Rotation Technique Research Articles

RCS Diagnostic Imaging Using Parameter Extraction Technique of State Space Method

AbstractThe signature extraction and processing are the key aspects of enhancing recognition ability for radar target characteristics. In this paper, to reveal the intrinsic property of the target and improve the accuracy of radar cross section (RCS), we proposed RCS diagnostic imaging technique, extracting the parameters of scattering center model by state space method (SSM), to analyze the signature of GTD‐based returns. To demonstrate the effectiveness of SSM, the comparison with estimating signal parameter via rotational invariance techniques method by the analysis of goodness‐of‐fit and root mean square error, reconstructing the RCS profile through original signal model, and employing SSM to extract the signature of specular and creeping wave from the PEC sphere. Furthermore, the RCS diagnostic imaging by SSM extracting position and amplitude is discussed, and range‐isolated pole technique specific to the creeping wave extraction is addressed the advantage of SSM.

Inovasi Pelapisan Glasir Pada Gerabah Di Industri Kecil Dan Menengah

Melikan Village, Wedi District, Klaten Regency is an area that is 90% working as traditional pottery craftsmen with one of the rare ceramic-making techniques in the world, namely the tilt rotation technique. This technique turned out to be a feature that distinguished it from the art of printing pottery and ceramics from other regions with a plain brown, blackish color being its hallmark. The products of this craft have been exported to Switzerland and other countries. The purpose of this community service activity includes improving creative skills and innovating in making pottery and glaze crafts. The method applied in this community service activity is through lectures (counseling), mentoring, and the practice of making pottery with glaze. The existence of this community service activity is able to encourage craftsmen to produce pottery that has been coated with glaze so that it can improve the quality of pottery/ceramics so that it is more marketable in the modern market as it is today.

Effect of different straw retention techniques on soil microbial community structure in wheat-maize rotation system.

Rotational straw return technique is considered an effective measure for improving soil quality and maintaining soil microorganisms. However, there are few reports on the influence of wheat-maize crop rotation and straw-returning tillage on crop soil microbial communities in China. This study aimed to investigate how wheat or maize straw-incorporation practices affect bacterial and fungal communities under wheat-maize rotational farming practices. To clarify the effects of straw incorporation on microbial composition, microbial communities from soils subjected to different treatments were identified using high-throughput sequencing. Our results showed that, before corn planting, wheat and maize straw returning reduced bacterial density and increased their diversity but had no effect on fungal diversity. However, before wheat planting, returning wheat and corn stalks to the field increased the diversity of soil bacteria and fungi, whereas returning corn stalks to the field reduced the diversity of fungi and other microorganisms. Straw return significantly increased the relative abundance of Ascomycota in the first season and decreased it in the second season; however, in the second season, wheat straw return increased the relative abundance of Bradyrhizobium, which can promote the soil microbial nitrogen cycle and provide nitrogen to the soil. Wheat and maize straw return increased the relative abundance of Chaetomium, whereas, individually, they decreased the relative abundance. In addition, we detected two fungal pathogens (Fusarium and Trichoderma) under the two planting patterns and found that the relative abundance of pathogenic Fusarium increased with wheat straw return (FW and SW). Trichoderma increased after treatment with maize straw return before wheat planting (S group). These results suggest that wheat straw return (FW and SW) and maize straw return might have a negative impact on the pathogenic risk. Therefore, further studies are needed to determine how to manage straw returns in agricultural production.

Accelerating L1-penalized expectation maximization algorithm for latent variable selection in multidimensional two-parameter logistic models.

One of the main concerns in multidimensional item response theory (MIRT) is to detect the relationship between observed items and latent traits, which is typically addressed by the exploratory analysis and factor rotation techniques. Recently, an EM-based L1-penalized log-likelihood method (EML1) is proposed as a vital alternative to factor rotation. Based on the observed test response data, EML1 can yield a sparse and interpretable estimate of the loading matrix. However, EML1 suffers from high computational burden. In this paper, we consider the coordinate descent algorithm to optimize a new weighted log-likelihood, and consequently propose an improved EML1 (IEML1) which is more than 30 times faster than EML1. The performance of IEML1 is evaluated through simulation studies and an application on a real data set related to the Eysenck Personality Questionnaire is used to demonstrate our methodologies.

