Group Of Operators Research Articles

Two sharp inequalities for operators in a Hilbert space

In this paper we obtained generalisations of the L. V. Taikov’s and N. Ainulloev’s sharp inequalities, which estimate a norm of function's first-order derivative (L. V. Taikov) and a norm of function's second-order derivative (N. Ainulloev) via the modulus of continuity or the modulus of smoothness of the function itself and the modulus of continuity or the modulus of smoothness of the function's second-order derivative. The generalisations are obtained on the power of unbounded self-adjoint operators which act in a Hilbert space. The moduli of continuity or smoothness are defined by a strongly continuous group of unitary operators.

Research priority setting for paediatric rheumatology in the UK.

The evidence base that underlies the management of children and young people with paediatric rheumatic diseases is deficient. In this field, there are many crucial unanswered questions. The UK Paediatric Rheumatology Clinical Studies Group, supported by UK National Institute for Health Research Clinical Research Network: children and Versus Arthritis, elicited ideas for research priorities from paediatric rheumatologists, trainees, allied health-care professionals, nurse specialists, patients, parents of patients, carers, and charities. These ideas were collected through online surveys and face-to-face meetings. A modified Delphi process was used, which included online research priority ranking surveys and a consensus workshop. A longlist of 55 disease-specific research priorities and 37 general research priorities were voted on in the first survey. A list of 11 top general research priorities was produced. The top ten disease-specific research priorities were discussed in depth at a Delphi workshop to determine their final ranking. This Health Policy paper will help to guide clinicians, academics, and funding bodies to prioritise research in paediatric rheumatic diseases, specifically in areas of unmet patient needs.

IMPLEMENTATION OF A METHOD FOR SYNTHESIZING GROUPS OF SYMMETRIC DOUBLE-OPERAND OPERATIONS OF CRYPTOGRAPHIC INFORMATION CODING FOR BLOCK ENCRYPTION SYSTEMS

The object of the study is the processes of building groups of symmetric double-operand operations of cryptographic coding of information. The subject of the study are features of the implementation of a generalized method of synthesis groups of symmetric two-operand operations of cryptographic coding information for "lightweight cryptography". The purpose of this work is to investigate the process of building and implementing a method of synthesis of groups of symmetric multibit double-operand operations of information cryptographic coding to provide automation for finding ways to increase the variability, and stability of lightweight cryptoalgorithms. The following tasks are solved in the article: to determine the mathematical group of single-operand operations, on the basis of which the realization of the method of synthesis of groups of symmetric double-operand operations of cryptographic coding will be presented; to offer the search technology of symmetric double-operand operations; to evaluate power of synthesized groups of operations, and their influence on variability and stability of " lightweight cryptography" algorithms. The following results were obtained: the technology for determining symmetric double-operand operations, which will be the basis for the synthesis of a group of symmetric double-operand operations, was proposed. A method for synthesizing groups of symmetric double-operand cryptographic information coding operations for block encryption systems was proposed and implemented. On the example of module-two addition with correction and the use of three-digit single-operand operations, the practical implementation of this method was shown. Based on the synthesized operations and the given quantitative characteristics of the set of single-operand operations, the power of synthesized groups of operations and their influence on the variability and stability of "lightweight cryptography" algorithms were evaluated. Conclusions: the proposed and implemented method of synthesis of groups of symmetric double-operand operations of cryptographic coding information allows to provide the possibility of increasing the variability of lightweight crypto-algorithms. Synthesis of symmetric cryptographic coding operations belonging to different mathematical groups provides increase of algorithm's crypto stability. Application of synthesized cryptographic coding operations leads to significant increase of variability of cryptoalgorithms and their complexity.

Clusters of Bicycle Taxi Operators and their Main Service Operation Patterns: Case Study of Quelimane, Mozambique

Bicycle taxi is a vital means of informal public transport service in most Sub-Saharan African cities, and for this reason, understanding who operates this service, and how they operate could help define initiatives to promote this service. This study considered clusters of bicycle taxi operators and their main service operation patterns. A survey was conducted among 105 regular bicycle taxi operators in Quelimane, Mozambique. Twostep cluster analysis identified homogeneous groups of bicycle taxi operators based on six socio-economic factors (age, income, education, household composition, bicycle ownership, and residence location). A Mann-Whitney U test was employed to compare pairs of clusters of bicycle taxi operators regarding a set of taxi services operation variables, such as the number of passengers carried daily, daily revenues, and service hours. Four clusters of bicycle taxi operators were identified which are, less-educated operators from large households (C1), educated migrants (C2), less-educated bicycle renters (C3), and young cyclists from small households (C4). When comparing differences in service operation patterns per cluster of bicycle taxi operators, the study showed that people in C1 produced fewer bicycle taxi trips than those in C2 and C4. For daily earnings, people in C2 earn more than those in C1 and C3. For service hours, individuals in C2 cycle long service hours when compared to those in C1, which could be harmful to their health. The result of this study could reorient bicycle taxi service promotional policies to make the service more sustainable.

