In this paper, seismic performance evaluation was carried out for eight circular reinforced concrete columns designed seismically by KRTA[1]and KCI[8]. Primary design parameters for such columns included many longitudinal reinforcements, yield strength of reinforcements, the vertical spacing of spirals, aspect ratio, and axial force ratio. The test results showed that all the columns exhibited stable hysteretic and inelastic responses. Based on the test results, drift ratios corresponding to each damage state, such as initial yielding, initial cover spalling, initial core concrete crushing, buckling, and fracture of longitudinal reinforcement and final spalled region, were evaluated. Then, those ratios were compared with widely accepted damage limit states. The comparison revealed that the existing damage states were considerably conservative. This implies that additional research is required for the damage limit states of such columns designed seismically by current Korean design codes.
최근, 시멘트 사용량을 줄이고, 경제성을 확보하기 위하여 혼화재료를 적용한 콘크리트 포장에 대하여 많은 연구가 이루어지고 있다. 국내외적으로 콘크리트 포장용 결합재로써 활용되어지고 있는 혼화재료로써 고로슬래그, 플라이애시 등이 있으며, 이 중 고로슬래그는 냉각방법에 따라 급수로 냉각처리된 급냉슬래그와 공기 중에 냉각처리된 서냉슬래그로 분류될 수 있다. 서냉슬래그는 화학조성이 급냉슬래그와 유사하고 염기도가 높아 콘크리트용 혼화재료로 사용될 경우, 콘크리트 중 수산화칼슘과의 잠재수경성 발현에 유리하여 콘크리트 포장용 결합재로써 활용이 가능할 것으로 보고되고 있으며, 서냉슬래그의 물리화학적 특성을 기반으로 하여 서냉슬래그를 콘크리트 포장재료로써 활용하기 위한 몇몇의 연구가 진행되어 오고 있다. 본 연구에서는 서냉슬래그를 콘크리트 포장재료로 사용하여 공시체를 제조하였으며, 콘크리트의 공학적 특성을 실험적으로 평가함으로써, 서냉슬래그의 콘크리트 포장재료로써 적용가능성을 실험적으로 검토하였다.
상온 아스팔트는 70년대 초반 석유위기 인하여 아스팔트 가격이 상승하여 대안으로 발전을 맞이 하였으나 이후 가열 아스팔트에 밀려 크게 활성화 되지 못하였다. 활성화 되지 못했던 중요한 이유 중에 하나는 상온 아스팔트는 양생시간이 필요하고 양생 후에도 가열 아스팔트에 비하여 공학적 성능이 우수하지 않았기 때문이다. 이산화탄소 배출을 억제하고 새로운 상온 화학 기술이 진보하고 아스팔트 재활용에 대한 관심이 고조 되면서 새로운 상온 아스팔트 공법이 개발되고 있다. 본 연구는 중속 경화(Medium setting: MS) 상온 아스팔트를 사용하여 혼합물을 제조하여 관련 시험을 수행하였다. 시험 결과 기존 상온 아스팔트에 비하여 양생 속도가 신속하고 성능이 향상되어 새로운 포장공법으로 기대된다.
It has been very important to have an exact evaluation for risk factors in order to prevent WMSDs(Work-related Musculoskeletal Disorders). However, most WMSDs evaluation methods have always been some problems of possibilities associated with subjective evaluation. Therefore, this study tried to conduct a sort of usability analysis on three major evaluation methods(OWAS, RULA, REBA). Specifically, major subjects in the study consisted of three parts as follows; comparison of the results between experienced and inexperienced observers, analysis for the consistency of the results in terms of different evaluation times, and analysis for the consistency of the results in terms of different job characteristics(based on the part of the automobile). The results of the study were summarized as follows; 1) There was statistically significant difference of the results by RULA and by REBA between experienced and inexperienced observers. This might be due to the fact that experienced observers have had better ability to detect the important working posture during evaluation. However, the results by OWAS did not give any significantly different results between experienced and inexperienced observers, 2) All three checklists applied by experienced subjects did not show any single result significantly different in terms of different evaluation times. This might have to do with high intra-observer reliability from some of previous studies, 3) The five parts of an automobile were selected as five major jobs with different job characteristics in the automobile industry. Specifically, they were door part, front part(hood, etc.), inside part(dash board, seats, etc.), rear part(trunk etc.), and bottom part. All three methods did not show any significant differences for the results from each observers. Further study on this subject would eventually provide a sophisticated evaluating guidelines for WMSDs regarding determination of observer-specific evaluation, identification of repetitive number of evaluations for stable results for each checklist, determination of job-specific evaluation methods, and so on.
