• Journal of Korean Society of Forest Science
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• v.36 no.1
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• pp.9-25
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• 1977

As a successive work of the variation studies of natural Pinus densiflora stands, some characteristics of individual trees of the three natural populations selected from the Kwang-won Province, the middle-east part of Korean peninsula, as shown in the location map, were investigated. And the statiscal differences between individuals within population, and between populations were analysed. Twenty trees from each population were selected for this study purpose. Doing this, those trees lagged in growth, usually showing poorer form, were eliminated. The results obtained are summarized as follows: 1. Though the average population ages had the ranage between 50 and 63, the growth of height or diameter was similar. Population No.9 is, however, considered to have better tree forms at glance. Population No.8 showed the heighest value not only in the clear-stem-length ratio. 0.53 but also in the crown-index 0.91. The higher value can be result from those trees having long lateral branches and relatively short crown height, meaning undesirable crown shape. In regard to the fine branchedness and the acuteness of branching angle, the population No.9. is considered to be a better one, whereas there was almost no difference in crown height among populations. 2. Checking the frequency distributions of the ratio of the clear-stem-height to the total height and the crown-indices, some difference between populations are considered. These might be attributed to the previous way of stand mangement which alters the density. 3. In the serration density, the average number of 54 per 1cm needle length, the significant differences exist between individual trees within population but not between populations. A few trees which extremly high serration density were observed. As in serration, so tendencies were in the number of stomata row and resin duct. 4. The population 8 had the resin duct index value of 0.074 as the highest which was twice or triple of the other ones. 5. The patterns of increasing process of the average 10-year-ring-segment were not similar till the 30 years of age, but beyond this, the tendency lines were aggregated. 6. Regading the average summer wood ratio, no diffrence between populations, but in the ranges, i.e. 23 to 30 in population No.8. and 16 to 36 in population No.9., with regad to the specific gravity of wood, there were hardly observed any difference between populations even in the ranges values. As the increase of tree ages, the increase of specific gravity was followed but the increasing patterns were not similar between populations. 7. No significant differences between populations in the average tracheid length and the range were detected. However, the length was increased according to the age increase. The increasing pattern was same between populations.

• Sleep Medicine and Psychophysiology
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• v.17 no.1
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• pp.28-33
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• 2010

Objectives: Working at other times than the regular day shift has been reported to be a stressor associated with health consequences and mental disorders as well as disturbance of sleep. In current study, we aimed at investigating the relationship between work schedule, sleep quality and depression among police officers. Methods: Eleven hundreds and forty five police officers (male: 1040, female: 105) completed questionnaires of basic socio-demographic data, Pittsburgh Sleep Quality Index (PSQI), Korean Scale of Occupational Stress (KOSS), Impact of Event Scale - Revised (IES-R) and Center for Epidemiologic Study-Depression (CES-D). Results: After controlling for age, sex and educational level, score of CES-D was correlated positively with the score of KOSS, PSQI and IES-R on partial correlation analysis (r=-0.077; p=0.009, r=0.262; p<0.000 and r=0.421, p<0.000, respectively). Logistic regression analysis revealed that female sex, age, the score of KOSS and IES-R and schedule of rotating shift work predicted higher score than 16 score of CES-D significantly in total subjects (p=0.023, p=0.015, p=0.000, p=0.000 and p=0.022, respectively). Conclusion: Current result suggested that not only female sex, age, higher occupational stress and impact of event scale but also rotating shift work schedule might be related to depression among police officers.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.339-347
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• 2019

This study was conducted from November 1, 2017 to November 30, 2017 in 268 women in late postmenopausal period in D and S shipyards located in G city. The subjects were divided into two groups according to the risk factors of cerebrovascular disease according to the presence or absence of risk factors of cerebrovascular disease. The subjects were divided into two groups according to their general characteristics, cerebrovascular disease prevention knowledge, attitude and health behavior. The variables that had statistically significant difference in health group and risk group were age (F=92.239, p<.001), cohabitation type ($x^2=20.056$, p<.001), income level ($x^2=39.023$, p<.001), the number of working hours per week (F=32.217, p<.001), the number of working years (F=12.310, p=.001), family history of cardiovascular disease ($x^2=233.442$, p<.001), subjective health status($x^2=19.058$, p=.001). There was a significant difference between the two groups in the degree of knowledge related to prevention of cardiovascular disease (F=2.679, p=.008) and health behavior fulfillment (F=4.339, p<.001). (r=.348, p<.001), the risk group had a higher knowledge (r=.279, p=.002), and the other group Attitude (r=.194, p=.030) showed a statistically significant correlation. Based on this, it is necessary to develop and apply an intervention program considering the characteristics of vulnerable group of cerebrovascular disease.

