Search results for: Feedback control
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 11757

Search results for: Feedback control

11487 End-Users Tools to Empower and Raise Awareness of Behavioural Change towards Energy Efficiency

Authors: G. Calleja-Rodriguez, N. Jimenez-Redondo, J. J. Peralta Escalante

Abstract:

This research work aims at developing a solution to take advantage of the potential energy saving related to occupants behaviour estimated in between 5-30 % according to existing studies. For that purpose, the following methodology has been followed: 1) literature review and gap analysis, 2) define concept and functional requirements, 3) evaluation and feedback by experts. As result, the concept for a tool-box that implements continuous behavior change interventions named as engagement methods and based on increasing energy literacy, increasing energy visibility, using bonus system, etc. has been defined. These engagement methods are deployed through a set of ICT tools: Building Automation and Control System (BACS) add-ons services installed in buildings and Users Apps installed in smartphones, smart-TVs or dashboards. The tool-box called eTEACHER identifies energy conservation measures (ECM) based on energy behavioral change through a what-if analysis that collects information about the building and its users (comfort feedback, behavior, etc.) and carry out cost-effective calculations to provide outputs such us efficient control settings of building systems. This information is processed and showed in an attractive way as tailored advice to the energy end-users. Therefore, eTEACHER goal is to change the behavior of building´s energy users towards energy efficiency, comfort and better health conditions by deploying customized ICT-based interventions taking into account building typology (schools, residential, offices, health care centres, etc.), users profile (occupants, owners, facility managers, employers, etc.) as well as cultural and demographic factors. One of the main findings of this work is the common failure when technological interventions on behavioural change are done to not consult, train and support users regarding technological changes leading to poor performance in practices. As conclusion, a strong need to carry out social studies to identify relevant behavioural issues and to identify effective pro-evironmental behavioral change strategies has been identified.

Keywords: energy saving, behavioral bhange, building users, engagement methods, energy conservation measures

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11486 Intelligent Quality Management System on the Example оf Bread Baking

Authors: Irbulat Utepbergenov, Lyazzat Issabekova, Shara Toybayeva

Abstract:

This article discusses quality management using the bread baking process as an example. The baking process must be strictly controlled and repeatable. Automation and monitoring of quality management systems can help. After baking bread, quality control of the finished product should be carried out. This may include an evaluation of appearance, weight, texture, and flavor. It is important to continuously work to improve processes and products based on data and feedback from the quality management system. A method and model of automated quality management and an intelligent automated management system based on intelligent technologies are proposed, which allow to automate the processes of QMS implementation and support and improve the validity, efficiency, and effectiveness of management decisions by automating a number of functions of decision makers and staff. This project is supported by the grant of the Ministry of Education and Science of the Republic of Kazakhstan (Zhas Galym project No. AR 13268939 Research and development of digital technologies to ensure consistency of the carriers of normative documents of the quality management system).

Keywords: automated control system, quality management, efficiency evaluation, bakery oven, intelligent system

Procedia PDF Downloads 38
11485 Implicit Force Control of a Position Controlled Robot - A Comparison with Explicit Algorithms

Authors: Alexander Winkler, Jozef Suchý

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This paper investigates simple implicit force control algorithms realizable with industrial robots. A lot of approaches already published are difficult to implement in commercial robot controllers, because the access to the robot joint torques is necessary or the complete dynamic model of the manipulator is used. In the past we already deal with explicit force control of a position controlled robot. Well known schemes of implicit force control are stiffness control, damping control and impedance control. Using such algorithms the contact force cannot be set directly. It is further the result of controller impedance, environment impedance and the commanded robot motion/position. The relationships of these properties are worked out in this paper in detail for the chosen implicit approaches. They have been adapted to be implementable on a position controlled robot. The behaviors of stiffness control and damping control are verified by practical experiments. For this purpose a suitable test bed was configured. Using the full mechanical impedance within the controller structure will not be practical in the case when the robot is in physical contact with the environment. This fact will be verified by simulation.

Keywords: robot force control, stiffness control, damping control, impedance control, stability

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11484 Knowledge Discovery from Production Databases for Hierarchical Process Control

Authors: Pavol Tanuska, Pavel Vazan, Michal Kebisek, Dominika Jurovata

Abstract:

The paper gives the results of the project that was oriented on the usage of knowledge discoveries from production systems for needs of the hierarchical process control. One of the main project goals was the proposal of knowledge discovery model for process control. Specifics data mining methods and techniques was used for defined problems of the process control. The gained knowledge was used on the real production system, thus, the proposed solution has been verified. The paper documents how it is possible to apply new discovery knowledge to be used in the real hierarchical process control. There are specified the opportunities for application of the proposed knowledge discovery model for hierarchical process control.

