Minimization Technique Research Articles

Thermoelectric properties of TaVO5 and GdTaO4: An experimental verification of machine learning prediction

Advancements in materials discovery tend to rely disproportionately on happenstance and luck rather than employing a systematic approach. Recently, advances in computational power have allowed researchers to build computer models to predict the material properties of any chemical formula. From energy minimization techniques to machine learning-based models, these algorithms have unique strengths and weaknesses. However, a computational model is only as good as its accuracy when compared to real-world measurements. In this work, we take two recommendations from a thermoelectric machine learning model, TaVO5 and GdTaO4, and measure their thermoelectric properties of Seebeck coefficient, thermal conductivity, and electrical conductivity. We see that the predictions are mixed; thermal conductivities are correctly predicted, while electrical conductivities and Seebeck coefficients are not. Furthermore, we explore TaVO5’s unusually low thermal conductivity of 1.2 Wm−1K−1, and we discover a possible new avenue of research of a low thermal conductivity oxide family.

Evaluation of Carisolv in the Chemico-Mechanical Removal of Carious Dentine in Primary Molars (In vivo study)

Caries removal by the Chemo-mechanical technique involves the application of chemical agents, to cause a selective softening of the carious dentine and facilitate removal by gentle excavation. Carisolv is one such new chemical agent used in this minimal invasive technique of carious dentine removal. The aims of this study was to evaluate the efficacy of Carisolv in the chemo-mechanical removal of carious dentine in primary teeth, the time taken for caries removal and to evaluate the restorations radiographically. Forty primary 1st and 2nd molars with dentinal carious lesions were excavated using this technique of caries removal. After isolation of the involved tooth, the Carisolv " new gel" marketed by Mediteam Dental AB (Goteborg, Sweden) was applied then the superficial softened carious dentine was gently excavated and scraped using a spoon excavator, the procedure repeated until the cavity was free from caries and the cavity was checked for remaining caries using an explorer. The time taken for the removal of carious dentine, beginning from the application of the gel until the completion of the procedure was evaluated using a stopwatch. After the placement of the restoration an intra-oral periapical radiograph was taken for immediate evaluation and after a period of six months, the longevity of the restorations and the presence of secondary caries at the restoration- dentine interface were evaluated radiographically. The statistical analysis of the results showed that the soft carious dentine was removed more effectively than the hard carious dentine and the removal of the soft carious dentine required a shorter period of time (4.96±0.99) minutes when compared to the removal of hard carious dentine (6.09±1.04) minutes and on radiographic evaluation of the restoration, none of the treated lesions showed the presence of secondary caries. In conclusion, the chemico-mechanical caries removal technique using Carisolv proved to be an effective atraumatic treatment modality with potential interest for use in clinical pediatric dentistry.

Non-Invasive Plant Root Tomography Through Optimized Sonar Array Transducer Antenna Design Using Genetic Swarm Metaheuristic

Plant root imaging is crucial for progress in various domains such as plant breeding and crop optimization. Traditionally, root tomography involves invasive methods that disrupt plant systems and yield non-reproducible results. As a result, non-invasive techniques, particularly electrical tomography, have gained significant attention. Despite the advantages, these techniques have limitations in terms of radiation efficiency and directivity due to suboptimal antenna design. This paper presents a comprehensive simulation on antenna design optimization focusing on dimensions, spacing, and integration of advanced algorithms. A micropatch transducer antenna was engineered for an existing in-silico plant root setup operating within a 3–5 MHz frequency range. The optimized dimensions of the antenna are 109.32 mm × 140.67 mm × 2.55 mm, and it resonates effectively within a frequency range of 3.1–5.68 MHz. Using scalar minimization techniques, patch transducers were interconnected into an antenna array with an optimized 3 mm spacing. Utilizing multi-objective optimization algorithm based on sperm fertilization procedure and shuffled frog leaping algorithm, optimal frequencies were obtained at 3,989,796.88 Hz and 3,989,951.83 Hz, respectively. Validated using CADFEKO software, the proposed antenna design demonstrated distinctive voltage distribution, superior directivity of 9.24 dBi, gain of 9.15 dBi, and 98.6% radiation efficiency when compared to the existing silicon-based root tomography antenna setups.

