• Title/Summary/Keyword: buffer state

Search Result 322, Processing Time 0.037 seconds

A Steady State Analysis of TCP Rate Control Mechanism on Packet loss Environment (전송 에러를 고려한 TCP 트래픽 폭주제어 해석)

  • Kim, Dong-Whee
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.22 no.1
    • /
    • pp.33-40
    • /
    • 2017
  • In this Paper, Analyse the Steady State Behavior of TCP and TFRC with Packet Error when both TCP and TFRC Flows Co-exist in the Network. First, Model the Network with TCP and TFRC Connections as a Discrete Time System. Second, Calculate Average Round Trip Time of the Packet Between Source and Destination on Packet Loss Environment. Then Derive the Steady State Performance i.e. Throughput of TCP and TFRC, and Average Buffer Size of RED Router Based on the Analytic Network Model. The Throughput of TCP and TFRC Connection Decrease Rapidly with the Growth of Sending Window Size and Their Transmission Rate but Their Declines become Smoothly when the Number of Sending Window Arrives on Threshold Value. The Average Queue Length of RED Router Increases Slowly on Low Transmission Rate but Increases Rapidly on High Transmission Rate.

An Electrochemical and Optical Study on the Corrosion and Passivation of Metals. An Electrochemical and Optical Study on the Passivation Film of Electrolytic Iron (금속 부식과 부동화에 관한 전기화학적 및 광학적 연구. 순철의 부동화 피막에 관한 전기화학적 및 광학적 연구)

  • Park Byung So;Paik Woon-Kie;Yeo, In Hyeong
    • Journal of the Korean Chemical Society
    • /
    • v.22 no.6
    • /
    • pp.365-369
    • /
    • 1978
  • Ellipsometric and reflectance measurements were made on an iron surface in a cathodically reduced state and in an anodically passivated state. From the differences in the optical parameters (${\Delta},\;{\psi}$, and reflectance) between the reduced (film-free) and passivated (film-covered) states the thickness and optical constants of the surface film were determined. In the passive state at -400 mV vs. SCE in borate-boric acid buffer solution the anodic film had a thickness of about 11${\AA}$ and optical constants of ${\tilde{n}}$= 2.8 - 0.8 i. This value indicates a substantial electronic conductivity of the anodic film.

  • PDF

A Transaction Level Simulator for Performance Analysis of Solid-State Disk (SSD) in PC Environment (PC향 SSD의 성능 분석을 위한 트랜잭션 수준 시뮬레이터)

  • Kim, Dong;Bang, Kwan-Hu;Ha, Seung-Hwan;Chung, Sung-Woo;Chung, Eui-Young
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.45 no.12
    • /
    • pp.57-64
    • /
    • 2008
  • In this paper, we propose a system-level simulator for the performance analysis of a Solid-State Disk (SSD) in PC environment by using TLM (Transaction Level Modeling) method. Our method provides quantitative analysis for a variety of architectural choices of PC system as well as SSD. Also, it drastically reduces the analysis time compared to the conventional RTL (Register Transfer Level) modeling method. To show the effectiveness of the proposed simulator, we performed several explorations of PC architecture as well as SSD. More specifically, we measured the performance impact of the hit rate of a cache buffer which temporarily stores the data from PC. Also, we analyzed the performance variation of SSD for various NAND Flash memories which show different response time with our simulator. These experimental results show that our simulator can be effectively utilized for the architecture exploration of SSD as well as PC.

