• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1422-1431
• /
• 2015

The reliability of power system components can be affected by a numbers of factors such as the health level of components, external environment and operation environment of power systems. These factors also affect the electrical parameters of power system components for example the thermal capacity of a transmission element. The relationship of component reliability and power system is, therefore, a complex nonlinear function related to the above-mentioned factors. Traditional approaches for reliability assessment of power systems do not take the influence of these factors into account. The assessment results could not, therefore, reflect the short-term trend of the system reliability performance considering the influence of the key factors and provide the system dispatchers with enough information to make decent operational decisions. This paper discusses some of these important operational issues from the perspective of power system reliability. The discussions include operational reliability of power systems, reliability influence models for main performance parameters of components, time-varying reliability models of components, and a reliability assessment algorithm for power system operations considering the time-varying characteristic of various parameters. The significance of these discussions and applications of the proposed techniques are illustrated by case study results using the IEEE-RTS.

• 재활치료과학
• /
• 제5권1호
• /
• pp.7-22
• /
• 2016

목적 : 본 연구는 양측상지기능 평가도구의 체계적 고찰을 통해, 대상자, 평가방법, 신뢰도, 타당도, 민감도 등을 분석하여 임상 및 연구에서의 자료로 활용하고자 하였다. 연구방법 : 2014년 12월 한달 동안 PubMed 데이터베이스에서 'upper extremity'와 'motor actiity' 'activities of daily living'와 'assessment instrument' 'disability evaluations'의 키워드로 검색하여, 최종적으로 68개의 연구에서 44개의 상지기능 평가도구를 추출하였다. 추출된 평가도구에서 양측상지기능 평가도구의 비율, 대상자, 측정방법, 신뢰도, 타당도, 민감도를 비교분석하였다. 결과 : 상지기능 평가도구 중 양측상지기능 평가도구는 2개로 가장 적었다. 모두 뇌졸중 환자를 대상으로 하였으며, 환자의 양측 상지수행을 통해 환측의 기능을 측정하는 평가도구였다. 평가도구의 신뢰도, 타당도, 민감도는 높은 것으로 조사되었다. 결론 : 본 연구를 통해 양측상지기능 평가도구의 개발 및 연구가 필요하며, 이를 통해 양측상지기능 치료 효과를 보기 위한 평가도구로 활용될 수 있기를 기대해 본다.

• 교육시설
• /
• 제8권2호
• /
• pp.5-12
• /
• 2001

As the exiting school facilities become old and unfit for new curriculum, the systematical remodelling process based on its educational and physical functions is required. due to the inadequate maintenance and repairing practices, unnecessary costs are expended. Therefore, this study aims to establish a remodelling decision-making model for improving the educational environment of the existing school facilities. According to the budget system, it proposes the concept of remodelling that includes the activities of extension, reconstruction, repair and improvement. This study classifies the performance evaluation for school facilities as that of safety, durability and educational function, and articulates the assessment standards, methods and elements. In the end, it suggests a rational model for remodelling decision-making that can provide efficient and comprehensive remodelling process, economic and sustainable school development.

• 대한수학교육학회지:학교수학
• /
• 제3권2호
• /
• pp.373-399
• /
• 2001

The function is a basic and key concept to understand mathematical problems. However, many students have difficulties to expand the knowledge to other related concepts and to transfer the knowledge to real world problems. The reasons for the problem may be that the concept of function is taught by simplified and abstracted formula without fully understanding of the reasoning process. Also, the examples for the concepts are artificial and not related to students' experiences. Situated learning theory provides great implications to solve these problems. So, this study was designed to teach the concept of function more meaningful to students by appling situated learning theory. Thirty-eight middle school students were participated in this study. Students were provided the instruction designed according to the principles of situated learning theory. Then, they were asked to complete attitude survey questionnair and a performance assessment task. The result showed that the instruction based on situated learning theory was useful to Promote students' understanding and motivation for learning. More implications of the study was provided in the paper.

• International Journal of Automotive Technology
• /
• 제8권3호
• /
• pp.375-382
• /
• 2007

The multi-driver off-road vehicle drive-line consists of many components, with close connections among them. In order to design and analyze the drive-line efficiently, a modular methodology should be taken. The aim of a modular approach to the modeling of complex systems is to support behavior analysis and simulation in an iterative and thus complex engineering process, by using encapsulated submodels of components and of their interfaces. Multi-driver off-road vehicles are comparatively complicated. The driving-line is an important core part to the vehicle, it has a significant contribution to the performance. Multi-driver off-road vehicles have complex driving-lines, so performance is heavily dependent on the driving-line. A typical off-road vehicle's driving-line system consists of a torque converter, transmission, transfer case and driving-axles, which transfers the power generated by the engine and distributes it effectively to the driving wheels according to the road condition. According to its main function, this paper proposes a modularized approach for design and evaluation of the vehicle's driving-line. It can be used to effectively estimate the performance of the driving-line during the concept design stage. Through an appropriate analysis and assessment method, an optimal design can be reached. This method has been applied to practical vehicle design, it can improve the design efficiency and is convenient to assess and validate the performance of a vehicle, especially of multi-driver off-road vehicles.

