• International Journal of Safety
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• v.5 no.1
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• pp.24-28
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• 2006

This study focuses on the issue of improving safety management of elevators. The role of certification and supervision in reducing the associated accidents is specifically addressed. The results of simple statistical analysis suggests that a certification procedure emphasizing the quality assurance during manufacturing and supervision during assembly and installation of elevators are needed and can be effective in minimizing the associated accidents.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.30 no.6
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• pp.47-58
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• 2012

• Journal of Broadcast Engineering
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• v.22 no.4
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• pp.438-447
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• 2017

The purpose of this study is to understand the recognition of gambling industry through the semantic analysis of news data on lottery, sports betting, horse racing and casino that was reported between 1990 to 2015 in South Korea. This paper revealed the difference between journalists' intention and public's perception about news by analyzing the frequency and connectivity of news with framing and public's interest through semantic network analysis and explored the policy characteristics and innovation task. The result of analysis, news on lottery game mainly has been reported social issue related with win such as 'winning number', 'prize money', 'suspicion of manipulation' and etc. News on sports betting has been reported mandatory information related with business project and illegal site such as 'bidding', 'illegal site', 'sales target' and etc. News about horse racing has been reported the information about the business advertisement such as 'online race track' and 'promotion'. Lastly, casino related news has been reported 'major information' such as illegality', 'gambling place' and 'foreigner'. As a result of times series analysis, news about casino in the 1990s, news about lottery in the 2000s and news about horse racing in 2010s have been increased. Public's interest also has been moved to 'business scandal', 'winning game', 'citizens' campaign' and etc. Gambling related news has been classified by four types, 1. advertising publicity(horse racing), 2. mandatory information(sports betting), 3. social issue(public agenda, lottery), 4. major information(casino). We could get the insight that news can be formed a public agenda, when news is reported as a social issue with high frequency and public's interest like lottery related news.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.49-57
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• 2020

In comparison with the existing static reliability analysis methods, the dynamic reliability analysis(DyRA) method is more suitable for estimating the failure probability of a structure subjected to earthquake excitations because it can take into account the frequency characteristics and damping capacity of the structure. However, the DyRA is known to have an issue of numerical stability due to the uncertainty in random sampling of the earthquake excitations. In order to solve this numerical stability issue in the DyRA approach, this study proposed two earthquake-scale factors. The first factor is defined as the ratio of the first earthquake excitation over the maximum value of the remaining excitations, and the second factor is defined as the condition number of the matrix consisting of the earthquake excitations. Then, we have performed parametric studies of two factors on numerical stability of the DyRA method. In illustrative example, it was clearly confirmed that the two factors can be used to verify the numerical stability of the proposed DyRA method. However, there exists a difference between the two factors. The first factor showed some overlapping region between the stable results and the unstable results so that it requires some additional reliability analysis to guarantee the stability of the DyRA method. On the contrary, the second factor clearly distinguished the stable and unstable results of the DyRA method without any overlapping region. Therefore, the second factor can be said to be better than the first factor as the criterion to determine whether or not the proposed DyRA method guarantees its numerical stability. In addition, the accuracy of the numerical analysis results of the proposed DyRA has been verified in comparison with those of the existing first-order reliability method(FORM), Monte Carlo simulation(MCS) method and subset simulation method(SSM). The comparative results confirmed that the proposed DyRA method can provide accurate and reliable estimation of the structural failure probability while maintaining the superior numerical efficiency over the existing methods.

