Design and implementation of a web based shop floor control system to maintain schedule feasibility in a dynamic job shop environment

The effective control of production activities in dynamic job shop with predetermined resource allocation for all the jobs entering the system is a unique manufacturing environment, which exists in the manufacturing industry. In this thesis a framework for an Internet based real time shop floor control system for such a dynamic job shop environment is introduced. The system aims to maintain the schedule feasibility of all the jobs entering the manufacturing system under any circumstance. The system is capable of deciding how often the manufacturing activities should be monitored to check for control decisions that need to be taken on the shop floor. The system will provide the decision maker real time notification to enable him to generate feasible alternate solutions in case a disturbance occurs on the shop floor. The control system is also capable of providing the customer with real time access to the status of the jobs on the shop floor. The communication between the controller, the user and the customer is through web based user friendly GUI. The proposed control system architecture and the interface for the communication system have been designed, developed and implemented.

A longitudinal study of Project Trio: A dropout prevention program in a large urban environment

The subject of dropout prevention/reduction is deservedly receiving attention as a problem that, if not resolved, could threaten our national future.^ This study investigates a small segment of the overall dropout problem, which has apparently unique features of program design and population selection. The evidence presented here should add to the knowledge bank of this complicated problem.^ Project Trio was one of a number of dropout prevention programs and activities which were conducted in Dade County school years 1984-85 and 1985-86, and it is here investigated longitudinally through the end of the 1987-88 school year. It involved 17 junior and senior high schools, and 27 programs, 10 the first year and 17 the second, with over 1,000 total students, who had been selected by the schools from a list of the "at risk" students provided by the district, and were divided approximately evenly into the classical research design of an experimental group and the control group, which following standard procedure was to take the regular school curriculum. No school had more than 25 students in either group.^ Each school modified the basic design of the project to accommodate the individual school characteristics and the perceived needs of their students; however all schools projects were to include some form of academic enhancement, counseling and career awareness study.^ The conclusion of this study was that the control group had a significantly lower dropout rate than the experimental group. Though impossible to make a certain determination of the reasons for this unexpected result, it appears from evidence presented that one cause may have been inadequate administration at the local level.^ This study was also a longitudinal investigation of the "at risk" population as a whole for the three and four year period, to determine if academic factors were present in records may be used to identify dropout proneness.^ A significant correlation was found between dropping out and various measures including scores on the Quality of School Life Instrument, attendance, grade point averages, mathematics grades, and overage in grade, important identifiers in selection for dropout prevention programs. ^

The development and analysis of a field project model curriculum and its impact on achievement and attitude toward science and the environment with at-risk eleventh and twelfth grade students

This study was an evaluation of a Field Project Model Curriculum and its impact on achievement, attitude toward science, attitude toward the environment, self-concept, and academic self-concept with at-risk eleventh and twelfth grade students. One hundred eight students were pretested and posttested on the Piers-Harris Children's Self-Concept Scale, PHCSC (1985); the Self-Concept as a Learner Scale, SCAL (1978); the Marine Science Test, MST (1987); the Science Attitude Inventory, SAI (1970); and the Environmental Attitude Scale, EAS (1972). Using a stratified random design, three groups of students were randomly assigned according to sex and stanine level, to three treatment groups. Group one received the field project method, group two received the field study method, and group three received the field trip method. All three groups followed the marine biology course content as specified by Florida Student Performance Objectives and Frameworks. The intervention occurred for ten months with each group participating in outside-of-classroom activities on a trimonthly basis. Analysis of covariance procedures were used to determine treatment effects. F-ratios, p-levels and t-tests at p $<$.0062 (.05/8) indicated that a significant difference existed among the three treatment groups. Findings indicated that groups one and two were significantly different from group three with group one displaying significantly higher results than group two. There were no significant differences between males and females in performance on the five dependent variables. The tenets underlying environmental education are congruent with the recommendations toward the reform of science education. These include a value analysis approach, inquiry methods, and critical thinking strategies that are applied to environmental issues. ^

Perceptions of family environment, body image and self-esteem of eating disordered and non-eating disordered women