• 재활간호학회지
• /
• 제7권1호
• /
• pp.7-14
• /
• 2004

To examine the cognitive function of elderly, the study examined the performance of Korean normal elderly population whose age over 65 using neuropsychological instruments. It was predicted that the performance of the Korean population would be different from the U, S. mainly due to their difference in language, culture, and education. Korean elderly people from the Chungchung and Daejeon Metropolitan city(n=97) participated. Two age scores were developed: below 74 years and over 75 years. The effect of age, gender and education was examined, which yield significant age, gender and education effect. The score of DSF, DSB, TMTA, and TMTB are expected to be utilized for research purposes, such as basic, clinical, epidemiological studies, as well as practice purposes such as diagnosis and assessment of the progression of cognitive decline and dementia with MMSE-K.

• Earthquakes and Structures
• /
• 제9권1호
• /
• pp.257-279
• /
• 2015

The primary objective of this study is to summarize results from previous experimental tests on laboratory specimens of RC/steel frames with masonry infills, in order to develop fragility functions that permit the estimation of damage in typical non-structural components of RC frame buildings, as a function of attained peak interstory drift. The secondary objective is to derive loss functions for such non-structural components, which provide information on the probability of experiencing a certain level of monetary loss when a given damage state is attained. Fragility curves and loss function developed in this study can be directly used within the FEMA P-58 framework for the seismic performance assessment of RC frame buildings with masonry infills.

• 성인간호학회지
• /
• 제16권2호
• /
• pp.245-255
• /
• 2004

Purpose: this study was to evaluate Cognitive Function Test for the Korean population. Digit Forward (DF), Digit Backward (DB) and Trail Making Test-A(TMT-A) and the translated version of the Trail Making Test-B (TMT-B) were used. The study examined the performance of Korean normal adult population whose age ranged from 20 to over 80. It was predicted that performances of the Korean population would be different from that of the United States population due primarily to their differences in language, and education. Method: Normal Korean adults at the Daejeon Metropolitan City and Chungchung Province (N=298) participated in this study. Seven age scores were evaluated; 20~29, 30~39, 40~49, 50~59, 60~69, 70~79, & >80s. The effects of age, gender, and years of education was examined, which yielded significant age and education effects. The scores were further specified accordingly in terms of years of education (0, 1~6, 7~12, 13~16, & >17), and gender. Result: As the age increased cognitive function score decreased. As the years of education increased, cognitive function scores increased. There was no difference in cognitive function scores according to gender. Age and year of education had significant effects on cognitive function and explained 52-58% of variants of each test. Conclusion: The data of the cognitive function tests are expected to be utilized for research purposes such as basic and clinical studies, as well as practical purpose such as cognitive assessment for traumatic brain injury, stroke, and elderly and nursing education for assessment tools.

• 설비공학논문집
• /
• 제26권4호
• /
• pp.181-192
• /
• 2014

Light-shelf is one of the most efficient natural lighting systems due to the improved function of the inflow level of the outdoor natural light. However, the existing research on the light shelf limits to the rectangular parallelepiped space, so do not provide sufficient data for various shapes of spaces. Thus, this study aims at deriving proper plan and relationship of the light shelf through its performance assessment depending on the indoor space shapes and utilizing them as basic data of light shelf design. The conclusions are as follows : 1) for 6m space depth, standard intensity of illumination satisfaction depth has shown 8.3%~26.3% improvement through the adjustment of the angle and width when installing light shelf compared to no light shelf installation; 2) $-30^{\circ}$, $-20^{\circ}$ and $-10^{\circ}$ light shelves set by this study play only as a blind regardless of the shape of ceiling on the summer solstice, and it is unsuitable; and 3) this study has derived proper plan of light shelf upon space shapes based on energy reduction and indoor evenness. The study results provide expanded data of the performance assessment of the light shelves according to the different space shapes and light shelf factors, which serves as a basis of the light shelves designing.

• Structural Engineering and Mechanics
• /
• 제87권6호
• /
• pp.555-574
• /
• 2023

An efficient optimization algorithm and damage-sensitive objective function are two main components in optimization-based Finite Element Model Updating (FEMU). A suitable combination of these components can considerably affect damage detection accuracy. In this study, a new hybrid damage-sensitive objective function is proposed based on combining two different objection functions to detect the location and extent of damage in structures. The first one is based on Generalized Pseudo Modal Strain Energy (GPMSE), and the second is based on the element's Generalized Flexibility Matrix (GFM). Four well-known population-based metaheuristic algorithms are used to solve the problem and report the optimal solution as damage detection results. These algorithms consist of Cuckoo Search (CS), Teaching-Learning-Based Optimization (TLBO), Moth Flame Optimization (MFO), and Jaya. Three numerical examples and one experimental study are studied to illustrate the capability of the proposed method. The performance of the considered metaheuristics is also compared with each other to choose the most suitable optimizer in structural damage detection. The numerical examinations on truss and frame structures with considering the effects of measurement noise and availability of only the first few vibrating modes reveal the good performance of the proposed technique in identifying damage locations and their severities. Experimental examinations on a six-story shear building structure tested on a shake table also indicate that this method can be considered as a suitable technique for damage assessment of shear building structures.