A systematic approach to reliable multistage interconnection network design

Bibliography: p. 34-35.Army Research Office grant no. DAAG29-84-K-0005 Advanced Research Projects Agency monitored by ONR, contract N00014-81-K-0742C.-C. Jay Kuo

Blocking performance of extended pruned vertically stacked optical banyan structure under different link failure conditions

The blocking performance of extended pruned vertically stacked optical banyan (VSOB) networks under different link failure conditions has been analyzed in this paper. We applied plane fixed routing with linear search and plane fixed routing with random search algorithms to route the optical data through the network in our simulation. Our simulation results show that adding one or two extra planes to the pruned VSOB network reduces the blocking probability significantly. Beyond two extra planes, the decrease of blocking probability is not so significant. A close approximation of the minimum number of planes required to make the extended pruned vertically stacked optical banyan networks nonblocking has been presented

Design of testbed and emulation tools

The research summarized was concerned with the design of testbed and emulation tools suitable to assist in projecting, with reasonable accuracy, the expected performance of highly concurrent computing systems on large, complete applications. Such testbed and emulation tools are intended for the eventual use of those exploring new concurrent system architectures and organizations, either as users or as designers of such systems. While a range of alternatives was considered, a software based set of hierarchical tools was chosen to provide maximum flexibility, to ease in moving to new computers as technology improves and to take advantage of the inherent reliability and availability of commercially available computing systems

A Performance evaluation of several ATM switching architectures

The goal of this thesis is to evaluate the performance of three Asynchronous Transfer Mode switching architectures. After examining many different ATM switching architectures in literature, the three architectures chosen for study were the Knockout switch, the Sunshine switch, and the Helical switch. A discrete-time, event driven system simulator, named ProModel, was used to model the switching behavior of these architectures. Each switching architecture was modeled and studied under at least two design configurations. The performance of the three architectures was then investigated under three different traffic types representative of traffic found in B-ISDN: random, constant bit rate, and bursty. Several key performance parameters were measured and compared between the architectures. This thesis also explored the implementation complexities and fault tolerance of the three selected architectures

A formalism for describing and simulating systems with interacting components.

This thesis addresses the problem of descriptive complexity presented by systems involving a high number of interacting components. It investigates the evaluation measure of performability and its application to such systems. A new description and simulation language, ICE and it's application to performability modelling is presented. ICE (Interacting ComponEnts) is based upon an earlier description language which was first proposed for defining reliability problems. ICE is declarative in style and has a limited number of keywords. The ethos in the development of the language has been to provide an intuitive formalism with a powerful descriptive space. The full syntax of the language is presented with discussion as to its philosophy. The implementation of a discrete event simulator using an ICE interface is described, with use being made of examples to illustrate the functionality of the code and the semantics of the language. Random numbers are used to provide the required stochastic behaviour within the simulator. The behaviour of an industry standard generator within the simulator and different methods of number allocation are shown. A new generator is proposed that is a development of a fast hardware shift register generator and is demonstrated to possess good statistical properties and operational speed. For the purpose of providing a rigorous description of the language and clarification of its semantics, a computational model is developed using the formalism of extended coloured Petri nets. This model also gives an indication of the language's descriptive power relative to that of a recognised and well developed technique. Some recognised temporal and structural problems of system event modelling are identified. and ICE solutions given. The growing research area of ATM communication networks is introduced and a sophisticated top down model of an ATM switch presented. This model is simulated and interesting results are given. A generic ICE framework for performability modelling is developed and demonstrated. This is considered as a positive contribution to the general field of performability research

Networking vendor strategy and competition and their impact on enterprise network design and implementation

