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Scholars and practitioners believe that the large-scale deployment of charging piles is imperative to our future electric transportation systems. Major economies ambitiously install charging pile networks, with massive construction spending, maintenance costs, and urban space occupation. However, recent developments in technology may significantly reduce the necessary charging capacity required by the system. This paper develops a linear programming model to characterize the effects of likely scenarios where vehicle-to-vehicle (V2V) charging is available via vehicle modularization or wireless charging. Specifically, we consider scenarios in which vehicles can transmit energy to each other (coordinated by a central platform) while traveling closely on the same road. We first estimate the number of charging piles needed for completing the travel plan of 73 cars from data, assuming a battery capacity of 400 km's range and no V2V charging. Our results show that once V2V charging technologies with an efficiency of 50% are available, more than 2/3 of the charging piles investment would be wasted. Additionally, if the efficiency of V2V charging increases to 75%, we can easily reduce the battery capacity of vehicles to 200 km, which will reduce production costs and improve energy efficiency. These results may reveal us an alternative pathway towards transportation electrification. [ABSTRACT FROM AUTHOR]

The present study examines the history of Depression era financing in the United States with respect to various New Deal programs and the impact they had on the development of stadia used by current institutions of the National Collegiate Athletic Association's Division I level (i.e., Football Bowl Subdivision and Football Championship Subdivision). Specifically, the current research provides findings and explanations regarding regional differences and presents data on the various New Deal programs. We further highlight the construction and renovation of stadia importantly created an atmosphere of "institutional legitimacy" for the universities, helped provide a substantial amount of work to the unemployed, and produced a significant amount of financial investments by the U.S. government. Practically, the present study offers the subsequent information as rhetorical work or as a resource for museums on and off campuses for the purpose of commercial gain, marketing, and cultivating the next generation of college football fans. [ABSTRACT FROM AUTHOR]

Forecasting construction spending is important for civil engineering practitioners to make business decisions. Currently, the main body of forecasting literature pertains exclusively to aggregate construction investment, such as total construction spending (TTLCON), private construction spending, or residential construction spending. But type-specific construction spending, such as that for education, healthcare, and religion, had yet to be explored using forecasting techniques. This case study presents a viable procedure by which aggregate and type-specific non-residential construction can be forecasted. The procedure that involves the use of the Granger causality test and the Vector Autoregression (VAR) model proved to be able to provide an accurate forecast pre-COVID-19, with some accuracy even during the COVID-19 pandemic period. Lessons learned include the following: (1) effort should be diverted towards model interpretation, as the impulse–response trial yields results conforming to current well-established empirical evidence; (2) a type-specific approach should be adopted when analyzing construction spending, as different types of construction spending react differently to potential indicators; and (3) complex models incorporating multiple indicators should be used to generate a forecast, as a complex model has a higher chance of containing parameters explanatory of the target variable's features during the testing period. [ABSTRACT FROM AUTHOR]

Forecasting construction spending is important for civil engineering practitioners to make business decisions. Currently, the main body of forecasting literature pertains exclusively to aggregate construction investment, such as total construction spending (TTLCON), private construction spending, or residential construction spending. But type-specific construction spending, such as that for education, healthcare, and religion, had yet to be explored using forecasting techniques. This case study presents a viable procedure by which aggregate and type-specific non-residential construction can be forecasted. The procedure that involves the use of the Granger causality test and the Vector Autoregression (VAR) model proved to be able to provide an accurate forecast pre-COVID-19, with some accuracy even during the COVID-19 pandemic period. Lessons learned include the following: (1) effort should be diverted towards model interpretation, as the impulse–response trial yields results conforming to current well-established empirical evidence; (2) a type-specific approach should be adopted when analyzing construction spending, as different types of construction spending react differently to potential indicators; and (3) complex models incorporating multiple indicators should be used to generate a forecast, as a complex model has a higher chance of containing parameters explanatory of the target variable’s features during the testing period.

