Genetic algorithm for sequencing in midex model non-permutation flowshops using constrained buffers

Este trabajo presenta un Algoritmo Genético (GA) del problema de secuenciar unidades en una línea de producción. Se tiene en cuenta la posibilidad de cambiar la secuencia de piezas mediante estaciones con acceso a un almacén intermedio o centralizado. El acceso al almacén además está restringido, debido al tamaño de las piezas.AbstractThis paper presents a Genetic Algorithm (GA) for the problem of sequencing in a mixed model non-permutation flowshop. Resequencingis permitted where stations have access to intermittent or centralized resequencing buffers. The access to a buffer is restricted by the number of available buffer places and the physical size of the products.

A Constructive Genetic Algorithm for permutation flowshop scheduling

The general flowshop scheduling problem is a production problem where a set of n jobs have to be processed with identical flow pattern on in machines. In permutation flowshops the sequence of jobs is the same on all machines. A significant research effort has been devoted for sequencing jobs in a flowshop minimizing the makespan. This paper describes the application of a Constructive Genetic Algorithm (CGA) to makespan minimization on flowshop scheduling. The CGA was proposed recently as an alternative to traditional GA approaches, particularly, for evaluating schemata directly. The population initially formed only by schemata, evolves controlled by recombination to a population of well-adapted structures (schemata instantiation). The CGA implemented is based on the NEH classic heuristic and a local search heuristic used to define the fitness functions. The parameters of the CGA are calibrated using a Design of Experiments (DOE) approach. The computational results are compared against some other successful algorithms from the literature on Taillard`s well-known standard benchmark. The computational experience shows that this innovative CGA approach provides competitive results for flowshop scheduling; problems. (C) 2007 Elsevier Ltd. All rights reserved.

ILS-ESP An efficient, simple, and parameter-free algorithm for solving the permutation flow-shop problem

From a managerial point of view, the more effcient, simple, and parameter-free (ESP) an algorithm is, the more likely it will be used in practice for solving real-life problems. Following this principle, an ESP algorithm for solving the Permutation Flowshop Sequencing Problem (PFSP) is proposed in this article. Using an Iterated Local Search (ILS) framework, the so-called ILS-ESP algorithm is able to compete in performance with other well-known ILS-based approaches, which are considered among the most effcient algorithms for the PFSP. However, while other similar approaches still employ several parameters that can affect their performance if not properly chosen, our algorithm does not require any particular fine-tuning process since it uses basic "common sense" rules for the local search, perturbation, and acceptance criterion stages of the ILS metaheuristic. Our approach defines a new operator for the ILS perturbation process, a new acceptance criterion based on extremely simple and transparent rules, and a biased randomization process of the initial solution to randomly generate different alternative initial solutions of similar quality -which is attained by applying a biased randomization to a classical PFSP heuristic. This diversification of the initial solution aims at avoiding poorly designed starting points and, thus, allows the methodology to take advantage of current trends in parallel and distributed computing. A set of extensive tests, based on literature benchmarks, has been carried out in order to validate our algorithm and compare it against other approaches. These tests show that our parameter-free algorithm is able to compete with state-of-the-art metaheuristics for the PFSP. Also, the experiments show that, when using parallel computing, it is possible to improve the top ILS-based metaheuristic by just incorporating to it our biased randomization process with a high-quality pseudo-random number generator.

A simple permutation test for clusteredness

Hierarchical clustering is a popular method for finding structure in multivariate data,resulting in a binary tree constructed on the particular objects of the study, usually samplingunits. The user faces the decision where to cut the binary tree in order to determine the numberof clusters to interpret and there are various ad hoc rules for arriving at a decision. A simplepermutation test is presented that diagnoses whether non-random levels of clustering are presentin the set of objects and, if so, indicates the specific level at which the tree can be cut. The test isvalidated against random matrices to verify the type I error probability and a power study isperformed on data sets with known clusteredness to study the type II error.

