Civil Engineering

This paper focuses on alternative forms to the post-lintel rigid box-frame. These alternative shapes shall be presented in the form of historical as well as contemporary projects designed by select architects and engineers.

From an architectural point of view, the box-frame is a convenient means of designing spaces. However, in terms of structure, the lateral movement subjects the fixed frame elements and joints to additional flexural stress, resulting in larger sizes and more material used, thus increasing the overall mass which, in turn, adds to the lateral stress, resulting in a vicious cycle.

In improving on the performance of the box-frame, the selection of alternatives are loosely organized according to: 1) shape of structural elements, 2) location of structural elements, 3) the use of diagonals, braces, and angled forms, 4) the use of curve profiles, and, 5) the use of post-tensioning and secondary systems.

While these different shapes add to the rich vocabulary of structures and architecture, it can be summarized that these “break-out-of-the-box” variations 1) improve material usage and structural behavior, 2) encourage more axial and less flexural behavior, and, in expressing it clearly and colorfully, 3) perhaps add to a sense of delight and achievement in our everyday experience of our environment.

Augustin-Louis Cauchy died in 1857, 150 years ago, and is considered one of the most important mathematicians of the 19th century. His mathematical work is characterized by a deep research of a rigorous approach to the concepts of the Calculus. Both from an historical and from an educational points of view, a correct hermeneutic approach (based, for instance, upon Gadamer’s work) can be very useful in order to interpret, nowadays, Cauchy’s research.

The works of Jacques (1654-1705) and Jean Bernoulli (1667-1748), two of the most important mathematicians lived between the XVII century and the XVIII century, are nowadays interesting also for the modern didactics of mathematics. In this paper, some thecniques and some examples from Jacques and Jean Bernoulli’s works are presented and their didactical importance is underlined.

The celebrated Euler’s formula allowed 18th century mathematicians to close the debate about logarithms of negative numbers, a debate dating back to a letter by Gottfried Wilhelm Leibniz to Johann Bernoulli (march 16th, 1712). In this paper we summarise the debate taking into account its description provided by the mathematician Francesco Maria Franceschinis of Udine.

The History of Sciences is a very important tool for Didactics. In this paper we propose two historical examples: a mathematical one, based upon the debate about the logarithms of negative numbers (XVIII century); and a physical one regarding the introduction of the concepts of work and of kinetic energy based upon a geometric analogy according to Gian Maria Ciassi’s work (1654-1679). An important educational problem consists in the verify of the learning; so we expose an experimental research related to the mathematical example presented.

In this paper we consider a problem related to the use of quantifiers in the High School (students aging 18-19), particularly dealing with existential quantifiers, and we propose a case study based upon an analytical example. We conclude that many students encounter obstacles with main logical concepts, particularly when considered propositions are expressed by a formal language. Symbols and language are linked with a wider socio-cultural dimension, so the presence of basic Logic in High Schools curricula must be considered as an important point.

Jacopo (1676-1754) and Vincenzo Riccati (1707-1775) studied several kinds of differential equations: in particular, Jacopo achieved some transformations to reduce equation’s order; Vincenzo solved some differential equations by methods based upon physical models.

In this paper we examinate by a test the learning of an important “chapter” of the mathematical education in the High School (in particular, referred to pupils aged 16-17 years, of II and III classes of the Italian Liceo scientifico). Many students are conditioned from didactical contract to apply always the “standard” rules given by the teacher, and this behaviour can be harmful: resolutions are mechanical, not creative and sometimes they become more complicated.

Elevators or lifts form the vertical transportation spine of modern high rise buildings. Safety and convenience being two critical issues, it is important to identify the associated risk factors. To complement the technological advancements of system design and greater users' expectation, there is a noted absence of maintainability aspect which not only ensures efficient system performance but also lowers the total life cycle cost through smooth operation and minimal maintenance. To address this knowledge gap, this research was undertaken to identify, analyse and quantify serious defects prevalent in the vertical transport system of commercial buildings of Singapore.

