• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.619-624
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• 2007

향상된 성능의 3 세대 무선 인터넷 서비스를 제공하기 위해 등장한 IEEE 802.16 표준은 VoIP를 적용 할 수 있는 QoS 기능을 규정하고 있으며 WiMAX 포럼의 장비 제조사들은 저마다의 scheduling 기법 구현을 통해 WiMAX 네트워크에서 voice service가 가능하도록 장비를 설계하고 있다. 그럼에도 불구하고, WiMAX 무선 구간에서 사용되는 MAC header는 제한된 RF 자원의 사용에 부담을 주고 있으며, BS(base station)와 BSC(BS controller)간에 사용되는 tunneling protocol의 헤더 역시 VoIP packet에 붙게 되어 대역폭의 비효율화를 초래한다. 유선상에서의 overheader는 저렴한 Gigabit Ethernet 링크를 사용하면 대역폭이 충분히 커지므로 별 문제가 되지 않지만 무선 상의 overheader는 반드시 줄여져야만 효율적인 무선 자원 이용 및 voice quality의 향상을 가져올 수 있다. 따라서 본 연구에서는 지금까지 제안된 IP/UDP/RTP 헤더 압축 기법 및 WiMAX MAC header 압축 기법을 분석하여, 무선 구간 WiMAX 네트워크에서 VoIP 서비스를 효율적으로 제공할 수 있는 방안을 제시하고자 한다.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.3
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• pp.59-68
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• 1998

This paper propose a hardware architecure of multimediasysgem for integrated processing of the multimedia data such as audio and video, and describes on the design and implementation of multimedia integrated processing Unit. The unit comprises most commonly needed multimedia processing function for computer-based video conference: audio-visual datacapture, playback, compression, decompression as well as interleaving/disinterleaving of compressed audio-visual data. The proposed architecture minimizes the CPU overhead that might be caused by multimedia data processing and assures the fluent data flow among system components. Also, this unit is tested and analyzed under the computer-based video conference to confirm the multimedia unit of proposed architecture using communication protocol and application software through Ethernet and FDDI (Fiber Distributed Data Interface) networks.

• Korean Journal of Adult Nursing
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• v.15 no.3
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• pp.383-392
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• 2003

Purpose: The purpose of this descriptive study was to gain basic data to develop a self-care protocol for the lymphedema patients. Method: The subjects of this study consisted of 115 patients with lymphedema from 8 hospitals and two community health and welfare centers in Busan and Seoul. The data was collected with questionnaire by self reporting of patients between March 2001 and December 2001. Data was analyzed by mean and percentage. Result: For self-care activities in daily life, compliance of 'use skin care preparations', 'use heat and cold', 'protect from local compression on affected limbs', 'protect from insect biting', 'use aids to protect affected limbs', 'take diuretics and take protein diet' did not reach to 50%. For self-care activities related to complex physical therapy, 28.7% of subjects complied with compression garment, 14.8% with manual lymph drainage, and 13.0% with exercise. 20.0% of subjects tried to treat with acupuncture and 13.9% with heat therapy. Conclusion: From this study, it is suggested that patients need to get a self-care education with correct information about self care activities and health care professionals need to develop more convenience self-care techniques of massage and exercise.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.7
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• pp.653-660
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• 2013

This paper deals with the problem of unfairness among uplink TCP (Transmission Control Protocol) flows associated with frame aggregation employed in IEEE 802.11n WLANs (Wireless Local Area Networks). When multiple stations have uplink TCP flows and transmit TCP data packets to an AP (Access Point), the AP has to compete for channel access with stations for the transmission of TCP ACK (acknowledgement) packets to the stations. Due to this contention-based channel access, TCP ACKs tend to be accumulated in the AP's downlink buffer. We show that the frame aggregation in the MAC (Medium Access Control) layer increases TCP ACK losses in the AP and leads to the serious unfair operation of TCP congestion control. To resolve this problem, we propose the TAC (TCP ACK Compression) mechanism operating at the top of the AP's interface queue. By exploiting the properties of cumulative TCP ACK and frame aggregation, TAC serves only the representative TCP ACK without serving redundant TCP ACKs. Therefore, TAC reduces queue occupancy and prevents ACK losses due to buffer overflow, which significantly contributes to fairness among uplink TCP flows. Also, TAC enhances the channel efficiency by not transmitting unnecessary TCP ACKs. The simulation results show that TAC tightly assures fairness under various network conditions while increasing the aggregate throughput, compared to the existing schemes.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.383-384
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• 2013

