ACCURACY TEST OF SUPERMARKET'S MUSHOLA QIBLA DIRECTION IN CIREBON CITY

This study aims to answer the questions that become the formulation of the problem “How is the method of measuring the Qibla direction of the supermarket prayer room in Cirebon City” and “How to analyze the accuracy of the supermarket prayer room Qibla direction in Cirebon City.” This study uses qualitative research; the data collected uses observation, interviews, documentation, and literature study. They were then analyzed by the descriptive analysis method in narration. The results of this study: that the Qibla direction of the supermarket in Cirebon City has all measured the Qibla direction. The method of measuring the Qibla direction was carried out by the musala supermarket, where the author’s research uses the Qibla compass and the Qibla direction application on the smartphone. Of course, using the Qibla direction application on a smartphone is an inaccurate method. This method’s method is partly an error in determining the Qibla direction. Due to his ignorance of astronomy in measuring the Qibla direction and ignorance of the magnitude of the Qibla direction angle in the Cirebon City area, resulting in the Qibla direction of the supermarket in the Cirebon City area experiencing a wrong Qibla direction.

Failure Detection in Eucalyptus Plantation Based on UAV Images

The information of the locations and numbers of failures is crucial to precise management of new afforestation, especially during seedling replanting in young forests. In practice, foresters are more accustomed to determining the locations of failures according to their rows than based on their geographical coordinates. The relative locations of failures are more difficult to collect than the absolute geographic coordinates which are available from an orthoimage. This paper develops a novel methodology for obtaining the relative locations of failures in rows and counting the number of failures in each row. The methodology contains two parts: (1) the interpretation of the direction angle of seedlings rows on an unmanned aerial vehicle (UAV) orthoimage based on the probability statistical theory (called the grid-variance (GV) method); (2) the recognition of the centerline of each seedling rows using K-means and the approach to counting failures in each row based on the distribution of canopy pixels near the centerline of each seedling row (called the centerline (CL) method). The experimental results showed that the GV method can accurately interpret the direction angle of rows (45°) in an orthoimage and the CL method can quickly and accurately obtain the numbers and relative locations of failures in rows. The failure detection rates in the two experimental areas were 91.8% and 95%, respectively. These research findings can provide technical support for the precise cultivation of planted seedling forests.

Data-Driven Simulation of Pedestrian Movement with Artificial Neural Network

To predict pedestrian movement is of vital importance in a wide range of applications. Recently, data-driven models are receiving increasing attention in pedestrian dynamics studies, demonstrating a great potential in enhancing simulation performance. This paper presents a pedestrian movement simulation model based on the artificial neural network, in which two submodels are, respectively, used to predict velocity displacement and velocity direction angle at each time step. Destination information, the pedestrian’s historical movement information, neighboring pedestrians, and environmental obstacles within a semicircular-shaped perception area are used as inputs to learn pedestrian movement behavioral rules. In the velocity direction angle submodel, a novel division method on pedestrian’s perception area is adopted. Specifically, perception radius is divided into several bands, and perception angle range is divided into a number of sectors, establishing a weighted spatial matrix to represent varied influences of neighboring pedestrians and obstacles. Experiments on two typical scenarios, the unidirectional flow and bidirectional flow in a long straight corridor, were conducted to obtain pedestrian movement datasets. Then, a series of simulation cases were conducted to investigate the proper values for critical parameters, including perception radius, perception angle division, weights of the spatial matrix, and historical movement adoption. In comparison of pedestrian trajectory between simulation results and real data, the mean trajectory error (MTE) and mean destination error (MDE) are, respectively, 0.114 m and 0.171 m in the unidirectional flow scenario, which are, respectively, 0.204 m and 0.362 m in the bidirectional flow scenario. In addition, the fundamental diagram representing density-velocity and density-flow relationships in simulation results agree well with that in real data. The results demonstrate great capacity and credibility of the presented model in simulating pedestrian movement in real applications.

Reaktualisasi Pengukuran Arah Kiblat Dengan Metode Segitiga Bola Pada Masjid Dan Musholla

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.

