• Design & Manufacturing
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• 제16권4호
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• pp.52-59
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• 2022

Currently, Korea is an aging society and is expected to become a super-aged society in about four years. X-ray devices are widely used for early diagnosis in hospitals, and many X-ray technologies are being developed. The development of X-ray device technology is important, but it is also important to increase the reliability of the device through accurate data management. Sensor nodes such as temperature, voltage, and current of the diagnosis device may malfunction or transmit inaccurate data due to various causes such as failure or power outage. Therefore, in this study, the temperature, tube voltage, and tube current data related to each sensor and detection circuit of the diagnostic X-ray imaging device were measured and analyzed. Based on QC data, device failure prediction and diagnosis algorithms were designed and performed. The fault diagnosis algorithm can configure a simulator capable of setting user parameter values, displaying sensor output graphs, and displaying signs of sensor abnormalities, and can check the detection results when each sensor is operating normally and when the sensor is abnormal. It is judged that efficient device management and diagnosis is possible because it monitors abnormal data values (temperature, voltage, current) in real time and automatically diagnoses failures by feeding back the abnormal values detected at each stage. Although this algorithm cannot predict all failures related to temperature, voltage, and current of diagnostic X-ray imaging devices, it can detect temperature rise, bouncing values, device physical limits, input/output values, and radiation-related anomalies. exposure. If a value exceeding the maximum variation value of each data occurs, it is judged that it will be possible to check and respond in preparation for device failure. If a device's sensor fails, unexpected accidents may occur, increasing costs and risks, and regular maintenance cannot cope with all errors or failures. Therefore, since real-time maintenance through continuous data monitoring is possible, reliability improvement, maintenance cost reduction, and efficient management of equipment are expected to be possible.

• 대한전기학회논문지:전력기술부문A
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• 제48권10호
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• pp.1356-1363
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• 1999

In this paper, a new method for controlling the pointing device using EOG(electrooculogram) signal generated from eye movement was suggested. The basic idea of the method is to control the direction of pointer, as using the results of measuring each component of the horizontal EOG and the vertical EOG by angle of eye-gaze. As a practical example, pointing device controlling the personal computer's pointer is manufactured. The designed pointing device consists of pre-amplifier, A/D converter, serial transmission device and PC program. That is, first, the EOG is amplified by pre-amplifier. Secondly, the amplified EOG is digitized and transmitted to personal computer by PIC16C74A. Finally, the software for controlling the pointer on personal computer is programed. As the result, the measured horizontal EOG and vertical EOG by eye-gaze angle had high linearity; the correlation coefficients of the regression line were 0.998 and 0.996 respectively. And the developed pointing device is able to control the personal computer's pointer, and the average of the errors between the objective value and the observed value had 3.77% for horizontal axis and 5.85% for vertical axis. The pointing device developed in this study is able to control personal computer's pointer by subject's eye movement, that is, the user's intention. Furthermore, the algorithm of this study is applicable for many field, such as a new method remote control, a new wheelchair control and so forth.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.21-26
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• 2012

햅틱 장치는 기존 장치대비 보다 편리하고 정확하며 직관적 조작이 가능한 인간-기계 교류 장치이다. 이 연구의 목적은 햅틱 장치의 색상을 독립적인 설계 변수로 고려한 설계 인자의 운전자 반응을 정의하는 것이다. 본 논문에서는 기존의 촉각 피드백을 이용한 햅틱 장치의 인지능력을 증가시키는 방법에 대하여 연구하였다. 기존의 차량용햅틱 장치에 색상 피드백을 더한 루미노 햅틱 디바이스를 이용하여 사용성 평가를 실시하였다. 감성 분석을 통하여 운전자가 갖는 햅틱 디바이스에 대한 감성분석을 도출하였다. 결과적으로 운전자를 만족시키는 설계 방향의 제안이 가능하였다.

• 한국안전학회지
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• 제16권2호
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• pp.57-62
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• 2001

In order to analyze the mechanism of semiconductor device damages by ESD, this paper adopts a new charged-device model(CDM), field-induced charged nudel(FCDM), simulator that is suitable for rapid routine testing of semiconductor devices and provides a fast and inexpensive test that faithfully represents ESD hazards in plants. The high voltage applied to the device under test is raised by the fie]d of non-contacting electrodes in the FCDM simulator. which avoids premature device stressing and permits a faster test cycle. Discharge current md time are measured and calculated The FCDM simulator places the device at a huh voltage without transferring charge to it, by using a non-contacting electrode. The only charge transfer in the FCMD simulator happens during the discharge. This paper examine the field charging mechanism, measure device thresholds, and analyze failure modes. The FCDM simulator provides a Int and inexpensive test that faithfully represents factory ESD hazards. The damaged devices obtained in the simulator are analyzed and evaluated by SEM Also the results in this paper can be used for to prevent semiconductor devices from ESD hazards.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제23회 추계학술대회 논문집
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• pp.146-154
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• 2004

