The Study on Indexing Techniques in Data Warehouse

2010 ◽  
Vol 439-440 ◽  
pp. 1505-1510
Author(s):  
Li Chen
Keyword(s):  
Performance Evaluation ◽  
Data Warehouse ◽  
Hot Spot ◽  
Performance Evaluations ◽  
Variable Size ◽  
Indexing Techniques ◽  
Speed Up ◽  
The Impact ◽  
Time And Space Complexity ◽  
Size Data

Nowadays, data warehouse has already become the hot spot in database studies. Indexes can potentially speed up a variety of operations in a data warehouse. In this paper, we present several relatively mature index techniques in data warehouse. Then, we give a comparison between them on performance evaluations. This paper focuses on the performance evaluation of three data warehouse queries with three different indexing techniques and to observe the impact of variable size data with respect to time and space complexity.

scholarly journals Performance Appraisal in the Era of New Normal

2020 ◽  
Vol 11 (1) ◽  
pp. 11-15
Author(s):  
Nitika Kaushik Nitika ◽  
Poonam Arora
Keyword(s):  
Performance Evaluation ◽  
Severe Acute Respiratory Syndrome ◽  
Human Resource Management ◽  
Performance Assessment ◽  
Performance Appraisal ◽  
Human Resource ◽  
Performance Evaluations ◽  
New Normal ◽  
New Challenges ◽  
The Impact

Performance Appraisal is the process of assessing the accomplishments of workforce & to ac­knowledge their capabilities for facilitating development. Performance evaluation is one of the areas in Human resource management which is considerably affected by the spread of pandemic severe acute respiratory syndrome corona virus 2. This virus outbreak posed new challenges for the companies across the globe. As a result in order to tackle this uncertainty various organiza­tions have taken measures to cut down the expenses like deferment in the appraisal cycle or for muted salary increments. Thus one of the objectives of this paper is to study the impact of Covid -19 on performance appraisal of employees. Further this pandemic is equally challenging for the managers also. As social distancing and working remotely have become a new normal, employees work remotely from each other and from managers, and this will be more common in the fu­ture. Managers are now searching for new ways to ‘do visibility’ without always being physically present. It has also become the vital demand of the situation as managers must be aware of the circumstances in which employees are working in. Therefore another objective of this paper is to suggest an approach to manage the performance evaluations of remote working employees. It is recommended that managers should adopt the choice based approach for performance evaluation instead of control based approach. The review is formed on articles and reports from various internet sources and journals. Further some ways of managing the performance assessment of remotely working employees and scope for the future are also discussed.

scholarly journals Commentary on Kopiez, Wolf, and Platz: The impact of playing from memory on performance evaluation

2017 ◽  
Vol 12 (1-2) ◽  
pp. 15
Author(s):  
Bruno Gingras
Keyword(s):  
Performance Evaluation ◽  
Experimental Design ◽  
Performance Evaluations ◽  
Future Research ◽  
Distractor Effect ◽  
Visual Distractor ◽  
Significant Negative Effect ◽  
Negative Effect ◽  
The Impact

Kopiez et al. (this volume) empirically investigated the effect of playing from memory (more specifically, playing with a conspicuously visible music stand) on the evaluation of audiovisual recordings of solo instrumental performances. Their study, a replication of Williamon (1999), corroborates the finding that the presence of a music stand has a small but significant negative effect on performance evaluations. In this commentary, I present some possible explanations for this effect and discuss relevant implications for future research and for professional performers. I also provide some suggestions for improving the experimental design, such as using a better measure of musical sophistication, controlling for the potential visual distractor effect of the music stand, and developing a more comprehensive and statistically robust scale for evaluating performances.

Comprehensive Income: which potential effects on firms' performance evaluation and users' decision process?

2016 ◽  
pp. 55-94
Author(s):  
Pier Luigi Marchini ◽  
Carlotta D'Este
Keyword(s):  
Performance Evaluation ◽  
Decision Process ◽  
Financial Analysts ◽  
Listed Companies ◽  
Financial Statement ◽  
Comprehensive Income ◽  
Other Comprehensive Income ◽  
Gains And Losses ◽  
The Impact

The reporting of comprehensive income is becoming increasingly important. After the introduction of Other Comprehensive Income (OCI) reporting, as required by the 2007 IAS 1-revised, the IASB is currently seeking inputs from investors on the usefulness of unrealized gains and losses and on the role of comprehensive income. This circumstance is of particular relevance in code law countries, as local pre-IFRS accounting models influence financial statement preparers and users. This study aims at investigating the role played by unrealized gains and losses reporting on users' decision process, by examining the impact of OCI on the Italian listed companies RoE ratio and by surveying a sample of financial analysts, also content analysing their formal reports. The results show that the reporting of comprehensive income does not affect the financial statement users' decision process, although it statistically affects Italian listed entities' performance.

