• Title/Summary/Keyword: Frame Changing

Search Result 260, Processing Time 0.047 seconds

Design and Performance Analysis of a Variable Configuration Tracked Vehicle (가변 형상 무한 궤도 차량의 성능 해석 및 설계)

  • 김한호;곽윤근
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.9 no.1
    • /
    • pp.20-27
    • /
    • 2001
  • A variable configuration tracked vehicle(VCTV) is developed to reduce turning energy and improve climbing ability for stairs. This mechanism has four track T-type frames. By changing the driving direction, each track T-type frame rotates to minimize the contact area with ground. It also has better performance than other VCTV in energy consumption of turning. Futhermore this mechanism is more stable than other VCTV on the rough terrain. When climbing stairs, each track T-type frame rotates to obtain a front attack angle and keep stability on steep stairs. The design parameters of components of track T-type frames are optimized to enhance the performance of climbing stairs. Performance indices include a stable angle, a climbing ability, a height of the vertical obstacle. In case that the overall length of the mechanism is 0.2m, it is required that the radius of the wheels should be 5mm and the length track contacted with he ground should be 0.09m to climb higher and steeper stairs.

  • PDF

A Study on the Textile for Protective Clothing of Fire Fighters (한국 소방대원 방수피복의 소재특성에 관한 비교 연구)

  • 정정숙;이연순
    • Journal of the Korean Home Economics Association
    • /
    • v.40 no.5
    • /
    • pp.15-24
    • /
    • 2002
  • The following research conclusions were made, relative to the experiments of the textiles of fire fighters Protective Clothing. 1. When the body protection efficiency such as the thickness, the strength and heat resistance are considered, Nomex(N) is tuned out the best outer shelf, Gore-tex(KG) the best moisture barrier, and Wool-felt(WC) the best thermal barrier. 2. In the hygienic and sanitary efficiency also, N is turned out the best outer shelf, KG the best moisture barrier, and WC the best thermal barrier in its degree of water resistance, water vapour permeability, and air permeability. 3. In the washing and maintenance efficiency, too. N is turned out the best outer shell, KG the best moisture barrier, and WC the best thermal barrier, being considered the material's rate of contraction, the changing rate of frame resistance, water resistance, and water vapour permeability. 4. When considered the frame resistance against the reflection tape and reflection efficiency, O is the best material for it marks the highest score in the frame resistance and reflective effect.

A study of warpage caused by glass fiber orientation in Injection Molding to Upper Frame of Magnetic Contactor in 85 AF (Magnetic Contactor Upper Frame 사출성형시 유리섬유 배향에 따른 뒤틀림 변형에 관한 연구)

  • Park, Jin-Young;Cho, Hae-Yong;Kim, Kil-Su;Hwang, Han-Seong
    • Proceedings of the KSME Conference
    • /
    • 2000.11a
    • /
    • pp.766-771
    • /
    • 2000
  • As using of insulating material of plastic to industrial electric field, thermoset has been gradually substituted for thermoplastic. But changing the material with crystalline has some problem, which is strength or warpage, Especially getting a strength to endure inner pressure is necessary when arc is occurred. So we use the material that is composed of glass fiber to compensate strength. By the way as the reinforced glass-fiber material is used in injection molding, unstableness of dimension is appeared frequently and it is difficult to know warpage pattern. So this paper will be contributed to know warpage pattern of mold product that is upper frame of magnetic contactor caused by glass-fiber orientation with fixed gate-system, when glass-fiber reinforced material with classification of poly-amide is used in injection molding.