This study explored the perceptions of family environment, body image and self esteem of women who suffer from anorexia nervosa, bulimia nervosa, and depression. Using a nonequivalent control group design, one hundred and fifty women with anorexia nervosa (n = 50), bulimia nervosa (n = 50), and depression (n = 50) were given the Family Environment Scale (FES) and the Eating Disorders Inventory-2 (EDI-2). The objectives of this study were to: (1) study how women with anorexia nervosa and bulimia nervosa perceive their family environment as measured by the FES; (2) compare and contrast perceptions of family environment of women with anorexia nervosa and bulimia nervosa with the control group; (3) compare and contrast perceived levels of self esteem and body image as measured by the EDI-2 of women with anorexia nervosa and bulimia nervosa with the control group; and (4) examine the perceived family environments of eating disordered and non-eating disordered women with regard to body image and self esteem. Results suggested, women who suffered from anorexia nervosa or bulimia nervosa scored significantly lower (p $<$.021) on the Expressiveness, Intellectual-Cultural Orientation, and Active-Recreational subscales of the FES. The results also indicated that women who suffered from bulimia nervosa scored significantly higher (p $<$.015) than women who suffered from anorexia nervosa on the Conflict and Independence subscales of the FES. The results of studying these three populations reflected that women who suffered from anorexia nervosa scored significantly different (p $<$.000) than women who suffered from bulimia nervosa on many of the subscales of the EDI-2. The findings of the study confirmed that women who suffered from anorexia nervosa or bulimia nervosa scored significantly different (p $<$.000) on the subscales of the EDI-2 compared to women who suffered from depression. It was also confirmed that a relationship does exist between perceptions of body image and self esteem and perceptions of family environment amongst women with anorexia nervosa and bulimia nervosa as compared to depressed women. The findings of the study indicated that women who suffered from anorexia nervosa tended to: be less expressive and independent; handle conflict less openly; have a greater drive for thinness; have greater body dissatisfaction; be more perfectionistic; and struggle more intensely with fears around maturity and social insecurity than did women who suffered from bulimia nervosa or depression. In addition, the findings of the study also suggested that women who suffered from bulimia nervosa tended to: be raised in homes where openly expressed anger is permitted amongst family members; have a lesser drive for thinness; have less body dissatisfaction; be less perfectionistic; and not struggle as intensely with fears around maturity and social insecurity as do women who suffered from anorexia nervosa, but more than women who suffer from depression. Treatment implications that may assist community college professors and counselors in meeting the special needs of this special group of women were also discussed. (Abstract shortened by UMI.) ^

Nonlinear dynamics and chaos simulation system analysis for improved design

Small errors proved catastrophic. Our purpose to remark that a very small cause which escapes our notice determined a considerable effect that we cannot fail to see, and then we say that the effect is due to chance. Small differences in the initial conditions produce very great ones in the final phenomena. A small error in the former will produce an enormous error in the latter. When dealing with any kind of electrical device specification, it is important to note that there exists a pair of test conditions that define a test: the forcing function and the limit. Forcing functions define the external operating constraints placed upon the device tested. The actual test defines how well the device responds to these constraints. Forcing inputs to threshold for example, represents the most difficult testing because this put those inputs as close as possible to the actual switching critical points and guarantees that the device will meet the Input-Output specifications. ^ Prediction becomes impossible by classical analytical analysis bounded by Newton and Euclides. We have found that non linear dynamics characteristics is the natural state of being in all circuits and devices. Opportunities exist for effective error detection in a nonlinear dynamics and chaos environment. ^ Nowadays there are a set of linear limits established around every aspect of a digital or analog circuits out of which devices are consider bad after failing the test. Deterministic chaos circuit is a fact not a possibility as it has been revived by our Ph.D. research. In practice for linear standard informational methodologies, this chaotic data product is usually undesirable and we are educated to be interested in obtaining a more regular stream of output data. ^ This Ph.D. research explored the possibilities of taking the foundation of a very well known simulation and modeling methodology, introducing nonlinear dynamics and chaos precepts, to produce a new error detector instrument able to put together streams of data scattered in space and time. Therefore, mastering deterministic chaos and changing the bad reputation of chaotic data as a potential risk for practical system status determination. ^

Blurring the lines between public and private spaces in residential design

This thesis explores the role of public space as an integral part of residential design to promote a sense of community, where neighbors can congregate and children can play in safety. ^ Through research and analysis of successful public spaces, I evaluated relationships between dwellings and public spaces that offer progressive levels of privacy, and between indoor and outdoor spaces. Further research of published studies on child development, human behavior and relationships with nature identified a human preference for natural environments, a need for adequate recreation space for children's development and the potential of open spaces to build a strong sense of community. ^ My project develops multiple transitional spaces between the street and the interior of dwellings that provide varying degrees of privacy closely related to the community's green spaces. The result is a community-oriented pedestrian environment that encourages family and community values and contributes to the healthy living of its residents without depriving them of their privacy. ^

