Tối ưu hóa topology

Mục tiêu nghiên cứu của đề tài là nghiên cứu lý thuyết tối ưu hóa hình học (Topology Optimisation) để xây dựng phương pháp tối ưu hóa trong việc thiết kế chi tiết trong lĩnh vực cơ khí sau đó mở rộng ra một số lĩnh vực khác như thiết bị y tế, thiết kế kết cấu xây dựng, kiến trúc; Xây dựng thuật toán thực hiện tối ưu hóa hình học từ đó xuất ra hình dạng hình học tối ưu cho chi tiết cần thiết kế; Xây dựng hình dáng tối ưu của chi tiết trên các phần mềm CAD;...

31p elysadinh 07-06-2021 32 7   Download

Mô hình giàn ảo là một công cụ đặc biệt thích hợp cho việc tính toán và xử lý các khu vực chịu lực cục bộ của kết cấu bê tông cốt thép. Bài báo này trình bày phương pháp tối ưu Topology với thuật toán mật độ để thiết lập tự động mô hình giàn ảo. Phương pháp phần tử hữu hạn cũng được sử dụng để mô hình và phân tích trong quá trình tối ưu. Các mô phỏng số áp dụng phương pháp trình bày để xây dựng mô hình cho một số vùng D của kết cấu cầu bê tông cốt thép.

5p slimzslimz 17-12-2019 55 4   Download

Bài viết này đề xuất cách tiếp cận sử dụng thuật toán tiến hóa đa mục tiêu (MOEA) để giải quyết bài toán thiết kế tối ưu kiến trúc mạng viễn thông (TND) với nhiều ràng buộc phức tạp, các mục tiêu của bài toán gồm các yếu tố chi phí và độ tin cậy. Mỗi cá thể trong quần thể là biểu diễn của một mô hình mạng (topology) có yếu tố chi phí được xác định nhờ thuật toán đơn hình trong bài toán quy hoạch tuyến tính (LP) và độ tin cậy được xác định nhờ thuật toán Monte Carlo...

8p hanh_tv29 24-04-2019 82 2   Download

ĐẠI HỌC QUỐC GIA HÀ NỘI TRƯỜNG ĐẠI HỌC CÔNG NGHỆ Đặng Ngọc Bền TỐI ƯU HÓA TOPOLOGY CHO MẠNG NGANG HÀNG CÓ CẤU TRÚC CHORD KHOÁ LUẬN TỐT NGHIỆP ĐẠI HỌC HỆ CHÍNH QUY Ngành: Công nghệ Thông tin Cán bộ hướng dẫn: TS. Nguyễn Hoài Sơn HÀ NỘI - 2009 .LỜI CẢM ƠN Em xin chân thành cảm ơn các thầy cô giáo trong trường Đại học Công nghệ Đại học Quốc gia Hà Nội đã tận tình giúp đỡ và truyền đạt kiến thức cho em trong suốt 4 năm học qua để em có đủ kiến thức hoàn thành khóa luận này. Đặc...

52p chieu_mua 27-08-2012 112 14   Download

Ngày nay, Internet đã thực sự phát triển và đi sâu vào đời sống của mỗi con người. Khả năng chia sẻ những tài nguyên lớn một cách nhanh chóng và hiệu quả luôn nhận được quan tâm từ những người nghiên cứu cũng như sử dụng Internet. Với những đặc điểm phù hợp, mạng ngang hàng, đặc biệt là mạng ngang hàng có cấu trúc ngày càng được sử dụng phổ biến cho các ứng dụng nêu trên. Tuy nhiên, bên cạnh những ưu điểm, mạng ngang hàng có cấu trúc cũng bộc lộ những hạn chế nhất định,...

54p chieu_mua 27-08-2012 160 34   Download

Channel Assignment Problems (CAPs) occur in the design of cellular mobile telecommunication systems (Jordan, 1996; Katzela and Naghshineh, 1996; MacDonald, 1979); such systems typically divide the geographical region to be serviced into a set of cells, each containing a base station. The available radio frequency spectrum is divided into a set of disjoint channels; these must be assigned to the base stations to meet the expected demand of each cell and to avoid electromagnetic interference during calls....

15p tienvovan 11-09-2010 78 5   Download

In the last two decades, wireless communication systems such as cordless phones, paging systems, wireless data networks, satellite-based and cellular mobile systems have been steadily increasing in both popular importance and technological sophistication. The firstgeneration wireless systems were developed in the late 1970s and 1980s and were based on analog technology (such as the Advance Mobile Phone Service (AMPS) by AT&T and Nordic Mobile Telephone (NMT) by Ericsson).

26p tienvovan 11-09-2010 61 5   Download

In recent years, flow control and network management in high speed networks have drawn much attention by researchers in the telecommunications field. In large-scale network environments with high complexity, decentralized control and decision making are required. Many research papers concerned with multidisciplinary approaches to modeling, controlling and managing networks from a computational intelligence point of view appear in the key telecommunication journals every year.

