Статті в журналах з теми "Correlation direction finder"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Correlation direction finder.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 статей у журналах для дослідження на тему "Correlation direction finder".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Сорочан, Анатолий Григорьевич, Дмитрий Александрович Добряк, and Оксана Анатольевна Добряк. "Doppler direction finder J-correlation processing." Eastern-European Journal of Enterprise Technologies 6, no. 9(66) (December 12, 2013): 4. http://dx.doi.org/10.15587/1729-4061.2013.19003.
Повний текст джерела
2
Kozeruk, S. O., and O. V. Korzhyk. "Correlation direction finder for small aircraft." Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, no. 79 (December 30, 2019): 41–47. http://dx.doi.org/10.20535/radap.2019.79.41-47.
Повний текст джерела
3
Kazakov, G. N., A. M. Petrakov, and V. A. Shevtsov. "Accuracy Estimation of a Correlation Interferometric Direction-Finder." Russian Aeronautics 61, no. 4 (October 2018): 620–28. http://dx.doi.org/10.3103/s1068799818040177.
Повний текст джерела
4
Tsyporenko, V. V., and V. G. Tsyporenko. "Research of Direct Digital Correlative-Interferometric Radio Direction Finder with Double Correlation-convolutional Processing." Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, no. 65 (June 30, 2016): 51–61. http://dx.doi.org/10.20535/radap.2016.65.51-61.
Повний текст джерела
5
Lapaev, N. G., A. V. Ksendzuk, and P. A. Gerasimov. "ACCURACY OF BEARING DETERMINATION IN A THREE-CHANNEL MONOPULSE AMPLITUDE CORRELATION DIRECTION FINDER." Issues of radio electronics, no. 3 (March 20, 2019): 36–40. http://dx.doi.org/10.21778/2218-5453-2019-3-36-40.
Повний текст джерелаАнотація:
In the work, the study of the achievable accuracy of determining the coordinates of the radiating in the radio range of spacecraft using a three‑element amplitude correlation direction finder has been performed. The proposed scheme makes it possible to select single and group low‑power complex signals and simultaneously determine the bearings of several sources, the signals of which can be separated in time‑frequency‑code space. As an example, the radiation pattern of a three‑element antenna system with an orthogonal arrangement of partial diagrams with respect to the equal‑signal direction is considered. The results of statistical modeling of the correlation processing algorithm obtained for a three‑channel monopulse system with a 3.7° pattern width and estimates of the potential accuracy of determining the bearing are presented. Simulation results are given to evaluate the instrumental accuracy of the direction finder. The proposed method of direction finding provides the ability to determine the geodetic coordinates of aerospace objects using the station electronic reconnaissance.
6
Sorochan, A. G., and Vladimir P. Kharchenko. "J-CORRELATION DIRECTION FINDER WITH IMPROVED CHARACTERISTICS OF A TIME DELAY METER." Telecommunications and Radio Engineering 77, no. 11 (2018): 957–69. http://dx.doi.org/10.1615/telecomradeng.v77.i11.30.
Повний текст джерела
7
Tsyporenko, V. V. "Optimization of Exactness of Direct Digital Correlation-Interferometer Direction-finder with Double Сorrelation Processing". Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, № 64 (30 березня 2016): 86–100. http://dx.doi.org/10.20535/radap.2016.64.86-100.
Повний текст джерела
8
Ципоренко, Віталій Валентинович, Валентин Григорович Ципоренко, Владислав Вікторович Чухов, and Олександр Володимирович Андреєв. "Analysis of the speed of a searchless digital correlation-interferometric direction finder with two-dimensional correlation processing of the spatial signal." Journal of Zhytomyr State Technological University. Series: Engineering, no. 1 (81) (June 21, 2018): 210–16. http://dx.doi.org/10.26642/tn-2018-1(81)-210-216.
Повний текст джерела
9
Uskov, S. "MODULE CALIBRATION CORRELATION INTERFEROMETRY DIRECTION FINDERS." Актуальные направления научных исследований XXI века: теория и практика 2, no. 4 (November 5, 2014): 282–85. http://dx.doi.org/10.12737/6166.
Повний текст джерела
10
Thomas, C. K., B. H. Ross, and R. B. Stein. "Motor-unit recruitment in human first dorsal interosseous muscle for static contractions in three different directions." Journal of Neurophysiology 55, no. 5 (May 1, 1986): 1017–29. http://dx.doi.org/10.1152/jn.1986.55.5.1017.
Повний текст джерелаАнотація:
Spike-triggered averaging was used to extract the twitch tensions and contraction times of 144 motor units from the first dorsal interosseous muscle of four subjects for three different directions of static contraction: abduction of the index finger, flexion of the index finger, and adduction of the thumb coupled with flexion of the index finger (hereafter referred to as adduction). Although the twitch tensions were generally largest for the abduction contraction, all units contributed tension to all three directions of contraction. A linear correlation was found for twitch tensions of motor units for the three directions of static contractions. Linear correlations were also found between twitch tension and threshold force of these motor units for each direction, which suggests that an orderly pattern of recruitment, according to increasing twitch size, adequately describes the function of human first dorsal interosseous muscle for all contraction directions. No clear evidence was found for separate groups of motor units in the muscle that were selectively activated for the different tasks. Rank order of recruitment for motor units in the three directions of contraction was correlated, but was not identical. The scatter in our data is discussed in relation to earlier reports of altered motor-unit recruitment during different movements.
11
Ашихмин, А. В., И. Б. Крыжко, А. Б. Токарев, and А. А. Фатеев. "COMPARISON OF THE CHARACTERISTICS OF THE CORRELATION-INTERFEROMETRIC BELLOWS WHEN USING DIRECTIONAL AND NON-DIRECTIONAL ANTENNA ELEMENTS." ВЕСТНИК ВОРОНЕЖСКОГО ГОСУДАРСТВЕННОГО ТЕХНИЧЕСКОГО УНИВЕРСИТЕТА, no. 5 (November 19, 2021): 59–69. http://dx.doi.org/10.36622/vstu.2021.15.5.009.
Повний текст джерелаАнотація:
При создании корреляционно-фазовых пеленгаторов, как правило, в качестве антенных элементов используют ненаправленные антенные элементы (АЭ). Для использования измерений направленных АЭ требуется модифицировать алгоритмы пеленгации. Представлены соответствующие модификации алгоритмов и проведено сравнительное исследование точности пеленгования применительно к двухканальным корреляционно-интерферометрическим стандартным пеленгаторам, использующим плоские антенные решетки из направленных и ненаправленных АЭ. Рассмотрена также возможность определения пеленгов лишь по энергетическим измерениям, отсутствующая применительно к пеленгаторам с ненаправленными АЭ. Показано, что применение направленных АЭ позволяет снизить вероятность возникновения аномальных ошибок, повысить точность пеленгования при существенно больших значениях угла места, определяющего направление на источник радиоизлучения, снизить негативное влияние отказа от учета сферичности приходящей волны и, следовательно, уменьшить размеры ближней зоны пеленгатора, для которой характерно появление аномальных ошибок пеленгования. В многосигнальной радиообстановке использование направленных свойств АЭ позволяет также формировать пеленгационную диаграмму, обеспечивающую частичное подавление помеховых сигналов. Вместе с тем эффективное использование направленных свойств антенных АЭ требует максимально точного учета их диаграмм направленности (ДН). Погрешности описания ДН могут приводить к заметным ошибкам при определении пеленга, поэтому повышение качества работы пеленгационной системы за счет использования направленных АЭ сопровождается повышением требований к определению и точности практической реализации ДН АЭ When creating correlation-phase direction finders, as a rule, non-directional antenna elements (AE) are used. To use directional AE measurements, it is necessary to modify the direction finding algorithms. We present the corresponding modifications of the algorithms and we carried out a comparative study of the direction finding accuracy in relation to two-channel correlation-interferometric standard direction finders using flat antenna arrays of directional and non-directional AEs. We also considered the possibility of determining bearings only from energy measurements, which is absent in relation to direction finders with nondirectional AE. We show that the use of directional AEs makes it possible to reduce the probability of occurrence of anomalous errors, to increase the accuracy of direction finding at significantly large values of the elevation angle, which determines the direction to the radio emission source, to reduce the negative effect of refusing to take into account the sphericity of the incoming wave and, consequently, to reduce the size of the near-field zone of a bearer, which is characterized by the appearance of abnormal direction finding errors. In a multi-signal radio environment, the use of the directional properties of the AE also makes it possible to form a direction finding diagram that provides partial suppression of interference signals. At the same time, the effective use of the directional properties of antenna AEs requires the most accurate consideration of their directional patterns (DP). Errors in the description of the pattern can lead to noticeable errors in determining the bearing, therefore, improving the quality of operation of the direction finding system due to the use of directional AEs is accompanied by increased requirements for the determination and accuracy of practical implementation of the pattern of AE
12
Fateev, A. A., A. B. Tokarev, O. V. Chernoyarov, and A. V. Salnikova. "Influence of the radiation pattern errors for the correlation interferometer." Journal of Physics: Conference Series 2094, no. 2 (November 1, 2021): 022054. http://dx.doi.org/10.1088/1742-6596/2094/2/022054.
