• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.145-154
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• 2004

The growing demand for customer-responsive, made-to-order manufacturing is stimulating the need for improved dynamic decision-making processes in commercial fleet operations. Moreover, the rapid growth of electronic commerce through the internet is also requiring advanced and precise real-time operation of vehicle fleets. Accompanying these demand side developments/pressures, the growing availability of technologies such as AVL(Automatic Vehicle Location) systems and continuous two-way communication devices is driving developments on the supply side. These technologies enable the dispatcher to identify the current location of trucks and to communicate with drivers in real time affording the carrier fleet dispatcher the opportunity to dynamically respond to changes in demand, driver and vehicle availability, as well as traffic network conditions. This research investigates key aspects of real time dynamic routing and scheduling problems in fleet operation particularly in a truckload pickup-and-delivery problem under various settings, in which information of stochastic demands is revealed on a continuous basis, i.e., as the scheduled routes are executed. The most promising solution strategies for dealing with this real-time problem are analyzed and integrated. Furthermore, this research develops. analyzes, and implements hybrid algorithms for solving them, which combine fast local heuristic approach with an optimization-based approach. In addition, various partitioning algorithms being able to deal with large fleet of vehicles are developed based on 'divided & conquer' technique. Simulation experiments are developed and conducted to evaluate the performance of these algorithms.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.149-155
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• 2003

This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP. According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

• International Commerce and Information Review
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• v.16 no.1
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• pp.3-24
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• 2014

When the Korean Wave was sweeping over China, Asia, Other Countries, Some people worried that the ambiguity of the copyright act would obstruct export of the entertainment contents. To solve this problem, the copyright authentication was introduced in the copyright act, enforcement for its, etc. There are two authentication systems at copyright. One is right authentication protected by copyright, Other one is licence authentication received from the owner. This study is meant to seeking the problem of insufficient regulation related to copyright authentication. According to analysis of FGI in this study, the existing system does not support a proper and specific way how to suggest a long term perspective in the transaction of Korean Contents between Korea and China. The key to success of copyright authentication system between Korea and China depends upon the implementation of the system of copyright mutual authentication. To do so, In reality, laws, institutions, technologies, policies, and operations, etc. should be Inter-operability. Also we should realize that this system gives mutual benefits at transaction between the two countries. Thus, it is important for two countries to effort trade cooperation continuously.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.665-682
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• 2004

GIS is considered as a big industry or business in the field of applied sciences. Recently GIS market in Korea is growing rapidly for LBS, Telematics, Web-geographic information services. This paper attempts to focus on the interrelationship between GIS and geography, and the question of how geography emerged out of intellectual trends within GIS to examine possible contribution of geographers in GIS fields. The application of GIS appears to be largely technical in nature. It is important for the GIS operator and the consumer of GIS products to be aware of the geographical concepts that underpin GIS operations. Also it is seen that many departments of geography in Korea have attempted to actively adopt GIS into their education program, with aim to improve the status. GIS has promoted a shift towards applied geography from academic geography. GIS researchers and educators in geography are concerned not with technology, but with the basic concepts and the issues relating to its use, in comparison with other academic fields. It is the responsibility of geography community to make sure that our students receive a geographical education that includes problem-solving, critical thinking and technical capabilities. It is concluded that promoting GIS technology in geography curriculum is essential for the further expansion of geography within GIS and also for the survival of geography.

• Journal of the Society of Disaster Information
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• v.10 no.4
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• pp.536-547
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• 2014

With the changing safety services and social order systems accompanied by the economic development and changing public security environment since the Chinese economic reform, the security service industry in China is growing daily and related problems are increasing. For the Chinese security service market to be activated, the monopoly of security services by the public security agencies must be removed. In addition, the research and development, expansion, and applications of safety and crime prevention technologies regarding the safety and protection of exhibition, sales, culture, sports, commerce activities, combinations of safety technologies and crime prevention processes, the provision of relevant technical operations, and the expansion of security service areas are required. Furthermore, the administration rights, property rights, and business management rights of security companies must be separated, the security headquarters must be integrated and coordinated for optimization of various resources solely by market needs, and their rights and affiliation relations must be clear. Besides, the competitiveness of security companies in the security service market must be enhanced by unifying the business management, and optimizing and sharing their resources. The security service ordinances of China that have been implemented now must be applied realistically, methods to activate the true market economy for security services must be researched, and various ordinances related to security services must be realigned in line with the characteristics of security services. Finally, for the mutual cooperation system between public and private security services, the public security agencies must acknowledge the importance of private security services and the status of security service providers in crime prevention and social order maintenance. They must establish partnership relations with each other beyond the unilateral direction and management system for security services and drive with positive attitudes the security service industry which is still in its infancy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.2015-2024
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• 1999

