• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.667-669
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• 2014

Development of 3 cylinder turbo charger engine is increasing due to engine down-sizing, cost reduction and emission regulations. However, 3 cylinder engine makes higher Exhaust manifold gas pressure(P3) pulsation than 4 cylinder engine and it generate boosting air with high pulsation. The mechanical waste-gate turbocharger just controlled by the boosting air has higher movement because of this high pulsation boosting air. This causes high vibrations to wasted gate and accelerate wear of the linkage system. So we need to understand out of the exhaust gas pressure pulsation changed by turbocharger compressor pressure(P2) Pulsation. In this study, we discuss how to prevent to abnormal movement of the turbo actuator by stabilized P2 Pulsation.

• 동력기계공학회지
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• 제11권1호
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• pp.45-50
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• 2007

Acoustic emission technology is applied to diagnosis the internal leak and operating conditions of the major valves at nuclear power plants. The purpose of this study is to verify availability of the acoustic emission as in-situ diagnosis method. In this study, acoustic emission tests are performed when the pressurized high temperature steam flowed through gate valve(1st stage reheater valve) and glove valve(main steam dump valve) on the normal size of 4 and 8". The valve internal leak diagnosis system for practical field was designed. The acoustic emission method was applied to the valves at the site, and the background noise was measured for the abnormal plant condition. To improve the reliability, a judgment of leak on the system was used various factors which are AE parameters, trend analysis, signal level analysis and RMS(root mean square) analysis of acoustic signal emitted from the valve operating condition internal leak.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.585-588
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• 2013

Electric motor with reduction gear systems are being adopted recently as main propulsion on the special-purposed ships. These specialized ships or offshore vessels require higher power rating generators for propulsion and accommodation power supply. This study investigated the cause of exciter components failure in the view of excessive vibration, force or abnormal ship motion in service. Countermeasures are proposed to address the exciter component failure. A 1.4 MW class dual-fuel engine generator using rigid foundation for a LNG carrier was used as research model.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.922-926
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• 2001

This paper deals with sensing ability of smart sensor that has a sensing ability to distinguish materials according to frequency changing. We have developed a new signal processing method that can distinguish among different materials. The smart sensor was developed for recognition of materials. We estimated the sensing ability of smart sensor with the $R_{SAI}$ method according to frequency changing. Experiments and analysis were executed to estimate the ability to recognize objects according to frequency changing. Sensing ability of smart sensors was evaluated relatively through a new $R_{SAI}$ method. Applications of smart sensors are for finding abnormal conditions of objects (auto-manufacturing), feeling of objects (medical product), robotics, safety diagnosis of structure, etc.etc.

• 한국소음진동공학회논문집
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• 제12권11호
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• pp.897-903
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• 2002

The periodic high vibration has been occurred one or two times a day for a 500 MW large steam turbine during 5 months. This abnormal vibration was caused by the rubbing between the rotor and the carbide accumulated on the seal tooth of oil deflector. It was found that the accumulated carbide was insulation material installed on the HIP casing from the examination of the chemical composition. Also, this paper presents the mechanism of the periodic high vibration and the proper method to eliminate this vibration problem. This result would be good practice to find the solution of similar high vibration in the steam turbines for power plant as well as industrial rotating machineries.

• 한국멀티미디어학회논문지
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• 제15권11호
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• pp.1330-1340
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• 2012

본 논문에서는 심음신호를 이용해 강한 심 잡음이 나타나는 심장판막협착 영역을 검출하는 새로운 알고리듬을 제안하였다. 심음의 주성분을 찾거나 심 잡음을 제거하기 위한 지금까지의 많은 연구들은 대동맥판막협착증이나 승모판막협착증과 같이 강한 심 잡음이 나타나는 비정상 심음의 경우, 강한 심 잡음으로 인해 좋은 결과를 보이지 못하였다. 본 논문에서는 구간 잡음강도함수를 이용한 잡음 검출 알고리듬을 제안하였다. 제안한 구간 잡음 강도 함수는 심음 신호에서 제 1심음과 제 2심음을 검출하여, 이를 이용한 심음 구간을 설정한 후 구간 자기상관변화량을 이용하여 도출할 수 있다. 제안한 구간 잡음강도함수를 이용하여 심 잡음의 강도를 판단하고 심 잡음 유무를 검출하였다. 제안한 알고리듬으로 실험한 결과, 심장판막협착 영역 검출에서 기존의 연구보다 뛰어난 성능을 가지는 것을 확인하였다.

