• Journal of Korea Multimedia Society
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• v.13 no.8
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• pp.1221-1234
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• 2010

MANET(Mobile Ad-hoc Network)s have been researched primary at routing protocols and at the guarantees of QoS(Quality of Service) for mobile environments. Otherwise the Ubiquitous Sensor Networks (USNs) have some limitations in power energies and in processing of sensing data, as well as their network topologies are frequently changed by fading off and node failures. Thus we should redesign network protocols with concerning to energy efficiency for the USNs above all. In this paper, we focus on the protocol interface for managing for USNs based on the surveys. And then we figure the topology of USNs out and design the network protocol interface to make power saved, with data gathering and processing more efficient using our designed packet structures.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.345-352
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• 2001

In this paper, a VoIP (Voice on Internet Protocol) terminal system, which can process voice in real time based on Linux, is designed and implemented. The hardware of it is designed using a i486 processor and a DSP codec chip which encodes and decodes voice data in real time. As an operating system, RTLinux, which is a real-time operating system based on Linux, is ported to manage real-time voice processing. The voice processing module of the system uses G.723.1 voice codec of ITU-T standard. It transfers voice data within 30ms to assure good voice quality. In order to satisfy the real time requirements and QoS (Quality-of-Service) for the voice data, the real-time voice processing device driver is designed and implemented. To verify the system, the chatting application program is developed and tested for QoS of the system.

• Land and Housing Review
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• v.14 no.2
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• pp.97-107
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• 2023

This study examined how to better provide quality temporary housing for people in the event of natural and social disasters. Design for Manufacture and Assembly (DfMA) is suitable for creating an efficient planning model for the mass production and transport of a modular house. The proposed DfMA model has the following three characteristics. First is the division of the modular house into service modules and functional modules and to create diversity by developing standard parts and multi-functional parts. Second is a flexible layout suitable for various site conditions. Such flexible layouts would allow identical homes to be mass produced and deployed to a variety of locations, both nationally and internationally. Third is to simplify and minimize the automation process with dry construction to increase production efficiency. Application of this DfMA design method can lead to reduced construction time and cost and improve housing quality.

• 재활복지
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• v.20 no.3
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• pp.17-43
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• 2016

This study is on understanding the reality of disabled seniors and investigation of factors that affect overall life satisfaction, making a proposal to improve their life quality. Situation data for the disabled, gathered by Korea Institute for Health and Social Affairs (KIHASA) in 2014, was used to perform the study, and the target group is 3,181 people with disability, above the age of 65. Descriptive statistics was presented for data analysis and logistic regression analysis was performed to investigate factors that affect life satisfaction. It was concluded from the analysis that gender, age, presence of spouse (demographic factors), house income, possession of house, presence of pensioner, registration to public pension plan, social discrimination (social-economical factors), level of disability, subjective health status, level of help needed for daily living, presence of care-giver, sufficiency of help, ability to go out by oneself, difficulty of using public transportations, and presence of medical checkups (disability and health factors.) make meaningful effects to life satisfaction of disabled seniors. Based on the derived results, this study suggests intensive interests and care-giving service for disabled seniors that live alone, institutional complementations to guarantee income security, including public or private pensions, improvements to social recognition and environments for discrimination of the disabled, organization of health and medical treatment service and health care system, comprehensive service provision to social welfare for both the disabled and seniors, and comprehensive service provision to both health care and social welfare.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.118-131
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• 2019

In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.19-29
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• 2017

Purpose : To describe and understand the experience of QI (quality improvement) nurses related to the hospital QI activities in public general hospitals. Methods : Purposive sampling was conducted 10 QI nurses and who have QI work experience for more than 1 year. Data were collected through focus group interviews. Interviews were recorded, transcribed and analyzed with qualitative content analysis using Strauss and Corbin's methodology. Results : The core categories of experience with QI activities were 'the success and failure of the medical care and overall health service sector', 'the degree of activation of current QI activities', 'characteristics of public hospital QI activities', 'what is needed to activate future QI activities'. The key themes were derived as follows. 'Success of quality enhancement activities according to the characteristic of public hospitals', 'activation of public hospital QI activities through leadership and QI education', 'reorganizing the role of regional hospitals in public hospitals'. Conclusion : Physician participation is important in the success of QI activities in public hospital practice. To lead these physician participation, Sharing doctor's QI experience and providing the necessary knowledge in QI activities and helping their leadership in QI activities are needed. QI nurses at public hospitals should lead QI activities to improve national hospitals' care quality through cooperating with local hospitals.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.25-33
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• 2017

