• 제목/요약/키워드: multiple scale

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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.

MULTIPLE SCALE ANALYSIS OF A DELAYED PREDATOR PREY MODEL WITHIN RANDOM ENVIRONMENT

  • Saha, Tapan;Bandyopadhyay, Malay
    • Journal of applied mathematics & informatics
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    • v.26 no.5_6
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    • pp.1191-1205
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    • 2008
  • We consider a delayed predator prey model. The local stability and Hopf bifurcation results are stated taking the time delay as a control parameter. We apply multiple scale analysis to analyze the effects of additive white noises near the Hopf bifurcation point at the positive interior equilibrium state. The governing equations for the amplitude of oscillations on a slow time scale are derived. We identify the process of amplitude of oscillations and derive its transient properties. We show that oscillations, which would decay in the deterministic system whenever time delay lies below its critical value, persists for long time under the validity of multiple scale analysis.

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The Congestion Control using Selective Slope Control under Multiple Time Scale of TCP (TCP의 다중 시간 간격에서 선택적 기울기 제어를 이용한 혼잡 제어)

  • Kim, Gwang-Jun;Kang, Ki-Woong;Lim, Se-Jung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.2 no.1
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    • pp.10-18
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    • 2007
  • 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 time scale control module 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. 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. If source traffic is not extended exceeding, when RTT is 450ms, in self similar burst environment, performance gain of TCP-SSC is up to 45% for ${\alpha}$=1.05. However, its is acquired only 20% performance gain for ${\alpha}$=1.95 relatively. Therefore we showed that by TCP-MTS at large time scale into a rate-based feedback congestion control, we are able to improve two times performance significantly.

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Prediction of defect shape change using multiple scale modeling during wire rod rolling process (멀티 스케일 모델을 적용한 선재 공정의 미세결함 형상 변화 예측)

  • Kwak, Eun-Jeong;Kang, Gyeong-Pil;Lee, Kyung-Hoon;Son, Il-Heon
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.169-172
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    • 2009
  • Multiple scale modeling has been applied to predict defect shape change during the wire rod rolling process. The size difference between bloom and defect prevent using usual FEM approaches due to the enormous number of elements required to depict the defect. The newly developed multiple scale model can visualize defect shape changes during the multi stands rolling process. The defect positioned at the top and side of bloom are smoothed out but the one at the middle evolved as folding or remained as crack. This approach can be used for defect control with roll shape design and initial bloom shape.

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A Study of Multiple Scale FEM Modeling for Prediction of Inner Void Closing Behavior in Open Die Forging Process (자유단조 공정 시 내부 기공 거동 예측을 위한 멀티스케일 유한요소해석 연구)

  • Kwak, E.J.;Kang, G.P.;Lee, K.
    • Transactions of Materials Processing
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    • v.21 no.5
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    • pp.319-323
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    • 2012
  • In order to predict the internal void closing behavior in open die forging process, multiple scale modeling has been developed and applied. The huge size difference between ingot and inner void makes it almost impossible to simultaneously model the actual loading conditions and the void shape. Multiple scale modeling is designed to integrate macro- and micro- models effectively and efficiently. The void closing behavior was simulated at 39 different locations in a large ingot during upsetting and cogging. The correlation between the closing behavior and variables such as effective plastic strain and maximum compressive strain was studied in order to find an efficient measure for predicting the soundness of the forging.

A PROPOSAL OF ENHANSED NEURAL NETWORK CONTROLLERS FOR MULTIPLE CONTROL SYSTEMS

  • Nakagawa, Tomoyuki;Inaba, Masaaki;Sugawara, Ken;Yoshihara, Ikuo;Abe, Kenichi
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.201-204
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    • 1998
  • This paper presents a new construction method of candidate controllers using Multi-modal Neural Network(MNN). To improve a control performance of multiple controller, we construct, candidate controllers which consist of MNN. MNN can learn more complicated function than multilayer neural network. MNN consists of preprocessing module and neural network module. The preprocessing module transforms input signals into spectra which are used as input of the following neural network module. We apply the proposed method to multiple control system which controls the cart-pole balancing system and show the effectiveness of the proposed method.

