4,069 research outputs found
Shu Ack Fong
No full text"Shu Ack Fong Evacuated to Adelaide by truck and train 29 March 1942".Date:199
Solving Ack inefficiencies in 802.11 networks
No full textThe founding idea behind this study was that 802.11 acks and TCP acks are substantial contributors to 802.11 overheads, yet, they both provide the same functionality; reliability. Initial experiments suggest that 802.11 acks contribute to over 20% of the overhead in 802.11 networks. Unfortunately, without 802.11 acks, paths with RTTs greater than a millisecond are unable to utilise this additional performance because lost packets, which occur frequently in unacknowledged (NoAck) 802.11, are interpreted as congestion. This study experiments with a range of PEPs (Performance Enhancing Proxies) which retransmit lost packets. A new proxy, known as D-Proxy, designed to solve the shortcomings of previous I-TCP and Snoop proxies, is experimentally developed and tested in Linux. D-Proxy is a distributed, proactive proxy that caches, analyses and resends packets based on TCP sequence numbers. The results suggest that D-Proxy can substantially improve 802.11 throughputs
ACK-clocking dynamics: modelling the interaction between windows and the network
No full textA novel continuous time fluid flow model of the dynamics of the interaction between ACK-clocking and the link buffer is presented. A fundamental integral equation relating the instantaneous flow rate and the window dynamics is derived. Properties of the model, such as well-posedness and stability, are investigated. Packet level experiments verify that this new model is more accurate than existing models, correctly predicting qualitatively different behaviors, for example when round trip delays are heterogeneous
Bibellektüre in den anglikanischen Kirchen: Prinzipien, Zugänge, Methoden, Formen
No full textNo abstract available
Ack - ack on LST, Sicily, 1943
No full textAnti-aircraft artillery ("ack-ack") from LST (Landing Ship, Tank) during the Allied invasion of Sicily as photographed by Dr. Edgar Hyde of the 91st Evacuation Hospital in 1943.Title by Edgar Hyde from original negative enclosure
ACK taste responsivity and physiological alterations associated with ACK treatment.
No full text<p>(A) Brief–access ACK taste response curve in WT(n = 6) mice. (B) 24 hour two-bottle taste preference test for ACK-supplemented water versus water-only control in WT(n = 8) and T1r3KO mice(n = 8). (C, D) Average daily food/fluid intake for water-treated (Con) or ACK-treated mice. (E) Bodyweight changes across study for water-treated or ACK-treated mice. (F) Ambulatory total X-axis activity in water-treated (black line) and ACK-treated (red line) mice. (G) Total Z-axis activity in water-treated (black line) and ACK-treated (red line) mice. (H) Total energy expenditure (TEE) in water-treated (black line) and ACK-treated (red line) mice. For panels F-H, activity was measured over a 48 hr period. In the chronic ACK treatment study, there are 6–8 mice for each group <i>i.e.</i> control (treated with water, n = 8) and ACK (treated with 12.5 mM ACK fluid, n = 6). A Student’s t-test was used for comparison between control and ACK treatment group and comparison between C57BL/6 mice and T1r3 KO mice. Data are means ± SEM. *p≤0.05, **p≤0.01, ***p≤0.001, n = 6–8/group.</p
Implementation of Class-Based ACK Spacer in Linux Platforms
No full text 在這篇論文中，我們提出了分級回覆封包(ACK)間隔器的實作方法，並且將其實現在Linux系統中。此分級ACK間隔器可以被安裝在伺服器端、使用者端、或是在路由器端的網路核心中，並且提供了不同優先權的排程以及頻寬管理的功能。ACK相對於資料封包來說，封包大小較小，是為控制與分析的理想對象。
對於不同類別(Class)的封包，分級ACK間隔器採用固定的優先權順序來控管。對於同一Class，不同的TCP Session之間，採用Token Round Robin (TRR)與Frequency-Based Rotation Priority Queue (FBRPQ) 來達到公平性的要求。
最後以實作來驗證提出的演算法，並改善了TCP傳輸的速率與穩定性。此外，也比較了在不同的排程方法下，分級ACK間隔器處理器的使用率。 In this thesis,we propose a novel architecture of the Class-Based ACK Spacer and implement it on Linux platforms. This ACK spacer could be installed on the server side, client side, or on the router to provide different priorities and bandwidth allocations of each TCP class and session over ACK packet control. Since ACK is relatively small compared to TCP data packet, we hypothesize that ACK is better for buffering or in CPU load.
We use static priority algorithm and token bucket to solve multi-class scheduling problem. To control the sessions in the same priority class, we propose two session scheduling algorithms, Token Round Robin and Frequency-Based Rotation Priority Queue, to achieve fairness between sessions.
