대공간 교육시설 축조를 위한 프리스트레스트 보에 사용되는 접합 강재의 성능평가에 대한 연구

이경훈,Lee, Kyoung-Hun 한국교육녹색환경연구원 2011 교육·녹색환경연구 Vol.10 No.2

An experimental study to evaluate structural capacity of an embedded plate connected with prestressed concrete beam was performed. Embedded steel plates and prestressed concrete beam were connected with stud-bolts at the ends of concrete beam specimens. About 1,000 kN concentrated load was applied at 450mm away from the end of beam specimen. A 3,000 kN capacity static Oil-jack was used to direct concentrated load. The maximum strain of stud-bolt recorded $90{\times}10^{-6}$(mm/mm) and wide width cracks were not founded. Any falling failures of concrete and large deformations were not founded either between steel plate and prestressed concrete specimen. As a result, construction performance can be improved using this embedded steel plate connection system apply to large space educational facilities.

대공간 교육시설에 사용되는 합성보 및 콘크리트 슬래브의 진동평가에 대한 연구

이경훈,정은호,Lee, Kyoung-Hun,Jeong, Eun-Ho 한국교육녹색환경연구원 2010 교육·녹색환경연구 Vol.9 No.3

In this study, vibration characteristics of reinforced concrete slab in large span educational facilities were evaluated. A 21.75m X 14.4m full scale reinforced concrete slab specimen was constructed with pre-flex hybrid beams. Vibrations were generated by three different methods such as free falling method of a 6kg sand bag, a 70kg person walking method and impact method by impulse hammer. Vibrations were generated more than 3 times at single location. Vibration characteristic data were collected by SA390 signal analyzer machine at 5 different locations.

교육시설 공사현장의 추락예방 보호구 지급개선에 관한 연구

이경훈,김정호,Lee, Kyoung-Hun,Kim, Jung-Ho 한국교육녹색환경연구원 2014 교육·녹색환경연구 Vol.13 No.2

Recently, a series of massive earthquakes have been occurred northeast Asia and there has also been constant sensible earthquakes in South Korea. Particularly, after diagnosing educational facilities with Sichuan earthquake momentum, remodeling construction of old educational facilities and buildings which were not designed not to resist earthquake are actively underway. Remodeling construction sites, however, are mostly small construction sites which consist of less than 30 full-time laborers, where a number of deaths from a fall occur by improper uses of protective gear. Therefore, to reduce the disaster from a fall caused by inadequate uses of protective gear in domestic small construction sites such as those for remodeling, this study conducts research into ways of decreasing accident rates by suggesting providing and administering protective gear as a national project so that donning protective gear is activated.

강판으로 접합된 프리스트레스트 콘크리트보의 구조성능 평가를 위한 실험연구

이경훈,김점한,Lee. Kyoung-Hun,Kim. Jeom-Han 한국방재학회 2010 한국방재학회논문집 Vol.10 No.5

In this study, a monotonic loading test to estimate structural capacity of 12 meter long full scale precast pre-stressed concrete beam specimen was performed with a 2,000 kN dynamic actuator. A couple of embedded steel plate was installed at the ends of the beam and specimens were connected to steel girder frame with high tension bolts. Nominal compressive strength of pre-stressed concrete beam and slab were 50 MPa and 24 MPa respectively. Two HD25 tensile steel reinforcements were welded on vertical plate of embedded steel plate. Pre-stressed concrete beam specimen was loaded by displacement control method with a certain loading pattern which was repeated loading and unloading with 10mm increment displacement. About 88.34%, 86.97% and 66.83% of displacement restoration ratios were evaluated at elastic, inelastic and plastic behavior region of specimen respectively. 본 연구에서는 2,000 kN 용량의 actuator를 이용, 12 m 경간의 실물 크기로 제작된 프리스트레스트 콘크리트 보의 구조성능 평가를 위한 실험을 수행하였다. 보의 양 단에는 접합을 위한 강판을 매립하였으며 시험체는 별도로 제작된 철골 보에 고력볼트접합 방식으로 세팅되었다. 프리스트레스트 콘크리트와 슬래브 콘크리트의 설계기준강도는 각각 50 MPa와 24 MPa이며, 인장 철근으로 사용된 2-HD25 철근은 매립강판의 구성요소 중 하나인 수직강판에 용접하였다. 실험은 변위제어법에 의하여 수행되었으며 10 mm의 변위를 증가시키며 loading과 unloading을 반복적으로 가력하였다. 실험결과를 살펴보면, 탄성거동구간에서는 약 88.34%, 비탄성거동구간에서는 약 86.97% 그리고 소성거동구간에서는 약 66.83%의 프리스트레싱에 의한 변위복원능력을 나타냄을 알 수 있었다.

