Causes Of Performance Differences Research Articles

Relationship between Government and Community, Mobilization Ability, and Organizational Performance: Comparative Case Analysis Based on Community Elderly Care Service Institutions

This study explores the reason why community service organizations with different operating modes in similar institutional environments have significant differences in their operational performance when providing the same services. Through comparative case analysis, this paper puts forward the analysis framework of government-community relationship, mobilization ability, and organizational performance to reveal the internal process of organizational operation and the root cause of performance differences. The findings are as follows. The relationship between the government and the community is the key variable to understanding the operation logic of community service organizations. The interaction between government and community is particularly key to the operation and development of the organization, and the different interaction between government and community is the root cause of the difference in the operation performance of the organization. The operational performance of community service organizations is based on the organization’s resource mobilization and organizational mobilization capacity and scope, whereby the two mobilization capabilities are related to the relationship between the government and the community. The research conclusion provides a new explanation for understanding the operational performance of organizations and can also be a reference for optimizing the operation of social organizations.

Study on the thrust fluctuation and vortices of a pump-jet propulsor under different duct parameters

Improving underwater propulsor performance is endlessly pursued, not only the propulsion but the vibration and radiated noise. The latter is highly related to the unsteady characteristics of forces and flow. This paper investigates the effects of duct parameters on the thrust fluctuation and flow features of a pre-swirl stator pump-jet propulsor (PJP) via embedded large eddy simulation (ELES). The duct parameters include inclination angle, tip clearance, axial length, maximum thickness, and diameters of duct inlet and duct outlet. The numerical approach is verified with experiments, showing good precision. The performance is first discussed, followed by the thrust fluctuation analysis to reveal the varying law of the thrust fluctuation level with duct parameters. Then, the velocity and pressure around the duct are presented to inspect the causes of differences in performance and thrust fluctuation. Finally, the vortices in the flow field are identified and considered the vortex evolution of the tip clearance vortex for inspecting the instability mechanism under different ducts. Results show that the duct parameters significantly affect the performance and thrust fluctuation. The instability mechanism of the tip clearance vortex also presents notable differences. Overall, the study should be helpful in the duct design and reduce thrust fluctuation, and will eventually benefit low-noise pump-jet design.

Plant effects on and response to soil microbes in native and non-native Phragmites australis.

Plant-soil feedbacks (PSFs) mediate plant community dynamics and may plausibly facilitate plant invasions. Microbially mediated PSFs are defined by plant effects on soil microbes and subsequent changes in plant performance (responses), both positive and negative. For microbial interactions to benefit invasive plants disproportionately, native and invasive plants must either (1) have different effects on and responses to soil microbial communities or (2) only respond differently to similar microbial communities. In other words, invasive plants do not need to cultivate different microbial communities than natives if they respond differently to them. However, effects and responses are not often explored separately, making it difficult to determine the underlying causes of performance differences. We performed a reciprocal-transplant PSF experiment with multiple microbial inhibition treatments to determine how native and non-native lineages of Phragmites australis affect and respond to soil bacteria, fungi, and oomycetes. Non-native Phragmites is a large, fast-growing, cosmopolitan invasive plant, whereas the North American native variety is comparatively smaller, slower growing, and typically considered a desirable wetland plant. We identified the effects of each plant lineage on soil microbes using DNA meta-barcoding and linked plant responses to microbial communities. Both Phragmites lineages displayed equally weak, insignificant PSFs. We found evidence of slight differential effects on microbial community composition, but no significant differential plant responses. Soils conditioned by each lineage differed only slightly in bacterial community composition, but not in fungal composition. Additionally, native and non-native Phragmites lineages did not significantly differ in their response to similar soil microbial communities. Neither lineage appreciably differed when plant biomass was compared between those grown in sterile and live soils. Targeted microbial inhibitor treatments revealed both lineages were negatively impacted by soil bacteria, but the negative response was stronger in non-native Phragmites. These observations were opposite of expectations from invasion theory and imply that the success of non-native Phragmites, relative to the native lineage, does not result from its interaction with soil microorganisms. More broadly, quantifying plant effects on, and responses to soil microbes separately provides detailed and nuanced insight into plant-microbial interactions and their role in invasions, which could inform management outcomes for invasive plants.

