• 한국멀티미디어학회논문지
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• 제23권4호
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• pp.566-573
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• 2020

Computers are the most common tool when using the Internet and utilizing a mouse to select and execute objects. Eye tracking technology is welcomed as an alternative technology to help control computers for users who cannot use their hands due to their disabilities. However, the pointer execution method of the existing eye tracking technique causes many malfunctions. Therefore, in this paper, we developed a gaze tracking interface that combines voice commands to solve the malfunction problem when the upper limb disabled uses the existing gaze tracking technology to execute computer menus and objects. Usability verification was conducted through comparative experiments regarding the improvements of the malfunction. The upper limb disabled who are hand-impaired use eye tracking technology to move the pointer and utilize the voice commands, such as, "okay" while browsing the computer screen for instant clicks. As a result of the comparative experiments on the reduction of the malfunction of pointer execution with the existing gaze interfaces, we verified that our system, Eye-Voice, reduced the malfunction rate of pointer execution and is effective for the upper limb disabled to use.

• 조명전기설비학회논문지
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• 제20권5호
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• pp.42-48
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• 2006

승강기 갇힘 사고 절대 건수가 매년 증가하고 있다. 또한 갇힘, 급상승, 급정지, 층 표시 오류 등 승객의 불안감을 유발시킬 수 있고, 인명 사고와 연결될 수 있는 오동작 사고가 많이 발생을 하고 있다. 따라서 본 논문에서는 이런 갇힘 및 오동작을 발생시킬 수 있는 순시전원품질(Sag, Swell, Interruption) 현상이 승강기가 설치되어 있는 현장에서 어느 정도의 크기와 지속시간으로 측정이 되는지를 실시간 측정 장비를 통하여 측정 분석 하였다. 또한 승강기 설비 두 세트에 대하여 유럽에서 승강기 내성시험(susceptibility)규정으로 적용하는 EN12016(2004) 규격으로 시험하여 순시전원품질 변화에 따른 승강기 설비의 멈춤 및 구동에 대한 성능 평가를 하였다. 분석 결과는 최종적으로 승강기 설비의 전원품질과 오동작의 상호 연관성 분석 및 승강설비의 전기적 장해에 대한 대책을 제시하는데 자료로 이용될 것이다.

• 전기학회논문지
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• 제58권10호
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• pp.1916-1922
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• 2009

Introducing distributed generators(DGs) to utility distribution system can cause malfunction of relay on the grid when ground faults or severe load unbalances are occurred on the system. Because DGs interconnected to the grid can contribute fault currents and make bidirectional power flows on the system, fault currents from DGs can cause an interference of relay operation. A directional over current relay(DOCR) can determine the direction of power flow whether a fault occurs at the source side or load side through detecting the phases of voltage and current simultaneously. However, it is identified in this paper that the contributed fault current(Ifdg) from the ground source when was occurred to contribute single-line-to-ground(SLG) fault current, has various phases according to the distances from the ground source. It means that the directionality of Ifdg may not be determined by simply detecting the phases of voltage and current in some fault conditions. The magnitude of Ifdg can be estimated approximately as high as 3 times of a phase current and its maximum is up to 2,000 A depending on the capacity of generation facilities. In order to prevent malfunction of relay and damage of DG facilities from the contribution of ground fault currents, Ifdg should be limited within a proper range. Installation of neutral ground reactor (NGR) at a primary neutral of interconnection transformer was suggested in the paper. Capacity of the proposed NGR can be adjusted easily by controlling taps of the NGR. An algorithm for unidirectional relay was also proposed to prevent the malfunction of relay due to the fault current, Ifdg. By the algorithm, it is possible to determine the directionality of fault from measuring only the magnitude of fault current. It also implies that the directionality of fault can be detected by unidirectional relay without replacement of relay with the bidirectional relay.

• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.1104-1111
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• 2014

The digital substations are being built based on the IEC 61850 network. The cooperation and protection of power system are becoming more intelligent and reliable in the environment of digital substation. This paper proposes a novel method to prevent the malfunction caused by the Transformer Magnetizing Inrush Current(TMIC) using the IEC 61850 based data sharing between the IEDs. To protect a main transformer, the current differential protection(87T) and over-current protection(50/51) are used generally. The 87T IED applies to the second harmonic blocking method to prevent the malfunction caused by the TMIC. However, the 50/51 IED may malfunction caused by the TMIC. To solve that problem, the proposed method uses a GOOSE inter-lock signal between two IEDs. The 87T IED transmits a blocking GOOSE signal to the 50/51 IED, when the TMIC is detected. The proposed method can make a cooperation of digital substation protection system more intelligent. To verify the performance of proposed method, this paper performs the real time test using the RTDS (Real Time Digital Simulator) test-bed. Using the RTDS, the power system transients are simulated, and the TMIC is generated. The performance of proposed method is verified in real-time using that actual current signals. The reaction of simulated power system responding to the operation of IEDs can be also confirmed.

• 한국전기전자재료학회논문지
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• 제31권1호
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• pp.44-49
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• 2018

This study analyzed the Vulnerability of Network Communication devices when IEMI is coupled with the Network System. An Ultra Wide Band Generator (180 kV, 700 MHz) was used as the IEMI source. The EUTs are the Switch Hub and Workstation, which are used to configure the network system. The network system was monitored through the LAN system configuration, to confirm a malfunction of the network device. The results of the experiment indicate that a malfunction of the network occurs as the electric field increases. The data loss rate increases proportionally with increasing radiating time. In the case of the Switch Hub, the threshold electric field value was 10 kV/m for all conditions used in this experiment. The threshold point causing malfunction was influenced only by the electric field value. The correlation between the threshold point and pulse repetition rate was not found. However, in case of the Workstation, it was found that as the pulse repetition rate increases, the equipment responds weakly and the threshold value decreases. To verify the electrical coupling of the EUT by IEMI, current sensors were used to measure the PCB line inside the EUT and network line coupling current. As a result of the measurement, it can be inferred that when the coupling current due to IEMI exceeds the threshold value, it flows through the internal equipment line, causing a malfunction and subsequent failure. The results of this study can be applied to basic data for equipment protection, and effect analysis of intentional electromagnetic interference.

