Information Technology (eBook)

Contents 6
Preface 8
Quality of Service in Information Networks 9
1. QUALITY OF SERVICE IN IP NETWORKS 9
2. RESOURCE ALLOCATION MECHANISMS IN ROUTERS 12
2.1 Classification of packets 12
2.2 Policing and marking 13
2.3 Management of queues 14
2.4 Scheduling 15
3. THE INTEGRATED SERVICES MODEL 16
4. THE DIFFERENTIATED SERVICES MODEL 18
5. INTEGRATED SERVICES OVER DIFFSERV NETWORKS 20
6. MULTIPROTOCOL LABEL SWITCHING 21
7. QUALITY OF SERVICE IN THIRD GENERATION WIRELESS NETWORKS 23
8. CONCLUSIONS 26
REFERENCES 27
Risk-Driven Development Of Security-Critical Systems Using UMLsec 29
1. Introduction 29
2. Related Work 30
3. Distributed System Security 31
4. UMLsec 32
5. Security evaluation of UML diagrams using formal semantics 34
5.1. Security analysis of UML diagrams 37
5.2. Important security properties 40
5.3. Tool support 42
6. Risk-Driven Development 42
6.1. IEC 61508 44
6.2. Model-based risk assessment: The CORAS approach 46
7. MBRA Development Process for Security-Critical Systems 47
8. Development of a AIBO-Lego Mindstorm Prototype Using the Approach 49
8.1. Concept and overall scope definition 50
8.2. Preliminary hazard analysis (PHA) 51
8.3. Risk management and specification of security requirements 55
8.4. Design and implementation 56
8.5. Testing and security validation 58
9. Conclusion 58
Acknowledgments 59
References 60
Developing Portable Software 63
1. INTRODUCTION 63
2. THE WHAT AND WHY OF PORTABILITY 64
2.1 What is Portability? 64
2.2 Why should we Port? 65
2.3 Why shouldn’t we Port? 66
2.4 Levels of Porting 67
2.5 Portability Myths 67
3. INTERFACES AND MODELS 67
4. THE ROLE OF STANDARDS 70
5. STRATEGIES FOR PORTABILITY 72
5.1 Three Key Principles 72
5.1.1 Control the Interfaces 72
5.1.2 Isolate Dependencies 72
5.1.3 Think Portable 73
5.2 Classifying the Strategies 73
5.3 Three Types of Strategies 74
5.3.1 Standardize the Interface 74
5.3.2 Port the Other Side 74
5.3.3 Translate the Interface 75
5.4 Language Based Strategies 75
5.4.1 Standard Languages 76
5.4.2 Porting the Compiler 76
5.4.3 Language Translation 77
5.5 Library Strategies 77
5.5.1 Standard Libraries 78
5.5.2 Portable Libraries 79
5.5.3 Interface Translation 79
5.6 Operating System Strategies 79
5.6.1 Standard APIs 80
5.6.2 Porting the Operating System 81
5.6.3 Interface Translation 81
5.7 Architecture Strategies 82
5.7.1 Standard Architectures 82
5.7.2 Generic Architectures 83
5.7.3 Binary Translation 84
6. THE SOFTWARE DEVELOPMENT PROCESS 84
6.1.1 The Software Lifecycle 84
6.1.2 Specification 85
6.1.3 Design 86
6.1.4 Implementation 87
6.1.5 Testing and Debugging 87
6.1.6 Documentation 88
6.1.7 Maintenance 89
6.1.8 Measuring Success 89
7. OTHER ISSUES 90
7.1.1 Transportation and Data Portability 90
7.1.2 Cultural Adaptation 91
8. CONCLUSION 91
REFERENCES 92
Formal Reasoning About Systems, Software and Hardware Using Functionals, Predicates and Relations 93
Introduction: motivation and overview 94
1. Calculating with expressions and propositions 95
1.1 Expressions, substitution and equality 95
1.2 Pointwise and point-free styles of expression 96
1.3 Calculational proposition logic 99
1.4 Binary algebra and conditional expressions 101
2. Introduction to Generic Functionals 102
2.1 Sets, functions and predicates 102
2.2 Concrete generic functionals, first batch 104
3. Functional Predicate Calculus 106
3.1 Axioms and basic calculation rules 106
3.2 Expanding the toolkit of calculation rules 108
4. Generic Applications 110
4.1 Applications to functions and functionals 110
4.2 Calculating with relations 112
4.3 Induction principles 113
5. Applications in Computing 114
5.1 Calculating with data structures 114
5.2 Systems specification and implementation 115
5.3 Formal semantics and programming theories 117
6. Applications in ncontinuous mathematics 119
6.1 An example in mathematical analysis 119
6.2 An example about transform methods 119
7. Some final notes on the Funmath formalism 120
References 121
The Problematic of Distributed Systems Supervision – An Example: Genesys 123
1. INTRODUCTION 123
2. STATE OF THE ART 125
2.1 Standards in Distributed Management 126
2.1.1 SMTP 126
2.1.2 JMX 128
2.1.3 Distributed Management Task Forces Standards 130
2.2 Supervision Frameworks 130
2.2.1 Tivoli (IBM) (http://www.tivoli.com) 130
2.2.1.1 Overview 131
2.2.1.2 TME Management Services 132
2.2.1.3 Communications and networks 133
2.2.2 Unicenter (Computer Associates) (http://www.cai.com) 134
2.2.2.1 Unicenter architecture 134
2.2.2.2 Unicenter TNG’s distributed management approach 135
2.2.2.3 Unicenter TNG agent technology and integration 136
2.2.2.4 Unicenter TNG’s Agent Factory environment 137
2.2.3 Openview (HP) (http://www.hp.com) 137
2.2.3.1 Overview 137
2.2.3.2 ITO functioning 138
2.2.3.3 ITO architecture 139
2.2.3.4 Integration of applications into ITO 139
2.2.4 Other frameworks 140
2.3 Related Projects 140
2.4 Intelligent Supervision 141
2.4.1 Case Database Approach 142
2.4.2 Topology Analysis 142
2.4.3 Prediction Systems 143
3. INTRODUCTION TO GENESYS 143
3.1 What is GeneSyS ? 143
3.2 Contexts 143
3.2.1 Preliminary Design Review 144
3.2.2 Distributed Training 145
