• 품질경영학회지
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• 제47권2호
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• pp.283-294
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• 2019

Purpose: Although the development of bulletproof helmets continues to be carried out, little has been improved in testing methods. Therefore, in this study, we studied the improvement of the test method of the domestic bulletproof helmet. Methods: The causes of head damage in the battlefield and the trends of bulletproof helmet development in developed countries were analyzed. In addition, improvements were derived by comparing the test methods of bulletproof helmet in Korea and the United States. Results: The results of the improvement by comparing the test methods of bulletproof helmet in Korea and the United States are as follows First, it is an addition to the scope of environmental treatment. Second, it is an addition to the level of protection. Third, the addition of the level of protection by impact. Conclusion: This study considered testing methods to prevent head injuries to shocks that cannot be identified by conventional methods. In addition, it considered testing methods for various threats by improving protection performance to advanced countries' levels.

• 한국지반신소재학회논문집
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• 제18권4호
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• pp.151-165
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• 2019

본 연구에서는 저유동성 몰탈 채움을 통한 기존 항만 구조물의 내진성능 향상을 위해 시공 위치에 따라 4가지(자중증가, 활동력 감소 등) 보강방안을 제시하였으며, 이론적 방법 및 수치해석적 방법으로 보강 시 효과(안정성, 시공성, 경제성)를 분석하여 최적 방안을 제시하였다. 본 연구 결과 인공지진파를 적용한 동적 시간이력해석을 수행한 결과 보강 후 수평변위는 보강 전 수평변위에 비해 감소하였으나 보강 방안별 지진시 변위 억제 효과는 큰 차이가 없는 것으로 평가되었다. 강도감소법과 한계평형해석법을 적용하여 원호활동 파괴특성을 검토한 결과 수동말뚝 형태의 개량 방안이 다른 보강방법에 비해 안전성이 높은 것으로 평가되었다. 이는 보강체로 인해 활동 파괴면의 전단강도가 증가하였기 때문이다. 또한, 시공성 및 경제성을 분석한 결과 토압 저감형태(Type 02)와 수동말뚝 형태(Type 03)가 우수한 것으로 나타났다. 다만, 수동말뚝 형태의 경우, 설계법 적용 사례가 미미하고, 지반 조건에 따라 시공이 불가하거나 경제성이 급격히 저감되는 등 여러 가지 제약조건을 가지고 있어 적용시 주의가 요구된다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1608-1614
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• 2009

In recent days, the study of urban regeneration has been conducting with purposeful and sincere intent starting out with the residential environment improvement works. Within the range of urban regeneration, the low-cost housing technology means development of totally-integrated housing technology that may be applied to the regeneration project, especially for the rundown areas where infrastructure facilities in the urban zone have been degraded and obsoleted. In line with this, among many and varied methods in order for realization of the low-cost housing as a part of urban regeneration project, this study should like to propose an improvement methods of the key technologies in relation to the construction works by type of work with which construction costs (directing cost) would be reduced. And, in order to elicit the method for element technology that has been developed and improved in the most optimal manner centering on the selected construction work by the type of work, the researcher conducted comparative review of summary of element technologies related to the construction works concerned, characteristics, and construction method thereof. In particular, the researcher investigated the expenses (construction cost and labor cost), constructions (contractibility and productivity), safety, quality of works, and the technical status in environmental aspects, and the researcher also conducted analyses and evaluations thereof.

• 품질경영학회지
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• 제36권4호
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• pp.37-46
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• 2008

There are big differences in six sigma projects between manufacturing processes and transactional/service processes. This paper analyzed the differences between the two areas by examining 18 six sigma case studies in Korean companies. To characterize six sigma case studies, step-by-step questions and check criteria were developed based on 12 step DMAIC methodology. On the basis of those characterized data, the differences between two areas were analyzed. Significant differences were found in the number of CTQs, validation of measurement systems, methods to determine improvement objectives, the methods to elicit improvement plans and types of control systems. The most significant difference was that statistical tools were widely used in manufacturing processes, but qualitative tools were used in transactional/service processes during improvement phase.

• 품질경영학회지
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• 제43권2호
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• pp.127-140
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• 2015

Purpose: To obtain the area for improvement, the Importance-Performance analysis(IPA) uses relatively simple questions, that is, satisfaction and importance at attribute level. However, no attempt has been made to consider the gap between own company's performance and those of competitors in IPA, in the field of quality management. This study is aimed to suggest a new prioritizing method for improvement and to test for validity of the proposed technique. Methods: This study used data collected from Song and Lim(2015), which is satisfaction of employees, customers and competitors as well as importance data for 7 quality attributes of K animal hospital. A correlation comparison with other priority methods such as Bacon(2003)'s model and Matzler and Hinterhuber(1998)'s QI index is conducted. Results: The priority results by the proposed method shows better in correlation coefficient with customer perceived priority for improvement than other methods. Conclusion: From the result of the current study, it can be concluded that the result of the proposed method is valid, while it is relatively easy to understand and analyze, and therefore no additional survey is necessary for improvement priority.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제3권8호
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• pp.261-270
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• 2014