Internal control and financial management of the national police of ecuador special operations group of Guayas G.O.E., 2021

The objective of the research is to determine the importance of planning in financial management and internal control for the fulfillment of the budget and finances in the Special Operations Group of Guayas G.O.E., management that has an important role because the planning of the budget allocated by the State must be adjusted to the needs that arise in the institution. A qualitative, documentary and descriptive study was carried out, in addition, a survey was used as an instrument of information collection, the results of the research are oriented to determine that an adequate internal control system is essential to make reliable the information of the entity, where it is evident that they satisfactorily comply with the components of internal control and ensure the various activities and operations with reasonableness.

Acid treatment of carbonate reservoir with a new dual action microemulsion: Selection of optimal application conditions

Complex emulsifying systems based on acid have been widely used in petroleum production. The advantage of these agents is that the rock dissolution rate is slow and the corrosion activity is reduced. This allows acid to penetrate deeper into the reservoir to increase the drainage area of the well while reducing the destructive impact on the surface of downhole equipment. This work is a continuation of the study of a unique acid emulsion for stimulation of carbonate reservoirs, which is already common in the fields in Russia. The new emulsion has a dual action, capable of forming wormholes in the bottomhole area and dissolving paraffin. The application of a single composition significantly reduces the cost of oil production. The main advantage of the technology is that it does not require workover crew when performing the treatment. The accumulated production experience in the implementation of acid treatments without the workover crew can evaluate whether this technology can be further popularized, showing a very broad prospect. We substantiated the selection criteria of candidate wells for stimulation of reservoir by double-action emulsion. The groups of effective and ineffective operations were determined by linear discriminant analysis. We can identify the factors that determine the final effectiveness of the measure through the analysis of field data. In order to ensure that the predicted value is highly consistent with the actual value, We developed a statistical model to estimate the potential increase in oil flow rate after acidizing. The model was piloted on two wells, which can better justify the design of measures and increase their final efficiency by 17–23%. The results confirm that acidizing technology of carbonate reservoir without workover crew is an excellent alternative to standard acidizing, characterized by reduced operating well time and improved profitability.

MANIFESTATIONS OF AGE- AND INDIVIDUALPSYCHOLOGICAL QUALITIES IN THE PROFESSIONAL ACTIVITY OF CONTACT CENTER OPERATORS

The article explores the concept of individual psychological qualities of the contact center operator, identifies the psychological features of the profession and traces individual such qualities through adolescence and adulthood. Individual-psychological qualities are defined as stable personality traits that develop through activities and determine the peculiarities of interaction with the environment. The empirical study was conducted on the basis of the contact center of the «Vodafone» mobile operator in Kyiv. The study involved operators from 18 to 47 years old, 50 subjects in total, inclIn the course of mathematical data processing (using Student’s T-test) the analysis and interpretation of the obtained data revealed the differences in individual psychological qualities between the groups of young and adult contact center operators. Age differences were recorded in the following individual psychological qualities: courage, emotional stability, diplomacy. Young operators are more characterized by emotional instability, expressiveness, low restraint in emotional manifestations, including negative ones, courage, propensity for reckless actions, determination. Mature professionals are more cautious, risk-averse, diplomatic, easy to get out of conflicts, capable of adapting to the interlocutor, able to find common ground, while the younger group is less diplomatic, more sharp, uncompromising in communication. It is concluded that a significant number of contact center operators need to transform and improve individual psychological qualities in order to increase openness, diplomacy, emotional stability and empathy.uding 25 young people (18–25 years) and 25 adults (26–47 years). R. Kettel’s 16-factor personality questionnaire and «Scale of Emotional Response» questionnaire by A. Megrabian and N. Epstein were used.

