Benefits valuation of potable water quality improvement in Malaysia: the case of Kajang Municipality

This article estimates the benefits of potable water quality improvements in Kajang Municipality in the state of Selangor, Malaysia, using the avertive cost method. Households were willing to pay MYR 322 annually to improve potable water quality. This represents about 80% of their average annual water bill. The present value of aggregate benefits over a period of 30 years at various social discount rates ranged from MYR 301 million to MYR 768 million. These estimates can be used as a reference for public investment criteria. The findings suggest that there is merit in an upward revision of water tariffs if they provide improvements in water quality.     

Nanoclay-modified asphalt materials: Preparation and characterization

The objective of this study is to review existing literature in the area of nano-modification of asphalt and proceed to apply nano-materials to asphalt to improve the performance. This study integrates literature review, preparation, and characterization of nano-modified asphalt materials. In the experimental testing montmorillonite, nanoclay at 2% and 4% by weight of asphalt was blended in asphalt binder at a high temperature to exfoliate the nanoclay within the asphalt. The asphalt binder was then characterized using the Superpave? rotational viscosity, dynamic shear modulus, and direct tension test. The rotational viscosity results indicate that the addition of the two types of nanoclay, Nanoclay A and Nanoclay B, increased the rotational viscosity by an average of 41% and 112%, respectively, across test temperatures 80, 100, 130, 135, 150 and 175 °C. It was found that the dynamic shear complex modulus (G*) value increases significantly across a range of testing temperatures (from 13 to 70 °C) and loading frequencies (0.01–25 Hz). With 2% Nanoclay A reinforcement in the asphalt binder, the complex shear moduli generally increased by 66% while the 4% Nanoclay A reinforcement in the asphalt binder generally increased the shear complex moduli by 125%. The 2% and 4% Nanoclay B increased the shear complex moduli by 184% and 196%, respectively. In terms of direct tension strength, the use of Nanoclay A and Nanoclay B reduced the strain failure rate of the original binder while the secant or direct tension moduli showed increase with the addition of the nanoclays. In furtherance of this research, nanoclay-modified asphalt is being tested at percentages higher than 4% to underscore the fact that nanoclays may have the potential to reduce rutting and cracking.     

Poisson Model of Construction Incident Occurrence

Construction incidents are essentially random events because they have a probabilistic component that causes their occurrence to be indeterministic. Thus, as with most random events, one of the best ways to understand and analyze construction incidents is to apply statistical methods and tools. Consequently, this paper presents a statistical framework based on the modified loss causation model (MLCM). Even though the MLCM has been used for the framework, the approach can be readily adapted for other incident causation models. The MLCM is separated into two basic components: random and systematic. The random component is represented by a probability density function (PDF), which has parameters influenced by the systematic component of the MLCM, while the systematic component is represented by the situational variables and quality of the safety management system. In particular, this paper proposes that the PDF can be represented by the Poisson distribution. Besides being a convenient and simple distribution that can be easily used in applications, the Poisson distribution had been used in various industries to model random failures or incidents. The differences in contexts and the undesirable effects of adopting an unrepresentative distribution will require formal analysis to determine the suitability of the Poisson distribution in modeling the random component of construction incident occurrence. Incident records for 14 major projects were used in the analysis. Hypothesis testing using the chi-square goodness-of-fit and dispersion tests shows that the incident occurrences can be modeled as a Poisson process characterized by some mean arrival rate. The paper also presents some applications of the proposed Poisson model to improve construction safety management, focusing on two specific concepts: the Bayesian approach and the partitioned Poisson.     

Advances in optical path crossconnect systems using planar-lightwave circuit-switching technologies

This article highlights advances in NTT's optical path crossconnect systems that use planar-lightwave circuit switches. A photonic MPLS router that can handle up to 256 optical label switched paths is developed as one result of our R&D activities; mature OPXC technologies are adopted to create a practical OPXC system.     

A new a-Si:H thin-film transistor pixel circuit for active-matrix organic light-emitting diodes

We propose a new pixel circuit using hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs), composed of three switching and one driving TFT, for active-matrix organic light-emitting diodes (AMOLEDs) with a voltage source method. The circuit simulation results based on the measured threshold voltage shift of a-Si:H TFTs by gate-bias stress indicate that this circuit compensates for the threshold voltage shifts over 10000 h of operation.     