Dielectric Properties of $Ta_2O_{5-X}$ Thin Films with Buffer Layers

  • Kim, In-Sung;Song, Jae-Sung;Yun, Mun-Soo;Park, Chung-Hoo
    • KIEE International Transactions on Electrophysics and Applications
    • /
    • v.12C no.4
    • /
    • pp.208-213
    • /
    • 2002
  • The present study describe the electrical performance of amorphous T $a_2$ $O_{5-X}$ fabricated on the buffer layers Ti and Ti $O_2$. T $a_2$ $O_{5-X}$ thin films were grown on the Ti and Ti $O_2$ layers as a capacitor layer using reactive sputtering method. The X-ray pattern analysis indicated that the two as-deposited films were amorphous and the amorphous state was kept stable on the RTA(rapid thermal annealing) at even $700^{\circ}C$. Measurements of dielectric properties of the reactive sputtered T $a_2$ $O_{5-X}$ thin films fabricated in two simple MIS(metal insulator semiconductor), structures, (Cu/T $a_2$ $O_{5}$ Ti/Si and CuT $a_2$ $O_{5}$ Ti $O_2$Si) show that the amorphous T $a_2$ $O_{5}$ grown on Ti showed high dielectric constant (23~39) and high leakage current density(10$^{-3}$ ~10$^{-4}$ (A/$\textrm{cm}^2$)), whereas relatively low dielectric constant (~15) and tow leakage current density(10$^{-9}$ ~10$^{-10}$ (A/$\textrm{cm}^2$)) were observed in the amorphous T $a_2$ $O_{5}$ deposited on the Ti $O_2$ layer. The electrical behaviors of the T $a_2$ $O^{5}$ thin films were attributed to the contribution of Ti- $O_2$ and the compositionally gradient Ta-Ti-0, being the low dielectric layer and high leakage current barrier. In additional, The T $a_2$ $O_{5}$ Ti $O_2$ thin films exhibited dominant conduction mechanism contributed by the Poole-Frenkel emission at high electric field. In the case of T $a_2$ $O_{5}$ Ti $O_2$ thin films were related to the diffusion of Ta, Ti and O, followed by the creation of vacancies, in the rapid thermal treated thin films.films.

Data Cache System based on the Selective Bank Algorithm for Embedded System (내장형 시스템을 위한 선택적 뱅크 알고리즘을 이용한 데이터 캐쉬 시스템)

  • Jung, Bo-Sung;Lee, Jung-Hoon
    • The KIPS Transactions:PartA
    • /
    • v.16A no.2
    • /
    • pp.69-78
    • /
    • 2009
  • One of the most effective way to improve cache performance is to exploit both temporal and spatial locality given by any program executive characteristics. In this paper we present a high performance and low power cache structure with a bank selection mechanism that enhances exploitation of spatial and temporal locality. The proposed cache system consists of two parts, i.e., a main direct-mapped cache with a small block size and a fully associative buffer with a large block size as a multiple of the small block size. Especially, the main direct-mapped cache is constructed as two banks for low power consumption and stores a small block which is selected from fully associative buffer by the proposed bank selection algorithm. By using the bank selection algorithm and three state bits, We selectively extend the lifetime of those small blocks with high temporal locality by storing them in the main direct-mapped caches. This approach effectively reduces conflict misses and cache pollution at the same time. According to the simulation results, the average miss ratio, compared with the Victim and STAS caches with the same size, is improved by about 23% and 32% for Mibench applications respectively. The average memory access time is reduced by about 14% and 18% compared with the he victim and STAS caches respectively. It is also shown that energy consumption of the proposed cache is around 10% lower than other cache systems that we examine.

Ultrafiltration and Separation Process Optimization of Hen Egg White Lysozyme as Natural Antimicrobial Enzyme (천연 항균 효소제 난백 lysozyme의 한외여과 조건 최적화)

