A Differential Game Described by a Hyperbolic System

An antagonistic differential game of hyperbolic type with a separable linear vector pay-off function is considered. The main result is the description of all ε-Slater saddle points consisting of program strategies, program ε-Slater maximins and minimaxes for each ε ∈ R^N > for this game. To this purpose, the considered differential game is reduced to find the optimal program strategies of two multicriterial problems of hyperbolic type. The application of approximation enables us to relate these problems to a problem of optimal program control, described by a system of ordinary differential equations, with a scalar pay-off function. It is found that the result of this problem is not changed, if the players use positional or program strategies. For the considered differential game, it is interesting that the ε-Slater saddle points are not equivalent and there exist two ε-Slater saddle points for which the values of all components of the vector pay-off function at one of them are greater than the respective components of the other ε-saddle point.

Synthesis of Cr and La-codoped SrTiO3 nanoparticles for enhanced photocatalytic performance under sunlight irradiation

In this study, we report a facile polymeric citrate strategy for the synthesis of Cr,La-codoped SrTiO3 nanoparticles. The synthesized samples were well characterized by various analytical techniques. The UV-vis DRS studies reveal that the absorption edge shifts towards the visible light region after doping with Cr, which is highly beneficial for absorbing the visible light in the solar spectrum. More attractively, codoping with La exhibits greatly enhanced photocatalytic activity for the degradation of Rhodamine B under sunlight irradiation. The optimum photocatalytic activity at 1 atom% of Cr,La-codoped SrTiO3 nanoparticles is almost 6 times higher than that of pure SrTiO3 nanoparticles and 3 times higher than that of Cr-doped SrTiO3 nanoparticles. The high photocatalytic performance in the present photocatalytic system is due to codoping with La, which acts as a most effective donor for stabilizing Cr3+ in Cr,La-codoped SrTiO3 nanoparticles. More importantly, the synthesized photocatalysts possess high reusability. A proposed mechanism for the enhanced photocatalytic activity of Cr,La-codoped SrTiO3 nanoparticles was also investigated by trapping experiments. Therefore, our results not only demonstrate the highly efficient visible light photocatalytic activity of the Cr,La-codoped SrTiO3 photocatalyst, but also enlighten the codoping strategy in the design and development of advanced photocatalytic materials for energy and environmental applications.

The Computer System for the Estimation of the Realizability of the Crew Activity Algorithms

When designing specification on-board algorithm (the algorithm, realized on on-board digital computing machine, and algorithm to activity of the crew necessary to conduct the estimation their realizing. Presented computer system allows in interactive mode with user to value the temporary expenseses of the operator on processes decision making and their realizing, participations it in process of the spying.

Analysis and improvement of performance in LCL filter-based PWM rectifier/inverter application using hybrid damping approach

A hybrid passive-active damping solution with improved system stability margin and enhanced dynamic performance is proposed for high power grid interactive converters. In grid connected active rectifier/inverter application, line side LCL filter improves the high frequency attenuation and makes the converter compatible with the stringent grid power quality regulations. Passive damping though offers a simple and reliable solution but it reduces overall converter efficiency. Active damping solutions do not increase the system losses but can guarantee the stable operation up to a certain speed of dynamic response which is limited by the maximum bandwidth of the current controller. This paper examines this limit and introduces a concept of hybrid passive-active damping solution with improved stability margin and high dynamic performance for line side LCL filter based active rectifier/inverter applications. A detailed design, analysis of the hybrid approach and trade-off between system losses and dynamic performance in grid connected applications are reported. Simulation and experimental results from a 10 kVA prototype demonstrate the effectiveness of the proposed solution. An analytical study on system stability and dynamic response with the variations of various controller and passive filter parameters is presented.

A System for Simulation and Estimation of Branching Processes

A computer code system for simulation and estimation of branching processes is proposed. Using the system, samples for some models with or without migration are generated. Over these samples we compare some properties of various estimators.

