Four-Dimensional Visualization of Construction Scheduling and Site Utilization

Four-dimensional (4D) models link three-dimensional geometrical models with construction schedule data. The visual link between the schedule and construction site conditions is capable of facilitating decision making during both the planning and construction stages. The emphases of these 4D developments have often been placed at the level of construction components. Practical features assisting site management are at times lacking in the following areas: (1) generation of site usage layouts; (2) estimation of quantities of construction materials; and (3) cost evaluation. In order to pinpoint these deficiencies, the objective of this work is to enable visual study of the effects of job progress on the logistics and resource schedules. This paper presents a 4D visualization model that is intended both to help construction managers plan day-to-day activities more efficiently in a broader and more practical site management context and to thereby add to our knowledge and understanding of the relevance of modern computer graphics to the responsibilities of the construction site manager. A brief site trial of the software is described at the conclusion of the paper.     

Generalized Hough Transform Using Regions with Homogeneous Color

A novel generalized Hough transform algorithm which makes use of the color similarity between homogeneous segments as the voting criterion is proposed in this paper. The input of the algorithm is some regions with homogeneous color. These regions are obtained by first pre-segmenting the image using the morphological watershed algorithm and then refining the resultant outputs by a region merging algorithm. Region pairs belonging to the object are selected to generate entries of the reference table for the Hough transform. Every R-table entry stores a relative color between the selected region pairs. This is done in order to compute the color similarity and in turn generate votes during the voting process and some relevant information to recover the transformation parameters of the object. Based on the experimental results, our algorithm is robust to change of illumination, occlusion and distortion of the segmentation output. It recognizes objects which were translated, rotated, scaled and even located in a complex environment.     

Flood control management system for reservoirs

Flood disaster is one of the most damaging natural disasters in China, with annual average losses more than 200 billion yuan in recent years. After 1995 floods in the Liaohe River and 1998 floods in the Yangtze River, the governments from national to local have realized that the flood control operation of reservoirs can play a major role in alleviating flood losses but there are some problems in flood control management for reservoirs. Most of the existing flood control management systems for reservoir were established for special purposes and are lack of data share and communication with governments, it is very difficult for decision-making departments to get real-time information in short time. Thus, a national programming about flood control management system for reservoirs is presented. The paper is a summary of the outcome of national programming about the flood control management system for reservoirs in China. The background, objectives, main challenges and main contents of the programming are introduced. The main focus is on the issues of the software integration flood control management system for reservoirs. Emphasis is concentrated on the flowchart design of the system and its core components. The current system can be applied to a river control center or a single reservoir because of using the national standard databases and easily integrated into the national flood control system in the future. An application system is briefly introduced in order to understand the system.     

Investigation of electrostrictive polymers as actuators for mesoscale devices

Abstact This paper presents an investigation of the use of electrostrictive silicone polymers as actuators for mesoscale devices. The generated strains of both flat and rolled actuators, based on Dow Corning Sylgard 182 and 184, with sputtered gold electrodes, are presented as functions of the applied electric field. Variables examined in this study include silicone film thickness, gold electrode thickness, cycling of the applied electric field, and actuator configuration (flat or rolled). In general, thinner silicone films and gold electrodes yielded greater strains, at a constant applied field. The actuator performance tended to deteriorate with repeated application of the electric field, and the gold electrodes cracked after being subjected to a large percentage strain.Nomenclature A Cross sectional area, mm² - a ₁ , a ₂ electrostrictive constants, m²/V² - D diameter, mm - E electric field, V/m - _o permittivity of free space, F/m - dielectric constant for silicones, F/m - F force, N - J work, J - l length, m - S _ij strain tensor, dimensionless - S _ijkl tensor of elastic compliance coefficients, m - t thickness, m - T _kl stress tensor, Pa - u _i displacement vector, mm - V volume, mm³ - Poisson ratio, dimensionless - w width, m - Y Youngs modulus, Pa     

