Impact of procurement systems on transaction costs: a structural equation modelling methodology

Within construction procurement, Transaction cost economics (TCE) offers a mechanism to understand ‘unseen’ costs associated with the pre and post-contract work. Pre-contract, these include costs related to information gathering and procurement. Post-contract they include activities of contract administration and enforcement. This paper aims to estimate transaction costs (TCs) for different delivery systems used in construction projects in New Zealand, specifically the Traditional and Design-Build. This study develops a conceptual model for the relationship between project delivery systems and TCs. The model was operationalized and developed into a questionnaire. A crosssectional sample approach was deployed, involving pilot and survey questionnaires. Data was sought from construction professionals in management, design and operations. TCs were measured using professionals’ time-spent in procurement as a surrogate for cost. Using using a Likert-Scale 1-5 in evaluation, comparing the Traditional and Design-Build systems. Data was triangulated with ‘real world’ cases to test and explain the developed model. The test included Validity and Reliability, Path Analysis, Regression Analysis, Factor Analysis, and Structural Equation Modelling (SEM). The primary analytical technique used was SEM to yield information on Goodness-of-Fit, model development and comparison, and confirmatory strategies. SPSS Amos 21 was used for data analysis and model development. The results suggest that project delivery systems have indirect effect on TCs. This effect is fully mediated by the costs of information, procurement, administration, and enforcement. Applying the developed models to ‘real world’ cases, it was found that TCs in the Traditional systems amounts to 18.5% of the annual salary cost of a project manager, while in the Design-Build systems, it amounts to 14.5% of the annual salary cost of a project manager. The findings have practical implications on construction business practice due to their robust empirical nature and theoretical framework, which might enhance the performance of the construction industry

KACST Arabic Text Classification Project: Overview and Preliminary Results

Electronically formatted Arabic free-texts can be found in abundance these days on the World Wide Web, often linked to commercial enterprises and/or government organizations. Vast tracts of knowledge and relations lie hidden within these texts, knowledge that can be exploited once the correct intelligent tools have been identified and applied. For example, text mining may help with text classification and categorization. Text classification aims to automatically assign text to a predefined category based on identifiable linguistic features. Such a process has different useful applications including, but not restricted to, E-Mail spam detection, web pages content filtering, and automatic message routing. In this paper an overview of King Abdulaziz City for Science and Technology (KACST) Arabic Text Classification Project will be illustrated along with some preliminary results. This project will contribute to the better understanding and elaboration of Arabic text classification techniques

Rare involvement of paranasal sinuses in sarcoidosis: case report and literature review

Sarcoidosis is a non-caseating inflammatory chronic systemic disease of unknown etiology, which may affect one or more organs. Paranasal sinuses involvement occurs sporadic in sarcoidosis. We report a patient with a medical history of sarcoidosis involving her lungs, liver, and lymphatic system for four years who now presented with nasal and sinuses symptoms. The primary treatment with local cortisone showed no improvement. Computed tomography (CT) scan of the paranasal sinuses (PNS) revealed signs of chronic pansinusitis. She was successfully treated with endoscopic sinonasal surgery. Subsequent histological analysis confirmed the involvement of the PNS with sarcoidosis. Her follow-up during the last 6 months was without recurrence

Transcriptome profile of early responsive genes in susceptible barley during Rhynchosporium secalis infection

Scald caused by Rhynchosporium secalis, is an economically important disease found worldwide. In order to profile genes and pathways responding to R. seclais infection, leaf transcriptomes before and after fungus inoculation in susceptible barley were compared using cDNA-AFLP technique. Transcriptional changes of 144 expressed sequence tags (ESTs) were observed, of which 18 have no previously described function. Functional annotation of the transcripts revealed a wide range of pathways including cell wall fortification, cytoskeleton construction and metabolic processes at different time points. Furthermore, the results of RT-PCR analysis on candidate genes, ABC transporters and lycine-specific demethylase were consistent with the cDNA-AFLP data in their expression patterns. Taken together, our data suggest that susceptible barley reprograms metabolic and biological processes to initiate a suitable response R. secalis infection

