• 한국동물위생학회지
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• 제43권3호
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• pp.167-171
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• 2020

The epidemiological investigation of outbreak in korea confirmed that the inflow of avian influenza (AI) is related to the migration of migratory birds. In this study, avian repellents instrument were implemented and developed using the visual effects of lasers in accordance with the situation of small domestic fowl farms, and monitoring cameras were installed around each instrument to investigate the frequency of wild birds appearing and evaluate the performance of the instrument. Observation showed that the appreance ratio was reduced by 95%, and no significant reduction in the intrusion prevention effect by adaptation was observed on all fowl farms. In conclusion, it is expected that the outbreak of wild bird-borne infectious diseases such as avian influenza will be decreased if the device is installed on domestic fowl farms.

• 한국방재학회 논문집
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• 제8권4호
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• pp.87-90
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• 2008

이 연구는 사찰의 화재 사례, 일본의 사찰 안전관리에 대하여 고찰 분석하였다. 그 결과를 토대로 사찰 화재예방시스템에 대한 개선방안 제안을 목적으로 하고 있다. 사찰 화재예방시스템의 개선방안으로는 첫째, 화재로 문화재 소실 등의 피해를 줄일 수 있도록 "문화재보호법"에 화재예방을 위한 규정 신설의 필요성 제기 둘째, 단독경보형 감지기 및 에어졸식 간이소화용구를 설치하여 화재의 조기발견 및 진화 그리고 인명피해를 최소화 방안 강구 셋째, 경미한 전기설비 설치공사에 있어서도 "국가기술자격법"에 의한 전기분야의 기술자격을 취득한 자가 시공할 수 있도록 "전기사업법령"상의 기준 마련 등이다.

• 전기학회논문지
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• 제64권1호
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• pp.182-187
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• 2015

In the three-phase power system, when any one-phase or two-phases is open-phase, the unbalanced current flows and the single-phase power supplies to three-phase loads. Specially, motor coil and transformer coil receive over-current. As a result, great damage as well as electrical fire can occur to the power system. In order to improve these problems, this paper proposes that an open-phase detection device is designed by a new algorithm using electric potential difference between the resultant voltage of neutral point and ground, and a control circuit topology of open-phase protector is composed of highly efficient semiconductor devices. It improves response speed and reliability. The control algorithm circuit also operates the cut-off of a conventional residual current protective device (RCD) which flows an enforced leakage current to ground wire at open-phase accident. Furthermore, time delay circuit is added to prevent the incapable operation of open-phase protector about instantaneous open-phase not open-phase fault. The time delay circuit improves more reliability.

• Steel and Composite Structures
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• 제44권4호
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• pp.569-586
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• 2022

This study introduces a novel friction damper as a component of a recentering frame connection, to solve the problem of structural repair costs, caused by stiffness deterioration and brittle fracture of the central brace frame (CBF). The proposed damper consists of shape memory alloy (SMA) bars with pretension applied to them to improve the stability. SMAs reduce the residual displacement by virtue of the properties of the materials themselves; in addition, a pretension can be applied to partially improve their energy dissipation capacity. The damper also consists of a friction device equipped with friction bolts for increased energy dissipation. Therefore, a study was conducted on the effects of the friction device as well as the pretension forces on the friction damper. For performance verification, 12 cases were studied and analyzed using ABAQUS program. In addition, the friction and pretension forces were used as variables in each case, and the results were compared. As a result, when the pretension and friction force are increased, the energy dissipation capacity gradually increases by up to about 94% and the recentering capacity decreases by up to about 55%. Therefore, it has been shown that SMA bars with adequate pretension in combination with bolts with adequate frictional force effectively reduce residual deformation and increase damper capacity. Thus, this study has successfully proposed a novel friction damper with excellent performance in terms of recentering and energy dissipation capacity.

• 한국인터넷방송통신학회논문지
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• 제24권2호
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• pp.71-77
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• 2024

대한민국에서 스마트디바이스의 사용이 급증함에 따라 척추 질환 환자 수도 증가하고 있다. 이로 인해 스마트디바이스 사용으로 인한 근골격계 질환인 척추 질환 환자 수가 계속 증가하고 있다. 이 연구는 안드로이드 어플리케이션을 개발하여 운동 유도 기능을 통해 척추 질환 예방을 목표로 하며, 헬스케어 어플리케이션의 활용성 향상과 안드로이드의 오버레이 기술을 활용하여 운동을 유도하는 방안을 모색하였다. 또한, 현재 대한민국의 총 인구를 고려하면, 스마트디바이스 사용으로 인한 척추 질환 환자 수가 상당할 것으로 추정되며, 이에 바른 자세 유지와 꾸준한 운동 습관의 중요성이 강조된다. 이러한 연구는 스마트디바이스 사용으로 인한 척추 질환 예방을 위해 보다 나은 어플리케이션 개발을 통해 사용자들에게 도움을 줄 수 있음을 제시하고 있다.

