A new constraint programming approach for optimising a coal rail system

Because of the bottlenecking operations in a complex coal rail system, millions of dollars are costed by mining companies. To handle this issue, this paper investigates a real-world coal rail system and aims to optimise the coal railing operations under constraints of limited resources (e.g., limited number of locomotives and wagons). In the literature, most studies considered the train scheduling problem on a single-track railway network to be strongly NP-hard and thus developed metaheuristics as the main solution methods. In this paper, a new mathematical programming model is formulated and coded by optimization programming language based on a constraint programming (CP) approach. A new depth-first-search technique is developed and embedded inside the CP model to obtain the optimised coal railing timetable efficiently. Computational experiments demonstrate that high-quality solutions are obtainable in industry-scale applications. To provide insightful decisions, sensitivity analysis is conducted in terms of different scenarios and specific criteria. Keywords Train scheduling · Rail transportation · Coal mining · Constraint programming

Delay optimal control algorithm for a multiaccess fading channel with peak power constraint

We consider an optimal power and rate scheduling problem for a multiaccess fading wireless channel with the objective of minimising a weighted sum of mean packet transmission delay subject to a peak power constraint. The base station acts as a controller which, depending upon the buffer lengths and the channel state of each user, allocates transmission rate and power to individual users. We assume perfect channel state information at the transmitter and the receiver. We also assume a Markov model for the fading and packet arrival processes. The policy obtained represents a form of Indexability.

Developmental origins of physiological stress reactivity

The model of developmental origins of health and disease proposes that organisms during fetal period utilize cues that enable their adaptation in the postnatal environment they are likely to live, having short-term advantages when trying to survive in environment but simultaneously in the long run have costs for health. A large body of epidemiological research has found that low birth weight, a marker of intrauterine conditions, is associated with cardiovascular (CV) disease. Since the reported associations of birth weight with normal variation in the resting blood pressure (BP), a major predictor of CV disease risk, have been modest, a key candidate mediating the link has been CV and hypothalamus-pituitary-adrenal axes (HPAA) reactivity to stress. In addition, not only weight at birth but also gestational age and early postnatal growth may have independent associations to stress reactivity. The aim of this thesis was to investigate whether pre- and postnatal growth and gestational age are associated with CV and HPAA activity before, during and after stress in childhood and in late adulthood. Altogether 287 men and women aged 60-70 and 299 boys and girls aged 7-9 underwent Trier Social Stress Test. Several indices of HPAA and CV were measured and birth size and gestational age were obtained from birth records. Results showed that low birth weight was associated with low HPAA activity during psychosocial stress, and rapid gain in BMI during years 7-11 was related to heightened stress reactivity to psychosocial stress. Size at birth in children and gestational age and early postnatal (0-2 years) gain in height in adults were associated with CV stress responses; however, in a sex-specific manner. Given that CV stress responses and HPAA activity are markers of CV disease vulnerability, our results may partly explain the associations between early environment and later CV disease.

Importance of carbon dioxide physiological forcing to future climate change

An increase in atmospheric carbon dioxide (CO2) concentration influences climate both directly through its radiative effect (i.e., trapping longwave radiation) and indirectly through its physiological effect (i.e., reducing transpiration of land plants). Here we compare the climate response to radiative and physiological effects of increased CO2 using the National Center for Atmospheric Research (NCAR) coupled Community Land and Community Atmosphere Model. In response to a doubling of CO2, the radiative effect of CO2 causes mean surface air temperature over land to increase by 2.86 ± 0.02 K (± 1 standard error), whereas the physiological effects of CO2 on land plants alone causes air temperature over land to increase by 0.42 ± 0.02 K. Combined, these two effects cause a land surface warming of 3.33 ± 0.03 K. The radiative effect of doubling CO2 increases global runoff by 5.2 ± 0.6%, primarily by increasing precipitation over the continents. The physiological effect increases runoff by 8.4 ± 0.6%, primarily by diminishing evapotranspiration from the continents. Combined, these two effects cause a 14.9 ± 0.7% increase in runoff. Relative humidity remains roughly constant in response to CO2-radiative forcing, whereas relative humidity over land decreases in response to CO2-physiological forcing as a result of reduced plant transpiration. Our study points to an emerging consensus that the physiological effects of increasing atmospheric CO2 on land plants will increase global warming beyond that caused by the radiative effects of CO2.