Tomorrow is Not Promised

Generations to come will hear a lot about the year 2020 and the major impacts it had on the world. 2020 affected thousands of people in many ways, including not only the loss of jobs but the loss of loved ones as well. People worked to adapt to remote workplaces and schools. Even a year later things are far from being ‘normal’. Some of us cannot even remember what normal is anymore. The mindset has always been “I’ll just do it tomorrow” but what if tomorrow never comes? One impact of the pandemic that affected many students around the country was the loss of graduation ceremonies or time of recognition. Graduating seniors had a rapid transition to online learning that tore them away from the friends, classmates, and planned senior activities. This project is a series of photographic images that show how different that experience was from what it might have been, from what seniors might have expected, from what I expected. Each image is a photo within a photo. Over the past three months I brought printed images that were taken during ‘normal’ times to many locations on campus and recreated the images in those spaces, spaces that are now very different. All of the original photos are from pre-COVID years and all of the new images were taken during COVID times. These photographs show the difference between what we used to call normal and what is our now “new normal”. I have selected 20 of these images that I feel most effectively show how the academic experience has changed for us during COVID. They provide a visual reminder of how much and how quickly expectations can change. We have seen that this past year, even until today. Photos speak a thousand words, so remember tomorrow is not promised

Studies on factors affecting the infiltration capacity of agricultural soils

Ziel der Arbeit war es, Einflussfaktoren der Infiltrationskapazität landwirtschaftlicher Böden zu identifizieren, um die „Infiltration“ als Indikator für den Schutz des Bodens gegen Degradation, z.B. Wassererosion, zu bewerten. Dazu wurden Langzeitversuche und Praxisschläge mit unterschiedlicher Landnutzung und Bewirtschaftungsform auf bodenphysikalische, bodenchemische und bodenbiologische Eigenschaften untersucht und deren Einfluss auf die Infiltrationskapazität der Böden quantifiziert. Die wichtigsten Einflussfaktoren für hohe Infiltrationsraten wurden mittels Regressionsanalyse bestimmt. Die unterschiedliche Einflussnahme der ausgewählten Parameter auf die Infiltrationskapazität wurde auf der Basis der multiplen Regressionsanalyse berechnet. Der Bodenschutzindikator "Infiltration" wurde durch abgeleitete Modell-Algorithmen angemessenen beschrieben.1 Die Untersuchung der Infiltrationsraten bei unterschiedlicher Landnutzung ergab folgende Ergebnisse:o Die Infiltrationsrate war unter forstwirtschaftlicher Nutzung am höchsten, gefolgt von der natürlichen Sukzession. Auf ackerbaulichen Flächen war sie am geringsten.o Die hohen Infiltrationsraten bei Waldböden waren das Ergebnis einer größeren Anzahl von Makroporen durch eine intensive Wurzelaktivität, die wiederum zu einem erhöhten lateralen Fluss und somit zu erhöhten Infiltrationsraten führte.o Bei der natürlichen Sukzession war besonders die verbesserte Strukturstabilität (großer Anteil stabiler Aggregate durch vermehrte organische Bodensubstanz) ausschlaggebend für erhöhte Infiltrationsraten. Zusätzlich war der Unterboden aufgrund der geringeren Trockenrohdichte weniger verdichtet. Hohe Anteile von Bioporen, die zum größten Anteil auf Regenwurmgänge zurückzuführen waren, trugen ebenfalls zu erhöhten Infiltrationsraten bei.2 Die Untersuchung der Infiltrationsrate für unterschiedliche Bewirtschaftungsformen ergab folgende Ergebnisse:o Ökologische Landwirtschaft führte zu höheren Infiltrationsraten im Vergleich zu konventioneller Landwirtschaft.o Die erhöhten Infiltrationsraten des ökologisch bewirtschafteten Feldes (Feld O3) waren im Vergleich zum konventionellen Feld (Feld C1) auf eine verbesserte mechanische Stabilität des Bodens sowie einen erhöhten Anteil von Makro- bzw. Bioporen (Bodenporen mit einem Durchmesser größer als 50 μm) durch eine hohe Regenwurmaktivität zurückzuführen. Die Regenwurmpopulation des Feldes O3 war doppelt so hoch als im Feld C1.3 Die Untersuchung der Infiltrationsrate für unterschiedliche Bodenbearbeitungssysteme ergab folgende Ergebnisse:o Die Infiltration von Wasser in den Boden war höher bei flacher im Vergleich zu tieferer Bodenbearbeitung. Zudem zeigte sich eine höhere Infiltrationsrate bei konservierender verglichen mit konventioneller Bodenbearbeitung.o Flache bzw. konservierende Bodenbearbeitung führte im Vergleich zu tiefer gepflügten Feldern zu einer höheren bodenbiologischen Aktivität, die sich durch eine erhöhte Anzahl von tief grabenden Regenwürmern (anecic species), eine erhöhte Dehydrogenaseaktivität und eine verbesserte Aggregatstabilität auszeichnet, was im Endeffekt ansteigende Infiltrationsraten garantiert.4 Die Untersuchung der Infiltrationsrate bei unterschiedlicher Düngungsstrategie ergab folgende Ergebnisse:o Die Infiltrationsrate war unter organischer (fym) und der kombinierten organischmineralischen Düngung (NPK + fym) höher als unter Einsatz von mineralischen Düngemitteln (NPK).o Organische (fym) und kombiniert organisch-mineralische Düngung (NPK + fym) resultierten in einer erhöhten Aggregatstabilität, geringerer Bodenverdichtung im Unterboden, einer höheren organischen Bodensubstanz, erhöhter Regenwurmbiomasse und insbesondere einer höheren Anzahl von tief grabenden Regenwürmern. Dieses erhöhte die Infiltrationsraten im Vergleich zu nur mineralisch gedüngten Feldern (NPK).5 Die multiple Regressionsanalyse für die wichtigsten die Wasserinfiltration in den Boden