지상라이다를 이용한 구조물의 안전 및 사용성 평가 모델

이홍민,박효선,Lee, Hong-Min,Park, Hyo-Seon 한국방재학회 2006 한국방재학회논문집 Vol.6 No.3

Structural health monitoring is important to maintain the safety and serviceability of the structures. The displacement in the structure should be precisely and frequently monitored because it is a direct assessment index indicating its stiffness. However, no practical method has been developed to monitor such displacement precisely, particularly for high-rise buildings and long span bridges because they cannot be easily accessible. To overcome such difficult accessibility, we propose to use a LIDAR system that remotely samples the surface of an object using laser pulses and generates the coordinates of numerous points on the surface. In this study, using terrestrial LiDAR, we develop a novel displacement measuring model for structural health monitoring and perform an indoor experiment to prove its performance. 구조물의 건전성 모니터링은 구조물의 안전 및 사용성을 위하여 중요하다. 구조물의 변위는 직접적인 구조물 강성의 평가 지표가 되기 때문에 정확하고 주기적으로 모니터 되어야 한다. 그러나 이러한 변위 모니터를 위한 실용적인 방법이 아직까진 없고, 특히 고층 건물이나 장 스팬 교량과 같이 접근성이 어려운 구조물의 경우는 더욱 그러하다. 이러한 문제점을 해결하기 위하여 레이저 펄스를 이용하여 원격으로 물체 표면을 탐사하고 수많은 좌표를 생성할 수 있는 라이다 시스템을 제안하였다. 본 연구에서는 지상 라이다를 이용하여 구조물의 헬스 모니터링을 위한 새로운 변위계측모델을 개발하였고 검증을 위한 실험이 수행되었다.

변위기여도 및 변형에너지밀도를 활용한 초고층 건물의 센싱 부재 선정

이홍민,박성우,박효선,Lee, Hong-Min,Park, Sung-Woo,Park, Hyo-Seon 한국전산구조공학회 2009 한국전산구조공학회논문집 Vol.22 No.4

초고층 건물의 안전성 및 사용성을 합리적으로 확보하고 유지하기 위해서 부재의 구조 반응 모니터링은 필요하다. 이러한 대형 건물의 건전도 모니터링은 최근 들어 많은 연구자들에 의해서 관심 되어지고 있지만 건물 특성상 계측 대상 부재가 많고 하중과 구조반응의 관계가 복잡하기 때문에 센싱 부재 선정의 어려움으로 그 적용에 한계가 있다. 본 논문에서는 부재의 변위기여도 및 변형에너지밀도를 기반으로 초고층 건물의 안전성 모니터링을 위한 구조반응 계측 부재 선정에 대한 연구를 수행하였다. To rationally secure and maintain the safety and serviceability of a high-rise building, monitoring of structural responses of members is necessary. As such health monitoring of large-scale building structures has received growing attention by researchers in recent years. However, due to a very large number of members complexity of structural responses of a high-rise building structure, practical difficulties exist in selection of structural members to be sensored for assessment of structural safety of a structure. In this paper, a selection technique for active members for safety monitoring of a high-rise building based on displacement participation factor and strain energy density of a member is investigated.

폴디드 모노폴 선로가 부착된 대수주기 구조를 이용한 다중대역 안테나

이홍민,Lee, hong-Min 한국정보전자통신기술학회 2014 한국정보전자통신기술학회논문지 Vol.7 No.3

본 논문에서는 4중대역 GSM/DCS/PCS/Bluetooth에서 동작 가능한 안테나를 제안하였다. 제안된 안테나는 소형화하여 광대역의 특성을 얻기 위해 모노폴 안테나를 기반으로 대수주기 톱니 형 사다리꼴 패치 안테나 안에 슬릿을 부설하였고, 다중 대역을 만족시키기 위해 마이크로 스트립 라인으로 설계하였다. 비유전율 4.4, 두께가 1 mm(GND포함), $35mm{\times}75mm$의 크기를 갖는 기판에 $35mm{\times}20mm$ 크기의 안테나를 설계하였으며, 제안된 안테나는 전 대역에서 임피던스 대역폭(VSWR ${\leq}$ 3)을 만족하고, 공진주파수는 920 MHz, 1.97 GHz, 2.45 GHz이며, 최대이득은 각각 1.92 dBi, 3.26 dBi, 3.97 dBi의 값으로 측정 되었다. In this paper, an antenna which has quad band in GSM/DCS/PCS/Bluetooth is proposed. This structure is designed with miniaturization for wide band characteristic based on monopole antenna and log-periodic toothed trapezoid patch antenna which has slots. To achieve multi-bandwidth is used the microstrip line on the substrate. An antenna size is $35mm{\times}20mm$ on FR-4(${\varepsilon}r=4.4$) ground substrate of $35mm{\times}75mm{\times}1mm$ size. And proposed antenna is satisfied with impedance bandwidth(VSWR ${\leq}$ 3). The simulated maximum radiation gain is 1.92 dBi, 3.26 dBi, 3.97 dBi at the center frequency of 0.92 GHz, 1.97 GHz, 2.45 GHz, respectively.

