• Journal of Digital Contents Society
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• v.16 no.2
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• pp.283-290
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• 2015

This study focused on SNS use of Chinese students who are studying in Korea. Communication media like SNS is strongly related with socialization of foreigners. Thus, it is expected to verify relationship between current SNS use tendency of Chinese students and their settlement in Korea based on analysis on the factor influencing SNS use of Chines students. For the study on the factor influencing to SNS use of Chinese students in Korea TAM model was used as a research frame. Based on TAM theory technological attribute, individual attribute and social attribute were taken out as independent variables. Perceived ease of use and perceived usefulness are applied as mediator variables. In research conclusion, some hypotheses are adopted the same as existing theory, but some hypotheses for example service quality and individual attribute are rejected as variables which influence positively to mediator variable perceived easy of use. For the next research more various variables and nationwide sampling will be needed. Based on this research it is expected to be analysed correlation between foreigners settlement in Korea and communication media like SNS.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.20-28
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• 2016

A Ubiquitous City (U-city, Smart City) is one that ties information communications technologies (ICT) into many facets of city construction, thereby implicitly intending to function as a smart city that aims to be efficiently managed as well as provide an enhanced standard of living for its residents. Laws related to the construction of such ubiquitous cities point to integrated city management centers, intelligent facilities, and U-City infrastructure, among others, as central components of U-Cities, but do not provide a standard for these structures. Consequently, building of U-Cities by local governments are based on arbitrary judgments constrained the myriad of practical limitations that they face. Such ambiguity brings to light the need to find ways to improve the quality of these efforts. The first and second stages of this research examine the status of the components of a U-City -ubiquitous planning, technology, infrastructure, and services - and undertakes a comprehensive review thereof, with evaluation criteria formulated on the characteristics of stability, connectivity, goal-orientation, and development potential. In the research's third stage, a realistic and detailed evaluation index by which U-Cities can be renewed, demonstrated, and applied (???) is introduced in a step-by-step fashion, which will allow for local governments to properly assess the standard of their U-City in relation to the realities of the locality. Through the research result, it is expected that the index will become a part of the continued development and advancement of the "smart" character of an autonomous U-City at the local scale, and contribute to the overall revitalization of the U-City.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.765-773
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• 2009

Currently Telematics traffic information services have been various because we can collect real-time traffic information through Intelligent Transport System. In this paper, we proposed and implemented a short-term traffic information prediction model for giving to guarantee the traffic information with high quality in the near future. A Short-term prediction model is for forecasting traffic flows of each segment in the near future. Our prediction model gives an average speed on the each segment from 5 minutes later to 60 minutes later. We designed a Bayesian network for each segment with some casual nodes which makes an impact to the road situation in the future and found out its joint probability density function on the supposition of GMM(Gaussian Mixture Model) using EM(Expectation Maximization) algorithm with training real-time traffic data. To validate the precision of our prediction model we had conducted various experiments with real-time traffic data and computed RMSE(Root Mean Square Error) between a real speed and its prediction speed. As the result, our model gave 4.5, 4.8, 5.2 as an average value of RMSE about 10, 30, 60 minutes later, respectively.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.937-950
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• 2004

With growing population of internet and web applications, distributed environment is considered to be the standard architecture of application. A network management systems(NMS) is necessary to control and monitor the complex network resources for providing and sharing the heft quality service. We recognize the NMS as a standard infrastructure for supporting efficient networking and a separate commercial applications. We believe every resource including software, hardware and environment for the network management should be separated from special protocols, vendors and applications. Therefore, We need a standard network management system that is efficient and consistent because of the heterogeous network features. In regards to software development, software reuse through assembling and extending the reusable elements such as patterns and components assures to realize the best productivity and quality The component based development(CBD) methodology that can assemble black box though well defined interfaces makes it possible to develop easer and quicker applications and is proved as the best software development solution involved in construction, selection and assembly of components. In this thesis, we describe the architecture for the network management and identify, define and design the components through analysis and design in the network management domain and Identified components mapped to the component architecture. We also specify the component development and design and implement the component for developing the network management. Implemented components apply to the component repository system that register, retrieve and understand the components. We analyze, design and implement the entire network management system based on configuration, connection, performance and fault management through the pre-developed components.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.5
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• pp.708-720
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• 1993

The new preventive control mechanisms for traffic management in BISDN/ATM networks can be divided into Connection Admission Control(CAC), Usage Parameter Control (UPC), and Priority Control. Of these mechanism, Usage Parameter Control continuously monitors the parameters admitted in the network's entry point to guarantee quality of service of connections already admitted. Upon detecting traffic that violates the negotiated parameter, it takes the necessary control measures to prevent congestion. Among these traffic control methods, this paper focuses on the Usage Parameter Control method, and proposes and designs GRACE-LB(Guaranteed Rate Acceptance & Control Element-using Leaky Bucket) which improves upon existing UPC models. GRACE-LB modifies the previous LB model by eliminating the cell buffer, dividing the token Pool into two pools, Long-term pool, Short-term pool, and changing the long-term token generating form using 'Cycle Token' into the same bursty form as the traffic source. Through this, GRACE-LB achieves effective control of the Average Bit Rate(ABR) and burst duration of bursty multimedia traffic which previous LB models found difficult to control. Also, since GRACE-LB can e implemented using only simple operations and there are no cell buffers in it, it has the merit of being easily installed at any place.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.1
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• pp.68-78
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• 2013