본 연구에서는 탄의 정밀타격을 위한 항력증가장치의 항력특성에 관한 전산해석을 실시하였다. 전산해석에서는 항력증가장치의 부착에 따른 항력증가 특성을 분석하였으며, 항력증가장치의 펼침 각도와 위치가 미치는 효과를 살펴보았다. 항력증가장치 펼침각이 $20^{\circ}$일 때 항력은 항력증가장치가 없는 경우에 비해 약 3.5배 증가하였다. 그리고 이때 필요한 항력증가장치의 무게는 약 26g인 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2606-2613
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• 2022

Spent resin often exceeds radiation limits for safe disposal, creating a need for commercial-scale treatment techniques to reduce resin radioactivity. In this study, the radiological safety of a commercialized spent resin treatment device with a treatment capacity of 1 ton/day was evaluated. The results confirm that the device is radiologically safe in the event of an accident. This device desorbs ¹⁴C from the spent resin, allowing disposal as low-level waste instead of intermediate-level waste. The device also reduces overall waste by recycling the extracted ¹⁴C. Potential accident scenarios were explored to enable dose assessments for both internal and external exposure while preventing further spillage of the device and processing the spilled resin. The scenarios involved the development of a surface fracture on the resin mixture separator and microwave systems, which were operated under pressure and temperature of 0-6 bar and 0-150 ℃, respectively. In the case of accidents with separator and microwave device, the maximum allowable working time of worker were derived, respectively, considering external and internal exposures. When wearing the respirator corresponding to APF 50, in the case of the microwave device accident scenario, the radiological safety was confirmed when the maximum worker worked within 132.1 h.

• 한국통신학회논문지
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• 제18권11호
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• pp.1754-1766
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• 1993

GPIB의 통합의 용이성과 VMEbus 시스템의 고속 데이터 전송의 장점을 갖춘 VXIbus 시스템은 계측기 산업의 표준으로 그 사용이 확산되고 있다. VXIbus 메시지 기반 디바이스(Message Based Device)는 VXIbus 레지스터 기반 디바이스(Register Based Device)에 비하여 속도면에서 불리한 점은 있으나 고수준의 명령어를 사용한 제어가 가능하여 통합리 용이하다는 장점을 지닌다. 한편 FFT분석기는 고속, 고해상도를 저렴하게 실현할 수 있는 신호분석용 장비로서 다양한 분석능력을 제공하므로 수많은 응용분야에 사용되고 있다. 따라서 FFT분석기를 VXIbus에 적용하는 것은 반드시 이루어져야 할 과제이다. 본 논문에서는 VXIbus 메시지 기반 디바이스(Message Based Device)로 FFT분석기를 구현하였다. 이를 위하여 VME용 신호처리모듈을 사용하였으며 A/D변환부와, VXIbus 인터페이스를 담당하는 제어무듈을 구현하였고 VXIbus 공유메모리 프로토콜(Shared Memory Protocol)을 지원하는 자원관리모듈 Slot0 Commander의 제어를 받도록 하였다.

• 한국통신학회논문지
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• 제38A권10호
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• pp.908-917
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• 2013

본 논문에서는 기기 간 직접(device-to-device) 통신 시스템에서 근접한 디바이스의 모바일 어플리케이션 및 서비스를 발견하기 위한 디스커버리 프로토콜을 제안한다. 기기 간 직접통신 기술을 기반으로 모바일 소셜네트워크, 모바일 마케팅 등의 근접 기반 어플리케이션을 실현할 수 있다. 이를 위해 우선적으로 주변에 있는 수많은 디바이스에서 원하는 어플리케이션을 찾아내는 디스커버리 프로토콜의 설계가 필수적이다. 기반 시설이 없는 에드혹 망에서 디스커버리 프로토콜을 구현하기 위해서는 디바이스 내부의 어플리케이션 정보를 축약해서 디스커버리 코드를 생성하고 이를 주기적으로 방송하는 방법을 쓸 수 있다. 본 논문에서는 해시함수 및 블룸필터(Bloom filter)를 이용하여 디스커버리 프로토콜을 설계하고 이의 성능을 수학적으로 분석한다.

• Journal of Multimedia Information System
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• 제3권4호
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• pp.135-140
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• 2016

To improve the throughput of Device-to-Device (D2D) communication, we focus on the scenario where D2D pair can reuse multi-channel of cellular communication. However, as sharing same channel with cellular communication can cause interference between D2D communication and cellular communication, a proper interference management is needed. In this paper, we propose interference-based channel allocation to select the channels to be used by D2D communication and a solution from game theory perspective to optimize the D2D communication throughput under multi-channel as well as guarantee the interference from it to cellular network. The simulation results verify the stability of the proposed method.

• 한국멀티미디어학회논문지
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• 제19권8호
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• pp.1415-1423
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• 2016

Interference in device-to-device (D2D) communication underlaying cellular network needs to be elaborately investigated because of channel sharing. The objective is to improve the quality of D2D communications while maintaining high performance for cellular users. In this paper, we solve the above problem by jointly considering channel allocation and power control using coalition formation game. Our cooperative game theoric approach allows to enhance network-wide performance. We design a merge-and-split algorithm to deal with the complexity of the combinatorial structure in coalition formation problem. The analytical and numerical results show that our algorithm converges to a stable point which achieves high network performance.