국가별 풍하중 기준과 풍동실험에 따른 대공간 구조물 지붕의 풍압계수 분석

천동진,윤성원,Cheon, Dong-jin,Yoon, Sung-Won 한국공간구조학회 2017 한국공간구조학회지 Vol.17 No.4

Spatial Structure has suffered from a lot of damage due to the use of lightweight roofs. Among them, the damage caused by strong winds was the greatest, and the failure of the calculation of the wind load was the most frequent cause. It provides that wind tunnel test is used to calculate the wind load. However, it is often the case that the wind load is calculated based on the standard of wind load in the development design stage. Therefore based on this, the structure type and structural system and member design are often determined. Spatial structure is usually open at a certain area. The retractable roof structure should be operated with the open roof in some cases, so the wind load for the open shape should be considered, but it is not clear on the basis of the wind load standard. In this paper, the design wind pressure of a closed and retractable roof structure is calculated by KBC2016, AIJ2004, ASCE7-10, EN2005, and the applicability of wind pressure coefficient is compared with wind tunnel test.

원형 밀폐 및 개방형 돔 지붕의 평균 및 변동 풍압 계수

천동진,김용철,이종호,윤성원 한국공간구조학회 2020 한국공간구조학회지 Vol.20 No.1

In this paper, the mean and fluctuating pressure coefficients derived from the results of wind tunnel tests on closed and open dome roofs were analyzed. The distribution characteristics of the fluctuating pressure according to the opening ratio and the height change were discussed. The analysis results showed that when the roof is open, the overall wind pressure decreases due to the open space, but more fluctuation occurred than the closed dome roof.

이산화탄소 감시를 위한 유비쿼터스 센서네트워크에 관한연구

천동진 국가위기관리학회 2010 국가위기관리학회 학술대회 Vol.2010 No.1

본 연구에서는 유해가스가 발생되는 산업현장 근로자들이 질식으로 인한 사고 방지를 위하여 유해 가스 상태량을 온-라인으로 감시할 수 있는 USN(Ubiquitous Sensor Network) 센서노드에 관하여 연구한다. 언제?어디에서나 유해가스를 검출하여 근로자에게 이동형 단말기로 위험정보제공 및 중앙감시가 될 수 있도록 Zigbee 기술을 이용한 센서노드를 제작하고, 이 센서노드에 유해가스 센서들을 접속하여 USN을 구축한다. 유해가스에는 CO, CO2, LNG/LPG 등을 검출할 수 있도록 센서장치가 부착되며, USN은 Gateway로 인터넷 망에 접속하여 인터넷이 되는 곳은 어디서나 감시가 되도록 한다. Zigbee 기술로 구현한 USN 센서노드에서 수집된 유해가스정보들은 원격감시프로그램을 통하여 동작특성이 검토된다.

풍동실험을 통한 개폐 유형별 개폐식 돔 지붕의 풍압 특성 분석

천동진,이종호,김용철,윤성원,Cheon, Dong-jin,Lee, Jong-Ho,Kim, Yong-Chul,Yoon, Sung-Won 한국공간구조학회 2021 한국공간구조학회지 Vol.21 No.1

In this study the characteristics of wind pressure that are depending on the open type of retractable dome roof were analyzed according to the wind pressure coefficient and wind pressure spectrum. The analysis results showed that the open type and shape of the roof both had a significant impact on the wind pressure changing. In case of the edge to center open type, the wind pressure has not changed much because of the complex turbulence of flow and open area. On the other hand, in case of the center to edge open type, it has confirmed that wind pressure increases due to the separation of flow in windward and open area.

