• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.335-347
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• 2007

VoIP (Voice over IP) is a technology to transport video and voice traffic over IP networks such as Internet. Today, the VoIP technology is viewed as the right choice for providing voice, video, and data communication among various terminals over the next generation network. This paper discusses a multipoint VoIP implementation with end-point mixing model which can support multipoint conference without a conference bridge. The multipoint VoIP is implemented with SIP (Session Initiation Protocol), and supports STUN (Simple Traversal of UDP Through NATs) since it works in an asymmetric NAT (Network Address Translator) environment. The characteristics of this paper are as follows. It is possible that all terminals in the hierarchical conference don't receive the duplicated media information because we use the end-point mixing model with the new media processing module. And, the paper solves the problem that the hierarchical conference session should be separated into several sessions when a mixing terminal terminates the hierarchical conference session.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.137-142
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• 2009

Purpose: This study was performed to find the current problems of positron emission tomography/computed tomography(PET/CT) data on CD for inter-hospital transfer. Materials and Methods: The subjects were 746 consecutive $^{18}F$-fluorodeoxyglucose PET/CT data CDs from 56 hospitals referred to our department for image interpretation. The formats and contents of PET/CT data CDs were reviewed and the email questionnaire survey about this was performed. Results: PET/CT data CDs from 21 of 56 hospitals(37.5%) included all transaxial CT and PET images with DICOM standard format which were required for authentic interpretation. PET/CT data from the others included only secondary capture images or fusion PET/CT images. According to this survey, the main reason of limited PET/CT data on CD for inter-hospital transfer was that the data volume of PET/CT was too large to upload to the Picture Archiving and Communication System. Conclusion: The majority of hospitals provided limited PET/CT data on CD for inter-hospital transfer, which could be inadequate for accurate interpretation and clinical decision making. It is necessary to standardize the format of PET/CT data on CD for inter-hospital transfer including all transaxial CT and PET images with DICOM standard format.

• Journal of Broadcast Engineering
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• v.11 no.1 s.30
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• pp.116-129
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• 2006

The progress of data transmission technology through the Internet has spread a variety of realistic contents. One of such contents is multi-view video that is acquired from multiple camera sensors. In general, the multi-view video processing requires encoders and decoders as many as the number of cameras, and thus the processing complexity results in difficulties of practical implementation. To solve for this problem, this paper considers a simple multi-view system utilizing a single encoder and a single decoder. In the encoder side, input multi-view YUV sequences are combined on GOP units by a video mixer. Then, the mixed sequence is compressed by a single H.264/AVC encoder. The decoding is composed of a single decoder and a scheduler controling the decoding process. The goal of the scheduler is to assign approximately identical number of decoded frames to each view sequence by estimating the decoder utilization of a Gap and subsequently applying frame skip algorithms. Furthermore, in the frame skip, efficient frame selection algorithms are studied for H.264/AVC baseline and main profiles based upon a cost function that is related to perceived video quality. Our proposed method has been performed on various multi-view test sequences adopted by MPEG 3DAV. Experimental results show that approximately identical decoder utilization is achieved for each view sequence so that each view sequence is fairly displayed. As well, the performance of the proposed method is examined in terms of bit-rate and PSNR using a rate-distortion curve.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.877-890
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• 1999

In this paper, a multimedia mail including video, sound, graphic data has been proposed as the next generation mail of the text based mail. In order to develop the multimedia mail, the most outstanding problem is the fact that the multimedia data are too huge to send them to the receiving end directly. The fact of big data may cause many problems in both transferring and storing the data of the multimedia mail. Our main idea is to separate between a control program for the multimedia presentation and multimedia data. Since the size of a control program is as small as a plain text mail, it has no problem to send it attached to the internet mail to the receiver directly. Instead, the big multimedia data themselves may remain on the sender's computer or be sent to a designated server so that the data may be transferred to the receiver only when the receiver activates the play of the multimedia mail. In this scheme, our research focus is paced on the buffer management and the thread scheduling for the real time play of the multimedia mail on internet. Another problem is to provide an easy way of editing a multimedia presentation for an ordinary people having no programming knowledge. For the purposed, VIP(Visual Interface Player) has been used and the results or multimedia mail implemented on LAN has been described.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.68-79
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• 2003

