Empirical Investigation into Factors Affecting Exporting Construction Services in SMEs in Singapore

The Singapore government is encouraging construction enterprises to venture abroad for exporting their services and become global players since the local construction pie is shrinking and the global market is growing. The Building and Construction Authority of Singapore has revamped the contractors registration system with the hope of bringing about merger and acquisition of companies for improving the local contractors’ standing in the global construction scene. To diversify into new markets in a new environment, which is very different from local environment, requires diversification vis-à-vis exporting strategy. This study examines the attitudes and views of contractors, operating in Singapore (excluding foreign contractors), on how the strategic move should be focused for diversification vis-à-vis exporting services. The aim of this study is to establish the survival skills necessary for Singapore’s construction small and medium sized enterprises (SMEs) to venture abroad. A postal questionnaire survey was conducted and the results show that local construction SMEs who have diversified have reaped the benefits derived from diversification into new markets abroad. The main conclusions are that construction SMEs have to export their services in order to survive and they can enhance their export capabilities by forming a consortium with the help of local government.     

Predictive Simulation of Advanced Nano-CMOS Devices Based on kMC Process Simulation

In this paper, accurate and advanced CMOS process and device simulations based on atomistic kinetic Monte Carlo (kMC) process simulator are presented. First, the methodology used to predict continuum 2-D/3-D doping profiles from 3-D atomistic distribution that can be directly transferred from process to device simulator is described. Calibration of damage evolution, dopant diffusion and clustering, interaction with interfaces, and the impact of impurities, which are crucial for accurate simulations, will be presented and discussed. Subsequently, comparison with a wide range of electrical-device characteristics showed that experimental results were remarkably well reproduced by the simulations. Finally, we shall demonstrate that device optimization can be achieved based on kMC process simulations, even for novel coimplant processes. This paves the way for the use of kMC in the design of devices and the optimization of device performance in technology computer-aided design for manufacturing.     

Minimizing control variation in nonlinear optimal control

In any real system, changing the control signal from one value to another will usually cause wear and tear on the system’s actuators. Thus, when designing a control law, it is important to consider not just predicted system performance, but also the cost associated with changing the control action. This latter cost is almost always ignored in the optimal control literature. In this paper, we consider a class of optimal control problems in which the variation of the control signal is explicitly penalized in the cost function. We develop an effective computational method, based on the control parameterization approach and a novel transformation procedure, for solving this class of optimal control problems. We then apply our method to three example problems in fisheries, train control, and chemical engineering.     

Ultrawide color gamut LCD display with CdSe/CdS nanoplatelets

We present a liquid‐crystal display (LCD) backlight made of nanoplatelets (NPLs) for the first time. Owing to the narrow emission linewidth of NPLs (8‐12 nm) and quantum dots (QDs), the spectrum exhibits a wide color gamut display with a 139.9% color gamut of National Television System Committee (NTSC) 1953 standard and 104.5% Rec.2020 (ITU‐R Recommendation BT.2020), realizing a truly ultrawide color gamut LCD display.     

Distributed adaptive control for vehicular platoon with unknown dead‐zone inputs and velocity/acceleration disturbances

This paper is focused on designing a distributed adaptive control scheme for a vehicular platoon with unknown bounded velocity/acceleration disturbances and unknown nonlinear dead‐zone inputs. Our aim is to design distributed adaptive controllers based on integral sliding mode control techniques that guarantee practical exponential convergence (i.e., exponential stability of an arbitrarily small neighborhood of zero) of the spacing errors and the string stability of the whole vehicular platoon. The contributions of this paper are that: (i) based on a modified constant time headway policy, the whole vehicular platoon is guaranteed to have string stability despite dead zone inputs; (ii) adaptive compensation terms are constructed to compensate for the time‐variant effects caused by unknown bounded velocity/acceleration disturbances, and unknown dead zone inputs; (iii) an efficient numerical method for avoiding the singularity problem of the control law is also proposed. Numerical simulation results show the validity and advantages of the proposed method are significantly higher traffic density and string stability. Copyright © 2016 John Wiley & Sons, Ltd.     

$nhbox{-ZnO}/nhbox{-GaAs}$ Heterostructured White Light-Emitting Diode: Nanoscale Interface Analysis and Electroluminescence Studies

n-ZnO/n-GaAs heterostructured light-emitting diodes have been fabricated by a low-cost ultrasonic spray pyrolysis technique. Nanoscale interface analysis was carried out with scanning transmission electron microscopy. An ~ 8.6-nm-thick amorphous GaAsZnInO was found in the n -ZnO/n-GaAs interface. A strong and broad white electroluminescence band centered at ~ 525 nm and a weak near-infrared emission peaked at ~ 815 nm were observed when n-GaAs was positively biased. The 815-nm emission is believed to be related to the interface layer, and the 525-nm emission is assigned to the recombination of electrons from conduction band to deep-level holes in the ZnO layer.     

