• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.198-202
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• 2004

This study proposes a new optimization algorithm which is combined with genetic algorithm and ANOM. This improved genetic algorithm is not only faster than the simple genetic algorithm, but also gives a more accurate solution. The optimizing ability and convergence rate of a new optimization algorithm is identified by using a test function which have several local optimum and an optimum design of rocker arm shaft. The calculation results are compared with the simple genetic algorithm.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.835-841
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• 2005

This study proposes a new optimization algorithm which is combined with genetic algorithm and ANOM. This improved genetic algorithm is not only faster than the simple genetic algorithm, but also gives a more accurate solution. The optimizing ability and convergence rate of a new optimization algorithm is identified by using a evaluation function which have several local optimum and an optimum design of rocker arm shaft. The calculation results are compared with the simple genetic algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.101-108
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• 2010

Domestic three-way catalyst satisfies exhaust gas conversion efficiency or pressure drop etc. but doesn't satisfy thermal durability. Thermal stress analysis for three-way catalyst was performed based on experimental temperature distribution. Thermal safety of three-way catalyst was estimated by safety factor. Aspect ratio variable had the most significant effect on thermal stress. Thickness variable had the least significant effect on thermal stress. Optimal conditions for premature failure prevention of three-way catalyst were as follows : (1) aspect ratio of three-way catalyst : 0.6:1 (2) 2.84mm thick (3) silicon nitride. The safety of Taguchi-optimized three-way catalyst were 4.7 times higher than that of existent three-way catalyst.

• 한국해양학회지
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• v.9 no.2
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• pp.19-30
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• 1974

Current observations were carried out in Jinhae Bay area during the period of January to February 1974. The data were synthetically analyzed and the characteristics of the water movement in Jinhae Bay were studied. The water movement in Jinhae Bay area is a reversing tidal current type and the Semi- diurnal tidal current is predominant. The ebb current begins at about high water time and the strongest current occurs at about 3 hour after high water. The flood current begins at 0.2-1.0 hour before low water and the strongest current occurs at about 3-4 hour after low water. The main ebb current flows to SE direction with the maximum welocity, about 100cm/sec and the lood flows to NW with the maximum velocity, about 70cm/sec. Generally, the ebb current in Jinhae Bay is more predominat than the flood current except at the west and the north coast area of Gadeog-do where the flood current is more predominant.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.102-115
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• 2015

Several emergy researches have been carried out to estimate the value of marine ecosystem services in Korea over the last decade. Their results cannot be compared mainly due to inconsistency in emergy-money ratios used to convert emergy unit into monetary unit. This study aimed at providing a standardized format for the emergy evaluation of the Korean economy and environment for different emergy evaluations to be compatible. Even though the area of the continental shelf increased in this study compared to those of previous studies, areaweighted average tidal range for the entire continental shelf of Korea resulted in smaller tidal range, decreasing the final emergy input from tide. However, emergy inputs from nonrenewable resources and purchased goods and services increased with new categorization and use of more detailed data, combined with updated unit emergy values. This led to higher emergy-money ratio for the Korean economy, indicating that previous emergy valuations might have overestimated the contributions of marine ecosystem to the real wealth of the Korean society. The base year for gross domestic product used in the emergy evaluation needs to be clearly indicated due to its impact on the calculation of the emergy-money ratio. A standardized emergy table for the Korean economy will contribute to ensuring consistency among future emergy researches on the valuation of marine ecosystem services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1063-1069
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• 2011

Today, tire performance becomes better as vehicle performance increases. Driviability, endurance, comfortability, noise, and antiwear performance is influenced by tire contour. Tire design method is developed by high-tech engineering technology. Among theses studies, tire performance improvement through tire contour optimization is performed by many vehicle investigator. Therefore, in the present study, an optimum contour design system satisfying the tire performance requirements is constructed by regression analysis and genetic algorithm by using design of experiments.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.348-348
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• 2011

신곡수중보와 전류수위표 사이의 한강 하류부는 홍수기에는 침식에 의한 하상저하가 지배적이고, 비홍수기는 조석에 의해 하류로부터 유입된 부유사의 퇴적으로 인한 하상상승이 지배적인 지역이다. 본 연구는 평면 이차원 하상변동 예측모형인 KU-RLMS 모형을 적용하여 한강 하류부의 지형변화를 예측하기 위한 연구의 일환으로 수행하였다. 본 연구에서는 기존의 KU-RLMS 모형에 포함되어 있던 van Rijn 공식, Ackers-White 공식, Engelund-Hansen 공식 이외에 Colby 공식, Ranga Raju 공식, Shen-Hung 공식, Yang(1973) 공식, Yang(1979) 공식을 추가도 도입하고, 각 공식에 의한 하상변동 예측결과를 실측치와 비교하였다. 이 공식들 중에서 Colby 공식, Ranga Raju 공식, Shen-Hung 공식, Yang(1973) 공식, 그리고 Yang(1979) 공식에 의하면 하상변동이 과도하게 발생하였으며, 특히 과도한 퇴적이 유발됨에 따라 흐름모형이 발산되는 결과가 나타났다. 따라서 이들 공식을 한강 하구부에 적용하는 것은 부적당하다고 판단된다. 유사량 공식 적용의 타당성을 검토한 결과, 대상 구간에 대해 van Rijn 공식과 Engelund-Hansen 공식의 사용이 타당한 것으로 나타났다. 실측 결과와 비교할 때 어느 공식이 적합하다고 판단하기는 어려우며, 향후 보다 엄밀하게 비교할 필요가 있다.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.216-216
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• 2011