beeinflussenden Faktoren ergab folgende Ergebnisse: o Auf dem Versuchsstandort Braunschweig hatte der Kohlenstoffvorrat im Boden den größten Einfluss auf die Infiltrationsrate, gefolgt von der Trockenrohdichte und der Regenwurmabundance. Auf den Standorten Trendhorst und Mariensee hatten die Bodentextur (Schluff- und Tongehalt des Oberbodens), Trockenrohdichte des Bodens, die Regenwurmanzahl pro Tonne Kohlenstoffvorrat und die Aggregatstabilität des Oberbodens den größten Einfluss.6 Die Auswertung der Untersuchungen zur Infiltration belegte, dass die Infiltrationskapazität ein adäquates, integrales Maß für die Bewertung der Bodenqualität darstellt. Verbesserte Bodeneigenschaften garantieren einen verbesserten Schutz des Bodens gegenüber Wassererosion und erhöhen gleichzeitig die Infiltrationskapazität des Bodens. Folglich reflektiert sich in der Infiltrationskapazität das Degradationsniveau des Bodens, welches die Grundlage für Maßnahmen des Bodenschutzes darstellt.The purpose of this work was to identify factors influencing the infiltration capacity of agricultural lands in order to evaluate “infiltration” as an indicator of soil protection against degradation or water erosion. Long-term field experiments and fields on experimental farms with different land use systems and agricultural management practices were investigated for soil physical, chemical and biological characteristics and their effects on the infiltration capacity. The most important factors affecting infiltration were selected on the basis of the single regression analysis. The different impacts of the selected parameters on infiltration have been identified based on the multiple regression analysis. The soil protection indicator “infiltration” was described according to adequate model algorithms.1 The investigation of soil infiltration rate under different land use systems produced the following findings:- The infiltration rate of soil was found to be highest in the forest followed by the natural succession and lowest in the arable land.- The high infiltration rates in the forest were attributed to higher macropores resulting from the great root activity, which leads also to high lateral fluxes into the soil resulting in higher infiltration rates.- The higher infiltration rate in the natural succession was due to a higher soil structural stability produced by a higher aggregate stability, which in turn was generated by a greater soil organic matter content. In addition, the natural succession soil had less subsoil compaction and a lower bulk density, besides a higher fraction of biopores mostly produced by larger earthworm abundance, which contributed to increased soil infiltration rates.2 The investigation of soil infiltration rate under different farming systems yielded the following results:- Organic farming resulted in higher soil infiltration rates in comparison to conventional farming.- The higher infiltration rate in the organically managed field ( Field O3), as contrasted with the conventionally managed field ( Field C1), was traced back to a higher soil mechanical stability, a higher fraction of macro- or biopores (soil pores with a diameter > 50μm) related to the earthworm activity. The earthworm population in Field O3 was twice as greater than in Field C1. 3 The investigation of soil infiltration rate under different soil tillage treatments reported the following consequences:- The soil infiltration rate was found to be higher under shallow tillage as compared to deep tillage. Also, conservation tillage yielded a higher infiltration rate in comparison to conventional tillage.- Conservation tillage resulted in a higher aggregate stability, which contributed to a higher soil infiltration rate in comparison to conventional tillage.- Shallow tillage produced a higher soil biological activity indicated by a larger earthworm population, especially a greater number of deep earthworms “anecic”, and a higher dehydrogenase activity, as well as a higher soil structural stability, which promoted higher infiltration rates compared to deep tillage.4 The investigation of soil infiltration rate under different fertilization treatments revealed the following effects:- The infiltration rate was higher under the organic (fym) and the combined (NPK+fym) fertilization than under the mineral fertilization (NPK).- The organic (fym) and the combined (NPK+fym) fertilization resulted in a higher soil stability, a lower subsoil compaction, a greater organic matter content, a larger earthworm biomass and number particularly a greater number of deep “anecic” earthworms which supported higher soil infiltration rates in comparison to the mineral fertilization (NPK).5 The multiple regression analysis for the most important factors affecting the water infiltration of soil resulted in the following findings:- At the site Braunschweig, the carbon stock had the highest influences on the infiltration rate followed by the soil dry bulk density and earthworm abundance.- At the sites Trenthorst and Mariensee together, the greatest effects on the infiltration rate emerged from the soil textural classes (silt and clay content of the topsoil) followed by the soil dry bulk density and the earthworm abundance per carbon stock, as well as the aggregate stability of the topsoil.6 The evaluation of the soil infiltration measurements revealed that the infiltration capacity is an adequate integrating measure for soil quality. The improved soil properties produce a high soil protection against water erosion and simultaneously a high soil infiltration capacity. Hence, the soil infiltration capacity can reflect the level of soil degradation and subsequently it can be used as a fundamental basis for measures of soil protection.&nbsp