In this paper, we propose a system that detects the current speaker in multi-speaker video conference by using lip motion. First, the system detects the face and lip area of each of the speakers using face color and shape information. Then, to detect the current speaker, it calculates the change between the current frame and the previous frame. To accomplish this, we used two CCD cameras. One is a general CCD camera, the other is a PTZ camera controlled by RS-232C serial port. The result is a system capable of detecting the face of current speaker in a video feed with more than three people, regardless of orientation of the faces. With this system, it only takes 4 to 5 seconds to zoom in on the speaker from the initial image. Also, it is amore efficient image transmission system for such things as video conference and internet broadcasting because it offers a face area screen at a resolution of 320X240, while at the same time providing a whole background screen.

• Korean Journal of Digital Imaging in Medicine
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• v.6 no.1
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• pp.69-77
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• 2003

목적 : 최근 들어 여러 가지 디지털 의료장비와 각종 의료정보시스템, 인터넷의 활용에 따라 다양한 종류의 의료정보와 지식이 엄청나게 증가하고 있고, 최신의 진료환경구축을 위해서 이러한 지식과 정보들을 통합 관리하려는 필요성과 요구가 대두되고 있다. 그러나 이러한 요구들은 기존의 종이로 된 차트나 필름 등의 기법에서는 물론이고 여러 가지 독립적인 전산 시스템들 <처방전달시스템(OCS), 의료영상저장전송시스템(PACS) 등>을 통해서도 충족되기 어려운 것이 현실이다. 왜냐하면 기존에 설치된 의료 정보 시스템들은 대체로 독자적인 처리방식과 내부구조를 가지고 있기 때문에 서로 다른 의료 정보 시스템간에 정보를 교환한다는 것이 사실상 매우 어렵거나 심지어는 불가능한 경우가 있기 때문이다. 그러나 이러한 의료 정보들을 최대한 유기적으로 활용하기 위해서는 이상의 여러 가지 의료 정보 시스템들을 완벽히 통합하는 것이 필수적이고 이러한 통합의료정보시스템이 비로소 진료에 있어서의 의사결정 과정에 중추적으로 활용될 수 있는 것이다. 특히 의료영상을 다루는 PACS에서는 다른 종류의 의료정보시스템인 OCS(처방전달시스템)와의 연계가 매우 중요하다. 그러나 이러한 중요성에도 불구하고 병원의 전산시스템이 서로 호환되지 않음으로 인해 OCS/PACS 통합은 PACS 도입과정 중에서 가장 어려운 부분으로 인식되어 온 것이 사실이다. 이제까지의 PACS에 있어서는 대량의 영상 데이터를 고속으로 처리하기 위한 기술적인 문제에 주로 관심을 기울였으며 기존의 정보 시스템과의 연계 또는 통합문제는 충분히 고려되지 않았다. 그 결과 PACS를 도입한 병원에서는 기대와는 달리 PACS 운용을 위한 많은 인력소모가 뒤따르거나 운용에 차질을 빚는 등 여러가지 문제가 발생하게 되었다. 따라서 이제까지의 PACS 개발이 기술적인 문제 해결을 위한 방향 접근에서 이루어졌다면, 이제부터는 기술적인 해결을 바탕으로 하여 병원내의 임상운용환경에서 그 효율성을 최대화할 수 있기 위하여 기존 OCS/PACS의 통합 연계성을 주 관심으로 하는 임상적인 접근이 이루어져야 할 시점이라고 파악된다. 이와 같은 OCS/PACS의 통합은 병원 내에서 일어나는 일련의 진료 과정들에 있어서 문자정보뿐 아니라 영상정보까지를 포함하는 모든 진료정보의 관리와 전달을 컴퓨터화 함으로써 진료효율을 비약적으로 형상 시키는 효과를 가져올 수 있으므로 궁극적으로는 모든 병원의 정보시스템이 지향하는 목표이기도 하다. 따라서 OCS/PACS의 통합을 구현하기 위해서는 기존 방식과 OCS/PACS 통합 방식의 차이점이 분석 되어져야 하며 이러한 분석을 바탕으로 차후 병원에 도입되는 시스템이 안정적이고 완성도 높은 병원 정보화 시스템으로 구축 되어져야 하므로 이에 따른 통합 시스템에 대한 분석을 하고자 한다.

