• Journal of Advanced Navigation Technology
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• 제9권2호
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• pp.156-163
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• 2005

In this paper, we analyzed the performance of VDL mode 3 system model whose specification is defined by ICAO(International Civil Aviation Organization). For performance evaluation, we obtained BER(Bit Error Rate), transmission delay time, burst retransmission rate and throughput. From the analysis result, we could explicitly define relationships among BER, transmission delay time, throughput and burst restransmission rate. In addition, it became known that V/D retransmission rate and throughput are closely related in down link channel.

• Journal of the Korean Solar Energy Society
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• 제29권2호
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• pp.22-30
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• 2009

In order to clarify predictive accuracy for the wind resource predicted by running WindPRO(Ver. 2.5) which is software for wind farm design developed by EMD from Denmark, an investigation was carried out at the northeast region of Jeju island. The Hangwon, Susan and Hoichun sites of Jeju island were selected for this study. The measurement period of wind at the sites was for one year. As a result, when the sites had different energy roses, though the two Wind Statistics made by STATGEN module were used for the prediction, it was difficult to exactly predict the energy rose at a given site. On the other hand, when the two Wind Statistics were used to predict the average wind speed, the wind power density and the annual energy production, the relative error was under ${\pm}20%$ which improved more than that when using only one Wind Statistics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.263-268
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• 2003

This paper presents a result of performance evaluation fur non-contact scanning probe microscopy with respect to the vibration characteristics of cantilevers with tips. One of the current issues of the scanning probe microscopy technology is to increase the measurement speed, which is closely tied with the dynamic characteristics of cantilevers. The primary concern in this research is to investigate the relation between the maximum possible speed of non-contact scanning probe microscopy and the dynamic characteristics of cantilevers. First, the finite element analysis is made fur the vibration characteristics of various cantilevers in use. The computed natural frequencies of the cantilevers are in good agreement with measured ones. Then, each cantilever is tested with topographic measurement for a standard sample with the scanning speed changed. The performances of cantilevers are analyzed along with the natural frequencies of cantilevers. Experiments are also performed to test the effects of how to attach cantilevers in the piezo-electric actuator. Finally, measurement sensitivity has been analyzed to enhance the performance of scanning probe microscopy.

• Journal of the Society of Disaster Information
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• 제9권2호
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• pp.206-213
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• 2013

The paper presents the field applications and evaluation results of solid epoxy asphalt mixture for steel bridge deck. The material was developed in Japan. The material properties of epoxy asphalt mixture were evaluated through various literature review, and the mix design and mixture evaluation were conducted. According to the research results, the application of epoxy asphalt mixture for steel bridge deck was noticeable compare to the conventional ones. In addition, results from 3D finite element analysis showed that the performance of epoxy asphalt mixture for steel bridge deck was proved to be satisfied. As a result, a pilot test section was constructed using the epoxy asphalt mixture produced from conventional batch plant system. BPT test results showed that friction of the epoxy asphalt mixture was higher than the requirements compare to that of the conventional one.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2008년 영문 학술대회
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• pp.346-357
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• 2008

Endothermic fuels are known as a probable fuel for hypersonic atmospheric flight vehicles and advanced propulsion systems, as well as cryogenic fuels. Especially, from the standpoint of the advanced regenerative cooling use, they are quite useful as a coolant fuel because of their large heat sink due to their chemical decompositions; so-called endothermic cooling effect. However, no heat transfer equations have been proposed taking into account such endothermic reactive behaviors concretely. This paper describes an analytical method for evaluation of the heat transfer rates between endothermic reacting coolant fuel and coolant-side wall in the regenerative cooling passages. Heat transfer mechanism is indicated based on a classical transport-phenomenological approach. A new relational expression of Nusselt number ratio for forcedconvective heat transfer with such endothermic reactions is also proposed by theoretical approaches using some classical hypotheses. Its applicability is assessed provisionally by comparison with confirmed results of heated tube tests for supercritical JP-7 fuel carried out at NASA Lewis Research Center, using its heat sink characteristics evaluated by United Technologies Research Center(UTRC). As a result, it has been suggested that the proposed relational equation is applicable to the evaluation of enhancement of Nusselt numbers due to such reactions in developed turbulent flows such as in the regenerative cooling passages.

• International Journal of Advanced Culture Technology
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• 제9권4호
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• pp.376-384
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• 2021

This study wants to provide basic data on effective escape safety plans when residents of apartment complex use residential convenience facilities. The findings of the analysis are as follows. First, when this study applied the actual number of users (No=54) of those facilities, the existence of elevator for escape reduced the escape time by 189.0 seconds. Second, when the number of users was calculated on the standard of the number of people who can be accommodated for performance based design (No=316), the existence of the elevator for escape reduced the escape time by 173.5 seconds. Finally, when the number of users was calculated on the standard of installing fire-fighting facilities (No=122), the existence of the elevator for escape reduced the escape time by 159.2 seconds. As a result, it was found that elevator for escape reduces the escape time from fire. Accordingly, it is necessary to revise the construction law to make it obligatory for residential convenience facilities to be equipped with elevator for escape. Currently, apartment buildings lower than 30 stories have either elevator for passengers or elevator for escape. Thus, in future studies, it is necessary to compare escape times in fire depending on the kinds of elevator, and identify the usefulness of elevator for escape.