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science; in conjunction with the Leaders for Manufacturing Program at MIT, 2006.Includes bibliographical references (leaves 93-99).While a significant amount of literature exists that discuss platform strategies used by general IT vendors, less of it has to do with corporate networking technology vendors specifically. However, many of the same strategic principles that are used to analyze general IT vendors can also be used to analyze networking vendors. This paper extends the platform model that was developed by Michael Cusumano and Annabel Gawer to networking vendors, outlining the unique strategic aspects that the networking market possesses. The paper then reviews the strategy of the first dominant corporate datacom vendor, IBM, how it achieved its dominance, and how it lost it. The paper then discusses the strategies of various vendors who attempted to replace IBM as the dominant networking platform vendor and how they failed to do so. Finally, the paper discusses Cisco Systems, a vendor who did manage to achieve a level of dominance that parallels IBM's, and how that company has utilized its strategy to achieve and maintain its current dominance. Finally, Cisco's current strategic challenges are discussed. The impact of the strategies of the various vendors on the evolution of corporate networking is also discussed.by Ray Fung.S.M.M.B.A

Reconfiguration for Fault Tolerance and Performance Analysis

Architecture reconfiguration, the ability of a system to alter the active interconnection among modules, has a history of different purposes and strategies. Its purposes develop from the relatively simple desire to formalize procedures that all processes have in common to reconfiguration for the improvement of fault-tolerance, to reconfiguration for performance enhancement, either through the simple maximizing of system use or by sophisticated notions of wedding topology to the specific needs of a given process. Strategies range from straightforward redundancy by means of an identical backup system to intricate structures employing multistage interconnection networks. The present discussion surveys the more important contributions to developments in reconfigurable architecture. The strategy here is in a sense to approach the field from an historical perspective, with the goal of developing a more coherent theory of reconfiguration. First, the Turing and von Neumann machines are discussed from the perspective of system reconfiguration, and it is seen that this early important theoretical work contains little that anticipates reconfiguration. Then some early developments in reconfiguration are analyzed, including the work of Estrin and associates on the fixed plus variable restructurable computer system, the attempt to theorize about configurable computers by Miller and Cocke, and the work of Reddi and Feustel on their restructable computer system. The discussion then focuses on the most sustained systems for fault tolerance and performance enhancement that have been proposed. An attempt will be made to define fault tolerance and to investigate some of the strategies used to achieve it. By investigating four different systems, the Tandern computer, the C.vmp system, the Extra Stage Cube, and the Gamma network, the move from dynamic redundancy to reconfiguration is observed. Then reconfiguration for performance enhancement is discussed. A survey of some proposals is attempted, then the discussion focuses on the most sustained systems that have been proposed: PASM, the DC architecture, the Star local network, and the NYU Ultracomputer. The discussion is organized around a comparison of control, scheduling, communication, and network topology. Finally, comparisons are drawn between fault tolerance and performance enhancement, in order to clarify the notion of reconfiguration and to reveal the common ground of fault tolerance and performance enhancement as well as the areas in which they diverge. An attempt is made in the conclusion to derive from this survey and analysis some observations on the nature of reconfiguration, as well as some remarks on necessary further areas of research