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.492-504
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• 2009

The delivery of multimedia that efficiently adapts its bit-rate to changing network characteristics and conditions is one of the important challenging tasks in the design of today's real-time multimedia streaming systems such as IPTV, Mobile IPTV and so on. In these work, the primary focus is on network congestion, to improve network stability and inter-protocol fairness. However, these existing works have problems which do not support QoE (Quality of Experience), because they did not consider essential characteristics of contents playback such as the media continuity. In this paper, we propose a novel rate control scheme for improving the QoE of multimedia streaming service in the Internet congestion, called NCAR (Network and Client-Aware Rate control), which is based on network-aware congestion control and client-aware flow control scheme. Network-aware congestion control of the NCAR offers an improving reliability and fairness of multimedia streaming, and reduces the rate oscillation as well as keeping high link utilization. Client-aware flow control of NCAR offers a removing the media discontinuity and a suitable receiver buffer allocation, and provides a good combination of low playback delay. Simulation results demonstrate the effectiveness of our proposed schemes.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.39-46
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• 2015

This paper presents an automatic method to detect and count the cells from microorganism images based on mobile environments. Cell counting is an important process in the field of biological and pathological image analysis. In the past, cell counting is done manually, which is known as tedious and time consuming process. Moreover, the manual cell counting can lead inconsistent and imprecise results. Therefore, it is necessary to make an automatic method to detect and count cells from biological images to obtain accurate and consistent results. The proposed multi-step cell counting method automatically segments the cells from the image of cultivated microorganism and labels the cells by utilizing topological analysis of the segmented cells. To improve the accuracy of the cell counting, we adopt watershed algorithm in separating agglomerated cells from each other and morphological operation in enhancing the individual cell object from the image. The system is developed by considering the availability in mobile environments. Therefore, the cell images can be obtained by a mobile phone and the processed statistical data of microorganism can be delivered by mobile devices in ubiquitous smart space. From the experiments, by comparing the results between manual and the proposed automatic cell counting we can prove the efficiency of the developed system.

• Journal of Korea Multimedia Society
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• v.8 no.10
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• pp.1383-1390
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• 2005

Mobile Multimedia Storage Server should provide to store and transfer a data that the number of concurrent datum by Personal Digital Assistant(PDA) requests in real time. simultaneously. But, While the large number of a PDA request connect to MTS (Mobile Translation Storage) server with BottleNeck problem in mobile internet environment by many constraints such as limited bandwidth can be introduced. This paper introduces an optimal method of new DVDS (Dynamic Variable Disk Scheduling) for MTS server which is based on the Weight Value to solve the BottleNeck problems that occur when transfer and store capture images through mounted digital camera on the PDA in real time simultaneously. The comparison with previous research shows that the proposed scheme provides better.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1260-1266
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• 2007

The information and communication technology under developing from was time of broadcast and communication Convergence. There is iCOD with representative service of broadcast and communication Convergence. This the superhigh speed Internet about under using is the service which provides information service, the video contents and broadcasting and others with TV. But this service when it searches broadcasting information of different Channel, again must analyze the stream of broadcasting there is a problem point. This thesis hereupon iCOD broadcasting services it searched efficiently from the terminal and in order the fact that it selects from iCOD broadcasting streams SI information about under extracting SD&S base iPG XML documents it created and it transmits with the distant mote cast the method which and it planned it embodied.