Report on a review of selected general and application controls over the University of Northern Iowa Accounts Payable/Purchasing System for the period of June 10, 2009 through August 20, 2009

Report on a review of selected general and application controls over the University of Northern Iowa Accounts Payable/Purchasing System for the period of June 10, 2009 through August 20, 2009

Innovative LIDAR 3D dynamic measurement system to estimate fruit-tree leaf area

In this work, a LIDAR-based 3D Dynamic Measurement System is presented and evaluated for the geometric characterization of tree crops. Using this measurement system, trees were scanned from two opposing sides to obtain two three-dimensional point clouds. After registration of the point clouds, a simple and easily obtainable parameter is the number of impacts received by the scanned vegetation. The work in this study is based on the hypothesis of the existence of a linear relationship between the number of impacts of the LIDAR sensor laser beam on the vegetation and the tree leaf area. Tests performed under laboratory conditions using an ornamental tree and, subsequently, in a pear tree orchard demonstrate the correct operation of the measurement system presented in this paper. The results from both the laboratory and field tests confirm the initial hypothesis and the 3D Dynamic Measurement System is validated in field operation. This opens the door to new lines of research centred on the geometric characterization of tree crops in the field of agriculture and, more specifically, in precision fruit growing.

Dynamic integrated system optimization and parameter estimation for discrete time optimal control of nonlinear systems

An algorithm for solving nonlinear discrete time optimal control problems with model-reality differences is presented. The technique uses Dynamic Integrated System Optimization and Parameter Estimation (DISOPE), which achieves the correct optimal solution in spite of deficiencies in the mathematical model employed in the optimization procedure. A version of the algorithm with a linear-quadratic model-based problem, implemented in the C+ + programming language, is developed and applied to illustrative simulation examples. An analysis of the optimality and convergence properties of the algorithm is also presented.

Model predictive control using dynamic integrated system optimisation and parameter estimation (DISOPE)

DISOPE is a technique for solving optimal control problems where there are differences in structure and parameter values between reality and the model employed in the computations. The model reality differences can also allow for deliberate simplification of model characteristics and performance indices in order to facilitate the solution of the optimal control problem. The technique was developed originally in continuous time and later extended to discrete time. The main property of the procedure is that by iterating on appropriately modified model based problems the correct optimal solution is achieved in spite of the model-reality differences. Algorithms have been developed in both continuous and discrete time for a general nonlinear optimal control problem with terminal weighting, bounded controls and terminal constraints. The aim of this paper is to show how the DISOPE technique can aid receding horizon optimal control computation in nonlinear model predictive control.

An algorithm for automatic checking of exercises in a dynamic geometry system: iGeom

One of the key issues in e-learning environments is the possibility of creating and evaluating exercises. However, the lack of tools supporting the authoring and automatic checking of exercises for specifics topics (e.g., geometry) drastically reduces advantages in the use of e-learning environments on a larger scale, as usually happens in Brazil. This paper describes an algorithm, and a tool based on it, designed for the authoring and automatic checking of geometry exercises. The algorithm dynamically compares the distances between the geometric objects of the student`s solution and the template`s solution, provided by the author of the exercise. Each solution is a geometric construction which is considered a function receiving geometric objects (input) and returning other geometric objects (output). Thus, for a given problem, if we know one function (construction) that solves the problem, we can compare it to any other function to check whether they are equivalent or not. Two functions are equivalent if, and only if, they have the same output when the same input is applied. If the student`s solution is equivalent to the template`s solution, then we consider the student`s solution as a correct solution. Our software utility provides both authoring and checking tools to work directly on the Internet, together with learning management systems. These tools are implemented using the dynamic geometry software, iGeom, which has been used in a geometry course since 2004 and has a successful track record in the classroom. Empowered with these new features, iGeom simplifies teachers` tasks, solves non-trivial problems in student solutions and helps to increase student motivation by providing feedback in real time. (c) 2008 Elsevier Ltd. All rights reserved.

