• Fire Science and Engineering
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• v.31 no.6
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• pp.83-90
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• 2017

If an overcurrent exceeding the rated value is applied to an electric wire, the temperature of the electric wire increases, and the electric wire covering deteriorates to cause a short circuit. The upper limit temperature of the wire varies according to the magnitude of the overcurrent. When a short circuit occurs at each upper temperature limit, a cooling speed difference occurs during the solidification process due to the temperature difference between the short circuit temperature and the wire surface temperature. At this time, the pattern characteristics of the dendritic structure formed on the molten cross section are different. In this study, the upper temperature limit, which varied according to the overcurrent magnitude, was measured. At the time a short circuit occurred, the second branch spacing (dendrite Arm Spacing : DAS) of the dendrite was analyzed and the numerical value was quantified. The experimental results showed that the upper temperature limit increases with the magnitude of the overcurrent, and that the second branch spacing increases with increasing wire temperature.

• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.1-6
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• 2020

This study is about the safe arm posture in case of emergency escape using the vertical dive rescue sack at the fire site. The experimental results are as follows. First, the arms extended upward contact with the endothelium and narrowing part of the rescue sack minimized the scratches did not occur. Second, the bent position with both arms open was subject to light abrasions of on the elbows due to friction between the elbows and the scapula and the endothelium. Third, in the posture where both arms were gathered in the chest, the body passed through the narrowing part and friction between the bag's narrowing part, All subjects had light abrasions on their elbows. Fourth, because the arms are lowered, the legs are extended to the width of the shoulders when descending, so that the back of the hand has friction with the narrowing part of the bag and the endothelial skin. Finally, posture with both arms below the front increased the volume of the front of the body, resulting in a slight back injury. As a future research task, it is necessary to study the proper posture of legs and the posture of landing on the ground.

• Fire Science and Engineering
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• v.27 no.6
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• pp.83-88
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• 2013

Catastrophic disasters are sprouting out recently, i.e., the radiation leaks and the hydrofluoric acid gas leaks, etc. The restoration work for these kinds of disasters is very harmful and dangerous for human beings to handle themselves, thus allowing manless robots to fly the reconnaissance planes over to the disaster stricken areas and do the necessary work instead. For this endeavor and purpose, we created and tested an intelligent robot that can inspect those areas, using Mbed (ARM processor) technology temperature sensors and gas sensors aided by CAM (Computer-Aided Manufacturing) cameras. Also, HTTP Server, PC, androids and their combined efforts allow their remote controlled operation from far away with timing control. These intelligent robots can be on duty for 24 hours, minimizing the accidents and crimes and what not, and can respond more quickly when these misfortunes actually happen. We can anticipate the economic effects as well, derived from the reduced needs for hiring human resources.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.7
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• pp.523-528
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• 2020

A lateral type MEMS inertial switch was designed on the same principle as spring-mass system. The MEMS switch is used for arming mechanism of the arm-fire device by sensing the applied acceleration. We analyzed the switching capability of the MEMS switch under various acceleration conditions via performance model. Simulation results showed that the MEMS switch works very well at 10 g when the applied acceleration slope does not exceed 10 g/msec. On the other hand, the threshold operating acceleration level simulation exceeded the requirement (10±2 g) due to the width and length of the spring by considering 10% tolerance of the design values. Design modification of doubling the width of the spring, which is difficult to reduce less than 10% tolerance in fabrication process, was proposed after confirming the simulation results comply the requirement.

• Journal of Acupuncture Research
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• v.32 no.4
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• pp.29-36
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• 2015

Objectives : The purpose of this study is to compare the efficacy of fire needling therapy and general acupuncture for the patient with lumbar herniated intervertebral disc. Methods : We observed 20 lumbar herniated intervertebral disc patients from March, 2014 to October, 2015. This study was randomized and assessor blinded. The patients were divided into two groups: one group(group A) was treated by general acupuncture only, and the other group(group B) was treated by fire needling therapy and general acupuncture. We evaluated the treatment effect experienced by each group using the visual analogue scale(VAS) and Oswestry disability index(ODI). Results : 1. In group A, VAS and ODI from before treatment to treatment 4, 8, 12, 16 were significantly improved in statistics. 2. In group B, VAS from before treatment to treatment 4, 8, 12, 16 was significantly improved, but ODI was significantly improved in statistics only from before treatment to treatment 12, not in treatment 4, 8, 16. 3. As a result of comparisons between group A and B, there were no statistical significance in VAS and ODI. Conclusions : This study was not able to determine statistical significance between the group treated by general acupuncture only and the group treated by fire needling therapy and general acupuncture, so further studies are required in the future.

