Length Measurement Techniques Research Articles

A Study on the Automation of Fish Species Recognition and Body Length Measurement System

The rapid depletion of fishery resources has led to the global implementation of Total Allowable Catch (TAC) systems. However, the current manual survey methods employed by land-based inspectors show limitations in accuracy and efficiency. This study proposes an automated system for fish species recognition and body length measurement, utilizing the RT-DETR (Real-Time Detection Transformer) model and ARCore technology to address these issues. The proposed system employs smartphone Time of Flight (ToF) functionality to measure object distance and automatically calculates the weight of 11 TAC-managed fish species by measuring their body length and height. Experimental results reveal that the RT-DETR-x model outperformed the YOLOv8x model by achieving an average mAP50 value 2.3% higher, with a mean recognition accuracy of 96.5% across the 11 species. Furthermore, the ARCore-based length measurement technique exhibited over 95% accuracy for all species. This system is expected to minimize data omissions and streamline labor-intensive processes, thereby contributing to the efficient operation of the TAC system and sustainable management of fishery resources. The study presents an innovative approach that significantly enhances the accuracy and efficiency of fishery resource management, providing a crucial technological foundation for the advancement of future fisheries management policies.

Advancing Precision in Penile Length Measurement: Evidence-based Synthesis of Stretched Penile Length INdicator Technique (SPLINT).

The purpose of this study was to synthesize evidence and propose a technique for estimation of stretched penile length (SPL) applicable to children. This review has been conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. PubMed, Embase, and Scopus databases were queried on penile length (PL) measurement techniques in humans published from 1990 onward. The devices and the techniques used for PL measurement, state of the penis, the habitus of the participants, proximal and distal landmarks for measurement, handling the foreskin and pubic pad of fat, optimal stretching of the penis, and other factors (including the environment) which should be accounted for in the technique were identified from the study cohort (90895 participants across 145 included studies). PL has been represented through flaccid (33.79%), stretched (81.3%), and erect (12.41%) PLs as well as the greatest corporeal length (1.4%). Following devices have been used to measure the PL in the study cohort: rulers [54.68%], calipers [9.7%], measuring tapes [14.5%], coloured measuring strips [2.06%], spatulas/tongue depressors [11.03%], FitKit, syringe [1.4%], cotton swab (and ruler), titan cylinders, slide gauge and ultrasonography [1.37%]. The factors relevant to SPL measurement have been incorporated into the proposed SPL INdicator Technique (SPLINT) which is essentially a holistic extension of the "Conventional PL Measurement" technique. There is a wide range of heterogeneity in the technique for estimation of PL across the study cohort; the underlying factors have been identified along with the respective variables, and the SPLINT for SPL has been described.

Functional Penile Length After Penile Plication: “Empha-sizing” What Matters

ObjectiveTo reassess penile length changes after penile plication (PP), we defined a novel measurement of functional penile length (FPL) and compared preoperative and postoperative measurements. PP reduces penile curvature in Peyronie's Disease (PD) patients, but is traditionally thought to reduce overall penile length. However, the literature on PD lacks a standardization for penile length measurement techniques, leading to high inter-study variability. MethodsA prospectively maintained database of PD patients who underwent PP from 2018-2021 was queried. FPL was obtained by measuring the erect penis from the base of the pubis to the tip of the glans, as a straight line disregarding any curvature. Intraoperative assessment of FPL was performed before incision and immediately after surgical correction. ResultsOf 28 patients included, the average age was 59, average SHIM was 17, and average PDQ was 9. Curvature was unidirectional in 16 patients (57%) and bidirectional in 12 (43%). Dorsal curvature was most common (71%). The average curve severity was 37 ± 8.6 degrees. Mean FPL pre-operatively was 11.1 ± 1.4 cm and 12.5 ± 1.3 cm post-operatively. This represented an average 12.8% ± 6.6% increase in FPL following plication. All 28 patients reported subjective improvement in their curvature. ConclusionFunctional penile length is a useful primary surgical outcome when describing post-operative expectations for penile plication. We report an increase in FPL achieved for PD treated with PP despite conventionally being considered a shortening procedure. This can be an invaluable tool for preoperative counseling and setting expectations for penile length.