Modeling flow in fractured geologic media : upscaling and application to deep geothermal reservoirs

Fractures constitute major pathways for flow and transport in fractured porous rocks. These types of rocks are encountered in a wide range of applications like for example gas and petroleum engineering, CO2 sequestration and geothermal energy extraction. The present thesis presents a framework to analyze geometrical, topological and hydraulic properties of 3D planar fracture networks with focus on upscaling these properties to obtain an equivalent continuum, in view of application to simulations of geothermal reservoir exploitation. The description of fractures and discrete fracture networks (DFN), their statistical properties and their generation procedures are studied. As permeability plays a key role in flow and transport in fractured porous rocks, we have developed a fast upscaling approach for determining the equivalent permeability tensor of 3D fractured porous media. This new approach is based on the superposition principle improved by empirical connectivity factors in order to take into account the connectivity and percolation properties of the fracture network. Although efficient in predicting permeability, the proposed method presents a major limitation due mainly to the difficulty in assessing the percolation and connectivity properties of the network. To overcome these limitations and for further insightful analyses of DFN composed of planar fractures, an original framework of geometrical and topological analysis of 3D fracture networks has been developed. In this framework, all the geometrical and topological attributes (intersections, areas, trace lengths, clusters, percolating clusters, etc.) of a DFN are explicitly calculated by a set of algorithms. These algorithms are validated in detail by comparison to commercial softwares, and their computational efficiency is highlighted. The final purpose of this framework is to give a graph representation of the DFN. Given the newly developed tools, our capabilities of treating fracture networks have drastically increased. Hence, using a graph representation of the DFN, new approaches have been developed concerning two main issues with fracture networks: (i) percolation, (ii) clustering phenomenon (i.e., the formation of clusters by groups of fractures) and (iii) permeability upscaling. A large scale thermo-hydraulic simulator has therefore been developed with the finite volume open source code “OpenFoam”. The purpose is to apply the upscaling techniques to large scale reservoir configurations with a full coupling with heat transfer. A typical example of injectionproduction wells in a 3D geothermal reservoir is presented, and other cases are being developed within the GEOTREF project ( www.geotref.com )