The impact of information technology on organizations: A study of enterprise resource planning system influences on job design and organizational culture

The primary purpose of this research is to study the linkage between perceived job design characteristics and information system environment characteristics before and after the replacement of a legacy information system with a new type of information system (referred to as an Enterprise Resource Planning or ERP system). A public state University implementing an academic version of an ERP system was selected for the study. Three survey instruments were used to examine the perception of the information system, the job characteristics, and the organizational culture before and after the system implementation. The research participants included two large departments resulting in a sample of 130 workers. Research questions were analyzed using multivariate procedures including factor analysis, path analysis, step-wise regression, and matched pair analysis. ^ Results indicated that the ERP system has introduced new elements into the working environment that has changed the perception of how the job design characteristics and organization culture dimensions are viewed by the workers. The understanding of how the perceived system characteristics align with an individual's perceived job design characteristics is supported by each of the system characteristics significantly correlated in the proposed direction. The stronger support of this relationship becomes visible in the causal flow of the effects seen in the path diagram and in the step-wise regression. The perceived job design characteristics aligning with dimensions of organizational culture are not as strong as the literature suggests. Although there are significant correlations between the job and culture variables, only one relationship can be seen in the causal flow. ^ This research has demonstrated that system characteristics of ERP do contribute to the perception of change in an organization and do support organizational culture behaviors and job characteristics. ^

Alternative service organizations: Funding environment, strategies, and patterns of adaptation

This study explored the strategies that community-based, consumer-focused advocacy, alternative service organizations (ASOs), implemented to adapt to the changes in the nonprofit funding environment (Oliver & McShane, 1979; Perlmutter, 1988a, 1994). It is not clear as to the extent to which current funding trends have influenced ASOs as little empirical research has been conducted in this area (Magnus, 2001; Marquez, 2003; Powell, 1986). ^ This study used a qualitative research design to investigate strategies implemented by these organizations to adapt to changes such as decreasing government, foundation, and corporate funding and an increasing number of nonprofit organizations. More than 20 community informants helped to identify, locate, and provide information about ASOs. Semi-structured interviews were conducted with a sample of 30 ASO executive directors from diverse organizations in Miami-bade and Broward Counties, in South Florida. ^ Data analysis was facilitated by the use of ATLAS.ti, version 5, a qualitative data analysis computer software program designed for grounded theory research. This process generated five major themes: Funding Environment; Internal Structure; Strategies for Survival; Sustainability; and Committing to the Cause, Mission, and Vision. ^ The results indicate that ASOs are struggling to survive financially by cutting programs, decreasing staff, and limiting service to consumers. They are also exploring ways to develop fundraising strategies; for example, increasing the number of proposals written for grants, focusing on fund development, and establishing for-profit ventures. Even organizations that state that they are currently financially stable are concerned about their financial vulnerability. There is little flexibility or cushioning to adjust to "funding jolts." The fear of losing current funding levels and being placed in a tenuous financial situation is a constant concern for these ASOs. ^ Further data collected from the self-administered Funding Checklist and demographic forms were coded and analyzed using Statistical Package for the Social Sciences (SPSS). Descriptive information and frequencies generated findings regarding the revenue, staff compliment, use of volunteers and fundraising consultants, and fundraising practices. The study proposes a model of funding relationships and presents implications for social work practice, and policy, along with recommendations for future research. ^

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.^

Physical dynamic simulation of shipboard power system components in a distributed computational environment

