• 제목/요약/키워드: materials recognition

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Induction of Single Helical Screw Sense in Poly (n-Hexyl Isocyanate) by End-capping with a Chiral Moiety

  • Nath G. Yogendra;Samal Shashadhar;Park, Sang-Yoon;Murthy C.N.;Lee, Jae-Suk
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.334-334
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    • 2006
  • Helical polymers like polyisocyanates with single screw sense are essential to exhibit sophisticated functions like molecular recognition, self-replication, chirality memory and catalytic activity. One approach that has not been explored is the effect on handedness of the polyisocyanates through end-capping with a chiral residue. Induction of chirality in poly(n-hexyl isocyanate) was studied by end-capping with chiral (R and S) 2-bromo-3-methylbutyryl chloride(R-BMBC and S-BMBC). We have shown that a control over living anionic polymerization of HIC by using a suitable initiator affords an opportunity to introduce chiral end-groups with 100% yield and in high purity. This has resulted in helicity induction through extended lengths several orders of magnitude.

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치과위생사의 근무기관 유형별 유해인자 노출과 물질안전보건자료 인식 연구 (Dental Hygienist's Harmful Factor Exposure and Recognition of Material Safety Data Sheets of Workplace Type)

  • 김해경;김지영;오나래
    • 한국콘텐츠학회논문지
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    • 제18권11호
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    • pp.540-549
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    • 2018
  • 본 연구는 대구 경북지역에서 근무하는 치과위생사 238명을 대상으로 자기기입식 설문을 통하여 근무유형별 치과재료에 대한 유해전달 실태를 파악하기위해 병원 유형별 유해인자 노출시간 및 근무환경특성 차이를 비교하고 물질안전보건자료(MSDS) 인지정도의 차이를 조사하였다. 연구 결과 병원 유형별 유해인자 노출시간을 비교한 결과 병원의 경우 화학물질에서 발생하는 분진유발에 노출되는 시간이 가장 길었고, 레진충전, 소독제 접촉 순으로 나타났다. 치과재료에 대한 물질안전보건자료(MSDS)를 인지하고 있는지에 대한 문항에 대하여 '인지한다'고 답한 대상자는 병원근로자는 37명(29.4%), 14명(12.5%)로 나타났으며(p<0.001), 치과재료를 사용하기 전 MSDS를 읽어본 경험이 있는 근로자는 병원근로자는 18명(14.3%), 의원근로자는 6명(5.4%)으로 조사되었다. 사용하는 치과재료의 물질안전보건자료(MSDS)를 비치한다고 응답한 대상자는 병원근로자의 경우 의원근로자에 비해 2.39배 물질안전보건자료(MSDS)를 비치하는 경우가 많았다. 이에 병원 유형별 특성에 맞게 화학물질의 건강상의 유해성에 대해 인지하고 안전보건교육을 지속적으로 실시함으로써 MSDS 정보에 대한 올바른 인식확립으로 근무환경이 개선되어져야 할 것이며, 치과재료의 제품에 사용설명서 및 MSDS 화학물질 정보제공 관리가 강화하여 전략적 접근 및 근로자의 알 권리를 보장할 수 있는 제도의 필요성을 제안한다.

학교 급식 조리 종사원들의 위생 의식 및 교육 수행 평가 -경기 지역을 중심으로- (Estimating Recognition of Sanitation and Sanitary Education in School Food Service Employees from the Kyunggi Area)

  • 신미혜;윤종순;강근옥
    • 동아시아식생활학회지
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    • 제19권2호
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    • pp.301-309
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    • 2009
  • This study investigated school food service employees' recognition of sanitation and sanitary education in the Kyunggi area of Korea. In terms of personal hygiene, over 90% of the food service employees acknowledged personal hygiene and regarded it as important. Inspection of personal hygiene before cooking occurred "everyday" (85.5%); however, 17.2% continued cooking after dissatisfactory personal hygiene was identified. The food service employees thought that contaminated food materials (35.3%) was the biggest cause of foodborne illness. Approximately 71.4% of the respondents answered that sanitation education and testing related to cooking were conducted "once every month". In addition, 56.4% answered that education on cooking sanitation was "lots of help" and 36.3% answered it was "very helpful". Upon examining the food service employees' awareness about cooking sanitation over 90% were aware of sanitary cooking methods, and 46.1% responded that their biggest difficulty in performing sanitary cooking procedures was excessive work duties due to a lack of food service employees.

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Speech Noise Cancellation using Time Adaptive Threshold Value in Wavelet Transform

  • Lee Chul-Hee;Lee Ki-Hoon;Hwang Hyang-Ja;Moon In-Seob;Kim Chong-Kyo
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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    • pp.244-248
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    • 2004
  • This paper proposes a new noise cancellation method for speech recognition in noise environments. We determine the time adaptive threshold value using standard deviations of wavelet coefficients after wavelet transform by frames. The time adaptive threshold value is set up by using sum of standard deviations of wavelet coefficients in cA3 and weighted cD1. cA3 coefficients represent the voiced sound with lower frequency components and cD1 coefficients represent the unvoiced sound with higher frequency components. In experiments, we removed noise after adding white Gaussian noise and colored noise to original speech. The proposed method improved SNR and MSE more than wavelet transform and wavelet packet transform does. As a result of speech recognition experiment using noise speech DB, recognition performance is improved by $2\sim4\;\%.$

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셀프서비스 기술에서의 서비스 품질 평가: 무인주문결제기술에 대한 근거이론 접근 (Evaluation of Service Quality in Self-Service Technology: Based on Grounded Theory for Unmanned Order Payment Technology)