Повний текст джерелаАнотація:
Abstract While designing phase-correlation direction finders, as antenna components, the non-directional ones are usually applied. Mounting the non-directional antenna components provides certain new options but makes the bearing computation procedure more problematic. In the present paper, the feasibility of using the directional antenna components is discussed and confirmed in terms of its positive influence on the stability of the bearing results in the case when the deviations of the implementations of the actual diagrams of the antenna components from their reference model occur.
13
Lim, JoongSoo, Young-Ho Kim, and Kichul Kim. "A Simulator for Analyzing the Accuracy of Correlative Interferometer Direction Finder." Convergence Society for SMB 7, no. 2 (April 30, 2017): 53–58. http://dx.doi.org/10.22156/cs4smb.2017.7.2.053.
Повний текст джерела
14
Gao, Zhitao, Jianxian Cai, Yanan Shi, Li Hong, Fenfen Yan, and Mengying Zhang. "Integration of Two-Dimensional Kernel Principal Component Analysis Plus Two-Dimensional Linear Discriminant Analysis with Convolutional Neural Network for Finger Vein Recognition." Traitement du Signal 38, no. 4 (August 31, 2021): 1181–87. http://dx.doi.org/10.18280/ts.380429.
Повний текст джерелаАнотація:
High complexity and low recognition rate are two common problems with the current finger vein recognition methods. To solve these problems, this paper integrates two-dimensional kernel principal component analysis (K2DPCA) plus two-dimensional linear discriminant analysis (2DLDA) (K2DPCA+2DLDA) into convolutional neural network (CNN) to recognize finger veins. Considering the row and column correlations of the finger vein image matrix and the classes of finger vein images, the authors adopted K2DPCA and 2DLDA separately for dimensionality reduction and extraction of nonlinear features in row and column directions, producing a dimensionally reduced compressed image without row or column correlation. Taking the dimensionally reduced compressed image as the input, the CNN was introduced to learn higher-level features, making finger vein recognition more accurate and robust. The public dataset of Finger Vein USM (FV-USM) Database was adopted for experimental verification. The results show that the proposed approach effectively overcome the common defects of original image feature extraction: the insufficient feature description, and the redundancy of information. When the training reached 120 epochs, the model basically realized stable convergence, with the loss approaching zero and the recognition rate reaching 97.3%. Compared with two-directional two-dimensional Fisher principal component analysis ((2D)2FPCA), our strategy, which integrates K2DPCA+2DLDA with CNN, achieved a very high recognition rate of finger vein images.
15
Sabibolda, Akezhan, Vitaliy Tsyporenko, Valentyn Tsyporenko, Nurzhigit Smailov, Kanat Zhunussov, Askar Abdykadyrov, Moldir Baigulbayeva, and Nurzak Duisenov. "Improving the accuracy and performance speed of the digital spectral-correlation method for measuring delay in radio signals and direction finding." Eastern-European Journal of Enterprise Technologies 1, no. 9(115) (February 28, 2022): 6–14. http://dx.doi.org/10.15587/1729-4061.2022.252561.
Повний текст джерелаАнотація:
A promising direction for the development of passive radar monitoring stations is to improve their efficiency by increasing their speed of performance. For the digital spectral-correlation method for determining the delay of radio signals and direction finding, analytical expressions have been derived for a variance of the estimation of the delay in receiving a signal by radio channels and directions to the source of radio emission. A feature of the method reported in this study is the use of two-stage temporal and spatial spectral analysis of the mutual spectrum, a single-iteration correlation analysis. The duration of estimating the direction finding has been evaluated through the total number of multiplication operations with accumulation. The proposed method, while providing for a gain of 27 times in terms of performance speed, demonstrated a slight decrease in accuracy compared to the optimal one due to energy signal loss. The result of the simulation has established the dependences of the standard deviation in the direction finding and delay estimates on the signal-to-noise ratio, the type of spectral analysis window, and the size of the antenna base. The standard deviation of the direction-finding estimate depends on the signal-to-noise ratio and varies over the range of values [0.08; 0.034]° with a change in the signal/noise ratio [−10; 40] dB. As the signal/noise ratio increases, the error decreases in line with a hyperbolic dependence. The standard deviation of the delay estimate depends on the signal-to-noise ratio and varies similarly to the error of the directional estimate, and is in the range of values [18.176; 1.56] ns, which corresponds to an error of [0.637; 0.055] %. The error of direction-finding estimation, depending on the size of the antenna base, decreases in the exponent within [1.6; 0.03]° with an increase in the antenna base in the range from 200 to 7,500 m. The results reported here could be used for the parametric optimization of spectral-correlation radio direction finders at passive radar monitoring stations.
16
Fujisawa, Yuhki, and Yasutomo Okajima. "Characteristics of Handwriting of People With Cerebellar Ataxia: Three-Dimensional Movement Analysis of the Pen Tip, Finger, and Wrist." Physical Therapy 95, no. 11 (November 1, 2015): 1547–58. http://dx.doi.org/10.2522/ptj.20140118.
Повний текст джерелаАнотація:
Background There are several functional tests for evaluating manual performance; however, quantitative manual tests for ataxia, especially those for evaluating handwriting, are limited. Objective This study aimed to investigate the characteristics of cerebellar ataxia by analyzing handwriting, with a special emphasis on correlation between the movement of the pen tip and the movement of the finger or wrist. Design This was an observational study. Methods Eleven people who were right-handed and had cerebellar ataxia and 17 people to serve as controls were recruited. The Scale for the Assessment and Rating of Ataxia was used to grade the severity of ataxia. Handwriting movements of both hands were analyzed. The time required for writing a character, the variability of individual handwriting, and the correlation between the movement of the pen tip and the movement of the finger or wrist were evaluated for participants with ataxia and control participants. Results The writing time was longer and the velocity profile and shape of the track of movement of the pen tip were more variable in participants with ataxia than in control participants. For participants with ataxia, the direction of movement of the pen tip deviated more from that of the finger or wrist, and the shape of the track of movement of the pen tip differed more from that of the finger or wrist. The severity of upper extremity ataxia measured with the Scale for the Assessment and Rating of Ataxia was mostly correlated with the variability parameters. Furthermore, it was correlated with the directional deviation of the trajectory of movement of the pen tip from that of the finger and with increased dissimilarity of the shapes of the tracks. Limitations The results may have been influenced by the scale and parameters used to measure movement. Conclusions Ataxic handwriting with increased movement noise is characterized by irregular pen tip movements unconstrained by the finger or wrist. The severity of ataxia is correlated with these unconstrained movements.
17
Riek, S., and P. Bawa. "Recruitment of motor units in human forearm extensors." Journal of Neurophysiology 68, no. 1 (July 1, 1992): 100–108. http://dx.doi.org/10.1152/jn.1992.68.1.100.
Повний текст джерелаАнотація:
1. Experiments were conducted on single motor units of two forearm muscles, extensor carpi radialis (ECR) and extensor digitorum communis (EDC) of human subjects. Our interest was whether or not task groups could be identified in these forearm muscles, and, if so, was there orderly recruitment within each task group. 2. To test for the presence of separate task groups within ECR, motor-unit recruitment was examined for two isometric contractions:wrist extension and radial deviation. Each of the ECR motor units tested repeatedly discharged during contractions in both directions, indicating the absence of separate task groups in ECR for contractions in these two directions. 3. Recruitment order between pairs of ECR motor-unit action potentials was examined for wrist extension and radial deviation. For 58 paired comparisons, the order of recruitment was the same in both directions. In terms of force output, plots of twitch torque versus recruitment threshold of ECR motor units showed a positive correlation for both directions, wrist extension and radial deviation, demonstrating size-ordered recruitment of ECR motoneurons for both contractions. 4. The EDC motoneuron pool exhibited two partially overlapping subpopulations of motoneurons on the basis of task, one subpopulation recruited for middle finger extension and the second one for ring finger extension. Contractions involving the index and little fingers were not examined. It is concluded that motor-unit task groups do exist within EDC motoneuron pool. Plots of twitch torque versus recruitment threshold showed positive correlations for each of these two task groups.(ABSTRACT TRUNCATED AT 250 WORDS)
18
Holmes, Luke, Tuesday M. Watts-Overall, Erlend Slettevold, Dragos C. Gruia, and Gerulf Rieger. "The relationship between finger length ratio, masculinity, and sexual orientation in women: A correlational study." PLOS ONE 17, no. 3 (March 28, 2022): e0259637. http://dx.doi.org/10.1371/journal.pone.0259637.
Повний текст джерелаАнотація:
Homosexual women are, on average, more masculine in their appearance and behavior than heterosexual women. We hypothesized that their masculinity was influenced by exposure to elevated levels of prenatal androgen during early development. We recruited 199 women (including 67 homosexual women) and measured their masculinity via self-report and observer ratings. Our measure of prenatal androgen exposure was the ratio of the index to ring finger (2D:4D), which is hypothesized to be lower in women exposed to elevated levels of androgens during prenatal development. Homosexual women were substantially more masculine than heterosexual women in both self-report and observer ratings. However, homosexual women neither had more male-typical finger length ratios, nor did their finger length ratios relate to their masculinity in any predicted direction. Thus, we found no evidence that increased prenatal androgen exposure influenced masculinity in homosexual women.
19
Hollins, Mark, Christopher Corsi, and Page Sloan. "Pacinian Signals Determine the Direction and Magnitude of the Effect of Vibration on Pain." Perception 46, no. 8 (February 22, 2017): 987–99. http://dx.doi.org/10.1177/0301006617694630.
