Slope stability evaluation using neural network optimized by equilibrium optimization and vortex search algorithm

A dependable evaluation of the stability of slopes is a prerequisite in many construction projects. Although machine learning models have been satisfactorily used for this purpose, combining them with metaheuristic optimizers has resulted in a larger accuracy. This study, therefore, suggests the use of equilibrium optimization (EO) and vortex search algorithm (VSA) for optimizing a multi-layer perceptron neural network (MLPNN) employed to anticipate the factor of safety of a single-layer soil slope. Two hybrid models, as well as the regular MLPNN, are fed by a total of 630 data acquired from finite element simulations. The results, first, showed the applicability of artificial intelligence in this field. Next, reducing the training root mean square error (RMSE) of the MLPNN (from 0.4715 to 0.3891 and 0.4383 by the EO and VSA, respectively) revealed the efficiency of the used algorithms in remedying the computational weaknesses of this model. Moreover, the testing RMSE declined from 0.5397 to 0.4129 and 0.5155, which indicates a higher generalization ability of the hybrid models. Furthermore, due to the larger accuracy of the EO-based ensemble, this algorithm outperformed the VSA in optimizing the MLPNN.

     

Prevalence and correlates of roll-your-own smoking in Thailand and Malaysia: Findings of the ITC-South East Asia Survey.

Roll-your-own (RYO) cigarette use has been subject to relatively limited research, particularly in developing countries. This paper seeks to describe RYO use in Thailand and Malaysia and relate RYO use to smokers' knowledge of the harmfulness of tobacco. Data come from face-to-face surveys with 4,004 adult smokers from Malaysia (N = 2,004) and Thailand (N = 2000), collected between January and March 2005. The prevalence of any use of RYO cigarettes varied greatly between Malaysia (17%) and Thailand (58%). In both countries, any RYO use was associated with living in rural areas, older average age, lower level of education, male gender, not being in paid work, slightly lower consumption of cigarettes, higher social acceptability of smoking, and positive attitudes toward tobacco regulation. Among RYO users, exclusive use of RYO cigarettes (compared with mixed use) was associated with older age, female gender (relatively), thinking about the enjoyment of smoking, and not making a special effort to buy cheaper cigarettes if the price goes up. Finally, exclusive RYO smokers were less aware of health warnings (RYO tobacco carries no health warnings), but even so, knowledge of the health effects of tobacco was equivalent.     

A Method for Evaluating All the Minimal Cuts of a Graph

This paper presents a new technique to determine all minimal cuts for all the sink nodes in a non-planar network. The algorithm uses a subset method and an iterative process to achieve high efficiency. For an N-sink node network there are (2N - 1) possible combinations of nodes (non-empty subsets). These subsets are checked against several conditions to see if they can be transformed into minimal cutsets. An iterative process is used to generate these non-empty subsets efficiently so that the number of subsets to be checked is about (2N - 1)/2. Since this algorithm generates all the minimal cutsets for all nodes in one operation, it is faster compared to conventional methods which compute for one sink node at a time. Tests using random graphs showed a small cpu time per minimal cutset.     

The development of GRAMSKIL: A call grammar program for learners of English as a Second Language

To improve the grammatical skills of university-level students in an English as a Second Language (ESL) environment, the authors created a prototype software called GRAMSKIL. GRAM- SKIL differs from the current trend of software development in computer assisted language learning in two ways. Firstly, our program aims to develop grammatical competence instead of communicative competence in ESL learners. Secondly, it adopts the not-so-common approach of using a general purpose software tool—dBase III—to produce the program. GRAMSKIL uses the programming facility of dBase III to design menu-driven tasks which are user-friendly, and so computer novices can run the program without having to learn to run the database package. Moreover, GRAMSKIL allows teachers with little knowledge of database management systems to create their own database or modify the data to tailor them to the needs of their learners.     

Survival and recovery of Listeria monocytogenes on ready-to-eat meats inoculated with a desiccated and nutritionally depleted dustlike vector

Dust from construction was theorized to serve as a vector for L. monocytogenes transmission to ready-to-eat (RTE) meats after heat processing but before packaging. A five-strain Listeria monocytogenes culture including serotype 4b was continually stressed on a sand vector under four sets of nutritionally depleted and dry conditions to simulate postprocessing contamination by dustlike particulates. The stresses included that associated with sand stored at different temperatures (10 and 22 degrees C) and levels of humidity (40% relative humidity [RH], 88% RH, or complete desiccation). Irradiated RTE meats, including frankfurters, bologna, chopped ham, and deli-style roast beef, were inoculated with the L. monocytogenes-contaminated sand every 2 to 3 days over a period of 1 1/2 months. After inoculation, the RTE meats were vacuum packed and stored at 4 degrees C for 24 h. Populations of L. monocytogenes were enumerated by surface plating on nonselective and selective media to recover cells on the basis of the different stresses presented (osmotic or antibiotic). L. monocytogenes was demonstrated to be capable of surviving on the sand vector for > 151 days at 10 degrees C and 88% RH, 136 days at 10 degrees C and 0% RH, 73 days at 22 degrees C and 40% RH, and 82 days at 22 degrees C and 0% RH. These results show that under the most conservative scenario, the 73-day-old L. monocytogenes-contaminated sand was able to attach to and be recovered from the RTE meats. This study illustrated that dust contaminated with L. monocytogenes, once in contact with meat surfaces, can survive and grow, posing a health hazard to consumers.     