Modules d'endo-permutation

Dans la th´eorie des repr´esentations modulaires des groupes finis, les modules d?endo-permutation occupent une place importante. En e_et, c?est le r?ole jou´e par ces modules dans l?analyse de la structure de certains modules simples pour des groupes finis p-nilpotents, qui a amen´e E. Dade `a en introduire le concept, en 1978. Quelques ann´ees plus tard, L. Puig a d´emontr´e que la source de n?importe quel module simple pour un groupe fini p-r´esoluble quelconque est un module d?endo-permutation. Plus r´ecemment, on s?est rendu compte que ces modules interviennent aussi dans l?analyse locale des cat´egories d´eriv´ees et dans l?´etude des syst`emes de fusion. La situation que l?on consid`ere est la suivante. On se donne un nombre premier p, un p-groupe fini P, un corps alg´ebriquement clos k de caract´eristique p et on veut d´eterminer tous les kP-modules d?endo-permutation couverts ind´ecomposables de type fini, c?est-`a-dire tous les kP-modules ind´ecomposables de type fini, tels que leur alg`ebre d?endomorphismes est un kP-module de permutation ayant un facteur direct trivial. On d´efinit une relation d?´equivalence sur l?ensemble de ces kP-modules et le produit tensoriel des modules induit une structure de groupe ab´elien sur l?ensemble des classes d?´equivalence. On appelle ce groupe, le groupe de Dade de P. Ainsi, classifier les modules d?endo-permutation couverts revient `a d´eterminer le groupe de Dade de P. Le groupe de Dade d?un p-groupe fini arbitraire est encore inconnu, bien qu?E. Dade, en 1978, ´etait d´ej`a parvenu `a la classification dans le cas o`u P est ab´elien. La premi`ere partie de ce travail de th`ese est consacr´ee au probl`eme de la classification dans le cas g´en´eral et r´esoud la question dans le cas de deux familles de p-groupes finis, `a savoir celle des p-groupes m´etacycliques, pour un nombre premier p impair, et celle des 2-groupes extrasp´eciaux, de la forme D8 _ · · · _ D8. Ces deux choix ont ´et´e motiv´es par le fait que ces groupes sont "presque" ab´eliens. De plus, certains r´esultats sur la structure du groupe de Dade d?un p-groupe fini quelconque rendent le groupe de Dade des groupes de ces deux familles plus simple `a ´etudier. Dans un deuxi`eme temps, nous nous sommes int´eress´es `a deux occurrences de ces modules dans la th´eorie de la repr´esentation des groupes finis, c?est-`a-dire `a deux raisons qui motivent leur ´etude. Ainsi, nous avons r´ealis´e des modules d?endo-permutation comme sources de modules simples. En particulier, il s?av`ere que, dans le cas d?un nombre premier p impair, tout module d?endo-permutation ind´ecomposable dont la classe est un ´el´ement de torsion dans le groupe de Dade est la source d?un module simple. Finalement, nous avons d´etermin´e, parmi tous les modules d?endo-permutation connus actuellement, lesquels poss`edent une r´esolution de permutation endo-scind´ee. Nous sommes arriv´es `a la conclusion que les seuls modules d?endo-permutation qui n?ont pas de r´esolution de permutation endo-scind´ee sont les modules "exceptionnels" apparaissant pour un 2-groupe de quaternions g´en´eralis´es.<br/><br/>In modular representation theory, endo-permutation modules occupy an important position. Indeed, the role that these modules play, in the analysis of the structure of some particular simple modules for finite p-nilpotent groups, induced E. Dade, in 1978, to give them their current name. A few years later, L. Puig proved that the source of any simple module for any finite psolvable group is an endo-permutation module. More recently, the occurrence of endo-permutation modules has also been noticed in the local analysis of splendid equivalences between derived categories and in the study of fusion systems. We consider the following situation. Given a prime number p, a finite pgroup P and an algebraically closed field k of characteristic p, we are looking for all finitely generated indecomposable capped endo-permutation kP-modules. That is, all finitely generated indecomposable kP-modules such that their endomorphism algebra is a permutation kP-module having a trivial direct summand. Then, we define an equivalence relation on the set of all isomorphism classes of such modules, and it turns out that the tensor product (over k) induces a structure of abelian group on this set. We call this group the Dade group of P. Hence, classifying all indecomposable finitely generated capped endo-permutation