Enhanced Fe2O3/Al2O3 Oxygen Carriers for Chemical Looping Steam Reforming of Methane with Different Mg Ratios

Fe2O3/Al2O3 oxygen carriers improved with Mg addition were used for the chemical looping steam reforming of methane (CLSR) in a lab-scale fluidized bed reactor. The oxygen carrier with a (Mg+Fe)/Al molar ratio of 0.5 exhibited the most promising reactivity and stability as CO selectivity, CH4 conversion, H2/CO, and H2 yield remained at 96%, 82%, around 2, and 0.75 mmol/g oxygen carrier, respectively, after the 15th cycle, and only the Mg–Fe–Al–O spinel appeared after 50 cycles. According to characterization, the Mg–Fe–Al interaction was the root cause of performance differences. With the increase of the Mg/Al ratio, the reacted oxygen carriers possessed a decreased Fe2+/Fe3+ and exhibited better lattice oxygen activity, but depressed the CH4 conversion and CO selectivity during the CH4 reduction stage. The oxygen carrier with low-lattice-oxygen activity followed the indirect mechanism with C as the intermediate product, leading to high CH4 conversion and CO selectivity.

Moderating Effects of Individual Differences in Causality Orientation on Relationships between Reward, Choice, and Intrinsic Motivation

This study examines the effects of external environmental factors, specifically monetary reward and choice, on intrinsic motivation, and tests whether they are moderated by individual differences in causality orientation. We randomly assigned 103 undergraduates to one of four conditions: reward (reward vs. no reward) × choice (choice vs. no choice). Participants were given puzzles to solve in the experimenters' presence, which they were free to continue tackling when the experimenters left the room. We measured the time spent solving puzzles when free to choose other activities, task enjoyment, and perceived competence as dependent variables. Interest in puzzles was unaffected by receiving a reward in participants with high autonomy orientation but dropped significantly in participants with low autonomy orientation. Choice over the task increased competence in participants with high autonomy orientation but lowered competence in low autonomy orientation. Finally, we found no significant effects on time spent on puzzles. The present study contributes to current literature regarding the causes of differences in performance in various achievement settings.

Performance Analysis of Edge Computing in IoT

Upcoming 5G technology and the demand for near real-time response services raise the need for optimizing current IoT solutions. The aim of this paper is to model and execute the performance analysis of network structures suitable for Edge Computing in IoT. The prior research into different topology and parameter sets have not provided sufficient clarity, on which parameters had a considerable impact on overall system performance; therefore, repetitive simulations were performed to express dispersion of alternating values, as well as determining its confidence intervals. The paper presents Edge Computing service simulation setup on known and newly derived network topologies with different complexity varying network bandwidth and network delay parameters. The experimental investigation has revealed that the IoT configuration network is more sensitive to network topology, while the Internet configuration is more sensitive to network parameters. The discussion on the results received debates possible causes of performance differences in network parameters and device configurations, the comparison to similar state-of-the-art research results has also been presented. Finally, conclusions with recommendations based on the results acquired have been provided.

Benchmarking sustainability of urban water infrastructure systems in China

The broad scope and definition of sustainability has perplexed assessment of water infrastructure systems, especially for the purpose of directing engineering practices when quantified criteria are desired. An input-oriented data envelopment analysis (DEA) was improved to benchmark the relative sustainability of the water infrastructure of 157 cities in China. The DEA calculates a single sustainability score using seven inputs and five outputs that represent the economic, resource and environmental dimensions of sustainability. Overall, 69 out of the 157 sampled systems obtained high sustainability scores. Eight specific efficiency indicators based on individual DEA input to output ratio were evaluated to identify the causes of performance differences. Compared to water supply systems, the performance of wastewater treatment plants has greater influence on the sustainability score of the overall system. For all systems, the sustainability scores are more sensitive to sludge production and electricity consumption than capital investment and removal efficiency of treatment processes. The DEA provides guidelines to cities for setting priorities in order to meet specific sustainability criteria. Statistical analysis indicates that the overall sustainability score primarily depends on the system scale, meteorological conditions such as air temperature and rainfall, and source water quality.