Frequency-diverse MIMO metasurface antenna for computational imaging with aperture rotation technique

Metasurface antennas have been proposed for computational imaging (CI) systems, which can reconstruct images without using mechanical scanning or large antenna arrays. In a CI system based on metasurface antennas, a variety of different radiation fields, which can be applied to sample the objects, are generated by exciting different frequency points in broadband. According to the compressed sensing theory, the imaging performance of the system is mainly limited by frequency-diversity radiation modes. In general, it is difficult to achieve rich radiation modes; therefore, a special design of metasurface aperture is required. In this paper, we propose a frequency-diversity MIMO metasurface antenna that consists of 2 × 2 sub-apertures with randomly distributed surface impedance. By employing the aperture rotation technique (ART) which rotates the MIMO metasurface antenna around the panel axis, the pseudo-randomness of the radiation fields is utilized. The diversity of the radiation field is improved on the premise of ensuring the relatively low complexity of the system. The ART significantly improves the measurement richness at the cost of increasing the measurement time. The performance of the proposed method is evaluated through simulations and experiments, suggesting that the proposed 2 × 2 MIMO metasurface antenna and the ART are effective to reconstruct high-quality images.

Noncontact Manipulation of Intracellular Structure Based on Focused Surface Acoustic Waves

Cell orientation is essential in many applications in biology, medicine, and chemistry, such as cellular injection, intracellular biopsy, and genetic screening. However, the manual cell orientation technique is a trial-and-error approach, which suffers from low efficiency and low accuracy. Although several techniques have improved these issues to a certain extent, they still face problems deforming or disrupting cell membranes, physical damage to the intracellular structure, and limited particle size. This study proposes a noncontact and noninvasive cell orientation method that rotates a cell using surface acoustic waves (SAWs). To realize the acoustic cell orientation process, we have fabricated a microdevice consisting of two pairs of focused interdigital transducers (FIDTs). Instead of rotating the entire cell, the proposed method rotates the intracellular structure, the cytoplasm, directly through the cell membrane by acoustic force. We have tested the rotational manipulation process on 30 zebrafish embryos. The system was able to orientate a cell to a target orientation with a one-time success rate of 93%. Furthermore, the postoperation survival rate was 100%. Our acoustic rotational manipulation technique is noninvasive and easy to use, which provides a starting point for cell-manipulation-essential tasks, such as single-cell analysis, organism studies, and drug discovery.

Standard Technique versus Rotational Technique of Insertion of Baska Mask®

Background and Aims: Baska Mask® is a new third-generation supraglottic airway device (SGAD). The placement of Baska Mask® using the standard technique causes posterior displacement of the tongue, leading to incorrect positioning and insertion failure. The rotation technique may alleviate this obstacle during insertion by decreasing resistance between the airway and tongue. The primary objective of this study was to compare the insertion time between the standard versus rotational technique of Baska Mask®, and the secondary outcome measures were ease of insertion, number of attempts and postoperative airway morbidity with both techniques. Methods: One hundred consenting adults of the American Society of Anaesthesiologists I-II, aged 20–65 years of either gender scheduled for a variety of surgical procedures under general anaesthesia in a tertiary care hospital (May 2019 to November 2020), were included in the study. The patients were randomly allocated to Group S and Group R using the standard and rotation techniques, respectively. All statistical analyses were done using the SPSS (Statistical Package for the Social Sciences) software. The comparison of quantitative variables between the study groups was done using the Student's t-test and Mann–Whitney test. For comparing categorical data, the Chi-square χ 2 test was performed. Results: The mean insertion time was significantly higher with the standard compared to the rotation technique of Baska Mask (20.90 ± 3.13 vs. 14.84 ± 1.11 s, P = 0.000). Device insertion was easy in rotation compared to the standard technique (P = 0.031). The number of attempts required for insertion was more with the standard technique than with the rotation technique (P = 0.011). Conclusion: Although the standard technique of Baska Mask® remains the first choice, the rotational technique of Baska Mask® has a higher success of insertion with fewer complications than the standard technique; hence, it can be accepted as an alternative.

