Adaptive traffic signal control using approximate dynamic programming

This paper presents a study on an adaptive traffic signal controller for real-time operation. The controller aims for three operational objectives: dynamic allocation of green time, automatic adjustment to control parameters, and fast revision of signal plans. The control algorithm is built on approximate dynamic programming (ADP). This approach substantially reduces computational burden by using an approximation to the value function of the dynamic programming and reinforcement learning to update the approximation. We investigate temporal-difference learning and perturbation learning as specific learning techniques for the ADP approach. We find in computer simulation that the ADP controllers achieve substantial reduction in vehicle delays in comparison with optimised fixed-time plans. Our results show that substantial benefits can be gained by increasing the frequency at which the signal plans are revised, which can be achieved conveniently using the ADP approach

Self-complementary graphs and Ramsey numbers Part I: the decomposition and construction of self-complementary graphs

AbstractA new method of studying self-complementary graphs, called the decomposition method, is proposed in this paper. Let G be a simple graph. The complement of G, denoted by Ḡ, is the graph in which V(Ḡ)=V(G); and for each pair of vertices u,v in Ḡ,uv∈E(Ḡ) if and only if uv∉E(G). G is called a self-complementary graph if G and Ḡ are isomorphic. Let G be a self-complementary graph with the vertex set V(G)={v1,v2,…,v4n}, where dG(v1)⩽dG(v2)⩽⋯⩽dG(v4n). Let H=G[v1,v2,…,v2n],H′=G[v2n+1,v2n+2,…,v4n] and H∗=G−E(H)−E(H′). Then G=H+H′+H∗ is called the decomposition of the self-complementary graph G.In part I of this paper, the fundamental properties of the three subgraphs H,H′ and H∗ of the self-complementary graph G are considered in detail at first. Then the method and steps of constructing self-complementary graphs are given. In part II these results will be used to study certain Ramsey number problems (see (II))

Professional ethics: a life-long pursuit by an engineer

After an engineering student has finished the studies in a college, he (or she) is prepared to, usually with much enthusiasm and high hopes, embark into a new world to make use of what he has learnt for the betterment of the society and the engineering profession. The pursuit of the “Real”, the “Good”, and the “Beautiful” has been the highest goal. With the dawning of the e-Commerce and “Dot-Com” era, with the IT (Information Technology) heat sweeping through the world and catching everyone by surprise, and with the rapid replacement of traditional materialistic substances by their electronic and cyber counterparts, we will witness a new economic order and have to adapt ourselves to changes in the engineering discipline. An important goal of continual and life-long education for an engineer is coping with changes around us while discharging various responsibilities required by the profession. This paper discusses, from the perspective of the IT profession and with reference to IT-related scenarios, the issues about professional ethics and the various expectation and requirements made on its members by a professional body

Interoperability Optimization and Service Enhancement in Vehicle Onboard Infortainment Systems

This paper presents an overview on optimizing interoperability between different applications for enhanced return-on-investment through utilization of business intelligence in conjunction with prognostics and health management methodology. Such implementation is particularly suitable for deployment in mass-produced vehicle onboard diagnostics system

Transfer Effect of Speech-sound Learning on Auditory-motor Processing of Perceived Vocal Pitch Errors

Speech perception and production are intimately linked. There is evidence that speech motor learning results in changes to auditory processing of speech. Whether speech motor control benefits from perceptual learning in speech, however, remains unclear. This event-related potential study investigated whether speech-sound learning can modulate the processing of feedback errors during vocal pitch regulation. Mandarin speakers were trained to perceive five Thai lexical tones while learning to associate pictures with spoken words over 5 days. Before and after training, participants produced sustained vowel sounds while they heard their vocal pitch feedback unexpectedly perturbed. As compared to the pre-training session, the magnitude of vocal compensation significantly decreased for the control group, but remained consistent for the trained group at the post-training session. However, the trained group had smaller and faster N1 responses to pitch perturbations and exhibited enhanced P2 responses that correlated significantly with their learning performance. These findings indicate that the cortical processing of vocal pitch regulation can be shaped by learning new speech-sound associations, suggesting that perceptual learning in speech can produce transfer effects to facilitating the neural mechanisms underlying the online monitoring of auditory feedback regarding vocal production

Enhancement of Membrane Fouling Control in Hybrid Aerobic Membrane Bioreactor System for Domestic Waste Water Application: Effect of Alum Concentration

AbstractAdditional of alum into the membrane bioreactor was found to be able to enhance the performance for the separation process. In this study, the influence of different alum concentrations on membrane fouling control and characteristics of activated sludge of membrane bioreactors were evaluated. Membrane bioreactor with low alum concentration of 1.0g/L was found able to provide better filterability performance compared to MBRs without and with excessive alum addition (3.0g/L and 5.0g/L). This study indicates that agglomeration of flocs and biodegradation mechanisms which took place simultaneously in the MBR with 1.0g/L of alum is able to reduce the total EPS concentration in the MBRs and subsequently contributing to better membrane fouling control

A mechanistic model for anisotropic thermal strain behavior of soft mudrocks

Under drained heating, soft mudrocks can expand or contract depending on its mineralogy, composition, structure, stress history, and the imposed temperature. Previous research on the physics behind the thermally induced deformation behavior is limited. The impact of clay minerals on the overall anisotropic deformation behavior has not been quantitatively considered. In this study, a compositional thermal strain model is proposed to quantify the thermally induced deformation in soft mudrocks through a homogenization approach. The intrinsic fabric of soft mudrock was examined and considered in the model. Theoretically, thermally induced deformation in a soft mudrock is contributed by the expansion of solid minerals and interlayer bound water, the removal or dehydration of clay-bound water, and thermal plastic strain (grain rearrangement). The overall deformation of soft mudrocks is governed by the thermal deformation behavior of individual constituents and their interactions. The interactions among non-clay minerals and clay-water composites can be considered by applying a structural state coefficient. The proposed thermal strain model was validated by a series of experimental results using reconstituted and natural soft mudrock samples with different clay fractions. The results indicate that soft mudrocks with a structural state of clay matrix-supported are on the risk of having thermal contraction behavior which comes from clay dehydration or thermal plastic strain. The oriented fabric in soft mudrocks contributes to the anisotropy in thermal strains. The proposed thermal strain model can be applied to estimate critical parameters in phenomenon-based thermal elastic-plastic models for constitutive modeling