Classification of Risks of Occupational Low Back Disorders with Support Vector Machines

Though technology has shown a rapid development, manual material handling (MMH) tasks are still usual activities in most industries. According to recent surveys, MMH tasks remain one of the main reasons for the emergence of occupational low back disorders (LBDs). It is critical to be able to discriminate as accurately as possible between MMH jobs that place workers at high versus low risk of LBDs. In this study, the risk of occupational LBDs has been classified by support vector machines (SVMs) considering both trunk motion variables and workplace variables, which have been extensively used to identify risk of LBDs. The LBDs‐SVM model has outperformed the existing models in terms of accuracy, which is equal to 88.5% for correct classification of high risk when 10‐cross validation is applied. In other words, the proposed model has correctly classified an average of 29.2 cases out of 33 high‐risk cases, which is critical to be determined compared to low‐risk cases. The results obtained in this study indicate that SVM is a better classifier than the other existing methods in the literature to classify LBDs risks.     

Endogenous Effects of Hubbing on Flow Intensities

Location of hub facilities and the allocation decisions in transport networks endogenously affect both the flow intensities and the transportation costs. Since the introduction of the hub location problem to the operations research literature in mid-1980s, many researchers investigated different ways of modelling the effects of hub facilities on the transportation costs. On the other hand, there has been very limited research on their effect on the flow intensities. This study proposes a new approach, inspired by the Bass diffusion model, to forecast the change in the demand patterns generated at different locations as a result of the placement of new hubs. This new model is used in the context of the uncapacitated single allocation p-hub median problem to investigate the effects of endogenous attraction, caused by the spatial interaction of present hubs, on future hub location decisions. Computational results indicate that the location and allocation decisions may be greatly affected when these forecasts are taken into account in the selection of future hub locations.     

Stabilizing maximum matching in bipartite networks

A matching ${E_\mathcal{M}}$ of graph G =  (V, E) is a subset of the edges E, such that no vertex in V is incident to more than one edge in ${E_\mathcal{M}}$ . The matching ${E_\mathcal{M}}$ is maximum if there is no matching in G with size strictly larger than the size of ${E_\mathcal{M}}$ . In this paper, we present a distributed stabilizing algorithm for finding maximum matching in bipartite graphs based on the stabilizing PIF algorithm of Cournier et al. (Proceedings of 21st IEEE international conference on distributed computing systems, 91–98, 2001). Since our algorithm is stabilizing, it does not require initialization and withstands transient faults. The complexity of the proposed algorithm is O(d × n) rounds, where d is the diameter of the communication network and n is the number of nodes in the network. The space complexity is O(log Δ +  log d), where Δ is the largest degree of all the nodes in the communication network. In addition, an optimal version of the proposed algorithm finding maximum matching in linear time is also presented.     

Object-oriented texture analysis for the unsupervised segmentation of biopsy images for cancer detection

Staining methods routinely used in pathology lead to similar color distributions in the biologically different regions of histopathological images. This causes problems in image segmentation for the quantitative analysis and detection of cancer. To overcome this problem, unlike previous methods that use pixel distributions, we propose a new homogeneity measure based on the distribution of the objects that we define to represent tissue components. Using this measure, we demonstrate a new object-oriented segmentation algorithm. Working with colon biopsy images, we show that this algorithm segments the cancerous and normal regions with 94.89 percent accuracy on the average and significantly improves the segmentation accuracy compared to its pixel-based counterpart.     

Dynamic Properties of Kinetic Spin-3/2 Ising Ferromagnetic Model in the Presence of the Crystal and External Oscillating Magnetic Fields

The kinetic spin-3/2 Ising system in the presence of crystal and external oscillating magnetic fields on the triangular lattice (TL) is examined within the mean-field approximation and the Glauber-type stochastic dynamics, namely dynamic mean-field approximation (DMFA). First, the dynamic equations describing the behavior of the system are derived for the TL. Then, the dynamic equations are solved numerically to obtain the dynamic hysteresis curves of the kinetic spin-3/2 Ising ferromagnetic system, which strongly depend on the Hamiltonian parameters. Moreover, the dynamic behaviors of the coercivity and remanent magnetizations are studied depending on the temperature, crystal field and frequency of the oscillating external magnetic field. Finally, the results are compared with some experimental and theoretical studies and a qualitatively good overall agreement is observed     

Dynamic Magnetic Hysteresis Behaviors in a Mixed Spin (3/2, 2) Bilayer System with Different Crystal-Field Interactions

Dynamic magnetic hysteresis (DMH) behaviors of the mixed spin-3/2 and spin-2 Ising bilayer system with different crystal-field interactions on a two-layer square lattice is studied by the use of dynamic mean field calculations based on the Glauber-type stochastic. The hysteresis loops are obtained for different reduced temperatures (T), magnetic field amplitudes (h), frequencies (w) and interlayer coupling constants (J ₃). Influences of the T, h, w and J ₃ on the DMH properties are investigated. We also study the temperature, frequency and interlayer coupling interaction dependence of the coercive field and remanent magnetization. We compare our results with some theoretical and experimental works and observe a quantitatively good agreement with some theoretical and experimental results.     

