본 연구는 하천 수환경 평가기법의 일환으로 multimetric 접근방식인 생물보전지수(Index of Biological Integrity, IBI)의 적용방법을 도입을 목적으로 하였다. 국내에서 IBI평가를 위해 Karr(1981)가 제시한 12개 메트릭 대신 11개 메트릭을 적용하였으며, 11개 중 5개 메트릭은 국내 수환경 특성에 맞게 변형하여 적용하였다. 본 평가기법의 적용을 위해 선정된 갑천에서 평균 IBI값은 36(범위:17~]4

어류군집을 이용한 생물보전지수(Index of Biological Integrity, IBI)와 서식지 평가지수 (qoalitativeHabitatEvaluationlndex, QHEI)를 적용하여 금호강의 수서 생태계를 평가하였다. 총체적으로 금호강의 IBI값은 13-37 범위에 있었으며, 연 평균값은 23(n=25, Std. error=1.16)으로서 Karr(1981) 와 U.S. EPA (1993) 기준에 따르면 "Poor" 또는 "Very Po

In this paper, the necessity of developing effective nondestructive testing and monitoring techniques for the evaluation of structural integrity and performance is described. The evaluation of structural integrity and performance is especially important when the structures and subject to abrupt external forces such as earthquake. A prompt and extensive inspection is required over a large area of earthquake-damaged zone. This evaluation process is regarded as a part of performance-based design. In the paper, nondestructive testing and monitoring techniques particularly for concrete structures are presented as methods for the evaluation of structural integrity and performance. The concept of performance-based design is first defined in the paper followed by the role of evaluation of structures in the context of overall performance=based design concept. Among possible techniques for the evaluation, nondestructive testing methods for concrete structures using radar and a concept of using fiber sensor for continuous monitoring of structures are presented.

본 논문에서는 가압열충격의 파괴역학적 해석에 필요한 이론을 조사하였고 원자로용기의 구조건전성을 평가하기 위하여 해석과정을 전산화하였다. 우선 사고 transient에 대하여 원자로용기내의 압력과 주입되는 냉각재의 온도변화가 주어지면 이들로 부터 시간에 따른 용기에서의 온도와 응력분포를 구하고, 중성자 조사량과 용기 재질의 화학성분으로 부터 기준무연성천이온도의 분포가 구해지며 이로부터 파괴인성치 KIA와 KIC의 분포가 얻어진다. 또한 응력분포로 부터 균열의 크기 및 형상에 따라 응력확대계수 KI이 구해지므로 이를 KIA및 KIC와 비교함으로써 균열의 성장거동을 예측할 수 있다. 지금까지 보고된 가압열충격을 유발할 수 있는 대표적인 사고 transient가 국내 발전소에 발생할 경우를 가정하여 해석을 수행하였고 그 결과에 대하여 검토하였다.

This study presents meteorological data integrity to improve environmental quality assessment in Yongdam catchment. The study examines both extreme ranges of meteorological data measurements and data reliability which include maximum and minimum temperature, relative humidity, dew point temperature, radiation, heat flux. There were some outliers and missing data from the measurements. In addition, the latent heat flux and sensible heat flux data were not reasonable and evapotranspiration data did not match at some points. The accuracy and consistency of data stored in a database for the study were secured from the data integrity. Users need to take caution when using meteorological data from the Yongdam catchment in the preparation of water resources planning, environmental impact assessment, and natural hazards analysis.

Purpose: This research aims to investigate the impact of corporate integrity on stock price crash risk. Research design, data, and methodology: Taking 1419 firms listed in Shenzhen Stock Exchange in China as a sample, this paper empirically analyzed the relationship between corporate integrity and stock price crash risk. The main integrity data was hand-collected from Shenzhen Stock Exchange Website. Other financial data was collected from CSMAR Database. Results: Findings show that corporate integrity can significantly decrease stock price crash risk. After changing the selection of samples, model estimation methods and the proxy variable of stock price crash risk, the conclusion is still valid. Further research shows that the relationship between corporate integrity and stock price crash risk is only found in firms with weak internal control and firms in poor legal system areas. Conclusions: Results of the study suggest that corporate integrity has a significant influence on behaviors of managers. Business ethics reduces the likelihood of managers to overstate financial performance and hide bad news, which leads to the low likelihood of future stock price crashes. Meanwhile, corporate integrity can supplement internal control and legal system in decreasing stock price crash risks.

