• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.127-134
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• 2012

Four river project in the South Korea contributes to solve flood damages and water shortages. Also, it has purpose for creating water ecosystem and improving the level of people' cultural leisure and quality of life through inducing water quality improvement and river restoration. It is necessary to monitor a variety of observing data in river areas among dozens to hundreds of kilometer for safe river administration. The 20th construction area of the four river project is located on Hapcheon areas, where wireless mesh network was installed to manage the basin. In the process of network construction, the characteristic of surrounding areas is considered about embodying secure service by investing the least expense. Besides, transmission environment analysis is performed such as LOS tests and reception level analysis, and transmission speed measurement to create safe service. Reception level in all places is confirmed among -55 dBm ~ -70 dBm, and data transmission speed proves more than 20 Mbps.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1581-1586
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• 2016

In this paper, we propose a central disaster monitoring system of the forest fire. This system provides the safe-zone and detection to reduce the suppression efforts. In existing system, it has a few providing the predicting of wildfire spread model and speed through topography, weather, fuel factor. This paper focus on the forest fire diffusion model and predictions of the path identified to ensure the safe zone. Also we have considering the forest fire of moving direction and speed for fire suppression and monitering. The proposed algorithm could provide the technique to analyze the attribute information that temperature, wind, smoke measured over time. This proposed central observing monitoring system could provide the moving direction of spred out forecast wildfire. This observing and monitering system analyze and simulation for the moving speed and direction forest fire, it could be able to predict and training the forest fire fighters in a given environment.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.113-123
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• 2000

In the navigation for a mobile robot, the collision avoidance with unexpected obstacles is essential for the safe navigation and it is independent of the technique used to control the mobile robot. This paper presents a new collision avoidance algorithm using neural network for the safe navigation of the autonomous mobile robot equipped with CAN and ultrasonic sensors. A tracked wheeled mobile robot has a stability and an efficiency to move on a rough ground. And its mechanism is simple. However it has difficulties to recognize its surroundings. Because the shape of the tracked wheeled mobile robot is a square type, sensor modules are generally located on the each plane surface of 4 sides only. In this paper, the algorithm using neural network is proposed in order to avoid unexpected obstacles. The important character of the proposed algorithm is to be able to detect the distance and the angle of inclination of obstacles. Only using datum of the distance and the angle, informations about the location and shape of obstacles are obtained, and then the driving direction is changed. Consequently, this algorithm is capable of real time processing and available for a mobile robot which has few sensor modules or the limited sensing range such as a tracked wheeled mobile robot. Effectiveness of the proposed algorithm is illustrated through a computer simulation and an experiment using a real robot.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.1 s.20
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• pp.15-22
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• 2004

The navigation area approach to Mokpo port consists of narrow channels with 30mile section, and the route is crossed with many fairways. In particular, fairway routeing except Mokpogu is not assigned and there are many threatening factors against the safe operation of vessel because fishing and mining areas are designated. Therefore, this paper proposed elements for safe passage through a marine traffic environmental assessment with the analysis of surrounding environment, dangerous elements, traffic survey and marine casualty.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.1
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• pp.9-18
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• 2010

Our country has so large mountain area that the tunnel construction is inevitable and the need of incident detection that provides safe management of tunnels is increasing. In this paper, we suggest a tunnel incident detection system using computer vision techniques, which can detect the incidents in a tunnel and provides the information to the tunnel administrative office in order to help safe tunnel operation. The suggested system enhances the processing speed by using simple processing algorithm such as image subtraction, and ensures the accuracy of the system by focused on the incident detection itself rather than its classification. The system is also cost effective because the video data from 4 cameras can be simultaneously analyzed in a single PC-based system. Our system can be easily extended because the PC-based analyzer can be increased according to the number of cameras in a tunnel. Also our web-based structure is useful to connect the other remotely located tunnel incident systems to obtain interoperability between tunnels. Through the experiments the system has successfully detected the incidents in real time including dropped luggage, stoped car, traffic congestion, man walker or bicycle, smoke or fire, reverse driving, etc.

• Journal of Agricultural Extension & Community Development
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• v.10 no.2
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• pp.181-192
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• 2003

With emphasis on environmentally safe and sustainable and economically sound and oriented to consumer, this study intends to assess the consumer's cognition and attitudes for safe food distribution, to investigate the supplying system of the organic farm products, to survey the consumer and life cooperatives dealing with organic farm products, and to draw some implications toward environment- and consumer-oriented agriculture. Related literatures and available documents were reviewed to conceptualize the environmental-and consumer-oriented agriculture and consumer and life cooperatives, to grasp the nationwide status of such alternative agriculture and consumer cooperatives, and investigate the consumers' cognition and attitude. In order to investigate the consumers' needs for organic farm products and to grasp the active consumer and life cooperatives dealing with organic farm products, questionnaire method and non-structured interview were applied. The environment-and consumer-oriented agriculture refers hero to the farming system in which any farm food and other living products giving no harm to human and livestock health and catering the consumers' need. The consumer and life cooperatives is consumer's group buying and selling organic farm products organized in the cooperative system with which any consumer can be affiliated to buy organic farm products safely and reasonably.