Under the contract and at common law, the Superintendent generally has two duties, firstly, as an agent to the employer and secondly, as a certifier. In construction contracts there is (at least) an implied term that even though the Superintendent is usually appointed and paid by the Employer, the Superintendent will act fairly and independent when exercising his duty as a certifier. This paper aims to investigate the Contractors' perception towards the impartiality of superintendent when performing his or her duties as certifier. In order to investigate this issue, a questionnaire study was conducted on a sample of Contractors. From the findings, superintendent's failure to act fairly and impartially in performing his or her duties is mainly attributed to undue influence by the Employer. This paper also includes findings on area of claims which superintendent usually finds difficult to arrive at a fair decision. This paper suggests some recommendations to improve the current practice in relation to the employment of superintendent.

Construction delay has become endemic in Nigeria. It is imperative to create awareness of the extent to which delays can adversely affect project delivery. This paper identifies, by questionnaire evaluates and through empirical method assesses the effects of construction delays. The findings showed that time and cost overruns were frequent effects of delay. Delay had significant effect on completion cost and time of 61 building projects studied. Client-related delay is significant in Nigeria. Acceleration of site activities coupled with improved clients' project management procedure and inclusion of appropriate contingency allowance in precontract estimate should assuage the adverse effect of construction delays. #

The use of groundwater models is prevalent in the field of environmental science. Models have been applied to investigate a wide variety of hydrogeologic conditions. More recently, groundwater models are being applied to predict the transport of contaminants for risk evaluation.

The development and management of fresh groundwater resources in coastal aquifers are seriously constrained by the presence of seawater intrusion. Underutilisation of the available groundwater resource means that valuable fresh water discharges naturally to the sea and is wasted; overdevelopment, on the other hand, mines the resource and will cause a gradual degradation of water quality due to the encroachment of seawater. Over the years, many models have been developed to represent and study the problem of seawater intrusion. They range from relatively simple analytical solutions to complex numerical models. Ernakulam is one of the important ports in west coast of India. Due to increase in population, fast urbanisation and land reforms, the district is facing a number of environment problems such as flooding, groundwater pollution due to discharge of industrial effluents, seawater intrusion etc. There exists an urgent need to study systematically the causes and remedial measures for seawater intrusion. This paper presents the simulation of seawater intrusion in a section of Ernakulam coast through Saturated-Unsaturated TRAnsport (SUTRA) model and examines the impact of increased pumping scenarios on extent of seawater intrusion.

Present day ship design is faced with a difficulty to successfully integrate multiple design tools. This paper introduces ng.zine, a new design system intended for conceptual and preliminary ship design, aiming to make the design tool integration easy. ng.zine acts through the flexible XML database, storing and on-demand supplying current and previous values of significant ship parameters and attributes. It does so without a demand for changes in either designers working environment, or in the tools it integrates, leading to the increased flexibility of the design process. ng.zine permits a parallel execution of multiple design tasks. To assure efficient control and management, ng.zine applies concepts of group decision-making. Every designer is supported in choosing the proper parameter values with respect to the particular task responsibility and the global ship performance. Considered concepts allow designers to model in their experiences, knowledge and organizational hierarchy.

The coastal aquifer system of eastern Thermaikos gulf is under many pressures e.g. urbanization, intensive agricultural, tourism, climatic changes etc. Water needs are mainly covered by groundwater abstracted from the aquifer systems via numerous wells and boreholes. The results of chemical analyses of groundwater samples, collected during the period April-May 2005, were used. High chloride concentrations and electrical conductivity values are recorded in the northern part of the study area. High nitrate concentrations are locally recorded and should be attributed to agricultural activities. The groundwaters are of various hydrochemical types, as illustrated by the Piper diagram. In order to define the areal extent of seawater intrusion hydrochemical section, ions ratio and several parameters were

