• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.670-675
• /
• 1994

Yhis paper describes a fault diagnosis simulation of the Real-Time Multiple Fault Dignosis System (RTMFDS) for forcasting faults in a system and deciding current machine state from signal information. Comparing with other diagnosis system for single fault,the system developed deals with multiple fault diagnosis,comprising two main parts. One is a remotesignal generating and transimission terminal and the other is a host system for fault diagnosis. Signal generator generate the random fault signal and the image information, and send this information to host. Host consists of various modules and agents such as Signal Processing Module(SPM) for sinal preprocessing, Performence Monotoring Module(PMM) for subsystem performance monitoring, Trigger Module(TM) for multi-triggering subsystem fault diagnosis, Subsystem Fault Diagnosis Agent(SFDA) for receiving trigger signal, formulating subsystem fault D\ulcornerB and initiating diagnosis, Fault Diagnosis Module(FDM) for simulating component fault with Hierarchical Artificial Neural Network (HANN), numerical models and Hofield network,Result Agent(RA) for receiving simulation result and sending to Treatment solver and Graphic Agent(GA). Each agent represents a separate process in UNIX operating system, information exchange and cooperation between agents was doen by IPC(Inter Process Communication : message queue, semaphore, signal, pipe). Numerical models are used to deseribe structure, function and behavior of total system, subsystems and their components. Hierarchical data structure for diagnosing the fault system is implemented by HANN. Signal generation and transmittion was performed on PC. As a host, SUN workstation with X-Windows(Motif)is used for graphic representation.

• Asia pacific journal of information systems
• /
• v.26 no.2
• /
• pp.268-289
• /
• 2016

While most of studies have paid attention to the initial adoption of a specific application, research on applications has not focused on an individual's update decision process. This study draws upon both dual information processing and status quo bias perspectives as a comprehensive theoretical lens to explain why individuals do not update their applications. This study assumes that individuals' inertia could be the main reason for their reluctance to update the applications. Based on a survey of 186 smartphone users, this study demonstrated that both habit as an affective trigger of system 1 thinking and sunk cost as a cognitive trigger of system 2 thinking promoted the two types of inertia (i.e., affective and cognitive based inertia) in individuals, which have a negative effect on their willingness to update their applications. By grounding the research model in a theoretical view, such as dual information processing and status quo bias, this study provides a unique theoretical lens from which to view individuals' behaviors, thereby gaining a better understanding of their decision not to update to the current version of applications. This study also investigates the moderating effect of the types of applications on the relationships between affective/cognitive-based inertia and willingness to update. Results show that both habit and sunk cost decrease the willingness to update because they increase both affective and cognitive-based inertia. This study also found that the effects of affective/cognitive based inertia differed depending on the type of applications.

• Asian Journal for Public Opinion Research
• /
• v.11 no.4
• /
• pp.304-326
• /
• 2023

News shows often deliver crosscutting information to their audiences by inviting commentators from rival political parties. If these news shows foster the formation of informed and balanced views of the audience, mass media could provide countermeasures against political polarization. To test the effect of such news shows, this study conducted an experiment with two variants of a simulated radio talk show. In the partisan scenario, the two guest commentators' affiliations suggested their ideological orientation. In the non-partisan scenario, the commentators had neutral affiliations. We divided participants into two ideology groups, liberals and conservative, and compared each group's evaluation of the commentators in the two scenarios. Two multivariate analysis of variance (MANOVA) tests were conducted to analyze the effect of the perceived ideology of the commentators on respondents' attitudes toward the commentators' arguments depending on their own ideological inclinations. The analyses results did not support the hypothesis that anticipated partisan attitudes towards the commentators' arguments. It was only the liberal respondents who showed statistically significant different attitudes toward commentators' arguments in each of the two scenarios. The findings suggest that such broadcast shows do not automatically trigger partisan message processing and may help the audience to develop informed and balanced opinions. While the current study failed to find conclusive evidence to support the hypotheses, it also found that the perceived ideology of the information source may trigger partisan attitudes for certain types of issues. Future studies with different experiment designs are needed to investigate the issue further.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.5
• /
• pp.50-57
• /
• 2008

In this paper, a high-efficiency charge pump for use in CMOS image sensor(CIS) is proposed. The proposed charge pump pursues high pumping efficiency by minimizing the switching and reversion losses by taking advantage of operation characteristics of CIS. That is, the proposed charge pump minimizes the switching loss by dynamically controlling the size of clock driver, pumping capacitor, and charge transfer switch based on the operation phase of CIS pixel sensor. The charge pump also minimizes the reversion loss by guaranteeing a sufficient non-overlapping period of local clocks using a tri-state local clock driver adapting the schmitt trigger. Comparison results using a 0.13-um CMOS process technology indicate that the proposed charge pump achieves up to 49.1% reduction on power consumption under no loading current condition as compared to conventional charge pump. They also indicate that the charge pump provides 19.0% reduction on power consumption under the maximum loading current condition.

