• 제목/요약/키워드: By-pass

검색결과 3,544건 처리시간 0.032초

비대칭 랩 스크롤 압축기의 바이패스 밸브 설계에 관한 연구 (A study on the by-pass valve design of a scroll compressor with asymmetric wrap)

  • 최진섭;곽상호;김현진
    • 설비공학논문집
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    • 제12권2호
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    • pp.181-189
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    • 2000
  • The scroll compressor used for heat pump has a wide range of operation condition. To cover both heating and cooling modes, the operating Pressure ratio ranges from 1.5 to 6.8. Since the scroll compressor, however, is a type of compressor whose pressure ratio is fixed, some loss in the compression work is caused by the operation at the pressure ratio different from the built-in pressure ratio. A way of avoiding this problem is to introduce by-Pass holes in compression chambers, so that the compressed gas of pressure higher than the discharge pressure, yet not reached to the discharge port can be released earlier through the by-Pass holes. In this paper, an optimum Positioning of the by-Pass hole and the effect of the by-pass valve on the compressor performance are studied.

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크로스 롤러가이드의 다단형상인발공정 패스 스케쥴에 관한 연구 (A Study on the Pass Schedule of Multi-Pas Shape Drawing Process for Cross Roller Guide)

  • 이태규;이찬주;이상곤;이선봉;김병민
    • 소성∙가공
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    • 제18권7호
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    • pp.550-555
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    • 2009
  • In the multi-pass shape drawing process, the pass schedule that includes the determination of reduction ratio and intermediate die shape is very important. This study used the equal reduction, equal load, and electric field analysis method for pass schedule of the multi-pass shape drawing. The reduction ratio was calculated by the equal reduction and equal load method. And the intermediate die shape was determined by the result of the electric field analysis and the calculated reduction ratio. The proposed pass schedule method was applied to a shape drawing for producing cross roller guide. Finally, FE-analysis and shape drawing experiment were performed to verify the effectiveness of the proposed method.

도시침수 저감을 위한 by-pass 빗물침투성 우수관거 (A by-pass rainwater penetration sewer system for urban flooding mitigation)

  • 이범섭;고건호;강호영;문영일
    • 한국수자원학회논문집
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    • 제49권9호
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    • pp.799-807
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    • 2016
  • 본 연구는 기상이변과 도시열섬현상으로 국지성 호우가 잦아져 도시침수피해가 매년 반복되고 있으며, 건기시에는 비가 모자라 지하수 부족으로 이어져 하천 건천화 현상이 빈번히 발생하고 있어 이를 해결하고자 "도시침수 저감을 위한 by-pass 빗물침투성 우수관거"를 제안한다. 집중호우로 확률년수 이상의 호우발생시 관거를 확대 교체하지 않고 기존우수 관거를 그대로 사용하며 배제시스템과 연계하여 by-pass 빗물침투성 우수관거를 설치하여 본 연구지역 대한민국 서울특별시 강남구 강남역사거리 지역 3.07 ha에서 관거확대공사와 비교시 평균 27백만원(44%) 공사비절감 및 기존 우수관거 유지로 별도의 우수처리 대책이 불필요하다. "도시침수 저감을 위한 by-pass 빗물침투성 우수관거"는 여름철 확률년수 이상의 비가 오더라도 by-pass관로를 통하여 통수능력을 증가시키며, 봄, 가을에 내리는 소량의 비는 by-pass 침투공을 통하여 전량 지중 수자원 확보에 기여한다.

뇌졸중 환자의 체간조절 능력과 동적균형 및 보행과의 상관관계 (The Relationships among Trunk Control Ability, Dynamic Balance and Gait in Stroke Patients)

  • 정은정;이종수;김성식;이병희
    • 대한한의학회지
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    • 제33권1호
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    • pp.148-159
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    • 2012
  • Objectives: This study investigated the correlation among Postural Assessment Scale for Stroke (PASS), Timed "Up and Go" Test (TUG) and gait (velocity, cadence, step-length, stride-length and single-limb support). Methods: The 70 subjects were assessed on trunk control measured with the use of the PASS, dynamic balance (TUG) and gait function (by GAITRite). The data were analyzed using Pearson product correlation. Results: The PASS total scores were significantly correlated with PASS-M, PASS-C, and PASS-T (r =.80 ~ .88 p<.01). All items of the PASS were significantly correlated with TUG (r = -.63 ~ -.81 p<.01), velocity (r = .44~.58 p<.01), cadence (r =.38 ~.51. p<.01), affected side step length (r = .44 ~.56 p<.01) and affected side stride length (r = .45 ~.59 p<.01). But affected side single-limb support was lowly correlated with PASS-M, PASS-C, PASS-T and PASS-total (r = .25~.36 p<.05). Conclusions: Measures of trunk control were significantly related with values of dynamic balance and gait. Based on these results, trunk control is an essential core component of balance and gait. Trunk control training programs after stroke should be developed and emphasized.

A Realization of High-pass, Band-stop and All-pass Transfer Functions with OTA-C Integrator Loop Structure

  • Tsukutani, Takao;Higashimura, Masami;Kinugasa, Yasutomo;Sumi, Yasuaki;Fukui, Yutaka
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -1
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    • pp.642-645
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    • 2002
  • This paper introduces a way to realize high-pass, band-stop and all-pass transfer functions using Operational Transconductance Amplifiers (OTAs) and grounded capacitors. The basic circuit configuration is constructed with five OTAs and two grounded capacitors. In the circuit with the proportional block, it is shown that the circuit parameters can be independently set and electronically tuned by the transconductance gains. Although the circuit configuration has been Down, it seems that the feature for realizing the high-pass, the band-pass and the all-pass transfer functions makes the structure more attractive and useful. An example is given together with simulated results by PSPICE.

