• Title/Summary/Keyword: Static alignment

Search Result 76, Processing Time 0.027 seconds

The present status of study on the behaviour of the line shafting (추진축계의 거동에 관한 연구 현황)

  • Hylarides, S.;Jeon, Hyo-Jung
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.10 no.3
    • /
    • pp.11-38
    • /
    • 1986
  • Past and present developments in the alignment procedures of the line shafting are discussed. It is shown that the effects of the propeller hydrodynamics and of the oil-films, built up in the journal bearings, can essentially change the static alignment. However, the inclusion of these phenomena in the alignment is not yet standard. Also the dynamic effects of natural frequencies and vibratory excitations are not yet accounted for in the general case, although also these aspects can influence the safe operation of the line shafting. Therefore a plea is made to develop a more complete and thus a more rational alignment procedure.

  • PDF

A Study on Optimum Shaft Alignment Analysis for VLCC (VLCC의 최적 축계정렬해석 연구)

  • Kim Hyu Chang;Kim Jun Gi
    • Special Issue of the Society of Naval Architects of Korea
    • /
    • 2005.06a
    • /
    • pp.134-137
    • /
    • 2005
  • Recently, in VLCC, shafting system is stiffer due to large engine power whereas hull structure is more flexible due to scantling optimization, which can be suffered from alignment damage by incompatibility between shafting and hull, In this study, shafting system without stern tube forward bush was adapted for less sensitive system against external factors. Also, shaft alignment analysis was considered with hull deflection at various ship loading conditions and stern tube after bush of long journal bearing was evaluated by static squeezing pressure and dynamic oil film pressure with sloping control. Whirling vibration was also reviewed to avoid resonance with propeller blade order. So, reliable shafting design for VLCC could be achieved through optimized alignment analysis for the system without stern tube forward bush.

  • PDF

Resistive breathing exercise using transverse abdominis strengthening and P.N.F affects pulmonary functions and static sitting posture of adult stroke patient : a case report (복횡근의 강화운동과 고유수용성신경근촉진법을 이용한 호흡저항운동이 뇌졸중 환자의 폐기능과 정적인 앉은자세에 미치는 영향 : 증례보고)

  • Lee, Byung-Ki
    • PNF and Movement
    • /
    • v.8 no.3
    • /
    • pp.49-54
    • /
    • 2010
  • Pupose : This study aimed to examine the Influence of stregthening for Transverse abdominis and resistive breathing exercise to use PNF on fulmonary functions and static sitting posture in adult stroke patient. Methods : Left hemi-plegic patient was masured pulmonary function test and analyzed sitting posture of alignment at pre intervention and post-intervention in 4weeks. Results : The pulmonary functions was increased and changed good alignment of trunk on sitting position after treatments. Conclusion : We were found that stregthening for Transverse abdominis and resistive breathing exercise to use PNF could improve pulmonary functions and sitting posture for stroke patient.

  • PDF

Pressure Analysis of Sterntube after Bush Bearing Considering Elastic Deflection of Misaligned Journal and Partial Slope of Bearing Bush (탄성 변형된 저어널의 편심과 베어링 부시의 부분경사를 고려한 선미관 후부 베어링의 압력분포 해석)

  • Choung, Joon-Mo;Choe, Ick-Heung
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.44 no.6
    • /
    • pp.666-674
    • /
    • 2007
  • It is very important to estimate static squeezing pressure distributions for lining material of sterntube after bearing at dry dock stage since the maximum squeezing pressure value can be one of the significant characteristics representing coming navigation performances of the propulsion system. Moderate oil film pressure between lining material and propulsion shaft is also essential for safe ship service. In this paper, Hertz contact theory is explained to derive static squeezing pressure. Reynolds equation simplified from Navier-Stokes equation is centrally differentiated to numerically obtain dynamic oil film pressures. New shaft alignment technology of nonlinear elastic multi-support bearing elements is also used in order to obtain external forces acting on lining material of bearing. For 300K DWT class VLCC with synthetic bush of sterntube after bearing, static squeezing pressures are calculated using derived external forces and Hertz contact theory. Optimum partial slope of the after bush is presented by parametric shaft alignment analyses. Dynamic oil film pressures are comparatively evaluated for partially bored and unbored after bush. Finally it is proved that the partial slope can drastically reduce oil film pressure during engine running.