Real-Time Step Length Estimation in Indoor and Outdoor Scenarios.

In this paper, human step length is estimated based on the wireless channel properties and the received signal strength indicator (RSSI) method. The path loss between two ankles, called the on-ankle path loss, is converted from the RSSI, which is measured by our developed wearable hardware in indoor and outdoor ambulation scenarios. The human walking step length is estimated by a reliable range of RSSI values. The upper threshold and the lower threshold of this range are determined experimentally. This paper advances our previous step length measurement technique by proposing a novel exponential weighted moving average (EWMA) algorithm to update the upper and lower thresholds, and thus the step length estimation, recursively. The EWMA algorithm allows our measurement technique to process each shorter subset of the dataset, called a time window, and estimate the step length, rather than having to process the whole dataset at a time. The step length is periodically updated on the fly when the time window is "sliding" forwards. Thus, the EWMA algorithm facilitates the step length estimation in real-time. The impact of the EWMA parameter is analysed, and the optimal parameter is discovered for different experimental scenarios. Our experiments show that the EWMA algorithm could achieve comparable accuracy as our previously proposed technique with errors as small as 3.02% and 0.30% for the indoor and outdoor scenarios, respectively, while the processing time required to output an estimation of the step length could be significantly shortened by 53.96% and 60% for the indoor walking and outdoor walking, respectively.

Determination of Cracks using Multiple DC Potential Drop Measurements – Experimental Verification of an Advanced Model

The Direct Current Potential Drop Method (DCPDM) is a frequently used technique for crack detection and crack length measurement in fatigue experiments. Recent investigations have shown that with multiple potential drop measurements the location of crack initiation can be determined in single edge notch specimens (Wiehler and Bär, 2020), (Bär and Nahbein, 2022) and in round bars (Hartweg and Bär, 2019). In the present work a more detailed investigation of crack initiation and propagation is undertaken on round bars to advance the geometrical model by Hartweg and Bär (2019). Three potential probes were equipped on notched steel bars – at 0° (U1), at 120° (U2) and at 240° (U3). The three potentials were measured simultaneously during the fatigue tests using amplifiers of the control electronics. Moreover, the introduction of overloads was used to mark the crack front on the fracture surface in defined intervals to compare crack and size calculated from the potential drop measurements with the real crack size and geometry.In the case of an initiated single crack, the experimental set-up delivers different potentials depending on the distance of the probes to the crack. The geometrical model can be used not only for the determination of the crack angle like performed by Hartweg and Bär (2019) but also to calculate the crack size. On the measured data a function is fitted that allows the calculation of the crack length independent of the location of the crack initiation site. The experimental results have shown that it is possible to determine a crack with a size of less than 1 % of the specimen cross-sectional area.

Accuracy of Paper Point Technique for Final Working Length Measurement after Canal Preparation

Objective: The aim this study was to check the accuracy of paper point technique for final working length measurement after canal preparation. Study Design: Randomized controlled trial Place and Duration: Study was performed in department of operative dentistry, Liaquat University of Medical & Health Sciences, Jamshoro for one year duration from January 2017 to December 2017. Methodology: This study was performed on 78 patients divided equally into two groups. In one group working length was established by using electronic apex locator while in second group working length was established by using electronic apex locator with paper point technique. To check the working length master apical gutta percha point (GP point) was inserted into canal and radiograph were taken by paralleling angle technique. Results: There were 34 (43.6%) males while 44 (56.4%) patients were females. Mean age of patients was 30.5±8.9 years. Mean tooth number was 28.8±11.0. Group A is concerned that was treated only with Electronic Apex Locator showed lesser number of acceptable length than group B. on the other hand, group B was treated with electronic apex locator and paper point technique showed higher acceptable length of respondents with a difference of 4 frequencies or 7% in excess. A less value of chi-square test showed relationship between observed and expected data; whereas, significance value indicated no significant difference between group A and B. Conclusion: Paper point technique is as reliable as other techniques for final working length measurement. Key Words: Electronic Apex Locator, Paper Point Technique, Endodontic Working Length

