• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.85-91
• /
• 2011

We developed carbon fabric/EPDM chamber insulation in order to protect motor case with high intensity gas flow. Six-inch simulation motor connected with extension tube was designed to test ablation characteristic of insulation. High intensity gas flow was induced by FRP disc with hole between motor and extension tube. After ground test, ablation depth of carbon fabric/EPDM insulation was decreased compared to another insulations after ground static test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.05a
• /
• pp.196-199
• /
• 2009

The most important thing is to analyze the Fast Cook Off problem of the solid motor case exposed to direct flame is a heat transfer analysis. Heat causes degradation and ignition of the propellant. To archive an acceptable reaction level in Fast Cook Off, the rocket motor case generally must fail structurally prior to propellant ignition. We investigate the responses of the solid motor case exposed to Fast Cook Off by using finite element method for the thermal analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.371-376
• /
• 2007

Pan and rayon materials, two types of carbon fabric/phenolics composites, are using as thermal protectors for SRM's nozzle. After burning tests, It was required to analyze the performance of nozzles by ablated shape because ablative patterns were different from each other. For studying of performance on supersonic nozzles that have ablated shape, 1-dimensional analysis and numerical analysis were performed and results were presented in this paper. As the results of this study, in case of the thrust loss, rayon was predicted about 0.53% higher than pan and in case of total impulse loss, rayon was predicted about 0.4% higher than pan.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1177-1178
• /
• 2015

국내 전력설비는 70년대 이후 제3차 경제개발 5개년 계획에 따라 중화학공업의 발전과 함께 급속히 성장해왔다. 과거 개발 위주의 산업구조에서 급속히 팽창한 전력설비는 21세기에 들어서면서 30~40년 장기 사용에 따른 노후화가 진행되었고, 증가하는 전력수요에 대응하기 위한 발전 및 송전 용지 확보의 어려움으로 인하여 전력설비의 신규 증설에 많은 어려움을 격고 있는 실정이다. 따라서 전력설비의 안전성과 신뢰성을 확보하기 위해 적절한 교체시기 선정 및 최적의 자산관리 필요성에 대해서 최근 관심을 가지기 시작하였고, 이러한 전력설비의 최적 자산관리에 핵심적인 전력설비의 상태평가 기술의 발달로 과거 시간기준의 유지보수(Time Based Maintenance)에서 최근 노후설비의 증가와 진단기술의 발달에 따른 예방보전(Preventive Maintenance)에 의한 상태기준 유지보수(Condition Based Maintenance)개념으로 전환되고 있다. 고전압 회전기기(발전기, 전동기)의 상태평가를 위한 핵심기술인 Off-line 부분방전시험이 널리 적용되고 있으며, 본 논문에서는 부분방전 측정 시험 시 대상설비 단자부의 인출케이블에 의한 감도저하 현상에 대해 고찰 하였다.

• Journal of the Korean Electrochemical Society
• /
• v.10 no.4
• /
• pp.262-264
• /
• 2007

This paper describes a two-step approach for the electrochemical deposition of CdZnS thin films on the polycrystalline Au electrode. Initially, an Au substrate is electrochemically modified with a sulfur layer. In the second step, the layer is electroreduced to $S^{2-}$ in the electrolyte dosed with the requisite amount of $Cd^{2+}$ and $Zn^{2+}$ ions to generate CdZnS films in situ. This approach was validated using a combination of linear sweep voltammetry and electrochemical quartz crystal microgravimetry. Thus synthesized CdZnS thin films have different composition depending on the composition of electrolytes. CdZnS thin films are characterized by energy-dispersive X-ray analysis and Raman spectroscopy.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.45 no.8
• /
• pp.91-97
• /
• 2008

The conventional WF(water-filling)-MIMO systems assumes that the channel state information is perfectly known at receiver. However, since, generally, the perfect channel state information is not available at receiver, channel estimation error should be considered at the system. Therefore, in this paper 4he performance of the conventional WF-MIMO systems is numerically analyzed when channel estimation error is considered. The analysis results show that mean square error of channel estimation up to $10^{-4}$ is tolerable to get the same performance obtained when perfect channel information is available.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.10 no.1
• /
• pp.47-57
• /
• 2004

Recently the elderly care facilities have increased according to the increase in the needs of the elderly care. However architectural studies of elderly facilities still leave much to be desired. The results of this thesis are as follows 1) There are three types of residential unit for elderly care facility such as the linear-type, and loop-type, the hall-type. 2) In the elderly care facilities, staffs' affairs are not separated distinctively, instead all of them join the service for the elders. 3) Since both case being easy and being difficult to find a way for elders are decided by the type of the building, space organization should be planned to be recognized the way for elders and organized straightly with joint area between buildings. This study analyzes the effects of the movement and the moving line of elders and staffs for the estimation of each residential space unit. The purpose of this study is to propose residential space organization of the elderly care facilities.

• Journal of Navigation and Port Research
• /
• v.32 no.10
• /
• pp.765-770
• /
• 2008

This paper presents the power control for the hybrid electric propulsion system. In this paper, the hybrid propulsion system consists cf the generator and battery as power supply system in ship. The hybrid control system is designed with energy saving algorithm for decreasing the power consumption of power supply system. This paper suggests the method to increase efficiency of hybrid electric propulsion system by developing battery charging system. The performance of power control system is analyzed with the experiment equipment for hybrid propulsion system, and the results showed a good property.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.6
• /
• pp.662-668
• /
• 2017

This study investigated the antimicrobial resistance patterns of Escherichia coli and Vibrio parahaemolyticus isolated from oysters Crassostrea gigas, short-necked clams Ruditapes philippinarum and corb shells Cyclina sinensis from the West Coast of Korea from June through November 2013. The antimicrobial susceptibility patterns of the isolated strains of E. coli and V. parahaemolyticus to 12 antimicrobial agents used in Korea for clinical or veterinary therapy were analyzed. Antimicrobial resistance to at least one antibiotic was seen in 52.0% of the E. coli isolates (156 strains) and 44.3% of the V. parahaemolyticus isolates (194 strains). The resistance of the E. coli (34.0%) and V. parahaemolyticus (41.8%) isolates to ampicillin was highest. Multiple antimicrobial resistance against at least three antimicrobials was seen in 9.0% of the E. coli isolates and 1.0% of the V. parahaemolyticus isolates.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.1
• /
• pp.1-7
• /
• 2018

We investigated patterns of antimicrobial resistance in Escherichia coli isolated from the water discharged from inland pollution sources in the Hansan-Geojeman and Jaranman-Saryangdo areas of Korea. A total of 217 strains of E. coli were isolated from 23 point-sources. These strains were tested for their susceptibility to 16 antimicrobial agents used in Korea for medical or veterinary therapy. The highest level of antibiotic resistance among the isolated strains was to tetracycline 10.6%, followed by ampicillin (3.2%), nalidixic acid (2.8%), rifampin (1.8%), trimethoprim (1.8%), trimethoprim/sulfamethoxazole (1.8%), chloramphenicol (1.4%), streptomycin (1.4%), cephalothin (0.5%) and gentamicin (0.5%). Resistance to at least one antimicrobial agent was present in 17.1% of the E. coli isolates. Only four of the isolated strains of E. coli showed multiple antibiotic resistance, which is defined as resistance to more than four antibiotics.