Spatial-temporal mining of archived automatic vehicle location (AVL) data for transit service planning applications

An Automatic Vehicle Location (AVL) system is a computer-based vehicle tracking system that is capable of determining a vehicle's location in real time. As a major technology of the Advanced Public Transportation System (APTS), AVL systems have been widely deployed by transit agencies for purposes such as real-time operation monitoring, computer-aided dispatching, and arrival time prediction. AVL systems make a large amount of transit performance data available that are valuable for transit performance management and planning purposes. However, the difficulties of extracting useful information from the huge spatial-temporal database have hindered off-line applications of the AVL data. ^ In this study, a data mining process, including data integration, cluster analysis, and multiple regression, is proposed. The AVL-generated data are first integrated into a Geographic Information System (GIS) platform. The model-based cluster method is employed to investigate the spatial and temporal patterns of transit travel speeds, which may be easily translated into travel time. The transit speed variations along the route segments are identified. Transit service periods such as morning peak, mid-day, afternoon peak, and evening periods are determined based on analyses of transit travel speed variations for different times of day. The seasonal patterns of transit performance are investigated by using the analysis of variance (ANOVA). Travel speed models based on the clustered time-of-day intervals are developed using important factors identified as having significant effects on speed for different time-of-day periods. ^ It has been found that transit performance varied from different seasons and different time-of-day periods. The geographic location of a transit route segment also plays a role in the variation of the transit performance. The results of this research indicate that advanced data mining techniques have good potential in providing automated techniques of assisting transit agencies in service planning, scheduling, and operations control. ^

System design and resource management in the next-generation integrated WLAN and 3G cellular networks

Next-generation integrated wireless local area network (WLAN) and 3G cellular networks aim to take advantage of the roaming ability in a cellular network and the high data rate services of a WLAN. To ensure successful implementation of an integrated network, many issues must be carefully addressed, including network architecture design, resource management, quality-of-service (QoS), call admission control (CAC) and mobility management. ^ This dissertation focuses on QoS provisioning, CAC, and the network architecture design in the integration of WLANs and cellular networks. First, a new scheduling algorithm and a call admission control mechanism in IEEE 802.11 WLAN are presented to support multimedia services with QoS provisioning. The proposed scheduling algorithms make use of the idle system time to reduce the average packet loss of realtime (RT) services. The admission control mechanism provides long-term transmission quality for both RT and NRT services by ensuring the packet loss ratio for RT services and the throughput for non-real-time (NRT) services. ^ A joint CAC scheme is proposed to efficiently balance traffic load in the integrated environment. A channel searching and replacement algorithm (CSR) is developed to relieve traffic congestion in the cellular network by using idle channels in the WLAN. The CSR is optimized to minimize the system cost in terms of the blocking probability in the interworking environment. Specifically, it is proved that there exists an optimal admission probability for passive handoffs that minimizes the total system cost. Also, a method of searching the probability is designed based on linear-programming techniques. ^ Finally, a new integration architecture, Hybrid Coupling with Radio Access System (HCRAS), is proposed for lowering the average cost of intersystem communication (IC) and the vertical handoff latency. An analytical model is presented to evaluate the system performance of the HCRAS in terms of the intersystem communication cost function and the handoff cost function. Based on this model, an algorithm is designed to determine the optimal route for each intersystem communication. Additionally, a fast handoff algorithm is developed to reduce the vertical handoff latency.^

Business process quantitative analysis and optimization for service industries

The total time a customer spends in the business process system, called the customer cycle-time, is a major contributor to overall customer satisfaction. Business process analysts and designers are frequently asked to design process solutions with optimal performance. Simulation models have been very popular to quantitatively evaluate the business processes; however, simulation is time-consuming and it also requires extensive modeling experiences to develop simulation models. Moreover, simulation models neither provide recommendations nor yield optimal solutions for business process design. A queueing network model is a good analytical approach toward business process analysis and design, and can provide a useful abstraction of a business process. However, the existing queueing network models were developed based on telephone systems or applied to manufacturing processes in which machine servers dominate the system. In a business process, the servers are usually people. The characteristics of human servers should be taken into account by the queueing model, i.e. specialization and coordination. ^ The research described in this dissertation develops an open queueing network model to do a quick analysis of business processes. Additionally, optimization models are developed to provide optimal business process designs. The queueing network model extends and improves upon existing multi-class open-queueing network models (MOQN) so that the customer flow in the human-server oriented processes can be modeled. The optimization models help business process designers to find the optimal design of a business process with consideration of specialization and coordination. ^ The main findings of the research are, first, parallelization can reduce the cycle-time for those customer classes that require more than one parallel activity; however, the coordination time due to the parallelization overwhelms the savings from parallelization under the high utilization servers since the waiting time significantly increases, thus the cycle-time increases. Third, the level of industrial technology employed by a company and coordination time to mange the tasks have strongest impact on the business process design; as the level of industrial technology employed by the company is high; more division is required to improve the cycle-time; as the coordination time required is high; consolidation is required to improve the cycle-time. ^

