• Structural Engineering and Mechanics
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• v.40 no.4
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• pp.489-500
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• 2011

The elastic seismic response of plan-asymmetric multi storey steel-frame buildings is investigated under earthquake loading with particular emphasis on forward-rupture directivity and fling records. Three asymmetric building systems are generated with different torsional stiffness and varying static eccentricity. The structural characteristic of these systems are designed according to UBC 97 code and their seismic responses subjected to a set of earthquake records are obtained from the response history analysis (RHA) as well as the linear static analysis (LSA). It is shown that, the elastic torsional response is influenced by the intensity of near-fault ground motions with different energy contents. In the extreme case of very strong earthquakes, the behaviour of torsionally stiff buildings and torsionally flexible buildings may differ substantially due to the fact that the displacement envelope of the deck depends on ground motion characteristics.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.172-175
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• 2003

The enterprise find a solution to the problems such as a reduction of manufacturing period, accurate analysis for customer demand, improvement for customer service and rise of manufacture accomplishment. Internet is a good solution to such problems. Internet offers WWW(World Wide Web), remote control, file transfer and e-mail service. Among the services, WWW takes large portion because of convenient GUI, easy information search and unlimited information registration. Remote Monitoring Server(RMS) system that uses network service is constructed for chip mounter. Hardware base consists of RMS, chip mounter and C/S(Customer Service) server. Software includes DBMS and various modules in server home page. This provide product number, bad product number, trouble code, content and countermeasure in real-time information module, user information in setup module, detailed error information in fault diagnosis module, fault history in fault history module and customer information in customer service management module.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1166-1167
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• 2008

풍력 발전기의 계통 연계 기준에서 Fault Ride Through 규정은 사고 시 계통의 응동 특성을 결정하기 때문에 해당 계통의 특징을 반영하여 결정되어야 한다. 이에 여기에서는 세계 각국의 풍력발전기에 적용되는 Grid code에 대해 분석하고, 이를 바탕으로 FRT 규정의 수립에 필요한 기술적 요건에 대해 검토한 후, 해당 규정 수립을 위한 방법론을 제시한다. 이때, 구체적인 parameter 설정은 제주계통을 대상으로 PSS/E를 이용한 안정도 모의 결과에 따라 사고 시 계통의 전압 특성을 반영할 수 있도록 하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.11
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• pp.569-574
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• 2001

In this paper, we described the new IEC method with fuzzy theory for detecting abnormal causes within transformer. The proposed technique presented the solution of limitation in case of lying nearly boundary conditions and not having codes for measured gas values in IEC code. Also, we proved the confidence of diagnosed results in the use of the gases values in real fault transformers.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.6
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• pp.624-629
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• 2014

The purpose of this study is to carry out the task of engine hesitation which occurred intermittently in driving due to the defective CKPS of LPI vehicles. As the result of the wrong data from the equipment of D-logger, the signal error of CKPS caused the engine hesitation. We performed a study in the followings to analyze and investigate the cause effectively. First, we have investigated the control wiring harness and connector pin contact defect inspection. Second, we have inspected the defection of CKPS separately. From this study, it was found that the engine hesitation were caused by the bad durability and we have showed how to diagnosis the fault of the engine hesitation intermittently while driving. Therefore, it is determined that we have to improve the durability of the CKPS through a strict quality control and to increase the reliability.

• Journal of Information Processing Systems
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• v.8 no.1
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• pp.21-54
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• 2012

As we know every software development process is pretty large and consists of different modules. This raises the idea of prioritizing different software modules so that important modules can be tested by preference. In the software testing process, it is not possible to test each and every module regressively, which is due to time and cost constraints. To deal with these constraints, this paper proposes an approach that is based on the fuzzy multi-criteria approach for prioritizing several software modules and calculates optimal time and cost for software testing by using fuzzy logic and the fault tolerance approach.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2197-2199
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• 2003

Most of distributed PLC system is secured reliability of the system by fully duplicated controller. But it costs too much. In this paper, we proposed fault tolerant control using minimum spare controllers. First, the system is modeled using Galois field. Next, we designed additional spare controllers using the parity code of two dimensions. Finally, the algorithm for producing estimated output in remote I/O when the fault occurs was suggested. This method will be applied to an automatic system in order to increase reliability and improve cost performance.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.3
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• pp.453-460
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• 2014

Fault injection attack is the process of attempting to acquire the information on-chip through inject artificially generated error code into the cryptographic algorithms operation (or perform) which is implemented in hardware or software. From the details above, the laser-assisted failure injection attacks have been proven particularly successful. In this paper, we propose an improved laser probing system for fault injection attack which is called the Dual-Laser FA tool set, a hybrid approach of the Flash-pumping laser and fiber laser. The main concept of the idea is to improve the laser probe through utilizing existing equipment. The proposed laser probe can be divided into two parts, which are Laser-I for laser cutting, and Laser-II for fault injection. We study the advantages of existing equipment, and consider the significant parameters such as energy, repetition rate, wavelength, etc. In this approach, it solves the high energy problem caused by flash-pumping laser in higher repetition frequency from the fiber laser.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.827-834
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• 2014

In order to meet the low voltage ride-through requirement in a grid code, a wind power plant (WPP) has to stay connected to a grid, supporting the voltage recovery for a grid fault. To do this, a plant-level controller as well as a wind generator (WG) controller is essential. The dynamic response of a WPP should be analyzed in order to design a plant-level controller. The dynamic response of a WPP for a grid fault is the collective response of all WGs, which depends on the wind speed approaching the WG. Thus, the dynamic response of a WPP should be analyzed by taking the wake effect into consideration, because different wind speeds at WGs will result in different responses of the WPP. This paper analyzes the response of a doubly fed induction generator (DFIG)-based offshore WPP with a grid fault taking into account the wake effect. To obtain the approaching wind speed of a WG in a WPP, we considered the cumulative impact of multiple shadowing and the effect of the wind direction. The voltage, reactive power, and active power at the point of common coupling of a 100 MW DFIG-based offshore WPP were analyzed during and after a grid fault under various wind and fault conditions using an EMTP-RV simulator. The results clearly demonstrate that not considering the wake effect leads to significantly different results, particularly for the reactive power and active power, which could potentially lead to incorrect conclusions and / or control schemes for a WPP.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.225-231
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• 2013

Low voltage ride through capability augmentation of a hybrid micro-grid system is presented in this paper which reflects enhanced reliability in the system. The control scheme involves parallel connected multiple ac-dc bidirectional converters. When the micro-grid system is subjected to a severe voltage dip by any transient fault single power converter may not be able to provide necessary reactive power to overcome the severe voltage dip. This paper discusses the control strategy of additional power converter connected in parallel with main converter to support extra reactive power to withstand the severe voltage dip. During transient fault, when the terminal voltage crosses 90% of its pre-fault value, additional converter comes into operation. With the help of additional power converter, the micro-grid system withstands the severe voltage fulfilling the grid code requirements. This multiple converter scheme provides the micro-grid system the capability of low voltage ride through which makes the system more reliable and stable.