입도조정기층 재료의 역학적 특성평가를 위하여 15개 시료에 대해 반복재하 삼축압축시험, CBR 시험, 투수계수시험을 수행하였다. 입도조정기층 재료의 CBR 값은 32~110 범위(평균 81)에서 매우 폭넓게 결정되었으며, 수침조건에서 팽창량은 0.04mm 이하로 나타났다. 입도조정기층 재료의 탄성계수는 체적응력의 영향을 매우 크게 받았으며 선형체적응력모델의 적용성이 가장 뛰어남을 확인하였다. 입도조정기층 재료의 탄성계수는 100MPa~600MPa, 모델계수 k1은 80~270, 모델계수 k2는 0.1~0.6 사이에서 결정 되었다. 체가름시험과 다짐시험에서 결정된 지수물성치로부터 입도조정기층 재료의 탄성계수를 결정하는 경험모형을 제안하였다. 제안된 경험모형의 결정계수는 모델계수 k1 결정에 있어서는 0.423, 모델계수 k2 결정에 있어서는 0.920, 응력단계별 탄성계수 결정에 있어서는 0.872로 평가되었다.
Cycling that transform human energy into mechanical energy is one of the man-machine systems out of sports fields. Benchmarking means "improving ourselves by learning from others', therefore benchmarking toward dominant cyclist is necessary on field. The goals of this study were to provide important factors on multi-disciplines (kinematics, physiology, power, psychology) for a tailored-training program that is suitable to individual characteristics. Two cyclists participated in this study and gave consent to the experimental procedure. One was dominant cyclist (years: 21 yrs, height: 177 cm, mass: 70 kg), and the other was non-dominant cyclist (years: 21, height: 176, mass: 70). Kinematic data were recorded using six infrared cameras (240Hz) and QTM (software). Physiological data (VO2max, AT) were acquired according to graded exercising test with cycle ergometer and power with Wingate test used by Bar-Or et. al (1977) and to evaluate muscle function with Cybex. Psychological data were collected with competitive state anxiety inventory (CSAI-2) that was devised by Martens et. al (1990) and athletes' self-management questionnaire (ASMQ) of Huh (2003). It appears that the dominant's CV of ankle joint angle was higher than non-dominant's CV and dominant's pedaling pattern was consistent in biomechanics domain, which the dominant's values for all factors ware higher than non-dominant's values in physical, and physiological domain, and their values between cognitive anxiety and somatic anxiety were contrary to each other in psychology. Further research on multi-disciplines may lead to the development of tailored-optimal training programs applicable with key factors to enhance athletic performance by means of research including athlete, coach and parents.
Cycling that transform human energy into mechanical energy is one of the man-machine systems out of sports fields. Benchmarking means " improving ourselves by learning from others ", therefore benchmarking toward dominant cyclist is necessary on field. the goals of this study were to provide important factors on multi-disciplines (kinematics, physiology, power, psychology) for a tailored-training program that is suitable to individual characteristics. Two cyclist participated in this study and gave consent to the experimental procedure. one was dominant cyclist (years:21 yrs, height:177 cm, mass:70 kg), and the other was non-dominant cyclist(years:21, height:176, mass:70). Kinematic data were recorded using six infrared cameras (240Hz) and QTM (software). Physiological data (VO2max, AT) were acquired according to graded exercising test with cycle ergometer and power with Wingate test used by Bar-Or et. al ( 1977) and to evaluate muscle function with Cybex. Psychological data were collected with competitive state anxiety inventory (CSAI-2) that were devised by Martens et. al (1990) and with athletes' self-management questionnaire (ASMQ) of Huh (2003). It appears that the dominant's CV(coefficient of variability) was higher than non-dominant's CV in Sports Biomechanics domain, that the dominant's values for all factors ware higher than non-dominant's values in physical, and physiological domain, and their values between cognitive anxiety and somatic anxiety were contrary to each other in psychology. Further research on multi-disciplines may lead to the development of tailored-optimal training programs applicable with key factors to enhance athletic performance by means of research including athlete, coach and parents.
