Queue Length Simulations in a Finite Single-line Queueing System with Repeated Calls

2000 Mathematics Subject Classification: 60K25.

The Limit Theorems for Transportation Networks

2000 Mathematics Subject Classi cation: 60K25 (primary); 60F05, 37A50 (secondary)

Social Recommendation Based on Content and Trust

Report published in the Proceedings of the National Conference on "Education and Research in the Information Society", Plovdiv, May, 2014

On the Poisson Process of Order k Space

2010 Mathematics Subject Classification: 60E05, 62P05.

Sobolev Type Decomposition of Paley-Wiener-Schwartz Space with Application to Sampling Theory

2000 Mathematics Subject Classification: 94A12, 94A20, 30D20, 41A05.

The Deformed Trigonometric Functions of two Variables

MSC 2010: 33B10, 33E20

On Some Generalizations of Classical Integral Transforms

MSC 2010: 44A15, 44A20, 33C60

Weitzenböck Derivations and Classical Invariant Theory: I. Poincaré Series

2000 Mathematics Subject Classification: 13N15, 13A50, 16W25.

Between plurality and proportionality: an analysis of vote transfer systems

The paper considers a general model of electoral systems combining district-based elections with a compensatory mechanism in order to implement any outcome between strictly majoritarian and purely proportional seat allocation. It contains vote transfer and allows for the application of three different correction formulas. Analysis in a two-party system shows that a trade-off exists for the dominant party between the expected seat share and the chance of obtaining majority. Vote transfer rules are also investigated by focusing on the possibility of manipulation. The model is applied to the 2014 Hungarian parliamentary election. Hypothetical results reveal that the vote transfer rule cannot be evaluated in itself, only together with the share of constituency seats. With an appropriate choice of the latter, the three mechanisms can be made functionally equivalent.

The unintended [or intended?] political consequences of electoral systems: The case of Bolivia

The present study was concerned with evaluating one basic institution in Bolivian democracy: its electoral system. The study evaluates the impact of electoral systems on the interaction between presidents and assemblies. It sought to determine whether it is possible to have electoral systems that favor multipartism but can also moderate the likelihood of executive-legislative confrontation by producing the necessary conditions for coalition building. ^ This dissertation utilized the case study method as a methodology. Using the case of Bolivia, the research project studied the variations in executive-legislative relations and political outcomes from 1985 to the present through a model of executive-legislative relations that provided a typology of presidents and assemblies based on the strategies available to them to bargain with each other for support. A complementary model that evaluated the state of their inter-institutional interaction was also employed. ^ Results indicated that executive-legislative relations are profoundly influenced by the choice of the electoral system. Similarly, the project showed that although the Bolivian mixed system for legislative elections, and executive formula favor multipartism, these electoral systems do not necessarily engender executive-legislative confrontation in Bolivia. This was mainly due to the congressional election of the president, and the formulas utilized to translate the popular vote into legislative seats. However, the study found that the electoral system has also allowed for anti-systemic forces to emerge and gain political space both within and outside of political institutions. ^ The study found that government coalitions in Bolivia that are promoted by the system of congressional election of the president and the D'Hondt system to allocate legislative seats have helped ameliorate one of the typical problems of presidential systems in Latin America: the presence of a minority government that is blocked in its capacity to govern. This study was limited to evaluating the impact of the electoral system, as the independent variable, on executive-legislative interaction. However, the project revealed a need for more theoretical and empirical work on executive-legislative bargaining models in order to understand how institutional reforms can have an impact on the incentives of presidents and legislators to form coherent coalitions. ^

An approach for design and analysis of User-centric Communication Middleware

Today, the development of domain-specific communication applications is both time-consuming and error-prone because the low-level communication services provided by the existing systems and networks are primitive and often heterogeneous. Multimedia communication applications are typically built on top of low-level network abstractions such as TCP/UDP socket, SIP (Session Initiation Protocol) and RTP (Real-time Transport Protocol) APIs. The User-centric Communication Middleware (UCM) is proposed to encapsulate the networking complexity and heterogeneity of basic multimedia and multi-party communication for upper-layer communication applications. And UCM provides a unified user-centric communication service to diverse communication applications ranging from a simple phone call and video conferencing to specialized communication applications like disaster management and telemedicine. It makes it easier to the development of domain-specific communication applications. The UCM abstraction and API is proposed to achieve these goals. The dissertation also tries to integrate the formal method into UCM development process. The formal model is created for UCM using SAM methodology. Some design errors are found during model creation because the formal method forces to give the precise description of UCM. By using the SAM tool, formal UCM model is translated to Promela formula model. In the dissertation, some system properties are defined as temporal logic formulas. These temporal logic formulas are manually translated to promela formulas which are individually integrated with promela formula model of UCM and verified using SPIN tool. Formal analysis used here helps verify the system properties (for example multiparty multimedia protocol) and dig out the bugs of systems.