• Journal of Korea Technology Innovation Society
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• v.21 no.3
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• pp.992-1020
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• 2018

The purpose of this study is to investigate the ways to enhance the creativity of R & D teams of government-funded research institutes through systematic empirical studies. For this purpose, a research model was established based on existing research on group creativity and verified through empirical studies. Specifically, This study first attempts to investigate the influence that team diversity, team cohesion, team autonomy and team efficacy have on team creativity. Second, it intends to verify the mediating effects of team efficacy between team characteristics and team creativity. An empirical study was conducted on 102 R & D teams of government-funded research institutes. In the team creativity measurement, the evaluation by the leaders and the self evaluation of the members were performed in parallel. This is to increase the accuracy of the evaluation and to compare the differences of the viewpoints of the two subjects. The result of the analysis demonstrated that team cohesion among the others had a positive influence on team creativity, and that team efficacy possessed certain positive qualities in mediating the relationship between team diversity, team autonomy, and team creativity. Based on these findings, this study discussed its academic implications as well as its practical limitations, and made suggestions on future research tasks that remain.

• Management & Information Systems Review
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• v.35 no.3
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• pp.95-113
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• 2016

The study examines the question of what discriminant factors may affect differences between two groups classified by researchers' satisfaction with and continuous use intention of genetic resources(microorganisms). Survey data from researchers who are using microorganisms from a gene bank was used to empirically test. The survey, covering 150 researchers, was conducted from March 26 through April 17 2015. Linear discriminant analysis was used to test the research questions described in the study. Results from the tests show that utilization value and suitability of genetic resources for researchers' R&D activities play key roles in discriminating between the two groups classified by researchers' satisfaction with and continuous use intention of genetic resources, relatively lower and higher groups. The results indicate that useful trait information of and degree in promotion of researches by genetic resources appear to be weak in discriminating between the two groups, and that novelty of genetic resources does not play a crucial role in making a distinction between the two groups. We propose some policy implications based on the results of the study.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.287-293
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• 2014

Matsumuraeses phaseoli is one of the main pests that attack the flowers and pods of red bean (Vigna angularis) and mungbean (Vigna radiata) in Korea. To elucidate the developmental characteristics and over-wintering stage of M. phaseoli, several stages of the insect were observed through artificial rearing under outdoor conditions in Suwon ($37^{\circ}$16'N $126^{\circ}$59'E 35ASL), Korea. In colonies in which neonate larvae were reared at about 2-week intervals for more than a year, the developmental period from larva to adult emergence became longer from spring to summer, but shorter from summer to autumn; aestivation was not observed during the summer season. The colony in which rearing started on Oct 8, 2008 over-wintered as pupae and emerged in late April next year with a survival rate of 6%. However, the colony in which the rearing started on Oct 23, 2008 over-wintered as mature larvae, pupated in late April, and emerged in early and mid-May with a survival rate of 2%. When the fifth instar larvae were transferred outside from the laboratory ($25^{\circ}C$, 15L:9D) between November and February, no larvae could survive during the winter season. Some newly laid eggs and newly emerged adults could not hatch and could not survive, respectively, in outdoor conditions in November and December. These results suggest that neonate larvae of M. phaseoli that hatch in October can over-winter as late larvae or pupae in Suwon, Korea.

• Journal of the Korean earth science society
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• v.40 no.5
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• pp.538-547
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• 2019

This study analyzes the conceptual understanding of in-service and pre-service earth science teachers about the H-R diagrams and evolution of stars using conceptual status analysis categories. The results show that (a) many teachers use unscientific language in the Intelligibility range, (b) teachers are categorized in Low scientific inquiry ability related to graph creation and unscientific analogy for scientific concept which is hightly corelated to the possibility of misunderstanding in the teaching process, and (c) pre-service teachers lack the understanding of the secondary science curriculum. It is necessary to develop pre-service curriculum that can be applied to the school site. In the category of Plausibility range, (d) both groups understood the cosmological meaning of stellar evolution. However, pre-service teachers do not specifically explain the mechanism of a star. In the category of Fruitfulness range, in-service teachers come up with educational problems reflecting the academic characteristics of earth science and apply their knowledge to actual problem solving. On the other hand, pre-service teachers show high nonresponse ratio, they do not see the H-R diagram and the evolution of stars as a practical concept. In the analysis process, both groups are found to have many unscientific conceptions about the H-R diagram and evolution of stars. Therefore, it is suggested that caution be used in developing a professional development program of earth science teachers.

