Ramified recurrence and computational complexity III: Higher type recurrence and elementary complexity

Cartesian closed Dialectica categories

Concurrency has been with us almost from the beginning of computing. Managing and programming for concurrency is a difficult problem and various solutions have been suggested over the years. Debates on message passing vs. remote procedure call, synchronous vs. asynchronous message passing, bounded vs. unbounded buffers, active vs. passive objects etc. still continue. No solution is entirely satisfactory. Concurrent programming usually depends heavily on the nature of the problem at hand and the architecture of the target machine.

The contribution of Mostowski to the foundations of second order arithmetic

SCTP is a reliable transport protocol that supports redundant paths by multiaddressing. Dynamic reconfiguration of IP addresses of an existing association is also supported by an extension called the ADD-IP feature. SCTP tries to use of all available addresses on both end hosts, but among them, there are addresses that should preferably not be used by certain policies or that are known to be unusable beforehand. Trials to use such addresses might cause unexpected degradations of performance or undesired termination of associations by time out. In this study, we propose a new feature by which a user can specify his own address usage policy, per process, according to which a host can determine which address may be used and which should be ignored. If an application program with SCTP is written in the protocol independent programming style, improper addresses are transparently removed so that the application program might use all and only usable addresses.

A bidirectional transformation is a pair of mappings between source and view data objects, one in each direction. When the view is modified, the source is updated accordingly with respect to some laws. One way to reduce the development and maintenance effort of bidirectional transformations is to have specialized languages in which the resulting programs are bidirectional by construction—giving rise to the paradigm of bidirectional programming. In this paper, we develop a framework for applicative-style and higher-order bidirectional programming, in which we can write bidirectional transformations as unidirectional programs in standard functional languages, opening up access to the bundle of language features previously only available to conventional unidirectional languages. Our framework essentially bridges two very different approaches of bidirectional programming, namely the lens framework and Voigtländer's semantic bidirectionalization, creating a new programming style that is able to obtain benefits from both.

A familial specification language for database application systems

Metapredicativity is a new general term in proof theory which describes the analysis and study of formal systems whose proof-theoretic strength is beyond the Feferman-Schutte ordinal Γ0 but which are nevertheless amenable to purely predicative methods. Typical examples of formal systems which are apt for scaling the initial part of metapredicativity are the transfinitely iterated fixed point theories IDα whose detailed proof-theoretic analysis is given by Jager, Kahle, Setzer and Strahm in [18]. In this paper we assume familiarity with [18]. For natural extensions of Friedman’s ATR that can be measured against transfinitely iterated fixed point theories the reader is referred to Jager and Strahm [20]. In the mid seventies, Feferman [3, 4] introduced systems of explicit mathematics in order to provide an alternative foundation of constructive mathematics. More precisely, it was the origin of Feferman’s program to give a logical account of Bishop-style constructive mathematics. Right from the beginning, systems of explicit mathematics turned out to be of general interest for proof theory, mainly in connection with the proof-theoretic analysis of subsystems of first and second order arithmetic and set theory, cf. e.g. Jager [15] and Jager and Pohlers [19]. More recently, systems of explicit mathematics have been used to develop a general logical framework for functional programming and type theory, where it is possible to derive correctness and termination properties of functional programs. Important references in this connection are Feferman [6, 7, 9] and Jager [17]. Universes are a frequently studied concept in constructive mathematics at least since the work of Martin-Lof, cf. e.g. Martin-Lof [23] or Palmgren [27] for

Computing physics is a discipline of computer science the aim of which is to model automatic computing. The basic idea is to use a collection of formal theories for describing mechanisms and reasoning about them scientifically, while formulating the problems to be used as design specifications by means of new functions and, in general, new conceptual and formalizable tools. A design problem must be formulated to define the desired solution as a compound expression, prove that it describes the computation to be designed for all possible cases and input data, and derive the corresponding mechanism. The authors present a case for which it is possible to specify compound expressions and their corresponding mechanisms. It concerns the modeling of a computing unit for the AFP functional language. The paper shows (1) the data structure suitable to represent AFP programs and their reduction, and (2) how from AFP program definition it is possible to derive the model of a computing unit performing arithmetic operations, of more than elementary complexity. >