노화(老化)의 연구동향(硏究動向)에 관한 고찰(考察)

이홍민,서정철,김용석,Lee, Hong-Min,Seo, Jung-Chul,Kim, Yong-Suk 대한침구의학회 2001 대한침구의학회지 Vol.18 No.1

Objectrve : To research the trends of the study related to aging process, and to establish the direction of the study on aging process. Method : We reviewed the journal and essay about the aging process which are published as well in Korea as in foreign country. Results : 1. The study on the Oriental Medicine field can be classfied with the fourth. first, the study of single herb medication's effect on the aging process. second, the study of multiple herb medication's effect on the aging process. third, the study of herb-acupuncture solution's effect on the aging process. fourth, journal review. We find the fact that the study on the Oriental Medicine is concerned with pathology of deficiency syndrome of the kidneys, retention of phlegm and fluid, blood stasis. 2. On the Western Medicine field, mechanism and pathology of aging pracess primarily has been studied. The mechanism of aging process is classified with 'Wear and tear theory' and 'Genome-based theory'. Among the mechanism of aging process, 'Free radical theory' is the most important. Additionally 'Senescence-Accelerated Mouse' has been studied. 3. We review the journal published in foreign country and its subject was the following: first, moxibustion combined with acu-area skin allograft therapy for the aging was effective, second, the traditional chinese medicine bu-zhong-yi-qi-tang in mice have anti-aging effect. third, the overview Preventive geriatrics of Traditional chinese medicine. 4. We researched anti-aging effect study in the journal of the Korean Acupuncture and Moxibustion, and we found a few journal of Herb-acupuncture solution's anti-aging effect. Hereafter, it is necessory that we will study about relationship between acupuncture-moxibustion therpy and anti-aging effect using Senescence-Accelerated Mouse.

족삼리(足三里) 경혈배합(經穴配合)에 따른 SHR의 뇌줄기, 소뇌(小腦) 영역(領域)에서 NADPH-diaphorase와 nNOS, 신경세포(神經細胞)의 변화연구(變化硏究)

이홍민,김창환,김용석,Lee, Hong-min,Kim, Chang-hwan,Kim, Yong-suk 대한침구의학회 2003 대한침구의학회지 Vol.20 No.6

Objective: This study examines the effects of acupoint combination on NADPH-diaphorase and neuronal nitric oxide synthase(nNOS) in the brainstem of spontaneously hypertensive rats. Methods: The changes of NADPH-d-positive neurons using a histochemical method and the changes of nNOS-positive neurons using an immunohistochemical method were evaluated. The optical densities of NADPH-d-positive neurons and nNOS-positive neurons of the Choksamni(ST36) Umnungchon(SP9) groups were significantly increased in all brainstem areas as compared to the Choksamni and Choksamni Kokchi(LI11) groups and decreased, with the exeption of the nNOS-positive neurons in the superficial gray of superior colliculus, as compared to the normal group. Results: Our results demonstrated that electroacupuncture changes the activity in the NO system in the brainstem of SHR and the acupoint combination is one of the important parameters for this effect.

