Comparison-Based Analysis Research Articles

Probabilistic service life prediction updating with inspection information for RC structures subjected to coupled corrosion and fatigue

The performance and remaining service life of deteriorating reinforced concrete (RC) structures decrease with time due to increased critical damage propagation based on coupled corrosion and fatigue. Since damage propagation prediction is highly uncertain, an updating process after each inspection and monitoring is required to improve the accuracy and applicability of the structural performance and service life prediction. This paper proposes a probabilistic approach for updating the service life prediction of deteriorating structures under coupled corrosion-fatigue deterioration processes. The probabilistic parameters involved in the coupled corrosion-fatigue deterioration model are updated using Bayesian inference (BI). In the updating process, the Markov Chain Monte Carlo (MCMC) sampling method is applied to integrate all the possible inspection results associated with no damage detection, corrosion damage, and/or fatigue crack damage. The most appropriate updating parameters of the deterioration model are determined by adopting a comparison-based analysis. Finally, the remaining service life of the deteriorating structures based on the updated coupled damage prediction model is re-estimated. The application of the proposed probabilistic approach is illustrated on an RC bridge girder. This paper shows that (a) the coupled corrosion-fatigue damage can reduce the structural service life compared to corrosion or fatigue damage separately, and (b) the errors and uncertainty in corrosion-fatigue damage prediction can be reduced through the parameter updating integrating multiple inspection outcomes.

Role of Online Retailers' Post-sale Services in Building Relationships and Developing Repurchases: A Comparison-Based Analysis Among Male and Female Customers.

Customers are skeptical about shopping online because e-commerce environments are typically considered impersonal. To assure product quality and to enhance customer proclivity in such environments, post-sale services (i.e., product returns, exchange, and maintenance) may be considered to alleviate customers’ skepticism. Therefore, this study’s objective is to investigate the role of an online retailer’s post-sale services (i.e., product return, exchange, and maintenance) on customers’ attitudinal (building relationships) and behavioral aspects (developing customers’ repurchase intentions). Structural equation modeling is applied to data collected through an online survey answered by 409 online customers of jd.com (after missing data were removed). Research findings show that product return, exchange, and maintenance services are strongly predictive of online customer satisfaction, and satisfaction significantly impacts customer trust. Both customer satisfaction and trust, as indicators of relationship quality, further mediate the links between product return, exchange, and maintenance services and online customer repurchase intention. In addition, differences between male and female customers were found in various aspects of online retailers’ product return, exchange, and maintenance services. This is the first empirical study that not only examines the influence of all three dimensions of online retailers’ post-sale services on customers’ online shopping perceptions and decisions, but also considers differences between male and female customers. Finally, this research provides theoretical and managerial implications based on conceptual and empirical evidence.

Conceptual Approach of Measuring the Professional and Economic Effectiveness of Drone Applications Supporting Forest fire Management

Abstract Introduction: Since the operation of manned aircraft at forest fires is expensive, in many cases managers miss the aerial reconnaissance however that would be required for the effective intervention. Drones can give real alternatives against traditional reconnaissance, therefore it is important to study both professional and economic effectiveness of its applications. Methods: Authors used three different approaches to study the effectiveness of drone applications; firstly they used comparison based analysis, then an analysis of indirect way and at last a damage – time function analysis, based on the drone applications at the tactical level. Research used their own experiences in this field, practical experiments, economic analysis and also expert estimation. Results and discussion: The meaning of efficiency for fire managers can be different from the meaning of efficiency for economists. Economic efficiency is more strict than technical effectiveness. Even if drone applications are cheaper than the manned aircraft, it is helpful to analyze its real economic effectiveness. This study points at principle mistakes used often by marketing to overrate the advantages of some product or procedure. Even if it is very difficult to calculate with all circumstances and assumptions found during firefighting process such as aerial patrol for detecting hot spots or fly for reconnaissance but authors show methods that can help us to rate the economic effectiveness more precisely than rated nowadays by the marketing.