We argue the need for a federated information infrastructure that is perceived by users to be functionally integrated, yet maintaining its autonomy. There are various ways to do this, but the crucial issue is the provision of a common semantics and a shared data model. For this purpose we have adapted the Functional Data Model1 and the Daplex language (originally designed for heterogeneous multi-database work) and developed a graphic user interface for it. We show how the model’s ability to compose functions makes it able to combine computed data with stored data. This makes it especially suitable for bioinformatics queries involving derived data and we give examples from antibodies. We also describe a view mechanism for creating derived relationships as functions which adapt objects to a given application program, in order to simplify a shared data model.

In this paper we describe an intuitionistic theory SLP. It is a relatively strong theory containing intuitionistic principles for functionals of many types, in particular, the theory of the “creating subject”, axioms for lawless functionals and some versions of choice axioms. We construct a Beth model for the language of intuitionistic functionals of high types and use it to prove the consistency of SLP.We also prove that the intuitionistic theory SLP is equiconsistent with a classical theory TI. TI is a typed set theory, where the comprehension axiom for sets of type n is restricted to formulas with no parameters of types > n. We show that each fragment of SLP with types ≤ s is equiconsistent with the corresponding fragment of TI and that it is stronger than the previous fragment of SLP. Thus, both SLP and TI are much stronger than the second order arithmetic. By constructing the intuitionistic theory SLP and interpreting in it the classical set theoryTI, we contribute to the program of justifying classical mathematics from the intuitionistic point of view.