A HIGH GAIN CIRCULARLY POLARIZED (CP) ANTENNA ARRAY USING SEQUENTIAL PHASE (SP) ROTATION TECHNIQUE FOR WLAN APPLICATIONS

This paper designs and investigates a high gain circularly polarized 2 × 2 antenna array for wireless applications using the sequential phase rotation technique. The feed network utilizes four rectangular lines of equal width and three 90° arcs. The length of all elements is equal to λ<sub>g</sub>/4 to provide 0°, 90°, 180°, and 270° phase differences at the four outputs of feed network to increase the axial ratio(AR) bandwidth and purity. Four corner truncated patch elements are connected to the feed network to fulfill the 2 × 2 antenna array design. The proposed design operates with an impedance bandwidth of 1.1 GHz from 4.9 GHz to 6 GHz bandwith and an AR bandwidth of 0.8 GHz from 5 GHz to 5.8 GHz band. The maximum measured gain of the antenna array is observed as 8.9 dBic in the operating band. The antenna array was prototyped and tested to validate its performance. This array is well suitable for high gain WLAN applications.

Rotational Augmentation Techniques: A New Perspective on Ensemble Learning for Image Classification

Rotational Augmentation Techniques: A New Perspective on Ensemble Learning for Image Classification

Surgical Strategies for Partial Breast Reconstruction in Medial-Located Breast Cancer: A 12-Year Experience.

Partial breast reconstruction is challenging in medially located breast cancer, particularly in terms of achieving satisfactory aesthetic coverage. Thus, we aimed to investigate surgical strategies for filling medial defects resulting from breast-conserving surgery to improve patient satisfaction and aesthetic outcomes. We retrospectively evaluated 113 patients (114 cases) with medially located breast cancer between 2007 and 2018. We analysed the patient data, such as breast size, specimen weight, complications, and aesthetic results obtained using a questionnaire. The mean body mass index and specimen weight were 23.43 kg/m² (range, 18.5-26.8) and 83.29 g (range, 15-290 g), respectively. The tennis racket and round-block techniques were chosen for small defects (< 10%-15%) in small- and medium-sized breasts. The rotational and perforator flap techniques were used for medium-sized defects. The latissimus dorsi (LD) flap technique was used for large defects (> 30%). Hematoma was found in 1 case (0.96%), linear skin necrosis was found in 1 case (0.96%), seroma in the LD flaps was found in 8 cases (7.69%); fat necrosis in the rotational flaps was found in 2 cases (1.92%); and fat necrosis in an anterior intercostal artery perforator flap was found in 1 case (0.96%). 91 patients (87.5%) were satisfied with the aesthetic results. The techniques used in this study for medially located breast cancer can produce fine aesthetic outcomes with regard to breast size and resection volume, with few complications.

Harmonic/inter-harmonics detection using modified exact model order-based ESPRIT

Problems related to harmonics/interharmonics are growing rapidly in power system with the increasing use of power electronic devices. This paper focuses on estimating the harmonics/interharmonics using modified exact model order - estimation of signal parameters via rotational invariance technique (MEMO-ESPRIT). The modified exact model order (EMO) method is used to reduce the computational burden in detecting the harmonics/interharmonics components. Comparison has been made between EMO and MEMO to demonstrate the effectiveness of MEMO based method. Moreover, various parameter values like noise, size of autocorrelation matrix, etc. are varied to see their effects on the computational burden and accuracy of MEMO method. The performance of MEMO-ESPRIT algorithm is analysed with synthetic signals, single-phase PWM inverter and 250 kW grid-connected PV arrays using MATLAB/Simulink. The root-mean-square relative error has been obtained to validate the accuracy of the algorithm.

Harmonic and Interharmonic Estimation using Poincaré Filtering Assisted ESPRIT Method

Accurate estimation of harmonics/interharmonics components is a crucial task in the electric power system. The parametric methods available for this purpose like Estimation of Signal Parameters via Rotational Invariance Technique (ESPRIT) give accurate result but suffer from very high computational burden. While on the other hand non-parametric methods like Fast Fourier Transform (FFT) are fast but have low spectral resolution. This paper proposes a Poincare plot-based periodicity filter to detect the presence of interharmonics and then selecting an algorithm based on the requirement of spectral resolution. The proposed Poincare plot-based method has been thoroughly tested for its accuracy by varying different parameters associated with interharmonics components. The method has been tested on synthetic signals as well as experimental validation has also been performed by analyzing the current signal from aeration blower installed at GIFT city, Gujarat.

