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2021 ◽  
Vol 11 (3) ◽  
pp. 20-25
Author(s):  
Mikhail V. MOZGOLOV ◽  
Arina V. TURANOVA

The distribution of forces in the beams of a straight and oblique monolithic reinforced concrete caisson fl oor of a square plan is compared. The forces in the beams are determined by well-known analytical methods and using fi nite element models of the SCAD PC. The calculations showed that the forces in the beams of the oblique caisson fl oor, determined analytically and using computer models, diff er signifi cantly, which indicates the complex operation of the spatial system, which is not taken into account by the analytical calculation method based on the theory of calculating plates supported by the contour. The obtained data indicate that a square caisson fl oor with beams installed at an angle of 450 to the reference contour has greater rigidity and lower values of bending moments compared to straight caissons. When the ratio of the sides of the overlap L2 > 1,5 . L1 to ensure the eff ect of supporting the contour, the location of the beams in relation to the outer contour should be at an angle of 45°.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anandhan Dhanasingh ◽  
Daniel Erpenbeck ◽  
Masoud Zoka Assadi ◽  
Úna Doyle ◽  
Peter Roland ◽  
...  

AbstractIdentification of the inner ear malformation types from radiographs is a complex process. We hypothesize that each inner ear anatomical type has a uniqueness in its appearance in radiographs. The outer contour of the inner ear was captured from the mid-modiolar section, perpendicular to the oblique-coronal plane, from which the A-value was determined from CT scans with different inner ear anatomical types. The mean A-value of normal anatomy (NA) and enlarged vestibular aqueduct syndrome (EVAS) anatomical types was greater than for Incomplete Partition (IP) type I, II, III and cochlear hypoplasia. The outer contour of the cochlear portion within the mid-modiolar section of NA and EVAS resembles the side view of Aladdin’s lamp; IP type I resembles the side-view of the Sphinx pyramid and type II a Pomeranian dog’s face. The steep spiraling cochlear turns of IP type III resemble an Auger screw tip. Drawing a line parallel to the posterior margin of internal auditory canal (IAC) in axial-view, bisecting the cavity into cochlear and vestibular portions, identifies common-cavity; whereas a cavity that falls under the straight-line leaving no cochlear portion identifies cochlear aplasia. An atlas of the outer contour of seventy-eight inner ears was created for the identification of the inner malformation types precisely.


Author(s):  
V.P. Rudnev ◽  

The use of transparent thermoplastics as construction materials imposes special requirements on them, both in terms of strength characteristics and physical properties. The stability of these properties plays an important role in the use of transparent thermoplastics in complex technical systems, where these materials are used as a structural material for the outer contour of the product, which is exposed to aggressive climatic factors. In this work, the influence of atmospheric factors in the warm humid climate zone (the coastal atmosphere of humid subtropics) on the optical properties of transparent thermoplastics was investigated, which made it possible to obtain important information for assessing the performance of polymers of this class in natural climatic conditions.


2021 ◽  
pp. 335-344
Author(s):  
Yusong Chen ◽  
Changxing Geng ◽  
Yong Wang ◽  
Guofeng Zhu ◽  
Renyuan Shen

For the extraction of paddy rice seedling centerline, this study proposed a method based on Fast-SCNN (Fast Segmentation Convolutional Neural Network) semantic segmentation network. By training the FAST-SCNN network, the optimal model was selected to separate the seedling from the picture. Feature points were extracted using the FAST (Features from Accelerated Segment Test) corner detection algorithm after the pre-processing of original images. All the outer contours of the segmentation results were extracted, and feature point classification was carried out based on the extracted outer contour. For each class of points, Hough transformation based on known points was used to fit the seedling row centerline. It has been verified by experiments that this algorithm has high robustness in each period within three weeks after transplanting. In a 1280×1024-pixel PNG format color image, the accuracy of this algorithm is 95.9% and the average time of each frame is 158ms, which meets the real-time requirement of visual navigation in paddy field.


