A new particle swarm algorithm for a multi-objective mixed-model assembly line sequencing problem

The sequencing of products for mixed-model assembly line in Just-in-Time manufacturing systems is sometimes based on multiple criteria. In this paper, three major goals are to be simultaneously minimized: total utility work, total production rate variation, and total setup cost. A multi-objective sequencing problem and its mathematical formulation are described. Due to the NP-hardness of the problem, a new multi-objective particle swarm (MOPS) is designed to search locally Pareto-optimal frontier for the problem. To validate the performance of the proposed algorithm, various test problems are solved and the reliability of the proposed algorithm, based on some comparison metrics, is compared with three distinguished multi-objective genetic algorithms (MOGAs), i.e. PS-NC GA, NSGA-II, and SPEA-II. Comparison shows that MOPS provides superior results to MOGAs.     

A study of an autonomous mobile robot for a sewer inspection system

This article describes a prototype autonomous mobile robot, KANTARO, designed for inspecting sewer pipes. It is able to move autonomously in 200–300-mm-diameter sewer pipes, to turn smoothly through 90° at a junction, and to go down a 5-cm step. KANTARO carries all the resources required, such as a control unit, a camera, a 2D laser, and an IR sensor. Damage or abnormalities in sewer pipes are detected based on recorded sensory data. KANTARO has demonstrated its effectiveness in inspection and in autonomous navigation in a dry sewer test field at the FAIS–Robotics Development Support Office (FAIS–RDSO). This work was presented in part at the 11th International Symposium on Artificial Life and Robotics, Oita, Japan, January 23–25, 2006     

TBM performance estimation using a classification and regression tree (CART) technique

Bulletin of Engineering Geology and the Environment - With widespread increasing applications of mechanized tunneling in almost all ground conditions, prediction of tunnel boring machine (TBM)...     

Comparative analysis of three numerical methods for estimating the onshore wind power in a coastal area

Although there are many studies concerning the estimation of wind potential in different locations of Iran, an adequate evaluation of wind power for onshore locations of this country has not been investigated yet. The purpose of this research is to evaluate the potential of onshore wind in the south of Iran along the Gulf of Oman by comparing three Weibull numerical methods. In the first step, it became clear that the maximum likelihood method (MLM) compared to other methods represented the actual wind data with the lowest error rate and therefore it was selected as an accurate statistical distribution to model the wind speed of the investigated location. Using the MLM, the estimation of wind speed characteristics as well as the techno-economic evaluation of different wind turbines has been investigated. It was concluded that both technically and economically the studied area does not have sufficient wind power for the development of large-scale or grid-connected wind turbines. However, it may have enough power for non-grid-connected mechanical applications, such as wind generators for water pumping. Therefore, in the last part of this paper, an investigation of water pumping potential of the studied site by using adequate and modern wind turbines with lower start-up wind speed was recommended for future studies. Furthermore, it was suggested that the current methodology used in this research could be employed and extended in future studies to evaluate the wind potential of all onshore locations of Iran including onshore locations along the Persian Gulf and Caspian Sea.     

Computer‐aided diagnosis software for vulvovaginal candidiasis detection from Pap smear images

Vulvovaginal candidiasis (VVC) is a common gynecologic infection and it occurs when there is overgrowth of the yeast called Candida. VVC diagnosis is usually done by observing a Pap smear sample under a microscope and searching for the conidium and mycelium components of Candida. This manual method is time consuming, subjective and tedious. Any diagnosis tools that detect VVC, semi‐ or full‐automatically, can be very helpful to pathologists. This article presents a computer aided diagnosis (CAD) software to improve human diagnosis of VVC from Pap smear samples. The proposed software is designed based on phenotypic and morphology features of the Candida in Pap smear sample images. This software provide a user‐friendly interface which consists of a set of image processing tools and analytical results that helps to detect Candida and determine severity of illness. The software was evaluated on 200 Pap smear sample images and obtained specificity of 91.04% and sensitivity of 92.48% to detect VVC. As a result, the use of the proposed software reduces diagnostic time and can be employed as a second objective opinion for pathologists.     

