Development of Measurement System for the Safety Analysis of Moored Floating Matters
성유창 Yu Chang Seong , 곽재민 Jae Min Kwak
18(3) 201-208, 2014
성유창 Yu Chang Seong , 곽재민 Jae Min Kwak
DOI: JANT Vol.18(No.3) 201-208, 2014
Due to diversification of ships and limited space of pier, when ships come alongside the shallow water or narrow pier, sea area with small mooring facilities and floating matter is frequently applied. Through these, coming alongside the various space is capable and cost effectiveness is enhanced. However, when ships, applying small mooring facilities and floating matter, come alongside, there can be some impulse by waves between the floating things and ships which possibly leads to mass disaster. Therefore, there should be forecasts and analysis of the movement caused by waves. On this study, we develop measuring system for movement analysis of mooring and floating matters which provides base data with movement traits by measuring 3-D exercise information and acceleration at mokpo maritime university marina facility. Also, the composition and principles of the developed system is explained.
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Design and Implementation of the Memory Management Module of a Vehicle Black Box
박지상 Ji Sang Park , 전민호 Min Ho Jeon , 이명의 Myung Eui Lee
18(3) 209-214, 2014
박지상 Ji Sang Park , 전민호 Min Ho Jeon , 이명의 Myung Eui Lee
DOI: JANT Vol.18(No.3) 209-214, 2014
Current black boxes have a problem of storing unnecessary imagery data recordings without data classification. For this reason, users have to erase videos every time. This method is inadequate for black boxes with limited memory capacity. In this paper, we design and implement a system that recognizes traffic accident situations and saves these recordings by classifying them according to weighted values. The system was made to save video recorded at a 30-sec interval of every event to black box folders by changing names based on weighted value data under the external environment in a 1:10 scale model car. Based on this, when the tests were performed as a major car accident while driving, the videos were created in w2 folder, and when the tests were performed as a minor car accident while stopped, the videos were created in w1 folder.
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Design of Trajectory Following Controller for Parafoil Airdrop System
양빈 Bin Yang , 최선영 Sun Young Choi , 이정태 Joung Tae Lee , 임동근 Dong Keun Lim , 황정원 Chung Won Hwang , 박승엽 Seung Yub Park
18(3) 215-222, 2014
양빈 Bin Yang , 최선영 Sun Young Choi , 이정태 Joung Tae Lee , 임동근 Dong Keun Lim , 황정원 Chung Won Hwang , 박승엽 Seung Yub Park
DOI: JANT Vol.18(No.3) 215-222, 2014
In this paper, parafoil airdrop system has been designed and analyzed. 6-degrees of freedom (6-DOF) model of the parafoil system is set up. Nonlinear model predictive control (NMPC) and Proportion integration differentiation (PID) methods were separately applied to adjust the flap yaw angle. Compared the results of setting time and overshoot time of yaw angle, it is found that the of yaw angle is more stable by using PID method. Then, trajectory following controller was designed based on the simulation results of trajectory following effects, which was carried out by using MATLAB. The lateral offset error of parafoil trajectory can be eliminated by its lateral deviation control. The later offset deviation reference was obtained by the interpolation of the current planning path. Moreover, using the designed trajectory, the trajectory following system was simulated by adding the wind disturbances. It is found that the simulation result is highly agreed with the designed trajectory, which means that wind disturbances have been eliminated with the change of yaw angle controlled by PID method.
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A Study on the Channel Capacity Simulator of Wireless Communication System
노재성 Jae Sung Roh , 김완태 Wan Tae Kim
18(3) 223-228, 2014
노재성 Jae Sung Roh , 김완태 Wan Tae Kim
DOI: JANT Vol.18(No.3) 223-228, 2014
Recently mobile communication systems have supported various multimedia services based on wideband code division multiple access (WCDMA). In November 2013, the statistics reported that the domestic subscriber number of mobile communication systems was totally 54 million 514 thousand 397 in using feature phones and smart phones. Therefore, the user number of mobile communication services has surpassed over 4 million rather than the whole number of population. The sharp increase of the mobile user number has made the network management and analysis for mobile communication services more important than before. Besides, the service quality has been studied in various ways. This paper has implemented the simulator calculating the channel capacity of mobile communication systems to support secure and stable services for both feature phones on CDMA and smart phones on WCDMA. By using the simulator, this paper has analyzed the characteristics of the various channel capacity in mobile communication environments.