A Comparative Analysis of Min-Min and Max-Min Algorithms based on the Makespan Parameter

In today’s computational environment, cloud computing has grown up as a utility. With increase in number of resource requests, there is a need for efficient resource allocation mechanism which aims at proper utilization of resources. Therefore in order to process these requests by making use of the available resources, an efficient task scheduling algorithm is required. An efficient task scheduling mechanism should be able to minimize completion time, maximize resource utilization and minimize makespan etc. Based on the efficiency metrics or parameters there are numerous type of existing scheduling algorithms but there is no such algorithm so far which can optimize all these parameters simultaneously, as each scheduling algorithm works on some particular parameter and tries to optimize it only. In this paper, two heuristic based algorithms: Min-Min and Max-Min have been described, simulated on CloudSim and then comparison based analysis has been done by taking makespan parameter into consideration. Keywords: Cloud Computing, Heuristic Algorithm, Max-Min Algorithm, Metatask, Min-Min Algorithm, Task Scheduling.

Wavelet and short-time Fourier transform comparison-based analysis of myoelectric signals

In this investigation, extracted features ofsignals have been analyzed for the recognition of arm movements. Short-time Fourier transform and wavelet transform based on Euclidian distance were applied to reordered signals. Results show that wavelet is a more useful and powerful tool for analyzing signals, since it shows multiresolution property with a significant reduction in the computation time for eliminating resolution problems. Finally, a statistical technique of repeated factorial analysis of variance for experimental recorded data was implemented in a way to investigate the effect of class separability for multiple motions for establishing surface electromyogram–muscular force relationship.

Whole-genome comparison clarifies close phylogenetic relationships between the phyla Dictyoglomi and Thermotogae

The anaerobic thermophilic bacterial genus Dictyoglomus is characterized by the ability to produce useful enzymes such as amylase, mannanase, and xylanase. Despite the significance, the phylogenetic position of Dictyoglomus has not yet been clarified, since it exhibits ambiguous phylogenetic positions in a single gene sequence comparison-based analysis. The number of substitutions at the diverging point of Dictyoglomus is insufficient to show the relationships in a single gene comparison-based analysis. Hence, we studied its evolutionary trait based on whole-genome comparison. Both gene content and orthologous protein sequence comparisons indicated that Dictyoglomus is most closely related to the phylum Thermotogae and it forms a monophyletic group with Coprothermobacter proteolyticus (a constituent of the phylum Firmicutes) and Thermotogae. Our findings indicate that C. proteolyticus does not belong to the phylum Firmicutes and that the phylum Dictyoglomi is not closely related to either the phylum Firmicutes or Synergistetes but to the phylum Thermotogae.

Analysing industrial district performances: A structured approach

The goals of an organization of data and information collected from the European industrial systems and concerning networks of enterprises, mainly small-mid enterprises (SMEs), are many: (a) to offer an intelligent support system (ISS) to industrial analysers when they try to understand if a SME network, either cluster or industrial district, could be enforced by proper financing, or it cannot give sufficient assurance for a new development; (b) to offer to political people a support in understanding the dynamics of these SME networks, in order to be able to take decisions about public politics; (c) to give tools for analysing the performance of these industrial bodies to industrial people, mainly technicians and managers, such to be able to apply new strategies for their improvement; (d) to give information and data to researchers operating in university and RTD centers, such to be able to improve their knowledge about these so important industrial bodies. To reach this goal, the aim of the EU-funded CODESNET (COllaborative DEmand & Supply NETwork) project is to give new ideas and concepts sufficient to drive the attention of the above-mentioned different types of people towards the SME networks and districts. To this aim, a crucial problem must be approached and solved: which model of a SME network should be stated and used as the basis for developing a clear and useful ISS, that is, able to collect information and data from existing SME networks and transfer such data into standard formats, easy to be read by both industrial people and scientific researchers. The present paper describes the theoretical methodology on which the data organization and interpretation adopted in the CODESNET project is based. The application of an original meta-model of SME network, developed in the mentioned project, is detailed according to the following steps. After the meta-model formulation (in Section 2), it is shown how the variables to be measured (such to have a clear understanding of the network status), have to be selected, and how the main issues concerning the design and management of the network has to be classified (Section 3). Then, it will be shown how the archive of both data/information from existing SME networks (for purpose of comparison-based analysis) and the catalogue of technical/scientific reports (for purpose of justifying the analysis considerations) has been organized in an integrated form. The scope is to give at disposal of industrial people the mentioned ISS which allow them to approach some main issues concerning the network design and management (Section 4). An example of ISS application in an Italian industrial district will be presented, such to illustrate the CODESNET results’ usefulness.