• Journal of Digital Convergence
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• v.20 no.1
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• pp.55-69
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• 2022

The purpose of this study is to verify whether there is a mediating effect of self-efficacy in the relationship between self-leadership and organizational commitment, self-leadership and job satisfaction. Specifically, hypotheses were established and a research model was established that behavior-focused strategies, natural reward strategies, and constructive thought pattern strategies have a significant positive (+) effect on organizational commitment, self-efficacy among these variables. In order to analyze this, 239 copies of survey data were collected from general domestic companies and analyzed through SPSS 25.0. The mediating analysis was conducted in the manner proposed by Baron & Kenny(1986). As a result, among the sub-factors of self-leadership, behavior-focused strategies and natural reward strategies had a significant positive (+) effect on organizational commitment, but constructive thought pattern strategies had no causal relationship with organizational commitment. In addition, in the relationship between these variables, self-efficacy showed a partial mediating effect. On the other hand, in the relationship between self-leadership and job satisfaction, only the natural reward strategies among the sub-factors of self-leadership showed a significant positive (+) effect, and behavior-focused strategies and constructive thought pattern strategies showed no causal relationship. Among these variables, self-efficacy was found to show partial mediation. Details and implications of the analysis results were dealt with in the conclusions and discussions of the study.

• Asia pacific journal of information systems
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• v.19 no.4
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• pp.47-75
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• 2009

Recently, researches on Management Information Systems (MIS) have laid out theoretical foundation and academic paradigms by introducing diverse theories, themes, and methodologies. Especially, academic paradigms of MIS encourage a user-friendly approach by developing the technologies from the users' perspectives, which reflects the existence of strong causal relationships between information systems and user's behavior. As in other areas in social science the use of structural equation modeling (SEM) has rapidly increased in recent years especially in the MIS area. The SEM technique is important because it provides powerful ways to address key IS research problems. It also has a unique ability to simultaneously examine a series of casual relationships while analyzing multiple independent and dependent variables all at the same time. In spite of providing many benefits to the MIS researchers, there are some potential pitfalls with the analytical technique. The research objective of this study is to provide some guidelines for an appropriate use of SEM based on the assessment of current practice of using SEM in the MIS research. This study focuses on several statistical issues related to the use of SEM in the MIS research. Selected articles are assessed in three parts through the meta analysis. The first part is related to the initial specification of theoretical model of interest. The second is about data screening prior to model estimation and testing. And the last part concerns estimation and testing of theoretical models based on empirical data. This study reviewed the use of SEM in 164 empirical research articles published in four major MIS journals in Korea (APJIS, ISR, JIS and JITAM) from 1991 to 2007. APJIS, ISR, JIS and JITAM accounted for 73, 17, 58, and 16 of the total number of applications, respectively. The number of published applications has been increased over time. LISREL was the most frequently used SEM software among MIS researchers (97 studies (59.15%)), followed by AMOS (45 studies (27.44%)). In the first part, regarding issues related to the initial specification of theoretical model of interest, all of the studies have used cross-sectional data. The studies that use cross-sectional data may be able to better explain their structural model as a set of relationships. Most of SEM studies, meanwhile, have employed. confirmatory-type analysis (146 articles (89%)). For the model specification issue about model formulation, 159 (96.9%) of the studies were the full structural equation model. For only 5 researches, SEM was used for the measurement model with a set of observed variables. The average sample size for all models was 365.41, with some models retaining a sample as small as 50 and as large as 500. The second part of the issue is related to data screening prior to model estimation and testing. Data screening is important for researchers particularly in defining how they deal with missing values. Overall, discussion of data screening was reported in 118 (71.95%) of the studies while there was no study discussing evidence of multivariate normality for the models. On the third part, issues related to the estimation and testing of theoretical models on empirical data, assessing model fit is one of most important issues because it provides adequate statistical power for research models. There were multiple fit indices used in the SEM applications. The test was reported in the most of studies (146 (89%)), whereas normed-test was reported less frequently (65 studies (39.64%)). It is important that normed- of 3 or lower is required for adequate model fit. The most popular model fit indices were GFI (109 (66.46%)), AGFI (84 (51.22%)), NFI (44 (47.56%)), RMR (42 (25.61%)), CFI (59 (35.98%)), RMSEA (62 (37.80)), and NNFI (48 (29.27%)). Regarding the test of construct validity, convergent validity has been examined in 109 studies (66.46%) and discriminant validity in 98 (59.76%). 81 studies (49.39%) have reported the average variance extracted (AVE). However, there was little discussion of direct (47 (28.66%)), indirect, and total effect in the SEM models. Based on these findings, we suggest general guidelines for the use of SEM and propose some recommendations on concerning issues of latent variables models, raw data, sample size, data screening, reporting parameter estimated, model fit statistics, multivariate normality, confirmatory factor analysis, reliabilities and the decomposition of effects.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.177-190
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• 2022