  • ;고준;박상철
    • 한국IT서비스학회지
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    • 제21권1호
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    • pp.21-40
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    • 2022
  • Advances in information and communication technology have introduced self-service technologies (SSTs) to service companies, changing the way they serve. In addition, as SSTs are expanding for low cost and high efficiency, opportunities for technology to interact with consumers have increased. Restaurant managers have the advantage of the SSTs win-win strategy, which allows consumers to freely receive the products or services they want, but some consumers have low satisfaction of the SSTs, especially elder people and the blind. This study examines the effect of unmanned order payment technology on service quality evaluation. For this, we interviewed a total of 12 consumers in their 10s to 50s with the experiences of using unmanned order payment technology, applying the Grounded Theory Method(GTM). Through a review of the research participant interview materials, totally 84 concepts were derived and the concepts were analyzed to derive 15 subcategories and 10 upper categories. Finally, a paradigm model of the effect of unmanned order payment technology on service quality assessment was derived. It also found the importance of consumers' sense of obligation to use unmanned order payment technology, recognition of advantages (e.g., time savings), recognition of shadow labor, and recognition of whether the technology usage process is in the service quality assessment stage.

국내 목재 놀이터의 현황 (Present Condition of Domestic Wooden Playground)

  • 홍성철;황성욱;이원희
    • 한국가구학회지
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    • 제23권2호
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    • pp.207-213
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    • 2012
  • It was investigated present condition and enhancement of wooden playground. Wood material is the concept of eco-friendly materials. Wood is the best material which helps children to improve their emotional and physical quality. Recently, the number of wooden playgrounds was reduced but synthetic resin material has greatly increased. It was because of the high construction cost of wooden playground. Therefore, to increase the number of wooden playgrounds, it is the most important to remind people of positive recognition about wood material.

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Neural Network에 의한 기계윤활면의 마멸분 해석 (Analysis of Wear Debris on the Lubricated Machine Surface by the Neural Network)

  • 박흥식
    • Tribology and Lubricants
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    • 제11권3호
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    • pp.24-30
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    • 1995
  • This paper was undertaken to recognize the pattern of the wear debris by neural network as a link for the development of diagnosis system for movable condition of the lubricated machine surface. The wear test was carried out under different experimental conditions using the wear test device was made in laboratory and wear testing specimen of the pin-on-disk type were rubbed in paraffine series base oil, by varying applied load, sliding distance and mating material. The neural network has been used to pattern recognition of four parameter (diameter, elongation, complex and contrast) of the wear debris and learned the friction condition of five values (material 3, applied load 1, sliding distance 1). The three kinds of the wear debris had a different pattern characteristic and recognized the friction condition and materials very well by the neural network. The characteristic parameter of the large wear debris over a few micron size enlarged recognition ability.

An Immersive Augmented-Reality-Based e-Learning System Based on Dynamic Threshold Marker Method

  • Lim, Sukhyun;Lee, Junsuk
    • ETRI Journal
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    • 제35권6호
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    • pp.1048-1057
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    • 2013
  • In recent years, augmented reality (AR) technologies have been the subject of great interest among many communities. In education applications, old-fashioned materials (or textbooks) are still used, despite remarkable AR developments in the industrial area. We present an AR system for education. Our system consists of an authoring tool that can be used to create educational content, a viewer that plays that content, and an engine to manage the tool and viewer. In our system, a marker unit recognizes a marker printed on a plane or a cubic plane by adaptively adjusting the threshold to have an excellent recognition rate in diverse environments and acquires corresponding data of the marker. Based on the system, we test 142 elementary school students for increased educational benefits using our system.

미소 결함 평가를 위한 지능형 데이터베이스 구축에 관한 연구 (A Study about the Construction of Intelligence Data Base for Micro Defect Evaluation)

  • 김재열
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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    • pp.585-590
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    • 2000
  • Recently, It is gradually raised necessity that thickness of thin film is measured accuracy and managed in industrial circles and medical world. Ultrasonic Signal processing method is likely to become a very powerful method for NDE method of detection of microdefects and thickness measurement of thin film below the limit of Ultrasonic distance resolution in the opaque materials, provides useful information that cannot be obtained by a conventional measuring system. In the present research, considering a thin film below the limit of ultrasonic distance resolution sandwiched between three substances as acoustical analysis model, demonstrated the usefulness of ultrasonic Signal processing technique using information of ultrasonic frequency for NDE of measurements of thin film thickness, sound velocity, and step height, regardless of interference phenomenon. Numeral information was deduced and quantified effective information from the image. Also, pattern recognition of a defected input image was performed by neural network algorithm. Input pattern of various numeral was composed combinationally, and then, it was studied by neural network. Furthermore, possibility of pattern recognition was confirmed on artifical defected input data formed by simulation. Finally, application on unknown input pattern was also examined.

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수정진동자에 의한 감응성막의 유기가스 응답특성 분석 (Analysis of Response Characteristics for Organic Gas of Polymeric Sensitive Films by Using Q. C. M.)

  • 김경철;김정명;장상목;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 추계학술대회 논문집
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    • pp.409-412
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    • 1996
  • In this paper, the response characteristics of organic gases were investigated by using quartz crystal microbalance(Q.C.M) with different polymeric sensitive materials. The new linear parameter was discussed in order to develope gas sensing system using neural network and pattern recognition. We analyzed the response characteristics by the area of resonant frequency shift of quartz crystal, which mean affinities of organic gases for polymeric sensitive firm. The experimental results shows that the parameter made by the area of frequency shift which was linear with injection amount of organic gases has possibility to be used for pattern recognition and neural network. And they have different normalized pattern.

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