In reinforced concrete structures, carbonation phenomena associated with deterioration is important. So, this study conducted a visual inspection and a concrete durability test in Precise Safety Diagnosis, analyzed the result, and tried to suggest a reasonable repair method and range of concrete carbonation.
This paper addresses simplified method for nonlinear soil–structure interactions (SSI) analysis of base-isolated nuclear power plant (NPP) structure under incident seismic waves. The accuracy and applicability of the method are evaluated by comparing with nonlinear time history responses obtained by the boundary reaction method (BRM).
Reinforced concrete is used as a main construction because it is excellent durability and strength. However, the problem of durability decrease due to enlargement, high-rise of structures and the cracking due to external force nowadays. Therefore, there is studying on the Textile Reinforced Concrete(TRC), which reinforcing bar changing into Textile. Also, studying on adhesion performance between concrete and Textile. Preceding studies have examined the adhesion performance of single fibers with no specific variable. It can not reflect about grid type and embedding length. Accordingly, on this study examines the change of bond strength according to bond length. As a result, the bond strength increased as the embedding length of the Textile increased, but there was not influence that the bond strength according to the lateral length.
Due to frequent localized torrential downpours caused by environmental contamination, collapses of retaining wall structure have increased, so that it is required to enhance structural strongness. This research focuses on the stability and effectiveness of the soil-nailed natural surface(SNS)”method, which is eco-friendly and functions as retaining wall structure.
This study suggested the improved safety certification marking system on the types of the temporary equipment. By surveying and interviewing the related persons in the construction company, the manufacturing company, and the rental company, the safety certification marking system was analyzed. The results show that the efficient marking was analyzed to utilize a depressed engraving on the target equipment and material. For marked contents, a certification mark, an identification number, and the production year should be displayed and the manufacturer name could be selectively presented. However, the opinions of the certification mark position among the users and manufacturers did not come into the agreement.
Current ASTM specification provide an approach for directly correlating attenuations of the bottom deck or the top rebar from ground penetrating radar (GPR) to deck condition when corrosion is the primary mechanism for concrete deterioration. In this study, GPR tests were conducted on the bridge decks in public service and the characteristics of signal attenuation were investigated with deck condition. As will be discussed, this approach is recommended for further evaluation and incorporation within ASTM D 6087-08.
The review of the existing facilities inspection guideline reveals that the water supply steel pipeline is evaluated mainly by visual and safety inspection. For the efficient maintenance it is necessary to inspect the pipeline using the performance-based evaluation method throughout quantitative measurement. In this study durability evaluation index and evaluation method for the steel pipeline is presented.
Recently, domestic waste policy has focused on resource circulation. In accordance with Article 3, Paragraph 2 of the “Enforcement Rules of Wastes Control Act”, which is targeted at waste incineration facilities, we established and announced methods for calculating the recovery and utilization rates of incineration-sourced heat in 2015. The lower heating value is important to energy recovery and utilization rate calculations. Hence, the lower heating values of the waste incineration facilities were estimated using the thermal method from KS B 6205. Heat loss decreases the heat recovery efficiency, and should be measured and evaluated. The surface temperatures of the incinerator and boiler are required to determine heat loss. Presently, the contact point temperature method is used to measure the surface temperature. It is difficult to apply this method to the average surface temperature of an incineration facility. In this study, 20 Korean waste incineration facilities were selected for heat loss estimates based on waste incineration temperature, incinerator type, and incineration capacity. Infrared thermal cameras were used to measure the surface temperatures of the waste incineration facilities.