Keywords: hierarchical process control, knowledge discovery from databases, neural network, process control

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11483 Investigating the Relationship Between Corporate Governance and Financial Performance Considering the Moderating Role of Opinion and Internal Control Weakness

Authors: Fatemeh Norouzi

Abstract:

Today, financial performance has become one of the important issues in accounting and auditing that companies and their managers have paid attention to this issue and for this reason to the variables that are influential in this field. One of the things that can affect financial performance is corporate governance, which is examined in this research, although some things such as issues related to auditing can also moderate this relationship; Therefore, this research has been conducted with the aim of investigating the relationship between corporate governance and financial performance with regard to the moderating role of feedback and internal control weakness. The research is practical in terms of purpose, and in terms of method, it has been done in a post-event descriptive manner, in which the data has been analyzed using stock market data. Data collection has been done by using stock exchange data which has been extracted from the website of the Iraqi Stock Exchange, the statistical population of this research is all the companies admitted to the Iraqi Stock Exchange. . The statistical sample in this research is considered from 2014 to 2021, which includes 34 companies. Four different models have been considered for the research hypotheses, which are eight hypotheses, in this research, the analysis has been done using EXCEL and STATA15 software. In this article, collinearity test, integration test ,determination of fixed effects and correlation matrix results, have been used. The research results showed that the first four hypotheses were rejected and the second four hypotheses were confirmed.

Keywords: size of the board of directors, duality of the CEO, financial performance, internal control weakness

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11482 How Different Perceived Affordances of Game Elements Shape Motivation and Performance in Gamified Learning: A Cognitive Evaluation Theory Perspective

Authors: Kibbeum Na

Abstract:

Previous gamification research has produced mixed results regarding the effectiveness of gamified learning. One possible explanation for this is that individuals perceive the game elements differently. Cognitive Evaluation Theory posits that external rewards can boost or undermine intrinsic motivation, depending on whether the rewards are perceived as informational or controlling. This research tested the hypothesis that game elements can be perceived as either informational feedback or external reward, and the motivational impact differ accordingly. An experiment was conducted using an educational math puzzle to compare the motivation and performance as a result of different perceived affordances game elements. Participants were primed to perceive the game elements as either informational feedback or external reward, and the duration of an attempt to solve the unsolvable puzzle – amotivation indicator – and the puzzle score – a performance indicator–were measured with the game elements incorporated and then without the game elements. Badges and points were deployed as the main game elements. Results showed that, regardless of priming, a significant decrease in performance occurred when the game elements were removed, whereas the control group who solved non-gamified math puzzles maintained their performance. The undermined performance with gamification removal indicates that learners may perceive some game elements as controlling factors irrespective of the way they are presented. The results of the current study also imply that some game elements are better not being implemented to preserve long-term performance. Further research delving into the extrinsic reward-like nature of game elements and its impact on learning motivation is called for.

Keywords: cognitive Evaluation Theory, game elements, gamification, motivation, motivational affordance, performance

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11481 Important Factors Affecting the Effectiveness of Quality Control Circles

Authors: Sogol Zarafshan

Abstract:

The present study aimed to identify important factors affecting the effectiveness of quality control circles in a hospital, as well as rank them using a combination of fuzzy VIKOR and Grey Relational Analysis (GRA). The study population consisted of five academic members and five experts in the field of nursing working in a hospital, who were selected using a purposive sampling method. Also, a sample of 107 nurses was selected through a simple random sampling method using their employee codes and the random-number table. The required data were collected using a researcher-made questionnaire which consisted of 12 factors. The validity of this questionnaire was confirmed through giving the opinions of experts and academic members who participated in the present study, as well as performing confirmatory factor analysis. Its reliability also was verified (α=0.796). The collected data were analyzed using SPSS 22.0 and LISREL 8.8, as well as VIKOR–GRA and IPA methods. The results of ranking the factors affecting the effectiveness of quality control circles showed that the highest and lowest ranks were related to ‘Managers’ and supervisors’ support’ and ‘Group leadership’. Also, the highest hospital performance was for factors such as ‘Clear goals and objectives’ and ‘Group cohesiveness and homogeneity’, and the lowest for ‘Reward system’ and ‘Feedback system’, respectively. The results showed that although ‘Training the members’, ‘Using the right tools’ and ‘Reward system’ were factors that were of great importance, the organization’s performance for these factors was poor. Therefore, these factors should be paid more attention by the studied hospital managers and should be improved as soon as possible.