Modern Societal Impulses and their Nordic Manifestations : On Emancipation and Constraint in Societal Development

The 1980s and the early 1990s have proved to be an important turning point in the history of the Nordic welfare states. After this breaking point, the Nordic social order has been built upon a new foundation. This study shows that the new order is mainly built upon new hierarchies and control mechanisms that have been developed consistently through economic and labour market policy measures. During the post-war period Nordic welfare states to an increasing extent created equality of opportunity and scope for agency among people. Public social services were available for all and the tax-benefit system maintained a level income distribution. During this golden era of Nordic welfare state, the scope for agency was, however, limited by social structures. Public institutions and law tended to categorize people according to their life circumstances ascribing them a predefined role. In the 1980s and 1990s this collectivist social order began to mature and it became subject to political renegotiation. Signs of a new social order in the Nordic countries have included the liberation of the financial markets, the privatizing of public functions and redefining the role of the public sector. It is now possible to reassess the ideological foundations of this new order. As a contrast to widely used political rhetoric, the foundation of the new order has not been the ideas of individual freedom or choice. Instead, the most important aim appears to have been to control and direct people to act in accordance with the rules of the market. The various levels of government and the social security system have been redirected to serve this goal. Instead of being a mechanism for redistributing income, the Nordic social security system has been geared towards creating new hierarchies on the Nordic labour markets. During the past decades, conditions for receiving income support and unemployment benefit have been tightened in all Nordic countries. As a consequence, people have been forced to accept deteriorating terms and conditions on the labour market. Country-specific variations exist, however: in sum Sweden has been most conservative, Denmark most innovative and Finland most radical in reforming labour market policy. The new hierarchies on the labour market have co-incided with slow or non-existent growth of real wages and with a strong growth of the share of capital income. Slow growth of real wages has kept inflation low and thus secured the value of capital. Societal development has thus progressed from equality of opportunity during the age of the welfare states towards a hierarchical social order where the majority of people face increasing constraints and where a fortunate minority enjoys prosperity and security.

T-type calcium channel:from physiological function to therapeutical targeting – Exploring neuronal development

