• Structural Engineering and Mechanics
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• v.26 no.4
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• pp.459-477
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• 2007

A bi-directional tuned mass damper (BTMD) in which a mass connected by two translational springs and two viscous dampers in two orthogonal directions has been introduced to control coupled lateral and torsional vibrations of asymmetric building. An efficient control strategy has been presented in this context to control displacements as well as acceleration responses of asymmetric buildings having asymmetry in both plan and elevation. The building is idealized as a simplified 3D model with two translational and a rotational degrees of freedom for each floor. The principles of rigid body transformation have been incorporated to account for eccentricity between center of mass and center of rigidity. The effective and robust design of BTMD for controlling the vibrations in structures has been presented. The redundancy of optimum design has been checked. Non dominated sorting genetic algorithm (NSGA) has been used for tuning optimum stages and locations of BTMDs and its parameters for control of vibration of seismically excited buildings. The optimal locations have been observed to be reasonably compact and practically implementable.

• Journal of the Korean association of regional geographers
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• v.17 no.3
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• pp.259-269
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• 2011

The meaning of fengshui was another cultural ecological environment in the pre-modern in Korea. Village residents made interrelations with village natural environment by the medium of the geomantic landscape. The functions of cultural ecology through the village fengshui are as follows: the spatial location, the population inflow, the regulation of the community's production or construction or land-use, the adjustment of the environmental carrying capacity, the environmental management, the forming of the collective environmental perception and attitude. Village fengshui is a cultural adaptation strategy to the local environment for the village residents. Fengshui can be evaluated as a traditional cultural ecological way and knowledge system for keeping sustainable village environment in East Asia.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.109-114
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• 2009

The dominant heating system used in Korean residential apartment buildings is a hydronic radiant floor heating system, known as the Ondol system. The most common control strategy applied to this traditional hydronic radiant system is a simple on-off control that intermittently supplies "hot water of a fixed temperature" at a "constant flow rate" to each room. However, the current problems with the aforementioned control are as follows: (1) since the simple on-off control is usually based on a one point measured temperature (a signal from a thermostat installed in a living room) in each dwelling unit, heating energy use for unoccupied rooms as well as a difference in temperatures between spaces (master bedroom, living room, bedroom1, bedroom2) can occur occasionally. (2) the most widely used residential water splitter has static valves, and is thus not able to change the flow rate to each room depending on the space heating load. In other words, the ratio of flow rates to rooms is fixed after construction, resulting in over- or under-heating and an improper use of energy. The aim of this paper is therefore to investigate the differences in the system's performance between control strategies in terms of the flow rate control and sensor location. It is shown that energy savings of control strategies are strongly influenced by occupant schedule.

• Structural Engineering and Mechanics
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• v.52 no.1
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• pp.149-172
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• 2014

Four algorithms for damage detection of trusses are presented in this paper. These approaches can detect damage by using both complete and incomplete measurements. The suggested methods are based on the minimization of the difference between the measured and analytical static responses of structures. A non-linear constrained optimization problem is established to estimate the severity and location of damage. To reach the responses, the successive quadratic method is used. Based on the objective function, the stiffness matrix of the truss should be estimated and inverted in the optimization procedure. The differences of the proposed techniques are rooted in the strategy utilized for inverting the stiffness matrix of the damaged structure. Additionally, for separating the probable damaged members, a new formulation is proposed. This scheme is employed prior to the outset of the optimization process. Furthermore, a new tactic is presented to select the appropriate load pattern. To investigate the robustness and efficiency of the authors' method, several numerical tests are performed. Moreover, Monte Carlo simulation is carried out to assess the effect of noisy measurements on the estimated parameters.

• Journal of the Korea Society of Computer and Information
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• v.9 no.2
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• pp.149-160
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• 2004

The purpose of this research is to study the effect of service qualify improvement strategy and its practices on firms' competitive advantage, and identify their influence on customer satisfaction and loyalty. According to this purpose. this paper hypothesized that high service qualify will satisfy customers' needs and result in improved customers' loyalty. Thus, empirical study was conducted to identify the relationships among factors which were identified through literature review. Data were collected from the customers of 3 luxurious japanese restaurants in Seoul. The result of data analyses shows (1) Serve quality factors such as customer service, qualify of meal, location and facility, and types of restaurants make significant difference among three restaurants in terms of customers' perception about service quality; (2) There is statistically significant difference among three restaurants in terms of customers' satisfaction, but there is no significant difference among them in terms of customers' loyalty; and (3) Not only the result from analysis on japanese restaurants inside hotels but also that on the independent japanese restaurant in Kangnam area, shows that service quality factors have significant effect on both customers' satisfaction and loyalty.