Dear SCPE Reader, We present a selection of papers which are extensions of papers presented at the 7-th International Symposium on Parallel and Distributed Computing, 1–5 July 2008, in Krakow, Poland. The motivation for publishing the selection in the SCPE Journal was, on the one hand, to present the flavour of the research reported at the conference and on the other hand to present some of the most relevant topics currently focused on the research on parallel and distributed computing in general. The selection contains only 6 papers out of about 60 presented at the conference, and thus, is far from covering all relevant topics represented at the ISPDC 2008. This is because not all of the invited authors were patient enough to accept a fairly long paper publishing process. Nevertheless, we hope that the presented papers will bring you closer to the research covered by the ISPDC conferences and will encourage you to participate in future ISPDC editions. The first paper ``The Impact of Workload Variability on Load Balancing Algorithms'' is by Marta Beltran and Antonio Guzman from King Juan Carlos University in Spain. It concerns an important topic of load balancing in cluster systems, namely adaptativity of the load balancing algorithms to changes of the workload in the system. Adequate accounting for additional load in the hosting system is of great relevance for correct optimization effects. The paper presents a thorough formal analysis of the workload variability metrics and their influence on the quality of load balancing algorithms. Four basic activities appearing in load balancing algorithms are identified, and based on them some algorithmic solutions are proposed to correctly deal with workload variability in system load balancing. The problem of dynamic load balancing algorithms robustness has been discussed. Two different robustness metrics sensitive to the applied type of opimization: local task-oriented or a global one enable selecting task remote execution or migration as load balancing operations. The proposed approach is illustrated with experiments. The second paper ``Model-Driven Engineering and Formal Validation of High-Performance Embedded Systems'' is by Abdoulaye Gamatie, Eric Rutten, Huafeng Yu, Pierre Boulet, Jean-Luc Dekeyser, from University of Lille and INRIA in France. The paper is concerned with a very advanced methodology of designing correct parallel embedded systems for intensive data-parallel computing. In their previous research, the authors of the paper designed the GASPARD embedded system design framework. It is based on the hardware/software co-design approach through model-driven engineering. The framework is based on an UML-like model specification language in which hardware and software elements are modelled using a component approach with special mechanisms for repetitive structures. This paper tries to combine the modelling framework of GASPARD with the mechanisms of synchronous languages to achieve design verifiability provided for such languages. The paper shows how GASPARD models can be translated into synchronous models based on data flow equations in order to formally check their correctness. The proposed approach is illustrated with an example of a video processing system. The third paper ``Relations Between Several Parallel Computational Models'' is by Stephan Bruda and Yuanqiao Zhang from Bishop’s University in Canada. The paper is concerned with theoretical aspects of shared memory systems described by the parallel random access machine PRAM model and aims in studying performance properties of different types of PRAM systems. The attention is focussed on analysing the computational power of two more sophisticated PRAM models (Combining CRCW and Broadcast Selective Reduction), which include data reduction in case of concurrent writes. The paper shows that these two models have equivalent computational power, which is a new result comparing the existing literature. The performance of both models applied to reconfigurable multiple bus machines was studied as a possible architectural solution for current VLSI processor implementations. It was shown that in such systems under reasonable assumptions concurrent-write does not enhance performance comparing the exclusive-write model. Another result important for the VLSI technology is that the Combining CRCW PRAM model (in which data of concurrent writes are arthmetically or logically combined before write) and the exclusive-write on directed reconfigurable busses perform in equivalent way under strong real-time requirements. The fourth paper ``Experiences with Mesh-Like Computations Using Prediction Binary Trees'' is by Gennaro Cordasco, Biagio Cosenza, Rosario de Chiara, Ugo Erra and Vittorio Scarano from the University ``degli Studi'' of Salerno and the University ``degli Studi della Biasilicata'' of Potenza in Italy. The paper concerns optimization methods for mesh-like computations in clusters of processors. The computations are perfomed assuming a phase-like program execution control using a tiling approach which reduces inter-processor communication. A temporal coherence is also assumed, which means that task sizes provide similar execution times in consecutive phases. Temporary coherent computations are structured in a Prediction Binary Tree, in which leaves represent computing tiles to be mapped to processors. A phase-by-phase semi-static load balancing is introduced to the scheduling algorithm. The scheduling algorithm is equipped with a predictor, which estimates the computation time of next phase tiles based on previous execution times and modifies the tiles to achieve balanced execution in phases. For this, two heuristics are used to leverage on data locality in processors. The proposed approach is illustrated by the example of interactive rendering with Parallel Ray Tracing algorithm. The fifth paper ``The Influence of the IBM pSeries Servers Virtualization Mechanism on Dynamic Resource Allocation in AIX 5L'' is by Maciej Mlynski from ASpartner Limited in Poland. The paper concerns a very up-to-date problem of system virtualization and presents the results of research carried on IBM pSeries servers. IBM is strongly developing the virtualization technique especially on IBM pSeries servers enabling an improved and flexible sharing of system resources between applications. The paper investigates novel facilities for dynamic resource management such as micro-partitioning and partition load manager. They enable dynamic creation of workload logical partitions of system resources and their dynamic mangement. It includes run-time resource re-alocation between logical partitions including setting of sharing specifications as well as run-time adding/removing/setting parameters of resources in the system. It remains an open question how to properly tune parameters of the operating system using the provided virtualization facilities to obtain the best efficiency for a given application program. The paper presents the results of experiments which study the effects of tuning the disk subsystem parameters under the IBM AIX 5L operating system with the use of the provided virtualization facilities on the resulting application execution performance. The results show that even small deterioration in the resource pool status requires an immediate adaptation of the operating system parameters to maintain the required performance. The sixth paper ``HeteroPBLAS: A Set of Parallel Basic Linear Algebra Subprograms Optimized for Heterogeneous Computational Clusters'' is by Ravi Reddy, Alexey Lastovetsky and Pedro Alonso from University College Dublin in Ireland and Polytechnic University of Valencia in Spain. The paper concerns the methodology for parallelization of linear algebra computations for execution in heterogeneous cluster environments. The design of the HeteroPBLAS library (Parallel Basic Linear Algebra Subprograms) for heterogeneous computational clusters is presented. The main contribution of the paper is the automation of the parallelization and optimization of the PBLAS, which is done by means of a special user interface and the underlying set of functions. An important element is here a performance model that is based on program code instrumentation, which determines parameters of the application and the executive heterogeneous platform relevant for execution performance of parallel code. The parameter values specified for or returned by execution of the performance model functions are next used for generation and optimal mapping of the parallel code of the library subroutines. The proposed approach is illustrated by experimental results of execution of optimized HeteroPBLAS programs on homogeneous and heterogeneous computing clusters. Marek Tudruj