In this study, using data from the second wave of Panel Survey of Employment for The Disabled[PESD] (2016) to the sixth year (2021), the longitudinal changes between disability acceptance and job satisfaction of adult wage workers aged 20 or older with disabilities and the correlation An autoregressive cross-lagged model was applied to analyze the causal relationship. As a result of the analysis, first, the disability acceptance and job satisfaction at the previous time point of the disabled workers were stably significant to the disability acceptance(𝛽=.556~.610) and job satisfaction(𝛽=.554~.585) at the later time point. Second, disability acceptance at the previous point in time for wage workers with disabilities crosses the job satisfaction at the later time point(𝛽=.077~.090), and the job satisfaction at the previous point crosses the disability acceptance at the later time point(𝛽=.087~.092). Third, as a result of model fit analysis according to the gender group of wage workers with disabilities, the difference in the autoregressive effect between disability acceptance and job satisfaction and the cross-lagged effect between disability acceptance and job satisfaction according to the passage of time was not significant.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.11-11
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• 2014

Fungal pathogens have huge impact on health and economic wellbeing of human by causing life-threatening mycoses in immune-compromised patients or by destroying crop plants. A key determinant of fungal pathogenesis is their ability to undergo developmental change in response to host or environmental factors. Genetic pathways that regulate such morphological transitions and adaptation are therefore extensively studied during the last few decades. Given that epigenetic as well as genetic components play pivotal roles in development of plants and mammals, contribution of microbial epigenetic counterparts to this morphogenetic process is intriguing yet nearly unappreciated question to date. To bridge this gap in our knowledge, we set out to investigate histone modifications among epigenetic mechanisms that possibly regulate fungal adaptation and processes involved in pathogenesis of a model plant pathogenic fungus, Magnaporthe oryzae. M. oryzae is a causal agent of rice blast disease, which destroys 10 to 30% of the rice crop annually. Since the rice is the staple food for more than half of human population, the disease is a major threat to global food security. In addition to the socioeconomic impact of the disease it causes, the fungus is genetically tractable and can undergo well-defined morphological transitions including asexual spore production and appressorium (a specialized infection structure) formation in vitro, making it a model to study fungal development and pathogenicity. For functional and comparative analysis of histone modifications, a web-based database (dbHiMo) was constructed to archive and analyze histone modifying enzymes from eukaryotic species whose genome sequences are available. Histone modifying enzymes were identified applying a search pipeline built upon profile hidden Markov model (HMM) to proteomes. The database incorporates 22,169 histone-modifying enzymes identified from 342 species including 214 fungal, 33 plants, and 77 metazoan species. The dbHiMo provides users with web-based personalized data browsing and analysis tools, supporting comparative and evolutionary genomics. Based on the database entries, functional analysis of genes encoding histone acetyltransferases and histone demethylases is under way. Here I provide examples of such analyses that show how histone acetylation and methylation is implicated in regulating important aspects of fungal pathogenesis. Current analysis of histone modifying enzymes will be followed by ChIP-Seq and RNA-seq experiments to pinpoint the genes that are controlled by particular histone modifications. We anticipate that our work will provide not only the significant advances in our understanding of epigenetic mechanisms operating in microbial eukaryotes but also basis to expand our perspective on regulation of development in fungal pathogens.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.261-273
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• 2022

This study aims to predict the land use demand of Seongnam-city using system dynamics and to simulate the effect of changes in family structure and land use density adjustment policy on land use demand. This study attempted to construct causal loop diagrams and an analysis model. The changes in land use demand over time were predicted through simulation results. As a result of the analysis, as of 2035, an additional supply of 2.08 km² for residential land and 1.36 km² for commercial land is required. Additionally, the current supply area of industrial land can meet the demand. Three policy experiments were conducted by changing the variable values in the basic model. In the first policy experiment, it was found that when the number of household members decreased sharply compared to the basic model, up to 7.99 km² of additional residential land were required. In the second policy experiment, if the apartment floor area ratio was raised from 200% to 300%, it was possible to meet the demand for residential land with the current supply area of Seongnam-city. In the third policy experiment, it was found that even if the average number of floors in the commercial area was raised from four to five and the building-to-land ratio in the commercial area was raised from 80% to 85%, the demand for commercial land exceeded the supply area of the commercial area in Seongnam-city. This study is meaningful in that it proposes a new analytical model for land use demand prediction using system dynamics, and empirically analyzes the model by applying the actual urban planning status and statistics of Seongnam-city.

• Journal of The Korean Association For Science Education
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• v.31 no.5
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• pp.734-744
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• 2011

The purpose of this study was to identify middle school students' mental models on plate tectonics and to compare the mental models of verbal-learning-style students with those of visual-learning-style students. 94 student participants in 9th grade were requested to draw and explain three topics; generation of magma, the formation of the mountain range and the interior of the Earth. The criterions for analyzing the mental models are derived from the data of the drawing task. The research results were as follows: The mental models on the generation of magma were classified as 'unstable model,' 'partial casual model,' 'causal model,' and 'conceptual model.' On the other hand, the mental models on the interior of the Earth were classified as 'static unstable model,' 'dynamic unstable model,' and 'conceptual model.' Students holding 'unstable model' were unable to relate the plate collision and the magma generation. They showed a variety of alternative conceptions of study areas, such as 'magma is generated from the core' and 'the mountain is formed by rising of the plates themselves.' Also, visual-learning-style students showed higher proportion of conceptual models and lower proportion of unstable mental models than verbal-learning-style students on three topics. The findings revealed that the students tend to have different concepts on the plate tectonics depending on their learning style.

