply will reduce driver fatigue.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.535-545
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• 2019

If the real estate auction market indicators are relevant and meaningful, they can be meaningful information to the real estate market in connection with general real estate. The purpose of this study is to examine whether time-supply logic is applied in auction market by identifying time series correlations for the number of auctions, the auction rate, and the auction price rate, which are major indicators of real estate auction market. The real estate types were classified into three categories: residential real estate, land, and commercial real estate. The monthly time series of auctions in the metropolitan real estate were compiled for 96 months. Based on this data, the auction market model for each type was established and the mutual influences between the indicators were analyzed. As a result, the supply and demand indicators, the number of auctions and the auction rate, showed the nature of supply and demand according to the supply and demand logic of the market. However, the correlation was high for residential real estate and relatively low for commercial real estate. the auction rate has a long-term impact on price indicators, especially residential real estate, which is quantitatively explanatory and significant. The three auction-related indicators differ in degree, but there is a correlation, especially for residential real estate, which can be useful information for policy making.