본 연구는 현재 상태에서 콘크리트 내부의 균열, 공극, 결함 등을 식별 및 판단하고 일반적인 초음파법 및 반발경도법 외에 S-wave 및 R-wave를 사용하여 미래의 머신러닝 기법의 적용 가능성을 설명합니다. 또한, 다양한 머신러닝 기법 중에서 서포트벡터머신(SVM) 및 인공신경망(ANN)을 사용하여 콘크리트 건전성 평가에 대한 모델 개발을 통해 실험데이터의 예측 결과에 대한 비교분석을 진행하였고 최종적으로 SVM 모델을 제시하였다.

막 여과는 막을 통해 물을 통과시켜 수중의 오염 물질이나 불순물을 제거하는 기술이며 고도수처리 및 하수 처리와 같은 다양한 분야에서 사용된다. 하지만, 우발적인 수질 오염이나 막 손상의 경우에는 대응하기 어렵다는 단점이 있다. 따라서 여과 과정을 거친 후 식수의 오염을 막기 위해 막의 손상을 모니터링 해야 한다. 본 연구에서는, 압전 센서를 사용하여 고주파 기반 전기역학적 임피던스(EMI)를 측정하여 막 완결성 시험을 수행하였다. 외부 배관에 부착된 압전 센서는 배관 내부 압력 변화로 인한 막의 물리적 특성의 변화를 검출 할 수 있다. 압력 감쇠 시험을 진행하는 동안, 부착된 압전 센서를 통해 EMI 를 측정함으로써 막 손상으로 인한 압력 강하를 측정 할 수 있다. 본 기술을 검증하기 위하여 실제 수원지에서 현장 테스트가 수행되었다. 신뢰성을 높이기 위해 각 측정 단계에서 20 회 실험을 수행 하였고 그 결과, 미세한 압력 강하를 검출함으로써 막의 손상을 모니터링 할 수 있음을 확인하였다.

This research provides techniques for the implementation of an integrity evaluation system developed for wind turbine structures to jack-up barge. The strain values obtained from the upper tip of the footing are to be converted into values at a single point in order to represent the structural behavior. These obtained values are evaluated simultaneously through P-M curve, generated by FEM results. Evaluating loads with P-M curve, structural stability of barge could then be monitored.

The Optical Wide-field patroL-Network (OWL-Net) is a global optical network for Space Situational Awareness in Korea. The primary operational goal of the OWL-Net is to track Low Earth Orbit (LEO) satellites operated by Korea and to monitor the Geostationary Earth Orbit (GEO) region near the Korean peninsula. To obtain dense measurements on LEO tracking, the chopper system was adopted in the OWL-Net’s back-end system. Dozens of angle-only measurements can be obtained for a single shot with the observation mode for LEO tracking. In previous work, the reduction process of the LEO tracking data was presented, along with the mechanical specification of the back-end system of the OWL-Net. In this research, we describe an integrity assessment method of time-position matching and verification of results from real observations of LEO satellites. The change rate of the angle of each streak in the shot was checked to assess the results of the matching process. The time error due to the chopper rotation motion was corrected after re-matching of time and position. The corrected measurements were compared with the simulated observation data, which were taken from the Consolidated Prediction File from the International Laser Ranging Service. The comparison results are presented in the In-track and Cross-track frame.

The Bridge Safety Department of Seoul Metropolitan Government has regularly conducted precise inspection and precision safety inspection to maintain the bridge's function and safety. During a precise safety inspection in 2015, oil leakage progression was found on the cable anchorage system within the stiffened girder of Nilsen Arch bridge and as a follow-up measure, the cable replacement for the cable ACD11 was carried out in order to identify the relevant cause of the oil leakage and evaluate the integrity of the existing cable. The mechanical properties and fatigue performance tests of the cable strands of bridge inservice for about 20 years and comprehensive analysis of oil leakage were carried out. They were described hereby.

In this study, Integrity evaluation of offshore wind turbine substructure was carried out. The strain values obtained by strain gauges circularly installed on upper part of the substructure was converted into vertical and moment load. Considering directions of the moment load through FEM, the most conservative P-M interaction diagram of the model was graphed. Obtained load values were evaluated by utilizing P-M interaction diagram.

The signal characteristic of radar wave on concrete decks is determined by the attenuation of the radar due to the conversion of EM(Electromagnetic) energy to thermal energy through electrical conduction, dielectric relaxation, scattering, and geometric spreading. In this study, it is found that the attenuation of radar signal received on top rebars in bare deck concrete with 2 way travel time shows a general decreasing linear trend because of its same relative permittivity and conductivity. The radar signal after depth-normalization, can then be interpreted as being principally influenced by the content of chlorides penetrating cover concrete, which caused corrosion of rebars in bridge decks.