• 응용통계연구
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• 제28권5호
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• pp.1013-1024
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• 2015

본 논문에서는 다변량 DCC(dynamic conditional correlation) GARCH 모형에서 동태적 상관계수를 추정하기 위한 대표적 방법인 쌍별 추정법과 다차원 추정법의 효율성을 비교한다. 이를 위하여 금융 시장의 변동성을 반영하는 다변량 시계열을 생성하고 이에 대한 DCC GARCH 모형을 수립 및 추정하는 시뮬레이션을 실시하였다. 또한 KOSPI 200 섹터지수를 이용하여 포트폴리오를 구성하고 이의 변동성 추정 및 VaR 계산을 통하여 동태적 상관계수 추정에 대한 정확성을 평가하였다. 그 결과로서, 전반적으로 다차원 추정법이 쌍별 추정법보다 우수함을 발견하였다. 특히, 다차원 추정법에서 상대적으로 상관관계가 낮은 시계열을 추가할수록 쌍별 시계열에 대한 동태적 상관계수 추정의 정확성을 높여줌을 발견하였다.

• Asia pacific journal of information systems
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• 제9권4호
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• pp.143-161
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• 1999

The objective of this research is to develop education and training systems for IS department and user department personnel, which is essential to effective implementation IT(information technology) strategies in most of organizations. In order to achieve this research objective, first this study theoretically derives six categories of education and training based on comprehensive review of the previous research, and explicates concrete items for each category. And then, with respect to each of these items, we empirically investigate the degree of necessity measured by the gap between the required level of knowledge and skills which staff members should have for effective implementation of IT strategies and the present level of them which they really have. Field survey is employed for the data collection: 270 questionnaires are distributed to the companies in private and public sectors, and 196 questionnaires are collected in useful condition and are analyzed. The findings of this research shows that six dimensions of education and training are empirically derived by factor analysis as following: (1) general knowledge for organizational overview, (2) management knowledge and skills, (3) knowledge and skills of the specific information system which IS department and user department personnel are directly involved in developing and operating, (4) knowledge and skills for strategic use of IT, (5) general knowledge and skills for IT and (6) advanced expert knowledge and skills for specific IT. And the degree of necessity turns out to be statistically significantly different among six dimensions of education and training needed by IS department and user department personnel respectively. Also for each dimension, the degree of necessity is shown to be statistically significantly different between IS department and user department personnel The results of this study can provide the theoretical basis for constructing the IT education and training system for effective implementation of IT strategies, Also they can be used as a practical guideline in developing and promoting specific IT education and training programs in real organizations.

• 한국산업정보학회논문지
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• 제24권1호
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• pp.65-79
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• 2019

그간 박물관은 전시 큐레이팅 중심으로 이루어져왔다. 그러나 최근 방문자 맞춤형 전시가 중시되면서 앱 기반 고객서비스 및 QR코드 인식을 통한 전시 설명 등 다양한 서비스가 제공되고 있다. 이러한 추세에 맞추어 스마트폰이나 소셜네트워크를 이용한 박물관 서비스 관련 연구는 종종 시도되었다. 그러나 정보기술 기반 서비스와 연계한 방문객 만족요인에 관한 연구는 거의 없었다. 따라서 본 연구에서는 ICT 기반 박물관 서비스 품질요인들을 식별, 분류하고 KANO모델에 근거하여 이들의 품질속성을 밝히고자 하였다. 나아가 한국과 오스트리아를 대상으로 표본설문조사를 실시하여 그 차이를 비교하였다. 그 결과 문화 차이가 서비스요인별 품질속성차원에 영향을 준다는 사실을 확인할 수 있었으며, 같은 차원으로 분류된 요인도 지각된 서비스 품질에는 차이가 있음을 알 수 있었다. 이러한 결과는 박물관 경영에도 문화적 차원을 고려해야 함을 시사한다.

• 복식문화연구
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• 제27권3호
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• pp.285-297
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• 2019

Retail firms have begun to pursue the marketing strategies, which stimulate consumers' sensibility and lead people to purchase their products. The visible effects of visual merchandising (VM) arouse consumers' interest and play an effective role in having busy people efficiently choose products. Apparel retail stores such as SPA use the offline store to be the experiential environment of their branding. Consumers' sensitivity and response toward various visual merchandising strategies needs to be accessed. The purpose of this study is to identify VM consciousness and VM evaluation attribute factors. Relationship of such variables with other variables were accessed. As consequence variables, product satisfaction and unplanned purchase behavior were included in the study. An empirical survey data was collected from men and women of various ages. Results indicated that VM consciousness and VM evaluation attribute factors were not correlated with consumer demographic variables. VM evaluation attributes were factored into appropriateness, attractiveness and functionality dimensions. Clothing involvement and brand orientation significantly influenced product satisfaction and unplanned purchase. The direct and indirect effect (via VM consciousness) were significant. For unplanned purchase, brand orientation only had indirect effect. The influence of VM evaluation attribute factors were significant. Appropriateness had stronger effect on product satisfaction whereas attractiveness had stronger effect on unplanned behavior. Functionality dimension had only indirect effect on product satisfaction but did not show significant direct and indirect effects on unplanned purchase. This study identified the pivotal role of VM consciousness in various shopping and purchasing circumstances in offline retail store of apparel brands.

