Displaying publications 41 - 60 of 454 in total

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  1. Barteit S, Sié A, Zabré P, Traoré I, Ouédraogo WA, Boudo V, et al.
    Front Public Health, 2023;11:1153559.
    PMID: 37304117 DOI: 10.3389/fpubh.2023.1153559
    BACKGROUND: Climate change significantly impacts health in low-and middle-income countries (LMICs), exacerbating vulnerabilities. Comprehensive data for evidence-based research and decision-making is crucial but scarce. Health and Demographic Surveillance Sites (HDSSs) in Africa and Asia provide a robust infrastructure with longitudinal population cohort data, yet they lack climate-health specific data. Acquiring this information is essential for understanding the burden of climate-sensitive diseases on populations and guiding targeted policies and interventions in LMICs to enhance mitigation and adaptation capacities.

    OBJECTIVE: The objective of this research is to develop and implement the Change and Health Evaluation and Response System (CHEERS) as a methodological framework, designed to facilitate the generation and ongoing monitoring of climate change and health-related data within existing Health and Demographic Surveillance Sites (HDSSs) and comparable research infrastructures.

    METHODS: CHEERS uses a multi-tiered approach to assess health and environmental exposures at the individual, household, and community levels, utilizing digital tools such as wearable devices, indoor temperature and humidity measurements, remotely sensed satellite data, and 3D-printed weather stations. The CHEERS framework utilizes a graph database to efficiently manage and analyze diverse data types, leveraging graph algorithms to understand the complex interplay between health and environmental exposures.

    RESULTS: The Nouna CHEERS site, established in 2022, has yielded significant preliminary findings. By using remotely-sensed data, the site has been able to predict crop yield at a household level in Nouna and explore the relationships between yield, socioeconomic factors, and health outcomes. The feasibility and acceptability of wearable technology have been confirmed in rural Burkina Faso for obtaining individual-level data, despite the presence of technical challenges. The use of wearables to study the impact of extreme weather on health has shown significant effects of heat exposure on sleep and daily activity, highlighting the urgent need for interventions to mitigate adverse health consequences.

    CONCLUSION: Implementing the CHEERS in research infrastructures can advance climate change and health research, as large and longitudinal datasets have been scarce for LMICs. This data can inform health priorities, guide resource allocation to address climate change and health exposures, and protect vulnerable communities in LMICs from these exposures.

    Matched MeSH terms: Research Design*
  2. Rigutto-Farebrother J, Ahles S, Cade J, Murphy KJ, Plat J, Schwingshackl L, et al.
    Eur J Nutr, 2023 Aug;62(5):2319-2332.
    PMID: 37099211 DOI: 10.1007/s00394-023-03137-5
    PURPOSE: Reporting guidelines facilitate quality and completeness in research reporting. The CONsolidated Standards Of Reporting Trials (CONSORT) statement is widely applied to dietary and nutrition trials but has no extension specific to nutrition. Evidence suggests poor reporting in nutrition research. The Federation of European Nutrition Societies led an initiative to make recommendations for a nutrition extension to the CONSORT statement towards a more robust reporting of the evidence base.

    METHODS: An international working group was formed of nutrition researchers from 14 institutions in 12 different countries and on five continents. Using meetings over a period of one year, we interrogated the CONSORT statement specifically for its application to report nutrition trials.

    RESULTS: We provide a total of 28 new nutrition-specific recommendations or emphasised recommendations for the reporting of the introduction (three), methods (twelve), results (five) and discussion (eight). We also added two additional recommendations that were not allocated under the standard CONSORT headings.

    CONCLUSION: We identify a need to provide guidance in addition to CONSORT to improve the quality and consistency of the reporting and propose key considerations for further development of formal guidelines for the reporting of nutrition trials. Readers are encouraged to engage in this process, provide comments and conduct specific studies to inform further work on the development of reporting guidelines for nutrition trials.

    Matched MeSH terms: Research Design*
  3. Begley A, Fisher I, Butcher L, Foulkes-Taylor F, Giglia R, Dhaliwal SS
    J Nutr Educ Behav, 2023 Sep;55(9):659-666.
    PMID: 37516955 DOI: 10.1016/j.jneb.2023.06.001
    OBJECTIVE: To determine the effect of Food Sensations for Adults on food literacy behaviors and selected dietary behaviors.