Dynamic whole system testing of combined renewable heating systems : the current state of the art

Objective: For the evaluation of the energetic performance of combined renewable heating systems that supply space heat and domestic hot water for single family houses, dynamic behaviour, component interactions, and control of the system play a crucial role and should be included in test methods. Methods: New dynamic whole system test methods were developed based on “hardware in the loop” concepts. Three similar approaches are described and their differences are discussed. The methods were applied for testing solar thermal systems in combination with fossil fuel boilers (heating oil and natural gas), biomass boilers, and/or heat pumps. Results: All three methods were able to show the performance of combined heating systems under transient operating conditions. The methods often detected unexpected behaviour of the tested system that cannot be detected based on steady state performance tests that are usually applied to single components. Conclusion: Further work will be needed to harmonize the different test methods in order to reach comparable results between the different laboratories. Practice implications: A harmonized approach for whole system tests may lead to new test standards and improve the accuracy of performance prediction as well as reduce the need for field tests.

Can FDI promote export diversification and sophistication of host countries? : dynamic panel system GMM analysis

Recent trade literature highlights the importance of export diversification and upgrading in fostering faster and sustainable economic growth. This study investigates the impact of FDI inflow and stock on the level of export diversification and sophistication in host country's export baskets. By utilizing the dynamic panel data model, we find that the five-year lagged FDI inflow correlates positively with both export diversification and sophistication, and FDI stock makes the positive contribution to export sophistication. These findings provide support for the possibility of successful capabilities transfer to and building by local firms. We also find that these positive impacts of FDI exist only in developing countries.

Bifurcation analysis of a dynamic power system with SVC devices

Bifurcation analysis is a very useful tool for power system stability assessment. In this paper, detailed investigation of power system bifurcation behaviour is presented. One and two parameter bifurcation analysis are conducted on a 3-bus power system. We also examined the impact of FACTS devices on power system stability through Hopf bifurcation analysis by taking static Var compensator (SVC) as an example. A simplified first-order model of the SVC device is included in the 3-bus sample system. Real and reactive powers are used as bifurcation parameter in the analysis to compare the system oscillatory properties with and without SVC. The simulation results indicate that the linearized system model with SVC enlarge the voltage stability boundary by moving Hopf bifurcation point to higher level of loading conditions. The installation of SVC increases the dynamic stability range of the system, however complicates the Hopf bifurcation behavior of the system

The lateral and ventromedial prefrontal cortex work as a dynamic integrated system:evidence from FMRI connectivity analysis

Recent functional magnetic resonance imaging (fMRI) investigations of the interaction between cognition and reward processing have found that the lateral prefrontal cortex (PFC) areas are preferentially activated to both increasing cognitive demand and reward level. Conversely, ventromedial PFC (VMPFC) areas show decreased activation to the same conditions, indicating a possible reciprocal relationship between cognitive and emotional processing regions. We report an fMRI study of a rewarded working memory task, in which we further explore how the relationship between reward and cognitive processing is mediated. We not only assess the integrity of reciprocal neural connections between the lateral PFC and VMPFC brain regions in different experimental contexts but also test whether additional cortical and subcortical regions influence this relationship. Psychophysiological interaction analyses were used as a measure of functional connectivity in order to characterize the influence of both cognitive and motivational variables on connectivity between the lateral PFC and the VMPFC. Psychophysiological interactions revealed negative functional connectivity between the lateral PFC and the VMPFC in the context of high memory load, and high memory load in tandem with a highly motivating context, but not in the context of reward alone. Physiophysiological interactions further indicated that the dorsal anterior cingulate and the caudate nucleus modulate this pathway. These findings provide evidence for a dynamic interplay between lateral PFC and VMPFC regions and are consistent with an emotional gating role for the VMPFC during cognitively demanding tasks. Our findings also support neuropsychological theories of mood disorders, which have long emphasized a dysfunctional relationship between emotion/motivational and cognitive processes in depression.

