• Steel and Composite Structures
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• 제17권2호
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• pp.145-157
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• 2014

This study aimed to investigate the fatigue crack growth behavior of a kind of fiber metal laminates (FML) under four different stress levels. The FML specimen consists of three 2024-T3 aluminum alloy sheets and two layers of glass/epoxy composite lamina. Tensile-tensile cyclic fatigue tests were conducted on centrally notched specimen at four stress levels with various maximum values. A digital camera system was used to take photos of the propagating cracks on both sides of the specimens. Image processing software was adopted to accurately measure the length of the cracks on each photo. The test results show that: (1) a-N and da/dN-a curves of FML specimens can be divided into transient crack growth segment, steady state crack growth segment and accelerated crack growth segment; (2) compared to 2024-T3 aluminum alloy, the fatigue properties of FML are much better; (3) da/dN-${\Delta}K$ curves of FML specimens can be divided into fatigue crack growth rate decrease segment and fatigue crack growth rate increase segment; (3) the maximum stress level has a large influence on a-N, da/dN-a and da/dN-${\Delta}K$ curves of FML specimens; (4) the fatigue crack growth rate da/dN presents a nonlinear accelerated increasing trend to the maximum stress level; (5) the maximum stress level has an almost linear relationship with the stress intensity factor ${\Delta}K$.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권9호
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• pp.512-519
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• 2000

A Neural networks has been used for a expert system and fault diagnosis system. It is possible to nonlinear function mapping and parallel processing. Therefore It has been developing for a Diagnosis system of nuclear plower plant. In general Neural Networks is a static mapping but Dynamic Neural Network(DNN) is dynamic mapping.쪼두 a fault occur in system a state of system is changed with transient state. Because of a previous state signal is considered as a information DNN is better suited for diagnosis systems than static neural network. But a DNN has many weights so a real time implementation of diagnosis system is in need of a rapid network architecture. This paper presents a algorithm for RCP monitoring Alarm diagnosis system using Self Dynamic Neural Network(SDNN). SDNN has considerably fewer weights than a general DNN. Since there is no interlink among the hidden layer. The effectiveness of Alarm diagnosis system using the proposed algorithm is demonstrated by applying to RCP monitoring in Nuclear power plant.

• 전기학회논문지
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• 제60권4호
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• pp.805-810
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• 2011

This paper deals with the method and algorithm used to find fault locations in gas insulated transmission line. The method uses UHF sensors and digital oscilloscope to detect discharge signals emitted to the outside through insulating spacer in the event of breakdown inside GIL. UHF sensors are the external type and installed at outside of insulating spacers of GIL. And we used wavelet signal processing to analyze the discharge signals and confirm the exact fault location findings in the GIL test line. This method can overcome demerit of TDR(Time Domain Reflectometer) method having been applied to detect fault location for conventional underground transmission lines, and Ground Fault Sensors used in conventional GIS systems. TDR method requires high level of specialty and experience in analyzing the measured signals. Ground fault sensors are installed inside GIL and can be destroyed by high transient voltage. This paper's method can simplify the fault location process and minimize the damage of sensors. In addition, this method can estimate the fault location only by the time difference when discharge signals are arrived to detecting sensors at the ends of GIL sections without reasons of breakdown. To test the performance of our method, we installed sensors at the ends of test line of GIL(84m) and sensed discharge signals occurred in GIL, energized with AC voltage generator up to 700kV.

• 한국정밀공학회지
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• 제27권6호
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• pp.24-31
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• 2010

Laser carbonization of a polymer layer can be employed in various applications in the microelectronics industry, e.g repairing brightness pixels of an LCD panel. In this work, the process of thermal degradation of LCD color filter polymer by various laser sources with pulsewidths from CW to fs is studied. LCD pixels are irradiated by the lasers and the threshold irradiance of LCD color filter polymer carbonization is experimentally measured. In the numerical analysis, the transient temperature distribution is calculated and the number density of carbonization in the polymer layer is also estimated. It is shown that all the lasers can carbonize the polymer layers if the output power is adjusted to meet the thermal conditions for polymerization and that pulsed lasers can result in more uniform distribution of temperature and carbonization than the CW laser.

