• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.1
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• pp.140-152
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• 2016

It is very important for the competitiveness and sustainable management of enterprises that the rapid changes in the managerial environments quickly and accurately are responded. For example, the large-scale investment accompanied by bad alternatives in accordance with misunderstanding of the managerial environments yields the huge cost and effort to modify and improve. In firm management, the quality of products and the productivity are influenced by changes of the endogenous factors yielded in manufacturing process and the exogenous factors as market, etc. These changes include not only changes in 4M (man, machine, material, method) but also those in the market, competitors, and technologies in the process of commodification, i.e., first, such disturbances make dispersion of the process big and odd. By Shewhart chart it can be checked that the process monitored is control-in or out. Business administration executes activities for input stabilization by monitoring changes in 4Ms, comparing with the standards, and taking measures for any abnormality. Second, TRM (technology road map) is to prospect product deployment and technological trend by predicting technologies in the competitive environment as the market, and to suggest the future directions of business. So, TRM must be modified and improved according to DR (design review) stages and changes in mass-production like input material change. Therefore, a role of TRM in input stabilization for reducing cost and man-hour is important. This study purposed to suggest that the environment changes are classified into endogenous factors and exogenous factors in production process, and then, quality and productivity should be stabilized efficiently through connection between TRM and input stabilization, and to prove that it is more effective for the display industry to connect TRM with input stabilization rather than to use TRM separately.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.89-96
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• 2023

Uric acid produced by guanine deaminase (GDA) is involved in photoaging and hyperpigmentation. Reactive oxygen species (ROS) generated by uric acid plays a role in photoaging. However, the mechanism by which uric acid stimulates melanogenesis in GDA-overexpressing keratinocytes is unclear. Keratinocyte-derived paracrine factors have been identified as important mechanisms of ultraviolet-induced melanogenesis. Therefore, the role of paracrine melanogenic growth factors in GDA-induced hypermelanosis mediated by uric acid was examined. The relationships between ROS and these growth factors were examined. Primary cultured normal keratinocytes overexpressed with wild type or mutant GDA and those treated with xanthine or uric acid in the presence or absence of allopurinol, H₂O₂, or N-acetylcysteine (NAC) were used in this study. Intracellular and extracellular bFGF and SCF levels were increased in keratinocytes by wild type, but not by loss-of-function mutants of GDA overexpression. Culture supernatants from GDA-overexpressing keratinocytes stimulated melanogenesis, which was restored by anti-bFGF and anti-SCF antibodies. Allopurinol treatment reduced the expression levels of bFGF and SCF in both GDA-overexpressing and normal keratinocytes exposed to exogenous xanthine; the exogenous uric acid increased their expression levels. H₂O₂-stimulated tyrosinase expression and melanogenesis were restored by NAC pretreatment. However, H₂O₂ or NAC did not upregulate or downregulate bFGF or SCF, respectively. Overall, uric acid could be involved in melanogenesis induced by GDA overexpression in keratinocytes via bFGF and SCF upregulation not via ROS generation.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1441-1444
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• 2007

It is now widely acknowledged that climate variability modifies the frequency spectrum of hydrological extreme events. Traditional hydrological frequency analysis methodologies are not devised to account for nonstationarity that arises due to variation in exogenous factors of the causal structure. We use Hierarchical Bayesian Analysis to consider the exogenous factors that can influence on the frequency of extreme floods. The sea surface temperatures, predicted GCM precipitation, climate indices and snow pack are considered as potential predictors of flood risk. The parameters of the model are estimated using a Markov Chain Monte Carlo (MCMC) algorithm. The predictors are compared in terms of the resulting posterior distributions of the parameters associated with estimated flood frequency distributions.

• Korean Journal of Acupuncture
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• v.20 no.2
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• pp.101-120
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• 2003

This study is performed to investigate the cause, symptom and acupuncture on Dudurugi through the literature of oriental medicine. The findings of this study are as follows: 1. Dudurugi is caused by exogenous pathogenic factors(wind, heat, cold, damp), sthenic inter damage factors(heat accumulated in the intestine and stomach, blood-heat, blood-stasia) and asthenia inter damage factors(asthenia of the spleen and stomach, blood-asthenia, asthenia of energy-blood, yin-asthenia and blood-dryness, yan-asthenia and energy-asthenia). 2. The symptom of Dudurugi is appeared in the skin and its surface is processed apparently or itch. 3. The treatment of Dudurugi was used by expelling the wind with removing pathogen. 4. In the treatment of Dudurugi, The su-yangmyong taejang-kyong of 12 merdians was mainly used and, the kokchi(LI11) of acupoints was most used in the acupuncture and moxibustion. 5. In the treatment of Dudurugi, acupoints of tok-maek and chok-t'aeyangkyong were mainly used in the case of showing symptoms caused by exogenous pathogenic factors and, acupoints of chok-t'aemkyong were mainly used in the case of showing symptoms caused by damp-heat accumulated in the intestine and stomach. When there were any other symptoms accompanied, other acupoints were more used.

