• Journal of the Korean housing association
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• v.13 no.6
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• pp.101-110
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• 2002

The purpose of this study was to examine needs of residents on the storage according to unit size in apartment. In order to achieve our goal, the questionnaire survey was used. We sampled the questionnaire surveys of 250 households in Seoul whose apartment sizes had been more than 20 pyung. The data collected by the questionnaire survey was analyzed by examining the frequency, percentage on the SPSS/PC+. The results of the study were obtained as follows: 1) In research on the actual storage condition, Residents tended to feel constraint on the storage of the season goods and the storage satisfaction on the service area was found lowest. Therefore, there needed to design the balcony more efficiently for the storage and the interior storage for the season goods. 2) In research on consciousness and attitude about the storage, residents tended to keep the goods of no use and prefered to arrange neatly rather than use conveniently. Therefore, there needed more efficient space in the balcony for the storage of the goods of no use and the closed furniture rather than the open furniture was suited for arrangement. 3) In research on the storage needs, needs for the built-in furniture in all apartment sizes showed highly and residents wanted a space for the exclusive use of the storage. In a solution, it was proposed to equip with the interior storage and the exterior cooperative storage. In the conclusion, needs of residents on the storage according to apartment size were different little. The small size apartment had the serious storage problems and wanted the efficient space plan for storage.

• Korean Journal of Social Welfare
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• v.61 no.4
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• pp.137-161
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• 2009

In an effort to identify predictors of job performance, research studies in social work administration has been so far on the individual practitioners' levels of knowledge and skills, which could be used in a workplace. As the theoretical concept of organizational environment was fully introduced into social work administration research, however, studies on practitioners' job performance began to have interest in the team or the organizational level variables as well as individual level variables. Along the course of this tendency, this study attempted to test the effect of individual, team, and organizational level variables on the job performance of human service workers. The individual level variables consisted of knowledge, skills, job satisfaction, personality, and counter-productive work behaviors of workers. The team or the organizational level variables included situational constraint, organizational justice, job characteristics, government-dependency, and inter-organizational cooperation. Multi-level complex survey data collected by cluster sampling method from 314 practitioners in 23 organizations were analyzed using Hierarchial Linear Model. Results showed that both task and contextual performance were affected by individual, team, and organizational level variables in various ways.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.11
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• pp.973-982
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• 2007

In this paper, optimal design framework is developed by automatic mesh generation and PSO(Particle Swarm Optimization) algorithm based on parallel computing environment and applied to structural optimal design of satellite adapter module. By applying automatic mesh generation, it became possible to change the structural shape of adapter module. PSO algorithm was merged with parallel computing environment and for maximizing a computing performance, asynchronous PSO algorithm was developed and could reduce the computing time of optimization process. As constraint conditions, eigen-frequency and maximum stress was considered. Finally using optimal design framework, weight reduction of satellite adapter module is derived with satisfaction of structural safety.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1759-1771
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• 1994

We proposed the iterative image restoration method based on the method of steepest descent with a regularization constraint for restoring the noisy motion-blurred images. The conventional method proposed by Jan Biemond et al, had drawback to amplify the additive noise and make ringing effects in the restored images by determining the value of regularization parameter experimentally from the degraded image to be restored without considering local information of the restored one. The method we proposed had a merit to suppress the noise amplification and restoration error by using the regularization parameter which estimate the value of it adaptively from each pixels of the image being restored in order to reduce the noise amplification and ringing effects efficiently. Also we proposed the termination rule to stop the iteration automatically when restored results approach into or diverse from the original solution in satisfaction. Through the experiments, proposed method showed better result not only in a MSE of 196 and 453 but also in the suppression of the noise amplification in the flat region compared with those proposed by Jan Biemond et al. of which MSE of 216 and 467 respectively when we used 'Lean' and 'Jaguar' images as original images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1113-1118
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• 2012

Smart grid and intelligent transportation system draw significant interest since they are considered as one of the green technologies. These systems require a large number of sensors, actuators, and controllers. Also, machine-to-machine (M2M) communications is important because of the automatic control. The LTE-Advanced networks is preparing a set of functions that facilitate the M2M communications, and particularly the development of an efficient call admission control mechanism is critical. A method that groups MTC devices according to QoS constraints and determines the admission depending on the QoS satisfaction is limitedly applied only if the data transmission period and the maximum delay are identical. This paper proposed a call admission control that is free from such limitation and also optimizes the admission process under the certain condition of the transmission period and maximum delay. The theorems regarding the proposed method are presented with the proofs. The simulations confirms its validity and shows it is better in call admission probability than existing works.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.3
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• pp.53-60
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• 1998