Keywords: Quality control circles, Fuzzy VIKOR, Grey Relational Analysis, Importance–Performance Analysis

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11480 A Regression Model for Predicting Sugar Crystal Size in a Fed-Batch Vacuum Evaporative Crystallizer

Authors: Sunday B. Alabi, Edikan P. Felix, Aniediong M. Umo

Abstract:

Crystal size distribution is of great importance in the sugar factories. It determines the market value of granulated sugar and also influences the cost of production of sugar crystals. Typically, sugar is produced using fed-batch vacuum evaporative crystallizer. The crystallization quality is examined by crystal size distribution at the end of the process which is quantified by two parameters: the average crystal size of the distribution in the mean aperture (MA) and the width of the distribution of the coefficient of variation (CV). Lack of real-time measurement of the sugar crystal size hinders its feedback control and eventual optimisation of the crystallization process. An attractive alternative is to use a soft sensor (model-based method) for online estimation of the sugar crystal size. Unfortunately, the available models for sugar crystallization process are not suitable as they do not contain variables that can be measured easily online. The main contribution of this paper is the development of a regression model for estimating the sugar crystal size as a function of input variables which are easy to measure online. This has the potential to provide real-time estimates of crystal size for its effective feedback control. Using 7 input variables namely: initial crystal size (Lo), temperature (T), vacuum pressure (P), feed flowrate (Ff), steam flowrate (Fs), initial super-saturation (S0) and crystallization time (t), preliminary studies were carried out using Minitab 14 statistical software. Based on the existing sugar crystallizer models, and the typical ranges of these 7 input variables, 128 datasets were obtained from a 2-level factorial experimental design. These datasets were used to obtain a simple but online-implementable 6-input crystal size model. It seems the initial crystal size (Lₒ) does not play a significant role. The goodness of the resulting regression model was evaluated. The coefficient of determination, R² was obtained as 0.994, and the maximum absolute relative error (MARE) was obtained as 4.6%. The high R² (~1.0) and the reasonably low MARE values are an indication that the model is able to predict sugar crystal size accurately as a function of the 6 easy-to-measure online variables. Thus, the model can be used as a soft sensor to provide real-time estimates of sugar crystal size during sugar crystallization process in a fed-batch vacuum evaporative crystallizer.

Keywords: crystal size, regression model, soft sensor, sugar, vacuum evaporative crystallizer

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11479 Integrating Wearable Devices in Real-Time Computer Applications of Petrochemical Systems

Authors: Paul B Stone, Subhashini Ganapathy, Mary E. Fendley, Layla Akilan

Abstract:

As notifications become more common through mobile devices, it is important to understand the impact of wearable devices on the improved user experience of man-machine interfaces. This study examined the use of a wearable device for a real-time system using a computer-simulated petrochemical system. The key research question was to determine how using the information provided by the wearable device can improve human performance through measures of situational awareness and decision making. Results indicate that there was a reduction in response time when using the watch, and there was no difference in situational awareness. Perception of using the watch was positive, with 83% of users finding value in using the watch and receiving haptic feedback.

Keywords: computer applications, haptic feedback, petrochemical systems, situational awareness, wearable technology

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11478 Balancing and Synchronization Control of a Two Wheel Inverted Pendulum Vehicle

Authors: Shiuh-Jer Huang, Shin-Ham Lee, Sheam-Chyun Lin

Abstract:

A two wheel inverted pendulum (TWIP) vehicle is built with two hub DC motors for motion control evaluation. Arduino Nano micro-processor is chosen as the control kernel for this electric test plant. Accelerometer and gyroscope sensors are built in to measure the tilt angle and angular velocity of the inverted pendulum vehicle. Since the TWIP has significantly hub motor dead zone and nonlinear system dynamics characteristics, the vehicle system is difficult to control by traditional model based controller. The intelligent model-free fuzzy sliding mode controller (FSMC) was employed as the main control algorithm. Then, intelligent controllers are designed for TWIP balance control, and two wheels synchronization control purposes.

