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Byline: Biswamohan. Mishra, Ankit. Sachan, Chandrasekhar. Bal, Achal. Srivastava, Amlesh. Seth, Anubhav. Narwal, Mehar. Sharma, Seema. Kaushal, Anoop. Saraya, Awadh. Pandit Sir, A 43-year-old male without any co-morbidity presented with [...]

This article discusses a quantiser-based stabilisation problem for uncertain nonlinear systems with the aid of robust $ \mathcal {[K, KL]} $ [ K , KL ] sector. We confirmed that the quantised-feedback control steers the state trajectories of the uncertain nonlinear systems within the robust $ \mathcal {[K, KL]} $ [ K , KL ] sector in finite time by adjusting the quantisation parameters. Furthermore, control-Lyapunov functions are helpful to obtain sufficient conditions for ensuring the closed-loop system's asymptotic stability and the reachability of the robust $ \mathcal {[K, KL]} $ [ K , KL ] sector. Finally, a nonlinear electronic circuit is provided to test the effectiveness of the designed control law. [ABSTRACT FROM AUTHOR]

This article is concerned with the problem of stabilising nonlinear uncertain systems subject to signal quantisation using nonlinear sector design. The boundary of nonlinear sector decided by the behaviour of the system showing an input-to-state stability is equivalent to $ \mathcal {KL} $ K L -stability. A novel control design based on supervisory-based quantised hands-off control is introduced. With this, the true state of the nonlinear plant is estimated and the quantised control steers the trajectory of the system inside the nonlinear sector in finite time and further to the origin asymptotically. The proposed approach is validated through an illustrative example to demonstrate its theoretical effectiveness. [ABSTRACT FROM AUTHOR]

The application of microgrids (MG) has a vital role in grid modernization. However, a larger number of installations of electronically coupled distributed energy resources (DER) units in MGs have created opportunities and threats for grid operations. Therefore, efficient and reliable control strategies for MG operation are essential. This article introduces the concept of sector design to show the stabilization of voltage source converter-interfaced DER units in MG applications. The sliding sector design is advanced sliding mode control to obtain a region of attraction such that the state space is divided into attractive and nonattractive regions. In addition, a variable structure-based controlling method has been introduced to drive the trajectories of a plant from the exterior to the interior of the sector and strictly inside throughout the process. In autonomous MG operation, the proposed controller focuses on stabilizing the electronically coupled DER unit's voltage and frequency response. Besides, it confirms the safety of the power conversion system from external disturbances. The system stability is proven using the Lyapunov candidate function. The proposed strategy has been effectively validated through PSCAD/EMTDC. The simulation results have examined the impact of balanced, unbalanced, nonlinear, and dynamic loading patterns in islanded MG. [ABSTRACT FROM AUTHOR]

Introduction: Abnormal levels of heavy metals (HM) and trace elements (TE) affect body metabolism and can induce carcinogenesis. This study aims to evaluate the role of HM and TE in carcinoma urinary bladder (CAUB). Methods: Patients with biopsy-proven CAUB (n = 100) were taken as the study group, while age-and sex-matched healthy volunteers were taken as control (n = 100). Blood and urine samples were compared for Arsenic (As), Copper (Cu), Manganese (Mn), Selenium (Se), Cadmium (Cd), Lead (Pb), and Mercury (Hg) levels. Serum glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and lipid peroxidation (LPO) levels were assessed to know the redox status between the two groups. Results: A significantly higher blood level of As, Mn, and Pb was observed in CAUB cases as compared to controls. Blood Se level was significantly lower in CAUB patients. On comparing urinary levels, CAUB patients had a higher As, Mn, and Pb levels compared to controls. Further, 68% and 59% of patients had their blood and urinary HM and TE levels above the permitted level, respectively. CAUB cases also had a lower GSH-Px (113.5 ± 44.7 vs. 163.9 ± 120.5, P = 0.0002), lower SOD levels (11.35 ± 5.6 vs. 13.75 ± 3.9, P = 0.008), and a higher LPO levels (15.5 ± 14.7 vs. 11.18 ± 11.2, P = 0.02) in the serum. Conclusions: A significantly higher concentration of As, Mn, and Pb was noted in the blood and urine of CAUB patients compared to controls. CAUB cases also had lower serum GSH-Px and SOD levels with a concomitant increased serum LPO assay suggesting underlying oxidative stress. [ABSTRACT FROM AUTHOR]