    METHODS: A quasi-experimental design using preprogram and postprogram questionnaires over 4 weeks with a control group (n = 75) matched for sex, age group, and socioeconomic disadvantage to program participants (n = 867). General linear mixed models assessed change in food literacy behavior frequency in 3 self-reported domains (plan and manage, selection, and preparation) and fruit and vegetable servings.

    RESULTS: Postprogram, Food Sensations for Adults participants reported modest yet statistically significant score improvements in 2 of the 3 domains of food literacy behaviors in the plan and manage (12.4%) and preparation (9.8%) domains, as well as servings of vegetables (22.6% or 0.5 servings).

    CONCLUSION AND IMPLICATIONS: Quasi-experimental designs indicate food literacy programs can produce modest short-term changes across a range of food literacy and dietary behaviors.

    Matched MeSH terms: Research Design*
  4. Ooi CP, Yusof Khan AHK, Abdul Manaf R, Mustafa N, Sukor N, Williamson PR, et al.
    BMJ Open, 2021 Jul 28;11(7):e050231.
    PMID: 34321306 DOI: 10.1136/bmjopen-2021-050231
    INTRODUCTION: Thyroid dysfunctions (TD) are common medical conditions affecting all global populations. Improved healthcare leading to increasing survival rates and delayed diagnosis rendered significant burden of the disease in the increasing number of patients with TD with comorbid illnesses. Therefore, reducing the burden of TD and improving the quality of care are crucial. Existing poor-quality data that guide evidence-based decisions only provide a fragmented picture of clinical care. The different outcomes across studies assessing the effectiveness of treatments impede our ability to synthesise results for determining the most efficient treatments. This project aims to produce a core outcome set (COS), which embeds the multiple complex dimensions of routine clinical care for the effectiveness studies and clinical care of adult patients with TD.

    METHODS AND ANALYSIS: This mixed-method project has two phases. In phase 1, we will identify a list of patient-reported and clinical outcomes through qualitative research and systematic reviews. In phase 2, we will categorise the identified outcomes using the Core Outcome Measures in Effectiveness Trials taxonomy of core domains and the International Classification of Functioning, Disability and Health. We will develop questionnaires from the list of outcomes identified from each domain for the two-round online Delphi exercise, aiming to reach a consensus on the COS. The Delphi process will include patients, carers, researchers and healthcare participants. We will hold an online consensus meeting involving representatives of all key stakeholders to establish the final COS.

    ETHICS AND DISSEMINATION: The study has been reviewed and approved by the Ethics Committee for Research Involving Human Subjects, Universiti Putra Malaysia and the Research Ethics Committee, National University of Malaysia. This proposed COS in TD will improve the value of data, facilitate high-quality evidence synthesis and evidence-based decision-making. Furthermore, we will present the results to participants, in peer-reviewed academic journals and conferences.

    REGISTRATION DETAILS: Core Outcome Measures in Effectiveness Trials (COMET) Initiative database registration: http://www.comet-initiative.org/studies/details/1371.

