Economic Performance Characteristics Research Articles

İki Dinamik Koşullu Korelasyon (DCC) Modeli Arasındaki Tahmin Doğruluğunun Karşılaştırılması

This study compares two commonly used DCC-family models to predict the linkage between the US equity and REIT markets within a global minimum-variance portfolio. Equity and REIT portfolios are constructed using variance-covariance matrices, which represent forward-looking covariance information. These matrices are constructed out-of-sample with ex-ante forecasting. By assessing the predictive precision of each model, the study aims to determine which one produces the lowest forecasting errors and performs better economically. According to a statistical comparison, ex-ante correlation forecasts based on the Asymmetric DCC model were more accurate than those based on the standard DCC model. An empirical comparison of the economic performance of these two models in a dynamic portfolio allocation framework reveals that, despite its complexity, the Asymmetric DCC model exhibits similar economic performance characteristics to the standard DCC model. Despite the lack of emphasis on the economic overperformance of the Asymmetric DCC model, investors who recalibrate their portfolios weekly will benefit from reduced forecast errors and the ability to create more efficient portfolios by using an asymmetric model instead of a standard model.

Business model hybridization but heterogeneous economic performance: Insights from low-cost and legacy carriers in Europe

Over the last decade, low-cost and legacy carriers have evolved their respective business models, leading to business model “hybridization”. However, the economic performance impacts of such convergence remain underinvestigated. We therefore evaluate whether airline business model hybridization has led to homogeneous economic performance in Europe. Using 2019 data for 25 European airlines, we implement hierarchical clustering based on principal components. We show that regardless of the analysis level (i.e., the number of clusters into which we group airlines), low-cost and legacy carriers remain distinct groups with specific economic performance characteristics (e.g., volume, revenue, cost and profitability). That is, despite increasing hybridization, the economic performance of airline business models is not homogeneous; overall, low-cost carriers remain more profitable (with lower costs and more affordable fares) than legacy carriers.

Analysis of the impact of non-sinusoidal voltage levels in the power grid of apartment buildings on the reliability and efficiency of transformers

The effects of mass implementation of energy-saving lighting on the permissible level of loading of the supply transformer were analyzed. The influence of non-sinusoidal voltages and currents on transformer wear was analyzed. Distortions of sinusoidal shape of voltages and currents lead to additional power losses in transformer. They cause heating of the insulation and windings of the transformer, increased losses and accelerated wear and tear. Higher harmonic components of voltage and current in a 0.4 kV network are caused by the presence of various energy-saving lighting lamps with non-linear volt-ampere characteristic, which include compact fluorescent and LED light sources. As a result, the transformer designed to operate at a frequency of 50 Hz experiences an additional adverse effect in the form of power losses and accelerated wear of electrical insulation, which leads not only to the deterioration of its technical and economic performance characteristics, but also to a significant decrease in reliability associated with the influence of higher harmonic components of voltage and current on equipment failure. It is shown that the lack of power factor correction schemes for low-power compact fluorescent and LED lamps causes the growth of nonsinusoidal voltage and current as they spread, which in turn causes the need to adjust the limit load of transformers to ensure their rated thermal mode. One way to maintain operational reliability under such conditions is to limit the transformer load depending on the level of higher harmonics in the network, as well as to predict the residual life of the operating transformer. Measuring the values of current transformer load and current levels of higher harmonic components of voltage and current will allow not only to calculate an acceptable load factor of the transformer (for the condition of insulation wear), but also to estimate the current residual life of transformer equipment using a neural network model.

Study on Agronomic and Economic Performance Characteristics of Cassava (Manihot utillisima L.) in Gunungkidul Regency Special Region of Yogyakarta

Study on agronomic and economic performance characteristics of cassava (Manihot utillisima L.) in Gunungkidul Regency Special Region of Yogyakarta was conducted in April – August 2016. The research aimed to identify the agronomic and economic performance characteristics of cassava in Gunungkidul regency. Technical implementation of the survey method was conducted by observation and interview. The location of research sampling was determined by stratified random sampling method based on the category of district that has the most or broadest, medium, and small amount of cassava planting area. The respondents were chosen by purposive sampling method as much as 10% from the number of cassava farmers in a village or farmer group. The data were analyzed by descriptive and farming system analysis. The research result showed that there were some cassava cultivars observed, i.e. ‘Ketan’, ‘Pahit’, ‘Adira’, ‘Ireng’, ‘GatotKaca’, ‘Genjah’, ‘Mentega’, ‘Oyeng’, ‘Randu’, ‘Ambira’, ‘Klentheng’, ‘Srondol’, ‘PandesiHijau’, ‘Adira 1’, ‘Pandesi’, ‘Kirik’, ‘Gambyong’, ‘Jowo’, ‘Bamban’, ‘Kacibali’, ‘UJ-5’, ‘Marekan’, ‘Kresno’, ‘Meni’, ‘Merah’, ‘Malang’, ‘Kropak’ and ‘Aban’. Cultivation technology of cassava applied in Gunungkidul Regency is conventional technology. The maximum tillage system is applied in the soil tillage. Generally, Cassava is grown intercropping with rice, beans and maize. Manure is applied in cultivation technology and weeding is done six until ten times. There are eight types of pests attacking cassava plants. Cassava is harvested in seventh until tenth month after planting. Cassava farming is feasible in Gunungkidul Regency with R/C ratio (Revenue Cost Ratio) and B/C ratio (Benefit Cost Ratio) gained > 1.

