• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.223-229
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• 2013

Restructuring and recent developments in the power system and problems arising from construction and maintenance of large power plants, increasing amount of interest in distributed generation (DG) source. Distributed generation units due to specifications, technology and location network connectivity can improve system and load point reliability indices. In this paper, the allocation and sizing of DG in distribution networks are determined using optimization. The objective function of the proposed method is to improve customer-based reliability indices at lowest cost. The placement and size of DGs are optimized using a Genetic Algorithm (GA). To evaluate the proposed algorithm, 34-bus IEEE test system, is used. The results illustrate efficiency of the proposed method.

• 한국신뢰성학회지:신뢰성응용연구
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• 제10권4호
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• pp.279-297
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• 2010

AQS(Air Quality Control System) is the important part of a car air conditioning system. This device intercepts automatically the influx of harmful waste gas. In this paper reliability assessment criteria for AQS are established in terms of quality certification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

• 한국안전학회지
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• 제27권4호
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• pp.115-120
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• 2012

In order to establish preventive maintenance standards through analysis & reliability prediction of about 60,000pcs of 20kindsof relays and contractors used for Seoul subway trains, several life prediction methodologies were applied. Firstly, Occurrence, Severity, Detection were defined and predicted by applying operation characteristic of EMU to the number of actions of relays & contactors which the manufacturers generally offer as the life cycle data. Secondly, failure distribution and average life of parts were analyzed through interpretation of field data based on a lot of experience which had built up in the field for a long time. Finally, using the 217PLUS standard as a reliability prediction program, comparative analysis of use reliability and inherent reliability was done through reliability prediction at the part level and system level.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권1호
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• pp.1-15
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• 2011

Automobile markets are so fierce in the world market that every major manufacturer assure the buyer of the car by give a provocative warranty plan for their cars. For instance Hyundai motor company offer 10 years and 100,000 miles of warranty whichever comes first. But in order for this effort to be successful every critical component such as window switch has to be proven to be reliable in an adverse environment. Therefore, in this article reliability assessment criteria for window switch are established in terms of basic performance test, environment test and life test.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권1호
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• pp.17-30
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• 2011

Many domestic manufacturers make reflectors for Lamps of BLU(back light units). However, color change and parting occur as a result of diverse usage environment. Therefore, many of the manufacturers are reluctant in R&D investment of reflectors for Lamps of BLU. Hence, in this article reliability assessment criteria for reflector for lamp of BLU are established in terms of performance test, environment test and life test.

• 한국군사과학기술학회지
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• 제8권4호
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• pp.32-40
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• 2005

The ASRP(Ammunition Stockpile Reliability Program) is a overall evaluation system of ammunitions to improve the combat strength, having a short history. The storage lifetime of ammunitions, more than 20 years since being produced, differs according to storage circumstance and period. And it shows the different reliability for munitions. Because most ammunitions in military have been stored for a long time, these ammunitions need to be evaluated to maintain Serviceability, Reliability, Safety and Performance for the use of military. In this paper, it suggested the need to develop the techniques for ourselves, to make more laboratories for surveillance and testing and to extend research funds & concerns.

• 수산해양기술연구
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• 제33권4호
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• pp.334-345
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• 1997

Reliability-based design approaches are needed for cylindrical shell structure whose design and operational experiences are few and which are subjected to external loads of random loads. In designing new type of structure, it is very difficult to evaluate the safety factors due to lack of previous design data and operational experience. To solve the above mentioned problem, much attention is being focussed on rational reliability based design approaches. This paper deals with weight-optional reliability-based design of cylindrical shell structure subjected to structural reliability constraints taking into account of the effect of local buckling and interactive behavior between local and global buckling. Present mentioned is compared with the exiting optional design method based only on safety factors. Numerical simulation reveals that the present method leads to lighter structure (4% reduction in weight compared to the existing optimal design) with the same reliability index. For larger structures with more number of structural members and possible failure modes, the present W0RBD procedure will be an efficient tool in designing cost-effective rationalized economic design.

• 산업경영시스템학회지
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• 제30권3호
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• pp.127-134
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• 2007

Predicting fatigue life of rubber components is an important issue in design procedure for industrial trucks to assure the durability and reliability. Main considerations in designing rubber components against fatigue failure are the compounding technology, shape design, and manufacturing process. Among them the rubber compounding technology is one of the most critical factor to determine more than 50% of component's quality. This paper presents how to improve the durability and reliability of industrial rubber mount during its design, development and prototype testing. The data presented illustrates explicitly the prediction of reliability growth in the product development cycle. The application of these techniques is a part of the product assurance function that plays an important role in rubber components reliability improvement.

• 산업기술연구
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• 제29권A호
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• pp.27-36
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• 2009

Reliability plays a pivotal role in products safety and quality. DoD RIAC recently developed a new reliability prediction methodology, $217Plus^{TM}$, for electronic systems. It officially replaces the well-known MIL-HDBK-217 and is expected to be widely used. Although theoretic study about $217Plus^{TM}$ and its application towards field systems seem to be attractive, it is also desirable to understand the general background of its development. In this paper, we performed a historical review of the arenas related to reliability prediction. Due to the vast of materials, our scope was limited to the development of $217Plus^{TM}$. We first reviewed Rome Laboratory and RIAC. We then explained the development course of reliability methods, MIL-HDBK-217, PRISM, and 217-Plus. This review will form not only a good understanding of the methodology but a basis for future study. We conclude this study with provision of future research areas.

• Journal of Electrical Engineering and Technology
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• 제7권1호
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• pp.46-50
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• 2012

The current paper presents an effective methodology for assessing the reliability of electromagnetic designs when considering uncertainties of design variables. To achieve this goal, the reliability index approach based on the first-order reliability method is adopted to deal with probabilistic constraint functions, which are expressed in terms of random design variables. The proposed method is applied to three different designs of a superconducting magnetic energy storage system that corresponds to initial, deterministic, and roust designs. The validity and efficiency of the method is investigated with reference values obtained from Monte Carlo simulation.