A Survey of Rain Fade Models for Earth–Space Telecommunication Links—Taxonomy, Methods, and Comparative Study

Satellite communication is a promising transmission technique to implement 5G and beyond networks. Attenuation due to rain begins at a frequency of 10 GHz in temperate regions. However, some research indicates that such attenuation effects start from 5–7 GHz, especially in tropical regions. Therefore, modeling rain attenuation is significant for propagating electromagnetic waves to achieve the required quality of service. In this survey, different slant link rain attenuation prediction models have been examined, classified, and analyzed, and various features like improvements, drawbacks, and particular aspects of these models have been tabulated. This survey provides various techniques for obtaining input data sets, including rain height, efficient trajectory length measurement techniques, and rainfall rate conversion procedures. No survey of the Earth–space link models for rain attenuation is available to the best of our knowledge. In this study, 23 rain attenuation models have been investigated. For easy readability and conciseness, the details of each model have not been included. The comparative analysis will assist in propagation modeling and planning the link budget of slant links.

Penile Length Measurement: Methodological Challenges and Recommendations, a Systematic Review

BackgroundPenile length measurement techniques vary widely in published studies leading to inaccurate and nonstandardized measurements. AimTo review the methodology used to report data in studies evaluating penile length and provide a detailed recommendation in conducting future high-quality research. MethodsThe MEDLINE database was searched for randomized clinical trials and open-label prospective or retrospective studies. OutcomesThe panel reviewed the modality of data reporting on these specific areas: patients’ age and assessment, patient position, type of measurement instrument used, penile length technique description, examination conditions, and actual examiner. ResultsOverall, 70 studies investigating penile length were selected; among these, 72.85% included at least 50 patients: 16 prospective studies, 5 randomized clinical trials, and 49 retrospective cross-sectional studies. Amongst all studies, 90% reported to measure penile length by health care practitioners in clinical settings. Penile length was assessed in all 70 studies, whereas penile girth was measured in 57.14% of patients. A semi-rigid ruler was the most commonly used measurement aid to assess penile length/girth in 62.86% of studies. Penile measurements were reportedly obtained: (i) stretched state, 60%; (ii) flaccid state only, 52.68%; and (iii) during erection, 27.43%. All studies investigating the penile length in an erect state were simultaneously assessing penile length in the flaccid state. About 90% of studies investigated penile length in adults, whereas 10% were conducted in adolescents. Clinical ImplicationsThe use of shared methodology to assess penile length in both adults and adolescents allows more accurate and standardized measurements. Strength & LimitationsA systematic review of the published literature allowed proper data interpretation in order to provide accurate recommendations. Main limitations of the study relied on a relatively limited number of databases for the identification of potentially eligible studies. ConclusionThe methodology used in studies measuring penile length should be precise and standardized in order to provide accurate data to both clinicians and researchers.Cakir OO, Pozzi E, Castiglione F, et al. Penile Length Measurement: Methodological Challenges and Recommendations, a Systematic Review. J Sex Med 2020;XX:XXX–XXX.

Extraction of source resistance in thin film transistors using a single gated-probe outside the channel

Extraction of source resistance in top contact thin film transistors (TFTs) is described using a gated three probe device structure. The three probes include a source terminal, a drain terminal and an electrode deposited outside the channel and kept open-circuited leading to unperturbed transistor operation. A measurement of floating potential of this probe together with a family of universal curves is presented, which allows estimation of source resistance from dc measurements in the linear mode of operation on a single device. Simulation results obtained for TFTs with different semiconductor technologies, like organic semiconductor pentacene, indium-gallium-zinc-oxide and amorphous silicon demonstrate the applicability of this technique. Experimental results obtained from organic TFTs with pentacene semiconductor confirm that the method gives estimates that are close to the values obtained from the relatively more complex transfer length measurement (TLM) technique. It is also shown that unlike the TLM method, the outside gated probe technique is much less sensitive to errors in device parameters and variations in device dimensions, such as the channel length.

Standard guidelines for the publication of telomere qPCR results in evolutionary ecology.