용이한 사설망 지원을 위한 IoT 플랫폼 구현 및 서비스 운영 방법

이경훈 ( Kyoung Hun Lee ),김두영 ( Dooyoung Kim ),송세헌 ( Se Heon Song ),이상일 ( Sang Il Lee ),박재현 ( Jae Hyun Park ) 한국정보처리학회 2016 정보처리학회논문지. 컴퓨터 및 통신시스템 Vol.5 No.5

현재 출시된 다양한 사물인터넷(IoT) 플랫폼은 대부분 IPv6의 네트워크 환경을 고려하여 개발되었지만, 아직까지 IPv4에서 IPv6로의 전환율은 저조하다. 따라서 IPv4기반의 네트워크에서 운용되는 IoT 플랫폼은 IP부족현상을 해결하기 위해 기구축된 사설망을 지원해야 한다. 기존 IoT 플랫폼들은 전문가에 의해 가상 사설망을 이용하거나 하드웨어 스위치/AP(Access Point)를 이용하여 사설망을 지원하고 있다. 본 연구에서는 기존 IoT 플랫폼들이 사설망 환경을 지원하기 위해 필요한 전문가 활용 또는 하드웨어 도입에 따른 추가 비용 문제를 해결하고, 비전문가도 사설망 환경에서 IoT 서비스를 제공할 수 있는 IoT 플랫폼을 개발하였다. 또한 IoT 플랫폼을 테스트베드에 적용하여 IoT플랫폼의 기능 검증을 수행하였다. Today various IoT platforms exist, but most of them only consider IPv6, without other types of network including private network. They support, therefore, the private network to use virtual private network or through the hardware gateway. To solve this limitation, we propose a IoT platform that provides IoT Services on private networks. Also we verify this platform though constructing a testbed.

권선형 유도기와 농형 유도기를 이용한 고조파 보상 시스템의 비교

이경훈(Kyoung-Hun Lee),정달호(Dal-Ho Cheong),오재윤(Jae-Yoon Oh) 전력전자학회 2001 전력전자학술대회 논문집 Vol.2001 No.7

본 논문에서 비교하는 두시스템은 모두 전력계통에서 발생할 수 있는 고조파 전류를 효과적으로 보상할 수 있는 시스템이다. 전력계통에서 고조파전류는 계통전압에 장해를 주기 때문에, 프릿카나 각종 전력용 기기의 발열, 진동, 소음 혹은 유도잡음 장해등의 원인이 된다. 따라서, 이에 대한 대책이 중요한 문제가 되고있다. 본 논문은 이러한 고조파보상 시스템의 새로운 형태로써, 폴라이훨에 의해서 만들어지는 에너지 저장시스템에, 전압형 PWM 인버터를 병용하여 순시제어가 가능한 시스템을 설계하는 것이다. 그리구 여기에 사용되는 회전기로 각각 권선형과 농형을 사용하여 시스템을 구성하고 그 특징과 장/단점을 비교 분석하였다.

고전적층판 이론을 이용한 카본튜브의 재료특성 해석과 원형 콘크리트 기둥의 압축강도 향상에 관한 연구

이경훈(Kyoung-Hun Lee) 한국열환경공학회 2022 열환경공학 Vol.17 No.2

Carbon fiber is a material that has a very high tensile strength and is flexible, so it is easy to manufacture into a desired shape. If carbon fiber is processed into a thin carbon sheet and then a circular concrete column is wound, the compressive strength can be improved due to the confined effect. In this study, the characteristics of multi-layered carbon sheets were identified by applying the Classical Lamination Theory. To directly measure tensile strength and lateral restraint pressure, tensile test and split disk test specimens were fabricated and then material experiments were conducted using a 2,000kN capacity UTM. The lateral restraint pressure of carbon sheet tube was about 5.4MPa and the tensile strength was 3,790Mpa, which is about 9.5 times the strength of steel reinforcing bars. The equation for predicting compressive strength of circular concrete confined by carbon sheet tubes manufactured at various angles was proposed through regression analysis. It is judged that this can be used as an analytical equation that can predict the strength in advance when a concrete column whose bearing strength has been lowered due to an earthquake, etc. is reinforced with a carbon sheet.

유도전동기의 속도 센서리스 제어를 위한 신경회로망 알고리즘의 추정 특성 비교

이경훈(Kyoung-Hun Lee),국윤상(Yoon-Sang Kook),최원범(Yoon-Ho Kim),김윤호(Won-Byum Choi) 전력전자학회 1999 전력전자학술대회 논문집 Vol.1999 No.7

This paper presents a newly developed speed sensorless drive using Neural Network algorithm Neural Network algorithm can be divided into three categories. In the first one, a Back Propagation-based NN algorithm is well-known to gradient descent method In the second scheme, a Extended Kalman Filter-based NN algorithm has just the time varying learning rate In the last scheme, a Recursive Least Square-based NN algorithm is faster and more stable than the classical back-propagation algorithm for training multilayer perceptrons. The number of iterations reqwred to converge and the mean-squared error between the desired and actual outputs is compared with respect to each method. The theoretical analysis and experimental results are discussed.