3.2.3 Web-Servers Monitoring 146
3.3 Requirements 147
4. GENESYS FRAMEWORK 148
4.1 Constraints of Existing Solutions 148
4.2 Design Objectives 148
4.3 Web Technologies as a Platform for a Supervision Framework 149
4.4 Basic Components and Communication Model 152
4.5 Intelligence 153
5. APPLICABILITY RESULTS 154
5.1 Preliminary Design Review Scenario 154
5.2 Distributed Training Scenario 155
5.3 Web Servers Scenario 156
6. CONCLUSION 157
REFERENCIES 158
Software Rejuvenation - Modeling and Analysis 159
1. Introduction 159
2. Classification and Treatment of Software Faults 161
3. Analytic Models for Software Rejuvenation 164
4. Measurement Based Models for Software Rejuvenation 174
5. Implementation of a Software Rejuvenation Agent 185
6. Approaches and Methods of Software Rejuvenation 185
7. Conclusions 187
Notes 187
References 187
Test and Design-for-Test of Mixed-Signal Integrated Circuits 191
1. INTRODUCTION 192
2. TEST METHODS 193
2.1 General background 193
2.2 Defects and fault models 195
2.3 Functional Test 197
2.4 Structural Test 199
2.4.1 Fault simulation 199
2.4.2 Test generation 201
3. DESIGN-FOR-TEST 202
3.1 Design-for-testability 203
3.2 Built-in self-test 206
3.2.1 Test generation and test compaction 207
3.2.2 Current testing 210
3.3 Self-checking circuits 211
3.4 Unified built-in self-test 213
4. CONCLUSIONS 215
5. REFERENCES 217
Web Services 221
1. INTRODUCTION 221
1.1 Characteristics of Web Services 222
1.2 Web Services Technologies 223
2. WEB SERVICES ARCHITECTURE 224
2.1 SOAP 225
2.1.1 SOAP Message Exchange 228
2.2 WSDL 229
2.2.1 WSDL Document Types 229
2.3 UDDI 231
2.3.1 Why UDDI? 232
2.3.2 UDDI Business Registry 232
3. TOWARDS SEMANTIC WEB SERVICES 233
3.1 Introduction 233
3.2 Web Services and their Complexity 234
3.3 Functionalities Required for Successful Web Services 235
3.4 Semantic Markup for Web Services 237
3.5 Services Composition 239
3.6 Web Services and Security 240
3.6.1 Typing and Pattern Matching 241
3.6.2 Trust in Web Services 242
4. CONCLUSION 242
References 243
Applications of Multi-Agent Systems 247
1. INTRODUCTION 247
2. MULTI-AGENT SYSTEMS 250
2.1 Agent architectures 252
2.2 Communication 254
2.3 Coordination 256
2.4 Negotiation 258
2.4.1 Distributive negotiation 258
2.4.2 Integrative negotiation 259
2.5 Learning 261
2.5.1 Reinforcement learning 261
2.5.2 Bayesian learning 262
2.5.3 Model-based learning 262
2.5.4 Nested representations 263
2.6 Methodologies for multi-agent system development 263
2.7 Multi-agent system development software 264
3. APPLICATIONS 266
3.1 Multi-agent systems infrastructures 266
3.1.1 RETSINA 266
3.1.2 SICS 267
3.2 Application areas 267
3.3 ARCHON’s electricity transportation management application 268
3.4 ADEPT business process management application 269
3.5 FACTS telecommunication service management 269
3.6 Challenger 269
3.7 Tele-MACS 270
3.8 TELE TRUCK 270
3.9 MetaMorphII 271
3.10 Fishmarket 271
3.13 MACIV 272
3.14 SMACE 272
3.15 COM_ELECTRON 272
3.16 VIRT_CONSTRUCT 273
4. CONCLUSION 274
Discrete Event Simulation with Applications to Computer Communication Systems Performance 279
1. FROM SYSTEM TO MODEL 280
2. CLASSIFICATION OF SIMULATION MODELS 283
3. CLASSIFICATION OF SIMULATION TOOLS 284
4. THE ROLE OF STATISTICS IN SIMULATION 285
4.1 Random Variate generation 285
4.2 Output Analysis 290
4.2.1 Point and Interval Estimates 291
4.2.2 Terminating vs. Steady State simulation 292
4.2.3 Initialization Bias 293
4.2.4 Dealing with Dependency [1] 293
4.2.5 Method of Batch Means 295
4.2.6 Variance Reduction Techniques 295
5. SOME APPLICATIONS 296
5.1 OPNET MODELER 296
5.1.1 Construction of Model in OPNET MODELER [19] 297
5.1.2 Example- Comparison of RED vs. FIFO with Tail-drop 300
5.2 ns-2 and NAM 305
5.2.1 Overview and Model construction in ns-2 305
5.2.2 Network Components (ns objects) 305
5.2.3 Event Schedulers 306
5.2.4 Data collection and Execution 307
5.2.5 Network Animator 307
5.2.6 Example- RED Analysis 307
6. SUMMARY 309
REFERENCES 310
Human-Centered Automation: A Matter of Agent Design and Cognitive Function Allocation 313
1. INTRODUCTION 313
2. LESSONS LEARNED FROM AERONAUTICS 315
3. WHAT IS AN AGENT? 317
4. POSSIBLE AGENT-TO-AGENT INTERACTION 318
5. AN ECOLOGICAL APPROACH: LOOKING FOR MATURITY 321
5.1Hiding unnecessary complexity while promoting necessary operations 321
5.2 Affordance: The ultimate maturity of an artifact 322
5.3 Discovering affordances using active design documents 324
5.4 Human-centered design of artificial agents 325
5.5 Adapting Henderson’s design cycle to agents 326
6. AN EXAMPLE OF COGNITIVE FUNCTION ANALYSIS 327
6.1 Design case 1: Allocation of cognitive functions to User 328
6.2 Design case 2: Allocation of cognitive functions to User and Artifact 330
6.3 Design case 3: Allocation of cognitive functions to Artifact 331
6.4 Design case 4: Allocation of cognitive functions to Organizational Environment 332
7. INTERPRETATION VERSUS AMPLIFICATION 334
8. CONCLUSION AND PERSPECTIVES 336
9. ACKNOWLEDGMENTS 338
10. REFERENCES 338
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5. Security evaluation of UML diagrams using formal semantics (p. 26- 27)