Повний текст джерелаАнотація:
Although the ability of vibration to reduce pain has been extensively documented, an occasional participant reports that vibration increases pain. For pain patients, such reports may reflect pathophysiology, but this is unlikely in studies of experimental pain in healthy participants. In the present series of experiments on 27 pain-free individuals, we manipulated both the frequency (12, 50, and 80 Hz) and amplitude of vibration to more fully characterize vibratory pain modulation. The noxious stimulus was pressure applied to a finger, and vibration was delivered to the fleshy palmar pad at the base of the same finger. Subjects continuously reported pain on a Visual Analog Scale. Intermittent vibration was used to minimize peripheral vibratory adaptation. Pain records at 12 and 50 Hz were similar; pooling them revealed significant hypoalgesia at the highest amplitude. At 80 Hz, in contrast, the middle amplitude produced hypoalgesia, but a significant shift toward hyperalgesia occurred at the highest amplitude. The strong correlation ( r = .81) between the Pacinian-weighted power of a vibration and the absolute value of the pain modulation it produces indicates that the Pacinian system plays a key role in vibratory hypoalgesia or hyperalgesia.
20
Hirakawa, Takehito, Hiroo Suzuki, Motoki Okumura, Kazutoshi Gohara, and Yuji Yamamoto. "Switching Dynamics Between Two Movement Patterns Varies According to Time Interval." International Journal of Bifurcation and Chaos 26, no. 10 (September 2016): 1630026. http://dx.doi.org/10.1142/s0218127416300263.
Повний текст джерелаАнотація:
This study investigated the regularity that characterizes the behavior of dissipative dynamical systems excited by external temporal inputs for pointing movements. Right-handed healthy male participants were asked to continuously point their right index finger at two light-emitting diodes (LEDs) located in the oblique left and right directions in front of them. These movements were performed under two conditions: one in which the direction was repeated and one in which the directions were switched on a stochastic basis. These conditions consisted of 12 tempos (30, 36, 42, 48, 51, 54, 57, 60, 63, 66, 69, and 72 beats per minute). Data from the conditions under which the input pattern was repeated revealed two different trajectories in hyper-cylindrical state space [Formula: see text], whereas the conditions under which the inputs were switched induced transitions between the two trajectories, which were considered to be excited attractors. The transitions between the two excited attractors were characterized by a self-similar structure. Moreover, the correlation dimensions increased as the tempos increased. These results suggest a relationship of [Formula: see text] ([Formula: see text] is the switching-time length; i.e. the condition) between temporal input and pointing behavior and that continuous pointing movements are regular rather than random noise.
21
Daliri, Ayoub, Roman A. Prokopenko, J. Randall Flanagan, and Ludo Max. "Control and Prediction Components of Movement Planning in Stuttering Versus Nonstuttering Adults." Journal of Speech, Language, and Hearing Research 57, no. 6 (December 2014): 2131–41. http://dx.doi.org/10.1044/2014_jslhr-s-13-0333.
Повний текст джерелаАнотація:
Purpose Stuttering individuals show speech and nonspeech sensorimotor deficiencies. To perform accurate movements, the sensorimotor system needs to generate appropriate control signals and correctly predict their sensory consequences. Using a reaching task, we examined the integrity of these control and prediction components separately for movements unrelated to the speech motor system. Method Nine stuttering and 9 nonstuttering adults made fast reaching movements to visual targets while sliding an object under the index finger. To quantify control, we determined initial direction error and end point error. To quantify prediction, we calculated the correlation between vertical and horizontal forces applied to the object—an index of how well vertical force (preventing slip) anticipated direction-dependent variations in horizontal force (moving the object). Results Directional and end point error were significantly larger for the stuttering group. Both groups performed similarly in scaling vertical force with horizontal force. Conclusions The stuttering group's reduced reaching accuracy suggests limitations in generating control signals for voluntary movements, even for nonorofacial effectors. Typical scaling of vertical force with horizontal force suggests an intact ability to predict the consequences of planned control signals. Stuttering may be associated with generalized deficiencies in planning control signals rather than predicting the consequences of those signals.
22
Ghafoor, Abdul, Jian S. Dai, and Joseph Duffy. "Stiffness Modeling of the Soft-Finger Contact in Robotic Grasping." Journal of Mechanical Design 126, no. 4 (July 1, 2004): 646–56. http://dx.doi.org/10.1115/1.1758255.
Повний текст джерелаАнотація:
This paper investigates the soft-finger contact by presenting the contact with a set of line springs based on screw theory, reveals the rotational effects, and identifies the stiffness properties of the contact. An elastic model of a soft-finger contact is proposed and a generalized contact stiffness matrix is developed by applying the congruence transformation and by introducing stiffness mapping of the line springs in translational directions and rotational axes. The effective stiffnesses along these directions and axes are hence obtained and the rotational stiffnesses are revealed. This helps create a screw representation of a six-dimensional soft-finger contact and produce an approach of analyzing and synthesizing a robotic grasp without resorting to the point contact representation. The correlation between the rotational stiffness, the number of equivalent point contacts and the number of equivalent contours is given and the stiffness synthesis is presented with both modular and direct approaches. The grasp thus achieved from the stiffness analysis contributes to both translational and rotational restraint and the stiffness matrix so developed is proven to be symmetric and positive definite. Case studies are presented with a two-soft-finger grasp and a three-soft-finger grasp. The grasps are analyzed with a general stiffness matrix which is used to control the fine displacements of a grasped object by changing the preload on the contact.
23
Burton, Leslie A., Debra Henninger, Jessica Hafetz, and John Cofer. "Aggression, gender-typical childhood play, and a prenatal hormonal index." Social Behavior and Personality: an international journal 37, no. 1 (February 1, 2009): 105–15. http://dx.doi.org/10.2224/sbp.2009.37.1.105.
Повний текст джерелаАнотація:
An evaluation was conducted of 134 university students (93 female, 41 male) with the Aggression Questionnaire of Buss and Perry (1992) and a Gender-Typical Play Behavior Questionnaire constructed for this study. Measurements were taken of an index of prenatal androgen activity – finger length ratios – for which gender differences have been reported. Gender differences in aggression and in the finger length ratios were found, in the directions reported in the literature. Correlations between greater current report of aggression and play style more typical of boys during childhood were found in both the male and female samples. This relationship between current level of aggression and gender-typical childhood play across time was notable. Gender-typical finger length ratios were associated with gender-typical patterns of play for several indices. The current findings provide support for the idea that physical aggression, childhood play style, and finger length ratios may reflect prenatal androgenic influence.
24
Wolski, Marcin, Martin Englund, Gwidon Stachowiak, and Pawel Podsiadlo. "Automated selection of bone texture regions on hand radiographs: Data from the Osteoarthritis Initiative." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 230, no. 12 (November 10, 2016): 1117–32. http://dx.doi.org/10.1177/0954411916676219.
Повний текст джерелаАнотація:
Manual selection of finger trabecular bone texture regions on hand X-ray images is time-consuming, tedious, and observer-dependent. Therefore, we developed an automated method for the region selection. The method selects square trabecular bone regions of interest above and below the second to fifth distal and proximal interphalangeal joints. Two regions are selected per joint (16 regions per hand). The method consists of four integral parts: (1) segmentation of a radiograph into hand and background, (2) identification of finger regions, (3) localization of center points of heads of distal phalanges and the distal interphalangeal, proximal interphalangeal, and metacarpophalangeal joints, and (4) placement of the regions of interest under and above the distal and proximal interphalangeal joints. A gold standard was constructed from regions selected by two observers on 40 hand X-ray images taken from Osteoarthritis Initiative cohort. Datasets of 520 images were generated from the 40 images to study the effects of hand and finger positioning. The accuracy in regions selection and the agreement in calculating five directional fractal parameters were evaluated against the gold standard. The accuracy, agreement, and effects of hand and finger positioning were measured using similarity index (0 for no overlap and 1 for entire overlap) and interclass correlation coefficient as appropriate. A high accuracy in selecting regions (similarity index ≥ 0.79) and a good agreement in fractal parameters (interclass correlation coefficient ≥ 0.58) were achieved. Hand and finger positioning did not affect considerably the region selection (similarity index ≥ 0.70). These results indicate that the method developed selects bone regions on hand X-ray images with accuracy sufficient for fractal analyses of bone texture.
25
Damon, James, Stefan Dietrich, Sasidhar Gorantla, Uwe Popp, Brando Okolo, and Volker Schulze. "Process porosity and mechanical performance of fused filament fabricated 316L stainless steel." Rapid Prototyping Journal 25, no. 7 (August 12, 2019): 1319–27. http://dx.doi.org/10.1108/rpj-01-2019-0002.
Повний текст джерелаАнотація:
Purpose This study aims to investigate the correlation between build orientation characteristics, part porosity and mechanical properties of the fused filament fabrication (FFF) process to provide insight into pore formation mechanisms and to establish guidelines for optimal process configurations. Design/methodology/approach Micro computed tomography and metallographic sections provide the basis for a correlation between porosity and extrusion path. Using the correlations found in this study, the way to improve printing strategies and filament properties can be deduced directly from an analysis of the print path and the final influence on mechanical performance. Findings With metal-FFF 3D printing technology, near-dense parts (0.5 Vol.%) can be fabricated. The pore architecture is strongly connected to the build direction and print strategy with parallel, elongated pore channels. Mechanical values of FFF samples are similar to metal injection-molded (MIM) parts, except the elongation to fracture. The high difference of yield strength of sintered samples compared to laser powder bed fusion (LPBF) samples can be attributed to the finer grains and a Hall–Petch hardening effect. The conclusions derived from this study are that the presented process is capable of producing comparable part qualities compared to MIM samples, with higher build rates in comparison to LPBF processes. Originality/value 316L stainless steel was successfully manufactured via FFF. This paper also addresses the effects of scanning strategies on the resulting porosity and proposes improvements to reduce residual porosity, thus increasing the mechanical performance in the future.