Keywords: balance control, synchronization control, two-wheel inverted pendulum, TWIP

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11477 The Control System Architecture of Space Environment Simulator

Authors: Zhan Haiyang, Gu Miao

Abstract:

This article mainly introduces the control system architecture of space environment simulator, simultaneously also briefly introduce the automation control technology of industrial process and the measurement technology of vacuum and cold black environment. According to the volume of chamber, the space environment simulator is divided into three types of small, medium and large. According to the classification and application of space environment simulator, the control system is divided into the control system of small, medium, large space environment simulator and the centralized control system of multiple space environment simulators.

Keywords: space environment simulator, control system, architecture, automation control technology

Procedia PDF Downloads 475
11476 Supply Air Pressure Control of HVAC System Using MPC Controller

Authors: P. Javid, A. Aeenmehr, J. Taghavifar

Abstract:

In this paper, supply air pressure of HVAC system has been modeled with second-order transfer function plus dead-time. In HVAC system, the desired input has step changes, and the output of proposed control system should be able to follow the input reference, so the idea of using model based predictive control is proceeded and designed in this paper. The closed loop control system is implemented in MATLAB software and the simulation results are provided. The simulation results show that the model based predictive control is able to control the plant properly.

Keywords: air conditioning system, GPC, dead time, air supply control

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11475 The Constraint of Machine Breakdown after a Match up Scheduling of Paper Manufacturing Industry

Authors: John M. Ikome

Abstract:

In the process of manufacturing, a machine breakdown usually forces a modified flow shop out of the prescribed state, this strategy reschedules part of the initial schedule to match up with the pre-schedule at some point with the objective to create a schedule that is reliable with the other production planning decisions like material flow, production and suppliers by utilizing a critical decision-making concept. We propose a rescheduling strategy and a match-up point that will have a determination procedure through an advanced feedback control mechanism to increase both the schedule quality and stability. These approaches are compared with alternative re-scheduling methods under different experimental settings.

Keywords: scheduling, heuristics, branch, integrated

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11474 Study on Eco-Feedback of Thermal Comfort and Cost Efficiency for Low Energy Residence

Authors: Y. Jin, N. Zhang, X. Luo, W. Zhang

Abstract:

China with annual increasing 0.5-0.6 billion squares city residence has brought in enormous energy consumption by HVAC facilities and other appliances. In this regard, governments and researchers are encouraging renewable energy like solar energy, geothermal energy using in houses. However, high cost of equipment and low energy conversion result in a very low acceptable to residents. So what’s the equilibrium point of eco-feedback to reach economic benefit and thermal comfort? That is the main question should be answered. In this paper, the objective is an on-site solar PV and heater house, which has been evaluated as a low energy building. Since HVAC system is considered as main energy consumption equipment, the residence with 24-hour monitoring system set to measure temperature, wind velocity and energy in-out value with no HVAC system for one month of summer and winter. Thermal comfort time period will be analyzed and confirmed; then the air-conditioner will be started within thermal discomfort time for the following one summer and winter month. The same data will be recorded to calculate the average energy consumption monthly for a purpose of whole day thermal comfort. Finally, two analysis work will be done: 1) Original building thermal simulation by computer at design stage with actual measured temperature after construction will be contrastive analyzed; 2) The cost of renewable energy facilities and power consumption converted to cost efficient rate to assess the feasibility of renewable energy input for residence. The results of the experiment showed that a certain deviation exists between actual measured data and simulated one for human thermal comfort, especially in summer period. Moreover, the cost-effectiveness is high for a house in targeting city Guilin now with at least 11 years of cost-covering. The conclusion proves that an eco-feedback of a low energy residence is never only consideration of its energy net value, but also the cost efficiency that is the critical factor to push renewable energy acceptable by the public.

Keywords: cost efficiency, eco-feedback, low energy residence, thermal comfort

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11473 Particle Swarm Optimisation of a Terminal Synergetic Controllers for a DC-DC Converter

Authors: H. Abderrezek, M. N. Harmas

Abstract:

DC-DC converters are widely used as reliable power source for many industrial and military applications, computers and electronic devices. Several control methods were developed for DC-DC converters control mostly with asymptotic convergence. Synergetic control (SC) is a proven robust control approach and will be used here in a so-called terminal scheme to achieve finite time convergence. Lyapunov synthesis is adopted to assure controlled system stability. Furthermore particle swarm optimization (PSO) algorithm, based on an integral time absolute of error (ITAE) criterion will be used to optimize controller parameters. Simulation of terminal synergetic control of a DC-DC converter is carried out for different operating conditions and results are compared to classic synergetic control performance, that which demonstrate the effectiveness and feasibility of the proposed control method.