In this paper, we propose an early spectrum sensing(ESS) as an advance preparation for radio-access trial, which enables multi-mode terminals to access the most appropriate radio-access system in a cloud-conceptual base station system where multiple radio access technologies(RATs) coexist. Prior to a random access to one of RATs, a multi-mode terminal conducts a spectrum sensing over entire frequency bands of whole RATs, then select the RAT with the lowest sensing power, that is likely to have the most available spectrum. Thus, an access failure caused by that the selected RAT has no available radio spectrum could be avoidable in advance. In computer simulation, we consider as various RATs as possible. First, circuit and packet systems are taken into consideration. In addition, the packet systems are classified according to the feasibility of carrier aggregation(CA). In case of terminal, three modes are considered with circuit-only, packet-only, and multi-mode. Subsequently, packet traffic is classified into real-time and non-real-time traffic with three different tolerable delay levels. The simulation includes a call process starting with a call generation and ending up with a resource allocation reflecting individual user's QoS requirements and evaluates the proposed scheme in terms of the successful access probability, system access time, system balancing factor and packet loss probability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.12 s.103
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• pp.1171-1178
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• 2005

Multi-code code division multiple access(MC-CDMA) has been proposed for providing the various service rates with different quality of service requirement by assigning multiple codes and increasing the capacity. However, it suffers from the serious problem of high peak to average power ratio(PAPR). So, it requires large input back-off, which causes poor power consumption in high power amplifier(HPA). In this paper, we propose a new method that can reduce PAPR efficiently by constraint codes based on the opposite correlation to the incoming information data in MC-CDMA. PAPR reduction depends on the length and indices of constraint codes in MC-CDMA system. There is a trade-off between PAPR reduction and the length of constraint codes. From the simulation results, we also investigate the BER improvement in AWGN channel with HPA. The simulation results show that BER performance can be similar with linear amplifier in two cases: 1) Using exact constraint codes without input back-off and 2) a few constraint codes with small input back-off.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.2
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• pp.63-71
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• 2012

Recently, web portals have been offering georeferenced SLI(Street-Level Imagery) services, such as Google Streetview. The SLI has a distinctive strength over aerial images or vector maps because it gives us the same view as we see the real world on the street. Based on the characteristic, applicability of the SLI can be increased substantially through conflation with other spatial datasets. However, spatial inconsistency between different datasets is the main reason to decrease the quality of conflation when conflating them. Therefore, this research aims to remove the spatial inconsistency to conflate an SLI with a widely used 2D vector map. The removal of the spatial inconsistency is conducted through three sub-processes of (1) road intersection matching between the SLI trace and the road layer of the vector map for detecting CPPs(Control Point Pairs), (2) inaccurate CPPs filtering by analyzing the trend of the CPPs, and (3) local alignment using accurate CPPs. In addition, we propose an evaluation method suitable for conflation result including an SLI, and verify the effect of the removal of the spatial inconsistency.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.4
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• pp.9-20
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• 2012

The purpose of this research is to confirm how the determinant factors for shopping mall selection (proximity, parking facility, benefits, mutual interaction effects, physical environment, surroundings) affect attractiveness (image and appraisal) of the traditional markets and revisit intention and suggest strategic methods for revitalization of the traditional markets. Results of this research are drawn from a survey of customers who visit any of the twenty-two traditional markets in the Seoul area at least twice a week. Moreover, the theory is verified through the structural equation model analysis using the SPSS win 18.0 and AMOS 18 version statistics package. From the determinant factors of visiting traditional markets, parking facility, physical environment, and the surroundings were significant in image attractiveness; benefits, mutual interaction effects, and physical environment showed significant effects on appraisal attractiveness. Additionally, image attractiveness was not significantly influential in retention proneness while appraisal attractiveness was a key factor in deciding whether or not to revisit. Therefore, improvement in image is important but appraisal aspects like product reliability that customers can personally assess, are more essential for revitalization of traditional markets.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3
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• pp.24-33
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• 2001

this paper describes a baseline for an implementation of a corpus-based Korean TTS system. The conventional TTS systems using small-sized speech still generate machine-like synthetic speech. To overcome this problem we introduce the corpus-based TTS system which enables to generate natural synthetic speech without prosodic modifications. The corpus should be composed of a natural prosody of source speech and multiple instances of synthesis units. To make a phone level synthesis unit, we train a speech recognizer with the target speech, and then perform an automatic phoneme segmentation. We also detect the fine pitch period using Laryngo graph signals, which is used for prosodic feature extraction. For break strength allocation, 4 levels of break indices are decided as pause length and also attached to phones to reflect prosodic variations in phrase boundaries. To predict the break strength on texts, we utilize the statistical information of POS (Part-of-Speech) sequences. The best triphone sequences are selected by Viterbi search considering the minimization of accumulative Euclidean distance of concatenating distortion. To get high quality synthesis speech applicable to commercial purpose, we introduce a domain specific database. By adding domain specific database to general domain database, we can greatly improve the quality of synthetic speech on specific domain. From the subjective evaluation, the new Korean corpus-based TTS system shows better naturalness than the conventional demisyllable-based one.