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The use of composites as an innovative new material is increasing. Composites are made from two or more materials that have different properties. This research was conducted to make multilayer composites and determine the effect of variations in the number of arrangements and the direction of the fiber angles on the physical properties of composites made from ramie fiber and epoxy. The physical properties of the composites analyzed in this study were density, porosity, water absorption, and thickness expansion. The composites in this study were made using the hand layup method with a volume fraction ratio of 30% and the ratio of epoxy and hardener was 2: 1. Before the composite was made, ramie fibers were soaked in 5% NaOH for 2 hours. This study succeeded in making epoxy ramie multilayer composites with variations in the number of arrangements and the direction of the fiber angles. Variations in the number of layers and the direction angle of the ramie fiber in the composite affect the density and porosity of the composite. Variations in the direction of the ramie fiber in the composite affect the water absorption of the composite. Variations in the number and direction of ramie fiber in the composite did not significantly affect the thickness of the composite.

The Monte Carlo probability (MCP) model, which has been used for official tropical cyclone (TC) warnings to the public by the United States’ National Hurricane Center (NHC), can estimate the probability of wind speed in the vicinity of a TC during the forecast period. It has been successful in the operational environment for many years. However, due to its strong dependence on a given forecast track (e.g., forecast from the NCEP Global Forecast System), the MCP model may generate a poor probability map for TCs near landfall. In this study, we proposed and tested a modified MCP method for TC forecasts near landfall. We first adjusted the MCP model by adding limits to the direction angle and motion distance to deal with the substantial change in TC moving direction and the low wind speeds during landfall. Then, we combined ensemble probability maps generated from ECMWF, United Kingdom Met Office (UKMO), and NCEP ensemble forecasts, obtained from The International Grand Global Ensemble (TIGGE), into the MCP model to configure a modified MCP model. Wind speed probability maps for the 0–120-h forecast from both the original and modified MCP models are compared. It is found that the modified MCP model can provide a better wind speed probability map during landfall, especially at wind speeds of 20–64 kt near TC landfall. The results from this study prove the benefits of combining the MCP model with ensemble forecasting in potential applications for improved TC forecasts.

An understanding of the Qibla direction is very important for Muslims, because facing the Qibla is one of the legal requirements for performing prayers. Although now the technology to determine the Qibla direction is sophisticated, it is necessary to know how to determine the actual Qibla direction. The determination of the direction of the Qibla with the spherical triangle method is based on a triangle on the surface of the globe which is formed by three large circles of the globe, namely two circles of the earth's longitude and one circle of Qibla. The intersection of the three large circles forms three points, namely point A (Makkah), point B (the location where the Qibla direction will be calculated), and point C (the North Pole). The steps in determining the Qibla direction include: (1) Prepare the data needed in calculating the Qibla direction of a place, namely latitude and longitude data for the Kaaba (Makkah city), as well as latitude and longitude data for the location/city to be calculated. the qibla direction; (2) Calculation of the Qibla direction using the formula , with: B = Angle of the direction of the Qibla of a place, C = The difference between the longitude of the Kaaba and the longitude of the place where the Qibla direction is being sought, a = 90o – tp (latitude), and b = 90o – ka (Kaaba latitude); (3) Calculation of true Qibla azimuth from true north in a clockwise direction, where true Qibla azimuth = 360o – Qibla direction angle (B); (4) Determination of the actual Qibla direction by measuring using an arc ruler as large as true Qibla azimuth from true north.

Griffin, J, Horan, S, Keogh, J, Andreatta, M, and Minahan, C. Time to be negative about acceleration: A spotlight on female football players. J Strength Cond Res 36(11): 3264-3271, 2022-Women's football requires players to perform frequent changes in velocity (i.e., speed and direction) for successful performance. Although increases in velocity ("acceleration") are important, decreases in velocity ("deceleration") should also be considered equally important to performance and load monitoring. Currently, there is a disproportionate focus on acceleration and creating faster players. The aim of this review is to provide an understanding of deceleration for female football players. Given the limited research in this area, data from studies involving male football players and from other team-sport athletes were used to supplement the review where necessary. Most research focused on eccentric strength and its relationship with deceleration ability, highlighting the importance of slow eccentric strength of the quadriceps and hamstrings to deceleration. Technical and kinematic characteristics of deceleration were also investigated. Importantly, with deceleration being a unilateral motor skill, development requires similar amounts of training for both legs. Imbalances between legs in skill and strength characteristics may compromise performance or increase the risk of injury. Given the dependent nature of deceleration, several contextual factors were identified as important when considering deceleration as a part of training programs and performance. Deceleration is affected by the following factors: an athlete's momentum, the approach speed, change of direction angle, time or distance, anticipated or unanticipated task, fatigue, and the positional requirements of female football players. Further research is needed into deceleration and the physical characteristics associated with deceleration performance, particularly for female football players.

