Quantile Judgments of Lognormal Losses: An Experimental Investigation

The present study aims to investigate the quality of quantile judgments on a quantity of interest that follows the lognormal distribution, which is skewed and bounded from below with a long right tail. We conduct controlled experiments in which subjects predict the losses from a future typhoon based on losses from past typhoons. Our experiments find underconfidence of the 50% prediction intervals, which is primarily driven by overestimation of the 75th percentiles. We further perform exploratory analyses to disentangle sampling errors and judgmental biases in the overall miscalibration. Finally, we show that the correlations of log-transformed judgments between subjects are smaller than is justified by the information overlapping structure. It leads to overconfident aggregate predictions using the Bayes rule if we treat the low correlations as an indicator for independent information.

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Fuzzy Evaluation Model of Process Improvement Capability with Costs Consideration

Applied Sciences ◽

10.3390/app11104344 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4344

Author(s):

Kuen-Suan Chen ◽

Shui-Chuan Chen ◽

Ting-Hsin Hsu ◽

Min-Yi Lin ◽

Chih-Feng Wu

Keyword(s):

Process Improvement ◽

Quality Evaluation ◽

Evaluation Model ◽

Fuzzy Evaluation ◽

Sampling Errors ◽

Capability Index ◽

Testing Method ◽

Improvement Potential ◽

Testing Accuracy

The Taguchi capability index, which reflects the expected loss and the yield of a process, is a useful index for evaluating the quality of a process. Several scholars have proposed a process improvement capability index based on the expected value of the Taguchi loss function as well as the corresponding cost of process improvement. There have been a number of studies using the Taguchi capability index to develop suppliers’ process quality evaluation models, whereas models for evaluating suppliers’ process improvement potential have been relatively lacking. Thus, this study applies the process improvement capability index to develop an evaluation model of the supplier’s process improvement capability, which can be provided to the industry for application. Besides, owing to the current need to respond quickly, coupled with cost considerations and the limits of technical capabilities, the sample size for sampling testing is usually not large. Consequently, the evaluation model of the process improvement capability developed in this study adopts a fuzzy testing method based on the confidence interval. This method reduces the risk of misjudgment due to sampling errors and improves the testing accuracy because it can incorporate experts and their accumulated experiences.

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Optimizing the quality of bootstrap-based prediction intervals

The 2011 International Joint Conference on Neural Networks ◽

10.1109/ijcnn.2011.6033627 ◽

2011 ◽

Cited By ~ 11

Author(s):

Abbas Khosravi ◽

Saeid Nahavandi ◽

Doug Creighton ◽

Dipti Srinivasan

Keyword(s):

Prediction Intervals

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Universidad EAN Breaking a Babel Tower Applying SAP as a Tool Under a PMO Model

Handbook of Research on Project Management Strategies and Tools for Organizational Success - Advances in Logistics, Operations, and Management Science ◽

10.4018/978-1-7998-1934-9.ch020 ◽

2020 ◽

pp. 443-470

Author(s):

Diego Cardona ◽

Diego Montañez ◽

Edwin Lozada ◽

Cesar Augusto Jiménez León

Keyword(s):

Quality Of Service ◽

Information Systems ◽

Information Security ◽

Academic Quality ◽

Administrative Efficiency ◽

Independent Information ◽

It Capabilities ◽

Innovation Project ◽

Scalable Hardware

This chapter describes the PMO model used to renovates the information systems of the Universidad EAN that before 2015 operated with multiple obsolete tools, generating incidents in the management of the information required for its operation. As part of the institutional innovation project implemented to ensure economic and administrative efficiency besides its strategic alignment, a SAP-based solution was implemented allowing it to move from a technological babel tower with almost 40 independent information systems in multiple platforms, towards a comprehensive platform that ensured a unified interoperability model with a scalable hardware infrastructure, using state-of-the-art applications supporting the provision of self-services to the community, expanding IT capabilities, reducing the risks, increasing the information security, improving the quality of service, and, despite being it in a stabilization stage, has been supporting the operation in an efficient and effective way, as shows the institutional results from the financial and academic quality perspectives.

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Experimental Investigation on a Hybrid Series Active Power Compensator to Improve Power Quality of Typical Households

IEEE Transactions on Industrial Electronics ◽

10.1109/tie.2016.2546848 ◽

2016 ◽

pp. 1-1 ◽

Cited By ~ 37

Author(s):

Alireza Javadi ◽

Abdelhamid Hamadi ◽

Lyne Woodward ◽

Kamal Al-Haddad

Keyword(s):

Experimental Investigation ◽

Power Quality ◽

Active Power

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Using Prediction Intervals to Improve Information Quality of Bankruptcy Prediction Models

Advances in Business and Management Forecasting ◽

10.1108/s1477-407020140000010014 ◽

2014 ◽

pp. 37-52 ◽

Cited By ~ 2

Author(s):

Marco Lam ◽

Brad S. Trinkle

Keyword(s):

Information Quality ◽

Prediction Models ◽

Bankruptcy Prediction ◽

Prediction Intervals

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Statistical Error Propagation Affecting the Quality of Experience Evaluation in Video on Demand Applications