• Journal of the Korean Society of Costume
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• v.28
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• pp.137-150
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• 1996

The objectives of this study were to classify daily clothing selection motives and to group men into life style types and to examine the differences in daily clothing selection motives according to the life style types. Questionnaire comprised of three sections: 36 Likert type items of life style measure; 29 Likert type items of daily clothing selection motives measure: and 4 demographic variables. Samples were 267 salary men in gheir 20's to 30's in Seoul Korea. The data were analyzed using factor analy-sis cluster analysis one-way ANOVA Dun-can's multiple range test and t-test. 1. Five factors of life style were derived by factor analysis ; F. 1 'appearance oriented' f. 2. 'positive activity' F. 3 'economy oriented': F.4 'active-leisure';F. 5 'contemporary' Four types of life style of men were defined by cluster analysis of the five factors: T. 1'posi-tive activity'; T. 2.'economy interest'; T. 3'contemporary' : T 2'economy interest' T.3'contemporary' ; T. 4 'appearance interest' 2. Four factors of daily clothing selection motives were derived by factor analysis: F.1 'clothing harmony'; F.2 'clothing utility'; F.3 'psychological influence'; F.4 'exogenous situ-ation adaptation 3. There were significant differences in daily clothing selection motives according to the life style types. The types of positive activity economy interest and contemporary had 'clothing utility' motive more than appearance interest type. Economy interest type had 'hpsychological influence' motive more than other three types. Economy interest type and appearance interest type had 'exogenous situ-ation adaptation' motive more than other two types 4. 20's and unmarried men had'psychological influence' motive more than 30's and married. Upper class had 'clothing harmony' and 'ex-ogeneous situation adaptation' motives more than middle and low. Men with less education had ' clothing utility' and 'exogenous situation adaptation' motives more than did more edu-cation.

• Health Policy and Management
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• v.8 no.1
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• pp.52-96
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• 1998

To find causal factors and improvement plans of organizational commitment of public servants in urban health centers, a hypothetical causal model, which included 2 endogenous variables(organizational commitment & organizational satisfaction) and 15 exogenous variables, was constructed. Exogenous variables consisted of individual factors (sex, age, education, job-grade, and annual salary), psychological variables(pride for organization, extrinsic motivation, intrinsic motivation and support of supervisor) ad structural variables(formalization, centralization, communication, job-conflict, job-decision, and workload). In the hypothetical causal model, organizational commitment was supposed to be effect variable, and organizational satisfaction was presumed to be intervening variable to mediate between organizational commitment and exogenous variables. For data collection, cross-sectional self-administered questionnaire survey was conducted to 1,295 public servants from 32 urban health centers nationwide. The survey responses were from 934, 72.1% of subjects. But 756 responses(58.4%) were analyzed because of excluding ones with missing values. The hypothetical causal model was fitted by covariance structural analysis with maximum likelihood method. Main results were as follows: (1) The fitted causal model accounted for 33 and 55 percent of total variance of organizational commitment and organizational satisfaction of public servants, respectively. (2) In order of effect size, pride for organization, supervisor support, communication, extrinsic motivation and centralization had an indirect effect effect on organizational commitment through organizational satisfaction. However, the effect of centralization was negative. (3) Pride for organiztion, intrinsic motivation, organizational satisfaction, job-conflict, supervisor support, communication, age, centralization, annual salar and extrinsic motivation had indirect or direct effects on organizational commitment in order of effect size. Among them, effects of job-conflict and centraldization were negative. In conclusion, these results suggested that organizational commitment of public servants in urban health centers could be enhanced by pride for organization, intrinsic and extrinsic motivations, prevention of job-conflict and excess centralization, supervisor support and active communication. Especially, pride for organization and intrinsic motivation were expected to play the most important role.