scholarly journals Power Hardware-in-the-Loop-Based Performance Analysis of Different Converter Controllers for Fast Active Power Regulation in Low-Inertia Power Systems

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3274
Author(s):  
Jose Rueda Torres ◽  
Zameer Ahmad ◽  
Nidarshan Veera Kumar ◽  
Elyas Rakhshani ◽  
Ebrahim Adabi ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Power Systems ◽  
Real Time ◽  
Control Strategies ◽  
Active Power ◽  
Power Electronic ◽  
Hardware In The Loop ◽  
Digital Controllers ◽  
Power Regulation ◽  
The Impact

Future electrical power systems will be dominated by power electronic converters, which are deployed for the integration of renewable power plants, responsive demand, and different types of storage systems. The stability of such systems will strongly depend on the control strategies attached to the converters. In this context, laboratory-scale setups are becoming the key tools for prototyping and evaluating the performance and robustness of different converter technologies and control strategies. The performance evaluation of control strategies for dynamic frequency support using fast active power regulation (FAPR) requires the urgent development of a suitable power hardware-in-the-loop (PHIL) setup. In this paper, the most prominent emerging types of FAPR are selected and studied: droop-based FAPR, droop derivative-based FAPR, and virtual synchronous power (VSP)-based FAPR. A novel setup for PHIL-based performance evaluation of these strategies is proposed. The setup combines the advanced modeling and simulation functions of a real-time digital simulation platform (RTDS), an external programmable unit to implement the studied FAPR control strategies as digital controllers, and actual hardware. The hardware setup consists of a grid emulator to recreate the dynamic response as seen from the interface bus of the grid side converter of a power electronic-interfaced device (e.g., type-IV wind turbines), and a mockup voltage source converter (VSC, i.e., a device under test (DUT)). The DUT is virtually interfaced to one high-voltage bus of the electromagnetic transient (EMT) representation of a variant of the IEEE 9 bus test system, which has been modified to consider an operating condition with 52% of the total supply provided by wind power generation. The selected and programmed FAPR strategies are applied to the DUT, with the ultimate goal of ascertaining its feasibility and effectiveness with respect to the pure software-based EMT representation performed in real time. Particularly, the time-varying response of the active power injection by each FAPR control strategy and the impact on the instantaneous frequency excursions occurring in the frequency containment periods are analyzed. The performed tests show the degree of improvements on both the rate-of-change-of-frequency (RoCoF) and the maximum frequency excursion (e.g., nadir).

scholarly journals The malaria burden of Amerindian groups of three Venezuelan states: a descriptive study based on programmatic data

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Juan C. Gabaldón-Figueira ◽  
Carlos Chaccour ◽  
Jorge Moreno ◽  
Maria Villegas ◽  
Leopoldo Villegas
Keyword(s):  
Risk Factors ◽  
Plasmodium Falciparum ◽  
Malaria Incidence ◽  
Hot Spot ◽  
Public Health Problem ◽  
Epidemiological Data ◽  
Descriptive Study ◽  
Malaria Burden ◽  
Indigenous Groups ◽  
The Impact

Abstract Background Fifty-three percent of all cases of malaria in the Americas in 2019 came from Venezuela, where the epidemic is heavily focused south of the Orinoco river, and where most of the country’s Amerindian groups live. Although the disease is known to represent a significant public health problem among these populations, little epidemiological data exists on the subject. This study aims to provide information on malaria incidence, geospatial clustering, and risk factors associated to Plasmodium falciparum infection among these groups. Methods This is a descriptive study based on the analysis of published and unpublished programmatic data collected by Venezuelan health authorities and non-government organizations between 2014 and 2018. The Annual Parasite Index among indigenous groups (API-i) in municipalities of three states (Amazonas, Bolivar, and Sucre) were calculated and compared using the Kruskal Wallis test, risk factors for Plasmodium falciparum infection were identified via binomial logistic regression and maps were constructed to identify clusters of malaria cases among indigenous patients via Moran’s I and Getis-Ord’s hot spot analysis. Results 116,097 cases of malaria in Amerindian groups were registered during the study period. An increasing trend was observed between 2014 and 2016 but reverted in 2018. Malaria incidence remains higher than in 2014 and hot spots were identified in the three states, although more importantly in the south of Bolivar. Most cases (73.3%) were caused by Plasmodium vivax, but the Hoti, Yanomami, and Eñepa indigenous groups presented higher odds for infection with Plasmodium falciparum. Conclusion Malaria cases among Amerindian populations increased between 2014 and 2018 and seem to have a different geographic distribution than those among the general population. These findings suggest that tailored interventions will be necessary to curb the impact of malaria transmission in these groups.

