• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.50-68
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• 2024

This study developed a bus route sketch (BRS) methodology for utilizing bus route design and operation steps in practice and evaluated the feasibility of the method. The BRS methodology consists of three steps: transportation zoning suitable for the provider and users of bus transit service; determining the bus operation route based on established transportation zones and path combination; optimizing the operation route based on the estimation of route alternatives in terms of the multi-performance measures from the standpoints of bus-transit service provider and user. The results of a case study showed that the estimation scores from the perspectives of provider and user were improved significantly from 8.83 and 7.13 to 9.50 and 9.89, respectively. Because the BRS method was designated and developed to be suitable for field application for route planning and operation, the method can be used instantly and directly to estimate and adjust the on-operation bus transit line and route design.

• Design & Manufacturing
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• v.18 no.3
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• pp.44-53
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• 2024

A injection mold usually requires 30 to 50 revisions, and as the number of revisions increases, the burden of increased costs, schedule delays, and decreased reliability increases, reducing the competitiveness of companies. In addition, these costs become a more serious problem when the customer is far away, which is an obstacle to the export of domestic mold companies with excellent technology. The objective of this study is to develop an augmented reality platform that will facilitate the sharing of realistic 3D virtual objects in real time and enable mold designers to collaborate using a range of tools in remote locations and virtual environments. The platform collaboration solution enables simultaneous participation and synchronization of design collaboration with four types of devices (PC, mobile, VR, and MR). The efficiency and precision of the high-speed injection molding analysis module were validated through rigorous testing, demonstrating a processing speed that ranges from 500 to 3,000 times faster than that of the conventional numerical analysis method, with a relative error of less than 15% and a service performance of more than 80 fps. The user-friendly and intuitive UI/UX was configured and the usability was verified through scenario verification.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.209-214
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• 2014

IMS(IP Multi-Media Subsystem) is in the limelight as the Integrated wire and wireless Systems because of a sudden increase of smart mobile devices and growth of multimedia additional services such as IPTV. The structure of IMS is designed as a session control layer to provide various multimedia summative service using SIP based on IP communication network in order to carry out set-up, change and release by NGN of course, the existing voice services. But now It is broadly substituting in the IPTV, wire phone company and it is substituted in internet platform base on the soft-switch in currently. Especially, in currently, 4G LTE in a mobile communication company is rapidly growing in market. Therefore, in this study, we had designed and developed to the main prosser that can admit to 1000 user over and SIP gateway which can link the IMS Core that can link SIP Device which adopt the standard protocol on the SIP and to provide variable multimedia services.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.203-209
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• 2016

Digital tourism is the digital support of the tourist experience before, during and after the tourist activity[1]. The GPS-enabled mobile phones provide location-based mobile applications such as tour guide and storytelling services. In this paper, we propose the smart tour guide service platform based on GIS and develop the mobile application to provide the smart tour guide service. The proposed smart tour guide service platform consists of CMS, the multi-modal navigation system, the tour attraction content creation and management system, the tour commodity creation and management system, the smart search system, and the user terminal. The smart tour guide application supports digital tourism in the pre-tour, during tour, and post-tour using the proposed smart tour guide service platform in the popular tourist attractions in Jeju.

• Journal of Communications and Networks
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• v.11 no.1
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• pp.26-35
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• 2009

In this paper, we investigate how to do resource allocation to guarantee a minimum user data rate at low signaling overhead in multi-cell orthogonal frequency division multiple access (OFDMA) wireless systems. We devise dynamic resource allocation (DRA) algorithms that can minimize the QoS violation ratio (i.e., the ratio of the number of users who fail to get the requested data rate to the total number of users in the overall network). We assume an OFDMA system that allows dynamic control of frequency reuse factor (FRF) of each sub-carrier. The proposed DRA algorithms determine the FRFs of the sub-carriers and allocate them to the users adaptively based on inter-cell interference and load distribution. In order to reduce the signaling overhead, we adopt a hierarchical resource allocation architecture which divides the resource allocation decision into the inter-cell coordinator (ICC) and the base station (BS) levels. We limit the information available at the ICC only to the load of each cell, that is, the total number of sub-carriers required for supporting the data rate requirement of all the users. We then present the DRA with limited coordination (DRA-LC) algorithm where the ICC performs load-adaptive inter-cell resource allocation with the limited information while the BS performs intra-cell resource allocation with full information about its own cell. For performance comparison, we design a centralized algorithm called DRA with full coordination (DRA-FC). Simulation results reveal that the DRA-LC algorithm can perform close to the DRA-FC algorithm at very low signaling overhead. In addition, it turns out to improve the QoS performance of the cell-boundary users, and achieve a better fairness among neighboring cells under non-uniform load distribution.