Robotics and automation technology (RAT) has emerged as one of the most important drivers of the Industry 4.0 digital transformation of industrial operations. Although RAT has been explored in construction over the last several decades, its applications in the field have been limited, despite its potential and rise in application opportunities. Prior studies have focused on the resistance factors that impact the adoption of RAT. However, there is limited work that simultaneously identifies the positive and negative factors that influence the decision of construction companies to adopt RAT. This study aims to identify, through semistructured interviews with prominent experts in the US, the positive and negative factors of adopting RAT and then use these adoption factors in a survey to allow these same experts to pairwise compare their importance. The survey results were prioritized based on their perceived impact on construction companies' decision-making using the analytic hierarchy process (AHP). The results indicated that the intention to use RAT is primarily positively affected by long-term cost savings and adversely affected mainly by the initial investment costs. Because construction professionals are inclined to make decisions on the adoption of RAT based mainly on costs, the understanding gained in this study of the other factors impacting RAT adoption decisions allows companies to improve how they manage their RAT adoption efforts. [ABSTRACT FROM AUTHOR]

In coal mining technology systems, it is very important to acquire, store, and represent basic geological data comprehensively and accurately. Based on the current working mode and information level in mining geology at coal mines, this paper proposes a process of building basic geological database for modeling of coal mines by using existing results' data of mining geology and develops the efficient program for getting the basic geological data from the important 2D plane drawings' achievement at mines, such as the contour maps of mine coal seam floors, geological cross-sections, underground drilling results, and geological survey results, based on AutoLISP, which is a programming language for the secondary development of AutoCAD. The obtained data in general text format is stored and managed by the MongoDB database, which realizes the storage, query, analysis, and correction of massive data of geological objects in the space of the underground coalmine. The application results show that compared with the previous data acquisition methods such as manual input and graphic transformation attribute, the extraction of spatial and attribute data from the existing mine 2D plane drawings by programming can effectively avoid the prominent problems such as artificial gross error, distortion of graph conversion, and different database structure, make the obtained spatial geological data more comprehensive, accurate, and effective, and, meanwhile, increase the rate by more than 60%, which plays an important role in data support for the construction of the geological modeling systems for transparent mines. [ABSTRACT FROM AUTHOR]

Proof of Work (PoW) is one of the key consensus mechanisms for blockchain systems to ensure trust and secure service. The PoW process, which is also known as mining, is computationally intensive, because the miners need to solve a well-crafted puzzle to add a new block to the chain. With cryptocurrency such as Bitcoin becoming more popular, it requires greater levels of mining power for successful mining. Most miners tend to join specific mining pools to share rewards contributed by their mining power. This leads to more centralized PoWbased blockchain systems, which contradicts the design goal of decentralization for blockchain. Mining power concentration may damage the trust and secure level of blockchain systems. However, no tools or studies could timely and quantitatively tell us how decentralized in terms of mining power the PoW blockchain system is. in this article, we design a decentralization index, called Endex, to efficiently quantify the degree of mining power decentralization and timely capture the abnormal phenomena of PoW blockchain systems. We then validate the effectiveness and accuracy of Endex over real mining datasets of four popular blockchain systems. The empirical study demonstrates that Endex can well capture the changes in mining power for these blockchain systems and detect in time the abnormal incidents such as double spending attack and hard fork. [ABSTRACT FROM AUTHOR]

The number of n-gaussoids is shown to be a double exponential function in n. The necessary bounds are achieved by studying construction methods for gaussoids that rely on prescribing 3-minors and encoding the resulting combinatorial constraints in a suitable transitive graph. Various special classes of gaussoids arise from restricting the allowed 3-minors. [ABSTRACT FROM AUTHOR]

The Korean domestic market is focused on the introduction of BIM (Building Information Modeling) owing to an influx of investment due to increased interest and mandatory application of BIM. However, the rate of BIM introduction is high, while BIM user proficiency is low. Against these problems, the authors proposed an acceptance model for BIM in construction organizations in 2012. As the number of BIM application cases increases and the number of BIM-trained users increases as time goes on, BIM users' positive perception of BIM values are expected to increase, which may change the BIM acceptance mechanism. Therefore, we conducted a longitudinal study of the 2012 BIM acceptance model against 2019 data to estimate changes in factors affecting BIM acceptance attitudes as well as the mechanism of the relationships between factors over time spent using the technology. To generalize the results, the respondents were spread across construction sites. The data obtained 119 samples from a sample of experienced users of BIM. We used AMOS 21.0 for hypothesis testing of structural equation modeling (SEM), and the 2019 BIM acceptance model was compared against the 2012 acceptance model using an independent sample t-test. As a result, it was confirmed that the 2012 BIM acceptance model is still suitable for describing the BIM acceptance mechanism of the construction organization, and there was a difference between the 2012 model and the 2019 model. This seems to have changed the mechanism of BIM acceptance by being change perception of BIM users as time goes on. The results of this study can be used to establish a BIM activation strategy for each BIM acceptance stage and are expected to be applicable to establishing a BIM activation strategy for construction organizations or countries with similar BIM acceptance stage. [ABSTRACT FROM AUTHOR]

