Parallel decomposition methods for linearly constrained problems subject to simple bound with application to the SVMs training

We consider the convex quadratic linearly constrained problem with bounded variables and with huge and dense Hessian matrix that arises in many applications such as the training problem of bias support vector machines. We propose a decomposition algorithmic scheme suitable to parallel implementations and we prove global convergence under suitable conditions. Focusing on support vector machines training, we outline how these assumptions can be satisfied in practice and we suggest various specific implementations. Extensions of the theoretical results to general linearly constrained problem are provided. We included numerical results on support vector machines with the aim of showing the viability and the effectiveness of the proposed scheme

A fast branch-and-bound algorithm for non-convex quadratic integer optimization subject to linear constraints using ellipsoidal relaxations

We propose two exact approaches for non-convex quadratic integer minimization subject to linear constraints where lower bounds are computed by considering ellipsoidal relaxations of the feasible set. In the first approach, we intersect the ellipsoids with the feasible linear subspace. In the second approach we penalize exactly the linear constraints. We investigate the connection between both approaches theoretically. Experimental results show that the penalty approach significantly outperforms CPLEX on problems with small or medium size variable domains. © 2015 Elsevier B.V. All rights reserved

Neural networks for small scale ORC optimization

This study concerns a thermodynamic and technical optimization of a small scale Organic Rankine Cycle system for waste heat recovery applications. An Artificial Neural Network (ANN) has been used to develop a thermodynamic model to be used for the maximization of the production of power while keeping the size of the heat exchangers and hence the cost of the plant at its minimum. R1234yf has been selected as the working fluid. The results show that the use of ANN is promising in solving complex nonlinear optimization problems that arise in the field of thermodynamics

Study and development of a magnetic steering system for microrobots

In a close future micro-scaled untethered robots might be able to access small spaces inside the human body, currently reachable only by using invasive surgical methods, thus revolutionizing future medicine. The aim of this Master Thesis work is to study and develop a system that can exploit static magnetic fields and gradients to steer purpose-developed microrobots. A concept of the device for the generation of magnetic fields is first elaborated, moving from the state-of-art systems based on Helmholtz and Maxwell coils, which can generate, respectively, nearly uniform magnetic fields and gradients. A uniform magnetic field can be used to orient a magnetic or magnetisable object, aligning it with the direction of the field, while a uniform magnetic gradient can be used to shift such an object. The developed system is formed by two coils in the Maxwell geometrical configuration and independently powered in order to generate a uniform magnetic gradient, a quasi-uniform magnetic field or a superimposition of the two, reducing the overall complexity of the hardware with respect to the systems also employing Helmholtz coils. An analytical model of the on-axis magnetic field generated by the device and a finite element model of the field in the workspace are developed. Three microrobot prototypes are then considered: a millimetre-sized NdFeB cylindrical permanent magnet, which allows to test the maximum performances of the developed device, a polymeric microbead, which is more compatible with biomedical applications but less reactive to magnetic fields than a permanent magnet, and a polymeric nanofilm, which allows to test the steering of very anisotropic shapes, both containing iron oxide nanoparticles. Models of their interaction with magnetic fields are presented. Furthermore, a model of the motion of the three prototypes employing the developed magnetic device is presented. The experimental set up is described, including the two coils and their support backing, the monitoring and powering circuitry and a software kit containing four graphical user interfaces for the calibration and validation of the system. After a set of trials performed for the calibration of the magnetic-field-generating device, the system is tested in steering the microrobot prototypes. The extrapolated data are compared to the behaviours predicted by the magnetic motion models. The abilities of the magnetic steering system and its main limits are finally examined, suggesting possible improvements of both the magnetic device and the microrobots in order to enhance their control and manipulation. In particular indications for developing the next-generation of wireless magnetically-actuated microrobots and the relative steering systems are extrapolated

Seeding Sequence:: A Process for Developing Complex Adaptive Systems.

Engaging architecture as an emergent, complex system, this paper examines the implementation of a critical design approach -- the Seeding Sequence -- in two diametrically different studio courses: A 5th year Integrative Design and a 1st year Beginning Design one. Drawing from a Systems Thinking approach to understanding relationships, this critical design approach trades the designer's impulse for formal control and fixation of the architectural object for one of a complex adaptive system. Framed against three past pedagogical approaches to beginning design, the Seeding Sequence process guides the students to work in a recursive cycle between two competing modes and scales of investigation: a modeling method that revels in the detail and a drawing method which considers the context. The Seeding Sequence moves beyond procedural actions by requiring a level of abstraction between the two methods. This paper presents the process, final results, and selective answers from the students' evaluation from both studios this paper concludes by discusses the effects of this design process on three aspects of the students' work: 1) withholding the ability to preconceive the result. 2) framing one methods of investigation against the strengths of another. 3) establishing direct connections between the design decisions and the unique attributes of the materials, program, and site of the project. This paper concludes by critiquing that the specific methods of investigation are selected to challenge the skill level of the students and the resolution of architectural design thinking required by the course. But more importantly, the pairing of two methods -- specifically two with dramatically different benefits and outcomes -- establishes an awareness in the student to actively question what each new method brings to their design process