Shipboard power systems have different characteristics than the utility power systems. In the Shipboard power system it is crucial that the systems and equipment work at their peak performance levels. One of the most demanding aspects for simulations of the Shipboard Power Systems is to connect the device under test to a real-time simulated dynamic equivalent and in an environment with actual hardware in the Loop (HIL). The real time simulations can be achieved by using multi-distributed modeling concept, in which the global system model is distributed over several processors through a communication link. The advantage of this approach is that it permits the gradual change from pure simulation to actual application. In order to perform system studies in such an environment physical phase variable models of different components of the shipboard power system were developed using operational parameters obtained from finite element (FE) analysis. These models were developed for two types of studies low and high frequency studies. Low frequency studies are used to examine the shipboard power systems behavior under load switching, and faults. High-frequency studies were used to predict abnormal conditions due to overvoltage, and components harmonic behavior. Different experiments were conducted to validate the developed models. The Simulation and experiment results show excellent agreement. The shipboard power systems components behavior under internal faults was investigated using FE analysis. This developed technique is very curial in the Shipboard power systems faults detection due to the lack of comprehensive fault test databases. A wavelet based methodology for feature extraction of the shipboard power systems current signals was developed for harmonic and fault diagnosis studies. This modeling methodology can be utilized to evaluate and predicate the NPS components future behavior in the design stage which will reduce the development cycles, cut overall cost, prevent failures, and test each subsystem exhaustively before integrating it into the system.

Customization of the design of antenna using genetic algorithm and finite-difference time-domain technique

Antenna design is an iterative process in which structures are analyzed and changed to comply with certain performance parameters required. The classic approach starts with analyzing a "known" structure, obtaining the value of its performance parameter and changing this structure until the "target" value is achieved. This process relies on having an initial structure, which follows some known or "intuitive" patterns already familiar to the designer. The purpose of this research was to develop a method of designing UWB antennas. What is new in this proposal is that the design process is reversed: the designer will start with the target performance parameter and obtain a structure as the result of the design process. This method provided a new way to replicate and optimize existing performance parameters. The base of the method was the use of a Genetic Algorithm (GA) adapted to the format of the chromosome that will be evaluated by the Electromagnetic (EM) solver. For the electromagnetic study we used XFDTD™ program, based in the Finite-Difference Time-Domain technique. The programming portion of the method was created under the MatLab environment, which serves as the interface for converting chromosomes, file formats and transferring of data between the XFDTD™ and GA. A high level of customization had to be written into the code to work with the specific files generated by the XFDTD™ program. Two types of cost functions were evaluated; the first one seeking broadband performance within the UWB band, and the second one searching for curve replication of a reference geometry. The performance of the method was evaluated considering the speed provided by the computer resources used. Balance between accuracy, data file size and speed of execution was achieved by defining parameters in the GA code as well as changing the internal parameters of the XFDTD™ projects. The results showed that the GA produced geometries that were analyzed by the XFDTD™ program and changed following the search criteria until reaching the target value of the cost function. Results also showed how the parameters can change the search criteria and influence the running of the code to provide a variety of geometries.

Design of an automated book reader as an assistive technology tool for blind persons

This dissertation introduces a novel automated book reader as an assistive technology tool for persons with blindness. The literature shows extensive work in the area of optical character recognition, but the current methodologies available for the automated reading of books or bound volumes remain inadequate and are severely constrained during document scanning or image acquisition processes. The goal of the book reader design is to automate and simplify the task of reading a book while providing a user-friendly environment with a realistic but affordable system design. This design responds to the main concerns of (a) providing a method of image acquisition that maintains the integrity of the source (b) overcoming optical character recognition errors created by inherent imaging issues such as curvature effects and barrel distortion, and (c) determining a suitable method for accurate recognition of characters that yields an interface with the ability to read from any open book with a high reading accuracy nearing 98%. This research endeavor focuses in its initial aim on the development of an assistive technology tool to help persons with blindness in the reading of books and other bound volumes. But its secondary and broader aim is to also find in this design the perfect platform for the digitization process of bound documentation in line with the mission of the Open Content Alliance (OCA), a nonprofit Alliance at making reading materials available in digital form. The theoretical perspective of this research relates to the mathematical developments that are made in order to resolve both the inherent distortions due to the properties of the camera lens and the anticipated distortions of the changing page curvature as one leafs through the book. This is evidenced by the significant increase of the recognition rate of characters and a high accuracy read-out through text to speech processing. This reasonably priced interface with its high performance results and its compatibility to any computer or laptop through universal serial bus connectors extends greatly the prospects for universal accessibility to documentation.

