• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.251-258
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• 2008

The purpose of this study is to examine the structural relationship among logistics service quality, relationship-orientation for on-line shopping malls, customer satisfaction and repurchase intention in on-line shopping malls. Based on extensive review of relevant literature, nine components of logistics service quality and six components of relationship orientation are introduced in this study. And a conceptual model is developed and four research hypotheses are empirically examined using structural equation modeling. The findings indicate that logistics service quality is positively and significantly associated with customer satisfaction, and relationship- orientation is the antecedent variable of repurchase intention in the on-line shopping mall. In conclusion, it is revealed that logistics service quality and relationship-orientation play a major role in the success of on-line shopping mall.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.491-494
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• 1996

주문이 매 시점마다 있는 것이 아니라 간헐적인, 즉 어느 시점에는 주문이 있고(ON) 다른시점에는 주문이 없는(OFF) 패턴에서 미래의 주문량에 대한 예측을 고려한다. 다음 시점의 예측량은 우선 주문이 있을 것인가에 대한 판단과 주문이 있다면 어느정도가 예상되는가 하는 문제의 두 가지 측면을 모두 고려해야 한다. 기존의 예측모델은 주문량 자체에 대한 고려가 일반적이며 주문시기에 대한 고려는 전무한 상태이기 때문에 이와 같은 주문패턴을 반영시키는데는 어려움이 따른다고 볼 수 있다. 본 논문에서는 이러한 주문패턴을 마코브 체인으로 모델링하고, 이러한 형태의 상태전이확률(state transition probaility) 추정식이 각각 독립적인 오목함수 (concave function)로 구성되어 있음을 보인다. 또한 확률적으로 표현되는 미래의 주문상태들에 대한 패턴을 확정시키는 알고리듬과 주문량 추정에 있어서 과거의 주문패턴을 반영시키는 모델을 제시한다.

• Information Systems Review
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• v.18 no.2
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• pp.23-38
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• 2016

Previous studies on information systems (IS) and finance suggest that information on stock message boards influence the investment decisions of individual investors. However, how information on online stock message boards influences an individual investor's buy or sell decisions is unclear. To address this research question, we investigate the relationship between a number of posts on stock message boards and order imbalance in stock markets. Order imbalance is defined as the difference between the daily sum of buy-side shares traded and the daily sum of sell-side shares traded. Therefore, order imbalance can suggest the direction of trades and the strength of the direction with trading volumes. In this regard, this study examines how the number of posts (information on stock message boards) influences order imbalance (stock trading behavior). We collected about 46,077 messages of 40 companies on the Korea Composite Stock Price Index from Paxnet, the most popular Korean online stock message board. The messages we collected were divided based on in-trading and after-trading hours to examine the relationship between the numbers of posts and trading volumes. We also collected order imbalance data on individual investors. We then integrated the balanced panel data sets and analyzed them through vector regression. We found that the number of posts on online stock message boards is positively related to prior order imbalance. We believe that our findings contribute to knowledge in IS and finance. Furthermore, this study suggests that investors should carefully monitor information on stock message boards to understand stock market sentiments.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.157-177
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• 2022

Investors are trading stocks by keeping a close watch on the order information submitted by domestic and foreign investors in real time through Limit Order Book information, so-called price current provided by securities firms. Will order information released in the Limit Order Book be useful in stock price prediction? This study analyzes whether it is significant as a predictor of future stock price up or down when order imbalances appear as investors' buying and selling orders are concentrated to one side during intra-day trading time. Using classification algorithms, this study improved the prediction accuracy of the order imbalance information on the short-term price up and down trend, that is the closing price up and down of the day. Day trading strategies are proposed using the predicted price trends of the classification algorithms and the trading performances are analyzed through empirical analysis. The 5-minute KOSPI200 Index Futures data were analyzed for 4,564 days from January 19, 2004 to June 30, 2022. The results of the empirical analysis are as follows. First, order imbalance information has a significant impact on the current stock prices. Second, the order imbalance information observed in the early morning has a significant forecasting power on the price trends from the early morning to the market closing time. Third, the Support Vector Machines algorithm showed the highest prediction accuracy on the day's closing price trends using the order imbalance information at 54.1%. Fourth, the order imbalance information measured at an early time of day had higher prediction accuracy than the order imbalance information measured at a later time of day. Fifth, the trading performances of the day trading strategies using the prediction results of the classification algorithms on the price up and down trends were higher than that of the benchmark trading strategy. Sixth, except for the K-Nearest Neighbor algorithm, all investment performances using the classification algorithms showed average higher total profits than that of the benchmark strategy. Seventh, the trading performances using the predictive results of the Logical Regression, Random Forest, Support Vector Machines, and XGBoost algorithms showed higher results than the benchmark strategy in the Sharpe Ratio, which evaluates both profitability and risk. This study has an academic difference from existing studies in that it documented the economic value of the total buy & sell order volume information among the Limit Order Book information. The empirical results of this study are also valuable to the market participants from a trading perspective. In future studies, it is necessary to improve the performance of the trading strategy using more accurate price prediction results by expanding to deep learning models which are actively being studied for predicting stock prices recently.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.10a
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• pp.3-8
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• 1998

주문형 비디오 시스템의 성능에서 중요한 문제는 클라이언트 요구를 만족시키기 위한 입출력 대역폭이다. 이러한 입출력 대역폭을 감소시키기 위해 하나의 비디오 스트림을 사용하여 다중 요청을 처리하는 많은 정책들; 배칭. 피기백 머징, 버퍼링이 연구되고 있다. 본 논문에서는 인기 있는 비디오들에 대한 서비스 요청들이 매 배칭 간격마다 스케줄될 수 있도록 인기 있는 비디오들을 위한 서버 스트림 용량을 동적으로 예약해 두는 예약 기반 동적 배칭 정책을 제안하고, 그것의 성능을 시뮬레이션을 통하여 단순 배칭 정책과 비교하고 평가한다.

