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Abstract

Construction projects are much appreciated by both client and contractor when completed on schedule and within budget so as to avoid cost overruns. The Zambian building sector normally experiences time and cost overruns. This study investigated the feasibility of using tilt-up construction in the construction of commercial building walls. The methodology used consisted of a literature review, a questionnaire survey and a scenario analysis consisting of a hypothetical 4900 square meter commercial building with a height of 8 meters. Sixty-six questionnaires were administered to design professionals operating in the Zambian building sector using simple random sampling and thirty-six were returned giving a response rate of 55%. The data were analyzed using descriptive statistics. Cost analysis was done on a hypothetical building as no contractor was found using tilt-up construction in the construction sector. The study established that tilt-up was, in fact, more expensive than the conventional methods (concrete blocks and in-situ reinforced concrete walls), but it was faster, hence, making it viable in respect to time and not cost in the Zambian construction industry (ZCI). Additionally, necessary expertise was available with the exception of a certified tilt-up practitioner and a sealant sub-contractor in cases where a sealant contractor is needed. The study has identified that currently in the Zambian building sector tilt-up construction can be used when time is more important than the cost. However, challenges such as site size (limited space), the unavailability of building regulation for tilt-up construction and the economic capacity of the client or capacity need to be addressed for enhancing the practical application of tilt-up construction in ZCI.

Abstract

This study tries to investigate project success through inclusive leadership role along with self-efficacy. Data sets were collected using adopted questionnaires of previous studies from employees working on the metro bus project, their supervisors and passengers of metro bus service from Rawalpindi to Islamabad route in Pakistan. This study is measuring the effects of inclusive leadership on project success through self-efficacy which makes it causal in nature. The time lag data collection method was adopted. In order to reach correct findings, potential biases were controlled by theoretical and statistical controls. Exploratory factor analysis was used to test structural modelling, average variance and composite reliabilities using Smart PLS. SPSS 21.0 was used for regression analysis, bias correction measures were also considered. The study revealed that inclusive leadership is associated in a positive manner with project success. The mediating role of self-efficacy in the relationship of inclusive leadership and project success was also supported. In addition, theoretical and practical implications in the context of this study are discussed in detail.

Abstract

Integrated Project Delivery (IPD) is introduced as a new delivery system that fosters high efficiency by delivering accurate information and new technologies in a collaborative team environment. In this sense, the research aimed to review the IPD principles and their main categories, such as contract, process, information & modeling (I&M), team and communication as well as perform a qualitative analysis to illustrate the current research trends. The qualitative analysis performed was made through a series of collected articles from 2001 to 2018 in 08 different scientific database websites. In terms of the results, the contract category illustrated a strong trend, where the studies are focus on collaborations and frameworks to enhance high efficiency in construction. In the I&M category, demonstrated an increasing trend applying the Building Information & Modeling (BIM) subject as well as team category, where showed the importance of a wellstructured team and their impact on the project., The process and communication categories illustrated a weak trend, allowing opportunities in the field. Finally, the current study reviewed and analyzed the IPD and its main categories allowing a solid basis for future research.

Abstract

Voice recognition technology has been in existence over several decades but its application in the construction industry has been minimal. Despite the several advantages it offers, its application has been limited to smart building integration only. This study has made a significant contribution by integrating voice recognition technology into key-in building quantities estimation software. The Visual Basic programming language was used to design and code the interface of the voice recognition system and key-in estimating software model. The prototype model continues to have some challenges because it cannot work efficiently in a noisy work environment and there is limited range of vocabulary it can recognize. This paper seeks to challenge the stakeholders of the construction industry to maximize the benefits of voice recognition technology and integrate it into other construction tasks. In addition, future research can consider integrating building information modeling and voice recognition technology.

Abstract

The load factor is the determining factor for airlines in economic terms and the prediction of the future development of the flight route. The combination of load factor and break-even point provides the airline with a comprehensive picture of the business of the flight route and the optimization of pricing for the flight route. The purpose of the article is to propose and adapt the development of air transport prices on a given line using maximally recalculated values and maximize profit. The optimized calculation algorithm then facilitates the understanding of the individual steps of the load factor calculation and the monitoring of price development by means of the chi-square mathematical method by which we observed the interconnection of the ticket price and the load factor. To describe the problem, we chose the Bratislava – Larnaca route.

