• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.273-279
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• 2022

In order to reduce the absorbed dose given to the patient during dental radiography, a sensor that inserts a shield into the intraoralsensor was designed. Using the designed sensor, the change in absorbed dose depending on whether or not a shield was used was evaluated. The system used to evaluate the absorbed dose is VEX-S300C from Vatech, and the energy spectrum of X-rays was obtained through SPEKTR simulation based on the irradiation conditions of 65 kV, 3 mA, and 0.15 sec, and the number of photons for each energy was derived. After designing the system through Genat4 Application for Tomographic Emission(GATE) simulation, the energy spectrum obtained was used as a radiation source to calculate the absorbed dose. Lead was used for the shield, and simulations were performed at 0.1 mm thickness intervals from 0.1 mm to 0.5 mm was evaluated. In the case of using an X-ray field with a diameter of 60 mm, the decrease in absorbed dose according to the presence or absence of a shield decreased exponentially as the thickness of the shield increased. In addition, when a 20 mm × 30 mm field was used, the absorbed dose was significantly reduced even when no shield was used, and it was confirmed that the absorbed dose was further reduced when a shield was used.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.40-44
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• 2009

지하구는 도시의 신경망이라 할 수 있는 통신, 전력, 상수도, 난방, 쓰레기 처리시설 등 도시 운용/관리를 위한 주요시설물을 안전하게 수용하고, 유지 관리하기 위한 시설로 IT기술을 이용하여 수용된 시설을 효과적으로 유지/관리하고, 재난으로부터 안전하게 보호함과 동시에 최소의 비용과 에너지로 수용된 시설물을 유지관리하기 위한 연구가 많이 진행되고 있다. 따라서 본 논문에서는 지하구(공동구, 통신구, 전력구)의 운용 및 유지관리와 지하구에서 발생될 수 있는 각종 재난에 대응하기 위한 지하구 운용 및 유지관리에 대해 알아보고, 지하구 내부에 수용된 시설물을 효과적으로 유지관리하고 재난에 신속히 대응하기 위한 지하구 환경모니터링 시스템에 대해 기술 하고자 한다. 지하구 환경모니터링 시스템은 지하구 내부에는 전력, 상수도, 통신, 난방 등 다양한 시설물이 수용되어 있으며, 이러한 시설물의 부식, 고장 등으로부터 보호하기 위해 지하구내부의 환기시스템의 송풍기와 지하수와 기상재해로 인한 지하구 및 수용시설물의 침수를 막기 위한 양수펌프에 대해 실시간 상태모니터링 통해 송풍기 및 펌프의 고장여부를 판단하여 관리자에게 알림으로써 관리자가 신속하게 대응 할 수 있도록 하였다. 송풍기의 제어는 지하의 내부와 외부에 설치된 온/습도 센서를 통해 지하구 내부환경을 최적으로 유지할 수 있도록 함으로써 쾌적한 지하 내부환경 유지하고, 급/배기가 필요할 경우에만 송풍기를 가동함으로써 에너지를 절약 할 수 있으며, 화재, 침수 등에 대한 재난시 환풍기의 급/배기, 정지 등을 신속하게 제어할 수 있도록 하였다. 또한 지하구내부에서 발생된 재난을 유/무선을 이용하여 신속하게 지하구 주변의 장치(U-Pole 또는 통합컨트롤러)를 통해 경보를 전파함으로써 주변 시민들이 안전하게 대피할 수 있도록 하였다. 그리고 지하구 환경모니터링 시스템을 검증하기 위해 실제 지하구 및 실험실에 시스템 및 Test Board을 설치하여 운용시험을 실시 하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.50-57
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• 2008

To change rail tracks from main track to another track, it needs a device that is called the turnout point. If the point which is composed of accurate parts and complex sensors does not work, And also, serious problems will be arisen. However, there are serious problems by the failure of the point. In this paper, after analyzing the failures of the conventional points, a new point is suggested. The proposed point is not affected by the surge caused by lightning.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.199-201
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• 2019

