• Journal of the Korean housing association
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• v.14 no.1
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• pp.77-86
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• 2003

The purpose of this study is to set up a model of affective evaluation to structurally and systematically analyse subjective affective expressions of human beings with regard to the residential environment and to analyse the correlation between affective responses of residents and physical elements by positively applying the model to the evaluation of outdoor space of apartment complexes as an area of study on evaluation of residential environment. The area for evaluation was limited to three apartment complexes situated in Daegu, and the subjects for evaluation were also limited to a group of residents(housewives) living at the three apartment complexes. The research method is summarized as follows. 214 affective words(adjective phrases) expressing outdoor space of apartments were selected from literature on random sampling basis, and reduced to 25 ones through factor analysis. Then, these 25 words were systematized by an affective evaluating scale with 7 categories of meaning. The evaluation was conducted with 324 homemakers living at the apartment complexes selected for evaluation from September 29, 2000 to October 5, 2000. SPSSWIN, a statistical program was used for analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1239-1242
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• 2006

Scintillation that is grainy patterns appeared on a screen has been one of a biggest issues in a rear projection TVs. In this paper, with focusing on the average size of random particle, it was proved that the particle size of calculated speckle and the one of measured scintillation are almost the equal. This result shows speckle phenomenon is an important factor of scintillation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1656-1660
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• 2006

Distributed coordination function(DCF) is the primary random access mechanism of IEEE 802.11, which is the basic protocol of wireless LAN based on the CSMA/CA protocol. It enables fast installation with minimal management and maintenance costs and is a very robust protocol for the best effort service in wireless medium. The current DCF, however, is known to be unsuitable for real-time applications such as voice message transmission. In this paper, we focus on the performance issues of IEEE 802.11 which accommodate the prioritized messages. Existing results use the initial window size and backoff window-increasing factor as tools to handle the priority of the messages. Instead, we introduce a novel scheme which chooses the backoff timer with arbitrary probabilities. By this, one can greatly reduce the backoff delay of the lower priority messages without degrading the performance of higher priority.

• Journal of KSNVE
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• v.8 no.5
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• pp.887-899
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• 1998

It has been resulted that Lagrange multiplier method with statistical approach was superior to traditional harmonic balance method in identifying the nonlinear loudspeaker parameters when output signals were contaminated with Gaussian random noise. We have known that the displacement-dependent characteristic values of nonlinear parameters identified by traditional harmonic balance method were estimated less than original values by the increase of output noise and the stiffness coefficients were very sensitive to output noise. Also, by the sensitivity analysis we have verified that the harmonic distortions in acoustic radiation was mainly due to nonlinearity of force factor caused by uneven magnetic fields and that reducing the nonlinearity of damping coefficients were very effective for improving second harmonic distrotion of acoustic radiation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.11
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• pp.1013-1020
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• 2007

In this paper, the predictions and measurements of sound transmission loss(STL) are discussed for various types of acoustical materials and carpets. Random incidence sound transmission losses are measured by the sound intensity method. The in-house software HONUS2005 is used to predict TL and estimate the various physical properties such as the flow resistivity, the structure factor, the porosity, the Possion's ratio, and etc. After this estimation, various multi-layered materials with a steel plate are measured and predicted. In particular, Carpets are assumed to be membranes to predict acoustical performance. To confirm this assumption, double and triple-layered cases are also observed including two different kinds of carpets.

• Structural Engineering and Mechanics
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• v.29 no.6
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• pp.603-622
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• 2008

This work deals with the design optimization of tuned mass damper (TMD) devices used for mitigating vibrations in high-rise towers subjected to seismic accelerations. A stochastic approach is developed and the excitation is represented by a stationary filtered stochastic process. The effectiveness of the vibration control strategy is evaluated by expressing the objective function as the reduction factor of the structural response in terms of displacement and absolute acceleration. The mechanical characteristics of the tuned mass damper represent the design variables. Analyses of sensitivities are carried out by varying the input and structural parameters in order to assess the efficiency of the TMD strategy. Variations between two different criteria are also evaluated.

• Journal of the Korean Society of Clothing and Textiles
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• v.2 no.2
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• pp.227-235
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• 1978

This study was designed to find out consumer's interest in garments label and to help home economists make interest for the further study in relation between producers and consumers as gap bridger. The questionnair method was used to obtained the data which was made by a result of self-administered questionnair. A size of random sample for this research was 364 subjects. The study found the following: (1) Most of consumers are relatively interested in garments label. The most concious age level was woman of fourty. (2) The most interest factor was label of size, price, fiber contents. brand name, directions and precautions on proper use and care. (3) The order of complaining item after washing was change of size, and color, seam pucker. deformation of collar. and button. (4) Most of consumers do not follow the direction when they clean their garments. (5) The respondents seem to be not understand the garment's informative label.

• Journal of Agricultural Extension & Community Development
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• v.13 no.2
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• pp.251-263
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• 2006

The purpose of this study was to analyze vocational competencies of rural youths. The study was carried out by focus group interview and questionnaire. The data were collected from 200 rural youths by stratified random sampling. The SPSSWIN / ver13 was used for analyzing data with t-test, ANOVA, and factor analysis. The major findings of this study were as follows; Firstly, rural youths showed higher competencies in handling and fixing machines, selecting seeds, where as rural youths showed lower competencies in goal setting, envisioning, acquiring agricultural policy information, management evaluation. Secondly, rural youths predicted optimistic future of their own farming even though the future of national farming should get smaller. Lastly, rural youths who are higher education, extending farming size, establishing farm had higher vocational competencies than other youths. Conclusionally, the study suggests adult-farmers give rural youths an opportunity to participate in decision making and farming.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.482-483
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• 2008

This paper compares particle swarm optimization techniques for PV allocation planning problem in power systems. PV allocation planning problem is formulated as a mixed-integer nonlinear problem. Five variants of PSO techniques are investigated for the applicability on the PV allocation problem. Namely, PSO with constant inertia weight approach (PSO-CIW), PSO with time varying inertia weight (PSO-TVIW), PSO with random inertia weight (PSO-RIW), PSO with constriction factor (PSO-CF) and PSO with time varying acceleration coefficients (PSO-TVAC).

• Transactions of the Korean Society of Mechanical Engineers
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• v.6 no.3
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• pp.204-210
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• 1982

The mechanical behaviors of an elastic body containing another materials are studied with the statistical method since they are generally distributed at random in size, orientation, and position. As the basis of this research, the size, the shape, and the ratio of volume for another material assumed to be constant, and only the positions of another material are changed randomly. The stress intensity factor, the compliance, and the modulus of elasticity are investigated in two-dimensional state by using the Monte Carlo Method and the Finite Element Method. The methodology of the simulation analysis for the mechanical behavior of such material is also proposed.