Realization of Differentiated Quality of Service for Wideband Code Division Multiple Access Core Network

The development of 3G (the 3rd generation telecommunication) value-added services brings higher requirements of Quality of Service (QoS). Wideband Code Division Multiple Access (WCDMA) is one of three 3G standards, and enhancement of QoS for WCDMA Core Network (CN) becomes more and more important for users and carriers. The dissertation focuses on enhancement of QoS for WCDMA CN. The purpose is to realize the DiffServ (Differentiated Services) model of QoS for WCDMA CN. Based on the parallelism characteristic of Network Processors (NPs), the NP programming model is classified as Pool of Threads (POTs) and Hyper Task Chaining (HTC). In this study, an integrated programming model that combines both of the two models was designed. This model has highly efficient and flexible features, and also solves the problems of sharing conflicts and packet ordering. We used this model as the programming model to realize DiffServ QoS for WCDMA CN. ^ The realization mechanism of the DiffServ model mainly consists of buffer management, packet scheduling and packet classification algorithms based on NPs. First, we proposed an adaptive buffer management algorithm called Packet Adaptive Fair Dropping (PAFD), which takes into consideration of both fairness and throughput, and has smooth service curves. Then, an improved packet scheduling algorithm called Priority-based Weighted Fair Queuing (PWFQ) was introduced to ensure the fairness of packet scheduling and reduce queue time of data packets. At the same time, the delay and jitter are also maintained in a small range. Thirdly, a multi-dimensional packet classification algorithm called Classification Based on Network Processors (CBNPs) was designed. It effectively reduces the memory access and storage space, and provides less time and space complexity. ^ Lastly, an integrated hardware and software system of the DiffServ model of QoS for WCDMA CN was proposed. It was implemented on the NP IXP2400. According to the corresponding experiment results, the proposed system significantly enhanced QoS for WCDMA CN. It extensively improves consistent response time, display distortion and sound image synchronization, and thus increases network efficiency and saves network resource.^

A large-scale dynamic vector and raster data visualization geographic information system based on parallel map tiling

With the exponential increasing demands and uses of GIS data visualization system, such as urban planning, environment and climate change monitoring, weather simulation, hydrographic gauge and so forth, the geospatial vector and raster data visualization research, application and technology has become prevalent. However, we observe that current web GIS techniques are merely suitable for static vector and raster data where no dynamic overlaying layers. While it is desirable to enable visual explorations of large-scale dynamic vector and raster geospatial data in a web environment, improving the performance between backend datasets and the vector and raster applications remains a challenging technical issue. This dissertation is to implement these challenging and unimplemented areas: how to provide a large-scale dynamic vector and raster data visualization service with dynamic overlaying layers accessible from various client devices through a standard web browser, and how to make the large-scale dynamic vector and raster data visualization service as rapid as the static one. To accomplish these, a large-scale dynamic vector and raster data visualization geographic information system based on parallel map tiling and a comprehensive performance improvement solution are proposed, designed and implemented. They include: the quadtree-based indexing and parallel map tiling, the Legend String, the vector data visualization with dynamic layers overlaying, the vector data time series visualization, the algorithm of vector data rendering, the algorithm of raster data re-projection, the algorithm for elimination of superfluous level of detail, the algorithm for vector data gridding and re-grouping and the cluster servers side vector and raster data caching.

Service Management Concepts: Implications for Hospitality Management

In - Service Management Concepts: Implications for Hospitality Management – a study by K. Michael Haywood, Associate Professor, School of Hotel and Food Administration, University of Guelph, Ontario, Canada, Associate Professor Haywood initially proffers: “The study and application of hospitality management has progressed on its own for many years; however, managers are not immune to the knowledge gained from study of other service industries. The author synthesizes what is happening in the area of service management, looks at its relevance to hospitality management, and identifies a few important implications of service management for hospitality managers.” The author draws a distinction between non-denominated service management, and service management as it applies to the hospitality industry. This is done to make an apparent comparison, as many people would assume the two are one in the same. They are not, and the contrast works well here. “While much of what we already know about effective management applies to service industries, some of the traditional concepts of management are inadequate in solving the problems faced by service businesses,” Haywood points out. “If a body of knowledge to be known as service management already exists, or is being developed, where does it fit relative to hospitality management,” Haywood asks. According to John Bateson, Testing a Conceptual Framework for Consumer Service Marketing, there are four criteria used to judge service management. Haywood details these for you, the reader, by way of citation. Haywood points to the difficulty in pin-pointing the intangibles that underpin the service industry. Since service is a concept rather than a touchable good, such as inventory, problems arise for both the organization and the client. Haywood points to a classic study of four service industries in France to illustrate the problems, although no realistic suggestions address the issues. “Over the past few years a variety of system models have been developed to explain the service process, that is, how the service is designed, produced, delivered, and consumed,” Haywood offers. These models are depicted in Appendices A-E. In offering perspectives on how the hospitality industry can gain from the experiences of service management, Haywood observes: “Service management places particular emphasis on a strategic outlook. Hospitality firms would be wise to carefully examine how they are perceived in the marketplace vis-a-vis their service concept, position, competitive situation, and management’s leadership abilities.” “Learning from the experiences of other service firms can help keep a company on track, that is, providing needed and valued services,” he closes the thought.