• 한국음향학회지
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• 제37권6호
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• pp.469-474
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• 2018

도시 유동인구가 증가함에 따라 도시 환경 소음에 관한 연구의 중요성이 증가하고 있다. 본 연구에서는 교통상황에서 발생하는 이상 소음을 최근 환경 소음 분류 연구에서 높은 성능을 보이는 딥러닝 알고리즘을 이용하여 분류한다. 구체적으로는 타이어 제동 마찰음, 자동차 충돌음, 자동차 경적음, 정상 소음 네 개의 클래스에 대하여 합성곱 신경망을 이용하여 분류한다. 또한, 실제 교통 상황에서의 환경잡음에 강인한 분류 성능을 갖기 위해 빗소리, 바람 소리, 군중 소리의 세 가지 환경잡음을 설정하였고 이를 활용하여 분류 모델을 설계하였으며 3 dB SNR(Signal to Noise Ratio) 조건에서 88 % 이상의 분류 성능을 가진다. 제시한 교통 소음에 대하여 기존 선행연구 대비 높은 분류 성능을 보이고, 빗소리, 바람 소리, 군중 소리의 세 가지 환경잡음에 강인한 교통 소음 분류 모델을 제안한다.

• ETRI Journal
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• 제29권3호
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• pp.371-380
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• 2007

This paper proposes a new automatic compensation network (ACN) for a system-on-chip (SoC) transceiver. We built a 5 GHz low noise amplifier (LNA) with an on-chip ACN using 0.18 ${\mu}m$ SiGe technology. This network is extremely useful for today's radio frequency (RF) integrated circuit devices in a complete RF transceiver environment. The network comprises an RF design-for-testability (DFT) circuit, capacitor mirror banks, and a digital signal processor. The RF DFT circuit consists of a test amplifier and RF peak detectors. The RF DFT circuit helps the network to provide DC output voltages, which makes the compensation network automatic. The proposed technique utilizes output DC voltage measurements and these measured values are translated into the LNA specifications such as input impedance, gain, and noise figure using the developed mathematical equations. The ACN automatically adjusts the performance of the 5 GHz LNA with the processor in the SoC transceiver when the LNA goes out of the normal range of operation. The ACN compensates abnormal operation due to unusual thermal variation or unusual process variation. The ACN is simple, inexpensive and suitable for a complete RF transceiver environment.

• Molecules and Cells
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• 제20권2호
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• pp.157-166
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• 2005

The c-myc proto-oncogene encodes a nuclear protein that is deregulated and/or mutated in most human cancers. Acting primarily as an activator and sometimes as a repressor, MYC protein controls the synthesis of up to 10-15% of genes. The key MYC targets contributing to oncogenesis are incompletely enumerated and it is not known whether pathology arises from the expression of physiologic targets at abnormal levels or from the pathologic response of new target genes that are not normally regulated by MYC. Regardless of which, available evidence indicates that the level of MYC expression is an important determinant of MYC biology. The c-myc promoter has architectural and functional features that contribute to uniform expression and help to prevent or mitigate conditions that might otherwise create noisy expression. Those features include the use of an expanded proximal promoter, the averaging of input from dozens of transcription factors, and real-time feedback using the supercoil-deformable Far UpStream Element (FUSE) as physical sensor of ongoing transcriptional activity, and the FUSE binding protein (FBP) as well as the FBP interacting repressor (FIR) as effectors to enforce normal transcription from the c-myc promoter.

• 디지털콘텐츠학회 논문지
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• 제19권9호
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• pp.1803-1810
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• 2018

사물인터넷 기술을 활용하는 연구가 활발하게 진행되고 있다. 사물인터넷을 활용하는 스마트 웨어러블 기기의 상황인식 기능을 향상시키기 위하여 센서부의 이벤트 데이터에 대한 잡음 제거방안을 제안하였다. 본 연구에서는 저역필터를 이용함으로써 비정상적으로 측정된 값에 대한 감쇠를 유도하고 센서의 이벤트 데이터를 이용한 상황 인지에서 유익을 얻을 수 있었다. 스마트 폰과 스마트워치에 기본 내장되어 있는 3축 가속도 센서가 감지하여 보고한 이벤트 데이터를 활용하여 검증한 결과 비정상적으로 과도하게 측정되어 입수된 잡음 값에 대한 값에 대한 감쇠처리를 실행할 수 있었다. 이와 같이 잡음이 제거된 값의 패턴을 분석함으로서 실시간 상황인식에 필요한 다양한 패턴 자료를 얻을 수 있었다.