In this paper, we proposed a set of ANSI-Korean character patterns for handwriting recognition that can be used as an input method of mobile computers like PDA (Personal Digital Assistant). In the case of bilinguals, two kinds of alphabets are written alternatively So the method of input character mode change must be provided, and this cause discomfort of writing. Our proposed written character patterns have some constraint but permit ANSI-Korean mixed writing without mode change keeping original form of alphabets and can be recognized with simple algorithm relatively. For ANSI character we analysis Graffiti and propose new writing pattern, which is more similar to original form. There are many researches about input method of unpacking Korean character and writing patterns. But they are not widely used because it's excessively contrary to original form of Korean characters. To show our proposed writing patterns usefulness, we studied the satisfaction and easiness of writing and the recognition rates. Writers are divided into two groups; PDA users, familiar to Graffiti, and others. The results satisfy usefulness in the both groups.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.648-658
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• 2018

Regarding the fact that wind power forecast accuracy is gradually improved as time is approaching, this paper proposes a two-stage rolling dispatch approach based on model predictive control (MPC), which contains an intra-day rolling optimal scheme and a real-time rolling base point tracing scheme. The scheduled output of the intra-day rolling scheme is set as the reference output, and the real-time rolling scheme is based on MPC which includes the leading rolling optimization and lagging feedback correction strategy. On the basis of the latest measured thermal unit output feedback, the closed-loop optimization is formed to correct the power deviation timely, making the unit output smoother, thus reducing the costs of power adjustment and promoting wind power accommodation. We adopt chance constraint to describe forecasts uncertainty. Then for reflecting the increasing prediction precision as well as the power dispatcher's rising expected satisfaction degree with reliable system operation, we set the confidence level of reserve constraints at different timescales as the incremental vector. The expectation of up/down reserve shortage is proposed to assess the adequacy of the upward/downward reserve. The studies executed on the modified IEEE RTS system demonstrate the effectiveness of the proposed approach.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1691-1696
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• 2010

The efforts of reflecting the system's uncertainties in design step have been made and robust optimization or reliabilitybased design optimization are examples of the most famous methodologies. The statistical moments of a performance function and the constraints corresponding to probability conditions are involved in the formulation of these methodologies. Therefore, it is essential to effectively and accurately calculate them. The sensitivities of these methodologies have to be determined when nonlinear programming is utilized during the optimization process. The sensitivity of statistical moments and probability constraints is expressed in the integral form and limited to the normal random variable; we aim to expand the sensitivity formulation to nonnormal variables. Additional functional calculation will not be required when statistical moments and failure or satisfaction probabilities are already obtained at a design point. On the other hand, the accuracy of the sensitivity results could be worse than that of the moments because the target function is expressed as a product of the performance function and the explicit functions derived from probability density functions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11A
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• pp.1113-1119
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• 2006

For a multi-user OFDM system in mobile channels which requires low-complexity in adaptive resource allocations, resource allocation algorithm using multi-threshold is proposed. The allocation scheme, which is performed by the multi-threshold values in descending order, considers only subcarriers over each threshold level. Moreover, some subcarriers with the lowest channel gain can be· removed in the present threshold level within the constraint of satisfaction of the required data rate, in order to allocate them to the other users when the allocation process of next threshold is executed. As a result, the proposed bandwidth and subcarrier algorithm has better system performances than the conventional allocation schemes in terms of required power and processing time, which is expected as a technique that improves the spectral efficiency of OFDM systems in a mobile environment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.78-83
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• 2004

Currently used DLC(Direct Load Control) algorithm is only focused on ON/OFF load control not concerning about reliving participated customer's inconvenience and load priority. Therefore, that is a major obstacle to attract customer participating in demand response program. To overcome the above defects, the authors represent direct load control algorithm using priority based dynamic programming. the proposed algorithm is that participant customer send E-mail to DLC center about priority of load before executing DLC, then DLC algorithm decide which load to be OFF by using priority and off time constraint of the load. By using dynamic programming based on the order of priority for DLC algorithm it is possible to maximize participating customer's satisfaction and it will help to attract more customer's participating in demand response program.