• 대한한의학방제학회지
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• 제15권1호
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• pp.1-19
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• 2007

This study was investigated to make sure the range of Gypsum treatment, the nature of disease, the pathology and the dosage of it in Dongeuybogam. The following conclusions were reached through investigations on the prescriptions that use Gypsum as a key ingredient. The Gypsum blended prescriptions are utilized in 23 fields of treatment such as cold, head. ect. Prescriptions that use Gypsum as the main ingredient are used commonly in the treatment of cold, head disease, fever, skin disease, diabetes, stroke, ophthalmic disease, jaundice, ENT disease and dental disease. The Gypsum is used for nature of disease which of cold, heat(fever), summer heat, phlegm, malfunction of liver, malfunction of liver and kidney, heat of stomach, malfunction of spleen and fever of stomach. The clinical dosage of Gypsum has ranged at a wide variety of amount from 1.6g to 16g per dose with 4g ${\sim}$ 8g being the typical dose for most treatment. The Gypsum is applied as a fundamental prescription with several herb remedies for the pathology.

• International Journal of Aeronautical and Space Sciences
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• 제14권1호
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• pp.91-98
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• 2013

The rigorous requirements of modern spacecraft missions necessitate a precise attitude determination strategy. This paper mainly researches that, based on three space-borne attitude sensors: 3-axis rate gyros, 3-antenna GPS receiver and star-sensor. To obtain global attitude estimation after an information fusion process, a feedback-involved Federated Kalman Filter (FKF), consisting of two subsystem Kalman filters (Gyros/GPS and Gyros/Star-sensor), is established. In these filters, the state equation is implemented according to the spacecraft's kinematic attitude model, while the residual error models of GPS and star-sensor observed attitude are utilized, to establish two observation equations, respectively. Taking the sensors' different update rates into account, these two subsystem filters are conducted under a variable step size state prediction method. To improve the fault tolerant capacity of the attitude determination system, this paper designs malfunction warning factors, based on the principle of ${\chi}^2$ residual verification. Mathematical simulation indicates that the information fusion strategy overwhelms the disadvantages of each sensor, acquiring global attitude estimation with precision at a 2-arcsecs level. Although a subsystem encounters malfunction, FKF still reaches precise and stable accuracy. In this process, malfunction warning factors advice malfunctions correctly and effectively.

• 대한기계학회논문집A
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• 제34권10호
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• pp.1529-1535
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• 2010

생산 장비로서 잉크젯 기술의 신뢰성을 증대 시키기 위하여 잉크젯 헤드의 작동 상태를 모니터링하고 이상 유무를 즉시 발견 할 수 있는 소프트웨어 및 하드웨어를 개발 하였다. 잉크젯 헤드의 작동 상태의 측정을 위하여 잉크젯 헤드의 피에조 전기 신호를 사용하였다. 이를 위하여 피에조의 변형량을 간접적으로 측정 할 수 있는 회로를 개발 하였고, 측정된 전기 신호를 사용하여 작동의 불량 여부를 판단 할 수 있도록 소프트웨어 알고리즘을 개발하였다. 또한 다중 노즐 헤드에 적용이 가능하도록 소프트웨어 개발 및 시스템 통합을 수행하였다.

• 한국안전학회지
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• 제29권5호
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• pp.54-59
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• 2014

The record type receivers that are operated in large industrial sites have strength in preventing fire. However, because of its long circuit lines and multiple detectors, the receivers are vulnerable to lightning, noise, and breakdown of equipments, resulting in malfunction. In case of malfunctioning of detection circuits of main protection areas, such as electrical room and server room, potential release of gaseous extinguisher agents may lead to property and life damage. In this paper, we present the results on the characteristics of the transponder that initiates the solenoid valves, with respect to various electromagnetic and lightning inflow conditions. Based on the measured data, we analyzed the systematic problems of the transponder. In order to prevent receiver malfunctions, a sequential circuit was configured with two additional transponders and a timer. The circuit was tested with a simulator with preference and delay circuit algorithms.

• 한국항공운항학회지
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• 제24권1호
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• pp.33-40
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• 2016

ROK issued its first type certificate to the KC-100 airplane, Part 23 normal category, and become the State of Design (SoD) in 2013. Before this, ROK aviation regulations were focused on the operation and continued airworthiness of aircraft registered and operated in ROK that were designed and manufactured in another contracting state. Therefore the implementation of reporting system were restricted to gather the failure and service difficulty reports from the owners or operators and transmit the information to the State of Design and/or the manufacture relating to the type certificated aircraft. However, ROK, to fulfill the accountability of the State of Design, has to ensure there is a system to address the information received from the State of Registry on failure, malfunctions, defects and other occurrences that might cause adverse effects on the continuing airworthiness of the korean type certificated aircraft. This paper presents an overview of ICAO requirements for the State of Design, and current implementation of reporting system of USA and Japan and discusses the current status and further considerations on the rule-making for the malfunction, defect and failure reporting system applicable to the korean indigenous aircraft.