Wind Coefficient Distribution of Arranged Ground Photovoltaic Panels

Solar panels installed on the ground receive wind loads. A wind experiment was conducted to evaluate the wind force coefficient acting on a single solar panel and solar panels arranged in an array. The surface roughness did not have a significant effect on the change in vertical force, which is the wind force coefficient acting on the vertical surface of a single solar panel. An examination of the change in wind direction angle showed that the largest vertical force coefficient was distributed in the 0° forward wind direction on the front of the solar panel, the 345° reverse wind direction on the rear side, and the 135° and 225° diagonal directions on the rear panel. Furthermore, an examination of the change in wind force coefficient according to the change in solar panel inclination angle (β) showed that the drag coefficient was the highest at the 40° inclination angle of the panel (β), followed by the 30° and 20° inclination angles. However, the lift coefficient and vertical force coefficient were not significantly affected by the inclination angle of the panel. The wind force coefficient of the panels arranged in an array was influenced by the wind direction angle and panel position. With the exclusion of the nearest row at a wind direction angle of 0°, all the panels in the array showed lower coefficients than those in the single-panel experiment. In the case of the panels placed inside, the wind speed was decreased by the surrounding panels. As a result, the wind force coefficient was lower than that of the single-panel experiment. This outcome is attributed to the small delamination at the end of the panels by the surrounding array of panels compared with that of the single-panel experiment.

Grain boundary migration and deformation mechanism influenced by heterogeneous precipitate

Understanding the interaction between heterogeneous precipitates and grain boundaries (GBs) is of great significance for tailoring the stability and mechanical properties of nanograined materials. In this work, the nanoscale interaction between the cylindrical precipitate and the migrating GB is investigated by atomic simulation. The results show that the resistance for GB migration can be increased by decreasing the direction angle $$\alpha$$ α (the angle between the axis of the precipitate and the tilt axis of GB). For the larger precipitate, the influence of direction angle is more pronounced. With the increase in shear strain, the interaction between the specific precipitate and GB changes the material deformation mechanism from “GB migration” to “GB migration accompanied with activated dislocations or GB deformation,” which contributes to the softening of the material. By simultaneously tuning the direction angle and size of heterogeneous precipitates, the GB deformation can be strongly inhibited and the stability of GBs can be significantly improved.

Hyoid kinematic features for poor swallowing prognosis in patients with post-stroke dysphagia

Identification of prognostic factors for swallowing recovery in patients with post-stroke dysphagia is crucial for determining therapeutic strategies. We aimed at exploring hyoid kinematic features of poor swallowing prognosis in patients with post-stroke dysphagia. Of 122 patients who experienced dysphagia following ischemic stroke, 18 with poor prognosis, and 18 age- and sex-matched patients with good prognosis were selected and retrospectively reviewed. Positional data of the hyoid bone during swallowing were obtained from the initial videofluoroscopic swallowing study after stroke onset. Normalized hyoid profiles of displacement/velocity and direction angle were analyzed using functional regression analysis, and maximal or mean values were compared between the good and poor prognosis patient groups. Kinematic analysis showed that maximal horizontal displacement (P = 0.031) and velocity (P = 0.034) in forward hyoid motions were significantly reduced in patients with poor prognosis compared to those with good prognosis. Mean direction angle for the initial swallowing phase was significantly lower in patients with poor prognosis than in those with good prognosis (P = 0.0498). Our study revealed that reduced horizontal forward and altered initial backward motions of the hyoid bone during swallowing can be novel kinematic features indicating poor swallowing prognosis in patients with post-stroke dysphagia.