  • PDF

The Effect of Cross Beam on the strength and Stiffness of the Frame in Shuttle Car for LMIT (LMTT용 Suhttle Car의 Frame 강도 및 강성에 미치는 Cross Beam의 영향)

  • Lim J. H.;Han G. J.;Lee K. S.;Han D. S.;Shim J. J.;Lee S. W.;Jeon Y. H.
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2004.11a
    • /
    • pp.323-328
    • /
    • 2004
  • According as the quantity of goods transported by ship is increasing about $7\%$ per year, a port environment is rapidly changing. To meet this situation successfully, the development of the next generation port loading and unloading system (LMTT) is studied. A Frame of shuttle car for LMTT(Linear Motor-based Transfer Technology) consist of three parts which are outer beam inner beam and cross boom. Outer boom supports a container and inner boom is a framework and cross boom reinforces outer and inner boom. In this study, we carried out the finite element analysis for the effect of cross boom on the strength and stiffness qf the frame according to the number if cross beam leading position of container, the distance ratio if inner boom from center.

  • PDF

Non-Reference P Frame Coding for Low-Delay Encoding in Internet Video Coding (IVC의 저지연 부호화 모드를 위한 비참조 P 프레임의 부호화 기법)

  • Kim, Dong-Hyun;Kim, Jin-Soo;Kim, Jae-Gon
    • Journal of Broadcast Engineering
    • /
    • v.19 no.2
    • /
    • pp.250-256
    • /
    • 2014
  • Non-reference P frame coding is used to enhance coding efficiency in low-delay encoding configuration of Internet Video Coding (IVC), which is being standardized as a royalty-free video codec in MPEG. The existing method of non-reference P frame coding which was adopted in the reference Test Model of IVC (ITM) 4.0 adaptively applies a non-reference P frame with a fixed coding structure based on the magnitude of motion vectors (MVs), however, which unexpectedly degrades the coding efficiency for some sequences. In this paper, the existing non-reference P frame coding is improved by changing non-reference P frame coding structure and applying a new adaptive method using the ratio of the amount of generated bits of non-reference frames to that of reference frames as well as MVs. Experimental results show that the proposed non-reference P frame coding gives 6.6% BD-rate bit saving in average over ITM 7.0.

Efficient Tracking of a Moving Object Using Representative Blocks Algorithm

  • Choi, Sung-Yug;Hur, Hwa-Ra;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2004.08a
    • /
    • pp.678-681
    • /
    • 2004
  • In this paper, efficient tracking of a moving object using optimal representative blocks is implemented by a mobile robot with a pan-tilt camera. The key idea comes from the fact that when the image size of moving object is shrunk in an image frame according to the distance between the camera of mobile robot and the moving object, the tracking performance of a moving object can be improved by changing the size of representative blocks according to the object image size. Motion estimation using Edge Detection(ED) and Block-Matching Algorithm(BMA) is often used in the case of moving object tracking by vision sensors. However these methods often miss the real-time vision data since these schemes suffer from the heavy computational load. In this paper, the optimal representative block that can reduce a lot of data to be computed, is defined and optimized by changing the size of representative block according to the size of object in the image frame to improve the tracking performance. The proposed algorithm is verified experimentally by using a two degree-of-freedom active camera mounted on a mobile robot.

  • PDF

A Study on Elevation Map Application for Offering Quantitative Analytic Frame of Streetscape - Focused on use GIS - (가로경관의 정량적 분석틀 제공을 위한 입면지도 적용에 관한 연구 - GIS 활용을 중심으로 -)

  • Jeong, Choon-kuk;Kim, Ki-hwan
    • KIEAE Journal
    • /
    • v.8 no.5
    • /
    • pp.43-48
    • /
    • 2008
  • This study is about offering quantitatively analytic frame of streetscape, and also about making a way to be standardized and adapt changing landscape. This allows us to manage a form of elevation map after the application to GIS. The form of elevation map is a visible and vertical arrangement method of data recognizable while walking or driving. Applying measurable traits enables us to make a quantitative control over each element of which streetscape consists. After all, it would play a great roll in organizing and maintaining fine streetscape of each city. As the basic ways to make the elevation map, this study proposes the methods of providing quantitative analytic frame of streetscape after applying elevation data, Raster Data and Vector Data, which were investigated on the basis of GIS. In addition, as a simulation for increasing reality, certain streets, where the streetscape is very important, were chosen so that they enable us to utilize quantitatively analytic data of streetscape with analyzing the +degree of opening ratio in the boundary of D/H=2, comparing between wall area and windowpane area, comparing between facade area and sign board area, and calculating both area and ratio which are applied to ecospace.

