현장 재하시험을 통한 국내고용 교량에 대한 동적효과 분석

황진하,박종희,박광림 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.2

A statistical analysis for estimation the dynamic characteristics of bridge structures is presented in this paper. The dynamic responses of the real bridges due to test vehicles and normal traffic loads are measured for 147 bridges with different types and span lengths etc. Using the measured data in field, correlation and regression analysis of vibration-related parameters are performed on SPSS, and the results are compared with Standard Specifications. From the results of this study, it considered that impact factors in Korean Specification seems to have low values, as the span length increases regardless of the structural types, and to give high load carrying factors.

상시계측자료의 관리를 위한 테이터베이스의 원형 설계

황진하,박종희,조대현 충북대학교 건설기술연구소 2003 建設技術論文集 Vol.22 No.2

Prototype design of the database for ambient measurement data management is presented in this paper. To express the associated data generated during the whole process of ambient measurement efficiently, requirement/task analysis for database management system are peformed. And then to define and organize objects and schema for data model, conceptual and logical design are performed, which convert data model into logical schema. This prototype database is constructed by using via the object-relational data modelling approach.

다층인공신경망에 기초한 구조계 정정

황진하,박종회,김주한 충북대학교 건설기술연구소 2004 建設技術論文集 Vol.23 No.1

The structural system identification using neural networks is presented in this study. Among the neural networks, backpropagation neural network is adopted to fulfill the damage assessment. When the damages occur, the structural responses are changed and the responses contain the damage locations and extents. The static displacements of the truss structure are induced by the various damage states under the static load. In the neural networks the displaces are the inputs and the damage locations and extents are the outputs. The simulation informs that it is efficient to apply the neural network to the damage detection.

Jacobi 반복법을 이용한 합성 근사 구조재해석

황진하,김경일 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.1

A design-oriented structural reanalysis method is presented in this paper. The new combined approximation method is based on combining the computed terms of Jacobi iteration and coefficients of a reduced basis method. Some examples are demonstrated to show the validity and efficiency of the present study. Satisfactory results compared to the exact method show that the proposed method is worth being incorporated into the design procedures of the large structural systems. This method can improves the total efficiency when they are appropriately used according to the design informations for the redesign process of large scale structures. The numerical results for some trusses show the validity and usability of the method.

설계조건 분할에 의한 다단계 구조최적화

황진하,박종회,정진덕 충북대학교 건설기술연구소 2002 建設技術論文集 Vol.21 No.1

A new method that performs multilevel design optimization for structural design is presented in this paper. This study demonstrates hybrid optimization method which combines a general mathematical programming algorithm with classical fully stressed design method. Systems optimization is achieved with system level constraints by the former, while the latter is exercised with local constraints in subsystem level. Numerical results for widely used truss models show the validity and efficiency of this study.

실험적 모드해석을 위한 장치구성 및 LabVIEW 프로그래밍

황진하,박종회,정진덕 충북대학교 건설기술연구소 2004 建設技術論文集 Vol.23 No.1

The purpose of this paper is to construct the vibration test equipments for experimental modal analysis which is more economical than commercial measurement equipments and to develop the analysis program which can be used to extract the dynamic characteristics of structures such as natural frequencies and mode shapes. To verify and validate the suggested hardwares and softwares for economical and accurate vibration test, a cantilever beam test was carried out and the results were compared with the numerical results which was calculated from FE analysis and theoretical values.

원격구조모니터링시스템 개발을 위한 개념설계

황진하,박종희,정진덕,김주한 충북대학교 건설기술연구소 2003 建設技術論文集 Vol.22 No.2

A conceptual design for the development of a remote structural monitoring system is presented in this study. First of all, to satisfy the engineering and customer requirements, requirements/functional analysis for the remote structural monitoring systems are performed in context of the systems approach. The problem definition is given, And the market competitors are analyzed by benchmarking and the alternatives are evaluated. Based on the informations from the above stage, the key elements of the systems are extracted through the functional decomposition and the schematic specifications are described.