Keywords: DC-DC converter, PSO, finite time, terminal, synergetic control

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11472 Control Configuration System as a Key Element in Distributed Control System

Authors: Goodarz Sabetian, Sajjad Moshfe

Abstract:

Control system for hi-tech industries could be realized generally and deeply by a special document. Vast heavy industries such as power plants with a large number of I/O signals are controlled by a distributed control system (DCS). This system comprises of so many parts from field level to high control level, and junior instrument engineers may be confused by this enormous information. The key document which can solve this problem is “control configuration system diagram” for each type of DCS. This is a road map that covers all of activities respect to control system in each industrial plant and inevitable to be studied by whom corresponded. It plays an important role from designing control system start point until the end; deliver the system to operate. This should be inserted in bid documents, contracts, purchasing specification and used in different periods of project EPC (engineering, procurement, and construction). Separate parts of DCS are categorized here in order of importance and a brief description and some practical plan is offered. This article could be useful for all instrument and control engineers who worked is EPC projects.

Keywords: control, configuration, DCS, power plant, bus

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11471 Control and Control Systems of Administration in Nigeria

Authors: Inuwa Abdu Ibrahim

Abstract:

Public officials are required to posses certain values to adequately protect public interest, by being leaders that are servants of the people. The reality in Nigeria is that leaders rule as masters of the people rather than servants. The paper looked at control and control systems of administration in Nigeria, its resultant consequences and ways of achieving true control of administrators and administration. Secondary source of data was adopted for the research. It concludes that the keys to administrative efficiency and effectiveness through control are implementation of the already existing procedures and laws, as well as commitment on the part of public officials.

Keywords: Accountability, Fraud, Administration, Nigeria

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11470 Efficacy of Clickers in L2 Interaction

Authors: Ryoo Hye Jin Agnes

Abstract:

This study aims to investigate the efficacy of clickers in fostering L2 class interaction. In an L2 classroom, active learner-to-learner interactions and learner-to-teacher interactions play an important role in language acquisition. In light of this, introducing learning tools that promote such interactions would benefit L2 classroom by fostering interaction. This is because the anonymity of clickers allows learners to express their needs without the social risks associated with speaking up in the class. clickers therefore efficiently help learners express their level of understanding during the process of learning itself. This allows for an evaluative feedback loop where both learners and teachers understand the level of progress of the learners, better enabling classrooms to adapt to the learners’ needs. Eventually this tool promotes participation from learners. This, in turn, is believed to be effective in fostering classroom interaction, allowing learning to take place in a more comfortable yet vibrant way. This study is finalized by presenting the result of an experiment conducted to verify the effectiveness of this approach when teaching pragmatic aspect of Korean expressions with similar semantic functions. The learning achievement of learners in the experimental group was found higher than the learners’ in a control group. A survey was distributed to the learners, questioning them regarding the efficacy of clickers, and how it contributed to their learning in areas such as motivation, self-assessment, increasing participation, as well as giving feedback to teachers. Analyzing the data collected from the questionnaire given to the learners, the study presented data suggesting that this approach increased the scope of interactivity in the classroom, thus not only increasing participation but enhancing the type of classroom participation among learners. This participation in turn led to a marked improvement in their communicative abilities.

Keywords: second language acquisition, interaction, clickers, learner response system, output from learners, learner’s cognitive process

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11469 Evaluation of the Notifiable Diseases Surveillance System, South, Haiti, 2022

Authors: Djeamsly Salomon

Abstract:

Background: Epidemiological surveillance is a dynamic national system used to observe all aspects of the evolution of priority health problems, through: collection, analysis, systematic interpretation of information, and dissemination of results with necessary recommendations. The study was conducted to assess the mandatory disease surveillance system in the Sud Department. Methods: A study was conducted from March to May 2021 with key players involved in surveillance at the level of health institutions in the department . The CDC's 2021 updated guideline was used to evaluate the system. We collected information about the operation, attributes, and usefulness of the surveillance system using interviewer-administered questionnaires. Epi-Info7.2 and Excel 2016 were used to generate the mean, frequencies and proportions. Results: Of 30 participants, 23 (77%) were women. The average age was 39 years[30-56]. 25 (83%) had training in epidemiological surveillance. (50%) of the forms checked were signed by the supervisor. Collection tools were available at (80%). Knowledge of at least 7 notifiable diseases was high (100%). Among the respondents, 29 declared that the collection tools were simple, 27 had already filled in a notification form. The maximum time taken to fill out a form was 10 minutes. The feedback between the different levels was done at (60%). Conclusion: The surveillance system is useful, simple, acceptable, representative, flexible, stable and responsive. The data generated was of high quality. However, it is threatened by the lack of supervision of sentinel sites, lack of investigation and weak feedback. This evaluation demonstrated the urgent need to improve supervision in the sites and to feedback information. Strengthen epidemiological surveillance.

