Software error detection is one of the most challenging problems in software engineering. Now, you can learn how to make the most of software testing by selecting test cases to maximize the probability of revealing latent errors. Software Error Detection through Testing and Analysis begins with a thorough discussion of test-case selection and a review of the concepts, notations, and principles used in the book.
Several 1985-7 deaths of cancer patients were due to overdoses of radiation resulting from a race condition between concurrent tasks in the Therac-25 software.
Errors in medical software have caused deaths. Details in B.W. Boehm, "Software and its Impact: A Quantitative Assessment," Datamation,19(5), 48-59(1973). cần kinh nghiệm khiểm thử, một vài sự hiểu biệt về các pha phát triển của dự án co1 thể có ích, toán học có thể trợ giúp
The process of executing a program (or part of a program) with the intention of finding errors (Myers, Humphrey) The purpose of testing is to find errors. Testing is the process of trying to discover every conceivable fault or weakness in a work product (Myers, Kit) The process of searching for errors (Kaner)
• Network errors are in the form of corrupted data or lost data.
• Network errors occur naturally on all networks due to electrical noise and distortion
and must be detected and corrected by either hardware or software.
• Bit Error Rates (BERs) are calculated as the number of bits in error divided by the
number of bits transmitted. A BER of 1 in 100,000 might be shown as 1:105
as a BER of 10-5
• Errors often occur in bursts where many bits in a sequence will be in...
When a computer software succeeds—when it meets the needs of the people
who use it, when it performs flawlessly over a long period of time, when it is
easy to modify and even easier to use—it can and does change things for the better.
But when software fails—when its users are dissatisfied, when it is error prone, when
it is difficult to change and even harder to use—bad things can and do happen. We
all want to build software that makes things better, avoiding the bad things that lurk
in the shadow of failed efforts.
Phần 6 (14 part)
Sổ tay gồm 305 bài, hướng dẫn 1 cách cơ bản nhất để các bạn tạo 1 gói AIO
AIO là viết tắt của All In One ( tất cả trong một ) được hiểu đơn giản là một chương trình tổng hợp nhiều nội dung của 1 lĩnh vực hay 1 công dụng ( AIO music , AIO Flash , AIO System Utilities , AIO CD-DVD Maker , AIO Download ... )
tclick on a file or folder to easily get rid of error message such as error deleting file or folder, cannot delete folder: it's being used...
Cointegration and error correction
Professor Roy Batchelor
City University Business School, London
& ESCP, Paris
r On the City University system, EVIEWS 3.1 is in
Start/ Programs/ Departmental Software/CUBS
r Analysing stationarity in a single variable using VIEW
r Analysing cointegration among a group of variables
r Estimating an ECM model
r Estimating a VAR-ECM model
A model of potential program faults is a valuable source of information for evaluating and designing test suites. Some fault knowledge is commonly used in functional and structural testing, for example when identifying singleton and error values for parameter characteristics in category-partition testing or when populating catalogs with erroneous values, but a fault model can also be used more directly.
The essential characteristics of system testing are that it is comprehensive, based on a specification of observable behavior, and independent of design and implementation decisions. Independence in system testing avoids repeating software design errors in test design. Acceptance testing abandons specifications in favor of users, and measures how the final system meets users' expectations. Regression testing checks for faults introduced during evolution.
Software reviews are a “filter” for the software process. That is, reviews are applied at various points during software engineering and serve to uncover errors and defects that can then be removed. Software reviews “purify” software engineering work products, including requirements and design models, code, and testing data.
Software is tested to uncover errors that were made inadvertently as it was designed and constructed. But how do you conduct the tests? Should you develop a formal plan for your tests? Should you test the entire program as a whole or run tests only on a small part of it? Should you rerun tests you’ve already conducted as you add new components to a large system? When should you involve the customer? These and many other questions are answered when you develop a software testing strategy.
Once source code has been generated, software must be tested to uncover (and correct) as many errors as possible before delivery to your customer. Your goal is to design a series of test cases that have a high likelihood of finding errors - but how? That’s where software testing techniques enter the picture. Chapter 18 provides knowledge of testing conventional applications.
Chapter 19: Testing object-oriented applications. The architecture of object-oriented (OO) software results in a series of layered subsystems that encapsulate collaborating classes. Each of these system elements (subsystems and classes) performs functions that help to achieve system requirements. It is necessary to test an OO system at a variety of different levels in an effort to uncover errors that may occur as classes collaborate with one another and subsystems communicate across architectural layers.
Chapter 20: Testing web applications. WebApp testing is a collection of related activities with a single goal: to uncover errors in WebApp content, function, usability, navigability, performance, capacity, and security. To accomplish this, a testing strategy that encompasses both reviews and executable testing is applied.
Chapter 3 - Critical systems. The learning objectives for this chapter include: To explain what is meant by a critical system where system failure can have severe human or economic consequence; to explain four dimensions of dependability - availability, reliability, safety and security; to explain that, to achieve dependability, you need to avoid mistakes, detect and remove errors and limit damage caused by failure.
Databases are software. I’ve based the second half of a software development career that began in 1978 on this simple idea.
If you’ve found this book, chances are you’re willing to at least entertain the possibility that databases and their attendant programmability are worthy of the same rigor and process as the rest of an application. Good for you! It’s a great pleasure for me to join you on this journey,however briefly, via this foreword.
If you need to create and interpret statistics in business or classroom settings, this easy-to-use guide is just what you need. It shows you how to use Excel's powerful tools for statistical analysis, even if you've never taken a course in statistics. Learn the meaning of terms like mean and median, margin of error, standard deviation, and permutations, and discover how to interpret the statistics of everyday life. You'll learn to use Excel formulas, charts, PivotTables, and other tools to make sense of everything from sports stats to medical correlations....
All rights reserved. No part of this documentation may be transmitted, transcribed, stored in a backup device or translated into another language without Fagor Automation’s consent. Unauthorized copying or distributing of this software is prohibited. The information described in this manual may be changed due to technical modifications. Fagor Automation reserves the right to make any changes to the contents of this manual without prior notice.
Good programming is difficult. It is especially arduous for new programmers given
the pace of change and the ever-expanding size of the software engineering body of
knowledge (www.swebok.org) that they must master. The authors of this book have
found that experience and in-depth understanding are key factors in both programmer
productivity and reliable software. The bottom line is that experienced programmers
don’t stumble around in the dark. They know the lay of the land, they recognize patterns,
and they avoid the hazardous areas.
The best way to write queres using LINQ to SQL is by having a DataContext-derived class in your code that exposes all the tables, stored procedures, and user-defined functions you need as properties of a class instance. You also need entity classes that are mapped to the database objects. As you have seen in previous chapters, this mapping can be made by using attributes to decorate classes or through an external XML mapping file. However, writing this information by hand is tedious and error-prone work. You need some tools to help you accomplish this work....