• 대한가정학회지
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• 제38권3호
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• pp.43-57
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• 2000

The aims of this study were to analyze the influence of related variables on a mode of housing life style, and the related variables to propensity to housing life stymie. The results of this study were as follows: 1. Variables influencing value orientation of family life were property and the price of housing. 2. Variables influencing spending habits were objective social class (SES), types of residence, education of wife, and price of housing. 3. Variables influencing propensity to using space were found to be objective social class (SES), education of wife, types of homeownership, and price of housing. 4. Variables influencing housing life style were objective social class (SES), subjective social class, housing class, family life cycle, housing life cycle, types of residence, site of residence, age of husband, age of wife, education of husband, education of wife, income, property, job of husband, types of homeownership, size of housing, and price of housing.

• 제어로봇시스템학회논문지
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• 제14권6호
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• pp.554-557
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• 2008

We analyze the stability property of a class of nonlinear time-delay systems with time-varying delays. We present a time-delay independent sufficient condition for the global asymptotic stability. In order to prove the sufficient condition, we exploit the inherent property of the considered systems instead of applying the Krasovskii or Razumikhin stability theory that may cause the mathematical difficulty of analysis. We prove the sufficient condition by constructing two sequences that represent the lower and upper bound variations of system state in time, and showing the two sequences converge to an identical point, which is the equilibrium point of the system. The simulation results illustrate the validity of the sufficient condition for the global asymptotic stability.

• Nuclear Engineering and Technology
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• 제34권1호
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• pp.90-103
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• 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
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• 제13권3호
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• pp.31-40
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• 2011

Profit-keeping behaviors naturally occur in the market to satisfy consumers, and the logic behind it lies in the economies of scale. On the flip side, some commodities transacted in the market are not available or can not be easily acquired unless the demand is high enough. Under this proposition, some consumers rise and find their own solution to meet the services at a reasonable cost or at an adequate level. The commonly adopted way is to establish a cooperative, and it stirs purchasing power by pooling resources and further bargains price and service quality. As a consumer cooperative, housing cooperatives notably found in rural towns enable the elderly to continue independent living. This study is to take a closer look at residential life of the rural elderly in housing cooperatives. Utilizing in-depth focus group interviews with 40 residents in four housing cooperatives, this qualitative research draws main factors affecting the decision to move in, residential assessment, and strengths and weakness of living in a housing cooperative. The primary factor influencing the moving decision is to continue to independent living in a familiar community, and the bottom line is planning ahead. Frailty and bereavement are found to be the leading occasions for them to move. The participants are satisfied with the independent living arrangement, and particularly, cited such features as safety and security, elderly-friendly design, common spaces, freedom, social activities and efficient living. Also, it is stated that some cooperative natures such as control over the property and giving a voice on management render positive impacts on the satisfaction with communal living. In spite of all the benefits and strengths, participants face with a public notion that an independent living arrangement like a housing cooperative has never done before in rural towns, so that most people recognize it as part of dependent living arrangements like nursing home.

• 한국재료학회지
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• 제20권5호
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• pp.271-277
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• 2010

In this paper two aspects of the percolation and conductivity of carbon black-filled polyethylene matrix composites will be discussed. Firstly, the percolation behavior, the critical exponent of conductivity of these composites, are discussed based on studying the whole change of resistivity, the relationship between frequency and relative permittivity or ac conductivity. There are two transitions of resistivity for carbon black filling. Below the first transition, resistivity shows an ohmic behavior and its value is almost the same as that of the matrix. Between the first and second transition, the change in resistivity is very sharp, and a non-ohmic electric field dependence of current has been observed. Secondly, the electrical conduction property of the carbon black-filled polyethylene matrix composites below the percolation threshold is discussed with the hopping conduction model. This study investigates the electrical conduction property of the composites below the percolation threshold based on the frequency dependence of conductivity in the range of 20 Hz to 1 MHz. There are two components for the observed ac loss current. One is independent of frequency that becomes prevalent in low frequencies just below the percolation threshold and under a high electrical field. The other is proportional to the frequency of the applied ac voltage in high frequencies and its origin is not clear. These results support the conclusion that the electrical conduction mechanism below the percolation threshold is tunneling.

