• Title/Summary/Keyword: HD-MAC

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Design of HD-MAC Decoding Filter (HD-MAC 디코더용 필터설계)

  • Nam, B.H.;Kim, H.J.;Lee, J.M.;Kim, H.J.;Jee, G.I.;Kim, G.T.
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.833-836
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    • 1991
  • This paper proposes several types of 2-D interpolation lifters for HD-MAC decoder. Filters considered here are FIR, IIR, median, and FMH. Their structure and coefficients have been determined to be appropriate for real-time computation as well as to have good reconstructability. Results or computer simulation are also presented to show the performance of those filters.

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Dynamic Retry Adaptation Scheme to Improve Transmission of H.264 HD Video over 802.11 Peer-to-Peer Networks

  • Sinky, Mohammed;Lee, Ben;Lee, Tae-Wook;Kim, Chang-Gone;Shin, Jong-Keun
    • ETRI Journal
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    • v.37 no.6
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    • pp.1096-1107
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    • 2015
  • This paper presents a dynamic retry adaptation scheme for H.264 HD video, called DRAS.264, which dynamically adjusts the retry limits of frames at the medium access control (MAC) layer according to the impact those frames have on the streamed H.264 HD video. DRAS.264 is further improved with a bandwidth estimation technique, better prediction of packet delays, and expanded results covering multi-slice video. Our study is performed using the Open Evaluation Framework for Video Over Networks as a simulation environment for various congestion scenarios. Results show improvements in average peak signal-to-noise ratios of up to 4.45 dB for DRAS.264 in comparison to the default MAC layer operation. Furthermore, the ability of DRAS.264 to prioritize data of H.264 bitstreams reduces error propagation during video playback, leading to noticeable visual improvements.

Evaluation of Nutritional Deficit Status in Hemodialysis Patients' Based on Usual Dietary Intake, Anthropometric and Biochemical Parameters (일상식이섭취상태와 신체계측 및 혈액화학적 영양지표에 의한 혈액투석 환자의 영양결핍상태 평가)

  • Sohng Kyeong-Yae
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.3 no.1
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    • pp.68-80
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    • 1996
  • Long-term hemodialysis(HD) patients manifest various signs of protein and caloric malutrition due to poor intake of nutrients and other causes. Poor nutritional status increases the mortality and morbidity rates in HD patients. Thus, mataintnance of adequate nutritional status has been a major task in taking care of patients receiving HD. This study was to evaluate the nutritional status of HD patients and to clarify the degree of nutritional deficit based on usual dietary intake, anthropometric and biochemical indicators. Sixty HD patients comprised a HD group, while the control group consisted of 60 healthy adults whose age and sex matched those of the HD group. Nutritional status was evaluated by dietrary intake using instant nutritional scale, anthropometric measures, serum protein concentrations and the number of lymphocytes. The data were analyzed by using Chi-square test and unpaired t-test. The results are as follows. 1. Regarding usual dietary intake of HD group. 1) Estimated caloric intake was significantly lower than the recommended daily allowance(RDA) and among them, 35% were taking calories less than 85% of the RDA. 2) Estimated protein intake was significantly higher than the RDA and among them 40% were taking protein more than 115% of the RDA. 3) Estimated fat intake was lower than the RDA. 4) Vitamin A, B, $B_1,\;B_2$, C and niacin in take was lower than the RDA respectively. 5) Estimated ferrous intake was within the normal limit the RDA while estimated calcium intake was higher than the RDA. 6) Both calorie and protein intake were higher for the 10 patients who had been under continuous ambulatory peritoneal dialysis than for the patients under HD from the beginning. 2. Regarding anthropometric measures : 1) Body mass index(BMI), midarm circumference(MAC), and triceps skinfold thickness(TSF) were lower in the HD group than in the control group. 2) Among HD group, 47.1% were within the normal limit of BMI, while 86.7% were within the same limit in the control group. 3) Among HD group, 35.0% were within the normal limit of MAC, while 83.3% were within the same limit in the control group. 4) Among HD group, only 8.3% were normal, 30.3% were mild deficit status of TSF, while 50% were normal and 48.3% were mild deficit status in the control group. 3. Regarding biochemical laboratory tests 1) Albumin, transferrin concentrations and the number of lymphocytes were lower in HD group than in the control group. 2) Among HD group, 98.3% were within the normal limit of albumin concentration and all were within the same limit in the control group. 3) Among HD group, only 11.7% were within the normal limit of transferrin concentration, while 81.7% were within the same limit in the control group. 4) Among HD group, 25% were within the normal limit, while 93.3% were within the same limit in the control group. The above findings suggest that HD patients were in nutritional deficit status. Adequate diet therapy and periodical evaluation of the nutritional status in HD patients are needed. Accordingly, it turned out that anthropometric measures were very reliable parameters and easy to use to evaluate nutritional status. So nurses are encouraged to adopt anthropometric measures to examine nutritional deficit status of HD patients.

