• Title/Summary/Keyword: Techniques

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Inspection Techniques for Photovoltaic Equipments (태양광 발전설비 검사 기술)

  • Jung, Jong-Wook;Kim, Sun-Gu
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1072_1073
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    • 2009
  • This paper describes the inspection techniques for photovoltaic equipments. Firstly failure case studies on solar cells were presented, and then their FMEA was carried out. Lastly several core techniques as well as the contents by the inspection items on photovoltaic equipments were also expatiated.

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Unequal Size, Two-way Analysis of Variance for Categorical Data

  • Chung, Han-Yong
    • Journal of the Korean Statistical Society
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    • v.5 no.1
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    • pp.29-34
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    • 1976
  • The techniques about the analysis of variance for quantitative variables have been well-developed. But when the variable is categorical, we must switch to a completely different set of varied techniques. R.J. Light and B.H. Margolin presented one kind of techniques for categorical data in their paper, where there are G unordered experimental groups and I unordered response categories.

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A STUDY ON THE TECHNIQUES OF ESTIMATING THE PROBABILITY OF FAILURE

  • Lee, Yong-Kyun;Hwang, Dae-Sik
    • Journal of the Chungcheong Mathematical Society
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    • v.21 no.4
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    • pp.573-583
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    • 2008
  • In this paper, we introduce the techniques of estimating the probability of failure in reliability analysis. The basic idea of each technique is explained and drawbacks of these techniques are examined.

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A Study on the Development of Measurement Techniques for Thermal Flows in MEMS

  • Ko Han-Seo;Yang Sang-Sik;Yoo Jai-Suk;Kim Hyun-Jung
    • Journal of Electrical Engineering and Technology
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    • v.1 no.3
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    • pp.387-395
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    • 2006
  • A review on advanced flow visualization techniques is presented particularly for applications to micro scale heat and mass transport measurements. Challenges, development and applications of micro scale visualization techniques are discussed for the study of heating/evaporating thin films, a heated micro channel, and a thermopneumatic micro pump. The developed methods are (1) Molecular Tagging Fluorescence Velocimetry (MTFV) using 10-nm caged seeding molecules (2) Micro Particle Velocimetry (MPIV) and (3) Ratiometric Laser Induced Fluorescence (LIF) for micro-resolution thermometry. These three methods are totally non-intrusive techniques and would be useful to investigate the temperature and flow characteristics in MEMS. Each of these techniques is discussed in three-fold: (1) its operating principle and operation, (2) its application and measurement results, and (3) its future challenges.

High Capacity Relay Protocols for Wireless Networks

  • Fan, Yijia;Krikidis, Ioannis;Wang, Chao;Thompson, John S.;Poor, H. Vincent
    • Journal of Communications and Networks
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    • v.11 no.2
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    • pp.196-206
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    • 2009
  • Over the last five years, relaying or multihop techniques have been intensively researched as means for potentially improving link performance of wireless networks. However, the data rates of relays are often limited because they cannot transmit and receive on the same frequency simultaneously. This limitation has come to the attention of researchers, and recently a number of relay techniques have been proposed specifically to improve the data efficiency of relaying protocols. This paper surveys transmission protocols that employ first single relays, then multiple relays and finally multiple antenna relays. A common feature of these techniques is that novel signal processing techniques are required in the relay network to support increased data rates. This paper presents results and discussion that highlight the advantages of these approaches.

Ultrafine Particle Toxicities, Current Measurement Techniques and Controls (Ultrafine Particle의 독성, 측정방법 및 관리)

  • Lee, Su-Gil;Kim, Seong-Soo
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.20 no.3
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    • pp.203-215
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    • 2010
  • This study is an overview of toxicities and measurement techniques of ultrafine particles (UFPs), and their exposure controls. UFPs are ubiquitous in many working situations. Exposure to UFPs is possibly causing adverse health symptoms including cardio-respiratory disease to humans. In order to measure exposure levels of airborne UFPs, there are current available measurement guidelines, instruments and other techniques (i.e. contour mapping, control banding). However, these risk assessment techniques including measurement techniques, controls and guidelines are dependent on background levels, metrics (e.g. size, mass, number, surface area, composition), environmental conditions and controls. There are no standardized measurement methods available and no generic and specific occupational exposure standards for UFPs. It is thought that there needs to be more effort to develop Regulations and Exposure Standards for generic UFPs should be based on more exposure data, health surveys, toxicological data and epidemiological data. A carefully considered hierarchy of controls can also reduce the maximum amount of airborne UFPs being emitted from diverse sources in industries.

Evaluating Variable Selection Techniques for Multivariate Linear Regression (다중선형회귀모형에서의 변수선택기법 평가)

  • Ryu, Nahyeon;Kim, Hyungseok;Kang, Pilsung
    • Journal of Korean Institute of Industrial Engineers
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    • v.42 no.5
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    • pp.314-326
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    • 2016
  • The purpose of variable selection techniques is to select a subset of relevant variables for a particular learning algorithm in order to improve the accuracy of prediction model and improve the efficiency of the model. We conduct an empirical analysis to evaluate and compare seven well-known variable selection techniques for multiple linear regression model, which is one of the most commonly used regression model in practice. The variable selection techniques we apply are forward selection, backward elimination, stepwise selection, genetic algorithm (GA), ridge regression, lasso (Least Absolute Shrinkage and Selection Operator) and elastic net. Based on the experiment with 49 regression data sets, it is found that GA resulted in the lowest error rates while lasso most significantly reduces the number of variables. In terms of computational efficiency, forward/backward elimination and lasso requires less time than the other techniques.

Current Status and Trend of Data Mining Techniques (데이터 마이닝 기법의 현황 및 추세)

  • 오승준;송영덕;오민근
    • KSCI Review
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    • v.8 no.2
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    • pp.67-74
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    • 2001
  • Recent times have seen an explosive growth in the availability of various kinds of data. It has resulted in an unprecedented opportunity to develop automated data-driven techniques of extracting useful knowledge. Data mining. an important step in this process of knowledge discovery consists of methods that discover interesting. non-trivial and useful Patterns hidden in the data In this paper. we surveyed data mining techniques. We find effective data mining techniques in applying real world. and suggest appropriate application area for the each techniques. We conclude the Paper with some research issues.

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3 Dimensional Machining System using Focused ion Beam (집속 이온빔에 의한 3차원 가공 시스템)

  • 박철우;이종항
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.490-493
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    • 2004
  • There is great difficulty in machine below 10 micrometers by conventional machining methods, such as micro-EDM. However, ultra micro machining using focused ion beam(FIB) is able to machine to 50 nanometers. Bie & moulds techniques are better than one-to-one machining techniques in regards to production costs in the mass production of ultra size structures. Also, it is advantageous to machine die & moulds to the 10 micrometers level by FIB technique rather than other techniques. It is difficult to machine the three dimensional machining, such as micro lens, using FIB system because of their machining characteristics. In this paper, three dimensional machining techniques were properly introduced, and also experiments showed effectiveness of their techniques.

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