• Journal of Oriental Neuropsychiatry
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• v.17 no.2
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• pp.133-145
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• 2006

Objective : The purpose of this experimental-controlled study was to investigate the characteristics of the autonomic nervous system in students with Keongke by using HRV(Heart rate variability) and PSV(Pupil size variability). Method : The study group was consisted of 11 students with self recognition as the experimental group, and 25 normal students as the control group. Informations on gender and age were obtained by medical charts and personal interviews. By using heart rate variability and pupil size variability, we measured the value of HRT(Heart rate), SDNN(Standard deviation of NN intervals), LFnorm(Low frequency normalization), HFnorm(High frequency normalization), LF/HF ratio, Pupil area, B.S.(Basic size), C.R.(Max Constriction Rate) and 1s.d.(1sec Dilation Rate). I compared the degrees of the sympathetic and parasympathetic activity. Result : 1. In the result of heart rate variability between experimental and control group, none of the parameters of experimental group were significantly different from control group. And even though there were no statistical significance, there were some numerical differences in SDNN, LF norm, HF norm. 2. In pupil size variability, C.R. and 1s.d. of the experimental group were increased compared to control group. Conclusion : The study results suggest that the group with Keongke has differences of autonomic nervous system as compared to those in normal state. Measurement value of PSV is a new technical approach to estimate the autonomic nervous system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.497-502
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• 2020

For the Navy to acquire the desired vessels in time, it is necessary to plan the schedule accurately for warships. On the other hand, until now, there has been only a subjective prediction of the period of warship construction through a survey by a group of experts. No academic studies have been conducted based on actual data. Therefore, this study presents a model for predicting the construction period of a warship through linear regression based on actual data. Experts first identified the factors that can affect the warship construction period. Actual data of the factors were collected, and regression analysis was performed to estimate the ship construction period. As a result, the key factors selected that influence the construction period of a ship were the number of operational test items, number and type of equipment, and the number and type of R&D equipment. The resulting regression model revealed 96.5% accuracy in terms of internal validity.

• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.107-129
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• 2022

It is important to preempt new technology because the technology competition is getting much tougher. Stakeholders conduct exploration activities continuously for new technology preoccupancy at the right time. Gartner's Hype Cycle has significant implications for stakeholders. The Hype Cycle is a expectation graph for new technologies which is combining the technology life cycle (S-curve) with the Hype Level. Stakeholders such as R&D investor, CTO(Chef of Technology Officer) and technical personnel are very interested in Gartner's Hype Cycle for new technologies. Because high expectation for new technologies can bring opportunities to maintain investment by securing the legitimacy of R&D investment. However, contrary to the high interest of the industry, the preceding researches faced with limitations aspect of empirical method and source data(news, academic papers, search traffic, patent etc.). In this study, we focused on two research questions. The first research question was 'Is there a difference in the characteristics of the network structure at each stage of the hype cycle?'. To confirm the first research question, the structural characteristics of each stage were confirmed through the component cohesion size. The second research question is 'Is there a pattern of diffusion at each stage of the hype cycle?'. This research question was to be solved through centralization index and network density. The centralization index is a concept of variance, and a higher centralization index means that a small number of nodes are centered in the network. Concentration of a small number of nodes means a star network structure. In the network structure, the star network structure is a centralized structure and shows better diffusion performance than a decentralized network (circle structure). Because the nodes which are the center of information transfer can judge useful information and deliver it to other nodes the fastest. So we confirmed the out-degree centralization index and in-degree centralization index for each stage. For this purpose, we confirmed the structural features of the community and the expectation diffusion patterns using Social Network Serice(SNS) data in 'Gartner Hype Cycle for Artificial Intelligence, 2021'. Twitter data for 30 technologies (excluding four technologies) listed in 'Gartner Hype Cycle for Artificial Intelligence, 2021' were analyzed. Analysis was performed using R program (4.1.1 ver) and Cyram Netminer. From October 31, 2021 to November 9, 2021, 6,766 tweets were searched through the Twitter API, and converting the relationship user's tweet(Source) and user's retweets (Target). As a result, 4,124 edgelists were analyzed. As a reult of the study, we confirmed the structural features and diffusion patterns through analyze the component cohesion size and degree centralization and density. Through this study, we confirmed that the groups of each stage increased number of components as time passed and the density decreased. Also 'Innovation Trigger' which is a group interested in new technologies as a early adopter in the innovation diffusion theory had high out-degree centralization index and the others had higher in-degree centralization index than out-degree. It can be inferred that 'Innovation Trigger' group has the biggest influence, and the diffusion will gradually slow down from the subsequent groups. In this study, network analysis was conducted using social network service data unlike methods of the precedent researches. This is significant in that it provided an idea to expand the method of analysis when analyzing Gartner's hype cycle in the future. In addition, the fact that the innovation diffusion theory was applied to the Gartner's hype cycle's stage in artificial intelligence can be evaluated positively because the Gartner hype cycle has been repeatedly discussed as a theoretical weakness. Also it is expected that this study will provide a new perspective on decision-making on technology investment to stakeholdes.