Telomere length has been used as a proxy of fitness, aging and lifespan in vertebrates. In the last decade, dozens of articles reporting on telomere dynamics in the fields of ecology and evolution have been published for a wide range of taxa. With this growing interest, it is necessary to ensure the accuracy and reproducibility of telomere length measurement techniques. Real-time quantitative PCR (qPCR) is routinely applied to measure relative telomere length. However, this technique is highly sensitive to several methodological variables and the optimization of qPCR telomere assays remains highly variable between studies. Therefore, standardized guidelines are required to enable the optimization of robust protocols, and to help in judging the validity of the presented results. This review provides an overview of preanalytical and analytical factors that can lead to qPCR inconsistencies and biases, including: (a) sample type, collection and storage; (b) DNA extraction, storage and quality; (c) qPCR primers, laboratory reagents, and assay conditions; and (d) data analysis. We propose a minimum level of information for publication of qPCR telomere assays in evolutionary ecology considering the methodological pitfalls and sources of error. This review highlights the complexity of the optimization and validation of qPCR for telomere measurement per se, demonstrating the importance of transparency and clarity of reporting methodological details required for reliable, reproducible and comparable qPCR telomere assays. We encourage efforts to implement standardized protocols that ensure the rigour and quality of telomere dynamics studies.

Surgical and Non-surgical Penile Elongation Techniques

To summarize data on lengthening treatments from PubMed-indexed scientific publications. Several surgical techniques achieve penile lengthening when combined with penile prosthesis (PP) implantation, including the sliding, incision/excision and grafting, and multiple incision techniques. Other factors associated with greater length with PP include use of AMS 700 LGX devices, new length measurement technique, immediate activation, and regular device cycling. Among non-surgical therapies, penile traction achieves lengthening in most studies, while vacuum therapies demonstrate milder improvements. Other treatments either have failed to demonstrate consistent benefits or have mixed data, including isolated incision/excision and grafting, scrotoplasty, lipectomy/escutcheonectomy, suspensory ligament release, placement of cylindrical silicone (Penuma), or penile injections with silicone, hyaluronic acid, or other similar materials. Although multiple surgical and non-surgical therapies exist for penile lengthening, most have limited data available. Additionally, injection and surgical treatments can result in severe complications in some cases.

Penile size in adult men-recommendations for clinical and research measurements.

Data regarding the size of the adult penis is of great importance to both clinicians and researchers. Currently, there is no consensus regarding the preferred method for the evaluation of penile size. Various and conflicting methods are reported in the literature. We review the data on measurement methods of the flaccid, stretched, and erected penis with the aim of constructing a recommendation for best practice. A systematic search for articles on penile length and girth measurement techniques was performed using PubMed, Google Scholar, and Cochran Library. Only peer-reviewed articles published in English before August 2018 were reviewed. All authors evaluated the methods and results sections presented in each publication. Relevant, demonstrative publications are reported in this review. We did not find definitive evidence favoring one measuring method over the other. Therefore, we advocate the use of our recommendations for penile size measurement in future publications.

A new approach to the effect of sample dimensions and measurement techniques on ultrasonic wave velocity

Though the velocity of ultrasonic waves passing through materials is a highly preferred parameter to indirectly and non-destructively determine the strength properties of rock and concrete, many studies have emphasized that such waves are influenced by many factors, such as sample diameter, length, and measurement techniques (semi-direct or indirect). Direct techniques use opposite sides of the materials, semidirect techniques use adjacent faces, and indirect techniques use the same face. In contrast to the results given in many studies so far, the results from this study indicate that the ultrasonic wave velocity is not dependent on the sample geometry and measurement techniques. The tests conducted on the materials of three different lengths showed that ultrasonic wave velocity was not affected by sample length because the differences in values obtained from different lengths were <0.5% for both the polypropylene and rock samples and 1.5% for the concrete samples. The ultrasonic tests were performed on the samples for four different diameters and the differences in values were <1.2% for the polypropylene samples and 1.8% for concrete the samples. The results of testing the different techniques showed that when the travel distance increases, the differences between the values obtained by different methods decrease and this difference is <3% if the sample length is >20 cm. The results clearly indicated that the ultrasonic velocity value of the materials is related to the material homogeneity rather than the sample diameter, length, and different measurement techniques.

