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Article
Publication date: 22 June 2012

Cihan Altuntas and Ferruh Yildiz

Laser scanning is increasingly used in many three‐dimensional (3‐D) measurement and modeling applications. It is the latest technique used in 3‐D measurement, and is…

Abstract

Purpose

Laser scanning is increasingly used in many three‐dimensional (3‐D) measurement and modeling applications. It is the latest technique used in 3‐D measurement, and is becoming increasingly important within a number of applications. However, many applications require photogrammetric data in addition to laser scanning data. The purpose of this paper is to present a range and image sensor combination for three‐dimensional reconstruction of objects or scenes.

Design/methodology/approach

In this study, a Nikon D80 camera was mounted on an Ilris 3D laser scanner and CPP was estimated according to the laser scanner coordinate system. The estimated CPP was controlled using three different methods which were developed in this study and a sample application as coloring of point cloud using image taken by the camera mounted on the laser scanner was performed.

Findings

It was found that when a high‐resolution camera is mounted on laser scanners, camera position parameters (CPP) should be estimated very accurately with respect to the laser scanner coordinate system.

Originality/value

The paper shows that the combination of high‐resolution camera and laser scanners should be used for more accurate and efficient results in 3D modeling applications.

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Article
Publication date: 5 September 2016

Krzysztof Olasek, Maciej Karczewski, Michal Lipian, Piotr Wiklak and Krzysztof Józwik

A solution to increase the energy production rate of the wind turbine is proposed by forcing more air to move through the turbine working section. This can be achieved by…

Abstract

Purpose

A solution to increase the energy production rate of the wind turbine is proposed by forcing more air to move through the turbine working section. This can be achieved by equipping the rotor with a diffusing channel ended with a brim (diffuser augmented wind turbine – DAWT). The purpose of this paper is to design an experimental stand and perform the measurements of velocity vector fields through the diffuser and power characteristic of the wind turbine.

Design/methodology/approach

The experiments were carried out in a small subsonic wind tunnel at the Institute of Turbomachinery, Lodz University of Technology. An experimental stand design process as well as measurement results are presented. Model size sensitivity study was performed at the beginning. The experimental campaign consisted of velocity measurements by means of particle image velocimetry (PIV) and pneumatic pitot probe as well as torque and rotational velocity measurements.

Findings

Characteristics (power coefficient vs tip speed ratio) of the bare and shrouded wind turbine were obtained. The results show an increase in the wind turbine power up to 70-75 per cent by shrouding the rotor with a diffuser. The mechanisms responsible for such a power increase were well explained by the PIV and pneumatic measurement results revealing the nature of the flow through the diffuser.

Research limitations/implications

Experimental stand for wind turbine rotor testing is of a preliminary character. Most optimal methodology for obtaining power characteristic should be determined now. Presented results can serve as good input for choice of stable and reliable control system of wind turbine operational parameters.

Practical implications

A 3 kW DAWT is being developed at the Institute of Turbomachinery, Lodz University of Technology. Aim of the study is to design a compact and smart wind turbine optimised for low wind speed conditions. Developed wind turbine has a potential to be used as an effective element within a net of distributed generation, e.g. for domestic use.

Originality/value

Research carried out is the continuation of theoretical study began in 1970s. It was also inspired by practical solutions proposed by Japanese researchers few years ago. Presented paper is the summary of work devoted to optimisation of the DAWT for wind conditions in the region. Original solution has been applied, e.g. for experimental stand design (3D printing application).

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 7
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 18 January 2019

Khosro Sayevand and Hossein Arab

The purpose of this paper is to propose a gauge for the convergence of the deterministic particle swarm optimization (PSO) algorithm to obtain an optimum upper bound for…

Abstract

Purpose

The purpose of this paper is to propose a gauge for the convergence of the deterministic particle swarm optimization (PSO) algorithm to obtain an optimum upper bound for PSO algorithm and also developing a precise equation for predicting the rock fragmentation, as important aims in surface mines.

Design/methodology/approach

In this study, a database including 80 sets of data was collected from 80 blasting events in Shur river dam region, in Iran. The values of maximum charge per delay (W), burden (B), spacing (S), stemming (ST), powder factor (PF), rock mass rating (RMR) and D80, as a standard for evaluating the fragmentation, were measured. To check the performance of the proposed PSO models, artificial neural network was also developed. Accuracy of the developed models was evaluated using several statistical evaluation criteria, such as variance account for, R-square (R2) and root mean square error.

Findings

Finding the upper bounds for the difference between the position and the best position of particles in PSO algorithm and also developing a precise equation for predicting the rock fragmentation, as important aims in surface mines.

Originality/value

For the first time, the convergence of the deterministic PSO is studied in this study without using the stagnation or the weak chaotic assumption. The authors also studied application of PSO inpredicting rock fragmentation.

