• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.465-472
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• 2001

This paper describes the characteristics of wind induced noise from high-voltage overhead transmission facilities which include transmission lines. insulator strings. and aviation beacon spheres installed on the overhead ground wires. High-voltage overhead transmission lines generate an audible wind noise due to the alternate shedding of wind-induced vortices. The frequency spectrum from the insulator strings reveals its resonance peak. This resonance sound mechanism has been supposed the self-excitation phenomenon of the resonance and the velocity fluctuation. The booming noises from the aviation beacon spheres are detected and analysed.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.77-80
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• 2006

In recent booming up of the ship building market, the supplying of large scale casting is difficult to keep the delivery schedule for ship yard because of the restrict manufacturer in Korea. And also, it is main cause to rise-up the cost of castings. This paper describes the outline of guidance of optimizing design for Rudder Horn Casting to reduce the risk of the delivery problem to ship yard.

• Journal of Aerospace System Engineering
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• v.6 no.3
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• pp.1-6
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• 2012

It is booming to use computer owing to the information society, and embedded software application have grown in airborne systems and equipment. So this introduces airborne software, RTCA DO-178B, life cycle and its data, and software development pitfalls in design and certification.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.89-93
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• 1995

일반적으로 건설장비의 운전자 소음은 자동차와는 달리 주행 시 소음에 관한 것은 크게 문제되지 않는다. 다만 모든 작동부들이 유압력에 의해 구동되므로 유압 이음이 새롭게 대두되며, 엔진 사용조건 또한 자동차와는 상이하다. 그러나, 운전자가 느끼는 관점에서 운전실내에서 안락함의 요구는 점차로 강해지고 있을 뿐만 아니라 소비자들의 직접적인 구매 의욕과 직결된다. 이에 본 연구에서는 굴삭기 운전실에서 문제시 되는 부밍(Booming)소음에 대해 고찰하고, 구조 기인 소음(structure-borne noise)에 초점을 둔 실험적 기법의 도입으로 주 소음원을 규명하고 주요 인자들에 대한 기여도 분석을 통해 운전실 소음 저감을 구현하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.737-740
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• 2007

A s wireless communications and mobile multimedia services are booming nowadays, systematic research of the overall aspects of mobile security is crucial. This paper presents a frame model for guising the systematic investigation of mobile security. Based on the introduction of some background viewpoints of security targets from n novel perspective, the framework is described as a hierarchical model in which mobile security research is partitioned into three different layers.

• Journal of KSNVE
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• v.9 no.6
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• pp.1145-1151
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• 1999

Sensitivity analysis and structural modification technique are used to reduce the interior noise of a passenger car. The sensitivity analysis for the noise level at the rear seat shows that the stiffness change at the front lower member and the rear roof rail are sensitive. Using the structural modification method, we verified that the reinforcements at those members decrease the noise transfer function from the body to the rear seat. The combined application of the sensitivity analysis and structural modification method can decrease the noise level effectively.

• The Journal of the Acoustical Society of Korea
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• v.16 no.4
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• pp.11-20
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• 1997

The passive noise control techniques used until now cancel the noise in terms of the characteristics of materials, which increase the mass and the dimension and have a limit that is effective only to attenuate the high frequency components of the noise. But the active noise control techniques developed in recent years have merits that they decrease the mass and the dimension and are effective to attenuating the low frequency noises. In this paper, the real-time active noise control system attenuating the engine booming noise in a car using the digital signal processing(DSP) techniques in terms of the principle of active noise control. The multiple-error filtered-x LMS(Least-Mean Square) algorithm is used as the adaptive algorithm for active noise control and is implemented using the DSP processor Motorola DSP56001 as a controller. According to the result that the experiments are performed for the engine as the RPM changes in a car, the noise attenuating performances are achieved in an overall car interior and is verified to be 20 dB higher for pure-tone and globally, 15 dB.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.5
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• pp.327-333
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• 2003

Several tests are performed to evaluate road booming noise. Baseline test delivers the information of road noise characteristics. Coupling effect between structure and acoustics is obtained from the mode shapes and the natural frequencies by the modal test. Equivalent stiffness at joint areas between chassis and car-body system can be determined by the input point inertance test. Noise sensitivity of body mounting point of a chassis part can be obtained from the noise transfer function test with input point inertance test. Operational deflection shape makes us analyze the actual vibration modes of the chassis system under actual leading and find noise sources very easily. Finally, the transfer path analysis is used to Identify noise Paths through the chassis system. The objectives and the procedures of the tests are described in this Paper Also, the guideline for efficient road noise evaluation test can be found.

• The Korean Journal of Air & Space Law and Policy
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• v.27 no.2
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• pp.193-209
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• 2012

China's airline industry is experiencing a booming development as one hand, on the other hand the incidents involving unruly behaviour on board aircraft also becomes a growing concern for the whole industry. The thesis examines the basic issues concerning the unruly behaviour, such as definition of unruly behaviour, the impact and root causes of unruly behaviour. Then it focuses on the China's legal sources governing the problem of unruly behaviour. Generally speaking, China's legislation with this respect is systematic and self-contained, except some minor shortcomings which need to be revised. Finally the thesis holds the view that the preventative measures jointly contributed by all the parties concerned are something more important than the legislation itself.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.146-148
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• 2012

Today, research on P2P live streaming has been booming. Live streaming service must ensure timeliness according to real-time. In this paper, suggest mechanism measuring about parent-nodes'dealy time which cuts down cost for selecting parent-node with utilizing ISP information and locality that participate P2P live streaming service.