Symptomatic Preperitoneal Lipoma Resected via Preperitoneal Approach: A Case Report and Review of the Literature

Introduction: Lipomas are benign adipose tissue tumors that can vary in size and location. Magnetic resonance images should be obtained for all soft-tissue masses that are deep to fascia or those >5 cm in subcutaneous tissue. In this case report, we present a minimal invasive technique to resect a large preperitoneal lipoma. Case Presentation: A 36-year-old woman presenting with left fossa pain caused by a large mass. MRI-imaging shows a large preperitoneal lipomatous lesion (61 × 58 × 40 mm) which compresses the bladder, tuba and surrounding vessels. We did a minimally invasive preperitoneal laparoscopic surgical resection. Postoperative follow-up was uneventful. The pathology report confirmed benign lipoma without signs of malignancy. Discussion: Preperitoneal lipomas should be considered in the diagnosis of lower abdominal pain and can be minimally invasive resected via preperitoneal laparoscopic approach in day clinic.

Particle swarm optimization technique for speed control and torque ripple minimization of switched reluctance motor using PID and FOPID controllers

Particle swarm optimization technique for speed control and torque ripple minimization of switched reluctance motor using PID and FOPID controllers

Planning Speed Mode of All-Wheel Drive Autonomous Vehicles Considering Complete Constraint Set

The study aims to improve the technique of motion planning for all-wheel drive (AWD) autonomous vehicles (AVs) by including torque vectoring (TV) models and extended physical constraints. Four schemes for realizing the TV drive were considered: with braking internal wheels, using a rear-axle sport differential (SD), with braking front internal wheel and rear-axle SD, and with SDs on both axles. The mathematical model combines 2.5D vehicle dynamics model and a simplified drivetrain model with the self-locking central differential. The inverse approach implies optimizing the distribution of kinematic parameters by imposing a set of constraints. The optimization procedure uses the sequential quadratic programming (SQP) technique for the nonlinear constrained minimization. The Gaussian N-point quadrature scheme provides numerical integration. The distribution of control parameters (torque, braking moments, SDs’ friction moment) is performed by evaluating linear and nonlinear algebraic equations inside of optimization. The technique proposed demonstrates an essential difference between forecasts built with a pure kinematic model and those considering the vehicle’s drive/control features. Therefore, this approach contributes to the predictive accuracy and widening model properties by increasing the number of references, including for actuators and mechanisms.

Lineaments Characterization and their Tectonic Significance in Mineralization using Landsat TM Data and Field Studies along Mambilla Plateau, Northeast, Nigeria

Lineament characterization and their tectonic significance in mineralization using Landsat TM data and field studies Along the Mambilla Plateau and environs, northeast Nigeria .The area forms part of the mineralized shear zone of the Northeastern, part of the Basement Complex. The Basement Complex rocks underlie more than two-thirds of the plateau and date back to the Precambrian to early Paleozoic eras. While the remaining part of the plateau and its surroundings are made up of volcanic rocks of the upper Cenozoic to Tertiary and Quaternary ages. Remote sensing imagery data and field measurements were integrated for mapping the structural elements and hydrothermal alteration zones related to mineralization. Tectonically the lineaments trends NE-SW, NNW-SSE, NW-SE, and NS, are the main trends controlling mineralization in the area based on data from remote sensing and field measurements. On the other hand, applying band ratios and the constrained energy minimization (CEM) technique to Landsat-8 data pointed out alteration minerals associated with the hydrothermal fluids. Silica, sericite, and chlorite are the common alteration minerals detected, while goethite and epidote are less common in the alteration zones of the area under study. A combination of CET structural complexity, circular features, and alteration zones produced a potential mineralization map, pointing out numerous prospective zones for mineralization that are proximate to areas where artisanal mining activities are carried out. The predictive map was validated by projecting the known prospect zones in the study area, reflecting an agreement between the known occurrences and the higher classes of the predictive zone. The techniques in the current research can be adopted as a direct indicator for structural mapping and detecting alteration zones related to mineralization elsewhere.

TUBER: Time-aware UAV-based energy-efficient reconfigurable routing scheme for smart wireless livestock sensor network.

