scholarly journals Determination of construction process duration based on labor productivity estimation: A case study

2021 ◽  
Vol 13 (2) ◽  
pp. 2521-2538
Author(s):  
Darja Kubečková ◽  
Stanislav Smugala
Keyword(s):  
Labor Productivity ◽  
Planning Process ◽  
Mean Value ◽  
Climatic Conditions ◽  
Statistical Analyses ◽  
Automated System ◽  
Performance Standard ◽  
Construction Process ◽  
Construction Costs ◽  
Time Required

Abstract Monitoring labor productivity and how to decrease construction costs are the key issues in the planning process of a construction project. The CONTEC automated system combined with statistical methods assists in predicting the amount of time required to complete construction works according to the specified number of deployed work crews, technological processes, and labor required for certain production in person-hours. This study applies statistical analyses and probability theories for plastering work, which represents a labor-intensive construction process. The goal of the research is to determine the probability of completion of the construction process based on monitoring the mean value of performance. By application of statistical analyses a decrease in the performance standard has been proved compared with the planned values given in the CONTEC database. The decrease in performance, which was also caused by the number of days with unfavorable climatic conditions and demonstrated by performing interval estimates based on the collection of statistical data, was later confirmed by a relative frequency test. The measures taken were in terms of establishing the required number of personnel capacities for complying with the construction schedule.

scholarly journals An Investigation into Factors Influencing Construction Costs Based on Japanese, UK and US Contractor Practice

2012 ◽  
Vol 2 (2) ◽  
pp. 27-35
Author(s):  
Hong Xiao ◽  
David Proverbs
Keyword(s):  
Indirect Costs ◽  
Construction Cost ◽  
Office Building ◽  
Construction Process ◽  
Close Attention ◽  
Construction Costs ◽  
Cost Performance ◽  
Factors Influencing ◽  
Site Design ◽  
The Uk

Construction cost is a major concern to both clients and contractors. Based on a hypotheticalconstruction project (a six-storey concrete framed office building), cost and otherrelated information was collected through a survey of contractors in Japan, the UK and theUS. Using multiple regression analysis it was found that lower overheads, less prefabricatedcomponents, and fewer design variations could reduce construction cost. Overheadslargely represent indirect costs to contractors and if reduced can lead to increased profitlevels and improved competitiveness. The use of prefabricated components may be problematicwhere there are delays in production, insufficient coordination between design andconstruction, and congested transportation on site. Design variations during constructionbring about uncertainties and are disruptive to the construction process. These factorshave paramount impact on construction cost and demand close attention and consideration.Contractors are advised to reduce the costs of their overheads and utilise prefabricationappropriately, while clients and designers should minimise the number of designvariations during construction if better cost performance is desired.

scholarly journals Phyllochron estimation in intercropped strawberry and monocrop systems in a protected environment

2012 ◽  
Vol 34 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Heloísa Ferro Constâncio Mendonça ◽  
Eunice Oliveira Calvete ◽  
Alexandre Augusto Nienow ◽  
Rosiani Castoldi da Costa ◽  
Lucas Zerbielli ◽  
...  
Keyword(s):  
Linear Regression ◽  
Production Systems ◽  
Block Design ◽  
Mean Value ◽  
Angular Coefficient ◽  
Degree Days ◽  
Camino Real ◽  
Fig Trees ◽  
Time Required ◽  
Strawberry Cultivars

The phyllochron is defined as the time required for the appearance of successive leaves on a plant; this characterises plant growth, development and adaptation to the environment. To check the growth and adaptation in cultivars of strawberry grown intercropped with fig trees, it was estimated the phyllochron in these production systems and in the monocrop. The experiment was conducted in greenhouses at the University of Passo Fundo (28º15'41'' S, 52º24'45'' W and 709 m) from June 8th to September 4th, 2009; this comprised the period of transplant until the 2nd flowering. The cultivars Aromas, Camino Real, Albion, Camarosa and Ventana, which seedlings were originated from the Agrícola LLahuen Nursery in Chile, as well as Festival, Camino Real and Earlibrite, originated from the Viansa S.A. Nursery in Argentina, were grown in white polyethylene bags filled with commercial substrate (Tecnomax®) and evaluated. The treatments were arranged in a randomised block design and four replicates were performed. A linear regression was realized between the leaf number (LN) in the main crown and the accumulated thermal time (ATT). The phyllochron (degree-day leaf-1) was estimated as the inverse of the angular coefficient of the linear regression. The data were submitted to ANOVA, and when significance was observed, the means were compared using the Tukey test (p < 0.05). The mean and standard deviation of phyllochrons of strawberry cultivars intercropped with fig trees varied from 149.35ºC day leaf-1 ± 31.29 in the Albion cultivar to 86.34ºC day leaf-1 ± 34.74 in the Ventana cultivar. Significant differences were observed among cultivars produced in a soilless environment with higher values recorded for Albion (199.96ºC day leaf-1 ± 29.7), which required more degree-days to produce a leaf, while cv. Ventana (85.76ºC day leaf-1 ± 11.51) exhibited a lower phyllochron mean value. Based on these results, Albion requires more degree-days to issue a leaf as compared to cv. Ventana. It was conclude that strawberry cultivars can be grown intercropped with fig trees (cv. Roxo de Valinhos).

