• Title/Summary/Keyword: curved type

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A New Species, Acanthobelba heterosetosa, of Oribatid Mite from Mt. Jiri in Korea (한국산 날개응애 1신종, 곧은낚시바늘염주응애)

  • 최성식
    • The Korean Journal of Soil Zoology
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    • v.2 no.1
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    • pp.16-18
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    • 1997
  • Compared with type specimen Acanthobelba tortuosa Enami and Aoki, 1993, a new species, A. heterosetosa sp. nov., of oribatid mites collected from Mt. Jiri has the following characteristic figures. Sensillus is long, slightly thickened at distal part, and covered with barbs sparsely. A pair of prodorsal tubercles Da are present. Natogastral frontal tubercles sa is elongated rather than hooked. Dorsal setae are not the same in shape and length: setae c1 and c2 are thick, blunt at tip, covered with small barbs and curved several times, but others are smooth.

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Nonlinear Analysis of the Monoleaflet Polymer Valve According to Shape of Supporting Members (지지대 형상에 따른 단엽식 고분자 판막의 비선형 해석)

  • 한근조;안성찬;심재준;김성윤
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.748-751
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    • 2001
  • Monoleaflet polymer artificial heart valve was known to show remarkable improvement in antithrombosis and pressure drop compared with other type of artificial valve. In this investigation monoleaflet the vertical and horizontal deflection pattern of polymer heart valve with three types of supporting members straight member, and two curved members was analysed using the large deformation nonlinear finite element method.

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Experimental Study of the Characteristics of 2-Dimensional Coanda Nozzle Jet (2차원 Coanda 노즐 제트 의 특성 에 관한 실험적 연구)

  • 이동호;정명균;김응태
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.6 no.3
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    • pp.222-231
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    • 1982
  • A single free jet formed by the interaction of two curved wall jets on a Cylinder surface is defined as "the Coanda nozzle jet" in this study. In order to investigate the characteristics of Coanda nozzle jet, an experimental analysis was carried out; measurements of the static pressure distribution on the cylinder surface, the mean velocity profile, the turbulence intensity, and the Reynolds shear stress by using x-type hot-wire probe.ire probe.

Nonlinear Analysis of the Monoleaflet Polymer Valve according to Shape of Supporting Members (지지대 형상에 따른 단엽식 고분자 판막의 비선형 해석)

  • 한근조;안성찬;심재준;김성윤
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.3
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    • pp.120-124
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    • 2003
  • Monoleaflet polymer artificial heart valve was known to show remarkable improvement in antithrombosis and pressure drop compared with other type of artificial valve. In this investigation of monoleaflet heart valve the vertical and horizontal deflection pattern of polymer heart valve with three types of supporting members, straight member and two curved members were analysed using the large deformation nonlinear finite element method.

A STUDY ON THE POSITIONAL RELATIONSHIP BETWEEN THE LIPS AND THE TEETH IN KOREAN ADULTS (한국인(韓國人) 성인(成人)의 치아(齒牙)에 대(對)한 구진(口唇)의 위치적(位置的) 연구(硏究))

  • Yu, Gwang-Gil
    • The Journal of Korean Academy of Prosthodontics
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    • v.11 no.1
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    • pp.15-21
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    • 1971
  • The prime objective of this study was to analyze the positional relationship of the lips to the anterior teeth according to age, sex, and both sides of the dental arch in 381 healthy Korean adults with normal occlusion ranging from 17 to 70 years over old. The results were as follows; 1. In the position of the corner of the mouth to the teeth, the range from center of canine to mesial side of first premolar was revealed the incidence of 81~87%, the distal side of canine was the hiqhest frequency of 39~43%. 2. A straight type (76~79%) of lip line was prevailed against the curved type in rest position. 3. In the exposed type of anterior teeth to upper lip in rest position, type III(50~52%) Grade 2 (26~29%) was revealed the highest frequency of occurences. 4. No significant difference in both sexes and sides of the dental arch was observed. 5. Lip position to the teeth with aging was showed the tendency toward straight type in lip line and toward reduction of the number of exposed type of upper anterior teeth to upper lip, and the corner of the mouth was placed posteriorly.

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A Study on the Shell Wall Thinning by Flow Acceleration Corrosion and Mitigation Plan and Design Modification of a Feedwater Heater Impingement Baffle (유동가속부식으로 인한 급수가열기 동체 감육현상 규명과 완화 방안 및 충격판 설계개선에 관한 연구)

  • Kim, Kyung-Hoon;Hwang, Kyeong-Mo;Kim, In-Tae
    • Journal of ILASS-Korea
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    • v.15 no.2
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    • pp.83-93
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    • 2010
  • Feedwater heaters of many nuclear power plants have recently experienced severe wall thinning damage, which will increase as operating time progresses. Several nuclear power plants in Korea have experienced wall thinning damage in the area around the impingement baffle inside feedwater heater installed downstream of the turbine extraction stream line. At that point, the extract steam from the turbine is two phase fluid at high temperature, high pressure, and high speed. Since it flows to reverse direction after impinging the impingement baffle, the shell wall of feedwater heaters may be affected by flow-accelerated corrosion. In this paper, to compare degree of shell wall thinning mitigation rate to squared type with mitigation rate of other type baffle plate, four different types of impingement baffle plate-squared, curved, mitigating type and multi-hole type-applied inside the shell. With these comparison data, this paper describes operation of experiments and numerical analysis which is composed similar condition with real feed water heater. And flow visualization is operated for verification of experiments and numerical analysis. In conclusion, this study shows that mitigating type and multi-hole type baffle plate are more effective than other baffle plate about prevention of pressure concentration and pressure value decrease.

