• Journal of Soil and Groundwater Environment
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• v.21 no.6
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• pp.36-45
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• 2016

Variability in precipitation due to climate change causes difficulties in securing stable surface water resource, which requires understanding of relation between precipitation and stream discharge. This study simulated stream discharge in a small mountainous forested catchment using antecedent precipitation index (API) models which represent variability of saturation conditions of soil layers depending on rainfall events. During 13 months from May 2015 to May 2016, stream discharge and rainfall were measured at the outlet and in the central part of the watershed, respectively. Several API models with average recession coefficients were applied to predict stream discharge using measured rainfall, which resulted in the best reflection time for API model was 1 day in terms of predictability of stream discharge. This indicates that soil water in riparian zones has fast response to rainfall events and its storage is relatively small. The model can be improved by employing seasonal recession coefficients which can consider seasonal fluctuation of hydrological parameters. These results showed API models can be useful to evaluate variability of streamflow in ungauged small forested watersheds in that stream discharge can be simulated using only rainfall data.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1785-1794
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• 2000

This paper presents a computational object model supporting CM(Continuous Media) stream interfaces including QoS(Quality of Service) required in the distributed application method for the proposed stream interface including QoS. A stream interface consists of a data channel and a control channel. In this paper, the CORBA supporting communication channel is used as the control channel and various transport protocols can be used as the dta channel of the stream interface. Also, specifications of the application QoS are included in stream interface specification. In implementation, FIFO queues and timers are used to support transmission rate, delay and jitter control mechanisms of he stream interface.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.100-108
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• 2007

Currently, multimedia stream services are provided in various network environments such as wireless networks. It is crucial to address QoS problem for multimedia service in heterogeneous networks. This paper suggests the scheme to increase the efficiency for the transmission of multimedia data. We also propose the adaptive algorithm that switch between UDP and TCP based on the size of the transmitted multimedia data. In addition, it presents the method that duplicates the multimedia data for the efficiency of transmission. We designed the MPEG stream service and conducted the simulation to verify our adaptive MPEG stream service.

• Journal of Korean Academy of Nursing Administration
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• v.18 no.2
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• pp.244-250
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• 2012

Purpose: The purpose of this study was to investigate the effect of a short message service intervention on adherence to maximal barrier precautions (MBP) and catheter-related blood stream infections. Method: The data were collected from March to September, 2008, at an 826-bed university-affiliated hospital in Daejeon. The study participants were 24 physicians who were inserting central catheters and 133 patients (control group 78 and intervention group 55) with central catheter insertions. The researcher sent the message (adherence to MBP and optimal recommendations) to each internal medicine doctor using the short message service (SMS) for cellular phones. Messages were sent monthly for 3 months. Data were analyzed by chi-square test and t-test using SPSS 12.0 windows program. Result: Adherence to maximal barrier precautions was significantly increased from 44.9% to 69.1% (p=.006) after the SMS intervention. But changes in the rate of CRBSI (catheter related blood stream infection) between the intervention group (1.89) and the control group (4.45) were not significant (p=.323). Conclusions: The results indicate that the SMS intervention is effective in increasing the adherence to maximal barrier precautions and the SMS intervention can be recommended for utilization in infection control nursing practice.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.79-84
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• 1998

This paper describes implementation of the core DSM-CC UU interface. It briefly describes the reference model for the DSM-CC and related standards that should be reviewed for the implementation. The Common Object Request Broker Architechture, Revision 2.0 (CORBA 2.0) is sued as a remote procedure call (RPC) scheme for the UU Interface. Entire system was implemented with C++ on Windows NT platforms. The implementation procedure has been decomposed ito two tasks. The first task is to implement the Naming Service for service navigation. The Naming Service is one of the CORBA Services that extend the core CORBA specification. A client GUI is implemented for easy navigation among various services. The second task is to construct multimedia server and client for a Video-on-Demand (VoD) system. MPEG-2 Transport Stream is transported via ATM AAL5 using the Windows Socket 2.2 ATM extension API. A GUI enables the user to navigate the service domain and select a program. After the selection the user can control the MPEG-2 stream with VCR-like buttons.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1766-1777
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• 2000

