• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.77-87
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• 2007

A typical VOD service allows that a number of remote clients playback a desired video from a large collection of videos stored in one or more video servers. The main bottleneck for a VOD service is the network bandwidth connecting to the VOD server to the client due to the high bandwidth requirements. Many previous researches have shown that VOD server can be greatly improved through the use of multicast, broadcast, or P2P scheme. Broadcast is one of the most efficient techniques because it can transmit a stream to many users without additional network bandwidth. But the broadcast has long latency time. In order to overcome the drawback, in this paper, we propose P2Prefix broadcast scheme that can solve the service latency time, which is the problem of broadcast scheme, by using P2P caching as well as minimizing the client buffer requirement.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.2
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• pp.209-220
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• 2004

The Goals of Intelligent Network(IN) provide the methods that create, test and apply the various hinds of services to satisfy the user's need. In this environments, we can create new IN service by description of GSL(Global Service Logic) using that SCE(Service Creation Environment). In the ITU-T CS-2, the various SIBs(Service Independent Building-blocks) are defined to develop the services. There are limitations to develop the various services using the SIBs defined in recommendation. So, in this paper, we define the new SIBs and implement the SCE. The new SIBs are defined in this paper are Connect SIB and BCSM Event SIB. The Connect Call SIB provides the connectivity between SLPI(Service Logic processing Program Instance) and call after connecting the calling party to called party. The BCSMEvent SIB provides the functions that request SSF to report the call processing event and receive it. In this paper, we design and implement the SCE that supports the SIBs defined by recommendation and this paper, provides GUI environment to specify GSI, and generates the code used by SCP.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.379-385
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• 2016

IT companies are increasingly taking interest in the automobile industry as a major industry of the future. Companies specializing in information technology, such as Google, Apple and Samsung, are actively taking part in the automobile industry and are conducting various research on connected cars. At this point in time, this study aims on understanding the concept of connected cars and the concept of mirror linking, which is one of the many methods in connecting cars. In this transitional period of connected cars, the purpose of this study is to present the method of mirror linking iPhones and to discover how this could be used in connected cars. By turning a normal car into a connected car, simply with a smartphone in hand, the ideas presented in this study will serve as an opportunity for many current automobile owners to experience the functions of connected cars of the future without shouldering additional expenses.

• The Research Journal of the Costume Culture
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• v.26 no.3
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• pp.265-281
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• 2018

Government policy supporting the fashion industry in Korea has focused on the future development of rising fashion designer's brands, and as a part of this support, several Fashion Creative Studios are presently operated. The purpose of this study is to identify the meaning of these facilities and suggest development strategies for their effective utilization. This paper presents a conceptual understanding based on a literature review, and deduces the direction of Fashion Creative Studios through an exploratory analysis of various case studies and in-depth interviews with five designers, who have graduated from the Seoul Fashion Creative Studio. The results are as follows. Firstly, fashion educational institutions have to provide sufficient information about the Fashion Creative Studios to students. They can also consider adding short-term residencies to the curriculum in which students prepare collections or portfolios for the studios. Secondly, Fashion Creative Studios are required to intensify business and marketing programs to increase real-world support. It would be helpful to provide 1:1 management programs with several segmented stages for the design brands, or connect them to investors who could provide financial support and business expansion. Thirdly, Fashion Creative Studios need to find a way to strengthen textile differentiation and craft characteristics to increase designer brand competitiveness. Broadening participation with textile designers, connecting with experts and ateliers, and promoting collaboration with artists and artisans in the Arts Creative Studios can be further examined to this end.

• Informatization Policy
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• v.23 no.1
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• pp.56-73
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• 2016

The Internet of Things (IoT) is expected to provide new business opportunities by connecting devices, persons, and their data. However, the value proposed by IoT cannot be realized without trust. As IoT premises on the seamless connections, it should guarantee trust among the connected persons and things. However, there is lack of relevant discussion on how to achieve trustworthy connections and interactions because most of academic studies have mainly focused on the development of IoT platforms and applications. To fill the gaps, recent EU-funded projects such as uTRUSTit, ABC4Trust, Inter-Trust, COMPOSE, and SMARTIE have been conducted under the FP7-ICT Framework Programme. This paper presents and discusses each project's purpose and approach. Although their approaches are somewhat different from each other, all of them dedicate to achieving both privacy and security by providing the trustworthy connections. It seems to be clear that Korea also needs more academic and practical contribution in terms of researches, to implement "trust"among connected things, which will eventually satisfy what really IoT is expected for.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.434-442
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• 2018

Recently, the threat to the security and damage of important data leaked by devices of intranet infected by malicious code through the Internet have been increasing. Therefore, the partitioned intranet model that blocks access to the server for business use by implementing authentication of devices connected to the intranet is required. For this, logical net partition with the VDI(Virtual Desktop Infrastructure) method is no information exchange between physical devices connected to the intranet and the virtual device so that it could prevent data leakage and improve security but it is vulnerable to the attack to expose internal data, which has access to the server for business connecting a nonregistered device into the intranet. In order to protect the server for business, we suggest a blockchain based network partition model applying blockchain technology to VDI. It contributes to decrease in threat to expose internal data by improving not only capability to verify forgery of devices, which is the vulnerability of the VDI based logical net partition, but also the integrity of the devices.

