• Title/Summary/Keyword: improved complex method

Search Result 563, Processing Time 0.029 seconds

Effects of Viscoelastic Dampers on the Improvement of Torsional Response of Asymmetric Buildings (비대칭 건물의 거동 개선을 위한 점탄성 감쇠기의 활용에 관한 연구)

  • 김진구;방성혁;이진수
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2000.10a
    • /
    • pp.249-256
    • /
    • 2000
  • The visco-elastic dampers were used to improve the torsional responses of an asymmetric buildings. The modal characteristic equation of an asymmetric structure with added viscoelastic dampers were derived using the complex modal analysis method. Parametric study has been performed based on the modal characteristics, and the appropriate condition for compensating the stiffness eccentricity was investigated. According to the results the torsional response of the asymmetric buildings could be improved significantly once the dampers were properly placed

  • PDF

Reconstruction of 3D Brain Model using Curvature Information (곡률 정보를 이용한 뇌의 3차원 모델 구성)

  • An, Kwang-Ok;Jung, Hyun-Kyo
    • Journal of Biomedical Engineering Research
    • /
    • v.29 no.2
    • /
    • pp.146-150
    • /
    • 2008
  • In order to study cortical properties in human, it is necessary to obtain an accurate and explicit representation of the cortical surface in individual subjects. Among many approaches, surface-based method that reconstructs a 3-D model from contour lines on cross-section images is widely used. The conventional method detects match points of contours using the minimum straight distance between any pair of contour points which lie on different contours. Then, it generates a triangle strip. In general, however, it might yield small mismatches between contours in case of brain due to complex anatomical structures. In this paper, therefore, we present an improved method for tilting operation that uses the curvature values calculated from surface information. The usefulness of the proposed method has been verified using brain image.

An improved modal strain energy method for structural damage detection, 2D simulation

  • Moradipour, Parviz;Chan, Tommy H.T.;Gallag, Chaminda
    • Structural Engineering and Mechanics
    • /
    • v.54 no.1
    • /
    • pp.105-119
    • /
    • 2015
  • Structural damage detection using modal strain energy (MSE) is one of the most efficient and reliable structural health monitoring techniques. However, some of the existing MSE methods have been validated for special types of structures such as beams or steel truss bridges which demands improving the available methods. The purpose of this study is to improve an efficient modal strain energy method to detect and quantify the damage in complex structures at early stage of formation. In this paper, a modal strain energy method was mathematically developed and then numerically applied to a fixed-end beam and a three-story frame including single and multiple damage scenarios in absence and presence of up to five per cent noise. For each damage scenario, all mode shapes and natural frequencies of intact structures and the first five mode shapes of assumed damaged structures were obtained using STRAND7. The derived mode shapes of each intact and damaged structure at any damage scenario were then separately used in the improved formulation using MATLAB to detect the location and quantify the severity of damage as compared to those obtained from previous method. It was found that the improved method is more accurate, efficient and convergent than its predecessors. The outcomes of this study can be safely and inexpensively used for structural health monitoring to minimize the loss of lives and property by identifying the unforeseen structural damages.

A Case of Central Pontine Myelinolysis in a Chronic Alcoholic (만성 알콜중독증 환자에서 발생한 중심성 뇌교 수초용해증 치험 1례)

  • Kim, Soo-Yeon;Choi, Ga-Young;Sun, Seung-Ho
    • The Journal of Internal Korean Medicine
    • /
    • v.30 no.3
    • /
    • pp.639-647
    • /
    • 2009
  • Objective : This study was case report to show the good effects of herbal medicine (Daekumeum-ja) and acupuncture complex therapy for central pontine myelinolysis (CPM). Method : A 44-year-old man suffering from CPM was chronic alcoholic without electrolyte disturbance. He showed symptoms of dysarthria, dysphagia, dizziness, weakness of lower extremities and gait disturbance. CPM was diagnosed at his former hospital by MR imaging. He had no positive response to western treatments. We treated the patient with herbal extract (Daekumeum-ja) and acupuncture. Results : After our treatments, there was no change of Brain CT. But overall symptoms of CPM were improved. Conclusion : This study suggests that herbal medicine (Daekumeum-ja) and acupuncture complex therapy is probably effective in the treatment of CPM.

  • PDF

Complex Agent for low alkalinity Deinking process of ONP (알칼리 저감형 신문지용 복합 탈묵제)

  • Yoon Kyoung-Dong;Park Heon- Sin;Kang Yun-Seog;Eom Tae-Jin
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
    • /
    • 2006.11a
    • /
    • pp.9-14
    • /
    • 2006
  • Deinking is a series of unit operations designed to detach ink from cellulose fibers and separate the dispersed ink from the pulp slurry. Deinking chemicals are process aids that enable expensive mill equipment used in these unit operations to operate more efficiently. This paper presents an overview of ONP deinking efficiency with cellulolytic enzymes and synthetic collector in low alkalinity process. The deinking efficiency of old news print even in low alkalinity condition was enhanced with enzyme contained complex agent. The brightness of deinked pulp was increased with less residual ink particles and yield of deinked pulp was improved compared to the deinked pulp of conventional alkaline method.