The effects of increased unilateral and bilateral calcaneal eversion on pelvic and trunk alignment in standing position

  • Yi, Jaehoon
    • Physical Therapy Rehabilitation Science
    • /
    • v.5 no.2
    • /
    • pp.84-88
    • /
    • 2016
  • Objective: Generally, it is known that there is a correlation between excessive calcaneus eversion and a patient with low back pain and it also affects pelvic alignment. However, there are not enough studies that show calcaneal eversion having an effect on the alignment of the trunk. Design: Cross-sectional study. Methods: A 3-dimensional motion analysis system was used to assess the lower limbs, pelvic alignment, and trunk alignment with increased unilateral and bilateral calcaneal eversion in twenty-one subjects. All subjects were asked to maintain a static posture for seven seconds on a wedge three times per posture for measurement and analysis purposes. The wedge used in the process was a lateral wedge with a 10-degree tilt to the lateral direction. To unify all of the subjects' foot position, the front and inner side of the wedge were marked. The height of the tilted wedge's inner side and flat wedge were balanced equally in order to be able to maintain the lateral part of the foot to the same height when producing an increased calcaneal eversion. Results: Comparing the changes in trunk and pelvic alignment in accordance to calcaneal eversion for each posture, there was a significant different in the X and Y-axis for each posture, but not in the Z-axis (p<0.05). Thus, it can be confirmed that calcaneal eversion in the sagittal plane and frontal plane may have and effect on the pelvis and the trunk. Conclusions: Postures with increased bilateral and unilateral calcaneal eversion has an effect on pelvic alignment, but does not cause any changes in trunk alignment.

PHYSICAL PROPERTIES OF FRESH RED PEPPER

  • W. J. La;D. B. Song;Lee, S. K.;Lee, T. K.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 2000.11c
    • /
    • pp.578-585
    • /
    • 2000
  • Geometrical characteristics of fresh red pepper(Capsicum annuum L.) were measured and indexed to define some important geometrical characteristics, and malformation of body and fruit stalk which are necessary for the design of the equipments for cutting, spreading and alignment of red pepper in developing a fruit stalk remover of fresh red pepper. The effects of bending of body and fruit stalk on the equipments of cutting, spreading and alignment were studied. The maximum lengths of some parts of fresh red pepper were found to be 180 mm, 125 mm, 144 mm, 67 mm and 76 mm for the body, the bent part of body, the fruit stalk, the bent part and the straight part of fruit stalk, respectively. The fresh red pepper with bending indices more than 0.4 and 0.3 for the body and the fruit stalk, respectively, was defined to be malformed based on the result of cutting rate using cutting unit; while the other ones to be normal in shape. Based on this, among the total fresh red peppers tested, 47%, 40% and 20% were found malformed for the body, the fruit stalk, and for both of the body and the fruit stalk. Malformed red peppers were poorer in spreading and alignment than normal ones, and the processed quantity was decreased with increased feed rate. The required time for the malformed peppers to pass on the alignment plate inclined at 30 increased rapidly at 8.3 Hz with increased feed rate. For the fresh red peppers with average moisture content of 85%,w.b., the maximum tensile strength between fruit stalk and body was 88.1 N; the maximum cutting resistances were 92.1 N and 94.9 N for the fruit stalk-calyx joint and body, respectively. Average coefficients of static friction were 0.99, 0.62, 0.59 and OJ, respectively, for the surfaces of rubber, galvanized iron, acryl and plywood.

  • PDF

The Study on Static Alignment Classification based on the Full Spine AP X-ray of Adults aged 30-39 (30대 성인의 골반, 척추 및 견갑대 정렬의 패턴 분석 - Full Spine AP X-ray 분석에 따른 -)

  • Park, Ji-Hyun;Hong, Seo-Young
    • Journal of Korean Medicine Rehabilitation
    • /
    • v.20 no.2
    • /
    • pp.89-99
    • /
    • 2010
  • Objectives : This study was designed to analyze the pattern of asymmetrical alignment. Methods : This study was carried out with the data from comprehensive medical testing. 91 subjects aged 30-39 were evaluated by full spine AP X-ray. For pelvis, innominate measurement(IM), off centering measurement(OCM), ilium shadow measurement(ISM), major axis of obturator foramen(MaF), minor axis of obturator foramen(MiF) were analyzed. Spinal curvature and height of shoulder girdle were analyzed. Results : 1. In pelvis, It. posterior-inferior and it. inflare combination pattern was 38 cases(42.8%). 2. In spinal curvature, "reverse S" curve was 45 cases(49.4%) and "reverse C" curve was 30 cases(33%). 3. In shoulder girdle, It. superior pattern was 42 cases(46.1 %) and It. superior pattern was 39 cases(42.9%). 4. In whole body analysis, It. posterior-inferior and It. inflare pelvis, "reverse S" spinal curvature and It. superior shoulder girdle combination patten was 11 cases(12.1 %). This pattern is similar to Kendall's right handedness pattern and Zink's common compensatory pattern. Conclusions : Results from this investigation showed asymmetrical alignment in 30-39 years-old adults. This results are expected to contribute to classifying the alignment pattern in clinic and systemic treatment.

