• Journal of electromagnetic engineering and science
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• v.9 no.3
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• pp.124-129
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• 2009

Although the maximum sum-rate capacity of multiple-input multiple output(MIMO) broadcast channels(BCs) can be achieved by dirty-paper coding(DPC), the results were obtained without fairness considerations in uncorrelated MIMO channels. In this paper, we propose new multiuser scheduling algorithms, which find a best user set for approaching the maximum sum-rate capacity while maintaining fairness among users. We analyze the performance of the proposed algorithms using zero-forcing dirty paper coding(ZF-DPC) in the correlated MIMO BCs for throughput and delay fairness, respectively. Numerical results demonstrate that a large time window can reduce the average throughput difference between users, but it increases head-of-line(HOL) delay jitters in the case of delay fairness.

• Journal of the Korea Computer Graphics Society
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• v.12 no.2
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• pp.13-18
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• 2006

Color quantization replaces the color of each pixel with the closest representative color, and thus it makes the resulting image partitioned into uniformly-colored regions. As a consequence, continuous, detailed variations of color over the corresponding regions in the original image are lost through color quantization. In this paper, we present a novel scheme for restoring such variations from a color-quantized input image. Our scheme identifies which pairs of uniformly-colored regions in the input image should have continuous variations of color in the resulting image. Then, such regions are seamlessly stitched using the Laplace equation. The user can optionally indicate which regions should be separated or stitched by scribbling constraint brushes across the regions. We demonstrate the effectiveness of our approach through diverse examples, such as photographs, cartoons, and artistic illustrations.

• Journal of Communications and Networks
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• v.10 no.3
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• pp.308-315
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• 2008

When operating in frequency-division duplex (FDD) mode, transmit beamforming in multiple-input single-output (MISO) wireless communication systems typically requires accurate knowledge of downlink channel state information (CSI) at the transmitter. In practical FDD systems, obtaining such downlink CSI at the transmitter is challenging, if not impractical. To circumvent such challenge and support user mobility, we present a new method for transmit beamforming based on simple beam-control commands (BCCs) in MISO FDD mobile systems. We then numerically evaluate the effects of BCC errors in terms of transmit power efficiency, system capacity, and outage probability.

• ETRI Journal
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• v.35 no.6
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• pp.1029-1037
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• 2013

This paper introduces a novel and fast synthesizing method for 3D motions of quadrupedal animals that uses only a small set of motion capture data. Unlike human motions, animal motions are relatively difficult to capture. Also, it is a challenge to synthesize continuously changing animal motions in real time because animals have various gait types according to their speed. The algorithm proposed herein, however, is able to synthesize continuously varying motions with proper limb configuration by using only one single cyclic animal motion per gait type based on the biologically driven Froude number. During the synthesis process, each gait type is automatically determined by its speed parameter, and the transition motions, which have not been entered as input, are synthesized accordingly by the optimized asynchronous motion blending technique. At the start time, given the user's control input, the motion path and spinal joints for turning are adjusted first and then the motion is stitched at any speed with proper transition motions to synthesize a long stream of motions.

• Journal of Information Technology Applications and Management
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• v.23 no.4
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• pp.83-100
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• 2016

In this paper, we present the DEA (Data Envelopment Analysis) application case study to investigate the regionally distinctive telco management characteristics of the Asia-Pacific countries. This study attempts to exploit the implications of DEA for the assessments of core process capabilities of telcos. Accordingly, we extract input variables of CAPEX (capital expenditure), operating expense, marketing expense, and number of employees, each to reflect the competitiveness of the core processes such as fixed asset utilization, operation & sales efficiency, and white collar productivity. In conjunction with the input variables, the output variables are chosen as EBITDA (Earnings Before Interest, Taxes, Depreciation and Amortization), ARPU (Average Revenue per User), and number of subscribers. The computational testing results, conducted with total 37 telcos of the 12 Asia-Pacific countries, are analyzed in various ways to understand the distinctive performance characteristics across the region. The managerial implication captured from this study provides useful insight for using DEA as the international telco management purpose.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.168-174
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• 2012

Flash is the most popular 2D animation and game development software, supporting vector and media technology at the core, which enables the development of small and pithy games. It is widely used in Web animation, courseware, TV commercials, game development, and other works of design. In this paper, we propose a control movement function and auxiliary functions for an alpine skiing game based on ActionScript 3.0. The control movement function is designed with moving phases (i.e., free fall, sliding, projectile, and landing). The auxiliary functions include drawing path, start/restart movement, and saving the highest score. In addition, for the visual design of our game, we designed animations in connection with a character and background. In order to facilitate testing the friction, users can input a chosen friction value. Without user input, the friction default is set at 0.97.

• Journal of information and communication convergence engineering
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• v.18 no.3
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• pp.176-182
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• 2020

In this paper, we propose a web-based open artificial intelligence (AI) platform which provides high convenience in input data pre-processing, artificial neural network training, and the configuration of subsequent operations according to inference results. The proposed platform has the advantages of the GUI-based environment which can be easily utilized by a user without complex installation. It consists of a web server implemented with the JavaScript Node.js library and a client running the tensorflow.js library. Using the platform, many users can simultaneously create, modify and run their projects to apply AI functionality into various smart services through an open web interface. With our implementation, we show the operability of the proposed platform. By loading a web page from the server, the client can perform GUI-based operations and display the results performed by three modules: the Input Module, the Learning Module and the Output Module. We also implement two application systems using our platform, called smart cashier and smart door, which demonstrate the platform's practicality.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.155.2-155
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• 2002

A visual environment for system analysis codes (hereinafter called "ViSA") has been developed to support code users in their input preparations, code executions, and output interpretations. ViSA provides a more convenient way for base input data generation and modification on a user-friendly basis. It also provides on-line graphical displays to give an in-depth understanding of transient thermal-hydraulic behaviors in nuclear power plants. This paper presents the main features of ViSA.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1131-1143
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• 2016

Differential detection schemes do not require any channel estimation, which can be employed under user mobility with low computational complexity. In this work, a soft-input soft-output (SISO) differential detection algorithm is proposed for amplify-and-forward (AF) over time-varying relaying channels based cooperative communications system. Furthermore, maximum-likelihood (ML) detector for M-ary differential Phase-shift keying (DPSK) is derived to calculate a posteriori probabilities (APP) of information bits. In addition, when the SISO is exploited in conjunction with channel decoding, iterative detection and decoding approach by exchanging extrinsic information with outer code is obtained. Finally, simulation results show that the proposed non-coherent approach improves detection performance significantly. In particular, the system can obtain greater performance gain under fast-fading channels.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.223-228
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• 2000

In this study, RFD(Rock Blasting Design) program was developed to perform easily on plans of rock blasting. This program has abilities as follows, that is. the test blasting plan, the bench blasting plan, and the blasting vibration analysis. The value of geological property and blasting constants was offered by database, input value of variety constants repeatedly is planned out, faster and easier. And a value of input constant may be used by user for necessity.