kPmodules is equivalent to determining the Dade group of P. At present, the Dade group of an arbitrary finite p-group is still unknown. However, E. Dade computed the Dade group of all finite abelian p-groups, in 1978 already. The first part of this doctoral thesis is concerned with the problem of the classification in the general case and solve it in the case of two families of finite p-groups, namely the metacyclic p-groups, for an odd prime number p, and the extraspecial 2-groups of the shape D8 _· · ·_D8. These two choices have been motivated by the fact that these groups are not far from being abelian. Moreover, some general results concerning the Dade group of arbitrary finite p-groups suggest that the Dade group of the groups belonging to these two families is easier to study. In the second part of this thesis, we have been looking at two particular occurrences of these modules in representation theory of finite groups which motivate the interest of their classification. Thus, we realised endo-permutation modules as sources of simple modules. In particular, it turns out that, in case p is an odd prime, any indecomposable module whose class in the Dade group is a torsion element is the source of some simple module. Finally, we considered all the modules we know at present and determined which ones have an endo-split permutation resolution. We could then conclude that all but the "exceptionnal" modules occurring in the generalized quaternion case have an endo-split permutation resolution.<br/><br/>"Module d?endo-permutation" n?est pas le nom d?une maladie exotique contagieuse (du moins pas `a ma connaissance), comme vous pourriez peut-?etre l?imaginer si vous faites partie des personnes qui croient que le titre de docteur n?est destin´e qu?aux m´edecins. Dans ce cas, il se peut que le sujet dont il est question ici vous cause quelques naus´ees et r´eveille de douloureux souvenirs d?´ecole, car un module d?endo-permutation est un objet math´ematique, alg´ebrique, plus pr´ecis´ement. Ce concept a ´et´e introduit il y a un quart de si`ecle, de l?autre c?ot´e de l?Atlantique, et il s?est r´ev´el´e su_samment int´eressant pour qu?aujourd?hui il ait franchi bien des fronti`eres, celles de l?alg`ebre y compris. Mais de quoi s?agit-il ? Si vous entendez le terme "endo-permutation" probablement pour la premi`ere fois, ce n?est certainement pas le cas pour celui de "module". Cependant, sa d´efinition dans le pr´esent contexte ne co¨ýncide avec aucune de celles figurant dans les dictionnaires ordinaires. Les personnes qui ont d´ej`a entendu parler de Frobenius, Burnside, Schur, ou encore Brauer, pourront vous dire qu?un module est une repr´esentation. "De quoi ?" vous demanderezvous. "Un spectacle de marionnettes, peut-?etre ?" Bien s?ur que non ! Un module d?endo-permutation est une repr´esentation particuli`ere de certains groupes finis, o`u un groupe n?est pas un groupe de rock, comme vous pouvez vous en douter, mais d´esigne un objet math´ematique connu par tous les ´etudiants en sciences au terme de leur premi`ere ann´ee universitaire (en th´eorie, du moins). La "popularit´e" de la notion de groupe, fini ou non, est due au fait que les groupes sont fr´equemment utilis´es, aussi bien dans le domaine abstrait des math´ematiques, que dans le monde r´eel des physiciens, chimistes et autres biologistes (pour ne citer qu?eux). "Mais comment peut-on utiliser concr`etement ces objets invisibles ?" vous demanderez-vous alors. Et bien, justement, en les consid´erant par l?interm´ediaire de leurs repr´esentations, c?est-`a-dire en leur associant des matrices, de fa¸con plus ou moins naturelle. Or, comme il y a "beaucoup trop" de matrices pour un groupe donn´e, elles sont classifi´ees selon certaines de leurs propri´et´es, ce qui permet de les r´epertorier dans diverses familles (celle des modules d?endo-permutation, par exemple). Un groupe est ainsi rendu "concret", car les donn´ees matricielles sont manipulables par tous les scienti- fiques (et leurs ordinateurs), qui peuvent alors les utiliser dans leurs recherches, afin de contribuer au progr`es de la science. En toute franchise, c?est bien loin de ces soucis terre-`a-terre que ce travail de th`ese sur la classification des modules d?endo-permutation a ´et´e accompli. En fait, quitte `a choquer certaines ?ames sensibles, sa r´ealisation est surtout due au caract`ere ´epicure de son auteur, qui, avouons-le, en a ´et´e pleinement satisfait !