A preliminary comparison on ophthalmic examination indices of workers with different occupations in Shenzhen

Objective: To compare the ophthalmic examination indices of different occupational groups in Shenzhen and analyze the possible health problems, so as to provide research basis for further health intervention. Methods: In March 2021, 5426 professionals with ophthalmic examination index data were selected from the basic health database of "Shenzhen occupational population protection action". Among them, radiation workers (694), port operators (1756), sanitation workers (946), teachers (224), video workers (154), police (927) and firefighters (100) were selected as the investigated occupational population. They were exposed to noise 625 workers with traditional occupational hazards such as noise, chemical poisons and dust were used as the control population.Ophthalmic examination indices included right eye vision, left eye vision, outer eye, conjunctiva, cornea, lens, and fundus oculi. The differences of each index in different occupational groups were compared. Results: Compared with the control group, the port operator group showed lower abnormal rates of binocular vision and fundus oculi (P<0.05), but higher abnormal rates of conjunctiva (P=0.029), the environmental sanitation worker group showed higher abnormal rates of binocular vision and conjunctiva (all P<0.01), the teacher group had higher abnormal rates of binocular vision, but only the difference of left eye vision was statistically significant (P=0.021), and the video worker group had higher abnormal rates of right and left eyes vision (P=0.029、0.006) . Conclusion: There were some degrees of ophthalmic problems in different occupational population, therefore targeted intervention measures should be taken according to the characteristics of each group.

Robot-Assisted Total Thyroidectomy with or without Robot-Assisted Neck Dissection in Pediatric Patients with Differentiated Thyroid Cancer.

Pediatric thyroid cancer more frequently develops cervical node metastasis than adult thyroid cancer, even in differentiated thyroid carcinoma (DTC). Thus, cervical neck dissection often needs to be performed simultaneously with thyroidectomy in pediatric patients. Herein, we describe our experience with robot-assisted total thyroidectomy with/without robot-assisted neck dissection in pediatric patients compared with the conventional operated group. A total of 30 pediatric patients who underwent thyroidectomy for DTC between July 2011 and December 2019 were retrospectively reviewed. Among them, 22 underwent robot-assisted operation, whereas 8 underwent conventional operation. There was no statistical difference in the mean operation times, blood loss, drainage amounts, and hospital stay length between the robot-assisted and conventional operation groups; however, the operation time was less in the retroauricular approach subgroup (robot-assisted operation group) with better satisfaction on cosmesis. No postoperative complications, such as seromas, hemorrhages, or hematomas were observed. Our experience suggested that robot-assisted thyroidectomy with or without neck dissection through the retroauricular approach is a feasible and safe alternative treatment, producing outstanding esthetic results compared to the conventional approach, especially in pediatric patients with DTC.

Decay Estimates for Unitary Representations with Applications to Continuous- and Discrete-Time Models

We present a new technique to obtain polynomial decay estimates for the matrix coefficients of unitary operators. Our approach, based on commutator methods, applies to nets of unitary operators, unitary representations of topological groups, and unitary operators given by the evolution group of a self-adjoint operator or by powers of a unitary operator. Our results are illustrated with a wide range of examples in quantum mechanics and dynamical systems, as for instance Schrödinger operators, Dirac operators, quantum waveguides, horocycle flows, adjacency matrices, Jacobi matrices, quantum walks or skew products.

Power system static and dynamic security studies for the 1st phase of Crete Island Interconnection

The island of Crete is currently served by an autonomous electrical system being fed by oil-fired (Heavy fuel or light Diesel oil) thermal power plants and renewables (wind and PVs). The peak load and annual electric energy consumption are approximately 600 MW and 3 TWh respectively; wind and photovoltaic parks contribute approximately 20% of the electricity needs of the island. Due to the expensive fuel used, the Cretan power system has very high electric energy generation cost compared to the Greek mainland. On the other side the limited size of the system poses severe limitations to the penetration of renewable energy sources, not allowing to further exploit the high wind and solar potential of the island. According to the Ten Year Network Development Plan (TYNDP) of the Greek TSO (Independent Power Transmission Operator S.A. IPTO S.A.), the interconnection of Crete to the mainland Transmission System of Greece will be realized through two links: A 150 kV HVAC link between the Peloponnese and the Crete (Phase I) and a HVDC link connecting the metropolitan area of Athens with Crete (Phase II). The total length of submarine and underground cable of the HVAC link will be approximately 174km; it is at the limits of the AC technology and the longest and deepest worldwide at 150 kV level. A number of studies have been conducted by a joint group of IPTO and Hellenic Electricity Distribution Network Operator (HEDNO) for the design of this interconnection. This paper presents briefly the power system static and dynamic studies conducted for the design of the AC link and its operation. Firstly, the paper presents the main results of the static security study regarding the calculation of the maximum power transfer capability of the link and the selection of the reactive power compensation scheme of the cable. Results from dynamic security analysis studies are also presented. The small-signal stability analysis concludes that a new (intra-area) electromechanical oscillation is introduced to the National System after the interconnection. The damping of the electromechanical oscillations is sufficient; however the operation of power system stabilizers at power plants located both at the mainland and at Crete power system can increase significantly the damping of important oscillation modes. Finally with respect to the risk of loss of synchronism after a significant disturbance in the system of Crete, such as a three-phase fault (“transient stability”)- enough safety margin is estimated by means of Critical Clearing Time calculations.

