• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.1
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• pp.1-14
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• 2021

Onions are a representative produce that requires supply-demand control measures due to large fluctuations in production and price by growing season. Accurate forecasts of crop production can improve the effectiveness of such measures. However, it is challenging to obtain accurate estimates of crop productivity for onions because they are mainly grown on the open fields. The objective of this study was to perform the empirical analysis of the relationship between factors for crop growth and meteorological conditions, which can support the development of models to predict crop growth and production. The growth survey data were collected from open fields. The survey data included the weight of above ground organs as well as that of the bulbs. The estimates of meteorological data were also compiled for the given fields. Correlation analysis between these factors was performed. The random forest was also used to compare the importance of the meteorological factors by the growth stage. Our results indicated that insolation in early March had a positive effect on the growth of the above-ground. There was a negative correlation between precipitation and the growth of the above-ground at the end of March although it has been suggested that drought can deter the growth of onion. The negative effects of precipitation and daylight hours on the growth of the above-ground and under-ground were significant during the harvest period. These meteorological factors identified by growth stage can be used to develop models for onion growth and production forecast.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1203-1210
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• 2012

As the area of upland crops increase, it is become more important for farmers to understand status of soil water at their own fields due to key role of proper irrigation. In order to estimate daily water balance and soil water content with simple weather data and irrigation records, we have developed the model for estimating water balance and soil water content, called AFKAE0.5, and verified its simulated results comparing with daily change of soil water content observed by soil profile moisture sensors. AFKAE0.5 has two hypothesis before establishing its system. The first is the soil in the model has 300 mm in depth with soil texture. And the second is to simplify water movement between the subjected soil and beneath soil dividing 3 categories which is defined by soil water potential. AFKAE0.5 characterized with determining the amount of upward and downward water between the subjected soil and beneath soil. As a result of simulation of AFKAE0.5 at Gongju region with red pepper cultivation in 2005, the water balance with input minus output is recorded as - 88 mm. the amount of input water as precipitation, irrigation, and upward water is annually 1,043, 0, and 207 mm, on the other, output as evapotranspiration, run-off, and percolation is 831, 309, and 161 mm, respectively.

• Journal of Digital Contents Society
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• v.19 no.3
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• pp.547-559
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• 2018

This study deals with the factors influencing acceptance of social media-based smart commerce service through personal innovativeness by quantitative empirical research method. Researchers have viewed that personal innovativeness affects the aesthetic criteria, hedonic value, economic value, and subjective norms, which are subdivided elements of emotion and characteristics. The hypothesis is that the emotional and characteristics variables affect the variables such as purchase intention and word of mouth intention of the TAM and the post acceptance model (PAM). The research model proposed in this study is a integrated model of proven models in previous studies, and it is expected that there will be a theoretical and practical contribution of research. The researchers hope that this study will make a significant contribution to the industry and policy in dealing with the acceptance of smart commerce services emerging in the area of e-commerce and social media marketing.

• The Journal of Korean Association of Computer Education
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• v.15 no.1
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• pp.23-31
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• 2012

The most adolescents have become themselves perpetrators and victims unknowingly about variety illegal behaviors of the Information Ethics(IE) in the Information-oriented society. To solve the problem, in this paper, we developed the IE Behavior Prediction model through various social psychology theories. And then, we analyzed the relationship between the factors influencing about the adolescents's behavioral intention to perform the Information Ethics by using regression analysis. As a result, 'Attitudes toward the behavior', 'Subjective norms', 'Perceived behavior control', and 'Past behavior' about behavioral intention of the Information Ethics have performed positively. And also they have statically significant. Especially, 'Attitudes toward the behavior' gave the larger effect than the other 3 factors about the Information Ethics Behavior. This result would provide the useful guideline to develop the educational resources, counsel materials, and test items for Information Ethics Behavior.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.216-224
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• 2008

In general, based on criteria of subway law, radius 500m from subway station is defined as SIA(Subway Station Influence Area). Therefore, in this paper, selection models of SIA are developed to identify appropriate SIA for recently developed 4 new towns based based on CART analysis. As a result, following outputs are obtained; (1) walking distance from subway station is the most influential factor to define SIA (2) SIAs vary with new towns (i.e., bundang city: 856m, ilsan sanbon city 508m, pyungchon city 495m), and (3) walking distance from subway station is influential to land price of SIA. In addition, bundang and pyungchon new town are more affected in land price and walking distance. Therefore, it is desirable for current definition of SIA (radius 500m from subway station) to reflect characteristics of land use and walking distance in the new towns.

