Vladimir Korkhov

• PhD
• Professor (Associate) at St Petersburg University

Bottlenecks and imbalance in parallel programs can significantly affect performance of parallel execution. Finding these bottlenecks is a key issue in performance analysis of MPI programs especially on a large scale. One of the ways to discover bottlenecks is to analyze the critical path of the parallel program: the longest execution path in the pr...

Decentralized computing and blockchain technology play a significant role in the implementation of modern digital economy business models. The most noticeable trends in this economy are the diversification and convergence of platforms and services, which is often achieved through undesirable fragmentation of the overall IT landscape. Business solut...

Decentralized finance (DeFi) is now a massive aggregator of many financial blockchain protocols. The overall value locked in them is currently valued at around 80 billion USD. Every day, a growing number of new users bring their investments to DeFi. Decentralized finance entails the creation of a single ecosystem of many blockchains that interact w...

Blockchain is a developing technology that can provide users with such advantages as decentralization, data security, and transparency of transactions. Blockchain has many applications, one of them is the decentralized finance (DeFi) industry. DeFi is a huge aggregator of various financial blockchain protocols. At the moment, the total value locked...

Data centers, clusters, and grids have historically supported High-Performance Computing (HPC) applications. Due to the high capital and operational expenditures associated with such infrastructures, we have witnessed consistent efforts to run HPC applications in the cloud in the recent past. The potential advantages of this shift include higher sc...

Complex distributed applications are highly depended on the quality of service of the underlying networks connecting their components. Common approaches for testing these applications may not be sufficient to ensure stability of a distributed system during networking issues. In this paper we try to explore the possibility of using lightweight virtu...

Electronic methods of managing the educational process are gaining popularity. Recently, a large number of user programs have appeared for such accounting. Based on this, the issue of personal data protection requires increased attention. The coronavirus pandemic has led to a significant increase in the amount of data distributed remotely, which re...

The process of digitalization of the Russian economy as the basis for the transition to the digital economy is conditioned by the requirements of objective reality and is based, first of all, on the introduction of digital technologies into the activities of its actors. The most promising is the Blockchain technology, which has the capabilities of...

Potential benefits of implementation of distributed ledger technology are widely discussedamong different business actors and governmental structures. Within the last decade, with growingpopularity of blockchain-based payment systems and cryptocurrencies, these discussions considerablysharpened. Therefore, an extensive body of research has emerged...

Applications in high-performance computing (HPC) may not use all available computational resources, leaving some of them underutilized. By co-scheduling, i.e., running more than one application on the same computational node, it is possible to improve resource utilization and overall throughput. Some applications may have conflicting requirements o...

P2P networks along with the other distributed systems need to satisfy the strict requirement of efficiency in terms of the information propagation process. Fast message transmission affects the whole network functionality which includes data processing, attacks robustness, topology changes, etc. In this paper we consider the most wide-spread gossip...

Blockchain is a developing and promising technology that can provide users with such advantages as decentralization, data security and transparency of transactions. Blockchain has many applications, one of them is the decentralized finance (DeFi) industry which is growing more and more recently. The concept of decentralized finance involves the cre...

Consensus algorithm is a crucial part of a blockchain system. In particular, in any blockchain-based Distributed Ledger Technology (DLT) solution the consensus algorithm plays the key role in maintaining consistency of databases. The choice of consensus type during design of the distributed system will inevitably and significantly affect such chara...

Efficient usage of shared high-performance computing (HPC) resources raises the problem of HPC applications co-scheduling, i.e. the problem of execution of multiple applications simultaneously on the same shared computing nodes. Each application may have different requirements for shared resources (e.g. network bandwidth or memory bus bandwidth). W...

In this paper, we report the main accomplishments obtained in the context of the CloudHPC project. Accepted in response to the BRICS Pilot Call 2016, the project gathered researchers from the Federal University of Rio Grande do Sul (UFRGS), the St. Petersburg State University (SPbSU), and Beijing Normal University (BNU). Its main objective was to i...

Data quality and security issues are very closely related. To ensure a high level of reliability in distributed systems and resilience from external attacks, the process of consolidating distributed data is critical. For consolidated systems, the access process relies heavily on data preprocessing, which, in turn, allows them to be anonymized. The...

Applications in high-performance computing (HPC) may not use all available computational resources, leaving some of them underutilized. By co-scheduling, i.e. running more than one application on the same computational node, it is possible to improve resource utilization and overall throughput. Some applications may have conflicting requirements on...