This article deals with the impacts of past mining activities and inefficient water resources management on groundwater quality in the Lavrio area. Thirty-three water samples were collected during March 1998 and were analyzed for major ions (Ca, Mg, Na, K, HCO 3 , Cl, NO 3 , SO 4 , PO 4 ), trace elements (Fe, Pb, Ni, Zn, Mn, Cu, Cr, Cd) and water parameters (Temperature, pH, conductivity, hardness and SiO 2 ). High concentrations of heavy metals (lead, cadmium, zinc, nickel) are recorded in groundwater samples in the Lavrio area. The highest concentrations are recorded in the unconfined aquifer (alluvial deposits and schists), due to mining activities. Quality deterioration of groundwater is also decumented and attributed to seawater intrusion and nitrate pollution of agricultural origin. The data were subjected to simple correlation analysis and R-mode factor analysis in order to examine the relationships between the parameters. There is a relationship between the elements participating in the sulfide (Pb, Zn, Cu, Cd) and iron-manganese mineralization and a strong relationship between Ni-Cr. In the factor analysis a four-factor model is suggested, which can explain 72.5% of the total variance. The contribution of each factor at every site is also computed and maps showing the geographical distribution are illustrated. The areas with high concentrations of heavy metals are defined from these maps.

With the increase of snow depth the most frequent is the circulation characterized by the air inflow from the north-west and the west, while with the decrease of the depth it is the cyclonic circulation characterized by the air inflow from the west. When the snow cover does not change its depth, most often it is connected with type Ka and the anticyclonic eastern type.
The appearance of the cyclonic type from one of the northern directions increases the probability of the growth of snow depth 2 – 3 times in relation to the probability defined with no information about the type. On the other hand, when the probability of a drop in snow depth is determined, the increase of this probability with added information about the appearance of a circulation type is slight. The probability reaches the greatest value with anticyclonic western circulation. The greatest probability of the snow cover occurrence with the same depth appears with anticycylonic circulation from east and south-east.

Key words:
atmospheric circulation type, snow cover, Carpathians, Bieszczady

"At the end of their service life, wood-based panels become eventually waste wood. Deploying in landfills is no longer considered as an acceptable solution for their handling due to the high organic load included. The recycling of this waste to be employed as raw material for the wood panel industry, which traditionally makes use of wood processing residues, has hence gained more importance and been examined from earlier times.
Technical problems and the lack of enforcing legislative regulations have delayed, however, the industrial implementation of the new technologies proposed. Recent research efforts
enabled the development of a new process for the recycling of end-use wood panels into new marketable fibreboards. This patent pending process is based on the refiner technique and
allows the use of mixtures of fresh wood and waste panel chips as a raw material for dry process fibreboard production. The process is applicable in existing fibreboard plants with only minor operation modifications and therefore, there is no need of major capital investment in additional equipment to effect the recycling. At the refining stage, chemical agents are employed and the process enables the use of significant amounts of waste
material replacing over 20% of the wood feed and providing significant savings. The aim of the present work was to validate the industrial applicability of the new process in the recycling of waste medium-density fibreboards. The new fibreboards obtained during the industrial scale tests were of acceptable quality, and the testing results revealed that under
conventional gluing and pressing conditions, the process effectively recycles the waste boards into new ones at least at 25% wood substitution level. Further validation and
optimisation work is underway in the direction of using other waste panel types and also increasing the level of waste in the feed material."

This thesis investigates the three-dimensional (3D) coordinate transformation from a global geocentric coordinate system to a national terrestrial coordinate system. Numerical studies are carried out using the Swedish geodetic data SWEREF 93 and RT90/RH70. Based on the Helmert transformation model with 7-parameters, two new models have been studied: firstly a general 3D affine transformation model has been developed using 9-parameters (three translations, three rotations and three scale factors) and secondly the model with 8-parameters (three translations, three rotations and two scale factors) has been derived. To estimate the 3D transformation parameters from given coordinates in the two systems, the linearized observation equations were derived. Numerical tests were carried out using a local (North, East, Up) topocentric coordinate system derived from the given global geocentric system. The transformation parameters and the residuals of the coordinates of the common points were computed. The investigation shows the horizontal scale factor is significantly different by the vertical scale factor. The residuals of the control points were expressed in a separate (North, East, Up) coordinate system for each control point. Some investigations on the weighting process between horizontal and vertical components were also carried out, and an optimal weighting model was derived in order to reduce the residuals in horizontal components without changing the coordinates.

