• Title/Summary/Keyword: space-time correlation

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A Critical Study about the Correlation between the Body without Organ and Blurring Boundary Fashion - Focusing on Philosophical and Sociological Discourses about the Body and the Desire - (기관 없는 신체와 탈영토화 된 패션 사이의 상관관계에 대한 비판적 고찰 - 철학적, 사회학적 신체 담론과 욕망이론을 중심으로 -)

  • Yang, Hee-Young;Lee, Myung-Hee
    • The Research Journal of the Costume Culture
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    • v.18 no.5
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    • pp.824-841
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    • 2010
  • In 21st century, subordinated relationship of fashion from the body has been disappearing, and fashion is understood as variable and creative field. This research aims at analysis about the relationship between the body and fashion depending on the theories about the authority and the desire. So, this utilizes between theoretical study and empirical analysis. For concentrated study, research period limits from 2000 to the present time 2010. Contemporary body and fashion have being changed into various forms and values, become complex and de-territory. Especially, body is symbol of ambivalence eroticism that gives point to sexual property, and the object of fetishism and machine having a desire. This study's purpose draw a parallel with between the limits of contemporary body that couldn't be rid of the capital and desire, and the liberty of fashion that escape from the body's influence has being changed independent and fluid space. This research's results are as follow as; contemporary de-territory fashion is expressed as 1) symbol of the object and physical material property, 2) self-transcendental instrument fashion, 3) independent spatial molding, 4) de-centering fashion.

An Antenna Selection and Switching System Robust to Spatially Correlated Channel (공간적 상관도가 존재하는 채널에 강인한 다중안테나 선택 및 스위칭 시스템)

  • 심세준;박승일;이학주;이충용
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.7
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    • pp.55-61
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    • 2004
  • This paper proposes an antenna selection and switching system between spatial multiplexing and diversity techniques. The proposed system overcomes spatial correlation by using antenna selection method and improve bit error performance with switching encoding nudes between a spatial multipexing encoder and a diversity encoder. Therefore, in a 4 transmit and 2 receive antenna system first, the proposed system selects 2 transmit antennas, and next, switches encoding modes between Space-Time Transmit Diversity and BLAST according to instantaneous channel information. Computer simulations showed that the proposed system improves about 2 or 3 ㏈ SNR in low correlated channel and about 3 ㏈ SNR in highly correlated channel rather than a 2 by 2 antenna switching system.

YZiCS: On the Mass Segregation of Galaxies in Clusters

  • Kim, Seonwoo;Contini, Emanuele;Choi, Hoseung;Han, San;Lee, Jaehyun;Oh, Sree;Kang, Xi;Yi, Sukyoung K.
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.31.2-31.2
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    • 2020
  • Mass segregation, a tendency of more massive galaxies being distributed closer to the cluster center, is naturally expected from dynamical friction, but its presence is still controversial. Using deep optical observations of 14 Abell clusters (KYDISC) and a set of hydrodynamic simulations (YZiCS), we find in some cases a hint of mass segregation inside the virial radius. Segregation is visible more clearly when the massive galaxy fraction is used instead of mean stellar mass. The trend is more significant in the simulations than in the observations. To find out the mechanisms working on mass segregation, we look into the evolution of individual clusters simulated. We find that the degree of mass segregation is different for different clusters: the trend is visible only for low-mass clusters. We compare the masses of galaxies and their dark haloes at the time of infall and at the present epoch to quantify the amount of tidal stripping. We then conclude that satellites that get accreted at earlier epochs, or galaxies in more massive clusters go through more tidal stripping. These effects in combination result in a correlation between the host halo mass and the degree of stellar mass segregation. This is a work submitted to The Astrophysical Journal (under review).

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The Origin of the Spin-Orbit Alignment of Galaxy Pairs

  • Moon, Jun-Sung;An, Sung-Ho;Yoon, Suk-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.28.3-29
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    • 2021
  • Galaxies are not just randomly distributed in space; instead, a variety of galaxy alignments have been found over a wide range of scales. Such alignments are the outcome of the combined effect of interacting neighbors and the surrounding large-scale structure. Here, we focus on the spin-orbit alignment (SOA) of galaxy pairs, the dynamical coherence between the spin of a target galaxy and the orbital angular momentum of its neighbor. Based on a recent cosmological hydrodynamic simulation, the IllustrisTNG project, we identify paired galaxies with mass ratios from 1/10 to 10 at z = 0 and statistically analyze their spin-orbit angle distribution. We find a clear preference for prograde orientations (i.e., SOA), which is more prominent for closer pairs. The SOA is stronger for less massive targets in lower-density regions. The SOA witnessed at z = 0 has been developed progressively since z = 2. There is a clear positive correlation between the alignment strength and the interaction duration with its current neighbor. Our results suggest the scenario in which the SOA is developed mainly by interactions with a neighbor for an extended period of time, rather than by the primordial torque exerted by the large-scale structure.

