• Title/Summary/Keyword: discontinuous surface

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Bond characteristics by joint condition between old and. new concrete (신ㆍ구 콘크리트의 접합면 조건에 다른 부착특성)

  • 주봉철;김영진;김병석;박성룡;김덕진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.859-864
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    • 2003
  • In these days, the deterioration of bridges make it necessary for decks to be replaced and it is inevitable to apply the precast decks to minimize the traffic control induced from the deck placement. This precast deck construction makes the physically discontinuous interface between old and new concrete. Usually, the adhesive force at this interface are ignored. However, for crack behavior and reliable long term behavior, it is required to evaluate the exact value of the cohesive force at the interface. This research investigates the cohesive characteristics at the interface. Four different interface surface conditions are tested and three different methods are used to measure the cohesive strength at the interface. In addition, cohesive characteristic at the surface between precast panels are investigated with different interface surface conditions.

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A Study on Inlet Pressure Build-up of Air-Lubricated Bearings (공기베어링에서의 선단압력발생에 관한 연구)

  • 김성국;김경웅
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.06a
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    • pp.127-132
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    • 1999
  • The inlet pressure build-up at the leading edge of bearings which have discontinuous lubrication surface is analyzed theoretically. The analyses of Inlet pressure build-up is obtained by means of full Navier-stokes equations. Beam-warming method is used to solve navier-stokes equations. The results show that inlet pressure is above atmosphere pressure in front of leading edge of hearing.

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Current distribution of a conducting body of revolution includig discontinuous surface (불연속면을 포함하고 있는 회전형 완전도체의 전류분포특성)

  • 김경언
    • Proceedings of the Optical Society of Korea Conference
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    • 1990.02a
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    • pp.29-33
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    • 1990
  • Efficient numerical method is developed for treating electromagnetic problems of scattering and radiation from surfaces. Special consideration is given to the treatment of edges so that rather arbitrary geometrical configurations may be handled. For the conducting body problems considered, an electric field integral formulation is used, and the method of moments is applied using pulse expantions to present currents. Numerial results indicate that the approach is free os anomalies in the behavior of current for body of revoution.

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The Stress Distribution in a Long Circular Cylinder under a Discontinuous Boundary Conditions on the Curved Surface (곡면상에 불연속경계조건을 간는 원주의 응력분포)

  • Lee, Doo-Sung
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.2 no.2
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    • pp.38-41
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    • 1978
  • 이 논문에서는 표면의 일부에 기지의 압력을 밥는 긴 원주내의 응력분포를 구하는 문제를 고찰하였다. 문제를 혼합경계치조건에서 발생되는 쌍적분방정식의 해를 구하는 문제로 간단히 한후에 제 2종 Fredholm 적분방정식을 해결하는 문제로 하였다. 이 적분방정식의 수직해를 전자계산기에 의하여 구한 다음 도시하였다.

Range Image Segmentation Based on Polynomial Function Approximation (다항식 함수 근사화에 근거한 거리 영상 분할)

  • 임영수;조택일;박규호
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.9
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    • pp.1448-1455
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    • 1990
  • In this paper, a range image segmentation method is proposed. This method consists of an initial segmentation stage by discontinuous edge detection and surface type labeling based on the sign of the principal curvatures. Initially type labeled image is oversegmented, this image is merged via stepwise optimal region merging stage based on polynomial function approxiamtion. The successful segmentation results are presented for two synthetic range images with noise and a real-world ERIM range image.

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Numerical Simulation of Dam-Break Problem Using SU/PG Scheme (SU/PG 기법을 이용한 댐붕괴 수치모의)

  • Seo, Il Won;Song, Chang Geun
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.198-198
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    • 2011
  • The numerical simulation of dam break problem suffers from several challenges in terms of accuracy, stability, and versatility of the simulation algorithm since the water flow is generally discontinuous and presents abrupt variations. Thus, to obtain stable and accurate solutions, flow models for this purpose require numerical schemes provided with shock-capturing properties, and with the ability to work with flexible two-dimensional meshes. In this context, SU/PG method(Hughes and Brooks, 1979) is excellent candidate for the solution of the dam break problem. The weak formulation of the equations and the discontinuous polynomial basis lead to an accurate representation of bore waves(shocks). Furthermore, the discretization of the domain in finite elements is extremely effective in modeling complex geometries. In this study, a finite element model based on the SU/PG scheme is developed to solve shallow water equations and the model is applied to dam break problem. It is found that the present model accurately captures the bore wave that propagates downstream while spreading laterally and the depression wave that moves upstream. Furthermore, the propagation and formation of water surface profile compared favorably with those obtained by the previously published results.