• International Journal of Highway Engineering
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• 제14권2호
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• pp.117-129
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• 2012

Road safety audit is the preventive enhancement strategy for safety. : it gets rid of beforehand the potential factor of a traffic accident in the stage of road planning and design and it evaluates the appropriation for road geometric structure or safety facility to prevent traffic accident in the stage of operation after the construction. Since this strategy is introduced to our country in the early 2000s, various projects have been processed and it was legislated recently. And now, the evaluation of past project for its continuation is needed. Therefore, in this study the evaluation of road safety audit on existing freeway is performed. The spatial extent of this study is Yong-dong line on which the safety treatment was executed in 2005 and 2006. And, the temporal range of this study is each 2-year of before and after from 2005 and 2006. The empirical bayes method of observational evaluation studies is applied to analyze. As a result, there is an effect of improvement on most of treated sections. But there is ineffective or negligible on some sections. Compared with the detail of treatment on each section, the effect of multiple or various treatments is good for that section. On the other hand, the section on which effect doesn't appear is the result of single or unimportant treatments. Throughout these results, the concrete analysis can be performed and the countermeasures designed for the section on which effect doesn't appear. Also it is used as reference to the future plan and direction of road safety audit on existing freeway.

• International journal of advanced smart convergence
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• 제12권2호
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• pp.193-200
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• 2023

This paper selects 100 IT companies listed on the Shenzhen Stock Exchange from 2016 to 2020, and the public announcement in Hwajung collects ESG integrated ratings and grades for each sector and empirically verifies the relationship between ESG ratings and stock returns. Huazheng ESG level data and QIANZHAN database Using corporate financial data, a total of 500 samples were selected through correlation analysis and linear regression analysis with SPSS23 to analyze the effect of ESG on Return. As a result of the analysis, first, the impact on stock returns was found to be a significant positive (+) value for ESG integrated ratings and ratings by E (environment), S (social), and G (governance) sectors, confirming that ESG ratings have a positive mold of corporate stock returns. Currently, the world's major economies have proposed sustainable development strategies and "carbon neutral" goals. Development strategies are very consistent with ESG concepts, and companies that agree and execute ESG concepts may have higher ratings than other companies in the same industry, resulting in certain evaluation premiums. In addition, capital market performance in recent years shows that companies with ESG concepts or "carbon neutrality" concepts are generally considered to have higher growth potential and stronger anti-risk capabilities in the market. For listed companies, they should focus on ESG investment, improve ESG performance, and actively disclose related information to investors. Improving ESG performance should deliver positive information to society, enhance corporate image, increase market confidence in the future development of listed companies, and positively improve corporate value to actively increase financial, financial, trading, and other aspects of negotiation.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.389-396
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• 2023

This paper selects 100 IT companies listed on the Shenzhen Stock Exchange from 2016 to 2020, and the public announcement in Hwajung collects ESG integrated ratings and grades for each sector and empirically verifies the relationship between ESG ratings and stock returns. Huazheng ESG level data and QIANZHAN database Using corporate financial data, a total of 500 samples were selected through correlation analysis and linear regression analysis with SPSS23 to analyze the effect of ESG on Return. As a result of the analysis, first, the impact on stock returns was found to be a significant positive (+) value for ESG integrated ratings and ratings by E (environment), S (social), and G (governance) sectors, confirming that ESG ratings have a positive mold of corporate stock returns. Currently, the world's major economies have proposed sustainable development strategies and "carbon neutral" goals. Development strategies are very consistent with ESG concepts, and companies that agree and execute ESG concepts may have higher ratings than other companies in the same industry, resulting in certain evaluation premiums. In addition, capital market performance in recent years shows that companies with ESG concepts or "carbon neutrality" concepts are generally considered to have higher growth potential and stronger anti-risk capabilities in the market. For listed companies, they should focus on ESG investment, improve ESG performance, and actively disclose related information to investors. Improving ESG performance should deliver positive information to society, enhance corporate image, increase market confidence in the future development of listed companies, and positively improve corporate value to actively increase financial, financial, trading, and other aspects of negotiation.

• Journal of the Korea Fashion and Costume Design Association
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• 제13권2호
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• pp.89-101
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• 2011

The economy blocking and price competitiveness caused by globalization has generated an on-going controversy of global sourcing among high-priced luxury brands. The consumers in the global market purchase luxury goods based on both craftsmanship and the reputation of luxury brands. Factors such as the origin, brand and pricing can affect the intention of consumers to buy luxury goods. This study analyzed the optimum brand combination using conjoint analysis. The analysis was based on the selection of origin, brand name and price as extrinsic factors among attributes of customer choice. These factors were subdivided into Italian and Chinese origins, Gucci, Prada, and Miu Miu in terms of brand names, and 450,000, 750,000, and 1,500,000 Won in terms of price levels. The result showed that origin was considered the most important factor followed by brand name and pricing. This tendency tells us that customers consider origin, brand name and price in that order when purchasing luxury brands. In regards to each factor, respondents preferred Italian to Chinese origins, the Gucci to Miu Miu brand name, and 750,000 to 450,000 won for price level. Generally, women in their 20s and 30s preferred products from advanced nations at a medium-level price.