3D Foot Reconstruction Based on Mobile Phone Photographing

Foot measurement is necessary for personalized customization. Nowadays, people usually obtain their foot size by using a ruler or foot scanner. However, there are some disadvantages to this, namely, large measurement error and variance when using rulers, and high price and poor convenience when using a foot scanner. To tackle these problems, we obtain foot parameters by 3D foot reconstruction based on mobile phone photography. Firstly, foot images are taken by a mobile phone. Secondly, the SFM (Structure-from-Motion) algorithm is used to acquire the corresponding parameters and then to calculate the camera position to construct the sparse model. Thirdly, the PMVS (Patch-based Multi View System) is adopted to build a dense model. Finally, the Meshlab is used to process and measure the foot model. The result shows that the experimental error of the 3D foot reconstruction method is around 1 mm, which is tolerable for applications such as shoe tree customization. The experiment proves that the method can construct the 3D foot model efficiently and easily. This technology has broad application prospects in the fields of shoe size recommendation, high-end customized shoes and medical correction.

Precision analysis of forced-oscillation device: numerical modelling and experimental investigations

Investigating the stress state of a sample-standard column in forced-oscillation apparatus is critical to clearly quantify measurement credibility, offering insights into revealing intrinsic frequency-dependent elastic characteristics of a rock sample. To investigate the effects of the jointing condition, the location of strain gauges and device resonance on the stress state of a sample-standard column, we experiment with a typical forced-oscillation setup numerically and experimentally at frequencies of 2–800 Hz. Overall, the numerical model captures the primary features of the forced-oscillation device, which makes the simulated data fit well with the measured results. Meanwhile, based on the configuration of the sample-standard column with variable static friction in jointing contacts, the simulated results also indicate that mechanical contacts of the sample-standard-vibrator assembly lead to stress concentration, resulting in coordinate-dependent strains on both the sample and standard. Additionally, strain magnitude is also frequency-dependent, causing a relatively large measurement error on the elasticity of the sample at higher frequencies. Ultimately, numerical results not only optimize measurement workflow but also create a solid foundation for the interpretation of measured data.

Improving the method for determining the dust penetration of textile materials for the human protective equipment manufacture

Purpose: Improving the accuracy of determining the coefficient of dust permeability of textile materials and protective products from them. Design/methodology/approach: The problem solution of human protection from the negative effects of road dust is to improve the quality control procedures of textile materials using modern measurement methods. A methodology has been developed for investigating the dust penetration coefficient of materials based on the use of a television informationmeasuring system (TIMS). Findings: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved, by increasing the accuracy of measurement and determining the patterns of the influence of structure on the permeability of textile materials. Research limitations/implications: Improving methods of quality control of textile materials through the use of modern methods of measuring techniques is by solving an important problem of human protection from the negative effects of road dust. Known methods do not take into account the forceful effect of the airflow on the structure of the test sample, which is essential for textile materials that are easily deformed, which affects the objectivity of the results. Significant inconvenience, complexity, and duration of the test process give a large measurement error. Practical implications: The methodology for determining the dust permeability of textile materials through the use of a television information-measuring system has been improved. This system allows an increase in the accuracy of measurements by 15%, and the availability of software to increase the speed of displaying the results of investigations on the screen. Originality/value: The main disadvantages of methods and means of determining the dust permeability of textile materials - is the inability to determine the duration and dynamics of the process of dust retention. Known methods do not take into account the force of air flow on the structure of the test sample, which is significant, especially for materials that are easily deformed, which affects the objectivity of the results. Significant inconveniences, complexity and duration of the test process give a large measurement error. A scientific novelty is the development of a modern and completely new method for determining the permeability of textile materials using a television information - measuring system, by increasing the accuracy of measurement and determining the patterns of influence of the structure of textile materials on dust permeability.