This paper is a follow-up to a recent work by the authors on recoverable UAV-based energy-efficient reconfigurable routing (RUBER) scheme for addressing sensor node and route failure issues in smart wireless livestock sensor networks. Time complexity and processing cost issues connected to the RUBER scheme are consequently treated in this article by proffering a time-aware UAV-based energy-efficient reconfigurable routing (TUBER) scheme. TUBER scheme employs a synchronized clustering-with-backup strategy, a minimum-hop neighborhood recovery mechanism, and a redundancy minimization technique. Comparative network performance of TUBER was investigated and evaluated with respect to RUBER and UAV-based energy-efficient reconfigurable routing (UBER) schemes. The metrics adopted for this comparative performance analysis are Cluster Survival Ratio (CSR), Network Stability (NST), Energy Dissipation Ratio (EDR), Network Coverage (COV), Packet Delivery Ratio (PDR), Fault Tolerance Index (FTI), Load Balancing Ratio (LBR), Routing Overhead (ROH), Average Routing Delay (ARD), Failure Detection Ratio (FDR), and Failure Recovery Ratio (FRR). With reference to best-obtained values, TUBER demonstrated improvements of 36.25%, 24.81%, 34.53%, 15.65%, 38.32%, 61.07%, 31.66%, 63.20%, 68.96%, 66.19%, and 78.63% over RUBER and UBER in terms of CSR, NST, EDR, COV, PDR, FTI, LBR, ROH, ARD, FDR, and FRR, respectively. These experimental results confirmed the relative effectiveness of TUBER against the compared routing schemes.

Effects on cardiorespiratory fitness of moderate-intensity training vs. energy-matched training with increasing intensity.

The present study investigated the role of training intensity in the dose-response relationship between endurance training and cardiorespiratory fitness (CRF). The hypothesis was that beginners would benefit from an increase in training intensity after an initial training phase, even if the energy expenditure was not altered. For this purpose, 26 weeks of continuous moderate training (control group, CON) was compared to training with gradually increasing intensity (intervention group, INC) but constant energy expenditure. Thirty-one healthy, untrained subjects (13 men, 18 women; 46 ± 8 years; body mass index 25.4 ± 3.3 kg m-2; maximum oxygen uptake, VO2max 34 ± 4 ml min-1 kg-1) trained for 10 weeks with moderate intensity [3 days/week for 50 min/session at 55% heart rate reserve (HRreserve)] before allocation to one of two groups. A minimization technique was used to ensure homogeneous groups. While group CON continued with moderate intensity for 16 weeks, the INC group trained at 70% HRreserve for 8 weeks and thereafter participated in a 4 × 4 training program (high-intensity interval training, HIIT) for 8 weeks. Constant energy expenditure was ensured by indirect calorimetry and corresponding adjustment of the training volume. Treadmill tests were performed at baseline and after 10, 18, and 26 weeks. The INC group showed improved VO2max (3.4 ± 2.7 ml kg-1 min-1) to a significantly greater degree than the CON group (0.4 ± 2.9 ml kg-1 min-1) (P = 0.020). In addition, the INC group exhibited improved Vmax (1.7 ± 0.7 km h-1) to a significantly greater degree than the CON group (1.0 ± 0.5 km h-1) (P = 0.001). The reduction of resting HR was significantly larger in the INC group (7 ± 4 bpm) than in the CON group (2 ± 6 bpm) (P = 0.001). The mean heart rate in the submaximal exercise test was reduced significantly in the CON group (5 ± 6 bpm; P = 0.007) and in the INC group (8 ± 7 bpm; P = 0.001), without a significant interaction between group and time point. Increasing intensity leads to greater adaptations in CRF than continuing with moderate intensity, even without increased energy expenditure. After 26 weeks of training in the moderate- and higher-intensity domain, energy-matched HIIT elicited further adaptations in cardiorespiratory fitness. Thus, training intensity plays a crucial role in the dose-response relationship between endurance training and fitness in untrained but healthy individuals. https://www.drks.de/DRKS00031445, identifier DRKS00031445.

Can Different Impression Techniques Affect the Chewing Efficiency of Mandibular Implant-Retained Overdentures?