• Animal cells and systems
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• 제7권1호
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• pp.63-68
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• 2003

Until recently, interest in human complement receptor type I (CR1) has focused on immune complex processing, which contributed to our understanding of regulatory mechanism of complement activation. However, the promoter structure and transcriptional regulation of human CR1 gene has not been clear. To study the unique regulation of human CR1 gene expression, we assessed promoter activity of the $5^1$-flanking region of human CR1 gene using transient transfection and gel mobility shift assays. In this study we demonstrated that NF-Y binds to the inverted CCAAT element and that the functional interaction with protein(s) which bind to the GC-rich motif may be necessary for optimal transcription of human CR1 gene. We also show that sequence elements which located at-95/58 and +45/+50 are important for optimal transcription of CR1 gene.

• 천문학회보
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• 제43권2호
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• pp.57.2-57.2
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• 2018

In astronomical observation, sequential device control and real-time data processing are important to maximize observing efficiency. We have developed series of automatic observing software (KAOS, KHU Automatic Observing Software), e.g. KAOS30 for the 30 inch telescope in the McDonald Observatory and KAOS76 for the 76 cm telescope in the KHAO. The series consist of four packages: the DAP (Data Acquisition Package) for CCD Camera control, the TCP (Telescope Control Package) for telescope control, the AFP (Auto Focus Package) for focusing, and the SMP (Script Mode Package) for automation of sequences. In this poster, we introduce KAOS10 which is being developed for controlling a small telescope such as aperture size of 10 cm. The hardware components are the QHY8pro CCD, the QHY5-II CMOS, the iOptron CEM 25 mount, and the Stellarvue SV102ED telescope. The devices are controlled on ASCOM Platform. In addition to the previous packages (DAP, SMP, TCP), KAOS10 has QLP (Quick Look Package) and astrometry function in the TCP. QHY8pro CCD has RGB Bayer matrix and the QLP transforms RGB images into BVR images in real-time. The TCP includes astrometry function which adjusts the telescope position by comparing the image with a star catalog. In the future, We expect KAOS10 be used on the research of transient objects such as a variable star.

• 정보처리학회논문지A
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• 제8A권4호
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• pp.319-330
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• 2001

가상 메모리 시스템에서 프로세스가 현재 물리 메모리에 없는 페이지에 접근하게 되면 페이지 폴트가 발생하고, 이를 처리하기 위하여 예측할 수 없는 지연을 초래하는 페이지 폴트 핸들러가 동작하게 된다. 따라서 가상 메모리 시스템은 실시간 태스크의 제한 시간 실패율을 높여주는 요인이 될 수 있으므로 실시간 시스템에서 사용하기 어렵다. 뿐만 아니라, 새로운 태스크가 동적으로 유입되는 범용 운영체제 환경에서 가상 메모리 시스템은 태스크의 집중적인 페이지 폴트로 인하여 일시적인 과부하 상태에 빠질 수 있다. 본 논문에서는 집중적으로 발생하는 페이지 폴트에 의한 일시적인 과부하를 효율적으로 처리할 수 있는 RBPFH(Rate-Based Page Fault Handling) 알고리즘을 제시하고 있다 알고리즘의 특징은 현재 시스템의 자원을 모니터링하면서 페이지 폴트가 제한된 범위를 초과하지 않도록 분산시키는 방법을 사용하고 있으며, 페이지 폴트 처리 비율을 조정해줌으로써 동적으로 시스템의 부하가 변하는 상황을 고려하고 있다. RBPFH 알고리즘은 리눅스 운영체제에서 구현하였으며, 실험을 통하여 멀티미디어와 같은 연성 실시간 태스크를 지원하는데 있어서 유용하게 사용될 수 있음을 확인하였다. 실험 결과 RBPFH는 태스크의 제한 시간 실패율을 10%∼20% 감소시키고, 평균 지연 시간을 50%∼60% 감소시켜주었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.221-221
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• 2014