A Review of the Advances Made in Improving the Durability of Welded Wood against Water in Light of the Results of African Tropical Woods Welding

Wood plays a major role in the production of furniture and wooden structures. Nevertheless, in this process, the massive use of adhesives and plural connectors remains a definite problem for health and the environment. Therefore, wood welding is a breakthrough in this respect. This paper reviews the applications of wood welding in furniture and construction and then examines advances in improving the durability of welded wood against water. Our contribution also highlights the need to join African tropical woods using the rotational friction welding technique. According to our results, these woods present interesting chemical singularities, which could provide solutions to the water vulnerability of the welded wood. Moreover, the use of such a joining method would first free the Cameroonian furniture industry from the chemical industry, secondly position it at the forefront of new eco-design trends and thirdly make it competitive with other countries in the Central African sub-region. These works enrich the long and rich bibliography on the technique of wood welding, which has long been conspicuous by its absence of tropical woods.

Efficacy of a Mulligan Concept Sustained Natural Apophyseal Glide Technique for Cervicogenic Headache: A Critically Appraised Topic

Clinical Question: In adults with cervicogenic headache (CGH), what are the effects of a clinician-applied Mulligan Concept C1–C2 rotational sustained natural apophyseal glide on cervicogenic symptomology? Clinical Bottom Line: Both Level 2b and Level 4 evidence of Grade B quality exists to support using the C1–C2 rotational sustained natural apophyseal glide to decrease CGH severity and participant-reported neck disability immediately posttreatment, while also increasing cervical range of motion in adult patients with CGH headaches and a positive flexion–rotation test. Further research should examine the long-term effects of the C1–C2 rotational sustained natural apophyseal glide technique on cervical range of motion, flexion–rotation test results, and CGH frequency and severity. In addition, the flexion–rotation test should be explored as a standard diagnostic assessment in CGH cases.

Comparative Study between Matrix Rotation Technique versus Wide Local Excision of Carcinoma of The Breast Located in The Upper/Upper Outer Quadrant

Comparative Study between Matrix Rotation Technique versus Wide Local Excision of Carcinoma of The Breast Located in The Upper/Upper Outer Quadrant

Compact Shared-Aperture Dual-Band Dual-Circularly-Polarized Waveguide Antenna Array Operating at K/Ka-Band

In this article, a compact shared-aperture dual-band dual-circularly polarized waveguide antenna array is presented to achieve high gain and wide bandwidth in full-duplex satellite communication at K/Ka-band. The designed antenna array can simultaneously operate at 20 GHz band with right-hand circular polarization (RHCP) radiation and 30 GHz band with left-hand circular polarization (LHCP) radiation. The array is composed of circular polarization (CP) waveguide antenna elements and full-corporate feed networks. The ridged spectrum polarizer is inserted in the square waveguide to form CP radiation in a stepped waveguide antenna element. The sequential rotation technique is adopted in feed networks to further improve CP axial ratio (AR) performance and bandwidth. The prototype of the proposed 4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times4$ </tex-math></inline-formula> antenna array is fabricated and measured for demonstration. Experimental results show that the overlapped bandwidth in terms of reflection coefficients less than −10 dB and AR lower than 2 dB is 18–22 GHz for RHCP radiation in K-band, and the corresponding bandwidth for LHCP radiation in Ka-band is 28–32 GHz. The measured cross-polarization levels are better than 25.82 dB at 20 GHz and 20.25 dB at 30 GHz, and the measured peak gains at K/Ka-band are 23.94 and 26.87 dBic, respectively.

Post-Operative Pain Intensity After Using Different Instrumentation Techniques for Canal Preparation

Objective: To measure the intensity of post-operative pain after using two techniques for root canal treatment.&#x0D; Study Design: Quasi-experimental study.&#x0D; Place of Study and Duration: Operative Dentistry Department, Fatima Jinnah Dental College, Karachi Pakistan, from May to Oct 2019.&#x0D; Methodology: The study was conducted on 60 patients referred to the Department of Endodontic, Fatima Jinnah Dental College. Enrolled patients were randomly divided into two groups (A and B) using the sealed envelope technique. Two different root canal file systems were used to assess the post-operative pain intensity in both groups.&#x0D; Results: The post-operative pain intensity considerably decreased in both groups. The difference between the rotational and reciprocal techniques was found to be statistically insignificant (p=0.86) in the 6 hours (p=0.73) and 24 hours’ periods (p=0.147) between the instrumentation techniques. However, pain experienced in the 48 hours was statistically different between the two groups (p=0.03).&#x0D; Conclusion: Post-operative pain is a consequence of both instrumentation techniques, which should be thoroughly investigated and assessed.Keywords: Instrumentation, Post-operative pain, Pro-taper, Root canal treatment, Wave-one.

