• Title/Summary/Keyword: boundary characteristics

Search Result 3,206, Processing Time 0.033 seconds

The character classifier using circular mask dilation method (원형 마스크 팽창법에 의한 무자인식)

  • 박영석;최철용
    • Proceedings of the IEEK Conference
    • /
    • 1998.06a
    • /
    • pp.913-916
    • /
    • 1998
  • In this paper, to provide the robustness of character recognition, we propose a recognition method using the dilated boundary curve feature which has the invariance characteristics for the shift, scale, and rotation changes of character pattern. And its some characteristics and effectieness are evaluated through the experiments for both the english alphabets and the numeral digits. The feature vector is represented by the fourier descriptor for a boundary curve of the dilated character pattern which is generated by the circular mask dilation method, and is used for a nearest neighbort classifier(NNC) or a nearest neighbor mean classifier(NNMC). These the processing time and the recognition rate, and take also the robustness of recognition for both some internal noise and partial corruption of an image pattern.

  • PDF

Estimation of the Heat Budget Parameter in the Atmospheric Boundary Layer considering the Characteristics of Soil Surface (지표면의 특성을 고려한 대기경계층내의 열수지 parameter 추정 -열수지 parameter를 이용한 중규모 순환의 수치예측-)

  • 이화운;정유근
    • Journal of Environmental Science International
    • /
    • v.5 no.6
    • /
    • pp.727-738
    • /
    • 1996
  • An one dimensional atmosphere-canopy-soil interaction model is developed to estimate of the heat budget parameter in the atmospheric boundary layer. The canopy model is composed of the three balance equations of energy, temperature, moisture at ground surface and canopy layer with three independent variables of Tf(foliage temperature), Tg(ground temperature), and qg(ground specific humidity). The model was verilied by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HAPEX-MOBILHY experiment. Also we applied this model in two dimensional land-sea breeze circulation. According to the results of this study, surface characteristics considering canopy acted importantly upon the simulation of meso-scale circulation. The factors which used in the numerical experiment are as follows ; the change for a sort of soil(sand and peat), the change for shielding factor, and the change for a kind of vegetation.

  • PDF

Vehicle Dynamic Analysis Using Virtual Proving Ground Approach

  • Min, Han-Ki;Park, Gi-Seob;Jung, Jong-An;Yang, In-Young
    • Journal of Mechanical Science and Technology
    • /
    • v.17 no.7
    • /
    • pp.958-965
    • /
    • 2003
  • Structural integrity of either a passenger car or a light truck is one of the basic requirements for a full vehicle engineering and development program. The results of the vehicle product performance are measured in terms of ride and handling, durability, noise/vibration/harshness (NVH), crashworthiness and occupant safety. The level of performance of a vehicle directly affects the marketability, profitability and, most importantly, the future of the automobile manufacturer In this study, we used the virtual proving ground (VPG) approach for obtaining the dynamic characteristics. The VPG approach uses a nonlinear dynamic finite element code (LS-DYNA3D) which expands the application boundary outside the classic linear static assumptions. The VPG approach also uses realistic boundary conditions of tire/road surface interactions. To verify the predicted dynamic results, a single lane change test has been performed. The prediction results were compared with the experimental results, and the feasibility of the integrated CAE analysis methodology was verified.

Steady Aerodynamic Characteristics of a Wing Flying Over a Nonplanar Ground Surface Part I : Rail

  • Han Cheol-Heui;Kim Hak-Ki;Cho Jin-Soo
    • Journal of Mechanical Science and Technology
    • /
    • v.20 no.7
    • /
    • pp.1043-1050
    • /
    • 2006
  • The aerodynamic interaction between a wing and a rail is investigated using a boundary-element method. The source and doublet singularities are distributed on the wing and its guide-way rail surface. The unknown strengths of the singularities are determined by inverting the aerodynamic influence coefficient matrices. Present method is validated by comparing computed results with the other numerical data. Rail width and rail height affect the aerodynamic characteristics of the wing only if the rail is narrower than the wing span. Although the present results are limited to the inviscid, irrotational flows, it is believed that the present method can be applied to the conceptual design of the high speed ground transporters moving over the rail.

Some Prosodic Characteristics in Apraxia - From a visual task point of view - (실행증 환자의 운율적 특성 연구 - 시각과제 중심으로 -)

  • Kim Sujung
    • Proceedings of the KSPS conference
    • /
    • 2003.10a
    • /
    • pp.125-127
    • /
    • 2003
  • The aim of the paper is to analyze prosodic characteristics in apraxia of speech and establish the fundamental sources in diagnosis of motor speech disorders. The sentences consist of two different types (declarative and interrogative) with different numbers of constituents which are one to three. The stimuli were constructed to assess apraxics speech with articulation and humming skills. The features of speech patterns were examined such as utterance duration, boundary tones, and etc. The results of the analysis are as follow: 1) In the interrogative sentences, the rising boundary tones appeared only in the humming tasks 2) the utterance duration is relatively shorter in the humming tasks than the speech with articulation.