Tämän tutkimuksen tarkoitus oli tutkia T-tyypin kalsiumkanavan toimintaa ja sen mahdollista roolia neuronaalisten kantasolujen migraatiossa. T-tyypin kalsiumkanavan tehtävän kehittyneissä aivoissa tiedetään olevan elektroenkefalografisten oskillaatioiden tuottaminen. Nämä taas ovat eräiden fysiologisten ja patofysiologisten tapahtumien säätelyssä avainasemassa. Tällaisia tapahtumia ovat uni, muisti, oppiminen ja epileptiset poissaolokohtaukset. Näiden lisäksi T-tyypin kalsiumkanavalla on myös periferaalisia vaikutuksia, mutta tämä tutkielma keskittyy sen neuronaalisiin toimintoihin. Tämän matalan jännitteen säätelemän kanavan toiminta neurogeneesin aikana on vähemmän tutkittua ja tunnettua kuin sen vaikutukset kehittyneissä aivoissa. T-tyypin kalsiumkanavan tiedetään edistävän kantasolujen proliferaatiota ja erilaistumista neurogeneesiksen aikana, mutta vaikutukset niiden migraatioon ovat vähemmän tunnetut. Tämä tutkimus näyttää T-tyypin kalsiumkanavan todennäköisesti osallistuvan neuronaaliseen migraatioon hiiren alkion subventrikkeli alueelta eristetyillä kanta- tai progeniittorisoluilla tehdyissä kokeissa. Selektiiviset T-tyypin kalsiumkanavan antagonistit, etosuksimidi, nikkeli ja skorpionitoksiini, kurtoxin hidastivat migraatiota erilaistuvissa progeniittorisoluissa. Tämä tutkimus koostuu kirjallisuuskatsauksesta ja kokeellisesta osasta. Tämän tutkimuksen toinen tarkoitus oli esitellä vaihtoehtoinen lähestymistapa invasiiviselle kantasoluterapialle, joka vaatii kantasolujen viljelyä ja siirtämistä ihmiseen. Tämä toinen tapa on endogeenisten kantasolujen eiinvasiivinen stimulointi, jolla ne saadaan migratoitumaan kohdekudokseen, erilaistumaan siellä ja tehtävänsä suoritettuaan lopettamaan jakaantumisen. Non-invasiivinen kantasoluterapia on vasta tiensä alussa, ja tarvitsee farmakologista osaamista kehittyäkseen. Joitain onnistuneita ei-invasiivisia hoitoja on jo tehty selkärangan vaurioiden korjaamisessa. Vastaavanlaisia menetelmiä voitaisiin käyttää myös keskushermoston vaurioiden ja neurodegeneratiivisten sairauksien hoidossa. Näiden menetelmien kehittäminen vaatii endogeenisten kantasoluja inhiboivien ja indusoivien mekanismien tuntemista. Yksi tärkeä kantasolujen erilaistumista stimuloiva tekijä on kalsiumioni. Jänniteherkät kalsiumkanavat osallistuvat kaikkiin neurogeneesiksen eri vaiheisiin. T-tyypin kalsiumkanava, joka ekspressoituu suuressa määrin keskushermoston kehityksen alkuvaiheessa ja vähenee neuronaalisen kehityksen edetessä, saattaa olla oleellisessa asemassa progeniittorisolujen ohjaamisessa.

Chaperone expression profiles correlate with distinct physiological states of Plasmodium falciparum in malaria patients

Background: Molecular chaperones have been shown to be important in the growth of the malaria parasite Plasmodium falciparum and inhibition of chaperone function by pharmacological agents has been shown to abrogate parasite growth. A recent study has demonstrated that clinical isolates of the parasite have distinct physiological states, one of which resembles environmental stress response showing up-regulation of specific molecular chaperones. Methods: Chaperone networks operational in the distinct physiological clusters in clinical malaria parasites were constructed using cytoscape by utilizing their clinical expression profiles. Results: Molecular chaperones show distinct profiles in the previously defined physiologically distinct states. Further, expression profiles of the chaperones from different cellular compartments correlate with specific patient clusters. While cluster 1 parasites, representing a starvation response, show up-regulation of organellar chaperones, cluster 2 parasites, which resemble active growth based on glycolysis, show up-regulation of cytoplasmic chaperones. Interestingly, cytoplasmic Hsp90 and its co-chaperones, previously implicated as drug targets in malaria, cluster in the same group. Detailed analysis of chaperone expression in the patient cluster 2 reveals up-regulation of the entire Hsp90-dependent pro-survival circuitries. In addition, cluster 2 also shows up-regulation of Plasmodium export element (PEXEL)-containing Hsp40s thought to have regulatory and host remodeling roles in the infected erythrocyte. Conclusion: In all, this study demonstrates an intimate involvement of parasite-encoded chaperones, PfHsp90 in particular, in defining pathogenesis of malaria.

A note on resolving infeasibility in linear programs by constraint relaxation

We study the problem of finding a set of constraints of minimum cardinality which when relaxed in an infeasible linear program, make it feasible. We show the problem is NP-hard even when the constraint matrix is totally unimodular and prove polynomial-time solvability when the constraint matrix and the right-hand-side together form a totally unimodular matrix.