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Characteristics in Nutritional Status of Patients on Hemodialysis and Continuous Ambulatory Peritoneal Patients in Chonbuk Area (전북지역 혈액투석 환자와 지속성 외래 복막 투석 환자의 영양상태 비교)

  • 김선형;김숙배
    • Journal of Nutrition and Health
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    • v.36 no.4
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    • pp.397-404
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    • 2003
  • The present study was designed to compare the nutritional status of hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. Subjects were 58 HD patients (male/female = 29/29) and 33 CAPD patients (male/female = 23/10) undergoing dialysis treatment in Artificial Kidney Unit of Chonbuk National University Hospital. For nutritional assessment, %IBW (ideal body weight), %TSF (tricep skin fold), %MAC (mid arm circumference), %MAMC (mid arm muscle circumference), serum albumin, serum transferrin, TLC (total lymphocyte count), SGA (subjective global assessment) and estimated energy and protein intakes by 1-month food frequency method were used. Between HD and CAPD group, mean age (50 $\pm$ 12 vs. 52 $\pm$ 12 yr), dialysis durations (37 $\pm$ 36 vs. 30 $\pm$ 26 mon), dietary energy intakes (28.3 $\pm$ 9.0 vs. 28.8 $\pm$ 8.6 kcal/kg/day), dietary protein intakes (1.1 $\pm$ 0.4 vs. 1.2 $\pm$ 0.3 g/kg/day) and incidence of co-morbid conditions (69.0% vs. 69.7%) were not significantly different. Data by using SGA showed a higher incidence of malnutrition in CAPD patients (45.6%) than in HD patients (36.2%). %IBW (p < 0.001), %TSF (p < 0.001) and %MAC (p < 0.001) were higher in CAPD patients than were in HD patients. But serum albumin (p < 0.001) and transferrin (p < 0.001) were significantly lower in CAPD patients than were in HD patients. A higher incidence of malnutrition was shown in CAPD Patients than in HD Patients due to different dialysis type. A significant finding was that CAPD showed protein deficient malnutrition and HD did calorie deficient malnutrition. It suggests that an adequate dietary intake considering dialysis type prevents a prevalence of malnutrition.

A Cross-layer Link Adaptive HD Video Transmission Scheme in WiMedia D-MAC based UWB Systems

  • Joo, Yang-Ick
    • Journal of Korea Multimedia Society
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    • v.15 no.12
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    • pp.1464-1474
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    • 2012
  • In this paper, we propose a QoS (Quality of Service)-aware and cooperative resource reservation scheme using cross-layer link adaptation for wireless high definition video transmission through UWB (Ultra Wide Band) network with D-MAC (Distributed Medium Access Control). A wireless high definition video transmission system usually requires stable high throughput even without line-of-sight, e.g., a destination device in another room separated by a wall. Since the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme causes lots of DRP resource reservation conflicts due to failure of beacon detection in wireless channel environment, overall performances of the WiMedia D-MAC can be deteriorated. And the current WiMedia MAC standard has not considered QoS provisioning even though QoS parameters such as a range of service rates are provided to each traffic stream. Therefore, we propose Relay DRP protocol with QoS-based relay node selection criterion, which makes a relay path to avoid DRP resource reservation conflicts and guarantee QoS more stably through cross-layer link adaptation of cooperative relay transmission scheme and is compliant with the current WiMedia D-MAC protocol. Simulation results demonstrate performance improvements of the proposed method for throughput and QoS provisioning.