• Korean Journal of Health Education and Promotion
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• v.30 no.5
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• pp.113-124
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• 2013

Objectives: The objective of this study was developing a community-based HIV prevention program to enhance the safe sexual behavior among rural Ethiopian female youth. Methods: A community-based HIV prevention program was developed using the Cox's Interaction Model of Client Health Behavior. The program development was carried out in four phases using a mixed research method: need-assessment which consisted of three steps (secondary-data analysis, key-informant interview, and focused-group interview); identification of preliminary program contents; expert's review of the program contents for the validity and cultural acceptability of the program; and refinement of the proposed program contents. Results: The HIV prevention program developed in this study consisted of three modules; the first module was for enhancing the youth's self-esteem, the second was for providing the youth with information regarding HIV/AIDS and safe sexual behavior, and the third was for improving the youth's communication skills and refusing skills. Conclusions: The need assessment and expert's review was very effective way to reflect sociocultural factors of rural Ethiopia for developing HIV prevention program for female youth. Further research is desirable for verifying the effectiveness of the developedprogram.

• Journal of the Korean Institute of Navigation
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• v.10 no.2
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• pp.97-114
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• 1986

Ship's maneuverability is very important factor in safe ship handling and economical ship operation. Steering characteristics are consisted of course stability and maneuverability. Today in many advanced ship-building countries, they study ship's course stability, using model ship tests, such as straight line tests, rotating arm tests and Planar Motion Mechanism (PMM) etc., in tow in tanks. It is the purpose of this paper to provide ship's handlers with better understanding of steering characteristics and to help them in safe controlling and manevering . In this paper, the author simulated response of various vessels, running straight course with constant speed, and they are disturbed by small external disturbance of one degree yaw angle with no angular velocity . The author used the hydrodynamic derivtives resulted at tests of Davidson's laboratory in Stevens Institute of Technology, New Jersey, U.S.A. Course stability was evaluated and analyzed in various respects, such as block coefficient, ratio of ship's length to beam, draft and rudder area ratio etc. The obtained results are as follows : (1) The ship's course stability is affected by magnitude of block coefficient greatly. In case that the block coefficient is more than 0.7, the deviation varies at nearly same rate but the requistite time to reach the steady course is different. (2) The ship's course stability is affected by magnitude of L/B. When the dimensionless time reaches about 3, the deviation and requisite time to reach the steady course are influenced nearly same. After the dimensionless time is about 3, they change on invariable ratio. (3) The effect to course stability by L/T and RA' can be neglected. (4) The reason why thy VLCC and container feeder vessel are unstable on their course is that their block coefficient is generally more than 0.8 and the ratio of ship's length to beam is about 6.0.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.1
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• pp.1-10
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• 2017

Various offshore structures such as FPSO, FSO, Semi-submersible, TLP and Spar are operated to develop offshore oil and gas fields. Most of the offshore structures shall be operated over 20 years under the harsh environments at sites so that the offshore structures should be designed to endure the harsh environments. In this study, the effect of the impact load (so called slapping load) by the steep waves acting on the FPSO bow is investigated through the model test. For measurement of the impact pressures on the frontal area, a bow-shaped panel was fabricated, and installed the pressure sensors on the bow starboard side of the model FPSO. During the model test campaign, the impact load was investigated using the steep waves with $Hs/{\lambda}$ greater than 1/16 of the representative wave condition. Consequently, it is confirmed through the model test that the impact loads acting on the FPSO bow are significantly increased with the steep waves ($Hs/{\lambda}$ > 1/16) than the representative wave conditions of a maximum significant wave height and a pitch forcing period. Therefore, for safe design of North Sea FPSO, it is necessary to consider the steep waves in addition to the representative wave conditions and to be applied as proper structural load. Also, the effect of random seeds in irregular waves should be considered to build the safe FPSO.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.513-520
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• 2004

A steady-state/transient performance simulation model was newly developed for the propulsion system of the CRW (Canard Rotor Wing) type UAV (Unmanned Aerial Vehicle) during flight mode transition. The CRW type UAV has a new concept RPV (Remotely Piloted Vehicle) which can fly at two flight modes such as the take-off/landing and low speed forward flight mode using the rotary wing driven by engine bypass exhaust gas and the high speed forward flight mode using the stopped wing and main engine thrust. The propulsion system of the CRW type UAV consists of the main engine system and the duct system. The flight vehicle may generally select a proper type and specific engine with acceptable thrust level to meet the flight mission in the propulsion system design phase. In this study, a turbojet engine with one spool was selected by decision of the vehicle system designer, and the duct system is composed of main duct, rotor duct, master valve, rotor tip-jet nozzles, and variable area main nozzle. In order to establish the safe flight mode transition region of the propulsion system, steady-state and transient performance simulation should be needed. Using this simulation model, the optimal fuel flow schedules were obtained to keep the proper surge margin and the turbine inlet temperature limitation through steady-state and transient performance estimation. Furthermore, these analysis results will be used to the control optimization of the propulsion system, later. In the transient performance model, ICV (Inter-Component Volume) model was used. The performance analysis using the developed models was performed at various flight conditions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the turbine inlet temperature overshoot limitation as well as the compressor surge margin. Because the engine performance simulation results without the duct system were well agreed with the engine manufacturer's data and the analysis results using a commercial program, it was confirmed that the validity of the proposed performance model was verified. However, the propulsion system performance model including the duct system will be compared with experimental measuring data, later.