Image Processing Technique for slug length measurement during Mixing and Separation of Two-phase Flows in T sections

Abstract Study of two phase flow regimes in a mini/micro channel finds its applications in micro-fluidic devices such as micro heat exchangers owing to its large heat transfer. Such systems have large surface to volume ratio. The present work detail the results obtained for bubbly and slug flow regimes formed in a T-junction for an air water mixture. Experiments are performed in two different tubes with internal diameters of 0.6mm and 2.5mm having a length of 100mm. Image processing techniques are employed using MATLAB software. The data will be helpful in designing fluid flow mini/micro channels commonly used in thermal MEMS.

Analysis of Three Commonly Used Tibia Length Measurement Techniques

This study analyzes three tibia length measurement techniques on a sample of 107 tibiae. Two of the techniques meet published criteria by resting the tibia on its posterior surface with the longitudinal axis parallel to an osteometric board. The third technique does not adequately keep the longitudinal axis parallel to the board. Statistical analyses show low levels of interobserver error for all techniques and statistically significant differences between the third technique and the other two techniques. Results report a maximum difference of 6 mm between measurement techniques with the third technique having greater than 95% directional bias. A survey sent out to the American Academy of Forensic Sciences forensic anthropology community reported more than 50% of respondents having been taught the third technique when an osteometric board with a slot/hole is not available. The intermixing of the third technique with the other two has likely contributed to higher levels of interobserver error in tibia length measurements.

Analytical model and error analysis of arbitrary phasing technique for bunch length measurement

An analytical model of an RF phasing method using arbitrary phase scanning for bunch length measurement is reported. We set up a statistical model instead of a linear chirp approximation to analyze the energy modulation process. It is found that, assuming a short bunch (σφ∕2π→0) and small relative energy spread (σγ∕γr→0), the energy spread (Y=σγ2) at the exit of the traveling wave linac has a parabolic relationship with the cosine value of the injection phase (X=cosφr|z=0), i.e., Y=AX2+BX+C. Analogous to quadrupole strength scanning for emittance measurement, this phase scanning method can be used to obtain the bunch length by measuring the energy spread at different injection phases. The injection phases can be randomly chosen, which is significantly different from the commonly used zero-phasing method. Further, the systematic error of the reported method, such as the influence of the space charge effect, is analyzed. This technique will be especially useful at low energies when the beam quality is dramatically degraded and is hard to measure using the zero-phasing method.

Effects of correlations between particle longitudinal positions and transverse plane on bunch length measurement: a case study on GBS electron LINAC at ELI-NP

In high-brightness LINear ACcelerators (LINACs), electron bunch length can be measured indirectly by a radio frequency deflector (RFD). In this paper, the accuracy loss arising from non-negligible correlations between particle longitudinal positions and the transverse plane (in particular the vertical one) at RFD entrance is analytically assessed. Theoretical predictions are compared with simulation results, obtained by means of ELEctron Generation ANd Tracking (ELEGANT) code, in the case study of the gamma beam system (GBS) at the extreme light infrastructure—nuclear physics (ELI-NP). In particular, the relative error affecting the bunch length measurement, for bunches characterized by both energy chirp and fixed correlation coefficients between longitudinal particle positions and the vertical plane, is reported. Moreover, the relative error versus the correlation coefficients is shown for fixed RFD phase 0 rad and rad. The relationship between relative error and correlations factors can help the decision of using the bunch length measurement technique with one or two vertical spot size measurements in order to cancel the correlations contribution. In the case of the GBS electron LINAC, the misalignment of one of the quadrupoles before the RFD between −2 mm and 2 mm leads to a relative error less than 5%. The misalignment of the first C-band accelerating section between −2 mm and 2 mm could lead to a relative error up to 10%.

