• Title/Summary/Keyword: Group Delay

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A Cross-Layer based Video Transmission Scheme using Efficient Bandwidth Estimation in IEEE 802.11e EDCA (IEEE 802.11e EDCA에서 효율적인 대역폭 측정을 통한 Cross-Layer 기반의 비디오 전송 기법)

  • Shin, Pil-Gyu;Lee, Sun-Hun;Chung, Kwang-Sue
    • Journal of KIISE:Information Networking
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    • v.35 no.3
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    • pp.173-182
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    • 2008
  • Promoting quality of streaming service in wireless networks has attracted intensive research over the years. Instable wireless channel condition causes high transmission delay and packet loss, due to fading and interference. Therefore, they lead to degrade quality of video streaming service. The IEEE 802.11 Working Group is currently working on a new standard called IEEE 802.11e to support quality of service in WLANs. And several schemes were proposed in order to guarantee QoS. However, they are not adaptable to network condition. Accordingly, they suffered video quality degradation, due to buffer overflow or packet loss. In this paper, to promote quality of video streaming service in WLANs, we propose a cross-layer architecture based on IEEE 802.11e EDCA model. Our cross-layer architecture provides differentiated transmission mechanism of IEEE 802.11e EDCA based on priority of MPEG-4 video frames and adaptively controls the transmission rate by dropping video frames through the efficient bandwidth estimation based on distinction of each AC. Through the simulation, proposed scheme is shown to be able to improve end-to-end qualify for video streaming service in WLANs.

The Analysis of Conservative Treatment in Midshaft Fractures of Clavicle (쇄골 간부 골절의 보존적 치료 분석)

  • Cha, Seung-Do;Chung, Soo-Tai;Kim, Yong-Hoon;Park, Sang-Jun
    • Clinics in Shoulder and Elbow
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    • v.13 no.1
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    • pp.27-33
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    • 2010
  • Purpose: Most clavicular fractures can be healed by conservative treatment, although there are many factors that influence healing. The aim of the present study was to analyze factors that influence (i) bone union of midshaft fractures of the clavicle treated conservatively and (ii) bone functioning, after union. The long-term goal was to determine which treatments are adequate. Materials and Methods: We evaluated factors that have an effect on bone union and bone function after union. We evaluated age, fracture site, comminution, displacement, shortening and other factors. Among 523 clavicular midshaft fractures that presented between January 2004 and Jun 2009 at our Department of Orthopaedic Surgery, we identified 270 who had conservative treatment and 173 patients who had surgical treatment. Results: The period required for bone union increased with the degree of displacement. For the group below 12 years of age, and the group without comminution, it took half the time to achieve bone union compared with the other groups. Displacement mostly occurred within 2 weeks after conservative treatment. Conclusion: In patients with a comminuted clavicular midshaft fracture, we might, because of expected delays in bone union, delay the start of rehabilitation until patients are more than 13 years old. Because the degree of displacement may be increased within 2 weeks during conservative treatment, we can think about surgical treatments.

Meta-analysis of the Efficacy of Infliximab in Patients with Moderate-Severe Ulcerative Colitis (중등도-중증 궤양성 대장염 환자에서 infliximab의 치료효과에 대한 메타분석)

  • Kim, Jong Yoon;Lee, Sukhyang;Rhew, Ki Yon
    • Korean Journal of Clinical Pharmacy
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    • v.22 no.3
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    • pp.251-259
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    • 2012
  • Ulcerative colitis (UC) is characterized by a life-long chronic course with remissions and exacerbations. Use of biological therapies may reduce or delay the surgical procedures in patients with UC. The aim of this study was to determine the impact of infliximab (IFX) use on the rate of remission, surgical interventions, and the effect on quality of life in patients with moderate to severe UC. Literature was searched for studies that investigated the efficacy of IFX on the rate of remission, colectomy and quality of life (QoL) between January 1990 and June 2012 at MEDLINE, January 1988 and June 2012 at EMbase and others. Eleven trials were included in the meta-analysis; divided into placebo controlled 8 trials and intravenous corticosteroid controlled group 3 trials. In comparison to placebo control groups, patients who received IFX had an odds ratio (OR) of 3.712 (95% CI: 2.714, 5.079) for the short-term clinical remission, and 3.053 (95% CI: 2.044, 4.559) for the rate of long-term remission. In colectomy rate and quality of life (QoL), odds ratio were 0.566(95% CI: 0.387, 0.827) and 0.658 (0.505, 0.811) respectively. Any adverse reactions including infections, infusion reaction, rash and arthralgia were equivalent in both groups. Compared with intravenous corticosteroid controlled group, patients who received IFX had lower remission rate with short-term odds ratio 0.227 (95% CI: 0.033, 1.556) and long-term odds ratio 1.054 (95% CI: 0.317, 3.502) respectively. However, statistical significance was not showed with both two analyses. The higher adverse drug reaction (ADR) rates were occurred in the corticosteroid controlled groups. 73.3% of patients treated corticosteroid reported Cushing-like syndrome with moon face. In conclusion, IFX does increase remission rate and decrease the rate of colectomy in patients with UC without elevating any adverse reactions significantly. IFX also improves QoL in moderate to severe UC patients. It would not exceed the efficacy of intravenous corticosteroid, whereas intravenous corticosteroid also reported high rate of adverse reactions.