Plasma Dechucking Process를 이용한 Dynamic Alignment Error 개선

  • Yu, Jin-Gyun;Chae, Min-Cheol;Yun, Jeong-Bong;Kim, Jong-Geuk
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.203.1-203.1
    • /
    • 2016
  • Poly etch 설비에서 발생하는 dechuck 불량에 의한 Dynamic Alignment(DA) error는 poly etch 설비에서의 고질 적인 문제이다. 발생 원인은 ElectroStatic Chuck(ESC)의 노후화 혹은process plasma에 의한 attack 등으로 ESC와 wafer간 dechucking이 진행될 때 wafer내의 전하가 완전히 discharge되지 못하여 wafer Sticking에 의한 sliding이 발생되며 심해지면 Dynamic Alignment(DA) Error가 발생한다. DA error 발생 되면 particle down으로 wafer는 scrap 되며 DA error가 지속적으로 발생하는 설비는 ESC 교체를 하고 있다. ESC 교체비용도 매우 크며 교체 전까지 설비가 멈추어있는 시간적인 손실이 발생하게 된다. Dechucking을 진행할 때 Wafer에 잔존하는 전하를 제거 하여 Wafer의 sticking을 줄여 DA error를 근원적으로 방지하기 위해 plasma를 이용하여 wafer와 ESC를 하나의 electric circuit으로 연결시키는 방법으로 wafer에 잔존하는 전하를 제거 시키고자 하였다.

  • PDF

A Study on Shaft Alignment of the Rotating Machinery by using Strain Gages (스트레인게이지를 이용한 회전체의 축정렬 연구)

  • 나상수
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 1999.10a
    • /
    • pp.63-68
    • /
    • 1999
  • Because misaligned shafts have caused noise, vibration, bearing failures, and stress concentration of coupling part, which decrease the efficiency and life of a shaft system, the proper alignment of shaft system should be monitored continuously in dynamic condition. To solve these problems under dynamic condition, a telemetry system is this study is used to find the condition of the least bending moment, which is known by analyzing the structure and stress induced by misalignment is investigated. The moment derived from two shaft strain at the nearby coupling is measured. The bending strain is measured 5 times for average in static state as well as dynamic state with 100~700 rpm.

  • PDF

Pretilt angle and EO Characteristics of Liquid Crystal via Ion-beam Irradiation Angles (이온빔 조사각도에 따른 액정의 프리틸트각과 전기 광학적 특성)

  • Lee, Kang-Min;Lee, Won-Kyu;Oh, Byeong-Yun;Kim, Byoung-Yong;Han, Jin-Woo;Jeon, Ji-Yeon;Han, Jeong-Min;Lee, Sang-Keuk;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2008.04a
    • /
    • pp.44-44
    • /
    • 2008
  • To date, rubbing has been widely used to align LC molecules uniformly. Although rubbing can be simple, it has fundamental problems such as the generation of defects by dust and static electricity, and difficulty in achieving a uniform LC alignment on a large substrate. Therefore, non contact alignment has been investigated. Ion beam induced alignment method, which provides controllability, nonstop process, and high resolution display. In this study, we investigated liquid crystal (LC) alignment with ion beam (IB) that non contact alignment technique on polyimide and electro-optical characteristics of twisted nematic (TN)-liquid crystal display (LCD) on the polyimide under various ion beam angles. In this experiment, Polyimide layer was coated on glass by spin-coating and Voltage-transmittance(VT) and response time characteristics of the TN cell were measured by a LCD evaluation system. The good characteristics of the nematic liquid crystal (NLC) alignment with the ion beam exposure polyimide surface was observed. The tilt angle of NLC on the PI surface with ion beam exposure can be measured under $1^{\circ}$ for all of irradiation angles. In addition, it can be achieved the good EO properties, and residual DC property of the ion beam aligned TN cell on polyimide surface.

  • PDF