    Matched MeSH terms: Research Design*
  5. Weaver C, Ahles S, Murphy KJ, Shyam S, Cade J, Plat J, et al.
    Adv Nutr, 2023 Nov 21.
    PMID: 37996044 DOI: 10.1016/j.advnut.2023.100154
    Creating effective dietary guidance requires a rigorous evidence base that is predominantly developed from robust clinical trials or large-scale cohort studies, with the quality of the data available depending on the completeness and accuracy of their reporting. An international group of academics from 14 institutions in 12 different countries and on 5 continents, working on behalf of the Federation of European Nutrition Societies within its "Improving Standards in the Science of Nutrition" initiative, reviewed the Consolidated Standards of Reporting Trials (CONSORT) statement checklist as it pertains to nutrition trials. This perspective piece documents the procedure followed to gain input and consensus on the checklist previously published by this group, including its presentation and interrogation at the International Union of Nutritional Sciences International Congress of Nutrition 2022 (IUNS-ICN 22), inputs from a survey of journal editors, and its piloting on 8 nutrition trials of diverse designs. Overall, the initiative has been met with considerable enthusiasm. At IUNS-ICN 22, refinements to our proposal were elicited through a World Café method discussion with participating nutrition scientists. The contributing journal editors provided valuable insights, and the discussion led to the development of a potential tool specific to assess adherence to the proposed nutrition extension checklist. The piloting of the proposed checklist provided evidence from real-life studies that reporting of nutrition trials can be improved. This initiative aims to stimulate further discussion and development of a CONSORT-nutrition-specific extension.
    Matched MeSH terms: Research Design*
  6. Spreafico A, Hansen AR, Abdul Razak AR, Bedard PL, Siu LL
    Cancer Discov, 2021 Apr;11(4):822-837.
    PMID: 33811119 DOI: 10.1158/2159-8290.CD-20-1301
    Clinical trials represent a fulcrum for oncology drug discovery and development to bring safe and effective medicines to patients in a timely manner. Clinical trials have shifted from traditional studies evaluating cytotoxic chemotherapy in largely histology-based populations to become adaptively designed and biomarker-driven evaluations of molecularly targeted agents and immune therapies in selected patient subsets. This review will discuss the scientific, methodological, practical, and patient-focused considerations to transform clinical trials. A call to action is proposed to establish the framework for next-generation clinical trials that strikes an optimal balance of operational efficiency, scientific impact, and value to patients. SIGNIFICANCE: The future of cancer clinical trials requires a framework that can efficiently transform scientific discoveries to clinical utility through applications of innovative technologies and dynamic design methodologies. Next-generation clinical trials will offer individualized strategies which ultimately contribute to globalized knowledge and collective learning, through the joint efforts of all key stakeholders including investigators and patients.
    Matched MeSH terms: Research Design/trends*
  7. Jackson T, Pinnock H, Liew SM, Horne E, Ehrlich E, Fulton O, et al.
    BMC Med, 2020 04 13;18(1):79.
    PMID: 32279658 DOI: 10.1186/s12916-020-01544-7
    BACKGROUND: Patient and public involvement (PPI) in research envisages a relationship built throughout the lifespan of a research project between academics, clinicians and PPI colleagues in order to inform, plan, execute and, in due course, disseminate and translate research. To be meaningful, all stakeholders need to actively engage in this exchange of expertise. However, despite some funders requiring PPI plans to be included in grant applications, there remains a gap between what is expected and what is delivered.

    MAIN BODY: As an exemplar, we reflect on how, in the Asthma UK Centre for Applied Research (AUKCAR), we set out to create a supportive, organised environment with the overarching value of 'keeping patients at the heart of everything we do'. The key has been in planning and creating a suitably funded organisational infrastructure with dedicated PPI researchers along with the development of and expectation to abide by an agreed set of norms and values. Specifically, expecting AUKCAR PhD students and early career researchers to engage with PPI has established a working mode that we hope will last. Regular interactions and proactive Patient Leads increase PPI network cohesion.

    CONCLUSION: With adaptation, the AUKCAR PPI model can be translated to international contexts.

    Matched MeSH terms: Research Design/standards*
  8. Ahmed A, Saeed F, Salim N, Abdo A
    J Cheminform, 2014;6:19.
    PMID: 24883114 DOI: 10.1186/1758-2946-6-19
    BACKGROUND: It is known that any individual similarity measure will not always give the best recall of active molecule structure for all types of activity classes. Recently, the effectiveness of ligand-based virtual screening approaches can be enhanced by using data fusion. Data fusion can be implemented using two different approaches: group fusion and similarity fusion. Similarity fusion involves searching using multiple similarity measures. The similarity scores, or ranking, for each similarity measure are combined to obtain the final ranking of the compounds in the database.

    RESULTS: The Condorcet fusion method was examined. This approach combines the outputs of similarity searches from eleven association and distance similarity coefficients, and then the winner measure for each class of molecules, based on Condorcet fusion, was chosen to be the best method of searching. The recall of retrieved active molecules at top 5% and significant test are used to evaluate our proposed method. The MDL drug data report (MDDR), maximum unbiased validation (MUV) and Directory of Useful Decoys (DUD) data sets were used for experiments and were represented by 2D fingerprints.

    CONCLUSIONS: Simulated virtual screening experiments with the standard two data sets show that the use of Condorcet fusion provides a very simple way of improving the ligand-based virtual screening, especially when the active molecules being sought have a lowest degree of structural heterogeneity. However, the effectiveness of the Condorcet fusion was increased slightly when structural sets of high diversity activities were being sought.