Weakened functional connectivity in patients with psychogenic non-epileptic seizures (PNES) converges on basal ganglia.

BACKGROUND: Psychogenic non-epileptic seizures (PNES) are involuntary paroxysmal events that are unaccompanied by epileptiform EEG discharges. We hypothesised that PNES are a disorder of distributed brain networks resulting from their functional disconnection.The disconnection may underlie a dissociation mechanism that weakens the influence of unconsciously presented traumatising information but exerts maladaptive effects leading to episodic failures of behavioural control manifested by psychogenic 'seizures'. METHODS: To test this hypothesis, we compared functional connectivity (FC) derived from resting state high-density EEGs of 18 patients with PNES and 18 age-matched and gender-matched controls. To this end, the EEGs were transformed into source space using the local autoregressive average inverse solution. FC was estimated with a multivariate measure of lagged synchronisation in the θ, α and β frequency bands for 66 brain sites clustered into 18 regions. A multiple comparison permutation test was applied to deduce significant between-group differences in inter-regional and intraregional FC. RESULTS: The significant effect of PNES-a decrease in lagged FC between the basal ganglia and limbic, prefrontal, temporal, parietal and occipital regions-was found in the α band. CONCLUSION: We believe that this finding reveals a possible neurobiological substrate of PNES, which explains both attenuation of the effect of potentially disturbing mental representations and the occurrence of PNES episodes. By improving understanding of the aetiology of this condition, our results suggest a potential refinement of diagnostic criteria and management principles.

Permutation Entropy Based Analysis of Complex Signals for Characterising Change in System Dynamics

Timely detection of sudden change in dynamics that adversely affect the performance of systems and quality of products has great scientific relevance. This work focuses on effective detection of dynamical changes of real time signals from mechanical as well as biological systems using a fast and robust technique of permutation entropy (PE). The results are used in detecting chatter onset in machine turning and identifying vocal disorders from speech signal.Permutation Entropy is a nonlinear complexity measure which can efficiently distinguish regular and complex nature of any signal and extract information about the change in dynamics of the process by indicating sudden change in its value. Here we propose the use of permutation entropy (PE), to detect the dynamical changes in two non linear processes, turning under mechanical system and speech under biological system.Effectiveness of PE in detecting the change in dynamics in turning process from the time series generated with samples of audio and current signals is studied. Experiments are carried out on a lathe machine for sudden increase in depth of cut and continuous increase in depth of cut on mild steel work pieces keeping the speed and feed rate constant. The results are applied to detect chatter onset in machining. These results are verified using frequency spectra of the signals and the non linear measure, normalized coarse-grained information rate (NCIR).PE analysis is carried out to investigate the variation in surface texture caused by chatter on the machined work piece. Statistical parameter from the optical grey level intensity histogram of laser speckle pattern recorded using a charge coupled device (CCD) camera is used to generate the time series required for PE analysis. Standard optical roughness parameter is used to confirm the results.Application of PE in identifying the vocal disorders is studied from speech signal recorded using microphone. Here analysis is carried out using speech signals of subjects with different pathological conditions and normal subjects, and the results are used for identifying vocal disorders. Standard linear technique of FFT is used to substantiate thc results.The results of PE analysis in all three cases clearly indicate that this complexity measure is sensitive to change in regularity of a signal and hence can suitably be used for detection of dynamical changes in real world systems. This work establishes the application of the simple, inexpensive and fast algorithm of PE for the benefit of advanced manufacturing process as well as clinical diagnosis in vocal disorders.

Aging and stationary properties of non-equilibrium symmetrical three-state models

We consider a non-equilibrium three-state model whose dynamics is Markovian and displays the same symmetry as the three-state Potts model, i.e. the transition rates are invariant under the cyclic permutation of the states. Unlike the Potts model, detailed balance is, in general, not satisfied. The aging and the stationary properties of the model defined on a square lattice are obtained by means of large-scale Monte Carlo simulations. We show that the phase diagram presents a critical line, belonging to the three-state Potts universality class, that ends at a point whose universality class is that of the Voter model. Aging is considered on the critical line, at the Voter point and in the ferromagnetic phase.