• Korean Journal of Legislative Studies
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• v.15 no.1
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• pp.65-92
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• 2009

Political trust is defined as the degree to which people perceive that government is producing outcomes consistent with their expectations. Political trust as a concept has endogenous as well as exogenous characteristics in that it can cause and be caused by other political factors. The purpose of this study is to introduce and evaluate various theoretical perspectives related to the causes and effects of political trust. With respect to its causes, this study focuses on the following five factors: government policies, unethical behaviors of politicians, citizens' penchant for participatory democracy, the public's misperceptions on government, and political culture. On the other hand, this study discusses the impacts of political trust on each stage of political process by paying attention to the following factors: government's governability, election outcomes, political recruitment, and the directions of government policies.

• Journal of the Korean Data and Information Science Society
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• v.27 no.6
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• pp.1511-1523
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• 2016

The increasing trend of the five violent crimes (murder, robbery, rape, violence, theft) in Korea is not independent of social and economic factors. Several social science research have discussed about this issue but most of them do not properly reflect the nature of the time-series data. Based on several time series models, we studied about the endogenous factors (time, seasonal and cycle factors) and exogenous factors (economical, social change and crime control factors) on violent crime occur in Korea. Autocorrelation were also taken into account. Through this study, we want to help to make preventive policy by explaining the cause of violent crime and predicting the future incidence of it.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.127-140
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• 1991

The Primary purpose of this study is to investigate factors and variables which have significant effects on user satisfaction with recreational facilities in Taejong-Dae recreational complex, thereby establishing indices of planning and development of urban parks and open space. To test the causal models of this research, the date were gathered by self-administered questionnaires from 967 households in Pusan City which were selected by the multi-stage probability sampling methood. The analysis of the multi-stage primarily consists of two phase : The first analysis dealt exploratory factor analysis which identified major factors involved in satisfaction with recreational activities and facilities in Taejong-Dae recreational complex and the second analysis tested the fit of the causal models of this research by employing LISREL methodology. There are three advantages of using LISREL over other multivariate analysis methods : First, measurement error is allowed and calculated in LISREL, otherwise there is a risk of seriously misleading estimates of coefficients ; Second, LISREL deals with latent variables or unmeasured variables ; Third, it enables to test causal relations among variables. The factors analysis identified that five factors are involved in satisfaction with recreational facilities. The five factors of satisfaction with recreational facilities are space for repose and relaxation, active recreation facilities such as pool and zoo, physical exercise facility, convenience and maintenance facility, and linear facility, and linear facility for walking. The second phase analysis tested the fit of the causal models for satisfaction with recreational facilities to the data and identified statistically significant causal linkage among overall satisfaction with Taejong-Dae recreational complex, other endogenous factors and exogenous variables. Overall fits of both causal models were very good. Among endogenous factors, facility for repose and relaxation. linear facility for walking, active recreation facility, facility for convenience and maintenance were identified as having significant effects on overall satisfaction. Exogenous variables which have significant effects on endogenous variables wer also identified. These significant relationships indicate important factors and variables that should be considered in planning and development of the recreational complex. On the basis of these significant causal relationships, implications for planning and the delovepment of Taejong-Dae recreational complex were suggested.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.4
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• pp.50-60
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• 1996

The purpose of this study is to investigate the prime factors that affect user satisfaction of area and facilities in urban forests, to classify those factors, to find out factorial structure of user satisfaction about them, and then to suggest important indicators in the urban forest planning, design, and development. The survey research was done using the self-administered questionnaire method by the people in the city of the Pusan who participated in recreational activities in the Mt. Keumjung. Factor analysis was used to extract the prime factors related to the recreational satisfaction concerning the area and facilities of the urban forest by the SPSS program, and then prime factors were used to investigate the factorial structure of user recreational satisfaction in the urban forest by the LInear Structure RELation program. According to the factor analysis concerning the 13 variables, 4 prime factors by the statistical values were considered as effective, indicating, 'health and recreational facilities', 'convenience and management facilities','facilities for the physical and psychological training' and 'historical and cultural areas'. The results of the causal structure analysis were identified as having significant effects mutually on endogenous variables, 'overall recreational satisfaction of the areas and facilities in the Mt. Keumjung','health and recreational facilities','convenience and management facilities','facilities for the psychological training', and 'historical and cultural areas'. But exogenous variables which have significant effects on endogenous variables were also indentified. Overall fits of both causal model were very good. The hypothetical causal structural equation models based on the results found partially significant correlation between dndogenous variables and between envogenous and exogenous variables. These significant relationships indiate important factors and variables that should be considered in planning, design, and development of the urban forests. Therefore, development direction of the Mt. Keumjung has to be analyzed as significant factors concerning user recreational satisfaction in a systematic was, recognized as important variables for planning process. The plan for development and management also should reflect the natural conservation policy from the environmental conservation movement like natural conservation advertisement and environmental education.