The study on Topology Optimization for Crashworthiness enhancement in Protective shell frame of Rolling Stock leading-cab (철도 차량 전두부 충돌 피해 저감을 위한 Protective shell frame의 위상 최적화에 관한 연구)

  • Kim, Hyun-Jun;Kim, Se-Hoon;Jung, Hyun-Seung;Kwon, Tae-Su;Suh, Myung-Won
    • Proceedings of the KSR Conference
    • /
    • 2007.05a
    • /
    • pp.138-143
    • /
    • 2007
  • The leading-cab (high energy absorption area) of rolling stock directly is impacted on the frontal crash unlike other cabs. Thus, leading-cab has a structurally complex shape to solve getting concentrated loads. However, in order to enhance structural performance and to achieve the weight reduction of cab, changing the sizes and adjusting the distance of members do not take an effective result. Therefore, in design phase, to find the material arrangement which helps structural capacity be better should be done. This research applies the topology optimization to concept design of protective shell frame on strategy of crush energy absorption with considering pressure and vertical loads acting on the principal part of leading-cab. In this research, topology optimization method focuses on structural design, and which yields optimal material arrangement under given loads and boundary conditions using density method which has the density of material as design variables. Finally, this research presents optimal material arrangement and structure of protective shell frame on given loads with applying topology optimization.

  • PDF

High-frame-rate Video Denoising for Ultra-low Illumination

  • Tan, Xin;Liu, Yu;Zhang, Zheng;Zhang, Maojun
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.8 no.11
    • /
    • pp.4170-4188
    • /
    • 2014
  • In this study, we present a denoising algorithm for high-frame-rate videos in an ultra-low illumination environment on the basis of Kalman filtering model and a new motion segmentation scheme. The Kalman filter removes temporal noise from signals by propagating error covariance statistics. Regarded as the process noise for imaging, motion is important in Kalman filtering. We propose a new motion estimation scheme that is suitable for serious noise. This scheme employs the small motion vector characteristic of high-frame-rate videos. Small changing patches are intentionally neglected because distinguishing details from large-scale noise is difficult and unimportant. Finally, a spatial bilateral filter is used to improve denoising capability in the motion area. Experiments are performed on videos with both synthetic and real noises. Results show that the proposed algorithm outperforms other state-of-the-art methods in both peak signal-to-noise ratio objective evaluation and visual quality.

Finite element model updating of in-filled RC frames with low strength concrete using ambient vibration test

  • Arslan, Mehmet Emin;Durmus, Ahmet
    • Earthquakes and Structures
    • /
    • v.5 no.1
    • /
    • pp.111-127
    • /
    • 2013
  • This paper describes effects of infill walls on behavior of RC frame with low strength, including numerical modeling, modal testing and finite-element model updating. For this purpose full scaled, one bay and one story RC frame is produced and tested for plane and brick in-filled conditions. Ambient-vibration testis applied to identify dynamic characteristics under natural excitations. Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are used to obtain experimental dynamic characteristics. A numerical modal analysis is performed on the developed two-dimensional finite element model of the frames using SAP2000 software to provide numerical frequencies and mode shapes. Dynamic characteristics obtained by numerical and experimental are compared with each other and finite element model of the frames are updated by changing some uncertain modeling parameters such as material properties and boundary conditions to reduce the differences between the results. At the end of the study, maximum differences in the natural frequencies are reduced on average from 34% to 9% and a good agreement is found between numerical and experimental dynamic characteristics after finite-element model updating. In addition, it is seen material properties are more effective parameters in the finite element model updating of plane frame. However, for brick in-filled frame changes in boundary conditions determine the model updating process.