• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.6
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• pp.2583-2605
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• 2016

Fingerprint positioning is a main stream and key technique for seamless positioning systems. In this paper, we develop a performance evaluation testbed for fingerprint based Wireless Local Area Network (WLAN) positioning system. The testbed consists of positioning server, positioning terminal, Access Point (AP) units, positioning accuracy analysis system and testing scenarios. Different from other testbeds tended to focus on testing in same situation, in the proposed testbed, a couple of scenarios are set to test the positioning system including indoor and outdoor environments. Handset-side positioning mode and network-side positioning mode are provided simultaneously. Variety of motion models, such as static model, low-speed model and high-speed model are considered as well as different positioning algorithms. Finally, some implementation cases are analyzed to verify the credibility of the testbed.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.3
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• pp.77-86
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• 2002

An experimental study of the vortex interaction characteristics of a delta wing/LEX configuration was conducted in a wind tunnel using the micro water droplet and laser beam sheet visualization technique. The main focus of this study was to analyze the effect of the angle of attack and sideslip angle on the vortex interaction and vortex breakdown. These tests were accomplished at angles of attack between $16^{\circ}$ and $28^{\circ}$ and sideslip angle between $0^{\circ}$ and $-15^{\circ}$ at free-stream velocity of 6.2 m/s. Flow visualization data provide a description of the vortex interaction between LEX and wing vortices, and of the vortex breakdown. The introduction of LEX vortex stabilized the vortical flow, and delayed the vortex breakdown up to higher angle of attack. The vortex interaction and breakdown was promoted on the windward side, whereas they are suppressed on the leeward side.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2A
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• pp.187-193
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• 2006

Multicarrier systems has major shortcomings due to the large numbers of subcarrier. One of the shortcomings is the high peak-to-average power ratio(PAPR), which causes nonlinearity distortion in the transmitter, and degrades the performance of the system significantly. Partial transmit sequence(PTS) is one of the best approaches that can significantly improve the statistics of the PAPR of an orthogonal frequency division multiplexing(OFDM) signal. Guided scrambling(GS) is an extension of self-synchronizing scrambling. It is also capable of guiding the scrambling process to produce a balanced encoded bit stream. In this paper, we propose a sub-optimal algorithm to optimize the phase factor in PTS. In addition, we integrate GS coding with this method. The proposed Hybrid algorithm can get much more PAPR reduction at the expense of incur a few error extension and do not require transmission of side information.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.4
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• pp.916-925
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• 1988

The Navier-Stokes equations of the vorticity-stream-function form are solved numerically for the flow past a semicircular arc for Reynolds numbers in the range 0.1

• Journal of architectural history
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• v.6 no.3 s.13
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• pp.23-44
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• 1997

There are two main halls in the Main Palace of the Koryo Dyansty in the 11th and 12th century. One, named Hoekyongjeon, was served only for special ceremony ; hundred Buddhist priests' sermons or receiption of Chinese emperor's letters. The other one, Kondukjeon, was used as ordinary throne hall. The ordinary throne hall was built when the palace was erected at the beginning era of the Koryo Danasty, while the special ceremony hall built after the reconstruction in the 11th century. The throne hall was located at northwest side of the special ceremony hall. Audience chamber and King's bedroom were located at west and northwest side of the throne hall. The basic layout of the Palace showed unsymmetrical shape. It seemed mainly effected by its undulating terraine. The acess road from main gate to the throne hall showed zigzag way, by following a stream penetrating the site obliquely, It could be said that the Main Palace of the Koryo Danasty achieved its originality on the aspect of unsymmetrical layout and zigzag acess road, which was not found in the former palaces.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.546-549
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• 1995

Recently, electric utility is facing substantially new stream of business environment, such as pressure of business restructuring, competition with private IPPs, diversification of supply-side and demand-side resource options, environmental externalities and uncertainties. Integrated resource planning(IRP) is very useful and powerful approach for solving complex and diversified electricity supply and demand problems. This paper presents a standardized IRP procedure using multi-attribute decision analysis approach. The selection of the most desirable plan is based on multi-attribute trade-off/risk analysis method and score ranking method. As a case study, 50 plans with 12 scenarios are analyzed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.4
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• pp.875-886
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• 1994

This study is to develop an advanced storm runoff analysis program which takes geomorphological characteristics of watershed into consideration in determining model parameters. Basic concept of storm runoff modelling is based upon the kinematic wave theory. And numerical solution is obtained by the characteristic curve method. The storm runoff analysis program developed by this study is composed of multiple equivalent roughness sub-basins, each of which has two equivalent catchments on both side of a stream. Because it is based upon the stream-order of the Strahler system, the equivalent catchment-stream network reflects the stochastic geomorphological characteristics in the model parameter. Applicability and reliability of the storm runoff analysis program is evidenced by model calibration and verification process utilizing geographical and hydrological data of the Bocheong-river area which is a representative watershed of IHP projects in Korea. This study will hopefully contribute to hydrological calculation essentially required to understand water quality effect caused by regional development.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.385-395
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• 1999

Video-On-demand system provides electronic video rental services from remote video servers on a broadband communication networks. When we assume some situation that serve the same video stream by batching, each time single video stream became available at server-end side, we face the problem that what video stream to be scheduled at what time instant. Hence, in order to manage the resource bandwidth which is different at each stream, the policy of channel allocation became important factor. In this work, we proposed three type of scheduling policies with queueing, as are cumulative Waiting Time(CWT), Mean Waiting Time(MWT) and Predictable Popular Factor(PPF). While CWT policy is good for popular video, MWT policy was good for non-popular video. Also, we know that PPT policy has some fairness for average wait time and reneging rate of user requests.

• Korean Journal of Acupuncture
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• v.35 no.3
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• pp.117-122
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• 2018

Objectives : Most meridians have each well point located at the distal end of fingers or toes, congruous with their meridian courses. Exceptively, ST45(Yeotae), stomach meridian(ST)'s final point, is located at the lateral side of the tip of the second toe, while the tip of the second toe was not mentioned in the course of ST. So, we studied the course of lower limb region of ST. Methods : Courses of ST in Categorized Collection of Literatures on Chinese Meridians and Collaterals(CCM) was examined. The literatures included in CCM was selected as study subjects to be studied if the meridian route was different from "Youngchu" or more detailed notes were attached. There are 3 branches in lower limb region of ST, we analyzed theories of scholars of all time about the 3 branches of ST. Results and Conclusions : Branch 1 descends along the lateral margin of the fibula to the dorsum of foot, entering into the medial side of the middle toe. Branch 2 leaves ST36 separately, terminating at the lateral side of the middle toe. Branch 3 leaves ST42 and descends to the end of the great toe. The medial side of the middle toe equate to the lateral side of the second toe, and it is connected to ST45. So branch 1 is the main stream of ST. Branch 3 drives to the great toe passing between first and second toe, it goes medial side of LR2.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1329-1340
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• 2016

Recently, Zhang proposed a scheme to hide information in encrypted images using synchronous stream ciphers. After the receiver decrypts the encrypted image and extracts data by calculating the spatial correlation property value using the fluctuation function which is designed to calculate spacial correlation between adjacent pixels in a decrypted image. Then, Hong improved the Zhang's data hiding scheme by introducing the side match technique. In this paper, a novel fluctuation function is proposed to reduce the recovery errors which arise during extracting hidden data. Then, we also demonstrated that the proposed fluctuation function outperforms the previous functions through computer simulations for sample images.