Details

Engineering Computations, vol. 36 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 3 May 2016

Rui Zhou, Johnny Siu-Hang Li and Jeffrey Pai

The application of weather derivatives in hedging crop yield risk is gaining more interest. However, the further development of weather derivatives – particularly…

Abstract

Purpose

The application of weather derivatives in hedging crop yield risk is gaining more interest. However, the further development of weather derivatives – particularly exchange-traded – in the agricultural sector has been impeded by concerns over their hedging performance. The purpose of this paper is to develop a new framework to derive the optimal hedging strategy and evaluate hedging effectiveness.

Design/methodology/approach

This framework incorporates a stochastic temperature model, a crop yield model, a risk-neutral pricing method and a profit optimization procedure. Based on a large number of simulated scenarios, the authors study crop yield hedge for a future year. The authors allow the hedger to choose from different types of exchange-traded weather derivatives, and examine the impact of various factors on the optimal hedging strategy.

Findings

The analysis shows that hedging objective, pricing method and geographical location of the hedged exposure all play important roles in choosing the best hedging strategy and assessing hedging effectiveness.

Originality/value

This framework is forward-looking, because it focusses on the crop yield hedge for a future year rather than on the historical hedging effectiveness often studied in literature. It utilizes the most up-to-date information related to temperature and crop yield, and hence produces a hedging strategy which is more relevant to the year under consideration.

Details

Agricultural Finance Review, vol. 76 no. 1
Type: Research Article
ISSN: 0002-1466

Keywords

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Book part
Publication date: 2 December 2021

Richard E. Wagner

I have been asked to explore how James Buchanan’s work on public finance and constitutional political economy might have emerged out of themes present in Frank Knight’s…

Abstract

I have been asked to explore how James Buchanan’s work on public finance and constitutional political economy might have emerged out of themes present in Frank Knight’s oeuvre, especially his Risk Uncertainty, and Profit. Buchanan’s body of work has inspired the development of a style of political economy sometimes described as Virginia or Constitutional Political Economy to distinguish it from the Chicago Political Economy with which George Stigler is associated, and with Stigler and Buchanan both being students of Knight. While Buchanan, unlike Stigler, did not write his dissertation under Knight’s supervision, this is a minor distinction because Buchanan regarded Knight as his de facto supervisor even though Roy Blough was his de jure supervisor. The author explains how Knight’s scholarly oeuvre can in large measure be detected in Buchanan’s effort to fashion an alternative approach to public finance and to articulate the field of study now called constitutional political economy.

Details

Research in the History of Economic Thought and Methodology: Including a Symposium on Frank Knight's Risk, Uncertainty and Profit at 100
Type: Book
ISBN: 978-1-80071-149-5

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Book part
Publication date: 13 October 2015

James C. Cox and Duncan James

This study first replicates, then perturbs, the centipede game as implemented by McKelvey and Palfrey (1992). It is thus both a replication study and an original research…

Abstract

This study first replicates, then perturbs, the centipede game as implemented by McKelvey and Palfrey (1992). It is thus both a replication study and an original research study. We use controlled laboratory experiments, with computer interfaces for each treatment, anonymous round-robin matching among the subjects across rounds, multiple (10) rounds within each treatment, and incremental changes between adjacent treatments allowing for an assessment of effects at the margin of different game configurations. We find unraveling to the subgame perfect equilibrium somewhat faster than did McKelvey and Palfrey (1992), when using their exact design. Perturbations to that design show that setting non-taker payoffs to zero induces earlier unraveling, as does the use of higher stakes (as in Murphy, Rapoport, and Parco (2006), and Rapoport, Stein, Parco, and Nicholas (2003), respectively). Other, subsequent perturbations show: that there is at most a subtle effect associated with using a 10-second timer with a default move, relative to untimed active moves; and that clock format versus tree format has a minimal effect in common information, unchanging payoff-parameterization environments. We verify the robustness of some key past findings in real-time games. We also explore in a common information environment, the effect of design features previously used in independent private values settings; here we find new evidence that features which might modulate information acquisition and/or processing in an independent private values setting may not restrict behavior in a common information setting.

Details

Replication in Experimental Economics
Type: Book
ISBN: 978-1-78560-350-1

Keywords

Open Access
Article
Publication date: 1 July 2021

Matteo Foglia and Peng-Fei Dai

The purpose of this paper is to extend the literature on the spillovers across economic policy uncertainty (EPU) and cryptocurrency uncertainty indices.

Abstract

Purpose

The purpose of this paper is to extend the literature on the spillovers across economic policy uncertainty (EPU) and cryptocurrency uncertainty indices.

Design/methodology/approach

This paper uses cross-country economic policy uncertainty indices and the novel data measuring the cryptocurrency price uncertainties over the period 2013–2021 to construct a sample of 946 observations and applies the time-varying parameter vector autoregression (TVP-VAR) model to do an empirical study.

Findings

The findings suggest that there are cross-country spillovers of economic policy uncertainty. In addition, the total uncertainty spillover between economic policies and cryptocurrency peaked in 2015 before gradually decreasing in the following periods. Concomitantly, the cryptocurrency uncertainty has acted as the “receiver.” More importantly, the authors found the predictive power of economic policy uncertainty to predict the cryptocurrency uncertainty index. This paper’s results hold robust when using alternative measurement of cryptocurrency policy uncertainty.