• ETRI Journal
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• v.27 no.5
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• pp.595-607
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• 2005

The widespread use of the Internet has led to the problem of intellectual property and copyright infringement. Digital rights management (DRM) technologies have been developed to protect digital content items. Digital content can be classified into static content (for example, text or media files) and dynamic content (for example, VOD or multicast streams). This paper deals with the protection of a multicast stream on set-top boxes connected to an IP network. In this paper, we examine the following design and architectural issues to be considered when applying DRM functions to multicast streaming service environments: transparent streaming service and large-scale user environments. To address the transparency issue, we introduce a 'selective encryption scheme'. To address the second issue, a 'key packet insertion scheme' and 'hierarchical key management scheme' are introduced. Based on the above design and architecture, we developed a prototype of a multicasting DRM system. The analysis of our implementation shows that it supports transparent and scalable DRM multicasting service in a large-scale user environment.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.2
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• pp.91-100
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• 2009

"How does advertising affect sales?" is the fundamental issue of modern advertising research. There is an interesting issue for estimating carryover effects of advertising on sales, and the aggregated data biases exist in the duration of advertising effect. This research suggests an extended model of Koyck Model which is employed for micro-data (Koyck 1954) to estimate aggregated advertising data, and empirically shows the aggregated data bias. Our developed model with the aggregated level of actual advertising data is more appropriate than the basic Koyck model for micro-data. The result figures out that it is important to consider the disaggregated data level in the analysis of dynamic effects of adverting such as carryover effects.

• The Korean Journal of Financial Studies
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• v.2 no.1
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• pp.215-244
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• 1995

The purpose of this paper is to examine the three anomalies phenomena that appear in the initial public offerings(IPOs) market. Of them, the first anomaly is that the new issues are underpriced in the short-run. Secondly, the hot issue market phenomenon appears. Thirdly, in the long-run, the initial public offerings of equities are overpriced. These phenomena have been documented by Inany studies using the us stock market data. In particular, we will investigate whether these three anomalies also appear in the UK new issues market. Firstly, the underpricing phenomenon of initial public offerings in the short-run will be examined. Then the long-run performance of new issues will be examined using cross-sectional and time-series analysis. Finally, we will briefly examine the existence of the hot issue market in the uk IPOs market.

• Journal of Information Technology Services
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• v.12 no.1
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• pp.259-270
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• 2013

Identity authentication sharing technologies which allow many service providers to share the result of identity authentication of an identity provider receive high attention as alternatives for current problematic identity authentications in the next-generation Internet environment, since they can provide crucial advantages including high usability, cost effectiveness of service providers, and privacy protection. However, in order for the identity authentication sharing technologies to be widely deployed in global Internet scale, the interoperability problem among different identity authentication sharing protocols and the trustworthiness issue among the participating identity providers, service providers, and users should be resolved in advance. This paper firstly analyzes current status of the protocol interoperability issue and existing trust frameworks for identity authentication sharing. And then, based on the result of analysis, this paper proposes a next generation identity authentication sharing architecture for global Internet.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.319-323
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• 2008

"How does advertising affect sales?" is the fundamental issue of modern advertising research. There is an interesting issue for estimating carry over effects of advertising on sales, and the aggregated data biases exist in the duration of advertising effect. This research suggests a modified model at micro-data using Koyck model (Koyck 1954) by estimated model the aggregate data, and empirically shows the aggregated data bias. Our modified model with the aggregated level of actual data is more appropriate than the base model for micro-data. The result shows that it is very important to consider the disaggregated data level in the analysis of dynamic effects of adverting such as lagged effects.

• Journal of Information Technology Services
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• v.8 no.2
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• pp.71-87
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• 2009

In this paper, the technology innovation for software firms are discussed. Through the literature study, the concepts about this issue and the environment and activity of software firm's the technology innovation related are described. The survey paper was developed for searching the obstacles, policy considerations, and performance of this issue etc. Also questionnaire sheet was made for identifying the relations on technology innovation activities and performance. The degree of understanding about the need of technology innovation were very high according to the analysis result from the response based on the 103 software firms. Among this survey the other results are described as follows; the motivation of technology innovation, the necessity and implementation, the duration acquired for innovation result, the favorite support program as for innovation policy, obstacles for innovation implementation, the reason for innovation collaboration etc. Finally, it is verified statistically that the performance of technology innovation be affected by the employment of external professional technician, research and development, the technical education.