26
CHEN, CHING-YAO, and ECKART MEIBURG. "Miscible porous media displacements in the quarter five-spot configuration. Part 2. Effect of heterogeneities." Journal of Fluid Mechanics 371 (September 25, 1998): 269–99. http://dx.doi.org/10.1017/s0022112098002201.
Повний текст джерелаАнотація:
Direct numerical simulations are employed to investigate the coupling between the viscous fingering instability and permeability heterogeneities for miscible displacements in quarter five-spot flows. Even moderate inhomogeneities are seen to have a strong effect on the flow, which can result in a complete bypass of the linear growth phase of the viscous fingering instability. In contrast to their homogeneous counterparts (cf. Part 1, Chen & Meiburg 1998), heterogeneous quarter five-spot flows are seen to exhibit a more uniform dominant length scale throughout the entire flow domain. In line with earlier findings for unidirectional displacements, an optimal interaction of the mobility and permeability related vorticity modes can occur when the viscous length scale is of the same order as the correlation length of the heterogeneities. This resonance mechanism results in a minimal breakthrough recovery for intermediate correlation lengths, at fixed dimensionless flow rates in the form of a Péclet number Pe. However, for a constant correlation length, the recovery does not show a minimum as Pe is varied.Confirming earlier observations, the simulations show a more rapid breakthrough as the variance of the permeability variations increases. However, this tendency is far more noticeable in some parameter regimes than in others. It is furthermore observed that relatively low variances usually cannot change the tendency for a dominant finger to evolve along the inherently preferred diagonal direction, especially for relatively small correlation lengths. Only for higher variances, and for larger correlation lengths, are situations observed in which an off-diagonal finger can become dominant. Due to the nonlinear nature of the selection mechanisms at work, a change in the variance of the heterogeneities can result in the formation of dominant fingers along entirely different channels.
27
Zienkiewicz, Aleksandra, Michelle Favre, Hany Ferdinando, Stephanie Iring, Jorge Serrador, and Teemu Myllylä. "Blood pressure wave propagation—a multisensor setup for cerebral autoregulation studies." Physiological Measurement 42, no. 11 (November 1, 2021): 115007. http://dx.doi.org/10.1088/1361-6579/ac3629.
Повний текст джерелаАнотація:
Abstract Objective. Cerebral autoregulation is critically important to maintain proper brain perfusion and supply the brain with oxygenated blood. Non-invasive measures of blood pressure (BP) are critical in assessing cerebral autoregulation. Wave propagation velocity may be a useful technique to estimate BP but the effect of the location of the sensors on the readings has not been thoroughly examined. In this paper, we were interested in studying whether the propagation velocity of a pressure wave in the direction from the heart to the brain may differ compared with propagation from the heart to the periphery, as well as across different physiological tasks and/or health conditions. Using non-invasive sensors simultaneously placed at different locations of the human body allows for the study of how the propagation velocity of the pressure wave, based on pulse transit time (PTT), varies across different directions. Approach. We present a multi-sensor BP wave propagation measurement setup intended for cerebral autoregulation studies. The presented sensor setup consists of three sensors, one placed on each of the neck, chest and finger, allowing simultaneous measurement of changes in BP propagation velocity towards the brain and to the periphery. We show how commonly tested physiological tasks affect the relative changes of PTT and correlations with BP. Main results. We observed that during maximal blow, valsalva and breath hold breathing tasks, the relative changes of PTT were higher when PTT was measured in the direction from the heart to the brain than from the heart to the peripherals. In contrast, during a deep breathing task, the relative change in PTT from the heart to the brain was lower. In addition, we present a short literature review of the PTT methods used in brain research. Significance. These preliminary data suggest that the physiological task and direction of PTT measurement may affect relative PTT changes. The presented three-sensor setup provides an easy and neuroimaging compatible method for cerebral autoregulation studies by allowing measurement of BP wave propagation velocity towards the brain versus towards the periphery.
28
He, Ketai, and Xue Zhao. "3D Thermal Finite Element Analysis of the SLM 316L Parts with Microstructural Correlations." Complexity 2018 (October 3, 2018): 1–13. http://dx.doi.org/10.1155/2018/6910187.
Повний текст джерелаАнотація:
In this study, a multitrack and multilayer finite element model was developed to simulate the temperature field and molten pool contours during selective laser melting (SLM) of 316L stainless steel powder under different scanning strategies. The simulated temperature field and its evolution over time were compared with experimental measurement results. Furthermore, a correlation was established by the presented results between the predicted thermal behavior and the microstructure of SLM specimens. It was found that the maximum temperature of the molten pool rose slightly with the increase of scanning tracks, but when laser scanned multilayer, the maximum temperature rose first and then decreased. There are large columnar crystals in molten pools, growing in the direction of the maximum temperature gradient. The microstructure defects are more likely to occur at the bonding regions between adjacent layers and islands, where the heat and stress are concentrated. Moreover, the results also showed that the scanning strategy affects the microstructure and microhardness. Also, the SLM 316L parts under the S-shaped strategy had finer grains and a higher Vicker hardness than that formed under the island strategy.
29
Bremner, F. D., J. R. Baker, and J. A. Stephens. "Effect of task on the degree of synchronization of intrinsic hand muscle motor units in man." Journal of Neurophysiology 66, no. 6 (December 1, 1991): 2072–83. http://dx.doi.org/10.1152/jn.1991.66.6.2072.
Повний текст джерелаАнотація:
1. Recordings were made of the firing of pairs of intrinsic hand muscle motor units active under different task conditions in man. The different tasks were defined as isometric contractions producing force in one of three different directions: finger abduction, finger extension, or finger flexion. The degree of motor-unit synchronization associated with each of these task conditions was compared with the use of cross-correlation analysis. 2. The average amount of synchronization between the firing of motor units recorded from within first dorsal interosseous muscle (IDI) was greater during index finger extension than during index finger abduction (n = 8 motor-unit pairings, 3 subjects). In addition, for another sample population of motor units, the average amount of synchronization was greater during index finger abduction than during index finger flexion (n = 11 motor-unit pairings, 4 subjects). 3. In a further series of experiments, one motor unit of each pair was recorded from second dorsal interosseous muscle (2DI), whereas the other motor unit of each pair was recorded from 1DI. The average amount of synchronization for these motor-unit pairings was greater during extension of the index and middle fingers than during abduction of the index and middle fingers (n = 8, 4 subjects). For another sample population of such motor-unit pairings, the average amount of synchronization was found to be greater during abduction of the index and middle fingers than during flexion of the index and middle fingers (n = 11, 4 subjects). 4. In approximately one-third of cases, it was not found possible to maintain the same firing rates from two motor units in 1DI when active under different task conditions. For instance, the "reference" motor unit might consistently fire at a faster rate than the "response" motor unit when active during index finger extension but consistently fire at a slower rate than the response motor unit when active during index finger abduction. Where such motor-unit pairs have been studied in detail, the pattern of task dependence in their synchronization was found to be similar to that described above for motor-unit pairs in which the firing rates remained constant under the different task conditions.(ABSTRACT TRUNCATED AT 400 WORDS)
30
Kurillo, Gregorij, Matjaž Mihelj, Marko Munih, and Tadej Bajd. "Isometric Finger Device for Assessment and Training of Force Coordination Using Virtual Reality." Journal of Medical Devices 1, no. 4 (August 14, 2007): 279–82. http://dx.doi.org/10.1115/1.2812428.
Повний текст джерелаАнотація:
Grasping of stroke patients is often affected by improper coactivation of muscles controlling the fingers. The restoration of hand function therefore represents an important goal in rehabilitation. Quantitative data on coordination between fingers can be helpful for the assessment of therapy effectiveness. We have designed a novel isometric finger device to assess three-dimensional forces applied by the thumb, index, and middle finger. The device was used in connection with a simple virtual reality task where the patient had to open a safe by sequentially rotating a knob using the isometric finger input. The presented virtual reality application was evaluated in a group of healthy subjects and a chronic stroke patient to obtain preliminary performance results. We analyzed the coordination of fingertip forces between the thumb and opposing fingers. Pearson correlation coefficient was determined to assess the coordination of force in each direction. In healthy subjects, the analysis of the fingertip forces showed precise coordination of force between the fingers to control a virtual object. The performance of the stroke patient was considerably lower due to reduced muscle control and presence of strong spasticity. The results showed use of excessive force in both hands and lower coordination of force between the fingers as compared to the healthy subjects. The proposed virtual reality system is considered as a complementary method to the existing methods used in physical and occupational therapy. Specific virtual reality tasks could be designed to train coordination of force between the affected fingers.