간단한 위치검출기를 이용한 SRM 가변속 디지털 제어시스템 개발

천동진,정도영,이상호,이봉섭,박영록 전력전자학회 2001 전력전자학회 논문지 Vol.6 No.2

A Switched Reluctance Motor(SRM) has double salient poles structure and the phase windings are wound in stator. SRM hase more simple structure that of other motor, thus manufacture cost is low, mechanically strong, reliable to a poor environment such as high temperature, and maintenance cost is low because of brushless. SRM needs position detector to get rotator position information for phase excitation and tachometer or encoder for constant speed operation. But, this paper doesn\`s use an encoder of high cost for velocity measurement of rotator. Instead of it, the algorithm for position detection and velocity estimation from simple slotted disk has been proposed and developed. To implement variable speed digital control system with velocity estimation algorithm, the TMS320F240-20MIPS fixed point arithmetic processor of TI corporation is used. The experimental results of the developing system are enable to control speed with wide range, not only single pulse, hard chopping mode and soft chopping, ut also variable speed control, and advance angle control. 스위치드 리럭턴스 모터(Switched Relutance Motor : 이하 SRM)는 이중 돌극형으로 되어있으며, 상권선은 고정자만 사용한다. 다른 어느 전동기보다도 간단한 구조를 가지고 있어 제작단가가 저렴하고, 기계적으로 견고하며, 고온 등의 열악한 환경에서도 신뢰성이 높으며, 브러쉬 등이 없어 유지비가 거의 들지 않는 장점을 지니고 있다. 그러나 SRM은 상여자를 위하여 회전자의 위치정보를 알아야하므로 위치 검출기가 필요하고, 정속도 운전을 위하여 타코 발전기나 엔코더가 부가적으로 필요하다. 그러나 본 논문에서는 회전자의 속도측정을 얻기 위하여 고가의 엔코더를 사용하지 않고, 단지 간단한 슬롯 디스크로부터 위치를 검출하여 속도를 추정할 수 있는 알고리즘을 제시하고 개발하였다. 속도 추정 알고리즘을 적용한 가변속 디지털 제어시스템을 구현하기 위하여 TI사의 TMS320F240-20MIPS 고정 소수점 연산용 프로세서를 사용하였다. 개발한 시스템을 실험한 결과 넓은 범위에 걸쳐 속도제어가 가능하였고, 단일 펄스모드, 하드 쵸핑모드 및 소프트 쵸핑모드 뿐만 아니라, 전류제어 동작모드에서 가변속 제어가 가능하였다. 그리고 어드밴스각 제어가 가능하였다.

화재감지데이터 전송용 USN망 구축을 위한 지그비 센서노드 구현

천동진,정도영,곽동걸 한국화재소방학회 2009 한국화재소방학회논문지 Vol.23 No.6

In this paper, USN of wireless communication with easy to install and effectiveness with variety information gathering has been proposed as a alternative of wired-based line for transmission of fire sensing data. But, The sensor node using USN should be considered for wireless transmission range and reliability of information. In this study, the zigbee protocol sensor node was implemented and then tested transmission range of sensor node as 10m interval using voltage information of DC 3V & 5V. Here, maximum transmission distance was confirmed 90m inside-outside. When used mesh routing relay node, distance was not limited. In USN network building, when fire sensing data transmitted, the sensing data same between direct sensing data from sensor and collecting data at USN. Therefore, was confirmed reliability for transmission range and information of proposed zigbee sensor node. 화재감지 데이터 전송에 있어서 기존의 유선기반의 전송선로보다 설치에 용이하고 다양한 정보수집에 효율성이 높은 무선기반의 USN망이 대안으로 제시되고 있다. 그러나 USN망 구축에 사용되는 센서노드 의 무선전송거리 및 정보의 신뢰성에 대해서는 문제점이 대두되고 있다. 본 연구에서는 국제적 표준규격 지그비 프로토콜을 사용하여 센서노드를 구현하였다. 제안한 센서노드 사이에 전송거리 및 수신된 정보의 신뢰성을 검증하고자 테스트 전압 3V와 5V를 센서노드 입력단자에 인가하고, 실내에서 10m씩 거리를 증 가시켜 실험한 결과 최대 유효전송거리가 90m 내외임을 확인하였다. 또한, Mesh Routing 중계센서노드 를 사용했을 때 전송거리에는 제한이 없었다. 제안한 센서노드로 USN망을 구축하고 실제 화재감지센서를 센서노드 입력단자에 연결하여 전송하였을 때 센서에서 직접측정 한 데이터와 USN망으로 전송하여 수집 된 화재감지데이터가 잘 일치하였다. 따라서 제안한 센서노드의 화재감지정보 전송용 USN망 구축에 있어 서 전송거리 및 정보의 신뢰성이 확인 되었다.

원형 밀폐 및 개방형 돔 지붕의 풍압 스펙트럼

천동진,김용철,이종호,윤성원 한국공간구조학회 2020 한국공간구조학회지 Vol.20 No.2

Wind tunnel tests were conducted to analyze the wind fluctuating pressures on a circular closed and open dome roof with a low span rise. Two dome models with various geometric parameters (height/span ratios and open ratios) were used for fixed span rise ratio dome and wind pressure spectrum were analyzed. The applicability was examined in comparison with the spectral model proposed in the previous studies. The analysis results show that the wind pressure spectrum of open dome roof tends to increase power in the high frequency range and the second peak is found in the area different from the closed dome roof. In addition, according to the comparison analysis with the previous proposed spectral model, it was found that it is not applicable to the closed and open dome roofs with low rise ratio due to the different peak frequencies.