Selecting POS Systems for Table Service Restaurants

A point-of-sale system can enhance decision making, operational control, guest service, and revenues. However, not all POS systems offer the same features and potential for profit improvement. The author discusses those factors which are critical to POS system selection for table service restaurants

Returning to Server-Centric Hospitality System Applications

Application service provider models represent an alternative to in-house information systems and are gaining favor within the hospitality industry: The models, which place technical system components at a remote site, are described as server-centric. ASPs allow hospitality management to share investment dollars, system costs, and technical staff expenditure with an ASP operator, thereby concentrating on providing enhanced guest services. Although considered a viable alternative to in-house processing, not everyone agrees this is a favorable trend.

On-Line Real-Time Service-Oriented Task Scheduling Using TUF

We present our approach to real-time service-oriented scheduling problems with the objective of maximizing the total system utility. Different from the traditional utility accrual scheduling problems that each task is associated with only a single time utility function (TUF), we associate two different TUFs—a profit TUF and a penalty TUF—with each task, to model the real-time services that not only need to reward the early completions but also need to penalize the abortions or deadline misses. The scheduling heuristics we proposed in this paper judiciously accept, schedule, and abort real-time services when necessary to maximize the accrued utility. Our extensive experimental results show that our proposed algorithms can significantly outperform the traditional scheduling algorithms such as the Earliest Deadline First (EDF), the traditional utility accrual (UA) scheduling algorithms, and an earlier scheduling approach based on a similar model.

It takes an institution's village to retain a student: A comprehensive look at two early warning system undergraduate retention programs and administrators' perceptions of students' experiences and the retention services they provide students in the early warning system retention programs

Institutions have implemented many campus interventions to address student persistence/retention, one of which is Early Warning Systems (EWS). However, few research studies show evidence of interventions that incorporate noncognitive factors/skills, and psychotherapy/psycho-educational processes in the EWS. A qualitative study (phenomenological interview and document analysis) of EWS at both a public and private 4-year Florida university was conducted to explore EWS through the eyes of the administrators of the ways administrators make sense of students' experiences and the services they provide and do not provide to assist students. Administrators' understanding of noncognitive factors and the executive skills subset and their contribution to retention and the executive skills development of at-risk students were also explored. Hossler and Bean's multiple retention lenses theory/paradigms and Perez's retention strategies were used to guide the study. Six administrators from each institution who oversee and/or assist with EWS for first time in college undergraduate students considered academically at-risk for attrition were interviewed. Among numerous findings, at Institution X: EWS was infrequently identified as a service, EWS training was not conducted, numerous cognitive and noncognitive issues/deficits were identified for students, and services/critical departments such as EWS did not work together to share students' information to benefit students. Assessment measures were used to identify students' issues/deficits; however, they were not used to assess, track, and monitor students' issues/deficits. Additionally, the institution's EWS did address students' executive skills function beyond time management and organizational skills, but did not address students' psychotherapy/psycho-educational processes. Among numerous findings, at Institution Y: EWS was frequently identified as a service, EWS training was not conducted, numerous cognitive and noncognitive issues/deficits were identified for students, and services/critical departments such as EWS worked together to share students' information to benefit students. Assessment measures were used to identify, track, and monitor students' issues/deficits; however, they were not used to assess students' issues/deficits. Additionally, the institution's EWS addressed students' executive skills function beyond time management and organizational skills, and psychotherapy/psycho-educational processes. Based on the findings, Perez's retention strategies were not utilized in EWS at Institution X, yet were collectively utilized in EWS at Institution Y, to achieve Hossler and Bean's retention paradigms. Future research could be designed to test the link between engaging in the specific promising activities identified in this research (one-to-one coaching, participation in student success workshops, academic contracts, and tutoring) and student success (e.g., higher GPA, retention). Further, because this research uncovered some concern with how to best handle students with physical and psychological disabilities, future research could link these same promising strategies for improving student performance for example among ADHD students or those with clinical depression.

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.