A note on permutation regularity

The existence of a small partition of a combinatorial structure into random-like subparts, a so-called regular partition, has proven to be very useful in the study of extremal problems, and has deep algorithmic consequences. The main result in this direction is the Szemeredi Regularity Lemma in graph theory. In this note, we are concerned with regularity in permutations: we show that every permutation of a sufficiently large set has a regular partition into a small number of intervals. This refines the partition given by Cooper (2006) [10], which required an additional non-interval exceptional class. We also introduce a distance between permutations that plays an important role in the study of convergence of a permutation sequence. (C) 2011 Elsevier B.V. All rights reserved.

Non-manipulable domains for the Borda count

We characterize the preference domains on which the Borda count satises Arrow's "independence of irrelevant alternatives" condition. Under a weak richness condition, these domains are obtained by xing one preference ordering and including all its cyclic permutations ("Condorcet cycles"). We then ask on which domains the Borda count is non-manipulable. It turns out that it is non-manipulable on a broader class of domains when combined with appropriately chosen tie-breaking rules. On the other hand, we also prove that the rich domains on which the Borda count is non-manipulable for all possible tie-breaking rules are again the cyclic permutation domains.

The kernel is in the least core for permutation games

Permutation games are totally balanced transferable utility cooperative games arising from certain sequencing and re-assignment optimization problems. It is known that for permutation games the bargaining set and the core coincide, consequently, the kernel is a subset of the core. We prove that for permutation games the kernel is contained in the least core, even if the latter is a lower dimensional subset of the core. By means of a 5-player permutation game we demonstrate that, in sense of the lexicographic center procedure leading to the nucleolus, this inclusion result can not be strengthened. Our 5-player permutation game is also an example (of minimum size) for a game with a non-convex kernel.

Egfr Activating Mutations And Their Association With Response To Platinum-doublet Chemotherapy In Brazilian Non-small Cell Lung Cancer Patients.

The aim of the study was to analyze the frequency of epidermal growth factor receptor (EGFR) mutations in Brazilian non-small cell lung cancer patients and to correlate these mutations with response to benefit of platinum-based chemotherapy in non-small cell lung cancer (NSCLC). Our cohort consisted of prospective patients with NSCLCs who received chemotherapy (platinum derivates plus paclitaxel) at the [UNICAMP], Brazil. EGFR exons 18-21 were analyzed in tumor-derived DNA. Fifty patients were included in the study (25 with adenocarcinoma). EGFR mutations were identified in 6/50 (12 %) NSCLCs and in 6/25 (24 %) adenocarcinomas; representing the frequency of EGFR mutations in a mostly self-reported White (82.0 %) southeastern Brazilian population of NSCLCs. Patients with NSCLCs harboring EGFR exon 19 deletions or the exon 21 L858R mutation were found to have a higher chance of response to platinum-paclitaxel (OR 9.67 [95 % CI 1.03-90.41], p = 0.047). We report the frequency of EGFR activating mutations in a typical southeastern Brazilian population with NSCLC, which are similar to that of other countries with Western European ethnicity. EGFR mutations seem to be predictive of a response to platinum-paclitaxel, and additional studies are needed to confirm or refute this relationship.

Fatty Acid Synthase Inhibitors Induce Apoptosis In Non-tumorigenic Melan-a Cells Associated With Inhibition Of Mitochondrial Respiration.