Several impression techniques and theories have been developed for implant-retained overdentures, each with its own set of advantages and limitations. This study aimed to assess the chewing efficiency of mandibular implant-retained overdentures fabricated using three distinct impression techniques (mucofunctional, selective, and minimal pressure impression techniques). Twenty-six patients with complete edentulism free from any oral or systemic disease were selected to participate in the study. Three complete mandibular implant-retained overdentures were constructed for each patient, and grouped into three groups according to the impression technique employed in overdenture construction; Group A: Patients were treated by mandibular implant-retained overdenture fabricated using mucofunctional impression technique; Group B: Patients were treated by mandibular implant-retained overdenture fabricated using selective pressure impression technique; Group C: Patients were treated by mandibular implant-retained overdenture fabricated using minimal pressure impression technique. Chewing efficiency was evaluated for each patient with the implant-retained mandibular overdenture after three months of prosthesis insertion as an adaptation period. The data were collected, tabulated, and statistically analyzed. Results indicated that mandibular implant-retained overdentures made using the mucofunctional impression technique showed higher mean values of chewing efficiency parameters than mandibular overdentures made using selective and minimal pressure impression techniques. Within the limitations of this study, it can be concluded that the mucofunctional impression technique may be effective in improving the chewing efficiency of mandibular implant-retained overdentures more than minimal or selective pressure impression techniques.

A Review of the State of the Art of Torque Ripple Minimization Techniques for Permanent Magnet Synchronous Motors

Industrial applications such as automation, robots, and electric vehicles are widely employing permanent magnet synchronous motors (PMSM) due to inherent characteristics such as high torque to power ratio, low maintenance, high efficiency, and wide operating range. However, PMSM drives can suffer from unwanted torque ripples caused by periodic disturbances of the electromagnetic effect. First, this paper analyses the sources of torque ripple in PMSMs. Second, the torque measurement techniques of the PMSM including torque sensors, torque observers, and indirect measurement methods are discussed to highlight their shortcomings. Third, this paper categorizes and summarizes advanced control-based torque ripple minimization (CB-TRM) techniques for the PMSM by critically evaluating their impacts. These CB-TRM techniques actively control the current waveforms to ensure smooth torque generation and mitigate the effects of torque ripples. Finally, the paper concludes by discussing remaining research questions and opportunities for future research on TRM techniques for PMSMs.

Increasing Client Fraud Risk Disclosure with Minimization Techniques

SYNOPSIS Auditing standards require auditors to conduct fraud inquiries as part of their risk assessment process. During fraud inquiries, auditors frequently ask client personnel directly about “fraud, alleged fraud, or suspected fraud,” using standard language taken from AS 2110. However, guidance from the Center for Audit Quality (CAQ) suggests that avoiding the word “fraud” results in greater disclosure regarding fraud risk. Although untested, the CAQ’s conjecture is supported by literature in psychology and criminology, which suggests that minimizing the seriousness of the offense (i.e., minimization) increases disclosure. This study examines two minimization strategies. The first involves replacing the word “fraud” with “questionable behavior.” The second employs social comparison to increase the perceived frequency that clients report misconduct to auditors. Experimental results suggest that either strategy increases client reporting intentions relative to a control condition using the language prescribed by AS 2110. Our findings may help auditors conduct more effective fraud inquiries. Data Availability: Data are available from the authors. JEL Classifications: M42; M48.

A comprehensive review on wind power spillage: Reasons, minimization techniques, real applications, challenges, and future trends

A comprehensive review on wind power spillage: Reasons, minimization techniques, real applications, challenges, and future trends

ENERGY EFFICIENCY IMPROVEMENT AND ENTROPY GENERATION MINIMIZATION THROUGH STRUCTURAL OPTIMIZATION OF A DOUBLE-LAYER LIQUID-COOLED PLATE WITH CIRCULAR ARC-SHAPED FLOW CHANNELS