• Journal of the Korean Home Economics Association
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• v.44 no.7 s.221
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• pp.63-72
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• 2006

The purpose of this study was to survey the wearing practices and problems in the working uniform for volunteer fire brigade members and then to develop its design with a improved movement adaptability, physical suitability, ease for equipment accommodation, functionality, convenience and fit. Based on the questionnaire, we have made a testing uniform for volunteer fire brigade members first. Through a subjective analysis for functionality and apparence, we suggested a final design. The final design includes the following elements: 1. It was a two-piece style composed of a jumper and trousers with the upper garments pulled out. Raglan sleeves were used to increase arm's movement scope. Pleats and velcro tapes were attached along the base hem of sleeves to prevent heat transmission. 2. Various types of pockets were attached to secure enough space for keeping things. 3. In trousers, spare space was given at the buttock area with rubber string inserted only at selected part of side lines, and knee pads were attached to prevent wearing out.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.361-367
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• 2003

Ad-hoc network is a multi-hop wireless network formed by a collection of mobile nodes without the aid of any establish infrastructure and this network can provide an extremely flexible method for establishing communications for fire, safety, rescue operations, battle field or other fields requiring rapidly deployable communications with survivable, efficient dynamic networking. Recently new expended mechanism is proposed as Ad-hoc relay system, so guarantee of QoS for multimedia applications is needed more and more. In this paper, we propose ARM based QoS Distribution Monitoring Mechanism to provide Quality of Service guarantees to multimedia application with MANET.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.169-172
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• 2010

유비쿼터스 화재 방재 시스템은 온도, 습도, 조도, 가속도, CO2, 등의 다양한 센서로부터 얻는 값을 이용해 화재를 판별하여 관리자에게 전달하고 시스템 설정 값에 따라 소화설비를 동작시키는 지능형 화재 탐지 시스템이다. 기존 화재 판별 기법은 크게 영상인식, 퍼지추론, 베이지안 추론으로 나뉠 수 있다. 본 논문에서는 앞선 기술들을 분석하고, ARM9 S3C2440/SHT-75를 이용한 센서기반 유비쿼터스 화재 방재 시스템 최적의 화재 판별 기술로서 가속도 알고리즘과 벡터 랜덤변수 표본공간 영역을 이용한 패턴인식 기술을 사용한 복합 화재 판별 방법을 제안한다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.3 s.303
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• pp.17-24
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• 2005

Various defects are found in PDP manufacturing process. Detecting these defects early and reprocessing them is an important factor that reduces the cost of production. In this paper, the image processing system for the PDP pattern inspection is designed and implemented using the high performance and accuracy CCD line scan camera. For the preprocessing of the high speed line image data, the Image Processing Part (IPP) is designed and implemented using high performance DSP, FIFO and FPGA. Also, the Data Management and System Control Part (DMSCP) are implemented using ARM processor to control many IPP and cameras and to provide remote users with processed data. For evaluating implemented system, experiment environment which has an area camera for reviewing and moving shelf is made. Experimental results showed that proposed system was quite successful.

• Journal of Electrical Engineering and Technology
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• v.1 no.2
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• pp.241-245
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• 2006

In this paper, the design and characteristics of a $\pi-shaped$ ultrasonic motor that is applicable to optical zoom operation of a lens system for mobile phones are investigated. Its design and simulation of performances are carried out by FEM (finite element method) commercial software. As a simulation result, by applying voltage with single phase, a combined vibration is produced at the surface of a stator arm. A prototype of the motor is fabricated and its outer size is $8*4*2mm^3$ including the cylindrical steel rod of 2 mm in diameter as the rotor. The motor exhibits a maximum speed of 500 rpm and a power consumption of 0.3 W when driven at 20 Vpp and 64 kHz.