조형은 세상의 모든 사물에 미적인 기준을 제시함으로, 디자인 교육에 있어서 조형의 중요성은 강조됐다. 특히, 컴퓨터를 이용한 디자인으로 조형에 대한 중요도가 약화 될 수 있기 때문이다. 디자인 스케치는 조형을 손으로 표현하는 과목이다. 창의적인 아이디어와 수준 높은 조형 그리고 시각적인 표현력을 습득한다. 그러므로 기초 조형을 중심으로 스케치 교육에 필요성을 강조하고자 한다. 그리하여 디자인 스케치에서 조형을 기본으로 창의적인 아름다움에 환경을 실천할 수 있기 때 문이다. 이러한 목적으로 조형에 관한 루벤스의 화면 구도를 중심으로, 조형 요소와 원근, 명암법으로 조형 교육을 위한 분석표를 제시하였다. 그리고 대학의 저학년이 수업에서 이해와 전달이 용이하도록 조형 분석 단계를 단순화하여서 약식 분석법을 제시하였다. 핵심은 조형 요소의 중요도를 기준으로 조화롭게 정리하는 것을 기본으로 하였다. 이러한 과정을 통하여 실질 적인 교육을 하였고, 효과적으로 학생들의 분석 결과를 만들 수 있었다. 이를 기반으로 스케치 조형을 위한 분석표를 기본 으로 디자인 스케치 결과를 만들 수 있었다. 결과적으로 루펜스의 화면구도를 중심으로 조형 교육을 위한 분석표와 약식 분석법, 스케치 조형을 위한 분석표 3단계 연 구와 교육을 통하여, 학생들의 스케치 수업에서 수준이 향상한 것을 확인할 수 있었다. 앞으로 스케치 능력에 조형의 원리 와 요소를 고려한 작업으로 조형의 이해와 스케치 작업 능력에 향상을 기대한다
In this study, It was purpose to provide preliminary data for extension of the applicability of deep corrugated steel plate composite members by steel grade and shear reinforcement method. From the result of flexural test on deep corrugated plates composite members using GR40 and SS590, positive moment capacity was increased about 28% by SS590 steel. But to change steel grade was proved to have insignificant effects for increasement of negative moment capacity. In the moment test result of same overlapping length, Increasement rate of positive and negative moment capacity was not significantly improved by increasing the number of bolt. It was estimated to be due to the characteristics of bolt connection such as distance between centers of bolts, edge distance of bolt. In the test result on the spacing of shear reinforcement, positive moment capacity was increased and deformation of negative moment was reduced as the distance decrease. In the test result on the shape of shear reinforcement, positive and negative moment resistance was increased about 2% ~ 7% by U shaped shear reinforcement. In conclusion It was estimated that moment capacity of deep corrugated steel plate composite members are depend on steel grade of deep corrugated steel plate, spacing of shear reinforcement and reinforcing bar.
본 연구는 강건성 지수와 불확실성 분석기법을 활용하여 기후변화 취약성 평가과정에서 발생하는 불확실성을 정량화하였다. 본 연구는 우리나 라의 6개 광역시(부산, 대구, 인천, 광주, 대전, 울산)를 대상으로 다기준 의사결정기법 중 하나인 TOPSIS 기법을 이용하여 용수공급 취약성 순위를 산정하였다. 강건성 지수는 두 대상 도시의 순위가 가중치의 변화로 인해 순위역전현상이 발생할 수 있는 가능성을 정량화하고 불확실성 분석 기법 은 두 도시 사이에 순위역전이 발생할 수 있는 가중치의 최소 변화량을 산정한다. 그 결과 인천과 대구는 용수공급 측면에서 취약한 것으로 나타났 으며, 대구와 부산은 용수공급 취약성에 민감한 것으로 나타났다. 따라서 대구는 다른 대안에 비해 상대적으로 용수공급이 취약한 지역으로 나타났 으나, 취약성에 민감하기 때문에 기후변화 적응대책 수립 및 시행을 통해 취약성이 크게 향상될 수 있을 것으로 판단된다. 본 연구는 기후변화와 용 수공급 측면에서의 적응전략을 계획하고 수립하는데 있어서 우선적으로 고려해야하는 방향을 제안하는 데 사용될 수 있다.
