Fiber-optic liquid level monitoring system using microstructured polymer fiber Bragg grating array sensors:performance analysis

A highly sensitive liquid level monitoring system based on microstructured polymer optical fiber Bragg grating (mPOFBG) array sensors is reported for the first time. The configuration is based on five mPOFBGs inscribed in the same fiber in the 850 nm spectral region, showing the potential to interrogate liquid level by measuring the strain induced in each mPOFBG embedded in a silicone rubber (SR) diaphragm, which deforms due to hydrostatic pressure variations. The sensor exhibits a highly linear response over the sensing range, a good repeatability, and a high resolution. The sensitivity of the sensor is found to be 98 pm/cm of water, enhanced by more than a factor of 9 when compared to an equivalent sensor based on a silica fiber around 1550 nm. The temperature sensitivity is studied and a multi-sensor arrangement proposed, which has the potential to provide level readings independent of temperature and the liquid density.

Guiding schools to improved performance using data envelopment analysis:an illustration with data from a local education authority

The educational process is characterised by multiple outcomes such as the achievement of academic results of various standards and non-academic achievements. This paper shows how data envelopment analysis (DEA) can be used to guide secondary schools to improved performance through role-model identification and target setting in a way which recognises the multi-outcome nature of the education process and reflects the relative desirability of improving individual outcomes. The approach presented in the paper draws from a DEA-based assessment of the schools of a local education authority carried out by the authors. Data from that assessment are used to illustrate the approach presented in the paper. (Key words: Data envelopment analysis, education, target setting.)

Technical efficiency and human capital in the retail sector

The performance of the British retail sectors in terms of productivity growth is not brilliant. This paper focuses on a specific component of productivity growth (technical efficiency) and tests the extent to which its variance across the sector can be explained by the differences in the educational attainment of the pool of workers to which retail firms have access. The empirical analysis is carried out on a sample of 1061 retail firms from the Annual Respondents Database, 1997-2005. The results confirm that the county-level differences of the stock of human capital can explain the technical efficiency differentials across the sector. © 2011 Taylor and Francis Group, LLC.

Performance analysis of polymer optical fibre based Fabry-Perot sensor formed by two uniform Bragg gratings

The stress sensitivity of polymer optical fibre (POF) based Fabry-Perot sensors formed by two uniform Bragg gratings with finite dimensions is investigated. POF has received high interest in recent years due to its different material properties compared to its silica counterpart. Biocompatibility, a higher failure strain and the highly elastic nature of POF are some of the main advantages. The much lower Young’s modulus of polymer materials compared to silica offers enhanced stress sensitivity to POF based sensors which renders them great candidates for acoustic wave receivers and any kind of force detection. The main drawback in POF technology is perhaps the high fibre loss. In a lossless fibre the sensitivity of an interferometer is proportional to its cavity length. However, the presence of the attenuation along the optical path can significantly reduce the finesse of the Fabry-Perot interferometer and it can negatively affect its sensitivity at some point. The reflectivity of the two gratings used to form the interferometer can be also reduced as the fibre loss increases. In this work, a numerical model is developed to study the performance of POF based Fabry-Perot sensors formed by two uniform Bragg gratings with finite dimensions. Various optical and physical properties are considered such as grating physical length, grating effective length which indicates the point where the light is effectively reflected, refractive index modulation of the grating, cavity length of the interferometer, attenuation and operating wavelength. Using this model, we are able to identify the regimes in which the PMMA based sensor offer enhanced stress sensitivity compared to silica based one.

Performance analysis of IEEE 802.11 cognitive radio ad hoc networks

IEEE 802.11 standard is the dominant technology for wireless local area networks (WLANs). In the last two decades, the Distributed coordination function (DCF) of IEEE 802.11 standard has become the one of the most important media access control (MAC) protocols for mobile ad hoc networks (MANETs). The DCF protocol can also be combined with cognitive radio, thus the IEEE 802.11 cognitive radio ad hoc networks (CRAHNs) come into being. There were several literatures which focus on the modeling of IEEE 802.11 CRAHNs, however, there is still no thorough and scalable analytical models for IEEE 802.11 CRAHNs whose cognitive node (i.e., secondary user, SU) has spectrum sensing and possible channel silence process before the MAC contention process. This paper develops a unified analytical model for IEEE 802.11 CRAHNs for comprehensive MAC layer queuing analysis. In the proposed model, the SUs are modeled by a hyper generalized 2D Markov chain model with an M/G/1/K model while the primary users (PUs) are modeled by a generalized 2D Markov chain and an M/G/1/K model. The performance evaluation results show that the quality-of-service (QoS) of both the PUs and SUs can be statistically guaranteed with the suitable settings of duration of channel sensing and silence phase in the case of under loading.