scholarly journals Impact of COVID-19 pandemic lockdown on myocardial infarction care

2021 ◽  
Author(s):  
Timo Schmitz ◽  
Christa Meisinger ◽  
Inge Kirchberger ◽  
Christian Thilo ◽  
Ute Amann ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Hot Spot ◽  
Population Based ◽  
Downward Trend ◽  
German Model ◽  
Model Region ◽  
The Impact ◽  
The City

AbstractThe aim of this study was to evaluate the impact of the COVID-19 pandemic lockdown on acute myocardial infarction (AMI) care, and to identify underlying stressors in the German model region for complete AMI registration. The analysis was based on data from the population-based KORA Myocardial Infarction Registry located in the region of Augsburg, Germany. All cases of AMI (n = 210) admitted to one of four hospitals in the city of Augsburg or the county of Augsburg from February 10th, 2020, to May 19, 2020, were included. Patients were divided into three groups, namely pre-lockdown, strict lockdown, and attenuated lockdown period. An additional survey was conducted asking the patients for stress and fears in the 4 weeks prior to their AMI. The AMI rate declined by 44% in the strict lockdown period; in the attenuated lockdown period the rate was 17% lower compared to the pre-lockdown period. The downward trend in AMI rates during lockdown was seen in STEMI and NSTEMI patients, and independent of sex and age. The door-to-device time decreased by 70–80% in the lockdown-periods. In the time prior to the infarction, patients felt stressed mainly due to fear of infection with Sars-CoV-2 and less because of the restrictions and consequences of the lockdown. A strict lockdown due to the Covid-19 pandemic had a marked impact on AMI care even in a non-hot-spot region with relatively few cases of COVID-19. Fear of infection with the virus is presumably the main reason for the drop in hospitalizations due to AMI.

scholarly journals Applying Harmonised Geothermal Life Cycle Assessment Guidelines to the Rittershoffen Geothermal Heat Plant

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3820
Author(s):  
Mélanie Douziech ◽  
Lorenzo Tosti ◽  
Nicola Ferrara ◽  
Maria Laura Parisi ◽  
Paula Pérez-López ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Heat Production ◽  
Hot Spot ◽  
Resource Depletion ◽  
Potential Contribution ◽  
Geothermal Systems ◽  
Geothermal Heat ◽  
The Future ◽  
The Impact

Heat production from a geothermal energy source is gaining increasing attention due to its potential contribution to the decarbonization of the European energy sector. Obtaining representative results of the environmental performances of geothermal systems and comparing them with other renewables is of utmost importance in order to ensure an effective energy transition as targeted by Europe. This work presents the outputs of a Life Cycle Assessment (LCA) performed on the Rittershoffen geothermal heat plant applying guidelines that were developed within the H2020 GEOENVI project. The production of 1 kWhth from the Rittershoffen heat plant was compared to the heat produced from natural gas in Europe. Geothermal heat production performed better than the average heat production in climate change and resource use, fossil categories. The LCA identified the electricity consumption during the operation and maintenance phase as a hot spot for several impact categories. A prospective scenario analysis was therefore performed to assess the evolution of the environmental performances of the Rittershoffen heat plant associated with the future French electricity mixes. The increase of renewable energy shares in the future French electricity mix caused the impact on specific categories (e.g., land use and mineral and metals resource depletion) to grow over the years. However, an overall reduction of the environmental impacts of the Rittershoffen heat plant was observed.

Human Performance Evaluation of a Metaphor Graphic Display for Respiratory Data

1994 ◽  
Vol 33 (04) ◽  
pp. 390-396 ◽  
Author(s):  
J. G. Stewart ◽  
W. G. Cole
Keyword(s):  
Performance Evaluation ◽  
Human Performance ◽  
Pattern Detection ◽  
Data Sets ◽  
Complex Task ◽  
Graphic Display ◽  
Literal Sense ◽  
Single Number ◽  
The Impact ◽  
Human Problem

Abstract:Metaphor graphics are data displays designed to look like corresponding variables in the real world, but in a non-literal sense of “look like”. Evaluation of the impact of these graphics on human problem solving has twice been carried out, but with conflicting results. The present experiment attempted to clarify the discrepancies between these findings by using a complex task in which expert subjects interpreted respiratory data. The metaphor graphic display led to interpretations twice as fast as a tabular (flowsheet) format, suggesting that conflict between earlier studies is due either to differences in training or to differences in goodness of metaphor, Findings to date indicate that metaphor graphics work with complex as well as simple data sets, pattern detection as well as single number reporting tasks, and with expert as well as novice subjects.

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