• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.9C
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• pp.842-852
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• 2002

The fast advance in the VoIP technologies gives a rich opportunity to create different kind of VoIP applications such as IP telephony services. The application level call signaling protocols such as ITU-T H.323 and IETF SIP provide the communication functions of end-to-end call setup and release. Currently, there is a lot of H.323 based VoIP products in the market, however SIP is considered as a suitable protocol for supporting applications in IP environments, so SIP based VoIP products and services begin to appear. In this paper, firstly we present the characteristics of some possible SIP based applications and describe the design and implementation of a VoIP example service named PC-to-PC Internet telephony service using the developed SIP network components. The PC-to-PC Internet telephony service and User Agent are developed in MS window 98/2000 using visual C/C++, and Proxy server and Registrar in Linux 7.0 using C, respectively.

• Ocean Science Journal
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• v.40 no.1
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• pp.17-24
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• 2005

A series of experiments were conducted to develop standard test organisms and test protocols for measuring sediment toxicity using candidate amphipods such as Mandibulophoxus mai, Monocorophium acherusicum, Haustorioides indivisus, and Haustorioides koreanus, which are indigenous to Korea. The relevant association of test species with sediment substrates was one of the important factors in sediment bioassay. The indigenous amphipods M mai and M. acherusicum were well associated with test sediments when they were exposed to various sediment substrates from sand to mud. The tolerant limits to various physico-chemical factors affecting bioassay results such as temperature, salinity and ammonia, as well as sensitivities to reference toxicant and contaminated sediments, were investigated using M. mai and M. acherusicum in the present study. These amphipods were tolerant to relatively wide ranges of salinity $(10{\sim}30\;psu)$ and ammonia (<50 ppm), and displayed relevant sensitivity to temperature as well. They are more sensitive to Cd, the reference toxicant, when compared to the standard test species used in other countries. Field-sediment toxicity tests revealed that M. mai would be more sensitive to sediment-associated pollutants than M. acherusicum, while the sensitivity of M. acherusicum was comparable to that of Leptocheirus plumulosus, which has been used as a standard test species in the United States of America. Overall results of this first attempt to develop an amphipod sediment toxicity test protocol in Korea indicated that M. mai and M. acherusicum would be applicable in the toxicity assessment of contaminated sediments, following the further evaluation encompassing various ecological and toxicological studies in addition to test method standardization.

• Journal of Korean Academy of Nursing
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• v.39 no.4
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• pp.508-517
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• 2009

Purpose: Despite recent advances in the surgical and postoperative management of infants with congenital heart disease, nutritional support for this population is often suboptimal. The purpose of this study was to develop a nutritional program for the postoperative period for infants who have had cardiac surgery and to evaluate effects of the program. Methods: A quasi-experimental design with pretest and posttest measures was used. A newly developed nutritional program including a feeding protocol and feeding flow was provided to the study group (n=19) and usual feeding care to the control group (n=19). The effects of the feeding program were analyzed in terms of total feed intake, total calorie intake, gastric residual volume, and frequency of diarrhea. Results: Calorie intake and feeding amount in the study group were significantly increased compared to the control group. However, the two groups showed no significant differences in gastric residual volume and frequency of diarrhea. Conclusion: The results indicate that the nutritional program used in the study is an effective nursing intervention program in increasing feeding amount and calorie intake in infants postoperative to cardiac surgery and does not cause feeding-related complications.

• Convergence Security Journal
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• v.8 no.3
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• pp.41-49
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• 2008

Other server based-application and the need of more complex interaction is required with functional strengthening and variational uses of mobile device. And mobile environments make a problem of continuous of web-service by making a problem of instance cutting between web-server and mobile device which acts as a client because of mobility. Therefore, this paper embodies a framework which keeps security and connectivity between HTTP based web-service and mobile device, and is for connection to web-service of mobile device which uses WAP in a standard protocol based mobile environment of mobile web-service for continuous web-service. This paper is analyzed in the same standard condition to compared functional delay which is based on HTTP and WAP access, and data transmission volume. Also it investigates improvement of execution overhead which is brought by interaction process.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1955-1963
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• 2009

In the application of wireless sensor networks to monitor valuable assets under concern, the appearance of a certain asset can be identified and reported simultaneously by several adjacent nodes, and this may dissipate the power of related nodes and network bandwidth as well. In the proposed method, a node that senses the appearance of some asset is allowed to send the sensing-reporting packet only after it has been being idle for a certain period without receiving any DRP(Don't Report Packet) from neighbors. It turns out that not only the cost of propagating DRPs but also that of reporting the events to the sink becomes minimal when depth of each DRP propagation is 2. In case of depth 1, at least, two routes are set up for the delivery of the sensing-reporting packet hence, reliable transfer to the sink is provided.

• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.539-544
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• 2004

This paper presents the implementation of the bluetooth headset and the audio gateway connected to the mobile Phone in the embedded environment. The bluetooth module includes the BC02 processor chip, the BCSP02 firmware and the bluelab software Including bluetooth protocol stack. The above components in the bluetooth module developed at CSR company are used as the development environment. The application program using API functions supported by bluelab is coded by C language and loaded on the flash ROM of the bluetooth module. The cail processing capacity measuring the call setup time and the clearing time between the audio gateway and the headset is considered as the performance parameter of the developed systems. As a call setup and clearing time between the audio gateway and the headset is about 88.8ms, the call processing capacity is about 11 calls per second. Therefore the performance result is satisfied in the aspect of the call processing time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.3
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• pp.239-246
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• 2013

The IEEE 802.15.4 offers standard about PHY and MAC layer and features low power, low bandwidth, and low speed data communication. Because of this reason, IEEE 802.15.4 is only within a limited range such as sensor detection and home network; nevertheless, the research about transmission multimedia data like voice packet through wireless sensor networks is conducted widely. In this paper, we proposed the group communication system based on the sensor network. TDMA/TDD MAC based on the IEEE 802.15.4 PHY for voice communication on the sensor network is designed by improvement existing peer-to-peer voice communication on the sensor network and hardware is implemented for group communication. To measure the quality of designed system, mean opinion score (MOS) is obtained from the experiment and verified by using sine wave method. As a result of an experiment, we expect that a many cases of application solution can be developed using presented system.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.13-20
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• 2013

Due to the global warming, international agreements have been propelled by industrialized countries. These days, there are various studies and projects to reduce the carbon emission quantity in South Korea, because South Korea is a strong candidate for a newly industrialized nation by Kyoto Protocol. Therefore, this study arranges plans to create various thematic map by producing database that can manage various datum based on grid spatial objects to manage quantity of forest biomass and carbon dioxide. Moreover, this study designs a system to create forest biomass by using the best method of calculation with LiDAR data and KOMPSAT-2 satellite images. In addition, this study designs a biomass monitoring system for public institutions to register biomass, suggesting actual plans to extract, manage, and utilized forest biomass.

• Journal of Digital Convergence
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• v.13 no.11
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• pp.141-148
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• 2015

In this paper, for developing and implementing the HLS(Http Live Streaming) transmitter based embedded linux which is operated easily and cheap and lower power, portable in all networks and client environments compared to exist video live streaming transmitters. We design the developed HLS transmitter hardware using the Arm11 core and then porting the Embedded Linux OS(Operating System) and implementing the HLS protocol using the open source FFmpeg and Segmenter. For proving the performance of developed HLS transmitter, we make the testing environment for testing the performance of HLS transmitter including the notebook, iPhone, android Phone, Notebook and then analysis the received video in the client displayer. In this paper, we suggest the developed HLS transmitter performance data values higher than the Apple company's HLS recommended specification values and the picture of developed HLS transmitter operation in the testing environment. The application field of this paper result is that the man who works in the emergency situation take HLS and transmit the live emergency situation to the head quarter using this portable HLS.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.49-58
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• 2016

In designing heterogeneous architecture based application-specific network-on-chips (NoCs), the opportunities of performance improvement would be expanded when applying asynchronous on-chip communication protocol. This is because the wire latency can be configured independently considering the wirelength of each link. In this paper, we develop the delay model of link-wire-length in asynchronous NoC and propose simulated annealing (SA) based floorplan-aware topology generation algorithm to optimize link-wirelengths. Incorporating the generated topology and the associated latency values across all links, we evaluate the performance using the floorplan-annotated sdf (standard delay format) file and RTL-synthesized gate-level netlist. Compared to TopGen, one of general topology generation algorithms, the experimental results show the reduction in latency by 13.7% and in execution time by 11.8% in average with regards to four applications.