The effectiveness of workplace coaching:A meta-analysis of learning and performance outcomes; scale development; theoretical model of individual differences and longitudinal study

The extant literature on workplace coaching is characterised by a lack of theoretical and empirical understanding regarding the effectiveness of coaching as a learning and development tool; the types of outcomes one can expect from coaching; the tools that can be used to measure coaching outcomes; the underlying processes that explain why and how coaching works and the factors that may impact on coaching effectiveness. This thesis sought to address these substantial gaps in the literature with three linked studies. Firstly, a meta-analysis of workplace coaching effectiveness (k = 17), synthesizing the existing research was presented. A framework of coaching outcomes was developed and utilised to code the studies. Analysis indicated that coaching had positive effects on all outcomes. Next, the framework of outcomes was utilised as the deductive start-point to the development of the scale measuring perceived coaching effectiveness. Utilising a multi-stage approach (n = 201), the analysis indicated that perceived coaching effectiveness may be organised into a six factor structure: career clarity; team performance; work well-being; performance; planning and organizing and personal effectiveness and adaptability. The final study was a longitudinal field experiment to test a theoretical model of individual differences and coaching effectiveness developed in this thesis. An organizational sample of 84 employees each participated in a coaching intervention, completed self-report surveys, and had their job performance rated by peers, direct reports and supervisors (a total of 352 employees provided data on participant performance). The results demonstrate that compared to a control group, the coaching intervention generated a number of positive outcomes. The analysis indicated that coachees’ enthusiasm, intellect and orderliness influenced the impact of coaching on outcomes. Mediation analysis suggested that mastery goal orientation, performance goal orientation and approach motivation in the form of behavioural activation system (BAS) drive, were significant mediators between personality and outcomes. Overall, the findings of this thesis make an original contribution to the understanding of the types of outcomes that can be expected from coaching, and the magnitude of impact coaching has on outcomes. The thesis also provides a tool for reliably measuring coaching effectiveness and a theoretical model to understand the influence of coachee individual differences on coaching outcomes.

Performance analysis of an experimental wireless relay sensor network

Communication through relay channels in wireless sensor networks can create diversity and consequently improve the robustness of data transmission for ubiquitous computing and networking applications. In this paper, we investigate the performances of relay channels in terms of diversity gain and throughput via both experimental research and theoretical analysis. Two relaying algorithms, dynamic relaying and fixed relaying, are utilised and tested to find out what the relay channels can contribute to system performances. The tests are based on a wireless relay sensor network comprising a source node, a destination node and a couple of relay nodes, and carried out in an indoor environment with rare movement of objects nearby. The tests confirm, in line with the analytical results, that more relay nodes lead to higher diversity gain in the network. The test results also show that the data throughput between the source node and the destination node is enhanced by the presence of the relay nodes. Energy consumption in association with the relaying strategy is also analysed. Copyright © 2009 John Wiley & Sons, Ltd.

Statistical Analysis of the Performance Data of Central and Eastern European Water Utilities - International Benchmarking Network for Water and Sanitation Utilities (IBNET)

A Világbank az 1990-es évek végén egy nagyszabású, nemzetközi teljesítmény-értékelési programot indított a víz- és szennyvíz-szolgáltató vállalatok körében. Az International Benchmarking Network for Water and Sanitation Utilities (IBNET) elnevezésű kezdeményezés keretében a szolgáltatók egy szabványosított kérdőíven információt adnak meg működésükről. Az egyedi, cégszintű adatokból egy adatbázis készül, mely lehetővé teszi a vállalatok működésének összehasonlító elemzését, amit teljesítmény-értékelésnek (benchmarking) is szokás nevezni. A programról és eddigi eredményeiről angol nyelvű információ a www.ib-net.org honlapon található. A felmérést eddig több, mint 70 országban végezték el, köztük Magyarországon is. Itthon a REKK kapott megbízást a feladat végrehajtására. Az adatgyűjtésen túl az adatbázisra alapozva Közép és Kelet-Európa országainak víziközmű cégeiről statisztikai elemzést végeztünk az alap adottságok és a költségek összefüggésének feltárására.