A Database Approach Integrating A Visually Interactive Load Flow For Low Voltage System

This paper presents an alternative approach to a visually interactive load flow and distribution loss calculation for a radially operated distribution network in buildings. By using the proposed database structure, any distribution network can be specified and modeled effectively, including the whole types and sizes of cables under different installation methods. Based on our proposed solution algorithm, matched with the database structure, load flow results can be calculated directly without formulating the admittance matrix. Thus, there is practically no limit to the number of nodes, and thus it does not require sparse techniques in matrix inversion. Any breaker in the network can be operated or tripped and a new load flow will be calculated and displayed. Based on the information in the database and a drawing algorithm, the single-line diagram of the network is drawn automatically and the calculated results can be dynamically positioned on the single line diagram. Test results confirm that the proposed system provides almost identical solution as compared with the conventional method.     

A comprehensive fault diagnostic system using artificialintelligence for sub-transmission and urban distribution networks

This paper describes an intelligent diagnostic system for an interconnected distribution network developed to assist the system operator with fault identification during restoration. The intelligent process utilizes only those data available in a standard SCADA system such as the post fault network status, the list of the tripped breakers, main protection alarm, and the conventional event log. The fault diagnostic system is implemented by three independent mechanisms, namely the generic core rule, the generic relay setting inference and the specific post-fault network matching and learning. The generic core rule generates various possible fault locations and the generic relay inference examines whether each possible fault location is logical and valid. The specific network matching compares whether the post fault network and the related tripped breakers are identical to a previous fault event. Test results obtained from two distribution networks confirm that the developed system is practical, reliable and accurate     

Transient interstitial fluid flow in brain tumors: Effect on drug delivery

The presence of high interstitial pressure within the tumor's center [Baxter, L.T., Jain, R.K., 1989. Transport of fluid and macromolecules in tumors I role of interstitial pressure and convection. Microvascular Research 37, 77-104] poses severe problems to chemotherapy via systemic administration. Removal of the tumor core by surgery and subsequent insertion of drug-carrying polymers in the resection cavity may improve the treatment [Wang, C.H., Li, J., 1998. Three dimensional simulation of IgG delivery to tumors. Chemical Engineering Science 53 (20), 3579-3600]. The operation establishes a favorable pressure gradient towards the center of the tumor and thus creates flow reversal immediately after the operation. The simulation results of the transient flow field of interstitial fluid in the surgical cavity of a brain tumor are presented. The simulation is carried out using a computational fluid dynamics software, Fluent, with the model geometry constructed from magnetic resonance images (MRI) with reference to the Gliadel^® wafers application [Sampath, P., Brem, H., 1998. Implantable slow-release chemotherapeutic polymers for the treatment of malignant brain tumors. Cancer control. Journal of Molecular and Cellular Cardiology 5 (2), 130-137]. The coupled mass and momentum equations are solved for the steady-state solutions of the pressure and velocity distributions at a cut section of a tumor. The steady-state solution thus obtained is then perturbed to compute the characteristic time scale of the variation in the interstitial fluid pressure and velocity in a surgical cavity immediately after surgery. Simulation results show that the flow field reaches an equilibrium state in less than 3 h. The surgery produces a transient enhancement of the drug delivery but the surgery alone is not capable of removing permanently the unfavorable pressure gradient against the delivery of drug to tumor. The presence of post-surgery edema increases the interstitial pressure and fluid velocity, thus causing higher relative toxicity in the surrounding normal tissues. Simulations employing complete 3D structure show qualitatively similar results with 2D simulation and hence the use of a cut section of the tumor for simplified model calculations is validated.     

A collaborative wheelchair system.

This paper describes a novel robotic wheelchair, and reports experiments to evaluate its efficiency and understand how human operators use it. The concept at the heart of the collaborative wheelchair assistant (CWA) is to rely on the user's motion planning skills while assisting the maneuvering with flexible path guidance. The user decides where to go and controls the speed (including start and stop), while the system guides the wheelchair along software-defined guide paths. An intuitive path editor allows the user to avoid dangers or obstacles online and to modify the guide paths at will. By using the human sensory and planning systems, no complex sensor processing or artificial decision system is needed, making the system safe, simple, and low-cost. We investigated the performance of the CWA on its interaction with able-bodied subjects and motion efficiency. The results show that path guidance drastically simplifies the control. Using the CWA, the wheelchair user needs little effort from the first trial, while moving efficiently with a conventional wheelchair requires adaptation.