1,721,125 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Efficient Randomized Algorithms for Graph Theoretic Applications
No full textRandomization is currently one of the major approaches which is used to design algorithms. A randomized algorithm is an algorithm that employs a degree of randomness as part of its logic. A randomized algorithm uses random input in the hope of achieving good performance in an average case. In addition to input, algorithm takes a source of random numbers and makes random choices during the execution. Its behavior may vary even on a fixed input.
This thesis provides comprehensive and integrated analysis of randomized algorithms over deterministic algorithms. We have also discussed the detailed literature of the multiobjective shortest path problem and multiobjective spanning tree problem. Deterministic polynomial time algorithms are extensively used for the shortest path and the minimum spanning tree problems.
In this thesis, we have presented a randomized algorithm to find Hamiltonian circuit in rectangular grid graphs with vertical size m and horizontal size n. The algorithm firstly finds all the restricted edges in linear time and then constructs a Hamiltonian circuit by joining the sub-graphs. Algorithm uses random selection to construct the Hamiltonian cycle. The computational model is a unit cost random access machine with the restriction
that only binary operation is allowed on edge selection.
Load balancing is extensively used in distributed network applications to decrease the response times. We have also discussed the backend load balancing (processor-to-dispatcher). Many algorithms are devised for front end load balancing e.g. JSQ, SQ(d) and JIQ. Join-Idle-Queue(JIQ) goes well in a distributed environment like cloud computing. In JIQ approach, at the backend, a processor joins the queue on either random or sampled basis.
In both the cases, I-Queue of any dispatcher might remain empty, resulting in degrading the performance. After finishing the job, the processor should join the dispatcher whose I-Queue is empty. To achieve this, we have used a dequeue to track the dispatcher with empty I-Queue. As the processor finishes the current job and reaches the idle state, it should refer the dequeue and join the dispatcher whose I-Queue is empty
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Relational cost analysis
Full text linkProgramming languages research has made great progress towards statically estimating the execution cost of a program. However, when one is interested in how the execution costs of two programs compare to each other (i.e., relational cost analysis), the use of unary techniques does not work well in many cases. In order to support a relational cost analysis, we must ultimately support reasoning about not only the executions of a single program, but also the executions of two programs, taking into account their similarities. This dissertation makes several contributions to the understanding and development of such a relational cost analysis. It shows how: • Refinement types and effect systems can express functional and relational quantitative properties of pairs of programs, including the difference in execution costs. • Relational cost analysis can be adapted to reason about dynamic stability, a measure of the update times of incremental programs as their inputs change. • A sound and complete bidirectional type system can be developed (and implemented) for relational cost analysis.Die Programmiersprachen-Forschung hat große Fortschritte bei der statischen Einschätzung der Ausführungskosten von Programmen gemacht.Wenn man allerdings wissen möchte, wie die Ausführungskosten zweier Programme sich zueinander verhalten (relationale Kostenanalyse), funktionieren unäre Methoden in vielen Fällen nicht gut. Eine relationale Analyse muss insbesondere nicht nur die Ausführung eines einzelnen Programmes betrachten, sondern die Ausführung beider Programme, um Ähnlichkeiten berücksichtigen zu können. Diese Dissertation liefert mehrere Beiträge zum Verständnis und zur Entwicklung solcher relationalen Kostenanalysen. Sie zeigt: • Refinement-Typsysteme und Effekt-System können funktional und relational qualitative Eigenschaften von Programmpaaren ausdrücken, insbesondere die Differenz der Ausführungskosten. • Relationale Kostenanalyse kann angepasst werden, um dynamische Stabilität zu analysieren. Diese misst die Update-Zeit inkrementeller Programme, wenn deren Eingaben sich ändern. • Ein korrektes und vollständiges bidirektionales Typsystem für die relationale Kostenanalyse kann entwickelt und implementiert werden
Routing Table Optimization Using T-Spanner Technique
No full textME, CSEDDynamically changing graphs are used in various applications of graph algorithms. The scope of these graphs is in graphics, in communication networks and VLSI design where graphs are subjected to change, such as addition and deletion of links and nodes. There is a rich body of the algorithms and data structures used for dynamic graphs. The thesis contains techniques and data structures used in various dynamic algorithms.