COVID-19 in Yemen: The present situation and the future plan to overcome the crisis

Since the WHO declared COVID-19 a pandemic on March 11, 2020, all countries worldwide have taken precautions to combat this pandemic, except for Yemen. The civil war and resulting humanitarian crises have diverted the attention of the Yemeni people and authorities away from COVID-19, potentially leading to the escalation of the pandemic. Following the initial denial, the internationally recognized government and the de facto authority of the Houthis acknowledged the first COVID-19 cases on March 11, 2020 and May 13, 2020, respectively. With only half of the Yemeni hospitals and medical facilities being fully operational, the authorities and humanitarian groups are working together to end the crisis. Due to paucity of information on the real number of cases in the country attributed to various reasons, no one can predict the future in this country, which will be most likely worse unless the civil war stops, and the humanitarian groups with the authorities need to work hard to strengthen the health system to prepare it for the current and all upcoming health crisis and pandemics.

Pentagram maps and refactorization in Poisson-Lie groups

The pentagram map was introduced by R. Schwartz in 1992 and is now one of the most renowned discrete integrable systems. In the present paper we prove that this map, as well as all its known integrable multidimensional generalizations, can be seen as refactorization-type mappings in the Poisson-Lie group of pseudo-difference operators. This brings the pentagram map into the rich framework of Poisson-Lie groups, both describing new structures and simplifying and revealing the origin of its known properties. In particular, for multidimensional pentagram maps the Poisson-Lie group setting provides new Lax forms with a spectral parameter and, more importantly, invariant Poisson structures in all dimensions, the existence of which has been an open problem since the introduction of those maps. Furthermore, for the classical pentagram map our approach naturally yields its combinatorial description in terms of weighted directed networks and cluster algebras.

Risk management of smart healthcare systems: Delimitation, state-of-arts, process, and perspectives

Sensing, communication, computation, and control technologies are facilitating smart healthcare to improve efficiency and effectiveness of medical treatment and care. This study focuses on the risk issues relevant with the adverse events where novel technical systems do not serve as expected. We discuss the unique challenges, define the scope of risk management in healthcare and review the state-of-art research on diverse topics under the framework widely used in risk management. Then, we present a systematic approach to identify the hazards to patients and other asset of interest in the perception, cyber communication, and execution of smart technologies and their operational contexts. We also investigate different methods for scenario, likelihood, and consequence analyses for specifying the risks of adverse events, and categorize the approaches of risk reduction, as the main strategy of treating risks of smart healthcare systems, into four groups of design, operation, organization, and legislation. At the last, the article proposes some research perspectives responding to the developing trend of smart healthcare.

Acceleration of the order of convergence of a family of fractional fixed-point methods and its implementation in the solution of a nonlinear algebraic system related to hybrid solar receivers

This paper presents one way to define an uncountable family of fractional fixed-point methods through a set of matrices that can generate a group of fractional matrix operators, as well as one way to define groups of fractional operators that are isomorphic to the group of integers under the addition, and shows one way to classify and accelerate the order of convergence of the family of proposed iterative methods, which may be useful to continue expanding the applications of the fractional operators. The proposed method to accelerate the order of convergence is used in a fractional iterative method, and with the obtained method are solved simultaneously two nonlinear algebraic systems that depend on time-dependent parameters, and that allow obtaining the temperatures and efficiencies of a hybrid solar receiver. Finally, two uncountable families of fractional fixed-point methods are presented, in which the proposed method to accelerate convergence can be implemented.

The prospect of using unmanned aerial vehicles to maintain an appropriate level of ecological safety

ObjectivesPossibilities of using drones in the ecological safety system.MethodsThe main purpose of the research conducted in the form of a questionnaire was to get the respondents' opinions on the usefulness of unmanned aerial vehicles (drones) to support the performance of official tasks . (The method of a diagnostic survey with the use of a questionnaire).ResultsThe collected research material showed that the UAVs are useful to carrying out tasks related to environmental protection. The main recommendations for usefulness of drones in the surveyed group of respondents from individual forest districts were as follows: 1) performing tasks related to fire protection; 2) making cartographic materials, inventory of damages caused by abiotic and biotic factors; 3) used to fight forest pests 4) missing persons searching; 5) detection of illegal dumps; 6) animals inventory; 7) water courses beaver dams monitoring; 8) forest health condition assessment and monitoring; 9) the possibility of quick localization of fires in hard-to-reach places; 10) UAV equipped with thermal camera would help in monitoring (animals tracking); 11) tourist traffic monitoring.ConclusionsThe collected research material shows that UAVs should be used by services and state authorities that perform tasks related to environmental protection. The results of the surveyed group of UAV operators show that drones would be useful in "tracking" illegal garbage dumps. Public services and bodies should use UAVs to monitor illegal garbage dumps. According to the surveyed group, there should be higher fines for throwing waste (garbage) in prohibited areas.