scholarly journals A new clustering and visualization method to evaluate urban energy planning scenarios

2018 ◽  
Author(s):  
Sara Torabi Moghadam ◽  
Silvia Coccolo ◽  
Guglielmina Mutani ◽  
Patrizia Lombardi ◽  
Jean Louis Scartezzini ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Urban Areas ◽  
Energy Demand ◽  
Planning Process ◽  
Energy Transition ◽  
Climatic Conditions ◽  
Energy Planning ◽  
Transition Strategies ◽  
Urban Energy ◽  
The City

The spatial visualization is a very useful tool to help decision-makers in the urban planning process to create future energy transition strategies, implementing energy efficiency and renewable energy technologies in the context of sustainable cities. Statistical methods are often used to understand the driving parameters of energy consumption but rarely used to evaluate future urban renovation scenarios. Simulating whole cities using energy demand softwares can be very extensive in terms of computer resources and data collection. A new methodology, using city archetypes is proposed, here, to simulate the energy consumption of urban areas including urban energy planning scenarios. The objective of this paper is to present an innovative solution for the computation and visualization of energy saving at the city scale.The energy demand of cities, as well as the micro-climatic conditions, are calculated by using a simplified 3D model designed as function of the city urban geometrical and physical characteristics. Data are extracted from a GIS database that was used in a previous study. In this paper, we showed how the number of buildings to be simulated can be drastically reduced without affecting the accuracy of the results. This model is then used to evaluate the influence of two set of renovation solutions. The energy consumption are then integrated back in the GIS to identify the areas in the city where refurbishment works are needed more rapidly. The city of Settimo Torinese (Italy) is used as a demonstrator for the proposed methodology, which can be applied to all cities worldwide with limited amount of information.

scholarly journals The mass balance of a cirque glacier in the Italian Alps (Ghiacciaio Della Sforzellina, Ortles–Cevedale Group)

1993 ◽  
Vol 39 (131) ◽  
pp. 87-90
Author(s):  
G. Catasta ◽  
C. Smiraglia
Keyword(s):  
Mass Balance ◽  
Mean Value ◽  
Climatic Conditions ◽  
Mass Balances ◽  
Italian Alps ◽  
Variation Data ◽  
Using Data

AbstractThe net mass balance (1986/87–1989/90) was calculated for a small cirque glacier in the Italian Alps (Ghiacciaio della Sforzellina, 0.42 k m2, Ortles–Cevedale Group). Four annual mass balances are presented here. All four balances were negative (mean value: –0.90 m year−1), with a maximum deficit of –1.16 m year−1 in 1989–90. The climatic conditions (which are analyzed using data from the S. Caterina Valfurva Station) consisted of a succession of cold, dry winters with little snowfall. Frontal-variation data available since 1925 show a constant retreat until 1966, followed by a brief advance period which has already terminated.

scholarly journals Labor Productivity Convergence in Indonesia: Spatially Dynamic Panel Data Analysis

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Ahmad Fajar Novianto ◽  
Waris Marsisno
Keyword(s):  
Panel Data ◽  
Labor Productivity ◽  
Panel Data Analysis ◽  
Estimation Method ◽  
Dynamic Panel Data ◽  
Tertiary Sector ◽  
Dynamic Panel ◽  
Productivity Convergence ◽  
Time Required ◽  
Dynamic Panel Data Analysis

