• 제목/요약/키워드: NEXT21

검색결과 1,184건 처리시간 0.024초

굽힘 붕괴 성능 향상을 위한 센터 필라 설계 (Center Pillar Design for High Bending Collapse Performance)

  • 강성종;박명재
    • 한국자동차공학회논문집
    • /
    • 제21권4호
    • /
    • pp.128-134
    • /
    • 2013
  • High bending collapse performance (maximum resistance force and mean resistance force) of body center pillar is an important design target for vehicle safety against side impact. In this study, effect of the upper section shape and the thickness of outer reinforcement on bending collapse performance was investigated for the center pillar of a large passenger car. First, through bending collapse analyses using simple models with uniform section, an optimized center pillar upper section was chosen. Next, bending collapse performance for various models of the actual center pillar with changing the thickness of outer reinforcement were analyzed. The finally designed model showed distinctive enhancement in bending collapse performance nearly without weight increase.

동맥관개존증의 외과적 요법 (Surgical Management of Patent Ductus Arteriosus)

  • 홍종완
    • Journal of Chest Surgery
    • /
    • 제21권6호
    • /
    • pp.990-995
    • /
    • 1988
  • Seventeen cases of vascular injuries treated in Chungnam National University Hospital during the period from Apr. 1980 to Sep. 1988 were reviewed. Common causes of injuries were stab wound, automobile accidents and iatrogenic injuries. Of the 11 arterial injuries, 3 were femoral artery which was the commonest in frequency, the next was 2 cases of subclavian, common carotid, iliac artery. Of the 10 venous injuries, the subclavian vein and internal jugular vein were common in frequency. The most frequent type of injuries was laceration[13 cases in 21]. Vascular reconstruction was done by lateral suture repair in 8 cases, autogenous vein graft in 2, prosthetic vascular graft in 5, direct anastomosis in 1 case. Simple ligation was done in 5 cases. There was 1 case of visual field defect as a sequelae in right common carotid artery transaction and 1 case of mortality.

  • PDF

압전 바이몰프 액츄에이터의 진동에 따른 자가 발전특성 (Self Power Generation from Vibration using Piezoelectric Bimorph Actuator)

  • 김창일;정영훈;이영진;백종후;남산
    • 한국전기전자재료학회논문지
    • /
    • 제21권12호
    • /
    • pp.1071-1076
    • /
    • 2008
  • This paper presents the self power generation from vibration using the piezoelectric bimorph actuator. The piezoelectric bimorph actuator was well developed with PZT-PNN-Fe piezoelectric ceramics. As the applied voltage was increased, a linear change of displacement was obtained with a relatively high ratio of 12.53 um/V for the bimorph actuator. Moreover, when the motor's rotational speed was 2000 rpm, the bimorph actuator, which has a resonance frequency of 68 Hz, exhibited the most efficient generation voltage of 10.4 V. This bimorph actuator could make the LED, emitting 60 mW, working successfully. Therefore, it is anticipated that the bimorph actuator will be useful as a power source for the next-generation electronic devices.

Free vibration and elastic analysis of shear-deformable non-symmetric thin-walled curved beams: A centroid-shear center formulation

  • Kim, Nam-Il;Kim, Moon-Young
    • Structural Engineering and Mechanics
    • /
    • 제21권1호
    • /
    • pp.19-33
    • /
    • 2005
  • An improved shear deformable thin-walled curved beam theory to overcome the drawback of currently available beam theories is newly proposed for the spatially coupled free vibration and elastic analysis. For this, the displacement field considering the shear deformation effects is presented by introducing displacement parameters defined at the centroid and shear center axes. Next the elastic strain and kinetic energies considering the shear effects due to the shear forces and the restrained warping torsion are rigorously derived. Then the equilibrium equations are consistently derived for curved beams with non-symmetric thin-walled sections. It should be noticed that this formulation can be easily reduced to the warping-free beam theory by simply putting the sectional properties associated with warping to zero for curved beams with L- or T-shaped sections. Finally in order to illustrate the validity and the accuracy of this study, finite element solutions using the isoparametric curved beam elements are presented and compared with those in available references and ABAQUS's shell elements.

Data-Compression-Based Resource Management in Cloud Computing for Biology and Medicine

  • Zhu, Changming
    • Journal of Computing Science and Engineering
    • /
    • 제10권1호
    • /
    • pp.21-31
    • /
    • 2016
  • With the application and development of biomedical techniques such as next-generation sequencing, mass spectrometry, and medical imaging, the amount of biomedical data have been growing explosively. In terms of processing such data, we face the problems surrounding big data, highly intensive computation, and high dimensionality data. Fortunately, cloud computing represents significant advantages of resource allocation, data storage, computation, and sharing and offers a solution to solve big data problems of biomedical research. In order to improve the efficiency of resource management in cloud computing, this paper proposes a clustering method and adopts Radial Basis Function in order to compress comprehensive data sets found in biology and medicine in high quality, and stores these data with resource management in cloud computing. Experiments have validated that with such a data-compression-based resource management in cloud computing, one can store large data sets from biology and medicine in fewer capacities. Furthermore, with reverse operation of the Radial Basis Function, these compressed data can be reconstructed with high accuracy.

