• Title/Summary/Keyword: Space Evaluation

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A CONDITIONAL FOURIER-FEYNMAN TRANSFORM AND CONDITIONAL CONVOLUTION PRODUCT WITH CHANGE OF SCALES ON A FUNCTION SPACE I

  • Cho, Dong Hyun
    • Bulletin of the Korean Mathematical Society
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    • v.54 no.2
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    • pp.687-704
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    • 2017
  • Using a simple formula for conditional expectations over an analogue of Wiener space, we calculate a generalized analytic conditional Fourier-Feynman transform and convolution product of generalized cylinder functions which play important roles in Feynman integration theories and quantum mechanics. We then investigate their relationships, that is, the conditional Fourier-Feynman transform of the convolution product can be expressed in terms of the product of the conditional FourierFeynman transforms of each function. Finally we establish change of scale formulas for the generalized analytic conditional Fourier-Feynman transform and the conditional convolution product. In this evaluation formulas and change of scale formulas we use multivariate normal distributions so that the orthonormalization process of projection vectors which are essential to establish the conditional expectations, can be removed in the existing conditional Fourier-Feynman transforms, conditional convolution products and change of scale formulas.

Noncoherent Detection of Orthogonal Modulation Combined with Alamouti Space-Time Coding

  • Simon, Marvin K.;Wang, Ji-Bing
    • Journal of Communications and Networks
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    • v.5 no.2
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    • pp.124-134
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    • 2003
  • In this paper, we investigate the error probability performance of noncoherently detected orthogonal modulation combined with Alamouti space-time block coding. We find that there are two types of pair-wise error probabilities that characterize the performance. We employ methods that allow a direct evaluation of exact, closed-form expressions for these error probabilities. Theoretical as well as numerical results show that noncoherent orthogonal modulation combined with space-time block coding (STBC) achieves full spatial diversity. We derive an expression for approximate average bit error probability for-ary orthogonal signaling that allows one to show the tradeoff between increased rate and performance degradation.

Evaluation of thermal performance for solar cooling and heating system (태양열 냉.난방 및 급탕 시스템 열성능)

  • Kwak, Hee-Youl;Joo, Hong-Jin;Lee, Ho
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.203-208
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    • 2009
  • This paper presents demonstration study results derived through field testing of a solar assisted cooling and heating system for the library of a cultural center building located in Gwangju, Korea. The area of demanded cooling and heating for building was about 350m2. Solar hot water was delivered by means of a 200m2 array of evacuated tubular solar collector (ETSC) to drive a single-effect (LiBr/H2O) absorption chiller of 10RT nominal cooling capacity. From March in 2008 to February in 2009, demonstration test were performed for solar cooling and heating system. After experiments and analysis, this study found that solar thermal system was 84% for the solar hot water supply and 12% for space heating and 4% for space cooling.

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Pyramidal reaction wheel arrangement optimization of satellite attitude control subsystem for minimizing power consumption

  • Shirazi, Abolfazl;Mirshams, Mehran
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.2
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    • pp.190-198
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    • 2014
  • The pyramidal reaction wheel arrangement is one of the configurations that can be used in attitude control simulators for evaluation of attitude control performance in satellites. In this arrangement, the wheels are oriented in a pyramidal configuration with a tilt angle. In this paper, a study of pyramidal reaction wheel arrangement is carried out in order to find the optimum tilt angle that minimizes total power consumption of the system. The attitude control system is analyzed and the pyramidal configuration is implemented in numerical simulation. Optimization is carried out by using an iterative process and the optimum tilt angle that provides minimum system power consumption is obtained. Simulation results show that the system requires the least power by using optimum tilt angle in reaction wheels arrangement.

Impact control of redundant manipulators using null-space dynamucs

  • Chung, W.J.;Choi, S.L.;kim, I.H.;Chung, G.J.
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.89-94
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    • 1994
  • This paper presents an impact control algorithm for reducing the potentially damaging effects by interation of redundant manipulators with their environments. In the. proposed control algorithm, the redundancy is resolved at the torque level by locally minimizing joint torque, subject to tire operational space dynamic formulation which maps tire joint torque set into the operational forces. For a given pre-impact velocity of the manipulator, the proposed approach is on generating joint space trajectories throughout the motion near the contact which instantaneously minimize the impulsive force which is a scalar function of manipulator's configurations. This is done by using the null space dynamics which does not affect the motion of an end-effector. The comparative evaluation of the proposed algorithm with a local torque optimization algorithm without reducing impact is performed by computer simulation. The simulation results illustrate the effectiveness of the algorithm in reducing both the effects of impact and large torque requirements.