• Journal of Navigation and Port Research
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• v.44 no.1
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• pp.44-52
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• 2020

More accurate forecasting of port cargo in the global long-term recession is critical for the implementation of port policy. In this study, the Busan Port container volume (export cargo and transshipment cargo) was estimated using the Vector Autoregressive (VAR) model and the vector error correction (VEC) model considering the causal relationship between the economic scale (GDP) of Korea, China, and the U.S. as well as ARIMA, a single volume model. The measurement data was the monthly volume of container shipments at the Busan port J anuary 2014-August 2019. According to the analysis, the time series of import and export volume was estimated by VAR because it was relatively stable, and transshipment cargo was non-stationary, but it has cointegration relationship (long-term equilibrium) with economic scale, interest rate, and economic fluctuation, so estimated by the VEC model. The estimation results show that ARIMA is superior in the stationary time-series data (local cargo) and transshipment cargo with a trend are more predictable in estimating by the multivariate model, the VEC model. Import-export cargo, in particular, is closely related to the size of our country's economy, and transshipment cargo is closely related to the size of the Chinese and American economies. It also suggests a strategy to increase transshipment cargo as the size of China's economy appears to be closer than that of the U.S.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.473-483
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• 2016

This study examines the relationship between sport confidence, exercise passion and re-participation intention of collegiate students participating in snow-ski class. The subjects for this study were 416 collegiate students who signed up for snow-ski class as a university curriculum. The reliability and validity test of the questionnaire were conducted by using SPSS & AMOS Window 18.0 program; the results of descriptive analysis, factor analysis, correlation analysis, structural equation model are as follows; First, sport confidence of collegiate students in ski-class affects their exercise passion. Second, sport confidence of collegiate students in ski-class has influence on their re-participation intention. Third, collegiate students' exercise passion in ski-class affects their re-participation intention. Lastly there is a causal relationship between sport confidence, exercise passion and re-participation intention of collegiate students in the snow-ski class.

• Journal of Environmental Impact Assessment
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• v.21 no.3
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• pp.367-380
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• 2012

There are many long and round shape shores due to terrain characteristics in Daecheong reservoir. Therefore it is indicated different spatial distribution of algae every year since the stream is being regulated by these terrain characteristics and reservoir operation about inflow and outflow discharge. Also oversupply of nutrient salt from tributaries of Daecheong reservoir where pollutants were concentrated generates massive growth of algae and depending on hydrological, reservoir operation condition, those proliferated algae at the stagnant tributaries moves to the mainstream of Daecheong reservoir which could create problems of water quality. In this study, it was analyzed the tendency of algae generation by examining algae occurring status for the last 4 years since 2008, and implemented hydraulic analysis at Daecheong reservoir through numerical tracer simulation by applying 3-dimensional hydrodynamic model, ELCOM. Also it was implemented a quantitative analysis of causal relationship based on the algae generation tendency and hydraulic behavior at Daecheong reservoir. Through numerical tracer simulation in this study, it could be noticed the degree of spread of inflow indicated similar trend to the algae occurring status at Daecheong reservoir and verified the different tendency of algae generation in 2011 unlike previous year caused by the rise of water temperature.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.2
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• pp.202-212
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• 2013

Outstanding service quality is a crucial factor to increase customer revisits, to increase customer revisits, to create new customers through positive word-of-mouth marketing and increase profits; in conjunction, the physical environment of department stores have a firsthand impact on customer purchasing behavior. This study examines the physical environment dimensions of department stores in China and the causal relationship with the physical environment, service environment, internal responses and store loyalty. The subjects in this study were male and female adults who finished the shopping the Lotte and Wangfujing Department Store located in Beijing. All participants were over the age of 20 and a one-on-one survey was conducted to gather data from October to November 2011. Data from 424 respondents were analyzed: in addition, AMOS factor analysis and path analysis were used. The results were as follows. First, physical environment factors consist of exterior aesthetic attraction, convenience, cleanliness and an interior aesthetic attraction. Second, exterior aesthetic attraction, convenience and cleanliness affect the overall service environment perception. Third, the service environment exercised an influence on internal responses, and internal responses impacted store loyalty. Fourth, a comparative analysis was made over Korean and Chinese department stores in China to check the research model. In Wangfujing Department Store, exterior aesthetic attraction, cleanliness and convenience had a statistically significant impact on service environment perceptions. In Lotte Department Store, the perception of service environment was under the statistically significant influence of all physical factors (exterior aesthetic attraction, interior aesthetic attraction, convenience and cleanliness). The findings of this study are helpful for Korean Department stores that plan to make inroads into China to formulate efficient service environment strategies tailored to local consumer characteristics.