• Journal of Multimedia Information System
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• v.2 no.3
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• pp.287-294
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• 2015

We are living in epoch of information when Internet touches all aspects of our lives. Therefore, it provides a plenty of services each of which benefits people in different ways. Electronic Mail (E-mail), File Transfer Protocol (FTP), Voice/Video Communication, Search Engines are bright examples of Internet services. Between them Social Network Services (SNS) continuously gain its popularity over the past years. Most popular SNSs like Facebook, Weibo and Twitter generate millions of data every minute. Twitter is one of SNS which allows its users post short instant messages. They, 100 million, posted 340 million tweets per day (2012)[1]. Often big amount of data contains lots of noisy data which can be defined as uninteresting and unclassifiable data. However, researchers can take advantage of such huge information in order to analyze and extract meaningful and interesting features. The way to collect SNS data as well as tweets is handled by crawlers. Twitter crawler has recently emerged as a great tool to crawl Twitter data as well as tweets. In this project, we develop Twitter Crawler system which enables us to extract Twitter data. We implemented our system in Java language along with MySQL. We use Twitter4J which is a java library for communicating with Twitter API. The application, first, connects to Twitter API, then retrieves tweets, and stores them into database. We also develop crawling strategies to efficiently extract tweets in terms of time and amount.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.8
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• pp.674-682
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• 2013

Along with increasing of its subscribers and traffic for high-speed LTE service, it is widely expected to bring about the 2nd data explosion and results in any inconvenience of users. This paper proposes a smart traffic management scheme and its system design based on user's participating with the mobile application, in order to provide a fast and stable service for end users as well as to resolve the network overhead with increasing traffic. By making use of a time shift by users who want to reduce data usage amount and communication cost, the proposed scheme tries to reduce the peak traffic by shifting the delay-tolerant services, such as file sharing and software download, into the other time line. It also reduces the high volumed video traffics by transforming them into a user customized one. In addition, we suggest a mechanism to select video size and service time, then proposes an overall system design and its user service scenarios.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.630-636
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• 2004

According to the increase of audio and video data utilization, the presentation of multimedia data contents and the work of retrieving, storing and manipulating a multimedia data have been the focus of recent work. The display for multimedia data should retrieve and access the contents easily that users want to present. This study is about the design and implementation of a system to retrieve multimedia data based on the contents of documentation or the caption information of a multimedia data for retrieving documentation including multimedia data. It intends to develop an filtering step to retrieve all of keyword within the caption information of multimedia data and text of a documentation. Also, the system is designed to retrieve a large amount of data quickly using an inverted file structure available for B+ tree.

• Journal of IKEEE
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• v.23 no.1
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• pp.249-253
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• 2019

Most of music-transcription systems that have been commercialized operate based on audio information. However, these conventional systems have disadvantages of environmental dependency, equipment dependency, and time latency. This paper studied a vision-based music-transcription system that utilizes video information rather than audio information, which is a traditional method of music-transcription programs. Computer vision technology is widely used as a field for analyzing and applying information from equipment such as cameras. In this paper, we created a program to generate MIDI file which is electronic music notes by using smart-phone cameras to record the play of piano.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.243-249
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• 2007

In this paper we introduce a system that assists news reporters to easily edit source video anywhere, and transfer the result from a remote site to the station. Presently reporters are bothered to edit source materials, compress and transfer using several separate tools. Moreover such tools have lots of too complicated features to use only for news production. We have integrated file sending and video editing functions together for seamless workflow. News programs usually need promptness in production. For this reason our system is designed to make it possible the one-stop production of news items outside the TV station. Also the system reflects the demands of field workers, that is, easy usage for the beginner and features for speedy news production. One of the most focused is that the reliability of the system is guaranteed in the process of transfer. To achieve this end, we have implemented several error-resilient schemes for unexpected network errors. Our system consists of remote laptop editing terminals and a newsgathering server. DV-format based editing and analog-to-DV converting device are adopted to capture video from not only lightweight DV camcorders but also old-fashioned ENG cameras into laptop computers. We expect that news reporters and cameramen can take terminals anywhere the Internet is available and both editing and sending will be done on the spot. This will help increase the competitive power of our news production.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.301-304
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• 2013

In this paper, to improve the fast boot and soft real-time for the responsiveness in Qplus with relative evaluation rather than an absolute evaluation using validated to perform the services actually used. Qplus is included soft real-time, fast booting, and file system technology. There is a development board that mounted on an embedded Linux and Qplus. AV (Audio / Video) group communications is ported on the development board for soft real-time multimedia streaming services and to evaluate the performance of communication. We performed three major evaluation such as booting time measurement experiment, own performance measurement experiments for soft real-time measurement experiment, and performance measurement experiments for via the network communication performance evaluation. They are a practical Qplus performance evaluation and analysis.