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Single Pass Algorithm for Text Clustering by Encoding Documents into Tables

  • Jo, Tae-Ho
    • 한국멀티미디어학회논문지
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    • 제11권12호
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    • pp.1749-1757
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    • 2008
  • This research proposes a modified version of single pass algorithm specialized for text clustering. Encoding documents into numerical vectors for using the traditional version of single pass algorithm causes the two main problems: huge dimensionality and sparse distribution. Therefore, in order to address the two problems, this research modifies the single pass algorithm into its version where documents are encoded into not numerical vectors but other forms. In the proposed version, documents are mapped into tables and the operation on two tables is defined for using the single pass algorithm. The goal of this research is to improve the performance of single pass algorithm for text clustering by modifying it into the specialized version.

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습식 다단 인발공정 해석 프로그램 개발 (Development of Analysis Program for Multi-Pass Wet Wire Drawing Process)

  • 이상곤;김병민;김민안;박병권
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.216-219
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    • 2001
  • The production of fine wire through multi-pass wet wire drawing process would be impossible with no backtension at inlet of dies. Backtension is affected by many process parameters, such as dies reduction, coiling number of wire at capstan, machine constant, slip between wire and capstan, characteristic of lubricant and so on. Up to date, dies design and dies pass schedule of multi-pass wet wire drawing process have performed by trial and error of expert in the Industrial field without consideration of quantitative relation among process variables. Thus study investigates the multi-pass wet wire drawing process considering the relation among process variables, such as dies reduction, coiling number of wire at capstan, machine constant, slip between wire and capstan, etc. And analysis program which can analyze many important process values(drawing force, backtension force, slip rate, slip velocity rate, etc) for die design and dies pass schedule of multi-pass wet wire drawing process was developed.

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KOMPSAT-1 EOC Pass 영상의 기하정확도 분석에 관한 연구 (A Study on the Analysis of Geo-Accuracy with KOMPSAT-1 EOC Pass Imagery)

  • 서두천;임효숙
    • 대한원격탐사학회지
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    • 제19권6호
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    • pp.447-456
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    • 2003
  • 본 연구에서는 KOMPSAT-1 위성에서 취득한 EOC Pass 영상과 scene 영상의 기하정확도를 평가함으로써, 비접근지역에 대한 3차원 지형정보 추출 방안에 대하여 연구하였다. 이를 위하여 다음과 같은 4가지 실험을 수행하여 KOMPSAT-1 EOC 위성데이터의 정확도를 평가하였다. 1) KOMPSAT-1 전처리 시스템으로 처리된 Level 1R의 ancillary 데이터와 영상좌표를 이용한 지상좌표계산 2) 보조자료를 이용하여 계산된 두 영상의 지상좌표를 공간교차이론으로 지상 3차원좌표 계산 3) 입체 Pass 영상의 일부분(KOMPSAT-1 EOC, 1 scene size)에서 획득된 GCP(Ground Control Point)을 이용하여 Bundle adjustment을 수행하고, 그 결과 계산된 외부표정요소로 지상좌표의 계산 4) 3)에서 계산된 외부표정요소를 이용하여 전체 Pass 영상에 적용하여 정확도를 평가하였다.

3-pass HAVAL의 축소 라운드 안전성에 관한 연구 (On the Security of reduced versions of 3-pass HAVAL)

  • 박상우;성수학;지성택;윤이중;임종인
    • 정보보호학회논문지
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    • 제12권4호
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    • pp.55-66
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    • 2002
  • HAVAL은 Zheng 등이 제안한 MD-계열의 해쉬 함수로서, 임의의 길이의 메시지를 입력으로 하며, 128, 160, 192, 224, 256 비트 길이의 해쉬값를 출력하는 해쉬 함수이다. HAVAL은 입력 메시지의 1024 비트 블록을 처리하는 회수에 따라 3-pass HAVAL, 4-pass HAVAL, 그리고, 5-pass HAVAL로 구분된다. 본 논문에서는 3-pass HAVAL의 축소 라운드의 충돌쌍을 찾는 방법을 제안한다. 본 논문에서 제안하는 방법에 의하여 3-pass HAVAL의 처음 두 라운드와 마지막 두 라운드에 대한 충돌쌍을 찾을 수 있다.

한국어 연속음성중 키워드 인식을 위한 반연속 은닉 마코브 모델과 One-Pass 알고리즘의 개선방안 (Improvement of Semicontinuous Hiden Markov Models and One-Pass Algorithm for Recognition of Keywords in Korean Continuous Speech)

  • 최관선
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1994년도 제11회 음성통신 및 신호처리 워크샵 논문집 (SCAS 11권 1호)
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    • pp.358-363
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    • 1994
  • This paper presents the improvement of the SCHMM using discrete VQ and One-Pass algorithm for keywords recognition in Korean continuous speech. The SCHMM using discrete VQ is a simple model that is composed of a variable mixture gaussian probability density function with dynamic mixture number. One-Pass algorithm is improved such that recognition rates are enhanced by fathoming any undesirable semisyllable with the low likelihood and the high duration penalty, and computation time is reduced by testing only the frame which is dissimilar to the previously testd frame. In recognition experiments for speaker-dependent case, the improved One-Pass algorithm has shown recognition rates as high as 99.7% and has reduced compution time by about 30% compared with the currently abailable one-pass algorithm.

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