The Study on the Performance of DS/CDMA with a Suppressed Pilot Channel in Mobile Satellite Communication System (이동위성 통신 시스템에서 억압 파일롯트 채널을 이용한 DS / CDMA의 성능 분석)

  • Chung, Boo-Young;Choi, Bong-Keun;Kang, Young-Heung;Lee, Jin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.2
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    • pp.151-160
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    • 1997
  • In this paper, we have carried out the DS/CDMA with a suppressed pilot channel, which is used in receiving coherently with Rake diversity and in synchronizing the chip timing, in the mobile satellite communication. Also, we have investigated the envelope variation of a shadowed Rician fading simulator, and analyzed the error performences of DS/CDMA in the mobile satellite communication. The results showed that the error performance in the Heavy shadowing environment might be degraded more than in the Rayleigh fading environment since the fading envelopes in the former environment are varied randomly compared with those in the latter environment. And the performence of DS/CDMA system could be improved about 10 dB compared with that of narrowband QPSK system. In conclusion, DS/CDMA with a suppressed pilot channel had the best performance in the case of the suppressed pilot channel to transmission power ratio $\beta$=-8 dB, the number of complex delay profiles $N_{profile}$=32, and using these values, the error performance of DS/CDMA in Light shadowing environment was identical to the ideal QPSK error performance.

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Study Protocol for the Most Effective Recall Method in a Cervical Cancer Screening Program in Klang, Malaysia

  • Rashid, Rima Marhayu Abdul;Dahlui, Maznah
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5867-5870
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    • 2013
  • Background: Cervical cancer is the second most common cancer among Malaysian women with an ASR of 17.9 and a mortality rate of 5.6 per 100,000 population in 2008 (GLOBOCAN, 2008). The 5 year prevalence was estimated to be 14.5 per 100,000 population. As the second most common cancer affecting productive females, cervical cancer imposes an impact to the socioeconomic aspect of the country. However, the poor uptake of cervical cancer screening is a major problem in detecting early pre-cancerous lesions and thus, delay in initiating treatment for cervical cancer. Realizing the urgency to increase the uptake of PAP smear, besides enhancing the promotion of PAP smear screening for women above 35 years old, the call-recall system for pap smear screening had been piloted in one of the suburban districts which aimed to improve regular participation of women for cervical and breast cancer screening. This is of public health importance as identifying the best feasible option to increase patient's respond to participate in the screening program effectively in our setting will be helpful in implementing an organized regular population based screening program tailored to our setting. The pilot program of cervical cancer screening in Klang was an opportunity to assess different options in recalling patients for a repeat pap smear to increase their participation and adherence to the program. Methods and Results: This was a population based randomized control trial. Women aged 20-65 years in the population that matched the inclusion and exclusion criteria were re-called for a repeat smear. There are four different intervention groups; letter, registered letters, short messages services (SMS) and phone calls where 250 subjects were recruited into each group. Samples were generated randomly from the same population in Klang into four different groups. The first group received a recall letter for a repeat smear similar to the one that has been given during the first invitation. The intervention groups were either be given a registered letter, an SMS or a phone call to re-call them. The socio-demographic data of the patients who came for uptake were collected for further analysis. All the groups were followed up after 8 weeks to assess their compliance to the recall. Conclusions: The study will provide recommendations about the most effective methods for recall in a population based pap smear screening program on two outcomes: i) patients response; ii) uptake for repeat pap smear.

