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排序方式: 共有75条查询结果,搜索用时 13 毫秒
1.
Alemayehu Molla 《Information Systems Frontiers》2013,15(5):705-723
IT firms vary in their performance to improve the environmental sustainability of their own operations and in their ability to provide products and solutions that enable and transform the environmental sustainability of other industries. In the parlance of the balanced scorecard, performance has two dimensions, that is, “drivers” and “outcomes”. The drivers, also known as leading performance indicators, refer to learning and innovation, processes, and customer value propositions. The outcomes, also known as lagging performance indicators, refer to financial results. This study has developed and validated an instrument to measure the environmentally sustainable IT performance (eSITP) drivers. We established the nomological network of the eSITP by drawing from several theoretical domains in the areas of innovation antecedents and values, balanced performance measurement and IT and eco-sustainability. Based on a survey of 133 IT firms, we developed and validated a four-dimension, 17 items eSITP instrument covering eco-learning, eco-process, eco-brand and eco-value governance. The instrument is validated by following a seven step rigorous process. The paper breaks new ground from both research and practice perspectives. The instrument makes it easier for other researchers who wish to explain the leading (drivers) and lagging (outcomes) of IT firms’ environmental sustainability and for IT business managers who want to improve their environmental sustainability performance. 相似文献
2.
Kuss and McLerran in a paper in this journal provide SAS code for the estimation of multinomial logistic models for correlated data. Their motivation derived from two papers that recommended to estimate such models using a Poisson likelihood, which is according to Kuss and McLerran "statistically correct but computationally inefficient". Kuss and McLerran propose several estimating methods. Some of these are based on the fact that the multinomial model is a multivariate binary model. Subsequently a procedure proposed by Wright is exploited to fit the models. In this paper we will show that the new computation methods, based on the approach by Wright, are statistically incorrect because they do not take into account that for multinomial data a multivariate link function is needed. An alternative estimation strategy is proposed using the clustered bootstrap. 相似文献
3.
Alemayehu Gebremedhin Jarle De Oliveira Granheim 《Renewable & Sustainable Energy Reviews》2012,16(3):1611-1615
This paper presents the results of a Norwegian power system analysis. An energy system analysis model based on linear programming is used for modelling and optimisation. The analyses cover a number of scenarios where the studied system is subjected to changes by introducing other renewable energy sources, energy conservation measures and measures to promote renewable energy. The study shows that due to a combination of cheap hydropower and high investment costs, it is quite difficult for new generation units to be profitable. This is also true during periods of low precipitation where the system tends to survive on imported power instead of investing in new generation units. However, this does not apply to energy conservation measures that easily enter the system. On the other hand, biomass based CHP, wind power and wave power could be viable if measures are introduced to promote their use. Most of the scenarios show a high potential for reducing global emissions. 相似文献
4.
Adam Alemayehu Dominika Zákutná Soňa Kohúteková Václav Tyrpekl 《Journal of the American Ceramic Society》2022,105(7):4621-4631
Ceria, pure or doped, is an important electrolyte material in solid oxide fuel cells, catalysts, and plutonium surrogates. Even though ceria is a widely studied material, its coprecipitation with the most common doping element, gadolinium, remains mostly overlooked. Here, we present a comprehensive study of gadolinium–cerium oxalates prepared by coprecipitation of gadolinium (III) and cerium (III) salts by oxalic acid under different reaction conditions and element ratios. For this purpose, we assessed the effects of basic precipitation conditions on the final oxalate size, shape, and conversion into the corresponding oxides. The results showed that coprecipitation with oxalic acid yields and ideal solid solution, which translates into the oxides. This low-cost and straightforward synthetic route provides then high-quality solid solutions of Ge–Gd in the oxide lattice. Thus, this approach has a high industrialization potential, with significant advantages over hydrolysis or hydrothermal techniques. 相似文献
5.
6.
Jürgen Liebscher Alemayehu Areda Berhanu Abegaz 《Advanced Synthesis \u0026amp; Catalysis》1983,325(5):689-694
7.
