• Journal of Advanced Marine Engineering and Technology
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• v.39 no.4
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• pp.483-488
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• 2015

This paper implements a long-term monitoring system (LMS) for ship's engine performance analysis (SEPA) based on the web, for the purpose of the communication speed and engine maintenance. This system is composed of a simulator, monitoring module with a multi channel A/D converter, monitoring computer, network attached storage (NAS), RS485 serial and wireless internet communication system. The existing products monitor the information transmitted from pressure sensors installed in the upper parts of each of engines in the local or web computer, but have a delay in the communication speed and errors in long-term monitoring due to the large volume of sampling pressure data. To improve these problems, the monitoring computer saves the sampling pressure data received from the pressure sensors in NAS, monitors the long-term sampling data generated by the sectional down sampling method on a local computer, and transmits them to the web for long-term monitoring. Because this method has one tenth of the original sampling data, it will use memory with small capacity, save communication cost, monitor the long-term sampling data for 30 days, and as a result, make a great contribution to engine maintenance.

• Journal of the Korean institute of surface engineering
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• v.22 no.2
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• pp.88-92
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• 1989

양극산화 피막의 졀정구조에 관한 연구는 1960년대부터 반응 Mechanism의 연구와 병행하여 많은 논란이 되어왔다. 결정구조의 정확한 Model 이 아직까지 확립되어 있지 않은 상태에서, 여러 가지 접근방식으로 연구되고 있는 실정이다. 최근에는 HRTEM, NAS-NMR등의 고성밀 장비의 응용에 의한 결정구조의 분석에 활발히 진행이 되고 있으며, 이론 물리학의 응용 또한 이곳까지 확산되고 있는 상태이다. 본 고에서는 반응 Mechanism을 연구하는데 가장 밀접한 분야인 양극산화 피막 결정 구조에 관해 1950년대이후 어떻게 연구되고 설명되었는가를 조명하기로 한다.

• Proceedings of the Korean Vacuum Society Conference
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• 2001.02a
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• pp.186-187
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• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1877-1880
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• 2003

We were interest in Deburring using MAF(magnetic abrasive finishing) method. So Magnetic inductor was designed and manufactured to generate proper magnetic induction fer deburring the burr formed in drilling SM45C. We experienced according to the Rotational speed, table feed rate, grain size of powder and working gap are changed to investigate the effect on deburring. At this time we experienced in abrasive effect mainly.

• Computational Structural Engineering
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• v.4 no.3
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• pp.40-43
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• 1991

한국과학기술연구원(KIST)부설 시스템공학연구소(SERI)가 보유하여 일반 사용자들에게 공개하고 있는 구조해석 S/W/로는 ABAQUS, ADINA, BOPACE-3D, DYNA-3D, MSC/NASTRAN, DIS/ADLPIPE, SAP5, KISTRAS, NONSAP, MARC 등을 들 수 있다. 이들 중 DIS/ADLPIPE, SAP5, KISTRAS, NONSAP은 CDC CYBER 960-31에 설치되어 있고 MARC는 NAS AS/XLV50에 설치되어 있으며 나머지는 CRAY-25 슈퍼컴퓨터에 설치되어 있다. 본 고에서는 이들 중에서 CRAY-2S 슈퍼컴퓨터에 설치되어 있으며 다양한 비선형 구조해석기능을 가지고 있는 ABAQUS, ADINA, MSC/NASTRAN 및 DYNA-3D에 대하여 개요, 기능 및 사용방법을 간략히 소개하고저 한다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.10-11
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• 2006

The use of hot gas in melt atomization has been widely reported, but little detailed experimental data on its precise effects and no satisfactory theory to explain them have been published. In this paper the authors present experimental data on the atomization of metals with gas at temperatures from ambient to 1000C, a semi-empirical equation relating particle size to gas temperature and flow rate, and an analysis of the gas dynamics of the atomization process that allows some insight into the process.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1254-1261
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• 2007

In the present study, we have constructed a bioluminescent bioreporter for the assessment of nitrate/nitrite bioavailability in wastewater. Specifically, an approximately 500-bp DNA fragment containing a nitrate/nitrite-activated nasR-like promoter (regulating expression of genes encoding nitrite reductase in the genus Klebsiella) was fused upstream of the Vibrio fischeri luxCDABE gene cassette in a modified mini-Tn5 vector. Characterization of this strain, designated W6-1, yielded dose-dependent increased bioluminescence coincident with increased nitrate, nitrite, and ammonium added to the growth medium from 1 to 11 ppm. Bioluminescence in response to nitrogen species addition was light dependent up to 10, 7, and 8 ppm with nitrate, nitrite, and ammonium, respectively. This response was linear in the range from 1 to 8 ppm for nitrate ($R^2=0.98$), 1 to 6 ppm for nitrite ($R^2=0.99$), and 1 to 7 ppm for ammonium ($R^2=0.99$). A significant bioluminescent response was also recorded when strain W6-1 was incubated with slurries from aged, nitrate/nitrite contaminated wastewater. Thus, bioreporter strain W6-1 can be used to elucidate factors that constrain the use of nitrate/nitrite in wastewaters.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.11-20
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• 2020

In this paper, we propose the possibility of using containers in the HPC ecosystem and the criteria for selecting a proper PMI library. Although demand for container has been growing rapidly in the HPC ecosystem, Docker container which is the most widely used has a potential security problem and is not suitable for the HPC. Therefore, several HPC containers have appeared to solve this problem and the chance of performance differences also emerged. For this reason, we measured the performance difference between each HPC container and Docker container through NAS Parallel Benchmark experiment and checked the effect of the type of PMI library. As a result, the HPC container and the Docker container showed almost the same performance as native, or in some cases, rather better performance was observed. In the result of comparison between PMI libraries showed that PMIx was not superior to PMI-2 in all conditions.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.914-923
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• 2015

UAS(Unmanned Aircraft System) has been used a lot in military applications but recently its usage is expanding to commercial applications due to its recent technical development and its market is expected to grow rapidly in the future. In hyper-connectivity society, especially UAS would play major role as an one of potential infrastructures for the architecture of the next 5G system. The ultimate goal is the successful integration of UAS in NAS(National Airspace System) relies heavily on ensuring reliable spectrum for the robust CNPC(Command and Non-Payload Communication) links as well as payload links for other various applications in the upcoming hyper-connectivity era. In this paper, we have focused on the analysis of the existing frequencies for UAS radio-control and the current issues for CNPC and payload frequencies, and proposed future efficient utilization policy for UAS in the hyper-connectivity society.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.841-850
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• 2008

Strength and failure of composite-to-aluminum rivetted, bonded, and rivet/bonding hybrid single-lap joints were investigated by experiment. A total of 82 joint specimens were tested with 3 different overlap lengths and 2 types of stacking sequence. FM73m adhesive film and NAS9308-4-03 rivet were used for hybrid joints. While failure loads of the bonded and hybrid joints increased as the overlap length increased, failure loads of the rivetted joints were not affected by the overlap length. Effect of the stacking sequence was not remarkable in the simple bonded or rivetted joints. Failure loads of the hybrid joints, however, showed the maximum of 30% difference depending on the stacking sequence. Major failure mode of the bonded and hybrid joints was the delamination of the composite adherend and failure mode of riveted joints was the rivet failure with local bearing.