Chahardouly basin is located in the western part of Iran and is characterized by semi-arid climatic conditions and scarcity in water resources. The main aquifer systems are developed within alluvial deposits. The availability of groundwater is rather erratic owing to the occurrence of hard rock formation and a saline zone in some parts of the area. The aquifer systems of the area show signs of depletion, which have taken place in recent years due to a decline in water levels. Groundwater samples collected from shallow and deep wells were analysed to examine the quality characteristics of groundwater. The major ion chemistry of groundwater is dominated by Ca 2C and HCO 3 , while higher values of total dissolved solids (TDS) in groundwater are associated with high concentrations of all major ions. An increase in salinity is recorded in the downgradient part of the basin. The occurrence of saline groundwater, as witnessed by the high electrical conductivity (EC), may be attributed to the long residence time of water and the dissolution of minerals, as well as evaporation of rainfall and irrigation return flow. Based on SAR values and sodium content (%Na), salinity appears to be responsible for the poor groundwater quality, rendering most of the samples not suitable for irrigation use.

L’essentiel des ressources en eau de la Côte d’Ivoire est contenu dans les aquifères formés par le socle fracturé. Il importe donc de mieux connaître ces aquifères fracturés car leur importance hydrogéologique est considérable. C’est dans cette perspective que s’inscrit la présente étude qui couvre la « Région des Montagnes » de l’Ouest de la Côte d’Ivoire. Le principal objectif de cette étude est une meilleure caractérisation des aquifères fracturés : quantification de l’organisation des réseaux de fractures. L’analyse de la fracturation a été conduite sur deux types de cartes : cartes extraites des photographies aériennes et des images satellites. Elle s’est appuyée sur les méthodes d’analyse géostatistiques. Les résultats montrent que les variogrammes de la fracturation globale sont structurés. Ils sont caractérisés par une portée, un plateau et un effet de pépite. Les variogrammes des familles de fractures indiquent aussi une structuration mais les familles NESW et NW-SE de la carte1 présentent un pur effet pépite. L’effet de pépite est dû à l’action combinée des erreurs de mesure et une microrégionalisation. Ces résultats indiquent que la fracturation se comporte comme une variable régionalisée. La structuration des variogrammes est meilleure sur la carte 2 (images satellites) que sur la carte 1 (photographies aériennes). La cartographie de la fracturation par les images satellites apporte des informations plus détaillées que celle par photographies aériennes.

Mot-clés : Fracturation, photographies aériennes, images satellitaires, géostatistique, variogramme, Man-Danané (Côte d’Ivoire)

The aim of this paper is to identify and map the risk of flooding areas in the semi-mountainous region of Côte d’Ivoire. This work is based on the integration within a GIS of data interpreted from Landsat TM imagery, image based on a digital elevation model (DEM), and hydroclimatic data. The processing steps, using remote sensing and GIS softwares, include : 1) DEM building with contour level extracted from topographic map, 2) determination of morphometric variables using DEM, 3) processing of Landsat TM imagery and thematic mapping, and 4) integration of the different layers deduced from satellite data, DEM and its derived data, complementary data and spatial analysis within a GIS. The main flooding risk factors are : rainfall, land cover, rivers network, slopes, lithologic and structural domains. Multicriteria spatial analysis into a GIS allowed mapping the hazards and the vulnerable areas. The integration of these layers allowed mapping the flooding risk of this study area of Côte d’Ivoire. The resulting map shows four clusters varying from low to very high flooding risk. The risk of mean and high flooding is about 65 % of the whole study area and concern alluvial area of southern, and toward the principle rivers : Sassandra (in the western) and Bafing (in the northern). The large extension of vulnerable flooding areas imposes us to take it into account to predict flooding risk and to manage natural resources in the Man region (western of Côte d’Ivoire).

Keywords : Remote Sensing ; GIS ; DEM . hazard ; flooding risk ; Côte d’Ivoire.