The present work proposes an improved numerical simulator for design and modification of large area capacitively coupled plasma (CCP) processing chamber. CCP, as notoriously well-known, demands the tremendously huge computational cost for carrying out transient analyses in realistic multi-dimensional models, because electron dissociations take place in a much smaller time scale (${\Delta}t{\approx}10-8{\sim}10-10$) than time scale of those happened between neutrals (${\Delta}t{\approx}10-1{\sim}10-3$), due to the rf drive frequencies of external electric field. And also, for spatial discretization of electron flux (Je), exponential scheme such as Scharfetter-Gummel method needs to be used in order to alleviate the numerical stiffness and resolve exponential change of spatial distribution of electron temperature (Te) and electron number density (Ne) in the vicinity of electrodes. Due to such computational intractability, it is prohibited to simulate CCP deposition in a three-dimension within acceptable calculation runtimes (<24 h). Under the situation where process conditions require thickness non-uniformity below 5%, however, detailed flow features of reactive gases induced from three-dimensional geometric effects such as gas distribution through the perforated plates (showerhead) should be considered. Without considering plasma chemistry, we therefore simulated flow, temperature and species fields in three-dimensional geometry first, and then, based on that data, boundary conditions of two-dimensional plasma discharge model are set. In the particular case of SiH4-NH3-N2-He CCP discharge to produce deposition of SiNxHy thin film, a cylindrical showerhead electrode reactor was studied by numerical modeling of mass, momentum and energy transports for charged particles in an axi-symmetric geometry. By solving transport equations of electron and radicals simultaneously, we observed that the way how source gases are consumed in the non-isothermal flow field and such consequences on active species production were outlined as playing the leading parts in the processes. As an example of application of the model for the prediction of the deposited thickness uniformity in a 300 mm wafer plasma processing chamber, the results were compared with the experimentally measured deposition profiles along the radius of the wafer varying inter-electrode gap. The simulation results were in good agreement with experimental data.

• 정보처리학회논문지C
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• 제10C권5호
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• pp.617-624
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• 2003

본 논문에서는 CDMA 시스템에서 전력제어의 성능을 향상시킬 수 있는 수정된 분산전력제어(M-DCPC) 알고리즘을 제안하였다. 제안한 방법의 제어 성능을 보이기 위해 각 이동국의 SIR 응답 속도와 셀(cell) 내에서의 Outage 확률을 기존의 DCPC, CSOPC와 LQPC과 비교하였다. SIR 명령이 변화되는 상황에서, M-DCPC의 SIR 응답 속도가 기존의 다른 알고리즘들에 비해 더 빠르고 적은 오버슈트를 가짐을 모의실험을 통해 확인하였다. Outage의 경우, M-DCPC의 수렴속도가 CSOPC의 수렴속도보다 더 빠름을 확인하였다 CSOPC의 경우 반복횟수가 거듭될수록 SIR 명령에 대한 응답 속도가 느려지게 되는데, 이 때 SIR 명령치가 변화할 경우, CSOPC에서는 다량의 Outage가 발생하지만, M-DCPC는 거의 영향을 받지 않는 것을 확인할 수 있었다.

• IEIE Transactions on Smart Processing and Computing
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• 제5권1호
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• pp.35-42
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• 2016

Developments in power electronics have enabled the widespread application of Pulse Width Modulation (PWM) inverters, notably for connecting renewable systems to the grid. This study demonstrates that a high-quality power can be achieved using a stand-alone inverter, whereby the comparison between the power quality of the stand-alone inverter with battery storage (off-grid) and the power quality of the utility network is presented. Multi-loop control techniques for a single phase stand-alone inverter are used. A capacitor current control is used to give active damping and enhance the transient and steady state inverter performance. A capacitor current control is cheaper than the inductor current control, where a small current sensing resistor is used. The output voltage control is used to improve the system performance and also control the output voltage. The inner control loop uses a proportional gain current controller and the outer loop is implemented using internal model control proportional-integral-derivative to ensure stability. The optimal controls are achieved by using the Sisotool tool in MATLAB/Simulink. The outcome of the control scheme of the numerical model of the stand-alone inverter has a smooth and good dynamic performance, but also a strong robustness to load variations. The numerical model of the stand-alone inverter and its power quality are presented, and the power quality is shown to meet the IEEE 519-2014. Furthermore, the power quality of the off-grid system is measured experimentally and compared with the grid power, showing power quality of off-grid system to be better than that of the utility network.