Alexander Vazhenin

E-Learning Computational Cloud (eLC2): Web Services Platform to Enhance Task Collaboration

A significant proportion of e-Learning services are delivered through Cloud Computing. These use Web services as an interface integrator to support communication across heterogeneous platforms over internet protocols. Similarly, a high level of task collaboration is needed to form an e-Learning community. Therefore, we propose an e-Learning Computational Cloud (eLC2) based on the Model-View-Controller design patterns paradigm. The reusable task objects collaborate in a Model that is wrapped inside the reconfigurable Controller which transforms the request/response parameters of the end user View to that of the Model. The eLC2 offers software development platform for e-Learning Task Management. The main deliverable of eLC2 is a Task as a Service which is decoupled from View as well as user session maintenance. It is directly exposed to external the e-Learning Cloud for scalability.

Enterprise Service Bus dependency injection on MVC design patterns

Paper deals with the design issues of an e-Learning Computational System based on a Task Management Model. One of the main components of the proposed e-Learning Computational Cloud is the Controller acting as an Enterprise Service Bus (ESB) for absolute Model abstraction from outside references. Simultaneously, View is completely decoupled from Model and ultimate privacy and security is achieved for the business data objects. This ESB bolstered with the Dependency Injection Pattern has reinforced protocol and message transformation, service loose coupling, global service contract, service implementation autonomy, service reusability, service modularity, statelessness and dynamic discoverability of the services. The ESB uses service virtualization that archives the services together as a single deployable unit which is managed by the Orchestration Engine as a central console. This allows the user to customize e-Learning Platforms by sourcing a diverse range of e-Learning services.

High-Performance Tsunami Wave Propagation Modeling

Strongest earthquake of December 26, 2004 generated catastrophic tsunami in Indian Ocean. This shows that, in spite of recent technology progress, population at coastal zone is not protected against tsunami hazard. Here, we address the problem of tsunami risks mitigation. Note that prediction of tsunami wave parameters at certain locations should be made as early as possible to provide enough time for evacuation. Modern computational technologies can accurately calculate tsunami wave propagation over the deep ocean provided that initial displacement (perturbation of the sea bed at tsunami source) is known. Modern deep ocean tsunameters provide direct measurement of the passing tsunami wave in real time, which help to estimate initial displacement parameters right after the tsunami wave is recorded at one of the deep ocean buoys. Therefore, fast tsunami propagation code that can calculate tsunami evolution from estimated model source becomes critical for timely evacuation decision for many coastal communities in case of a strong tsunami. Numerical simulation of tsunami wave is very important task for risk evaluation, assessment and mitigation. Here we discuss a part of MOST (Method of Splitting Tsunami) software package, which has been accepted by the USA National Ocean and Atmosphere Administration as the basic tool to calculate tsunami wave propagation and evaluation of inundation parameters. Our main objectives are speed up the sequential program, and adaptation of this program for shared memory systems (OpenMP) and CELL architecture. Optimization of the existing parallel and sequential code for the task of tsunami wave propagation modeling as well as an adaptation of this code for systems based on CELL BE processors (e.g. SONY PlayStation3) is discussed. The paper also covers approaches and techniques for programs optimization and adaptations, and obtained results.

Movie-Based multimedia environment for programming and algorithms design

In the presented work, we introduce a concept of the Movie-Based Programming based on movie-like representation of algorithms and methods. It provides correspondence between algorithmic movie frames and problem solution steps that any frame should visualize/animate a part of a program/algorithm execution. The programming process is in manipulating with special movie-program objects (MP-objects) generating automatically a part of an executable code as well as producing frames, which are adequate to the code generated. It also includes a special multimedia language with high-level constructions and operators in order to make the programming process more efficient and comfortable. Both movie and program can synchronously be generated and debugged. A debugging scheme allows visualizing and controlling all references to the structure elements.

