• Ocean Systems Engineering
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• v.7 no.3
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• pp.247-273
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• 2017

Many different engagement situations require naval ships to achieve some level of effectiveness. The performance of the naval ships is very important for such effectiveness. There have been many studies that analyze the effectiveness and the performance. The former are largely related to engagement level simulations, while the latter are largely related to engineering level simulations. However, there have been few studies that consider both the engagement level and the engineering level at the same time. Therefore, this study presents three case studies using engagement simulation of the engineering level to check the performance of the related parameters. First, detection performance simulations are carried out by changing the specifications of the passive sonars of a submarine in different scenarios. Maneuvering performance simulations are carried out by changing the specification of the hydroplanes of a submarine in different scenarios. Lastly, in order to check whether or not our forces would succeed in attacking enemy forces, we perform an engagement simulation with various naval ship models that consist of several engineering level models, such as command systems, weapon systems, detection systems, and maneuver systems. As a result, the performance according to the specifications of the naval ships and weapons is evaluated.

• Journal of Korean Medicine for Obesity Research
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• v.12 no.2
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• pp.44-55
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• 2012

Objectives: The purpose of this study is to investigate biological effects of Euiiin-tang(Y$\grave{i}$y$\check{i}$r$\acute{e}$n-t$\bar{a}$ng) extracts by extraction methods. Methods: To investigate the effects of anti-oxidative and anti-inflammatory activity, we measured DPPH radical scavenging assay, collagenase inhibition assay and COX-2 inhibition assay. Results: In case of measuring anti-oxidative and anti-inflammatory activities of Euiiin-tang(Y$\grave{i}$y$\check{i}$r$\acute{e}$n-t$\bar{a}$ng) by collagenase and COX-2 inhibition activity, it came out that Euiiin-tang(Y$\grave{i}$y$\check{i}$r$\acute{e}$n-t$\bar{a}$ng) was unable to inhibit collagenase, but was effective to inhibit COX-2. Cytotoxicity analysis of Euiiin-tang(Y$\grave{i}$y$\check{i}$r$\acute{e}$n-t$\bar{a}$ng) extracts by MTT assay principles, there was no cytotoxicity in aqueous and 50% ethanol extracts in any level of concentration. Conclusions: This results suggest that Euiiin-tang(Y$\grave{i}$y$\check{i}$r$\acute{e}$n-t$\bar{a}$ng) extracts have anti-oxidative and anti-inflammatory activities.

• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.80-84
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• 1997

This study was conducted from April 11, 1996 to May 12, 1996 in Taegu and its vicinities. The purpose of this study was to determine storage conditions of pasteurized fluid milk at retail food establishments. The results are summarized as follows 1. 12(9.5%) out of 126 retail food establishments displayed out dated fluid milk. In a county, more out dated fluid milk(18.2%) were found in retail food establishments in town area eup than those (2.5%) in township area myeon.(P<0.05) 2. 47(37.3%) retail food establishments stored fluid milk below 10$\circ$C, and 79(62.7%) stored them above 10$\circ$C. 3. Only 18(14.3%) refrigerators out of 126 had thermometers to check temperature of a refrigerator. 4. Coliform bacteria were isolated from 3(2.4%) out of 126 fluid milk samples.

• Proceedings of the CALSEC Conference
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• 1998.10a
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• pp.69-78
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• 1998

SGML/XML 기반 문서 정보 시스템의 문서 포맷은 인간이 비교적 쉽게 이해할 수 있으며 기존의 문서 정보 시스템에서는 접근 불가한 레벨까지 인간이 접근할 수 있는 통로를 제공한다. 또한, 문서처리 관점에서 보면 기존의 각 CAL/EC관련 응용 프로그램에서 생성된 데이터는 문서 또는 파일 단위의 접근으로 업무레벨에 도움을 주는 것이 제한적인 것에 반해 SGML/XML 기반 문서정보 시스템은 DTD(Document Type Definition)에서 설계된 엘리먼트, 속성, 엔티티 등의 단위까지 접근할 수 있는 Mechanism으로 기존의 문서 정보 시스템과 차별화 되는 지식 매체로서 지식기반 시스템의 하부 프레임워크를 제공한다. SGML/XML 기반 문서 정보 시스템의 요소로서 SGML/XML 문서 정보 검색 시스템은 표현된 계층적 논리정보를 이용하여 다양한 문서 접근점을 제공할 수 있으며, 사용자 요구에 적합한 문서의 재사용 및 동적인 문서제시를 가능하게 한다. 또한, SGML/XML 문서 정보 관리 시스템은 공동 저작을 위한 세부 논리적 단위별 check-in/check-out, 액세스 제어, 버전닝 기능 등을 제공하여 기업 내 자산 관리를 위한 새로운 파라다임을 제공한다. 본 논문에서는 구현 사례와 더불어 SGML/XML 기술이 CALS/EC 추진에 주는 영향과 향후 바람직한 CALS/EC 또는 가상기업(Virtual Enterprise)구축을 위한 기술적 방향에 대해 논한다.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.637-642
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• 2011