≪음빙행정력(飮氷行程曆)≫과 ≪연행일록(燕行日錄)≫내용비교

이경훈 ( Kyoung Hun Lee ) 전북대학교 인문학연구소 2018 건지인문학 Vol.0 No.23

In this study, I compare the recorded travelogues in the same time and find out common points and differences in the records of the people who have the same time but different reason and values, and give meaning to the value of each travelogue, the Yonhaengnok. These synchronic and comparative works are not suddenly populated by a single individual that is unique to a single Yonhaengnok. On the contrary, although the amount of the contents of the record or the depth of the reason were different, the contents already mentioned in the preceding travel record and the peer one were already recognized in various forms. Not only that, but it will also be a process of confirming that it has taken context with many existing Yonhaeng recordings and made it possible to move forward with supplementary and advanced thinking based on it. This paper focused on examining the Korean emissary to Qing China in the 18C, Lee Gi-gyeong’s travelogue ≪Umbinghaengjongnyok≫ and compared it with the ≪Yonhaengillok≫, the travelogues of Korean emissaries to Beijing in 17-19C by Chung Kwang-chung who accompanied it as a deputy of the winter solstice in the same year(1755). In doing so, I tried to analyze how the results of experience differed although they sharing the same path and time as a different person. I feel confident that this comparison will be a process that confirms the accuracy of the record or the authenticity of the data through comparison with the synchronic view.

유공강판 전단연결재로 보강된 강관말뚝 머리의 인발실험

이경훈(Kyoung-Hun Lee) 한국산학기술학회 2016 한국산학기술학회논문지 Vol.17 No.12

본 연구의 목적은 유공강판 전단연결재로 보강된 강관말뚝의 인발실험을 통하여 구조성능을 평가하는 것이다. 인발실험에 앞서 재료의 특성을 파악하기 위하여 콘크리트 압축강도 실험을 수행하였으며, 실험에 사용되는 철근 및 철판의 항복하중, 인장강도 및 연신율 등의 재료적 특성을 미리 파악하였다. 유공강판 전단연결재로 보강된 강관말뚝의 인발실험은 2,000kN 용량의 UTM을 이용하여 0.01mm/sec 재하속도의 변위제어 방법으로 실험을 수행하였다. 계측을 위하여 철근 및 유공강판 중앙에 strain gauge를 부착하였으며, 가력판과 충전콘크리트 사이의 상대변위 측정을 위하여 변위계(LVDT)를 설치하였다. 유공강판 전단연결재로 보강된 실험체의 항복하중은 각각 923.8kN과 981.1kN으로 기존 설계법에 의하여 제작된 실험체의 항복하중인 641.7kN에 비하여 1.44배 ∼ 1.53배 증가됨을 알 수 있었다. 또한 유공강판 전단연결재로 보강된 실험체의 극한하중은 각각 1004.4kN과 1055.5kN으로 기존 설계법에 의하여 제작된 실험체의 극한하중인 813.7kN에 비하여 1.23배 ∼ 1.29배 증가됨을 알 수 있었다. 반면, 유공강판 전단연결재로 보강된 실험체의 항복변위 및 극한상태의 변위는 기존 설계법에 의하여 제작된 실험체에 비하여 각각 0.61배 및 0.42배 감소됨을 알 수 있었다. 따라서 유공강판 전단연결재로 보강된 강관말뚝은 강성은 증가하고 상대변위 및 변형률은 낮게 측정되어 기존 말뚝머리 보강방법을 대체할 수 있는 적절한 보강방법임 알 수 있었다. The purpose of this study was to evaluate the structural capacity of steel pipe pile specimens reinforced with hollow steel plate shear connectors by pull-out test. Compressive strength testing of concrete was conducted and yield forces, tensile strengths and elongation ratios of re-bars and hollow steel plate were investigated. A 2,000kN capacity UTM was used for the pull-out test with 0.01mm/sec velocity by displacement control method. Strain gauges were installed at the center of re-bars and hollow steel plates and LVDTs were also installed to measure the relative displacement between the loading plate and in-filled concrete pile specimens. The yield forces of the steel pipe pile specimens reinforced with hollow steel plate shear connectors were increased 1.44-fold and 1.53-fold compared to that of a control specimen, respectively. Limited state forces of steel pipe pile specimens reinforced with hollow steel plate shear connectors were increased 1.23-fold and 1.29-fold compared to that of a control specimen, respectively. Yield state displacement and limited state displacement of steel pipe pile specimens reinforced with hollow steel plate shear connector were decreased 0.61-fold and 0.42-fold compared to that of a control specimen, respectively.