Applied Sciences ◽

10.3390/app10103662 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3662 ◽

Cited By ~ 1

Author(s):

Abdul Wahab ◽

Nafi Ahmad ◽

John Schormans

Keyword(s):

Error Propagation ◽

Quality Of Experience ◽

Statistical Error ◽

Video On Demand ◽

Sampling Errors ◽

On Demand ◽

Subjective Testing ◽

Qos Parameters ◽

Latency Jitter

In addition to the traditional Quality of Service (QoS) metrics of latency, jitter and Packet Loss Ratio (PLR), Quality of Experience (QoE) is now widely accepted as a numerical proxy for the actual user experience. The literature has reported many mathematical mappings between QoE and QoS, where the QoS parameters are measured by the network providers using sampling. Previous research has focussed on sampling errors in QoS measurements. However, the propagation of these sampling errors in QoS through to the QoE values has not been evaluated before. This is important: without knowing how sampling errors propagate through to QoE estimates there is no understanding of the precision of the estimates of QoE, only of the average QoE value. In this paper, we used industrially acquired measurements of PLR and jitter to evaluate the sampling errors. Additionally, we evaluated the correlation between these QoS measurements, as this correlation affects errors propagating to the estimated QoE. Focusing on Video-on-Demand (VoD) applications, we use subjective testing and regression to map QoE metrics onto PLR and jitter. The resulting mathematical functions, and the theory of error propagation, were used to evaluate the error propagated to QoE. This error in estimated QoE was represented as confidence interval width. Using the guidelines of UK government for sampling in a busy hour, our results indicate that confidence intervals around estimated the Mean Opinion Score (MOS) rating of QoE can be between MOS = 1 to MOS = 4 at targeted operating points of the QoS parameters. These results are a new perspective on QoE evaluation and are of potentially great significance to all organisations that need to estimate the QoE of VoD applications precisely.

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An Experimental Investigation of the External Wind Effects on the Ceiling Temperature Distribution of Fire-Induced Thermal Flow in a Corridor Connected to a Compartment

Energies ◽

10.3390/en13071826 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1826

Author(s):

Bei Cao ◽

Xiaodong Zhou ◽

Yubiao Huang ◽

Yuan Zheng ◽

Kai Ye ◽

...

Keyword(s):

Experimental Investigation ◽

Temperature Distribution ◽

Wind Velocity ◽

Shielding Effect ◽

Temperature Profiles ◽

Building Structures ◽

Thermal Flow ◽

Ceiling Temperature ◽

Higher Temperature

Fire-induced thermal flow is the greatest threat to trapped people and the heat-resistant quality of building structures. This paper presents an experimental investigation of the effects of external wind on the ceiling temperature distribution of fire-induced thermal flow in a one-sixth scale corridor connected to a compartment. In the experiments, the fire source was placed in the compartment with hot thermal flow spilled into the connected corridor. The heat release rate (HRR) was changed from 10 to 20 kW and the external wind velocity was changed from 0 to 2.09 m/s. The ends of the corridor could be adjusted to be fully or partially open to the environment with dam-boards arranged at the ends of the corridor. An effective corridor HRR, Qcorridor, was defined to account for the amount of the spilled plume into the corridor. Results show that the temperature under the ceiling changed in a non-monotonic way with wind velocity: it first increased and then decreased with wind velocity. It was revealed that the dam-boards at the corridor opening had an evidently shielding effect, leading to higher temperature compared to the fully open environment. Finally, uniform correlations are proposed for predicting the attenuation law of ceiling temperature profiles in corridors for different wind conditions.

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The Experimental Investigation of Scroll Expanders Operating in the ORC System with HFE7100 as a Working Medium

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.831.245 ◽

2016 ◽

Vol 831 ◽

pp. 245-255 ◽

Cited By ~ 2

Author(s):

Tomasz Z. Kaczmarczyk ◽

Eugeniusz Ihnatowicz

Keyword(s):

Experimental Investigation ◽

Magnetic Coupling ◽

Gear Pump ◽

Working Medium ◽

Maximum Current ◽

Glycol Solution ◽

Thermal Oil ◽

Scroll Expanders ◽

Regenerative Cycle

The paper presents the results of experimental investigation on the ORC system with a droplet separator (which was used to improve the quality of working medium vapour) and two scroll expanders, which operated individually. The research aimed at verifying the correctness of scroll expanders performance in the ORC installation, equipped with the electric flow heater for thermal oil as a heat source. The paper contains the characteristics of the heat exchangers installation that were obtained for the ORC system variant using a regenerative cycle. The tests were conducted for selected flow rates and various temperatures of the working medium HFE7100, glycol solution and thermal oil. The unit with a gear pump and a magnetic coupling functioned as a circulating pump. Following the results of tests carried out on two scroll expanders it may be concluded that the electric power output that was measured at the generator terminals was approximately 750 W. The maximum voltages generated by the expanders amounted to around 200 V and the maximum current was about 4 A.

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