Keywords: evaluation, notifiable diseases, surveillance, system

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11468 SVM-DTC Using for PMSM Speed Tracking Control

Authors: Kendouci Khedidja, Mazari Benyounes, Benhadria Mohamed Rachid, Dadi Rachida

Abstract:

In recent years, direct torque control (DTC) has become an alternative to the well-known vector control especially for permanent magnet synchronous motor (PMSM). However, it presents a problem of field linkage and torque ripple. In order to solve this problem, the conventional DTC is combined with space vector pulse width modulation (SVPWM). This control theory has achieved great success in the control of PMSM. That has become a hotspot for resolving. The main objective of this paper gives us an introduction of the DTC and SVPWM-DTC control theory of PMSM which has been simulating on each part of the system via Matlab/Simulink based on the mathematical modeling. Moreover, the outcome of the simulation proved that the improved SVPWM- DTC of PMSM has a good dynamic and static performance.

Keywords: PMSM, DTC, SVM, speed control

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11467 Compact Low-Voltage Biomedical Instrumentation Amplifiers

Authors: Phanumas Khumsat, Chalermchai Janmane

Abstract:

Low-voltage instrumentation amplifier has been proposed for 3-lead electrocardiogram measurement system. The circuit’s interference rejection technique is based upon common-mode feed-forwarding where common-mode currents have cancelled each other at the output nodes. The common-mode current for cancellation is generated by means of common-mode sensing and emitter or source followers with resistors employing only one transistor. Simultaneously this particular transistor also provides common-mode feedback to the patient’s right/left leg to further reduce interference entering the amplifier. The proposed designs have been verified with simulations in 0.18-µm CMOS process operating under 1.0-V supply with CMRR greater than 80dB. Moreover ECG signals have experimentally recorded with the proposed instrumentation amplifiers implemented from discrete BJT (BC547, BC558) and MOSFET (ALD1106, ALD1107) transistors working with 1.5-V supply.

Keywords: electrocardiogram, common-mode feedback, common-mode feedforward, communication engineering

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11466 Synchronization of Chaotic T-System via Optimal Control as an Adaptive Controller

Authors: Hossein Kheiri, Bashir Naderi, Mohamad Reza Niknam

Abstract:

In this paper we study the optimal synchronization of chaotic T-system with complete uncertain parameter. Optimal control laws and parameter estimation rules are obtained by using Hamilton-Jacobi-Bellman (HJB) technique and Lyapunov stability theorem. The derived control laws are optimal adaptive control and make the states of drive and response systems asymptotically synchronized. Numerical simulation shows the effectiveness and feasibility of the proposed method.

Keywords: Lyapunov stability, synchronization, chaos, optimal control, adaptive control

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11465 A Study on the Effect of Design Factors of Slim Keyboard’s Tactile Feedback

Authors: Kai-Chieh Lin, Chih-Fu Wu, Hsiang Ling Hsu, Yung-Hsiang Tu, Chia-Chen Wu

Abstract:

With the rapid development of computer technology, the design of computers and keyboards moves towards a trend of slimness. The change of mobile input devices directly influences users’ behavior. Although multi-touch applications allow entering texts through a virtual keyboard, the performance, feedback, and comfortableness of the technology is inferior to traditional keyboard, and while manufacturers launch mobile touch keyboards and projection keyboards, the performance has not been satisfying. Therefore, this study discussed the design factors of slim pressure-sensitive keyboards. The factors were evaluated with an objective (accuracy and speed) and a subjective evaluation (operability, recognition, feedback, and difficulty) depending on the shape (circle, rectangle, and L-shaped), thickness (flat, 3mm, and 6mm), and force (35±10g, 60±10g, and 85±10g) of the keyboard. Moreover, MANOVA and Taguchi methods (regarding signal-to-noise ratios) were conducted to find the optimal level of each design factor. The research participants, by their typing speed (30 words/ minute), were divided in two groups. Considering the multitude of variables and levels, the experiments were implemented using the fractional factorial design. A representative model of the research samples were established for input task testing. The findings of this study showed that participants with low typing speed primarily relied on vision to recognize the keys, and those with high typing speed relied on tactile feedback that was affected by the thickness and force of the keys. In the objective and subjective evaluation, a combination of keyboard design factors that might result in higher performance and satisfaction was identified (L-shaped, 3mm, and 60±10g) as the optimal combination. The learning curve was analyzed to make a comparison with a traditional standard keyboard to investigate the influence of user experience on keyboard operation. The research results indicated the optimal combination provided input performance to inferior to a standard keyboard. The results could serve as a reference for the development of related products in industry and for applying comprehensively to touch devices and input interfaces which are interacted with people.

