This paper describes a chat room application suitable for teaching basic network programming and security protocols. A client/server design illustrates the structure of current scalable network services while a multic...
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ISBN:
(纸本)1581133294
This paper describes a chat room application suitable for teaching basic network programming and security protocols. A client/server design illustrates the structure of current scalable network services while a multicast version demonstrates the need for efficient simultaneous distribution of network content to multiple receivers (e.g., as required by video broadcasts). The system also includes implementations of two security protocols, one similar to Kerberos and another based on public key encryption.
Hlavním cílem této diplomové práce je implementace obecného zabezpečeného peer-to-peer komunikačního systému. Systém má schopnost zcela automatizovaně naváz...
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Hlavním cílem této diplomové práce je implementace obecného zabezpečeného peer-to-peer komunikačního systému. Systém má schopnost zcela automatizovaně navázat a provozovat zabezpečené spojení mezi koncovými uzly komunikace. Tuto schopnost má i v případě, kdy se v cestě k cílovému systému nachází překladače síťových adres, bez nutnosti explicitně tyto překladače konfigurovat. Zabezpečovací procedury tohoto systému jsou transparentně skryty před jednotlivými síťovými aplikacemi, které tento problém musely řešit každá samostatně. Odpovědnost za bezpečnost je přenesena na aplikačně nezávislý subsystém pracující v rámci jádra operačního systému. Bezpečnost tohoto subsystému je založena na zachytávání odchozích a příchozích IP paketů a jejich autentizaci a šifrování. Systém se podařilo implementovat na operačním systému Microsoft Windows XP, v programovacím jazyku C++. Byla změřena přenosová rychlost komunikačního tunelu systému na různých šířkách pásma sítě. Výsledky ukazují, že při použití systému na běžných dnešních počítačích nedochází k prakticky žádnému zpomalení přenosové rychlosti oproti nešifrovanému kanálu.
This thesis describes the Flexible Internetwork Stack (FINS) Framework, an open-source tool to facilitate experimental research in wireless networks on multiple platforms. The FINS Framework uses a module-based archit...
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This thesis describes the Flexible Internetwork Stack (FINS) Framework, an open-source tool to facilitate experimental research in wireless networks on multiple platforms. The FINS Framework uses a module-based architecture that allows cross-layer behavior and runtime reconfiguration of the protocol stack. Version 1.0 of the framework makes use of existing physical and data link layer functionality, while enabling modifications to the stack at the network layer and above, or even the implementation of a clean-slate, non-layered protocol architecture. Protocols, stubs for communicating with intact layers, and management and supervisory functions are implemented as FINS Framework modules, interconnected by a central switch. This thesis describes the FINS Framework architecture, presents an initial assessment along with experiments on Android and Ubuntu enabled by the tool, and documents an intuitive mechanism for transparently intercepting socket calls that maintains efficiency and flexibility.
Polling I/O mechanisms on the Unix platform such as select() and poll() cause high processing overhead when they are used in a heavily-loaded network server with many concurrent open sockets. Large waste of processing...
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Polling I/O mechanisms on the Unix platform such as select() and poll() cause high processing overhead when they are used in a heavily-loaded network server with many concurrent open sockets. Large waste of processing power incurs not only service degradation but also various troubles such as high electronic power consumption and worsened MTBF of server hosts. It is thus a serious issue especially in large-scale service providers such as an Internet data center (iDC) where a great number of heavily-loaded network servers are operated. As a solution of this problem, we propose a technique of fine-grained control on the invocation intervals of the polling I/O function. The uniqueness of this study is the utilization of POSIX real-time scheduling to enable the fine-grained execution control. Although earlier solutions such as an explicit event delivery mechanism also addressed the problem, they require major modification in the OS kernel and transition from the traditional polling I/O model to the new explicit event-notification model. On the other hand, our technique can be implemented with low cost because it just inserts a few small blocks of codes into the server program and does not require any modification in the OS kernel.
This paper presents a mathematical model for two-stage planning of transportation and inventory for many sorts of products (multi-commodity). The situation considered in this paper, which happens in a local furniture ...