Abstract

The paper analyzes the costs of production of wood sawdust briquettes, manufactured by the company Brykiet-Pol2, based in Goleszów in southern Poland. In addition, production technology, raw material supply and distribution of the finished product were analyzed. The costs of producing one ton of briquettes for the four assessed variants ranged from PLN 364.8 (option D) to PLN 648.7 (option A). The cost structure was dominated by the purchase of raw material and depreciation of the technological line. The most economically advantageous production variant was option C, currently implemented in the company (production costs: PLN 458.7·t−1), and the proposed option D, using two briquetting presses. The latter option increased production efficiency and reduced unit costs of briquette production in a three-shift system around the clock.

Abstract

One of the important factors on which road safety depends is adequate visibility. This article analyses horizontal visibility within road intersections. The visibility condition depends on many factors, primarily on the geometric parameters of road elements and the location of buildings, fences, vegetation etc., neighboring the road. The aim of the research presented in the study was to determine the current condition of horizontal visibility, on the example of twenty two intersections located mostly in built-up rural area along a provincial road near Czestochowa. The research was carried out by two methods (the analysis of satellite photographs and the visual method) and the obtained results were compared. The assessment of the security level was based on applicable regulations and technical guidelines. It was found that the results of the visibility assessment based only on the analysis of maps and satellite photographs are in many cases overestimated, due to the fact that many small elements not visible in the photographs are not taken into account and the occurrence of convex vertical road arches within the field of visibility. However, the main reason for the insufficient visibility at the many intersections is the fact that the geometrical parameters of roads and their surroundings were shaped in the past when the traffic conditions were completely different. It was also noted that road managers perceive this problem and take measures to increase safety within road intersections.

Abstract

The article presents an analysis of the energy, mechanical and chemical properties of pellets made of wood material. According to the manufacturer, wood pellets were made of hard wood shredded to fractions approx. 1 mm thick and up to 3-4 mm long, and of a waste source - sawdust. Measurements of the selected properties were carried out on pellets with a diameter of 6 and 8 mm. Mechanical durability, humidity, crumble rate, ash quantity, calorific value were determined, as well as macronutrient and heavy metals content. The calorific value of pellets, with moisture content from 7.48% to 6.76% and ash content from 0.31% to 0.55%, ranged from 17.71-19.18 MJ·kg−1, which testified to the beneficial energy use of the tested raw material. Based on the conducted research, it was found that the mechanical properties of pellets made of both sawdust and hard wood predispose them for use as boiler fuel. The tested materials met high quality standards for wood pellets used for non-industrial and industrial purposes.

Abstract

Field tests on the quality of shaking off redcurrant fruit Rosetta cultivar with a half-row trailer harvester “Marek” produced by Dom-Wid were carried out. The tests were performed at two average working speeds ῡ1 = 0.47 m·s−1; ῡ2 = 0.60 m·s−1 and two rotational speeds of a tractor n1 = 1500 rpm; n2 = 1900 rpm. The length and diameter of shoots of redcurrant, length of a bunch, number of fruits in a bunch and mass of fruit were measured. Weather conditions were presented: rain fall, air temperature and moisture. Analysis of results showed that the working speed and the rotational speed has a significant impact on the quality and amount of the yield. At the highest rotations, the harvesting quality of fruit by a harvester was the worst and was 77.15%.

Abstract

Designing and proper implementation of effective processes and providing the customer with high quality products undoubtedly determines the stable position on the market. The aim of the study was to analyse the cost and value of the technological process of doors in the context of creating added value and to identify unnecessary processes (not creating added value) in relation to which appropriate corrective actions could contribute to their elimination. Thanks to the application of remedial measures, consistent with the lean manufacturing concept, the study eliminated, among other things, operations related to unnecessary transport and storage of products, which resulted in both the reduction of time and costs of process implementation.