Power batteries for new energy vehicles and other high-power electrical devices benefit greatly from liquid-cooled plates for thermal control. In the present work, a liquid-cooled plate with a double-layer arc-channel structure is developed to achieve a uniform temperature distribution on the surface of lithium-ion powered batteries and to reduce operating temperatures. Numerical simulations are employed to examine the flow properties and heat transfer capabilities of the plate. Subsequently, the model is validated experimentally. The structure of the liquid-cooled plate is optimized using a genetic algorithm. In the research, two methods for optimizing the structure of liquid-cooled plates have been proposed based on defining the fitness function of genetic algorithms. The first method uses a dimensionless number to represent the amount of pump power needed to allow the working fluid to absorb one joule of heat energy. The other method uses the entropy generation of the liquid-cooled plate as the fitness function of genetic algorithms. Genetic algorithms may be used to find the minimum dimensionless number and the minimal amount of entropy. The structural characteristics of the liquid-cooled plate may be obtained with the best energy efficiency and the least amount of entropy production using the dimensionless number minimization (DNM) and entropy generation (EGM) optimization techniques, respectively. The performance of the two optimization techniques is contrasted. The maximum temperature of the plate is reduced by 2.58 K and 0.14 K, and the standard deviation of the temperature is reduced by 0.685 K and 0.408 K after the optimization using the creatively established dimensionless number and the entropy generation minimization methods, respectively. The pump work required by the working fluid to absorb one joule of heat energy from the plate is reduced by 70.5% and 12.1%. At two distinct boundary conditions, the proposed liquid-cooled plate outperforms the plates with serpentine and parallel channels in terms of cooling performance or energy efficiency.

Evaluation of new nano-cutting fluids for the processing of carbon fiber-reinforced composite materials

Carbon fiber-reinforced composites (CFRP), known for its impressive specific strength and modulus, finds extensive applications in defense, aerospace, automotive, and various other industries. Nevertheless, the widespread application of dry cutting in machining Carbon Fiber Reinforced Polymer (CFRP) presents significant challenges, including dust pollution, fiber layer delamination, and uneven surface quality. These issues make the machining of CFRP a formidable task. In the present investigation, a novel nanohybrid cutting fluid was successfully prepared by adding molybdenum disulfide (MoS2)/silicon carbide (SiC) nanoparticles to a base-cutting fluid synthesize from ethanol, polyethylene glycol, and sodium dodecyl sulfate. Moreover, employing minimal lubrication techniques, the nano-cutting fluid was applied to the milling process of CFRP. The feasibility of applying the cutting fluid to CFRP machining was demonstrated through short beam shear tests. Horizontal comparative milling tests were executed on CFRP, varying operational parameters and cooling-lubrication scenarios. The cooling-lubrication mechanisms of the nanofluid were analyzed, providing further validation of the effectiveness of the cutting fluid in CFRP machining. The results suggest that the nanofluid has a negligible impact on the interlaminar shear strength of CFRP, with only a 3.85% reduction. In comparison to other cooling-lubrication conditions, milling CFRP with the novel nanofluid resulted in a reduction of milling forces by 4.78%–24.84%, a decrease in milling temperatures by 15.38%–69.37%, a lowering of surface roughness by 10.78%–35.93%, and a reduction in tool tip wear by 6.25%–53.81%. Observable phenomena such as fiber pull-out and fracture were significantly reduced.

Resonant ultrasound spectroscopy applications: Elastic moduli computation with x-ray computed tomography input for irregularly shaped objects.

Resonant ultrasound spectroscopy is a technique that uses a combination of experimentally measured resonant frequencies and physics-based computation of these frequencies to determine the entire set of single crystal elastic moduli of the material. Computation of the resonances is most often accomplished using the Rayleigh-Ritz energy minimization technique, and a basis function that requires sample with canonical geometry, such as a cylinder or a rectangular parallelepiped. Any deviation from canonical geometry can have a significant impact on the calculated resonance frequencies and the inverted elastic moduli. To overcome this limitation, this paper describes an approach that uses x-ray computed tomography data to generate accurate solid part model of components with complex geometry. The part model is then imported into an off-the-shelf finite element method (FEM) software to perform the forward problem. The FEM was combined with surrogate modeling for computation of resonance frequencies of both canonical and non-canonical samples, and ultimately, the inversion of elastic moduli.