Perhetaustan yhteys oppimistuloksiin Suomessa PISA- ja rekisteriaineistojen valossa

Aikaisempien tutkimusten mukaan oppimistulosten eriarvoisuus vanhemman taustan mukaan on kasvanut Suomessa viime vuosina. Tutkimusnäyttö perustuu vahvasti koulukyselyaineistoihin kuten PISA-aineistoon, jossa vanhempien koulutuksen ja ammattiasema on kysytty lapsilta. Tällaiset kyselyaineistot ovat alttiita vastausharhan aiheuttamalle mittausvirheelle. Tässä tutkimuksessa osoitamme, että PISA-aineistot sisältävät suurta mittausvirhettä vanhempien koulutuksen osalta. Siksi vanhemman ammattiasema on luotettavampi mittari, kun halutaan tutkia kotitaustan yhteyttä oppimistuloksiin PISA-aineistolla. Kun mittausvirhe ja negatiivinen valikoituminen vuosien välillä huomioidaan, oppimistulosten eriarvoisuus ei ole kasvanut Suomessa viime vuosina. / According to previous studies, the inequality of learning outcomes according to family background has increased in Finland in recent years. The evidence is strongly based on school surveys such as PISA data, where children are asked about their parental educational and occupation status. However, such surveys are prone to measurement error due to reporting bias. We show that the PISA data contain a large measurement error in terms of parental education. Therefore, parental occupational status is a more reliable indicator of family background when association between family background and learning outcomes are studied with PISA data. When the measurement error and the negative selection are taken into account, the results show that the inequality of learning outcomes has not increased in Finland in recent years.

A Calibration Method for the Logging Instrument Used in Harsh Environments

Due to the impact of harsh environments with temperatures higher than 150 °C, the characteristics of the amplifying circuits of logging instrument can be changed, to cause the large measurement error. Therefore, a new calibration method is proposed to obtain the gain value and offset for pre-amplifier system. This method use multiple calibration signals and based on the last square theory to complete the calibration work. At the experiment of calibration for the multi-parameter formation water logging instrument, the gain error for the pre-amplifier system by this calibration be improve to no exceed 0.15% to compare with over 1% by tradition method.

INFLUENCES OF AGGREGATION ON THE TWO-PHOTON FLUORESCENCE PROCESS

Rhodamine B (RhB) is most often used as the reference in the two-photon induced fluorescence (TPIF) method to measure the two-photon absorption (TPA) cross-section. In this work, we investigate the influences of dimer formation, energy transfer and self-absorption on the two-photon fluorescence process. Those three effects will result in a large measurement error of the TPA cross-section. We thus provide a concentration gradient correction method by considering the above three processes to eliminate the measurement error.

Measurement error of waist circumference: gaps in knowledge

ObjectiveIt is not clear whether measuring waist circumference in clinical practice is problematic because the measurement error is unclear, as well as what constitutes a clinically relevant change. The present study aimed to summarize what is known from state-of-the-art research.DesignTo identify the magnitude of the measurement error of waist circumference measurements from the literature, a search was conducted in PubMed from 1975 to February 2011.ResultsThe measurement error may vary between 0·7 cm and 15 cm. Taking a realistic range of measurable waist circumference into account (60–135 cm), we argue that a short-term clinically relevant change in waist circumference of 5 % may lie between 3·0 and 6·8 cm and a maintained clinically relevant change of 3 % between 1·8 and 4·1 cm.ConclusionsBased on these results, we conclude it may be difficult to distinguish clinically relevant change from measurement error in individual subjects, due to the large measurement error and unclear definition of clinically relevant change. More research is needed to address these gaps in knowledge. To minimize measurement error, we recommend using a uniform measurement protocol, training and repeated measurements.

The Association of Stock Distribution Announcements and Earnings Performance

This paper analyzes the association of unexpected earnings with stock dividend and stock split announcements. Unexpected earnings are modeled as the percentage deviation of actual earnings from expected. Value Line's earnings forecasts are used as a surrogate for the market's timely expectation of future earnings. The primary findings are: (1) postdistribution earnings realizations are greater than expected; and (2) deviations of realized earnings from expected are (a) directly related to the size of the stock distribution and (b) inversely related to the level of market anticipation of the event. Further, distribution size may be a proxy for market anticipation in that small distributions (stock dividends) are dominated by anticipated events and large distributions (stock splits) by unanticipated events. These findings are robust across samples that control for large measurement error due to small levels of forecasted earnings, and event contamination due to the simultaneous announcement of firm-related events. Examination of analysts' forecasts immediately following the event indicates a significant upward revision in earnings expectations. This finding, coupled with an analysis of a control sample of Value Line earnings forecasts, indicates that the observed unexpected earnings are not the result of systematic Value Line forecast error. Therefore, the paper provides support for the notion that stock distribution announcements convey future earnings information.