31
Blouin, Jean, Anahid H. Saradjian, Nicolas Lebar, Alain Guillaume, and Laurence Mouchnino. "Opposed optimal strategies of weighting somatosensory inputs for planning reaching movements toward visual and proprioceptive targets." Journal of Neurophysiology 112, no. 9 (November 1, 2014): 2290–301. http://dx.doi.org/10.1152/jn.00857.2013.
Повний текст джерелаАнотація:
Behavioral studies have suggested that the brain uses a visual estimate of the hand to plan reaching movements toward visual targets and somatosensory inputs in the case of somatosensory targets. However, neural correlates for distinct coding of the hand according to the sensory modality of the target have not yet been identified. Here we tested the twofold hypothesis that the somatosensory input from the reaching hand is facilitated and inhibited, respectively, when planning movements toward somatosensory (unseen fingers) or visual targets. The weight of the somatosensory inputs was assessed by measuring the amplitude of the somatosensory evoked potential (SEP) resulting from vibration of the reaching finger during movement planning. The target sensory modality had no significant effect on SEP amplitude. However, Spearman's analyses showed significant correlations between the SEPs and reaching errors. When planning movements toward proprioceptive targets without visual feedback of the reaching hand, participants showing the greater SEPs were those who produced the smaller directional errors. Inversely, participants showing the smaller SEPs when planning movements toward visual targets with visual feedback of the reaching hand were those who produced the smaller directional errors. No significant correlation was found between the SEPs and radial or amplitude errors. Our results indicate that the sensory strategy for planning movements is highly flexible among individuals and also for a given sensory context. Most importantly, they provide neural bases for the suggestion that optimization of movement planning requires the target and the reaching hand to both be represented in the same sensory modality.
32
Schwarz, Theresa, Yasmin Striedner, Andreas Horner, Karin Haase, Jasmin Kemptner, Nicole Zeppezauer, Philipp Hermann, and Irene Tiemann-Boege. "PRDM9 forms a trimer by interactions within the zinc finger array." Life Science Alliance 2, no. 4 (July 15, 2019): e201800291. http://dx.doi.org/10.26508/lsa.201800291.
Повний текст джерелаАнотація:
PRDM9 is a trans-acting factor directing meiotic recombination to specific DNA-binding sites by its zinc finger (ZnF) array. It was suggested that PRDM9 is a multimer; however, we do not know the stoichiometry or the components inducing PRDM9 multimerization. In this work, we used in vitro binding studies and characterized with electrophoretic mobility shift assays, mass spectrometry, and fluorescence correlation spectroscopy the stoichiometry of the PRDM9 multimer of two different murine PRDM9 alleles carrying different tags and domains produced with different expression systems. Based on the migration distance of the PRDM9–DNA complex, we show that PRDM9 forms a trimer. Moreover, this stoichiometry is adapted already by the free, soluble protein with little exchange between protein monomers. The variable ZnF array of PRDM9 is sufficient for multimerization, and at least five ZnFs form already a functional trimer. Finally, we also show that only one ZnF array within the PRDM9 oligomer binds to the DNA, whereas the remaining two ZnF arrays likely maintain the trimer by ZnF–ZnF interactions.
33
OUGHTON, SEAN, and ROSSELLA PRANDI. "Kinetic helicity and MHD turbulence." Journal of Plasma Physics 64, no. 2 (August 2000): 179–93. http://dx.doi.org/10.1017/s0022377800008424.
Повний текст джерелаАнотація:
The issue of dynamical anisotropy in helical three-dimensional magnetohydrodynamic turbulence with a mean magnetic field B0 is investigated. Using high-resolution direct numerical simulations, we follow the evolution of various isotropic initial states characterized by their different values of the kinetic helicity. The cross helicity and magnetic helicity of the initial conditions are also varied. In agreement with earlier work, we find that such initial states become anisotropic in of order an eddy-turnover time, with correlation lengths parallel to B0 remaining largely unchanged while finer scales are excited in the perpendicular directions. Moreover, it is found that the development of both the anisotropy and the energy are essentially independent of the initial level of kinetic helicity. The physics associated with this latter feature is discussed.
34
He, Qingqing, Mengya Wang, and Steve Hung Lam Yim. "The spatiotemporal relationship between PM<sub>2.5</sub> and aerosol optical depth in China: influencing factors and implications for satellite PM<sub>2.5</sub> estimations using MAIAC aerosol optical depth." Atmospheric Chemistry and Physics 21, no. 24 (December 17, 2021): 18375–91. http://dx.doi.org/10.5194/acp-21-18375-2021.
Повний текст джерелаАнотація:
Abstract. Satellite aerosol retrievals have been a popular alternative to monitoring the surface-based PM2.5 concentration due to their extensive spatial and temporal coverage. Satellite-derived PM2.5 estimations strongly rely on an accurate representation of the relationship between ground-level PM2.5 and satellite aerosol optical depth (AOD). Due to the limitations of satellite AOD data, most studies have examined the relationship at a coarse resolution (i.e., ≥ 10 km); thus, more effort is still needed to better understand the relationship between “in situ” PM2.5 and AOD at finer spatial scales. While PM2.5 and AOD could have obvious temporal variations, few studies have examined the diurnal variation in their relationship. Therefore, considerable uncertainty still exists in satellite-derived PM2.5 estimations due to these research gaps. Taking advantage of the newly released fine-spatial-resolution satellite AOD data derived from the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm and real-time ground aerosol and PM2.5 measurements, this study explicitly explored the relationship between PM2.5 and AOD as well as its plausible impact factors, including meteorological parameters and topography, in mainland China during 2019, at various spatial and temporal scales. The coefficient of variation, the Pearson correlation coefficient and the slope of the linear regression model were used. Spatially, stronger correlations mainly occurred in northern and eastern China, and the linear slope was larger on average in northern inland regions than in other areas. Temporally, the PM2.5–AOD correlation peaked at noon and in the afternoon, and reached a maximum in winter. Simultaneously, considering relative humidity (RH) and the planetary boundary layer height (PBLH) in the relationship can improve the correlation, but the effect of RH and the PBLH on the correlation varied spatially and temporally with respect to both strength and direction. In addition, the largest correlation occurred at 400–600 m primarily in basin terrain such as the Sichuan Basin, the Shanxi–Shaanxi basins and the Junggar Basin. MAIAC 1 km AOD can better represent the ground-level fine particulate matter in most domains with exceptions, such as in very high terrain (i.e., Tibetan Plateau) and northern central China (i.e., Qinghai and Gansu). The findings of this study have useful implications for satellite-based PM2.5 monitoring and will further inform the understanding of the aerosol variation and PM2.5 pollution status of mainland China.
35
Zhou, Y., X. Qie, and S. Soula. "A study of the relationship between cloud-to-ground lightning and precipitation in the convective weather system in China." Annales Geophysicae 20, no. 1 (January 31, 2002): 107–13. http://dx.doi.org/10.5194/angeo-20-107-2002.
Повний текст джерелаАнотація:
Abstract. In this paper, the correlation between cloud-to-ground (CG) lightning and precipitation has been studied by making use of the data from weather radar, meteorological soundings, and a lightning location system that includes three direction finders about 40 km apart from each other in the Pingliang area of east Gansu province in P. R. China. We have studied the convective systems that developed during two cold front processes passing over the observation area, and found that the CG lightning can be an important factor in the precipitation estimation. The regression equation between the average precipitation intensity (R) and the number of CG lightning flashes (L) in the main precipitation period is R = 1.69 ln (L) - 0.27, and the correlation coefficient r is 0.86. The CG lightning flash rate can be used as an indicator of the formation and development of the convective weather system. Another more exhaustive precipitation estimation method has been developed by analyzing the temporal and spatial distributions of the precipitation relative to the location of the CG lightning flashes. Precipitation calculated from the CG lightning flashes is very useful, especially in regions with inadequate radar cover.Key words. Meteorology and atmospheric dynamics (atmospheric electricity; lightning; precipitation)
36
Parnow, Abdolhossein, Sadegh Amani-Shalamzari, and Magni Mohr. "The Repeated Curve Sprint Test Appears to be an Appropriate Tool for Estimating Anaerobic Fitness in Young Trained Male Futsal Players." Journal of Human Kinetics 82, no. 1 (April 15, 2022): 181–89. http://dx.doi.org/10.2478/hukin-2022-0044.
Повний текст джерелаАнотація:
Abstract This study aimed to determine the magnitude of correlation between the repeated curve sprint test (RCST), the running-based anaerobic sprint test (RAST) and the Wingate anaerobic test (WAnT) in elite male futsal players to determine whether the field test can be a futsal-specific alternative assessment tool compared to the other tests. Fifteen trained futsal players (20±3 yrs) performed the RCST, RAST and WAnT in a crossover design over three weeks. Peak power (PP), average power (AP) and the fatigue index (FI) were obtained from the tests. Finger-prick blood-lactate measurements were performed before and after the tests, and heart rate loading was recorded. To assess the magnitude and direction of the relationship between variables the Pearson’s correlation coefficient (r) was calculated. In respect of AP, there was a significant correlation between the RCST and both the WAnT (r=0.63, p=0.012) and the RAST (r=0.67, p=0.006). In respect of PP, the RCST only correlated with the RAST (r=0.71, p=0.003). In respect of the FI, the RCST did not correlate with either the RAST or the WAnT (p>0.05). Post-test heart rate values in the RCST correlated with those in both the WAnT (r=0.88, p=0.001) and the RAST (r=0.77, p=0.001). Also, post-test blood-lactate levels in the RCST correlated with those in both the RAST (r=0.58, p=0.025) and the WAnT (r=0.54, p=0.039). In conclusion, the RCST can be a valid and practical field test for measuring anaerobic fitness in competitive futsal players.