This study aims to apply the ultrasound technique in the
field of clean technology to protect environment. The principle
of ultrasound was conducted here to study the effect of applying
high frequency of ultrasound waves. Four kinds of water
namely; Seawater from Aqaba gulf, Red Sea, brackish from
Maan desert southern part of Jordan, hot spring from northern
part of Jordan and tap water (Amman City) were selected to
study the effect of ultrasound on its physical properties. High
ultrasound frequency device with 1.7 MHz was applied to
study the effect of ultrasound waves. All conducted experiments
were fixed at room temperature. The effect of liquid volume
while applying a constant ultrasound waves on the water properties
were investigated here. Exposing time of ultrasound
waves was fixed at 0.5, 1.0 and 1.5 h. The experimental
results showed that ultrasonic wave irradiation for different
samples of water at different period of time has its significant
impacts on physical and chemical properties of water such as
pH, total dissolved solids and consequently the conductivity.
Key Words: High frequency ultrasound, Total dissolved
solids, Water desalination, Water treatment, Environmental
protection, Physical properties.

In this paper, two recently derived linear models for the transverse vibrations of a spinning plate are considered. The disk is modelled as a pure plate with no membrane effects. Furthermore, the effect of the rotary inertia of the plate is taken into account. The first model is based on the assumption of linear (Kirchhoff) strains. The second model is based on the assumption of non-linear (von Karman) strains. The merits of both models are considered and their predictions are compared with those of the traditional linear model. © 2001 Elsevier Science Inc. All rights reserved.

A linear time-domain thermoelastic (photothermoacoustic) theory of a composite solid-liquid geometry has been developed. The theory includes multiple interreflections at all interfaces, acoustic diffraction and viscosity effects, and natural mixed, rigid, and free boundary conditions at the solid surface where laser-pulse incidence occurs (air-polystyrene interface). The theory was applied to experimental pressure-wave pulses from a Nd:YAG laser in a polystyrene well target and water system used for photomechanical drug delivery studies. Good fits of the linear theory to tripolar experimental pressure waveforms were possible at laser-pulse irradiances ≤100 MW/cm2, especially at distances ≤5 mm from the solid-fluid interface. It was further determined from the combined theoretical and experimental approach that the onset of significant hydrodynamic nonlinearity in the water appears for laser-pulse irradiances in the 165-MW/cm2 range, especially at axial distances z ∼ 8 mm, as expected theoretically from the laser-ablation-induced nonlinearity of stress-wave propagation in the solid-water system. © 2005 Optical Society of America.

This paper considers the dynamics of a spinning disk with the inclusion of in-plane inertia. The inclusion of the in-plane inertia couples the in-plane and transverse vibrations of the spinning disk. By considering one mode of each vibration, the problem can be reduced to a non-linear 2 DOF model. An analytical solution of this 2 DOF model is then developed using a time-averaged canonical perturbation approach and is compared with that of a numerical procedure. Through the use of these analytical and numerical tools, it becomes apparent that the inclusion of the in-plane inertia leads to the possibility of internal resonance between the oscillators, depending on the relationship between the natural frequencies of the two oscillators. © 2005 Elsevier Ltd. All rights reserved.

The word tensegrity is a contraction of tensional integrity. In simple structural terms, tensegrity systems are selfstressed pin-jointed networks. Each node receives at least one strut (compression member) and three cables (tension members). Tension members are thus prestressed against adjoining compression members. This is a pure form of tensegrity where only compression and tension members co-exist to form free-standing structures requiring minimum anchorage system compared with conventional types of structures. Double layer tensegrity systems are interesting because the compression members are relatively short, making the network quite rigid and compact. In the non-prestressed state, the system could be easily deployed. The present paper reviews limited research so far conducted at Coventry University on double layer tensegrity networks. It also reviews future directions in research into this fascinating field that has yet to be fully explored and exploited to find proper applications for it in the civil engineering discipline

The aim of the present paper is to review a novel modular constructional element for the building and construction industries that was patented by Coventry University. Modular elements have been used in the past in the construction of structures in order to speed construction and cut on time and cost. The modular element, the subject of this study, comprises hexagonal elements made of steel or other appropriate material, assembled together to form a constructional assembly of honeycomb form secured by fixings that clamp together the sides of adjacent elements. Concrete, or other appropriate material, is disposed within the elements providing a composite type of action. Reinforcement is also present in the form of bars or tubes, providing extra strength to the assembled element. The novel type of modular construction has potential applications in the building, construction, substructure and highways sectors. It could be used as a permanent or temporary structure for roofs and walls. It may also be used for concrete pavements, tunnelling, and retaining wall structures.