Since golf is one of the popular worldwide sports, a lot of biomechanical and/or motor learning research on the golf swing have been done. However, information of a good motion pattern of the driver swing is likely to be sporadic. The present paper intended to create a standard motion model of the driver swing and to identify critical points in the driver swing, based on coefficient of variation of segment direction angles. Twenty-five skilled male golfers performed a driver swing for the maximum distance with full effort in a laboratory setting. Their swing motions were captured by Vicon MX+ system with 12 cameras to obtain three-dimensional coor-dinate data of body segments and golf club. The averaged motion model of the driver swing was created as a standard motion model by the method of Ae et al. (2007), and coefficients of variation of direction angles for body segment and club vectors were calculated.The findings obtained were summarized as follows.1) The created standard motion model was similar to that of sequential pictures illustrated in textbooks and manuals for the golf swing, which would imply that the standard motion model could be used as a tool for learning of the driver swing.2) The upper torso’s rightward rotation started around mid downswing, followed by the forward rotation during the downswing and follow-through phases through ball impact.3) The magnitude and change in the direction angle for the upper limbs during the swing were larger than those of the lower limbs and trunk.4) The coefficients of variation in the lower limbs and upper and lower torsos were smaller than that of the upper limbs, which indicated the motions for these body segments were critical in teaching and evaluating the driver swing.5) The coefficients of variation in the shaft and head of the club increased around ball impact because both mean and standard deviation in the direction angle for the club were small around ball impact, which implied to be a critical point.The coefficients of variation would be one of criteria to identify critical points in the driver swing. However, as the means of direction angle and coefficients of variation tended to be contrary to each other, it should be considered that the coefficient of variation could become large in the phase in which the mean of direction angle was small. In this case, mean and standard deviation of direction angles for body segments should be referred in identifying critical points., ゴルフは世界中で人気のあるスポーツの1つであり，ゴルフスイングに関するバイオメカニクスや運動学習の研究が多く行われている。しかし，ヨイゴルフスイングの動作パターンに関する情報は散見される程度である。本論文は，ドライバースイングの標準動作モデルを作成するとともに，動作変動度に基づいてドライバースイングにおいて重要なポイントを明らかにすることを試みたものである。25名の熟練男子ゴルファーに飛距離をねらいとする全力でのドライバースイングを行わせ，身体各部，クラブの計測点の3次元座標データをVicon MX+システムを用いて収集した。得られた3次元座標データからAeら（2007）の方法によりスイングの平均動作（標準動作という）を作成するとともに，身体各部およびクラブベクトルの方向角および変動係数を算出した。得られた知見をまとめると，以下のようになる。1）ドライバースイングの標準動作モデルの動作パターンは，指導書で記述されている基本スイングと大きな相違はなく，本研究で作成した標準動作モデルは指導用動作モデルとして活用できると考えられる。2）上胴の回転はダウンスイング中間点あたりから始まり，さらに前方回転が加わり，インパクトを経てフォロースルーまで続いた。3）スイング中の上肢の方向角の大きさや変化は下肢や上胴，下胴よりも大きかった。4）下肢および上胴，下胴の変動係数は上肢のものよりも小さかった。このことはこれらの部分がドライバースイングの指導では重要な点であることを示している。5）クラブシャフトおよびヘッドの変動係数はインパクトあたりで増加したが，これはこれらの方向角の平均値と標準偏差が小さいためであり，インパクトが重要なポイントであることを示唆する。変動係数はドライバースイングにおいて重要なポイントを明らかにする指標になり得ると考えられる。しかし，方向角の平均値と変動係数は相反する傾向があるので，方向角の平均値が非常に小さい局面では変動係数が大きくなる場合があるので，重要なポイントを明らかにするには変動係数を手がかりとするが，身体各部の方向角の平均や標準偏差を参照する必要がある。