MR 유체 입자 속도 계측을 위한 디지털 홀로그래피 현미경 시스템의 개발 (Development of Digital Holographic Microscopy System for Measurements of Particle Velocities in MR Fluids)

  • ;강보선
    • 한국분무공학회지
    • /
    • 제21권2호
    • /
    • pp.88-94
    • /
    • 2016
  • In this study digital holographic microscopy system for measurements of 3-D velocities of particles in MR fluid is developed. Holograms are recorded using either a CCD camera with a double pulse laser or a high-speed camera with a continuous laser. To process recorded holograms, the correlation coefficient method is used for focal plane determination of particles. To remove noise and improve the quality of holograms and reconstructed images, a Wiener filter is adopted. The two-threshold and image segmentation methods are used for binary image transformation. For particle pairing, the match probability method is adopted. The developed system will be applied to measurements of the characteristics of unsteady 3-D particle velocities in MR fluids through the next stage of this study.

Relationship between Body Image and Breast Self-examination Intentions and Behaviors among Female University Students in Malaysia

  • Samah, Asnarulkhadi Abu;Ahmadian, Maryam
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권21호
    • /
    • pp.9499-9503
    • /
    • 2014
  • This study aimed to examine the relationship between body image satisfaction and breast self-screening behaviors and intentions. The sample for this cross-sectional study consisted of 842 female university students who were recruited from a number of public and private universities. Data were obtained between the months of November and December, 2013, using multistage random cluster sampling. Main research variables were breast cancer screening behavior and intentions, demographic factors, and the total scores on each of the Multidimensional Body-Self Relations Questionnaire (MBSRQ-Appearance Scales) subscales. Results of multivariate analysis showed that having higher satisfaction and more positive evaluation of appearance were related to having performed breast self-examination more frequently in the last year and intending to perform breast self-examination more frequently in the next year. Longitudinal research can potentially provide detailed information about overall body image satisfaction and breast cancer screening behavior among various communities.

태풍 진로에 영향을 미치는 열적 및 역학적 효과에 관한 수치적 연구 (Comparing the Effect of Both Thermal and Mechanical Forcing on the Error of Typhoon Track)

  • 김해동;원성희;최기선;박상욱;장기호
    • 한국환경과학회지
    • /
    • 제21권2호
    • /
    • pp.263-266
    • /
    • 2012
  • To compare the effects of two external forcing on track of typhoon, TWRF(Typhoon WRF) based ensemble experiments are carried out in the case of Typhoon Morako which is the 8th typhoon at Northwest Pacific region in 2009. The two forcing are tropical SST and topography induced thermal and mechanical forcing, respectively. According to the result of numerical experiment for five-day forecast, the effect of mechanical forcing is about two times stronger than thermal forcing on the track error of the typhoon. More case study for other typhoon will be done as a next paper.

PR형 공압 머니퓰레이터의 위치서보제어 (Position servo control of a PR type pneumatic manipulator)

  • 임승철;어윤범
    • 대한기계학회논문집A
    • /
    • 제21권10호
    • /
    • pp.1619-1625
    • /
    • 1997
  • This paper concerns a 2-axis PR type pneumatic manipulator system translating in vertical and rotating in horizontal directions. A simplified linear model is mathematically formulated similar to the pneumatic acturators in dynamic responses in order to devise an appropriate position control scheme. A PD controller preceding the on/off solenoid valve turns out not only economical but also effective in reducing rise time and amplitude of limit cycles, if its control gains are determined on the basis of frequency response. And, additional implementation of symmetric or asymmetric deadband at the PD controller output greatly helps minimize valve opening numbers, positional error, and undesirable direction-dependent property due to the gravitational load. Such a control concept is synthesized through numerical simulations and next applied to the experimental set-up, featuring enhanced positional servo characteristics.

최근 10년간 간호사의 스트레스에 관한 국외연구 동향분석 (Trend Analysis of Nurses' Stress Based on the Last 10 Years of International Research)

  • 이복임
    • 한국직업건강간호학회지
    • /
    • 제21권1호
    • /
    • pp.27-36
    • /
    • 2012
  • Purpose: The purpose of this study was to identify the trends of nurses' stress based on the last 10 years of international research and to suggest directions for future research. Methods: Fifty three articles between 2002 and 2011 were selected using key words such as 'nurse' and 'stress' from the PubMed and CINAHL. Results: The number of experimental studies increased. The nurses from the various fields were studied. Most studies used a reliable and valid tool for measuring stress of specific nursing staff. The Internet survey was recently used for a data collection method. Significant variables correlated with nurses' stress were categorized into 8 domains: Individual susceptibility, quantitative workload, qualitative workload, physical environment, organizational factors, and interpersonal conflict. Conclusion: In Korea, the next phase of research on nurses' stress needs to consider the experimental study design to find more specific causal relationships. Also, it is necessary to develop the nurses' stress tool for reliable and valid measurement.