The fact that over 2000 programs exist for working with various types of data, including Big Data, makes the issue of flexible storage a quintessential one. Storage can be of various types, including portals, archives, showcases, data bases of different varieties, data clouds and networks. They can have synchronous or asynchronous computer connecti...

In this paper the virtual testbed as a problem-solving environment is considered in different aspects. Fundamental questions for virtual testbed development are (1) characteristics of mathematical models and their interaction; (2) computational aspects and mapping of algorithms onto hardware; (3) information streams and data smanagement. The author...

Issues related to reliable electronic voting are still very relevant and not fully resolved. The use of distributed ledger technologies for these purposes has great potential, but even private blockchain solutions often have insufficient bandwidth to satisfy the needs of at least corporate voting, not to mention the public elections. The article st...

In order for Automated Guided Vehicles (AGV’s) to handle KLT bins (Kleinladungsträger, Small Load Carrier) in a flexible way, a robust bin detection algorithm has to be developed. This paper presents a solution to the KLT bin detection and pose estimation task. The Mask R-CNN network is used to detect a KLT bin on color images, while a simple plane...

In this paper we describe typical HPC workloads in terms of scheduling theory models. In particular, we cover machine environments that are common for high performance computing (HPC) field, possible objective functions and available jobs characteristics. We also describe resources that are required by HPC applications and how to monitor and contro...

In high performance computing (HPC) job schedulers usually divide resources of computing nodes into slots. Each slot can be assigned to execute only a single job from the queue. In some cases, jobs do not fully utilize all available resources from the slot which leads to internal fragmentation, wasted resources and to an increase of queue wait time...

Fisheye cameras have recently became very popular in computer vision applications due to their wide field of view. In addition to a better overview of the surrounding area, they enable to capture objects at extremely close ranges. These advantages come at a cost of strong image distortion, which cannot be removed completely maintaining image contin...

Data centers, clusters and grids have historically supported High-Performance Computing (HPC) applications. Due to the high capital and operational expenditures associated with such infrastructures, in recent past, we have witnessed consistent efforts to run HPC applications in the cloud. The potential advantages of this shift include higher scalab...

Since the issue of using e-voting in both corporate and government voting has not yet been fully resolved, there remains a wide scope for improving existing approaches and proposing new protocols enabling the voting system to be resistant to various kinds of attacks. Due to the rapid development of distributed ledger technologies and their potentia...

Developers do not properly take into account possible problems on the Internet. This fact can cause problems in the operation of blockchain systems. The subject of our analysis was Ethereum due to its short block creation time and, as a result, a strong reaction to faults in the network. We checked the possible threats from the miners during the un...

This paper examines how to implement electronic expertise based on the Corda platform. The paper aims to implement such a system, taking as an example the organization of the online contest. A draft solution is created for this task, which demonstrates the necessary tools to solve it and key capabilities that will be required from the platform for...

The use of blockchain technology introduces the possibility to decentralize logistic systems. These are more efficient and the information inside is easy accessible and verifiable. Additionally, data security is preserved at this time. This paper presents the architecture of a smart container that uses blockchain technology. It stores its location...

In this article, we observe the prospective approaches and techniques in the modern system of automatic control of a group of robots based on distributed ledger technology, using modern methods and development tools. The architecture of this solution is based on the junction of two rapidly developing technologies, such as the Internet of Things (Io...

Despite the fact that the extent of interest in distributed ledger technologies has slightly decreased after the peak of Bitcoin popularity this area continues to evolve. One of the popular areas is the development of smart contracts which introduces a new paradigm of writing programs. This inflicts additional difficulties associated primarily with...

This paper discusses several formal verification instruments and compares them. These tools are Isabelle/HOL, Coq, Verdi, and TLA+. All of them are developed for automatic verification of distributed systems. However, there are a number of differences in implementation and application. Verdi provides an effortless way of implementation to verify so...

This paper describes a method for analyzing and comparing the activity of various distributed ledger platforms. The presented topics are the criteria for evaluating platforms, the method of their ranking and methods for automated collection information about them. A system that allows automatic assessment and ranking of distributed ledger technolog...

The logical structure of the underlying network is often neglected in the design and deployment of new distributed systems and sometimes can come into play only after the system reach the production state. This can lead to the vulnerability of the system against intruders controlling the properties of the network. This paper describes a simulation...

В работе аннотируются цели и задачи планируемого совместного российско-израильского научного проекта, направленного на комплексную оценку данных, полученных в ходе обследования пациентов с мягким когнитивным снижением и расстройствами аутистического спектра. Процесс их анализа будет строиться на комплексных методиках, эффективное применение которых...