A cost assessment study for a large-scale water gas shift catalytic membrane reactor module in the presence of uncertainty

Abstract A comprehensive economic performance evaluation framework for an actual large-scale water-gas-shift Pd-based catalytic membrane reactor (CMR) module for hydrogen production is presented. Since a detailed assessment of the technical performance of the CMR built at WPI has been reported previously (Catalano et al., 2013), the present research study focuses on an assessment of the module’s economic performance characteristics, and thus, can be viewed as complementary. The proposed evaluation framework encompasses comprehensive baseline models for both Fixed Capital Investment (FCI) and Total Capital Investment (TCI) while various sources of uncertainty are identified whose effect on CMR’s economic performance is explicitly taken into account using Monte Carlo techniques. As a result, insightful distribution profiles of FCI and TCI are derived rather than single-point value estimates and more realistic distributions of CMR economic performance outcomes are generated and statistically characterized. The latter could potentially inform development efforts of this new technology option for hydrogen production purposes.

The Success and Failure of Combined Heat and Power (CHP) in the UK, Germany and the Netherlands: Revisiting Stewart Russell’s Perspective on Technology Choices in Society

Stewart Russell’s research work on combined heat and power / district heating (CHP/DH) in the UK was among the first empirical contributions to demonstrate that technological change is not just determined by seemingly objective technical and economic performance characteristics, but rather the result of social choices. His rich conceptual thinking is reconstructed in a coherent framework, and its explanatory power explored by analysing the innovation diff usion paradox of CHP/DH: in spite of very similar technical and economic characteristics, the patterns of innovation and diff usion diff er signifi cantly across countries. To this end, the evolution of CHP/DH in the UK, Germany and the Netherlands is compared. Russell’s ideas can be regarded as a predecessor of recent multi-level approaches to the analysis of socio-technical change. He put much emphasis on studying power relations for explaining the (non-) occurrence of socio-technical change; an issue that is still debated today.

Agronomic and Economic Performance Characteristics of Conventional and Low‐External‐Input Cropping Systems in the Central Corn Belt

We conducted a 9‐ha field experiment near Boone, IA, to test the hypothesis that yield, weed suppression, and profit characteristics of low‐external‐input (LEI) cropping systems can match or exceed those of conventional systems. Over a 4‐yr period, we compared a conventionally managed 2‐yr rotation system {corn (Zea mays L.)/soybean [Glycine max (L.) Merr.]} with two LEI systems: a 3‐yr corn/soybean/small grain + red clover (Trifolium pratense L.) rotation, and a 4‐yr corn/soybean/small grain + alfalfa (Medicago sativa L.)/alfalfa rotation. Synthetic N fertilizer use was 59 and 74% lower in the 3‐ and 4‐yr systems, respectively, than in the 2‐yr system; similarly, herbicide use was reduced 76 and 82% in the 3‐ and 4‐yr systems. Corn and soybean yields were as high or higher in the LEI systems as in the conventional system, and weed biomass in corn and soybean was low (≤4.2 g m−2) in all systems. Experimentally supplemented giant foxtail (Setaria faberi Herrm.) seed densities in the surface 20 cm of soil declined in all systems; supplemented velvetleaf (Abutilon theophrasti Medik.) seed densities declined in the 2‐ and 4‐yr systems and remained unchanged in the 3‐yr system. Without subsidy payments, net returns were highest for the 4‐yr system ($540 ha−1 yr−1), lowest for the 3‐yr system ($475 ha−1 yr−1), and intermediate for the 2‐yr system ($504 ha−1 yr−1). With subsidies, differences among systems in net returns were smaller, as subsidies favored the 2‐yr system, but rank order of the systems was maintained.

Optimizing maintenance of a serial-structure system depending on the operation time of each element

A semi-Markovian model of a system with serial structure is developed. The model accounts for the nonfailure-operation time of each element. Stationary reliable and economic performance characteristics of the system are found, and optimal terms of maintenance are determined.