There are many applications in distributed systems and communication networks where spanner appears as the underlying graph structures. For instance in dynamically changing graphs where the edge weights are changing can be visualized as a communication network where the load on the links is changing.
In this thesis, a new clustering technique is introduced that is based on two parameters; radius and degree of node. This thesis work proposes an algorithm of constructing sparse t-spanners for arbitrary undirected weighted graphs.
This thesis also explains fully dynamic algorithm for maintaining t-spanner of undirected weighted graphs under a sequence of update operations like insertion and deletion of links.
This algorithm is applied on communication networks to optimize routing table space and also for good routing scheme by taking weight as congestion load of network link among two routers.
All the algorithms are suggested in this thesis are practically implemented and tested for undirected weighted graph by varying number of nodes and number of link of graph
Choosing the Efficient Algorithm for Vertex Cover Problem
No full textM.E. (CSED)The vertex cover (VC) problem belongs to the class of NP-complete graph theoretical
problems, which plays a central role in theoretical computer science and it has a
numerous real life applications. We are unlikely to find a polynomial-time algorithm for
solving vertex-cover problem exactly. Vertex-cover exhibits a coverable–uncoverable
phase transition. The relationship of vertex-cover with other NP-complete problems is
thoroughly studied in this work. This thesis work also analyzes the various algorithms
on minimum vertex cover for standard classes of random graphs. The performance of
all algorithms is compared with the complexity and the output solution that of the
branch-and-bound problem solver (BB), approximation algorithm, greedy algorithm,
simple genetic algorithm (GA), primal-dual based algorithm (PDB) and the alom’s
algorithm. The results indicate that all algorithms give near optimal solutions. The
performance differences of all algorithms on a graph are relatively small to obtain a
vertex-cover. For undirected graphs, better performance is achieved by alom’s
algorithm and for weighted graphs, better performance is achieved by primal-dual based
approach. Additionally, alom’s algorithm is extended in order to give the all possible
vertex-covers of a graph and the algorithm is implemented in c++.Department of Computer Science and Engineerin
Random Number Generation and its Better Technique
No full textRandom number generators based on linear recurrences modulo 2 are among the fastest
long-period generators currently available. The uniformity and independence of the
points they produce, over their entire period length, can be measured by theoretical
figures of merit that are easy to compute, and those having good values for these figures
of merit are statistically reliable in general. Some of these generators can also provide
disjoint streams and substreams efficiently. In this paper, we review the most interesting
construction methods for these generators, examine their theoretical and empirical
properties, and make comparisons.
Random number generation is the art and science of deterministically generating a
sequence of numbers that is difficult to distinguish from a true random sequence. This
thesis introduces the field of random number generation, and studies three types of
random number generators in depth. It also includes mathematical techniques for
transforming the output of generators to arbitrary distributions, and methods of evaluating
and comparing random number generators. It concludes with a summary and historical
perspective on the field of random number generation. The mathematics in this thesis is
drawn mainly from number theory, with a few fundamental ideas taken from probability
and statistics
A type-theory for higher-order amortized analysis