Malleability in educational effectiveness: what are realistic expectations about effect sizes? Introduction to the special issue

ABSTRACTEducational effectiveness research separates hypothetical causes of performance differences into “given”, “contextual”, “endogenous”, or simply “prior” conditions, on the one hand, and malleable factors, or treatments, on the other hand. Recent studies indicate that the effects of background conditions tend to be bigger, and those of malleable variables and interventions smaller, than usually expected. These findings give reason to pose “limited malleability” as the central hypothesis of the special issue. This hypothesis is addressed in the 5 articles that make up this special issue. The themes addressed in these articles are respectively: optimizing the choice of adjustment variables, the development of a nomological network of educational achievement at country level, the stability of system-level educational performance, modelling approaches to the estimation of size, stability, and consistency of school effects, and treatment effects in schooling. The final article makes up the balance on the “limited malleability” thesis and discusses implications for educational policy and practice.

An Investigation into Capacitive Performances and Impedance Contributions Due to Structural Differences of Biochar Thin Film and Monolith Supercapacitor Electrodes

Supercapacitors are an upcoming, high power density energy storage technology. Unlike in batteries, energy is stored physically through the adsorption of oppositely charged ions to a surface. Electrode materials that facilitate this process have high conductivity, extensive porosity, and high specific surface area. Porous carbon powders are used commercially, being pressed into thin films and held together with a binder material [1]. While carbon nanotubes and graphene are the focus of many researchers in this field, our group is investigating a unique alternative: biochar. Biochar is pyrolyzed biomass, and our group uses different types of wood as precursor materials. Through a controlled pyrolysis process, it is possible to preserve the internal macrostructures of wood, creating pathways throughout the carbon structure that should facilitate ion transport. By creating large, continuous monolithic pieces of carbon, devices can be constructed differently from the status quo. Using monolithic slices as electrodes simplifies the manufacturing process, reduces the number of ancillary components required per device, eliminates the need for a non-conductive binder material, and enables the construction of larger electrodes. Currently there is a lack of understanding regarding the relationships between biochar macrostructures and capacitive performance. While monolithic biochar electrodes were found to show similar capacitive performance to their thin film counterparts in [2], the study did not include an evaluation from a structural point of view. Additionally, although it was found that increasing electrode thickness of thin films resulted in an increase in device resistance [3], this relationship has not been explored for monolithic electrodes nor at a relevant scale, as it becomes possible to make electrodes hundreds of times thicker than those currently used [1]. Competitive capacitive performance of powdered biochar thin film electrodes compared to thin film alternatives has been demonstrated in [4] and [5]. The overall goal of this project is to determine if monolithic biochar electrodes can compete with the capacitive performance of powdered biochar thin film electrodes. By constructing monolithic slices and powdered thin films from the same biochar, electrochemical influences of the macrostructure are investigated. Capacitive performance metrics such as charge/discharge rate capability and self-discharge rates are explored for the two electrode structures, as well as for different electrode thicknesses. Frequency-dependent resistances and their respective contributions to total device resistance are analyzed through Electrical Impedance Spectroscopy (EIS). Mass transfer and diffusional resistances, which are believed to be highly dependent on both electrode geometry and structure will be reported. Characterization of the electrode materials using N2 and CO2 physisorption; helium pycnometry; and SEM imaging coincides with the electrochemical testing methods to help resolve the causes of performance differences and evaluate their significance. Preliminary results show that monolithic biochar electrodes up to 1mm thick have comparable specific capacitance performance to the thin films at 100mA/g, which was the highest current density employed thus far. Upcoming work will apply larger current densities to determine if the channels of the macrostructures contribute to high power performance or reduce volumetric capacitance. Monolithic electrodes up to 5mm thick are able to achieve similar specific capacitances to the thin films at a low current density (5mA/g), but their performance degrades significantly with charge rate. The experiments mentioned in the preceding paragraphs were all conducted on biochar from sugar maple wood. Research direction for early 2017 will involve analysis on biochar from different types of precursor wood. Soft and hard woods, and the variety of species within these categories have vastly different types and sizes of internal structures (Figure) [6]. The effects of these macrostructures on capacitive performance and ion transport will be assessed, and these results will be available for presentation.