An Efficient Constraint Grammar Parser based on Inward Deterministic Automata

Pappret conceptualizes parsning med Constraint Grammar på ett nytt sätt som en process med två viktiga representationer. En representation innehåller lokala tvetydighet och den andra sammanfattar egenskaperna hos den lokala tvetydighet klasser. Båda representationer manipuleras med ren finite-state metoder, men deras samtrafik är en ad hoc -tillämpning av rationella potensserier. Den nya tolkningen av parsning systemet har flera praktiska fördelar, bland annat det inåt deterministiska sättet att beräkna, representera och räkna om alla potentiella tillämpningar av reglerna i meningen.

Influence of crack tip constraint on void growth in ductile FCC single crystals

Effect of constraint (stress triaxiality) on void growth near a notch tip in a FCC single crystal is investigated. Finite element simulations within the modified boundary layer framework are conducted using crystal plasticity constitutive equations and neglecting elastic anisotropy. Displacement boundary conditions based on model, elastic, two term K-T field are applied on the outer boundary of a large circular domain. A pre-nucleated void is considered ahead of a stationary notch tip. The interaction between the notch tip and the void is studied under different constraints (T-stress levels) and crystal orientations. It is found that negative T-stress retards the mechanisms of ductile fracture. However, the extent of retardation depends on the crystal orientation. Further, it is found that there exists a particular orientation which delays the ductile fracture processes and hence can potentially improve ductility. This optimal orientation depends on the constraint level. (C) 2010 Published by Elsevier B.V.

Effect of the valine-threonine constraint on the dynamics of the proline helix — A molecular dynamics study

Proline residues in helices play an important role in the structure of proteins. The proline residue introduces a kink in the helix which varies from about 5-degrees to 50-degrees. The presence of other residues such as threonine or valine near the proline region can influence the flexibility exhibited by the kinked helix, which can have an important biological role. In the present paper, the constraint introduced by threonine and valine on a proline helix is investigated by molecular dynamics studies. The systems considered am (1) a poly-alanine helix with threonine-proline residues (TP) and (2) a poly-alanine helix with valine-threonine-proline residues (VTP), in the middle. Molecular dynamics simulations are carried out on these two systems for 500 ps. The results are analyzed in terms of structural transitions, bend-related parameters and sidechain orientations.

Suboptimal Midcourse Guidance of Interceptors for High-Speed Targets with Alignment Angle Constraint

Using the recently developed computationally efficient model predictive static programming and a closely related model predictive spread control concept, two nonlinear suboptimal midcourse guidance laws are presented in this paper for interceptors engaging against incoming high-speed ballistic missiles. The guidance laws are primarily based on nonlinear optimal control theory, and hence imbed effective trajectory optimization concepts into the guidance laws. Apart from being energy efficient by minimizing the control usage throughout the trajectory (minimum control usage leads to minimum turning, and hence leads to minimum induced drag), both of these laws enforce desired alignment constraints in both elevation and azimuth in a hard-constraint sense. This good alignment during midcourse is expected to enhance the effectiveness of the terminal guidance substantially. Both point mass as well as six-degree-of-freedom simulation results (with a realistic inner-loop autopilot based on dynamic inversion) are presented in this paper, which clearly shows the effectiveness of the proposed guidance laws. It has also been observed that, even with different perturbations of missile parameters, the performance of guidance is satisfactory. A comparison study, with the vector explicit guidance scheme proposed earlier in the literature, also shows that the newly proposed model-predictive-static-programming-based and model-predictive-spread-control-based guidance schemes lead to lesser lateral acceleration demand and lesser velocity loss during engagement.

Unified approach to the constraint counting theory of glasses

An approach to the constraint counting theory of glasses is applied to many glass systems which include an oxide, chalcohalide, and chalcogenides. In this, shifting of the percolation threshold due to noncovalent bonding interactions in a basically covalent network and other recent extensions of the theory appear natural. This is particularly insightful and reveals that the chemical threshold signifies another structural transition along with the rigidity percolation threshold, thus unifying these two seemingly disparate toplogical concepts. [S0163-1829(99)11441-3].