Dynamic Channel Allocation of WiMedia UWB MAC Protocol Supporting Mixed HD Video Data and Shipboard Control Data with Link Parameter Optimization

  • Lee, Yeonwoo
    • International Journal of Internet, Broadcasting and Communication
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    • v.8 no.4
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    • pp.1-10
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    • 2016
  • This paper considers WiMedia UWB network based wireless ship area network (WSAN) so as to support high-quality multimedia video data services and important shipboard control data. In this paper, prioritized contention access (PCA) and distributed reservation protocol (DRP) based on WiMedia UWB (ECMA-368) MAC protocols are combined and proposed to support mixed high-quality video traffic and shipboard control data traffic applying varying DRP and PCA data periods according to channel condition and link parameter ptimization. It is shown that the proposed dynmaic channel allocation of WiMedia UWB MAC protocol can provide reliable mixed video and shipboard control data traffic as well.

HDTV의 현황과 전망

  • 이충웅
    • 전기의세계
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    • v.39 no.1
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    • pp.10-17
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    • 1990
  • HDTV는 High Definition Television의 약어로서 아주 섬세한 영상을 대화면에 비추고 원음에 가까운 음질을 즐길수 있도록 개발된 차세대의 텔레비전을 의미한다. HDTV를 우리말로는 고선명TV 또는 고정세도TV라고 한다. 원래 HDTV라는 용어는 약4반세기전에 세계에서 먼저 HDTV개발을 시작한 일본에서 생긴 말이다. 최근에 일본에서 HDTV를 Hivision이라고 한다. 미국에서는 ATV(advanced television), 유럽에서는 HD-MAC(high definion multiplexed analog component television)이라고 한다.

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Control of HD Video Streaming Using IEEE802.11e MAC Parameters (IEEE802.11e의 MAC 파라미터를 이용한 적응적인 HD급 비디오 스트리밍 제어)

  • Park, Chun-Bae;Lee, Yong-Hyun;Park, Gwang-Hoon;Kim, Kyu-Heon;Chung, Young-Sik;Huh, Jae-Doo;Suh, Doug-Young
    • Journal of Broadcast Engineering
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    • v.13 no.5
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    • pp.696-706
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    • 2008
  • In this paper we show the performance of the network-adaptive high-definition scalable video streaming using QWLAN board with IEEE 802.11e MAC monitoring and control. Realtime collected MAC parameters are used to determine which video data is extracted for the predicted available bandwidth. To achieve performance, extraction through R-D is proposed instead of the standard video packet extraction. It is shown through experiments that streaming video quality can be enhanced by fast adaptation to network conditions by using the proposed method.

Effects of Nutrition Education on Nutritional Status of Hemodialysis Patients (영양교육이 혈액투석환자의 영양상태에 미치는 효과)

  • 양정례;서혜정;김양하
    • Journal of Nutrition and Health
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    • v.36 no.7
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    • pp.749-758
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    • 2003
  • Malnutrition is a common problem in patients undergoing maintenance hemodialysis (HD) and compromised food intake is an important cause. Malnutrition is one of the important factors influencing mortality in these patients. This study was conducted to evaluate the effectiveness of nutrition education at improving nutritional status of 23 Korean HD patients (mean : 48.6 $\pm$ 10.4 years, men : 8, women : 15). Anthropometric indices, nutrient intakes, and biochemical blood indices were measured before and after a 6-month nutrition education intervention. Anthropometric indices such as percent ideal body weight [PIBW (%)], body fat, body mass index (BMI), mid-arm circumference (MAC), mid-arm muscle circumference (MAMC), and calculated arm muscle area (CAMA) of subjects were within the normal range and not changed by nutrition education. Subjective global assessment (SGA) was significantly increased (p < 0.05) after nutrition education. Intake of total energy, carbohydrate, lipid, Ca, and vitamin B1 was increased significantly (p < 0.05) but intake of phosphorus, potassium, and sodium was decreased (p < 0.05). The serum concentrations of albumin, total protein, and Ca were significantly increased (p < 0.05), but levels of P and K were decreased (p < 0.05) after the intervention. These findings suggest that nutrition education for HD patients can be effective for positively changing nutrient intakes, leading to improvements in blood indices and nutritional status.