A new methodology for designing PID controllers

It is known that it is impossible to select fixed gains for a PD controller that will critically damp the response to disturbances for all configurations of a given robot system. Because of this the potential for overshoot is always present and cannot be avoided unless the system is severely overdamped. This is not necessarily a practical solution and can be an economically unacceptable approach. On the other hand, however, if overshoot is permissible to some degree for some systems in the case of conventional Serial robots it is still prohibited in the case of Parallel robots as it may easily bring the robot to one of its possible singular configurations, causing damage to the system. This paper introduces a new algorithm for the design of PD controllers that ensures uniform and fast dynamic responses, which are free from overshoots for all robot configurations. The technique also satisfies general stability requirements for the system

Sparsity-Based Error Detection in DC Power Flow State Estimation

This paper presents a new approach for identifying the measurement error in the DC power flow state estimation problem. The proposed algorithm exploits the singularity of the impedance matrix and the sparsity of the error vector by posing the DC power flow problem as a sparse vector recovery problem that leverages the structure of the power system and uses $l_1$-norm minimization for state estimation. This approach can provably compute the measurement errors exactly, and its performance is robust to the arbitrary magnitudes of the measurement errors. Hence, the proposed approach can detect the noisy elements if the measurements are contaminated with additive white Gaussian noise plus sparse noise with large magnitude. The effectiveness of the proposed sparsity-based decomposition-DC power flow approach is demonstrated on the IEEE 118-bus and 300-bus test systems

Zeros of polynomials orthogonal with respect to a signed weight

AbstractIn this paper we consider the monic polynomial sequence (Pnα,q(x)) that is orthogonal on [−1,1] with respect to the weight function x2q+1(1−x2)α(1−x),α>−1,q∈N; we obtain the coefficients of the tree-term recurrence relation(TTRR) by using a different method from the one derived in Atia et al. (2002) [2]; we prove that the interlacing property does not hold properly for (Pnα,q(x)); and we also prove that, if xn,nα+i,q+j is the largest zero of Pnα+i,q+j(x), x2n−2j,2n−2jα+j,q+j<x2n−2i,2n−2iα+i,q+i,0≤i<j≤n−1

VHDL Based Maximum Power Point Tracking of Photovoltaic Using Fuzzy Logic Control

It is important to have an efficient maximum power point tracking (MPPT) technique to increase the photovoltaic (PV) generation system output efficiency. This paper presents a design of MPPT techniques for PV module to increase its efficiency. Perturb and Observe method (P&amp;O), incremental conductance method (IC), and Fuzzy logic controller (FLC) techniques are designed to be used for MPPT. Also FLC is built using MATLAB/ SIMULINK and compared with the FLC toolbox existed in the MATLAB library. FLC does not need knowledge of the exact model of the system so it is easy to implement. A comparison between different techniques shows the effectiveness of the fuzzy logic controller techniques.  Finally, the proposed FLC is built in very high speed integrated circuit description language (VHDL). The simulation results obtained with ISE Design Suite 14.6 software show a satisfactory performance with a good agreement compared to obtained values from MATLAB/SIMULINK. The good tracking efficiency and rapid response to environmental parameters changes are adopted by the simulation results

Association between Low Adiponectin Level and Cardiovascular Complications in Diabetic and non Diabetic Patients with End Stage Renal Disease

Introduction: Adiponectin is a collagen-like protein synthesized by adipose tissue that has anti-inflammatory and anti-atherogenic properties. We aimed to evaluate adiponectin levels in end stage renal disease (ESRD) patients with and without diabetes mellitus and its relation to the presence of cardiovascular complications (CVC). Methods: The study included 20 healthy subjects who served as controls (group I), 20 non-diabetic ESRD patients without CVC (group IIA), 20 non-diabetic ESRD patients with CVC (group IIB), 20 diabetic ESRD patients without CVC (group IIIA) and 20 diabetic ESRD patients with CVC (group IIIB). Evaluation included mean arterial blood pressure (MABP), body mass index (BMI), fasting plasma glucose, fasting plasma insulin, homeostasis model assessment for insulin resistance (HOMA-IR), lipid profile, and serum adiponectin levels. Results: Adiponectin level in the control group was 6.4±1.2 mcg/ml, and was significantly lower than both group II and III (

Dynamic web forms development using RuleML. Building a framework using metadata driven rules to control Web forms generation and appearance.

