• Title/Summary/Keyword: Time Pattern

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Low Cost Endurance Test-pattern Generation for Multi-level Cell Flash Memory

  • Cha, Jaewon;Cho, Keewon;Yu, Seunggeon;Kang, Sungho
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.1
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    • pp.147-155
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    • 2017
  • A new endurance test-pattern generation on NAND-flash memory is proposed to improve test cost. We mainly focus on the correlation between the data-pattern and the device error-rate during endurance testing. The novelty is the development of testing method using quasi-random pattern based on device architectures in order to increase the test efficiency during time-consuming endurance testing. It has been proven by the experiments using the commercial 32 nm NAND flash-memory. Using the proposed method, the error-rate increases up to 18.6% compared to that of the conventional method which uses pseudo-random pattern. Endurance testing time using the proposed quasi-random pattern is faster than that of using the conventional pseudo-random pattern since it is possible to reach the target error rate quickly using the proposed one. Accordingly, the proposed method provides more low-cost testing solutions compared to the previous pseudo-random testing patterns.

Image Set Optimization for Real-Time Video Photomosaics (실시간 비디오 포토 모자이크를 위한 이미지 집합 최적화)

  • Choi, Yoon-Seok;Koo, Bon-Ki
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.502-507
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    • 2009
  • We present a real-time photomosaics method for small image set optimized by feature selection method. Photomosaics is an image that is divided into cells (usually rectangular grids), each of which is replaced with another image of appropriate color, shape and texture pattern. This method needs large set of tile images which have various types of image pattern. But large amount of photo images requires high cost for pattern searching and large space for saving the images. These requirements can cause problems in the application to a real-time domain or mobile devices with limited resources. Our approach is a genetic feature selection method for building an optimized image set to accelerate pattern searching speed and minimize the memory cost.

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A Study on the Economic Repair Pattern of the Building Components in the Apartment Housing (공동주택 구성재의 경제적 수선형태 설정 연구)

  • Lee, Kang-Hee;Chae, Chang-U
    • Journal of the Korean housing association
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    • v.17 no.5
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    • pp.87-95
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    • 2006
  • Building components have been deteriorated by various factors such as location, a building type, a surrounding environment and so on. In addition, each component has a peculiar characteristics, compared with other components in properties of matter an used part. Building components would be required to maintain its function and performance to provide the resident with a decent living condition. It is important to decide the repair time, scope and a required cost in repair plan, considering the each component's characteristics. In this parer, it aimed at providing the economic repair pattern to analyze the relation of the time-elapse and the cumulative repair cost in the apartment housing using 3rd quadratic function. Results of the study are as follows: First, the shape of the function for the economic repair is classified into two type. One is the continuous increase type of the cumulative cost which properly means the iterative repair type after built. The other is that the function has the maximum state at a point which means one-repair after its repair would be delayed to a scheduled time. Second, the iterative repair pattern would include window, roof proof, lighting and water supply pipe. The other repair pattern would include the paintings, heating pipe and sign board.

Effects of Shift Pattern and Expertise on Perceived Workload and Performance for Aviation Security Screeners (항공보안검색요원의 교대근무유형과 경력에 따른 주관적 업무부하와 수행)

  • Chung, Eun Kyoung;Shin, Younghwan;Sohn, Young Woo
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.24 no.3
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    • pp.1-9
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    • 2016
  • The study examined the effects of shift pattern and expertise on perceived workload and performance for aviation security screeners. 18 security screeners participated in this study, in which data were analyzed by dividing them into two groups (experts vs. less-experts). We measured their perceived workloads and performances (i.e., reading time through X-ray) as a function of shift pattern and time condition. As a result, highly experienced screeners (experts) showed high workload during the morning shift, while lowly experienced screeners (less-experts) reported high workload during the full-day and the afternoon shifts. In addition, less-experts took a longer time to inspect the baggage when they worked for the full-day and the afternoon shifts. Particularly, in the last time slot of the full-dat shift, expert screeners had a high workload, while both groups showed a high-level of workload at around 17:30 in the afternoon shift.

Improving 3D Measurement Speed using CUDA (CUDA를 이용한 3D 측정 속도 향상)

  • Kim, Ho-Joong;Cho, Tai-Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.331-334
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    • 2017
  • Recently, a method using a fringe pattern is widely used for 3D measurements. This is a method of measuring by using a phase value obtained by projecting a pattern to an object to be measured. This method requires many operations such as calculating the phase value and calculating the height. It takes a lot of time depending on the amount of computation. In this paper, we present a method using NVIDIA's CUDA to reduce this time. And we introduce the method of calculating phase value and height. It also shows the exact time difference between the CPU version and the CUDA version. This method is very effective because it can process the same operation in a shorter time.