Summary: This paper presents the design of output feedback controllers for discrete‐time (DT) linear systems. New sufficient LMI conditions are derived for designing static H2$$ {H}_2 $$ and H∞$$ {H}_{\infty } $$ controllers using decomposition of an auxiliary matrix. The decomposition facilitates linearization of nonlinear term of reduced size to obtain linear matrix inequality criteria. This leads to less conservative results as shown in the numerical examples. In addition, the proposed static output feedback criteria is also used for designing dynamic output feedback controllers for DT systems. Furthermore, a comparative study is also made for the proposed design method with the results existing in the literature. Finally, a DT static output feedback H∞$$ {H}_{\infty } $$ controller is designed for a quarter‐car suspension system. Simulation results are provided to show the efficacy of the proposed design method. [ABSTRACT FROM AUTHOR]

A man in his 50s presented with shortness of breath and was found to have a large paracaval mass, which on further evaluation with CT, showed a large heterogeneously enhancing mass lesion adjacent to right renal hilum. His 24-hour urinary metanephrines and nor-metanephrines were normal. In view of location and features on CT, paraganglioma was considered as a possibility. A 68Ga-DOTATATE positron emission tomography/CT demonstrated avidity in the lesion with maximum standardised uptake value of 16.5. He underwent right laparoscopic converted to open mass excision along with nephrectomy. Histopathological examination was suggestive of hyaline vascular Castleman disease. [ABSTRACT FROM AUTHOR]

This paper addresses the invariant [ K , K L ] sector as a special class of [ K , K L ] sector that holds the invariant characteristics with some appropriate control input, i.e. the energy of the system drastically decreases and state trajectory always remains inside the sector once it moves into it by the suitable control signal. The analysis of the nonlinear sector is regarded in comparison function prospective to outreach the property of uniformity. Here, the construction of [ K , K L ] sector and invariant [ K , K L ] sector relies on the selection of well-suited control-Lyapunov function. The switching control with invariant [ K , K L ] sector is designed to ensure the state trajectories move inside the nonlinear sector in finite-time and stay inside for all future time. Finally, the effectiveness of the proposed algorithm is illustrated with real physical examples. [ABSTRACT FROM AUTHOR]

A Hands-off control law is investigated to asymptotically stabilize a nonlinear system with input-quantization. The quantization parameters generated at the coder and decoder sides of the communication channel are mismatched and a time-varying ratio is modeled to show the non-synchronous adjustment of the quantization parameters. By the means of $[\mathcal {K,KL}]$ sector, the state-space is roughly divided into an attractive and non-attractive regions and a controller based on On-Off logic is utilized to remove the model uncertainties caused by the mismatch of the quantization parameters with limited control effort. Finally, the illustration of the proposed scheme is verified for an electronic circuit. [ABSTRACT FROM AUTHOR]

This paper proposes a distributed artificially delayed output feedback‐based leader–follower and leaderless consensus control for the uncertain general linear multiagent systems (MASs) with an arbitrary relative degree. Based on the measured relative output and their delayed information with respect to neighbours, two distributed controllers are designed, which relaxes the requirement of all relative states information of agents. Through the Lyapunov–Krasovskii functional, linear matrix inequalities (LMIs) are formulated, and these LMIs are feasible for arbitrary small delays selected by the user. Delay‐dependent sufficient conditions are provided to guarantee the asymptotic convergence of nominal error systems and ultimately uniform boundedness in the case of a perturbed error system, using the input to state stability (ISS) theory. Finally, the efficacy of the proposed method is illustrated through numerical examples. [ABSTRACT FROM AUTHOR]