• International Journal of Advanced Culture Technology
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• v.4 no.4
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• pp.81-86
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• 2016

In this paper, we propose a simple and effective vision-based tracking controller design for autonomous object tracking using multicopter. The multicopter based automatic tracking system usually unstable when the object moved so the tracking process can't define the object position location exactly that means when the object moves, the system can't track object suddenly along to the direction of objects movement. The system will always looking for the object from the first point or its home position. In this paper, PID control used to improve the stability of tracking system, so that the result object tracking became more stable than before, it can be seen from error of tracking. A computer vision and control strategy is applied to detect a diverse set of moving objects on Raspberry Pi based platform and Software defined PID controller design to control Yaw, Throttle, Pitch of the multicopter in real time. Finally based series of experiment results and concluded that the PID control make the tracking system become more stable in real time.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.721-728
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• 2011

This study investigates the users' perception of the importance and performance of National Recreation Forest Service Programs quality, forest environmental education and cultural benefits, with the aim of improving the level of service quality within the programs. An Important-Performance Analysis (IPA) was performed to determine significant patterns. The IPA results showed that most users' perceived as important how well the service programs performed to meet their expectations. The enclosed study finds, for example, users' answered that three factors which were less important to them were entrance fee, size of program center or facilities and amount of information. These factors performed poorly, and the program of guidance indicates the need for improvement of these factors. In addition, the finding also suggests how recreational service programs in the future can complement and improve what they offer. These are as follows. The process of preparation and content of the program order need to be effectively established. The Program Director needs to maintain a friendly attitude and must have ongoing training on how to provide effective programs. For programs to be enjoyable and satisfying for users, the location of the programs should provide a comfortable environment. Also, detailed program guidance is required for users' convenience. It is expected that the results of this study will be useful when ameliorating and establishing the marketing strategy of the National Recreation Forest Service Programs.

• Journal of the Korea Fashion and Costume Design Association
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• v.16 no.3
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• pp.117-133
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• 2014

The purpose of this study was to compare with shopping behavior and satisfaction of who have visited Dongdaemun and Myeongdong and to provide the fundamental data for differentiation strategy of two fashion trading area. The survey was carried out targeting shoppers who were in Dongdaemun and Myeoongdong and then a total of 778 questionnaires were used for the data analysis; frequency, t-test, chi-squre independence test using SPSS. 20. The results of this study were as follows. Main shoppers in Dongdaemun were the teenagers and twenties, and in Myeongdong were twenties and thirtys. The shoppers who have visited Dongdaemun significantly considered 'store factor' such as store size and comfortability, store interior, store location and accessibility, and 'product factor' including material and quality, design, formfitting, and various sizes, while Myeongdong visitors thought 'promotion factor'such as business hours, one stop shopping, sale and event etc. as important factor. The degree of satisfaction for marketing mix of Myeongdong trade area was higher than Dongdaemun's one. The case of impulse buying in two trade area was not high, while intention to revisit Dongdaemun and Myenongdong was all higher than average. Consumers were more intended to recommend Myeongdong over Dongdaemun to others.

• Transactions of the KSME C: Technology and Education
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• v.3 no.3
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• pp.209-215
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• 2015

The effects of the mounting location of ICI cables on severe accident mitigation systems, specially IVR-ERVC (In-Vessel Retention by External Reactor Vessel Cooling) and core catcher (Ex-vessel corium retention and cooling system), are investigated. The effects of bottom-mounted ICI strategy on severe accident mitigation are summarized and advantages of top-mounted ICI to improve severe accident mitigation are also highlighted.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.801-806
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• 2008

Large quantity of bending deformation as well as rotating torque fluctuation at the balance shaft are main struggles during the operation in a high speed rotation and thereby, two issues should be cleared at the design process of balance shaft module. Since two issues are highly related with balance shaft itself and particularly much sensitive to the location of both supporting bearing and unbalance mass, the design strategy on balance shaft should be investigated at the aspect of controlling two critical issues at the early stage of balance shaft design. To tackle two main problems, the formulation of objective function that minimizes critical issues, both bending deformation as well as torque fluctuation, is suggested to derive the optimal information on balance shaft. Then, optimal informations are reviewed at the practical logics and the guideline at the selection of locations, both supporting bearing and unbalance mass, is addressed at the final chapter.