풍동 실험을 통한 개폐식 돔 지붕의 외장재용 풍압 계수와 풍하중 기준 비교

천동진,김용철,윤성원 한국공간구조학회 2018 한국공간구조학회지 Vol.18 No.3

The biggest impact on the cladding design of buildings is wind loads. Wind tunnel tests were conducted to examine the applicability of current wind load standards about membrane retractable roof spatial structure. A dome model with a circular shape that is retractable to the center of the dome was made (Opening ratio = 0, 10, 30, 50). In addition, height adjustable turntables were made and tested with five patterns with H/D = 0.1, 0.2, 0.3, 0.4 and 0.5. The maximum wind pressure coefficient and the minimum wind pressure coefficient for the cladding were analyzed and the experimental wind pressure coefficient were compared with the current wind load standards, KBC2016 and AIJ-RLB(2015). The experimental value and the reference value of the enclosed roof were very similar and showed possibility of application, but opened roof case was found that the reference value was underestimated.

유해가스(CO,CO₂) 감지정보 전송을 위한 USN 지그비센서노드 구현

천동진(Dong-Jin Cheon),박영직(Young-Jik Park),이승호(Seung-Ho Lee),김정섭(Jeong-Seop Kim),곽동걸(Dong-Kurl Kwak),정도영(Do-Young Jung) 대한전기학회 2010 전기학회논문지 Vol.59 No.7

In this study, Zigbee Sensor Node to transmit harmful gases CO and CO₂ information using wireless communication within the ground and underground structures were developed. Wireless communication protocol was used Zigbee Stack included IEEE 802. 15.4 MAC protocol. For wireless transmission of detected harmful gas signal from ADC of MCU was implemented Zigbee Sensor Node that was developed protocol using Serial-Port-Profile(SPP) here. The proposed Zigbee Sensor Node was verified transmission distance from experiments. Transmission distance was into 90m in experiments. Distance experiments were measured at 10m intervals using sine & pulse wave input signal at indoors. The proposed Route Sensor Node was applied mesh routing protocol. When built up USN(Ubiquitous Sensor Network)using Route Sensor Node, transmission distance was not limited. On the experimental results, harmful gas values between direct measurements and USN measurements were consistent. The semiconductor CO sensor and N-DIR CO₂ sensor module as a harmful sensor was used. Therefore, the proposed Zigbee Sensor Node was verified about reliability and validity to build USN for transmission of harmful gas information.

u-IT기반 계측정보를 이용한 급경사지붕괴 예측 시스템 개발

천동진(Cheon, Dong-Jin),박영직(Park, Young-Jik),이승호(Lee, Sung-Hou),김정섭(Kim, Jeong-Seop),정도영(Jung, Do-Young) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.10

본 논문은 급경사지(산사태 및 사면붕괴, 축대 등)붕괴 등으로 인하여 많은 생명과 재산피해 방지를 목적으 로 붕괴 위험성을 감지하고 신속히 대응을 할 수 있도록 하기 위하여 u-IT기반의 급경사지 붕괴예측 감시용 실시간 모니터링 시스템을 개발하였다. 급경사지붕괴 감시에 중요한 계측기로서 강우량 계측기, 간극수압 계측기, 지표변위 계측기, 지중경사 계측기, 함수비계측기, 영상분석 계측기 등을 선정하고 테스트베드에 적용하였다. 각 계측기의 신뢰 성 검증에 필요한 동작기능 및 성능확인은 현장에 설치된 계측기 별로 실험을 통하여 확인하였다. 본 연구에서 개발 한 급경사지붕괴 감지를 위한 USN기반의 실시간 급경사지 모니터링 시스템을 급경사지 붕괴감지뿐만 아니라 도로변 절개사면과 암반사면 등에 상시계측을 통하여 붕괴위험 예측에도 적용할 수 있으므로 인명피해와 재산피해를 최소할 수 있을 것으로 판단되며, 이 시스템은 본 연구의 시범적용 결과를 바탕으로 급경사지 전역에 확산될 계획에 있다. This paper has studied about the development and application of landslide collapse prediction real-time monitoring system based on USN to detect and measure the collapse of landslide. The rainfall measuring sensor, gap water pressure sensor, indicator displacement measuring sensor, index inclination sensor, water content sensor and image analysis sensor are selected and these are applied on the test bed. Each sensor's operation and performance for reliability verification is tested by the instrument which is installed in the field. As the result, u-IT based real-time landslide monitoring system which is developed by this research for landslide collapse detection could minimize life and property damages because it makes advance evacuation with collapse risk pre-estimate through real-time monitoring on roadside cut and bedrock slopes. This system is based on the results of this study demonstrate the effect escarpment plan are spread throughout.