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A Clinical Case Report on Multiple Sclerosis Treated by Korean Medicine (다발성 경화증에 대한 한방치료 치험 1례)

  • Jeon, Yong-Tae;Park, Sang-Hun;Ko, Youn-Seok
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.9 no.2
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    • pp.21-33
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    • 2014
  • Objectives : This study was to report the improvement of the patient with multiple sclerosis treated by Korean Medical treatment. Methods : The patient diagnosed as multiple sclerosis treated by acupuncture, bee venom pharmacupuncture, chuna manual therapy, and herbal medicine. To evaluate the effects of korean medicine, we used manual muscle test(MMT), the standard for assessment of the effect of stroke treatment, functional system(FS), visual analog scale(VAS). Results : 1. The patient's pain and optic dysfunction were reduced by the above therapy. 2. There was no change in manual muscle test(MMT), but there was mild improvement in finger joints function in the standard for assessment of the effect of stroke treatment. 3. In functional system(FS) scale, there was enhancement in optic function within a range. And there was improvement in expanded disability statue scale(EDSS) from 4.0 to 3.0. 4. In visual analog scale(VAS), there was considerable improvement from 9 to 6. Conclusions : The korean medical treatment was reduced pain and optic dysfunction.

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A Clinical Case Report of Multiple Sclerosis Treated with Only Hominis Placental Pharmacopuncture (자하거 약침 단독치료로 호전된 다발성 경화증 치험 1례)

  • Hwang, Gyu-sang;Yu, Keun-jeong;Lee, Su-yeong;Lee, Jun-yeong;Kim, Du-ri;Hong, Ka-kyung;Shin, Sun-ho;Shin, Yong-jeen
    • The Journal of Internal Korean Medicine
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    • v.38 no.2
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    • pp.289-300
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    • 2017
  • Objectives: This case report describes the effect of Hominis placenta pharmacopuncture (HPP) on multiple sclerosis. Methods: A multiple sclerosis patient with gait disturbances, tremors, spasms of both lower limbs, and diplopia was treated with only HPP for two weeks. To evaluate the effects of HPP on the balance ability of the patient, the Functional System (FS) scale, Expanded Disability Statue Scale (EDSS), visual analog scale (VAS), manual muscle test (MMT), and Berg Balance Scale (BBS) were used. Results: The HPP treatment reduced the patient's gait disturbance, tremors, spasms of the lower limbs, and diplopia. According to the FS scale, the patient's cerebellar and optic functions were enhanced. In addition, the patient's performance on the EDSS improved from 4.0 to 3.0.3. As shown by the MMT, the lower extremities showed a mild improvement (from F+ to G.4). Furthermore, the VAS showed a considerable improvement, decreasing from 9 to 6.5 post-treatment. The patient's performance on the BBS, which denotes balance ability, showed a considerable improvement, increasing from 38 to 49. Conclusion: Treatment with only HPP could help to ameliorate the symptoms of multiple sclerosis.

High performance ultrafine-grained Ti-Fe-based alloys with multiple length-scale phases

  • Zhang, Lai-Chang
    • Advances in materials Research
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    • v.1 no.1
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    • pp.13-29
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    • 2012
  • In order to simultaneously enhance the strength and plasticity in nanostructured / ultrafine-grained alloys, a strategy of introducing multiple length scales into microstructure (or called bimodal composite microstructure) has been developed recently. This paper presents a brief overview of the alloy developement and the mechanical behavior of ultrafine-grained Ti-Fe-based alloys with different length-scale phases, i.e., micrometer-sized primary phases (dendrites or eutectic) embedded in an ultrafine-grained eutectic matrix. These ultrafine-grained titanium bimodal composites could be directly obtained through a simple single-step solidification process. The as-prepared composites exhibit superior mechanical properties, including high strength of 2000-2700 MPa, large plasticity up to 15-20% and high specific strength. Plastic deformation of the ultrafine-grained titanium bimodal composites occurs through a combination of dislocation-based slip in the nano-/ultrafine scale matrix and constraint multiple shear banding around the micrometer-sized primary phase. The microstructural charactersitcs associated to the mechanical behaivor have been detailed discussed.

Fabrication of Biochip Using Gray-scale Photolithography (Gray-scale photolithography를 이용한 바이오칩 제작)

  • Bae, Young-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.1
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    • pp.137-141
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    • 2008
  • Biochip, which implements bioanalytical process on a tiny surface, is one of candidates for medical diagnosis, drug screening, and molecular sensing. In general, a type of biochip based on microfluidics is composed of microcomponents including microchannel, pump, and valve, which require complicated processes. In this study, gray-scale photolithography(GSPL) was applied to fabricate a biochip with multiple layers. A mould for casting PDMS(polydimethylsiloxane) channel, was fabricated using GSPL. A gray-photomask was prepared by printing gray patterns on a high-quality glossy paper followed by photoreducing by 10:1 onto the photo-film. The formation of multiple layers was studied according to the change of gray level of pattern and the developing time. A biochip composed of a weir(multiple layer structure) and a reaction chamber in a single microchannel was fabricated in a glass plate. Finally, we investigated the application of biochip to antigen-antibody reaction by packing the microbead coated with antibody.