• Title/Summary/Keyword: Filter Criteria

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Comparison & Analysis for Fine Sand Migration in Filter (조립 Filter내에서 세상의 이동현상에 대한 비교분석)

  • Kim, Hyun-Ki;Kwon, Moo-Nam
    • Current Research on Agriculture and Life Sciences
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    • v.16
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    • pp.15-23
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    • 1998
  • This experiment did comparison and analysis that protected soil particle migration have affect on function of the filter and therefore fall function of the filter. Results obtained are as follows: 1.High water head makes to be much movement of fine sand and out flow of particle to the outside. The filter have large opening size that reached stability an early stage, but much fine sand is washed away. If the velocity turns fast and becomes small, blocking phenomenon is remarkable nearby the filter-sand interface. 2. The movement of fine sand that effect on function of filter depend on opening size and change of water head. Under the same condition, USCE filter and USSPL filter is reached earlier than other filter that is stability of stage, because it's opening size is large. 3. Residual quantity of fine sand migration was largly come out in order of USSPL, USCE, USBR, Newton & Hurley, Bertram filter. 4. The time required to stability of flow was taken less in order of Bertram, Newton & Hurley, USBR, USSPL, USCE filter and coefficient of permeability was highly come out in order of USBR, Bertram, Newton & Hurley, USSPL, USCE filter. 5. It proved that USCE and USSPL is suitable for the filter criteria.

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An Application of AHP for the Selection of Optimum Product of BWTS for over 10,000 TEU Container Ship (AHP 기법을 이용한 10,000 TEU 이상 컨테이너선에 적용되는 선박평형수 처리장치 최적제품 선정에 관한 연구)

  • Lee, Sang-Won;Kim, Dong-Joon;Seo, Won-Chul
    • Journal of the Society of Naval Architects of Korea
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    • v.52 no.5
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    • pp.395-406
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    • 2015
  • The Ballast Water Treatment System was developed to prevent the unintended transport of unwanted organisms from one region to another as demanded by the IMO (International Maritime Organization). Although various types of BWTS in the world have been developed until now and applied to various ships, there has been no systematic basis for its selection and installation. Currently, the system selection and installation are as per ship owner’s suggestion or by easy installation point of view by the shipyard. In order to organize, systemize and solve problems related to the selection and installation of BWTS, a definitive study has been performed to come up with the best alternative to derive value and criteria which were to be met for vessels which are to be equipped with BWTS. Multiple criteria were compared alongside each other during the course of this study. Accordingly an AHP (Analytic Hierarchy Process) analysis method for A, B and C companies were done for container ships with size 10,000 TEU and above. Equipment type for “A” company is “Filter, UV & TiO2” combined type. For “B” company it is “Filter & UV” combined type. Finally for “C” company it is “Electrolysis” type. Henceforth, the results of this study aims to come up with the optimum way to select the best and the most suitable BWTS for a certain vessel.

Determining Quality Criteria for Online Health Information: A Qualitative Study

  • Cha, Myeong-Hwa;Park, Jyung-Rewng
    • Preventive Nutrition and Food Science
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    • v.11 no.4
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    • pp.305-310
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    • 2006
  • The Web is an important source of information for health care consumers, and the resources they find on the Web have a direct affect on their health outcomes. Despite the enormous benefits of online health care, the quality of health information on the Internet is an area of increasing concern. Therefore, there's a need to develop quality assessment tools that can filter out poor quality online health information. The purpose of this study is to explore the critical attributes for assessing website quality and for developing quality assessment measurements. We completed three focus group discussions with 24 participants that were administered by a moderator and based on specifically focused group questions. The results suggest that the most important quality criteria, as identified by the respondents, were related to issues of credibility and accuracy. To determine the credibility of Internet health information, the respondents stated one must consider the following: the information source, disclosure of the author's or organization's credentials/qualifications, disclosure of ownership and the updating of the content. For the accuracy of content, elements such as a statement of purpose, evidence-based information, relevance and completeness should be considered. Interactivity, accessibility, and design were additional quality criteria.

The Effects of Consumers' Mask Selection Criteria on Mask Brand Awareness and Purchase Intention for Fashion Masks (마스크 선택기준이 브랜드 인지와 패션 마스크 구매의도에 미치는 영향)

  • Kim, Min Su;Lee, Ha Kyung;Kim, Hanna
    • Journal of the Korean Society of Clothing and Textiles
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    • v.46 no.1
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    • pp.116-131
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    • 2022
  • This study used text mining to analyze big data to understand consumers' demand for and perceptions of fashion masks. Based on the text-mining analysis results, a survey was conducted with those living in Korea to investigate the influence of consumers' mask selection criteria on mask brand awareness and purchase intention for fashion masks. "Fashion mask" and "functional mask" were used as the keywords in a text-mining analysis, and an online survey of 242 respondents was conducted. The analysis results were as follows: First, the text-mining analysis extracted commonly appearing words that had a high frequency and TF-IDF, such as "COVID-19," "fashion," "celebrity," "antibacterial," and "filter." This confirmed that during the COVID-19 pandemic, consumers have demanded masks that are both functional and fashionable. Second, among consumers' mask selection criteria, trend and design had positive effects on face-mask brand awareness. Third, face-mask brand awareness had a positive effect on the purchase intention for both brand and fashion masks, and the purchase intention for brand masks had a positive effect on the purchase intention for fashion masks.

