• 대한의용생체공학회:의공학회지
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• 제18권3호
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• pp.315-323
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• 1997

Driving is a complex vigilance task that includes improper lookout, excessive speed and inattention. The primary objective of this research is to detect driver drowsiness so that the driver can be alerted to an impending traffic accident in performance. We developed the automatic detection and warning system during drowsy driving. A drowsiness detection system must be able to monitor driver status and detect the detrimental changes of a driver performance. Eyeblink has been found to be a reliable factor of drowsiness detection in earlier studies. As an additional parameter, we also considered the yawning which often occurs in a low vigilance state and predicts the drowsy state. We used a computer vision method to extract the eyeblink and yawning in the face image sequences. When the drowsy state was detected, the driver was refreshed by alarming device and menthol scent generator after deciding the warning level by fuzzy logic. For the evaluation of our system, we measured the physiological parameters such as EOG and EEG. The results indicated that it is possible to detect and alert the driver drowsiness temporarily or continuously by using our system.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권4호
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• pp.269-276
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• 2013

Information and communication technology (ICT) is a promising solution for mitigating road traffic congestion. ICT allows road users and vehicles to be managed based on real-time road status information. In Tanzania, traffic congestion causes losses of TZS 655 billion per year. The main objective of this study was to develop an optimal approach for integrating real-time road information (RRI) to mitigate traffic congestion. Our research survey focused on three cities that are highly affected by traffic congestion, i.e., Arusha, Mwanza, and Dar es Salaam. The results showed that ICT is not yet utilized fully to solve road traffic congestion. Thus, we established a possible approach for Tanzania based on an analysis of road traffic data provided by organizations responsible for road traffic management and road users. Furthermore, we evaluated the available road information management techniques to test their suitability for use in Tanzania. Using the floating car data technique, fuzzy logic was implemented for real-time traffic level detection and decision making. Based on this solution, we propose a RRI system architecture, which considers the effective utilization of readily available communication technology in Tanzania.

• 한국추진공학회지
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• 제12권6호
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• pp.1-6
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• 2008

본 연구에서는 계측 데이터의 성능 추이를 분석하여 가스터빈 엔진의 결함 여부를 탐지하기 위한 퍼지 경향감시 방법을 제안하였다. 제안된 경향감시 방법은 연료유량, 배기가스 온도, 로터회전수, 진동수와 같은 중요 엔진 파라미터를 모니터링 하여 시간에 따른 변화를 분석하여 엔진 상태를 진단하는 것이다. 이를 위해 먼저 선형회귀분석을 통해 엔진 상태 변화를 수식화하고 퍼지 로직을 통해 진단 결과를 분석하여 예측되는 손상 원인을 제시한다.

• 전자공학회논문지T
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• 제36T권1호
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• pp.51-57
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• 1999

본 논문은 온도센서 RSD. Pt 100Ω의 감지신호가 Temperature Controller의 릴레이 출력을 발생시키고 PLC 입력접점으로 입력시켜 1Scan Time으로 연산된 PLC 출력을 접점 P030에 Interface Unit를 연결시키므로 부하를 구동시키는 개발장비인 Wired Logic Type Unit에 대해서 기술하였다. 현재 PLC 교육장에서 프로그램 되어진 PLC가 부하를 구동시킬 수 있는 국내의 교육 PLC Test Kit로는 PLC와 부하 사이에 Interface 과정이 무시된 상태에서 PLC의 교육을 하도록 되어있다. 개발 키 트는 이 점을 보안하기 위해서 각종 센서 중 전자에서 언급한 온도 센서 Pt 100Ω을 이용한 온도 제어기의 릴레이 출력이 PLC 입력으로 피드백 되었을 때, 연산된 PLC 출력접점에 WLTU를 삽입시켜 PC, PLC와 부하 사이에 실시간 시스템으로 구동 시킬 수 있는 설비로, PLC 사용의 핵심원리를 쉽게 이해하고 알아 볼 수 있었다. 부하 Interface Unit인 WLTU의 구성은 구동 부분인 유 접점, 무접점, 센서, 지시 등, A접점, B접점 부하인 Motor로 나누었다.

• 전기학회논문지
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• 제57권1호
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• pp.128-136
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• 2008

In this paper, we propose a new cache structure for effective error correction of soft error. We added check bit and SEEB(soft error evaluation block) to evaluate the status of cache line. The SEEB stores result of parity check into the two-bit shit register and set the check bit to '1' when parity check fails twice in the same cache line. In this case the line where parity check fails twice is treated as a vulnerable to soft error. When the data is filled into the cache, the new replacement algorithm is suggested that it can only use the valid block determined by SEEB. This structure prohibits the vulnerable line from being used and contributes to efficient use of cache by the reuse of line where parity check fails only once can be reused. We tried to minimize the side effect of the proposed cache and the experimental results, using SPEC2000 benchmark, showed 3% degradation in hit rate, 15% timing overhead because of parity logic and 2.7% area overhead. But it can be considered as trivial for SEEB because almost tolerant design inevitably adopt this parity method even if there are some overhead. And if only parity logic is used then it can have $5%{\sim}10%$ advantage than ECC logic. By using this proposed cache, the system will be protected from the threat of soft error in cache and the hit rate can be maintained to the level without soft error in the cache.

