openssl源碼
The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS) protocols as well as a full-strength general purpose cryptography library. The project is managed by a worldwide community of volunteers that use the Internet to communicate, plan, and develop the OpenSSL toolkit and its related documentation.
matlab有限元網格劃分程序
DistMesh is a simple MATLAB code for generation of unstructured triangular and tetrahedral meshes. It was developed by Per-Olof Persson (now at UC Berkeley) and Gilbert Strang in the Department of Mathematics at MIT. A detailed description of the program is provided in our SIAM Review paper, see documentation below.
One reason that the code is short and simple is that the geometries are specified by Signed Distance Functions. These give the shortest distance from any point in space to the boundary of the domain. The sign is negative inside the region and positive outside. A simple example is the unit circle in 2-D, which has the distance function d=r-1, where r is the distance from the origin. For more complicated geometries the distance function can be computed by interpolation between values on a grid, a common representation for level set methods.
For the actual mesh generation, DistMesh uses the Delaunay triangulation routine in MATLAB and tries to optimize the node locations by a force-based smoothing procedure. The topology is regularly updated by Delaunay. The boundary points are only allowed to move tangentially to the boundary by projections using the distance function. This iterative procedure typically results in very well-shaped meshes.
Our aim with this code is simplicity, so that everyone can understand the code and modify it according to their needs. The code is not entirely robust (that is, it might not terminate and return a well-shaped mesh), and it is relatively slow. However, our current research shows that these issues can be resolved in an optimized C++ code, and we believe our simple MATLAB code is important for demonstration of the underlying principles.
To use the code, simply download it from below and run it from MATLAB. For a quick demonstration, type "meshdemo2d" or "meshdemond". For more details see the documentation.
We show in the context of a new economic geography model that when
labor is heterogenous trade liberalization may lead to industrial agglomeration
and inter-regional trade. Labor heterogeneity gives local monopoly
power to firms but also introduces variations in the quality of the job match.
Matches are likely to be better when there are more firms and workers in
the local market, giving rise to an agglomeration force which can offset the
forces against, trade costs and the erosion of monopoly power. We derive
analytically a robust agglomeration equilibrium and illustrate its properties
with numerical simulations
We consider the problem of target localization by a
network of passive sensors. When an unknown target emits an
acoustic or a radio signal, its position can be localized with multiple
sensors using the time difference of arrival (TDOA) information.
In this paper, we consider the maximum likelihood formulation
of this target localization problem and provide efficient convex
relaxations for this nonconvex optimization problem.We also propose
a formulation for robust target localization in the presence of
sensor location errors. Two Cramer-Rao bounds are derived corresponding
to situations with and without sensor node location errors.
Simulation results confirm the efficiency and superior performance
of the convex relaxation approach as compared to the
existing least squares based approach when large sensor node location
errors are present.
Intensive development of digital technologies coincided in time with the beginning
of the new era in telecommunications. It made possible to formalize many proce-
dures of data exchange and to atomize some operations which made providing of
serviceandmakeworkofmanytelecommunicationworkersmucheasier. Somenew
telecommunication technologies were born out of the necessity for use of specific
configurations of network elements and networks, as well as for a possibility of
providing maximum characteristics of efficiency combined with high requirements
to the stability of operation, the overcoming of different catastrophic situations and
deadlockconditions,such as failuresand ”pending”of the networkandthe like. The
thresholdbetweeninformationsystems andtelecommunicationsystems has become
practically invisible. It resulted in such a new term as ”infocommunication”
ESD is a crucial factor for integrated circuits and influences their quality and reliability.
Today increasingly sensitive processes with deep sub micron structures are developed. The
integration of more and more functionality on a single chip and saving of chip area is
required. Integrated circuits become more susceptible to ESD/EOS related damages.
However, the requirements on ESD robustness especially for automotive applications are
increasing. ESD failures are very often the reason for redesigns. Much research has been
conducted by semiconductor manufacturers on ESD robust design.
In this research, we have designed, developed implemented a wireless sensor
networks based smart home for safe, sound and secured living environment for
any inhabitant especially elderly living alone. We have explored a methodology
for the development of efficient electronic real time data processing system to
recognize the behaviour of an elderly person. The ability to determine the
wellness of an elderly person living alone in their own home using a robust,
flexible and data driven artificially intelligent system has been investigated. A
framework integrating temporal and spatial contextual information for
determining the wellness of an elderly person has been modelled. A novel
behaviour detection process based on the observed sensor data in performing
essential daily activities has been designed and developed.
This book is written for engineers involved in the operation, control, and
planning of electric power systems. In addition, the book provides information and
tools for researchers working in the fields of power system security and stability. The
book consists of two volumes. The first volume provides traditional techniques for the
stability analysis of large scale power systems. In addition, an overview of the main
drivers and requirements for modernization of the traditional methods for online
applications are discussed. The second volume provides techniques for online security
assessment and corrective action studies. In addition, the impact of variable generation
on the security of power systems is considered in the second volume. The first volume
may be considered as a background builder while the second volume is intended for
the coverage of edge techniques and methods for online dynamic security studies.
The electrical power grid is often referred to as one of the most complex man-
made systems on Earth. Its importance to all aspects of our daily lives, economic
stability, and national security cannot be overstated, and the need for an updated,
secure, resilient, and smarter power grid infrastructure is increasingly recognized
and supported by policy makers and market forces.
