• 가정과삶의질연구
• /
• 제15권3호
• /
• pp.1-14
• /
• 1997

The purpose of this study is to review current home-based work study and identify factors associated with the choice of home-based work. Home-based work as an alternative form of employment is being sought today by both workers and business. The information age with its empasis on the recoding and transfer of information along with the technology of telectommuting has increased potential for and attention to home-based work. Home-based work seems to have several advantages particulary for women who carry the double burden of household work and paid work. The reduction in traffic congestion and demand of fossil fuels that accompanies the elimination of commuting has also been seen as a important social benifit. Home-base work has potential that can improve women's labor force participation. Further study is needed to evaluate home-based work and critical advice to current and prospect workers.

• Journal of Advanced Marine Engineering and Technology
• /
• 제22권5호
• /
• pp.702-711
• /
• 1998

The characteristics of corrosion resistance for the surface of medium high carbon steels and low alloy steels utilizing as manufacturing the machinery structures and machining tools and treating by plasma/ion nitriding process have been studied in terms of electrochemical polarization behav-iors including corrosion potential(Ecorr) anodic polarization trends and polarization resistance(Rp) The seven base materials showed a clear passivation behavior for the polarization tests in the ASTM standard solution 1N ${H_2){SO_4}$ Although the treated surface by plasma nitriding for the seven test materials showed a significant increase in hardness the treatment gave a detri-mental effect in corrosion resistance. The various characteristics including corrosion potential polarization curves microstructures corrosion current polarization resistance among non-treat-ed nitriding and/or soft-nitriding treated specimens have been investigated and some of the mechanisms discussed.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집A
• /
• pp.573-578
• /
• 2001

For the corrosion protect ion of the natural gas transmission pipelines, two methods are used, cathodic protection and coating technique. In the case of cathodic protection, defects are embrittled by occurring hydrogen at the crack tip or material surface. It is however very important to evaluate whether cracks in the embrittled area can grow or not, especially in weld metal. In this work, on the basis of elastic plastic fracture mechanics, we performed CTOD test ing with varying test conditions, such as the potential and current density. The CTOD of the base steel and weld metal showed a strong dependence of the test conditions. The CTOD decreased with increasing cathodic potential and current density. The morphology of the fracture surface showed quasi-cleavage. Hydrogen introduced fractures, caused by cathodic overprotection.

• 동력기계공학회지
• /
• 제8권4호
• /
• pp.38-43
• /
• 2004

Thermal spraying onto the metal substrate has been widely used as a technique of the surface treatment in the various industrial field. A wide range of thermal spray technologies exist and all rely on the fundamental process of fusing a metal feedstock, atomizing it and transporting it to the surface of a substrate. Specially, these methods have been taken into account as the protection method against the corrosion. In this study, the polarization characteristics were carried out on the thermal sprayed coating layer immersed in various pH of diluted aqueous solutions at $25^{\circ}C$. Aluminum, Zinc, Ni-base alloy, alumina and polyethylene powder were used with sprayed coating materials. From the polarization curves, the electrochemical corrosion potential($E_{corr}$) and the corrosion current density($I_{corr}$) were investigated.

• Corrosion Science and Technology
• /
• 제8권4호
• /
• pp.133-138
• /
• 2009

For the corrosion protection of the natural gas transmission pipelines, two methods are used, cathodic protection and coating technique. In the case of cathodic protection, defects are embrittled by occurring hydrogen at the crack tip or material surface. It is however very important to evaluate whether cracks in the embrittled area can grow or not, especially in weld metal. In this work, on the basis of elastic plastic fracture mechanics, we performed the CTOD testing with various test conditions, such as testing rate and potential. The CTOD of the base metal and the weld metal showed a strong dependence of the test conditions. The CTOD decreased with decreasing testing rate and with increasing cathodic potential. The morphology of the fracture surface showed the quasi-cleavage at low testing rate and cathodic overprotection. The low CTOD was caused by hydrogen embrittlement at crack tip.

• 대한화학회지
• /
• 제6권1호
• /
• pp.61-63
• /
• 1962

The polarographic behaviors of Tl(I) was investigated in EDTA and NTA as supporting electrolytes for determination of Tl(I). A base solution containing 0.005 % gelatine, 0.1 M EDTA, and 0.05 M NTA was used. The halfwave potential of Tl(I) determined is -0.495 V v.s. S.C.E. in 0.1 M EDTA at pH 4.1 and -0.520V v.s. S.C.E. in 0.05 M NTA at pH 6.3. In this paper, the effects of gelatine concentration and pH values was investigated. The half-wave potentials of common elements was determined and compared with the half-wave potential of Tl(I).