For some of the constraints used to define the UMLsec extensions we need to refer to a precisely defined semantics of behavioral aspects, because verifying whether they hold for a given UML model may be mathematically non-trivial. Firstly, the semantics is used to define these constraints in a mathematically precise way. Secondly, in ongoing work, we are developing mechanical tool support for analyzing UML specifications (for example in [Sha03; Men], and a few other student projects). For this, a precise definition of the meaning of the specifications is necessary, and it is useful to formulate this as a formal model for future reference before coding it up. For security analysis, the security-relevant information from the security-oriented stereotypes is then incorporated.

Note that because of the complexities of the UML, it would take up too much space to recall our formal semantics here completely. Instead, we just define precisely and explain the interfaces of the semantics that we need here to define the UMLsec profile. More details on the formal semantics can be found in [Jür03b]. Our formal semantics of a simplified fragment of UML using Abstract State Machines (ASMs) includes the following kinds of diagrams:

Class diagrams define the static class structure of the system: classes with attributes, operations, and signals and relationships between classes.
On the instance level, the corresponding diagrams are called object diagrams.

Statechart diagrams (or state diagrams) give the dynamic behavior of an individual object or component: events may cause a change in state or an execution of actions.

Sequence diagrams describe interaction between objects or system components via message exchange.

Activity diagrams specify the control flow between several components within the system, usually at a higher degree of abstraction than statecharts and sequence diagrams. They can be used to put objects or components in the context of overall system behavior or to explain use cases in more detail.

Deployment diagrams describe the physical layer on which the system is to be implemented.

Subsystems (a certain kind of packages) integrate the information between the different kinds of diagrams and between different parts of the system specification.

There is another kind of diagrams, the use case diagrams, which describe typical interactions between a user and a computer system. They are often used in an informal way for negotiation with a customer before a system is designed. We will not use it in the following. Additionally to sequence diagrams, there are collaboration diagrams, which present similar information. Also, there are component diagrams, presenting part of the information contained in deployment diagrams.

The used fragment of UML is simplified significantly to keep a formal treatment that is necessary for some of the more subtle security requirements feasible and to allow model-checking of UML specifications. Note also that in our approach we identify system objects with UML objects, which is suitable for our purposes. Also, as with practical all analysis methods, also in the real-time setting [Wat02], we are mainly concerned with instance-based models.

Although simplified, our choice of a subset of UML is reasonable for our needs, as we have demonstrated in several industrial case-studies (some of which are documented in [Jür03b]).