• 제목/요약/키워드: Data Length

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신호의 길이 특성을 이용한 효율적인 CAN 데이터 압축 알고리즘 (Efficient CAN Data Compression Algorithm Using Signal Length)

  • 오유경;정진균
    • 스마트미디어저널
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    • 제3권3호
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    • pp.9-14
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    • 2014
  • 차량에 연결된 ECU 개수의 증가는 CAN 버스 점유율을 증가시킬 뿐만 아니라 메시지 전송오류 확률의 증가를 초래한다. CAN 데이터 전송 시간은 CAN 프레임의 길이에 비례하기 때문에 프레임의 길이를 줄이게 되면 효율적으로 CAN 버스로드와 오류확률을 감소시킬 수 있다. 본 논문에서는 CAN 메시지의 길이를 단축시키기 위해서 비트재배열과 Data Length Code (DLC)를 이용한 압축 방법을 제안한다. 실제 차량 주행에서 얻은 데이터로 제안한 알고리즘을 시뮬레이션 해본 결과, 기존의 방법에 비해 최대 54%까지 CAN 데이터가 더 압축됨을 확인하였다.

한글 Graphic Image Date의 통계적 특성에 관한 연구 (A Study on the Statistical characteristics of Hagul Graphic Image Date)

  • 김재석;김재균
    • 대한전자공학회논문지
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    • 제17권2호
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    • pp.15-22
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    • 1980
  • Graphic image data의 효율적인 coding을 위해서, 한글 image와 영문 image의 통계적인 특성들이 측정 비교되었다. 또한 Markov model에 의한 run length의 확률분포와 측정된 run length의 확률분포가 비교 검토되었다. 측정된 run length 분포는 negative-power 분포에 유사하며, 이것은 한글 image 에서 더욱 뚜렷한 것으로 나타났다. 대표적 네가지 run length code의 coding 특성이 비교되었는데, 영문 image보다 한글image의 coding 특성이 더욱 우수한 것으로 밝혀졌다.

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5축 볼엔드밀 가공 NC 데이터의 최적 공구 길이 계산 (Optimal Tool Length Computation of NC Data for 5-axis Ball-ended Milling)

  • 조현욱;박정환
    • 한국CDE학회논문집
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    • 제15권5호
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    • pp.354-361
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    • 2010
  • The paper presents an efficient computation of optimal tool length for 5-axis mold & die machining. The implemented procedure processes an NC file as an initial input, where the NC data is generated by another commercial CAM system. A commercial CAM system generates 5-axis machining NC data which, in its own way, is optimal based on pre-defined machining condition such as tool-path pattern, tool-axis control via inclination angles, etc. The proper tool-length should also be provided. The tool-length should be as small as possible in order to enhance machinability as well as surface finish. A feasible tool-length at each NC block can be obtained by checking interference between workpiece and tool components, usually when the tool-axis is not modified at this stage for most CAM systems. Then the minimum feasible tool-length for an NC file consisting of N blocks is the maximum of N tool-length values. However, it can be noted that slight modification of tool-axis at each block may reduce the minimum feasible tool-length in mold & die machining. This approach can effectively be applied in machining feature regions such as steep wall or deep cavity. It has been implemented and is used at a molding die manufacturing company in Korea.

Deciding a sampling length for estimating the parameters in Geometric Brownian Motion

  • Song, Jun-Mo
    • Journal of the Korean Data and Information Science Society
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    • 제22권3호
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    • pp.549-553
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    • 2011
  • In this paper, we deal with the problem of deciding the length of data for estimating the parameters in geometric Brownian motion. As an approach to this problem, we consider the change point test and introduce simple test statistic based on the cumulative sum of squares test (cusum test). A real data analysis is performed for illustration.

Prediction of Length of ICU Stay Using Data-mining Techniques: an Example of Old Critically Ill Postoperative Gastric Cancer Patients

  • Zhang, Xiao-Chun;Zhang, Zhi-Dan;Huang, De-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권1호
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    • pp.97-101
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    • 2012
  • Objective: With the background of aging population in China and advances in clinical medicine, the amount of operations on old patients increases correspondingly, which imposes increasing challenges to critical care medicine and geriatrics. The study was designed to describe information on the length of ICU stay from a single institution experience of old critically ill gastric cancer patients after surgery and the framework of incorporating data-mining techniques into the prediction. Methods: A retrospective design was adopted to collect the consecutive data about patients aged 60 or over with a gastric cancer diagnosis after surgery in an adult intensive care unit in a medical university hospital in Shenyang, China, from January 2010 to March 2011. Characteristics of patients and the length their ICU stay were gathered for analysis by univariate and multivariate Cox regression to examine the relationship with potential candidate factors. A regression tree was constructed to predict the length of ICU stay and explore the important indicators. Results: Multivariate Cox analysis found that shock and nutrition support need were statistically significant risk factors for prolonged length of ICU stay. Altogether, eight variables entered the regression model, including age, APACHE II score, SOFA score, shock, respiratory system dysfunction, circulation system dysfunction, diabetes and nutrition support need. The regression tree indicated comorbidity of two or more kinds of shock as the most important factor for prolonged length of ICU stay in the studied sample. Conclusions: Comorbidity of two or more kinds of shock is the most important factor of length of ICU stay in the studied sample. Since there are differences of ICU patient characteristics between wards and hospitals, consideration of the data-mining technique should be given by the intensivists as a length of ICU stay prediction tool.

