• Title/Summary/Keyword: self-similar

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The Congestion Control using Multiple Time Scale under Self-Similar Traffic of TCP (TCP의 자기 유사성 트래픽 조건하에서 다중 시간 간격을 이용한 혼잡 제어)

  • 김광준;윤찬호;김천석
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.310-323
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    • 2004
  • In this paper, we extend the multiple time scale control framework to window-based congestion control, in particular, TCP This is performed by interfacing TCP with a large tine scale control nodule which adjusts the aggressiveness of bandwidth consumption behavior exhibited by TCP as a function of "large time scale" network state. i.e., conformation that exceeds the horizon of the feedback loop as determined by RTT Our contribution is threefold. First, we define a modular extension of TCP-a function call with a simple interface-that applies to various flavors of TCP-e.g., Tahoe, Reno, Vegas and show that it significantly improves performance. Second, we show that multiple time scale TCP endows the underlying feedback control with preactivity by bridging the uncertainty gap associated with reactive controls which is exacerbated by the high delay-bandwidth product in broadband wide area networks. Third, we investigate the influence of three traffic control dimensions-tracking ability, connection duration, and fairness-on performance. Performance evaluation of multiple time scale TCP is facilitated by a simulation bench-mark environment which is based on physical modeling of self-similar traffic.

Performance Evaluation of DiffServ Networks Considering Self-Similar Traffic Characteristics (자기유사 트래픽 특성을 고려한 차등서비스 망의 성능 평가)

  • Park, Jeong-Sook;Jeon, Yong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.5B
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    • pp.344-355
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    • 2008
  • In this paper, we are dealing with the problems of performance evaluation of Differentiated Services(DiffServ) networks. For successful performance evaluation, the ability to accurately represent "real" traffic on the network by suitable traffic models is an essential ingredient. Many research results on the nature of real traffic measurements demonstrated LRD(long-range dependence) property for the Internet traffic including Web, TELNET, and P2P traffic. The LRD can be effectively represented by self-similarity. In this paper, we design and implement self-similar traffic generator using the aggregated On/Off source model, based on the analysis of the On-Off source model, FFT-FGN(Fast Fourier Transform-Fractional Gaussian Noise) model, and RMD(Random Midpoint Displacement) model. We confirmed the self-similarity of our generated traffic by checking the packet inter-arrival time of TCPdump data. Further we applied the implemented traffic generator to the performance evaluation of DiffServ networks and observed the effect of performance to the a value of the On/Off model, and performance of EF/BE class traffic by CBQ.

A Study on the Congestion Control with Multiple Time Scale under Self-Similar Traffic (자기유사성 트래픽 조건에서 다중 시간 간격을 이용한 혼잡제어에 관한 연구)

  • Cho, Hyeon-Seob;Kim, Young-Cho;Kim, Hui-Suk
    • Proceedings of the KAIS Fall Conference
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    • 2006.05a
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    • pp.294-297
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    • 2006
  • Measurement of network traffic have shown that the self-similarity is a ubiquitous phenomenon spanning across diverse network environments. In previous work, we have explored the feasibility of exploiting the long-range correlation structure in a self-similar traffic for the congestion control. we show that a multiple time scale TCP endows the underlying feedback control with proactivity by bridging the uncertainty gap associated with reactive controls which is exacerbated by the high delay-bandwidth product in broadband wide area networks. Third, we investigate the influence of the three traffic control dimensions-tracking ability, connection duration, and fairness-on performance.

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Mandibular arch orthodontic treatment stability using passive self-ligating and conventional systems in adults: A randomized controlled trial

  • Rahman, Norma Ab;Wey, Mang Chek;Othman, Siti Adibah
    • The korean journal of orthodontics
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    • v.47 no.1
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    • pp.11-20
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    • 2017
  • Objective: This randomized controlled trial aimed to compare the stability of mandibular arch orthodontic treatment outcomes between passive self-ligating and conventional systems during 6 months of retention. Methods: Forty-seven orthodontic patients with mild to moderate crowding malocclusions not requiring extraction were recruited based on inclusion criteria. Patients (mean age $21.58{\pm}2.94years$) were randomized into two groups to receive either passive self-ligating ($Damon^{(R)}$ 3MX, n = 23) or conventional system (Gemini MBT, n = 24) orthodontic treatment. Direct measurements of the final sample comprising 20 study models per group were performed using a digital caliper at the debonding stage, and 1 month, 3 months, and 6 months after debonding. Paired t-test, independent t-test, and non-parametric test were used for statistical analysis. Results: A significant increase (p < 0.01) in incisor irregularity was observed in both self-ligating and conventional system groups. A significant reduction (p < 0.01) in second interpremolar width was observed in both groups. Mandibular arch length decreased significantly (p = 0.001) in the conventional system group but not in the self-ligating system group. A similar pattern of stability was observed for intercanine width, first interpremolar width, intermolar width, and arch depth throughout the 6-month retention period after debonding. Comparison of incisor irregularity and arch dimension changes between self-ligating system and conventional system groups during the 6 months were non-significant. Conclusions: The stability of treatment outcomes for mild to moderate crowding malocclusions was similar between the self-ligating system and conventional system during the first 6 months of retention.