Unsupervised identification of arbitrarily-damped structures using time-scale independent component analysis: Part I

In this study, a new method is proposed to identify the dynamic parameters of structures with higher accuracy compared to current methods. First, the wavelet-transformed representation of system responses is extracted from measured responses, and then the independent component analysis is used to achieve the modal characteristics. The simulation results of a multi-degree-of-freedom system illustrate that this method is capable of accurately identifying the modal information of lightly- and highly-damped structures. It is represented that continuous wavelet transform, due to its adaptive time-frequency resolution, is more efficient to be incorporated into independent component analysis compared to Short time Fourier transform (STFT). The latter is unable to accurately determine the modal response, especially at higher frequencies, while the proposed method can identify the system with marked accuracy. The efficiency of proposed method is also investigated under additive noise. Results shown that for highly- and lightly- damped system, the proposed method is able to capture the modal parameters especially in higher frequencies of vibration, along with the modal assurance criterion values with satisfactory accuracy, which indicates the robustness of the procedure compared to other available methodologies.     

Studio in Transformation: Transformation in Studio

To explore the potential of a holistic pedagogical model that incorporates motion studies into existing curricular structures, the Pedagogy of Motion provides a methodical series of steps regarding the best methods for teaching the principles of transformable architecture. The development of this pedagogy could recast the architectural design process, transmuting the landscape of how we do architecture. As vehicles for examining the opportunities of this approach, two design studios¹¹ transLAB was offered at Virginia Tech University, and transSTUDIO was taught at Texas A&M University.View all notes in two schools of architecture at Virginia Tech and Texas A&M University were offered, occasioning theoretical overviews and practical methods for designing morphological changes in architecture.     

Dynamic DTI (dDTI) shows differing temporal activation patterns in post-exercise skeletal muscles

Object

To assess post-exercise recovery of human calf muscles using dynamic diffusion tensor imaging (dDTI).

Materials and methods

DTI data (6 directions, b = 0 and 400 s/mm²) were acquired every 35 s from seven healthy men using a 3T MRI, prior to (4 volumes) and immediately following exercise (13 volumes, ~7.5 min). Exercise consisted of 5-min in-bore repetitive dorsiflexion-eversion foot motion with 0.78 kg resistance. Diffusion tensors calculated at each time point produced maps of mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (RD), and signal at b = 0 s/mm² (S₀). Region-of-interest (ROI) analysis was performed on five calf muscles: tibialis anterior (ATIB), extensor digitorum longus (EDL) peroneus longus (PER), soleus (SOL), and lateral gastrocnemius (LG).

Results

Active muscles (ATIB, EDL, PER) showed significantly elevated initial MD post-exercise, while predicted inactive muscles (SOL, LG) did not (p < 0.0001). The EDL showed a greater initial increase in MD (1.90 × 10^?4mm²/s) than ATIB (1.03 × 10^?4mm²/s) or PER (8.79 × 10^?5 mm²/s) (p = 7.40 × 10^?4), and remained significantly elevated across more time points than ATIB or PER. Significant increases were observed in post-exercise EDL S₀ relative to other muscles across the majority of time points (p < 0.01 to p < 0.001).

Conclusions

dDTI can be used to differentiate exercise-induced changes between muscles. These differences are suggested to be related to differences in fiber composition.

     

Viscoelastic fatigue resistance of asphalt binders modified with crumb rubber and styrene butadiene polymer

In the present research study, the fatigue behavior of modified asphalt with crumb rubber (CR) and styrene-butadiene-styrene (SBS) are investigated. Each of these additives was mixed with a 85–100 neat bitumen at two different dosages. The time sweep test was used to investigate the viscoelastic fatigue properties of asphalt binders in terms of energy dissipation. Linear amplitude sweep tests were conducted to study the fatigue life of asphalt binders under varying loads based on the concepts of viscoelastic continuum damage mechanics. Results showed that adding CR and SBS can enhance the fatigue resistance of modified asphalts based on the energy approach and viscoelastic continuum damage analysis.