Presented in this paper are a new complex-umber filter architecture, which is suitable for an efficient implementation of baseband signal processing of digital communication systems, and a chip-set design of adaptive decision-feedback equalizer (ADFE) employing the proposed structure. The basic concept behind the approach proposed in this paper is to apply redundant binary (RB) arithmetic instead of conventional 2’s complement arithmetic in order to achieve an efficient realization of complex-number multiplication and accumulation. With the proposed way, an N-tap complex-number filter can be realized using 2N RB multipliers and 2N-2 RB adders, and each filter tap has its critical delay of $T_{m.RB}+T_{a.RB}$ (where $T_{m.RB}, T_{a.RB}$are delays of a RB multiplier and a RB adder, respectively), making the filter structure simple, as well as resulting in enhanced speed by means of reduced arithmetic operations. To demonstrate the proposed idea, a prototype ADFE chip-set, FFEM (Feed-Forward Equalizer Module) and DFEM (Decision-Feedback Equalizer Module) that can be cascaded to implement longer filter taps, has been designed. Each module is composed of two complex-number filter taps with their LMS coefficient update circuits, and contains about 26,000 gates. The chip-set was modeled and verified using COSSAP and VHDL, and synthesized using 0.8- μm SOG (Sea-Of-Gate) cell library.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.351-375
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• 2018

This paper aims to i) introduce the characteristics of HF ocean radar and the major results and information produced by the radar networks in the Korean coasts to the readers, ii) make an up-to-date inventory of the existing radar systems, and iii) share the information related to the radar operating skill and the ocean current data application. The number of ocean radars has been showing a significant growth over the past 20 years, currently deploying more than 44 radars in the Korean coasts. Most of radars are in operation at the present time for the purposes related to the marine safety, tidal current forecast and understanding of ocean current dynamics, mainly depending on the mission of each organization operating radar network. We hope this overview paper may help expand the applicability of the ocean radar to fisheries, leisure activity on the sea, ocean resource management, oil spill response, coastal environment restoration, search and rescue, and vessel detection etc., beyond the level of understanding of tidal and ocean current dynamics. Additionally we hope this paper contributes further to the surveillance activity on our ocean territory by founding a national ocean radar network frame and to the domestic development of ocean radar system including signal processing technology.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.79-91
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• 2006

The intelligent disk can improve the overall performance of the I/O subsystem by processing the I/O operations in the disk side. At present time, however, realizing the intelligent disk seems to be impossible because of the limitation of the I/O subsystem and the lack of the backward compatibility with the traditional I/O interface scheme. In this paper, we proposed new model for the intelligent disk that dynamically optimizes the I/O subsystem using the information that is only related to the physical sector. In this way, the proposed model does not break the compatibility with the traditional I/O interface scheme. For these works, the boosting algorithm that upgrades a weak learner by repeating teaming is used. If the last learner classifies a recent I/O workload as the multimedia workload, the disk reads more sectors. Also, by embedding this functionality as a firmware or a embedded OS within the disk, the overall I/O subsystem can be operated more efficiently without the additional workload.

• Korean Journal of Optics and Photonics
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• v.16 no.4
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• pp.326-333
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• 2005

Phase-only encryption scheme using exclusive-OR rules in Fourier plane and a single path decryption system are presented. A zero-padded original image, multiplied by a random phase image, is Fourier transformed and its real-valued data is encrypted with key data by using XOR rules. A decryption is simply performed based on 2-1 setup with spatial filter by Fourier transform for multiplying phase-only encrypted data by phase-only key data, which are obtained by phase-encoding process, and spatial filtering for zero-order elimination in inverse-Fourier plane. Since the encryption process is peformed in Fourier plane, proposed encryption scheme is more tolerant to loss of key information by scratching or cutting than previous XOR encryption method in space domain. Compare with previous phase-visualization systems, due to the simple architecture without a reference wave, our system is basically robust to mechanical vibrations and fluctuations. Numerical simulations have confirmed the proposed technique as high-level encryption and simple decryption architecture.

• Atmosphere
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• v.31 no.2
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• pp.241-249
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• 2021

A smart city utilizes data collected from various sensors through the internet of things (IoT) and improves city operations across the urban area. Recently substantial research is underway to examine all aspects of data that requires for the smart city operation. Atmospheric data are an essential component for successful smart city implementation, including Urban Air Mobility (UAM), infrastructure planning, safety and convenience, and traffic management. Unfortunately, the current level of conventional atmospheric data does not meet the needs of the new city concept. New and innovative approaches to developing high spatiotemporal resolution of observational and modeling data, resolving the complex urban structure, are expected to support the future needs. The geographic information system (GIS) integrates the atmospheric data with the urban structure and offers information system enhancement. In this study we proposed the necessity and applicability of the high resolution urban meteorological dataset based on heavy fog cases in the smart city region (e.g., Sejong and Pusan) in Korea.