• International Commerce and Information Review
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• v.17 no.3
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• pp.3-27
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• 2015

As hostile online reviews can have a negative impact on a company's reputation, it is not surprising that online reviewers and business owners often get involved in conflicts which sometimes evolve into legal disputes. This research examines the legal dispute case in which the business owner charges an online reviewer for a defamation. Further, this research compares the supreme court's decision with general public's view on this defamation case, using a survey method. From the legal point of view, an online reviewer's primary motive determines whether the online reviews are defamatory statements or not. Specifically, if an online reviewer's primary motive is to increase the overall benefits for the public society, the online review does not bear any legal liability. According to our survey, consumers' view aligns with the final decision of the supreme court. They believe that online reviews should bear a minimum level of legal liability as online reviews often contain useful and valuable information which can enhance overall public benefits.

• Journal of the Korea Computer Industry Society
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• v.4 no.10
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• pp.731-740
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• 2003

Since motion estimation remove the redundant data to employ the temporal correlations between adjacent frames in a video sequence, it plays an important role in digital video coding. And in the block matching algorithm, search patterns of different shapes or sizes and the distribution of motion vectors have a large impact on both the searching speed and the image quality. In this paper, we propose a new fast block matching algorithm using the small-cross search pattern and the block-based gradient descent search pattern. Our algorithm first finds the motion vectors that are close to the center of search window using the small-cross search pattern, and then quickly finds the other motion vectors that are not close to the center of search window using the block-based gradient descent search pattern. Through experiments, compared with the block-based gradient descent search algorithm(BBGDS), the proposed search algorithm improves as high as 26-40% in terms of average number of search point per motion vector estimation.

• Composites Research
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• v.12 no.4
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• pp.42-54
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• 1999

FMLC(Fiber-Metal Laminate Composites) is a new structural material combining thin metal laminate with adhesive fiber prepreg, it nearly include all the advantage of metallic materials, for example: good plasticity, impact resistance, processibility, light weight and excellent fatigue properties. This research studied the optimum design of the FMLC subject to various loading conditions using genetic algorithm. The finite element method based on the shear deformation theory was used for the analysis of FMLC. Tasi-Hill failure criterion and Miser yield criterion were taken as fitness functions of the fiber prepreg and the metal laminate, respectively. The design variables were fiber orientation angles. In genetic algorithm, the tournament selection and the uniform crossover method were used. The elitist model was also used to be effective evolution strategy and the creeping random search method was adopted in order to approach a solution with high accuracy. Optimization results were given for various loading conditions and compared with CFRP(Carbon Fiber Reinforced Plastic). The results show that the FMLC is more excellent than the CFRP in point and uniform loading conditions and it is more stable to unexpected loading because the deviation of failure index is smaller than that of CFRP.

• Journal of Information Technology Services
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• v.19 no.2
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• pp.125-138
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• 2020

Currently, subway crowding is estimated by observing a specific point at specific hours once or twice every 1 or 2 years. Given the extensive subway network in Seoul Metropolitan Area covering 588 stations, 11 lines and 80 transfer stations as of 2017, implementing crowding mitigation policy may have its limitations due to data uncertainty. A proposal has recently been made to effectively use smart card data, which generates big data on the overall subway traffic related to an estimated 8 million passengers per day. To mitigate subway crowding, this study proposes two viable options based on data related to smart card used in Seoul Metropolitan Area. One is to create a subway passenger pattern model to accurately estimate subway crowding, while the other is to prove effectiveness of early bird policy to distribute subway demand that is concentrated at certain stations and certain time. A subway passenger pattern model was created to estimate the passenger routes based on subway terminal ID at the entrance and exit and data by hours. To that end, we propose assigning passengers at the routes similar to the shortest routes based on an assumption that passengers choose the fastest routes. In the model, passenger flow is simulated every minute, and subway crowding level by station and line at every hour is analyzed while station usage pattern is identified by depending on passenger paths. For early bird policy, highly crowded stations will be categorized based on congestion level extracted from subway passenger pattern model and viability of a policy which transfers certain traveling demands to early commuting hours in those stations will be reviewed. In particular, review will be conducted on the impact of policy implemented at certain stations on other stations and lines from subway network as a whole. Lastly, we proposed that smart card based subway passenger pattern model established through this study used in decision making process to ensure effective implementation of public transport policy.

• The Journal of Industrial Distribution & Business
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• v.8 no.5
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• pp.87-93
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• 2017

Purpose - This paper investigates whether managerial overconfidence is associated with firm-specific crash risk. Overconfidence leads managers to overestimate the returns of their investment projects, and misperceive negative net present value projects as value creating. They even use voluntary disclosures to convey their optimistic beliefs about the firms' long-term prospects to the stock market. Thus, the overconfidence bias can lead to managerial bad news hoarding behavior. When bad news accumulates and crosses some tipping point, it will come out all at once, resulting in a stock price crash. Research design, data and methodology - 7,385 firm-years used for the main analysis are from the KIS Value database between 2006 and 2013. This database covers KOSPI-listed and KOSDAQ-listed firms in Korea. The proxy for overconfidence is based on excess investment in assets. A residual from the regression of total asset growth on sales growth run by industry-year is used as an independent variable. If a firm has at least one crash week during a year, it is referred to as a high crash risk firm. The dependant variable is a dummy variable that equals 1 if a firm is a high crash risk firm, and zero otherwise. After explaining the relationship between managerial overconfidence and crash risk, the total sample was divided into two sub-samples; chaebol firms and non-chaebol firms. The relation between how I overconfidence and crash risk varies with business group affiliation was investigated. Results - The results showed that managerial overconfidence is positively related to crash risk. Specifically, the coefficient of OVERC is significantly positive, supporting the prediction. The results are strong and robust in non-chaebol firms. Conclusions - The results show that firms with overconfident managers are likely to experience stock price crashes. This study is related to past literature that examines the impact of managerial overconfidence on the stock market. This study contributes to the literature by examining whether overconfidence can explain a firm's future crashes.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.223-233
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• 2017