This second part contains these chapters, in two files:

1 Chemistry: Reading Spectrograms
2 Performance Art: Problems of Documentation
3 Field Geology: Deductions from Beach Stones
4 Economics: Sirens in Classics, in Philosophy, and in Economic Theory
5 Linguistics: Medieval Irish Color Terms
6 Astrophysics: Doppler Tomography of Accretion Disks
7 Law: Video-game Technology in the Irish Bloody Sunday Tribunal
8 Computer Science: Visualizing the Internet
9 Occupational Therapy: Exercises in Doing, Being, and Becoming
10 Speech and Hearing Science: Speech Spectrograms
11 Restorative Dentistry: Matching Colours in Porcelain Crowns
12 Radio Astronomy: Observations of the Galactic Center
13 Archaeology: Imaging and Mapping Practices
14 Mapping: Uses of Geological Maps
15 Art History: Iconographic Analysis
16 Civil Engineering: A High Resolution Aerial Photograph

Originally published as Visual Practices Across the University, with contributions by thirty-five scholars (Munich: Wilhelm Fink Verlag, 2007).

1] We analyze inelastic off-fault response during earthquakes. Spontaneous crack-like rupture, with slip weakening, is modeled in 2-D plane strain using an explicit dynamic finite element procedure. A Mohr-Coulomb type elastic-plastic description describes the material bordering the fault. We identify the factors which control the extent and distribution of off-fault plasticity during dynamic rupture. Those include the angle with the fault of the maximum compressive prestress, the seismic S ratio, and the closeness of the initial stress state to Mohr-Coulomb failure. Plastic response can significantly alter the rupture propagation velocity, delaying or even preventing a transition to supershear rupture in some cases. Plastic straining also alters the residual stress field left near the fault. In part 1, we consider ''dry'' materials bordering the fault, or at least neglect pore pressure changes within them. Part 2 addresses the effects of fluid saturation, showing that analysis procedures of this part can describe undrained fluid-saturated response. Elastic-plastic laws of the type used are prone to shear localization, resulting in an inherent grid dependence in some numerical solutions. Nevertheless, we show that in the problems addressed, the overall sizes of plastic regions and the dynamics of rupture propagation seem little different from what are obtained when we increase the assumed plastic hardening modulus or dilatancy parameter above the theoretical threshold for localization, obtaining a locally smooth numerical solution at the grid scale. Evidence for scaling of some localization features with a real (nongrid) length scale in the model is also presented.

We analyze the observed dynamic slip transfer from the Denali to Totschunda faults during the M w 7.9 3 November 2002 Denali fault earthquake, Alaska. This study adopts the theory and methodology of and , in which it was shown that the propensity of the rupture path to follow a fault branch is determined by the preexisting stress state, branch angle, and incoming rupture velocity at the branch location. Here we check that theory on the Denali-Totschunda rupture process using 2D numerical simulations of processes in the vicinity of the branch junction. The maximum compression direction with respect to the strike of the Denali fault near the junction has been estimated to range from approximately 73Њ to 80Њ. We use the values of 70Њ and 80Њ in our numerical simulations. The rupture velocity at branching is not well constrained but has been estimated to average about 0.8 c s throughout the event. We use 0.6 c s , 0.8 c s , 0.9 c s , and even 1.4 c s as parameters in our simulations. We simulate slip transfer by a 2D elastodynamic boundary integral equation model of mode II slip-weakening rupture with self-chosen path along the branched fault system. All our simulations except for 70Њ and 0.9 c s predict that the rupture path branches off along the Totschunda fault without continuation along the Denali fault. In that exceptional case there is also continuation of rupture along the Denali fault at a speed slower than that along the Totschunda fault and with smaller slip. Dynamic Slip Transfer from the Denali to Totschunda Faults, Alaska: Testing Theory for Fault Branching

WE CONSIDER quasistatic motion and stability of a single degree of freedom elastic system undergoing frictional slip. The system is represented by a block (slider) slipping at speed V and connected by a spring of stillness k to a point at which motion is enforced at speed V,. We adopt rate and state dependent frictional constitutive relations for the slider which describe approximately experimental results of Dieterich and Ruina over a range of slip speeds % In the simplest relation the friction stress depends additively on a term A In V and a state variable 0; the state variable B evolves, with a characteristic slip distance, to the value -B In K where the constants A, Bare assumed to satisfy B > A > 0. Limited results are presented based on a similar friction Iaw using two state variables.