Effect of Education of Natural Disaster on Eco-friendly Attitude of Children in Integrated Class in the Lower Grades in Elementary School (자연재해 교육이 초등학교 저학년 통합학급 아동의 환경친화적 태도에 미치는 효과)

  • Oh, Sook-Hyun;Kim, Hai-Gyoung
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.1004-1013
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    • 2013
  • The purpose of this study was to investigate the effect of education of natural disaster on eco-friendly attitude of children in integrated class in the lower grades in elementary school. For the above mentioned purpose, 2 children with developmental delay and 45 general children enrolled in two integrated classes in the first grade in C Elementary School located in G City. The class that wanted to participate in this program was designated as an experimental group and the other class as a comparative group. Total 18 times of session of experimental treatment were performed during the second semester of the first grade. The effect of education of natural disaster was measured by using the tool revised and adapted by Heoh, Yun Jeong on the basis of CATES-PV designed by Musser and Diamond. As results, it was appeared that education of natural disaster was effective to increase eco-friendly attitude of children in integrated class in the lower grades in elementary school. The results that ability and attitude which were goals of the current education related to environment such as love and concern for animals and plants, life respect consciousness, preference for natural environment rather than artificial environment, conservation of nature and resources saving etc of children who received education of natural disaster suggest necessity to rethink the meaning and scope about education of natural disaster for Korean children in the preset.

An Analysis of Effects on Vision Care Program Including Traditional Korean Treatment for Elementary School Students (초등학생에서 한의학적 치료를 접목한 시력증진 프로그램의 효과 분석)

  • Kim, Chang-Hun;An, Jong-Min;Kim, So-Hi;Seol, Jong-So;Kim, Hyo-Jin;Park, Jee-Hyun
    • The Journal of Korean Medicine
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    • v.32 no.2
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    • pp.92-101
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    • 2011
  • Purpose: To evaluate the effects on vision care program including traditional Korean treatment for elementary school students. Methods: 172 eyes of eighty-six older elementary students underwent a vision care program, including traditional Korean treatment, for 3 months between March 2010 and June 2010. The vision care program included health education, such as lifestyle modification, vision strengthening exercises and a course of treatment with traditional Korean methods. Traditional Korean treatment covered periocular acupuncture point stimulation, periauricular acupuncture point stimulation and herbal drug therapy. All patients were examined for visual acuity and auto-refraction and filled out a satisfactory questionnaire about ocular discomforts and quality of life before and after treatments. Results: Patients with mild myopia (-0.75~-2.00) were 61 (35.5%), and 46 (26.7%) were emetropia (${\pm}0.50$ or less). After treatment, uncorrected visual acuity in both eyes was $0.77{\pm}0.46$, which was lower than that before treatment ($0.82{\pm}0.51$), but corrected visual acuity was $0.98{\pm}0.21$, which was higher than that before treatment ($0.93{\pm}0.28 $). About the refractive change, the emetropia group showed a slightly myopic shift while the mild myopia group intended to reduce the myopic error. However, this was not statistically significant. The scales of eyeball pain or discomfort decreased significantly from $17.59{\pm}22.5$ before treatment to $10.28{\pm}17.80$ after treatment, and the scales of the quality of life increased from $1.85{\pm}1.25$ before treatment to $2.25{\pm}1.30$ after treatment. Most patients (90.7%) were satisfied with their treatment results. Conclusions: The vision care program including traditional Korean treatment for elementary school students was effective to improve corrected visual acuity in both eyes and delay the progression of school myopia. In addition, it helped to reduce eyeball pain and discomfort and ultimately to enhance quality of life. Long-term follow-up studies will be needed.

Characteristics and Methods of Bandwidth Allocation According to Flow Features for QoS Control on Flow-Aware Network (Flow-Aware Network에서 QoS제어를 위해 Flow 특성에 따른 대역할당 방법과 특성)

