• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.1
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• pp.11-18
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• 1999

The objective of this study are to figure out the physical attributes of the three predictors in the Informational Approach: complexity, coherence, mystery and to investigate the relationships between these attributes and the preference exploratively. Visual inspection of the scenes relative to their rated levels of the predictors revealed the existence of relationship between these variables and the physical attributes. The following are the summary of the relationship between three predictors and the physical attributes: (1) The level of complexity was associated with the pattern of physical attributes which were the amount of facility, line, shape, color plant and arrangement of the visual elements. (2) The level of coherence was related with the regular arrangement of the visual elements. For example, there was certain pattern founded the color, shape, texture was applied to the various space repetitively and symmetrically. (3) The level of mystery had the relationship with the physical attributes of screen, spatial definition, distance of view, physical accessibility, radiant forest, the depth of space.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3A
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• pp.231-237
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• 2010

Multi-input multi-output (MIMO) systems are used to improve the transmission rate in proportion to the number of antennas. However, their computational complexity is very high for the detection in the receiver. The sphere decoding (SD) is a detection algorithm with reduced complexity. In this paper, an improved Schnorr-Euchner SD (SE SD) is proposed based on the minimum mean square error (MMSE) and the Euclidean distance criteria without additional complexity.

• Journal of Communications and Networks
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• v.17 no.5
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• pp.463-472
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• 2015

This paper considers a limited feedback system for two-way wireless relaying channels with physical network coding (PNC). For full feedback systems, the optimal structure with the PNC has already been studied where a modulo operation is employed. In this case, phase and power of two end node channels are adjusted to maximize the minimum distance. Based on this result, we design new quantization methods for the phase and the power in the limited feedback system. By investigating the minimum distance of the received constellation, we present a code-book design to maximize the worst minimum distance. Especially, for quantization of the power for 16-QAM, a new power quantization scheme is proposed to maximize the performance. Also, utilizing the characteristics of the minimum distance observed in our codebook design, we present a power allocation method which does not require any feedback information. Simulation results confirm that our proposed scheme outperforms conventional systems with reduced complexity.

• Journal of Korea Multimedia Society
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• v.24 no.9
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• pp.1242-1250
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• 2021

Detection of outliers deviating normal data distribution in high dimensional data is an important technique in many application areas. In this paper, a distance-based outlier detection method using landmarks in high dimensional data is proposed. Given normal training data, the k-means clustering method is applied for the training data in order to extract the centers of the clusters as landmarks which represent normal data distribution. For a test data sample, the distance to the nearest landmark gives the outlier score. In the experiments using high dimensional data such as images and documents, it was shown that the proposed method based on the landmarks of one-tenth of training data can give the comparable outlier detection performance while reducing the time complexity greatly in the testing stage.

• Journal of Korea Multimedia Society
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• v.14 no.6
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• pp.711-718
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• 2011

The k-Nearest Neighbor classifier that does not require a training phase is appropriate for a variable number of classes problem like face recognition, Recently distance metric learning methods that is trained with a given data set have reported the significant improvement of the kNN classifier. However, the performance of a distance metric learning method is variable for each application, In this paper, we focus on the face recognition and compare the performance of the state-of-the-art distance metric learning methods, Our experimental results on the public face databases demonstrate that the Mahalanobis distance metric based on PCA is still competitive with respect to both performance and time complexity in face recognition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12C
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• pp.1184-1193
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• 2006

Image interpolation has been widely used and studied in the various fields of image processing. There are many approaches of varying complexity and robustness. In this paper, a new distance weight is proposed for the conventional linear interpolation. In comparison with the conventional linear weight, the new distance weight uses a quadratic or cubic polynomial equation to reflect that the interpolated value should be influenced more by the value of closer pixels in an input image. In this paper, the new adaptive linear (NAL) interpolation, which considers patterns near the interpolated value, is also proposed. This algorithm requires a pattern weight, which is used to determine the ratio of reflection on local patterns, to obtain an interpolated image that exhibits better quality at various magnification factors (MF). In the computer simulation, not only did the NAL interpolation exhibit much lower computational complexity than conventional bicubic interpolation, it also improved peak signal-to-noise ratios (PSNR).

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.832-844
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• 2020

The degree of dispersion of a random variable can be described by the variance, which reflects the distance of the random variable from its mean. However, the time complexity of the traditional variance calculation algorithm is O(n), which results from full calculation of all samples. When the number of samples increases or on the occasion of high speed signal processing, algorithms with O(n) time complexity will cost huge amount of time and that may results in performance degradation of the whole system. A novel multi-step recursive algorithm for variance calculation of the time-varying data series with O(1) time complexity (constant time) is proposed in this paper. Numerical simulation and experiments of the algorithm is presented and the results demonstrate that the proposed multi-step recursive algorithm can effectively decrease computing time and hence significantly improve the variance calculation efficiency for time-varying data, which demonstrates the potential value for time-consumption data analysis or high speed signal processing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3702-3707
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• 2009

In this paper, a new approximated MAP algorithm for soft bit decision from QAM symbols is proposed for Gray Coded QAM signals, based on the Max-Log-MAP and a Gray coded QAM signal can be separated into independent two Gray coded PAM signal, M-PAM on I axis with M symbols and N-PAM on Q axis with N symbols. The Max-Log-MAP used distance comparisons between symbols to get the soft bit decision instead of mathematical exponential or logarithm functions. But in accordance with the increase of the number of symbols, the number of comparisons also increase with high complexity. The proposed algorithm is used with the Euclidean distance and constituted with plain arithmetic functions, thus we can know intuitively that the algorithm has low implementing complexity comparing to conventional ones.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.4
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• pp.255-261
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• 2013

In this paper, we compare two methods that improve the reliability of soft output at the receiver of MIMO communications. The receiver complexity of spatially mutiplexed MIMO system is in proportion to the number of candidate vectors. Low complexity receiver techniques involving a small number of candidate vectors, provide soft output values of low reliability. In order to improve the low reliability of soft output, two previous methods can be used; the first method involves a clipping threshold, the second method uses Euclidian distance instead of squared Euclidian distance. In the paper, we address the theoretical similarity of the two methods, then we compare the two methods from the perspective of hardware implementation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.1
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• pp.53-59
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• 2008

In this paper, we compare two methods that improve the reliability of soft output at the receiver of MIMO communications. The receiver complexity of spatially mutiplexed MIMO system is in proportion to the number of candidate vectors. Low complexity receiver techniques involving a small number of candidate vectors, provide soft output values of low reliability. In order to improve the low reliability of soft output, two previous methods can be used; the first method involves a clipping threshold, the second method uses Euclidian distance instead of squared Euclidian distance. In the paper, we address the theoretical similarity of the two methods, then we compare the two methods from the perspective of hardware implementation.