This paper is focused on orthogonal function approximation technique FAT-based adaptive backstepping control of a geared DC motor coupled with a rotational mechanical component. It is assumed that all parameters of the actuator are unknown including the torque-current constant (i.e., unknown input coefficient) and hence a control system with three motor control modes is proposed: 1) motor torque control mode, 2) motor current control mode, and 3) motor voltage control mode. The proposed control algorithm is a powerful tool to control a dynamic system with an unknown input coefficient. Each uncertain parameter/term is represented by a linear combination of weighting and orthogonal basis function vectors. Chebyshev polynomial is used as a strong approximator for estimation of uncertainty. The designed control law includes three terms: a feedforward term, a feedback term and a robust term for compensation of modeling error. Lyapunov stability is used to prove the validity of the proposed controller and to derive the update laws for the weighting vectors of orthogonal Chebyshev approximators. A case study of a geared DC motor in connection with a rotating output load is simulated to prove the effectiveness of the proposed controller structure.
Solar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct rep
Three hundred Iraqi people participated in demographic and attitudes study about red and white meat consumption. The mean age of the participants was 50 SD ± 11 years (mean 30-72); 51% were females and 49% males, mostly in forties who lived ≥ 5 years in Baghdad. The results showed that 80% of individuals prefer red meat. A 90% of people prefer fresh meat compared to frozen and processed meat. A 60% of people buy meat from popular markets. Nearly 87% of respondents believe the improving of livestock sector is essential and 80% of people confirmed there are obstacles to development this sector. An 80% of participates thought the reasons of the high prices of local fresh meat is the lack of plann
... Show MoreThis research aims primarily to highlight personal tax exemptions A comparative study with some Arab and European regulations. And by conducting both theoretical comparative analyses. Most important findings of the study is the need to grant personal and family exemptions that differ according to the civil status of the taxpayer (single or married). In other words, the exemption increases as the number of family members depend on its social sense. Also taking into account some incomes that require a certain effort and looking at the tax rates, it is unreasonable for wages to be subject to the same rates applied to commercial profits.
Due to the potential cost saving and minimal temperature stratification, the energy storage based on phase-change materials (PCMs) can be a reliable approach for decoupling energy demand from immediate supply availability. However, due to their high heat resistance, these materials necessitate the introduction of enhancing additives, such as expanded surfaces and fins, to enable their deployment in more widespread thermal and energy storage applications. This study reports on how circular fins with staggered distribution and variable orientations can be employed for addressing the low thermal response rates in a PCM (Paraffin RT-35) triple-tube heat exchanger consisting of two heat-transfer fluids flow in opposites directions throug
... Show MoreMPEG-DASH is an adaptive bitrate streaming technology that divides video content into small HTTP-objects file segments with different bitrates. With live UHD video streaming latency is the most important problem. In this paper, creating a low-delay streaming system using HTTP 2.0. Based on the network condition the proposed system adaptively determine the bitrate of segments. The video is coded using a layered H.265/HEVC compression standard, then is tested to investigate the relationship between video quality and bitrate for various HEVC parameters and video motion at each layer/resolution. The system architecture includes encoder/decoder configurations and how to embedded the adaptive video streaming. The encoder includes compression besi
... Show MoreSovereign wealth funds have attracted the attention of the governments of the oil and non-oil countries alike, with a variation of the size of those funds to those states, based on the size of the financial surpluses resulting from Alriadat oil or foreign reserves, or state revenues for other sovereign assets. Raj use these funds remarkably during the financial crises the world has seen, including the crisis of 2008-2007., And Iraq is a oil-producing countries, which has the third largest reserves of crude oil (Crude Oil) at the level of the Arab world and of 140 300)) million barrels after Saudi Saudi Arabia and the Islamic Republic of Iran, and the fourth reserves of crude oil in the world after issued Venezuela to the reserve
... Show MoreMany economic entities working in multiple industrial fields suffer fromlow techniques in using modern administrative means in their works. The mostused tool in measuring required procedures is to adopt and use quality costs. inspite of complications and bronchial of operations in construction projects, Theresearcher was able to find a structure to quality costs according to traditionclassification (prevention, Appraisal, failure) which enables the calculation ofthese costs and then analyze results and setting standards which can beimplemented in evaluating strategic performance for targeted project. and theforge research in theoretical fly to quality and costs concerning it inconstruction section , as well as strategically performance a
... Show MoreThis paper discusses the role of Auditors' Technological Maturity in reinforcing the quality of auditing profession, through focusing on the concepts of Technological Maturity and quality of auditing profession, as well as designing a proposed model for Technological Maturity which includes five evolutionary and sequential stages, and this proposed model would contribute to reinforce the quality of auditing. This proposed model will be employed in the field of auditing profession because the importance of the development and investment in this profession and the importance of the need for specialized knowledge in Information Technology, and the result of a proposed model is development of technological knowledge for the auditor to reach
... Show MoreThis research deals with compound sentences in the German language and how to transform them and transfer them into a main sentence, touching on their functions and characteristics. Actual to nominative, which is a unique feature of the German language, with some diverse examples taken from various sources.This case is distinguished, like other grammatical cases
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