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Batch-Constructing of Multilevel Grid Files Using the Z-ordering Scheme (Z-순서화 기법을 이용한 계층 그리드 화일의 일괄 구성)

  • Kim, Sang-Wook
    • Journal of Industrial Technology
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    • v.16
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    • pp.247-256
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    • 1996
  • The multilevel grid file(MLGF) is a dynamic multidimensional file organization supporting multi-attribute accesses efficiently. The paper proposes new method for batch-constructing MLGFs. Our method consists of two phases. The first phase begins by relocating all the objects in order that logically adjacent objects in multidimensional domain space are clustered in one dimensional physical space. For this, our method employs the Z-ordering scheme, which effectively maps multidimensional space into one dimensional space preserving proximity. The second phase paginates the relocated objects and creates leaf level directory entries, each of which corresponds to a object page. Simultaneously, it performs same actions on the directory entries recursively in a bottom-up fashion until the root directory fits in a page. For performance evaluation, we analyze our method in terms of the number of page accesses. The result shows the optimality of our method.

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Use of Importance-Performance Analysis to Evaluate Open Space Environment functions in Taejon City (중요도(重要度)-성취도(成就度) 분석(分析)에 의한 대전시(大田市) 녹지환경(綠地環境) 기능(機能) 평가(評價))

  • Song, Hyung Sop
    • Korean Journal of Agricultural Science
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    • v.21 no.2
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    • pp.92-102
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    • 1994
  • This study examined Public Evaluation for functions of urban open space environment using a marketing strategy called Importance-Performance analysis. 12 main function attributes for urban open space environment were selected 150 respondents were sampled in Taejon city by personal interview. Ratings used mean values from a seven-point scale. Results were then graphically displayed on an easily interpreted two-dimensional 'Action Grid'. Generally Importance Ratings were high, but Performance Ratings were low relatively for various open space environment functions. In air pollution control function the difference was the most large. The results of rating scale analysis indicated repondents' sexual and residence period difference.

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The Probabilities and Entropies of HANGUL Elements including the sopace (공백소를 포함한 한글 자소발생 확률과 엔트로피)

  • 안수길;안지환
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.17 no.2
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    • pp.23-28
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    • 1980
  • The foundation of information theory mainly established by C. E. Shannon , opened the way to profuse studies on the linguistics of various languages. The statistics of Korean letters composed of elements and space are analyzed. The Korean alphabetic elements including the space have their probabilities . And information techniques can be applied to them. This paper extended the previous statistics of Korean letters to include the space. We have also calculated the entropies and redundancy for the case. The result can be used to modify the evaluation of Korean letter information processing devices and used as the basis for letter coding method for eventual future information processors.

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A Study on the Measurement of Spatial Density and Structural Characteristic Evaluation using Discrete Event Simulation (이산사건 시뮬레이션을 활용한 공간밀도측정 및 구조특성평가)

  • Yoon, So Hee;Kim, Gun A;Kim, Suk Tae
    • Journal of Korea Multimedia Society
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    • v.20 no.7
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    • pp.1090-1101
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    • 2017
  • This study analyzes spatial density and integration of Space Syntax and Discrete Event Simulation (DEVS) of complex system theory and analyzes spatial structure by property, type and depth. The aim of this study is to secure the validity of the theoretical application. The study evaluated the correlation between spatial density and integration by setting up eight types of analysis models. In addition, analyzed the correlation of structural characteristics and approached the application of discrete event simulation of spatial syntax theory. It is confirmed that the concept of integration of spatial syntax theory and analysis using discrete event simulation are valid as new spatial analysis methodology. Also expect that realistic and concrete predictions will be possible if discrete event simulation evolves into research for space allocation and space efficiency optimization.

Human Hand Detection Using Color Vision (컬러 시각을 이용한 사람 손의 검출)

  • Kim, Jun-Yup;Do, Yong-Tae
    • Journal of Sensor Science and Technology
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    • v.21 no.1
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    • pp.28-33
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    • 2012
  • The visual sensing of human hands plays an important part in many man-machine interaction/interface systems. Most existing visionbased hand detection techniques depend on the color cues of human skin. The RGB color image from a vision sensor is often transformed to another color space as a preprocessing of hand detection because the color space transformation is assumed to increase the detection accuracy. However, the actual effect of color space transformation has not been well investigated in literature. This paper discusses a comparative evaluation of the pixel classification performance of hand skin detection in four widely used color spaces; RGB, YIQ, HSV, and normalized rgb. The experimental results indicate that using the normalized red-green color values is the most reliable under different backgrounds, lighting conditions, individuals, and hand postures. The nonlinear classification of pixel colors by the use of a multilayer neural network is also proposed to improve the detection accuracy.