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        검색결과 919

        645.
        2013.02 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to evaluate fish passage efficiency, based on fish-trap monitoring methodology, in the fishway of Seungchon Weir, which was constructed on the lower region of Yeongsan River in 2011. Seasonal patterns and diel variations of fish movements, fish fauna, and compositions in the fishway were analyzed in relation to the current velocity and location of the trap-setting in the fishway. For the analysis, we conducted seven times surveys in 2012 on the fishway and also conducted intensive monitoring of the fishway as 3 hrs interval for the diel variations of fish fauna and compositions in the fishway. According to the fish-trap monitoring methodology, the total number of fish species was 13 species, which was a 43.3% of the total. Most dominant fish used the fishway was Squalidus chankaensis tsuchigae and the relative abundance of the species used the fishway was 33.5% of the total. The season and time zone (in diel variation) observed most frequently in the fishway were July and 18:00-21:00 PM, respectively. The fish movements and use-rates of fishway varied depending on the locations of trap-setting; Fish biomass and the number of species were statistically (p < 0.05) greater in the most right or left-sided traps than in the mid-traps. Also, fish movements and use-rates of fishway were influenced by current velocity on the fishway; fish in the fishway preferred the low current velocity (mean 0.71 m/sec) than the high current velocity (mean 1.13 m/sec). Further long-term studies should be monitored for the efficiency evaluations of the fishway.
        646.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        한국원자력연구원의 지하처분연구시설인 KURT 주변의 지하수 유동 환경과 관련하여 수집 및 분석된 자료를 바탕으로, 가상의 처분장에서 누출된 방사성 핵종의 이동 현상을 시간 영역(time domain)에서 계산하였다. KURT에서 실시된 현장 시험에서 밝혀진 수리지질학적 특성을 바탕으로 지하수 유동 모의를 실시하였고, 그 결과를 통해 파악된 지하수 유동 경로를 따라 방사성 핵종이 이동하는데 걸리는 시간은 시간 영역에서 용질 이동 모의를 하는 TDRW(Time Domain Random Walk) 방식을 통해 평가하였다. 이류(advection)와 분산(dispersion) 현상 외에 방사성 핵종의 붕괴(decay), 평형 흡착(equilibrium sorption),암반 기질로의 확산(matrix diffusion) 현상이 용질의 이동 시간에 영향을 주는 것으로 설정되었다. 모의 결과를 통해 방사성핵종과 지하 매질의 특성에 의한 흡착 현상, 기질 확산 현상이 핵종 이동에 미치는 영향이 분석되었으며, 방사성 핵종의 연쇄반응에 의한 영향도 평가하였다. KURT 부지 환경에서 지표로 유출될 수 있다고 계산된 방사성 핵종의 유출량은 처분장에서 누출될 수 있는 양의 10-3배 미만이었고, 암반 기질로의 확산 및 흡착이 고려되면 그 비율이 더욱 낮아졌다. 본 연구에서 사용된 핵종 이동 모의 방법은 방사성붕괴나 흡착, 확산 등 이동 지연 현상을 고려하면서 핵종의 이동 시간을 계산할 수 있어 안전성 평가에서 요구되는 심부 지하에서의 방사성 핵종 이동 관련 자료를 작성하는데 활용될 수 있을 것이다.
        647.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        원전이 위치한 동해 월성 연안역 주변에서 오염물 이동·확산에 대한 수치 모사를 수행하였다. 월성 연안역의 유속장 재현을 위한 해수유동 수치모형 실험은 EFDC(Environmental Fluid Dynamics Code) 모델을 사용하여 조위 시계열 검증 및 조화분석을 통한 검증을 실시한 결과 양호한 재현성을 나타내었다. 월성 주변해역의 유속장 산정 결과 창조류시에는 남향, 낙조류 시에는 북향으로 진행되는 결과를 알 수 있었다. 또한 국립수산과학원에서 관측한 수온, 염분의 자료를 이용하여 수치모델을 통한 계산값과 관측값을 비교한 결과 양호한 재현성을 나타내었다. 계산된 해수유동자료와 수온, 염분의 결과를 이용하여 오염물질의 확산특성을 해석하였다.
        648.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구에서는 콜로이드와 핵종의 복합이동에 관한 수치모델을 개발하였다. 콜로이드와 핵종의 반응-이동 지배방정식을 풀기 위하여 Operator Splitting Method 중 Strang의 분리 SNI 방식을 수치해석 방법으로 채택하였고 이는 MATLAB을 이용하여코드화 되었다. 개발된 수치모델은 용질의 이동 및 분산만을 고려한 해석해를 통한 검증과정에서 피어슨 상관계수의 제곱값(r2)이 0.99 이상으로 나타나 모델의 정확성이 입증되었다.
        649.
        2012.11 서비스 종료(열람 제한)
        A strain compatibility method is based on the strain compatibility approach proposed by AISC (American Institute of Steel Construction, Inc.). The strain compatibility method assumes a linear strain of all the members. After that, set up the equilibrium equations of the state of stress in each component for calculating the location of the neutral axis of the cross-section in the presence. In this study, the reinforced concrete simple beam is analyzed by strain compatibility method for calculating the neutral axis and the bending moment. And then, a variation of neutral axis of the reinforced concrete simple beam is measured.
        650.
        2012.11 서비스 종료(열람 제한)
        The slope adjacent to the road, when it is difficult to observe the shape and if not at the bottom of the upper slopes or steep high due to the presence of the upper slopes of the exact visual inspection is difficult, there is a direct investigation lengthy complaints. In this study, the disadvantages of having the inspection personnel based complementary and mixed low-cost single global region is the number of slope maintenance and safety can be managed efficiently so that helicopters and hexa mobile survey vehicle was developed. Equipment developed difficulties in spatial or temporal slope Visually inspect efficient investigation to be able to support. Survey vehicle computer to the Internet environment because it contains Slope check immediately to determine test results sent to the Center, and the efficient maintenance can be performed.