The impact of perceived corporate environmental performance on the behavior of capital market decision makers : analysis of food industry companies

Environmental protectionism and sustainable development has been gaining increased attention among governments, investors and consumers alike. As a result, firms are facing growing pressure from the various stakeholders to improve their environmental performance. This study is focusing on the food industry, which in recent years has been a subject of increased scrutiny due to their role in resource consumption, waste generation and unsustainable production practices. Our research is aiming to examine how the financial community evaluates the environmental stewardship of food industry companies as proxied by market reactions in response to environmental news. Are all company related environmental news items evaluated equally, and which financial and non-financial firm-specific attributes can influence market responses? Have there been changes in reactions on the stock exchange in the past two decades?

An analysis of the on-time graduation rate in the two-year program at National Taipei Institute of Technology in Taiwan

Taiwan's technical vocational educational system includes three levels: (1) institutes of technology (two and four year programs), (2) junior colleges (two, three and five year programs), and (3) senior vocational schools. Two-year junior colleges enroll their students through two channels: (1) based on results of the Particular Screening Entrance Examination (PSEE), (2) based on the Joint College Entrance Examination (JCEE). The PSEE has two categories: Category I includes on-time graduates with excellent performance, which means that they are within the top ten of their classes; Category II students include award-winning students in talent contests who have achieved a minimum grade point average of 75%. The JCEE is a regular entrance examination given to any senior vocation school graduate.^ Basic courses have a great impact on the students' academic performance. The purpose of the study was to focus on the effectiveness of teaching mathematics in two-year junior colleges and to analyze and correlate the results of two-year junior college students' performance in calculus and on-time graduation. The target group consisted of 521 students enrolled at National Taipei Institute of Technology in 1993.^ Calculus is a very important course for engineering majors in two-year junior colleges and has a great impact on the students' academic performance. This retrospective study showed that there was a correlation between students' performance in calculus and on-time graduation after two years of study.^ The conclusions of the study urge the Ministry of Education to reform two-year junior college curriculum standards to emphasize basic rudimentary courses. It is recommended that engineering majors receive three hours of calculus per week as the current requirement of only two hours per week is inadequate. The future job market will require a technologically advanced labor force that can be trained in a higher education system. More channels of higher education for two-year junior college graduates should be made available for those wishing to pursue bachelor degrees. Additional work in calculus will not only enhance the opportunities for two-year junior college graduates to continue their pursuit of an advanced academic degree, but also serve them well as they seek career advancement. ^

A comparative analysis of self-determined evaluations of work performance and support needs by adults with mental retardation in supported work and in sheltered workshop environments

The purpose of this study was to determine if there was a difference in the self-determined evaluations of work performance and support needs by adults with mental retardation in supported employment and in sheltered workshop environments. The instrument, Job Observation and Behavior Scale: Opportunity for Self-Determination (JOBS: OSD; Brady, Rosenberg, & Frain, 2006), was administered to 38 adults with mental retardation from sheltered workshops and 32 adults with mental retardation from supported employment environments. Cross-tabulations with Chi-square tests and independent samples t-tests were conducted to evaluate differences between the two groups, sheltered workshop and supported work. Two Multivariate Analyses of Variance (MANOVAs) were conducted to determine the effect of work environment on Quality of Performance (QP) and Types of Support (TS) test scores and their subscales. ^ This study found that there were significant differences between the groups on the QP Behavior and Job Duties subscales. The sheltered workshop group perceived themselves as performing significantly better on job duties than the supported work group. Conversely, the supported work group perceived themselves to have better behavior than the sheltered workshop group. However, there were no significant differences between groups in their perception of support needs for the three subscales. ^ The findings imply that work environment affects the self-determined evaluations of work performance by adults with mental retardation. Recommendations for further study include (a) detailing the characteristics of supported work and sheltered workshops that support and/or discourage self-determined behaviors, (b) exploring the behavior of adults with mental retardation in sheltered workshops and supported work environments, and (c) analysis of the support needs for and understanding of them by adults with mental retardation in sheltered workshops and in supported work environments. ^