37
JIJI, C. V., and RAVI KRISHNAN UNNI. "FUSION OF MULTISPECTRAL AND PANCHROMATIC IMAGES BASED ON THE NONSUBSAMPLED CONTOURLET TRANSFORM." International Journal of Image and Graphics 13, no. 03 (July 2013): 1350010. http://dx.doi.org/10.1142/s0219467813500101.
Повний текст джерелаАнотація:
This paper proposes two different methods for fusing multispectral (MS) and panchromatic (PAN) satellite images using the nonsubsampled contourlet transform (NSCT). The NSCT decomposes the images into several directional subbands at flexible resolutions. The finer subbands of the MS image decomposition, which represent the high frequency details, are modified with the subbands from PAN image. The inverse transform gives a high resolution MS representation of the given low resolution MS image. The paper also proposes the use of the parameters mean structural similarity index measure (MSSIM) and edge stability mean square error (ESMSE) to measure the quality of the fused image, in addition to standard parameters like correlation coefficient, PSNR, RASE and ERGAS. Experiments show that the proposed methods outperform standard fusion techniques in terms of both visual quality and quantitative error measures. The fused images obtained using the proposed methods show good structural similarity and better edge stability as the contourlet transform very well extracts the oriented edge details from the high resolution PAN image.
38
Ermolenko, Aleksandr S. "RONTGEN-MORPHOMETRIC DATA TO THE CORRELATION OF THE PHALANXES LENGTH WITH A LENGTH OF HUMAN HANDS FINGERS." Morphological newsletter 28, no. 4 (February 28, 2021): 25–30. http://dx.doi.org/10.20340/mv-mn.2020.28(4):489.
Повний текст джерелаАнотація:
Data on the anatomical variability of the phalanges and fingers of the hand are needed to expand biometric databases in robotics, prosthetics, and forensic medicine. The aim of the study was to study the X-ray morphometric variability of the length of individual phalanges of the fingers of the hand, their relationship with the length of the fingers. By the method of morphometry, the lengths of individual phalanges and fingers of the hands were determined on 100 certified radiographs of the hands of persons of the second mature age (50 men and 50 women), and a correlation was established between the length of the phalanges and fingers. To identify the statistical relationship between quantitative characteristics, the parametric Pearson correlation coefficient was used. The relationship between quantitative indicators was assessed using multiple regression analysis. Classification and grouping were carried out using cluster analysis by the complete connection method, the Euclidean distance served as a measure of the relationship. The variability in the length of the phalanges and fingers increases towards the ulnar edge. The X-ray morphometric length of individual phalanges and fingers is characterized, regardless of gender, by regular formulas of variability: the length of the proximal phalanges is III>IV>II>V>I, the length of the middle phalanges is III>IV>II>V, the length of the distal phalanges is I>IV> III>II>V, finger length - III>IV>II>V>I. The degree of dependence of the length of the fingers on the length of the phalanges in both men and women decreases in the distal direction in the longitudinal axis and the ulnar edge in the transverse axis of the hand. As a result of cluster analysis, the organization of the objects of study was established depending on the degree of correlations of their length: groups of proximal phalanges of II-IV and I, V fingers, groups of middle phalanges of III-IV and II-V fingers, distal phalanges and fingers are organized somewhat more complexly - groups III -IV, II, V fingers and group I fingers. The data obtained can be used in the development of innovative anatomically grounded anthropomorphic robotic manipulators, in anthropological reconstructions, and in identification in forensic practice.
39
C., Harish Kumar, and Yaam Kumar C. "Comparative study of aspiration versus non-aspiration fine needle technique in thyroid nodule and its correlation with post-operative histopathological examination." International Surgery Journal 5, no. 3 (February 26, 2018): 1046. http://dx.doi.org/10.18203/2349-2902.isj20180828.
Повний текст джерелаАнотація:
Background: Thyroid gland is unique of all endocrine glands because it is the largest, superficial and the only one amendable to direct physical examination. A discrete swelling in one lobe and with no palpable abnormality elsewhere is termed as solitary swelling. Fine needle aspiration cytology (FNAC) is the investigation of choice in solitary thyroid swellings. There is another technique fine needle non aspiration cytology (FNNAC) which avoids aspiration but still permits cytologic review of the swellings which can also be done in thyroid swellings. The objective of the study was to compare and analyze the preoperative efficiency of FNAC vs FNNAC in solitary thyroid nodules and its correlation with post-operative histopathological examination findings.Methods: A total of 72 patients presenting with thyroid nodule in this hospital in BMCRI, Bengaluru during period of January2017 to December2017 underwent both FNAC and techniques. 23 G needles was used for both FNAC and FNNAC. FNAC was performed using needle and a syringe using aspiration. In FNNAC technique the needle held between thumb and fore finger of one hand was gently inserted into the nodule and was moved in different directions. Material entering the needle hub by capillary action was then expressed onto clean glass slides after attaching syringe filled with air to it and smears were prepared. Cases which underwent total/hemi thyroidectomy, the specimen was sent to pathology department in 10% formalin solution.Results: FNNAC produced diagnostically superior samples and less diagnostically inadequate samples than FNAC.Conclusions: As thyroid is a vascular and a colloid organ, in FNAC aspiration gives blood/colloid with less cellular architecture in most of the cases. In FNNAC cellular architecture was preserved with less blood/colloid background which aids in easier cytological diagnosis. Hence FNNAC is a better technique than FNAC in cytological diagnosis of solitary thyroid nodule.
40
Liu, Yang, Brandon M. Sexton, and Hannah J. Block. "Spatial bias in estimating the position of visual and proprioceptive targets." Journal of Neurophysiology 119, no. 5 (May 1, 2018): 1879–88. http://dx.doi.org/10.1152/jn.00633.2017.
Повний текст джерелаАнотація:
When people match an unseen hand to a visual or proprioceptive target, they make both variable and systematic (bias) errors. Variance is a well-established factor in behavior, but the origin and implications of bias, and its connection to variance, are poorly understood. Eighty healthy adults matched their unseen right index finger to proprioceptive (left index finger) and visual targets with no performance feedback. We asked whether matching bias was related to target modality and to the magnitude or spatial properties of matching variance. Bias errors were affected by target modality, with subjects estimating visual and proprioceptive targets 20 mm apart. We found three pieces of evidence to suggest a connection between bias and variable errors: 1) for most subjects, the target modality that yielded greater spatial bias was also estimated with greater variance; 2) magnitudes of matching bias and variance were somewhat correlated for each target modality ( R = 0.24 and 0.29); and 3) bias direction was closely related to the angle of the major axis of the confidence ellipse ( R = 0.60 and 0.63). However, whereas variance was significantly correlated with visuo-proprioceptive weighting as predicted by multisensory integration theory ( R = −0.29 and 0.27 for visual and proprioceptive variance, respectively), bias was not. In a second session, subjects improved their matching variance, but not bias, for both target modalities, indicating a difference in stability. Taken together, these results suggest bias and variance are related only in some respects, which should be considered in the study of multisensory behavior. NEW & NOTEWORTHY People matching visual or proprioceptive targets make both variable and systematic (bias) errors. Multisensory integration is thought to minimize variance, but if the less variable modality has more bias, behavioral accuracy will decrease. Our data set suggests this is unusual. However, although bias and variable errors were spatially related, they differed in both stability and correlation with multisensory weighting. This suggests the bias-variance relationship is not straightforward, and both should be considered in multisensory behavior.
41
Chen, Ting, Peng Pan, Wei Wei, Yanmin Zhang, Guanghui Cui, Zhendong Yu, and Xin Guo. "Expression of Zeb1 in the differentiation of mouse embryonic stem cell." Open Life Sciences 17, no. 1 (January 1, 2022): 455–62. http://dx.doi.org/10.1515/biol-2022-0042.
Повний текст джерелаАнотація:
Abstract Embryonic stem cells (ESCs) differentiation is a process of replication and refinement, and the directional lineage differentiation of ESCs involves the epithelial-mesenchymal transition (EMT)- mesenchymal-epithelial transition (MET) process. A previous study revealed that Zinc finger E-box-binding homeobox 1 (Zeb1) plays a vital role in EMT, which could repress E-cadherin promoter and induce an EMT in cells. To verify the expression of Zeb1 and its correlation with Lin28a in mouse ESCs differentiation, we performed qRT-PCR and western blots to detect the expression of Lin28a mRNA and protein after Zeb1 knockdown. The expression of Zeb1 decreased over time of mouse ESCs differentiation but significantly increased in mouse embryonal carcinoma cells. After knockdown of Zeb1, Lin28a and Vimentin expression were decreased, while E-cadherin expression increased both in mouse ESCs, EBs, GC1, and P19 cells. We found that Zeb1 promoted the invasive ability of mouse embryonal carcinoma cells. These results revealed that expression of Zeb1 decreased during the differentiation of ESCs, and Lin28a and EMT processes can be regulated by Zeb1, which need to be verified in the future studies.