For a dual-motor-driven elliptical vibrating screen, the driving frequencies of the two motors are studied in this paper and it exposes the significant influences of different driving frequencies on the vibration direction angle of the self-synchronous system. A dynamic model is established to demonstrate the new concepts and innovative ideas put forth in this paper. Simulink and prototype experiments are implemented to further study the influences of different driving frequencies on the phase angle and the vibration direction angle. The results of simulation and experiments shows that vibrating screen driven by the two motors can not only achieve a stable synchronization within a certain frequency range by changing the driving frequency of either of the two motors, but also the vibration direction angle significantly changes at similar but different driving frequencies. This is an important finding that has important significance for the future operations of dual-motor-driven vibrating screen in industry. The method developed in this study would be a valuable engineering tool which can be used in design and application of the screens and the screening operations.

Several methods have been developed to design and analyze moire magnifier, but these methods are all lack of quantitative consideration on the depth of moire imaging. In this paper, a new design method for moire magnifier based on depth cues from disparity is proposed. By using of the proposed method, the period magnification, the rotation angle of moire pattern can also be calculated, and the moire depth can be analyzed, too. According to the design and analysis results using MATLAB, the period of arrays and the cross angle are the important influence factors as the moire pattern above or below the microlens array. Moreover, with our 3D design method, we can design different moire magnifier with different size, direction angle and depth of moire pattern as required.

In this study, an equivalent tool geometry was presented, while taking into account the cutting-tool nose and edge radii. The main idea consists in considering that the equivalent geometry induces the same cutting force components as the real tool. In this context, equivalent cutting angle, equivalent direction angle, equivalent uncut chip thickness, and equivalent depth of cut are defined for the new tool geometry. A dual contact at the tool-chip interface, sticking and sliding zones, is considered in the developed thermomechanical model. The influences of the nose and edge radii on the cutting performances are studied. A well agreement was found between analytical and experimental results for different cutting conditions. It is underlined that feed and radial forces are the most sensitive components to nose and edge radii. The proposed equivalent tool has great potential for other applications such as tool wear studying while considering coatings and chip breaker.

In this study we propose a method to achieve the surface layer current direction information using SAR Doppler frequency shift with a high resolution and a relatively simple method. We calculated the distribution of the direction angle and the vector direction, which shows a good match with the lower resolution measurements.

A fractured rock mass was characterized by strong heterogeneity, discontinuity, and anisotropy. The study of flow in a fractured rock mass was a complex and challenging task. As the main s...

The Dadushan Tunnel, which is located in the southwestern karst region of China in Guizhou Province, is one of the key elements of the Hukun High-Speed Railway. Cavities occur unpredictably in the tunnel, and well-developed karst conduits are frequently encountered. These features result in safety problems, such as water gushing and rapid flooding. In this paper, on the theoretical basis of the surface Magnetic Resonance Sounding (MRS) method, we propose Tunnel Magnetic Resonance Sounding (TMRS) in the tunnel space model and derive the expression of the MRS response signal with a vertical antenna. A direction angle formula is then created to calculate the perpendicular component of the transmitting field at arbitrary geomagnetic field and antenna directions. In addition, we present a comprehensive study on the TMRS based on forward modeling and numerical experiments. The relationship between the magnetic resonance signal response and the position and water content of water-bearing structures is obtained by forward modeling. In the numerical examples, the inversion results agree with the numerical model. The application of the method to a case study involving the Dadushan Tunnel indicates that the prediction results agree well with the excavation results. This paper establishes a theoretical basis for the development of a magnetic resonance sounding instrument for use in tunnels for the advanced detection of water-rich geological structures that can produce tunnel disasters.

Wave drift force is the key factor affecting the mooring ability of semi-submersible platform. Aiming at the mooring system composed of replenishment ship and semi-submersible platform, the influence of hydrodynamic interference on semi-submersible platform is analyzed. Based on the three-dimensional potential flow theory and AQWA software, the effects of different wave directions and spacing on the wave drift force of semi-submersible platform are considered. The results show that the hydrodynamic interference of the replenishment ship will affect the wave drift force of the semi-submersible platform, and the influence of the distance between adjacent vessels and the wave direction angle is more sensitive in the middle and high wave frequencies. This paper can provide support for the research of hydrodynamic interference of semi-submersible platform.

