• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.27-34
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• 2016

In the train system, railway vehicles are connected in a line. Therefore, this feature should be considered in composing network topology in a train system. Besides, inter-car communication should be distinguished from in-car communication. As for the inter-car communication, the hybrid topology was proposed to use rather than the conventional ring, star, daisy-chain, and bus topologies. In the hybrid topology, a number of cars are bound to be a group. Then star topology is used for the communication in a group and daisy-chain topology is used for the communication between groups. Hybrid topology takes the virtue of both star and daisy-chain topologies. Hence it maintains communication speed with reducing the number of connecting cables between cars. Therefore, it is important to choose the number of cars in a group to obtain higher performance. In this paper, we focus on the optimization of hybrid topology for railway cars. We first assume that the size of data and the frequency of data production for each car is identical. We also assume that the importance for the maximum number of cables to connect cars is variable as well as the importance of the communication speed. Separated weights are granted to both importance and we derive the optimum number of cars in a group for various number of cars and weights.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.4
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• pp.334-348
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• 2005

The goal of next generation digital broadcasting is offering the interaction among consumers and providers as well as variety services. One of the important factors for this new broadcasting environment keeps the interoperability among providers and consumers since the environment is distributed. Therefore a standard metadata for digital broadcasting is required and TV-Anytime metadata is one of the metadata standards for digital broadcasting. The terminal nodes of TV-Anytime metadata are defined by using MPEG-7 metadata. MPEG-7 metadata is standard metadata for describing multimedia content. Therefore, if we use the MPEG-7 metadata for describing broadcasting content can offer multimedia search services like content-based search by the extension of metadata. The efficient management system for these metadata is important for offering the services with high Duality on real broadcasting environment TV-Anytime metadata and MPEG-7 metadata are technically defined using a single XML schema, so its instances are XML data. Currently, a lot of systemsfor managing XML data are proposed in many researchers and we can expect to adapt these systems for managing broadcasting metadata. But the methods used in these systems are not specific methods for managing broadcasting metadata because of methods for general-purpose. In this paper, we find the properties of broadcasting metadata and develop an efficient metadata management system that is based on the found properties. Since our systemis implemented on real broadcasting environment, we expect that the system is most efficient and suitable. Also our system is interoperable since we use XQuery as query language for querying broadcasting metadata.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.370-388
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• 2019

From 2010, new keyword of so-called devising theatre in the Korean performing arts scene has emerged. The backdrop is the antipathy to the hierarchical creative environment, the search for a language that can reflect increasingly complex societies, and the influx of new performances from abroad. Of course, devising theatre can be realized in a wide variety of forms in the actual field, so it cannot be defined as one methodology. But commonly all these various forms of the attempts aim to create a democratic relationship among participants, and process-centered breakthrough in the hierarchy of creative materials such as texts, sounds. light and human body. In 2017, Creative VaQi seeks to find new keyword called 'Reality of Division in Korean Peninsula' and to develop it into performance languages experimenting inter-disciplinary devising methodology. The company conducted a walking trip alongside the division line(300km) and tried to achieve the landscape and traces of division. After the walking, they created a specific form and performing contents called "Walking Holiday" out of their experiences. In this thesis, I will analyze the whole process of the devising "Walking Holiday" and examine what kind of result it led to. Furthermore, I, as the director of "Walking Holiday" will continue to discuss new possibilities and limitations of devising theatre methods that the company tries and aim at this time.

• KIPS Transactions on Computer and Communication Systems
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• v.6 no.11
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• pp.453-462
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• 2017

OpenDaylight is an SDN (Software Defined Networking) open source framework, which is popular in network fields recently. This paper analyzes the performance of a controller cluster architecture by focusing on distributed datastore and Raft leader election algorithm. In addition, we propose an enhanced version of Raft algorithm in order to improve the performance of distributed datastore by distributing shard leaders over controller cluster. This paper compares the conventional Raft algorithm with the proposed version of the Raft algorithm. Moreover, we compare the performance of distributed datastore according to shard roles such as leader and follower. Experimental results show that Shard leaders provide better performance than followers and Shard updating requests need to be distributed over multiple controllers. So, by using proposed version of Raft algorithm, controller performance can be improved. The details of the experiment results are cleary described.

