• Journal of Korea Multimedia Society
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• 제6권3호
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• pp.496-507
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• 2003

Rapidly increasing Internet traffic demands require IP protocol based on high quality networking technology. Accordingy, our Internet has evolved from best-effort service toward differentiated service framework so as to implement QoS as prerequisite to a series of new applications. In addition, it is forecasted that existing transport network will be reorganized into DWDM-based optical Internet sooner or later under the influence of Internet demands for higher bandwidth based on QoS. This study shows a way to an effective implementation in some aspects: QoS implementation on DWDM-based optical Internet network, control protocol, backbone network architecture and switching technology for the Next Generation Internet (NGI).

• Journal of the Korean Mathematical Society
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• 제52권5호
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• pp.1037-1049
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• 2015

It is well-known that the spectrum of a $spin^{\mathbb{C}}$ Dirac operator on a closed Riemannian $spin^{\mathbb{C}}$ manifold $M^{2k}$ of dimension 2k for $k{\in}{\mathbb{N}}$ is symmetric. In this article, we prove that over an odd-dimensional Riemannian product $M^{2p}_1{\times}M^{2q+1}_2$ with a product $spin^{\mathbb{C}}$ structure for $p{\geq}1$, $q{\geq}0$, the spectrum of a $spin^{\mathbb{C}}$ Dirac operator given by a product connection is symmetric if and only if either the $spin^{\mathbb{C}}$ Dirac spectrum of $M^{2q+1}_2$ is symmetric or $(e^{{\frac{1}{2}}c_1(L_1)}{\hat{A}}(M_1))[M_1]=0$, where $L_1$ is the associated line bundle for the given $spin^{\mathbb{C}}$ structure of $M_1$.

• Journal of Korea Multimedia Society
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• 제8권10호
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• pp.1306-1313
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• 2005

Relevance Feedback(RF), a method to use perceptual feedback in image retrieval, refines a query by the relevance information from a user. However, the user's feedback information is thrown away as soon as a search session ends. So, this paper proposes an enhanced version of RF, which is designed to accumulate human perceptual responses over time through relevance feedback and to dynamically combine the accumulated high-level relevance information with low-level features to further improve the retrieval effectiveness. Experimental results are presented to prove the potential of the proposed RF.

• Journal of Korea Multimedia Society
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• 제17권1호
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• pp.34-42
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• 2014

In this paper an embedding algorithm based on commute time is implemented by organizing patches according to the graph-based metric, and its performance is analyzed by comparing with the results of principal component analysis embedding. It is usual that the dimensionality reduction be done within some acceptable approximation error. However this paper shows the proposed manifold embedding method generates the intrinsic geometry corresponding to the signal despite severe approximation error, so that it can be applied to the areas such as pattern classification or machine learning.

• Journal of Korea Multimedia Society
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• 제19권1호
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• pp.68-79
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• 2016

Electromyographic (EMG) signals have been widely used as motion commands of prosthetic arms. Although EMG signals contain meaningful information including the movement intentions of human body, it is difficult to predict the subject's motion by analyzing EMG signals in real-time due to the difficulties in extracting motion information from the signals including a lot of noises inherently. In this paper, four Ag/AgCl electrodes are placed on the surface of the subject's major muscles which are in charge of four upper arm movements (wrist flexion, wrist extension, ulnar deviation, finger flexion) to measure EMG signals corresponding to the movements. The measured signals are sampled using DAQ module and clustered sequentially. The Fuzzy C-Means (FCMs) method calculates the center values of the clustered data group. The fuzzy system designed to detect the upper arm movement intention utilizing the center values as input signals shows about 90% success in classifying the movement intentions.

• Journal of Korea Multimedia Society
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• 제15권6호
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• pp.784-793
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• 2012

Defects of TFT-LCD is detected by thresholding the difference image between the input image and template one because LCD panel has its inherent patterns. However, the pitch corresponding to pattern period is gradually changed according to the distance from the center of camera due to geometric distortion of camera characteristics. This paper presents a method to detect defects through comparing the pitch area with neighbor pitch areas where the perspective transform is performed with the extracted features to correct the distortion. The experimental results show that the performance of the proposed method is very effective for real data.

• Bulletin of the Korean Mathematical Society
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• 제51권3호
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• pp.659-666
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• 2014

Let $\mathcal{A}$ be the class of analytic functions f in the open unit disk $\mathbb{U}$={z : ${\mid}z{\mid}$ < 1} with the normalization conditions $f(0)=f^{\prime}(0)-1=0$. If $f(z)=z+\sum_{n=2}^{\infty}a_nz^n$ and ${\delta}$ > 0 are given, then the $T_{\delta}$-neighborhood of the function f is defined as $$TN_{\delta}(f)\{g(z)=z+\sum_{n=2}^{\infty}b_nz^n{\in}\mathcal{A}:\sum_{n=2}^{\infty}T_n{\mid}a_n-b_n{\mid}{\leq}{\delta}\}$$, where $T=\{T_n\}_{n=2}^{\infty}$ is a sequence of positive numbers. In the present paper we investigate some problems concerning $T_{\delta}$-neighborhoods of function in various classes of analytic functions with $T=\{2^{-n}/n^2\}_{n=2}^{\infty}$. We also find bounds for $^{\delta}^*_T(A,B)$ defined by $$^{\delta}^*_T(A,B)=jnf\{{\delta}&gt;0:B{\subset}TN_{\delta}(f)\;for\;all\;f{\in}A\}$$ where A, B are given subsets of $\mathcal{A}$.

• Journal of Korea Multimedia Society
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• 제11권11호
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• pp.1536-1546
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• 2008

RSVP-capable router supporting guaranteed services on the internet generally uses a packet scheduler based on the Weighted Fair Queuing (WFQ) algorithm to secure required qualities of traffic flows. A RSVP-capable router based on the LOFQ (Latency optimized fair queuing) algorithm had been proposed to improve the performance of the WFQ-based RSVP-router, but it required not only the RESV message to be expanded but also its performance could be evaluated only through simulation. This paper proposed a LOFQ based RSVP-capable router using the conventional RESV message and developed an algorithm to analyze the performance of the LOFQ based RSVP-capable routers. The performance evaluation using the developed algorithm showed that in terms of performance improvement the proposed router is inferior to the one using the expanded RESV message under a small packet size, but on the range of a large packet size both routers provide the same improvement.

• Journal of Korea Multimedia Society
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• 제13권9호
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• pp.1272-1284
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• 2010

As the mobile computers are becoming powerful and are used like general-purpose computers, operating systems for mobile computers also require swap system functionality that utilizes main memory efficiently. Flash memory is widely used as storage device for mobile computers but current linux swap system does not consider flash memory. Swap system is tightly related with process execution since it stores the contents of process in execution. By taking advantage of this characteristics, in this paper, we study a new linux swap system called PASS(Process-Aware Swap System), which allocates the different flash memory blocks to each process. Trace-driven experimental results show that PASS outperforms existing linux swap system with existing garbage collection schemes in terms of garbage collection cost.

• Journal of Korea Multimedia Society
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• 제11권5호
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• pp.579-587
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• 2008

Typically, the file sizes of JPEG compressed images with various complexity differ from images regardless of same image size. So, it is not easy to estimate the remaining image counts that should be stored in the limited storage equipped with the digital camera. To solve the problem, the bit rate control employs the modification of quantization table. The previous work assumed that there is linear relation between image activity and modification factor of quantization table, but in this paper, more accurate functional relations based on statistics are employed to improve the bit rate control accuracy. Computer simulations reveals that the standard deviation of the bit rate error of the proposed scheme is 50% less than that of the conventional method.