Web forms development for Web based applications is often expensive, laborious, error-prone, time consuming and requires a lot of effort. Web forms are used by many different people with different backgrounds and a lot of demands. There is a very high cost associated with the need to update the Web application systems to achieve these demands. A wide range of techniques and ideas to automate the generation of Web forms exist. These techniques and ideas however, are not capable of generating the most dynamic behaviour of form elements, and make Insufficient use of database metadata to control Web forms¿ generation and appearance. In this thesis different techniques are proposed that use RuleML and database metadata to build rulebases to improve the automatic and dynamic generation of Web forms. First this thesis proposes the use of a RuleML format rulebase using Reaction RuleML that can be used to support the development of automated Web interfaces. Database metadata can be extracted from system catalogue tables in typical relational database systems, and used in conjunction with the rulebase to produce appropriate Web form elements. Results show that this mechanism successfully insulates application logic from code and suggests that Abstract iii the method can be extended from generic metadata rules to more domain specific rules. Second it proposes the use of common sense rules and domain specific rules rulebases using Reaction RuleML format in conjunction with database metadata rules to extend support for the development of automated Web forms. Third it proposes the use of rules that involve code to implement more semantics for Web forms. Separation between content, logic and presentation of Web applications has become an important issue for faster development and easy maintenance. Just as CSS applied on the client side to control the overall presentation of Web applications, a set of rules can give a similar consistency to the appearance and operation of any set of forms that interact with the same database. We develop rules to order Web form elements and query forms using Reaction RuleML format in conjunction with database metadata rules. The results show the potential of RuleML formats for representing database structural and active semantics. Fourth it proposes the use of a RuleML based approach to provide more support for greater semantics for example advanced domain support even when this is not a DBMS feature. The approach is to specify most of the semantics associated with data stored in RDBMS, to overcome some RDBMSs limitations. RuleML could be used to represent database metadata as an external format

Anterior Pituitary Endocrine Dysfunctions in Patients with Traumatic Brain Injury in the Neurosurgical Units of the Yaounde Central and General Hospitals: A Cross-Sectional Study

Background: Post-traumatic endocrine dysfunction (PTED) is an important and relatively common complication of TBI (traumatic brain injury). It is usually undiagnosed and untreated making it a major cause of poor outcome in TBI patients as it can lead to death, delayed recovery, cognitive impairment, depression, sexual dysfunctions and infertility. Study Design:&nbsp;Analytic cross-sectional study at the Yaounde Central and General Hospitals from January 2022 to April 2022. The main aim of this study was to evaluate the endocrine dysfunctions and factors associated to their occurrence in patients presenting TBI at the neurosurgical units of the Yaounde Central and General Hospitals. Methods:&nbsp;Patients were enrolled at the neurosurgical units Data was collected with the help of a questionnaire after obtaining their informed consent alongside with blood samples in the morning (between 8AM and 10AM) for screening of anterior hypothalamo-pituitary axis hormones (FSH, LH and TSH) and relative peripheral hormones (cortisol, T4, oestrogene in women and testosterone in men) using fluorescence immunoassay. The study population was made up of all patients diagnosed with TBI during the study period at study sites. Patients taking medications affecting the hypothalamo-pituitary axis were excluded. Variables of interest included socio-demographic variables, clinical variables and paraclinical variables. Data was inserted and analyzed using the software Statistical Package for Social Sciences (SPSS) version 26.0. Association between variables was done using Fisher’s exact test. The association measure used was odd’s ratio (OR) with confidence interval (CI) of 95%. Results: A total of 33 participants were enrolled, out of which 26 responding to our inclusion criteria were retained and 7 excluded because they were on medications affecting the hypothalamo-pituitary axis.&nbsp;The median age of participants was 34 (26,75–41,25) years. There was a predominance of the male population with a sex ratio of 12:1. A total of 17 participants developed PTED (65.38%). The PTED encountered were FSH deficiency (12 patients at 46,1%), LH deficiency (10 patients at 38,4%), morning cortisol deficiency (5 patients at 19,2%), TSH deficiency (7 patients at 26,9%), testosterone deficiency (5 patients at 19,2%) and multiple deficiencies (12 patients at 46,1%). PTED was also found in 6 patients with severe TBI, 6 patients with moderate TBI and 5 patients with mild TBI (35.3%, 35.3% and 29.4%). In ≤7 days from TBI, 11 patients suffered PTED (64.7%) while after 7 days post-TBI, only 6 patients suffered PTED (35.3%). Tiredness was the most frequent symptom observed in 15 patients with PTED (88.2%). No factors associated to the occurrence of PTED were found in this study (p-values were all &gt;0.05). Conclusion:&nbsp;This study suggests that PTED is a common condition amongst sufferers of TBI. PTED occurs in both genders and the most frequent types of anterior pituitary endocrine dysfunctions were hypogonadism, hypothyroidism and lastly corticotropic insufficiency. Most patients with PTED had associated CT-scan lesions. No factors was significantly associated to the occurrence of PTED probably due to small sample size