내후성 폴리머 콘크리트의 제조 및 특성연구

연규석,김기성,이기원,황진하 강원대학교 석재복합신소재제품연구센터 2001 석재연 논문집 Vol.6 No.-

본 연구에서는 불포화 폴리에스터 수지비율을 변수로 하는 자외선 흡수제 첨가유ㆍ무 시편에 대한 Xenon lamp, 52±3℃, 실내습도 50±5%, 시험체 걸이 직경 20inches의 조건의 내후성 시험기로 각각 100, 200, 400, 800, 1600 시간 인공촉진열화 시킨 시편의 색차변화를 측정하여 불포화 폴리에서터 수지량 및 자외선 흡수제의 첨가에 의한 열화특성을 고찰하였다. 그 결과 100% 불포화 폴리에스터 수지량 및 자외선 흡수제의 첨가에 의한 열화특성을 고찰하였다. 그 결과 100% 불포화 폴리에스터 수지 시편과 상대적으로 수지비율이 큰 폴리머 페이스트에서는 자외선 조사시간에 따른 큰 색차변화 및 자외선 첨가에 의한 열화방지 효과를 확인 할 수 있었고 불포화 폴리에스터 수지비율이 상대적으로 작은 폴리머 모르타르에서는 자외선 조사에 의한 색차변화 및 자외선 흡수제 첨가에 의한 열화방지가 그리 크지 않음을 확인할 수 있었다. 이러한 것은 야외에 설치되는 폴리머 모르타르(콘크리트) 제품은 자외선에 의한 열화가 그리 크지 않음을 보여주는 결과이기도 하다. This study was to investigate the characteristics of deterioration of polymer concrete due to wethering Two sets of specimens with a various mixing ratio of unsaturated polyester resin, UV absorber added and not-added, were artificially exposed by the weathering test machine to ultraviolet (UV) radiation 100, 200, 400, 800 and 1600 hours under the conditions that the temperature was set by Xenon lamp at 52±3℃, the chamber humidity at 50±5%, and specimen rack diameter 20 inches to measure the color change to examine the characteristics of deterioration. Color difference increased as the exposure time to UV radiation increased, but decreased 20-30%, comparing to the case of non-absorber added, as the ultraviolet absorber was added. On the other hand, the effect of addition of ultraviolet absorber decreased as addition of aggregate increase. Thus, the effect of addition of ultraviolet absorber was a little on the polymer concrete containing aggregate, Especially, increment of color difference in polymer mortar specimen was lower than that of polymer resin and polymer paste specimen, when the resin volume for specimen mixture proportion was below 30%, as fine aggregate increased. As a result, outdoor-installed polymer concrete product is believed to be hardly affected by ultraviolet radiation.

全北地方의 放射能資源 探査

盧鈑愚,金駿培,嚴大翼,朴鎭夏,黃鎬觀,李春鎬 全北大學校 文理科大學 1975 論文集 Vol.2 No.-

For the utilization of atomic energy, radioactive mineral survey was projected in Jeonbuk District of the north of 3°50′ N. L. and 127°00 E-127°45′ E. Consequently, Mt. Yongwha, Mt. Chonho and Bibong areas were chemically and physically selected as the most prospective ones, and these areas, which have the radioactivities more than 28 cpm, were assumed to have the radioactive minerals related with black slates of Ockchon System.

저수축형 폴리머 콘크리트의 제조 및 물리·역학적 특성

연규석,이윤수,최동순,정경현,황진하 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

본 연구에서는 폴리머 콘크리트의 수축저감을 목적으로 수지량, 수축저감제함량과 S/a 비등을 변화시켜 경화수축의 변화와 강도 특성을 실험적으로 구명하였다. 경화수축량은 수치량이 105%일 때 보다 11.5%일 때, 즉 수지량이 증가할수록 커짐을 알 수 있었다. 수축저감제의 첨가에 따른 경화수축량은 감소함을 알 수 있었다. B10.5-SR10일 경우 수축저감제가 첨가되지 않았을 때 보다 약 30%, B10.5-SR20 일 경우 약 53%, B11.5-SR10일 경우 약 31%, B11.5-SR20 일 경우 약 47% 정도의 수축저감의 효과를 볼 수 있었다. S/a 비에 따른 경화 수축챨ㅇ은 S/a 60일 때 가장 적은 값을 보였으며, S/a 50, S/a 40 일때는 S/a60 일 때 가장 적은 값을 보였으며, S/a 50, S/a 40일 때는 S/a 60일 때 보다 각각 10%, 30% 정도 수축량이 증가함을 알 수 있었다. 압축 및 휨 강도특성은 수지량이 증가할수록 높아지고, 수축저감제의 첨가량이 증가할수록 낮아짐을 알 수 있었다. S/a 비에 따른 강도 특성은 압축강도와 휨강도 모두 S/a 비가 60일 때 가장 큰 값을 보였으며, S/a 비가 50,40 순으로 감소하였다. Many different polymer based concrete materials are known today, but the large setting or hardening shrinkage of polymer concrete is a problem to overcome in their practical applications. The setting shrinkage reaches about five to ten times the drying shrinkage of ordinary cement concrete, i.e, 50 to 60 ×10^4. This paper deals with a reduction in the hardening shrinkage of unsaturated polyester resin concrete which is treated with respect to shrinkage-reducing agent content, S/a ratio and catalyst content, and tested for length change during hardening, and flexural and compressive strengths. It is shown that the change of shrinkage-reducing agent content and S/a ration the length change of the unsaturated polyester resin concrete during hardening.