Design of feedforward and feedback position control for passive bilateral teleoperation with delays

Kostyukova, Olga,Vista IV, Felipe P.,Chong IV, Kil To Elsevier 2019 ISA transactions Vol.85 No.-

<P><B>Abstract</B></P> <P>Bilateral teleoperation systems connected to computer networks such as the internet must be able to operate with varying time delays since such systems can easily become unstable. A passivity concept has been used as the framework to solve the stability problem in the bilateral control of teleoperation systems. Passivity and tracking performance are recovered using a control architecture that incorporates time varying gains into the transmission path, feedforward, and feedback position control. The proposed architecture has an inner component that can accommodate any configuration but still remain stable and passive even with varying time delay. The simulation results for a single degree of freedom master/slave system demonstrate the performance of the proposed control architecture.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Passive & stable architecture even with any config in the middle & varying time delay. </LI> <LI> Position and tracking errors are bounded. </LI> <LI> Adapt to varying time delay w/time varying gains using master ff & fb position data. </LI> <LI> Passivity of proposed architecture proven through two Lyapunov like function theorems. </LI> <LI> Explicit position & force tracking simulations under various control models & gains. </LI> </UL> </P>

Facile Fabrication of Platinum Nanodots Assembly Core–Silica Shell Nanosystems

Kostyukova, D.,Yoo, H. Springer Science + Business Media 2016 Journal of electronic materials Vol.45 No.5

<P>Nanosystems using a platinum (Pt) nanodots assembly (multi-Pt nanoparticles, m-Pt) as the core and silica (SiO2) shells were successfully synthesized as m-Pt@SiO2 spherical nanoparticles (NPs) and m-Pt@SiO2 nanochains (NChs) by a reverse microemulsion (water-in-oil)-based method. The kinetically controlled reduction of K2PtCl4 by the Brij35 surfactant within reverse micelles, followed by condensation of tetraethyl orthosilicate, led to the formation of multi-Pt nanodots core-silica shell systems. The reduction kinetics for the growth of core-shell systems was studied in both the presence of reducing agents such as ascorbic acid, glucose, and ethylene glycol and in the absence of supplementary agents, as well as the variation of water-to-surfactant ratio. To assemble Pt NPs within a one-dimensional SiO2 matrix, we attempted to grow Pt NPs ina situ pound while the SiO2 materials grew one-dimensionally in a modified microemulsion system. By changing the pH of the reaction media or using highly concentrated ethylene glycol in the synthetic approach, we successfully synthesized m-Pt@SiO2 NChs.</P>

Hybrid discretization method for time-delay nonlinear systems

Zhang, Zheng,Kostyukova, Olga,Zhang, Yuanliang,Chong, Kil-To 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.3

A hybrid discretization scheme that combines the virtues of the Taylor series and Matrix exponential integration methods is proposed. In the algorithm, each sampling time interval is divided into two subintervals to be considered according to the time delay and sampling period. The algorithm is not too expensive computationally and lends itself to be easily inserted into large simulation packages. The mathematical structure of the new discretization scheme is explored and described in detail. The performance of the proposed discretization procedure is evaluated by employing case studies. Various input signals, sampling rates, and time-delay values are considered to test the proposed method. The results demonstrate that the proposed discretization scheme is better than previous Taylor series method for nonlinear time-delay systems, especially when a large sampling period is inevitable.

Worst-case optimal control for an electrical drive system with time-delay

Gao, Yu,Kostyukova, Olga,Chong, Kil To Wiley (John WileySons) 2009 Asian journal of control Vol.11 No.4

Optimal Control Policy for Linear-Quadratic Control Problems with Delay and Intermediate State Constraints

Kil To Chong,Olga Kostyukova,Mariya Kurdina 대한전기학회 2008 International Journal of Control, Automation, and Vol.6 No.6

In this paper, we consider a terminal, linear control system with delay, subject to unknown but bounded disturbances. For this system, we consider the problem of constructing a worst-case optimal feedback control policy, which can be corrected at fixed, intermediate time instants. The policy should guarantee that for all admissible uncertainties the system states are in prescribed neighborhoods of predefined system states, at all fixed, intermediate time instants, and in the neighborhood of a given state at a terminal time instant, and the value of the cost function is the best guaranteed value. Simple explicit rules (which can be easily implemented on-line) for constructing the optimal control policy in the original control problem are derived.

