• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.578-579
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• 2010

최근 내연 기관에서 엔진상태 및 잠재적인 결함의 발견을 위해 연료분사, 실린더 내 연소과정, 실린더 내부와 피스톤 마모상태, 흡 배기 밸브 및 과급기 (turbocharger) 등의 상태 모니터링을 통해서 결함에 대한 진단 및 경향관리에 대한 연구들이 진행되고 있다. 본 연구에서는 기 개발된 선박용 대형디젤엔진에 대한 상시 모니터링 시스템을 이용하여 엔진상태 및 잠재적인 결함을 진단하고자 하였으며, 일차적으로 가속도 신호를 이용하여 실린더 내 연소과정에서 정상적인 상태와 착화실패에 따른 진동 양상을 비교 분석하였다. 신호 분석 기법으로 시간-주파수 분산 기법들은 충격파 신호인 엔진 폭발신호를 분석하는데 적합하였으며, 그 기법들 중 Short Time Fourier Transform 기법과 Wavelet Transform 기법을 이용하였다.

• International Journal of Precision Engineering and Manufacturing
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• 제2권4호
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• pp.54-60
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• 2001

This paper deals with control design method having anticipation delay which is proposed for the discrete nonlinear engine where system dynamics is not accurate. Due to the induction-to-power delay in internal combustion(IC) engine having abrupt torque loss, underdamping and chattering in engine idle speed becomes a serious problem and it could make drivers uncomfortable. For this reason, Three types of the closed-loop controller are developed for the stable engine idle speed control. The inputs of the controllers are an engine idle speed and air conditioning signal. The output of the controllers is an duty cycle to operate the idle speed control valve(ISCV). The proposed controllers will be useful for improving actual vehicles since these shows good test

• 제어로봇시스템학회논문지
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• 제16권10호
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• pp.991-996
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• 2010

In this paper, a new indoor positioning system based on incident angle measurement of infrared sensor has been suggested. Though there have been various researches on indoor positioning systems using vision sensor or ultrasonic sensor, they have not only advantages, but also disadvantages. In a new positioning system, there are three infrared emitters on fixed known positions. An incident angle sensor measures the angle differences between each two emitters. Mathematical problems to determine the position with angle differences and position information of emitters has been solved. Simulations and experiments have been implemented to show the performance of this new positioning system. The results of simulation were good. Since there existed problems of noise and signal conditioning, the experimented has been implemented in limited area. But the results were acceptable. This new positioning method can be applied to any indoor systems that need absolute position information.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.43-45
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• 2007

We developed a portable urodynamics monitoring system using personal digital assistance (PDA) and proposed a new method for measuring the abdominal pressure in non invasive mode using surface EMG signals. This system is consisted of a signal conditioning and control module and could measure the vesical, abdominal and detrusor pressure. The result showed a high correlation coefficient between the practical abdominal pressure, using a conventional rectal catheter and the estimated values, by our proposed algorithm (r=0.81). This system should prove a useful tool in the future evaluations of ambulatory urodynamics monitoring study.

• 한국컴퓨터산업학회논문지
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• 제8권2호
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• pp.123-130
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• 2007

본 논문에서는 신호조정 회로로서 필수적인 다중 채널 심장 전기도 전치 증폭기를 제작하기 위한 설계조건의 분석 및 전기 회로적 해석을 수행하였다. 설계된 회로는 기존의 64 채널의 공간 분해능을 향상시키기 위하여 128채널로 구성하였으며, 전치증폭기는 입력회로부, 차동증폭부, 오른다리구동회로 및 주증폭기의 노치필터로 구성되도록 설계하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.505-508
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• 2002

AN EMBEDDED PC-BASED HARDWARE AND SOFTWARE SYSTEM HAS BEEN DEVELOPED TO AUTOMATE THE DATA ACQUISITION AND ANALYSIS OF BRAKE SQUEAL. THE DEVELOPED SYSTEM INTEGRATES ADVANCED SIGNAL CONDITIONING HARDWARE AND SOFTWARE TO ACQUIRE BRAKE NOISE AND VIBRATION DATA RAPIDLY, CONSISTENTLY AND OBJECTIVELY. A SPECIAL PEAK-PICKING ALGORITHM IS USED TO DETERMINE WHEN BRAKE NOISE OCCURS DURING A STOP EVENT AND ACTUALLY DEFINE FROM WHICH CORNER OF THE VEHICLE IT ORIGINATES. A SPECIAL NOISE-RATING TABLE IS FEATURED TO ENABLE THE USER TO DEVELOP CORRELATIONS BETWEEN DRIVER RATINGS AND OBJECTIVE MEASUREMENTS.

• Journal of Biosystems Engineering
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• 제28권4호
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• pp.335-342
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• 2003

A simple disposable thick-film potentiometric strip has been developed and evaluated for hydroponics application. The strip consisted of low ion-selective electrodes (ISE) fabricated by screen-printing technology. The electrochemical responses of ion sensors for nitrate, ammonium, potassium, and magnesium were measured with specially designed 16-channel low voltage signal transducers. The analytical characteristics of the sensors were comparable with those of conventional ISE sensors. The thick-film sensors exhibit linear relationships over five concentration decades. The concentration of N $O_3$ - ion in standard solution can be determined by direct potentiometric measurements without any conditioning before measurements. However, measurement of $K^{+}$, N $H_4$$^{+}$, and $Mg^{2+}$ ionic concentrations in nutrient solutions seems not feasible.

• Journal of Construction Engineering and Project Management
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• 제1권1호
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• pp.18-23
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• 2011

Conservation of energy and fuel is the trend in smart building design. Radio Frequency Integrated Circuit (RFIC) technology is often used in temperature sensing and signal transmission to manage indoor temperature, but it is rarely applied to the shell of the building. Heat retention and poor insulation in building shells are the largest causes of high energy consumption by indoor air conditioning. Through combining RFIC technology with temperature sensors, this study will develop smart temperature information material that can be embedded in concrete. In addition to accurately evaluating the effectiveness of shell insulation material, the already-designed Building Physiology Information System can monitor long-term temperature changes, leading to smarter building health management.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권3호
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• pp.380-386
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• 2016

This paper presents a compact and low-power on-chip touch sensor and readout circuit using shunt proximity touch sensor and its design scheme. In the proposed touch sensor readout circuit, the touch panel condition depending on the proximity of the finger is directly converted into the corresponding voltage level without additional signal conditioning procedures. Furthermore, the additional circuitry including the comparator and the flip-flop does not consume any static current, which leads to a low-power design scheme. A new prototype touch sensor readout integrated circuit was fabricated using complementally metal oxide silicon (CMOS) $0.18{\mu}m$ technology with core area of $0.032mm^2$ and total current of $125{\mu}A$. Our measurement result shows that an actual 10.4 inches capacitive type touch screen panel (TSP) can detect the finger size from 0 to 1.52 mm, sharply.

• 전기학회논문지
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• 제59권2호
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• pp.267-271
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• 2010

Photovoltaic system simulator is under being developed for the performance test of Power conditioning system (PCS). The photovoltaic system simulator is required to emulate real system, which can be obtained by fast response controller. In this paper, we suggest a robust control method as a tool to design the simulator controller. The performance of the controller is determined by weighting functions, sensitivity function $W_1$ complementary sensitiviey function $W_3$, and a control signal shaping function $W_u$. Experimental results show that robust control method is promising for obtaining better performance of the photovoltaic system simulator.