DOA Estimation Method in Echo-localization Ability for Human-beings

The principle of echo-localization processing of human beings is quite similar with animals like bats and dolphins, which has been widely applied in sonar. Direction of Arrival (DOA) methods plays an important role in estimating the radar, sonar and many other echo-localization communication fields. Typical methods in resolving echo-localization problems including classical (Multiple Signal Classification) MUSIC, (Estimation of Signal Parameter via Rotational Invariance Technique), ESPRIT and compressed sensing. The echo-localization methods and the resolving ambiguity methods via uniform array are systematically introduced in this paper. On this basis, the fast and accurate algorithms for human-being echo-localization in parameter (azimuth angle, elevation angle and range) estimation of signal are further introduced from time domain and frequency domain. The accuracy of the angle and distance estimation of the algorithm calculated by computer simulation experiment is over 99.9% and 97% respectively. The effectiveness of DOA method was verified according to MUSIC algorithm, which provides a rapid and accuracy information in echo-localization ability of human being.

Deep learning model for the automated evaluation of contact between the lower third molar and inferior alveolar nerve on panoramic radiography

Background/purposeIn lower third molar (LM3) surgery, panoramic radiography (PAN) is important for the initial assessment of the anatomical association between LM3 and the inferior alveolar nerve (IAN). This study aimed to develop a deep learning model for the automated evaluation of the LM3–IAN association on PAN. Further, its performance was compared with that of oral surgeons using original and external datasets. Materials and methodsIn total, 579 panoramic images of LM3 from 384 patients in the original dataset were utilized. The images were divided into 483 images for the training dataset and 96 for the testing dataset at a ratio of 83:17. The external dataset comprising 58 images from an independent institution was used for testing only. The LM3–IAN associations on PAN were categorized into direct or indirect contact based on cone-beam computed tomography (CBCT). The You Only Look Once (YOLO) version 3 algorithm, a fast object detection system, was applied. To increase the amount of training data for deep learning, PAN images were augmented using the rotation and flip techniques. ResultsThe final YOLO model had high accuracy (0.894 in the original dataset and 0.927 in the external dataset), recall (0.925, 0.919), precision (0.891, 0.971), and f1-score (0.908, 0.944). Meanwhile, oral surgeons had lower accuracy (0.628, 0.615), recall (0.821, 0.497), precision (0.607, 0.876), and f1-score (0.698, 0.634). ConclusionThe YOLO-driven deep learning model can help oral surgeons in the decision-making process of applying additional CBCT to confirm the LM3–IAN association based on PAN images.

Assessing self-reported core competencies of public health practitioners in Lebanon using the WHO-ASPHER validated scale: a pilot study

BackgroundThe World Health Organization and the Association of Schools of Public Health in the European Region recommend the self-assessment of public health core competencies to strengthen the proficiency of the public health workforce and prepare them for future challenges. A framework for these competencies is lacking and highly needed in Lebanon. This study aims to validate the WHO-ASPHER self-declared scale and evaluate the perceived competency level of the different categories of Lebanese public health practitioners.MethodsThis population-based cross-sectional study conducted online between July and September 2021 involved 66 public health practitioners who graduated from different universities in Lebanon. Data were collected using the snowball technique via a self-report questionnaire that assessed public health proficiency, categorized into 1) content and context, 2) relationship and interactions, and 3) performance and achievements. The rotated component matrix technique was used to test the construct validity of the scales. Bivariate and multivariate analyses were performed after ensuring the adequacy of the models. Significance was set at a p-value < 0.05.ResultsThe factor analysis for scale domains showed that the Barlett test sphericity was significant (p < 0.001), high loadings of items on factors, and Cronbach’s alpha values of more than 0.9 in all three categories, showing an appropriate scale validity and reliability. The perceived level of competencies was significantly different between public health professionals and other health professionals with public health activities. All respondents scored low in most public health categories, mainly science and practice.ConclusionData findings showed variability of self-declared gaps in knowledge and proficiency, suggesting the need to review the national public health education programs. Our study offers a valuable tool for academia and public health professionals to self-assess the level of public health proficiency and guide continuous education needs for professional development.