The six volumes LNCS 11619-11624 constitute the refereed proceedings of the 19th International Conference on Computational Science and Its Applications, ICCSA 2019, held in Saint Petersburg, Russia, in July 2019. The 64 full papers, 10 short papers and 259 workshop papers presented were carefully reviewed and selected form numerous submissions. Th...

The six volumes LNCS 11619-11624 constitute the refereed proceedings of the 19th International Conference on Computational Science and Its Applications, ICCSA 2019, held in Saint Petersburg, Russia, in July 2019. The 64 full papers, 10 short papers and 259 workshop papers presented were carefully reviewed and selected form numerous submissions. Th...

The six volumes LNCS 11619-11624 constitute the refereed proceedings of the 19th International Conference on Computational Science and Its Applications, ICCSA 2019, held in Saint Petersburg, Russia, in July 2019. The 64 full papers, 10 short papers and 259 workshop papers presented were carefully reviewed and selected form numerous submissions. Th...

The six volumes LNCS 11619-11624 constitute the refereed proceedings of the 19th International Conference on Computational Science and Its Applications, ICCSA 2019, held in Saint Petersburg, Russia, in July 2019. The 64 full papers, 10 short papers and 259 workshop papers presented were carefully reviewed and selected form numerous submissions. Th...

The six volumes LNCS 11619-11624 constitute the refereed proceedings of the 19th International Conference on Computational Science and Its Applications, ICCSA 2019, held in Saint Petersburg, Russia, in July 2019. The 64 full papers, 10 short papers and 259 workshop papers presented were carefully reviewed and selected form numerous submissions. Th...

Currently, the problem of “Big Data” is one of the most, if not the most urgent in computer science. Its solution implies the possibility of processing uncorrelated and heterogeneous data of large volume, the implementation of their integration from distributed sources by consolidation or federalization methods and ensuring the security of access a...

We discuss some of the main solutions we see fit for the future of Blockchain 4.0, look at how with broader spread of blockchain-related economic interaction such networks as DEC and platforms alike BGX would change businesses, developers, and market relations. We discuss the current problems and conceptual solutions for them that include new gener...

Complex modeling of the behavior of marine objects under the influence of real external excitation is the most important problem. At present, the accuracy of direct simulation of phenomena with known physics is comparable to the accuracy of the results obtained during the model experiment in towing tanks. Particularly relevant is the creation of su...

This year the Blockchain technology celebrates ten years since its inception in 2008. The technology is in its third generation now, however many issues still exist and the fourth generation is already anticipated. In this paper we consider some of the problems of Blockchain 3.0 and discuss possible approaches to their resolution on the way to the...

An effective cluster management system is the key to solving many problems that arise in the field of distributed computing. One of the major problems is to map applications and available computing resources in such a way that optimal application performance is achieved and resources are used efficiently. The traditional way is to tune applications...

Comprehensive studies in the field of brain pathology require strong information support for the consolidation of data from different sources. The heterogeneity of data sources and the resource-intensive nature of preprocessing make it difficult to conduct comprehensive interdisciplinary research. To solve this problem for brain studies, an informa...

Software suites for ship simulations are typically used for statistical studies of ship dynamics, but also as a simulator for training ship crew in dangerous situations. One problem that arises during training is speeding-up a part of the session which does not involve actions from the crew. The aim of the study reported here is to accelerate solut...

Cloud computing became a routine tool for scientists in many domains. In order to speed up an achievement of scientific results a cloud service for execution of distributed applications was developed. It obliviates users from manually creating virtual cluster environment or using batch scheduler and allows them only to specify input parameters to p...

Parallel tasks work-stealing schedulers yield near-optimal tasks distribution (i.e. all CPU cores are loaded equally) and have low time, memory and inter-thread synchronizations. The key idea of work-stealing strategy is that when scheduler worker runs out of tasks for execution, it start stealing tasks from the queues of other workers. It’s been s...

Recently, the creation of a barrier-free environment for disabled people is becoming more and more important. All this is done so that people do not feel difficulties in filing their ordinary needs, including communication. For this purpose, a communicator application was developed that allows communication using card-pictograms for people with spe...

Modern heterogeneous computer systems offer an exceptional computational potential, but require specific knowledge and experience on the part of the programmer to fully realize it. In this paper we explore different approaches to the task of adapting an application to the heterogeneous computer system. We provide performance evaluation of the test...

Complex human research, in particular, research in the field of brain pathologies requires strong informational support for consolidation of clinical and biological data from various sources to enable data processing and analysis. In this paper we present design and implementation of an information system for patient data collection, consolidation...