Solomon Guadie Worku Chunxiang XuAuthor VitaeJining ZhaoAuthor Vitae Xiaohu HeAuthor Vitae 《Computers & Electrical Engineering》2014
Cloud computing poses many challenges on integrity and privacy of users’ data though it brings an easy, cost-effective and reliable way of data management. Hence, secure and efficient methods are needed to ensure integrity and privacy of data stored at the cloud. Wang et al. proposed a privacy-preserving public auditing protocol in 2010 but it is seriously insecure. Their scheme is vulnerable to attacks from malicious cloud server and outside attackers regarding to storage correctness. So they proposed a scheme in 2011 with an improved security guarantee but it is not efficient. Thus, in this paper, we proposed a scheme which is secure and with better efficiency. It is a public auditing scheme with third party auditor (TPA), who performs data auditing on behalf of user(s). With detail security analysis, our scheme is proved secure in the random oracle model and our performance analysis shows the scheme is efficient. 相似文献
8.
E Barry A Krumholz GK Bergey H Chatha S Alemayehu L Grattan 《Canadian Metallurgical Quarterly》1998,39(4):427-431
BACKGROUND: The aim of this experimental study was to evaluate the risk of tumor recurrence after laparoscopic cecal resection (LCR) of colonic carcinoma in the rat. METHODS: The experimental cancer consisted of one million cells (DHK/K12), incorporated in an extracellular matrix, placed and secured to the cecal serosa in 110 BD9 rats. Four weeks later, all animals were reoperated through a laparotomy to control tumor growth, and animals with diffuse carcinomatosis were excluded. Eligible animals were randomized either to laparoscopic cecal resection (group LCR, n = 10), to open resection (group OCR, n = 13), or to a control group without resection (group C, n = 13). Resection was always considered as macrocopically complete. All animals were killed 4 weeks after the resection to determine the tumor recurrence and quantify carcinomatosis. RESULTS: We noted diffuse carcinomatosis in 70% of rats in groups C and LCR versus 23% in group OCR (p = 0.038). For tumors noted as S- (not extending outside the serosa), diffuse carcinomatosis was observed in all animals of group C (3 of 3), in 6 of 8 in group LCR, and 0 of 6 in group OCR (p = 0.004). The rate of port site or incisional metastases was not significantly different between groups. CONCLUSIONS: These preliminary results demonstrated the deleterious impact of the laparoscopy for resection of large bowel malignancy. LCR increased significantly the incidence of a diffuse carcinomatosis even when performed for locally noninvasive tumors (S-). 相似文献
9.
Regions with densely concentration of industries and district heating systems (DHS) could be interesting study object from the light of an integrated heat market on local basis. System analysis with a widened system boundary could be used as an approach to evaluate the benefit of an integrated heat supply system. In this study, an energy system model consisting of totally seven different participants is designed and the optimization results of the system analysis are presented. With applied data and assumptions, the study shows that a significant amount of the heat demand within two sub‐systems can be covered by heat supply from the heat market (the entire heat comes from two industries). Shadow prices, which can be used for heat pricing, indicate the advantage of an integrated system. The system cost reduction through integration and the availability of several actors with diverse energy supply system, makes the region under study an interesting area to prove a locally deregulated heat market. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
10.
Alemayehu Ambaw Randolph BeaudryInge Bulens Mulugeta Admasu DeleleQ. Tri Ho Ann SchenkBart M. Nicolaï Pieter Verboven 《Journal of food engineering》2011,102(3):257-265
The purpose of this research was to model the kinetics of adsorption of 1-methylcyclopropene (1-MCP) in apple fruit and non-target solid materials found in apple storage rooms. The process was described by Fick’s second law of diffusion of the gas through the pores of the material coupled with adsorption kinetics of the gas on the material’s binding sites. A finite element formulation of the model, describing the diffusion and adsorption mechanisms separately, was first developed. The values of the relevant parameters were estimated based on headspace measurements of the decrease of 1-MCP in jars containing the different materials. The headspace concentration of 1-MCP was measured using gas chromatography. Apple fruit (Golden Delicious and Jonagold) and the following bin construction materials were investigated: high density polyethylene (HDPE), oak, poplar wood and card lining. The range in the magnitude of the diffusion coefficient, adsorption coefficient, and concentration of active sites in the various solids was 10,000-, 8-, and 30-fold, respectively. 相似文献