Asymptotic Analysis of a Schrödinger-Poisson System with Quantum Wells and Macroscopic Nonlinearities in Dimension 1

2000 Mathematics Subject Classification: 35Q02, 35Q05, 35Q10, 35B40.

Dynamic variability in adaptive systems

One of the reasons for using variability in the software product line (SPL) approach (see Apel et al., 2006; Figueiredo et al., 2008; Kastner et al., 2007; Mezini & Ostermann, 2004) is to delay a design decision (Svahnberg et al., 2005). Instead of deciding on what system to develop in advance, with the SPL approach a set of components and a reference architecture are specified and implemented (during domain engineering, see Czarnecki & Eisenecker, 2000) out of which individual systems are composed at a later stage (during application engineering, see Czarnecki & Eisenecker, 2000). By postponing the design decisions in such a manner, it is possible to better fit the resultant system in its intended environment, for instance, to allow selection of the system interaction mode to be made after the customers have purchased particular hardware, such as a PDA vs. a laptop. Such variability is expressed through variation points which are locations in a software-based system where choices are available for defining a specific instance of a system (Svahnberg et al., 2005). Until recently it had sufficed to postpone committing to a specific system instance till before the system runtime. However, in the recent years the use and expectations of software systems in human society has undergone significant changes.Today's software systems need to be always available, highly interactive, and able to continuously adapt according to the varying environment conditions, user characteristics and characteristics of other systems that interact with them. Such systems, called adaptive systems, are expected to be long-lived and able to undertake adaptations with little or no human intervention (Cheng et al., 2009). Therefore, the variability now needs to be present also at system runtime, which leads to the emergence of a new type of system: adaptive systems with dynamic variability.

The financial stability and access to financing of SMEs in Hungary

The present study was prepared within the framework of cooperation between the Competitiveness Research Centre, operating within the Institute of Business Economics of Corvinus University of Budapest, and the National Association of Entrepreneurs, based on a commission from the latter. Th e goal of the study was to survey the self-financing capabilities and borrowing opportunities of majority Hungarian-owned small and medium-sized enterprises (SMEs), and to identify potential problems. The results of the research revealed that the high proportion of owner’s equity in the financing structure is not due to difficulties with borrowing, but because enterprises that cover their fi nancing primarily from their own resources have other financing opportunities at their disposal. Although general satisfaction with banks shows a diminishing tendency, it can still be interpreted favourably. The majority of companies have not encountered serious borrowing difficulties. With regard to the system of competitive tenders, company managers have sensed some improvement, but general satisfaction is still lacking. Although the research results suggest that the primary obstacle to growth in 2013 was not the lack of credit or external funding, it is important to emphasize that start-ups, young enterprises and micro-enterprises, which struggle the most with financing worries, were not represented in the analysed database.

A study of the effects of a service-learning experience on student success at an urban community college

The purpose of this study was to explore the effects of a service-learning experience on student success as measured by class attendance, course completion, final course grades, and end-of-term evaluation data.^ Though many outcomes of service-learning experiences have been studied, including ethical values, self-esteem, student personal development, and career preparation, relatively few studies have been conducted on the effects of such experiences on academic achievement, and the studies that have been done have primarily studied students at traditional, four-year, residential universities.^ The study consisted of 286 students enrolled in six paired courses taught by five instructors at a community college in the Fall term 1996. One section of each pair (the control group) was taught using traditional subject matter and course materials and the other section of each pair (the treatment group) participated in a 20-hour required service-learning activity in addition to the regular course curriculum. The courses in the study included American History, Sociology, College Preparatory English, and Introduction to English Composition.^ The results of this study indicate that, overall, students who participated in a class in which service-learning was a requirement, achieved higher final course grades and reported greater satisfaction with the course, the instructor, the reading assignments, and the grading system, and the treatment section of one course pair had fewer absences. In addition, the faculty members reported that, in the treatment sections, class discussions were more stimulating, the sections seemed more vital in terms of student involvement, the students seemed more challenged academically, more motivated to learn, and seemed to exert more effort in the course. ^

The efficacy of the Ellison model as a retention initiative for first semester freshmen

The freshman year is the most critical year of matriculation for students in higher education. One in four freshman students drops out of higher education after the first year. In fact, the first two to six weeks of college represent a very critical transition period when students make the decision to persist or depart from the institution. Many students leave because they are unable to make a connection with the institution. Retention is often profoundly affected by student involvement in the academic environment, satisfaction with the campus climate and the institution's response to diversity. Therefore, the purpose of this study was to examine and evaluate an effective institutional response that promotes freshman retention and academic success. The tenets (diversity training, conflict management, and community building) of a mentoring model were applied to the freshman experience seminar class (experimental group) as a pedagogical method of instruction to determine its efficacy as a retention initiative when compared with the traditional freshman experience seminar class (comparison group). ^ The quantitative study employed a quasi-experimental research design based on Astin's (1993) I-E-O model. The model examined the relationships between the characteristics students bring with them to college, called inputs, their experiences in the environment during college, and the outcomes students achieved during matriculation. Fifty-two students enrolled in the freshman seminar class participated in the study. ^ Demographic data and input variables between groups were analyzed using chi-square, t-tests and multivariate analyses. Overall, students in the experimental group had significantly higher satisfaction (campus climate) scores than the comparison group. An analysis of the students' willingness to interact with others from diverse groups indicated a significant difference between groups, with the experimental group scoring higher than the comparison group. Students in the experimental group were significantly more involved in campus activities than students in the comparison group. No significant differences were found between groups relative to the mean grade point average and re-enrollment for fall semester 2001. ^ While the mentoring model did not directly affect re-enrollment of students, the model did promote student satisfaction with the institution, an appreciation for diversity of contact and it encouraged involvement in the campus community. These are all essential outcomes of a quality retention program. ^