This study created a computerized information system of the collected job analysis data and analyzed the computerized job analysis data to derive critical job factors. Based on the ratings on each critical job factor, possible employment opportunities for the various types of disability could be derived according to the match between job condition and handicap condition. The results can be utilized by the Employment and Vocational Training Administration to expand both the counselor and counselee's perspectives about job possibilities and job requirements.
The goal of this study is to investigate the ergonomic factors in designing or selecting the hand tool handle. Electromyogram (EMG) were measured for various wrist postures and handle sizes under two loading conditions. Anthropometric data were measured and the correlation with EMG measurement data were analyzed. Investigations of this study show that wrist posture should be neutral for minimum muscle tension and optimum handle size can be found by measuring the EMG measurement data. It show that hand width and EMG measurement data is greatly correlated also. This study can be a guide of designing or selecting a hand tool, but further study with large sample sizes and various groups is needed for making general conclusion.
A standardized ergonomics kit is suggested to evaluate and reduce musculoskeletal hazards that yield large socioeconomic burdens in the work system. This kit comprises basic and detailed analysis tools with proper tool selection rules. The basic tool includes a checklist for various risk factors to screen potentially hazardous jobs among manual works. Selective detailed analysis tools can then be applied to the screened job lists for more quantitative and precise evaluation. The tool selection rules are devised for using the basic and detailed analysis tools in a mutually supplemental way. To validate the standardized ergonomics kit, it was applied to evaluate jobs related to the musculoskeletal hazards in a paper-making industry. Among 101 manual jobs investigated, 44 potential hazardous jobs were screened during basic investigation phase and finally 16 hazardous jobs were identified by the detailed analysis phase. The result provided fairly promising ideas of ergonomic interventions for the hazardous jobs.
패션소재로서의 유용성을 결정하는 속성을 두께, 무게, 밀도, 광택, 색상 등으로 한정한 후 다속성 모델을 구축하였다. 각 속성들의 가중치는 의류 매장의 방문객 대상의 설문 조사에 의해 결정되었으며, 한 소재의 최종가치는 퍼지 추론 시스템에 의해 계산되었다. 구축된 "퍼지-다속성" 모델을 이용하여 패션소재의 총 가치를 i) 품질로부터의 가치, ii) 품질을 기반으로 부가되는 가치, iii) 품질과는 무관하게 형성되는 브랜드 가치의 세 가지 요소를 분해하였다. 시중의 유명 스포츠 의류 브랜드 2종을 선정하여 위의 모델을 적용하였다.모델을 적용하였다.
The prevention of accidents or diseases is one of the most profitable activities in any business. The useful tools to diagnose existing safety problems and to systematically guide the improvement of those deficiencies have been developed in the world. In the recent, however, the importance of the interface between workers and workplaces has been increasingly recognized. In order to audit the correlations of job environments and workers we developed the rating system called "Ergonomic Workplace Assessment Index" for ergonomic condition in this study. The auditors will measure the degree of compliance of the criteria using judgement techniques, checks and interviews with EWAI(Ergonomic Workplace Assessment Index) which involves 5 categories and total 50 elements. elements.
This paper investigate and compare the appraisement methods and programs are related in Ergonomic, which in foreign country are approved to appraise worker's posture and environment. First, Search the appraisement program to need and develop the program. Second, Design and develop the standard model that easy and accurate, and apply to our country workstation. To response above mention, we made the EWAP(Ergonomic Workplace Analysis program) and purpose of EWAP is assisting the activity of safety management to assess more detail and delicate through quantitative methodology in which operated the Ergonomic Workplace safety management. EWAP can provide the more convenience where need to analyze their Ergonomic Workplace problem and developed by the algorithm of Ergonomic Workplace Analysis management.