Classification of Texts' Authorship Using a Regression Model on Compressed Data

2010 Mathematics Subject Classification: 68T50,62H30,62J05.

Impact of denial of service solutions on network quality of service

The Internet has become a universal communication network tool. It has evolved from a platform that supports best-effort traffic to one that now carries different traffic types including those involving continuous media with quality of service (QoS) requirements. As more services are delivered over the Internet, we face increasing risk to their availability given that malicious attacks on those Internet services continue to increase. Several networks have witnessed denial of service (DoS) and distributed denial of service (DDoS) attacks over the past few years which have disrupted QoS of network services, thereby violating the Service Level Agreement (SLA) between the client and the Internet Service Provider (ISP). Hence DoS or DDoS attacks are major threats to network QoS. In this paper we survey techniques and solutions that have been deployed to thwart DoS and DDoS attacks and we evaluate them in terms of their impact on network QoS for Internet services. We also present vulnerabilities that can be exploited for QoS protocols and also affect QoS if exploited. In addition, we also highlight challenges that still need to be addressed to achieve end-to-end QoS with recently proposed DoS/DDoS solutions. © 2010 John Wiley & Sons, Ltd.

Az innováció hatása a vállalati teljesítményre és versenyképességre (The impact of innovation activities on firm's performance and competitiveness)

A tanulmány az innovációnak a vállalati teljesítményre és a versenyképességre gyakorolt hatását vizsgálja, valamint a magyarországi innováció gazdasági környezetének néhány elemét próbálja feltérképezni a Budapesti Corvinus Egyetem Versenyképesség Kutató Központjának 2009-es felmérése alapján. A termékinnováció fontos szerepet játszik a versenyképes vállalatok sikerében, azonban - elsősorban adatbázisunk keresztmetszeti jellege miatt - az eljárásinnovációról ezt nem tudjuk megállapítani. Ugyancsak nem találtunk szignifikáns kapcsolatot az innováció és a termelékenység között. Az innovatív vállalatok nagyobb valószínűséggel vesznek részt a külkereskedelemben, nagyobb arányban vannak külföldi tulajdonban, s az innovációs folyamat során leginkább saját tudásbázisukra támaszkodnak. Az innováció egyik fő hátráltató tényezőjének tartják az állam szerepét, gyakran néznek szembe finanszírozási problémákkal és a piaci szereplők új termékek iránti igénytelenségével. _____ The paper deals with the impact of innovation on performance and competitiveness based on firm-level data. The research is based on a survey conducted by the Competitiveness Research Centre at Budapest Corvinus University. According to the econometric analysis, the firms that are more innovative are export oriented and foreign owned. Product innovation has an eminent role in competitiveness, but no significant relationship was found between innovation and productivity. As for sources of innovation, internal ones are more important than universities, customers or open sources. Firms themselves perceive legislation and taxation as highly important factors that hamper their innovation activity.

A cash flow-kimutatás szabályozásainak nemzetközi összehasonlítása és csoportosítása (International comparison and classification of Cash Flow Statement regulations)

Az egyes nemzetek számviteli szabályozásának vizsgálatánál az adott ország sajátosságaiból eredően részben eltérő szabályozások alakultak ki. Az induktív megközelítésű vizsgálatok jellemzően a szabályozási kérdések széles körét fogják át, de csak néhány tényező mentén közelítve. A cash flow-kimutatások témakörénél a legtöbbször csak azt nézték, hogy van-e előírás a kimutatás elkészítésére, de a részletekkel már kevésbé foglalkoztak. Ebből adódóan e területen viszonylag kis különbséget mutattak ki ezek a felmérések. A szerző kutatása szerint a nemzeti cash flow-kimutatások szabályozásának részleteiben eltérések tapasztalhatók, és ezek alapján a nemzetek klaszterelemzéssel hierarchikusan csoportokba rendezhetők. _____ Research has found that as a result of their particularities, different countries have established partly different accounting frameworks. Studies with inductive approaches typically encompass a wide range of regulatory issues, but based on a limited number of factors only. In the case of Statements of Cash Flows, most studies have so far only examined the existence of rules governing the presentation of the statement, without an in-depth analysis of the details. Therefore, these studies only found relatively minor differences in this field. The author’s research shows that many differences exist in the details of national Cash Flow Statement regulations, which makes it possible to classify the countries in groups using the method of hierarchical clustering.