• 한국화재소방학회논문지
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• 제34권3호
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• pp.43-48
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• 2020

본 연구에서는 누전경보 기능이 내장된 누전경보차단기(JER-E2S, ETECKOREA Co., Korea)를 개발하고, 그 특성을 분석하였다. 개발된 누전경보차단기는 단상 220 V 전용으로 정격전류는 32 A, 20 A, 20 A(화장실용), 16 A 등이다. JER-E2S는 기존 누전차단기(ELB)의 특성을 모두 만족하고 있으며, 13 ± 2 mA의 저항성누설전류(Igr)인 화재전류가 전선로에 흐르면 실시간 검출하여 LED 램프로 위험 상태를 점멸할 수 있는 제품이다. 개발된 누전경보차단기는 LED 램프 및 통신기기 등에서 필연적으로 발생되는 용량성누설전류(Igc)에 대한 내성이 있어서 안정적인 전기 공급이 가능하다. 또한, 누전경보차단기는 순간지락 정전보호 기능이 있어서 작은 물방울 및 나뭇잎 등의 순간지락에 따른 차단기의 오동작 없이 전원 공급이 가능하다. 그리고 개발된 누전경보차단기의 대기전력은 0.1 W 이하로 기존 ELB에 비해 절전 성능이 3~8배 우수한 특성을 나타냈으며, 일반 120 ㎡의 아파트 1 세대에 10개 정도의 누전경보차단기가 설치되었을 때 1 개월에 2~5 kWh의 전기를 절감할 수 있다. 개발된 누전경보차단기는 기존 누전차단기의 특성을 만족할 뿐만 아니라 전기화재 예방기능 및 오동작 방지기능이 있어서 전원 품질이 우수하고, 전기화재 예방에 혁신적으로 기여할 수 있는 제품이다.

• 인터넷정보학회논문지
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• 제15권6호
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• pp.27-34
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• 2014

현대의 사회에서 스마트 디바이스들의 발전은 다양한 분야에 사용되고 있다. 특히, 위치 정보를 활용한 위치기반서비스(LBS)들이 증가하고 있다. LBS는 기본적으로 GPS를 이용한 실외 위치 정보를 기반으로 네비게이션, 증강현실, 친구찾기 등과 같은 다양한 서비스들을 제공한다. 하지만, 대부분의 LBS 서비스들은 실내 환경에서 GPS의 음영지역과 허용오차가 크기 때문에 취약점을 드러내고 있다. 이러한 실내 위치 측위 기술을 지원하기 위해서 iBeacon이 제안되고 있다. iBeacon은 저전력 송신 기술을 가지고 있고, 설치가 용이하기 때문에 저비용으로 실내 위치를 측위 할 수 있다. iBeacon은 각 스마트 디바이스와의 연결이 손쉽기 때문에 다양한 분야에서 활용될 수 있다. 사용자가 스마트 디바이스들의 활용이 높아지고, 각 스마트 디바이스들의 활용 방법이 다르기 때문에 사용자는 다양한 스마트 디바이스를 활용한다. 따라서 본 논문은 iBeacon의 통신 범위내 스마트 디바이스들간의 연동을 통한 분실 방지 시스템을 제안한다.

• 한국정밀공학회지
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• 제28권11호
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• pp.1330-1338
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• 2011

Social activities of the elderly have been increasing as our society progresses toward an aging society. As their activities increase, so does the occurrence of falls that could lead to fractures. Falls are serious health hazards to the elderly. Therefore, development of a device that can detect fall accidents and prevent fracture is essential. In this study, we developed a portable fall detection system for the fracture prevention system of the elderly. The device is intended to detect a fall and activate a second device such as an air bag deployment system that can prevent fracture. The fall detection device contains a 3-axis acceleration sensor and two 2-axis tilt sensors. We measured acceleration and tilt angle of body during fall and activities of daily(ADL) living using the fall detection device that is attached on the subjects'. Moving mattress which is actuated by a pneumatic system was used in fall experiments and it could provide forced falls. Sensor data during fall and ADL were sent to computer and filtered with low-pass filter. The developed fall detection device was successful in detecting a fall about 0.1 second before a severe impact to occur and detecting the direction of the fall to provide enough time and information for the fracture preventive device to be activated. The fall detection device was also able to differentiate fall from ADL such as walking, sitting down, standing up, lying down, and running.

• Journal of Information Technology Applications and Management
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• 제11권2호
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• pp.179-190
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• 2004

This paper describes the design of hacking prevention systems using a smart card. It consists of two parts, i.e., PC authentication and Keyboard-buffer hacking prevention. PC authentication function is a procedure to handle the access control to the target PC. The card's serial number is used for PIN(Personal Identification Number) and is converted into hash-code by SHA-1 hash-function to verify the valid users. The Keyboard-buffer hacking prevention function converts the scan codes into the encoded forms using RSA algorithm on the Java Card, and puts them into the keyboard-buffer to protect from illegal hacking. The encoded information in the buffer is again decoded by the RSA algorithm and displayed on the screen. in this paper, we use RSA_PKCS#1 algorithm for encoding and decoding. The reason using RSA technique instead of DES or Triple-DES is for the expansion to multi-functions in the future on PKI. Moreover, in the ubiquitous computing environment, this smart card security system can be used to protect the private information from the illegal attack in any computing device anywhere. Therefore, our security system can protect PC user's information more efficiently and guarantee a legal PC access authority against any illegal attack in a very convenient way.

• 대한안전경영과학회지
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• 제13권2호
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• pp.77-82
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• 2011

In the industrial site of 21st century, there are many and various powders of material, product and fuel of coal, chemical, detergent, paint, feed and more. Therefore, there always is a possible danger of dust explosion in each and every procedure and actually, there are increasing frequency of dust explosion as the use of dust and its amount increases in processes. Therefore, if we leave the current status like now, the unexpected massive dust explosion and its risk cannot be effectively prevented so there has to be effective application of understanding and development of explosion-prevention technology about dust explosion. Therefore, this research set the limit of research to systematically arrange the research results about dust explosion phenomenon and its prevention up to date and has its purpose to theoretically establish the prevention technology about dust explosion based on these theories.