• Journal of The Korean Association of Information Education
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• v.18 no.4
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• pp.461-470
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• 2014

This study is to analyze students' perception about junior SW education by giving the questionnaire to the participants in Scratch-day. We taught the creative computing to 558 juniors on Scratch-day in 2013, 2014 and researched the questionnaire about their perceptions of creative computing education. We analyzed the current status of SW education from this process and extracted considerations about elementary SW education. We also proposed the possibility of its application to the elementary and middle school education. As a result of this study, it is observed that students think that creative computing education is fun and useful, and want to apply it to the public school education. Also, male students think more positive than female students about an intention to use, and students who have experienced with Scratch education consider it more useful and positive intention to use than those who have not. According to the structural model, it is found that the pleasure, easy of use, and usefulness of creative computing education have a positive influence on students' perception that it should be applied to public school education.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.164-176
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• 2011

To get an implication for desirable direction for Collaboration between Reporter & Producer, I found that had 4 modes of collaboration such as, Producer System, Reporter System, Double Reporting System, Co-Work System, and each was distinguished by field cover, on-mic, editing, writing. Producer system and Reporter system got no chemical synergy because of simple array of single reports due to physical assemble. The achievements of collaboration was birth of new news which had different duration, visual, sound & perspective. It also offered fertile soil for new program and genre literacy of 8 o'clock news. The success factor of collaboration was surprisingly turned out to be personnel rather than system. The balance of reporter & producer was also good factor. But the wall between 2 groups was so high that, after disappearance of extraordinary leader, system began to crumble and at last program was repealed.

• Journal of KIISE:Databases
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• v.34 no.6
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• pp.473-482
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• 2007

Network-based IDS(Intrusion Detection System) gathers network packet data and analyzes them into attack or normal. They raise alarm when possible intrusion happens. But they often output a large amount of low-level of incomplete alert information. Consequently, a large amount of incomplete alert information that can be unmanageable and also be mixed with false alerts can prevent intrusion response systems and security administrator from adequately understanding and analyzing the state of network security, and initiating appropriate response in a timely fashion. So it is important for the security administrator to reduce the redundancy of alerts, integrate and correlate security alerts, construct attack scenarios and present high-level aggregated information. False alarm rate is the ratio between the number of normal connections that are incorrectly misclassified as attacks and the total number of normal connections. In this paper we propose a false alarm classification model to reduce the false alarm rate using classification analysis of data mining techniques. The proposed model can classify the alarms from the intrusion detection systems into false alert or true attack. Our approach is useful to reduce false alerts and to improve the detection rate of network-based intrusion detection systems.

• Journal of KIISE:Databases
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• v.29 no.3
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• pp.159-167
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• 2002

Recently, a major issue in the research of metadata is the standardization of metadata format. The new extension capability of metadata in the standardization requires some changes - storing and managing dynamic data consistently. In this paper, we define the characteristics of new metadata and propose a concurrency control called Two Version Latch (2VL). 2VL uses a latch and maintains two versions. Maintaining two versions using latch minimizes conflicts between read operation and write operation. The removal of unnecessary lock holding minimizes refresh latency. Therefore, this algorithm presents fast response time and recent data retrieval in read operation execution. As a result of the performance evaluation, the 2VL algorithm is shown to be better than other algorithms in metadata management system.

• Journal of KIISE:Databases
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• v.34 no.3
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• pp.232-243
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• 2007

Metadata IR model has high precision and low recall because the query in Metadata IR model is strict that is, the query can express user information need exactly, while Full-text IR model has low precision and high recall because the query in Full-text IR model is a kind of simple keyword query which expresses user information need roughly. If user can translate one's information need into structured query well, the retrieval result will be improved. However, it is little possible to make relevant query without understanding characteristics of metadata. Unfortunately, most users do not interested in metadata, then they cannot construct well-made structured query. Amount of information contained in metadata is less than text information. In this paper, we suggest hybrid IR model using metadata and text which can provide users with lots of relevant documents by retrieving from metadata field and text field complementarily.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.105-118
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• 2021

The purpose of this study is to explore the American Youth Film Director Damien Chazelle and his cinema world. Chazelle as a youth director directs three movies as (2014), (2016), (2018) in Hollywood, and represents youth directors in Hollywood. For this study, adopt two research methodologies which are 'Auteurism' and 'culture studies', and explore traits of esthetics, subject and context meaning by analyzing representative three movies. Lastly examines significance of his movies in Hollywood history. This study concludes that Chazelle is a 'Auteurism director of self-reflexivity' who has three things in common as 'narrative: success myth', 'mise-en-scene: Chazelle's world', 'self-reflexivity: Auteurism film directing'. Youth film director Chazelle is opening up the future of Hollywood as a 'Auteurism film of self-reflexivity' and the creative film directing of the youth generation.