Lower urinary tract symptoms in females can be due to various factors. Most of the time it is due to simple urinary tract infection and lower urinary tract pathology such as urethral stricture, meatal stenosis, bladder stones, underactive detrusor, and primary bladder neck obstruction. Commonly found neurologic causes among females are detrusor–external sphincter dyssynergia, associated with various brain and spine diseases and diabetic neuropathy. Labial fusion is a rare cause of female voiding difficulty. We herein present two elderly postmenopausal diabetic female patients who had nearly total urethral occlusion due to labial fusion. After thorough history taking and local genitourinary examination, the patients were operated. Treatment included surgical correction followed by the local application of 1% estrogen ointment. Both patients were symptom-free after the procedure. Thus, with a correct diagnosis followed by simple operative procedure, we can treat such patients successfully. [ABSTRACT FROM AUTHOR]

A woman in her 30s had robotic pyeloplasty done for right ureteropelvic junction obstruction. Incidentally she developed dengue viral fever starting on postoperative day 1 itself, which progressed to dengue haemorrhagic shock by 1week, complicating pyeloplasty due to pelvicalyceal haematoma. Dengue associated shock was superimposed with subsequent gram-negative bacterial sepsis, further complicated later with Trichosporon fungal sepsis. She was managed under multidisciplinary care, involving urology, infectious disease and ICU care. Her diagnostic and difficult management issues due to these rare sequential medical issues in an otherwise usually uncomplicated postsurgical phase are discussed along with short review of literature. This case highlights the importance of early diagnosis, timely supportive care and appropriate management in such tropical infections with significant associated mortality. [ABSTRACT FROM AUTHOR]

In this article, an implicit Euler algorithm for digital implementation of constrained stabilization is studied for the second‐order systems. For that, a switching controller is designed in a discrete‐time framework such that the system's position output converges to some predefined range, that is, ϱ ∈ (−ε, ε) in finite‐time while the velocity output converges to the origin, that is, ϱ˙=0, in finite‐time. The switching controller is switched to the implicit Euler implementation of twisting algorithm when ϱ ∉ (−ε, ε) and to an implicit Euler implementation of first‐order sliding mode control when ϱ ∈ (−ε, ε). The combination of the two implicit Euler implementations achieves discrete‐time constrained stabilization of second‐order systems, avoiding the chattering caused by conventional explicit integration schemes. The usefulness of the proposed algorithm for constrained stabilization is illustrated by considering the container‐slosh coupled dynamical system. [ABSTRACT FROM AUTHOR]

This paper addresses a quantized feedback hands‐off control for a class of nonlinear systems. Here, [K,KL] sector is constructed with the suitable choice of control‐Lyapunov function. With adjustment policy of quantization parameters, the quantized feedback hands‐off control can force the states of the nonlinear feedback system to the interior of a continuous‐time [K,KL] sector infinite time and the Lyapunov‐candidate function decreases automatically inside the designed sector. Finally, the effectiveness of the proposed method is illustrated by numerical examples. [ABSTRACT FROM AUTHOR]

This brief suggests an approach to design a robust ${[\mathcal {K,KL}]}$ sector for nonlinear system subjected to parametric/model uncertainty and this design relies on the Matrosov’s results. The nonlinear surface to decide the boundaries of a sector is designed by using a control-Lyapunov function. Here, a Hands-Off control consists of constant and state-dependent gain is used to force the state vectors to the interior of robust ${[\mathcal {K,KL}]}$ sector and shows asymptotic stability with minimum support to the nonlinear system by avoiding the redundant control effort. The usefulness of the proposed design is illustrated by a nonlinear electronic circuit. [ABSTRACT FROM AUTHOR]

Summary: This article presents a hands‐off control design for discrete‐time nonlinear system with a special type of nonlinear sector termed as "discrete‐time [𝒦,𝒦ℒ] sector." The design method to define the boundary of a discrete‐time [𝒦,𝒦ℒ] sector is done with control‐Lyapunov function. The generalization of nonlinear system is viewed in the perspective of a comparison function. By means of a proposed sector, a switching control is designed such that no control action is experienced inside the sector thus, saving unnecessary control efforts. However, to study the robustness for discrete‐time system, a hands‐off control is modified to ensure the monotonic decrease in the energy of the system. Finally, the proposed approach is verified with the simulation results. [ABSTRACT FROM AUTHOR]