Enhancing the Reliability of Performance Measures in Empirical Based Research: Leverage Ratios and Theoretical Based Research

As well as incorporating and exploring the role of formal analytical methods as a means of highlighting and discovering foundational and fundamental strategy issues, such as the determinants/causes of performance differences between banking institutions and other corporate structures across various jurisdictions, this paper aims to contribute to the literature on how limitations of empirical based research can be mitigated. Such causes of performance differences will incorporate a consideration of what these determinants are, how they operate, how performance should be measured, the extent to which such differences persist, the extent to which such performance measures should be relied upon. Performance measures to be incorporated in this paper will focus primarily on firm performance measures, such as leverage ratios, as well as a brief discussion of macro-economic indicators. From this perspective, the rise of macroeconomics, micro economic inefficiency debates - as well as the validity of such debates will be considered. In its aim to accentuate why many doubts have arisen as regards the reliability of the Basel III Leverage Ratio as a performance measure, and principally in respect of calibration issues, this paper will also provide an analysis of the recent updates which have taken place in respect of the Basel III Leverage Ratio and the Basel III Supplementary Leverage Ratio – both in respect of recent amendments introduced by the Basel Committee and proposals introduced in several jurisdictions such as the United Kingdom and the United States. The paper will also aim to highlight the role of enforcement and the enforceability of rules, ratios and standards, in ensuring that more comparable, consistent, objective and ultimately reliable performance measures are generated.

Enhancing Firm Competitiveness through Concurrent Implementation of TQM, JIT and TPM

As a continuation of the previous paper by the author for this conference, this article provides empirical evidence for the impact of concurrent implementation of TQM, JIT and TPM in enhancing company performance, and hence its competitiveness. In doing this, ingredients of World Class Manufacturing company performance are reviewed, hypotheses and research methodology are developed, and data are analysed to verify the hypotheses. It is confirmed that plants implementing TQM, JIT and TPM concurrently outperform those, which implement only one or two of the methods, and there is no difference in performance among plants using either one or two of the methods. Further investigation on the causes of difference in performance reveals that, in addition to simultaneous implementation of the three methods, the establishment of performance targets leads to better performance. However, there is insufficient evidence to claim that involving employees in target setting has an effect on performance.

Incomplete Desorption of Liquid Excipients Reduces the in Vitro and in Vivo Performance of Self-Emulsifying Drug Delivery Systems Solidified by Adsorption onto an Inorganic Mesoporous Carrier

The purpose of the current study was to provide a mechanistic basis for in vitro and in vivo performance differences between lipid-based formulations solidified by adsorption onto a high surface area material and their respective liquid (i.e., nonadsorbed) counterparts. Two self-emulsifying formulations (based on either medium-chain or long-chain lipids) of the poorly water-soluble drug danazol were solidified by adsorption onto Neusilin US2. Liquid and adsorbed lipid-based formulations were subjected to in vitro dispersion-digestion tests, and additional in vitro experiments were performed to elucidate the cause of performance differences. The bioavailability of danazol after oral administration to rats was also assessed. The percentage of the dose solubilized in the aqueous phase during in vitro dispersion-digesting was ∼35% lower for the adsorbed formulations when compared to their liquid counterparts. This trend was also reflected in vivo, where the bioavailability of danazol after administration of the adsorbed formulations was ∼50% lower than that obtained after administration of the equivalent liquid formulation. Incomplete desorption of the microemulsion preconcentrate from the carrier on dispersion-digestion was identified as the main contributor to the reduced pharmaceutical performance of the adsorbed formulations. The results of the current study indicate that solidification of lipid-based formulations through adsorption onto a high surface area carrier may limit formulation (and drug) release in vivo and thereby reduce oral bioavailability.

