• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.597-600
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• 1997

In this paper, the authors propose a new method for linearizing a nonlinear dynamical system by use of polynomial compensation. In this method, an M-sequence is applied to the nonlinear system and the crosscorrelation function between the input and the output gives us every crosssections of Volterra kernels of the nonlinear system up to 3rd order. We construct a polynomial compensation function from comparison between lst order Volterra kernel and high order kernels. The polynomial compensation function is, in this case, of third order whose coefficients are variable depending on the amplitude of the input signal. Once we can get compensation function of nonlinear system, we can construct a linearization scheme of the nonlinear system. That is. the effect of second and third order Volterra kernels are subtracted from the output, thus we obtain a sort of linearized output. The authors applied this method to a saturation-type nonlinear system by simulation, and the results show good agreement with the theoretical considerations.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.443-445
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• 2002

In this paper, we present a novel efficient semaphore implementation scheme which diminishes completion time of high priority tasks and improves reliability of a system. The real-time system is constrained to complete their tasks in time. Especially, the task of a hard real-time system must meet its deadline under unfavorable conditions. In this paper, the number and sort of the locked semaphores, when an event occurred, decide whether the context switch should occur or not, so higher priority tasks diminish in their completion time. The experimental results show that the proposed method gives performance improvements in finish time of high priority tasks of about 11% over the Zuberi.

• 산업기술연구
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• 제10권
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• pp.83-88
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• 1990

The samples used for this work were low grade c1ay($Fe_2O_3$ : 2.90%, $TiO_2$ : 1.65%) produced from Youngsan-po district, and for the iron-bearing impurities removal having a bad influence on Kaoline sample was carried out column floatatoin using Oleic acid, Potassium oleat, Aero 840 promotor, Aero 870 promotor and Keroseneas collectors. For removal of the iron-vearing impurities from the kaoline, investigated first chemical composition size distribution of Kaoline sample, also performanced a basic study on pulp density, collector and pH change on a sort of frother. The flotation separation of impurities from kaoline can be achieved by using both oleic acid and Aero 840 promotor as collectors within narrow acid limits(pH 2-3). Pine oil was more effective frother than MIBC with olelic acid as aa collector.

• 한국가구학회지
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• 제29권1호
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• pp.8-17
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• 2018

Economic crisis in 2008 has changed South Korean market including furniture related field. Owing to Subprime Mortgage Crisis, new economic order, in other words, New Normal was established. Low growth rate, low interest, high unemployment rate, high risks, regulation strengthening, and all that sort of negative things have became generalized. South Korean economy has developed drastically since the Korean War, however recent economic crisis and Internet and smart phone have leading roles in shaping new consumption market. In a way, furniture market has expanded despite economic recession. Total service for housing is suited to South Korean consumers and shortened Product Life Cycle induces consumers to buy more furniture. In addition, Internet and smart phone allow people to show off their private spaces to unspecified masses. As a result, consumer prefers inexpensive and expendable furniture. It is certain that furniture market makes quantitative growth, but qualitative sides are questionable. Even though the study is focused on the existent circumstances, It will help to find out the proper ways of future furniture market in South Korea.

• 아동학회지
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• 제20권1호
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• pp.199-211
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• 1999

This study identified and explained the prototypes of belief systems about the kindergarten curriculum with the use of Stephenson's Q-methodology. The sample consisted of 15 preschool teachers and 15 college students majoring in early childhood education. A Q-deck composed of 48 cards was developed by the researchers and sorted by the subjects. The obtained Q-sort scores were analyzed by factor analysis. The findings revealed that the subjects were divided into 3 types: "the practical-disciplinary type" consisting of mostly of teachers, "the theoretical-openness type" consisting mostly of students, and "the compromising type" consisting of some teachers and some students.

• 한국응용과학기술학회지
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• 제32권2호
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• pp.320-325
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• 2015

Flow mark is a sort of surface defect on the composite that can arise during the filling stage of the injection molding process. The purpose of this study is to clarify a mechanism of the flow mark which appears on the surface of injection molded Polypropylene (PP) through the characterization of the surface structure. The materials used in this report are PP/rubber and PP/talc compounding, which are widely used in automobile part. The flow mark shows two different constitutions, such as a luster part and a cloud part on the surface of the injection molded PP. We have investigated the surface structure of PP/rubber and PP/talc composites by using scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDAX) and optical microscopy (OM). As a result, the cloud part contains higher contents of the rubber and talc compare to the luster part.

• International Journal of Knowledge Content Development & Technology
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• 제5권1호
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• pp.69-88
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• 2015

This study seeks to present an option for including a variety of information resources in a reference linking service system. Discussion on reference linking service in journals began in 1999 and applied to real systems, but linking to research papers and patent registers has more recently emerged. This study further suggests that system construction include various information resources such as books and dissertations. This paper also presents principles and prerequisites that should be considered essential when building such systems, including expansion of resources and media formats, development of identifiers on every sort of information resource, linking methods to existing DB, publication revolution and managing copyright-holders, use and improvement of OPACs, and building perfect authority DB.

• Steel and Composite Structures
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• 제27권1호
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• pp.35-48
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• 2018

In this paper, the response of a sandwich cylindrical shell over any sort of boundary conditions and under a general distributed static loading is investigated. The faces and the core are made of some isotropic materials. The faces are modeled as thin cylindrical shells obeying the Kirchhoff-Love assumptions. For the core material it is assumed to be thick and the in-plane stresses are negligible. The governing equations are derived using the principle of the stationary potential energy. Using harmonic differential quadrature method (HDQM) the equations are solved for deformation components. The obtained results primarily are compared against finite element results. Then, the effects of changing different parameters on the stress and displacement components of sandwich cylindrical shells are investigated.

• 대한수학회지
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• 제55권5호
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• pp.1257-1268
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• 2018

In this article we first investigate a sort of unit-IFP ring by which Antoine provides very useful information to ring theory in relation with the structure of coefficients of zero-dividing polynomials. Here we are concerned with the whole shape of units and nilpotent elements in such rings. Next we study the properties of unit-IFP rings through group actions of units on nonzero nilpotent elements. We prove that if R is a unit-IFP ring such that there are finite number of orbits under the left (resp., right) action of units on nonzero nilpotent elements, then R satisfies the descending chain condition for nil left (resp., right) ideals of R and the upper nilradical of R is nilpotent.

• Asian Journal of Innovation and Policy
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• 제4권3호
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• pp.360-380
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• 2015

Technological innovations, as the key to building competitive advantage, need a comprehensive review to address the issues related to transformation of the Indian industries. The present paper reports the broad findings of the first National Innovation Survey undertaken by the Department of Science and Technology, Government of India. The findings presented here highlight the status of innovation related activities in different industrial sectors, its weaknesses, and areas requiring institutional interventions. The survey results underline the fact that the innovation activities in Indian industries are more for survival in a competitive market conditions than to create market advantage. A sort of disconnect between the innovation support system and the production system is a discernible fact that surfaces from the study. The study also indicates certain characteristics of the innovation behaviour of firms that brings out developing country issues of innovation.