• Structural Engineering and Mechanics
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• 제77권4호
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• pp.441-461
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• 2021

Reinforced concrete (RC) columns are crucial in building structures and they are of higher vulnerability to terrorist threat than any other structural elements. Thus it is of great interest and necessity to achieve a comprehensive understanding of the possible responses of RC columns when exposed to high intensive blast loads. The primary objective of this study is to derive analytical formulas to assess vulnerability of RC columns using an advanced numerical modelling approach. This investigation is necessary as the effect of blast loads would be minimal to the RC structure if the explosive charge is located at the safe standoff distance from the main columns in the building and therefore minimizes the chance of disastrous collapse of the RC columns. In the current research, finite element model is developed for RC columns using LS-DYNA program that includes a comprehensive discussion of the material models, element formulation, boundary condition and loading methods. Numerical model is validated to aid in the study of RC column testing against the explosion field test results. Residual capacity of RC column is selected as damage criteria. Intensive investigations using Arbitrary Lagrangian Eulerian (ALE) methodology are then implemented to evaluate the influence of scaled distance, column dimension, concrete and steel reinforcement properties and axial load index on the vulnerability of RC columns. The generated empirical formulae can be used by the designers to predict a damage degree of new column design when consider explosive loads. With an extensive knowledge on the vulnerability assessment of RC structures under blast explosion, advancement to the convention design of structural elements can be achieved to improve the column survivability, while reducing the lethality of explosive attack and in turn providing a safer environment for the public.

• 한국전산구조공학회논문집
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• 제35권1호
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• pp.1-8
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• 2022

본 연구에서는 토양-탄체 간 분리 및 재접촉을 고려한 IFL 기반 침투해석 기술을 개발하고 이를 기존 문헌의 실험결과와 비교하는 연구를 수행했다. 탄체를 강체로 가정한 후, 토양 내로 침투 시 발생하는 구형공동팽창 현상을 고려함으로써 탄체의 궤적을 예측할 수 있다. 토양에 대한 저항함수는 Mohr-Coulomb 항복 모델을 활용했으며, 입사각 혹은 AOA에 따른 J-hook 현상을 모사할 수 있다. 기존 문헌에서의 실험결과(총 6회)와의 비교 결과, 수치해석으로부터 예측한 탄체의 침투 깊이는 실험대비 약 13.4%의 평균오차를 나타냈다. 일반적으로 탄체의 침투 경로를 예측하기 위해 유한요소법이 널리 활용된다. 하지만, 유한요소법 활용 시, 탄체의 모델링을 위해 많은 시간과 노력이 필요하며, 해석 수행을 위해 수 시간이 소요된다. 본 연구를 통해 개발한 모델을 활용할 시, 탄체의 치수 입력만 필요하며 해석 시간도 수 초 이내이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.136-136
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• 2021

In this study, a deep convolutional neural network (DCNN) model is proposed for short-term precipitation forecasting using weather radar-based images. The DCNN model is a combination of convolutional neural networks, autoencoder neural networks, and U-net architecture. The weather radar-based image data used here are retrieved from competition for rainfall forecasting in Korea (AI Contest for Rainfall Prediction of Hydroelectric Dam Using Public Data), organized by Dacon under the sponsorship of the Korean Water Resources Association in October 2020. This data is collected from rainy events during the rainy season (April - October) from 2010 to 2017. These images have undergone a preprocessing step to convert from weather radar data to grayscale image data before they are exploited for the competition. Accordingly, each of these gray images covers a spatial dimension of 120×120 pixels and has a corresponding temporal resolution of 10 minutes. Here, each pixel corresponds to a grid of size 4km×4km. The DCNN model is designed in this study to provide 10-minute predictive images in advance. Then, precipitation information can be obtained from these forecast images through empirical conversion formulas. Model performance is assessed by comparing the Score index, which is defined based on the ratio of MAE (mean absolute error) to CSI (critical success index) values. The competition results have demonstrated the impressive performance of the DCNN model, where the Score value is 0.530 compared to the best value from the competition of 0.500, ranking 16^th out of 463 participating teams. This study's findings exhibit the potential of applying the DCNN model to short-term rainfall prediction using weather radar-based images. As a result, this model can be applied to other areas with different spatiotemporal resolutions.