ANALYSIS of the deformation field consistent with a Prandtl stress distribution travelling with an advancing plane-strain crack reveals the functional form of the near tip crack profile in an elastic-plastic solid. The crack opening 6 is shown to have the form 6 N r In (const./r) at a distance r from the tip. This observation coupled with data generated from finite element investigations of growing cracks in small-scale yielding permits the construction of a relation characterizing the deformation at an extending crack tip. A ductile crack-growth criterion consisting of the attainment of a critical opening at a small characteristic material distance from the tip is adopted. Predictions of the stability of a growing crack for both small-scale yielding specimens and those subject to general yielding are discussed.

We investigate the problem of monotonicity reconstruction, as defined in , in a distributed setting. We have oracle access to a nonnegative real-valued function f defined on domain [n] d = {1, . . . , n} d . We would like to closely approximate f by a monotone function g. This should be done by a procedure (a filter) that given as input a point x ∈ [n] d outputs the value of g(x), and runs in time that is highly sublinear in n. The procedure can (indeed must) be randomized, but we require that all of the randomness be specified in advance by a single short random seed. We construct such an implementation where the time and space per query is (log n) O(1) and the size of the seed is polynomial in log n and d. Furthermore the distance of the approximating function g from f is at most a constant multiple of the minimum distance of any monotone function from f . This allows for a distributed implementation: one can initialize many copies of the filter with the same short random seed, and they can autonomously handle queries, while producing outputs that are consistent with the same approximating function g.

A methodology of investigation and diagnosis of the built heritage of historic centres in seismic areas of Italy is proposed. The aim is to collect an extensive knowledge on the structural typologies and behaviour of historic masonry buildings for the prevention and/or repair of damages caused by earthquakes. Small historic centres or residential buildings in larger centres have been for long time considered as “minor architecture”, but they are meaningful testimonies of the Italian cultural heritage. The results of the investigation also allowed a critical review of the reliability of the analytical models and of the effectiveness of the repair techniques applied in the past decades. The guidelines emerging from the results of an extensive research are presented in this paper (Part 1 of the study). A "minimal" investigation program, which can support the designers in their projects and appropriate mathematical models to study the vulnerability of the structures is suggested.

This paper presents an axiomatic model of medical decision making and discusses its potential applications. The medical decision problems envisioned concern the choice of a medical treatment following a diagnosis in situations in which data allow construction of an empirical distribution over the potential outcomes associated with the alternative treatments. In its descriptive interpretation, the model is an hypothesis about the patient's choice behavior. The theory also aims to aid physicians recommend treatments in a coherent manner. * I benefited from comments of Ani

In 1994, Witkin and Heckbert developed a method for interactively modeling implicit surfaces by simultaneously constaining a particle system to lie on an implicit surface and vice-versa. This interface was demonstrated to be effective and easy to use on example models containing a few blobby spheres and cylinders. This system becomes much more difficult to implement and operate on more complex implicit models. The derivatives needed for the particle system behavior can become laborious and error-prone when implemented for more complex models. We have developed, implemented and tested techniques for automatic and numerical differentiation of the implicit surface function. Complex models also require a large number of parameters, and the management and control of these parameters is often not intuitive. We have developed adapters, which are special shape-transformation operators that automatically adjust the underlying parameters to yield the same effect as the transformation. These new techniques allow constrained particle systems to sample and control more complex models than before possible.

Each tree is unique because of the physical environment it experiences over the course of its life. Environmental factors shape a tree within the bounds of its genotype. Only by modeling the environmental influences can we create realistic models of trees. To this end, we constructed a structural simulation that calculates the mass of each branch of the tree to emulate the mechanisms the tree uses to balance its weight, and that estimates the photosynthesis return of the leaves to simulate phototropism. Our effort is motivated by a desire to construct a predictive tool that can be used by both those in computer graphics and forest management, with applications in image synthesis, dendrochronology, mensuration and the simulation of forest succession.