42
Jawak, S. D., M. Joshi, A. J. Luis, P. H. Pandit, S. Kumar, and S. F. Wankhede. "MAPPING VELOCITY OF THE POTSDAM GLACIER, EAST ANTARCTICA USING LANDSAT-8 DATA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W13 (June 5, 2019): 1753–57. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w13-1753-2019.
Повний текст джерелаАнотація:
<p><strong>Abstract.</strong> Most of the glaciers have been retreating and thinning globally due to climate change. Glacier velocity is one such important parameter of glacier dynamics, which helps to understand the mass balance. The variations in velocity at different areas of the glacier can be used to identify the zones of ablation and accumulation. Zones of accumulation are identified as areas with higher velocity. This data is useful to incorporate in the glacier mass balance analysis. This study aims to derive the glacier velocity, using feature tracking technique for Potsdam glacier, east Antarctica. Feature tracking is an efficient way to derive glacier velocity, which is based on a cross-correlation algorithm that seeks offsets of the maximal correlation window on repeated satellite images. In this technique, two temporally different images are acquired for the same area and a distinct feature on both images is identified and the velocity is calculated with respect to the movement of that particular feature from one image to the other. Landsat-8 data for the year 2016 was used to derive velocity. Finer resolution promotes better feature tracking so the panchromatic band (band 8) of Landsat-8 OLI with a resolution of 15&thinsp;m was utilized for deriving velocity. This technique was performed using COSI-Corr module in ENVI. This tool calculates displacement between the east-west and north-south directions, and the resultant velocity is calculated using the displacement in both directions and the temporal difference of two images. The velocity map generated at a resolution of 240&thinsp;m showed that the resultant velocity ranged between 18.60 and 285.28&thinsp;ma<sup>&minus;1</sup>. Bias and root mean square error (RMSE) have been calculated with respect to the point-by-point MEaSUREs data provided by National Snow and Ice Data Centre at 1000&thinsp;m resolution. The RMSE was found to be 78.06&thinsp;ma<sup>&minus;1</sup> for 2016. The velocity for Potsdam glacier was also pictorially validated with the DGPS measurements from literature.</p>
43
Pixner, Florian, Fernando Warchomicka, Patrick Peter, Axel Steuwer, Magnus Hörnqvist Colliander, Robert Pederson, and Norbert Enzinger. "Wire-Based Additive Manufacturing of Ti-6Al-4V Using Electron Beam Technique." Materials 13, no. 15 (July 24, 2020): 3310. http://dx.doi.org/10.3390/ma13153310.
Повний текст джерелаАнотація:
Electron beam freeform fabrication is a wire feed direct energy deposition additive manufacturing process, where the vacuum condition ensures excellent shielding against the atmosphere and enables processing of highly reactive materials. In this work, this technique is applied for the α + β-titanium alloy Ti-6Al-4V to determine suitable process parameter for robust building. The correlation between dimensions and the dilution of single beads based on selected process parameters, leads to an overlapping distance in the range of 70–75% of the bead width, resulting in a multi-bead layer with a uniform height and with a linear build-up rate. Moreover, the stacking of layers with different numbers of tracks using an alternating symmetric welding sequence allows the manufacturing of simple structures like walls and blocks. Microscopy investigations reveal that the primary structure consists of epitaxial grown columnar prior β-grains, with some randomly scattered macro and micropores. The developed microstructure consists of a mixture of martensitic and finer α-lamellar structure with a moderate and uniform hardness of 334 HV, an ultimate tensile strength of 953 MPa and rather low fracture elongation of 4.5%. A subsequent stress relief heat treatment leads to a uniform hardness distribution and an extended fracture elongation of 9.5%, with a decrease of the ultimate strength to 881 MPa due to the fine α-lamellar structure produced during the heat treatment. Residual stresses measured by energy dispersive X-ray diffraction shows after deposition 200–450 MPa in tension in the longitudinal direction, while the stresses reach almost zero when the stress relief treatment is carried out.
44
Dreimanis, Aleksis, Paul F. Karrow, and Peter J. Barnett. "Lobal affinity of Late Wisconsin tills at St. Marys in southwestern Ontario, Canada." Canadian Journal of Earth Sciences 51, no. 9 (September 2014): 837–49. http://dx.doi.org/10.1139/cjes-2014-0029.
Повний текст джерелаАнотація:
The exposures at the St. Marys Cement Inc. quarry at St. Marys, Ontario, have been studied by geologists since the mid-1950s. This paper summarizes previous and new information collected in 2009, 2010, and 2012 and discusses the record of sediments resting on the bedrock surface that have been exposed during quarry operations. The exposed sediments illustrate the dynamic behavior of the Laurentide Ice Sheet in this area during the Late Wisconsin. Evidence for subglacial meltwater activity, shifting ice-flow directions during till deposition, a local or regional erosion event, possible subaerial exposure, and ice-marginal sedimentation is observed in the sequence of tills and stratified sediments exposed in the quarries. It also highlights how rapid lateral facies changes, complex contact relationships, and steep erosional contacts can prove to be challenging for correlation and extrapolation of subsurface units into three-dimensional stratigraphic models. Fourteen units were identified of which the lower six were deposited during the Nissouri age (Catfish Creek Drift). This included five layers of till deposited by a glacier that alternated from flowing out of the Lake Huron basin to that of a regional flow to the south-southwest. An angular unconformity cuts into these sediments and separates them from a finer-grained sediment sequence (primarily of Port Bruce age) consisting of glaciofluvial gravel, two fine-textured till layers, and rhythmically bedded glaciolacustrine sediments, all overlain by the uppermost till, the Rannoch Till, and Mitchell Moraine ice-marginal fan sediments.
45
Huynh, Toan, Roozbeh Jafari, and Wan-Young Chung. "An Accurate Bioimpedance Measurement System for Blood Pressure Monitoring." Sensors 18, no. 7 (June 29, 2018): 2095. http://dx.doi.org/10.3390/s18072095.
Повний текст джерелаАнотація:
One potential method to estimate noninvasive cuffless blood pressure (BP) is through measurement of pulse wave velocity (PWV), which can be characterized by measuring the distance and the transit time of the pulse between two arterial sites. To obtain the pulse waveform, bioimpedance (BI) measurement is a promising approach because it continuously reflects the change in BP through the change in the arterial cross-sectional area. Several studies have investigated BI channels in a vertical direction with electrodes located along the wrist and the finger to calculate PWV and convert to BP; however, the measurement systems were relatively large in size. In order to reduce the total device size for use in a PWV-based BP smartwatch, this study proposes and examines a horizontal BI structure. The BI device is also designed to apply in a very small body area. Our proposed structure is based on two sets of four-electrode BI interface attached around the wrist. The effectiveness of our system and approach is evaluated on 15 human subjects; the PWV values are obtained with various distances between two BI channels to assess the efficacy. The results show that our BI system can monitor pulse rate efficiently in only a 0.5 × 1.75 cm2 area of the body. The correlation of pulse rate from the proposed design against the reference is 0.98 ± 0.07 (p < 0.001). Our structure yields higher detection ratios for PWV measurements of 99.0 ± 2.2%, 99.0 ± 2.1%, and 94.8 ± 3.7% at 1, 2, and 3 cm between two BI channels, respectively. The measured PWVs correlate well with the BP standard device at 0.81 ± 0.08 and 0.84 ± 0.07 with low root-mean-squared-errors at 7.47 ± 2.15 mmHg and 5.17 ± 1.81 mmHg for SBP and DBP, respectively. Our results inform future designs of smart watches capable of measuring blood pressure.
46
Babineau, Marielle, Solvejg K. Mathiassen, Michael Kristensen, Niels Holst, Roland Beffa, and Per Kudsk. "Spatial Distribution of Acetolactate Synthase Resistance Mechanisms in Neighboring Populations of Silky Windgrass (Apera spica-venti)." Weed Science 65, no. 4 (May 25, 2017): 479–90. http://dx.doi.org/10.1017/wsc.2017.11.
Повний текст джерелаАнотація:
Silky windgrass is a serious weed in central and northern Europe. Its importance has escalated in recent years because of its growing resistance to acetolactate synthase (ALS)-inhibiting herbicides. This study investigated the resistance level for three herbicide sites of action in eight silky windgrass populations, collected in fields neighboring a field where iodosulfuron sodium salt–resistant silky windgrass had previously been found. Target site resistance (TSR) and non–target site resistance (NTSR) mechanisms were identified, and a spatial gradient distribution hypothesis of ALS resistance was tested. Populations showed large variations in ED50values to iodosulfuron, with resistance indices (RIs) ranging from 0.1 to 372. No cross-resistance was found to other herbicide groups with the same site of action as iodosulfuron. In contrast, resistance was observed to the acetyl-CoA carboxylase inhibitor, fenoxaprop ethyl ester (RI from 0.7 to 776), while the activity of prosulfocarb, an inhibitor of long-chain fatty-acid synthesis, was unaffected. Iodosulfuron-resistant phenotypes were associated with NTSR, while fenoxaprop ethyl ester resistance was caused by both NTSR and TSR (Ile-1781-Leu mutation). A large-scale trend in the spatial distribution of resistance to ALS indicated a decreasing resistance with increased distance from an epicenter. After finer-scale analysis, less than 0.05% of the residual variation could be attributed to spatial autocorrelation. The spatial resistance pattern was not correlated with the dominant wind direction, while there was a correlation between the resistant phenotype and type of crop. This study underlines that NTSR mechanisms do not always confer broad resistance to different herbicide subclasses and site of action, hence the complex relationship to resistant phenotype. NTSR mechanisms, in particular detoxification, were present at different levels for the herbicides tested in the silky windgrass populations of this study. The factors contributing to the spatial distribution of resistance remain elusive.
