• Nuclear Engineering and Technology
• /
• v.34 no.1
• /
• pp.90-103
• /
• 2002

The thermal and mechanical properties of compacted bentonite and bentonite-sand mixture were collected from the literatures and compiled. The thermal conductivity of bentonite is found to increase almost linearly with increasing dry density and water content of the bentonite. The specific heat can also be expressed as a function of water ontent, and the coefficient of thermal expansion is almost independent on the dry density. The logarithm of unconfined compressive strength and Young’s modulus of elasticity increase linearly with increasing dry density, and in the case of constant dry density, it can be fitted to a second order polynomial of water content. Also the unconfined compressive strength and Young’s modulus of elasticity of the bentonite-sand mixture decreases with increasing sand content. The Poisson’s ratio remains constant at the dry density higher than 1.6 Mg/m$_3$, and the shear strength increases with increasing dry density.

• Architectural research
• /
• v.19 no.2
• /
• pp.35-43
• /
• 2017

In South Korea, problems such as low fertility, aging population, and income polarization have recently become more serious. In this time of social change, it is necessary to examine the current changes occurring to residences in order to improve the stability and health of residential areas. The purpose of this study is to investigate the changes of residential areas that occurred between 2000 and 2010 based on detached houses, which are the foundation of residential areas in Seoul. Changes in residential areas can be observed by examining changes in the type of housing and the characteristics of the residents. Since the type of housing and the characteristics of the residents change in the same area, it is necessary to study them together, not as individual elements. Census data is suitable for this purpose, because it can show the changes that have occurred to the housing type and the residents' characteristics within the neighborhood unit. Among the census output areas identified as residential areas based on detached houses, six sites were selected as the case study area based on the rate of change of detached houses. From the result of the case study using the census data, the study area was categorized into three regional types: (i) an urban development and redevelopment area; (ii) an area with a concentration or increasing number of detached houses; (iii) an area with an increasing number of multi-family houses based on detached houses.

• Journal of the Korean housing association
• /
• v.25 no.5
• /
• pp.93-102
• /
• 2014

This study aims to develop the Korean types of continuing care retirement communities (CCRCs). CCRC is well evaluated as a residence that applies aging-in place concept, which is ideal for senior housing. Recently, in USA the CCRCs in which the increasing seniors' population and older households are guaranteed to get continuous protection without moving regardless of their deteriorating health are increasing. In Korea, CCRCs have emerged but not well developed in status quo. We conducted case study using three facilities located at Seoul and its suburbs in Korea to compare five categories such as application of 'aging in place' concept, location, architectural features, services or programs, and management. This study is expected to be used basic materials for CCRCs' complex and architectural planning, management strategies, and services or programs.

• Korean Journal of Construction Engineering and Management
• /
• v.4 no.4 s.16
• /
• pp.106-113
• /
• 2003

The purpose of this thesis is to provide an appropriate trade-off information for the conflicting interests caused by the various factors between building owner and contractor during selecting the contractor and performing the construction work, in which the construction was contracted by open bidding from the government or private organizations. In order to propose the legitimate evidence, the differences between the domestic contract sheet of drawing change and the process of drawing change and those of the foreign countries were compared and analysed The number of construction ordered in Youngdong area in 2001 whose construction expenses are more than 100,000,000 won is 218 items and 147,005,000,000 won in total cost Among them, the number of 218 items whose total cost amounts to 16,705,000,000 (11.36$\%$) is in case of increase of construction expenses due to the drawing changes, and the number of 48 items whose tool cost amounts to 2,009,000,000 won (1.37$\%$) is the case of decrease. In conclusions, the contractor could have more benefits than the building owner in case they submit the detailed estimate sheet without eliminating the increasing expenses of construction. It is shown that the building owner's loss is increasing whenever the labor cost is higher material cost Therefore, this thesis proposes a proper standards for the harmonious compromise between the contractor and the building owner for the problems caused by the drawing changes when the contract agreement is occurred.