2021 ◽  
Vol 13 (S) ◽  
pp. 5-12
Author(s):  
Sergey A. ASTAKHOV ◽  
Vasiliy I. BIRYUKOV

The article analyses the choice of a rational layout of the test object with a propulsion system (PS). One of the design examples of calculating the longitudinal stability and strength of the structure is given. The purpose of the article is to solve the problem of bending the elastic line of a cantilever tubular rod with a hinged termination during tests of a propulsion system for various aircrafts. On the example, the estimates of the approximate test object, accelerated on the track to a speed of 1200 m/s, are carried out. The aerodynamic loading of the structure of the mobile track installation is considered using the methods of mathematical modelling and the development of an algorithm for the numerical solution of the problem of bending the elastic line of a cantilever tubular rod. The deflection from the forces of external and internal loads of the outer shell of a movable track installation is considered, provided that the diameter of the outer contour is equal to the minimum and it is constant along the entire length.


BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhi-yong Zhang ◽  
Zhi Zhou ◽  
Hai-bo Zhang ◽  
Jin-song Jiao

Abstract Background The precise etiology of anterior inferior cerebellar artery (AICA) infarction is difficult to identify because of the high anatomic variability of vertebrobasilar arteries and the limitations of conventional vascular examinations. Basi-parallel anatomic scanning magnetic resonance imaging (BPAS-MRI) can reveal the outer contour of the intracranial vertebrobasilar arteries, which may be helpful to distinguish the arteriosclerosis from congenital dysplasia and dissection. Case presentation In this study, we reported 3 cases of AICA infarction and discussed the diagnostic value of BPAS-MRI in the evaluation of vascular etiology. Conclusions The BPAS-MRI could be considered as an important supplementary in the diagnosis of vascular etiology of infarction in AICA territory.


Author(s):  
Naoto Morikawa

sing a simple mathematical model, we propose two approaches to externally infer how the amino-acid sequence is folded in a protein. One is the previously proposed differential geometric approach. The other is a new category theoretical approach proposed in this paper. As an example, we consider detecting the presence of internal singularities from the outside. Knowledge of Category theory is not required. Proteins are represented as a loop of triangles. In both approaches, the outer contour of the loop is examined to detect the presence of singular triangles (such as isolated triangles) inside. By considering the interaction between loops, the new approach allows us to detect more singular triangles than the previous approach. We hope that this research will provide a new perspective on protein structure analysis and promote further collaboration between mathematics and biology.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
K Jain ◽  
M Jain