  • Kim, Jae-Hong;Han, Chi-Moon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.9
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    • pp.39-48
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    • 2008
  • Recently, many multimedia services have emerged in Internet such as real-time and non- real time services. However, in this Internet environment, we have some limitations to satisfy each service feature. To guarantee the service features in Measurement-Based Admission Control(MBAC) based system on the flow-aware network, there is the method applying Dynamic Priority Scheduling(DPS) algorithm that gives a higher priority to an earlier incoming flow in all of the link bandwidth. This paper classifies all flows under several groups according to flow characteristics on per-flow MBAC algorithm based system. In each flow group, DPS algorithm is applied. This paper proposes two methods that are a DPS based bandwidth borrowing method and a bandwidth dynamic allocation method. The former is that if low priority class has available bandwidths, the flow of high priority class borrows the bandwidth of low priority class when high priority flow has insufficient bandwidth to connect a flow call. The later is that the each group has a minimum bandwidth and is allocated the bandwidth dynamically according to the excess rate for available bandwidth. We compare and analyze the characteristics of the two proposed methods through the simulation experiments. As the results of the experiment, the proposed methods are more effective than existing DPS based method on the packet loss and delay characteristics. Consequently the proposed two methods are very useful in various multimedia network environments.

DNA Synthesis and Radiosensitivity in Synchronized Human Kidney Cells in Vitro (동화시킨 사람의 신장세포에 있어서의 DNA 합성과 방사선감수성)

  • Kang, Yung-Sun;Park, Sang-Dai;Lee, Chung-Keel
    • The Korean Journal of Zoology
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    • v.14 no.4
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    • pp.175-180
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    • 1971
  • The effects of X-irradiation on the mitotic activity, the chromosome aberration and the DNA synthetic pattern in synchronized human kidney cells treated with 5-AU were measured in the present experiment. When 5-AU was added, mitotic activity was markedly suppressed. After removal of the cells from the chemical, its activity proceeded synchronouly and reached peaks at hours 10. In 5-AU+100R groups, it was observed the X-ray caused mitotic delay, the irregularity of the time when mitotic peak appeared and the inhibiton of mitotic activity. In the control group, chromosome aerrations per cell was 0.030, whereas 0.147 in 5-AU treated group. In 5-AU+100R and 5-AU+200R groups, chromosome aberrations per cell were 0.583 and 0.669 respectively and the average chromosome aberrations per cell per R was 0.0035. 5-AU increased the frequency of labeled metaphases together with labeling intensity, and this is thought to be due to the accumulation of cells by 5-AU at S stage. On the contrary, X-ray decreased the labeling intensity and the frequency of labeled metaphases.

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Repeated Intramuscular-dose Toxicity Test of Water-soluble Carthami Flos (WCF) Pharmacopuncture in Sprague-Dawley Rats

  • Choi, Yoo-Min;Jung, Da-Jung;Kim, Seok-Hee;Kim, Jong-Uk;Yook, Tae-Han
    • Journal of Pharmacopuncture
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    • v.18 no.1
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    • pp.36-43
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    • 2015
  • Objectives: Water-soluble carthami flos (WCF) is a new mixture of Carthami flos (CF) pharmacopuncture. We conducted a 4-week toxicity test of repeated intramuscular injections of WCF in Sprague-Dawley rats. Methods: Forty male and 40 female rats were divided into 4 groups of 10 male and 10 female SD rats: The control group received 0.5 mL/animal/day of normal saline whereas the three experimental groups received WCF at doses of 0.125, 0.25, and 0.5 mL/animal/day, respectively. For 4 weeks, the solutions were injected into the femoral muscle of the rats alternating from side to side. Clinical signs, body weights, and food consumption were observed; opthalmological examinations and urinalyses were performed. On day 29, blood samples were taken for hematological and clinical chemistry analyses. Then, necropsy was conducted in all animals to observe weights and external and histopathological changes in the bodily organs. All data were tested using a statistical analysis system (SAS). Results: No deaths were observed. Temporary irregular respiration was observed in male rats of the experimental group for the first 10 days. Body weights, food consumptions, opthalmological examinations, urinalyses, clinical chemistry analyses, organ weights and necropsy produced no findings with toxicological meaning. In the hematological analysis, delay of prothrombin time (PT) was observed in male rats of the 0.25- and the 0.5-mL/animal/day groups. In the histopathological test, a dose-dependent inflammatory cell infiltration into the fascia and panniculitis in perimuscular tissues was observed in all animals of the experimental groups. However, those symptoms were limited to local injection points. No toxicological meanings, except localized changes, were noted. Conclusion: WCF solution has no significant toxicological meaning, but does produce localized symptoms. No observed adverse effect level (NOAEL) of WCF in male and female rats is expected for doses over 0.5 mL/animal/day.