A generalized multidimensional index structure for multimedia data to support content-based similarity searches in a collaborative search environment

Since multimedia data, such as images and videos, are way more expressive and informative than ordinary text-based data, people find it more attractive to communicate and express with them. Additionally, with the rising popularity of social networking tools such as Facebook and Twitter, multimedia information retrieval can no longer be considered a solitary task. Rather, people constantly collaborate with one another while searching and retrieving information. But the very cause of the popularity of multimedia data, the huge and different types of information a single data object can carry, makes their management a challenging task. Multimedia data is commonly represented as multidimensional feature vectors and carry high-level semantic information. These two characteristics make them very different from traditional alpha-numeric data. Thus, to try to manage them with frameworks and rationales designed for primitive alpha-numeric data, will be inefficient. An index structure is the backbone of any database management system. It has been seen that index structures present in existing relational database management frameworks cannot handle multimedia data effectively. Thus, in this dissertation, a generalized multidimensional index structure is proposed which accommodates the atypical multidimensional representation and the semantic information carried by different multimedia data seamlessly from within one single framework. Additionally, the dissertation investigates the evolving relationships among multimedia data in a collaborative environment and how such information can help to customize the design of the proposed index structure, when it is used to manage multimedia data in a shared environment. Extensive experiments were conducted to present the usability and better performance of the proposed framework over current state-of-art approaches.

Structure of international cooperation in trade, investment and environment

This dissertation analyzes the obstacles against further cooperation in international economic relations. The first essay explains the gradual nature of trade liberalization. I show that existence of asymmetric information between governments provides a sufficient reason for gradualism to exist. Governments prefer starting small to reduce the cost of partner’s betrayal when there is sufficient degree of information asymmetry regarding the partner’s type. Learning about partner’s incentive structure enhances expectations, encouraging governments to increase their current level of cooperation. Specifically, the uninformed government’s subjective belief for the trading partner being good is improved as the partner acts cooperatively. This updated belief, in turn, lowers the subjective probability of future betrayal, enabling further progress in cooperation. The second essay analyzes the relationship between two countries facing two policy dilemmas in an environment with two way goods and capital flows. When issues are independent and countries are symmetric, signing separate agreements for tariffs (Free Trade Agreements-FTA) and for taxes (Tax Treaties-TT) provides the identical level of enforcement as signing a linked agreement. However, linkage can still improve the joint welfare by transferring the slack enforcement power in a case of asymmetric issues or countries. I report non-results in two cases where the policy issues are interconnected due to technological spillover effect of FDI. Moreover, I show that linking the agreements actually reduces enforcement when agreements are linked under a limited punishment rule and policy variables are strategic substitutes. The third essay investigates the welfare/enforcement consequences of linking trade and environmental agreements. In the standard literature, linking the agreements generate non-trivial results only when there is structural relation between the issues. I focus on institutional design of the linkage and show that even if environmental aspects of international trade are negligible linking the agreements might still have some interesting welfare implications under current GATT Rules. Specifically, when traded goods are substitutes in consumption, linking the environmental agreement with trade agreement under the Withdrawal of Equivalent Concession Rule (Article XXVIII) will reduce the enforcement. However, enforcement in environmental issue increases when the same rule is implemented in the absence of linkage.

Long-Term Effects of Adding Nutrients to an Oligotrophic Coastal Environment

Management of ecological disturbances requires an understanding of the time scale and dynamics of community responses to disturbance events. To characterize long-term seagrass bed responses to nutrient enrichment, we established six study sites in Florida Bay, USA. In 24 plots (0.25 m2) at each site, we regularly added nitrogen (N) and phosphorus (P) in a factorial design for 7 years. Five of the six sites exhibited strong P limitation. Over the first 2 years, P enrichment increased Thalassia testudinum cover in the three most P-limited sites. After 3 years, Halodule wrightii began to colonize many of the P-addition plots, but the degree of colonization was variable among sites, possibly due to differences in the supply of viable propagules. Thalassia increased its allocation to aboveground tissue in response to P enrichment; Halodule increased in total biomass but did not appear to change its aboveground: belowground tissue allocation. Nutrient enrichment did not cause macroalgal or epiphytic overgrowth of the seagrass. Nitrogen retention in the study plots was variable but relatively low, whereas phosphorus retention was very high, often exceeding 100% of the P added as fertilizer over the course of our experiments. Phosphorus retentions exceeding 100% may have been facilitated by increases in Thalassia aboveground biomass, which promoted the settlement of suspended particulate matter containing phosphorus. Our study demonstrated that lowintensity press disturbance events such as phosphorus enrichment can initiate a slow, ramped successional process that may alter community structure over many years.