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A Study of Web based Screening for Visual Stress Syndrome (웹 기반의 시각적 스트레스 증후군 선별에 관한 연구)

  • Jang, Young-Gun
    • Journal of the Ergonomics Society of Korea
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    • v.28 no.4
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    • pp.91-99
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    • 2009
  • A visual stress may provoke migraine, cephalalgia, intervene a long term reading and learning capability and reduce the productivity of a laborer who uses computer for a good while. In this study, a web based screening tool for visual stress was developed, it applied to 72 visually normal young persons in parallel with traditional questionnaire about symptoms of visual stress. To estimate visual stress, It is proposed to measure difference of visual search time of Han Gul characters as targets between visual stressful pattern and non-visual stressful pattern as global background of characters. As a result of test, 5 subjects were screened whose mean visual search time in the stressful pattern with 6 CPD spatial frequency increase significantly more than in none stressful pattern(t-test, one-tailed, p=1.0407×1011). 2 of them were diagnosed as mild visual stress syndrome in the clinic. None had visual distortion and 50% of subjects had visual discomfort in results of the questionnaire. Correlation between visual search time increase rate and normalized number of visual discomfort may be slight(C. coefficient=0.1355). This study may contribute as a basic research for screening person with migraine, visual reading disabilities and VDT syndrome. It is required to apply the test to visual reading disabilities, migraine with visual distortion and/or visual discomfort as well as normal person for higher reliability of the screening tool.

Comparative Studies of Evacuation Time According to the Distribution Characteristics of Training Ship's Personnels (운항실습선 승선자의 분포특성에 따른 대피시간 비교)

  • Hwang, Kwang-Il
    • Journal of Navigation and Port Research
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    • v.35 no.3
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    • pp.213-218
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    • 2011
  • This study simulates and compares the evacuation time and characteristics according to the living patterns on board a training ship which was launched in Dec. 2005, on the viewpoint of the various activities being possible on board a cruise ship. Based on interviews with personnels on board, 3 living patterns are set as representative living conditions; Pattern A(all personnels are positioned at their cabins), Pattern B(all personnels are positioned at lecture rooms, offices or else), Pattern C(all personnels are positioned at restaurant or cafeteria). The simulation results show that Pattern B is comparatively ideal because the evacuation time is short and there is less delay of personnels' movement on each deck. On the contrary, Pattern C is evaluated as the worst because the average evacuation time took more than 360 seconds and the bottle-neck happened at Upper deck. As a result, this study proposes the needs of various countermeasures against the fire and/or disaster, considering the various living patterns on cruiser(s) and/or passenger ship(s).

Electrochemical Ion Migration Sensitivity of Printed Circuit Board Plated with Sn-3.0Ag-0.5Cu and Sn-37Pb (Sn-3.0Ag-0.5Cu, Sn-37Pb 표면처리 기판의 전기화학적 이온 마이그레이션 민감도)

  • Hong, Won-Sik;Park, No-Chang;O, Cheol-Min;Kim, Gwang-Bae
    • Proceedings of the KWS Conference
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    • 2006.10a
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    • pp.136-138
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    • 2006
  • Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. Ion migration phenomena has been observed in the field of exposing the specific environment and using for a long time. Also as the RoHS restriction was started in July 1st, 2006, Pb-free solder was utilized in electronics assemblies. In this case, it is very important to compatible between components and printed circuit board(PCB), thus surface treatment materials of PCB was changed to Sn, Sn-3.0Ag-0.5Cu, Cu. Therefore these new application become to need to reevaluate the sensitivity about electrochemical ion migration. This study was evaluated the occurrence time of electrochemical ion migration using by water drop test. We utilized PCB(printed circuit board) having a comb pattern as follows 0.1, 0.318, 0.5, 1.0 mm pattern distance. Sn-3.0Ag-0.5Cu and Sn-37Pb were electroplated on the comb pattern. 6.5V and 15.0V were applied in the comb pattern and then we measured the electrical short time causing by occurring the ion migration. In these results, we evaluate the sensitivity and derived the prediction models of ion migration occurrence time depending on the pattern materials, applied voltage and pattern spacing of PCB conductor.

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A Sequential Pattern Mining based on Dynamic Weight in Data Stream (스트림 데이터에서 동적 가중치를 이용한 순차 패턴 탐사 기법)

  • Choi, Pilsun;Kim, Hwan;Kim, Daein;Hwang, Buhyun
    • KIPS Transactions on Software and Data Engineering
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    • v.2 no.2
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    • pp.137-144
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    • 2013
  • A sequential pattern mining is finding out frequent patterns from the data set in time order. In this field, a dynamic weighted sequential pattern mining is applied to a computing environment that changes depending on the time and it can be utilized in a variety of environments applying changes of dynamic weight. In this paper, we propose a new sequence data mining method to explore the stream data by applying the dynamic weight. This method reduces the candidate patterns that must be navigated by using the dynamic weight according to the relative time sequence, and it can find out frequent sequence patterns quickly as the data input and output using a hash structure. Using this method reduces the memory usage and processing time more than applying the existing methods. We show the importance of dynamic weighted mining through the comparison of different weighting sequential pattern mining techniques.

Analysis of Textile Pattern Design Focusing an the Age of After Industrial Revolution in England (영국산업혁명이후의 텍스타일에 표현된 패턴에 관한 연구)

  • 구희경
    • Journal of the Korea Fashion and Costume Design Association
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    • v.1 no.1
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    • pp.141-156
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    • 1999
  • This paper is to analyze the classification of textile pattern design focusing on the 19th century in England. The purpose of this study is. firstly to research the thoughts and ideas of these design in the time of mid-Victorian age; Secondly. to classify the textile pattern design from many points of view. We could find such William Morris's thought and ideas of 19th century to reform from textile pattern design. We wish to use these studies for textile pattern designers to develop this tradition onward to modern and future trends.

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