A Study on the Relationship between Image of Physiotherapist and Self-Esteem of Physiotherapy Students (물리치료(학)과 학생들이 지각한 물리치료사의 이미지와 자아존중감과의 관련성 분석)

  • Kim, Eun-Ae;Lee, Geon-Cheol;Bae, Won-Sik;Kim, Chi-Hyok
    • Journal of the Korean Society of Physical Medicine
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    • v.8 no.1
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    • pp.19-27
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    • 2013
  • PURPOSE: The purpose of this study is to look into relationship between image of physiotherapist and self-esteem of physiotherapy students and desirable image of physiotherapists offer to establish basic materials. METHODS: The subjects of this study are consist of 603 students of department of Physical therapy university and college in Busan and Kim-hae. Data are collected from June 9 to July 9 in 2011 by structured questionnaires. RESULTS: The result are as follows. 1. at the physiotherapist image score, the highest score question is "Physiotherapist is specialist"(3.45) and the lowest score question is "Physiotherapist is treated samely with doctor"(2.15). 2. at the self-esteem score, the highest score question is "I think that I am at least as valuable as others"(3.37) and the lowest score question is "I can be poorly sometimes"(2.81). 3. at the static results of physiotherapist image score gap by general characteristics, there are significantly different in gender(t=2.27, p=.02), similar profession distinction(t=4.30, p=.00), major satisfaction(t=5.74, p=.00), school system (t=-2.54, p=.01). 4. at the static results of self-esteem score gap by general characteristics, there are significantly different in years (f=5.14, p=.00), gender(t=4.09, p=.00), religion(f=2.87, p=.04), similar profession distinction(t=3.97, p=.00), major satisfaction(t=4.26, p=.00). 5. at the static results of good reputation of physiotherapists increase self-esteem of physiotherapy students score question are significantly different(r=0.53, p=.00). CONCLUSION: Accordingly, these results of this study that there is a very correlation between image of physiotherapist and self-esteem of physiotherapy students. Therefore, good reputation of physiotherapists increase self-esteem of physiotherapy students.

Breeding of Self-compatible Pear "Wonkyo Na-jasoojung 2" (배 자가결실성 "원교 나-자수정 2호")

  • Shin, Il Sheob;Shin, Yong Uk;Hwang, Hae Sung;Heo, Seong;Kim, Ki Hong;Kang, Sam Seok;Kim, Yoon Kyeong
    • Korean Journal of Breeding Science
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    • v.41 no.2
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    • pp.154-157
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    • 2009
  • Pear has a gametophytic self-incompatibility (SI) system and its SI reaction is controlled by a single multi-allelic S-locus. 'Wonkyo Na-jasoojung 2' was selected from a cross between 'Wonwhang', early season major pear cultivar with high fruit quality and self-incompatible, and 92-18-79 (${S_4}^{sm}{S_4}^{sm}$) obtained from self cross of 'Osa-nijisseiki' (${S_2S_4}^{sm}$) (SM, stylar-part mutant), self-compatible bud mutant that originated from self-incompatible 'Nijisseiki' ($S_2S_4$) made in 2001 at the National Institute of Horticultural and Herbal Science, Rural Development Administration in Korea. '92-18-79' was selected as a self-compatible source through field investigation. It bloomed 1 day earlier than 'Osa-Nijisseiki' and similar to 'Wonwhang' in 2008. It is medium in tree vigor and spreading in tree habit. 'Wonkyo Na-jasoojung 2' is classified as highly susceptible to pear scab (Venturia nashicola) similar to 'Osa-Nijisseiki' and as resistant to black spot (Alternaria kikuchiana) similar to 'Wonwhang'. It had 65.7% fruiting rate by self pollination. The average optimum harvest time of 'Wonkyo Na-jasoojung 2' was 148 days after full bloom and it matured 2 days earlier than 'Osa-Nijisseiki' and 11 days later than 'Wonwhang'. The fruit is roundish oblate in shape and yellowish brown in skin color. Average fruit weight was 445 g and soluble solids content was 13.3 $^{\circ}Brix$. The flesh had abundant juice and negligible grit.