Improving novice analyst performance in modeling the sequence diagram in systems analysis: A cognitive complexity approach

The Unified Modeling Language (UML) has quickly become the industry standard for object-oriented software development. It is being widely used in organizations and institutions around the world. However, UML is often found to be too complex for novice systems analysts. Although prior research has identified difficulties novice analysts encounter in learning UML, no viable solution has been proposed to address these difficulties. Sequence-diagram modeling, in particular, has largely been overlooked. The sequence diagram models the behavioral aspects of an object-oriented software system in terms of interactions among its building blocks, i.e. objects and classes. It is one of the most commonly-used UML diagrams in practice. However, there has been little research on sequence-diagram modeling. The current literature scarcely provides effective guidelines for developing a sequence diagram. Such guidelines will be greatly beneficial to novice analysts who, unlike experienced systems analysts, do not possess relevant prior experience to easily learn how to develop a sequence diagram. There is the need for an effective sequence-diagram modeling technique for novices. This dissertation reports a research study that identified novice difficulties in modeling a sequence diagram and proposed a technique called CHOP (CHunking, Ordering, Patterning), which was designed to reduce the cognitive load by addressing the cognitive complexity of sequence-diagram modeling. The CHOP technique was evaluated in a controlled experiment against a technique recommended in a well-known textbook, which was found to be representative of approaches provided in many textbooks as well as practitioner literatures. The results indicated that novice analysts were able to perform better using the CHOP technique. This outcome seems have been enabled by pattern-based heuristics provided by the technique. Meanwhile, novice analysts rated the CHOP technique more useful although not significantly easier to use than the control technique. The study established that the CHOP technique is an effective sequence-diagram modeling technique for novice analysts.

The development of optimized high performance liquid chromatography systems for the analysis of improvised explosives

Existing instrumental techniques must be adaptable to the analysis of novel explosives if science is to keep up with the practices of terrorists and criminals. The focus of this work has been the development of analytical techniques for the analysis of two types of novel explosives: ascorbic acid-based propellants, and improvised mixtures of concentrated hydrogen peroxide/fuel. In recent years, the use of these explosives in improvised explosive devices (IEDs) has increased. It is therefore important to develop methods which permit the identification of the nature of the original explosive from post-blast residues. Ascorbic acid-based propellants are low explosives which employ an ascorbic acid fuel source with a nitrate/perchlorate oxidizer. A method which utilized ion chromatography with indirect photometric detection was optimized for the analysis of intact propellants. Post-burn and post-blast residues if these propellants were analyzed. It was determined that the ascorbic acid fuel and nitrate oxidizer could be detected in intact propellants, as well as in the post-burn and post-blast residues. Degradation products of the nitrate and perchlorate oxidizers were also detected. With a quadrupole time-of-flight mass spectrometer (QToFMS), exact mass measurements are possible. When an HPLC instrument is coupled to a QToFMS, the combination of retention time with accurate mass measurements, mass spectral fragmentation information, and isotopic abundance patterns allows for the unequivocal identification of a target analyte. An optimized HPLC-ESI-QToFMS method was applied to the analysis of ascorbic acid-based propellants. Exact mass measurements were collected for the fuel and oxidizer anions, and their degradation products. Ascorbic acid was detected in the intact samples and half of the propellants subjected to open burning; the intact fuel molecule was not detected in any of the post-blast residue. Two methods were optimized for the analysis of trace levels of hydrogen peroxide: HPLC with fluorescence detection (HPLC-FD), and HPLC with electrochemical detection (HPLC-ED). Both techniques were extremely selective for hydrogen peroxide. Both methods were applied to the analysis of post-blast debris from improvised mixtures of concentrated hydrogen peroxide/fuel; hydrogen peroxide was detected on variety of substrates. Hydrogen peroxide was detected in the post-blast residues of the improvised explosives TATP and HMTD.