The paper addresses the issues of solving complex problems that require using supercomputers or multiprocessor clusters available for most researchers nowadays. Efficient distribution of high performance computing resources according to actual application needs has been a major research topic since high-performance computing (HPC) technologies beca...

Dealing with large volumes of data is resource-consuming work which is more and more often delegated not only to a single computer but also to a whole distributed computing system at once. As the number of computers in a distributed system increases, the amount of effort put into effective management of the system grows. When the system reaches som...

Virtualized computing infrastructures are often used to create clusters of resources tailored to solve tasks taking into account particular requirements of these tasks. An important objective is to evaluate such requirements and request optimal amount of resources which becomes challenging for parallel tasks with intercommunication. In previous wor...

In this paper we highlight one of the possible acceleration approaches for the standing wave model simulation model with the use of OpenCL framework for GPGPU computations. We provide a description of the wave’s mathematical model, an explanation for the technology selection, as well as the identification of the algorithm part that can be accelerat...

Modern architectures of data acquisition and processing often consider low-cost and low-power devices that can be bound together to form a distributed infrastructure. In this paper we overview possibilities to organize a distributed computing testbed based on microcomputers similar to Raspberry Pi and Intel Edison. The goal of the research is to in...

With the help of Augmentative and Alternative Communication (AAC, which includes all types of communications except oral speech) and modern mobile technologies, it is possible to allow people with speech and language disorders to interact with each other and eliminate the relational barrier. Also it could be important from doctors’ perspective to b...

The article highlights the set of problems associated with automation of computing and informational support of scientific research and offers a possible integrated solution based on the service desk system. The attention is focused on the common organizational and technical activities related to the lifecycle of scientific research, such as regist...

Science gateways often rely on workflow engines to execute applications on distributed infrastructures. We investigate six software architectures commonly used to integrate workflow engines into science gateways. In tight integration, the workflow engine shares software components with the science gateway. In service invocation, the engine is isola...

In the present work we use the technologies of machine learning and OLAP for more accurate forecasting of such phenomena as a thunderstorm, hail, heavy rain, using the numerical model of convective cloud. Three methods of machine learning: support vector machine, logistic regression and ridge regression are used for making the decision on whether o...

Distributed computing clusters are often built with commodity hardware which leads to periodic failures of processing nodes due to relatively low reliability of such hardware. While worker node fault-tolerance is straightforward, fault tolerance of master node poses a bigger challenge. In this paper master node failure handling is based on the conc...

There are disabilities like Autism, Down Syndrome, Cerebral Palsy which can be reason for disorders in speech and writing. Special card-pictograms are widely spread for people with such disabilities to help them to communicate in daily and educational purposes. Today, the digital communication developed and different methods exist (applications, pr...

This paper discusses a possible approach to distributed visualization and rendering system infrastructure organization, based on Linux environment with the usage of virtualization technologies. Particular attention is paid to the minutiae, which may be encountered due to the environment setup and exploitation processes, and may affect system perfor...

Modern scientific and business applications often require fast provisioning of an infrastructure tailored to particular application needs. In turn, actual physical infrastructure contains resources that might be underutilized by applications if allocated in dedicated mode (e.g., a process does not utilize provided CPU or network connection fully)....

Master node fault-tolerance is the topic that is often dimmed in the discussion of big data processing technologies. Although failure of a master node can take down the whole data processing pipeline, this is considered either improbable or too difficult to encounter. The aim of the studies reported here is to propose rather simple technique to dea...

The paper is a continuation of the works [1–3] where complex information system for organization of the input data for the models of convective clouds is presented. In the present work we use the information system for obtaining statistically significant amount of meteorological data about the state of the atmosphere in the place and at the time wh...

The paper describes numerical environment for forecasting the results of cloud seeding. Cloud seeding is a form of weather modification intended to change the amount or type of precipitation or to suppress fog and hail appearance. The effect of such a modification is crucially depended on the moment of seeding and the stage of evolution of the clou...

Modern scientific applications often require provisioning of computing and networking infra-structures tailored to particular application needs which might not be clearly defined. In addition, allo-cated resources of an actual physical infrastructure might be underutilized by applications (e.g., a pro-cess does not utilize provided CPU or network c...

The paper is focused on setting up a system of continuous integration within the available infrastructure of MPD Root project. The system’s deployment and debugging for MPD Root purposes are considered; the installation and setup of the required tools using GitLab, GitLab CI Runner and Docker are described. The deployment of various MPD Root config...

The paper is focused on computational experiments on a system of continuous integration within the available infrastructure of MPD Root project. Test results of execution speed and its optimization options are presented for the builds in question. The load of a computing node employed in continuous integration was analyzed in terms of performance o...