In multimedia new service on the internet, there are problems such as server overload, network congestion and initial latency. To overcome these problems, we propose a proxy push-caching scheme that stores a portion of continuous media stream or entire stream, and a transmission scheme of NOD continuous media, RTP-RR and RTP-nR to exploit push-caching scheme. With the proposed push-caching scheme, NOD server pushes fixed portion of stream to a proxy when new data is generated, and the cached size of each stream changes dynamically according to the caching utility value of each stream. As a result, the initial latency of client side could be reduced and the amount of data transmitted fro ma proxy server to client could be increased. Moreover, we estimate a caching utility value of each stream using correlation between disk space occupied by the stream and the amount of data stream requested by client. And we applied the caching utility value ot replacement policies. The performance of the proxy push-caching and continuous media transmission schemes proposed were compared with other schemes using simulations. In the simulation, these schemes show better results than other schemes in terms of BHR (Byte Hit Rate), initial latency, the number of replacement and packet loss rate.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.21-22
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• 2011

The growth of using smartphone and tablet pc has enabled variety kinds of realtime applications. In these applications, the data which we called data stream is multidimensional, continuous, rapid, and time-varying. However the traditional Database Management System (DBMS) suffers from processing the real time and complex application, in this paper we proposed the framework for CCR Data Stream Server's design and implementation that compiled with Data Stream Database Management System (DSMS) and DBMS in EMR system. The system enables users not only to query stored CCR information from DBMS, but also to execute continues query for the real-time CCR Data Stream.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.11
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• pp.1010-1018
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• 2013

The dual-stream based stereoscopic 3D broadcasting standard was developed in 2011. EBS broadcasted 3DTV experimental service according to this standard in April 2012. Dual-stream based 3DTV broadcasting is service-compatible and backward-compatible, so viewers who have legacy 2D HDTV can watch the broadcasting content as 2D. And 3DTV viewers can select watching 2D or 3D. Since 3D content production is not usual yet for terrestrial broadcasters, only some particular programs in specific periods will be broadcasted as 3D at the initiatory stage. For it, stable viewing condition is strongly required for both 2D viewers and 3D viewers. This paper suggests broadcasting transmission system structure and effective switching scheme for stable 2D and 3D viewing conditions in the case of dual-stream based terrestrial 3DTV broadcasting.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.207-216
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• 2002

This paper present a design and implementation of a distributed audio, Video stream service framework based on CORBA for efficient processing and control of audio/video stream. We design software components which support processing, control and transmission of audio/video streams as distributed objects. For optimization of stream transmission performance, we separate the transmission path of control data and media data. Distributed objects are defined by IDL and implemented using JAVA. And device dependent facilities like media capturing, playing and communication channels are implemented using JMF (Java Media Framework) components. We show a connection establishment and control procedure of streams communication. And for evaluation, we implement a test system and experiment a system performance. Our experiments show that test system has somewhat longer connection latency time compared to TCP connection establishment, but has optimized media transmission time compared to CORBA IIOP. Also test system show acceptable service quality of media transmission.

• Journal of Korea Multimedia Society
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• v.5 no.6
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• pp.697-703
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• 2002

In this paper, we propose the adaptive multi stream transmission technique based on SPIHT video signal for the highest quality service over the current Internet that does not guarantee QoS. In addition to the reliable transmission of the video stream over the asynchronous packet network, the proposed approach provides the transmission using the adaptive frame pattern control and multi steam over the TCP for continuous replay. The adaptive frame pattern control makes the transmission date scalable in accordance with the client's buffer status. Apart from this, the multi stream transmission improves the efficiency of video stream, and is robust to the network jitter problem, and maximally utilizes the bandwidth of the client's. As a result of the experiment, the DR(delay ratio) in the proposed adaptive multi-stream transmission is more close to zero than in the existing signal stream transmission, which enables the best-efforts service to be implemented.