• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.785-787
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• 2005

In the Bluetooth specification version 1.0, one specific frequency in one piconet was created depending upon the device clock and the Bluetooth native address at one specific time slot in the frequency hopping method. The basic hopping pattern was arranging the 79 ISM frequency band in pseudo-random fashion. Possible problem is the chance of collision of ownership of one specific frequency by more than 2 wireless devices when they are within the communication-active range. In this paper, we propose the adaptive frequency hopping method in order to resolve the possible problem so that more than 2 wireless devices communicates with their own client devices without being interfered. The proposed method was implemented with HDL later to be synthesized with an automatic EDA synthesizer and verified as well. The implemented adaptive frequency hopping circuit operated normally at 24MHz which will be the target clock frequency of the target Bluetooth device.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.918-925
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• 2004

SCM means that production companies set up schedules for the purchase, manufacture and sales of production parts, go on smoothly the flow of products (added value and material flow) by systematically arranging the demand plans of customers and the distribution situation, thereby executing the management of them in an effective way. This article aims at analyzing the external flow between government and companies and presenting the problems and the improvement plans, which can make clear all the information flow of supply networks including the internal integration.

• Journal of Sensor Science and Technology
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• v.14 no.2
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• pp.101-108
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• 2005

The research on the avoidance of the large-obstacles such as a wall, a large box, etc. using ultrasonic sensors has been generally progressed up to now. But the mobile robot could meet a small-obstacle such as a small plastic bottle, a small sphere, and so on in its designated path, and could be disturbed by them in the locomotion of the mobile robot. So, it is necessary to research on the avoidance of a small-obstacle. In this paper, a robot's small-obstacle perceiving system was designed and fabricated by arranging four ultrasonic sensors on the plastic plate to avoid small-obstacles. The system was installed on the upper part of the mobile robot with the slope angles between $40.7^{\circ}$ and $23.3^{\circ}$ to a horizontal line and the dynamic characteristic test of the robot was performed. As the result, it was confirmed that the mobile robot with the system could avoid small-obstacles in indoor environment safely.

• Journal of the Korean Institute of Rural Architecture
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• v.6 no.3
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• pp.87-95
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• 2004

At the beginning of 1990s, in the on of ways improving tyong he structure of comunity in the agri cultural country. A creation of Munhwa-Maule has been begun. It has been performed for Center village of Munhwa-Maule, and worked in order to improve the creation budiness for Munhwa-Maule was starte d for the qualitative rasing of the people life in the agricultural zone. Through this study : utilization of residence between a farming family and a non-farmig family, I made an analysis about problem with finding out the whole of the village, but the condition of using house com es to the end. I use a lot of studies be lasted in many ways about estimation and craft arranging village after moving into the Munhwa-Maule.

• Proceedings of the Korean Sanitation Conference
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• 2005.12a
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• pp.50-63
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• 2005

Cheap, low quality food products that are unhealthy are prevailing among children. These low quality products are stirring up the urge to purchase among children and so it is pointed out as a problem. In order to arrive at a solution for the indication of negligence on the side of manufacturing, processing, circulation, and marketing management, a survey asking about interests and preferences on insanitary food products was held during May 2, 2005 to June 30. The subjects were 540 students and 510 parents form 5 elementary schools located at Gwangjin Gu, Seoul including Ja-yang elementary school, etc. This study aims at arranging measures against insanitary food products and contribution to maintenance of children's health.

• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.63-66
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• 2002

The Flow patterns around two cylinders in various arrangements were studied by a discrete vortex method. The flow for the surface of each cylinder was represented by arranging bound vortices at adequate intervals. The viscous diffusion of fluid was represented by the random walk method. The vortex distributions, streaklines, timelines and velocity vectors around two cylinders were calculated for centre-to-centre pitch rations of P/D=1.5 and 2.5, attack angles of $\alpha=0^{\circ},\;30^{\circ},\;60^{\circ},\;and\;90^{\circ}$, correspond to the photographs by flow visualization and the flow intereference between two cylinders in var ious arrangements was clearly visualized by a numerical simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.10a
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• pp.5-18
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• 1993

This paper reports the recent trends in active vibration control in Japan, especially, based on papers selected in the Proceedings of First International Conference on Motion and Vibration Control (1st MOVIC) held at Yokohama, Japan on Sept.7-11, 1992. Firstly, it classifiers vibration control methods and vibration controllers, especially active dynamic absorbers which are widely used in mechanical and civil engineering. Secondly, it covers basic problems in the control of vibration of flexible structures such as formulating a reduced-order model required for designing vibration controller, proper arranging of sensors and actuators, and preventing of spillover instability. Finally, the practical use of control theories such as LQ control theory, $H^{\infty}$ control theory, neural network theory, and other topics are discussed..

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.6-7
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• 2019

Asbestos has been widely used for construction materials due to its sound absorption and insulation properties. Despite the announcement that asbestos may cause cancer, asbestos demolition work has become more active. Asbestos was scattered by demolition work and the government started to regulate it. This study was started to predict the scattering asbestos concentration according to the research that it can cause cancer even if the concentration of asbestos meets legal standards. Therefore, in this paper, a regression analysis was conducted to derive a predictive equation after collecting and arranging the variables affecting scattering asbestos. As well as, artificial neural network analysis was used to make a more suitable prediction model.

• Steel and Composite Structures
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• v.18 no.2
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• pp.467-480
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• 2015

The steel-concrete composite decks have high fatigue durability and deformability in comparison with ordinary RC slabs. Withal, the steel-concrete composite deck is mostly heavier than the RC slabs. We have proposed herein a new type of steel-concrete composite deck which is lighter than the typical steel-concrete composite decks. This can be achieved by arranging hollow sectional members as shear connectors, namely, half-pipe or channel shear connectors. The present study aims to experimentally investigate mechanical characteristics of the half-pipe shear connectors under the direct shear force. The shear bond capacity and deformability of the half-pipe shear connectors are strongly affected by the thickness-to-diameter ratio. Additionally, the shear strengths of the hollow shear connectors (i.e. the half-pipe and the channel shear connectors) are compared. Furthermore, shear capacities of the hollow shear connectors equivalent to headed stud connectors are also discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.63-73
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• 1996

With the success of flexible manufacturing systems (FMSs), flexible assembly systems (FASs) have been developed to automate factories further. As in a cellular FMS, a cellular FAS is considered as the most flexible and feasible assembly system configuration Because of the differences between manufacturing and assembly operation, the logic of cell formation and cell layout between a FMS and a FAS is not the same. Since the time for assembly operation is usually relatively short, the transfer time is thus very crucial for the performance of assembly systems. Therefore in assembly systems it is important to reduce the transfer time by sequencing operations efficiently and arranging machines like the sequences. The network-type layout is not only feasible for the machine arrangement based on operation sequences, but it has also layout flexibility. Therefore it is a reasonable layout configuration for cellular FASs. This paper presents a method for the cell layout based on the network-type layout in a cellular FAS design.