UDK: 556.115:574.587(282.249 Neretva) This paper presents the research results of benthos community (phytobenthos and macroinvertebrates) on three locations of the Neretva River: Glavatičevo, Žitomislići and Višići. According to typology of rivers, the site Glavatičevo belongs undertype 10a, while sites Žitomislići and Višići are undertype JIVT (heavily modified water bodies). Research of the benthos community has been done in December 2016 with the simultaneous monitoring chemical parameters of water. All research states showed a great number and a high diversity of benthic taxa, although sampling was spent in December. The saprobic values of benthos community at the site Glavatičevo indicates to oligosaprobic level, the water unloaded with organic substances. The site Žitomislići points to oligo/betamesosaprobic level, the water a bit loaded with organic substances. The site Višići according to phytobenthos demonstrates to oligo/betamesosaprobic level, while according to benthic macroinvertebrates point to betamesosaprobic level (the water loaded with organic substances). Based on saprobic values and chemical parameters of water in keeping with The decision on the characterization of the surface and underground water, reference conditions and parameters for the detection of water state and water monitoring (Official newspapers FBiH, No. 1/14), a maximum ecological potential has been registered on sites Žitomislići and Višići, while a high ecological status has been registered on the site Glavatičevo.
Introduction: The method of carrying out PTB is one of the most controversial topics of modern perinatology, because there are no clear and undeniable works and studies that would in any case support vaginal delivery (VD) or delivery to the cesarean section (CS). Aim: To determine more frequent mode of delivery in different groups of birth weights and degrees of prematurity from single and twin pregnancies. To determine the degree of vitality of premature born vaginal delivery (VD) in relation to the cesarean section (CS) in different degrees of prematurity from single and twin pregnancies. Patients and methods: Research has retrospective cohort character. Data were collected from the databases of University Clinic of Gynecology and Obstetrics Tuzla for the period of five years (January 1st, 2012–December 31st, 2016). The study included newborns of both genders, gestational age from 24 to 37 weeks of gestation (WG) in singleton and twin pregnancies. Results: Out of 19506 births, 1350 (6.92%) were preterm birth (PTB). Singleton PTB was 1180 (87.40%), and the twins were 170 (12.59%). Vaginal delivery (VD) was born 788 (58.37%). Cesarean section (CS) was born 562 (41.63%). There was statistically significant association between the mode of delivery (MD) in singleton and twins pregnancy in all three subgroups of birth weight (BW) 1000-1499, 2000-2499 and >2500 grams in 33-37 WG. In this group was more frequent VD than CS mode of singleton delivery, and CS than VD mode of twins delivery. In contrast to newborn with BW 1500-1999 grams (chi-square = 23.16, P <0.0001) in same gestational period where was more frequent CS than VD (OR: 2.56, 95% CI: 1.71-3,85). Apgar score (AS) at first and five minute 5-7 and 8-10 in the period 28-32 and 33-37 was a statistically significant frequent in VD and singletons in contrast to CS and twins. Conclusion: VD was more frequent in the higher WG, as well as the higher AS in singletons in contrast to twins delivery.
Abstract The purpose of this study is to examine links between, on the one hand, employee satisfaction, loyalty and performance, and on the other, the relationship between customer satisfaction and loyalty, as well as their inter-relationship. We conducted a study with employees (53 employees) and students (262 students) across seven departments of a private university in a developing European country. In order to test the cross-level effects of employee-level constructs on student-level constructs, a multilevel analysis was conducted using hierarchical linear modeling. The results confirmed the positive effect of employee satisfaction on employee loyalty and employee performance, but not the impact of the employees’ loyalty on their performances. At the same time, the results showed that students’ satisfaction was positively related to loyalty. Finally, the results showed that, unlike employee performance, employee loyalty at the level of the department had a positive and significant impact on the students’ loyalty and also enhanced the effect of students’ satisfaction on student loyalty.
Based on the available documents, the author has analysed the connections between converts to Islam and the Christian part of their families, and the way in which the conversions infl uenced the lives of converts and their Christian relatives. Adopting another religion did not mean abandoning the old habits and Christian traditions. Regardless of the change of religion and the new religious practices they had to follow, there were those who continued living in accordance with the Christian tradition. Th e converts’ contacts with their Christian families contributed to that considerably. Th e diff erence in name and religion did not break family ties even when families were separated.
Dynamic adaptive streaming over HTTP (DASH) is widely adopted for video transport by major content providers. However, the inherent high variability in both encoded video and network rates represents a key challenge for designing efficient adaptation algorithms. Accommodating such variability in the adaptation logic design is essential for achieving a high user quality of Experience (QoE). In this paper, we present ARBITER+ as a novel adaptation algorithm for DASH. ARBITER+ integrates different components that are designed to ensure a high video QoE while accommodating inherent system variabilities. These components include a tunable adaptive target rate estimator, hybrid throughput sampling, controlled switching, and short-term actual video rate tracking. We extensively evaluate the streaming performance using real video and cellular network traces. We show that ARBITER+ components work in harmony to balance temporal and visual QoE aspects. Additionally, we show that ARBITER+ enjoys a noticeable QoE margin in comparison to state-of-the-art adaptation approaches in various operating conditions. Furthermore, we show that ARBITER+ also achieves the best application-level fairness when a group of mobile video clients shares a cellular base station.
