• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.6
• /
• pp.604-608
• /
• 2015

In this paper, we study the characteristics of heat transfer for an insulated multi-core tube using glass wool as an insulator for the multi-core tube. By performing experiments and modeling, we examine the variations in the temperature characteristics of hydraulic oil inside the multi-core tube with atmosphere temperature, inlet temperature, and the flow rate of hydraulic oil for the insulated multi-core tube that we developed. When the minimum inlet flow rate of hydraulic oil employed within the scope of the research is 0.29 l/min, the temperature difference obtained in the experiments and numerical analysis was a maximum of $3^{\circ}C$. For a constant atmospheric temperature, as the inlet temperature of the hydraulic oil increases, the outlet temperature of the hydraulic oil will also increase, regardless of its inlet flow rate. Further, when the inlet flow rate of the hydraulic oil is more than 1.01 l/min, the effect of the atmospheric temperature on the temperature drop of the hydraulic oil is low.

• Journal of Cadastre & Land InformatiX
• /
• v.47 no.2
• /
• pp.159-174
• /
• 2017

The long-term imbalances between supply and demand in office market can weaken urban growth since excessive supply of offices led to office market instability and excessive demand of offices weakens growth of urban industry. Recently, there have been a lot of new large-scale supplies, which increased volatility in Seoul office market. Nevertheless, new supply of Seoul office has not been fully examined. Given this, the focus of this article was on confirming the influences of profitability, replacement cost, and demand on new office supplies in Seoul. In examining those influences, another focus was on their relative influences over time. For these purposes, we analyzed quarterly data of Seoul office market between 2003 and 2015 using a vector error correction model (VECM). As a result, in terms of the influences on the current new supply, the impact of supply before the first quarter was negative, while that of office employment before the first quarter was positive. Also, that of interest rate before the second quarter was positive, while those of cap rate before the first quarter and cap rate before the second quarter were negative. Based on the findings, it is suggested that prediction models on Seoul offices need to be developed considering the influences of profitability, replacement cost, and demand on new office supplies in Seoul.

• Composites Research
• /
• v.29 no.3
• /
• pp.111-116
• /
• 2016

The tilting pad journal bearing for the turbo compressor application has a role to support high speed and heavy loading rotor. White metal has been widely used for the bearing material but the conventional bearing is immediately suspended and induces serious serious damage to the rotor under the unexpected oil cut situation or the insufficient oil film formation. The carbon fiber reinforced composite having high specific stiffness, specific strength and excellent tribological characteristics can solve these seizure problems. In this work, the study on the durability of high thermal resistance carbon fiber/epoxy composite tilting pad journal bearing under oil cut situation was conducted. The material properties of the composite materials including tensile, compressive and interlaminar properties were measured at room and high temperature of oil cut situation. To investigate the possibility of failure of composite tilting pad journal bearing under oil cut situation, the stress distribution of the composite bearing was analyzed via finite element analysis and the Tsai-Wu Failure index was calculated. To verify the failure analysis results, the oil cut tests for the composite tilting pad journal bearing were conducted using industrial test bench.

• 주택과사람들
• /
• s.222
• /
• pp.62-65
• /
• 2008

정부가 서민들의 주거 안정을 위해 오는 2018년까지 연간 50만 가구씩 총 500만 가구의 주택을 공급하기로 했다. 기존의 도시 외곽이 아닌 도심이나 도시 근교에 주택을 집중 공급하고, 분양가보다 15% 저렴한 중소형 주택과 10년 임대 후 분양 전환되는 지분형 임대 주택 등을 공급하기로 한 것이다. 정부가 발표한 '보금자리 주택의 공급 방안과 청약 방법 및 전략에 대해 알아보았다.

• Life and Agrochemicals
• /
• s.259
• /
• pp.14-17
• /
• 2010

안전농산물에는 친환경농산물, GAP농산물, 관행농산물 중 안전성이 검증된 것 모두가 포함될 수 있다. '안전농산물 무상공급'으로 하지 않는다면 어떻게 그 많은 학교에 공급되는 모든 농산물을 친환경농산물중 유기농산물로 공급을 할 수 있겠는가?

• Journal of the Korean Chemical Society
• /
• v.46 no.4
• /
• pp.317-323
• /
• 2002

The composition of trace materials in domestic circulated LPG are determined. The sampling points are two cylinders of LPG cylinder re-inspection center, six vaporizer of LPG-supplying group facilities, and the compressed oil from one LPG station. In the trace materials from cylinder of LPG cylinder-reinspection center, alkene and diene derivative (No. of carbon ${\leq}9),$ aromatic compounds, and tarry chemicals(No. of carbon ${\geq}10)$ are 1.5~39.9%, 0.7%, 57.8~96.0%, respectively. While in the trace materials from LPG-supplying group facilities and in the oil from LPG station, tarry chemicals(No. of carbon>10) exceed 96.6%. Nine samples are classified into three clusters. One cluster is the sample of SE company cylinder-reinspection center(Euclidian distance between S company LPG cylinder-reinspection center and SE company cylinder-reinspection center=2.11), the other is the sample of SE company LPG cylinder-reinspection center(Euclidian distance between from samples of LPG-supplying group facilities including compressed oil from LPG station=0.110) the third is the samples of LPG-supplying group facilities(Euclidian distances among them<0.075). The compositions of samples from LPG-supplying group facilities are similar to those of oil from LPG station. Furthermore densities of samples from LPG-supplying group facilities and compressed oil in LPG station are 0.873, 0.873 [0.00798 (99% confidence limits) respectively. It was presumed that tarry chemicals had been leached from the compressed oil of LPG supplying facilities.

• 주택과사람들
• /
• s.204
• /
• pp.36-39
• /
• 2007

분양가 상한제, 원가 공개 등으로 주택 공급 시장이 혼란을 겪고 있다. 오는 9월 분양가 상한제 시행 이전에 분양 물량을 털어버리고 그 이후 주택 공급 계획에 대해서는 건설사들조차 갈피를 못 잡고 있다. 수요자들도 청약가점제, 분양가 상한제 등으로 바뀌는 청약 시장에 어떻게 대응할지 촉각을 곤두세우고 있다. 바뀌는 주택 공급 정책에 대해 살펴보고 현 시장 상황을 진단해보았다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.3
• /
• pp.37-43
• /
• 2004

Engine lubrication system is generally affected by vehicle driving conditions; acceleration, braking deceleration, and cornering. The oil supply system such as oil pan, baffle plate, and oil pick-up pipe should be optimized to cope with severe driving conditions. The main purpose of this paper is to understand the effect of the engine tilting angle on the oil supply system using engine tilting test rig. For the purpose, the oil pressure fluctuation and oil aeration in the main gallery are measured at various engine tilting angles. In addition, the oil flow is visualized by using transparent oil pan to investigate the cause of the formation of oil aeration. The test results show there is a strong correlation between the main gallery oil pressure fluctuation and oil aeration. It is also found that the visualization technique is helpful to stabilize the oil supply system at severe driving conditions.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.6
• /
• pp.90-95
• /
• 2004

In this study, for the crankshaft bearing design adapting discontinuous oil supply system, analyses were conducted to determine the lubrication characteristics such as oil flow rate and increase of oil temperature at main bearing and connecting rod bearing. Additionally, supplied oil pressure and temperature effects on the bearings were simulated to figure out lubrication characteristics on the bearings. Finally the effects of increasing the bearing width and clearance were introduced on the lubrication characteristics.

• Bulletin of Korea Environmental Preservation Association
• /
• v.9 no.14
• /
• pp.32-36
• /
• 1987