The inter- and intra-rater reliability of the Maestro and Barroco metatarsal length measurement techniques

BackgroundThe relationship between metatarsal length and various forefoot pathologies is a topic of contention in Orthopaedics. The results of such investigations have been shown to depend on the method of metatarsal length measurement used. The aim of this study was to assess the inter- and intra-rater reliability of the Maestro and Barroco metatarsal length measurement techniques.MethodsA retrospective and quantitative study was performed on 15 randomly selected radiographs to determine the reliability of the two measurement techniques across all five metatarsals (M1 to M5). This was done at one week apart for three weeks by three raters. The intraclass correlation coefficient (ICC), and the 95% lower confidence limit (95% LCL) were calculated.ResultsThe Maestro and Barroco techniques produced high to very high ICC vlaues for length measurements across all metatarsals. The 95% lower confidence limit for inter-rater measurements ranged between 0.92–0.98 for Maestro’s and 0.86–0.99 for Barroco’s technique. For intra-rater measurements the 95% LCL ranged between 0.83–0.99 for Maestro’s and 0.75–0.99 for Barroco’s technique.ConclusionsOur study found that both the Maestro and Barroco methods of measurements produced high to very high inter- and intra-rater reliability. Both methods may be suitable for the use of peri-operative planning and clinical research relating metatarsal length and forefoot pathology. Besides having a more simplistic method of application, the novel Barroco technique is comparable to the more established Maestro method in both repeatability and reproducibility.

Post-operative Refractive Prediction Error After Phacovitrectomy: A Retrospective Study.

IntroductionMany authors have reported on a myopic post-operative refractive prediction error when combining phacoemulsification with pars plana vitrectomy (phacovitrectomy). In this study we evaluate the amount of this error in our facility and try to elucidate the various factors involved.MethodsThis was a retrospective study which included 140 patients who underwent phacovitrectomy (39 with macular holes, 88 with puckers, and 13 with floaters). Post-operative refractive error was defined as the difference between the actual spherical equivalent (SEQ) and expected SEQ based on the SRK/T and Holladay-II formulas. Both univariate (paired t test, independent t test, one-way analysis of variance, or Mann–Whitney test) and multivariate (regression analysis) statistical analyses were performed.ResultsOverall, a refractive error of − 0.13 dpt (p = 0.033) and − 0.26 dpt (p < 0.01) were found in the SRK/T and Holladay-II formulas, respectively. For the independent diagnoses, only macular holes showed a myopic error with the SRK/T (− 0.31 dpt; p < 0.01) and Holladay-II (− 0.44 dpt; p < 0.01) formulas. In univariate analysis, significant factors involved in myopic refractive error were macular hole as diagnosis (p < 0.01 for SRK/T and Holladay-II), gas tamponade (SRK/T p = 0.024; Holladay-II p = 0.025), pre-operative myopia (p < 0.01 for SRK/T), and optical technique for axial length measurement (SRK/T and Holladay-II p < 0.01). In the multivariate analysis, pre-operative axial length (p = 0.026), optical technique for axial length measurement (p < 0.01), and pre-operative SEQ (p < 0.01) were independent predictors for myopic refractive error in the SRK/T formula. For the Holladay-II formula, optical technique for axial length measurement (p < 0.01) and pre-operative SEQ (p = 0.04) were predictive.ConclusionVarious factors are involved in determining the myopic refractive error after phacovitrectomy. Not every factor seems to be as important in each individual patient, suggesting a more tailored approach is warranted to overcome this problem.

Interferometric focal length measurement of positive and negative lenses using a lateral-shearing cyclic path optical configuration setup and polarization phase-shifting interferometry.

We present a simple interferometric focal length measurement technique for measuring the focal length of positive and negative lenses using a lateral-shearing cyclic path optical configuration (CPOC) setup and polarization phase-shifting interferometry (PPSI). The technique requires an auxiliary lens, whose focal length need not be known accurately, for generating a focused point source at its focal plane. The focal point of the test lens is adjusted to be in the vicinity of the focus of the auxiliary lens. The radii of the resulting spherical wave fronts emerging from the test lens, due to the defocus, for two different longitudinal shifted positions of the test lens are measured using the lateral-shearing CPOC setup and PPSI. Focal length of the test lens is determined from the known longitudinal shift and from the measured radii of the spherical wave fronts. Results obtained for 200.0mm convex and 100.0mm concave test lenses are presented.