  • Lee, Eun-Young;Woo, Gun-Jo
    • Korean Journal of Food Science and Technology
    • /
    • v.30 no.2
    • /
    • pp.397-406
    • /
    • 1998
  • Hen egg white lysozyme (HEWL) is very valuable as a natural preservative in food processing due to its selective bactericidal activity. HEWL which traditionally isolated by crystallization or freeze drying was simply separated from 13 different hen egg white (HEW) proteins by a single-step ultrafiltration. Freeze dried HEW (0.25%, w/v) dissolved in a citrate-phosphate buffer (pH 4.6) was ultrafiltered with a PM30 membrane under various operating conditions, by changing concentration, temperature, transmembrane pressure $({\triangle}P_T)$, and stirring speed. Optimum separation conditions were decided when maximal flux was obtained. Under the optimum separation conditions, the effect of membrane material and fouling on flux as time passed as well as lysozyme concentration, protein concentration, specific activity (SA) in the permeate were measured. Best separation conditions of HEWL with PM30 membrane were sample concentration 0.25%, temperature $35^{\circ}C$, ${\Delta}P_T\;30\;psi$, and stirring speed 300 rpm. During the first 12 min, the flux of YM30 was higher, but at the steady-state it was lower than that of PM30. The SA of the PM30 permeate was over 2 times higher in spite of the lysozyme and protein concentration being lower than that of YM30 permeate. The flux of 5 times used PM30 decreased 30% compared to a new PM30, but both had the same tendency in flux decrease when time passed. Both of them reached a steady-state after 35 min and remained at 70% of the initial flux. In the PM30 permeate, the lysozyme concentration and SA were 110 units/mL and 2,821 units/mg protein, respectively. Therefore, PM30 membrane separation was very effective for separation of antimicrobial lysozyme.

  • PDF

Improving TCP Performance by Limiting Congestion Window in Fixed Bandwidth Networks (고정대역 네트워크에서 혼잡윈도우 제한에 의한 TCP 성능개선)

  • Park, Tae-Joon;Lee, Jae-Yong;Kim, Byung-Chul
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.42 no.12
    • /
    • pp.149-158
    • /
    • 2005
  • This paper proposes a congestion avoidance algorithm which provides stable throughput and transmission rate regardless of buffer size by limiting the TCP congestion window in fixed bandwidth networks. Additive Increase, Multiplicative Decrease (AIMD) is the most commonly used congestion control algorithm. But, the AIMD-based TCP congestion control method causes unnecessary packet losses and retransmissions from the congestion window increment for available bandwidth verification when used in fixed bandwidth networks. In addition, the saw tooth variation of TCP throughput is inappropriate to be adopted for the applications that require low bandwidth variation. We present an algorithm in which congestion window can be limited under appropriate circumstances to avoid congestion losses while still addressing fairness issues. The maximum congestion window is determined from delay information to avoid queueing at the bottleneck node, hence stabilizes the throughput and the transmission rate of the connection without buffer and window control process. Simulations have performed to verify compatibility, steady state throughput, steady state packet loss count, and the variance of congestion window. The proposed algorithm can be easily adopted to the sender and is easy to deploy avoiding changes in network routers and user programs. The proposed algorithm can be applied to enhance the performance of the high-speed access network which is one of the fixed bandwidth networks.

Analysis of an M/G/1/K Queueing System with Queue-Length Dependent Service and Arrival Rates (시스템 내 고객 수에 따라 서비스율과 도착율을 조절하는 M/G/1/K 대기행렬의 분석)

  • Choi, Doo-Il;Lim, Dae-Eun
    • Journal of the Korea Society for Simulation
    • /
    • v.24 no.3
    • /
    • pp.27-35
    • /
    • 2015
  • We analyze an M/G/1/K queueing system with queue-length dependent service and arrival rates. There are a single server and a buffer with finite capacity K including a customer in service. The customers are served by a first-come-first-service basis. We put two thresholds $L_1$ and $L_2$($${\geq_-}L_1$$ ) on the buffer. If the queue length at the service initiation epoch is less than the threshold $L_1$, the service time of customers follows $S_1$ with a mean of ${\mu}_1$ and the arrival of customers follows a Poisson process with a rate of ${\lambda}_1$. When the queue length at the service initiation epoch is equal to or greater than $L_1$ and less than $L_2$, the service time is changed to $S_2$ with a mean of $${\mu}_2{\geq_-}{\mu}_1$$. The arrival rate is still ${\lambda}_1$. Finally, if the queue length at the service initiation epoch is greater than $L_2$, the arrival rate of customers are also changed to a value of $${\lambda}_2({\leq_-}{\lambda}_1)$$ and the mean of the service times is ${\mu}_2$. By using the embedded Markov chain method, we derive queue length distribution at departure epochs. We also obtain the queue length distribution at an arbitrary time by the supplementary variable method. Finally, performance measures such as loss probability and mean waiting time are presented.