• Proceedings of the Safety Management and Science Conference
• /
• 2005.11a
• /
• pp.537-557
• /
• 2005

The estimate on volatility of stock price is related with optimum of portfolio and Important for allocation of capital asset. If the volatility of stock price is varied according to macroeconomic variables on monetary policy and industrial production, it will assist capital asset to allocate. This paper is related with stock market volatilities on macroeconomic variables in U.S. and Europe, Korea. And, it Is pertain to vary in time of this variables. Thus, this paper is related with volatilities of monetary and physical macroeconomic variables on basis of statistics. And, it is ranged front capital investment to portfolio allocation. Also, this paper takes out of sample forecast and study more after this. In case Germany, France, Italy and the Netherlands, the relative importance of monetary policy and Industrial production Is different from these countries. In case Italy and the Netherlands, monetary policy is primary factor at stabilizing for volatility of stock price. In case Korea, increasing monetary policy and industrial production is positively affected stock market. It is that the positive effect of stock price is caused by mollifying monetary policy and economic growth. Specially, this conclusion is similar to US. In Korea, gradual increase in monetary and industrial production is necessary to stability of stock market. It is different to previous results on basis of increasing stock price of money in long period.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.18 no.2
• /
• pp.15-19
• /
• 1990

This survey was carried to determine the crowd In the city parks on the basis of the crowding and using denSity. The using density was vary different by season and day, and the density was much higher in this experiment than in the case of the foreign countries. This survey shows a high correlation between the using density and crowd as the crowd level was more influenced by the increasing number of park - users in the case of low using density than the high using density. The possible using space per individual was around 10㎥ in the parks, which means a strong endurance of the surveying group to the massing space, in the saturated crowding value that the crowd was not significantly affected by the increasing number of users.

• Journal of Soil and Groundwater Environment
• /
• v.7 no.2
• /
• pp.23-33
• /
• 2002

There are two case history. One is the case of 3 wells-group well system-drilled and artificially hydrofractured for dewatering to help to excavate and treat deep building foundation. The recoveries of groundwater of 3 wells are increased 29%, 42% and 110% respectively through hydrofracturing. Simultaneous pumping test reveals that 3 wells are geohydrologically interconnected considering lowered specific capacity comprising influence of additional drawdown effect by other 2 wells compared to single well test. Response time effect during single well test shows that dorminant lineaments are more expandable to other geological structures. The other one is the case of 28% increasing of groundwater productivity for domestic use by hydrofracturing.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.105-105
• /
• 2010

Voltage circuit breakers are widely used in power distribution systems to interrupt fault current rapidly and to assure the reliability of the power supply. Power distribution system requires the transformer with higher capacity than ever, but this ever, but this may be the cause. of the increasing of short circuit current in contrast to conventional one when short-circuit accident is occurred. Therefore molded case circuit breaker improved in aspects of interrupting capacity of short circuit current in this system is needed. By using the proposed methods in this paper, such as new arc quenching structure of grid would contribute to minimizing the MCCB, realization of high interrupting performance and reducing the design time and development cost.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1081-1099
• /
• 2010

The TVM 430 system manufactured by Ansaldo STS in France is currently used in ground signalling system for Kyungbu HSR. It transmits the speed information to the on-board signalling system in the form of continuous signal via the track, and the rolling stock in Kyungbu HSR runs with 300km/h max. operating speed by using the corresponding information. Looking from the recent international trends in HSR, reducing the travelling time and increasing of the line capacity is promoting via the improvement of train speed. In case of TGV Est, they are realizing the normal operation with 320km/h max. operating speed by using TVM SEI signalling system, which is similar to TVM 430. Furthermore, in case Honam HSL, which is under construction, is looking over faster speed than the limited one of Kyungbu HSR(i.e. over 300km/h). In this paper, it is assumed that the existing TVM 430 ground signalling system is used and train speed is improved, therefore the number of block section to be increased depending on the increase of train speed and the standard speed to be used in this case is drawn via the simulation of the train model and described the method accordingly.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.1
• /
• pp.85-92
• /
• 2011

Main characteristic in railroad is the guided movement of the wheel by the track through a metal-to-metal contact, conferring to the rail vehicle a single degree of freedom. There are defects such as head check, shelling, corrugation, squats etc in surface of the rail by interface between the wheel and rail. These defects bring about reducing the life-cycle of rails and track components and increasing noises. In case of bad conditions, it is possible to happen to full-scale accident such as derailment. Recently, the track capacity has been increased for increasing speed and operation efficiency. So, maintenance and indirect cost have been increased. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. Rails are used as the earth in electrical railroad systems. Currently traction return current is flowed through wheels of trains. In case of rails coated, problems are caused in the contact power between wheel and coating material of spray. In this paper, electric model is presented in the AT feeding method. In case of rails coated, electric model is presented. Also, standard resistance of the ceramic is demonstrated by contact power between wheel and coating material of spray.