Originality/value

This study is the first research that deeply investigates the association between two uncertainty indicators, namely economic policy uncertainty and the cryptocurrency uncertainty index. We provide fresh evidence about the dynamic connectedness between country-level economic policy uncertainty and the cryptocurrency index. Our work contributes a new channel driving the variants of uncertainties in the cryptocurrency market.

Details

Journal of Asian Business and Economic Studies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2515-964X

Keywords

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Book part
Publication date: 16 January 2014

Tomoki Kitamura and Munenori Nakasato

Previous studies showed mixed results as to the cause of myopic loss aversion (MLA). This paper reexamines the main driver of MLA, considering two factors from previous…

Abstract

Purpose

Previous studies showed mixed results as to the cause of myopic loss aversion (MLA). This paper reexamines the main driver of MLA, considering two factors from previous studies and an additional factor.

Design/methodology/approach

Experimentally investigate whether flexibility of investment, frequency of information feedback, or timing of decision cause MLA.

Findings

Timing of decision and flexibility of investment explain most differences in subject behavior. Frequency of information feedback makes only a marginal contribution.

Originality/value of the paper

The differences in subject behavior can be interpreted by a shift in their reference points depending on the difference in flexibility of investment, frequency of information feedback, or timing of decision.

Details

Experiments in Financial Economics
Type: Book
ISBN: 978-1-78350-141-0

Keywords

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Article
Publication date: 21 June 2021

Erhan Mugaloglu, Ali Yavuz Polat, Hasan Tekin and Edanur Kılıç

This study aims to measure economic uncertainty in Turkey by a novel economic uncertainty index (EUI) employing principal component analysis (PCA). We assess the impact of…

Abstract

Purpose

This study aims to measure economic uncertainty in Turkey by a novel economic uncertainty index (EUI) employing principal component analysis (PCA). We assess the impact of Covid-19 pandemic in Turkey with our constructed uncertainty index.

Design/methodology/approach

In order to obtain the EUI, this study employs a dimension reduction method of PCA using 14 macroeconomic indicators that spans from January 2011 to July 2020. The first principal component is picked as a proxy for the economic uncertainty in Turkey which explains 52% of total variation in entire sample. In the second part of our analysis, with our constructed EUI we conduct a structural vector autoregressions (SVAR) analysis simulating the Covid-19-induced uncertainty shock to the real economy.

Findings

Our EUI sensitively detects important economic/political events in Turkey as well as Covid-19-induced uncertainty rising to extremely high levels during the outbreak. Our SVAR results imply a significant decline in economic activity and in the sub-indices as well. Namely, industrial production drops immediately by 8.2% and cumulative loss over 8 months will be 15% on average. The losses in the capital and intermediate goods are estimated to be 18 and 25% respectively. Forecast error variance decomposition results imply that uncertainty shocks preserve its explanatory power in the long run, and intermediate goods production is more vulnerable to uncertainty shocks than overall industrial production and capital goods production.

Practical implications

The results indicate that monetary and fiscal policy should aim to decrease uncertainty during Covid-19. Moreover, since investment expenditures are affected severely during the outbreak, policymakers should impose investment subsidies.

Originality/value

This is the first study constructing a novel EUI which sensitively captures the critical economic/political events in Turkey. Moreover, we assess the impact of Covid-19-driven uncertainty on Turkish Economy with a SVAR model.

Details

Journal of Economic Studies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0144-3585

Keywords

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Book part
Publication date: 13 October 2015

Xu Jiang, Radhika Lunawat and Brian Shapiro

We replicate and extend the social history treatment of the Berg, Dickhaut, and McCabe (1995) investment game, to further document how the reporting of financial history…

Abstract

We replicate and extend the social history treatment of the Berg, Dickhaut, and McCabe (1995) investment game, to further document how the reporting of financial history influences how laboratory societies organize themselves over time. We replicate Berg et al. (1995) by conducting a No History and a Financial History session to determine whether a report summarizing the financial transactions of a previous experimental session will significantly reduce entropy in the amounts sent by Investors and returned by Stewards in the investment game, as Berg et al. (1995) found. We extend Berg et al. (1995) in two ways. First, we conduct a total of five sessions (one No History and four Financial History sessions). Second, we introduce Shannon’s (1948) measure of entropy from information theory to assess whether the introduction of financial transaction history reduces the amount of dispersion in the amounts invested and returned across generations of players. Results across sessions indicate that entropy declined in both the amounts sent by Investors and the percentage returned by Stewards, but these patterns are weaker and mixed compared to those in the Berg et al. (1995) study. Additional research is needed to test how initial conditions, path dependencies, actors’ strategic reasoning about others’ behavior, multiple sessions, and communication may mediate the impact of financial history. The study’s multiple successive Financial History sessions and entropy measure are new to the investment game literature.

Details

Replication in Experimental Economics
Type: Book
ISBN: 978-1-78560-350-1

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