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 C
• /
• pp.1557-1559
• /
• 2000

In this paper, we intend to establish the judgement of electrical fire through analysis of PT(Potential Transformer) using the power installation. The columnar structure and the void generated by abrupt heat grew at the tenter of boundary-face on the metallurgical microscope analysis. The detection of OK lines was confirmed by EDX(Energy Dispersive X-ray spectroscopy) as melting and recombination due to the layer-short of the wiring. We found that the thermal-weight decrease occurred at 300$^{\circ}C$ in case of being the thermal-deterioration on the base of the result that analyzed the insulated-materials by using TGA, and the thermal reaction limited-value of PT insulator was about 300$^{\circ}C$ on the DSC curve. As this analysis, we confirmed what the layer-short appeared in the wiring of PT.

• Bulletin of the Korean Chemical Society
• /
• 제24권7호
• /
• pp.937-942
• /
• 2003

The relaxation phenomena of ionic currents through the charged membrane under the constant applied potentials has been studied. The formulation was obtained for the non stationary current by assuming that the ion mobility is independent of concentration and the potential gradient is a constant within membrane, and it was applied to the experimental results with the sulfonated polystyrene collodion base membrane. It has been shown that the initial ion distributions in the membrane play a predominant role in the relaxation phenomena.

• 한국IT서비스학회지
• /
• 제7권1호
• /
• pp.131-149
• /
• 2008

Bandwidth Trading(BT) represents a potential market with over 1 trillion USD across the world and high growth potential. BT is also likely to accelerate globalization of the telecommunications industry and massive restructuring driven by unbundling rush. However, systematic researches on BT remain at an infant stage. This study starts with structure analysis of the Internet industry, and discusses significance of Internet interconnection with respect to BT Issues. We also describe the bandwidth commoditization trends and review technical requirements for effective Internet interconnection with BT capability. Taking a step further, this study explores the possibility of improving efficiency of network providers and increasing user convenience by developing an architectural prototype of Hub-&-Spoke interconnection model required to facilitate BT. The BT market provides an Innovative base to ease rigidity of two-party contract and Increase service efficiency. However, as fair, efficient operation by third party is required, this research finally proposes an exchanging hub named NIBX(New Internet Business eXchange).

• 대한교통학회지
• /
• 제19권2호
• /
• pp.89-98
• /
• 2001

본 연구는 중차량이 혼재하고 있는 비신호 교차로(혹은 로타리형 교차로)에서 용량분석을 실시하는 경우 중차량에 대한 용량 보정계수의 도출에 관한 것이다. 1997년과 2000년도 미국도로용량편람(Highway Capacity Manual)의 비신호 교차로의 용량분석방법에 의하면 이 경우 기초 임계간격(Base Critical Cap)과 기초 추종시간(Base Follow-up Time)에 각각 보정을 하여 실제 임계간격과 실제 추종시간을 산출한 뒤에 이를 이용하여 잠재용량(Potential Capacity)을 산출하도록 되어 있다. 그러나, 미국도로용량편람에서 제시된 이 방법을 사용하는 경우 다양한 종류의 중차량에 대한 용량보정이 매우 임의적으로 처리될 뿐만 아니라 그 부정확성으로 인하여 실제 비신호 교차로의 운영분석 및 설계를 담당하는 실무자들에게 많은 어려움을 주게 된다. 따라서 본 연구는 비신호 교차로에 대하여 미국도로용량편람에서 채택하고 있는 접근방법을 개선하여 보다 손쉬운 방법으로 용량을 보정할 수 있는 간단한 보정계수의 산정 공식을 제공하여 이 분야의 발전에 도움을 주고자 한다. 본 연구에서 제시하고 있는 중차량 용량 보정식은 비신호 교차로에 대한 미국도로용량편람의 제시된 공식과는 달리 일반 고속도로의 용량분석시에 사용되는 중차량 보정식과 유사한 형태의 것으로 유도가 되며 이 보정식의 도출과정에서 새로운 개념의 승용차 환산계수(PCU)의 산정식이 소개된다.