  • PDF

Parameter Study for Long-Span Bridge of High-Speed Railway considering CWR Axial Force (장대레일 축력을 고려한 고속철도 특수교량의 변수별 분석)

  • Lee, Jong-Soon;Cho, Soo-Ik;Park, Man-Ho;Joo, Hwan-Joong;Nam, Hyoung-Mo
    • Proceedings of the KSR Conference
    • /
    • 2010.06a
    • /
    • pp.1452-1459
    • /
    • 2010
  • Application of long-span bridge, which is affected by parameters such as span length, shoe boundary condition, track property and stiffness of superstructure and substructure etc., can vary. Especially, by CWR aspects of the axial force, that can be less constraints of construction depending on whether the application of rail expansion joint(REJ), which has disadvantaged in terms of maintenance. In this study, it was performed parameter study for multiple variables (shaft length, the upper and lower cross-section characteristics, track characteristics, etc.) in terms of CWR aspects. Structure-rail interaction analysis was applied to the typical simple span PSC Box and 3 span continuous bridge Extradosed Bridge(50m+80m+50m) excluding REJ. If you set the boundary e of variables for long-span railway bridge excluding REJ through the this study, when designing future is expected to be able to useful.

  • PDF

Local Heat Transfer Characteristics in the Wake Region of a Circular Cylinder (원형 실린더 후류 영역의 국소 열전달 특성)

  • Chang Byong Hoon
    • Journal of Energy Engineering
    • /
    • v.14 no.1
    • /
    • pp.30-36
    • /
    • 2005
  • This paper reports the experimental study of the heat transfer characteristics of the wake region behind a cylinder in cross flow. Local heat transfer coefficient was measured from the stagnation point (θ=0°) to 180°, and the variation of Nu in the axial direction along the cylinder was also studied. The results show that the heft transfer rate at the rear (θ=180°) near the duct wall can increase as much as 58% over the 2 dimensional value at the center of the duct. The heat transfer profiles in the wake region also show distinct effects of the aspect ratio and the heat transfer boundary condition.

An Analysis of Vibration and Sound Radiation of Sandwich Panels Using the Rayleigh-Ritz Method (Rayleigh-Ritz법을 이용한 샌드위치 패널의 진동 및 소음방사 특성 분석)

  • Kim, Dong-Kyu;Kim, Jae-Hyun;Jeon, Jin-Yong;Park, Jun-Hong
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.21 no.5
    • /
    • pp.430-436
    • /
    • 2011
  • The purpose of this study is to analyze the vibration and sound generation characteristics of the sandwich panel. Two thick panels were assumed to be separated by a compliant viscoelastic core. The transverse vibration induced by an external impact was analyzed using the Rayleigh-Ritz method. For applying arbitrary boundary condition of the panels, the edges were assumed to be supported by the translational and rotational springs. The beam functions were used as the trial functions. The effect of the boundary condition and viscoelastic core on the resulting vibration characteristics was investigated. The radiated sound power was analyzed using the proposed numerical model and the Rayleigh integral. The dynamic properties of the core and the mass-stiffness-mass resonance frequency had significant influence on the impact sound.

An Image Enhancement Algorithm for Panoramic Infrared Images (파노라믹 적외선 영상에서의 영상 향상 기법)

  • 김영춘;이종원;김병주;권기구;김기홍;신용달;안상호
    • Journal of Korea Multimedia Society
    • /
    • v.6 no.6
    • /
    • pp.977-984
    • /
    • 2003
  • In this paper, we propose an image enhancement algorithm for panoramic infrared image. This method divides a panoramic infrared image into disjoint subimages and performs the contrast stretch for subimages using statistical characteristics of each subimage. But these cause blocking artifact in boundary regions of neighboring subimages which different to the statistical characteristic. To remove blocking artifact, we perform the contrast stretch for subimage's boundary regions using statistical characteristics of horizontally neighboring subimages. Experimental results show that the proposed method effectively improves their appearance to human viewers.

  • PDF

Analysis of Acoustic Noise Characteristics of Jindo-Cheju HVDC (진도-제주 HVDC 변환설비 소음특성 분석)

  • Kim, Jae-Han;Kim, Chan-Ki;Lee, Seong-Doo;Kim, Jin-Young
    • Proceedings of the KIPE Conference
    • /
    • 2010.07a
    • /
    • pp.574-576
    • /
    • 2010
  • HVDC converter station consists of a number of noise sources such as converter transformer, ac filter, cooling system and so on. In this paper, we analyzed the simulation results of the outdoor acoustic noise characteristics for HVDC converter station. It shows that maximum noise level in boundary of HVDC converter station exceeds regulation value. The main factors in generating maximum noise level are ac filter and converter transformer. Then we applied some soundproof countermeasure in HVDC converter station. Shielding wall is enough to reduce transformer noise level but not enough to reduce ac filter noise level. In case of ac filter, soundproof building is effective in satisfying noise level regulation in boundary of HVDC converter station. In addition, we also studied effects of season, soundproof woods, ground.

  • PDF