Disconnected Processes, Mechanisms and Architecture for Mobile E-Business

With the tremendous advances in hand-held computing and communication capabilities, rapid proliferation of mobile devices, and decreasing device costs, we are seeing a growth in mobile e-business in various consumer and business markets. In this paper, we present a novel architecture and framework for end-to-end mobile e-business applications (e.g., point of sales). The architecture takes into consideration disconnection, application context, synchronization, transactions and failure recovery modes to provide mobile users with seamless and transparent access to business transactions and business-context specific data. In our architecture, we consider a novel business process design based on state-machines and event management to handle disconnection, resource limitations and failures. We designed, implemented and deployed a system for mobile e-business on clients (e.g., PDAs and PocketPCs) integrated with private exchanges and sell-side servers. The state-machine model with failure recovery mechanisms enables handling of one-to-many and many-to-one disconnections in large mobile e-business environments. The e-business framework on mobile clients is implemented based on J2ME, Webservices, and open XML standards. A detailed performance study of commerce transactions was done on different mobile client devices with diverse computing, memory and storage capabilities. We compare the performance of a purchasing application and the middleware on various devices such as PDAs and Laptops. We demonstrated that for small devices with limited capability the performance is reasonable. For devices with more computing capability, the response time is excellent.     

Some procedures for decision making in controlling high yield processes

Statistical process control based on the cumulative counts of conforming items instead of occurrences of non-conformances has proved to be useful for the manufacture of high-quality products. In this paper we study some interesting and useful issues of using cumulative counts in practice. The general problem in the control of high-quality products is first discussed, which leads to the calculation of the probability that a process is out of control when a single non-conforming item is detected. A decision graph is introduced with which we can easily judge whether the process is out of control when a non-conforming item is observed after a number of conforming ones, accompanied by the certainty level of this judgement. Next, using the equivalence of information on one non-conforming item found in a number of inspected items to that on zero non-conforming items in a smaller sample, we give a method for choosing a new starting point to reset the cumulative count after the detection of the non-conforming item. The procedures are all statistically justified and have the practical merit of simplicity in actual applications.     

Systematic Reliability-Based Environmental Design of Erosion for Efficient Engineered Landscape Profiling

Evolving environmental legislation has received increased attention worldwide in the last two decades, reported by Bradfield, Schultz, and Stone in 1996 in Environmental management in the Australian minerals and energy industries. The focus of concern by the industry, environmental regulatory agencies, and members of the public is the potential impacts associated with unstable landscapes which sometimes lead to slope failures, especially in hillside development. Engineered landscape profiles, though stable at the end of construction, may deteriorate over time due to erosion. There is thus a need to increase the base of knowledge on the existing practices of engineered profile design, hillside development, reshaping practices, and erosion control. With escalating production costs and the keen competitiveness in the industry world wide, the necessity to increase the efficiency of engineered profile development is further gaining prominence. This paper reviews the advancement of erosion management research in the industry, economics of landscape profiling, the practical application of the Point Estimate probabilistic technique, and the optimum design selection for the systematic planning and reshaping of engineered landscape profiles. The probabilistic engineering design erosion nomographs developed is useful in determining and illustrating quantitatively the reliability of final engineered landscape designs and the reshaping costs involved for different soil texture types. Landscape designs, which meet environmentally acceptable levels of reliability against erosion failure at optimum earthmoving reshaping costs, can be obtained using this probabilistic engineering design approach whilst satisfying environmental standards and community expectations for erosion minimisation.     

trans-polyoctenylene as a processing aid for rubber: Influence on energy consumption and properties of rubber compounds

trans-Polyoctenylene rubber, TOR, was melt blended with different types of rubber in various proportions in a Brabender Plasti-corder. Energy consumption in mixing the blends indicated that TOR is an effective processing aid for a variety of rubber and inclusion of TOR in a blend can result in significant saving of energy. TOR of lower molecular weight (e.g. Vestenamer 8012) performs significantly better than TOR of higher molecular weight (e.g. Vestenamer 6213), both as a processing aid and as a dimension stabilizer.     

Control charts for processes subject to random shocks

In this paper, a charting technique for controlling processes subject to random shocks is presented. This type of process is common in a high-yield production environment and the conventional Shewhart control charts are not efficient for its monitoring and control. This technique is able to detect process improvement, easy for decision making, and more concise and informative than other methods used for this type of process. In addition, it could provide diagnostic information which is highly useful in practice.