• Convergence Security Journal
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• v.11 no.4
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• pp.11-17
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• 2011

In this paper, we propose system design and implementation of FLV Move Picture Solution based on IDC apply to Mini IPTV. IDC of energy minimize and Green Data Center design resources make use of maximization, and Mini IPTV of diverse contents service provider and network provider offer Mini IPTV customers to transmit network. at this time implemented on the improve Move Picture of motion blur and compressibility using FLV solution file format and a compression technique, and reduced traffic cost and solved security question. specially, on the web quickly growing a branch of e-Learning wish to be of help.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.691-708
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• 2010

An important issue of supporting multi-users with diverse quality-of-service (QoS) requirements over wireless networks is how to optimize the systematic scheduling by intelligently utilizing the available network resource while, at the same time, to meet each communication service QoS requirement. In this work, we study the problem of a variety of communication services over multi-media heterogeneous cognitive OFDM system. We first divide the communication services into two parts. Multimedia applications such as broadband voice transmission and real-time video streaming are very delay-sensitive (DS) and need guaranteed throughput. On the other side, services like file transmission and email service are relatively delay tolerant (DT) so varying-rate transmission is acceptable. Then, we formulate the scheduling as a convex optimization problem, and propose low complexity distributed solutions by jointly considering channel assignment, bit allocation, and power allocation. Unlike prior works that do not care computational complexity. Furthermore, we propose the FAASA (Fairness Assured Adaptive Sub-carrier Allocation) algorithm for both DS and DT users, which is a dynamic sub-carrier allocation algorithm in order to maximize throughput while taking into account fairness. We provide extensive simulation results which demonstrate the effectiveness of our proposed schemes.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.10
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• pp.734-745
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• 2006

This paper presents a PC cluster-based distributed VOD server that minimizes the load of an interconnection network by adopting the VIA communication protocol and the interval cache algorithm. Video data is distributed to the disks of the distributed VOD server and each server node receives the data through the interconnection network and sends it to clients. The load of the interconnection network increases because of the large amount of video data transferred. This paper developed a distributed VOD file system, which is based on VIA, to minimize cost using interconnection network when accessing remote disks. VIA is a user-level communication protocol removing the overhead of TCP/IP. This papers also improved the performance of the interconnection network by expanding the maximum transfer size of VIA. In addition, the interval cache reduces traffic on the interconnection network by caching, in main memory, the video data transferred from disks of remote server nodes. Experiments using the distributed VOD server of this paper showed a maximum performance improvement of 21.3% compared with a distributed VOD server without VIA and the interval cache, when used with a four-node PC cluster.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.258-263
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• 1995

미래 정보와 시대에서 중추적인 역할을 할 광관련 멀티미디어 장비들은 최근 관련 산업계에서 주목을 받기 시작하고 있고 특히 기존 VTR(Video Tape Recorder) 시장을 대체할 차세대 DVDR(Digital Video Disk Recorder)는 기술전쟁이라고 할 정도로 선진 기업의 연구가 치열해지고 있다. DVDR 시스템에서는 필요한 정보들을 레이저빔을 이용한 광학신호로 바꾸어 광디스크에 기록, 재생하는 광픽업이 절대적으로 필요하게 된다. 그런데 광픽업의 위치추종기구인 Actuator는 정확한 위치추종(.+-.1.$\mu$m 오차이내)을 할 수 있는 성능이 요구되며 서보의 특성상 20KHz 이하에서 불필요한 모우드가 가진되지 않는 정밀부품이어야 하므로 Actuator 각 부품의 동적인 특성을 명확히 규명할 필요가 있다. 따라서 본 연구에서는 우선 Actuator 각 부품과 가동부 전체의 중량 및 진동해석을 통해 동특성을 조사하였다. 그리고 Actuator의 중요한 기본성능중 하나인 구동감도 확보여부를 검토할 필요가 있기 때문에 유한요소법 프로그램인 ANSYS를 이용하여 자기회로 부분에 대한 해석을 구하였다. 또한 가동부와 자기회로 등 하위부품을 조립하는 과정에서 발생하는 조립오차로 인해 불필요한 공진과 회전형상이 야기될 수 있으므로 동특성 및 문제점 파악을 위한 민감도 분석이 필요하다. 따라서 본 연구에서는 가동부의 관성 모멘트 값과 강체에 대한 일반식을 이용한 자체 프로그램을 작성하여 조립공차를 구하였다. 이와같은 과정을 통해 구해진 설계값을 바탕으로 실제 제작된 Actuator에 대해서는 비접촉식 측정방법을 통해 동특성값을 측정하였고 이를 해석값과 상호 비교하였다.동강성행렬법(dynamic stiffness matrix method)을 이용하여 해석하고자 한다. 수준임이 입증되었다. 본 연구의 결과를 토대로우리나라 젊고 건강한 남성에게 적합한 무게상수는 작업자군에 대하여 25.05kg, 학생군에 대하여 20.24kg 으로 나타나 이는 미국 NIOSH 안전기준과 대체로 일치함을 발견하였다.ive structures utilized in Client/server architecture for distribution and cooperative processing of application between server and client this study presents two different data management methods under the Client/server environment; one is "Remote Data Management Method" which uses file server or database server and. the other is "Distributed Data Management Method" using distributed database management system. The result of this study leads to the conclusion that in the client/server environment although distributed application is assumed, the data could become centralized (in the case of file server or database server) or decentralized (in the case of distributed