Keywords: input performance, mobile device, slim keyboard, tactile feedback

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11464 RAPDAC: Role Centric Attribute Based Policy Driven Access Control Model

Authors: Jamil Ahmed

Abstract:

Access control models aim to decide whether a user should be denied or granted access to the user‟s requested activity. Various access control models have been established and proposed. The most prominent of these models include role-based, attribute-based, policy based access control models as well as role-centric attribute based access control model. In this paper, a novel access control model is presented called “Role centric Attribute based Policy Driven Access Control (RAPDAC) model”. RAPDAC incorporates the concept of “policy” in the “role centric attribute based access control model”. It leverages the concept of "policy‟ by precisely combining the evaluation of conditions, attributes, permissions and roles in order to allow authorization access. This approach allows capturing the "access control policy‟ of a real time application in a well defined manner. RAPDAC model allows making access decision at much finer granularity as illustrated by the case study of a real time library information system.

Keywords: authorization, access control model, role based access control, attribute based access control

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11463 Design and Motion Control of a Two-Wheel Inverted Pendulum Robot

Authors: Shiuh-Jer Huang, Su-Shean Chen, Sheam-Chyun Lin

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Two-wheel inverted pendulum robot (TWIPR) is designed with two-hub DC motors for human riding and motion control evaluation. In order to measure the tilt angle and angular velocity of the inverted pendulum robot, accelerometer and gyroscope sensors are chosen. The mobile robot’s moving position and velocity were estimated based on DC motor built in hall sensors. The control kernel of this electric mobile robot is designed with embedded Arduino Nano microprocessor. A handle bar was designed to work as steering mechanism. The intelligent model-free fuzzy sliding mode control (FSMC) was employed as the main control algorithm for this mobile robot motion monitoring with different control purpose adjustment. The intelligent controllers were designed for balance control, and moving speed control purposes of this robot under different operation conditions and the control performance were evaluated based on experimental results.

Keywords: balance control, speed control, intelligent controller, two wheel inverted pendulum

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11462 Establishing Control Chart Limits for Rounded Measurements

Authors: Ran Etgar

Abstract:

The process of rounding off measurements in continuous variables is commonly encountered. Although it usually has minor effects, sometimes it can lead to poor outcomes in statistical process control using X̄ chart. The traditional control limits can cause incorrect conclusions if applied carelessly. This study looks into the limitations of classical control limits, particularly the impact of asymmetry. An approach to determining the distribution function of the measured parameter ȳ is presented, resulting in a more precise method to establish the upper and lower control limits. The proposed method, while slightly more complex than Shewhart's original idea, is still user-friendly and accurate and only requires the use of two straightforward tables.

Keywords: SPC, round-off data, control limit, rounding error

Procedia PDF Downloads 75
11461 Feasibility Study of Distributed Lightless Intersection Control with Level 1 Autonomous Vehicles

Authors: Bo Yang, Christopher Monterola

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Urban intersection control without the use of the traffic light has the potential to vastly improve the efficiency of the urban traffic flow. For most proposals in the literature, such lightless intersection control depends on the mass market commercialization of highly intelligent autonomous vehicles (AV), which limits the prospects of near future implementation. We present an efficient lightless intersection traffic control scheme that only requires Level 1 AV as defined by NHTSA. The technological barriers of such lightless intersection control are thus very low. Our algorithm can also accommodate a mixture of AVs and conventional vehicles. We also carry out large scale numerical analysis to illustrate the feasibility, safety and robustness, comfort level, and control efficiency of our intersection control scheme.