Design of a dynamic test system for traction batteries

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Sähköisten hankintamenettelyjen taloudelliset yritysvaikutukset

Pro gradu -tutkielmassa tutkitaan julkisissa hankinnoissa käyttöön otettavien uusien sähköisten menettelyjen, sähköisen huutokaupan ja dynaamisen hankintajärjestelmän, yritysvaikutuksia. Ydintutkimustehtävänä on tutkia, millaisia taloudellisia vaikutuksia sähköisillä menettelyillä tulee olemaan yrityksiin niiden tarjotessa palveluita tai tavaroita julkiselle sektorille ja mitkä ovat sähköisten menettelyjen käytön motiivit. Tutkielman teoriaosa on pohja empiiriselle tutkimukselle, jossa aineistona on käytetty suppeaa kyselytutkimusta, haastatteluja ja lisäksi materiaalia on tuotettu analysoimalla hallinnollisten kustannusten määrää sähköisissä hankintamenettelyissä. Yritysvaikutusten arvioinnissa tarkasteltiin sähköisten hankintamenettelyjen käytön motiiveja. Motiiveiksi tunnistettiin tehokkuuden tavoittelu, kustannussäästöt, ajankäytön ja henkilöresurssien käytön tehostaminen sekä avoimuus. Tutkimuksessa onnistuttiin todentamaan edellä mainittuja tekijöitä taloudellisilla malleilla. Määrälliset ja laadulliset tutkimustulokset osoittavat kokonaisuudessaan tuloksellisella tavalla sähköisten hankintamenettelyjen käytön motiiveita ja vaikutuksia yrityksiin. Sähköisillä hankintamenettelyillä voidaan perustellusti tehostaa hankintaprosessia ja saavuttaa kustannussäästöjä. Monia yleisiä yritysten julkisiin hankintoihin pääsyn esteinä pitämiä seikkoja voitaisiin vähentää tai poistaa käyttämällä sähköisiä hankintoja. Sähköistä huutokauppaa ja dynaamista hankintajärjestelmää koskevan lainsäädännön luodessa puitteet menettelyiden käytölle, tulee menettelyjen käyttöönoton motiivien ja kannustimien riittävyyttä seurata. Hallinnollisten kustannusten väheneminen ja muiden esteiden pieneneminen ei välttämättä synnytä pysyvää kannustinvaikutusta, vaan hankintaprosessia tulee pyrkiä sähköistämään kokonaisvaltaisesti myös muissa hankintalain mukaisissa hankintamenettelyissä ja kilpailuttamisen ulkopuolisissa hankinnan osa-alueissa kuten laskuttaminen, maksatus ja tilaus.

Sähköinen huutokauppa ja dynaaminen hankintajärjestelmä

Opinnäytetyöni tavoitteena on esitellä olennaiset kohdat julkisten hankintojen sähköisessä menettelyssä. Arvioinnin kohteena on lokakuussa 2011 voimaan astunut laki sähköisestä huutokaupasta ja dynaamisesta hankintajärjestelmästä. Opinnäytetyöni on kirjoituspöytätutkimus, joka perustuu julkisia hankintoja koskevaan lainsäädäntöaineistoon sekä julkisia hankintoja tutkivien sidosryhmien tuottamaan kirjallisuuteen. Näkökulmana on sähköisen menettelyn sääntelyn tarkoituksenmukaisuus hankintayksiköiden sekä toimittajien näkökulmista. Sääntely julkisten hankintojen sähköisestä menettelystä tarkoittaa julkisilla varoilla hankittavien palvelujen sekä tavaroiden hankintaa sähköisessä verkkoympäristössä. Hankintayksikkö, kuten valtion tai kunnan viranomainen, voi tämän lain myötä suorittaa hankintaprosessin sähköisesti käyttöliittymän kautta haluamastaan tuotteesta tai palvelusta.