Replacing parametrization of a domain with polyhedral approximations we give an optimal extension of the Divergence Theorem. Permitted domains of integration, called chainlets, range from smooth submanifolds to structures that may not be locally Euclidean and have no tangent vectors defined anywhere. One may still calculate divergence over the domain, and flux through its boundary which itself may have no normal vectors defined anywhere.

An apology is an explanation or defense of actions which may otherwise be misunderstood. There are several sources of misunderstanding concerning the proof of the Riemann hypothesis. An obstacle lies in the narrow perception of the Riemann hypothesis as a mechanism for counting prime numbers. The Riemann hypothesis is significant because of its significance in mathematical analysis. The proof cannot be read as an isolated argument because of its roots in the history of mathematics. Another obstacle lies in the unexpected source of the proof of the Riemann hypothesis. The proof is made possible by events which seem at first sight to have no relevance to mathematics. Exceptional people and exceptional circumstances prepared the proof of the Riemann hypothesis.

The dynamics of slender filaments or fibers suspended in Stokesian fluids are fundamental to understanding many flows arising in physics, biology and engineering. Such filaments can have aspect ratios of length to radius ranging from a few tens to several thousands. Full discretizations of such 3D flows are very costly. Instead, we employ a non-local slender body theory that yields an integral equation, along the filament centerline, relating the force exerted on the body to the filament velocity. This hydrodynamical description takes into account the effect of the filament on the fluid, and is extended to capture the interaction of multiple filaments as mediated by the intervening fluid. We consider filaments that are inextensible and elastic. Replacing the force in the slender body integral equation by an explicit expression that uses Euler-Bernoulli theory to model bending and tensile forces yields an integral expression for the velocity of the filament centerlines, coupled to auxiliary integro-differential equations for the filament tensions. Based on a regularized version of these slender body equations that is asymptotically equivalent to the original formulation, we construct a numerical method which uses a combination of finite differences, implicit time-stepping to avoid severe stability constraints, and special quadrature methods for nearly singular integrals. We present simulations of single flexible filaments, as well as multiple interacting filaments, evolving in a background shear flow. These simulations show shear induced buckling and relaxation of the filaments, leading to the storage and release of elastic energy. These dynamics are responsible for the development of positive first normal stress differences, commonly associated with visco-elastic fluids that are suspensions of microscopic elastic fibers.

Animation through the numerical simulation of physicsbased graphics models offers unsurpassed realism, but it can be computationally demanding. Likewise, the search for controllers that enable physics-based models to produce desired animations usually entails formidable computational cost. This paper demonstrates the possibility of replacing the numerical simulation and control of dynamic models with a dramatically more efficient alternative. In particular, we propose the NeuroAnimator, a novel approach to creating physically realistic animation that exploits neural networks. NeuroAnimators are automatically trained off-line to emulate physical dynamics through the observation of physicsbased models in action. Depending on the model, its neural network emulator can yield physically realistic animation one or two orders of magnitude faster than conventional numerical simulation. Furthermore, by exploiting the network structure of the NeuroAnimator, we introduce a fast algorithm for learning controllers that enables either physics-based models or their neural network emulators to synthesize motions satisfying prescribed animation goals. We demonstrate NeuroAnimators for a variety of physics-based models.

VANETs (vehicular ad hoc networks) are emerging as a new network environment for intelligent transportation systems. Many of the applications built for VANETs will depend on the data push communication model, where information is disseminated to a group of vehicles. In this paper, we present a formal model of data dissemination in VANETs and study how VANET characteristics, specifically the bidirectional mobility on well defined paths, affects the performance of data dissemination. We study the data push model in the context of TrafficView, a system we have implemented to disseminate information about the vehicles on the road. Traffic data could be disseminated using vehicles moving on the same direction, vehicles moving in the opposite direction, or vehicles moving in both directions. Our analysis as well as simulation results show that dissemination using only vehicles in the opposite direction increases the data dissemination performance significantly.