Unmanned military vehicles (UMVs) will be increasingly applied to the various military operations. These UMVs are most commonly characterized as dealing with “4D” task – dull, dirty, dangerous and difficult with automations. Although most of the UMVs are designed to a high degree of autonomy, the human operator will still intervene in the robots operation, and tele-operate them to achieve his or her mission. Thus, operator capacity, along with robot autonomy and user interface, is one of the important design factors in the research and development of the UMVs. In this paper, we propose the method to assess the operator capacity of the UMVs. The method is comprised of the 6 steps (problem, assumption, goal function identification, operator task analysis, task modeling & simulation, results and assessment), and herein colored Petri-nets are used for the modeling and simulation. Further, an illustrative example is described at the end of this paper.
The Expanded Guide Circle (EGC) method has been originally proposed as the guidance navigation method for improving the efficiency of the remote operation using the sensory information. The previous algorithm is, however, concerned only for the omni-directional mobile robot, so it needs to suggest a suitable one for a mobile robot with non-holonomic constraints. The ego-kinematic transform is a method to map points of R2 into the ego-kinematic space which implicitly represents non-holonomic constraints for admissible paths. Thus, robots with non-holonomic constraints in the ego-kinematic space can be considered as “free-flying object”. In this paper, we propose an effective obstacle avoidance method for mobile robots with non-holonomic constraints by applying EGC method in the ego-kinematic space using the ego-kinematic transformation. This proposed method shows that it works better for non-holonomic mobile robots such as differential-drive robot than the original one. The simulation results show its effectiveness of performance.
원전 해체 이후 원전 부지의 제한적 또는 무제한적 이용에 대해서 미국 NRC는 NUREG-1757 문서를 통해 제한적 또는 무제한적 부지 이용에 관한 방사선학적 기준을 제시하였고 사업자가 제염 및 복원 후 이 선량 기준이 충족됨을 증명할 수 있어야만 부지가 제한적 또는 무제한적으로 해제될 수 있다고 하였다. 이와 관련하여 NRC는 운영허가종료계획서(LTP; License Termination Plan)에 방사선학적 부지 해제 기준 준수를 입증하기 위하여 부지 해제 기준, 부지 특성 평가, 최종 방사선 조사 계획에서 주요 방사선원항, 유도농도기준(DCGL) 등을 기재하도록 하고 있다. 이 논문은 국내 원전 해체에 있어서 참조사례가 될 수 있는 Rancho Seco 원전 해체 사례를 참고 및 절차를 분석함으로써 2017년 영구정지가 예정된 고리 1호기뿐만 아니라 향후 해체 원전 부지의 해제 기준 마련에 있어 사용될 수 있는 방법을 검토하였다.
In maintaining infra-structure, the conventional assessment and maintenance system has focused on safety. As the importance of performance-based assessment increases, considering the performance indices has became essential to assess in perspective of comprehensive evaluation of infrastructure. Therefore, in this study, the conventional evaluation system in Korea and suggested future direction of the maintenance system are analyzed.
Performance-based maintenance system is necessary to prepare for social disasters as domestic water supply facilities age. The maintenance methods of domestic Social Overhead Capital(SOC) facilities focuse on safety. However, considering the performance of facilities is essential in perspective of the deterioration due to aging this study introduces the future direction of the performance-based maintenance system on assessment of water supply facilities.
As the aging of domestic establishment progresses, the maintenance cost of the establishment is expected to have a great influence on the national economy. In this study, we introduce the performance - based maintenance method considering safety, durability and service performance of airport establishment
In the Gangwon province, severe freezing damage to road tunnels are occurred due to freezing condition such as snowfall, cold waves and icing. As a result, serious damage occurs on the lining and road surface of the tunnel entrance and exit. Therefore, it is necessary to develop appropriate mitigation methods to protect damage to people and property by freezing. In this paper, we introduce that the trend of research for reducing the freezing damage and the required performance to be secured for the maintenance of road tunnels in cold region and the future research plans.
The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we evaluated the stability of the corrugated steel plate culvert structure using an inspecting deformation rates between designs and measured 3D shapes. Also, a proper repair and reinforcement method will be proposed through analytical and experimental verification.