Four-well comparison in Papua New Guinea: high-risk, high-angle wells demonstrate extended wellbore stability and faster drilling time with inhibitive high-performance water-based fluid

A four-well project located onshore Papua New Guinea provided an opportunity to compare the performance of two inhibitive drilling fluids in the problematic 12¼” interval. Wells A and B were drilled using a conventional KCl/glycol fluid. Wells C and D used a high-performance water-based fluid (HPWBF) containing a shale inhibitor that also provides lubricity. All four wells were drilled with the same rig. The base brine for both fluids was KCl. All hole sections were directionally drilled from vertical to near horizontal by section TD through a claystone interval. Tectonic wellbore breakout was present in all four wells, and the position of the breakout in the wellbore varied from well to well. Well A was regarded as the easiest well to drill due to the breakout being on the sides on the inclined well bore (horizontal), and Well D was regarded as being the most difficult well to drill due to the breakout being located directly on the top and bottom of the wellbore (vertical). Performance comparisons were made using on bottom rates of penetration, tripping times, casing running times, and overall hole section costs. These data have been normalised to remove non hole related NPT events. The KCl/glycol system provided sufficient wellbore stability in Wells A and B with horizontal breakouts and with non-optimal breakouts with very limited openhole exposure. For higher risk wells C and D with non-optimal breakout positions however, the HPWBF offered improved reliability and ensured there was no performance decline. Outstanding performance occurred in Well D where the HPWBF maintained good wellbore stability over a 56-day exposure. Although the KCl/glycol fluid had a lower cost/bbl, improved overall cost savings were achieved by using the HPWBF in the high-risk wells. This paper addresses all operations performed while drilling and casing the 12¼” interval. Possible causes for performance differences are evaluated, taking into account that mud systems represent only one variable. As other variables were introduced progressively, it was possible to back these out to determine mud system effectiveness.

Investigation of Effects of Testing Methods on Characterization of Asphalt Concrete

Abstract A variety of testing methods are employed by researchers to characterize the fatigue performance of asphalt concrete. These testing methods need to be evaluated based on their performance to characterize the fundamental properties and field performance of mixtures. In this study, the indirect tensile tests and the uniaxial tests were investigated. The indirect tensile creep tests and the uniaxial tensile creep tests were performed on a North Carolina mix to study the characterization of the fundamental properties and on WesTrack mixes to study the characterization of field performance. It was found that that the values of creep compliance from the indirect tensile creep and the unaxial tensile creep tests on North Carolina mix cannot be compared favorably. Fracture energies from the indirect tensile strength tests on WesTrack mixes highly correlate with the field performances, while those from uniaxial direct tension tests did not match field performances. It is believed that anisotropicity could be the cause of differences in performance of the two test methods. It is disconcerting when researchers attempt to establish a constitutive relationship between the property parameters of mixtures and laboratory fatigue life using different testing methods, without knowing if the laboratory fatigue life from these testing methods really reflects field performance. Further research is needed to obtain a better understanding of different testing methods.

Performance analysis of five interprocess communication mechanisms across UNIX operating systems

The availability of a variety of UNIX implementations necessitates the evaluation of their performance with respect to specific application characteristics. This paper concentrates on the performance evaluation of five different Interprocess Communication (IPC) mechanisms––pipes, FIFOs, messages, shared memory (with semaphores), and UNIX domain sockets. Benchmark programs were created for each mechanism, simulating a simple Producer/Consumer message transfer problem. Results were obtained for six UNIX releases––Linux 2.2.5-15, Linux 2.2.17, Linux 2.4.0-test9, RTLinux v2.3, FreeBSD 4.1, and FreeBSD 4.2. The UNIX source code was rigorously examined, and additional tests were created to determine implementation differences that would explain performance variations. Identified causes for performance differences include memory allocation schemes, transfer buffer sizes, data transfer mechanisms, locking mechanism implementations, and underlying code complexity. For all IPC mechanisms with the exception of shared memory, Linux 2.2.5-15 exhibited the best performance, followed by the remaining Linux kernels, with the FreeBSD releases finishing last. When compared against each other, pipes outperformed the other mechanisms. The developed benchmarks and ancillary tests attempt to isolate each aspect of the tested IPC mechanisms to facilitate a full understanding of IPC at the source code level.