ANALYSIS OF DEVELOPMENT TRENDS OF MOBILE MORTAR SYSTEMS OF MODERN ARMIES OF THE WORLD IN COMPARISON WITH MOBILE MORTAR SYSTEMS OF DOMESTIC PRODUCTION

The article compares the tactical and technical characteristics, combat capabilities of mobile mortar systems of world‟s leading armies with the domestic development of a mobile mortar complex. The domestic defense-industrial complex in cooperation with foreign representatives have developed a new model of mobile mortar complex Bars- 8MMK in which modern technologies for combat use, complex fire for effect based on the integration of intelligence have been implemented. The mortar system is mounted on the chassis of a specialized armored vehicle Bars-8 with a mobile mortar system "ALAKRAN UKR-MMS"; on-board electronic computer provides control of the mortar system in an automated mode - from receiving a command via code calling to automatic guidance of the mortar horizontally and vertically, resumption of guidance after each shot, the issuance of commands and prompts for indicators to mortar crew members, automatic control of guidance. There is a system of automatic alignment and orientation with the accuracy of determining the coordinates of the height of its own position not more than 1-3 m, and the accuracy of determining the direction angle of the longitudinal axis of the vehicle not more than 0-03. GPS system automatically and continuously determines the current rectangular coordinates, the height of the station point and the direction angle of the vehicle axis both in motion and in a stable position, as well as outputs to external devices measured values of orientation and exact time navigation parameters. There is also meteorological system that constantly records data on weather conditions in real time and transmits them to automated fire-control system for the subsequent calculation of firing data. Integrally, the system meets modern operational and strategic requirements. It is also capable of operating under high sustainable conditions, technological in production and repair; provides resistance to the impacts of existing and prospective advanced weapons systems, including those based on new physical principles.

Wind Tunnel Tests and Numerical Simulations of Wind-Induced Snow Drift in an Open Stadium and Gymnasium

A long-span sports centre generally comprises multiple stadiums and gymnasiums, for which mutual interference effects of wind-induced snow motion are not explicitly included in the specifications of various countries. This problem is addressed herein by performing wind tunnel tests and numerical simulations to investigate the snow distribution and mutual interference effect on the roofs of long-span stadiums and gymnasiums. The wind tunnel tests were used to analyse the influences of the opening direction (0°, 90°, 180°, and 270°) and spacing (0.3 L, 0.5 L, 1 L, 1.5 L, 2 L, and 2.5 L, where L is the gymnasium span) of the stadium and gymnasium. The wind tunnel tests and numerical simulations were used to analyse the influence of the wind direction angle (from 0° to 315°, there are a total of eight groups in 45° intervals). The following results were obtained. The stadium opening had a significant effect on the snow distribution on the surface of the two structures. An even snow distribution was obtained when the stadium opened directly facing the gymnasium, which corresponded to the safest condition for the structures’ surfaces. As the spacing between the buildings increased, the interference effect between the two structures was reduced. The interference was negligible for a spacing of 2 L. The stadium had the most significant amplification interference effect on the gymnasium for a wind direction angle of 45°, which was extremely unfavourable to the safety of the structure. The most favourable wind direction angle was 270°, where there were both amplification interference and blockage interference.

Tooth crest chamfering method of spiral bevel gear using ball end milling cutter

A chamfering method is proposed in order to improve processing accuracy and efficiency of tooth crest chamfering of spiral bevel gear. Coordinates of discrete points of upper and lower edges of chamfering surface are calculated based on the mathematical model of tooth surface and face cone. Distances between center of ball end milling cutter and upper and lower edges are set equal to radius of the ball end milling cutter, chamfering tool path is generated by particle swarm algorithm solving, both sides of tooth crest can be chamfered simultaneously to ensure processing efficiency. Direction angle of the cutter axis is calculated based on the relationship between direction of the cutter axis and contact positions of the cutter surface. Aiming to prolong service life of cutter, direction angle varies uniformly within the feasible region and contact positions distribute evenly on the cutter surface. Pinion without tooth crest chamfering is installed on four-axis CNC machine tools, edge detector is used to detect axial and circumferential cutter positions, then chamfering experiment is completed. Widths of chamfering surface are measured on different measuring positions, maximum error is 0.08 mm compared with design width 1 mm which appears at tooth crest inner end of convex side. Measuring results show that chamfering error is much smaller than that with manual chamfering, which indicates that the chamfering method is feasible.