목포는 지형 특성상 도시기반이 낮게 조성되어 있어 폭풍해일에 의한 영향이 그리 크지 않더라도 조위가 크게 상승하는 대조기에 해안 저지대에서는 침수범람이 빈번하게 발생하는 지역이다. 특히 1997년 8월 태풍 WINNIE(9713)와 2004년 7월 태풍 MINDULLE(0407)의 간접영향시기가 대조기 고조와 중첩됨에 따라 목포 내항 및 북항 일대에 해수범람 피해가 발생한 바 있으며, 이러한 피해에 대응하여 목포 해안시설물 표고는 1997년 이전의 D.L.(+)480~500cm(목포지방해양수산청, 1998)를 D.L.(+)550cm로 증고한 상태이다. 태풍이 발생하여 내습하는 시기에 해당하는 2010년 7월~9월까지 목포지역 조석예보표(www.khoa.go.kr)에 따르면 거의 매달 500cm 이상의 조위가 예측(최고 511cm, 2010년 8월 11일)되었고, 2004년 범람이 발생한 7월과 8월에는 5.2m 이상의 조위가 3회 이상 예측된 바 있다. 또한 2000년 이후 목포지역의 태풍에 의한 해일고가 매년 50cm 내외로 기록(최고 59 cm, 태풍 RUSA(0215)됨을 고려할 때 D.L.(+)550cm의 목포 해안시설물 표고는 범람피해로부터 안전을 확보하기에는 어려움이 있을 것으로 우려된다. 특히, 최근 2년 동안은 우리나라에 직접 영향을 미친 태풍이 없었으나, 올해 8월 중순에는 대조기에 태풍 DIANMU(1004)가 내습하여 남해안 일대에 피해가 발생하였고, 올해 9월 초에 서해안으로 상륙한 태풍 KOMPASU(1007)는 강한 세력을 유지하면서 북상하여 서해안 일대 및 수도권에 큰 피해가 발생하였다. 만약 태풍 KOMPASU(1007)가 태풍 DIANMU(1004)가 내습했던 대조기 또는 9월 중순의 대조기에 내습했다고 가정한다면, 목포와 같은 서남해안의 저지대는 물론 많은 해안지역에 엄청난 피해가 발생했을 것으로 사료된다. 이에 본 연구에서는 관련연구와 자료분석을 통해 목포해역의 침수범람 위험성을 파악하고, 올해 발생한 태풍의 수치모의 적용을 통해 위험성을 검토하고자 한다.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.3
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• pp.333-349
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• 2015

This study examined the application of the FRBR model to newspapers and news articles. In order to meet the purpose that was mentioned above, we analyzed data items based on the level of newspapers and articles and discussed how the FRBR model may be applied. In terms of the level of a newspaper, each of newspapers, morning/evening paper, issue and edition are regarded as an individual work, and the relationship among them are considered to be the 'whole-part relationship'. Each article on the level of article basis was considered to be a work and was in a relationship of 'whole-part relationship' with the edition of each level of newspapers. Newspaper articles can be represented as texts, photographs, graphics, and tables, etc., and regarded as an individual work. Each work can be a part of the article on a newspaper or can be an independent article itself. Moreover, a uniform heading of each boxed article and running story is included in the work of each article and is forming a 'whole-part relationship'. Because of the changes of the newspaper name, the uniform title of each name regarded as a single binding. It is called the superwork and it is forming 'whole-part relationship' with each name.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.3003-3014
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• 2018

This paper investigates whether the value relevance of unbilled revenue in the construction company is differentiated according to the degree of company's operational efficiency. Unbilled revenue is an item that appears in the assets of the statement of financial position based on the IFRS. It is an item that has a nature of accounts receivable, but it is calculated based on subjective judgment of management. In this paper, we hypothesized that the value relevance of unbilled revenue will be differentiated according to operational efficiency of the construction company. The results of hypothesis test are as follows. First, unbilled revenue has a significant relationship with firm's value, which is consistent with previous research results. Second, the value relevance of unbilled revenue is higher in companies with high operational efficiency. In conclusion, this paper is different from previous researches in that this paper presents not only that unbilled revenue has a value relevance but also provides evidence that it can be differentiated according to the degree of operational efficiency.