본 연구는 스포츠용 탄력 압박 스타킹(Essential compression calf sleeve, SKINS, Australia)을 착용하고 최대 운동을 하였을 때, 하지 부종에 어떠한 효과가 있는지를 알아보고자 한다. 실험 대상자는 젊은 성인 남녀 30명으로(남자 15명, 여자15명) 근 골격계 및 심혈관계에 특이 병력이나 사고에 의한 외상 등이 없었으며, 규칙적으로 운동을 하는 자는 제외하였다. 대상자들의 신체적 특성을 파악하기 위해서 자동 신장계(BSM330, Biospace, Korea)를 사용하였다. 부종정도를 알기위해서 줄자로 운동 전후의 장딴지 근(종아리)의 둘레와 체성분 분석기(InBody 720, Biospace, Korea)를 사용하여 하지의 부종 수치를 측정하였다. 최대의 운동은 호흡가스 분석기와 연결된 트레이드밀(CPEX-1, IRS, Japan)을 사용하여 변형된 BRUCE Protocol TR-3에 따라 호흡 교환율(R) 값이 1.15이상 되거나 all-out 될 때까지 하였다. 실험 대상자들은 동일 집단으로 전이효과를 방지하기 위하여 일주일의 간격을 두고 스포츠 탄력 압박 스타킹 착용 유무에 따른 동일한 실험을 두 번 하였다. 측정은 최대 운동 전후의 장딴지 근(종아리)의 둘레와 부종 수치를 하였다. 스포츠용 탄력 압박 스타킹 착용 유무와 운동 전후를 비교하기 위하여 MANOVA(다변량 분산분석)를 사용하였고 유의수준은 .05로 설정하였다. 탄력 압박 스타킹을 착용한 상태에서 최대 운동 전후의 부종 정도를 측정한 결과 스타킹을 착용하지 않았을 때 운동 전후의 둘레가 유의하게 증가하였고(p<0.05), 스타킹을 착용 하였을 때 운동 전후의 둘레가 유의하게 증가하지 않았다(p>0.05). 부종 수치(세포외액/전체체액)는 탄력 압박 스타킹을 착용하였을 때 오른쪽 다리는 유의하지 않게 감소하였고(p>0.05), 왼쪽 다리는 유의하게 감소하였다(p>0.05). 탄력 압박 스타킹을 착용하고 운동할 경우 하지의 부종 경감에 어느 정도 효과가 있다고 사료된다.

• The Journal of Korean Physical Therapy
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• v.17 no.4
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• pp.457-467
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• 2005

Physiotherapyists frequently use manipulative therapy technique to treat dysfunctionand pain resulting from ankle sprain. Despite the high prevalence of lateral ankle ligament injuries, few studies are available indicating any physical associations with the development of lateral ankle ligament injuries, or information of treatment for lateral ankle ligament injuries. To investigate the effect of passive joint mobilization, the anteroposterior glide on the talus, on increasing weight-bearing dorsiflexion, single support time and VAS. Sixty lateral ankle ligament injuries (grade I and grade II) aged between 17 and 27 years (mean age 21) were recruited. Subjects were randomly assigned to 1 of 2 treatment groups. The control group received a protocol of rest, ice, compression, and elevation (RICE) and massage. The experimental group received the anteroposterior mobilization, using a force that avoided incurring any increase in pain, in addition to the RICE protocol. Subjects in both groups were treated every second day for a maximum of 2 weeks or until the discharge criteria were met, and all subjects were given a home program of continued RICE application. Outcomes were measured after each treatment. The results showed that the experimental group than the control group. Weight-bearing dorsiflexion (F=7.640, P<0.05), single support time (F=85.532, P<0.05) and VAS (F=10.610, P<0.050). Between-groups differences were observed as; experimental group is increased weight-bearing dorsiflexion, single support time and reduced VAS.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.2 s.332
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• pp.89-96
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• 2005

In this paper, we propose a customer premise platform for processing multimedia data service on the ATM network. The proposed platform has a specific AAL2 processor that includes AAL2 protocol and scheduler algorithm so as to off-load large potion of burden from host processor and make it easy to process multimedia data from the ATM network in real time compared with conventional platform in which AAL/ATM tasks are processed by software. The ATS scheduler that is implemented based on 2-level time slot ring provides a simple and efficient method for scheduling data of VBR-rt, UBR and CBR traffics. TMS320C5402 DSP is used to process voice-related tasks such as voice compression and voice packet manupulation and AAL2 processor is implemented on $0.35\;{\mu}m$ process line. We implemented the customer premise equipment for VoDSL service and tested the proposed platform on a test bed network. The experimental results show that the proposed equipment has the call success rate of $97\%$ at least and provides voice service of toll-qualify.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.363-367
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• 1999

As the subscription rate to both Internet services and wireless communications services increases rapidly, traffic in the future wireless communications will be dominated by Internet applications. Current research for wireless technology is focused to the multimedia data transmission mainly for the personal computer or notebook whose display which has large display and abundant memory. But in the near future, Internet access request from the handphone or PDA device which is already spreaded in the world will be large. Special handset terminals which has small display monitor, low capacity memory and poor processing power has to be managed differently from torrent wireless communications protocols. So, WAP Forum is organized with wireless handset manufacturers in the world and the standardization process for wireless application is being actively developed. In this paper, basic model and architecture of WAP is introduced and adaptation requirements for change from HTML documents to WML formats are proposed. Also, compression ratio gained in the transform from the existing web documents to WML is shown.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.9-15
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• 2001

Very low bit rate video coding uses the inter-picture video coding method for high compression. The inter-picture video coding is coded based on the information of the previous frames so any packet loss can lead to reduce the image quality on the transmission. In this paper, we proposed the multi-stream generation method for inter-media synchronization of very low bit rate video based on TCP for reliable transmission. The proposed approach performs a reliable transmission via a TCP based protocol. This method incorporates multi-streams in order to enhance the robustness of delivery and can withstand against network jitter. Moreover, the client bandwidths are fully utilized in a highly efficient way.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1101-1104
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• 2005

As intelligence of robot is developed, consumer of robot changes by ordinary people. Intelligent service robot is produced to a target of ordinary people. It is risen that need the most service robot business. Among the control mobile robot because using network by real time. Do to appear on mobile phone LCD screen being transmitted image from device that acquire transmit of mobile phone user interface development and real time mobile robot in this study. Use the BREW that is Qualcomm's Mobile platform for mobile phone user interface development. Mobile phone JPEG compression function chooses excellent camera phone and display transmit image which send connection setting screen and mobile robot on LCD screen by real time. At the same time, materialize to make screen that can process button input that can control transfer of robot. Also, Relay Server used to help processing of protocol to control direction of mobile robot.