Development and evaluation of a geographic information system based method to estimate flooding susceptibility in an area of Broward County, Florida

The objective of this study was to develop a GIS-based multi-class index overlay model to determine areas susceptible to inland flooding during extreme precipitation events in Broward County, Florida. Data layers used in the method include Airborne Laser Terrain Mapper (ALTM) elevation data, excess precipitation depth determined through performing a Soil Conservation Service (SCS) Curve Number (CN) analysis, and the slope of the terrain. The method includes a calibration procedure that uses "weights and scores" criteria obtained from Hurricane Irene (1999) records, a reported 100-year precipitation event, Doppler radar data and documented flooding locations. Results are displayed in maps of Eastern Broward County depicting types of flooding scenarios for a 100-year, 24-hour storm based on the soil saturation conditions. As expected the results of the multi-class index overlay analysis showed that an increase for the potential of inland flooding could be expected when a higher antecedent moisture condition is experienced. The proposed method proves to have some potential as a predictive tool for flooding susceptibility based on a relatively simple approach.

Design and implementation of a relative localization system for ground and aerial robotic teams

The main focus of this thesis is to address the relative localization problem of a heterogenous team which comprises of both ground and micro aerial vehicle robots. This team configuration allows to combine the advantages of increased accessibility and better perspective provided by aerial robots with the higher computational and sensory resources provided by the ground agents, to realize a cooperative multi robotic system suitable for hostile autonomous missions. However, in such a scenario, the strict constraints in flight time, sensor pay load, and computational capability of micro aerial vehicles limits the practical applicability of popular map-based localization schemes for GPS denied navigation. Therefore, the resource limited aerial platforms of this team demand simpler localization means for autonomous navigation. Relative localization is the process of estimating the formation of a robot team using the acquired inter-robot relative measurements. This allows the team members to know their relative formation even without a global localization reference, such as GPS or a map. Thus a typical robot team would benefit from a relative localization service since it would allow the team to implement formation control, collision avoidance, and supervisory control tasks, independent of a global localization service. More importantly, a heterogenous team such as ground robots and computationally constrained aerial vehicles would benefit from a relative localization service since it provides the crucial localization information required for autonomous operation of the weaker agents. This enables less capable robots to assume supportive roles and contribute to the more powerful robots executing the mission. Hence this study proposes a relative localization-based approach for ground and micro aerial vehicle cooperation, and develops inter-robot measurement, filtering, and distributed computing modules, necessary to realize the system. The research study results in three significant contributions. First, the work designs and validates a novel inter-robot relative measurement hardware solution which has accuracy, range, and scalability characteristics, necessary for relative localization. Second, the research work performs an analysis and design of a novel nonlinear filtering method, which allows the implementation of relative localization modules and attitude reference filters on low cost devices with optimal tuning parameters. Third, this work designs and validates a novel distributed relative localization approach, which harnesses the distributed computing capability of the team to minimize communication requirements, achieve consistent estimation, and enable efficient data correspondence within the network. The work validates the complete relative localization-based system through multiple indoor experiments and numerical simulations. The relative localization based navigation concept with its sensing, filtering, and distributed computing methods introduced in this thesis complements system limitations of a ground and micro aerial vehicle team, and also targets hostile environmental conditions. Thus the work constitutes an essential step towards realizing autonomous navigation of heterogenous teams in real world applications.

A PHR system with policy-based fine-grained access control and revocation mechanism

Collaborative sharing of information is becoming much more needed technique to achieve complex goals in today's fast-paced tech-dominant world. Personal Health Record (PHR) system has become a popular research area for sharing patients informa- tion very quickly among health professionals. PHR systems store and process sensitive information, which should have proper security mechanisms to protect patients' private data. Thus, access control mechanisms of the PHR should be well-defined. Secondly, PHRs should be stored in encrypted form. Cryptographic schemes offering a more suitable solution for enforcing access policies based on user attributes are needed for this purpose. Attribute-based encryption can resolve these problems, we propose a patient-centric framework that protects PHRs against untrusted service providers and malicious users. In this framework, we have used Ciphertext Policy Attribute Based Encryption scheme as an efficient cryptographic technique, enhancing security and privacy of the system, as well as enabling access revocation. Patients can encrypt their PHRs and store them on untrusted storage servers. They also maintain full control over access to their PHR data by assigning attribute-based access control to selected data users, and revoking unauthorized users instantly. In order to evaluate our system, we implemented CP-ABE library and web services as part of our framework. We also developed an android application based on the framework that allows users to register into the system, encrypt their PHR data and upload to the server, and at the same time authorized users can download PHR data and decrypt it. Finally, we present experimental results and performance analysis. It shows that the deployment of the proposed system would be practical and can be applied into practice.

Context-Aware Personalised Service Delivery

Postprint