Abstract text MULLERIAN ANOMAIES – DEBATE USG OR ENDOSCOPY Mullerian duct anomalies are a complex spectrum of congenital anomalies resulting from defective fusion or canalization leading to different uterine anomalies. Early detection and proper diagnosis of uterine anomalies are paramount for proper management. Outflow obstruction defects like transvers septal defects or non canalised functional horn present early with complaint of pain while rest of patients present with amenorrhoea , infertility, repeated first-trimester abortion, fetal intrauterine growth restriction, and obstetric complications.The prevalence of uterine malformations is variable depending on the population studied , 0.4% , 4 % respectively in the general population and in infertile women while a high prevalence between 3 and 38% is reported in patients with repeated spontaneous miscarriages. Imaging plays an important role in diagnosis and treatment planning in mullerian duct anomalies. There are different imaging and endoscopic modalities that can be used for the diagnosis and confirmation of uterine malformations. All modalities are having limitations and one need to select and combine various modalities depending on the clinical presentation of patient and pelvic examination. In younger patients or acute cases, trans abdominal ultrasonography (US) is the preferred method because it is readily available, inexpensive, and rapid and does not use ionizing radiation. However it may not give the complete picture because of poor demarcation especially in fatty patient and owing to complex nature of defects , Field-of-view restrictions with US, patient body habitus, and artefact from bowel gas. Pelvic magnetic resonance imaging (MRI) is an excellent tool in the diagnosis of Mullerian duct anomalies due to high soft tissue resolution. But it is more expensive and less available. 3D ultrasound may be a valid alternative to pelvic MRI as It is less expensive and better tolerated by patients however in doubtful cases of complex nature , hysteroscopy combined with laparoscopy may be considered to confirm the diagnosis. Another advantage of endoscopy is the opportunity to correct the defect in the same sitting in most of the cases. Hysterosalpingography (HSG) and hysteroscopy are considered good modalities to assess the uterine cavity. Hysteroscopy provide the direct visualisation of the defect and considered as gold standard for cavity evaluation in doubtful cases of septate and bicornuate uterus and for simultaneous correction. However outer contour cannot be visualised so one need to use laparoscopy for complete evaluation which is a major drawback. Three-dimensional transvaginal sonography provides image quality like those provided by MRI and is being extensively used for diagnosis of all sorts of mullerian defects. it has got the advantage of realtime imaging which is helpful in distorted pelvic anatomy , visualisation of outer contour is possible ,which is considered very important to differentiate between bicornuate and septate uterus and unicornuate uterus with rudimentary horn. however it may not be possible in all cases to get a definitive diagnosis inspite of using a high end 3D machine specially in presence of artefacts , distorted contour and retroverted uterus. In such cases both modalities including MRI and endoscopy may be required to reach to a definitive diagnosis. It can be concluded that primary imaging tool is still 2d ultrasound but 3D TVS should be included in all suspected anomalies along with complete careful pelvic examination to corroborate the findings of USG. In doubt ful or complex cases, MRI should be performed particularly for cervical and vaginal atresia and septum. endoscopy should be reserved for all doubtful cases for confirmation and for acute cases where a corrective surgery can also be planned to relieve the distress.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3695
Author(s):  
Shu-Dong Lin ◽  
Shi Pu ◽  
Chen Wang ◽  
Hai-Yang Ren

In this paper, a series of four novel microstrip antenna array designs based on different annular-microstrip feeding lines at 60-GHz millimeter wave (mmW) band are proposed, aiming at the potential usage of the mmW coverage antenna with multi-directional property. As the feeding network, the annular contour microstrip lines are employed to connect the patch units so as to form a more compact array. Our first design is to use an outer contour annular microstrip line to connect four-direction linear arrays composed of 1 × 3 rectangular patches, thus the gain of 8.4 dBi and bandwidth of over 300 MHz are obtained. Our second design is to apply the two-direction pitchfork-shaped array each made up of two same linear arrays as the above, therefore the gain of 9.65 dBi and bandwidth of around 250 MHz are achieved. Our third design is to employ dual (inner and outer contour) annular-microstrip feeding lines to interconnect the above four-direction linear arrays, while our fourth design is to bring bridged annular-microstrip feeding lines, both of which can realize the goal of multi-directional radiation characteristic and higher gain of over 10 dBi.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jiansheng Zhang ◽  
Qiuyun Wang ◽  
Guiqian Xiao ◽  
Jie Zhou

To improve the service life of hot forging die, the additive manufacturing algorithm and additive manufacturing device for die remanufacturing are developed. Firstly, a compound filling algorithm in which the inner zone is filled by linear scanning and the outer contour is filled by offsetting is developed in order to solve the problems encountered in filling path planning for wire arc additive manufacturing (WAAM) like staircase effect at marginal division, degenerated edge at outer contour, programming difficulty, and so forth. Meanwhile, the attitude control algorithm of welding gun is proposed to control the angle between welding gun and welding path so as to improve the welding forming quality. Secondly, the high-temperature and low-temperature wear resistances of Fe-based and Ni-based alloy are tested. The results show that Ni-based alloy has higher high-temperature wear resistance. Finally, a disabled crankshaft hot forging die is selected for application test and the results show that, using the techniques discussed in this paper, welding materials can be saved by more than 50% and machining cost can be saved by more than 60%. In addition, the surface of automatic-repaired die is smooth without oxidation, collapse, and other defects after forging 3000 times, which is much better than that of manual-repaired die.


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