23p tienvovan 11-09-2010 60 5   Download

Today an ever increasing number of social and financial services can be provided over data networks. Individuals and businesses alike initiate and complete a large number of commercial transactions over the Internet or other specially constructed networks. Home banking, home shopping, video on demand, buying and selling of stocks and other financial securities can now be undertaken from almost any part of the world where an access to a local network can be achieved.

23p tienvovan 11-09-2010 71 6   Download

The software crisis is usually defined in terms of projects running over budget and over schedule, though an equally important aspect is the poor quality of software measured in terms of its correctness, reliability and performance. The consequences of releasing faulty software into service may be devastating in safety-related applications, telecommunications and other areas. When the USA telecommunications system failed and half of the nation was isolated, lives and property were clearly put at risk....

18p tienvovan 11-09-2010 74 5   Download

Many of today’s data intensive applications have the common need to access exceedingly large databases in a shared fashion, simultaneously with many other copies of themselves or similar applications. Often these multiple instantiations of the client application are geographically distributed, and therefore access the database over wide area networks. As the size of these ‘industrial strength’ databases continue to rise, particularly in the arena of Internet, Intranet and Multimedia servers, performance problems due to poor scalabilty are commonplace. ...

0p tienvovan 11-09-2010 77 6   Download

As Internet connectivity is reaching the global community, information systems are becoming more and more distributed. Inevitably, this overnight exponential growth has also caused traffic overload at various places in the network. Until recently, it was believed that scaling the Internet was simply an issue of adding more resources, i.e. bandwidth and processing power could be brought to where they were needed.

11p tienvovan 11-09-2010 93 6   Download

The explosive growth of distributed computing has been fuelled by many factors. Applications such as video conferencing, teleoperation and most notably the World Wide Web are placing ever more demanding requirements on their underlying communication systems. Having never been designed to support such diverse communication patterns these systems are failing to provide appropriate services to individual applications. Artificial neural networks have been used in areas of communication systems including signal processing and call management (Kartalopolus, 1994)....

21p tienvovan 11-09-2010 71 6   Download

Computer networks are gaining increasing importance as they penetrate business and everyday life. Technological evolution results in increased computational power and transmission capacity. These phenomena open the way to the development and exploitation of new applications (e.g. video conferencing) which require demanding services from the network. As a result, computer networks are in continuous evolution and the protocols regulating their operation must be assessed for their suitability to new technologies and ability to support the new applications. ...

14p tienvovan 11-09-2010 78 5   Download

All point-to-point communication networks have a means of directing traffic from a source to a destination via intermediate nodes. This routing function must be performed efficiently as it affects all aspects of network communications including jitter, latency and total bandwidth requirement. Other issues related to routing, such as policing and traffic control are not dealt with in this chapter. There are two distinct approaches to ‘routing’ traffic, namely connection-oriented and connectionless. ...

17p tienvovan 11-09-2010 77 5   Download

A routing algorithm constructs routing tables to forward communication packets based on network status information. Rapid inflation of the Internet increases demand for scalable and adaptive network routing algorithms. Conventional protocols such as the Routing Information Protocol (RIP) (Hedrick, 1988) and the Open Shortest-Path First protocol (OSPF) (Comer, 1995) are not adaptive algorithms; they because they only rely on hop count metrics to calculate shortest paths. In large networks, it is difficult to realize an adaptive algorithm based on conventional approaches. ...

16p tienvovan 11-09-2010 80 7   Download

This chapter describes the joint application of two soft computing methods – evolutionary algorithms and fuzzy reasoning – to the problem of adaptive distributed routing control in packet-switched communication networks. In this problem, a collection of geographically distributed routing nodes are required to adaptively route data packets so as to minimise mean network packet delay. Nodes reach routing decisions locally using state measurements which are delayed and necessarily only available at discrete sampling intervals. ...

14p tienvovan 11-09-2010 68 5   Download

The telecommunications access network is the section of the network that connects the local exchange to the customers. At present most of the access network is composed of low bandwidth copper cable. Electronic communications are becoming an essential feature of life both at home and at work. The increasing use of applications that require larger bandwidths (such as the internet and video on demand) are making the copper infrastructure inadequate. These demands could be met using optical fibre technologies....

19p tienvovan 11-09-2010 85 6   Download

Telecommunications is a vital and growing area, important not only in its own right, but also for the service it provides to other areas of human endeavour. Moreover, there currently seems to be a demand for an ever-expanding set of telecommunication services of ever-increasing bandwidth. One particular technology that has the potential to provide the huge bandwidths necessary if such broadband services are to be widely adopted, is multiwavelength all-optical transport networks (Mukherjee, 1997)....

16p tienvovan 11-09-2010 72 5   Download

In line with the rapid growth of telecommunications networks in recent years, there has been a corresponding increase in the level of network complexity. Consequently, it is now generally accepted that advanced computer aided simulation and analysis methods are essential aids to the management of large networks. The 1990s will be recalled as the decade of business process re-engineering

19p tienvovan 11-09-2010 98 6   Download