ISA: Precedent Studies in Arch Structures III

Engaging structures as impetus for architectural design, this paper examines the implementation of an approach to precedent analysis -- the ISA -- within an architectural structures course. As a means to graft the knowledge digested into familiar design languages, this pedagogy frames the precedent work in three perspectives: First, an understanding of the designers’ intent through assigned readings, essays, and in-class discussions; Second, computational modeling of structural components utilizing Revit’s Adaptive Families; and finally, a comparative analysis of the impact of formal variations on the structural efficacy through diagramming load-path and lateral resistance. Selected for their passion regarding structural logic, the semester spans a wide breadth of structural considerations through three paramount engineers; Eugene Viollet-le- Duc, Eladio Dieste, and Peter Rice. Aiming to develop a strong relationship between structural logic and architectural design decisions, the ISA approach weaves an understanding of the designers Intent ( I ) through the readings, Skills learning ( S ) within Autodesk Revit, and Analysis ( A ) documented in diagrams

Not just for fun! social play as a springboard for adult social competence in human and non-human primates

Play is one of the most difficult behaviors to quantify and for this reason, its study has had a very rocky history. Social play is ephemeral, difficult to distinguish from the other so-called serious behaviors, not so frequent (especially in sexually mature subjects), fast, and complex to describe. Due to its multifaceted nature, it has often been considered as a wastebasket category that has included all kinds of the behaviors not showing any immediate, obvious goal. Yet, play is widespread across the whole primate order and can have a strong impact on the development of cognitive, psychological, and social skills of many species, including humans. Unlike functional behaviors that are specifically and economically performed to reduce uncertainty and to increase the opportunity to gain resources, play seems to introduce and increase uncertainty, creating new challenges for the animals. For this reason, social play has been hypothesized to be the engine of behavioral innovation in ontogeny. From the first mild and gentle interactions with the mother to the most sophisticated play fighting sessions and acrobatic action sequences with peers, play represents for juveniles (and not only for them!) a window onto the social and physical environment. In this review, I focus on social play and its relation to adult social competence. By playing, juveniles acquire competence to manage interactions with conspecifics, enlarge their social networks, and test their physical power and motor skills (i.e., long-term benefits). At the same time, I propose the view that play—due to its plastic and versatile nature—can be used in an opportunistic way, as a joker behavior, throughout life to strategically obtain short-term or immediate benefits. I put forward the hypothesis that, during ontogeny, the joker function of play can be modulated according to the differing inter-individual relationships present in the diverse societies, characterizing the primate order

Seeding Sequence:: A Process for Developing Complex Adaptive Systems.

Engaging architecture as an emergent, complex system, this paper examines the implementation of a critical design approach -- the Seeding Sequence -- in two diametrically different studio courses: A 5th year Integrative Design and a 1st year Beginning Design one. Drawing from a Systems Thinking approach to understanding relationships, this critical design approach trades the designer's impulse for formal control and fixation of the architectural object for one of a complex adaptive system. Framed against three past pedagogical approaches to beginning design, the Seeding Sequence process guides the students to work in a recursive cycle between two competing modes and scales of investigation: a modeling method that revels in the detail and a drawing method which considers the context. The Seeding Sequence moves beyond procedural actions by requiring a level of abstraction between the two methods. This paper presents the process, final results, and selective answers from the students' evaluation from both studios this paper concludes by discusses the effects of this design process on three aspects of the students' work: 1) withholding the ability to preconceive the result. 2) framing one methods of investigation against the strengths of another. 3) establishing direct connections between the design decisions and the unique attributes of the materials, program, and site of the project. This paper concludes by critiquing that the specific methods of investigation are selected to challenge the skill level of the students and the resolution of architectural design thinking required by the course. But more importantly, the pairing of two methods -- specifically two with dramatically different benefits and outcomes -- establishes an awareness in the student to actively question what each new method brings to their design process

Sharing emotions builds bridges between individuals and between species

Many animal species express, perceive and share emotions. These abilities have been favoured by natural selection because they allow subjects to respond to various situations in an appropriate way, thus facilitating survival and increasing fitness. The same-face/same-emotion phenomenon is at the basis of sharing feelings and emotions. Recent studies show that this capacity is not unique to humans and that it plays an important role in creating cohesive societies in many different species