• Journal of KIISE:Information Networking
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• v.32 no.3
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• pp.391-403
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• 2005

Several nv6 mobility support protocols for mobile Internet services are proposed in IETP : Mobile Ipv6, Hierarchical Mobile Ipv6, and Fast Handovers over Mobile Ipv6. Recently, IEEE 802.11 network has also been widely deployed in public areas for mobile Internet services. In the near future, IPv6 mobility support over IEEE 802.11 network is expected to be a key function to actualize the All If-based mobile various services. For appropriate application of these protocols, the IPv6 mobility support protocols should be analyzed according to their characteristics in terms of signaling, handover latency, lost packets, and required buffer sire as well as the impact of lower layer such as IEEE 802.11 network. In this paper, we analyze the performance of the protocols over IEEE 802.11 network. We define a packet-level traffic model, a network system model, and a mobility model. From these models, we construct a framework for the performance analysis. We also make cost functions to formalize each protocol's performance. Lastly, we analyze the effect of varying parameters used to show diverse numerical results, and compare with each other. From the analysis results, it is concluded that each Protocol has contrary or contrastive advantages with other Protocols, so there is no protocol that holds a dominant position.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.129-135
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• 2015

The Ubiquitous City (U-City) spatial information technology aimed to provide services freely anytime and anywhere by converging high-tech information & communication technology in urban infrastructure has been available in diverse patterns. In particular, there have been studies on the development of 3D spatial information after selecting and matching key points with stereo images from the many Closed Circuit TV (CCTV) in the U-City. However, the data mostly used in extracting matching points haven't considered external environmental impacts such as illuminance. This study tested how much the matching points needed to construct 3D spatial information with the CCTV whose image quality is dependent upon changes in illuminance fluctuate under the same hardware performances. According to analysis on the number of matching points by illuminance, the number of matching points increased up to 3,000Lux in proportion to the illuminance when IRIS, shutter speed and ISO were fixed. In addition, a border between an object and background became more distinctive. When there was too much light, however, the page became brighter, and noise occurred. Furthermore, it was difficult to name key points because of the collapse of an inter-object border. It appears that if filmed with the study results, the number of matching points would increase.

• Journal of Internet Computing and Services
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• v.20 no.6
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• pp.129-135
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• 2019

Recently, studies have been conducted to improve the m-commerce process in the NFC-based mobile environment and the increase of the number of smart phones built in NFC. Since authentication is important in mobile electronic payment, FIDO(Fast IDentity Online) and 2 Factor electronic payment system are applied. In addition, block-chains using distributed raw materials have emerged as a representative technology of the fourth industry. In this study, for the mobile gallery auction of the traders using NFC embedded terminal (smartphone) in a small gallery auction in which an unspecified minority participates, password-based authentication and biometric authentication technology (fingerprint) were applied to record transaction details and ownership transfer of the auction participants in electronic payment. And, for the cost reduction and data integrity related to gallery auction, the private distributed director block chain was constructed and used. In addition, domestic and foreign cases applying block chain in the auction field were investigated and compared. In the future, the study will also study the implementation of block chain networks and smart contract and the integration of block chain and artificial intelligence to apply the proposed method.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.2
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• pp.177-182
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• 2010

The flow of a universal system-level design methodology consists of system specification, system-level hardware/software partitioning, co-design, co-verification using virtual or physical prototype, and system integration. In the developing process of a hardware component in system, the design phase has been regarded as a phase consuming lots of time and cost. However, the verification phase in which functionality of the designed component is verified has recently been considered as a much important phase. In this paper, the implementation of a verification environment which is based on SystemC infrastructure and verifies the functionality of a hardware component is described. The proposed verification system uses SystemC user-defined channel as communication interface between variables of SystemC module and registers of Verilog module. The functional verification of an UART is performed on the proposed verification system. SystemC provides class library for hardware modeling and has an advantage of being able to design a system consisting hardware and software in higher abstraction level than register transfer level. Source codes of SystemC modules are reusable with a minor adaptation on verifying functionality of another hardware component.

• Journal of KIISE:Information Networking
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• v.33 no.4
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• pp.289-298
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• 2006

Algorithms for application-level multicast often use trees to deliver data from the source to the multiple receivers. With the tree structure, the throughput experienced by the descendant nodes will be determined by the performance of the slowest ancestor node. Furthermore, the failure of an ancestor node results in the suspension of the session of all the descendant nodes. This paper focuses on the transmission of data using multiple virtual forwarders, and suggests a scheme to overcome the drawbacks of the plain tree-based application layer multicast schemes. The proposed scheme elects multiple forwarders other than the parent node of the delivery tree. A receiver receives data from the multiple forwarders as well as the parent node and it can increase the amount of receiving data per time unit. The multiple forwarder helps a receiver to reduce the impact of the failure of an ancestor node. The proposed scheme suggests the forwarder selection algorithm to avoid the receipt of duplicate packets. We implemented the proposed scheme using MACEDON which provides a development environment for application layer multicast. We compared the proposed scheme with Bullet by applying the implementation in PlanetLab which is a global overlay network. The evaluation results show that the proposed scheme enhanced the throughput by 20 % and reduced the control overhead over 90 % compared with Bullet.