• Journal of Welding and Joining
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• 제16권5호
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• pp.119-133
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• 1998

To implement full automation in pipe welding, it si most important to develop special sensors and their related systems which act like human operator when detecting irregular groove conditions. In this study, an automatic pipe Gas Metal Arc Welding (GMAW) system was proposed to full control pipe welding procedure with intelligent sensor systems. A five-axes manipulator was proposed for welding torch to automatically access to exact welding position when pipe size and welding angle were given. Pool status and torch position were measured by using a weld-pool image monitoring and processing technique in root-pass welding for weld seam tracking and weld pool control. To overcome the intensive arc light, pool image was captured at the instance of short circuit of welding power loop. Captured image was processed to determine weld pool shape. For weld seam tracking, the relative distance of a torch position from the pool center was calculated in the extracted pool shape to move torch just onto the groove center. To control penetration of root pas, gap was calculated in the extracted pool image, and then weld conditions were controlled for obtaining appropriate penetration. welding speed was determined with a fuzzy logic, and welding current and voltage were determined from a data base to correspond to the gap. For automatic fill-pass welding, the function of human operator of real time weld seam control can be substituted by a sensor system. In this study, an arc sensor system was proposed based on a fuzzy control logic. Using the proposed automatic system, root-pass welding of pipe which had gap variation was assured to be appropriately controlled in welding conditions and in torch position by showing sound welding result and good seam tracking capability. Fill-pass welding by the proposed system also showed very successful result by tracking along the offset welding line without any control of human operator.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1167-1175
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• 2021

The process of automation and monitoring in industrial control system involves the use of many types of sensors. A programmable logic controller plays an important role in the automation of the different processes in the power plant system. The major control units are boiler for temperature and pressure, turbine for speed of motor, generator for voltage, conveyer belt for fuel. The power plant units are controlled using microcontrollers and PLCs, but FPGA can be the feasible solution. The paper focused on the design and simulation of hardware chip to monitor boiler, turbine, generator and conveyer belt. The hardware chip of the plant is designed in Xilinx Vivado Simulator 17.4 software using VHDL programming. The methodology includes VHDL code design, simulation, verification and testing on Virtex-5 FPGA hardware. The system has four independent buzzers used to indicate the status of the boiler, generator, turbine motor and conveyer belt in on/off conditions respectively. The GSM is used to display corresponding message on the mobile to know the status of the device in on/off condition. The system is very much helpful for the industries working on plant automation with FPGA hardware integration.

• 성인간호학회지
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• 제16권1호
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• pp.156-165
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• 2004

Purpose: This descriptive - comparison study was conducted to investigate the critical thinking disposition of senior nursing students in three types of nursing program. Method: The convenience sample was drawn from 472 nursing students. Instruments used in this study were made California Critical Thinking Disposition Inventory developed by Facione & Facione (1994). Data was analyzed by descriptive statistics, t-test, ANOVA, Scheffe test with SAS 6.12 program. Result: 1. The total mean score of critical thinking disposition was 279.06. Inquisitiveness was the highest with an mean score 45.50, while systematicity was the lowest with mean score of 36.15. There was a statistically significant difference in critical thinking disposition(F=14.36, p=.00)according to senior nursing students in three types of nursing programs. 2. There was a statistically significant difference in critical thinking disposition(F=5.53, p=.00) according to age, marital status(t=-3.15, p=.00), religion(F=3.26, p=.02) and critical thinking course taken previously(t=3.10, p=.00). Conclusion: There was a statistically significant difference in critical thinking disposition(F=14.36, p=.00) according to senior nursing students in three types of nursing program. There was a statistically significant difference in Critical thinking disposition according to age, marital status, religion, logic, philosophy, critical thinking course.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권1호
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• pp.50-58
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• 2013

Estimating a driver's head pose is an important task in driver-assistance systems because it can provide information about where a driver is looking, thereby giving useful cues about the status of the driver (i.e., paying proper attention, fatigued, etc.). This study proposes a system for estimating the head pose using monocular images, which includes a novel use of backprojection. The system can use a single image to estimate a driver's head pose at a particular time stamp, or an image sequence to support the analysis of a driver's status. Using our proposed system, we compared two previous pose estimation approaches. We introduced an approach for providing ground-truth reference data using a mannequin model. Our experimental results demonstrate that the proposed system provides relatively accurate estimations of the yaw, tilt, and roll angle. The results also show that one of the pose estimation approaches (perspective-n-point, PnP) provided a consistently better estimate compared to the other (pose from orthography and scaling with iterations, POSIT) using our proposed system.

• 항공우주정책ㆍ법학회지
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• 제23권2호
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• pp.207-223
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• 2008

1967년 우주조약은 제1조에서 우주공간의 이용의 자유를 규정하고 있으나, 우주공간의 법적지위는 물론, 우주활동의 개념도 규정하고 있지 않다. 이에 우주공간에서 발생하는 활동에 대해서 우주공간의 이용의 자유가 적용된다는 법 규범은 엄격한 논리에서는 성립되지 않는다. 아울러 우주공간을 이용하는 행위, 즉 동 조약에서 사용하고 있는 우주활동의 개념도 정의되어 있지 않기에 어떠한 활동이 우주공간의 이용의 자유를 향유할 수 있는가에 대한 법 규범도 성립되지 않는다. 다만, 우주활동이 제반국제법 원칙 및 관련 우주법의 규정을 준수하여야 한다는 것만이 동 조약에 규정되어 있다. 이에 우주활동에의 적용 규범의 선택 문제는 법률적인 것이 아니라 정치적인 논리에 의하게 된다. 그 결과 우주공간의 군사적 이용을 규율할 수 있는 법규범은 법적안정성을 결여하고 있다고 판단된다.