Tooth segmentation of dental study models using range images

The accurate segmentation of the teeth from the digitized representation of a dental study model is an important component in computer-based algorithms for orthodontic feature detection and measurement and in the simulation of orthodontic procedures such as tooth rearrangement. This paper presents an automated method for tooth segmentation from the three-dimensional (3-D) digitized image captured by a laser scanner. We avoid the complexity of directly processing 3-D mesh data by proposing the innovative idea of detecting features on two range images computed from the 3-D image. The dental arch is first obtained from the plan-view range image. Using the arch as the reference, a panoramic range image of the dental model can be computed. The interstices between the teeth are detected separately in the two range images, and results from both views are combined for a determination of interstice locations and orientations. Finally, the teeth are separated from the gums by delineating the gum margin. The algorithm was tested on 34 dental models representing a variety of malocclusions and was found to be robust and accurate.     

Did the CIE get it right? A critical test of the CIE color domains for signal lights

Since 1951, the Commission Internationale de L'Eclairage (CIE) has provided influential guidance on the choice of the most suitable colors for colored signal lights. In 1994, the CIE reviewed its 1975 recommendations for signal colors and has recently revised them. These revised recommendations have now been published as a CIE standard. This article reports an experiment designed to test those recommendations and to provide data on the reliability of signal color recognition under a range of conditions. Thirty young subjects (aged 18–28 years) and thirty older subjects (aged 50–64 years) named the colors of lights, the colors of which were located on or close to the color boundaries defined by the CIE for red, yellow, white, green, and blue colors. The angular diameter of the light was one min of arc. In a second experiment, half the subjects named the colors of the lights when the angular diameter was 5 min of arc. Observations were made under both dark and light adaptation. Red signals, especially those located in the CIE Class A domain, were reliably recognized under all conditions. Yellow near the red boundary of the CIE yellow domain tended to be confused with red, especially under dark adapted conditions at low signal illuminances. White was not a reliable signal color and was often confused with yellow, except for a white located near the blue boundary of CIE white. Green colors located near the blue boundary of the CIE color domain for green were less reliably recognized than those of longer dominant wavelength. Blue signal colors located within the CIE Class A blue domain were more reliable than expected, except at very low signal illuminances. There were significant differences in the performance of older compared to younger subjects, some of which can be explained by color shifts occurring as the result of the yellowing of the lens of the eye with age. © 2001 John Wiley & Sons, Inc. Col Res Appl, 26, 109–122, 2001     

Biodiesel combustion in an optical HSDI diesel engine under low load premixed combustion conditions

An optically accessible single-cylinder high-speed direct-injection (HSDI) diesel engine was used to investigate the spray and combustion processes for biodiesel blends under different injection strategies. The experimental results indicated that the heat release rate was dominated by a premixed combustion pattern and the heat release rate peak became smaller with injection timing retardation. The ignition and heat release rate peak occurred later with increasing biodiesel content. Fuel impingement on the wall was observed for all test conditions. The liquid penetration became longer and the fuel impingement was stronger with the increase of biodiesel content. Early and late injection timings result in lower flame luminosity due to improved mixing with longer ignition delay. For all the injection timings, lower soot luminosity was seen for biodiesel blends than pure diesel fuel. Furthermore, NO_x emissions were dramatically reduced for premixed combustion mode with retarded post-TDC injection strategies.     

A 0.8-μW window SAR ADC with offset cancellation for digital DC–DC converters

This letter presents the design of a window successive approximation (SAR) analog-to-digital converter (ADC) using an ultra-fast, offset-cancelled auto-zero comparator for digital DC–DC converters. It is designed in a standard CMOS 0.18 μm process. The ADC has a dynamic reference voltage range to reduce power consumption. The auto-zero scheme of the comparator is realized internally with a preamplifier stage and a latch stage. Post-layout simulation shows that the response time of the comparator from low-to-high and high-to-low is 3.78 ns and 2.47 ns, respectively. The resolution of the proposed window SAR ADC is 7.5 mV. The ADC is fabricated as part of a digital DC–DC converter integrated circuit and measurement results show that an average power consumption of 0.8 μW is achieved. The transient time of the DC–DC converter is within 150 ns for a load current change of 495 mA.     

Template‐Directed Liquid ALD Growth of TiO2 Nanotube Arrays: Properties and Potential in Photovoltaic Devices

Dense and well‐aligned arrays of TiO₂ nanotubes extending from various substrates are successfully fabricated via a new liquid‐phase atomic layer deposition (LALD) in nanoporous anodic alumina (AAO) templates followed by alumina dissolution. The facile and versatile process circumvents the need for vacuum conditions critical in traditional gas‐phase ALD and yet confers ALD‐like deposition rates of 1.6–2.2 Å cycle^?1, rendering smooth conformal nanotube walls that surpass those achievable by sol–gel and Ti‐anodizing techniques. The nanotube dimensions can be tuned, with most robust structures being 150–400 nm tall, 60–70 nm in diameter with 5–20 nm thick walls. The viability of TiO₂ nanotube arrays deposited on indium tin oxide (ITO)–glass electrodes for application in model hybrid poly(3‐hexylthiophene) (P3HT):TiO₂ solar cells is studied. The results achieved provide platforms and research directions for further advancements.