Stochastic Self-similarity Analysis and Visualization of Earthquakes on the Korean Peninsula (한반도에서 발생한 지진의 통계적 자기 유사성 분석 및 시각화)

  • JaeMin Hwang;Jiyoung Lim;Hae-Duck J. Jeong
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.11
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    • pp.493-504
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    • 2023
  • The Republic of Korea is located far from the boundary of the earthquake plate, and the intra-plate earthquake occurring in these areas is generally small in size and less frequent than the interplate earthquake. Nevertheless, as a result of investigating and analyzing earthquakes that occurred on the Korean Peninsula between the past two years and 1904 and earthquakes that occurred after observing recent earthquakes on the Korean Peninsula, it was found that of a magnitude of 9. In this paper, the Korean Peninsula Historical Earthquake Record (2 years to 1904) published by the National Meteorological Research Institute is used to analyze the relationship between earthquakes on the Korean Peninsula and statistical self-similarity. In addition, the problem solved through this paper was the first to investigate the relationship between earthquake data occurring on the Korean Peninsula and statistical self-similarity. As a result of measuring the degree of self-similarity of earthquakes on the Korean Peninsula using three quantitative estimation methods, the self-similarity parameter H value (0.5 < H < 1) was found to be above 0.8 on average, indicating a high degree of self-similarity. And through graph visualization, it can be easily figured out in which region earthquakes occur most often, and it is expected that it can be used in the development of a prediction system that can predict damage in the event of an earthquake in the future and minimize damage to property and people, as well as in earthquake data analysis and modeling research. Based on the findings of this study, the self-similar process is expected to help understand the patterns and statistical characteristics of seismic activities, group and classify similar seismic events, and be used for prediction of seismic activities, seismic risk assessments, and seismic engineering.

The Relationships Between the Clothes Self-image and Clothes Design Preferences of Elderly Women (노년층여성의 의복 자아이미지와 선호 디자인과의 관계)

  • 배현숙;유태순
    • Journal of the Korean Society of Costume
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    • v.50 no.2
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    • pp.151-165
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    • 2000
  • This study was to find out clothing design preferences, according to the clothing self-image of elderly women and to grasp the variety on clothing of elderly women and thereby to help in merchandise production planning and putting the brands into markets and to provide data for establishing a sales strategy a d to itemize women with the goods which can satisfy the desire and taste of consumer groups in the quality market. For this purpose , various researches as above were conducted .The object of this study was a total of 488 elderly women above full 55 from an elderly women and who lived in downtown Pusan. The data were analysed by using MANOVA, ANOVA , factors analysis and frequency analysis, and the Cronbach α was also applied . The conclusions made based on the theoretical background and the result of questionnaire surveys are as follows ; 1. The realistic self-image of clothing showed a similar pattern by age. 50's and 60's showed little difference by item but 70's was greater in variation between items compared to 60's. The response to each item was that most people answered "common" and they showed a pattern that responded low only in items of 'colorful' , individualistic', 'susceptible to fashion'. A similar pattern was shown by age band also in the ideal self-image and the response to each item appeared higher than in the realistic self-image , and also in items of 'colorful', 'individualistic ' , 'susceptible to fashion' the response appeared low and showed a unity. 2. The results of clothing design preferences examined on the self-image according to age are as follows ; 1) Fro jacket in the realistic self-image , 50's and 60's preferred 'tailed collar' , 'set-in sleeve', 'hips long' and 'plain jacket' and 70's agreed to the design preferences in the items except 'open collar' and also in the idealistic self-image , the degree of preference was same. 2) For skirt in the realistic self-image , 50's and 60's preferred 'tight skirt', 'normal length' , 'plain skirt' and it was appeared that 70's preferred 'pleat skirt' , 'medium length' , 'plain skirt'. Also in the idealistic self-image , the degree of preference was same. 3) For blouse in the realistic self-image, 50's preferred 'open collar', 'round neck line' , 'long set-in sleeve' , 'plain separation belt', 'open front', 'zipper' ad 60's agreed to the favorite designs with 50's except puff sleeve, and 70's appeared to prefer fastening buttons without belt. In the designs preferred in the idealistic self-image, 50's agreed with 50's of the realistic self-image and for 60's , the designs except puff sleeve type and no belt type agreed to 50's and 70's except puff sleeve agreed with 70's of the realistic self-image in their design preferences.

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SCALING METHODS FOR QUASI-NEWTON METHODS

  • MOGHRABI, ISSAM A.R.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.6 no.1
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    • pp.91-107
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    • 2002
  • This paper presents two new self-scaling variable-metric algorithms. The first is based on a known two-parameter family of rank-two updating formulae, the second employs an initial scaling of the estimated inverse Hessian which modifies the first self-scaling algorithm. The algorithms are compared with similar published algorithms, notably those due to Oren, Shanno and Phua, Biggs and with BFGS (the best known quasi-Newton method). The best of these new and published algorithms are also modified to employ inexact line searches with marginal effect. The new algorithms are superior, especially as the problem dimension increases.

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A Study on Self-excitations in Laminar Coflow Jet Flames (층류 동축류 제트화염에서의 화염진동에 관한 실험적 연구)

  • Yoon, Sung Hwan;Park, Jeong;Yun, Jin Han;Keel, San In;Kwon, Oh Boong
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.83-85
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    • 2012
  • Experimental study in coflow jet flames has been conducted to investigate the effects of adding $N_2$, $CO_2$ and He to coflowing air-side in self-excitations. Differences in the behaviors between buoyancy-driven and diffusive-thermal self-excitations with similar frequency range are explored and discussed in laminar coflow jet flames.

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