• 한국산학기술학회논문지
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• 제17권9호
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• pp.718-723
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• 2016

중형 차량용 에어컨에 사용되는 스크롤 압축기는 토크변동이 적고 에너지 효율이 높으며, 소음이 적어 적용이 확대되어 가고 있다. 또한 경량화에 따라 압축기를 구성하는 주요부품이 스틸에서 알루미늄으로 변경하는 등 소재에 대한 연구가 활발히 이루어지고 있다. 또한 스크롤 압축기는 고정 스크롤과 선회 스크롤의 인벌루트 랩의 가공 정밀도가 $10{\mu}m$ 이하로 정밀도가 높은 전용장비와 전용 툴은 물론 숙련된 가공기술이 요구되므로 가공 품질을 확인하기 위하여 표면조도와 윤곽도를 측정하였으며, 알루미늄을 모재로하여 양극 산화 처리하여 사용되고 있는 선회스크롤의 경도를 향상시키기 위한 방법의 일환으로 봉공처리를 수행에 따른 특성들을 살펴보았다. 알루미늄 소재는 Al-Mg-Cu계 합금으로 미량의 Ni, Fe, Zn 이 부가된 것으로 나타났으며, 표면조도는 $3{\mu}m$이하로 가공 정밀도 기준 $10{\mu}m$를 만족하였다. 또한 양극산화 후 나노다이아몬드, CNT로 봉공처리 한 경우 경도는 450 이상으로 수봉공처리의 경우 보다 50% 이상 경도가 향상됨을 알 수 있었으며, 봉공재로 사용하기 위한 소재로서 탄소나노튜브나 나노다이아몬드는 큰 차이를 보이지 않았다.

• 한국세라믹학회지
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• 제47권1호
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• pp.86-91
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• 2010

Among various fuel cells, solid oxide fuel cells (SOFCs) offer the highest energy efficiency, when taking into account the thermal recycling of waste heat at high temperature. However, the highest efficiency and lowest pollution for a SOFC can be achieved through the sophisticated control of its constituent components such as electrodes, electrolytes, interconnects and sealing materials. The electrochemical conversion efficiency of a SOFC is particularly dependent upon the performance of its electrode materials. The electrode materials should meet highly stringent requirements to optimize cell performance. In particular, both mass and charge transport should easily occur simultaneously through the electrode structure. Matter transport or charge transport is critically related to the configuration and spatial disposition of the three constituent phases of a composite electrode, which are the ionic conducting phase, electronic conducting phase, and the pores. The current work places special emphasis on the quantification of this complex microstructure of composite electrodes. Digitized images are exploited in order to obtain the quantitative microstructural information, i.e., the size distributions and interconnectivities of each constituent component. This work reports regarding zirconia-based composite electrodes.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (D)
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• pp.196-198
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• 2006

Ubiquitous Computing 시대가 도래하면서 USN은 다양한 분야에 적용되고 결국 지능형 유비쿼터스 센서 네트워크로 진화될 것이다. 센서네트워크는 네트워크를 구성하는 일정지역에 많은 수의 센서 노드가 배치되는 만큼 그에 따른 가장 큰 제약조건은 유한한 battery수명이다. 따라서 가용에너지가 작은 sensor node를 에너지 효율성을 고려하여 제작해서 적은 에너지 소모를 가지는 long-life sensor node를 만든다면 보다 현실적인 USN 실현에 가까이 갈수 있다. 여기에 우리는 DVS(Dynamic Voltage Sealing)라는 scheme을 기반으로 power-efficiency sensor node을 제작하였다. Variable Voltage을 CPU에 공급하거나 사용하지 않는 state에 있는 경우의 RF transceiver, clock, sensor등을 on/off control함으로서 성능향상을 가할 수 있다.