• Journal of Korean Library and Information Science Society
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• v.51 no.3
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• pp.123-148
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• 2020

The purpose of this study is to explore factores for subject teachers to actively participate in the LBI by establishing a relationship model between the acceptance variable and the variable for LBI and verifying with a structural equation based on the UTAUT model that explains the relationship between the variables that affect the process of accepting and utilizing the new information technology. As a result of the study, first, the performance expectancy and social influence of the subject teachers on LBI influenced the intention of teaching. Second, behavioral intention affected use behavior. Third, there were moderating effects of LBI perceived risk level on the relationship of subject teachers' social influence on LBI to behavioral intention. Based on the results above, performance expectancy, social influence, and perceived risks should be considered for activating LBI of subject teachers.

• Journal of Digital Contents Society
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• v.19 no.1
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• pp.141-147
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• 2018

This study analyzed the early retired employees who stayed in company no longer than 3 years based on a certain company's personality evaluation result data. The predicted model was analyzed by dividing into two categories; the manufacture group and the R&D group. Independent variables were selected according to the stepwise method. A logistic regression model was selected as a prediction model among various supervised learning methods, and trained through cross-validation to prevent over-fitting or under-fitting. The accuracy of the two groups were confirmed by the confusion matrix. The most influential factor for early retirement in the manufacture group was revealed as "immersion," and for the R&D group appeared as "antisocial." In the past, people concentrated on collecting data by questionnaire and identifying factors that are highly related to the retirement, but this study suggests a sustainable early retirement prediction model in the future by analyzing the tangible outcome of the recruitment process.

• 한국디지털정책학회:학술대회논문집
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• 2006.06a
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• pp.431-441
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• 2006

본 연구는 모바일 비즈니스(Mobile-business)에서 모바일 서비스 특성이 고객충성도와 재구매에 미치는 영향에 관하여 연구하고자 한다. 모바일 서비스를 제공하는 기업들이 성공하기 위해서 사용자의 서비스에 대한 충성도를 높일 수 있는 확실한 콘텐츠를 개발하는 것은 매우 중요하다. 모바일 비즈니스의 기존연구를 살펴보면 고객의 충성도와 재구매를 높이기 위해 구체적 어떠한 서비스 특성이 영향을 미치는 가에 대한 연구는 미진한 편이다. 따라서 본 연구는 선행연구에서 연구된 모바일 비즈니스의 특성과 인터넷 특성을 고려하여 모바일만의 서비스 특성을 제시하고, 이를 실증 분석하여 주요한 영향요인을 도출하고자 한다. 본 연구에 제시하고자 하는 모바일 특성의 3가지 유형은 모바일 정보 특성과 인터페이스 특성, 모바일 이용 특성으로 분류하고 있다. 본 연구를 수행하는 방법은 모바일 특성을 선행변수로 하고, 재구매 의도와 고객충성도를 결과변수로 하는 연구 모형을 설정하여 실증연구를 수행하였다. 모바일 사용 주계층인 10대에서 30대를 대상으로 총 226부을 연구에 사용하였다. 연구 결과 첫째, 고객충성도와 재구매 의도간에 강한 영향정도가 있었고, 둘째, 고객충성도에 영향을 미치는 요인으로는 정보 특성 요인과 인터페이스 요인 중 간결성으로 나타났으며, 셋째, 재구매 의도에 영향을 주는 요인은 정보 특성 요인 중 정확성과 최신성과 인터페이스 특성 요인으로 나타났다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.679-687
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• 2017

This study examines financial factors affecting cash holdings of firms in the domestic capital markets. Specifically, this study focuses on regional firms with headquarters in Chungcheong province, the Republic of Korea, which features little previous research concentrating on the firms in the particular region. Three primary hypotheses were empirically tested utilizing robust econometric models, including static panel data, Tobit regression, and logistic models.Results reveal only five explanatory variables, including DSO, LIQUID, LEVERAGE, PMARGIN, and SIZE, showed statistically significant effects on the level of cash holdings among the nine variables studied. In addition two IDVs, LEVERAGE and FOS, showed significant differentiated effects between firms with headquarters in North and South Chungcheong regions. With continued debate among interested parties on the optimal level of cash reserves, the study provides a new vision for the optimal cash reserves for firms with headquarters in Chungcheong Province, where unprecedented socio-economic factors are driven.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.121-129
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• 2011

The purpose of this study is to determine the relationship between observed traffic data and NOx concentrations from not an ideal condition but a real road in real-time. Also we aim to develop an estimation model for NOx emission concentrations due to vehicle exhaust gas, and it can be applied to monitor the degree of air pollution on National Road in real-time. To eliminate outliers which are occurred due to errors of equipments and other variables, we use the robust analysis and develop two models. which are considering and not considering wind impact. The result of this research can be used for understanding present condition of air pollution caused by vehicle exhaust gas and evaluating for environmental effects of transportation policy.