        651.
        2012.10 KCI 등재 서비스 종료(열람 제한)
        As increasing incidents of FMD (Foot and Mouth Disease) in recent years, the country has struggled with huge economic losses and environmental problems. Because of relying only on the burial method according to domestic condition, it needs to consider the alternative measure such as the incineration with being no secondary environmental pollution. In addition, such FMD and AI (Avian Influenza) as classifying in the first-class malignant diseases are very important to be ready with rapidly initial response because of the fact being quickly spreaded with high infection speed. Accordingly, a favorable initial response by the introduction of mobile incinerators has been forced to consider. In this study, it analyzed and compared the existing disposal regulations and methods of carcasses to establish the reasonableness about introducing an incineration technology. In addition, domestic and international disposal status was compared as investigating regulations or disposal law, guidelines of livestock in major developed countries. To introduce the mobile incineration facilities in domestic, it is surveyed international examples and related regulations of using and developing mobile incinerators. The results of study could be used as basic information to design and utilize a mobile incineration process for slaughter animals by deceases.
        652.
        2012.10 KCI 등재 서비스 종료(열람 제한)
        본 연구는 오른쪽 어깨관절에 칼텐본-에비엔즈컨셉 미끄러뜨림 등급Ⅱ와 Ⅲ으로 아래쪽미끄러뜨림적용시 위팔뼈머리의 이동거리 및 벌림각도(abduction angle)의 변화를 알아보고자 하였다. 미끄러뜨림 등급Ⅱ(Grade Ⅱ) 적용시 위팔뼈머리는 초기보다 아래쪽으로 5㎜ 가량 이동하였고 등급Ⅲ 적용시 8㎜ 가량 이동하였다. 이동거리에 대한 성별 비교에서는 남자가 여자에 비해 등급별로 이동거리가 높게 나타났으나 통계적으로 유의한 차이는 나타나지 않았다. 등급Ⅱ(Grade Ⅱ) 적용시 벌림각도는 초기보다 10°가량, 등급Ⅲ(Grade Ⅲ) 적용시 12°가량 증가하였다. 벌림각도에 대한성별 비교에서는 모든 등급별로 여자가 남자보다 벌림각도가 크게 나타났으나 통계적으로 유의한 차이는 나타나지 않았다.본 연구를 통해 미끄러뜨림 등급 적용시 위팔뼈머리의 운동형상학적 변화를 알아보았으며 향후 추가 연구를 통해이들 변화가 주변 구조물에 미치는 영향에 대해 알아본다면 보다 과학적인 근거중심의 치료를 기대할 수 있을 것으로사료된다.
        656.
        2012.07 KCI 등재 서비스 종료(열람 제한)
        This study analyzed mass concentrations of TSP, PM10 and PM2.5 and elemental constituents according to the isentropic backward trajectories of air parcel from Cheongwonin East Asia during the period January – October, 2011. Mass concentrations of the continental polluted airflow (CP) showed levels of TSP and PM10 mass concentrations higher than the continental background airflow (CB). Also, PM2.5 mass concentrations of anthropogenic fine particles ran higher in CP than in CB. The elemental constituents and elemental constituent ratio ended up varying depending on the origin of atmospheric aerosols generated. The average absolute content of elemental constituents reached its height in CB, the ratio of anthropogenically originating elements (PE) among the all elements (AE) analyzed marked a high in CP, and Mg+Na/AE reached its height in the oceanic airflow (OA). At the same time, TSP, PM10 and PM2.5 mass concentrations, the ratio of PM2.5/TSP and PE/AE element ratio ran higher in CP than CB. Episodes of large-scale transport of atmospheric pollutants as observed at Cheongwon were 8 cases and 22 days. The ratios of PM10, PM2.5 among TSP mass concentrations showed different results and the ratios of PM2.5 showed an increasing trend in the episodes of anthropogenic air pollution transport. Overall, dustfall episodes show a level of elemental constituents higher than those of anthropogenic air pollution.Dustfall episodes were observed to contain more of Fe, Al and Ca originating from continental soils and those of air pollution were observed to contain more of Zn, Mn, Cu and Pb. By difference in contents of absolute elemental constituents, episodes of anthropogenic air pollution showed a high PE/AE rate, and dustfall episodes a high SE/AE rate.
        657.
        2012.05 KCI 등재 서비스 종료(열람 제한)
        In this paper, we propose a cable climbing robot which can climb up and down the cables in the bridges. The robot mechanism consists of three parts: a wheel based driving mechanism, adhesion mechanism, and safe landing mechanism. The wheel based driving mechanism is driven by tooth clutches and motors. The adhesion mechanism plays the role of maintaining adhesion force by a combination of pantograph, ball screw, and springs even when the power is lost. The safe landing mechanism is developed for guaranteeing the safety of the robot during operations on cables. It can make the robot fall down with reduced speed by dissipating the gravitational forces. The robot mechanism is designed and manufactured for validating its effectiveness.
        658.
        2012.05 KCI 등재 서비스 종료(열람 제한)
        This paper introduces several mobile robots developed by using LEGO MIDSTORM for experimental studies of robotics engineering education. The first mobile robot is the line tracer robot that tracks a line, which is a prototype of wheel-driven mobile robots. Ultra violet sensors are used to detect and follow the line. The second robot system is a two-wheel balancing robot that is somewhat nonlinear and complex. For the robot to balance, a gyro sensor is used to detect a balancing angle and PD control is used. The last robot system is a combined system of a line tracer and a two-wheel balancing robot. Sensor filtering and control algorithms are tested through experimental studies.