scholarly journals Xolotl: An Intuitive and Approachable Neuron and Network Simulator for Research and Teaching

2018 ◽  
Author(s):  
Srinivas Gorur-Shandilya ◽  
Alec Hoyland ◽  
Eve Marder

ABSTRACTConductance-based models of neurons are used extensively in computational neuroscience. Working with these models can be challenging due to their high dimensionality and large number of parameters. Here, we present a neuron and network simulator built on a novel automatic type system that binds object-oriented code written in C++ to objects in MATLAB. Our approach builds on the tradition of uniting the speed of languages like C++ with the ease-of-use and feature-set of scientific programming languages like MATLAB. Xolotl allows for the creation and manipulation of hierarchical models with components that are named and searchable, permitting intuitive high-level programmatic control over all parts of the model. The simulator’s architecture allows for the interactive manipulation of any parameter in any model, and for visualizing the effects of changing that parameter immediately. Xolotl is fully featured with hundreds of ion channel models from the electrophysiological literature, and can be extended to include arbitrary conductances, synapses, and mechanisms. Several core features like bookmarking of parameters and automatic hashing of source code facilitate reproducible and auditable research. Its ease of use and rich visualization capabilities make it an attractive option in teaching environments. Finally, xolotl is written in a modular fashion, includes detailed tutorials and worked examples, and is freely available at https://github.com/sg-s/xolotl, enabling seamless integration into the workflows of other researchers.

2019 ◽  
Vol 29 (8) ◽  
pp. 1125-1150
Author(s):  
FERRUCCIO GUIDI ◽  
CLAUDIO SACERDOTI COEN ◽  
ENRICO TASSI

In this paper, we are interested in high-level programming languages to implement the core components of an interactive theorem prover for a dependently typed language: the kernel – responsible for type-checking closed terms – and the elaborator – that manipulates open terms, that is terms containing unresolved unification variables.In this paper, we confirm that λProlog, the language developed by Miller and Nadathur since the 80s, is extremely suitable for implementing the kernel. Indeed, we easily obtain a type checker for the Calculus of Inductive Constructions (CIC). Even more, we do so in an incremental way by escalating a checker for a pure type system to the full CIC.We then turn our attention to the elaborator with the objective to obtain a simple implementation thanks to the features of the programming language. In particular, we want to use λProlog’s unification variables to model the object language ones. In this way, scope checking, carrying of assignments and occur checking are handled by the programming language.We observe that the eager generative semantics inherited from Prolog clashes with this plan. We propose an extension to λProlog that allows to control the generative semantics, suspend goals over flexible terms turning them into constraints, and finally manipulate these constraints at the meta-meta level via constraint handling rules.We implement the proposed language extension in the Embedded Lambda Prolog Interpreter system and we discuss how it can be used to extend the kernel into an elaborator for CIC.


2013 ◽  
Vol 23 (5) ◽  
pp. 1032-1081 ◽  
Author(s):  
GILLES BARTHE ◽  
DAVID PICHARDIE ◽  
TAMARA REZK

Non-interference guarantees the absence of illicit information flow throughout program execution. It can be enforced by appropriate information flow type systems. Much of the previous work on type systems for non-interference has focused on calculi or high-level programming languages, and existing type systems for low-level languages typically omit objects, exceptions and method calls. We define an information flow type system for a sequential JVM-like language that includes all these programming features, and we prove, in the Coq proof assistant, that it guarantees non-interference. An additional benefit of the formalisation is that we have extracted from our proof a certified lightweight bytecode verifier for information flow. Our work provides, to the best of our knowledge, the first sound and certified information flow type system for such an expressive fragment of the JVM.


2021 ◽  
Vol 43 (1) ◽  
pp. 1-46
Author(s):  
David Sanan ◽  
Yongwang Zhao ◽  
Shang-Wei Lin ◽  
Liu Yang

To make feasible and scalable the verification of large and complex concurrent systems, it is necessary the use of compositional techniques even at the highest abstraction layers. When focusing on the lowest software abstraction layers, such as the implementation or the machine code, the high level of detail of those layers makes the direct verification of properties very difficult and expensive. It is therefore essential to use techniques allowing to simplify the verification on these layers. One technique to tackle this challenge is top-down verification where by means of simulation properties verified on top layers (representing abstract specifications of a system) are propagated down to the lowest layers (that are an implementation of the top layers). There is no need to say that simulation of concurrent systems implies a greater level of complexity, and having compositional techniques to check simulation between layers is also desirable when seeking for both feasibility and scalability of the refinement verification. In this article, we present CSim 2 a (compositional) rely-guarantee-based framework for the top-down verification of complex concurrent systems in the Isabelle/HOL theorem prover. CSim 2 uses CSimpl, a language with a high degree of expressiveness designed for the specification of concurrent programs. Thanks to its expressibility, CSimpl is able to model many of the features found in real world programming languages like exceptions, assertions, and procedures. CSim 2 provides a framework for the verification of rely-guarantee properties to compositionally reason on CSimpl specifications. Focusing on top-down verification, CSim 2 provides a simulation-based framework for the preservation of CSimpl rely-guarantee properties from specifications to implementations. By using the simulation framework, properties proven on the top layers (abstract specifications) are compositionally propagated down to the lowest layers (source or machine code) in each concurrent component of the system. Finally, we show the usability of CSim 2 by running a case study over two CSimpl specifications of an Arinc-653 communication service. In this case study, we prove a complex property on a specification, and we use CSim 2 to preserve the property on lower abstraction layers.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2485
Author(s):  
Shakir Ullah ◽  
Saeed Ur Rehman ◽  
Peter Han Joo Chong