• Proceedings of the KIPE Conference
• /
• 2019.07a
• /
• pp.230-232
• /
• 2019

Light Triggerd Thyristor (LTT)는 HVDC 및 산업용 스위치 등에 사용되는 대전력 반도체소자이다. 일반적인 Thyristor가 전기적 신호에 의해 trigger 되는 것과는 다르게 LTT는 광신호에 의해 동작하는 소자이다. 본 논문에서는 5,000V, 2,200A 급의 4인치 LTT 소자의 제작 및 전기적인 특성평가 결과를 기술하였다. 4인치 LTT의 구조적인 특징은 전면부 중앙에 광신호가 주입되는 수광부가 위치해 있으며 입력 전류 증폭을 위한 4-단계 증폭 게이트 (gate) 구조를 가지도록 설계하였다. $400{\Omega}{\cdot}cm$ 비저항을 갖는 1mm 두께의 n-형 실리콘 웨이퍼에 boron 이온주입과 열처리 공정으로 약 $30{\mu}m$ 깊이의 p-base를 형성하였으며, 고내압 저지를 위한 edge termination은 VLD (variable lateral doping) 기술을 적용하였다. 제작된 4인치 LTT는 6,500 V의 순방향 항복전압 ($V_{DRM}$) 특성을 나타내었으며, 100V의 어노드전압 ($V_A$)과 20 mA의 게이트전류 ($I_G$)에 의하여 thyristor가 trigger 됨을 확인하였다. 제작한 LTT 소자는 disk형 press-pack 패키지를 진행한 후, LTT의 수광부에 $10{\mu}s$, 50 mW의 900 nm 광 펄스를 조사하여 전류 특성을 평가하였다. LTT 패키지 샘플에 60 Hz 주파수의 광 펄스를 조사한 경우 2,460 A의 순방향 평균전류 ($I_T$)와 $336A/{\mu}s$의 반복전류상승기울기 (repetitive di/dt)에 안정적으로 동작함을 확인하였다. 또한, 펄스 전류 시험의 경우 61.6 kA의 최대 통전 전류 (ITSM, surge current)와 $1,050A/{\mu}s$의 펄스전류 상승 기울기 (di/dt of on-state pulse current)에도 LTT의 손상 없이 동작함을 확인하였다.

• Proceedings of the KIEE Conference
• /
• 1996.11a
• /
• pp.302-304
• /
• 1996

In this paper, a new algorithm for sensorless speed control of switched reluctance motor (SRM) is proposed. It is based on the measurement of initial rate of change of phase current. The initial rate of rise of phase current mainly depends up on the phase inductance at the time instant when the phase is excited. Therefore, the measurement of initial di/dt permits rotor position estimation, which is used to trigger the next phase. In the proposed technique, there is no need to generate additional current pulses when a phase is not excited. Therefore, this scheme does not introduce the unwanted braking torque. Also, only one current measurement is made every time a phase is excited. This reduces the computational load on the micro-controller and enhances the speed range of the sensorless drive. By using this scheme it is possible to implement the sensorless control of SRM using low cost micro-controller.

• Journal of IKEEE
• /
• v.12 no.3
• /
• pp.172-175
• /
• 2008

An improved triangular/square-wave VCO using OTAs is presented. It consists of two OTAs, a timing capacitor, and a resistor. A prototype circuit built with commercially available components exhibits less than 0.01% nonlinearity in its current-to-frequency transfer characteristic from 0.2 to 14 kHz and 450 ppm/$^{\circ}C$ temperature coefficient of frequency over $-20^{\circ}C$ to $40^{\circ}$.

• Journal of Sensor Science and Technology
• /
• v.3 no.1
• /
• pp.46-53
• /
• 1994

In the following paper, the high frequency oscillation proximity sensor system, one of the sensor systems used in FA, is designed using CMOS. According to the proximity of metal objects, two differing amplitudes of sinusoidal waves are set, and by using rectifiers, dc voltages, which determine the constant current source circuit's output current levels, can be abstracted from these waves. To remove any disturbances in the dc voltage levels, a schmitt trigger is used. Some advantages of this CMOS high frequency oscillation proximity sensor are miniturization, light weight and low power disspation.

• Proceedings of the IEEK Conference
• /
• 1998.06a
• /
• pp.347-350
• /
• 1998

차세대 CMOS 구조에서 래치업 최소화를 위하여 고에너지 이온주입을 이용한 retrograde well 과 매몰층의 최적 공정 설계 변수 값들을 설정하였다. 본 논문에서는 두 가지의 모듸 모델 구조를 제안하고 silvaco 틀에 의한 시뮬레이션 결과를 비교 분석하엿다. 첫 번째 모델은 매몰층과 retrograde well을 조합한 구조이며, p+ injection trigger current가 600.mu.A/.mu.m 이상의 결과를 얻었고, 두번째 모델은 twin retrograde well을 이용하여 p+ injection 유지전류가 2500.mu.A/.mu.m이상의 결과를 얻었다. 시뮬레이션 결과, 두 모델 모두 도즈량이 많을수록 래치업 면역 특성이 좋아짐을 보았다. 시뮬레이션 조건에서 두 모델 모두 n+/p+ 간격은 2..mu.m 로 고정하였다.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2001.02a
• /
• pp.189-192
• /
• 2001

In order to design thermally trigger controlled persistent current switch (PCS) for superconducting magnet system, it is very important to know information of applied adiabatic method and condition to get designed resistance and characteristics In this paper, we used cotton-gummed tape as thermal insulator and derived experimentally averaged thermal conductivity of it around 10K on the assumption that adiabatic structure of PCS is shape of pipe. The result value is about 0.29 W/mK and it is verified reasonable value by computer simulation and experiment of test PCS. Test PCS was designed and manufactured different dimensions. The experimental results of test PCS were in good agreement with the calculated results.