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The Machinability of 2011 P/M Al Alloys Extruded Rapidly solidified by Rotating Disc Atomization (원심 분부법으로 제조된 P/M 2011 Al 합금 압출재의 절삭성)

  • Jeon, Chang-Bae;Kim, Jong-Chan
    • Korean Journal of Materials Research
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    • v.8 no.7
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    • pp.641-647
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    • 1998
  • The machinability properties of P/M 2011 AI alloys extruded rapidly solidified by rotating disc atomization were investigated in this study. The Pb-Bi particles were very uniformly and finely dispersed in the P/M 2011 AI alloys extruded rapidly solidified. According to the increase of cutting speed, the short discontinuous chips were produceed and continuous chips were formed from the lower feed values of O.lmm/rev. The surface roughness is depend on the feed values, not cutting depth and cutting speed. The short discontinuous chips were formed due to dispersed $AI_20_3$ particles and Pb- Bi inclusion.

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Robust Vibration Control of Smart Structures via Discrete-Time Fuzzy-Sliding Modes (이산시간 퍼지-슬라이딩모드를 이용한 스마트구조물의 강건진동제어)

  • Choi, Seung-Bok;Kim, Myoung-Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.11
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    • pp.3560-3572
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    • 1996
  • This paper presents a new discrete-time fuzzy-sliding mode controller for robust vibration control of a smart structure featuring a piezofilm actuator. A governong equation of motion for the smart beam structure is derived and discrete-time codel with mismatched uncertainties such as parameter variations is constructed ina state space. A discrete-time sliding mode control system consisting of an equivalent controller and a discontinuous controller is formulated. In the design of the equivalent part, so called an equivalent controller separation method is adopted to achieve vzster convergence to a sliding surface without extension of a sliding region, in which the system robustness maynot be guaranteed. On the other hand, the discontinuous part is constructed on the basis of both the sliding and the convergence conditions using a time-varying feedback gain. The sliding moide controller is then incorporated with a fuzzy technique to appropriately determine principal control parameters such as a discountinuous feedback gain. Experimental implementation on the forced and random vibraiton controls is undertaken in order to demonstrate superior control performance of the proposed controller.

In silico Design of Discontinuous Peptides Representative of B and T-cell Epitopes from HER2-ECD as Potential Novel Cancer Peptide Vaccines

  • Manijeh, Mahdavi;Mehrnaz, Keyhanfar;Violaine, Moreau;Hassan, Mohabatkar;Abbas, Jafarian;Mohammad, Rabbani
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5973-5981
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    • 2013
  • At present, the most common cause of cancer-related death in women is breast cancer. In a large proportion of breast cancers, there is the overexpression of human epidermal growth factor receptor 2 (HER2). This receptor is a 185 KDa growth factor glycoprotein, also known as the first tumor-associated antigen for different types of breast cancers. Moreover, HER2 is an appropriate cell-surface specific antigen for passive immunotherapy, which relies on the repeated application of monoclonal antibodies that are transferred to the patient. However, vaccination is preferable because it would stimulate a patient's own immune system to actively respond to a disease. In the current study, several bioinformatics tools were used for designing synthetic peptide vaccines. PEPOP was used to predict peptides from HER2 ECD subdomain III in the form of discontinuous-continuous B-cell epitopes. Then, T-cell epitope prediction web servers MHCPred, SYFPEITHI, HLA peptide motif search, Propred, and SVMHC were used to identify class-I and II MHC peptides. In this way, PEPOP selected 12 discontinuous peptides from the 3D structure of the HER2 ECD subdomain III. Furthermore, T-cell epitope prediction analyses identified four peptides containing the segments 77 (384-391) and 99 (495-503) for both B and T-cell epitopes. This work is the only study to our knowledge focusing on design of in silico potential novel cancer peptide vaccines of the HER2 ECD subdomain III that contain epitopes for both B and T-cells. These findings based on bioinformatics analyses may be used in vaccine design and cancer therapy; saving time and minimizing the number of tests needed to select the best possible epitopes.

Position Control of DC Motor Using the Sliding Mode Control with Distur bance Ovserver (외란 관측기를 가지는 슬라이딩 모드 제어를 사용한 직류 전동기의 위치 제어)

  • 문용기;이정훈;이대식;이주장;윤명중
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.41 no.2
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    • pp.135-143
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    • 1992
  • A novel sliding mode control with disturbance observer for position control of DC servo motor is presented. The conventional sliding mode controller changes the control structure depending on the state of switching surface and consequently, the control law is discontinuous and theoretically chatters at an infinite frequency. To overcome this problem in view of the practical implementation, the disturbance observer is used to compensate the effects of the parameter variations and the load disturvances. We can obtain the performance predetermined by the switching surface with continuous control law while the controlled system remains robust. The performance of the proposed controller with that of the conventional sliding mode controller through digital computer simulation and experiment.