• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.5
• /
• pp.55-66
• /
• 2010

As people's living standards and expectations for life increase, by applying advanced technology in the city, to enhance the convenience and safety needs are being expanded gradually. Accordingly, so the future of the city to see a viable alternative to that the ubiquitous city fused information communication technologies, large-scale projects conducted at the national level. Sectoral Disaster Prevention is ready for sure how much the lack of response capabilities in the field for checking solution has been suggested for The National Emergency Management Agency. These results present a Sectoral Disaster Prevention response capabilities somewhat different in were identified. Through these are proposed policy recommendations about Sectoral Disaster Prevention and insufficient areas of step response capabilities and building fire protection system approach combines ubiquitous technology in the new paradigm rather than traditional disaster management, greet era of ubiquitous.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2006.11a
• /
• pp.399-402
• /
• 2006

The purpose of this study is to propose a method for protecting injector face for prolonged combustion time and heat flux measurement technique at the injector face. To obtain basic design data and verify the performance of the proposed method, a regenerative cooling injector face was designed and manufactured for the hot firing test. Due to the safety reason, hot fire test were performed 3, 10, 30, 60 and 120 seconds time step. The discrepancy between analytical results adapting to combustion and nozzle and experimental results is believed due to the over estimation of the convection heat transfer calculation. for the injector face, flow velocity is almost negligible, therefore radiation is more important than convection. Consecutive hot firing test during 10, 30, 60 and 120 seconds combustion time shows good repeatability.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.3
• /
• pp.112-118
• /
• 2011

Ship can be faced with more dangerous situations than ground vehicles due to the opened surroundings, sea. Therefore, it is very important to prevent the ship emergency by finding risk factor. In this paper, We propose context-aware monitoring system which that frequently check the condition of ship using the data that get through the installed sensor in the ship as gyro-sensor, strain-gage sensor. We analyzed sensor data through backpropagation algorithm and the Condition and Safety Information of sailing ship is transmitted to the crew's personal mobile device in the ship. Thus, moving crew can check the ship's condition in real time. As a result, we obtained about 95% accuracy for fire risk context and about 89% accuracy for body of Ship risk context in the simulated experiments.

• Tunnel and Underground Space
• /
• v.23 no.4
• /
• pp.319-325
• /
• 2013

The objective of this study is to assess risks which might occur in connection with the storage of the highly compressed air in underground opening. Risk factors were selected throughout literature survey and analysis for the characteristic of CAES. Large risk factors were categorized in three components; planning and design phase, construction phase, and operation & maintenance phases. Large category was composed of 8 medium risk groups and 24 sub-risks. AHP technique was applied in order to analyze the questionnaires answered by experts and high-risk factors were selected by evaluating the relative importance of risks. AHP analysis showed that the operation & maintenance phases are the highest risk group among three components of large category and the highest risk group of eight medium risk groups is risk associated with the quality and safety. Risk having the highest risk level in 24 sub-risks is evaluated to be a failure of tightness security of inner containment storing compressed air.

• Journal of Korean Society of Steel Construction
• /
• v.23 no.1
• /
• pp.125-135
• /
• 2011

To obtain a lower story height with a long span and better fire resistance, a new composite floor system using GFRP (glass-fiber-reinforced plastics) was proposed. This floor system consists of asymmetric steel with a web opening, a hollow core ball, concrete, and GFRP. To evaluate the flexural performance of the new composite floor system, an experiment was conducted. The test parameters were the presence of GFRP, the void ratio in relation to the hollow core balls, and the web opening. The test results showed that the resistance and stiffness of the specimen with GFRP were 10% higher than those of the reference specimen, and that fully composite action was accomplished up to the yielding point. After the attainment of the yield strength, the ductility of the specimen was reduced due to the stress concentration around the web openings. The slip between the concrete and steel beam, however, was small. Thus, in the design of the proposed new floor systems, it is desirable that the calculated resistance be reduced by 15%, for safety.

• 전자공학회논문지 IE
• /
• v.48 no.2
• /
• pp.61-70
• /
• 2011

IEEE 802.11 wireless network supports control frames like RTS/CTS(Request To Send / Clear To Send). Because they is defend to frame collection problems. It helps to solve the frame collection problem but decreases the throughput rate. Also, control frame makes False Node Problem. This problem is makes to other wireless nodes don't work and don't find channels in the same cell and near cells. We proposed a reformed new control frame for efficiency throughput rate and solution of False Node Problem. New control frame is to have added to 4 bytes of channel detection ability at the RTS frames. Channel detection ability supported to check channel at the wireless node start to transmit data frame, We expect that channel detection ability make prevent False Node Problem for increase to access number to channel. We perform comparative analysis in terms of delay(sec) and load(bits/sec) with reform RTS/CTS method which proves the efficiency of the proposed method.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.21 no.3
• /
• pp.25-33
• /
• 2017

In this study, combustion tests were performed to investigate combustion performance of a pintle injector engine with double row rectangular slot which uses kerosene and liquid oxygens as propellants. The double row rectangular slot was designed to improve the combustion performance of a pintle engine with a single row and the blockage factor was changed from 0.7 to 1.0. The main design parameters of the double row were distance between rows, area ratio and aspect ratio. The characteristic velocity efficiency was measured from 92.4 to 96.9 percentage for double row but 86.8 percentage for single row. It showed the highest combustion performance at the BF 0.85.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.11
• /
• pp.189-200
• /
• 2011

With rapid development and contribution of IT technology IT fushion healthcare service which is a form of future care has been changed a lot. Specially, as IT technology unites with healthcare, because delicate personal medical information is exposed and user's privacy is invaded, we need preperation. In this paper, u-healthcare service model which can manage patient's ID information as user's condition and access level is proposed to protect user's privacy. The proposed model is distinguished by identification, certification of hospital, access control of medical record, and diagnosis of patient to utilize it efficiently in real life. Also, it prevents leak of medical record and invasion of privacy by others by adapting user's ID as divided by user's security level and authority to protect privacy on user's information shared by hospitals.

• Journal of the Korean Society for Railway
• /
• v.11 no.4
• /
• pp.364-370
• /
• 2008

In this paper, we proposed new sensor network architecture with autonomous robots based on beacon mode and implemented real time monitoring system in real test-bed environment. The proposed scheme offers beacon based real-time scheduling for reliable association process with parent nodes and dynamically assigns network address by using NAA (Next Address Assignment) mechanism. For the large scale multi-sensor processing, our real-time monitoring system accomplished the intelligent database processing, which can generate not only the alert messages to the civilians but also process various sensing data such as fire, air, temperature and etc. Moreover, we also developed mobile robot which can support network mobility. Though the performance evaluation by using real test-bed system, we illustrate that our proposed system demonstrates promising performance for emergence monitoring systems.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.22 no.2
• /
• pp.115-124
• /
• 2018

In this study, a cold flow test was carried out on a high-speed vehicle facility with a high-altitude environment simulator. Variable test was carried out according to the blockage ratio, angle, and length of the test model. It is confirmed that the blockage rate can be operated in the range of 40%, and that the model should be selected at an angle of 45 degrees or less. The variables of length are less dominant compared to the variables of blockage rate and angle. Through this, a database is obtained according to the parameters of the conical model of the high-speed vehicle test facility.