The metabolic enzyme fatty acid synthase (FASN) is responsible for the endogenous synthesis of palmitate, a saturated long-chain fatty acid. In contrast to most normal tissues, a variety of human cancers overexpress FASN. One such cancer is cutaneous melanoma, in which the level of FASN expression is associated with tumor invasion and poor prognosis. We previously reported that two FASN inhibitors, cerulenin and orlistat, induce apoptosis in B16-F10 mouse melanoma cells via the intrinsic apoptosis pathway. Here, we investigated the effects of these inhibitors on non-tumorigenic melan-a cells. Cerulenin and orlistat treatments were found to induce apoptosis and decrease cell proliferation, in addition to inducing the release of mitochondrial cytochrome c and activating caspases-9 and -3. Transfection with FASN siRNA did not result in apoptosis. Mass spectrometry analysis demonstrated that treatment with the FASN inhibitors did not alter either the mitochondrial free fatty acid content or composition. This result suggests that cerulenin- and orlistat-induced apoptosis events are independent of FASN inhibition. Analysis of the energy-linked functions of melan-a mitochondria demonstrated the inhibition of respiration, followed by a significant decrease in mitochondrial membrane potential (ΔΨm) and the stimulation of superoxide anion generation. The inhibition of NADH-linked substrate oxidation was approximately 40% and 61% for cerulenin and orlistat treatments, respectively, and the inhibition of succinate oxidation was approximately 46% and 52%, respectively. In contrast, no significant inhibition occurred when respiration was supported by the complex IV substrate N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD). The protection conferred by the free radical scavenger N-acetyl-cysteine indicates that the FASN inhibitors induced apoptosis through an oxidative stress-associated mechanism. In combination, the present results demonstrate that cerulenin and orlistat induce apoptosis in non-tumorigenic cells via mitochondrial dysfunction, independent of FASN inhibition.

Imported Malaria In A Non-endemic Area: The Experience Of The University Of Campinas Hospital In The Brazilian Southeast.

Although malaria in Brazil almost exclusively occurs within the boundaries of the Amazon Region, some concerns are raised regarding imported malaria to non-endemic areas of the country, notably increased incidence of complications due to delayed diagnoses. However, although imported malaria in Brazil represents a major health problem, only a few studies have addressed this subject. A retrospective case series is presented in which 263 medical charts were analysed to investigate the clinical and epidemiological characterization of malaria cases that were diagnosed and treated at Hospital & Clinics, State University of Campinas between 1998 and 2011. Amongst all medical charts analysed, 224 patients had a parasitological confirmed diagnosis of malaria. Plasmodium vivax and Plasmodium falciparum were responsible for 67% and 30% of the infections, respectively. The majority of patients were male (83%) of a productive age (median, 37 years old). Importantly, severe complications did not differ significantly between P. vivax (14 cases, 9%) and P. falciparum (7 cases, 10%) infections. Severe malaria cases were frequent among imported cases in Brazil outside of the Amazon area. The findings reinforce the idea that P. vivax infections in Brazil are not benign, regardless the endemicity of the area studied. Moreover, as the hospital is located in a privileged site, it could be used for future studies of malaria relapses and primaquine resistance mechanisms. Finally, based on the volume of cases treated and the secondary complications, referral malaria services are needed in the non-endemic areas of Brazil for a rapid and efficient and treatment.

Evaluation Of Fe Uptake And Translocation In Transgenic And Non-transgenic Soybean Plants Using Enriched Stable (57)fe As A Tracer.

A tracer experiment is carried out with transgenic T (variety M 7211 RR) and non-transgenic NT (variety MSOY 8200) soybean plants to evaluate if genetic modification can influence the uptake and translocation of Fe. A chelate of EDTA with enriched stable (57)Fe is applied to the plants cultivated in vermiculite plus substrate and the (57)Fe acts as a tracer. The exposure of plants to enriched (57)Fe causes the dilution of the natural previously existing Fe in the plant compartments and then the changed Fe isotopic ratio ((57)Fe/(56)Fe) is measured using a quadrupole-based inductively coupled plasma mass spectrometer equipped with a dynamic reaction cell (DRC). Mathematical calculations based on the isotope dilution methodology allow distinguishing the natural abundance Fe from the enriched Fe (incorporated during the experiment). The NT soybean plants acquire higher amounts of Fe from natural abundance (originally present in the soil) and from enriched Fe (coming from the (57)Fe-EDTA during the experiment) than T soybean ones, demonstrating that the NT soybean plants probably absorb higher amounts of Fe, independently of the source. The percentage of newly incorporated Fe (coming from the treatment) was approximately 2.0 and 1.1% for NT and T soybean plants, respectively. A higher fraction (90.1%) of enriched Fe is translocated to upper parts, and a slightly lower fraction (3.8%) is accumulated in the stems by NT plants than by T ones (85.1%; 5.1%). Moreover, in both plants, the Fe-EDTA facilitates the transport and translocation of Fe to the leaves. The genetic modification is probably responsible for differences observed between T and NT soybean plants.