• Structural Engineering and Mechanics
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• 제12권6호
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• pp.633-656
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• 2001

In this paper, modal control with direct output feedback is formulated in a systematic manner for easy implementation. Its application to the seismic protection of structural systems is verified by a shaking table test, which involves a full-scale building model and an active bracing system as the control device. Two modal control cases, namely, one full-state feedback and one direct output feedback control were tested and compared. The experimental result shows that in mitigating the seismic response of building structures, modal control with direct output feedback can be as effective and efficient as that with full-state feedback control. For practical concerns, the control performance of the proposed method in the presence of sensor noise and stiffness modeling error was also investigated. The numerical result shows that although the control force may be increased, the maximum floor displacements of the controlled structure are very insensitive to sensor noise and modeling error.

• ETRI Journal
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• 제29권6호
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• pp.755-768
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• 2007

A very promising application of active RFID systems is the electronic seal, an electronic device to guarantee the authenticity and integrity of freight containers. To provide freight containers with a high level of tamper resistance, the security of electronic seals must be ensured. In this paper, we present the design and implementation of an electronic seal protection system. First, we propose the eSeal Protection Protocol (ePP). Next, we implement and evaluate various cryptographic primitives as building blocks for our protocol. Our experimental results show that AES-CBC-MAC achieves the best performance among various schemes for message authentication and session key derivation. Finally, we implement a new electronic seal system equipped with ePP, and evaluate its performance using a real-world platform. Our evaluation shows that ePP guarantees a sufficient performance over an ARM9-based interrogator.

• Journal of Power Electronics
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• 제2권2호
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• pp.88-94
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• 2002

The demand for protection of power electronic application has during the last couple of vears increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight inductance over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection of adding inductance of existing High-speed and new Typower Fuse protection. First, the problem of adding inductance of exiting High-speed and new Typower Fuse DC-link circuit is treated, second a short discussion of protection of the IGBT module is done, and finally, the impect of the high frwquency loading on the currying capability of the fuses is presented.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권1호
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• pp.49-57
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• 2013

해양플랜트의 설계는 위험요인을 정량적 위험성평가를 통해 계량화하여 그 결과를 설계에 반영하는 것이 일반화되어 있다. 대표적인 위험요소인 화재 위험에 대해서도 이는 마찬가지다. 계량화된 화재 위험에 대해 작업자들이 탈출하는 동안 안전설비의 기능을 유지하고 발생된 화재가 더 크게 전이(escalation)되는 것을 방지하는 것이 방화대책의 궁극적인 목적이다. 본 논문에서는 대표적인 방화대책인 능동방화대책과 수동방화대책의 적용사례를 살펴보고 수동방화대책의 설계기법들을 소개한다. 수동방화대책은 효과적인 방화기법이지만 초기 투자비가 많이 소요되고 운용과 유지보수에 애로사항이 크다. 따라서, 최근 들어 발주자들은 수동방화대책을 최적화하도록 해양플랜트 설계자에게 요청하는 추세이다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.80-83
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• 2001

We studied on effective quench protection method to prevent damage from unexpected quench of superconducting magnet for magnetic resonance imaging. And we suggested quench protection circuit that is combined with several protection techniques. This circuit has the capacity to maintain the symmetric nature of the magnetic field and the active shielding effect and to protect shim coils during a quench.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.227-243
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• 1997

Fire and smoke can from a small ignition source develop rapidly. Active systems in combination with Passive Fire Protection measures will offer highest safety standards to the building's developers and occupants. Nevertheless, the fire growth is very unpredictable and it is therefore essential at the planning stage that tested solutions are well selected according to National codes and later on installed by qualified contractors to ensure optimum performance. This demonstrates that Passive Fire Protection as safety measure cannot be neglected. Recent fire cases all over the world still proof that fire can develop any time and any where even in countries of high safety standards.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.703-707
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• 2001

The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight increase the over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection. First, the problem of adding inductance of existing High-Speed and new Typower fuses in DC-link circuit is treated, second a short discussion of the protection of the IGBT module is done, and finally, the impact of the high frequency loading on the current carrying capability of the fuses is presented.

• 전력전자학회논문지
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• 제3권4호
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• pp.426-436
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• 1998

Identification of fault current during the operation of a power semiconductor switch and activation of suitable remedial actions are important for reliable operation of power converters. A short circuit is a basic and severe fault situation in a circuit structure such as voltage source converters. This paper presents a new active protection circuit for fast and precise clamping and safe shutdown of fault currents of the IGBTs. This circuit allows operation of the IGBTs with a higher on-state gate voltage, which can thereby reduce the conduction loss in the device without compromising the short circuit protection characteristics. The operation of the circuit is studied under various conditions, considering variation of temperature, rising rate of fault current, gate voltage value, and protection circuit parameters. An evaluation of the operation of the circuit is made using IGBTs from different to confirm the effectiveness of the protection circuit.

• 한국염색가공학회지
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• 제18권6호
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• pp.80-87
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• 2006

Nowadays, interests of ultraviolet(UV) protection increased, since the UV dosage on the earth surface has increased over years. Overdose of UV can cause various skin, eye, and even DNA damages. Therefore, it is need to develop a proper mean to protect human skin and eye from UV radiation. In this study, the UV protective effect of green tea extract dyed fabrics with various fiber types were examined. Green tea has an active moiety called 'catechin' having benzene rings in its structure, which would exert a proper UV protective property. Green tea dyed fabrics showed the increase in UV protection, and silk showed the highest increase in UV protection (from 52.2% to 84.5% in UV-A, from 66.1% to 90% in UV-B). The order of UV-A protection increase is silk, wool, nylon and acrylic, PET, and cotton. The order of UV-B protection increase is silk nylon, wool, acrylic, cotton, and PET. In case of silk and nylon, the UV protection property gradually increased as the concentration of green tea extract increased. As a result, it was proven that green tea extract dyeing can improve UV protection property of dyed fabrics in environment-friendly and biocompatible manners.

• Journal of Power Electronics
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• 제2권3호
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• pp.171-180
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• 2002

New 42-volt automotive electrical systems can provide significant improvements in vehicle performance and fuel economy. It is crucial to provide protection against load dump and other overvoltage transients in 42-volt systems. While advanced active control techniques are generally considered capable of providing such protection, the use of passive transient voltage suppression (TVS) devices as a secondary or supplementary protection means can significantly improve design flexibility and reduce system costs. This paper examines the needs and options for passive TVS devices for 42-volt applications. The limitations of the commonly available automotive TVS devices, such as Zener diodes and metal oxide varistors (MOV), are analyzed and reviewed. A new TVS device concept, based on power MOSFET and thin-film polycrystalline silicon back-to-back diode technology, is proposed to provide a better control on the clamp voltage and meet the new 42-volt specification. Both experimental and modeling results are presented. Issues related to the temperature dependence and energy absorbing capability of the new TVS device are discussed in detail. It is concluded that the proposed TVS device provides a cost-effective solution for load dump protection in 42-volt systems.