• 제목/요약/키워드: absolute terms

검색결과 375건 처리시간 0.023초

이미지 검색을 위한 칼라 분포 기술자의 성능 평가 (An Empirical Evaluation of Color Distribution Descriptor for Image Search)

  • 이춘상;이요환;김영섭;이상범
    • 반도체디스플레이기술학회지
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    • 제5권2호
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    • pp.27-31
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    • 2006
  • As more and more digital images are made by various applications, image retrieval becomes a primary concern in technology of multimedia. This paper presents color based descriptor that uses information of color distribution in color images which is the most basic element for image search and performance of proposed visual feature is evaluated through the simulation. In designing the image search descriptor used color histogram, HSV, Daubechies 9/7 and 2 level wavelet decomposition provide better results than other parameters in terms of computational time and performances. Also histogram quadratic matrix outperforms the sum of absolute difference in similarity measurements, but spends more than 60 computational times.

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지능 접속을 위한 인체 운동 포착 및 재현 시스템 (A motion capture and mimic system for intelligent interactions)

  • 윤중선
    • 제어로봇시스템학회논문지
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    • 제5권5호
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    • pp.585-592
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    • 1999
  • A new paradigm of technology, based on the overall interactions of technology, human and environment, is explored. History of technology and machines is reviewed in terms of the interactions of human and machines. Two main concepts of intelligent interactions proposed, holism and embodiment, are based on the interactions of machines and human through human body : Korperlichkeit ( corporeality). Human body movements are the result of long periods of evolution and, thus, are very optimized motions. Complicated and flexible motions could be easily achieved by mimicking human body movements. Motion capture and mimic systems based on the electromagnetic, visual, and gyroscopic type trackers, are being implemented to demonstrate these concepts. Also, various motion mappings are investigated on these interactive systems. By exploring a new paradigm of technology through Korperlichkeit, an oriental view of technology as relativities may evolve to embrace the limitations of western view of machines as an absolute independent form.

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Haptic Friction Display of a Hybrid Active/Passive Force Feedback Interface

  • An, Jin-Ung;Kwon, Dong-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1673-1678
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    • 2005
  • This paper addresses both theoretical and experimental studies of the stability of haptic interfaces during the simulation of virtual Coulomb friction. The first objective of this paper is to present an analysis of how friction affects stability in terms of the describing function method and the absolute stability theory. Two different feedback methods are introduced and are used to evaluate the analysis: an active force feedback, using a motor, and a passive force feedback, using controllable brake. The second objective of this paper is to present a comparison of the theoretical and experimental results. The results indicate that the sustained oscillations due to the limit cycle occur when simulating friction with an active force feedback. In contrast, a passive force feedback can simulate virtual friction without the occurrence of instability. In conclusion, a hybrid active/passive force feedback is proposed to simulate a highly realistic friction display.

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식료품 소비구조의 분석 -소득을 중심으로(1975~1985년)- (An Analysis of the Food consumption Expenditure Patterns: 1975~1985)

  • 김미향
    • 대한가정학회지
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    • 제26권1호
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    • pp.109-122
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    • 1988
  • This study attempts to analyse the food consumption expenditure patterns of wage-Earner's Households n terms of the changes in income during 1975∼1985. For the purpose of these time-series analysis and cross-section analysis, household survey data 'Annual Report on the Family Income and Expenditure Survey'- was used. The main results can be summarized as follows : 1. The proportion of the food expenditures has decreased with the increased of income in the city families during 1975∼1985. The Income-Elasticity and limit spending habits has decreased with the increase of income in the city families during 1975∼1985. 2. Analyzing the structure of the food consumption of each income class, the results reflected the Engel's law. That is to say, the higher income was, the more absolute expense for food was, but the rate of it was.

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Stochastic optimum design of linear tuned mass dampers for seismic protection of high towers

  • Marano, Giuseppe Carlo;Greco, Rita;Palombella, Giuseppe
    • Structural Engineering and Mechanics
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    • 제29권6호
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    • pp.603-622
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    • 2008
  • This work deals with the design optimization of tuned mass damper (TMD) devices used for mitigating vibrations in high-rise towers subjected to seismic accelerations. A stochastic approach is developed and the excitation is represented by a stationary filtered stochastic process. The effectiveness of the vibration control strategy is evaluated by expressing the objective function as the reduction factor of the structural response in terms of displacement and absolute acceleration. The mechanical characteristics of the tuned mass damper represent the design variables. Analyses of sensitivities are carried out by varying the input and structural parameters in order to assess the efficiency of the TMD strategy. Variations between two different criteria are also evaluated.