3D TerraFly: Quality of service management for online interactive 3D geographic information system

3D geographic information system (GIS) is data and computation intensive in nature. Internet users are usually equipped with low-end personal computers and network connections of limited bandwidth. Data reduction and performance optimization techniques are of critical importance in quality of service (QoS) management for online 3D GIS. In this research, QoS management issues regarding distributed 3D GIS presentation were studied to develop 3D TerraFly, an interactive 3D GIS that supports high quality online terrain visualization and navigation. ^ To tackle the QoS management challenges, multi-resolution rendering model, adaptive level of detail (LOD) control and mesh simplification algorithms were proposed to effectively reduce the terrain model complexity. The rendering model is adaptively decomposed into sub-regions of up-to-three detail levels according to viewing distance and other dynamic quality measurements. The mesh simplification algorithm was designed as a hybrid algorithm that combines edge straightening and quad-tree compression to reduce the mesh complexity by removing geometrically redundant vertices. The main advantage of this mesh simplification algorithm is that grid mesh can be directly processed in parallel without triangulation overhead. Algorithms facilitating remote accessing and distributed processing of volumetric GIS data, such as data replication, directory service, request scheduling, predictive data retrieving and caching were also proposed. ^ A prototype of the proposed 3D TerraFly implemented in this research demonstrates the effectiveness of our proposed QoS management framework in handling interactive online 3D GIS. The system implementation details and future directions of this research are also addressed in this thesis. ^

Statistical analysis and optimal classification of blood cell populations using Gaussian distributions

This dissertation develops a new figure of merit to measure the similarity (or dissimilarity) of Gaussian distributions through a novel concept that relates the Fisher distance to the percentage of data overlap. The derivations are expanded to provide a generalized mathematical platform for determining an optimal separating boundary of Gaussian distributions in multiple dimensions. Real-world data used for implementation and in carrying out feasibility studies were provided by Beckman-Coulter. It is noted that although the data used is flow cytometric in nature, the mathematics are general in their derivation to include other types of data as long as their statistical behavior approximate Gaussian distributions. ^ Because this new figure of merit is heavily based on the statistical nature of the data, a new filtering technique is introduced to accommodate for the accumulation process involved with histogram data. When data is accumulated into a frequency histogram, the data is inherently smoothed in a linear fashion, since an averaging effect is taking place as the histogram is generated. This new filtering scheme addresses data that is accumulated in the uneven resolution of the channels of the frequency histogram. ^ The qualitative interpretation of flow cytometric data is currently a time consuming and imprecise method for evaluating histogram data. This method offers a broader spectrum of capabilities in the analysis of histograms, since the figure of merit derived in this dissertation integrates within its mathematics both a measure of similarity and the percentage of overlap between the distributions under analysis. ^

Best practices in exemplary service delivery: A multiple case study of service quality

The purpose of this study was to explain how exemplary service providers in luxury hotels provide consistently excellent service. Using a case study framework, the study investigated the service provider's strategies and concepts of service delivery, the importance and implementation of organizational and individual controls, and the role of training and learning. The study identified barriers to service provision and characteristics of the exemplary individuals that affect their ability to deliver luxury service. This study sought to better understand how exemplary service providers learn, think about, and do their work. The sample population of three Five-Diamond-Award winning resorts was selected for their potential for learning about the phenomenon of interest. The results demonstrate that exemplary service providers possess individual characteristics that are enhanced by the organizations for which they work. Exemplary service providers are often exemplary communicators who are emotionally generous and genuinely enjoy helping and serving others. Exemplary service organizations treat their employees as they treat their customers, as suggested by the Service-Profit Chain (Heskett, Sasser & Schlesinger, 1997). Further, they have systems and standards to guarantee satisfactory service experiences for every guest. They also encourage their service providers to personalize their service delivery and to seek opportunities to delight their guests, using a combination of controls, traditions and cultural values. Several customer service theories are discussed in relationship to whether they were or were not supported by the data. The study concluded that the delivery of exemplary service is a complex phenomenon that requires successful interactions between guests, service providers and the organization. A Model of Exemplary Service Delivery is presented and discussed that demonstrates the components of service quality as shown in the data. The model can be used by practitioners seeking to create, enhance, or evaluate their service quality, and by researchers seeking insights into the complex concepts in service quality research. Implications for future research are discussed.