Does management capacity increase organizational performance? An empirical analysis of public housing agencies

Since the 1990s, scholars have paid special attention to public management’s role in theory and research under the assumption that effective management is one of the primary means for achieving superior performance. To some extent, this was influenced by popular business writings of the 1980s as well as the reinventing literature of the 1990s. A number of case studies but limited quantitative research papers have been published showing that management matters in the performance of public organizations. ^ My study examined whether or not management capacity increased organizational performance using quantitative techniques. The specific research problem analyzed was whether significant differences existed between high and average performing public housing agencies on select criteria identified in the Government Performance Project (GPP) management capacity model, and whether this model could predict outcome performance measures in a statistically significant manner, while controlling for exogenous influences. My model included two of four GPP management subsystems (human resources and information technology), integration and alignment of subsystems, and an overall managing for results framework. It also included environmental and client control variables that were hypothesized to affect performance independent of management action. ^ Descriptive results of survey responses showed high performing agencies with better scores on most high performance dimensions of individual criteria, suggesting support for the model; however, quantitative analysis found limited statistically significant differences between high and average performers and limited predictive power of the model. My analysis led to the following major conclusions: past performance was the strongest predictor of present performance; high unionization hurt performance; and budget related criterion mattered more for high performance than other model factors. As to the specific research question, management capacity may be necessary but it is not sufficient to increase performance. ^ The research suggested managers may benefit by implementing best practices identified through the GPP model. The usefulness of the model could be improved by adding direct service delivery to the model, which may also improve its predictive power. Finally, there are abundant tested concepts and tools designed to improve system performance that are available for practitioners designed to improve management subsystem support of direct service delivery.^

An Analysis of Stock Market Performance:The Dow Jones Industrial Average and the Three Top Performing Lodging Firma: 1982-1988

In their dialogue - An Analysis of Stock Market Performance: The Dow Jones Industrial Average and the Three Top Performing Lodging Firms 1982 – 1988 - by N. H. Ringstrom, Professor and Elisa S. Moncarz, Associate Professor, School of Hospitality Management at Florida International University, Professors Ringstrom and Moncarz state at the outset: “An interesting comparison can be made between the Dow Jones lndustrial Average and the three top performing, publicly held lodging firms which had $100 million or more in annual lodging revenues. The authors provide that analytical comparison with Prime Motor Inns Inc., the Marriott Corporation, and Hilton Hotels Corporation.” “Based on a criterion of size, only those with $100 million in annual lodging revenues or more resulted in the inclusion of the following six major hotel firms: Prime Motor Inns, Inc., Marriott Corporation, Hilton Hotels Corporation, Ramada Inc., Holiday Corporation and La Quinta Motor Inns, Inc.,” say Professors Ringstrom and Moncarz in framing this discussion with its underpinnings in the years 1982 to 1988. The article looks at each company’s fiscal and Dow Jones performance for the years in question, and presents a detailed analysis of said performance. Graphic analysis is included. It helps to have a fairly vigorous knowledge of stock market and fiscal examination criteria to digest this material. The Ringstrom and Moncarz analysis of Prime Motor Inns Incorporated occupies the first 7 pages of this article in and of itself. Marriot Corporation also occupies a prominent position in this discussion. “Marriott, a giant in the hospitality industry, is huge and continuing to grow. Its 1987 sales were more than $6.5 billion, and its employees numbered over 200,000 individuals, which place Marriott among the 10 largest private employers in the country,” Ringstrom and Moncarz parse Marriott’s influence as a significant financial player. “The firm has a fantastic history of growth over the past 60 years, starting in May 1927 with a nine-seat A & W Root Beer stand in Washington, D.C.,” offer the authors in initialing Marriot’s portion of the discussion with a brief history lesson. The Marriot firm was officially incorporated as Hot Shoppes Inc. in 1929. As the thesis statement for the discussion suggests the performance of these huge, hospitality giants is compared and contrasted directly to the Dow Jones Industrial Average performance. Reasons and empirical data are offered by the authors to explain the distinctions. It would be difficult to explain those distinctions without delving deeply into corporate financial history and the authors willingly do so in an effort to help you understand the growth, as well as some of the setbacks of these hospitality based juggernauts. Ringstrom and Moncarz conclude the article with an extensive overview and analysis of the Hilton Hotels Corporation performance for the period outlined. It may well be the most fiscally dynamic of the firms presented for your perusal. “It is interesting to note that Hilton Hotels Corporation maintained a very strong financial position with relatively little debt during the years 1982-1988…the highest among all companies in the study,” the authors paint.