A highly efficient online compression of vehicle trajectories is important to the application of the Internet-of-Vehicles (IoV) system. However, the high time-space complexity of existing vehicle trajectory compression algorithms makes them unable to adapt effectively to actual IoV applications under the condition of a resource-constrained mobile vehicle terminal, bandwidth cost, and latency. This paper addresses these issues by proposing a trajectory compression algorithm using a combination of road width (W), vehicle driving direction (D), and swerve angle (A). The proposed WDA compression algorithm determines whether the vehicle trajectory points are rectilinear within a permitted error range according to W and D and then determines the trajectory points where a vehicle swerves significantly according to A. The algorithm considers the constraints of road shape on vehicle trajectories according to whether the trajectory forms an approximately straight line or a curve indicative of a swerving trajectory. It adopts different compression methods for rectilinear and swerving vehicle trajectories, which allows for highly efficient compression and high similarity between the compressed and original trajectories. In addition, the algorithm preserves direction information regarding D. Testing employing a Microsoft GeoLife dataset demonstrates that the proposed algorithm attains an average compression ratio of 4.03% for vehicle trajectory data, and the average compression time is 1.15 m/each. Relative to the existing compression algorithms, the proposed algorithm reduced compression time and storage space to adapt for the development of the large-scale IoV applications.

A comprehensive study of the influence of geometric characteristics (model dimensions, crack length), temperature, strain rate, and the loading mixing parameter on the plate strength, crack growth and crack propagation direction angle is carried out. The material selected for this study is aluminum. The crack propagation direction angles of a central crack in an aluminum plate under mixed-mode loading are determined using the molecular dynamics method implemented in LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). Atomistic modeling of mixed-mode loadings of the plane medium with the central crack allowed us to find all the crack propagation direction angles in the full range of the mixed-mode loadings. An embedded atom potential (EAM) available in LAMMPS molecular dynamics (MD) software is utilized to pinpoint accurately mixed-mode crack growth.

Accurate identification of different behaviours of fishing vessels is important for fisheries management and fisheries ecology, which can enhance the management of overfishing and marine resources. In this study we identify fishing vessel fishing behavior through Vessel Monitoring System (VMS) data and BP neural networks. The change trend of the direction angle and speed of the fishing vessel is selected as the input parameters of the model, and the accuracy of identifying the fishing behavior is 79%. The fishery distribution is drawn according to the behavior of the fishing vessel identified by the model, which is similar to the distribution of the actual fishery and the fishing density. This laid the foundation for the deep exploration of the spatio-temporal characteristics of VMS in the future and the high-precision prediction of the distribution of fishing areas in China's offshore fisheries.

Due to its under-actuating characteristics, the snake-like robot has become a research hotspot and a difficult point. Based on the model established by Pal Lilebak, a linear path tracking algorithm is proposed, which is based on neural network identifier and can automatically search PI parameters. At the same time, the line-of-sight guidance law with variable forward distance is used to speed up the side shift and track the target straight line. More over the algorithm is extended to curve path tracking. The simulation results show that this path tracking algorithm can stabilize the control system and speed up the tracking of the direction angle by dynamically adjusting PI parameters. The proposed line-of-sight guidance law can significantly accelerate the side shift speed. The result also show that the neural network identification control can avoid the problem that PI control will be unstable due to the change of the forward distance. And the path tracking algorithm also performs well in curve path tracking.

Introduction Change of direction (COD) manoeuvres are important for many field sports, however they are unfortunately associated with non-contact ACL injuries. Although players frequently COD at >90° angles, limited knowledge is available on knee joint kinematics and kinetics during COD at 90° and 135° and whether limb preference impacts knee mechanics during COD at these angles, which formed the aims of this study. Methods Healthy male recreational soccer players were recruited to take part in the study. 3D kinematics and kinetics were collected during COD manoeuvres at 90° and 135°. Running speed was controlled at 4±0.4 m/s and 3.5±0.3 m/s, respectively. To determine differences on variables associated with ACL risk; knee abduction angle and moment, across cutting angles and preferred legs, a paired sample t-test was conducted using a Holm method correction, α=(0.05/ (8 comparisons – rank +1). Results 36 individuals took part in the study (24.25±6.21 years, 1.72±0.06 m and 66.41±10.83 kg). COD at 135° showed greater knee abduction angles and moments than at 90° but with similar peak VGRF. There were no differences between preferred and non-preferred legs, apart from the increased knee flexion angle during COD manoeuvres at 90° in the non-preferred leg. Conclusion In male recreational soccer players, sharper cutting angles place the knee at more risk for ACL injuries with little asymmetry between preferred and non-preferred limbs. Sharper angles of examination should be utilized in the evaluation of individuals.