Light Fidelity (LiFi) is a new candidate for wireless networking that utilizes the visible light spectrum and exploits the existing lighting infrastructure in the form of light-emitting diodes (LEDs). It provides point-to-point and point-to-multipoint communication on a bidirectional channel at very high data rates. However, the LiFi has small coverage, and its optical gain is closely related to the receiver’s directionality vis-à-vis the transmitter, therefore it can experience frequent service outages. To provide reliable coverage, the LiFi is integrated with other networking technologies such as wireless fidelity (WiFi) thus forming a hybrid system. The hybrid LiFi/WiFi system faces many challenges including but not limited to seamless integration with the WiFi, support for mobility, handover management, resource sharing, and load balancing. The existing literature has addressed one or the other aspect of the issues facing LiFi systems. There are limited free source tools available to holistically address these challenges in a scalable manner. To this end, we have developed an open-source simulation framework based on the network simulator 3 (ns-3), which realizes critical aspects of the LiFi wireless network. Our developed ns-3 LiFi framework provides a fully functional AP equipped with the physical layer and medium access control (MAC), a mobility model for the user device, and integration between LiFi and WiFi with a handover facility. Simulation results are produced to demonstrate the mobility and handover capabilities, and the performance gains from the LiFi-WiFi hybrid system in terms of packet delay, throughput, packet drop ratio (PDR), and fairness between users. The source code of the framework is made available for the use of the research community.


2014 ◽  
Vol 599-601 ◽  
pp. 1407-1410
Author(s):  
Xu Liang ◽  
Ke Ming Wang ◽  
Gui Yu Xin

Comparing with other High-level programming languages, C Sharp (C#) is more efficient in software development. While MATLAB language provides a series of powerful functions of numerical calculation that facilitate adoption of algorithms, which are widely applied in blind source separation (BSS). Combining the advantages of the two languages, this paper presents an implementation of mixed programming and the development of a simplified blind signal processing system. Application results show the system developed by mixed programming is successful.


2010 ◽  
Vol 19 (01) ◽  
pp. 65-99 ◽  
Author(s):  
MARC POULY

Computing inference from a given knowledgebase is one of the key competences of computer science. Therefore, numerous formalisms and specialized inference routines have been introduced and implemented for this task. Typical examples are Bayesian networks, constraint systems or different kinds of logic. It is known today that these formalisms can be unified under a common algebraic roof called valuation algebra. Based on this system, generic inference algorithms for the processing of arbitrary valuation algebras can be defined. Researchers benefit from this high level of abstraction to address open problems independently of the underlying formalism. It is therefore all the more astonishing that this theory did not find its way into concrete software projects. Indeed, all modern programming languages for example provide generic sorting procedures, but generic inference algorithms are still mythical creatures. NENOK breaks a new ground and offers an extensive library of generic inference tools based on the valuation algebra framework. All methods are implemented as distributed algorithms that process local and remote knowledgebases in a transparent manner. Besides its main purpose as software library, NENOK also provides a sophisticated graphical user interface to inspect the inference process and the involved graphical structures. This can be used for educational purposes but also as a fast prototyping architecture for inference formalisms.


Author(s):  
Heri Akhmadi ◽  
Muhammad Fauzan

Smartphone is one of the information technology devices that widely used by traders in marketing activities. Aside from being a communication tool, traders also utilize smartphones to obtain market information and communicate about products and services to consumers. This study aims to analyze profile and perceptions of fruit traders in using smartphones as a marketing communication tool. This research employed quantitative method and descriptive analysis using five point Likert scale to examine  the  perception of fruit traders in Yogyakarta City. The results revealed that traders adopted smartphones on fruit marketing communication due to it perceived to provide a relative advantage, with a high level of ease of use, visible benefits, and low complexity and risk. Furthermore, Samsung, Telkomsel, and WhatsApp were brands of smartphones, telecommunications providers, and social media applications mostly chose by traders.


Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1275
Author(s):  
Changdao Du ◽  
Yoshiki Yamaguchi

Due to performance and energy requirements, FPGA-based accelerators have become a promising solution for high-performance computations. Meanwhile, with the help of high-level synthesis (HLS) compilers, FPGA can be programmed using common programming languages such as C, C++, or OpenCL, thereby improving design efficiency and portability. Stencil computations are significant kernels in various scientific applications. In this paper, we introduce an architecture design for implementing stencil kernels on state-of-the-art FPGA with high bandwidth memory (HBM). Traditional FPGAs are usually equipped with external memory, e.g., DDR3 or DDR4, which limits the design space exploration in the spatial domain of stencil kernels. Therefore, many previous studies mainly relied on exploiting parallelism in the temporal domain to eliminate the bandwidth limitations. In our approach, we scale-up the design performance by considering both the spatial and temporal parallelism of the stencil kernel equally. We also discuss the design portability among different HLS compilers. We use typical stencil kernels to evaluate our design on a Xilinx U280 FPGA board and compare the results with other existing studies. By adopting our method, developers can take broad parallelization strategies based on specific FPGA resources to improve performance.


2021 ◽  
pp. 86-89
Author(s):  
Dmitry Aleksandrovich Solovyev ◽  
Viktor Vladislavovich Korsak ◽  
Galina Nikolaevna Kamyshova ◽  
Olga Nikolaevna Mityureva ◽  
Pavel Olegovich Terekhov

The article presents the results of the development of a digital technology for optimizing the parameters of moisture in the calculated soil layer. The introduction of precision irrigation technologies requires the development of new approaches to the development of decision support systems for their technical implementation in modern high-level programming languages. The developed computer program for determining the optimal moisture parameters of the calculated soil layer for the main irrigated crops of the Saratov region is easy to use and easily integrated into digital automated irrigation control systems.


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