  • PDF

Low Temperature Dyeing Process by Intercellular diffusion through Cell Membrane Complex Modification of Wool. - Technology based on CSIRO and ICI (양모의 저온 염색 소개 - Sirolan LTD Process from ICI)

  • 윤일남
    • Proceedings of the Korean Society of Dyers and Finishers Conference
    • /
    • 2001.11a
    • /
    • pp.3-11
    • /
    • 2001
  • Fundamental studies at the CSIRO division of Wool technology and ICI on the diffusion of dyes into wool〔1,2〕have let to development of a new approach to wool dyeing. In this method, the cell membrane complex of wool is modified before dyeing by treatment under mildly alkaline conditions with a special chemicals. Wool pretreated with ethoxylated quaternary ammonium salt has an increased rate of dyebath exhaustion and dye penetration early in the dyeing cycle. This enables the treated material to be dyed below the boil for a similar time to the conventional cycle. This technique can be used on untreated and shrinkresist-treated wool and wool/nylon blends. In addition to good macro-levelness and excellent coverage of tippiness, the low temperature dyeing process give higher exhaustion levels of dyestuffs and insect-resist agent and hence cleaner effluent liquors, compared with conventional dyeing process. Low Temperature Dyeing process cause significantly less fiber damage than conventional way. The reduction in damage is reflected in improved processing performance of the dyed wool.

  • PDF

The Study on The Complex Composition By SFCL and Power Equipments for Fault Detection in HVDC Line (HVDC 선로 내 초전도 한류기와 전력기기들의 복합 구성을 통한 고장 검출에 관한 연구)

  • Kim, Myong-Hyon;Kim, Jae-Chul
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.67 no.8
    • /
    • pp.1113-1118
    • /
    • 2018
  • Protection in HVDC(High Voltage Direct Current) have the very fast velocity of fault detection. Because Fault in HVDC has the fast propagation, large currents, high interruption cost. The focus to velocity caused possibility of errors like a detection error like a high impedance fault. In this paper, Proposed complex composition for get the reliability and velocity. That used SFCL(Super Conducting Fault Current Limiter), Protection Zone and DTS(Distributed Temperature Sensing). The SFCL was detect the fault by quench and DTS&Protection Zone were perceive the detect by variation too. To examine the proposed method, PSCAD/EMTDC simulated. The results of simulation, proposed methods could the detect of fault to whole HVDC line. And that improved the reliability of fault clearing.

Numerical investigation of flow structures and aerodynamic pressures around a high-speed train under tornado-like winds

  • Simin Zou;Xuhui He;Teng Wu
    • Wind and Structures
    • /
    • v.38 no.4
    • /
    • pp.295-307
    • /
    • 2024
  • The funnel-shaped vortex structure of tornadoes results in a spatiotemporally varying wind velocity (speed and direction) field. However, very limited full-scale tornado data along the height and radius positions are available to identify and reliably establish a description of complex vortex structure together with the resulting aerodynamic effects on the high-speed train (HST). In this study, the improved delayed detached eddy simulation (IDDES) for flow structures and aerodynamic pressures around an HST under tornado-like winds are conducted to provide high-fidelity computational fluid dynamics (CFD) results. To demonstrate the accuracy of the numerical method adopted in this study, both field observations and wind-tunnel data are utilized to respectively validate the simulated tornado flow fields and HST aerodynamics. Then, the flow structures and aerodynamic pressures (as well as aerodynamic forces and moments) around the HST at various locations within the tornado-like vortex are comprehensively compared to highlight the importance of considering the complex spatiotemporal wind features in the HST-tornado interactions.

Off-line Handwritten Digit Recognition by Combining Direction Codes of Strokes (획의 방향 코드 조합에 의한 오프라인 필기체 숫자 인식)

  • Lee Chan-Hee;Jung Soon-Ho
    • Journal of KIISE:Software and Applications
    • /
    • v.31 no.12
    • /
    • pp.1581-1590
    • /
    • 2004
  • We present a robust off-line method recognizing handwritten digits by only using stroke direction codes as a feature of handwritten digits. This method makes general 8-direction codes for an input digit and then has the multi-layered neural networks learn them and recognize each digit. The 8-direction codes are made of the thinned results of each digit through SOG*(Improved Self-Organizing Graph). And the usage of these codes simplifies the complex steps processing at least two features of the existing methods. The experimental result shows that the recognition rates of this method are constantly better than 98.85% for any images in all digit databases.

K-band Predistortive Linearizer of Reflective Diode Structure for Satellite TWTA Using Carrier Complex Power Series (Carrier Complex Power Series를 이용한 K-대역 위성 TWTA용 반사형 다이오드 구조의 전치왜곡 선형화기)

  • Jeong Hee-Young;Jeong Yong-Chae;Yom In-Bok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.16 no.6 s.97
    • /
    • pp.644-651
    • /
    • 2005
  • In this paper, a new predistortion method to reduce nonlinearity or a traveling wave tube amplifiers(IWTAs) is proposed. Nonlinear transfer characteristics of TWTA are analyzed using carrier complex power series. Inverse carrier complex power series or a predistortion linearizer to linearizer TWTA are also proposed. The inverse nonlinear distortion characteristics of predistorter can be realized with reflective structure that is composed of Schottky diode and resistive-terminated transmission line. The AM-to-AM and the AM-to-PM characteristics for TWTA by proposed predistortive linearizer on K-band were improved from -5.825 dB and -37.321^{\circ} to 0.786 dB and 6.742^{\circ}, respectively.