The problem of labor productivity in Indonesia is a regional and sectoral inequality. To know the time required to remove inequality, can be measured by the level of convergence of labor productivity. The research would analyze the rate of sectoral labor productivity convergence among provinces in Indonesia spatially and identify the determinant factors of labor productivity. The analytical methods used is spatial dinamic panel data with Spatially Corrected Blundell-Bond (SCBB) estimation method. The results show that there are spatially sectoral labor productivity convergence. Primary sector takes the longest half-life convergence of 7-8 years, while secondary takes 1-2 years and tertiary sector takes 3-4 years. Furthermore, the Gross Capital Fixed Formation, Mean Years of Schooling, and real wage sectoral are significantly have positive affect to the labor productivity while Life Expectancy is significantly have negative affect to labor productivity.Keywords : convergence, spatial analysis, labor productivity

The influence of climatic conditions on physiological and behavioural parameters in dairy cows kept in open stables

2004 ◽  
Vol 78 (1) ◽  
pp. 139-147 ◽  
Author(s):  
M. Zähner ◽  
L. Schrader ◽  
R. Hauser ◽  
M. Keck ◽  
W. Langhans ◽  
...  
Keyword(s):  
Mean Value ◽  
Climatic Conditions ◽  
Air Humidity ◽  
Lactating Cows ◽  
Relative Air Humidity ◽  
Infra Red ◽  
Commercial Farms ◽  
Humidity Index ◽  
Body Surface Temperature ◽  
Night And Day

AbstractThis study aimed to assess whether cows are able to cope with the range of climatic conditions they are exposed to in open stables on commercial farms in central Europe. On each of four farms, ten lactating cows were observed over a total of five weeks in winter, spring and summer. Based on continuous measurements of air temperature (–13·8 to 28·7ºC) and relative air humidity (0·26 to 0·99), a mean value of a temperature humidity index (THI) was calculated for each farm and each observation day for night and day.THI had significant effects on skin temperature and body surface temperature (infra-red thermography) both during night and day. Rectal temperature, duration of lying and cortisol concentration in the milk was significantly affected by THI during the day but not during the night. Heart rate and frequency of lying did not significantly covary with THI. Differences between farms and interactions between THI and farm were significant for most parameters. These results suggest that the climatic conditions during the day induced stronger thermoregulatory responses than the conditions during the night. Within the measured range of climatic conditions the cows were hardly exposed to severe cold or heat stress.

scholarly journals Management of defective works in infrastructure projects

2018 ◽  
Vol 9 (1) ◽  
pp. 73-80
Author(s):  
E. Gashi
Keyword(s):  
Complex Nature ◽  
Skilled Labor ◽  
Construction Process ◽  
Construction Costs ◽  
Engineering Project ◽  
Construction Company ◽  
Professional Groups ◽  
Project Costs ◽  
Construction Defects

Constructing a new building or any other civil engineering project from scratch is a challenge for the construction industry as novelty designs may be produced by designers but they are often constructed by low skilled labor on site. The unique and sometimes complex nature of the construction sector arises because a large number of different professional groups have different interests and requirements, which often conflict with one another. In principle, each construction company aims to construct a project without any defects from the very first activity on site right up to final completion. This aim is almost impossible to achieve throughout the entire construction duration because of many factors, including: low skilled labor, difficult site conditions, and incomplete designs, varying quality cultures in each company, poor communication and poor management. Therefore, construction defects are things which we can assume to have occurred on the site. Defects occurring during the construction process are sometimes costly and preventable mistakes. Research has shown that correcting defective components that are identified late in the construction process or during the maintenance period accounts for approximately 15% of the total construction costs. This paper presents a case study of the defects that occurred during a motorway construction project as a consequence of poor workmanship by an untrained workforce and it aims to raise awareness of the need for on-the-job training for quality managers in order to minimize defective works and reduce the project costs spent on correcting them. It also identifies the various factors that cause construction defects and suggests measures that can be taken to reduce them.

scholarly journals Chromosomal Q-Heterochromatin and Atherosclerosis

2017 ◽  
Vol 7 (1) ◽  
pp. 143
Author(s):  
A. I. Ibraimov
Keyword(s):  
Homo Sapiens ◽  
Single Species ◽  
Causative Factor ◽  
Mean Value ◽  
Biological Species ◽  
Climatic Conditions ◽  
Cold Climate ◽  
High Mountain ◽  
Mountain Areas ◽  
Blood Temperature