Effects of service-learning on student attitudes toward academic engagement and civic responsibility

This empirical study explored the impact of service-learning participation on high school students' attitudes toward academic engagement and civic responsibility. This study focused whether a group of high school students who participated in a service-learning project had more positive attitudes toward academic engagement and civic responsibility than their high school peers who did not participate in a service learning project. ^ Data were collected from 67 volunteer students as participants in grades 9–12. A service-learning treatment group of 34 high school students was examined relative to a comparison group of 33 high school students with similar demographic and academic characteristics. The investigator used questionnaires, an oral history/service-learning project, and interviews with the teacher-coordinators of the project to collect the data. The two surveys, one investigating high school students' attitudes about academic engagement, the other investigating high school students' attitudes toward civic responsibility, were administered in a pre-treatment/post-treatment design. There were 90 days between the pre-treatment and post-treatment administrations. A factor analysis of the civic responsibility instrument and multivariate analysis of gain scores were used to compare the means of the total aggregate scores of the treatment and comparison groups. Factor analysis was performed on the academic engagement instrument but it was determined that only the total scores could be used in subsequent analyses. Results were used to determine the efficacy of service-learning as interpreted in student attitudes toward academic engagement and student attitudes toward civic responsibility. ^ The study found no significant difference between the academic engagement and the civic responsibility attitudes of a high school service-learning project group and a high school comparison group with comparable school and similar demographic characteristics. One of the implications for educational practice and policy from the study results is a need to design and implement more powerful studies, studies implemented at many sites rather than just at two sites that were the basis of this study, and studies that investigate the research questions over longer time periods. Although it was not a focus of the study, the investigator concluded that service learning projects such as this might be more effective if they were better aligned with Dewey's principles. ^

Automated detection of hematological abnormalities through classification of flow cytometric data patterns

Flow Cytometry analyzers have become trusted companions due to their ability to perform fast and accurate analyses of human blood. The aim of these analyses is to determine the possible existence of abnormalities in the blood that have been correlated with serious disease states, such as infectious mononucleosis, leukemia, and various cancers. Though these analyzers provide important feedback, it is always desired to improve the accuracy of the results. This is evidenced by the occurrences of misclassifications reported by some users of these devices. It is advantageous to provide a pattern interpretation framework that is able to provide better classification ability than is currently available. Toward this end, the purpose of this dissertation was to establish a feature extraction and pattern classification framework capable of providing improved accuracy for detecting specific hematological abnormalities in flow cytometric blood data. ^ This involved extracting a unique and powerful set of shift-invariant statistical features from the multi-dimensional flow cytometry data and then using these features as inputs to a pattern classification engine composed of an artificial neural network (ANN). The contribution of this method consisted of developing a descriptor matrix that can be used to reliably assess if a donor’s blood pattern exhibits a clinically abnormal level of variant lymphocytes, which are blood cells that are potentially indicative of disorders such as leukemia and infectious mononucleosis. ^ This study showed that the set of shift-and-rotation-invariant statistical features extracted from the eigensystem of the flow cytometric data pattern performs better than other commonly-used features in this type of disease detection, exhibiting an accuracy of 80.7%, a sensitivity of 72.3%, and a specificity of 89.2%. This performance represents a major improvement for this type of hematological classifier, which has historically been plagued by poor performance, with accuracies as low as 60% in some cases. This research ultimately shows that an improved feature space was developed that can deliver improved performance for the detection of variant lymphocytes in human blood, thus providing significant utility in the realm of suspect flagging algorithms for the detection of blood-related diseases.^

Creating Memories: The Interactive Process of Service Delivery

A model is presented that captures the complex nature of the service experience in an attempt to aid in the design, development and evaluation of service delivery personnel and systems.

Model of Service Quality: Customer Loyalty for Hotels

The authors investigate the relationship between loyalty and perceived service quality of hotel customers and discus managerial implications to develop strategies to enhance loyalty of hotel customers. A survey was conducted among customers in the San Francisco Bay Area. Results indicate that customer loyalty is dependent on perceived service quality which is observed in terms of timelines, facilities, and ambience.

Examining the Impact of Service Times on Overall Guest Satisfaction Perception in the Casual Dining Environment

A mystery shopper study was used to examine the influence of service times on customer satisfaction. The impact of management emphasis on service quality was also examined. In the restaurants studied, service time influenced customer satisfaction. Management attention to service time improved performance in direct relationship to the level of emphasis.