• Journal of Satellite, Information and Communications
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• v.5 no.2
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• pp.50-56
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• 2010

Most mission trajectory design technologies for space exploration have been utilized the Patched Conic Approximation which is based on Hohmann transfer in two-body problem. The Hohmann transfer trajectory is basically an elliptic trajectory, and Patched Conic Approximation consists of Hohmann transfer trajectories in which each trajectory are patched to the next one. This technology is the most efficient method when considering only one major planet at each patch trajectory design. The disadvantages of the conventional Patched Conic Approach are more fuel (or mass) needed and only conic trajectories are designed. Recent space exploration missions need to satisfy more various scientific or engineering goals, and mission utilizing smaller satellites are needed for cost reduction. The geometrical characteristics of three-body dynamics could change the paradigm of the conventional solar system. In this theoretical concept, one can design a trajectory connecting around the solar system with comparably very small energy. In this paper, the basic three-body dynamics are introduced and a spacecraft mission trajectory is designed utilizing the three-body dynamics.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.613-619
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• 2011

Objective: The purpose of this study is to compare the muscle activities of lumbar and lower extremity muscles between left and right sides using EMG(Electromyogram) when patients are transferred by physical therapists. Background: Asymmetrical lift was recognized as a major cause of musculoskeletal disorder. Several studies show that physical therapists' transferring patients needs caution as it could cause a lumbar pain to patients but there is not sufficient data to support. Method: Forty healthy rehabilitation hospital physical therapists joined for this study. The subjects were transferred from wheelchair to treatment mat(from left to right) by connecting the EMG device to the patients' body both on erector spine and rectus fermoris. At the moment when subjects were being transferred, the EMG device collected data from both erector spine and rectus femoris and it was normalized as %MVC. Then the EMG data was statistically analyzed using paired t-tests. Results: The EMG data show that the left erector spinae and rectus femoris are more activated than right erector spinae and rectus femoris in all position(p<.05) in a significant degree. Conclusion: The result implies that physical therapists' asymmetrical lifting when patients are transferred by them has a potential cause of musculoskeletal disorder of patients. Further studies will be conducted to find out a same tendency in other muscles of a body and to see if there are other factors to affect to patients during asymmetrical lifting. Application: These results can be used to provide baseline information for more understanding to asymmetrical lift loading.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.115-121
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• 2020

As the participation of blockchain increases, governance to maintain the ecosystem is being activated. Governance must be managed/supervised to maintain and improve the blockchain. However, as the usage of blockchain increases, there is a limit for people to manage it individually. In addition, smart contracts applied from Ethereum need to be verified for trade that are determined according to status values, as new trade types are possible. This research proposes a surveillance system, Blockchain Watchdog, based on the state monitoring of the blockchain smart contract as a tool for maintaining and developing the blockchain ecosystem of governance, and implemented and tested the surveillance system. As a case study, we conducted experiments on Ropsten and Ganache, and were able to see real-time information collection and visualization using dashboards, graphs, and charts. We expect to contribute to the maintenance and development of the ecosystem of blockchain governance through Blockchain Watchdog.

• The Journal of Korean Association of Computer Education
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• v.10 no.6
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• pp.11-18
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• 2007

The proposed virtual laboratory system for digital logic circuits is composed of two main sessions, which are concept-learning session and virtual experiment session by virtual digital kit. During concept-learning session the learners can easily understand the important principles in the digital circuits to be performed. In addition, during virtual laboratory session the virtual experiments are performed by assembling and connecting the circuits on the virtual bread board, applying input voltages, making the output measurements, and comparing and transmitting the virtual experimental data. Every activity done during the virtual laboratory session is recorded on database and will be provided with the learners as a preliminary report form including personal information. Thus, the educators may check out the submitted preliminary report to estimate how well the learners understand the circuit operations. Finally, in order to show the validity of our virtual laboratory system we investigated and analysed the damage rate of real experimental equipment during class and assessed student performance on the five quizzes for one semester.