Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1975 / Bibliography: leaves 129-130. / M.S. / M.S. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

Online sexual solicitors are individuals who deceptively earn the trust of minors online with the goal of eventual sexual gratification. Despite the prevalence of online solicitation, conversations in the domain are difficult to acquire due to the sensitive nature of the data. As a result, researchers studying online solicitors often study conversations between solicitors and decoys which are publicly available online. However, researchers have begun to believe such conversations are not representative of solicitor-victim conversations. Decoys and law enforcement are restricted in that they are unable to initiate contact, suggest meeting, or begin sexual conversations with an offender. Additionally decoys and law enforcement officers both have a goal of gathering evidence which means they often respond positively in contexts which would normally be considered awkward or inappropriate. Multiple researchers have suggested differences may exist between offender-victim and offender-decoy conversations and yet little research has sought to identify the differences and similarities between those talking to solicitors. In this study, the author identifies differences between decoys, officers, and victims within the manipulative process used by online solicitors to entrap victims which is known as grooming. The author looks at differences which occur within grooming stages and strategies within the grooming stages. The research in this study has implications for the data choices of future researchers in this domain. Additionally, this research may be used to inform the training process of officers who will engage in online sex stings.

An emerging trend in computing is to use distributed heterogeneous computing (HC) systems to execute a set of tasks. Cluster computer systems, grids, and Desktop Grids are three popular kinds of HC systems. An important component of an HC system is its resource management system (RMS). The main responsibility of an RMS is assigning resources to tasks in order to satisfy certain performance requirements. For cluster computer systems, we propose a new mapping heuristic which requires less state information than current heuristics. For Desktop Grids, we propose a new scheduling policy that exploits knowledge of the effective computing power delivered by the machines and the distribution of their fault times in order to improve performance. Finally, for grids, we propose a new decentralized load balancing policy which dramatically cuts down the communication overhead incurred in state information update. The proposed resource management policies utilize the solution to a linear programming problem (LP) which maximizes the system capacity. Our simulation experiments show that these policies perform very competitively, especially in highly heterogeneous systems. / Thesis / Doctor of Philosophy (PhD)

A study was performed to develop an interactive plane frame analysis program. The program was designed to run on Unix-based workstations and to be independent of the hardware platform. This was achieved by selecting the XWindow system as the underlying graphical user-interface. An event-driven, window-based program was developed using the XWindow Toolkit. The entire program was written in the C programming language. The program consists of two parts: a preprocessor and a processor. The preprocessor employs pull-down menus and pop-up dialog boxes and provides a convenient way of creating and modifying structural models. The processor performs linear elastic analysis of plane frame structures based on the matrix displacement method. The processor computes joint displacements, support reactions and local member-end forces of the structure. It also handles internal hinges, joint loads, member loads, prescribed displacements, multiple load cases and load combinations. Other features include automatic mesh generation for orthogonal frames, automatic computation of self-weight and specification of output options. To verify the accuracy of the program, analysis results from the program were compared with results obtained from a commercial structural analysis program. A comparison of joint displacements, support reactions and member-end forces indicate that the difference in the values obtained from the two programs is less than two percent and that the program provides accurate analysis results. / Master of Science

Analysis of rotating machinery requires the collection and evaluation of large quantities of data. For just one machine, the amount of data may become so overwhelmingly great that a thorough examination of all the data is rendered impractical. <b>IMTS</b> (Intelligent Monitoring And Trending System) is a data acquisition system that has been developed to help resolve this problem. <b>IMTS</b> is a pc based system which can collect data that is relevant to diagnostic considerations, perform an evaluation by filtering the data through special standards and store the results for later review. The system is flexible because the data is evaluated by user defined, multi-level references called standards. <b>IMTS</b> operates in the Microsoft Windows 3.0 operating system, which has the advantage of multitasking two or more programs and thereby allows the data to be collected, evaluated and displayed simultaneously. This means that the user does not experience any temporary periods of system inaccessibility as would be the case in a sequential operating system, such as DOS. This thesis discusses the development of <b>IMTS</b> and explains the capabilities of the current system configuration and gives examples of the monitor screen options and trend plotting capabilities. / Master of Science

In order to produce an Interactive MultiMedia Application (IMMA), the developer of that application needs a set of tools for such tasks as capturing, modifying, editing, sequencing, synchronizing, archiving, versioning, and backing up. The heart of this set of tools is an Integrator which can be used by the developer to assemble various multimedia objects into an IMMA and provide the end-user with ways of interacting with that IMMA. This work focuses on that essential tool - the multimedia Integrator. The Integrator uses a graphical interface that exploits a notation like that of a musical score. The IMMA produced by the Integrator is inherently parallel and includes elements required to define the asynchronous nature of applications, along with a standard set of multimedia objects. The timing and synchronization representation used by the Integrator is based on the model presented by the HyTime standard group. We also have explored the representation of our objects and their attributes according to the Multimedia Hypermedia Expert Group (MHEG) standard model as defined by the MHEG committee. This work formalizes the design of the Integrator and its constructs using the HyTime Draft International Standard (ISO/IEC DIS 10744). Multimedia application objects and their attributes are described, timing and synchronization aspects of the Integrator and some examples of IMMAs are explained, and several of these examples using the HyTime document structuring language are given. / Master of Science