    Matched MeSH terms: Research Design
  9. Mustafa F, Hashim AM
    Sensors (Basel), 2014;14(2):3493-505.
    PMID: 24561400 DOI: 10.3390/s140203493
    We report the RF-to-DC characteristics of the integrated AlGaAs/GaAs Schottky diode and antenna under the direct injection and irradiation condition. The conversion efficiency up to 80% under direct injection of 1 GHz signal to the diode was achieved. It was found that the reduction of series resistance and parallel connection of diode and load tend to lead to the improvement of RF-to-DC conversion efficiency. Under direct irradiation from antenna-to-antenna method, the output voltage of 35 mV was still obtainable for the distance of 8 cm between both antennas in spite of large mismatch in the resonant frequency between the diode and the connected antenna. Higher output voltage in volt range is expected to be achievable for the well-matching condition. The proposed on-chip AlGaAs/GaAs HEMT Schottky diode and antenna seems to be a promising candidate to be used for application in proximity communication system as a wireless low power source as well as a highly sensitive RF detector.
    Matched MeSH terms: Research Design
  10. Said HM, Bakar WZ, Farea M, Husein A
    J Conserv Dent, 2012 Jul;15(3):257-60.
    PMID: 22876014 DOI: 10.4103/0972-0707.97952
    The aim of this in vitro study was to evaluate the sealing ability of an endodontic sealer following different techniques of its placement.
    Matched MeSH terms: Research Design
  11. Gan SM, Najmiah Radiah Mohamad, Nur Akmar Jamil, Burhanuddin Yeop Majlis, Susthitha Menon P
    Sains Malaysiana, 2018;47:2565-2571.
    In this paper, Taguchi experimental design technique was applied for optimization of chromium (Cr)/silver (Ag)/indium
    tin oxide (ITO) SPR sensor for operation in near infrared region. Four factors were considered which include wavelength,
    thickness of Cr, thickness of Ag, and thickness of ITO. Finite-difference-time-domain (FDTD) method was used in numerical
    analysis for minimum reflectance (Rmin) and full-width-at-half-maximum (FWHM) performance parameters. The results
    obtained from the Taguchi method shows that the optimized parameter for Rmin was 785 nm of wavelength, Cr (1 nm),
    Ag (40 nm) and ITO (20 nm), whereas the optimized parameter for FWHM was 785 of wavelength, Cr (0 nm), Ag (40 nm)
    and ITO (0 nm). In short, the optimum parameters for achieving the desired performance of sensor were successfully
    predicted using Taguchi optimization method.
    Matched MeSH terms: Research Design
  12. Ismail A, Idris MYI, Ayub MN, Por LY
    Sensors (Basel), 2018 Dec 10;18(12).
    PMID: 30544660 DOI: 10.3390/s18124353
    Smart manufacturing enables an efficient manufacturing process by optimizing production and product transaction. The optimization is performed through data analytics that requires reliable and informative data as input. Therefore, in this paper, an accurate data capture approach based on a vision sensor is proposed. Three image recognition methods are studied to determine the best vision-based classification technique, namely Bag of Words (BOW), Spatial Pyramid Matching (SPM) and Convolutional Neural Network (CNN). The vision-based classifiers categorize the apple as defective and non-defective that can be used for automatic inspection, sorting and further analytics. A total of 550 apple images are collected to test the classifiers. The images consist of 275 non-defective and 275 defective apples. The defective category includes various types of defect and severity. The vision-based classifiers are trained and evaluated according to the K-fold cross-validation. The performances of the classifiers from 2-fold, 3-fold, 4-fold, 5-fold and 10-fold are compared. From the evaluation, SPM with SVM classifier attained 98.15% classification accuracy for 10-fold and outperformed the others. In terms of computational time, CNN with SVM classifier is the fastest. However, minimal time difference is observed between the computational time of CNN and SPM, which were separated by only 0.05 s.
    Matched MeSH terms: Research Design
  13. Sadia F, Mahmud I, Dhar E, Jahan N, Hossain SS, Zaidi Satter AKM
    Data Brief, 2019 Apr;23:103741.
    PMID: 31372407 DOI: 10.1016/j.dib.2019.103741
    The article identifies the relationship among different agile software development approaches such as response extensiveness, response efficiency, team autonomy, team diversity, and software functionality that software teams face difficult challenges in associating and achieving the right balance between the two agility dimensions. This research strategy, in terms of quantity, is descriptive and correlational. Statistical analysis of the data was carried out, using SmartPLS 3.0. Statistical population, consist of employees of software industries in Bangladesh, who were engaged in 2017 and their total number is about 100 people. The data show that the response extensiveness, response efficiency, team autonomy, team diversity, and software functionality have impact on software development agility and software development performance.
    Matched MeSH terms: Research Design
  14. Ahmad P, Dummer PMH, Noorani TY, Asif JA
    Int Endod J, 2019 Jun;52(6):803-818.
    PMID: 30667524 DOI: 10.1111/iej.13083
    AIM: To analyse the main characteristics of the top 50 most-cited articles published in the International Endodontic Journal from 1967 to 2018.