The aim of this expert paper is to show development in the area of cartography in chronological order from the time when Albania first appeared on maps by well-known Venetian cartographers (with toponyms in Albanian). An overview of various topographic maps and maritime charts is presented, along with the relevant local and international institutions whose main activities were cartography and geoinformation during different periods. An expert opinion is expressed on the current state of cartographic and geoinformation data as a scientific discipline, with a special emphasis on alignment with international standards. [ABSTRACT FROM AUTHOR]

Strategically aligned and efficiently implemented spare parts logistics can differentiate a business from its competitors, lower costs, increase revenues, and thus help firms generate greater value for customers and ultimately increase profits. Based on multiple case studies with manufacturers in the machine and plant construction industry, this article examines the key components of a superior spare parts logistics strategy. The study suggests that an efficient spare parts logistics strategy can be developed with a three-step model that consists of nine components. [ABSTRACT FROM AUTHOR]

A set of lines through the origin in Euclidean space is called equiangular when any pair of lines from the set intersects with each other at a common angle. We study the maximum size of equiangular lines in Euclidean space and use a graph theoretic approach to prove that all the currently known constructions for maximum equiangular lines in R d cannot be added by any more lines to form a larger equiangular set of lines when d = 14 , 16 , 17 , 18 , 19 , and 20. We give new constructions of large equiangular lines which are 248 equiangular lines in R 42 , 200 equiangular lines in R 41 , 168 equiangular lines in R 40 , 152 equiangular lines in R 39 with angle 1/7, and 56 equiangular lines in R 18 with angle 1/5. [ABSTRACT FROM AUTHOR]

The US Consensus bureau estimated the total construction spending at 1,320,305 Million Dollars, in February 2020, with an increase of 1.1% since last February. The construction market is large, and risky. Prediction of the market behavior, for several years ahead, is needed in order to take strategic investment decision for long and expensive projects. The goal of this research is to study the relationship between population growth and the housing market. To that end, a system dynamics model is developed. System dynamics is a top-down approach that starts with the high-level behavior of a complex system to simulate the behavior of that system over time. The developed model simulates the housing market by matching the population growth with the housing demand in monthly time steps. As such, the parameters of the developed model include birth rate, life expectancy, immigration, emigration, and construction seasonality. Using these parameters, the model simulates the population size and demand for housing. For validation, the outputs of the model are compared with real-life data for the US. When complete, the model should assist market researchers in simulating the housing market. This research benefits large real estate developers, construction companies, governmental and financial agencies. [ABSTRACT FROM AUTHOR]

The shape of the mesoporous silica particles is rich and colorful. It has long been believed that the macroscopic structure of mesoporous silica particles is formed by continuously building microstructural units and growing them step by step. However, in this work, it is found that the growth process of mesoporous silica particles is not linear but stepped. The mesoporous silica particles grow up by repeating the process of "rapid construction of framework structure first and then slow construction of fine structure". The size of the mesoporous silica particles only grows stepwise when constructing the framework structure, but remains almost unchanged during subsequent fine structure construction. During the growth of the mesoporous silica particles, about one-sixth of the time is used to construct the framework structure, and the rest of the time is spent on the construction of fine structure. [ABSTRACT FROM AUTHOR]

This article presents a case study, explaining the effects of labor unions in context of residential construction industry. Several major hypotheses have been advanced to explain the greater efficiency which was found in the Ann Arbor study, (1) The higher union wage rate had led to a selective process by which the less efficient workers had been weeded out in the unionized city; (2) The union apprenticeship program had resulted in the training of superior workers in the union area; (3) Entrepreneurial efficiency in the Ann Arbor area was of a higher order because of (a) the "high-wage effect," and (b) the presence of an efficient competitive leader who was frequently from the Detroit area. The article summarizes the significance of the hypotheses for each trade. These evaluations are based on information gathered in the interviews. They reflect the relative emphasis placed on the hypotheses by interviewees in each of the trades. The results of this study give some cause for believing that unionization may bring an increase in efficiency and a much smaller rise in costs than had heretofore been expected.