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High Efficiency Power Amplifier using Analog Predistorter
최장헌 Jang Hun Choi , 김영 Young Kim , 윤영철 Young Chul Yoon
18(3) 229-235, 2014
최장헌 Jang Hun Choi , 김영 Young Kim , 윤영철 Young Chul Yoon
DOI: JANT Vol.18(No.3) 229-235, 2014
This paper presents the Doherty power amplifier with a digitally controlled analog predistorter circuit of Scintera Corp. to produce high power efficiency and high linearity performance. The analog predistorter improves the linearity performance because of controlling amplitude and phase values of input signal in order to improve intermodulation performance of power amplifier. Also, the power amplifier is designed by the Doherty technology to obtain the high efficiency performance. To validate the Scintera`s analog predistorter, we are implemented the power amplifier with Doherty method at center frequency 2150 MHz. Compared with the balanced amplifier, the power amplifier is improved above 11% enhanced efficiency and more than 15 dB ACPR improvement.
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Multipath Routing Protocol based on Multi-Rate Transmission in Mobile Ad Hoc Networks
이강건 Kang Gun Lee , 박형근 Hyung Kun Park
18(3) 236-241, 2014
이강건 Kang Gun Lee , 박형근 Hyung Kun Park
DOI: JANT Vol.18(No.3) 236-241, 2014
In a mobile ad hoc networks, multi-hop transmission is used to transfer data from source node to destination node and the routing protocol is the one of the important technical issues. The links between nodes can be unstable due to the changes of node location and channel conditions, and it can induce link error. To solve this problem, multipath routing was proposed. Multipath routing can reduce the data congestion and increase data throughput. In the multipath routing, however, each path can be interfered by the other path, and it can aggravate network performance. In this paper, we propose the multipath routing technique in the multi-rate MANET. The proposed multipath routing can avoid interference without the knowledge of node location. Simulation results show that the proposed multipath routing can reduce transmission delay and error.
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Prospect of Non-Touch User Interface Technique
김수균 Soo Kyun Kim , 성경 Kyung Sung
18(3) 242-247, 2014
김수균 Soo Kyun Kim , 성경 Kyung Sung
DOI: JANT Vol.18(No.3) 242-247, 2014
The advancement of touch user interface technology is mostly due to the debut and success of the new user experience (UX), the iPhone. The introduction of Apple`s iPhone especially made possible for the user experience to break away from the traditional input device of the mouse and keyboard. It is advancing from the current 3rd generation touch interface technology into the 4th generation non-touch user interface technology. This paper will present a non-touch interaction technology that allows interaction in a three dimensional setting through 3-D space touch. It will analyze current technologies and future emerging technologies.
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A Study on the Multi Servo Press System Development of Low Velocity Using Serial Communication
유환신 Hwan Shin Yu , 박형배 Hyung Bae Park
18(3) 248-253, 2014
유환신 Hwan Shin Yu , 박형배 Hyung Bae Park
DOI: JANT Vol.18(No.3) 248-253, 2014
In this paper, press and nut runner used in press-fit or tightening the bolts and nuts at assembling process of automobile parts companies continually demand accuracy and improved productivity. Simultaneous control of production systems through synchronization configuring of the combination multi press-fit system developed multi servo press system using the low-speed serial communication. As a result, the accuracy and the productivity is improved and product quality improvement could be achieved.
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A Study on the Drum Water Level Versus Incoming Water Quantities for Small Vertical Hydraulic Water Turbine Plant
최규식 Gyu Shik Choi , 정주원 Ju One Jung
18(3) 254-260, 2014
최규식 Gyu Shik Choi , 정주원 Ju One Jung
DOI: JANT Vol.18(No.3) 254-260, 2014
We studied water level rising of drum versus time in the small hydraulic vertical water turbine system in this paper. The water level rises continuously up to a certain point with the passage of time if the constant incoming water is supplied, while it stops rising and maintains equilibrium state without any more rising because it increases position energy and evatually makes outgoing velocity and outgoing water quantities of runner area. The water level of drum is determined independent of size, height, width, figure of drum or runner configuration. It comes out that the water level is dependent only on the incoming and outgoing water quantities, and the output power has similar behavior. Therefore, desirable water level and output power are not available unless incoming water quantities is abundant. We validate this phenomina through applyng our methodolgies to the real small hydraulic vertical water turbine system under constructing and testing in industrial facilities in Korea
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