NUMERICAL SOLUTION FOR WOOD DRYING ON ONE-DIMENSIONAL GRID

  • Lee, Yong-Hun;Kang, Wook;Chung, Woo-Yang
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제11권1호
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    • pp.95-105
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    • 2007
  • A mathematical modeling for the drying process of hygroscopic porous media, such as wood, has been developed in the past decades. The governing equations for wood drying consist of three conservation equations with respect to the three state variables, moisture content, temperature and air density. They are involving simultaneous, highly coupled heat and mass transfer phenomena. In recent, the equations were extended to account for material heterogeneity through the density of the wood and via the density variation of the material process, capillary pressure, absolute permeability, bound water diffusivity and effective thermal conductivity. In this paper, we investigate the drying behavior for the three primary variables of the drying process in terms of control volume finite element method to the heterogeneous transport model on one-dimensional grid.

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유압 서보 시스템의 속도 제어를 위한 적응제어기의 설계에 관한 연구 (An adaptive control algorithm for the speed control of hydraulic-servo system)

  • 윤지섭;조형석
    • 한국정밀공학회지
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    • 제3권1호
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    • pp.29-39
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    • 1986
  • An adaptive controller which is robust to the unknown load disturbance is developed for electro-hydraulic speed control systems. Since the load disturbance degrades the performance of the controller such as a steady state error and rise time in the conventional control system, appropriate adjustment of the controller is necessary in order to obtain the desired performances. The adaptation mechanism was designed to tune the feedforward gain, based upon minimization of ITAE (integral of time-multiplied absolute error) performance. The unknown load distrubance was identified by using an analog computer from the relationship between the velocity of the hydraulic motor and the load pressure. To evaluate the performance of the controller a series of simulations and experiments were conducted for various load conditions. Both results show that the proposed adaptive controller shows abetter performance than the conventional controller in terms of the steady state error and rise time.

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Self-Calibration of High Frequency Errors of Test Optics by Arbitrary N-step Rotation

  • Kim, Seung-Woo;Rhee, Hyug-Gyo
    • International Journal of Precision Engineering and Manufacturing
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    • 제1권2호
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    • pp.115-123
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    • 2000
  • We propose an extended version of multi-step algorithm of self-calibration of interferometric optical testing instruments. The key idea is to take wavefront measurements with near equal steps in that a slight angular offset is intentionally provided in part rotation. This generalized algorithm adopts least squares technique to determine the true azimuthal positions of part rotation and consequently eliminates calibration errors caused by rotation inaccuracy. In addition, the required numbers of part rotation is greatly reduced when higher order spatial frequency terms are of particular importance.

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ON NONLINEARITY AND GLOBAL AVALANCHE CHARACTERISTICS OF VECTOR BOOLEAN FUNCTIONS

  • Kim, Wan-Soon;Hwang, Hee-Sung
    • Journal of applied mathematics & informatics
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    • 제16권1_2호
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    • pp.407-417
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    • 2004
  • It is well known that the nonlinearity of vector Boolean functions F on n-dimensional vector space $GF(2)^n$ to $GF(2)^m$ is bounded above by $2^{n-1} - 2 ^{\frac{n}{2}-1}$. In this paper we derive upper bounds and a lower bound on the nonlinearity of vector Boolean functions in terms of auto-correlations. Strengths and weaknesses of each bounds are examined. Also, we modify the notions of the sum-of-square indicator and absolute indicator for Boolean functions to the case of vector Boolean functions to measure global avalanche characteristics of vector Boolean functions. Using those indicators we compare the global avalanche characteristics of DES (Data Encryption System) and Rijndael.

세포페라존피바로일옥시메칠에스텔의 유-수 계면 이행에 관한 연구 (Oil-Water Interface Transfer of Cefoperazone Pivaloyloxymethyl Ester)

  • 최영욱;김종갑
    • Journal of Pharmaceutical Investigation
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    • 제19권1호
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    • pp.21-27
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    • 1989
  • Kinetic and thermodynamic aspects of the interface transfer of cefoperazone and its pivaloyloxymethyl ester were studied in a two-phase system composed of aqueous buffers and n-octanol by using the absolute reaction rate theory. In terms of the net thermodynamic parameters for the process, ${\Delta}S$ increased and ${\Delta}F$ decreased as the lipophilicity increased. With the increased ratio of forward $(k_f)$ to backward rate constants $(k_b)$, the ester was more lipophilic than cefoperazone, but the aqueous solubility was reduced.

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