It is surprising how little sound guidance is available to the corporate official who is about to acquire costly new facilities. In this article, five approaches to purchasing building construction are described and their cost and time attributes and relative advantages are analyzed. [ABSTRACT FROM AUTHOR]

The requirement for efficient public spending leads contracting authorities to use electronic reverse auctions (e-RA), a tool that allows achieving financial savings. In this study, we aim to explore the relationships between the different acting e-RA variables and to check for predictive models in order to infer on the savings amount in construction public procurement. Data on real construction auctions in Slovakia were statistically analysed by means of graphics tools, multiple regression analysis, test, and statistics for measuring the association between categorical variables. The results revealed that one should take the type of contract into account when considering the use of e-RA. This research provides several implications for purchasing practitioners in the area of construction procurement, especially with regard to the level of competition in the auction and estimation of savings potential. Presented findings aid managerial decision-making process of e-RA adoption. At the end, recommended future research directions in the investigated area are outlined. [ABSTRACT FROM AUTHOR]

Identification of costs drivers and their influence level on building development costs play a key role in the development of construction models and improve the efficiency and effectiveness of any project. Forty-five indicators influencing building development costs in New Zealand are explored by literature review and pilot interviews. These indicators are grouped into seven categories. The determination and ranking of the cost drivers are carried out by a questionnaire survey distributed to key professionals working in New Zealand's construction industry. Structural equation modeling (SEM) software was employed for analysis of the collected data. One of the key advantages of this powerful software is to provide the p-value according to the structure of the research model. Findings of this study indicate that the property market and construction industry factor, statutory and regulatory factor, and socio-economic factors are major factors affecting building development costs in New Zealand. [ABSTRACT FROM AUTHOR]

Purpose The purpose of this paper is to examine the assumptions concerning how the processes that foster trust are influenced by contractual control and managers’ propensity to trust. More specifically, the paper investigates the extent to which distinct types of trust (i.e. cognition- and affect-based trust) are differentially and interactively associated with contractual control and the propensity to trust.Design/methodology/approach The authors collected survey data on 260 architect–contractor project-based relationships in China.Findings The results of this paper show that contractual control and a project manager’s propensity to trust are positively related to the managers’ trust in their partners. However, the interaction of the propensity to trust and contractual control has a negative effect on cognition-based trust. Cognition-based trust, in turn, is linked to the unique and interactive relationships between contractual control, the propensity to trust and affect-based trust.Research limitations/implications While this paper adds to the literature on trust and control, future research is needed to fully understand the differences in interpersonal trust across alliances and countries.Practical implications These findings provide important implications for firms hoping to facilitate active trust development processes.Originality/value More is now known about the trust in inter-organizational settings at the individual level. [ABSTRACT FROM AUTHOR]

Various works have been carried out on both the physical and mechanical properties of rubberized concrete in previous research. But the chemical composition of rubberized concrete has not been fully investigated. The scanning electron microscopy (SEM) and energy-dispersive x-ray spectrum (EDX) analysis were used to determine the element composition and the peak intensity of chemical elements in the waste rubber concrete. The SEM and EDX analysis results showed that, ferrous iron, oxygen, calcium, and silicon were the dominant elements, and these elements reduced as more waste rubber were added to the concrete. Carbon and sulphur elements increased as rubber crumbs were added to the rubberized concrete. The work concluded that the presence of rubber crumb in the concrete samples contributed to both mechanical and chemical changes in the property of rubberized concrete. [ABSTRACT FROM AUTHOR]

Surpassing of the planned budget and delivery time is a common feature during the implementation of building investments in Poland. Only a small number of companies use effective methods of project monitoring during investment performance. One of the popular tools used to control projects with regard to cost and time is the earned value method (EVM). There is, however, no detailed guidance how to deploy the method to the specific characteristics and conditions during the execution of building investments. This fact has contributed to this paper, which presents the results of application and adaptation of the earned value method (EVM) and its further extensions in the control of building projects during their execution (with regard to cost and time), prediction of the final duration and costs, and presentation of the effects resulting from calculations. The analyses were performed in terms of the contractor for 5 selected completed and ongoing building projects in Poland. [ABSTRACT FROM AUTHOR]

This paper is set in the context of constraint-based construction alternative scheduling with complex temporal constraints. In construction schedules, the relationships among constraints directly impact the scheduling solution. Conflicting constraints make solving a scheduling problem infeasible, while redundant constraints, especially disjunctive ones, could tremendously increase computation time. Conflicting and redundant constraints hence should be determined in the prescheduling stage to enhance scheduling feasibility and efficiency. In this regard, a constraint integration reasoning framework is developed to identify primary and secondary conflicts and redundancies in schedule constraints. The framework comprises sets of rules for the inference of these conditions within each activity or between two activities. It also computes the feasible range of activity durations, which will be useful for planners in modifying and updating schedules. The framework has been applied to alternative construction scheduling and implemented in ECLiPSe, a constraint logic programming language. An illustrative example of a simplified gas pipe installation project is presented to demonstrate the usage of the framework as a prescheduling constraint analysis tool. [ABSTRACT FROM AUTHOR]