A Preceding Study on Drive System of the Ropeless Elevator (로프리스 엘리베이터 구동시스템 선행연구)

  • Kim, Youn-Hyun;Kim, Sol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.402-410
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    • 2014
  • This paper suggests a preceding study to introduce implementing problems and improving direction when commercializing a ropeless elevator. In this study, the implementation of the study of pilot systems in order to produce the ropeless elevator and also build a linear velocity sensor, this system is applied to the speed control experiment was investigated through testing. Speed control test is carried out in all track including a curved section. This study verified the feasibility of the ropeless elevator and its drive controller is good enough to be accepted. This study also extracted many more problems that still need to be improved in the future for commercializing such as the sensor, high-performance controller, precision structures, safety devices, efficiency improvements and so on.

Performance analysis of light guide panel implemented with laser-processed inner and surface patterns (레이저 가공된 내부 및 표면패턴을 가지는 도광판 성능 분석)

  • Choi, Young-Hee;Shin, Yong-Jin;Choi, Eun-Seo
    • Laser Solutions
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    • v.11 no.1
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    • pp.1-6
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    • 2008
  • We proposed new light guide panel (LGP) fabrication method exploiting laser-processed inner scatterers and surface pattern. The proposed method has achieved LGP performance improvement in both brightness and uniformity. The inner scatterers and surface pattern of grid type were fabricated with a 2nd harmonic Nd:YAG pulse laser engraving system and a $CO_2$ laser scanning system, respectively. In the implementation of LGP, inner scatterers was arranged in accordance with linear or curved pattern with changing density and surface pattern was engraved on the surface of an inner-scatterers embedded LGP. The increase of scatterers' density and the use of surface patterns in both linear and curved pattern provided high luminance and uniformity enhancement. While thecurved pattern incorporated with increased scatterers' density and surface patterns yielded brightness improvement with preserving good uniformity, the linear pattern showed highly localized brightness near the light entrance of the LGP. We can also observe that the uniformity was mainly determined by pattern of inner scatterers, and the brightness was improved by the higher density and the utilization of surface patterns. From the results, the use of laser-processed inner and surface patterns can be a potential alternative for efficient and simple LGP fabrication method.

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Measurement of Inward Turbulent Flows Subject to Plane Rate of Strain in a Rotating 90 Deg. Curved Duct of Variable Cross-Section (단순변형율 조건 하의 회전하는 가변단면 $90^{\circ}$ 곡덕트 내 내향 난류유동 측정)

  • Kim, Dong-Chul;Choi, Young-Don
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.765-770
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    • 2000
  • Hot-wire measurements are reported on the developing turbulent flows subject to plane rate of strain in a rotating $90^{\circ}$ dog bend. The cross-section of the bend varies from $100mm{\times}50mm$ rectangular shape at the bend inlet gradually to the $50mm{\times}100mm$ shape at the bend outlet with remaining a constant area. Data signals from the rotating test section are transmitted through a slip ring to the personal computer which is located at the outside of the rotating disc. 3-dimensional velocity and 6 Reynolds stress components were calculated from the equations which correlate the fluctuating and mean voltage values measured with rotating a slant type hot-wire into 6 orientations. The effects of Coriolis and centrifugal forces on the mean motions and turbulence structures are investigated with respect to rotational speed.

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Development of Frequency Dependent Type Apex-Locator Improvementation by Auto-calibration Using Impedance Difference (주파수 의존형 전자근관장측정기 개발 및 임피던스차를 이용한 자동보정에 의한 성능향상)

  • Nam, K.C.;Kim, S.C.;Kim, D.W.;Lee, S.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.399-402
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    • 1997
  • It is important to find a accurate root canal length or successful endodontic therapy. By X-ray method takes a long time and difficult in a curved canal. After developed electronic apex locator has allowed to measure the root canal length with easy, in a short time also in a curved canal. But most electronic apex locators have the disadvantage which is too short reading or sometimes the measurement itself becomes impossible if there are electrolytes in the canal. To overcome this drawback, impedance ratio method has been developed. In this study, we have developed frequency dependent electronic apex locator to minimize the interference of electrolytes. And based on that also some error in clinic use, we added the other method. Difference of two signals which are used in calculation of impedance ratio was can be represent the status of root canal fluid. As a result, using impedance ratio method and auto-calibration by voltage difference method can reduce the measurement error.

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