47
Haddad, Farah, Samuel Boudet, Laurent Peyrodie, Nicolas Vandenbroucke, Julien Poupart, Patrick Hautecoeur, Vincent Chieux, and Gérard Forzy. "Oligoclonal Band Straightening Based on Optimized Hierarchical Warping for Multiple Sclerosis Diagnosis." Sensors 22, no. 3 (January 18, 2022): 724. http://dx.doi.org/10.3390/s22030724.
Повний текст джерелаАнотація:
The detection of immunoglobulin G (IgG) oligoclonal bands (OCB) in cerebrospinal fluid (CSF) by isoelectric focusing (IEF) is a valuable tool for the diagnosis of multiple sclerosis. Over the last decade, the results of our clinical research have suggested that tears are a non-invasive alternative to CSF. However, since tear samples have a lower IgG concentration than CSF, a sensitive OCB detection is therefore required. We are developing the first automatic tool for IEF analysis, with a view to speeding up the current visual inspection method, removing user variability, reducing misinterpretation, and facilitating OCB quantification and follow-up studies. The removal of band distortion is a key image enhancement step in increasing the reliability of automatic OCB detection. Here, we describe a novel, fully automatic band-straightening algorithm. The algorithm is based on a correlation directional warping function, estimated using an energy minimization procedure. The approach was optimized via an innovative coupling of a hierarchy of image resolutions to a hierarchy of transformation, in which band misalignment is corrected at successively finer scales. The algorithm’s performance was assessed in terms of the bands’ standard deviation before and after straightening, using a synthetic dataset and a set of 200 lanes of CSF, tear, serum and control samples on which experts had manually delineated the bands. The number of distorted bands was divided by almost 16 for the synthetic lanes and by 7 for the test dataset of real lanes. This method can be applied effectively to different sample types. It can realign minimal contrast bands and is robust for non-uniform deformations.
48
Hussain, Mahbub, Lameed O. Babalola, and Mustafa M. Hariri. "Heavy minerals in the Wajid Sandstone from Abha-Khamis Mushayt area, southwestern Saudi Arabia: implications on provenance and regional tectonic setting." GeoArabia 9, no. 4 (October 1, 2004): 77–102. http://dx.doi.org/10.2113/geoarabia090477.
Повний текст джерелаАнотація:
ABSTRACT The Wajid Sandstone (Ordovician-Permian) as exposed along the road-cut sections of the Abha and Khamis Mushayt areas in southwestern Saudi Arabia, is a mediun to coarse-grained, mineralogically mature quartz arenite with an average quartz content of over 95%. Monocrystalline quartz is the dominant framework grain followed by polycrystalline quartz, feldspar and micas. The non-opaque heavy mineral assemblage of the sandstone is dominated by zircon, tourmaline and rutile (ZTR). Additional heavy minerals, constituting a very minor fraction of the heavies, include epidote, hornblende, and kyanite. Statistical analysis showed significant correlations between zircon, tourmaline, rutile, epidote and hornblende. Principal component R-mode varimax factor analysis of the heavy mineral distribution data shows two strong associations: (1) tourmaline, zircon, rutile, and (2) epidote and hornblende suggesting several likely provenances including igneous, recycled sedimentary and metamorphic rocks. However, an abundance of the ZTR minerals favors a recycled sedimentary source over other possibilities. Mineralogical maturity coupled with characteristic heavy mineral associations, consistent north-directed paleoflow evidence, and the tectonic evolutionary history of the region indicate a provenance south of the study area. The most likely provenances of the lower part (Dibsiyah and Khusayyan members) of the Wajid Sandstone are the Neoproterozoic Afif, Abas, Al-Bayda, Al-Mahfid, and Al-Mukalla terranes, and older recycled sediments of the infra-Cambrian Ghabar Group in Yemen to the south. Because Neoproterozic (650-542 Ma) rocks are not widespread in Somalia, Eritrea and Ethiopia, a significant source further to the south is not likely. The dominance of the ultrastable minerals zircon, tourmaline and rutile and apparent absence of metastable, labile minerals in the heavy mineral suite preclude the exposed arc-derived oceanic terrains of the Arabian Shield in the west and north as a significant contributor of the sandstone. An abundance of finer-grained siliciclastic sequences of the same age in the north, is consistent with a northerly transport direction and the existence of a deeper basin (Tabuk Basin?) to the north. The tectonic and depositional model presented in this paper differs from the existing model that envisages sediment transportation and gradual basin filling from west to east during the Paleozoic.
49
Maizza, Giovanni, Antonio Caporale, Christian Polley, and Hermann Seitz. "Micro-Macro Relationship between Microstructure, Porosity, Mechanical Properties, and Build Mode Parameters of a Selective-Electron-Beam-Melted Ti-6Al-4V Alloy." Metals 9, no. 7 (July 15, 2019): 786. http://dx.doi.org/10.3390/met9070786.
Повний текст джерелаАнотація:
The performance of two selective electron beam melting operation modes, namely the manual mode and the automatic ‘build theme mode’, have been investigated for the case of a Ti-6Al-4V alloy (45–105 μm average particle size of the powder) in terms of porosity, microstructure, and mechanical properties. The two operation modes produced notable differences in terms of build quality (porosity), microstructure, and properties over the sample thickness. The number and the average size of the pores were measured using a light microscope over the entire build height. A density measurement provided a quantitative index of the global porosity throughout the builds. The selective-electron-beam-melted microstructure was mainly composed of a columnar prior β-grain structure, delineated by α-phase boundaries, oriented along the build direction. A nearly equilibrium α + β mixture structure, formed from the original β-phase, arranged inside the prior β-grains as an α-colony or α-basket weave pattern, whereas the β-phase enveloped α-lamellae. The microstructure was finer with increasing distance from the build plate regardless of the selected build mode. Optical measurements of the α-plate width showed that it varied as the distance from the build plate varied. This microstructure parameter was correlated at the sample core with the mechanical properties measured by means of a macro-instrumented indentation test, thereby confirming Hall-Petch law behavior for strength at a local scale for the various process conditions. The tensile properties, while attesting to the mechanical performance of the builds over a macro scale, also validated the indentation property measurement at the core of the samples. Thus, a direct correlation between the process parameters, microstructure, porosity, and mechanical properties was established at the micro and macro scales. The macro-instrumented indentation test has emerged as a reliable, easy, quick, and yet non-destructive alternate means to the tensile test to measure tensile-like properties of selective-electron-beam-melted specimens. Furthermore, the macro-instrumented indentation test can be used effectively in additive manufacturing for a rapid setting up of the process, that is, by controlling the microscopic scale properties of the samples, or to quantitatively determine a product quality index of the final builds, by taking advantage of its intrinsic relationship with the tensile properties.
50
Li, Meng, Zbigniew Klimont, Qiang Zhang, Randall V. Martin, Bo Zheng, Chris Heyes, Janusz Cofala, Yuxuan Zhang, and Kebin He. "Comparison and evaluation of anthropogenic emissions of SO<sub>2</sub> and NO<sub><i>x</i></sub> over China." Atmospheric Chemistry and Physics 18, no. 5 (March 8, 2018): 3433–56. http://dx.doi.org/10.5194/acp-18-3433-2018.
Повний текст джерелаАнотація:
Abstract. Bottom-up emission inventories provide primary understanding of sources of air pollution and essential input of chemical transport models. Focusing on SO2 and NOx, we conducted a comprehensive evaluation of two widely used anthropogenic emission inventories over China, ECLIPSE and MIX, to explore the potential sources of uncertainties and find clues to improve emission inventories. We first compared the activity rates and emission factors used in two inventories and investigated the reasons of differences and the impacts on emission estimates. We found that SO2 emission estimates are consistent between two inventories (with 1 % differences), while NOx emissions in ECLIPSE's estimates are 16 % lower than those of MIX. The FGD (flue-gas desulfurization) device penetration rate and removal efficiency, LNB (low-NOx burner) application rate and abatement efficiency in power plants, emission factors of industrial boilers and various vehicle types, and vehicle fleet need further verification. Diesel consumptions are quite uncertain in current inventories. Discrepancies at the sectorial and provincial levels are much higher than those of the national total. We then examined the impacts of different inventories on model performance by using the nested GEOS-Chem model. We finally derived top-down emissions by using the retrieved columns from the Ozone Monitoring Instrument (OMI) compared with the bottom-up estimates. High correlations were observed for SO2 between model results and OMI columns. For NOx, negative biases in bottom-up gridded emission inventories (−21 % for MIX, −39 % for ECLIPSE) were found compared to the satellite-based emissions. The emission trends from 2005 to 2010 estimated by two inventories were both consistent with satellite observations. The inventories appear to be fit for evaluation of the policies at an aggregated or national level; more work is needed in specific areas in order to improve the accuracy and robustness of outcomes at finer spatial and also technological levels. To our knowledge, this is the first work in which source comparisons detailed to technology-level parameters are made along with the remote sensing retrievals and chemical transport modeling. Through the comparison between bottom-up emission inventories and evaluation with top-down information, we identified potential directions for further improvement in inventory development.