• 열처리공학회지
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• 제4권1호
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• pp.37-41
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• 1991

In this study, the effect of solution treatment temperature on the tensile property in intermediate thermo-mechanical treated Al-Li alloys are investigated. After the intermediate thermo-mechanical treated Al-Li, Al-Li-Mg and Al-Li-Mg-Zr alloys were solution treated at various temperatures (500, 520 and $540^{\circ}C$), these were aged at $190^{\circ}C$, $240^{\circ}C$ and tested tensile properties. The results obtained from the experiment are as follows ; 1) The optimum solution heat-treatment temperature is $540^{\circ}C$ for a Al-Li alloy, and the recrystallized grain size is about $70{\mu}m$. 2) The optimum solution heat-treatment temperature is $500^{\circ}C$ for a Al-Li-Mg alloy, and the recrystallized grain size is the most coarse in all alloys. 3) The tensile property is independent of the solution treatment temperature in a Al-Li-Mg-Zr alloy, and the recrystallized grain size is the finest owing to addition of Zr.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1123-1126
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• 1990

A new controller design algorithm based on the Hessenberg form for linear control systems has een proposed. The controller is composed of the dynamic compensator and the state feedback (dynamic state feedback). The algorithm gives a simple way to assign the eigenstructure (eigenvalues and eigenvectors) of the closed loop system and it also provides a method to assign the frequency shapes near the corner frequencies of the closed loop transfer function matrix. Because of this property, the algorithm is called the independent frequency shape control (IFSC) method.

• Journal of electromagnetic engineering and science
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• 제4권2호
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• pp.93-96
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• 2004

In this paper we introduce a new escalator(ESC) structure-based adaptation algorithm. The proposed algorithm is independent of eigenvalues spread ratio(ESR) of channel and has faster convergence speed than that of the conventional ESC algorithms. This algorithm combines the fast adaptation ability of least square methods and the orthogonalization property of the ESC structure. From the simulation results the proposed algorithm shows superior convergence speed and no slowing down of convergence speed when we increase the ESR of the channel.

• Korean Journal of Mathematics
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• 제27권1호
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• pp.17-51
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• 2019

In the paper we establish some new results depending on the comparative growth properties of composite entire and meromorphic functions using relative $_pL^*$-order, relative $_pL^*$-lower order and differential monomials, differential polynomials generated by one of the factors.

• 부동산연구
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• 제28권2호
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• pp.7-20
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• 2018

본 연구는 오피스 매매가격에 영향을 주는 결정요인에 대한 연구를 진행하였다. 그 중에서도 특히 부분매매가 미치는 영향에 대해 초점을 맞춰서 헤도닉 가격모형을 활용하여 실증분석을 실시하였다. 본 연구에는 2000년부터 2017년까지 서울에서 거래된 오피스 사례 1,171건이 분석에 이용되었다. 오피스 매매가격에 영향을 주는 요인을 분석하기 위해 거시경제변수, 입지특성변수, 자산특성변수, 거래특성변수, 거래시점변수로 독립변수를 구성하였다. 본 연구에 있어서 주요 관심사항인 부분매매에 대해서 분석결과를 살펴보면, 부분매매는 전체매매보다 약 156만원 정도 평당 매매가격이 할인 효과가 있는 것으로 나타났다. 할인율 측면에서는 전체매매에 비해 부분매매가 12.6% 할인되는 것으로 나타나 부분매매가 오피스 매매가격에 적지 않은 영향을 미치고 있는 것으로 밝혀졌다. 이는 집합건물의 경우 소유자가 재산권에 대한 행사와 유지관리에 따른 비용 배분 등 측면에서 단독소유보다 어려움을 겪고 있기 때문이라고 볼 수 있다. 본 연구 결과를 통해 향후 오피스 거래 특히 부분매매의 경우 거래 투명성 확보 및 리스크 관리 측면에서 일정부분 기여를 할 수 있을 것으로 기대된다.