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Dst Prediction Based on Solar Wind Parameters (태양풍 매개변수를 이용한 Dst 예측)

  • Park, Yoon-Kyung;Ahn, Byung-Ho
    • Journal of Astronomy and Space Sciences
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    • v.26 no.4
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    • pp.425-438
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    • 2009
  • We reevaluate the Burton equation (Burton et al. 1975) of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q) and the decay time ($\tau$) of the equation, we examine the relationships between $Dst^*$ and $VS_s$, ${\Delta}Dst^*$ and $VS_s$, and ${\Delta}Dst^*$ and $Dst^*$ during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to he solar wind forcing. The injection term is found to be $Q(nT/h)\;=\;-3.56VS_s$ for $VS_s$ > 0.5mV/m and Q(nT=h) = 0 for $VB_s\;{\leq}\;0.5mV/m$. The $\tau$ (hour) is estimated as $0.060Dst^*\;+\;16.65$ for $Dst^*$ > -175nT and 6.15 hours for $Dst^*\;{\leq}\;-175nT$. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted $Dst^*$ is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975) and O'Brien & McPherron (2000a). The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms ($Dst^*\;{< \atop \sim}\;-200nT$).

Prediction of Failure Time of Tunnel Applying the Curve Fitting Techniques (곡선적합기법을 이용한 터널의 파괴시간 예측)

  • Yoon, Yong-Kyun;Jo, Young-Do
    • Tunnel and Underground Space
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    • v.20 no.2
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    • pp.97-104
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    • 2010
  • The materials failure relation $\ddot{\Omega}=A{(\dot{\Omega})}^\alpha$ where $\Omega$ is a measurable quantity such as displacement and the dot superscript is the time derivative, may be used to analyze the accelerating creep of materials. Coefficients, A and $\alpha$, are determined by fitting given data sets. In this study, it is tried to predict the failure time of tunnel using the materials failure relation. Four fitting techniques of applying the materials failure relation are attempted to forecast a failure time. Log velocity versus log acceleration technique, log time versus log velocity technique, inverse velocity technique are based on the linear least squares fits and non-linear least squares technique utilizes the Levenberg-Marquardt algorithm. Since the log velocity versus log acceleration technique utilizes a logarithmic representation of the materials failure relation, it indicates the suitability of the materials failure relation applied to predict a failure time of tunnel. A linear correlation between log velocity and log acceleration appears satisfactory(R=0.84) and this represents that the materials failure relation is a suitable model for predicting a failure time of tunnel. Through comparing the real failure time of tunnel with the predicted failure times from four curve fittings, it is shown that the log time versus log velocity technique results in the best prediction.

A simple test method to evaluate workability of conditioned soil used for EPB Shield TBM (토압식 쉴드 TBM 굴진을 위한 화강풍화토의 컨디셔닝을 평가하는 간편 시험법)

  • Kim, Tae-Hwan;Kwon, Young-Sam;Chung, Heeyoung;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.6
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    • pp.1049-1060
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    • 2018
  • Soil conditioning is one of the key factors for successfull tunnel excavations utilizing the earth pressure-balanced (EPB) shield tunnel boring machine (TBM) by increasing the tunnel face stability and extraction efficiency of excavated soils. In this study, conditioning agents are mixed with the weathered granite soils which are abundant in the Korean peninsula and the workability of the resulting mixture is evaluated through the slump tests to derive and propose the most suitable conditioning agent as well as the most appropriate agent mix ratios. However, since it is cumbersome to perform the slump tests all the time either in the laboratory or in-situ, a simpler test may be needed instead of the slump test; the fall cone test was proposed as a substitute. In this paper, the correlation between the slump value obtained from the slump test and the cone penetration depth obtained from the proposed fall cone test was obtained. Test results showed that a very good correlation between two was observed; it means that the simpler fall cone test can be used to assess the suitability of the conditioned soils instead of the more cumbersome slump test.