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This paper presents a mathematical model for two-stage planning of transportation and inventory for many sorts of products (multi-commodity). The situation considered in this paper, which happens in a local furniture manufacturing firm, is that the total supply in origins exceeds the current-stage's total demand from all destinations (markets). Therefore, the problem is how to arrange the current-stage's shipping in consideration of next-stage's (that is, future's) inventory in both origins and destinations. A mathematical model is proposed for the problem with the objective of minimizing the total cost of both shipping and inventory for all products within two stages. Meanwhile, since the next-stage's shipping costs usually are unknown, this paper presents a new concept of rational unit shipping cost: a forecasted average cost with weight of next-stage's shipping amount. Finally, a numerical example extracted from the furniture manufacturing company with 4 origins, 4 destinations and 4 commodities is illustrated in the paper. Significance: This paper presents a mathematical model for multi-commodity, two-stage transportation and inventory problem. The developed model is flexible for adjusting of the next-stage's shipping plan in accordance with the practical conditions at that time. It is also proved that many variables can be reduced by use of the rational unit shipping cost.
Considering the complexity of the networks and the need for telecommunication operators (Telco) to present innovations to their clients, the quickest possible, one of the solutions for this complexity could be to ce...
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Considering the complexity of the networks and the need for telecommunication operators (Telco) to present innovations to their clients, the quickest possible, one of the solutions for this complexity could be to centralize its configuration. Thus the SDN (software-defmed networking) concept may be an important solution. This paper suggests the implementation of a tool to support the development and testing of networks and services before they are put into production. The use of a tool that simplifies the configuration of a network service makes the networks and services to be less susceptible to errors and failures by those who set them up, thus allowing telecom operators, among others, to be able to create new services, improve the monitorization of their human resources and, above all, improve their fmancial results. In the end, success will be achieved because with a simple interaction and basic knowledge we are able to manage network services.
This paper describes a method for optimizing cable logging layouts using a heuristic network algorithm. A timber harvest unit layout is formulated as a network problem. Each grid cell containing timber volume to be ha...
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This paper describes a method for optimizing cable logging layouts using a heuristic network algorithm. A timber harvest unit layout is formulated as a network problem. Each grid cell containing timber volume to be harvested is identified as an individual entry node of the network. Mill locations or proposed timber exit locations are identified as destinations. Each origin will then be connected to one of the destinations through alternative links representing alternative cable corridors, harvesting equipment, landing locations, and truck road segments. A heuristic algorithm for network programming is used to solve the cost minimization network problem. A computerized model has been developed to implement the method. Logging feasibility and cost analysis modules are included in the model in order to evaluate the logging feasibility of alternative cable corridors and estimate yarding and transportation costs. The model was successfully applied to a harvest planning area to generate harvesting plans. This case study indicates that the planning method is best used for pre-planning since modeling assumptions with respect to tail spar availability and unconstrained road alignments may require modification of the plan before implementation.
From the Publisher: Pure JSP gives a very concise conceptual overview of the JavaServer Pages technology and its related components. Once you have a firm foundation with the JSP technology, related topics such as Java...
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ISBN:
(纸本)9780672319020;0672319020
From the Publisher: Pure JSP gives a very concise conceptual overview of the JavaServer Pages technology and its related components. Once you have a firm foundation with the JSP technology, related topics such as JavaBeans, JDBC and Servlets are covered at a very high level. The book moves on to explain a large number of JSP techniques, which were determined by studying problems faced by JSP users in the professional world. The final section covers the more technical aspects of the JSP technology. Topics include related API's, server configuration, and charts and diagrams related to developing JSP applications.
This friendly, solutions-oriented guide is filled with step-by-step examples that illustrate how to write basic to advanced JavaScript applications, as well as modify existing scripts to suit individual needs. Each ch...
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ISBN:
(纸本)9780072228878;0072228873
This friendly, solutions-oriented guide is filled with step-by-step examples that illustrate how to write basic to advanced JavaScript applications, as well as modify existing scripts to suit individual needs. Each chapter begins with the specific how-to topics that will be covered. Within the chapter, each topic is accompanied by a solid, easy-to-follow walkthrough of the process. Table of contents Part I: Learn JavaScript Basics 1: Prepare to Program in JavaScript 2: Learn JavaScript Fundamentals 3: Use Built-in JavaScript Classes 4: Organize Data into Arrays 5: Create Your Own JavaScript Classes Part II: Build JavaScript-Enabled Web Sites 6: Embed JavaScript in a Web Page 7: Create Scripts That Work in Every Browser 8: Manipulate Web Forms 9: Handle Browser Events 10: Communicate Between Browser Frames 11: Interact with the Web Browser 12: Perform Simple Animation Part III: Take JavaScript to the Next Level 13: Debug JavaScript Programs 14: Make Your Program Errorproof 15: Use JavaScript to Manage Browser Plug-Ins A: HTML 4.01 Tags B: JavaScript Quick Reference
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