• The KIPS Transactions:PartB
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• v.11B no.2
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• pp.207-212
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• 2004

This paper presents a reinforcement learning framework for stock trading systems. Trading system parameters are optimized by Q-learning algorithm and neural networks are adopted for value approximation. In this framework, cooperative multiple agents are used to efficiently integrate global trend prediction and local trading strategy for obtaining better trading performance. Agents Communicate With Others Sharing training episodes and learned policies, while keeping the overall scheme of conventional Q-learning. Experimental results on KOSPI 200 show that a trading system based on the proposed framework outperforms the market average and makes appreciable profits. Furthermore, in view of risk management, the system is superior to a system trained by supervised learning.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.345-348
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• 2009

오늘날 폐쇄형 IPTV 서비스 환경에서는 일방적인 콘텐츠 제공자로부터 생성 및 생성된 콘텐츠를 소비자가 일방적으로 소비하는 형태이다. 그러나 기존 디지털 콘텐츠의 유통 및 소비과정에서 콘텐츠를 보호하기 위한 각 제공 업체의 솔루션이 독자적인 방식으로 개발되어 이들 간의 호환성 문제가 발생한다. 본 논문은 IP 네트워크를 통해 소비자가 개인 방송 콘텐츠 사업자와 같이 멀티미디어 콘텐츠를 생성, 편집하고 고유한 방식으로 스타일대로 콘텐츠를 메타데이타와 함께 패키지 콘텐츠로 재가공하여 소비할 수 있을 뿐 아니라 재가공된 패키지 콘텐츠를 공유 또는 재판매 할 수 있게 하는 개방형 IPTV 서비스 환경에서의 패키지 콘텐츠의 실시간 스트리밍 및 주문형 서비스의 차별적 제공 방안을 제안한다.

• Management & Information Systems Review
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• v.31 no.4
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• pp.309-337
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• 2012

This study aims to suggest theoretical models and background for the analysis of antecedent factors such as customer satisfaction and repurchasing decision by use of Technology-Based Self-Service (TBSS) delivery service. Specifically, the study have focused on the analysis that after the values of customer satisfaction and repurchasing decision were transformed into the values of Cost-Benefit analysis and then compared with the values of result benefits, process benefits, financial costs and non-financial costs. After analysis, it was found that ordering and delivery service by use of TBSS has a positive influence on customer satisfaction in terms of result benefits, process benefits, time savings and financial cost savings. In addition, it was confirmed that sub-category of customer satisfaction such as overall satisfaction, satisfaction for expectations, satisfaction for ideals has also a positive impact on repurchasing decision. It is expected that the results of this study will help analyze the customer satisfaction and repurchasing decision and provide a practical help for a business.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.206-213
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• 2022

Ecological characteristics of a brown alga, Scytosiphon lomentaria, were investigated from January 2021 to December 2021 in its natural habitat off Sodol, Jumunjin, eastern coast of Korea. The S. lomentaria population at the site formed widespread patches on mid shore. During the investigation, environmental conditions including seawater temperature, salinity, and dissolved oxygen were monitored at the site. Growth and maturation of the S. lomentaria population were identified through qualitative and quantitative investigations. An estimation of the effective cumulative temperature for maturation of the alga was obtained based on growth data and a biological zero temperature of 8℃. Sporangia were observed from February to May when seawater temperatures ranged from 7.7℃ to 16.4℃. A maturation peak was detected in April when seawater temperature was 12.1℃. After zoospore release, the alga became bleached and only the crust remained after June. Developmental initiation of the thallus occurred at temperatures above 8℃. Its maturation required approximately 162 degree-days.

• International Commerce and Information Review
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• v.14 no.3
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• pp.231-251
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• 2012

The remedies available to a seller that has suffered a breach of contract by the buyer are addressed in Section III of Chapter III of Part III. The first provision in the section, 61, catalogues those remedies and authorizes an aggrieved seller to resort to them. The remaining provisions of the section address particular remedies or prerequisites to remedies. The subject matter of the current section remedies for breach of contract by the buyer obviously parallels that of Section III of Chapter II of Part III remedies for breach of contract by the seller. Many individual provisions within these sections form matched pairs. Thus 61, which catalogs the seller's remedies, which catalogs the buyer's remedies. Other provisions in the current section that have analogues in the section on buyer's remedies include 62, seller's right to require buyer's performance 63, seller's right to fix an additional period for buyer to perform and 64, seller right to avoid the contract. As was the case with the provisions on buyers' remedies, the articles governing sellers' remedies operate in conjunction with a variety of provisions outside the current section. Thus the seller's right to require performance by the buyer is subject to the rule in 28 relieving a court from the obligation to order specific performance in circumstances in which it would not do so under its own law. The authorization in 61 for a seller to claim damages for a buyer's breach operates in connection with 74-76, which specify how damages are to be measured. 49, stating when an aggrieved seller can avoid the contract, is part of a network of provisions that address avoidance, including the definition of fundamental breach, the requirement of notice of avoidance, provisions governing avoidance in certain special circumstances, measures of damages available only if the contract has been avoided and the provisions of Section V of Part III, Chapter V on effects of avoidance.