An Electric Load Forecasting Scheme with High Time Resolution Based on Artificial Neural Network (인공 신경망 기반의 고시간 해상도를 갖는 전력수요 예측기법)

  • Park, Jinwoong;Moon, Jihoon;Hwang, Eenjun
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.11
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    • pp.527-536
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    • 2017
  • With the recent development of smart grid industry, the necessity for efficient EMS(Energy Management System) has been increased. In particular, in order to reduce electric load and energy cost, sophisticated electric load forecasting and efficient smart grid operation strategy are required. In this paper, for more accurate electric load forecasting, we extend the data collected at demand time into high time resolution and construct an artificial neural network-based forecasting model appropriate for the high time resolution data. Furthermore, to improve the accuracy of electric load forecasting, time series data of sequence form are transformed into continuous data of two-dimensional space to solve that problem that machine learning methods cannot reflect the periodicity of time series data. In addition, to consider external factors such as temperature and humidity in accordance with the time resolution, we estimate their value at the time resolution using linear interpolation method. Finally, we apply the PCA(Principal Component Analysis) algorithm to the feature vector composed of external factors to remove data which have little correlation with the power data. Finally, we perform the evaluation of our model through 5-fold cross-validation. The results show that forecasting based on higher time resolution improve the accuracy and the best error rate of 3.71% was achieved at the 3-min resolution.

${T_2}weighted$- Half courier Echo Planar Imaging

  • 김치영;김휴정;안창범
    • Investigative Magnetic Resonance Imaging
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    • v.5 no.1
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    • pp.57-65
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    • 2001
  • Purpose : $T_2$-weighted half courier Echo Planar Imaging (T2HEPI) method is proposed to reduce measurement time of existing EPI by a factor of 2. In addition, high $T_2$ contrast is obtained for clinical applications. High resolution single-shot EPI images with $T_2$ contrast are obtained with $128{\times}128$ matrix size by the proposed method. Materials and methods : In order to reduce measurement time in EPI, half courier space is measured, and rest of half courier data is obtained by conjugate symmetric filling. Thus high resolution single shot EPI image with $128{\times}128$ matrix size is obtained with 64 echoes. By the arrangement of phase encoding gradients, high $T_2$ weighted images are obtained. The acquired data in k-space are shifted if there exists residual gradient field due to eddy current along phase encoding gradient, which results in a serious problem in the reconstructed image. The residual field is estimated by the correlation coefficient between the echo signal for dc and the corresponding reference data acquired during the pre-scan. Once the residual gradient field is properly estimated, it can be removed by the adjustment of initial phase encoding gradient field between $70^{\circ}$ and $180^{\circ}$ rf pulses. Results : The suggested T2EPl is implemented in a 1.0 Tela whole body MRI system. Experiments are done with the effective echo times of 72ms and 96ms with single shot acquisitions. High resolution($128{\times}128$) volunteer head images with high $T_2$ contrast are obtained in a single scan by the proposed method. Conclusion : Using the half courier technique, higher resolution EPI images are obtained with matrix size of $128{\times}128$ in a single scan. Furthermore $T_2$ contrast is controlled by the effective echo time. Since the suggested method can be implemented by software alone (pulse sequence and corresponding tuning and reconstruction algorithms) without addition of special hardware, it can be widely used in existing MRI systems.

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An Improved Fractal Color Image Decoding Based on Data Dependence and Vector Distortion Measure (데이터 의존성과 벡터왜곡척도를 이용한 개선된 프랙탈 칼라영상 복호화)

  • 서호찬;정태일;류권열;권기룡;문광석
    • Journal of Korea Multimedia Society
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    • v.2 no.3
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    • pp.289-296
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    • 1999
  • In this paper, an improved fractal color image decoding method using the data dependence parts and the vector distortion measure is proposed. The vector distortion measure exploits the correlation between different color components. The pixel in RGB color space can be considered as a 30dimensional vector with elements of RGB components. The root mean square error(rms) in RGB color for similarity measure of two blocks R and R' was used. We assume that various parameter necessary in image decoding are stored in the transform table. If the parameter is referenced in decoding image, then decoding is performed by the recursive decoding method. If the parameter is not referenced in decoding image, then the parameters recognize as the data dependence parts and store its in the memory. Non-referenced parts can be decoded only one time, because its domain informations exist in the decoded parts by the recursive decoding method. Non-referenced parts are defined the data dependence parts. Image decoding method using data dependence classifies referenced parts and non-referenced parts using information of transform table. And the proposed method can be decoded only one time for R region decoding speed than Zhang & Po's method, since it is decreased the computational numbers by execution iterated contractive transformations for the referenced range only.

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