The contact problem of a rigid stamp with friction on a functionally graded magneto-electro-elastic half-plane

We consider in this study the frictional sliding contact problem between a functionally graded magneto-electro-elastic material and a perfectly conducting rigid punch subjected to magneto-electro-mechanical loads. The problem is formulated under plane strain conditions. Using Fourier transform, the resulting plane magneto-electro-elasticity equations are converted analytically into three coupled singular integral equations in which the unknowns are the normal contact stress, the electric displacement and the magnetic induction. These integral equations are then solved numerically to obtain the distributions of the normal contact stress, electric displacement and magnetic induction at the surface of the graded medium. The main objective of this paper is to study the effect of the non-homogeneity parameter, the friction coefficient and the elastic, electric and magnetic coefficients on the surface contact pressure, electric displacement and magnetic induction distributions for the case of flat and circular punch profiles.     

Software development with imperfect information

Delivering software systems that fulfill all requirements of the stakeholders is very difficult, if not at all impossible. We consider the problem of coping with imperfect information, like interpreting incomplete requirement specifications or vagueness in decisions, one of the main reasons that makes software design difficult. We define a method for tracing design decisions under imperfect information. To model and compare requirements with estimations, we present fuzzy and stochastic techniques. This approach offers adequate decision support that can deal with imperfect information during software design. The approach is illustrated by a real-world example, based on a storm surge barrier system.     

Porous magnetic chelator support for albumin adsorption by immobilized metal affinity separation

Magnetic poly(2‐hydroxyethylmethacrylate) (mPHEMA) beads are modified by iminodiacetic acid (IDA) to implify the reactive groups and subsequent binding of Cu²⁺ ions to form metal chelate. mPHEMA beads, in the size range of 80–120 μm, were produced by a modified suspension polymerization technique. mPHEMA beads were characterized by swelling tests, electron spin resonance (ESR), FTIR, and scanning electron microscopy (SEM). Important results obtained in this study are as follows. The swelling ratio of mPHEMA beads was 34%. The presence of magnetite particles in the polymeric structure was confirmed by ESR. FTIR data confirmed that the magnetic polymer beads were modified with functional groups IDA. The mPHEMA beads have a spherical shape and porous structure. The effect of pH and concentration of human serum albumin (HSA), on the adsorption of HSA to the metal‐chelated magnetic beads, were examined in a batch reactor. Most importantly, the magnetic beads had little nonspecific adsorption for HSA (0.5 mg/g) before introducing IDA groups. Cu²⁺ chelation increased the HSA adsorption up to 28.4 mg/g. Adsorption behavior can be described at least approximately with the Langmuir equation. Regeneration of the metal‐chelated magnetic beads was easily performed with 1.0M NaSCN, pH 8.0, followed by washing with distilled water and reloading with Cu²⁺. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2501–2510, 2004     

Energy and exergy analysis of a ground-coupled heat pump system with two horizontal ground heat exchangers

In this paper we investigate of energetic and exergetic efficiencies of ground-coupled heat pump (GCHP) system as a function of depth trenches for heating season. The horizontal ground heat exchangers (HGHEs) were used and it were buried with in 1 m (HGHE1) and 2 m (HGHE2) depth trenches. The energy efficiency of GCHP systems are obtained to 2.5 and 2.8, respectively, while the exergetic efficiencies of the overall system are found to be 53.1% and 56.3%, respectively, for HGHE1 and HGHE2. The irreversibility of HGHE2 is less than of the HGHE1 as about 2.0%. The results show that the energetic and exergetic efficiencies of the system increase when increasing the heat source (ground) temperature for heating season. And the end of this study, we deal with the effects of varying reference environment temperature on the exergy efficiencies of HGHE1 and HGHE2. The results show that increasing reference environment temperature decreases the exergy efficiency in both HGHE1 and HGHE2.