Rails are subjected to damage from rolling contact fatigue, which leads to defects such as cracks. Rolling contact fatigue damages on the surface of rail such as head check, squats are one of growing problems. Another form of rail surface damage, known as "Ballast imprint" has become apparent. This form of damage is associated with ballast particles becoming trapped between the wheel and the surface of rail. These defects are still one of the key reasons for rail maintenance and replacement. In this study, we have investigated whether the ballast imprint is an initiator of head check type cracks and effect of defect size using Finite element analysis. The FE analysis were used to investigate stresses and strains in subsurface of defects according to variation of defect size. Based on loading cycles obtained from FE analysis, fatigue analysis for each point was carried out.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.309-316
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• 2000

When highly compressible, clayey soil layers lies at a limited depth and large consolidtion settlements are expected as the result of construction, precompression of soil may be used to minimize postconstruction settlement. In this study, we tried to find the possibility about the effect of ground improvement using flat dilatometer at the Inchon International Airport where preloading was installed. Field and laboratory tests were performed for soft ground before and after preloading in order to check the effectiveness of the soft ground improvement and compared with the test results of dilatometer which obtained before and after preloading at the same location Field tests such as flat dilatometer, vane, CPTu tests were performed before and after preloading and undisturbed samples are obtained to carry out laboratory tests. As comparing results, after preloading, unit weight, effective stress, undrained shear strength were increased and we can also check the decrease of consolidation late caused of decrease of void ratio. Furthermore, it is assumed that the possibility on the effect of ground improvement by using the flat dilatometer

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.125-130
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• 2013

In this paper, in order to overcome shortcomings of manual inspection for the automotive PWM Shaft, we developed an automated inline inspection system. The automated inline inspection system consists of the work feeder unit, conveying unit, outer diameter check unit, run-out and roundness check unit, machine vision, defective separation unit and status alarm unit. We used the machine vision system for automatic inspection process and designed the inline systems for automatic feeding and selecting process. Also the repeated operation test was performed in order to verify the precision and reliability of the proposed automated inline inspection system.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.3
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• pp.127-132
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• 2013

In order to check traction of the elevator, the load-test is positively necessary on the inspection of elevator in Korea. So actual loads are used in the elevator car for the load-test. However, some of advanced countries in Europe, for example Germany, are using the alternative method with no load test instead of traditional load-test. Commonly hydraulic elevator, compared to passenger elevator is mainly used for loading heavy weights. It requires a great deal of labor to carry out load-test. The reason is why we developed a new inspection skill for the load-test of hydraulic elevator without actual loads. The results of studies show that the new method of the load-test can be replace the traditional load-test.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.1-7
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• 2008

In order to enhance the performance of an automotive engine, many researchers have been carried out. An oil jet cooling a piston is one of important parts for engine performance. Therefore, the efficient cooling system of an oil jet is needed. In this paper, unsteady flow analysis of the oil jet which consists of a check valve and a nozzle has been accomplished. And the reaction between mass flow rate and ball movement was also investigated.

• Bulletin of the Korean Mathematical Society
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• v.57 no.2
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• pp.459-479
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• 2020

In the last two decades, codes over noncommutative rings have been one of the main trends in coding theory. Due to the fact that noncommutativity brings many challenging problems in its nature, still there are many open problems to be addressed. In 2015, generator polynomial matrices and parity-check polynomial matrices of generalized quasi-cyclic (GQC) codes were investigated by Matsui. We extended these results to the noncommutative case. Exploring the dual structures of skew constacyclic codes, we present a direct way of obtaining parity-check polynomials of skew multi-twisted codes in terms of their generators. Further, we lay out the algebraic structures of skew multipolycyclic codes and their duals and we give some examples to illustrate the theorems.