La place du capital social comme facteur explicatif des différences de performance des conseils régionaux de déaveloppement du Québec

Abstract: This work presents the results of an empirical study on the regional institutions set up in Quebec in 1991, when a new regional development strategy was adopted. The purpose of the study was to measure and compare the relative performance of the regional development boards and to assess the role of the regional social capital as a factor that could explain the discrepancies found. The performance was assessed on the basis of eighteen indicators using quantitative and qualitative data. The results were collated into a single performance indicator; depending on the region, the performance ranged from merely fair to good. In order to determine the underlying causes of differences in performance, seven hypotheses based on sociological theory were tested. Only the social capital hypothesis was confirmed, as it accounted for nearly fifty‐eight per cent of the performance variation. Moreover, the analysis raised a number of issues pertaining to social capital.

High Reynolds Number, Multielement Airfoil Flowfield Measurements

A unique set of high Reynolds number experimental results are presented that illustrate some of the crucial e ow physics issues controlling the aerodynamic performance characteristics of transport-aircraft-type high-lift geometries. Data include static-pressure distributions, lift and drag measurements, and boundary-layer and wake surveys. Results presented provide important insights into the underlying causes of differences in performance associated with various geometry modie cations. The two most signie cant and instructive examples involve the effects of a relatively small e ap gap change at a e xed e ap dee ection and the effects of an increase in e ap dee ection. For the former, decreasing the e ap gap eliminates an observed e ow separation on the e ap at (lower) approach angles of attack, but also results in a reduction in maximum lift caused by enhanced merging and spreading of the wakes above the e ap. For the latter, it is observed that the wake spreading is increased substantially at the higher e ap dee ection, thereby minimizing improvement in maximum lift. These data have been used for computational e uid dynamics (CFD) code calibration and should provide a means to identify the shortcomings of existing CFD methods, thereby identifying areas where improvements are required.

Profit, productivity, and price differential: an international performance comparison of the natural gas transportation industry

The objective of this paper is to evaluate the performance of natural gas transportation utilities, focusing on the three-key strategic performance measures of profit, productivity, and price differential. We propose a methodology that expresses the three performance measures in a unified single equation using the Edgeworth index. The proposed methodology is applied to an international comparison of the performance of 28 natural gas transportation utilities operating in eight countries in which the business environments differ greatly. The empirical results show the possible causes of performance differences and may shed some light on the direction of regulatory policy, especially for developing countries that have relatively short histories in the natural gas industry, such as Korea.

Analysis of a coal fired combined cycle with carried-heat gasification

In the research of a more efficient, less costly, more environmentally responsible and less technically difficult method for generating electrical power from coal, the Carried-heat Gasification Combined Cycle (CGCC) is introduced by Tsinghua University. The high efficiency cycle includes carried-heat partial gasification, compressed air heating in a fluidized bed immersed air heater followed by a combustor and the heat recovery of gas turbine exhaust used as the combustion air for the differential-velocity atmospheric circulating fluidized bed (DFBC). Superheat steam is raised in the DFBC boiler. The comparison of results identifies the causes of performance difference between eight cases. Features of the cycle ensure a high coal conversion efficiency within current state of the art.

Exergetic Comparison of Two KRW-Based IGCC Power Plants

In studies supported by the U.S. Department of Energy and the Electric Power Research Institute, several design configurations of Kellogg-Rust-Westinghouse (KRW)-based Integrated Gasification-Combined-Cycle (IGCC) power plants were developed. Two of these configurations are compared here from the exergetic viewpoint. The first design configuration (case 1) uses an air-blown KRW gasifier and hot gas cleanup while the second configuration (reference case) uses an oxygen-blown KRW gasifier and cold gas cleanup. Each case uses two General Electric MS7001F advanced combustion turbines. The exergetic comparison identifies the causes of performance difference between the two cases: differences in the exergy destruction of the gasification system, the gas turbine system, and the gas cooling process, as well as differences in the exergy loss accompanying the solids to disposal stream. The potential for using (a) oxygen-blown versus air-blown-KRW gasifiers, and (b) hot gas versus cold gas cleanup processes was evaluated. The results indicate that, among the available options, an oxygen-blown KRW gasifier using in-bed desulfurization combined with an optimized hot gas cleanup process has the largest potential for providing performance improvements.