    METHODOLOGY: The Clarivate Analytics' Web of Science 'All Databases', Elsevier's Scopus, Google Scholar and PubMed Central were searched to retrieve the 50 most-cited articles in the IEJ published from April 1967 to December 2018. The articles were analysed and information including number of citations, year of publication, contributing authors, institutions and countries, study design, study topic, impact factor and keywords was extracted.

    RESULTS: The number of citations of the 50 selected papers varied from 575 to 130 (Web of Science), 656 to164 (Elsevier's Scopus), 1354 to 199 (Google Scholar) and 123 to 3 (PubMed). The majority of papers were published in the year 2001 (n = 7). Amongst 102 authors, the greatest contribution was made by four contributors that included Gulabivala K (n = 4), Ng YL (n = 4), Pitt Ford TR (n = 4) and Wesselink PR (n = 4). The majority of papers originated from the United Kingdom (n = 8) with most contributions from King's College London Dental Institute (UK) and Eastman Dental Hospital, London. Reviews were the most common study design (n = 19) followed by Clinical Research (n = 16) and Basic Research (n = 15). The majority of topics covered by the most-cited articles were Outcome Studies (n = 9), Intracanal medicaments (n = 8), Endodontic microbiology (n = 7) and Canal instrumentation (n = 7). Amongst 76 unique keywords, Endodontics (n = 7), Mineral Trioxide Aggregate (MTA) (n = 7) and Root Canal Treatment (n = 7) were the most frequently used.

    CONCLUSION: This is the first study to identify and analyse the top 50 most-cited articles in a specific professional journal within Dentistry. The analysis has revealed information regarding the development of the IEJ over time as well as scientific progress in the field of Endodontology.