최근 경주 포항 지역에 지진피해 등 대구 경북권의 잦은 재난 발생으로 인해 증대되고 있는 노후학교 건축물의 안전성 위험 문제에 대한 선제 대응이 필요한 상황이 요구되고 있다. 학교 건축물에 건물의 위험도를 파악할 수 있는 센서들을 부착하고, 실시간 모니터링을 통해 건물의 구조적 위험성을 판단한다. 건물의 위험도가 심각한 단계에 이르면 스마트폰(Smart Phone) 앱(Application)과 음성안내방송을 통해 건물의 재실자와 관리자에게 즉시 경보를 발령하며, 대피할 수 있도록 가이드를 제시 한다. 이에 본 논문에서는 스마트 재난경보방송을 위한 스마트폰 애플리케이션(application)을 통해 재난 상황을 전파하고 대응할 수 있게 건물의 위험성 발생 위치정보를 제공하며 대피 안내 정보를 제공한다. 동시에 건물의 구내방송 시스템과 연계를 통해 음성 안내방송을 자동으로 수행하며, 두 가지 방식으로 재난 메시지를 전파하여 중복성을 가지고 경보 전파를 수행한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.404-409
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• 2007

To change rail tracks from main track to another track, it needs some device that is called turnout point. If the point which is composed of accurate parts and complex sensors does not work, serious problems will be arisen. However, there serious problems by the failure of the point. In this paper, after analyzing the failures of the conventional points, a new point is presented. The proposed point is not affected by surge caused by lighting.

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.69-77
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• 2005

The purposes of this study were to develop and introduce a novel intraoral appliance for bruxism composed of power switch and biofeedback device and further to examine inter- and intra-reliability of the appliance prior to clinical tests. The newly-developed appliance consisted of detection sensors, a central processing unit (CPU), a reactor and a storage unit and a displayer. Compact-sized, waterproof switches were selected as bruxism detection sensor and any sensor activation by clenching or grinding event was processed at the CPU and transmitted, by radio wave, to the reactor and storage unit and triggered auditory or vibratory signal, subsequently producing biofeedback to the patient with bruxism. The data on bruxing event in the storage unit can be displayed on the computer, making it possible analyzing frequency, duration and nature of bruxism. Cast models were obtained from ten volunteers with normal occlusion to evaluate reliability of the appliances. For inter-operator reliability on the intraoral appliances, each operator of the two fabricated the appliance for the same subject and compared the minimal contact forces provoking auditory biofeedback reaction in vertical, lateral and central directions. Intra-operator reliability was also investigated on the appliances made by a single operator at two separate times with an interval of two days. Conclusively, the newly-developed appliance is compact and safe to use in oral circumstance and easy to make. Furthermore, it had to be proven reliability excellent enough to apply in clinical settings. Thus, it is assumed that this appliance with the processor and the storage of data and auditory or vibratory biofeedback function is available and useful to analyze and control bruxism.

• Journal of the Korean Institute of Gas
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• v.22 no.2
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• pp.29-33
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• 2018

Accident likelihood is growing due to a correlation for gas and electricity installed in the area of dense energy consumption like traditional market and underground shopping center. In order to prevent and respond accident risks related to gas and electricity in this area, it should be monitored and predicted for factors of gas leak or electricity by developing safety management system. This study is about accident prediction model development considering fire risk factor related to gas accident. The temperature variation characteristic near a gas burner was analyzed. Also, accident prediction algorithm and related module were developed to prevent fire in the area of dense energy consumption.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.94-101
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• 2011

Various kinds of medical imaging devices have been studied to develop periapical radiography. However, there are some problems such as high x-ray exposure rate and pains for patients because of the problems caused by intra-oral sensor based radiography system. In this study, a new concept of periapical radiography, intra oral X-ray tube and detector system, is introduced to solve these problems. This system is made up of miniature X-ray tube based on subminiature thermal electron or cold electron, CMOS based detector, and a body including automatic position and system control devices. In order to confirm the possibility of proposed new concept to periapical radiography, miniature x-ray tube from XOFT corporation is used to develop new x-ray system, and the performance evaluation of this system is performed according to collimator. Also, dental images are compared after acquiring both images from existing system versus new concept of system. As a result, new concept of system showed excellent image. Thus, it is considered that new concept of system will have a significant effect on medical imaging technology.