Analysis of the Involving Mechanism of Kim Eun-Sook Drama : Focused on the Audience's Predictability and the Activities of Constructing Hypotheses (김은숙 드라마 <도깨비>의 몰입기제 구축과정 분석 - 관람자 예측성과 가설 구성 활동을 중심으로 -)

  • Kim, Eui-Jun
    • Journal of Korea Entertainment Industry Association
    • /
    • v.13 no.2
    • /
    • pp.79-91
    • /
    • 2019
  • In the entertainment industry, risk management is crucial for securing competitiveness due to the risk of investment. The competitiveness of contents is reinforced when external factors such as industrial environment and internal factors centering on involving mechanism are simultaneously provided. The involving mechanism is a form of cognitive response behavior of the audience and occurs through signal processing of the brain when watching the image contents. The signal processing of the brain related to the contents watching is mainly performed in the working memory area, and in the case of the captivating movie, the information other than the contents transmitted to the audience is blocked to generate a temporary dissociation state. A dissociation state similar to a symptom such as hypnosis or amnesia occurs when the audience's level of involving is high. On the other hand, contents information in which the audience is concentrating his attention is used intensively for constructing future thinking through an episodic buffer while the inflow of external information is relatively blocked or delayed. The spectator's future thinking configuration takes the form of a hypothesis-forming activity and is based on the predictability of the brain. When these hypothesized behaviors correspond to the problem solving simulation of story and predictability which is an evolutionary function of the brain, the audience' s brain is involved in the contents at a high level. In order for the act to be effective, the factors such as the background of the hypothesis, the subject of the hypothesis, the internal information of the person, the type and position and quantity of the hypothesis information, and the hypothesis relevance and type of information are important. Based on these factors, analysis of the Kim Eun Sook Drama 'Goblin' shows that the above elements are operated in a very organic and meaningful way.

Program Cache Busy Time Control Method for Reducing Peak Current Consumption of NAND Flash Memory in SSD Applications

  • Park, Se-Chun;Kim, You-Sung;Cho, Ho-Youb;Choi, Sung-Dae;Yoon, Mi-Sun;Kim, Tae-Yun;Park, Kun-Woo;Park, Jongsun;Kim, Soo-Won
    • ETRI Journal
    • /
    • v.36 no.5
    • /
    • pp.876-879
    • /
    • 2014
  • In current NAND flash design, one of the most challenging issues is reducing peak current consumption (peak ICC), as it leads to peak power drop, which can cause malfunctions in NAND flash memory. This paper presents an efficient approach for reducing the peak ICC of the cache program in NAND flash memory - namely, a program Cache Busy Time (tPCBSY) control method. The proposed tPCBSY control method is based on the interesting observation that the array program current (ICC2) is mainly decided by the bit-line bias condition. In the proposed approach, when peak ICC2 becomes larger than a threshold value, which is determined by a cache loop number, cache data cannot be loaded to the cache buffer (CB). On the other hand, when peak ICC2 is smaller than the threshold level, cache data can be loaded to the CB. As a result, the peak ICC of the cache program is reduced by 32% at the least significant bit page and by 15% at the most significant bit page. In addition, the program throughput reaches 20 MB/s in multiplane cache program operation, without restrictions caused by a drop in peak power due to cache program operations in a solid-state drive.