We suppose that at study of the pathogenesis of atherosclerosis, it is possible that some evolutionary aspects of the problem are missed. This aspect is related to the peculiarity of human adaptation to climatic geographic conditions of Eurasia, which differ significantly from the climate of East Africa, where Homo sapiens was formed as a tropical biological species and so it has remained to this day. A hypothesis has been put forward that the pathogenesis of atherosclerosis is associated with some previously unknown features of the genome and the physical properties of the human body that arose in the process of its adaptation to a mild and cold climate. These adaptive genetic changes that have contributed to the development (settling) by Homo sapiens of non-tropical, including cold and high mountain areas of the Earth, resulted to the fact that a man became the single species vulnerable (predisposed) to atherosclerosis.Atherosclerosis is apparently a purely human disease that appeared after adaptation of man to climatic conditions of temperate and northern latitudes of the northern hemisphere. The type of vessels (arteries or veins) and the site of their lumen have no role in the development of atherosclerotic changes. The primary and main causative factor in the development of atherosclerosis is blood temperature. The degree of blood cooling in the lungs depends on geographical latitudes and altitude above sea-level of the site of permanent residence of man. The preclinical stage of atherosclerosis may develop into a pathological form predominantly in individuals in the genome of which the amount of chromosomal Q-heterochromatin material is higher than its mean value per individual in the population.

scholarly journals Testing of IQ™ 200 Automated Urine Analyzer Analytical Performances in Comparison with Manual Techniques

2009 ◽  
Vol 28 (2) ◽  
pp. 122-128
Author(s):  
Velibor Čabarkapa ◽  
Mirjana Đerić ◽  
Zoran Stošić
Keyword(s):  
Comparative Analysis ◽  
Urine Analysis ◽  
Automated System ◽  
Automated Systems ◽  
Sample Analysis ◽  
Operation Procedure ◽  
Time Required ◽  
Very High ◽  
Higher Sensitivity

Testing of IQ™ 200 Automated Urine Analyzer Analytical Performances in Comparison with Manual Techniques Automation is necessary in laboratory systems. It enables reduction of time required for sample analysis, as well as standardization of methods. However, automation of urine control in laboratories is much less common than in hematological analyses. Not long ago, the necessary automated systems for urine analysis have also been developed. The objective of this study is a comparison of the IQ™ 200 automated system for urine analyzing with standardized manual urine analyzing techniques. Comparative analysis of 300 samples was performed by the IQ™ 200 system and by the standardized methods of manual microscopy and chemical urine analysis. The results acquired point to very high compatibility between urine analyses by manual techniques and by the automated system IQ™ 200, and in some analyses IQ™ 200 showed higher sensitivity. It can be concluded, with the aim of standardization and shortening of time required for urine analysis, that utilization of automated urine analyzing systems is recommendable, especially in institutions with a large number of daily analyses. This is also supported by the fact that operation procedure on automated systems is much more simple in comparison to manual techniques.

scholarly journals Open BIM-based quantity take-off system for schematic estimation of building frame in early design stage

2014 ◽  
Vol 2 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Jungsik Choi ◽  
Hansaem Kim ◽  
Inhan Kim
Keyword(s):  
Construction Projects ◽  
Design Stage ◽  
Prototype System ◽  
Construction Costs ◽  
Building Frame ◽  
Early Design ◽  
Early Design Stage ◽  
Construction Automation ◽  
Time Required ◽  
Stage 1

Abstract Since construction projects are large and complex, it is especially important to provide concurrent construction process to BIM models with construction automation. In particular, the schematic Quantity Take-Off (QTO) estimation on the BIM models is a strategy, which can be used to assist decision making in just minutes, because 70–80% of construction costs are determined by designers' decisions in the early design stage [1]. This paper suggests a QTO process and a QTO prototype system within the building frame of Open BIM to improve the low reliability of estimation in the early design stage. The research consists of the following four steps: (1) analyzing Level of Detail (LOD) at the early design stage to apply to the QTO process and system, (2) BIM modeling for Open BIM based QTO, (3) checking the quality of the BIM model based on the checklist for applying to QTO and improving constructability, and (4) developing and verifying a QTO prototype system. The proposed QTO system is useful for improving the reliability of schematic estimation through decreasing risk factors and shortening time required.

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