Lateral load distribution for curved steel I -girder bridges

Lateral load distribution factor is a key factor for designing and analyzing curved steel I-girder bridges. In this dissertation, the effects of various parameters on moment and shear distribution for curved steel I-girder bridges were studied using the Finite Element Method (FEM). The parameters considered in the study were: radius of curvature, girder spacing, overhang, span length, number of girders, ratio of girder stiffness to overall bridge stiffness, slab thickness, girder longitudinal stiffness, cross frame spacing, and girder torsional inertia. The variations of these parameters were based on the statistical analysis of the real bridge database, which was created by extracting data from existing or newly designed curved steel I-girder bridge plans collected all over the nation. A hypothetical bridge superstructure model that was made of all the mean values of the data was created and used for the parameter study. ^ The study showed that cross frame spacing and girder torsional inertia had negligible effects. Other parameters had been identified as key parameters. Regression analysis was conducted based on the FEM analysis results and simplified formulas for predicting positive moment, negative moment, and shear distribution factors were developed. Thirty-three real bridges were analyzed using FEM to verify the formulas. The ratio of the distribution factor obtained from the formula to the one obtained from the FEM analysis, which was referred to as the g-ratio, was examined. The results showed that the standard deviation of the g-ratios was within 0.04 to 0.06 and the mean value of the g-ratios was greater than unity by one standard deviation. This indicates that the formulas are conservative in most cases but not overly conservative. The final formulas are similar in format to the current American Association of State Highway and Transportation Officials (AASHTO) Load Resistance and Factor Design (LRFD) specifications. ^ The developed formulas were compared with other simplified methods. The outcomes showed that the proposed formulas had the most accurate results among all methods. ^ The formulas developed in this study will assist bridge engineers and researchers in predicting the actual live load distribution in horizontally curved steel I-girder bridges. ^

Formal modeling and analysis techniques for high level Petri nets

Petri Nets are a formal, graphical and executable modeling technique for the specification and analysis of concurrent and distributed systems and have been widely applied in computer science and many other engineering disciplines. Low level Petri nets are simple and useful for modeling control flows but not powerful enough to define data and system functionality. High level Petri nets (HLPNs) have been developed to support data and functionality definitions, such as using complex structured data as tokens and algebraic expressions as transition formulas. Compared to low level Petri nets, HLPNs result in compact system models that are easier to be understood. Therefore, HLPNs are more useful in modeling complex systems. ^ There are two issues in using HLPNs—modeling and analysis. Modeling concerns the abstracting and representing the systems under consideration using HLPNs, and analysis deals with effective ways study the behaviors and properties of the resulting HLPN models. In this dissertation, several modeling and analysis techniques for HLPNs are studied, which are integrated into a framework that is supported by a tool. ^ For modeling, this framework integrates two formal languages: a type of HLPNs called Predicate Transition Net (PrT Net) is used to model a system's behavior and a first-order linear time temporal logic (FOLTL) to specify the system's properties. The main contribution of this dissertation with regard to modeling is to develop a software tool to support the formal modeling capabilities in this framework. ^ For analysis, this framework combines three complementary techniques, simulation, explicit state model checking and bounded model checking (BMC). Simulation is a straightforward and speedy method, but only covers some execution paths in a HLPN model. Explicit state model checking covers all the execution paths but suffers from the state explosion problem. BMC is a tradeoff as it provides a certain level of coverage while more efficient than explicit state model checking. The main contribution of this dissertation with regard to analysis is adapting BMC to analyze HLPN models and integrating the three complementary analysis techniques in a software tool to support the formal analysis capabilities in this framework. ^ The SAMTools developed for this framework in this dissertation integrates three tools: PIPE+ for HLPNs behavioral modeling and simulation, SAMAT for hierarchical structural modeling and property specification, and PIPE+Verifier for behavioral verification.^

A descriptive study of the ratio of approval to disapproval demonstrated by music teachers and classroom teachers in first, second, and third grades

The purpose of this study was to determine the approval to disapproval ratios of feedback given by music and classroom teachers to first, second and third grades. Eight teachers from a South Florida Elementary School were selected for this study. Twelve 20-minute videos were taken for further examination. Analyses of data using percentage formulas were used to determine the ratio of each of the teacher reinforcement. Classroom teachers gave 2.3% social approval feedback, 59% academic approval feedback, 22% social disapproval feedback, 16.5% academic disapproval feedback, and 0% errors. Music teachers gave .7% social approval feedback, 67% academic approval feedback, 22% social disapproval feedback, 10% academic disapproval feedback, and 0% errors. Today's teachers are 8% more academically approving than thirty years ago. Results also show that today's music teachers are still more approving than classroom teachers.

Imunidade recíproca e livre concorrência: considerações acerca de sua fruição por empresas estatais

This study begins with a brief overview of tax immu nities in general, dealing with the concept, legal, doctrinal ratings and limits. Then enters into the reciprocal immunity, since its birth in the United States, its justifica tions, until her current developments in the Brazilian Supreme Court, which has expanded it quite considerably. That Court has extended to state owned enterprises, even if pa id by public prices or rates, or if acts somewhat away from its essential functions, es pecially if they are public services provider. Given this linkage, these are also treate d in own topic, grounded in newer doctrinal proposals and less attached to historical formalisms (see such Supremacy of Public Interest over Private one). Public services are approached in its diversity, oblivious to traditional monolithic nature and accu stomed to the modern doctrine of fundamental human rights. It deals also the princip les of free enterprise and free competition, given that the public service provider s have lived intensely in this environment, be they public or private agents. In d ialectical topic, these institutes are placed in joint discussion, all in an attempt to in vestigate their interactions and propose criteria less generic and removed from real ity, to assess the legitimacy of the mutual enjoyment of immunity by certain agents. Sev eral cases of the Court are analyzed individually, checking in each one the app lication of the proposed criteria, such logical-deductive activity and theory of pract ice approach. At the end, the conclusions refer to a reciprocal immunity less rhe torical and ideological and more pragmatic and consequentialist. It is proposed the end to the general rules or abstract formulas of subsumption, with concerns on the one h and the actual maintenance of the federal pact, and on the other by a solid econo mic order without inapt advantages to certain players, which flatly contradicts the co nstitutional premises.