One‐Dimensional Variational Ionospheric Retrieval Using Radio Occultation Bending Angles: 1. Theory

AbstractA new one‐dimensional variational (1D‐Var) retrieval method for ionospheric GNSS radio occultation (GNSS‐RO) measurements is described. The forward model implicit in the retrieval calculates the bending angles produced by a one‐dimensional ionospheric electron density profile, modeled with multiple “Vary‐Chap” layers. It is demonstrated that gradient based minimization techniques can be applied to this retrieval problem. The use of ionospheric bending angles is discussed. This approach circumvents the need for Differential Code Bias (DCB) estimates when using the measurements. This new, general retrieval method is applicable to both standard GNSS‐RO retrieval problems, and the truncated geometry of EUMETSAT's Metop Second Generation (Metop‐SG), which will provide GNSS‐RO measurements up to about 600 km above the surface. The climatological a priori information used in the 1D‐Var is effectively a starting point for the 1D‐Var minimization, rather than a strong constraint on the final solution. In this paper the approach has been tested with 143 COSMIC‐1 measurements. We find that the method converges in 135 of the cases, but around 25 of those have high “cost at convergence” values. In the companion paper (Elvidge et al., 2023), a full statistical analysis of the method, using over 10,000 COSMIC‐2 measurements, has been made.

Impact of Different Methods of Wheat Cultivation on the Occurrence of Carabidae Family Representatives (Carabidae, Coleoptera)

The aim of this study was to evaluate the impact of different methods of wheat cultivation on the occurrence of Carabidae (Coleoptera, Carabidae). The collection was carried out during a three-year period from 2016 to 2018, on research areas in Borovce, which belong to the Research Institute of Plant Production (VÚRV) in Piešťany. The collection of epigeic material was done in five variants: V1: mulching technique; V2: conventional technique; V3: minimization technique; V4: no-till technique; and ECO: ecological technique. During the three-year period, we obtained 11,362 specimens from eight epigeic groups. Out of all the epigeic groups, the dominant order was Coleoptera with the number of individuals 7593. We addressed the Coleoptera order in more detail. It was represented by six families, of which the Carabidae family was dominant. We recorded 6656 specimens from the mentioned family, of which we determined 20 species. The eudominant species were Pterostichus melanarius (Illiger, 1798) and Pseudoophonus rufipes (DeGeer, 1774) throughout the whole period on all types of variants. Based on the specimens obtained, we calculated the values of dominance, frequency, species similarity of communities, diversity of communities and statistically evaluated the correlation of the impact of meteorological factors and the occurrence of Carabidae.

Sun-Cross Running Suture Combined with Transverse to Longitudinal Skin Closure to Correct Severe Inverted Nipple.

Inverted nipple deformity presents an unsatisfactory appearance that may induce an unpleasant sex life, but can also be associated with psychological discomfort and increased the functional problems, such as local irritation and inflammation. Multiple techniques have been used to correct inverted nipples, but they mostly lead to different problems such as deficiency of the nerve or duct, recurrence of the inverted nipple, and hypopigmented scars in the areola. To minimize complications and maintain the stability of the reconstructed nipple, we presented a minimal incision technique that designed four 3-mm-sized horizontal microincisions, which ran a sun-cross through the periphery and the core of the nipple to push the nipple together, then a vertical suture ran longitudinal to close the transverse incision to stabilize the projection. This technique was performed in 71 patients classified as grade II or III of the inverted nipples, comprising 53 congenital cases and 18 patients with acquired deformity. Thirty-four patients had bilateral inverted nipples, and 37 patients had unilateral inverted nipple. During a mean follow-up period of 15months, 70 corrected nipples remained raised without recurrence, and one nipple was found retracted at the outpatient clinic after 3months. There were no serious complications associated with surgery regarding nipple necrosis, seven patients got temporary swelling, two patients got infected after touching water, three patients got extravasated blood, eight patients indicated that they touched scar under the nipple, and two patients reflected nipple dysesthesia. In the 15months follow-up, the patients with Grade II nipple inversion maintained a nipple average height of 9.54 ± 0.95, and the patients with Grade III nipple inversion maintained a nipple average height of 9.19 ± 1.09, and 86.63% of patients were satisfied with their results. This is a simple, safe, effective and reliable technique that should be considered, providing sustained results over the long-term follow-up period with a high rate of stable eversion and low incidence of ischemia, necrosis, scarring and dysesthesia. The vertical scar of the transverse incision closure leads to an esthetic appearance without apparent scarring and minimizes the risk of an altered nipple sensation. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Radiofrequency electromagnetic radiation exposure assessment, analysis, computation, and minimization technique in 5G networks: A perspective on QoS trade-offs

Radiofrequency electromagnetic radiation exposure assessment, analysis, computation, and minimization technique in 5G networks: A perspective on QoS trade-offs