The Criteria and Methods for Evaluating of Internet Website Documents (인터넷 웹사이트 문서의 평가 기준 및 방법 - 내용적인 측면을 중심으로 -)

  • Lee Eung-Bong
    • Journal of Korean Library and Information Science Society
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    • v.30 no.1
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    • pp.151-169
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    • 1999
  • The availability and growth of the Internet offers users the opportunity to find information and data all over the world. The development of the WWW has made the Internet easier to use, both for finding information and for publishing it electronically. Because so much information is available, and because that information can appear to be fairly 'anonymous', It is necessary to develop skills to evaluate what you find. Every printed information resources you find has been evaluated in one way or another before you ever see it. But when you are using the WWW, none of this applies. There are no filters between you and Internet. In addition, the ease of constructing Web documents results in information of the widest range of quality, written by authors of the widest range of authority, available on an even playing field Excellent information resources reside along side the most dubious. This study discusses the criteria arid methods by which scholars and researchers in most fields evaluate print information, and shows how the same criteria and methods can be used to assess Internet Website document. This study applied seven criteria, that is essential Web document element, authorship, publishing body, point of view or bias, referral to other sources, verifiability and currency. All information, whether in print or by byte, needs to be evaluated by users for some objective criteria and methods mentioned above. If you find information that is 'too good to be true', it probably is. Never use information that you can't verity. Always remember that the best counterfeit looks the most like the real thing. Establishing and learning criteria and methods to filter information you find on the Internet is a good beginning for becoming a critical consumer of information in all forms.

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Personalized Anti-spam Filter Considering Users' Different Preferences

  • Kim, Jong-Wan
    • Journal of Korea Multimedia Society
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    • v.13 no.6
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    • pp.841-848
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    • 2010
  • Conventional filters using email header and body information equally judge whether an incoming email is spam or not. However this is unrealistic in everyday life because each person has different criteria to judge what is spam or not. To resolve this problem, we consider user preference information as well as email category information derived from the email content. In this paper, we have developed a personalized anti-spam system using ontologies constructed from rules derived in a data mining process. The reason why traditional content-based filters are not applicable to the proposed experimental situation is described. In also, several experiments constructing classifiers to decide email category and comparing classification rule learners are performed. Especially, an ID3 decision tree algorithm improved the overall accuracy around 17% compared to a conventional SVM text miner on the decision of email category. Some discussions about the axioms generated from the experimental dataset are given too.

Analysis of Randomness Characteristics of Hardware Noise Generator (하드웨어 잡음발생기의 랜덤 특성 분석)

  • Hong, Jin-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.263-267
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    • 2011
  • This paper analyzed randomness characteristics of output data in generator based on hardware noise source. Also it is enhanced security randomness in the output stream of generator, which is applied on Laplacian filter. First it reviews criteria of randomness verification of output stream of hardware noise generator, and presents the enhanced results of output stream of generator, which is applied on Laplacian filter.

Design Method for the LCL Filters of Three-phase Voltage Source PWM Rectifiers

  • Guo, Xizheng;You, Xiaojie;Li, Xinran;Hao, Ruixiang;Wang, Dewei
    • Journal of Power Electronics
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    • v.12 no.4
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    • pp.559-566
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    • 2012
  • A new design method for the LCL filters of three-phase voltage source PWM rectifiers is presented in this paper. Based on the single-phase harmonic equivalent model, the harmonic voltage of the rectifier side is calculated to design the LCL filter parameters by an iterative algorithm, in which the resonance frequency $f_{res}$ and the ratio r between the grid-side inductance and the rectifier-side inductance are selected as known constants. The design criteria and process are introduced and the influence on the design result by the value of the resonance frequency $f_{res}$, ratio r is analyzed. Finally an example (600V, 500kW) is tested by simulation and experiment to verify the validity of the new design method.

Missile Aerodynamic Structure and Parameter Identification Using the Extended Kalman Filter and Maximum Likelihood Method (확장칼만필터와 최대공산법을 이용한 미사일 공력계수 모델의 설정 및 계수추정)

  • 성태경;이장규
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.35 no.6
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    • pp.246-256
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    • 1986
  • Determination of an aerodynamic structure is a very important problem in missile modeling. The structure problem is to choose an appropriate set of aerodynamic coefficients to represent chosen missile dynamics. A methodology and criteria to determine a structure from windtunnel data are presented in this paper. Aerodynamic coeffecients in the determined structure are then identified by parameter identification algorithms. The identified coefficients are in turn used to verify appropriateness of the structure. The extended Kalman filter (EKF) and the maximum likelihood mithod (ML) are adopted as the parameter identification algorithm. Both methods exhibit satisfactory results. While the model identified by the ML more closely follows dynamics of the chosen missile than that by the EKF.

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A Study on the noise & vibration properities of Fan Filter Unit and evaluation of effect to Clean Room (Fan Filter Unit 소음ㆍ진동 특성과 청정실에 미치는 영향성 평가에 관한 연구)

  • 백재호;손성완
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.778-784
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    • 2002
  • FFU are used increasingly by the microeleceronics industry to provide clean recirculating air for the fabrication of integrated circuits and laminar flow air. There may be several hundred ffu in a large cleanroom, covering 100% of the ceiling area. Hence, there is of often knowledge in the inside and outside of the country the flu give rise to noise & vibration trouble to microelectronics industry. Noise & Vibration control for satisfication about noise & vibration criteria in TFT-LCD factory cleanroom be in need of exact noise & vibration data of accurence from utility & equipment that can be exert a bad influence upon cleanroom. In this pater, hence we found out noise and vibration properities of ffu by using experimental method. And, we performed noise & vibration analysis about noise it vibration level in cleanroom using semiempirical method for quantative approach about noise & vibration level in cleanroom.

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