Background : Many hospitals in the examination of pedis AP projection use 0o or perpendicular. It is not based on the theory. So that, it is done research about the variation of direction angle of AP projection in pedis examination toward anatomy information. The examination is aim to find how big the direction angle toward anatomy information which is result by examination pedis AP projection and angle which is result by optimal anatomy information. Methods : The research which is used descriptive quantitative research by experiment approach. The research is done by pedis phantom which eksposes four times with same expose factor with difference angle variation 0o, 5o, 10o and 15o cephalad and quenstionnaire filling. The research using the independent variable is the direction angle on the examination pedis AP projection and the dependent variable is anatomical information on the radiograph pedis AP projection. The quenstionnaire is filled by three respondents, they are Radiologist. The scoring result of the respondents processes and present in table and graphic to describe and analyse for getting conclusion. Results : From the scoring result, it is seen the influence of angle toward pedis anatomy information difference.When use of the angle 0o and 5o cephalad show very clear navicular. While the angle of 10o cephalad show open joint space between medial cuneiform and the intermediate cuneiform and a very clear cuboid. The angle of 15o cephalad shows a very clear tarsometatarsal joint. And then, the angle which is yield optimal anatomy information in examination pedis AP projection is the angle of 10 o cephalad. Conclusion : The radiographic technique of the AP projection pedis with a variation of 0o, 5o, 10o and 15o cephalad produces different anatomical information. At angle 0o and 5o showing very clear navicular, 10o cephalad revealed joints between the medial cuneiform and intermediate cuneiform and cuboid and 15o cephalad shows the tarsometatarsal joint very clearly. The optimal angle in generating anatomical information on the AP projection examination is 10 o cephalad.

This paper is a comprehensive analysis on various experimental and numerical studies on slopes. Small-scale physical modeling of slopes under surcharge loads was performed on loose sand slopes. Digital images were captured during the incremental loading from the model’s side. Particle image velocimetry and 3D numerical model were applied to investigate the slope under surcharge loading; several important factors that control pile performance are investigated. Safety factors and location of critical failure surfaces of various reinforced and unreinforced slopes are obtained and compared. The results shows, the 3D failure surface shape in front of the piles is triangular for stabilized homogenous slopes, which is different from its conical shape in laterally loaded piles. This paper also analyzes the effects of soft bound interlayer, soil properties, pile spacing, pile position, and surcharge distance on the safety factor and slip surface shape of the stabilized and non-stabilized slopes. The results indicate that the distance of soft soil layer from ground surface and its horizontal direction angle strongly influence the optimum location of the piles. The numerical modeling results show that increasing the distance between the piles prevents the arching phenomenon from developing, and instead, increases the failure volume in the slope.

Polycrystalline cubic boron nitride (PcBN) is a highly wear resistant material. Due to its high hardness this material is typically machined with diamond grinding tools. The high hardness and high-temperature hardness of PcBN leads to a significant grinding tool wear. The applied cutting direction angle during face plunge grinding offers the possibility to influence the geometry of the contact area between the grinding tool and the PcBN workpiece. However, the underlying principal mechanisms and influences of parameters are not fully understood today. The contact zone geometry is described by the width of cut and the geometric contact length. The paper provides a mathematical description of these two parameters for S-shapes PcBN cutting inserts depending on the workpiece geometry and the cutting direction angle. It is shown that the contact length significantly determines the wear mechanism.