• 한국유체기계학회 논문집
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• 제16권1호
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• pp.5-10
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• 2013

The performance of screw air compressor is affected by rotor profile, lobe number, air end wrap angle, rotor L/D ratio, suction and discharge ports, revolutions of air end and load regulation control, etc. In general, an efficient screw compressor needs a rotor profile of which has a large flow cross-section area, short sealing lines and a small blow-hole. In this study, experimental study was performed with newly designed $5{\times}6$ rotor profile and various shapes of air end. Results show that the measured specific power consumption of the newly designed screw compressor appeared to be lower than any other published data for the equivalent screw compressors manufactured.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.38-41
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• 2004

Weatherstrip seals protect passengers form noise, dust, rain and wind out of the vehicle. The more contact area between a body frame and a weatherstrip, the higher efficiency of sealing. A weatherstrip is a sort of an elastomer. Mechanical properties of the weatherstrip is obtained by uniaxial tension test. In this study, nonlinear finite element(FE) analysis is performed to obtain displacements and contact shapes of the weatherstrip. The FE model is developed by using Ogden-foam formulation. In the results of nonlinear FE analysis, the most valuable deformation of the weatherstrip occurred when displacement control value reaches 7.2mm. Severe deformation is observed as the displacement control value become more increased.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.156-158
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• 2005

This paper presents an Optimal Power Flow (OPF) algorithm using Interior Point Method (IPM) to swiftly and precisely perform the five minute dispatch. This newly suggested methodology is based on Affine Sealing Interior Point Method (AS IPM), which is favorable for large-scale problems involving many constraints. It is also eligible for OPF problems in order to improve the calculation speed and the preciseness of its resultant solutions. Big-M Method is also used to improve the solution stability. Finally, this paper provides a relevant case study to confirm the efficiency of the proposed methodology.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.873-881
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• 2004

A serious of EK remediation tests on contaminated soil are performed under unsaturated conditions and analyzed for electrical potential, water content, pH and so on. The results indicated that electrical potential and pH distributions in the sample are dependent on the amount and inward/outward flow of hydrogen ion. Specially, for the closed system the water content is largely decreased with the flow of hydrogen. The maximum electrical conductivity is measured at the catholyte of CEM(Sealing) test and directly related to the remedial efficiency. Although pHs in the region near to the anode are similarly developed, the different concentration of lead is measured with the electrical gradient contrary to the lead concentration dependent on pH within the sample.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.140-141
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• 2017

This study is based on the evaluation of a single component injection type adhesive repair material and a new 2 component type used in leakage of underground concrete structures. The studies showed that based on different mix ratio of the 2 component type adhesive sealant comprised of an asphalt main and latex mixture agent the viscosity of the material compound differed significantly. Based on a permeability testing, injection and economic efficiency, and performance, the appropriate ratio was determined to be 6:1 and was proceeded to the KS F 4935 evaluation method. The 2 component type adhesive sealant uses a static mixer and a cartridge type container for the injection procedure and was able to satisfy the evaluation criteria outlined in the KS F 4935 standard.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.255-258
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• 2005

In this study, new types of counter electrode discharge cells for PDP were designed. The counter electrode discharge cells were designed to realize long-gap discharge mode, low firing voltage and moderate conductance for evacuation and sealing process of the panel. In order to test the concept of the design, macro discharge cells were prepared and the discharge characteristics were evaluated. The results indicate that discharge behavior may be modified significantly by changing the morphology of discharge cells.

• 한국산업보건학회지
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• 제27권4호
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• pp.291-301
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• 2017

Objectives: In order to improve the working environment and solve the complaints, many efforts have been made to remove the odor from the industrial process. There are many disposal methods to remove odor, but there are many disadvantages and inadequate applications. The Purpose of this study was to develop a bag-filer system for odor removal using powder adsorbent. Methods: The bag-filter system is composed of a shear bag filter, an absorbent spraying system and an absorbent circulation system. The spraying absorbent system was connected with the inlet duct of the shear bag filter for inputting adsorbent. And the absorbent circulation system can transport the collecting adsorbent from hoper to the inlet duct of the system. As a result, the adsorbent can remove odor with recycling in the system. Also affective factors like the powdered absorbent combination and injection method was researched for maximization of system efficiency. The study was conducted in two stages. The first step was testing equipment made and the second is to evaluate the efficiency of the odor control by connecting to the actual odor generation process. Results: Both experiment stages showed efficient odor control ability. The adsorption efficiency of the system is demonstrated and the odor was adsorbed well by the powder adsorbent. It is essential to accurately understand the characteristics of the odorous and use the appropriate adsorbent. Although the powder adsorbent was used in the experiment, the problem of scattering did not occur due to the high degree of system sealing. Also the system manufactured in this study was designed to recycle the adsorbent, so adsorbent reuse or batch processing is convenient. Conclusions: The applicability of the system has been proven through this research. Customized systems for industrial process and the appropriate adsorbent base on the characteristics of pollutant generation will show efficient odor collection ability.