일수문량의 RUN-LENGTH 및 RUN-SUM의 SIMULATION (Simulation of Run-Length and Run-Sum of Daily Rainfall and Streamflow)

  • 이순택;지홍기
    • 물과 미래
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    • 제10권1호
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    • pp.79-94
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    • 1977
  • 본 연구는 Run-Length와 Run-Sum에 의한 강우량과 하천유량을 분석하여 그 특성을 구명하고, 이로부터 모의발생 모델(Simulation Model)을 설정하여 검토하는데 목적을 두고 있다. 분석에 있어서는 우리나라의 주요도시(서울, 대구 및 부산)의 일강우량과 주요하천(한강, 낙동강 및 금강)의 일류량 자료들을 사용하였다. 또한 해석에 있어서는 Run-Length와 Run-Sum에 대한 각각의 분포형 분석으로부터 Weibull 분포 및 1-변수지수 분포를 하고 있음을 알았으며, 이로부터 Monte Carlo 기법(Monte Carlo technique)을 기초로 하는 Weibull모델(Weibull model)과 1-변수지수 모델(One-Parameter Exponential Model)에 의해서 Run-Length와 Run-Sum을 모의발생 시켰다. 그 결과 기록치(Historical Data)에 근사한 모의발생 자료(Simulation Data)를 얻었다.

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기간편의분포하(其間偏倚分布下)에서 수명분포(壽命分布)의 편순서(偏順序) 보존(保存) (Preservation of some partial orderings of life distributions under length biased distributions)

  • 최진갑;김상룡
    • Journal of the Korean Data and Information Science Society
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    • 제4권
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    • pp.45-51
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    • 1993
  • For studies in reliability, biometry and survival analysis, the length biased distribution is frequently appropriate for certain natural sampling plans. So, we shall convey the preservation of some partial orderings under life length biasd distributions and closures of ILR and NBU classes under life length biasd distributions.

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Variable length Chromosomes in Genetic Algorithms for Modeling the Class Boundaries

  • Bandyopadhyay, Sanghamitra;Pal, Sankar K.;Murthy, C.A.
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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    • pp.634-639
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    • 1998
  • A methodology based on the concept of variable string length GA(VGA) is developed for determining automatically the number of hyperplanes and their appropriate arrangement for modeling the class boundaries of a given training data set in RN. The genetic operators and fitness functionare newly defined to take care of the variability in chromosome length. Experimental results on different artificial and real life data sets are provided.

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한국인을 위한 장갑 패턴 고찰 (2) - 장갑 원형 설계를 중심으로 - (A Study on the Pattern-making for Korean Glove - Focusing on Pattern-making for Glove -)

  • 류경옥
    • 복식문화연구
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    • 제17권6호
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    • pp.981-991
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    • 2009
  • The purpose of this study was to develop the pattern-making for Korean glove. To develop the pattern-making for glove this study comprehensive list of candidate hand data was reviewed and the manufacturers(career over th 15 years) were interviewed on the method of glove. The results of regression analysis(hand data) were as follows (unit: cm): wrist thumb tip length = middle finger length + 3.22, hand bread = 1.25 $\times$ middle finger length + 2.18, middle finger breadth at dist = 0.23 $\times$ index finger circumference + 0.4, maximum hand circumference = 3.15 $\times$ index finger circumference + 4.13, middle finger circumference = 0.91 $\times$ index finger circumference + 0.47, maximum hand thickness = 0.69 $\times$ index finger circumference -0.02. Hand measurements for glove pattern-making were developed: There were palmar hand length, hand circumference, index finger circumference and middle finger length.

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한국 연근해 어업에서 수집되는 어류 개체군 체장자료의 표집(sampling) 방법 제안 (How Should We Randomly Sample Marine Fish Landed at Korea Ports to Represent a Length Frequency Distribution of Those Fish?)

  • 박민규;현상윤
    • 한국수산과학회지
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    • 제54권1호
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    • pp.80-89
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    • 2021
  • In Korea, marine fish landed at ports are randomly sampled on a periodic basis (e.g., daily or weekly), and body sizes (e.g., lengths and weights) of those sampled fish are measured. The motivation for our study is whether or not such measurements reflect the size distribution, especially the length distribution of fish landed (= a population), because such length measurements are key data for a length-based assessment model. The current sampling method is to sample fish landed at ports by body size group (e.g., very small, small, medium, large, very large), using the sampling weights as the number of boxes by body size group. In this study, we showed that length composition data about fish sampled by the current method did not represent the length frequency distribution of the fish landed, and suggested that an alternative sampling method should be applied of using the sampling weights as the number of fish landed by body size group. We also introduced a method for determining an appropriate sample size.