Keywords: intersection control, autonomous vehicles, traffic modelling, intelligent transport system

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11460 Minimize Wear and Tear in Y12 Aircraft Tyres

Authors: N. D. Hiripitiya, H. V. H. De Soysa, H. S. U. Thrimavithana, B. R. Epitawala, K. A. D. D. Kuruppu, D. J. K. Lokupathirage

Abstract:

This research was related to identify the reasons which lead for early wear and tear of aircraft tyres. Further this research focused to rectify those issues in tyres with some modifications. The aircraft tyres of Y12 aircraft was selected for the study as due to Y12 aircraft fly frequently. Self-structured questionnaire was prepared and it was distributed among Y12 aircraft technicians. Based on their feedback several issues were identified related to tyre wear and tear. One of the reasons was uneven tyre wearing. But it could rectify after interchanging the tyre sides after completion of 50 landings. Several modifications were done in order to rectify all the identified issues. Several devices were constructed in order to enhance the life time of the Y12 aircraft tyre. Mechanical properties were measured for the worn-out tyres. The properties were compared with the control tyre sample. It was found that there was an average increment of tensile strength by 38.14 % of control tyre, when compared with the worn-out tyres which were completed 50 number of landings. The suggested modifications are in the process of implementation. It is confident that above mentioned solutions will lead to increase the life span of tyres in Y12 aircraft.

Keywords: aircraft, devices, enhance life span, modifications for tyre wear

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11459 Postgraduate Supervision Relationship: Practices, Challenges, and Strategies of Stakeholders in the Côte d’Ivoire University System

Authors: Akuélé Radha Kondo, Kathrin Heitz-Tokpa, Bassirou Bonfoh, Francis Akindes

Abstract:

Postgraduate supervision contributes significantly to a student’s academic career, a supervisor’s promotion, and a university’s reputation. Despite this, the length of graduation in the Côte d’Ivoire University system is beyond the normal duration, two years for a master's and three years for a PhD. The paper analyses supervision practices regarding the challenges and strategies mobilised by students, supervisors, and administration staff to manage various relationships. Using a qualitative research design, this study was conducted at three public universities in Côte d’Ivoire. Data were generated from thirty-two postgraduate students, seventeen supervisors, and four administration staff through semi-structured interviews. Data were analysed using content analysis and presented thematically. Findings revealed delegated supervision and co-supervision, two types of supervision relationship practices. Students pointed out that feedback is often delayed from their supervisors in delegation supervision. However, they acknowledged receiving input and scientific guidance. All students believed that their role is to be proactive, not to wait to receive everything from the supervisor, and need to be more autonomous and hardworking. They developed strategies related to these qualities. Supervisors were considered to guide, give advice, control, motivate, provide critical feedback, and validate the work. The administration was rather absent in monitoring supervision delays. Major challenges were related to the supervision relationships and access to the research funds. The study showed that more engagement of the main supervisor, administration monitoring, and secured funding would reduce the time and increase the completion rate.

Keywords: Côte d’Ivoire, postgraduate supervision, practices, strategies

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11458 Numerical Study of Flapping-Wing Flight of Hummingbird Hawkmoth during Hovering: Longitudinal Dynamics

Authors: Yao Jie, Yeo Khoon Seng

Abstract:

In recent decades, flapping wing aerodynamics has attracted great interest. Understanding the physics of biological flyers such as birds and insects can help improve the performance of micro air vehicles. The present research focuses on the aerodynamics of insect-like flapping wing flight with the approach of numerical computation. Insect model of hawkmoth is adopted in the numerical study with rigid wing assumption currently. The numerical model integrates the computational fluid dynamics of the flow and active control of wing kinematics to achieve stable flight. The computation grid is a hybrid consisting of background Cartesian nodes and clouds of mesh-free grids around immersed boundaries. The generalized finite difference method is used in conjunction with single value decomposition (SVD-GFD) in computational fluid dynamics solver to study the dynamics of a free hovering hummingbird hawkmoth. The longitudinal dynamics of the hovering flight is governed by three control parameters, i.e., wing plane angle, mean positional angle and wing beating frequency. In present work, a PID controller works out the appropriate control parameters with the insect motion as input. The controller is adjusted to acquire desired maneuvering of the insect flight. The numerical scheme in present study is proven to be accurate and stable to simulate the flight of the hummingbird hawkmoth, which has relatively high Reynolds number. The PID controller is responsive to provide feedback to the wing kinematics during the hovering flight. The simulated hovering flight agrees well with the real insect flight. The present numerical study offers a promising route to investigate the free flight aerodynamics of insects, which could overcome some of the limitations of experiments.

Keywords: aerodynamics, flight control, computational fluid dynamics (CFD), flapping-wing flight

Procedia PDF Downloads 348