An experimental model of Chinese textual database

Abstract

A textual database deals with retrieval and manipulation of documents. It allows a user to search on‐line complete documents or parts of documents rather than attributes of documents. Resembling a formatted database which uses a data model as its underlying structure, a textual database has to base its development upon a document model. In this paper, a document model, called the ECHO model, is proposed. The ECHO model provides a document representation, called the ECHO structure, for expressing documents and operations on the representation that serve to express queries and manipulations on documents. It has the ability to provide multiple document structures for a document, a flexible search unit for retrieving textual information, and a subrange search on a textual database. In addition, the ECHO structure is relatively easy to maintain. An architecture of a textual database based on the ECHO model is also proposed. In order to improve the query performance, a refined character inversion method, called ARCIM, is proposed as the text‐access method of the Chinese textual database. The ARCIM can retrieve texts faster than a simple inversion method and requires less space overhead.     

Examining the impact of review tag function on product evaluation and information perception of popular products

Information Systems and e-Business Management - Since online reviews have become an increasingly important information source for consumers to evaluate products during online shopping, many...     

Manipulation of Training Sets for Improving Data Mining Coverage-Driven Verification

The constant pressure for making functional verification more agile has led to the conception of coverage driven verification (CDV) techniques. CDV has been implemented in verification testbenches using supervised learning techniques to model the relationship between coverage events and stimuli generation, providing a feedback between them. One commonly used technique is the classification- or decision-tree data mining, which has shown to be appropriate due to the easy modeling. Learning techniques are applied in two steps: training and application. Training is made on one or more sets of examples, which relate datasets to pre-determined classes. Precision of results by applying the predictive learning concept has shown to be sensitive to the size of the training set and the amount of imbalance of associated classes, this last meaning the number of datasets associated to each class is very different from each other. This work presents experiments on the manipulation of data mining training sets, by changing the size and reducing the imbalances, in order to check their influence on the CDV efficiency. To do that, a circuit example with a large input space and strong class imbalance was selected from the application domain of multimedia systems and another one, with a small input space that affects the coverage occurrences, was selected from the communication area.     

The impact of property price on construction output

The interaction between the construction market and the overall economy has attracted much attention, but few studies have investigated the influence of the property market on the construction market in terms of property price. The disaggregated data of Hong Kong’s housing and retail construction sectors are collected to investigate the impact of property price on construction output. The newly developed autoregressive distributed lag (ARDL) bounds testing approach and the error correction (EC)-based Granger causality test are employed. The bounds testing results suggest that there exist stable long-run relationships between construction output and property price for both housing and retail construction sectors. Specifically, a 1.00% increase in the housing price and retail price lead to a 0.55% and 0.42% increase in construction outputs for the two sectors respectively. In addition, the Granger causality tests confirm a distinct long-run causal flow from property price to construction output. Furthermore, the proposed ARDL approach provides an effective method for forecasting construction output.     

Information technology, operational, and management competencies for supply chain agility: Findings from case studies

Given the growing emphasis on the need for supply chain agility to sustain competitive advantage, this study explores the impact of the relationship between supply chain competence and supply chain agility on firm performance. Although the influence of supply chain agility on firm performance has been acknowledged, this study further articulates the relationship from the perspective of inter-organizational collaboration. We develop a conceptual model based on the resource-based view and employ a multi-case study method in this exploratory research. Our findings highlight the importance of distinguishing the difference between supply chain agility and supply chain competence and their impact on firm performance. This study contributes to the growing body of conceptual and empirical literature on supply chain agility and adds to the understanding of the complexity of supply chain competence.     

Calorimetric study of magnesium potassium phosphate cement

The thermal behavior of magnesium potassium phosphate cement (MKPC) during the early reaction period has been monitored by isothermal conduction calorimetry at 298 K. It is found that the typical heat evolution curve of the MKPC hydration has one endothermic valley and two distinct exothermic peaks. It is believed that the endothermic valley corresponds to the dissolution of potassium dihydrogen phosphate and the exothermic peaks are related to the dissolution of magnesia and the formation of magnesium potassium phosphate hexahydrate, respectively. The influences of the water to powder ratio, the magnesium to phosphate molar ratio and the setting retarder content on the reaction can be reflected in a change of shape and intensity of the peaks on the heat flow curve. The variation trend is consistent with the change of the setting time of MKPC pastes.