Mutation Operator Reduction for Cost-effective Deep Learning Software Testing via Decision Boundary Change Measurement

&lt;p&gt;Mutation testing has been deemed an effective way to ensure Deep Learning (DL) software quality. Due to the requirements of generating and executing mass mutants, mutation testing suffers low-efficiency problems. In regard to traditional software, mutation operators that are hard to cause program logic changes can be reduced. Thus, the number of the mutants, as well as their executions, can be effectively decreased. However, DL software relies on model logic to make a decision. Decision boundaries characterize its logic. In this paper, we propose a DL software mutation operator reduction technique. Specifically, for each group of DL operators, we propose and use DocEntropy to measure the model&amp;rsquo;s decision boundary changes among mutants generated and the original model. Then, we select the operator group with the highest entropy value and use the involved operators for further mutation testing. An empirical study on two DL models verified that the proposed approach could lead to cost-effective DL software mutation testing (i.e., 33.61% mutants and their executions decreased on average) and archive more accuracy mutation scores (i.e., 9.45% accuracy increased on average).&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

A Real-Time Fatigue Sensing and Enhanced Feedback System

This paper describes a real-time fatigue sensing and enhanced feedback system designed for video terminal operating groups. This paper analyzes the advantages and disadvantages of various current acquisition devices and various algorithms for fatigue perception. After comparison, this study uses an eye movement instrument to collect user PERCLOS, and then calculates and determines the user’s fatigue state. A detailed fatigue discrimination calculation method is provided in this paper. The fatigue level is divided into three levels: mild fatigue, moderate fatigue and severe fatigue. Finally, this study uses the fatigue method demonstrated above to achieve real-time discrimination of the fatigue level of the user in front of the video operation terminal. This paper elaborates a method for waking up users and enhancing feedback based on their fatigue level and the importance of information. This study provides a solution for avoiding the operational risks caused by fatigue and lays the foundation for the machine to sense the user and provide different service solutions based on the user’s status.

Correlation of human capital sustainability leadership style and resilience of the managers in airline operations group of an AIRLINE Company

correlation of human capital sustainability leadership style and resilience of the managers in airline operations group of an AIRLINE Company

Patient related outcomes of mechanical lead extraction techniques (PROMET) study: A comparison of two professions.

With an increasing number of cardiac implantable electronic devices (CIEDs), there has been a paralleled increase in demand for transvenous lead extraction (TLE). Cardiac surgeons (CS) and cardiologists perform TLE; however, data comparing the two groups of operators is scarce. We compared the outcomes of TLE performed by cardiologists and CS from six European lead extraction units. Data was collected retrospectively of 2205 patients who had 3849 leads extracted (PROMET) between 2005 and 2018. Patient demographics and procedural outcomes were compared between the CS and cardiologist groups, using propensity score matching. A multivariate regression analysis was also performed for variables associated with 30-day mortality. CS performed the majority of extractions (59.8%), of leads with longer dwell times (90 [57-129 interquartile range (IQR)] vs. 62 [31-102 IQR] months, CS vs. cardiologists, p<.001) and with pre-dominantly non-infectious indications (57.4%vs. 50.2%, CS vs. cardiologists, p<.001). CS achieved a higher complete success per lead than the cardiologists (98.1%vs. 95.7%, respectively, p<.01), with a higher number of minor complications (5.51%vs. 2.1%, p<.01) and similar number of major complications (0.47%vs. 1.3%, p=.12). Thirty-day mortality was similarly low in the CS and cardiologist groups (1.76%vs. 0.94%, p=.21). Unmatched data multivariate analysis revealed infection indication (OR 6.12 [1.9-20.3], p<.01), procedure duration (OR 1.01 [1.01-1.02], p<.01) and CS operator (OR 2.67, [1.12-6.37], p=.027) were associated with 30-day mortality. TLE by CS was performed with similar safety and higher efficacy compared to cardiologists in high and medium-volume lead extraction centers.