Developing Re-usable Components Based on the Virtual-MVC Design Pattern

In modern complex enterprise applications re-usability and interoperability of software components are of vital importance due to the increasing heterogeneous development platforms and variety of end user devices in which computational services need to be exposed. The need of code solutions re-usability led to the development of Design Patterns, which are means to encapsulate proven solutions to recurrent problems and they provide developers with a common language to abstract the logic encrypted under source code implementation structures. In this article we focus on the Model-View-Controller (MVC) design pattern. Although it represented a step forward for components re-usability, the model and view are still coupled compromising the business logic and introducing a degree of complexity for the applications development. We discuss two main variations of the MVC pattern that are aiming to complete decoupling of Model from View, as well as platforms supporting the development of MVC based applications. Our research is based on the original Virtual-MVC design pattern, in which we model the controller as middleware to achieve full decoupling of the model from view. Our main contribution is to demonstrate the development process of re-usable components in the framework of the V-MVC pattern, through a development platform that supports Virtual-MVC based applications.

Efficient High-Accuracy Computations in Massively Parallel Systems

An efficient way to avoid the rounding errors is the use of multiprecision and interval arithmetics. In this case, the high accuracy of results and the high rate of problem solution can be reached when a computer system combines the possibilities of the dynamic control of operand length, and parallel data processing.

Stream Computation of Shallow Water Equation Solver for FPGA-based 1D Tsunami Simulation

MOST (Method Of Splitting Tsunami) is widely used to solve shallow water equations (SWEs) for forecasting tsunami generated by an earthquake. Toward development of a power-efficient and high-performance computing system for 2D tsunami simulation, we conduct feasibility study on stream computation of 1D SWE solver with FPGA.We analyze an original code and design a stream algorithm with techniques of kernel fusion, shift buffering for streamed stencil-data access, and cascading processing elements for a longer pipeline. We implement a deep pipeline with at most 744 stages of 4 SPEs on 28 nm Stratix V FPGA, which achieves 82.4 GFlop/s at 200 MHz.

Service-oriented tsunami wave propagation modeling tools

A big variety of methods and services for Tsunami Modeling require developing special approaches supporting integration of these heterogeneous components with respect to the various development platforms and architectures. In this paper, we are considering a way of transforming the Tsunami Wave Propagation Modeling Software to a Service-Oriented Architecture (SOA). The transformation was implemented based on the original Virtual MVC-design pattern (VMVC-pattern) that is demarcating a Functional (View) and an Implementation (Model) task by inducing an Integrator (Controller). The paper describes basic features of the MOST (Method of Splitting Tsunami) software package that was used as an initial Propagation Software Engine. It also includes an analysis the initial and output tsunami data and the description of a VMVC-based prototype in which control and resource management operations can be implemented via WEB-interface.

Movie-based representation of reduction operations in numerical computing

Movie-based visual programming is an approach for creating computational programs utilizing animation frames of space structure scanning correlated with arithmetic and logical operations. The assignment of the operations on the frame structure nodes is implemented by coloring corresponding structure areas and specifying appropriate formulas on those areas. This programming is based on special acquisition of data/knowledge to generate executable code and to help application programmers in decision making. In this paper, an approach is considered for representing group reduction procedures (reduction and prefix sums, products, maximum/minimum search, etc.) that are widely used in various applications and libraries oriented to parallel and distributed computations. Within a process, new visual constructs and symbols including their syntax and semantics are introduced to define the procedures. In addition, a method of automatic production of template programs supporting the code generation is presented. The applicability of the procedures for high-level visual programming is demonstrated by an algorithm implementing the least-squares fitting method.

WEB-based task management tools in e-learning environment

In the presented paper, we discuss an approach implementing comfortable task management procedures for problems or exercises requiring processing of mathematical expressions, and providing verifications procedures not only for numerical answers but also formulas. An on-line task management teacher-student collaboration scheme is proposed. E-learning task management components are shown including the system database structure, formula engine architecture as well as answers verification strategies. The verifications of formula answers are based on transforming to a unified ordered form using symbolic algebraic conversions. The human/computer interface features are demonstrated including HTML- and GUI-interfaces.