최근 인터넷 트래픽이 증가하면서 웹 서버의 성능 향상에 많은 노력들을 기울여왔다. 고사양 하드웨어로의 교체 또는 서버 수의 증설과 같은 하드웨어 측면 해결방법 외에 소프트웨어 측면의 해결 방법들이 있는데 최근 이에 대한 연구들이 활발히 진행되고 있다. 본 논문에서는 기존 TCP 네트워킹 수신과정에서 발생하는 성능 저하 문제점들을 파악하고 이를 해결할 수 있는 방법을 제안한다. 리눅스 TCP 네트워킹 성능 개선에 관한 기존 방법 세 가지와 본 논문에서 새로 제안하는 두 가지 방법을 통합 적용하여 성능을 향상시킨다. 기존 개선 방법들로는 멀티코어 환경에서 패킷을 흐름단위로 코어에 할당하는 방법, 과도한 인터럽트 요청을 조절하는 ITR(Interrupt Throttle Rate) 방법, sk_buff 자료구조 recycling 방법이다. 본 논문에서 새로 제안하는 방법은 fd 자료구조 recycling 방법과 epoll_event 자료구조 recycling 방법이다. 웹 서버 환경에서 실험을 통해 본 논문의 제안방법들의 성능 개선효과, 또한 기존방법들과의 통합 적용했을 경우 성능 개선효과를 검증한다. 웹 서버로는 간단한 웹 서버, 리눅스에서 일반적으로 사용하는 Lighttpd와 Apache 웹 서버를 사용한다. 간단한 웹 서버 환경에서 본 논문에서 제안한 fd 재사용과 epoll_event 재사용을 적용할 경우 성능이 각각 7%와 6% 개선되고, 이 두 가지 방법을 기존의 세 가지 방법과 통합하여 적용한 경우 성능이 총 40%까지 개선된다. Lighttpd와 Apache 웹 서버 환경에서 다섯 가지 통합 방법을 적용한 경우 성능이 각각 총 36%, 20%까지 개선된다.

• 한국가구학회지
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• 제15권2호
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• pp.1-17
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• 2004

This paper attempted to review measuring methods of formaldehyde emission from wood-based panel products. Methods included for the discussion were desiccator methods, extraction method, and various chamber methods. First, the procedures and testing conditions of 24-hour desiccator method was critically reviewed, and an improvement of this method was proposed to meet international standards. Two different small chamber methods ($20\ell$ and $1m^3$ chamber methods) were also compared in terms of their advantages and disadvantages. In addition, the regulation levels of formaldehyde emission of wood-based composite panels were compared for different countries. The selection of a reference method of measuring formaldehyde emission of wood panel products should consider the ease of conducting test and cost required. Results should be exchangeable for different methods.

• Journal of Welding and Joining
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• 제24권2호
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• pp.42-47
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• 2006

While it is known that the weld toe grinding method may give 3.4 times of fatigue strength improvement, this improvement may significantly vary according to weld bead shapes and loading modes. Although tremendous interest have been given in improving fatigue strength improvement for ship structures, quantitative results are yet in need. In this context, a series of fatigue tests is carried out for a type of test specimen that are typically found in ship structures. Weld burr grinding is carried out using a electric grinder in order to remove surface defects and improve the weld bead profile. The test results are compared with the same type of test specimen without applying the fatigue improvement technique in order to obtain a quantitative measure of the fatigue strength improvement. On the other hand, both hot spot stress and structural stress methods are employed to compare the effectiveness of the two methods in evaluating the fatigue strength improvement of welded structures.

• 한국지반공학회지:지반
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• 제12권2호
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• pp.115-132
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• 1996

연약지반 안정화공법으로서 각종 고결공법이 성행하고 있으나 해성점토지반이나 통수지반과 같은 특수조건하에서는 시공도 까다롭지만 강도발현이나 내구성 등의 측면에서 보강효과가 저하하는 것을 볼 수 있다. 고결공법은 혼합(고압)처리방식과 주입방식으로 대별할 수 있는 데, 본 연구에서는 첫째로 해성점토지반에 시멘트에 의한 지반보강시의 강도열화문제와 두번째로 지하수흐름이 있는 지반에서의 물유리계 약액주입시의 주입효과증대 및 내구성 문제에 촛점을 맞추어 그 해결방안을 검토 하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권1호
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• pp.19-25
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• 2018

Objective: In practical breeding, selection is often performed by ignoring the accuracy of evaluations and applying economic weights directly to the selection index coefficients of genetically standardized traits. The denominator of the standardized component trait of estimated genetic evaluations in practical selection varies with its reliability. Whereas theoretical methods for calculating the selection index coefficients of genetically standardized traits account for this variation, practical selection ignores reliability and assumes that it is equal to unity for each trait. The purpose of this study was to clarify the effects of ignoring the accuracy of the standardized component trait in selection criteria on selection responses and economic weights in retrospect. Methods: Theoretical methods were presented accounting for reliability of estimated genetic evaluations for the selection index composed of genetically standardized traits. Results: Selection responses and economic weights in retrospect resulting from practical selection were greater than those resulting from theoretical selection accounting for reliability when the accuracy of the estimated breeding value (EBV) or genomically enhanced breeding value (GEBV) was lower than those of the other traits in the index, but the opposite occurred when the accuracy of the EBV or GEBV was greater than those of the other traits. This trend was more conspicuous for traits with low economic weights than for those with high weights. Conclusion: Failure of the practical index to account for reliability yielded economic weights in retrospect that differed from those obtained with the theoretical index. Our results indicated that practical indices that ignore reliability delay genetic improvement. Therefore, selection practices need to account for reliability, especially when the reliabilities of the traits included in the index vary widely.