Finally, we construct experiment environment to verify our implementations. The TCP throughput could be stabilized and improved with proper parameters set. Bandwidth fair-share could be achieved. At last, we also analyze CPU load using different scheduling algorithms.Contents
Abstract i
1 Introduction 1
1.1 TCP Burstiness and TCP Pacing 1
1.2 TCP Congestion Control 5
1.3 Related Work on TCP Pacing and Bandwidth Management 7
1.4 Motivation and Goals 9
2 Class-Based ACK Spacer Architecture and Algorithms 12
2.1 Class-Based ACK Spacer Architecture 12
2.2 Packet Classification 14
2.3 Decision Flow 18
2.4 Multi-Class Scheduling Algorithm 20
2.5 Multi-Session Scheduling Algorithm – The Token Round Robin Algorithm 24
2.6 Multi-Session Scheduling Algorithm – The Frequency-Based
Rotation Priority Queue Algorithm 26
3 ACK Spacer Implementation in Linux 30
3.1 Introduction of Linux Network Architecture 30
3.2 netfilter/iptables Architecture 33
3.3 Linux Programming Space Design 37
3.4 The ACK Spacer using libipq in iptables 38
3.5 Implementation Flexibility 41
3.6 Spacer Automation Requirement 43
3.7 Timing Control Issue and RTLinux 43
4 Implementation Results 48
4.1 Throughput Improvement and Stabilization 48
4.1.1 Environment Setup 48
4.1.2 Class with Static Priority Algorithm 50
4.1.3 Session Control with Token Round Robin Algorithm 57
4.1.4 Session Control with Frequency-Based Rotation Priority Queue Algorithm 62
4.1.5 Conclusions 66
4.2 Session Fairness Verification 68
4.2.1 Environment Setup 68
4.2.2 Results Analysis 70
4.2.3 Conclusions 79
4.3 CPU Load Comparison 80
4.3.1 Environment Setup 81
4.3.2 Results Analysis 83
4.3.3 Conclusions 84
5 Conclusions 86
5.1 Conclusions 86
5.2 Future Works 88
Appendix 90
A. Buffer Usage Comparison between ACK and data spacer 90
Reference 9
“ACK būve” marketing communications.
No full textBakalaura darba izvēlētā tēma – mārketinga komunikācijas uzņēmumā “ACK būve”. Darba mērķis – izpētīt uzņēmuma SIA “ACK būve” līdzšinējās mārketinga komunikācijas darbības, lai noskaidrotu izmantoto mārketinga komunikāciju veidu atdevi, atklātu vājās puses vai trūkumus un veiktu iespējamos labojumus, balstoties uz teorētiskām un praktiskām atziņām par mārketinga komunikācijas vidi un komunikācijas veidiem, un darba gaitā veikto kvalitatīvo un kvantitatīvo pētījumu pamata. Darba pirmā nodaļa sastāv no komunikācijas vides un veidu dažādu aspektu teorētiskās analīzes, salīdzinot dažādu mārketinga avotu autoru viedokli. Otrajā nodaļā tiek raksturotas un analizētas uzņēmuma “ACK būve” līdzšinējās mārketinga komunikācijas aktivitātes. Trešā nodaļa sastāv no kvalitatīvo un kvantitatīvo veidu pētījumiem – aptaujas un uzņēmuma vadītāju intervijām un iegūto datu analīzes. Balstoties uz darba kopējiem secinājumiem tiek izstrādāti priekšlikumi mārketinga komunikāciju pilnveidošanai. Darba apjoms: Kopējais lapaspušu skaits – 72 lapas (neiekļaujot pielikumus), iekļauj 19 attēlus un 6 tabulas. Pielikumu skaits – 17 pielikumi. Atslēgas vārdi: Mārketinga komunikācija, mārketinga vide, reklāma, produktu realizācijas veicināšana, sabiedriskās attiecības, personiskā pārdošana, SIA “ACK būve”The subject chosen for the bachelor's thesis is marketing communications in “ACK Būve”. The aim of the thesis is to study “ACK būve” marketing communications so that the thesis author can identify the effectiveness of the types of marketing communications used, identify weaknesses or shortcomings, and make possible corrections based on theoretical and practical knowledge of the marketing communication environment and types of communication, and based on the qualitative and quantitative studies carried out in the course of the thesis. The first chapter of the bachelor’s thesis consists of theoretical analysis of different aspects of the marketing communication environment and types of communication, by comparing the views of various marketing source authors. The second chapter consists of “ACK būve” company description and analysis of the past marketing communication activities. The third chapter consists of qualitative and quantitative study types – survey and interviews of the company’s executives, analysis of the data obtained. On the basis of the bachelor’s thesis overall conclusions, proposals for improving marketing communications in the company are developed. Bachelor’s thesis volume: The total number of pages – 72 (not including attachments), includes 19 illustrations and 6 tables. Number of attachments – 17. Keywords: Marketing communication, marketing environment, advertising, sales promotion, public relations, personal selling, SIA “ACK būve
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