• 경영정보학연구
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• 제26권2호
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• pp.59-81
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• 2024

온라인 소비자 리뷰는 만족과 불만족 측면에서 고객 측면의 다양한 정보를 제공한다. 부정적 감정표현은 리뷰 유용성의 잠재적 선행요인이면서, 동시에 잠재 소비자의 태도와 의사결정에도 영향을 미칠 수 있다. 또한, 국가문화는 개인이 세상을 바라보고 행동하는 관점을 제공하기 때문에, 부정적 감정표현은 문화에 따라 차이가 발생할 가능성이 크다. 본 연구는 국가문화와 부정적 감정표현 간의 관계를 인상관리 이론을 기반으로 탐색하고 궁극적으로 리뷰 유용성에 미치는 영향을 분석하고자 한다. 실증분석을 위해 서울에 위치한 140개 호텔의 리뷰 16,076개를 수집하여 PLS-SEM 방법으로 분석하였다. 분석결과, 권력거리와 남성성 문화 차원은 리뷰어의 부정적 감정표현에 긍정적인 영향을 미쳤으며, 불확실성회피 및 장기지향은 부정적인 영향을 미치는 것으로 분석되었다. 또한, 부정적 감정표현은 리뷰 평점을 통제한 상황에서도 리뷰 유용성에 긍정적인 영향을 미치는 것으로 분석되었다.

• Asia pacific journal of information systems
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• 제18권1호
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• pp.97-115
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• 2008

Introduction The e-government is concerned with using Internet and Web technologies to exchange information and services with citizens, businesses and other related organizations, and it centers on three functions, namely informational, interactive, and transactional [UN, 2001]. Many developed countries like the U.S. have been actively involved in e-government projects, since they enable both more effective public services for citizens and more efficient internal operations. Korea is among these leading countries that are planning to leverage computer and communication technologies to provide for integration of work processes and information as well as convenient access to information and services. For this reason, evaluating e-government projects is becoming a crucial issue for both researchers and policy-makers. However, most research to date has primarily focused on a model of success of an e-government system designed for citizens, overlooking internal systems specifically created for employees working in a public organization. This paper is intended to propose a model to measure the success of a Web-based information system designed for use by internal users at Chungwadae, the executive branch of Korea's central government. The paper is also aimed at applying the model to the assessment of the present system being used at Chungwadae in comparison with the preceding system. Evaluating an e-Government System The most widely cited model of information systems success today is that of DeLone and McLean[1992, 2003, 2004]. The original model states that the success of an information system can be measured using six dimensions, including system quality, information quality, use, user satisfaction, individual impact, and organizational impact. Although the ultimate success of an information system may be reflected in the impact that the system has upon individuals as well as an organization, aspects of using the system such as system use and user satisfaction can play an important role in determining the system success, because the system would be a sheer failure if users don't like and use the system. As a response to criticisms given by numerous researchers, the authors adapted their model to fit the emerging Web-based environment. The revised model[DeLone and McLean, 2003] they offered included an additional quality dimension, namely service quality, and combined individual and organizational impacts into net benefits which can also influence user satisfaction. The e-government system success model can be built around this updated model. Our model incorporates information quality, system quality, and service quality as in the DeLone and McLean model. However, the 'system use' dimension has been replaced by perceived usefulness, as suggested by Seddon[1998]. In addition, because the e-government systems that this paper focuses on are internal public systems used in government agencies, the 'net benefits' dimension has been replaced by perceived work efficiency. Based on the proposed model, a total of nine hypotheses have been formulated which we tested using an empirical analysis. Methods A questionnaire form has been created with items that are designed to examine the relationships among the variables in the model. The questionnaire has been handed over, in person, to 65 members of Chungwadae staff who are now actively using the E-Support System, the present information system created to support internal work at Chungwadae. We made arrangements to meet with each individual who agreed to participate in our survey, and helped to fill out the survey form with explanations. Of the 65 copies that were delivered, only 33 were returned, and 30 responses of these have been adopted for our analysis, since three were not valid. The extremely small sample size was due to the limited number of staff members who had adequate experience required of this study. Results We gathered data from the questionnaire survey and analyzed them using a regression analysis to test the hypotheses. As shown in the table below, the results indicated that all three dimensions of an information system’s quality are positively related to user satisfaction. However, information quality and system quality were found to be positively related to perceived usefulness, while service quality was not. In addition, perceived usefulness is not positively related to user satisfaction, implying that a user may find a system useful, but may not be satisfied with it. Finally, user satisfaction and perceived usefulness both are positively related to perceived work efficiency. This suggests that workers' positive experience with the system is important to guarantee favorable work efficiency. Conclusions We conclude that the proposed model proved useful in measuring the success of an internal information system used by a government agency. To demonstrate the applicability and usefulness of the model in the paper, we applied the model to the assessment of the present internal system used at Chungwadae in comparison with the preceding system. The results showed that the present system outperforms the preceding one in a statistically significant way. Future research will have to focus on applying the model to Korea's governmental agencies other than Chungwadae and examine whether it proves applicable in different types of governmental organizations.