구조물의 변위 및 변형 형상 계측을 위한 지상 레이저 스캐닝 시스템

이홍민(Hong Min Lee),박효선(Hyo Seon Park) 한국강구조학회 2009 韓國鋼構造學會誌 Vol.21 No.4

FEM 기반 TLS를 이용한 철골 보의 응력추정에 관한 연구

이홍민(Lee Hong-Min),박효선(Park Hyo-Seon) 대한건축학회 2008 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.28 No.1(구조계)

Terrestrial laser scanning (TLS) is the system that can remotely obtain three-dimensional coordinates of an object using laser pluses. It is advantageous in obtaining not only the specific location of a target object but also three-dimensional coordinate data of its overall shape. The advantages of terrestrial laser scanning will not further require installation of a sensor to a target structure whose structural response will be assessed, and they will resolve the limitations that the measurement of the specific part to which the conventional type of sensor was attached. This paper presents the method for the automatic estimation of the stress of structure using terrestrial laser scanning in association with finite element method (FEM). The method is experimentally applied to estimation of stress of a simply supported steel beam subjected to a concentrated load. The results of the experimental application indicate that terrestrial laser scanning is useful in assessing the stress of structural members.

금속 접지 판이 없는 이중대역 메타 물질 흡수체

이홍민(Hong-Min Lee),이형섭(Hyung-Sup Lee) 한국전자파학회 2012 한국전자파학회논문지 Vol.23 No.7

본 논문에서는 SRR의 자계 공진을 이용한 새로운 이중 대역 메타 물질 구조의 흡수체를 제안하였다. 제안된 메타 물질 구조의 단위 셀은 두 개의 OCSRR과 SRR의 구조로 이루어 졌다. 연구에서는 금속 접지 면을 갖지 않는 구조로 설계하기 위하여 평면 배열된 SRR들은 입사 전자파의 진행 방향과 평행하게 놓여졌다. FR-4 기판 양면에 총 39×39개의 단위 셀들의 배열로 이루어진 흡수체 시작품을 제작하고 측정하였다. 제안된 금속 접지판이 없는 구조는 마이크로파 주파수대 흡수체로 응용이 가능함을 보였다. In this paper, the authors present a new design for a dual-band metamaterial(MTM) absorber that utilizes resonantmagnetic inclusion of a split-ring resonator(SRR). The proposed MTM unit cell is constructed by two open complementary split-ring resonators(OCSRRs) and an SRR arrangement. To avoid the need for metallic back plate a planar array of SRRs for resonant-magnetic inclusion is placed facing toward the incident wave propagation direction. Each unit cell is printed on the two sides of a FR-4 substrate. A prototype absorber was fabricated with a planar array of 39×39 unit cells, and measured. The proposed backplane-less absorber can be used for microwave applications.

진동현 센서의 평균변형률을 이용한 보-기둥의 최대응력 추정

이홍민(Lee Hong-Min),박효선(Park Hyo-Seon) 대한건축학회 2009 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.29 No.1(구조계)

Vibrating wire strain gages are frequently used for measuring strains of a structure in fields of structural monitoring of buildings and civil engineering. The attached or imbedded gages measure the deformation of a structure by measuring the average strain on a member's section equal to the gage length. In the case of beam-column members, however, the longitudinal strain distribution is non-uniform since the members are subjected to both axial forces and bending moments. Therefore, it is difficult to directly measure the maximum strain from vibrating wire strain gages for safety assessment. This paper presents a method that can estimates the maximum stress of a beam-column member from the average strain measured from vibrating wire strain gages. To verify the usefulness of the method, experimental tests on a two-dimensional steel frame structure with a beam-column member, which is subject to axial force and bending moments, are performed.

전기산화공법을 이용한 고농도폐수 처리공정의 모델링 및 최적화

이홍민 ( Hong Min Lee ),이상선 ( Sang Sun Lee ),황성원 ( Sung Won Hwang ),진동복 ( Dong Bok Jin ) 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.3

Electro oxidation system was designed in this study for the reduction of COD (Chemical Oxygen Demand) from high-strength wastewater, produced during refinery turnaround period. First, BDD (Boron Doped Diamond) electrode was synthesized and electro oxidation system of actual industrial wastewater was developed by adopting the synthesized BDD electrode. The experiments were carried out under various operating conditions under certain range of current density, pH, electrolyte concentration and reaction time. Secondly, reaction kinetics were identified based on the experimental results, and the kinetics were embedded into a genetic mathematical model of the electro oxidation system. Lastly, design and operating parameters of the process were optimized to maximize the efficiency of the pretreatment system. The coefficient of determination (R2) of the model was found to be 0.982, and it proved high accuracy of the model compared with experimental results.