• Journal of the Korean Society for information Management
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• v.30 no.3
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• pp.297-315
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• 2013

Anyone curious to easily access and learn Korean history has become interested in Korean history data bases, which will provide accurate and reliable historical information. Furthermore, user demands for information sharing and reusability, available through setting up a semantic web, have been increased, which have taken the shape of linked data. Efforts have been made to construct public data bases containing readily usable contents a user can understand and utilize with ease. They have been produced by several organizations, portal sites, and individuals, trying to deviate from existing mainstreams - expert-based text data bases. A problem with those data bases is that they have not considered such vital factors as the sharing and utilizing of information as a whole. This study suggests a LOD-based Korean history contents implementation system, providing rich information environment by way of multi-dimensional web-data connections. In doing so, this system has tried a historic information circulation service system which is based on information sharing and connecting.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.10
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• pp.429-438
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• 2021

In recent, realistic content has been applied in various ways due to the development of display technology and hologram, the final realistic content technology, have been used limitedly in accordance with the growing public demand. However, most realistic content requires additional devices of HMD (head mounted device) or glasses type, and other realistic content display technologies deliver a single image plane in the experience space to the user, providing a monotonous content experience. Various realistic contents with hologram technology are introduced in this work. In addition, we propose an interaction based realistic hologram service based that combines projection mapping and floating holograms. Projection-mapped screens and multi-floating hologram device provide a three-dimensional volumetric space with extended depth orientation from the user's point of view, while allowing users' entire and partial motions to be recognizable through multiple sensors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.4
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• pp.207-215
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• 2014

Password based authentication systems are most widely used for user convenience in web services. However such authentication systems are known to be vulnerable to various attacks such as password guessing attack, dictionary attack and key logging attack. Besides, many of the web systems just provide user authentication in a one-way fashion such that web clients cannot verify the authenticity of the web server to which they set access and give passwords. Therefore, it is too difficult to protect against DNS spoofing, phishing and pharming attacks. To cope with the security threats, web system adopts several enhanced schemes utilizing one time password (OTP) or long and strong passwords including special characters. However there are still practical issues. Users are required to buy OTP devices and strong passwords are less convenient to use. Above all, one-way authentication schemes generate several vulnerabilities. To solve the problems, we propose a multi-channel, multi-factor authentication scheme by utilizing QR-Code. The proposed scheme supports both user and server authentications mutually, thereby protecting against attacks such as phishing and pharming attacks. Also, the proposed scheme makes use of a portable smart device as a OTP generator so that the system is convenient and secure against traditional password attacks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.11C
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• pp.1112-1123
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• 2002

Providing a multimedia service requires efficient network bandwidth allocation scheduling. Typically, transmission of information with bursty characteristics, such as a video data stream, utilizes some type of smoothing technique that reduces the transmission rate fluctuation. While capable of a drastic reduction in the peak transmission rate, even the optimum smoothing algorithm proposed to date, however, is rather inadequate for multi-stream applications that share network bandwidth since such an algorithm has been designed and applied toward handling each independent stream. In this paper, we proposed an efficient bandwidth allocation algorithm that addresses these shortcomings. The proposed bandwidth allocation algorithm is divided into two steps, a static bandwidth allocation and a dynamic bandwidth allocation. In the former case, the peak rate reduction is achieved by maintaining the accumulated data in the user buffer at a high level, whereas the concept of real demand factor is employed to meet the needs of multi-stream bandwidth allocation in the latter case, Finally, the proposed algorithm's performance was verified with ExSpect 6.41, a Petri net simulation tool.

• The Transactions of the Korea Information Processing Society
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• v.13 no.8
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• pp.356-366
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• 2024

Users of intelligent robots require access to the status data of the robots for various reasons. The status data of intelligent robots can be generated by combining the status data of the functional agents that constitute the intelligent robot. However, existing intelligent robot systems do not generate the necessary agent status data for creating the status data of intelligent service robots, or they generate it in different ways, making it impossible to collect this information in a uniform manner. Furthermore, these systems have limitations such as collecting the same information redundantly if multiple users request it and only using a single method of communication to deliver robot information, thereby failing to offer the communication methods desired by users. This paper proposes a multi-agent monitoring system for intelligent service robots designed to overcome these limitations. This monitoring system generates status data in response to the actions performed by functional agents, thereby allowing for the unified generation and collection of agent status data. Additionally, the monitoring system resolves data redundancy issues by collecting the necessary data just once, in accordance with user monitoring demands, and delivers status data through a proxy that supports the preferred communication methods of users, thereby providing compatibility with various communication methods. Through experiments, we have verified that this monitoring system can deliver the status data of intelligent robots to multiple users using various communication methods.