• Asia pacific journal of information systems
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• 제20권1호
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• pp.141-170
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• 2010

User created content (UCC) is created and shared by common users on line. From the user's perspective, the increase of UCCs has led to an expansion of alternative means of communications, while from the business perspective UCCs have formed an environment in which an abundant amount of new contents can be produced. Despite outward quantitative growth, however, many aspects of UCCs do not meet the expectations of general users in terms of quality, and this can be observed through pirated contents and user-copied contents. The purpose of this research is to investigate effective methods for fostering production of creative user-generated content. This study proposes two core elements, namely, reward and motivation, which are believed to enhance content creativity as well as the mediating factor and users' committement, which will be effective for bridging the increasing motivation and content creativity. Based on this perspective, this research takes an in-depth look at issues related to constructing the dimensions of reward and motivation in UCC services for creative content product, which are identified in three phases. First, three dimensions of rewards have been proposed: task dimension, social dimension, and organizational dimention. The task dimension rewards are related to the inherent characteristics of a task such as writing blog articles and pasting photos. Four concrete ways of providing task-related rewards in UCC environments are suggested in this study, which include skill variety, task significance, task identity, and autonomy. The social dimensioni rewards are related to the connected relationships among users. The organizational dimension consists of monetary payoff and recognition from others. Second, the two types of motivations are suggested to be affected by the diverse rewards schemes: intrinsic motivation and extrinsic motivation. Intrinsic motivation occurs when people create new UCC contents for its' own sake, whereas extrinsic motivation occurs when people create new contents for other purposes such as fame and money. Third, commitments are suggested to work as important mediating variables between motivation and content creativity. We believe commitments are especially important in online environments because they have been found to exert stronger impacts on the Internet users than other relevant factors do. Two types of commitments are suggested in this study: emotional commitment and continuity commitment. Finally, content creativity is proposed as the final dependent variable in this study. We provide a systematic method to measure the creativity of UCC content based on the prior studies in creativity measurement. The method includes expert evaluation of blog pages posted by the Internet users. In order to test the theoretical model of our study, 133 active blog users were recruited to participate in a group discussion as well as a survey. They were asked to fill out a questionnaire on their commitment, motivation and rewards of creating UCC contents. At the same time, their creativity was measured by independent experts using Torrance Tests of Creative Thinking. Finally, two independent users visited the study participants' blog pages and evaluated their content creativity using the Creative Products Semantic Scale. All the data were compiled and analyzed through structural equation modeling. We first conducted a confirmatory factor analysis to validate the measurement model of our research. It was found that measures used in our study satisfied the requirement of reliability, convergent validity as well as discriminant validity. Given the fact that our measurement model is valid and reliable, we proceeded to conduct a structural model analysis. The results indicated that all the variables in our model had higher than necessary explanatory powers in terms of R-square values. The study results identified several important reward shemes. First of all, skill variety, task importance, task identity, and automony were all found to have significant influences on the intrinsic motivation of creating UCC contents. Also, the relationship with other users was found to have strong influences upon both intrinsic and extrinsic motivation. Finally, the opportunity to get recognition for their UCC work was found to have a significant impact on the extrinsic motivation of UCC users. However, different from our expectation, monetary compensation was found not to have a significant impact on the extrinsic motivation. It was also found that commitment was an important mediating factor in UCC environment between motivation and content creativity. A more fully mediating model was found to have the highest explanation power compared to no-mediation or partially mediated models. This paper ends with implications of the study results. First, from the theoretical perspective this study proposes and empirically validates the commitment as an important mediating factor between motivation and content creativity. This result reflects the characteristics of online environment in which the UCC creation activities occur voluntarily. Second, from the practical perspective this study proposes several concrete reward factors that are germane to the UCC environment, and their effectiveness to the content creativity is estimated. In addition to the quantitive results of relative importance of the reward factrs, this study also proposes concrete ways to provide the rewards in the UCC environment based on the FGI data that are collected after our participants finish asnwering survey questions. Finally, from the methodological perspective, this study suggests and implements a way to measure the UCC content creativity independently from the content generators' creativity, which can be used later by future research on UCC creativity. In sum, this study proposes and validates important reward features and their relations to the motivation, commitment, and the content creativity in UCC environment, which is believed to be one of the most important factors for the success of UCC and Web 2.0. As such, this study can provide significant theoretical as well as practical bases for fostering creativity in UCC contents.