The railway turnout system is one of the most important systems that set train routes. Turnout system integrity should be guaranteed for robust train operation. To diagnose the turnout system status, LVDT and accelerometers are installed on a turnout system in a high speed line. The LVDT and accelerometers produce signals containing physical meaning of the turnout systems. The LVDT produces the displacement of the rail gauge and vibration when point moving or a train passes on turnout systems and the accelerometer produces impact forces induced by wheel sets. We performed data extraction from the measured signals and parameterized the extracted signals into meaningful quantities. The parameters are used for classifying whether the turnout status is normal. We proposed two methods for the classification, one uses probabilistic distribution and the other artificial neuron networks. The probabilistic distribution is used for the parameter being classified by the quantities and the artificial neuron networks for the form classification. Finally, we show how to learn the normal status of a turnout system.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.5 no.1
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• pp.3-11
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• 1994

Childhood depression was not officially accepted as a separate diagnosis until 20-25years ago. Although DSM-III R criteria gave us a starting point and are gaining acceptances as a useful tool for diagnosing childhood depression recently, many professionals feel that additional modifications are needed to better reflect the developmental aspects of children. And because children are relatively poor in expressing their moods or feelings due to weak reality sence and/or cognitive and linguistic limitations, the author too carefully suggest that developmental perspectives of children should be considered in diagnosing childhood depression. Little is known about the extent to which childhood depression precedes adult depression and persists into adult life and about the impact of it on the personality formation. Some evidences that childhood depressive symtoms can be quite enduring make it important to make an early diagnosis and treatment.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.733-742
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• 2002

It has been known that the host mobility feature has very significant impact on the QoS (Quality of Service), which is usually required to a real-time multimedia application. The existing QoS support mechanisms to provide the real-time services to fixed network environment, like as RSVP, are inadequate to accommodate the mobile hosts which can frequently change their point of attachments to the fixed network. So, MRSVP (Mobile RSVP) protocol has been proposed to reduce the impacts of host mobility on QoS guarantees, in which a mobile host needs to make advance resource reservations at multiple locations it may possibly visit during the lifetime of the connection. This paper proposes a dynamic dual anchor node (DDAN) architecture which integrates the MRSVP and RSVP tunnel, in addition to the Mobile IP Regional Registration protocol. By limiting the resource reserved in local area, it preserves the lower level of resource reservation, but provides approximately the same degree of QoS support as the existing MRSVP.

• Journal of Distribution Research
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• v.1 no.1
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• pp.41-63
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• 1996

In spite of economy has a critical cycle such as, production, distribution and consumption, we hardly concentrated our study to distributional system and behavior. Especially in Korea, Traditional idea had tried to ignore the people who work in this economic value at all. Manufacturers, other than retailers and wholesalers, had a belief that the manufacturing can control distributional channels forever. Unfortunately, technological and educational advances caused the quality equalization among developing and developed countries as well as among big and small manufacturers in their products. By this reason, economists are searching the economists dark continet' mentioned by Peter Drucker as a new source of wealth. According to a report by well-known economic research institute in Switzerland, Korea has classified in the lower level group in terms of international compatitive power. At the same time, business firms complain that they are suffering from lack of SOC and infrastructures. As an important mean to overcome the economic bottleneck, economists suggest in improve our distributional atmosphere. Basically, distributional study has two sub-fields as: commercial and physical distributions, Distributional system mainly concerns about to shorten the distances of time and space between production and consumption. The closer the distances, the higher efficiency can be achieved. Building distributional system will cost, but tile results will save social costs. Based on this idea, economists proposed several ways to cut the distances and to save costs, Naturally, they hope their beliefs can be adapted by business firms and governments. But frequently, their theories doesn't make any fruit. This paper has studied about the composition of joint transportational and distributional systems. And, even though there's no Marshall in tile real world at this point authors are trying to define the transportational and physical distributional costs, the most powerful factor that can impact to economic decision making.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.399-407
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• 2018

This study examines the psychological factors of consumers to On-Demand O2O service which is different from the previous study on O2O service. To investigate the relative influence of consumer's psychological attachment of On-Demand O2O service, enjoyment, and trust on consumer's satisfaction and attitude, I conducted qualitative and quantitative surveys to investigate consumers' perception. Through the quantitative survey on 152 participants, the study shows that the consumer's psychological attachment to the service has the greatest influence on the attitude toward On-Demand O2O service and the trust has the highest effect on satisfaction with service. This study is meaningful in that the consumer's psychological factors to the O2O service is examined from the consumer's point of view. This study suggests that the consumer's attachment and trust should be considered primarily to expand the On-Demand O2O service.