Full text linkDie Verifikation von "Worst-Case" Schranken für Ressourcennutzung ist ein wichtiges Problem in der Informatik. Der Nutzen einer solchen Verifikation hängt von der Präzision der Analyse ab. Aus Gründen der Präzision ist es manchmal nützlich, die durchschnittlichen Kosten einer Folge von Operationen zu berücksichtigen, statt die Kosten jeder einzelnen Operation getrennt zu betrachten. Diese Art von Analyse wird oft als amortisierte Ressourcenanalyse bezeichnet. Typischerweise profitieren Programme, die ihren Zustand optimieren, um die Kosten zukünftiger Ausführungen zu reduzieren, von solchen Ansätzen. Die Analyse der Ressourcennutzung einer mit zwei (LIFO) Listen implementierten funktionalen (FIFO) Schlange ist ein klassisches Beispiel für eine amortisierte Analyse. In dieser Arbeit präsentieren wir λamor, eine Typentheorie für die amortisierte Analyse der Ressourcennutzung höherstufiger Programme. Eine typische amortisierte Analyse speichert einen "ghost state", der als Potenzial bezeichnet wird, zusammen mit den Datenstrukturen. Die Kernidee der amortisierten Analyse ist es, zu zeigen, dass das dem Programm zur Verfügung stehende Potenzial ausreicht, um die Ressourcennutzung des Programms zu erfassen. Die Verifikation in λamor basiert auf der Realisierung dieser Idee in einer Typentheorie. Wir erreichen dies indem wir ein allgemeines typentheoretisches Konstrukt zur Darstellung des Potenzials auf der Ebene von Typen definieren und anschließend eine affine Typentheorie aufbauen. Mit λamor zeigen wir, dass eine typentheoretische amortisierte Analyse mit gut verstandenen Konzepten aus substrukturellen und modalen Typentheorien durchgeführt werden kann. Trotzdem ergibt sich ein äußerst aussagekräftiges Framework, das für die Ressourcenanalyse von höherstufigen Programmen, sowohl ein einem "strikten", als auch in einem "lazy" Setting, verwendet werden kann. Wir präsentieren Einbettungen zweier stark verschiedener Arten von typentheoretischen Ressourcenanalyseframeworks (eines basiert auf Effekten, das andere auf Koeffekten) in λamor. Wir zeigen, dass λamor korrekt (sound) ist (mithilfe eines "Logical relations" Modells) und, dass es vollständig für PCF-Programme ist (unter Verwendung einer der Einbettungen). Als nächstes verwenden wir Ideen von λamor, um eine andere Typentheorie (genannt λcg) für einen ganz anderen Anwendungsfall - Informationsflusskontrolle (IFC) - zu entwickeln. λcg verwendet ähnliche typentheoretische Konstrukte wie λamor für das Potenzial verwendet, um die Vertraulichkeitsmarkierungen (den "ghost state" für IFC) darzustellen. Schließlich abstrahieren wir von den spezifischen "ghost states" (Potenzial und Vertraulichkeitsmarkierungen) und entwickeln eine Typentheorie für einen allgemeinen "ghost state" mit einer monoidalen Struktur.Verification of worst-case bounds (on the resource usage of programs) is an important problem in computer science. The usefulness of such verification depends on the precision of the underlying analysis. For precision, sometimes it is useful to consider the average cost over a sequence of operations, instead of separately considering the cost of each individual operation. This kind of an analysis is often referred to as amortized resource analysis. Typically, programs that optimize their internal state to reduce the cost of future executions benefit from such approaches. Analyzing resource usage of a standard functional (FIFO) queue implemented using two functional (LIFO) lists is a classic example of amortized analysis. In this thesis we present λamor, a type-theory for amortized resource analysis of higher-order functional programs. A typical amortized analysis works by storing a ghost state called the potential with data structures. The key idea underlying amortized analysis is to show that, the available potential with the program is sufficient to account for the resource usage of that program. Verification in λamor is based on internalizing this idea into a type theory. We achieve this by providing a general type-theoretic construct to represent potential at the level of types and then building an affine type-theory around it. With λamor we show that, type-theoretic amortized analysis can be performed using well understood concepts from sub-structural and modal type theories. Yet, it yields an extremely expressive framework which can be used for resource analysis of higher-order programs, both in a strict and lazy setting. We show embeddings of two very different styles (one based on effects and the other on coeffects) of type-theoretic resource analysis frameworks into λamor. We show that λamor is sound (using a logical relations model) and complete for cost analysis of PCF programs (using one of the embeddings). Next, we apply ideas from λamor to develop another type theory (called λcg) for a very different domain – Information Flow Control (IFC). λcg uses a similar typetheoretic construct (which λamor uses for the potential) to represent confidentiality label (the ghost state for IFC). Finally, we abstract away from the specific ghost states (potential and confidentiality label) and describe how to develop a type-theory for a general ghost state with a monoidal structure
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