This study was conducted to analyze the Job Satisfaction, Nursing Professionalism, and Nursing Work Environment of Comprehensive Nursing Care Ward nurses and General Ward nurses and provide a convergent basic data. The participants of this study were clinical nurses in the Seoul and Gyeonggi provinces in May 1st.~July 30th., 2016. The data was analysed using SPSS WIN 23.0. When comparing General Ward 100 nurses and Comprehensive Nursing Care Ward 92 nurses, the Nursing Work Environment levels (t=3.027, p=.003) and Job Satisfaction levels (t=2.451, p=.015) were higher in General Wards. Among the General Ward nurses, higher Nursing Professionalism levels had positive correlations to Job Satisfaction levels(r=.605, p<.001). Among the Comprehensive Nursing Care Service Ward nurses, higher Nursing Professionalism levels also had positive correlations to Job Satisfaction levels(r=.642, p<.001). In conclusion, a strategy for the establishment of Nursing Work Environment and Nursing Professionalism is necessary in order to guarantee a higher quality of comprehensive nursing care service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.336-339
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• 2011

In the RTLS(Real Time Location Based System), in case of existing a number of moving target, extremely complecated data flow is can be occurred. In the network where single gateway exists, various data which was collected from sensor node is transmitted along the simple route as time goes by. In case of multi-gateway configuration, the collected data is transmitted through diverse routes rather than simple route. This kind of data causes jams on nodes and this brings down the performance of the network. Different from existing studies, in this thesis, MAC (Media Access Control) protocol which minimizes data collision between nodes and guarantees QoS(Quality of Service) is suggested, in order to communicate efficiently in multi-gateway underwater sensor network environment. In the suggested protocol, source node which wants to transmit data makes a channel reservation to a number of destination node using a RTS packet. Source node reserves a channel without collision, by scheduling CTS response time using expected delay information from neighbor nodes. Once the reservation is made, source node transmit data packet without collision. This protocol analyzes/estimates the performance compared to a method provided from existing studies via simulation. As a results of the analysis, it was comfirmed that the suggested method has better performance, such as efficiency and delay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.96-103
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• 2000

The voice traffic is one of the most important real-time objects in WATM(Wireless Asynchronous Transfer Mode) networks. In this paper, we propose a new MAC(Medium Access'Control) protocol for the efficienttransmission of voice traffic over WATM networks in the multimedia environment and compare the performanceto existing similar protocols. The new protocol separates the reservation slot period for voice and that for data toguarantee some level of QoS(Quality of Service) in voice traffic. This is denoted by a slot assignment functiondepending on the frame size. According to the characteristics of voice traffic which is repeatedly in silent states,the protocol allocates voice reservation request slots dynamically with respect to the number of silent(off state)voice sources and also sends the first block of talkspurt restarted after silent period with a reservation requestslot to reduce the access delay.The simulation results show that the proposed protocol has better performance than Slotted Aloha in bandwidthefficiency, and can serve a certain level of QoS by the given slot assignment function even when the number ofvoice terminals varies dynamically. This means we can observe that the new MAC protocol is much better thanthe NC-PRMA(None Collision-Packet Reservation Multiple Access) protocol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7C
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• pp.691-699
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• 2006

Despite of the in-depth effort to cantrol the variability in IP networks, quality of service (QoS) is still not guaranteed in the IP networks. Thus, it is necessary to deal with the audible artifacts caused by packet lasses. To overcame the packet loss problem, most speech coding standard have their own embedded packet loss concealment (PLC) algorithms which adapt extrapolation methods utilizing the dependency on adjacent frames. Since many low bit rate CELP coders use predictive schemes for increasing coding efficiency, however, error propagation occurs even if single packet is lost. In this paper, we propose an efficient PLC algorithm with consideration about the speech characteristics of lost frames. To design an efficient PLC algorithm, we perform several experiments on investigating the error propagation effect of lost frames of a predictive coder. And then, we summarize the impact of packet loss to the speech characteristics and analyze the importance of the encoded parameters depending on each speech classes. From the result of the experiments, we propose a new PLC algorithm that mainly focuses on reducing the error propagation time. Experimental results show that the performance is much higher than conventional extrapolation methods over various frame erasure rate (FER) conditions. Especially the difference is remarkable in high FER condition.