The combined effect of group velocity dispersion (GVD) and nonlinearity limits the transmission distance of fiber optic communication systems. By designing a circuit that can model this effect and simulating it using the Block Oriented Systems Simulator (BOSS), we can study the pulse distortion and broadening that may occur. The nonlinearity considered here is self-phase modulation (SPM). A loop system is designed where each pass of the system corresponds to 200 km of fiber. The system mainly consists of a Butterworth bandpass filter which models the dispersion in the fiber and a VCO that imposes a phase modulation on the input signal thus modeling the intensity dependent phase shift due to SPM. By changing various parameters of the circuit, the dispersion limited distance, the nonlinearity limited distance and other related factors can be altered. With D=-0.04 ps/km.nm, the effect of changing the nonlinear limited distance and thus the nonlinear effect is studied and simulated. The results are compared with a simple theoretical model for pulse broadening that has appeared in the literature. Although the simulation results exhibit the same qualitative behavior as the theory, there are significant quantitative differences. The reason for these differences are discussed. / Master of Science

This thesis describes a new CAD tool, TIMESPEC, developed for solving the timing distribution problem of allocating realistic delays to the internal primitives of a digital device. The inconsistencies in the manufacturer's specifications are also detected and corrected. Therefore, TIMESPEC enables the use of imbedded timing in behavioral VHDL models, thereby providing accurate VHDL descriptions. Due to this modeling methodology, the end-to-end delays for all the paths in the digital device are made available. Also, due to the Register Transfer Level (RTL) of abstraction, which is represented by a process model graph, there is close correspondence with the actual device being modeled. Thus a better insight into the timing problems is provided and synthesis is possible from the resulting models. A linear programming approach is employed for solving the timing distribution problem. An interface is provided with an X-windows based graphical tool, the Modeler's Assistant. This provides a graphical interface for TIMESPEC. An important feature, that is made available by this interface, is the enumeration of all the input-to-output paths in the device. Thus a CAD tool is made available for system or chip designers/modelers for building accurate VHDL models where the timing is incorporated using the imbedded timing method. / Master of Science

This thesis describes the development of a graphical CAD tool for VHDL model development. The tool was developed for the X Windows environment. The graphical representation used is the process model graph [1,4]. The process model graph is input interactively and the tool generates the corresponding VHDL code. The design style is restricted to behavioral models. A new scheme was formulated for the development and use of reusable code in the form of primitives. A default set of primitives as presented in [5] was also developed. The tool can also attach to any VHDL analyzer available on the system and analyze the developed code. This tool is designed for use by system modelers and should simplify the process of model development, thus improving productivity. / Master of Science

The problems of incidents arising in computer networks and the computer system security level evaluation are considered in the thesis. The main research objects are incidents arising in computer networks, intrusion detection systems and network scanning types. The aim of the thesis is the investigation of the incidents in the computer networks and computer system security level evaluation. The following main tasks are solved in the work: classification of attacks and numerical evaluation of the attack severity level evaluation; quantitative evaluation of the computer system security level; investigation of the dependence of the computer system performance and availability on the attacks affecting the system and defense mechanisms used in it; development of the model simulating the computer network horizontal and vertical scanning. The thesis consists of general characteristic of the research, five chapters and general conclusions. General characteristic of the thesis is dedicated to an introduction of the problem and its topicality. The aims and tasks of the work are also formulated; the used methods and novelty of solutions are described; the author‘s publications and structure of the thesis are presented. Chapter 1 covers the analysis of existing publications related to the problems of the thesis. The survey of the intrusion detection systems is presented and methods of the intrusion detection are analyzed. The currently existing techniques of the attack classification are... [to full text] / Disertacijoje nagrinėjamos incidentų kompiuterių tinkluose ir kompiuterių sistemų saugumo lygio įvertinimo problemos. Pagrindiniai tyrimo objektai yra incidentai kompiuterių tinkluose, atakų atpažinimo sistemos ir kompiuterių tinklo žvalgos būdai. Disertacijos tikslas – incidentų kompiuterių tinkluose tyrimas ir kompiuterių sistemų saugumo lygio įvertinimas. Darbe sprendžiami šie pagrindiniai uždaviniai: atakų klasifikavimas ir jų sunkumo lygio skaitinis įvertinimas; kompiuterių sistemos saugumo lygio kiekybinis įvertinimas; kompiuterių sistemos našumo ir pasiekiamumo priklausomybės nuo sistemą veikiančių atakų ir joje naudojamų apsaugos mechanizmų tyrimas; modelio, imituojančio kompiuterių tinklo horizontalią ir vertikalią žvalgą kūrimas. Disertaciją sudaro įvadas, penki skyriai ir bendrosios išvados. Įvadiniame skyriuje nagrinėjamas problemos aktualumas, formuluojamas darbo tikslas bei uždaviniai, aprašomas mokslinis darbo naujumas, pristatomi autoriaus pranešimai ir publikacijos, disertacijos struktūra. Pirmasis skyrius skirtas literatūros apžvalgai. Jame apžvelgiamos atakų atpažinimo sistemos, analizuojami atakų atpažinimo metodai. Nagrinėjami atakų klasifikavimo būdai. Didelis dėmesys skiriamas kompiuterių sistemos saugumo lygio įvertinimo metodams, kompiuterių prievadų žvalgos būdams ir žvalgos atpažinimo metodams. Skyriaus pabaigoje formuluojamos išvados ir konkretizuojami disertacijos uždaviniai. Antrajame skyriuje pateikta sudaryta atakų nukreiptų į kompiuterių... [toliau žr. visą tekstą]