There is a difference in terms of the views of coaches and specialists regarding the fixed foot and position of the body. No study has been noted on futsal in which the variables of the kinematics of the fixed foot and body were analyzed. These variables have a significant importance in terms of the angle of fixed foot and body and their direction and distance. They are important in order to be accurate in scoring and specifically in the fixed balls. The objective of the study was to identify the relationship of some kinematic variables of the fixed foot and body to the accuracy of scoring when performing penalty by futsal players. The research participants were the team of the University of Koya for the academic year 2016-2017. The researcher chose the sample by deliberate method and reached 13 players. Each player has played for at least four years, and all players use the right foot, while the the average age of sample is 23.4 years, body mass 67.37 kg, body height 171 cm, and leg length 93.76 cm. The conclusions of the researcher are that the fixed foot as other parts of the body have an effective role during the scoring of a fixed ball in the game of futsal. The direction angle of the fixed foot has an impact on the mechanical axis of the body and is reflected on the accuracy of the scoring in fixed balls in futsal.

In order to improve the screening effect of grain combine harvester, it is necessary to study the influence of different screening parameters on screening performance.In this paper, discrete element method was used to simulate the screening process of soybean and short stems by selecting different screening parameters, and dynamic screening efficiency and the number of short stems under screening were introduced as evaluation criteria.The results show that under certain other conditions, the vibration frequency, amplitude and direction angle have significant influence on the screening performance, while the inclination angle of the upper screen has little influence on the screening performance. With the increase of vibration frequency, amplitude and direction angle, screening efficiency increased first and then decreased, while the number of short stalks under screening increased first and then decreased. Considering the screening efficiency and the number of short stalks under the screening, it is concluded that the screening performance is better when the amplitude is 25 mm, the vibration frequency is 4 Hz, the vibration direction angle is 25 degrees and the upper screening angle is 3 degrees. The simulation results are verified by field experiments, and the simulation results meet the requirements of field experiments.

Urinary stone disease has an increasing prevalence across the globe, and endoscopic treatment modalities have replaced open surgery. Percutaneous nephrolithotomy (PCNL) is a successful, safe and reliable minimally invasive method in the treatment of renal stones, especially big (≥2 cm) or complex ones. Gaining access is the most critical step of this procedure, which can affect the rest of the operation. Although previously described techniques, eye of the needle and triangulation techniques, are being used for gaining access, urologists (especially novice ones) can still have problems during this step. Some navigation concepts have been developed in order to make the access safer, easier and more successful, however, none of them has been incorporated in daily routine practice till now because of either complicated techniques or requirement of sophisticated equipment. Our hypothesis is that the access point, direction angle and access angle in order to touch a stone during PCNL can be calculated by the data obtained from the computed tomography images with the help of mathematical formulations, namely the theorem of the cosine.

In this paper, the effects of vibration parameters of a banana screen, i.e. frequency, amplitude and vibration direction angle, on the screening efficiency per unit time were studied using the discrete element method (DEM). The simulations were validated according to data collected from an experimental prototype screen. Functional relationships between vibration parameters and screening efficiency per unit time are presented. The results showed that the screening efficiency per unit time first displays an increase and later a decrease when the frequency, amplitude or vibration direction angle increased respectively. Vibration parameter optimization was also investigated, using an orthogonal experiment. Based on the banana screen model, it can be concluded that when the frequency is 22 Hz, the amplitude is 2.2 mm and the vibration direction angle is 39°, the screening efficiency of a banana screen is optimal.

An electronically steerable monopulse antenna based on reconfigurable reflectarray antenna (RRA) has been designed, fabricated and tested. The large-scale RRA at X-band is consisted of $160\times 64$ elements integrated with PIN diodes, and is controlled by arrays of 160 field-programmable gate arrays (FPGAs) in parallel, for the steerable monopulse patterns. The steerable sum-difference beams are achieved by the diode state distributions of the RRA. The gain of the RRA is measured to be 37.35dBi, and the null-depth is measured to be -43.51dB at the direction angle of 0 o. A null-depth of under -37.54dB is verified at the direction angle of 60°. The electronically steerable monopulse antenna based on RRA presents a low-cost solution for high resolution tracking applications.

Automatically driving vehicle’s steering control is investigated. The problem is simplified as a dynamic model of wheeled mobile robot, and a linear active disturbance rejection controller is designed to make the robot reach the desired direction angle. Root locus method is used to tune the parameters of the controller. The simulation and experiment results demonstrate the effectiveness of the proposed control strategy.