This study uses the Mendeley application programming interface to gather Mendeley reader statistics for the comprehensive F1000Prime publication set (nr=149,227 records, np = 114,582 papers). F1000Prime is a post-publication peer-review system for papers of the biomedical research. Reader statistics are investigated with regard to the location of Mendeley readers. This paper has been presented at the ISSI 2015 conference.

Common research in the field of Virtual Reality (VR) considers acoustic stimulation as a highly important necessity for enhanced immersion into virtual scenes. However, most common VR toolkits do only marginally support the integration of sound for the application programmer. Furthermore, the quality of stimulation that is provided usually ranges from system sounds (e.g. beeps while selecting a menu) to simple 3D panning. In the latter case, these approaches do only allow the user to correctly detect sounds that are at quite a distance from his current position. Binaural synthesis is an interesting way to allow the spatial auditory representation by using few loudspeakers or headphones. This paper describes a system that combines the efforts of creating a binaural representation for the listener who is interacting in a common visual VR application in real-time, thus allowing the research on interaction between visual and auditory human perception systems. It will describe the theoretical background to establishing a binaural representation of a sound and the necessary hardware set-up for this. Afterwards, the infrastructure and software interface which will allow the connection of the audio renderer to a visual VR toolkit is discusse

Information technology continues to develop along with the ability of humans to design and make computers and are able to provide solutions to problems in various fields. Based on this research, the system of registering the establishment of a legal entity CV in Padang Class 1A District Court still has many problems, where each time there is a certificate of incorporation of the CV legal entity that is only recorded in the register book that has been provided. So during the recording process data errors often occur, because there is no database as a place to store data registering a good CV legal entity. The purpose of this study is to design a system using the Java programming language. Data collection methods used questionnaires and interviews conducted on Padang District Court 1A District Court legal staff. The results of this research are an application program which can later provide convenience in processing and restating the information needed and provide one solution to improve the performance of employees of the Padang 1A Class District Court

It is our great pleasure to welcome you to the 3rd ACM SIGPLAN Workshop on Functional High-Performance Computing. FHPC 2014 brings together researchers who explore declarative high level programming technology in application domains where large-scale computations arise naturally, and high performance is essential. The workshop is in its third year. Our goal is to establish FHPC as a regular annual forum for researchers interested in applying functional programming techniques in the area of high-performance computing. Functional programming is increasingly recognized as presenting a nice sweet spot between expressiveness and efficiency for parallel programming, reconciling execution performance with programming productivity. Making FHPC'14 happen depended on a number of people and organizations, which we would like to acknowledge here. We thank the authors for providing the content of the programme. We would like to express our gratitude to the programme committee, who worked very hard in reviewing papers and providing suggestions for their improvement. Special thanks go to ACM SIGPLAN and the ICFP workshop chairs for accepting our workshop proposal and being flexible with organizational matters. The call for papers attracted 11 submissions. The number of submissions was a little disappointing, but the quality was reassuringly high. An international programme committee selected 10 contributions for publication. These papers cover a variety of topics. Some touch upon optimizing compilation techniques and programming techniques for GPU applications. Others consider patterns for distributed programming, the use of functional programming in a computational science application and compilation techniques for embedded and standalone languages. In addition to the refereed contributions, FHPC'14 features an invited talk. Our original plan was to welcome Keshav Pingali but a medical emergency means that that we hope to return to this another year. Instead, Dimitrios Vytiniotis from Microsoft Cambridge will present Ziria, a Software Defined Radio platform, based on functional programming, that is easily programmable and produces high performance code. We have put together an exciting programme; we look forward to lively discussions during the third FHPC workshop, and a successful follow-up FHPC workshop at ICFP 2015.