Researcher and Author Impact Metrics: Variety, Value, and Context

Armen Yuri Gasparyan,Marlen Yessirkepov,Akmaral Duisenova,Vladimir I. Trukhachev,Elena I. Kostyukova,George D. Kitas 대한의학회 2018 Journal of Korean medical science Vol.33 No.18

Numerous quantitative indicators are currently available for evaluating research productivity. No single metric is suitable for comprehensive evaluation of the author-level impact. The choice of particular metrics depends on the purpose and context of the evaluation. The aim o this article is to overview some of the widely employed author impact metrics and highlight perspectives of their optimal use. The h-index is one of the most popular metrics for research evaluation, which is easy to calculate and understandable for non-experts. It is automatically displayed on researcher and author profiles on citation databases such as Scopus and Web of Science. Its main advantage relates to the combined approach to the quantification of publication and citation counts. This index is increasingly cited globally. Being an appropriate indicator of publication and citation activity of highly productive and successfully promoted authors, the h-index has been criticized primarily for disadvantaging early career researchers and authors with a few indexed publications. Numerous variants of the index have been proposed to overcome its limitations. Alternative metrics have also emerged to highlight ‘societal impact.’ However, each of these traditional and alternative metrics has its own drawbacks, necessitating careful analyses of the context of social attention and value of publication and citation sets. Perspectives of the optimal use of researcher and author metrics is dependent on evaluation purposes and compounded by information sourced from various global, national, and specialist bibliographic databases.

Specialist Bibliographic Databases

Armen Yuri Gasparyan,Marlen Yessirkepov,Alexander A. Voronov,Vladimir I. Trukhachev,Elena I. Kostyukova,Alexey N. Gerasimov,George D. Kitas 대한의학회 2016 Journal of Korean medical science Vol.31 No.5

Specialist bibliographic databases offer essential online tools for researchers and authors who work on specific subjects and perform comprehensive and systematic syntheses of evidence. This article presents examples of the established specialist databases, which may be of interest to those engaged in multidisciplinary science communication. Access to most specialist databases is through subscription schemes and membership in professional associations. Several aggregators of information and database vendors, such as EBSCOhost and ProQuest, facilitate advanced searches supported by specialist keyword thesauri. Searches of items through specialist databases are complementary to those through multidisciplinary research platforms, such as PubMed, Web of Science, and Google Scholar. Familiarizing with the functional characteristics of biomedical and nonbiomedical bibliographic search tools is mandatory for researchers, authors, editors, and publishers. The database users are offered updates of the indexed journal lists, abstracts, author profiles, and links to other metadata. Editors and publishers may find particularly useful source selection criteria and apply for coverage of their peer-reviewed journals and grey literature sources. These criteria are aimed at accepting relevant sources with established editorial policies and quality controls.

Preserving the Integrity of Citations and References by All Stakeholders of Science Communication

Armen Yuri Gasparyan,Marlen Yessirkepov,Alexander A. Voronov,Alexey N. Gerasimov,Elena I. Kostyukova,George D. Kitas 대한의학회 2015 Journal of Korean medical science Vol.30 No.11

Citations to scholarly items are building bricks for multidisciplinary science communication. Citation analyses are currently influencing individual career advancement and ranking of academic and research institutions worldwide. This article overviews the involvement of scientific authors, reviewers, editors, publishers, indexers, and learned associations in the citing and referencing to preserve the integrity of science communication. Authors are responsible for thorough bibliographic searches to select relevant references for their articles, comprehend main points, and cite them in an ethical way. Reviewers and editors may perform additional searches and recommend missing essential references. Publishers, in turn, are in a position to instruct their authors over the citations and references, provide tools for validation of references, and open access to bibliographies. Publicly available reference lists bear important information about the novelty and relatedness of the scholarly items with the published literature. Few editorial associations have dealt with the issue of citations and properly managed references. As a prime example, the International Committee of Medical Journal Editors (ICMJE) issued in December 2014 an updated set of recommendations on the need for citing primary literature and avoiding unethical references, which are applicable to the global scientific community. With the exponential growth of literature and related references, it is critically important to define functions of all stakeholders of science communication in curbing the issue of irrational and unethical citations and thereby improve the quality and indexability of scholarly journals.