The paper analyzes the problems of scalability of modern computational systems, and offers a new paradigm for solving complex problems on them. It implies (1) Creating a virtual computing cluster with shared virtual memory, (2) Selecting a representation for the problem that minimizes the interaction between computing threads and (3) Configuring th...

Nowadays supercomputer centers strive to provide their computational resources as services, however, present infrastructure is not particularly suited for such a use. First of all, there are standard application programming interfaces to launch computational jobs via command line or a web service, which work well for a program but turn out to be to...

Virtualization technologies enable flexible ways to configure computing environment according to the needs of particular applications. Combined with software defined networking technologies (SDN), operating system-level virtualization of computing resources can be used to model and tune the computing infrastructure to optimize application performan...

There are several types of infrastructures to allow people to interact distributed. Together with development of information technologies, the use of such infrastructures is gaining momentum at many organizations and opens new trend in scientific researches. On the other hand, rapid increase of mobile technologies allows individuals to apply soluti...

Efficient management of a distributed system is a common problem for university’s and commercial computer centres, and handling node failures is a major aspect of it. Failures which are rare in a small commodity cluster, at large scale become common, and there should be a way to overcome them without restarting all parallel processes of an applicat...

Virtual machines are usually associated with an ability to create them on demand by calling web services, then these machines are used to deliver resident services to their clients; however, providing clients with an ability to run an arbitrary programme on the newly created machines is beyond their power. Such kind of usage is useful in a high per...

Workflow management has been widely adopted by scientific communities as a valuable tool to carry out complex experiments. It allows for the possibility to perform computations for data analysis and simulations, whereas hiding details of the complex infrastructures underneath. There are many workflow management systems that offer a large variety of...

One of efficient ways to conduct experiments on HPC platforms is to create custom virtual computing environments tailored to the requirements of users and their applications. In this paper we investigate virtual private supercomputer, an approach based on virtualization, data consolidation, and cloud technologies. Virtualization is used to abstract...

Researchers want to analyse Health Care data which may requires large pools of compute and data resources. To have them they need access to Distributed Computing Infrastructures (DCI) To use them it requires expertise which researchers may not have. Workflows can hide infrastructures. There are many workflow systems but they are not interoperable....

Scientific workflow management is heavily used in our organization. After six years, a large number of workflows are available and regularly used to run biomedical data analysis experiments on distributed infrastructures, mostly on grids. In this paper we present our first efforts to better understand and characterise these workflows. We start with...

Cloud computing is a model of provisioning configurable computing resources, IT infrastructures and applications which can be easily allocated and deallocated by consumer without provider interaction. It can be hard to evaluate performance of newly developed cloud application or infrastructure. Using testbeds for this limits experiments to the scal...

Neuroimaging is a field that benefits from distributed computing infrastructures (DCIs) to perform data processing and analysis, which is often achieved using Grid workflow systems. Collaborative research in neuroimaging requires ways to facilitate exchange between different groups, in particular to enable sharing, re-use and interoperability of ap...

Virtual private supercomputer is an efficient way of conducting experiments on high-performance computational environment and the main role in this approach is played by virtualization and data consolidation. During experiment virtualization is used to abstract application from underlying hardware and also from operating system offering consistent...

The term e-Science describes computational and data-intensive science. It has become a complementary experiment paradigm alongside the traditional in vivo and in vitro experiment paradigms. e-Science opens new doors for scientists and with it, it exposes a number of challenges such as how to organize huge datasets and coordinate distributed executi...

Simulation of beam dynamics is an important step needed to aid the design and configuration of particle beam accelerators. A number of methods and software packages have been developed to address modeling in accelerator physics. However, the results of simulations often need to be validated by simultaneous usage of several packages for solving simi...

Patients with mild cognitive impairment (MCI) do not always convert to dementia. In such cases, abnormal neuropsychological test results may not validly reflect cognitive symptoms due to brain disease, and the usual brain-behavior relationships may be absent. This study examined symptom validity in a memory clinic sample and its effect on the assoc...

Scientific research has become very data and compute intensive because of the progress in data acquisition and measurement devices, which is particularly true in Life Sciences. To cope with this deluge of data, scientists use distributed computing and storage infrastructures. The use of such infrastructures introduces by itself new challenges to th...

Neuroimaging is a field that benefits from distributed computing infrastructures (DCIs) to perform data- and compute-intensive processing and analysis. Using grid workflow systems not only automates the processing pipelines, but also enables domain researchers to implement their expertise on how to best process neuroimaging data. To share this expe...