• Journal of The Korean Association For Science Education
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• v.35 no.5
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• pp.885-893
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• 2015

In this study, we compared the use of information and communications technology (ICT) by middle school teachers in Korea and other countries utilizing the teacher survey data of the IEA International Computer and Information Literacy Study (ICILS) 2013. The ICILS target population consisted of all students in the eighth grade. We compared Korea with Australia, the Czech Republic, Norway, and Poland, which are nations showing the highest achievements in computer and information literacy. We selected nine questions from the teacher questionnaire and divided them into the categories of computer use, use of ICT for teaching and learning, and the ICT support environment in school. In comparison to their counterparts in other countries, Korean middle school science teachers used computers frequently and also had high ICT self-efficacy. They were confident in their ability to use computers for general tasks, but not in their ability to use computers for teaching and learning. The Korean teachers also had a high percentage of utilization of presentation and graphics software. Also, the proportion of activities concerning the information provided and teacher-led tasks was high, but the proportion of activities for student collaboration or peer interaction was low. In Korea, middle school science teachers had more negative than positive views of using ICT in teaching and learning. The teachers thought that computer-related resource support and digital learning materials were insufficient and that the computer model was outdated in schools. Therefore, we propose to build an ICT infrastructure and to develop and disseminate ICT teaching and learning methods for student activities.

• Korean journal of communication and information
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• v.66
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• pp.242-272
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• 2014

This study examines why follow-up investigative programs about the sinking of the Cheonan Patrol Combat Corvette(ROKS Cheonan) have not been produced, despite much speculation surrounding the cause of the sinking since November 2010, when KBS investigative program, In-Depth 60 Minutes which had covered the incident was aired. We have uncovered four reasons through a series of in-depth interviews with producers and reporters, as follows. First, Korean military authorities monopolized relevant information, while the producers could not prove or confirm the validity of the findings of the JIG(Joint Civilian-Military Investigation Group)'s report because the facts had been revealed partially and selectively by the authorities and the press' scientific investigation were rejected by the authorities. Second, the crew of In-Depth 60 Minutes was subjected to severe disciplinary action by the Korea Communications Commission. This caused a chilling effect, - it broke the producers' resolve to further explore the reason behind the sinking. Furthermore, the screening of the investigative documentary, Project Cheonan Ship was cancelled without prior notice, presumably by the power of the State and markets. Third, the reorganization and shake-up of personnel by broadcasting stations' presidents appointed by the power of the State crushed the spirit of PD Journalism. Finally, the "red purge" factions stigmatized by the political or military, or the mainstream press, caused the producers or broadcasters to engage in self-censorship. The idea has been used in Korea as a smoke screen to deflect public attention. Nevertheless, the producers hope to shed light on the Cheonan sinking incident and to prove reasonable doubts by pursuing follow-up investigations.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.1-10
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• 2011

Recently, cloud computing which has provided enabling convenience that users can connect from anywhere and user friendly environment that offers on-demand network access to a shared pool of configurable computing resources such as smart-phones, net-books and PDA etc, is to be watched as a service that leads the digital revolution. Now, when business practices between departments being integrated through a cooperating system such as cloud computing, data streaming between departments is getting enormous and then it is inevitably necessary to find the solution that person in charge and find data they need. In previous studies the clustering simplifies the search process, but in this paper, it applies Hash Function to remove the de-duplicates in large amount of data in business firms. Also, it applies Bayesian Network of data mining for classifying the respect data and presents handling cloud computing based data. This system features improved search performance as well as the results Compared with conventional methods and CPU, Network Bandwidth Usage in such an efficient system performance is achieved.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.147-161
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• 2015

CEO's leadership is considered most important to cope with the rapidly changing ICT industry environment. Thus, this study attempted to investigate the impacts of the CEO's transformational leadership (referred to as "TL") on the organizational members' innovative/organizational citizenship behavior("IB/OCB") in the domestic ICT businesses. For this, this study conducted an on-line survey with the employees of businesses that belonged to the ICT industry, and received 417 valid responses. The analysis results by SPSS & Amos showed that the ICT business CEO's TL had a significantly positive impact on the members' self-efficacy; the members' self-efficacy not only had a positive impact on their own IB/OCB, but also had a mediating roles in the relationship between CEO's TL and IB/OCB. The Results indicated that the TL should be a CEO's core competency to arouse the members' IB/OCB through members' self-efficacy in the ICT industry.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.691-699
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• 2012

"Information", which is circulated in society by information technology development represented by computer, has brought innovation not only to physical civilization, but also deep into our daily lives. This is to say that information has brought fundamental change to its form of existence, and value system through being faster regarding the circulation and the way of management being diverse. As time goes by, this kind of change would stimulate more changes to be made as the development of scientific civilization. Therefore, informatization is one of the important characteristic that defines modern society's essence, but on the other side, information has been taken advantage of that temperament and abused in a lot of different ways. "The Law Regarding Computer Network Diffusion Expansion and Usage Promotion"(1986), as a counterplan of informatization is our nation's first Act about informatization, which enacts national policy and system about this issue. Since then, many laws has been enacted down to "Private Information Protection Act"(2011), forming a comprehensive system. The basic background of these laws are based upon the premise that even if the place where the information is managed is virtual space, rules that are considered valid in the real world should be basically applied in the virtual space. Therefore, the violation of the law in the real world is also considered the violation in the virtual space. This direction of current law regarding information is shared with both the theories and the reality. However, current law system and notion are based upon the premise that the law regards material objects, thus the characteristic of the information, which is "Immaterial Being" is not reflected. Also, the management and approach to this issue is allopathic, exposing many problems. Thus, this paper examines the way of protecting information stipulated in the current law, contemplates its protection scope and limitation, and seeks the direction of the improvement, based on the critical mind explained above.