Empirical Analysis of Construction Enterprise Information Systems: Assessing System Integration, Critical Factors, and Benefits

Attaining higher levels of system integration is seen as the primary goal of construction enterprise information systems (CEIS). Increased system integration resulting from CEIS implementation is expected to lead to numerous benefits. These benefits encompass information technology infrastructure and strategic, operational, organizational, and managerial aspects of the firm. By adopting CEIS, firms seek tangible and intangible benefits, such as cost reduction, improved productivity, enhanced efficiency, and business growth. Through the use of statistical analysis, this study quantifies the critical success factors that impact CEIS integration and the ensuing benefits. Furthermore, it analyzes the effects of system integration on CEIS induced benefits. It also investigates the impact of CEIS strategy on CEIS induced benefits and identifies the relationship between CEIS strategy and system integration. Finally, it assesses the effects of CEIS induced benefits on user satisfaction and provides a CEIS implementation guide map for construction firms.     

Geometric versus geographic models for the estimation of an FTTH deployment

Optical access networks provide a future proof platform for a wide range of services, and today, several operators are deploying fibre to the home (FTTH) networks. Installing an FTTH infrastructure, however, involves very high investment cost. Therefore, a good estimation of the investment cost is important for building a successful business strategy and, consequently, to speed up the FTTH penetration. In this paper, for calculating the amount of cable and fibre in the outside plant together with the associated civil works, and the number of required network elements, two different approaches are investigated: (1) geometric modelling of the fibre plant based on approximate mathematical models and (2) geographic modelling of the fibre plant based on map-based geospatial data. The results obtained from these two approaches can then be used as input for preliminary investment cost calculations and/or techno-economic evaluations. Compared to more complex and accurate geographic modelling, we verify that especially with uneven population density and irregular street system, simple geometric models do not provide accurate results. However, if no geospatial data is available or a fast calculation is desired for a first estimation, geometric models definitely have their relevance. Based on the case studies presented in this paper, we propose some important guidelines to improve the accuracy of the geometric models by eliminating their main distortion factors.     

Air gauges as a part of the dimensional inspection systems

Air gauges for dimensional measurement are known for decades. They have been applied in many technological processes, especially in the systems of in-process control. The air gauges are connected with pneumatic measuring devices able to generate control signals. Nowadays, however, it is not enough to just indicate dimensional bounds of tolerance. The Quality Management Systems require recorded and processed data achieved during the measurement. Investigations led to the development of air gauges integrated with piezoresistive pressure transducers. In those systems the results of measurement are achieved in digital form, they are processed and recorded. Additionally, dynamical properties of integrated air gauges appear much better. Multipoint linearization of the air gauge appears to be advantageous, though some companies offer the adjustment using one setting master only.     

Linear programming approach to construction equipment and labour assignments

At present, well established practices for the analysis of construction costs exist. However, a need to scrutinize with more detail the construction cost components may arise when a possibility of employing various resources to construct a project is present. Two mathematical models that allow the performance of such analyses are presented and suggestions for further research are given. The presented procedures could also be utilized as a tool to determine new required performance for equipment in large volume projects.     

Improving the Physicochemical Properties of Fe–25Cr Ferritic Steel for SOFC Interconnects via Y-Implantation and Y2O3-Deposition

The present study investigated the role of the reactive-element effect (REE) in improving the corrosion resistance, chromium vaporization rate, and electrical conductivity of the Fe–25Cr ferritic steel modified either by means of yttrium implantation or chemical deposition of yttrium oxide from metaloorganic compound vapors. The corrosion kinetics of the Fe–25Cr steel, both pure and modified, were determined under isothermal conditions in air and an Ar–H₂–H₂O gas mixture at 1,073 K. A significant improvement in corrosion resistance was observed after surface modification. XRD and SEM–EDS investigations showed that the protective Cr₂O₃ layer formed the main part of the scale. Measurements of Cr vaporization rate in the air–H₂O gas mixture revealed that both surface modifications of the steel significantly suppressed the formation of volatile chromium compounds to a large degree. The yttrium-implanted steels oxidized both in air and the Ar–H₂–H₂O mixture were characterized by the lowest area specific resistance and thereby did not exceed the acceptable ASR level (0.1 Ω cm²) for interconnect materials in the temperature range of 973–1,073 K, unlike pure steel and the steel coated with Y₂O₃.     

A new formula for determining a minimum recommended value of inlet air velocity from UFAD system to prevent occupants from draught risk

During the winter period the natural convection flow along a cold window surface can be the cause of thermal discomfort. Warm air blown into the room near the window prevents occupants from draught risk. The paper presents a new formula for determining a minimum recommended value of inlet air velocity. A balance of a momentum flux of flow of the down draught currents and the warm air jet inflow from the UFAD (under floor air distribution) system was a base for the analytical solution. In order to estimate air movement in a typical room, numerical simulations are executed. A computational model of the room with the UFAD system is constructed within the CFD environment developed by Fluent Inc. Ten cases with varying inlet air parameters and a window U$U$-value are considered. The analytical estimation of minimum inlet air velocity is confirmed by simulation results of temperature and velocity distributions.     

The accuracy of a solid packing fraction model in recognizing zones of different dendritic structures

A front tracking method on a fixed control-volume grid, based on assumed dendrite tip kinetics, is applied to discuss the accuracy of a numerical model where the coherency solid fraction is used in the identification of diverse dendritic regions developing within a mushy zone during binary alloy solidification driven by diffusion and thermo-solutal buoyancy forces. It is shown that this critical value of a solid volume fraction is not constant but changes with time and along the border separating the regions.     

Determination of thoron equilibrium factor from simultaneous long-term thoron and its progeny measurements

With 3-month simultaneous measurements of thoron and its progeny concentrations in the lowest floors of 109 homes, the geometric mean (GM) of thoron equilibrium factor was determined to be 0.019 with a geometric standard deviation (GSD) of 3.63. Combined with the analysis from results obtained from a previous study in 138 homes, the GM of thoron equilibrium factor was determined to be 0.022 with a GSD of 3.02. The results indicate that the F value of 0.02 for thoron recommended by UNSCEAR is a reasonable value for those Canadian homes tested.     

AMON: a wearable multiparameter medical monitoring and alert system

This paper describes an advanced care and alert portable telemedical monitor (AMON), a wearable medical monitoring and alert system targeting high-risk cardiac/respiratory patients. The system includes continuous collection and evaluation of multiple vital signs, intelligent multiparameter medical emergency detection, and a cellular connection to a medical center. By integrating the whole system in an unobtrusive, wrist-worn enclosure and applying aggressive low-power design techniques, continuous long-term monitoring can be performed without interfering with the patients' everyday activities and without restricting their mobility. In the first two and a half years of this EU IST sponsored project, the AMON consortium has designed, implemented, and tested the described wrist-worn device, a communication link, and a comprehensive medical center software package. The performance of the system has been validated by a medical study with a set of 33 subjects. The paper describes the main concepts behind the AMON system and presents details of the individual subsystems and solutions as well as the results of the medical validation.