• 한국전자파학회논문지
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• 제14권3호
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• pp.226-232
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• 2003

본 논문에서는 파워 아일랜드(power island)의 설계지침을 연구하였다. 일반적으로 파워 아일랜드는 각 파워버스(power bus)의 구조적 공진에 의해 잡음 전달이 증가하는 단점이 있다. 따라서 본 논문에서는 잡음원의 위치를 변화시킴으로서 공진을 억제하였으며 개선된 잡음 특성을 위해서 EGI(Elevated Ground Island)를 제안하였다. 해석결과, 잡음원의 위치에 따라 파워 버스의 공진을 최소로 감소시켰으며, EGI를 이용하여 공진에 의해 발생되는 잡음 전달을 11 $\Omega$까지 감소시켰다.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.237-243
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• 2017

This paper presents an analysis of the electromagnetic interference of a heterogeneous power bus where electromagnetic bandgap (EBG) cells are irregularly arranged. To mitigate electrical-noise coupling between high-speed circuits, the EBG structure is placed between parallel plate waveguide (PPW)-based power buses on which the noise source and victim circuits are mounted. We examine a noise suppression characteristic of the heterogeneous power bus in terms of scattering parameters. The characteristics of the dispersion and scattering parameters are compared in the sensitivity analysis of the EBG structure. Electric field distributions at significant frequencies are thoroughly examined using electromagnetic simulation based on a finite element method (FEM). The noise suppression characteristics of the heterogeneous power bus are demonstrated experimentally. The heterogeneous power bus achieves significant reduction of electrical-noise coupling compared to the homogeneous power buses that are adopted in conventional high-speed circuit design. In addition, the measurements show good agreement with the FEM simulation results.

• Journal of electromagnetic engineering and science
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• 제6권4호
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• pp.197-202
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• 2006

This paper presents a study on the differential signaling for the rectangular power-bus structure. The full-wave modal analysis method analyzes how the differential-signaling can lower the power-bus resonance noise levels. The methodology is validated by the use of the FDTD method and reference measurements.

• International Journal of Internet, Broadcasting and Communication
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• 제9권2호
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• pp.42-47
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• 2017

In these days, the size of urban is growing and the function of city becomes complicated. And also, in city, people lives a lot. The life of urban is getting closer and linked with neighboring people in many parts. Especially, when peoples are exposing during using public transportation, even though does not be known, in they were living. Seoul is the most crowded place in Korea. In Seoul,The village buses have been serviced to the narrow streets. And people who use this bus, wants to seek the comfort of the ride, air quality and noise during in vehicle. In this paper, we determine the degree of annoyance with the noise inside the town bus in dB scale. And, such a situation was confirmed annoyance see their effect. The Interior noise did not see a big difference in the new car and the old car. Annoyance but also according to the skill of the bus driver remains the difference was confirmed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.658-664
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• 2012

This paper presents an investigation into driveline clonk noise of midi-bus. Test was performed for operational acceleration and pressure, torsional vibration of driveline and FRF to TPA. Wavelet analysis was used to study spectral-time characteristics to all measurement data and specially for torsional vibration, lash analysis was carried out. To investigate the path of the clonk in detail, time domain TPA was introduced. With time domain TPA, the contribution of each path for the clonk was estimated by both subjectively and objectively. As a result, Transmission mount part was came to light as the main contributor of issued clonk. This was verified by reinforcing the bracket of transmission side. And 1D torsional nvh performance simulation model was built with measured torsional vibration. The simulation tool was used for prediction of some clonk behavior in tip in-out transient condition.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.330-335
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• 2012

A Bus Trunk System for Wind Tower is introduced. A marine cable has been widely used in wind tower or other offshore structure. However, as the electric load capacity is getting increased, the large number of cable lines should be used to cover such a huge amount of electric capacities, which makes the installation make quite difficult due to the heavy weight and volume of the present cables. On the other hand, by using a single bus trunk system line, the power capacity amount of 16 number of cable can be delivered with significant compactness. However, unlike flexible cable, the bus trunk is relatively stiff which could arise resonance phenomenon in the operating condition of wind tower, therefore, the vibration characteristics of bus trunk should be investigated and verify its long-term reliability during the life time of the wind tower.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.1013-1013
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• 2004

Soundscape design is applied for the purpose of expressing the characteristics of places, by supplying suitable background sound for various places expressing their identity. Bus stations are a place for aggregating people using transportation. That is, people go into a station, buy a ticket, and wait for departure or for other passengers. Therefore, they need to create a more comfortable sound environment. This study aims to make bus stations a comfortable place acoustically for users. In this study, analysis on behavior at various locations in the space was performed. Measurements were taken on the approaching path, waiting place, departure and arrival platforms for sound levels and frequency characteristics. In addition, on acoustic specialists evaluation, using questionnaires, was also performed ambient noise, information broadcasting and users dialogue.

• 마이크로전자및패키징학회지
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• 제10권1호
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• pp.13-18
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• 2003

본 논문에서는 파워 아일랜드(power island)에서 발생되는 잡음 전달을 개선하는 방법에 대해서 연구하였다. 일반적으로 파워 아일랜드는 각 파워 버스(power bus)의 구조적 공진에 의해 잡음 전달이 증가하는 단점이 있다. 따라서 본 논문에서는 두 가지의 잡음 전달 개선 방법을 제시하였다. 첫 번째로 잡음원의 위치를 변화시킴으로서 구조적 공진을 억제하였다. 두 번째로 공진이 발생할 경우 잡음 전달을 감소시키기 위해서 EGI(Elevated Ground Island)를 제안하였다. 해석결과, 잡음원의 위치에 따라 파워 버스의 공진을 최소로 감소시켰으며, EGI를 이용하여 잡음 전달을 효과적으로 감소할 수 있었다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.354-357
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• 2004

In this paper, a sensitivity analysis technique is presented for performing effective structural optimization of bus system. Design sensitivities are analyzed on natural frequency of bus substructures using super-element. Vibration modes of substructure, which large affect on the global vibration mode of bus B.I.W., are found through the sensitivity analysis using the chain rule. And design variables, which are determined from the sensitivity analysis, are changed through optimum design.

• 한국전자파학회논문지
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• 제13권10호
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• pp.1040-1047
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• 2002

본 논문에서는 인쇄회로기판을 기구물에 기계적으로 고정시키고, 전기적으로 접지시키기 위해 사용되는 스크류 연결이 파워버스 잡음에 미치는 영향을 분석하였다. 스크류는 인쇄회로기판과 기구물을 연결하기 위하여 파워버스를 관통하게 되며, 이는 파워버스 잡음에 영향을 미치게 된다. 이러한 스크류 연결의 효과를 확인하기 위하여 스크류가 없는 기판과 5개의 스크류를 사용하여 인쇄회로기판과 기구물의 간격을 0.5 mm로 설정한 경우를 비교하였다. 비교 결과 제안된 방법은 스크류가 없는 경우에 비해 0.1 GHz - l GHz의 주파수 대역에서 5 dB 이상 잡음 특성이 개선되는 것을 확인하였다. 또한 신호선이 존재하는 4층 인쇄회로기판에 스크류를 사용한 경우 600 MHz까지 신호의 특성이 개선되는 것을 확인하였다. 본 연구는 고속 회로 및 기구물 설계에 유용하게 활용될 수 있을 것으로 기대된다.