Identification of a complete dynamic network affected by sensor noise using the prediction error method is often too complex. One of the reasons for this complexity is the requirement to minimize a non-convex cost function, which becomes more difficult with more complex networks. In this paper, we consider serial cascade networks affected by sensor noise. Recently, the Weighted Null-Space Fitting method has been shown to be appropriate for this setting, providing asymptotically efficient estimates without suffering from non-convexity; however, applicability of the method was subject to some conditions on the locations of sensors and excitation signals. In this paper, we drop such conditions, proposing an extension of the method that is applicable to general serial cascade networks. We formulate an algorithm that describes application of the method in a general setting, and perform a simulation study to illustrate the performance of the method, which suggests that this extension is still asymptotically efficient.
In preference learning, it is beneficial to incorporate monotonicity constraints for learning utility functions when there is prior knowledge of monotonicity. We present a novel method for learning utility functions with monotonicity constraints using Gaussian process regression. Data is provided in the form of pairwise comparisons between items. Using conditions on monotonicity for the predictive function, an algorithm is proposed which uses the weighted average between prior linear and maximum a posteriori (MAP) utility estimates. This algorithm is formally shown to guarantee monotonicity of the learned utility function in the dimensions desired. The algorithm is tested in a Monte Carlo simulation case study, in which the results suggest that the learned utility by the proposed algorithm performs better in prediction than the standalone linear estimate, and enforces monotonicity unlike the MAP estimate.
We study the design of state observers for nonlinear networked control systems (NCSs) that are implemented over WirelessHART (WH). WH is a wireless communication protocol for process automation applications. It is characterised by its multi-hop structure, slotted communication cycles, and simultaneous transmission over different frequencies. We present a solution based on the emulation approach. That is, given an observer designed with a specific stability property in the absence of communication constraints, we implement it over a WH network and we provide sufficient conditions on the latter, to preserve the stability property of the observer. In particular, we provide explicit bounds on the maximum allowable transmission interval. We assume that the plant dynamics and measurements are affected by noise and we guarantee an input-to-state stability property for the corresponding estimation error system.
Many natural and engineered systems exhibit a singularly perturbed structure where different time scales inherently lead to difficulties in the design of observers for the system. In our related work [1], we have shown that, under appropriate assumptions, an observer designed for the slow part of the system can be applied and results in semi-global practical asymptotical (SPA) stability of the estimation error. In this paper, we show that assumptions from [1] hold for two classes of plants and nonlinear observers. In fact, we show that the provided framework in [1] covers current results in the literature and also other cases that are not covered by existing results. Hence, we demonstrate that we generalise existing results in the literature.
This paper presents an analytical framework to design and analyze hybrid extremum seeking controllers for plants with hybrid dynamics. The extremum seeking controllers are characterized by a hybrid dither generator, a hybrid Jacobian estimator, and a hybrid dynamic optimizer. This structure allows us to consider a family of novel extremum seeking controllers that have not been studied in the literature before. Moreover, the hybrid extremum seeking controllers can be applied to plants with hybrid dynamics generating well-defined response maps. A convergence result is established for the closed -loop system by using singular perturbation theory for hybrid dynamical systems with hybrid boundary layers.
We consider supervisory control of nonlinear systems which are implemented on digital networks. In particular, two candidate controllers are orchestrated by a supervisor to stabilize the origin of the plant by following a dwell time logic, i.e. evaluating a control-mode switching rule at instants which are at least spaced by some dwell time interval. The plant, the controllers and the supervisor communicate via a network and the transmissions are triggered by a mechanism at the discrete sampling instants, which leads to periodic event-triggered control. Thus, there are possibly two kinds of events generated at the sampling instants: the control-mode switching event to activate another control law and the transmission event to update the control input. We propose a systematic design procedure for periodic event-triggered supervisory control for nonlinear systems. We start from a supervisory control scheme which robustly stabilizes the system in the absence of the network. We then implement it over the network and design event-triggering rules to preserve its stability properties. In particular, for each candidate controller, we provide a lower bound for the control-mode dwell time, design criterion to generate transmission events and present an explicit bound on the maximum sampling period with which the triggering rules are evaluated, to ensure stability of the whole system. We show that there exist relationships among the control-mode dwell time, a parameter used to define the transmission event-triggering condition and the bound of the sampling period. An example is given to illustrate the results.
A popular design framework for networked control systems (NCSs) is the emulation-based approach combined with hybrid dynamical systems analysis techniques. In the rich literature regarding this framework, various bounds on the maximal allowable transmission interval (MATI) are provided to guarantee stability properties of the NCS using Lyapunov-based arguments for hybrid systems. In this work, we provide a generalization of these Lyapunov-based proofs, showing how the existing results for the MATI can be improved by only considering a different, more general hybrid Lyapunov function, while not altering the conditions in the analysis itself.
Estimation of physical variables of nonlinear systems with two-time scales is a hard task to address. Whilst nonlinear systems exhibiting a singularly perturbed structure are common in engineering applications, current observer design results apply only to a specific class of plants and observers. We consider a broader class of plants and observers to generalise existing results on observer design for slow states of nonlinear singularly perturbed systems. Under reasonable assumptions, it is shown that the estimation error can be made semi-globally practically asymptotically stable in the singular perturbation parameter. This subsequently leads to appropriate conditions for the observer design for slow variables that guarantee satisfactory estimation error performance in the full system.
A secure nonlinear networked control system (NCS) design using semi-homomorphic encryption, namely, Paillier encryption is studied. Under certain assumptions, control signal computation using encrypted signal directly is allowed by semi-homomorphic encryption. Thus, the security of the NCSs is further enhanced by concealing information on the controller side. However, additional technical difficulties in the design and analysis of NCSs are induced compared to standard NCSs. In this paper, the stabilization of a nonlinear discrete time NCS is considered. More specifically, sufficient conditions on the encryption parameters that guarantee stability of the NCS are provided, and a trade-off between the encryption parameters and the ultimate bound of the state is shown.
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