    Matched MeSH terms: Research Design
  15. Khairur Rijal Jamaludin, Nolia Harudin, Faizir Ramlie, Mohd Nabil Muhtazaruddin, Che Munira Che Razali, Wan Zuki Azman Wan Muhamad
    MATEMATIKA, 2020;36(1):69-84.
    MyJurnal
    Prediction analysis has drawn significant interest in numerous field. Taguchi’s T-Method is a prediction tool that developed practically but not limited to small sample analysis. It was developed explicitly for multidimensional system prediction by relying on historical data as the baseline model and adapting the signal to noise ratio (SNR) as well as zero proportional concepts in strengthening its robustness. Orthogonal array (OA) in T-Method is a variable selection optimization technique in improving the prediction accuracy as well as help in eliminating variables that may deteriorate the overall performance. However, the limitation of OA in dealing with higher multidimensionality restraint the optimization accuracy. Binary particle swarm optimization used in this study helps to cater to the limitation of OA as well as optimizing the variable selection process to better prediction accuracy. The results show that if the historical data consist of samples with higher correlation of determination (R2) value for the model creation, the optimization process in reducing the number of variables would be much reliable and accurate. Comparing between T-Method+OA and T-Method+BPSO in four different case study, it shows that T-Method+BPSO performing better with greater R2 and means relative error (MRE) value compared to T-Method+OA.
    Matched MeSH terms: Research Design
  16. JEFFREY, YEE KHONG LOONG
    MyJurnal
    The research interview is a common method of choice for collecting data, particularly within the qualitative research tradition. This is because it lends well to the emergent nature and exploratory aims of qualitative research. Detailed accounts of what and how things happened, and who was involved, that is elaborate stories, can be located in interview responses. This is irrespective of whether or not the stories were deliberately elicited or regardless of the methodological stance adopted by the researcher. The ubiquity of stories therein signals the need for researchers using qualitative interviews to be cognizant of the narratives surrounding these stories and the analytical value they hold in their research. This paper presents the philosophical underpinnings and strategy of narrative inquiry, and illustrates how methods of collection and analysis can be shaped in concert with the methodology
    Matched MeSH terms: Research Design
  17. Mohd Rivaie, Fuziyah Ishak, Nur Idalisa, Nurul Hafawati Fadhilah
    MATEMATIKA, 2020;36(3):197-207.
    MyJurnal
    Conjugate Gradient (CG) methods have an important role in solving large
    scale unconstrained optimization problems. Nowadays, the Three-Term CG method has
    become a research trend of the CG methods. However, the existing Three-Term CG
    methods could only be used with the inexact line search. When the exact line search
    is applied, this Three-Term CG method will be reduced to the standard CG method.
    Hence in this paper, a new Three-Term CG method that could be used with the exact
    line search is proposed. This new Three-Term CG method satisfies the descent condition
    using the exact line search. Performance profile based on numerical results show that
    this proposed method outperforms the well-known classical CG method and some related
    hybrid methods. In addition, the proposed method is also robust in term of number of
    iterations and CPU time.
    Matched MeSH terms: Research Design
  18. Da'u A, Salim N
    PeerJ Comput Sci, 2019;5:e191.
    PMID: 33816844 DOI: 10.7717/peerj-cs.191
    Aspect extraction is a subtask of sentiment analysis that deals with identifying opinion targets in an opinionated text. Existing approaches to aspect extraction typically rely on using handcrafted features, linear and integrated network architectures. Although these methods can achieve good performances, they are time-consuming and often very complicated. In real-life systems, a simple model with competitive results is generally more effective and preferable over complicated models. In this paper, we present a multichannel convolutional neural network for aspect extraction. The model consists of a deep convolutional neural network with two input channels: a word embedding channel which aims to encode semantic information of the words and a part of speech (POS) tag embedding channel to facilitate the sequential tagging process. To get the vector representation of words, we initialized the word embedding channel and the POS channel using pretrained word2vec and one-hot-vector of POS tags, respectively. Both the word embedding and the POS embedding vectors were fed into the convolutional layer and concatenated to a one-dimensional vector, which is finally pooled and processed using a Softmax function for sequence labeling. We finally conducted a series of experiments using four different datasets. The results indicated better performance compared to the baseline models.
    Matched MeSH terms: Research Design
  19. Rahman MA, Muniyandi RC, Albashish D, Rahman MM, Usman OL
    PeerJ Comput Sci, 2021;7:e344.
    PMID: 33816995 DOI: 10.7717/peerj-cs.344
    Artificial neural networks (ANN) perform well in real-world classification problems. In this paper, a robust classification model using ANN was constructed to enhance the accuracy of breast cancer classification. The Taguchi method was used to determine the suitable number of neurons in a single hidden layer of the ANN. The selection of a suitable number of neurons helps to solve the overfitting problem by affecting the classification performance of an ANN. With this, a robust classification model was then built for breast cancer classification. Based on the Taguchi method results, the suitable number of neurons selected for the hidden layer in this study is 15, which was used for the training of the proposed ANN model. The developed model was benchmarked upon the Wisconsin Diagnostic Breast Cancer Dataset, popularly known as the UCI dataset. Finally, the proposed model was compared with seven other existing classification models, and it was confirmed that the model in this study had the best accuracy at breast cancer classification, at 98.8%. This confirmed that the proposed model significantly improved performance.
    Matched MeSH terms: Research Design
  20. Tarusan SAA, Jidin A, Jamil MLM
    ISA Trans, 2021 Apr 16.
    PMID: 33931170 DOI: 10.1016/j.isatra.2021.04.005
    Direct Torque Control (DTC) scheme introduces a robust and simple control of electrical drive. However, its shortcomings such as broad torque ripple and variable switching frequency have offered several improvements like Space Vector Modulation (SVM) strategy, multilevel inverter (MLI) topology, etc. The conventional DTC which is fed by the two-level inverter has limited voltage vector, results in some difficulties to optimize the operation, especially at low operating speed. In contrast to MLI, the abundant of voltage vector has provided various amplitudes and angles that can overcome the problem of conventional DTC. Thus, this paper introduces the selected optimal voltage vector obtained from five-level Cascaded H-Bridge (CHB) inverter that employs in DTC hysteresis-based to achieve better optimization that similar to the DTC-SVM. Initially, the research work begins with an investigation on the performance comparison between a DTC hysteresis-based between two-level inverter (conventional method) and a five-level CHB inverter (proposed method). Here, a DC generator acted as a load is employed to control the operating speed instead of the speed controller (speed controller is negligible). Hence, the DTC method is optimized by minimizing the torque ripple as well as retaining the torque control capability at constant torque region on several operating speed. The selected optimal vector from the look-up table DTC of five-level CHB inverter must be dynamically appropriate to any change of torque (increased or decreased torque). For simplicity, this paper will only discuss the experimental results for both topologies of drive system. From the experimental results, it is verified that the torque ripples by the proposed method have achieved 10% and 50% reduction at high and low operating speed respectively. It is found that the DTC hysteresis-based result simpler control method than DTC-SVM while maintaining similar output performance.
    Matched MeSH terms: Research Design
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