Early career special education teachers' perceptions of school site induction support

Research highlights teacher attrition as one of the biggest challenges facing public schools and their attempts to provide a quality teacher for every student (Ingersoll & Smith, 2003). The teacher shortage is particularly daunting in special education where teachers are over twice as likely to leave the field. The first few years of teaching are the most critical in determining whether or not a beginning teacher will stay in the teaching profession (Whitaker, 2000). ^ A mixed-methods sequential explanatory design was utilized to examine research questions focused on the components of induction support that early career teachers received at their school site, including what they considered most valuable to their long-term retention in the classroom and their development as a quality teacher. Eighty seven early career special education teachers were surveyed during the first phase of the study and six participants were interviewed during the second phase. ^ Data analysis of the Likert-scale survey used in the study revealed that the majority of the respondents received at least 21 of the 25 listed induction components. Moreover, early career special education teachers indicated that they valued all 25 induction components. In addition, findings revealed that over two thirds of the respondents indicated a desire to remain a special education teacher. Overall, early career special education teachers felt confident in their abilities to teach students with disabilities; however, nearly half of the respondents did not feel satisfied with the induction they received. Independent t-tests showed a statistically significant difference between teachers who indicated a desire to remain in special education and those that did not on the level of satisfaction with their induction experience. ^ The six interviews provided elaboration and clarification of the survey responses. The participants expressed their passion for the art of teaching, their dedication to students with disabilities, and their frustration with being a beginning teacher. Furthermore, it was reported that the overall school culture was not very supportive. Participants offered relevant ideas for additional or alternate induction components that would be more effective.^

Customer Satisfaction, Quality in Cruise Industry

Record numbers of passengers are sailing on board cruise ships, with the industry claiming high levels of customer satisfaction. Conversely, little is known about the specific factors which make up customer satisfaction with the cruise experience. The authors examine customer satisfaction data from nearly 15,000 guests of a large U.S. cruise line to determine which aspects of the cruise experience have the greatest impact on overall satisfaction and perceptions of quality.

Employee Job Satisfaction in Major Cruise Lines

A survey of 244 crew members with six major cruise Iines indicated the most satisfaction with organization and supervision, satisfaction with working environment and ship life, and least satisfaction with rewards. The study suggests that the analysis of job satisfaction level may be used to develop organizational strategies to improve shipboard employee job satisfaction.

Differential Impacts of Information Technology Services in the Korean Hotel Industry: A Study of Management Perceptions

Successful introduction of information technology applications in various operations of hotel management is vital to most service firms. In recent decades, technologies of information, automation, and communication are increasingly recognized as essential components of a hotel company’s strategic plan. In this study, 62 super-deluxe hotels (5 star), deluxe hotels (4 star), and tourist hotels (3 star) in Korea are examined for differences in the impact of information technology services on guest’ satisfaction, guest convenience, and operational efficiency. The findings generally suggest that the impacts of information technology-enhanced services vary according to the category of hotels in Korea. The results of the study are expected to assist managers in the selections and implementation of information technology systems in their hotel.

A Study of Satisfaction Level of Hong Kong Tourists with Hot Springs Hotels and Resorts in Guangdong, China

The research reported here aimed at examining Hong Kong tourists’ level of satisfaction with hot springs hotels and resorts in Guangdong, China. Primary data were collected and service quality and tourist satisfaction levels were measured using the SERVQUAL model. The empirical findings indicate that most tourists are satisfied with the service quality of these hotels and resorts. Among the different dimensions of service quality, empathy receives the highest score. Overall satisfaction receives a score only slightly better than average. The results also reveal significant relationships among customer satisfaction level, loyalty, and recommendation.