Estimating the shadow economy in Jordan: causes, consequences, and policy implications

2011 Fall.Includes bibliographical references.Economists have been paying increasing attention to the study of the shadow economy in many developed and developing countries in recent years. This attention is due to the consequences and the policy implications related to the shadow economy. Due to the unobserved and hidden nature of the shadow economy, it is difficult to get accurate estimates of its size. However, there are some techniques that have been used by economists to indirectly estimate the size of the shadow economy. This dissertation estimates the annual size of the shadow economy in Jordan during the period 1976-2010 using two methodologies: the currency approach and the multiple indicators multiple causes (MIMIC) approach. It also analyzes the economic consequences and the policy implications of the shadow economy, estimating the amount of tax evasion in Jordan during the aforementioned time period. This is the first study that differentiates the effect of taxes on imports (custom duties) on the shadow economy from the effect of other taxes (income and sales taxes). It hypothesizes, unlike other studies, that taxes on imports negatively affect the size of the shadow economy. The currency approach results are consistent with this hypothesis. This study is also the first one to take into consideration religious factors as one of the determinants of the demand for money in circulation which is used in the currency approach to estimating the shadow economy. It is hypothesizes that the number of Islamic banks in Jordan negatively affects the demand for money in circulation. The coefficient of this variable has a negative sign, which is consistent with this hypothesis; however, this variable is insignificant at the 10 percent level. The other determinants of the demand for money in circulation in Jordan are: the effective tax rate on sales, the effective income tax rate, the effective tax rate on imports, the weighted average of interest rates on savings, and a dummy variable for the depreciation of the Jordanian dinar in 1988. According to the MIMIC approach, the causal variables for the shadow economy in Jordan are found to be: the total effective tax rate (tax revenues/GDP), the unemployment rate, the extent of government regulation (government intervention in the economy), and depreciation of the Jordanian dinar in 1988. The growth rate of real GDP and the growth rate of real private consumption are found to be indicators of the shadow economy in Jordan. The MIMIC approach results are consistent with previous studies that have found taxes and regulations to be the main causes of the shadow economy. The results also support the hypothesis that the depreciation of the Jordanian dinar in 1988 has a positive effect on the shadow economy in Jordan. The unemployment rate is found to have a negative effect on the shadow economy in Jordan. This indicates that the income effect of unemployment is greater than the substitution effect. In this dissertation, the main consequences and the policy implications of the shadow economy are analyzed. Tax evasion in Jordan is estimated for the period of study based on the results of the currency demand and the MIMIC approaches. It has been shown that the shadow economy has a distorting effect on the accuracy of a country's national accounts statistics. In addition, some policy recommendations are presented to reduce the distorting impact of the shadow economy. Taking into consideration the existence of the shadow economy when conducting the economic policy will increase the efficiency of this policy. There is a need for further research into the impact of the shadow economy on some economic policy issues in Jordan

State Estimation for Various Systems with Partially Unknown Dynamics

This thesis is on state estimation for various system and measurement models with uncertain dynamics. The uncertain dynamics may be due to imprecise system modeling or change in parameters due to varying environmental conditions. Uncertainty may be a result of malicious acts such as hacking of sensors or actuators in the system. Uncertainty may also be a result of external disturbances whose waveforms, magnitudes and arrival times may not be known. These types of model uncertainties will be considered and different estimators will be implemented to deal with such uncertainties in state estimation. In this thesis, for linear stochastic systems with additive noise, the measurements and input are available and noises statistics are known, Kalman filter is used to estimate the state. However, for nonlinear systems, Extended Kalman filter is used under the same conditions. When noise statistics are unknown, H-infinity filter is used to estimate the state of the system if the noises are assumed to be of finite energy. For identification of parameters, coefficients in transfer functions are identified by using Kalman and H-infinity filters. By using Extended Kalman and H-infinity filters, unknown parameters of the state-space model can be estimated. For parameters whose range of values is available, a bank of Kalman filters is used to find the actual values. For detection of an intrusion signal that attacks a sensor or actuator of a system, there are several methods considered in this thesis, including the sample mean method, Kalman filter method and stochastic parameter estimation method.The simulation results of the various applications of these filters will be presented and the performance of these filters will be discussed