Islamicization Strategies in Kao Ancient Village, North Halmahera

Situs permukiman Kampung kuno Kao terletak di pedalaman Halmahera Utara, berdiri di atas tanah yang relatif basah diapit oleh sungai Aer Kalak, Ake Ngoali, dan Ake Jodo dan dikelilingi oleh hutan sagu dan rawa. Kondisi permukiman di situs ini membuatnya memiliki keterbatasan ruang hunian, namun orang-orang yang menghuni Kampung kuno Kao bermukim di wilayah ini dalam jangka waktu yang relatif panjang, yaitu antara 100-200 tahun, dan bahkan tercatat dalam rekam sejarah bahwa wilayah Kao dahulu menjadi penyuplai makanan pokok Ternate. Penelitian ini bersifat deduktif, yaitu menyusun sebuah hipotesa yang kemudian diuji di lapangan. Metode pengumpulan data dalam penelitian ini menggunakan metode observasi lapangan dan ekskavasi arkeologi. Ragam data arkeologi baik artefak maupun tradisi lisan yang diperoleh di lapangan kemudian dianalisa dengan merujuk pada sumber referensi yang relevan. Hasil penelitian menunjukkan bahwa Situs Kao merupakan permukiman yang cukup maju  dan memiliki peran cukup penting sebagai wilayah pusat Islamisasi di Halmahera. Orang-orang di Kampung kuno Kao tinggal dalam waktu lama di satu lokasi didukung oleh sumber air dan potensi tanah-tanah pertanian menjadikan wilayah Kao sebagai bagian dari jaringan perdagangan yang ramai. Kao menjadi bagian dari strategi dalam penyebaran Islam ke wilayah-wilayah pedalaman lainnya, juga daerah-daerah pesisir di Halmahera Utara.The Kao Ancient Village settlement site is located in the hinterland of North Halmahera, standing on relatively wet ground flanked by the river Aer Kalak, Ake Ngoali, and Ake Jodo and surrounded by sago and swamp forests. The settlement conditions on the site make it limited for residential space, but a community of Kao people settled in this area for a relatively long period of time between 100-200 years and even recorded in history that Kao region is the main food supplier for Ternate in the past. This research conducted surface surveys and limited excavations, then mapped the areas of artifactual findings, and identified patterns of spatial use by analyzing surface features and artifact scatters. Variety of archeological data both artifacts and oral traditions are then analyzed guided by relevant reference sources. The results show that Kao Site is an advanced settlement and has a significant role as the center of Islamicization in Halmahera. The Kao people settled for a long time in one location supported by water sources and the potential of farming lands making the Kao area a part of bustling trade networks. Kao became part of a strategy in spreading Islam to other inland areas, as well as coastal areas in North Halmahera

Devices and networks for optical switching

This thesis is concerned with some aspects of the application of optics to switching and computing. Two areas are dealt with: the design of switching networks which use optical interconnects, and the development and application of the t-SEED optical logic device. The work on optical interconnects looks at the multistage interconnection network which has been proposed as a hybrid switch using both electronics and optics. It is shown that the architecture can be mapped from one dimensional to two dimensional format, so that the machine makes full use of the space available to the optics. Other mapping rules are described which allow the network to make optimum use of the optical interconnects, and the endpoint is a hybrid optical-electronic machine which should be able to outperform an all-electronic equivalent. The development of the t-SEED optical logic device is described, which is the integration of a phototransistor with a multiple quantum well optical modulator. It is found to be important to have the modulator underneath rather than on top of the transistor to avoid unwanted thyristor action. In order for the transistor to have a high gain the collector must have a low doping level, the exit window in the substrate must be etched all the way to the emitter layer, and the etch must not damage the emitter-base junction. A real optical gain of 1.6 has been obtained, which is higher than has ever been reached before but is not as high as should be possible. Improvements to the device are suggested. A new model of the Fabry-Perot cavity is introduced which helps considerably in the interpretation of experimental measurements made on the quantum well modulators. Also a method of improving the contrast of the multiple quantum well modulator by grading the well widths is proposed which may find application in long wavelength transmission modulators. Some systems which make use of the t-SEED are considered. It is shown that the t-SEED device has the right characteristics for use as a neuron element in the optical implementation of a neural network. A new image processing network for clutter removal in binary images is introduced which uses the t-SEED, and a brief performance analysis suggests that the network may be superior to an all-electronic machine

Webly Supervised Learning of Convolutional Networks

We present an approach to utilize large amounts of web data for learning CNNs. Specifically inspired by curriculum learning, we present a two-step approach for CNN training. First, we use easy images to train an initial visual representation. We then use this initial CNN and adapt it to harder, more realistic images by leveraging the structure of data and categories. We demonstrate that our two-stage CNN outperforms a fine-tuned CNN trained on ImageNet on Pascal VOC 2012. We also demonstrate the strength of webly supervised learning by localizing objects in web images and training a R-CNN style detector. It achieves the best performance on VOC 2007 where no VOC training data is used. Finally, we show our approach is quite robust to noise and performs comparably even when we use image search results from March 2013 (pre-CNN image search era)