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Research on Slope Model Reconstruction Based on Mobile Terminal Monocular Vision
Li Jishan,
Shi Xingxi,
Wang Xianghong
Issue:
Volume 9, Issue 1, February 2021
Pages:
1-6
Received:
2 December 2020
Accepted:
Published:
18 January 2021
Abstract: In this paper, a method of slope surface model reconstruction based on smart phone is proposed for the problems of point layout limitation, expensive measuring equipment and easy operation of monitoring personnel. By explaining the principle and steps of the SfM-MVS algorithm, the slope surface model is reconstructed based on the slope image taken by smart phone. In this paper, the principle of partial reconstruction is described, which involves the principle of polar geometry and projection error, and the corresponding description of motion recovery structure algorithm and dense reconstruction algorithm steps. The concrete steps of slope 3D reconstruction are as follows: first, the mobile phone camera is calibrated by Zhang Zhengyou camera and the slope image is enhanced for subsequent processing. Finally, the SfM-MVS algorithm is used for sparse reconstruction and dense reconstruction to obtain point cloud data, and the slope surface model is reconstructed by triangulation and texture mapping. The slope surface model obtained by smartphone image lays the foundation of slope shape change monitoring and coordinate calculation, and has the characteristics of perfect slope overall information. The model reconstruction based on mobile terminal image acquisition can reduce the equipment cost of slope monitoring and the maneuverability of monitoring personnel, and has certain application value.
Abstract: In this paper, a method of slope surface model reconstruction based on smart phone is proposed for the problems of point layout limitation, expensive measuring equipment and easy operation of monitoring personnel. By explaining the principle and steps of the SfM-MVS algorithm, the slope surface model is reconstructed based on the slope image taken ...
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Study on the Good Wind Characteristics over a Large Central City by Laser Radar Measurement
Issue:
Volume 9, Issue 1, February 2021
Pages:
7-12
Received:
29 December 2020
Accepted:
Published:
28 January 2021
Abstract: In recent years, the process of urbanization in my country has accelerated, the density of buildings in large cities has been increasing, and the height of buildings has also increased, resulting in an increasingly complex wind environment in the city center. An accurate and reasonable description of the characteristics of the wind field within the height of the atmospheric boundary layer in the city center is very important for determining the wind load of the high-rise building structure. This paper uses Windcube 100S Doppler laser wind measurement radar, taking Shanghai as an example, to carry out long-term actual measurement of good wind in the height range of 50m~1200m above Tongji University Wind Engineering Hall and obtain specific and detailed observation data. The time history of wind speed and direction in July and December 2019 is analyzed, and the average wind speed profile and average wind direction profile classified by incoming direction are studied, and the variation law of ground roughness index is obtained. The results show that there is no significant difference in the ground roughness index between different wind directions and seasons. The fitting values of ground roughness index in different directions for heights below 250m are greater than corresponding values for heights above 250m in the same direction, and are greater than the load specification values under class D landforms.
Abstract: In recent years, the process of urbanization in my country has accelerated, the density of buildings in large cities has been increasing, and the height of buildings has also increased, resulting in an increasingly complex wind environment in the city center. An accurate and reasonable description of the characteristics of the wind field within the...
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Study of Interference Effect of Wind Pressure on Roof of Multi-storey Residential Buildings
Issue:
Volume 9, Issue 1, February 2021
Pages:
13-20
Received:
5 January 2021
Accepted:
Published:
30 January 2021
Abstract: In this paper, a series of wind tunnel experiments were carried out on the rigid model of 5-6 storey residential buildings to study the influence of the location, spacing and wind direction of the buildings on the roof wind pressure of multi-storey residential buildings. The test results show that the maximum average wind pressure and extreme negative wind pressure of a single building occur in the roof ridge area at the corner and both ends of the roof, taking a multi-storey building with length × width × height of 60m×12m×20m as an example. For the buildings with three rows and three columns, when the building is located at the corner, the most unfavorable wind direction is 30°, 210°, and 330°. The most unfavorable extreme value of negative wind pressure is -8.72. The negative wind pressure coefficient of the most unfavorable extreme value of the building roof at the corner position and the middle position of the first row decreased with the length-width ratio and the spacing increased. The negative wind pressure coefficient of the most unfavorable extreme value of the building roof at the edge and middle of the second row did not change significantly with the increase of length-width ratio but increased with the increase of space. In the corner area of the roof, the interference factor of the corner position and the middle position of the first row decreased with the space, while the interference factor of the edge position and the middle position of the second row increased with the space. The variation trend of the middle area of the roof is the same as that of the corner area, but the interference factor is generally small. The interference factor of the wall area is always greater than 1.0.
Abstract: In this paper, a series of wind tunnel experiments were carried out on the rigid model of 5-6 storey residential buildings to study the influence of the location, spacing and wind direction of the buildings on the roof wind pressure of multi-storey residential buildings. The test results show that the maximum average wind pressure and extreme negat...
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A Meta-analysis of the External Treatment of Traditional Chinese Medicine for Granulomatous Mastitis
Liang Hongyi,
Chen Hanhan
Issue:
Volume 9, Issue 1, February 2021
Pages:
21-26
Received:
2 February 2021
Accepted:
Published:
9 March 2021
Abstract: Objective: to systematically evaluate the clinical efficacy of external treatment of granulomatous mastitis (including clinical efficiency and the change of mass size). Methods: the computer was used to search CNKI, Wanfang database, VIP net, CBM, PubMed and Embase, and it was used to search and select the clinical randomized controlled trials of treating granulomatous mastitis by external treatment of traditional Chinese medicine, the retrieval time limit was from the establishment of the database to December 2020, and the key words were granulomatous mastitis, external treatment of traditional Chinese medicine. After selecting literatures, extracting datas and evaluating the risk of bias included in the study, the data included in the study were analyzed by RevMan5.3 software. Results: Seven clinical randomized controlled trials were included and 600 patients met the inclusion criteria. Seven of the trials were effective observations, and four of them were tumor size observations. There were 310 cases in the experimental group and 290 cases in the control group. All the included documents were Chinese literature. The results of the study showed that the effective rate of the experimental group (combined with the external treatment of traditional Chinese medicine) for granulomatous mastitis was 95.9%, which was significantly higher than that of the control group (without the external treatment of traditional Chinese medicine). The effective rate was 82.8% [95% CI (1.02, 1.22), Z=2.41, P=0.02<0.05]. The experimental group (combined with the external treatment of traditional Chinese medicine) had a significantly higher degree of the tumor size recovery than the control group (without the external treatment of traditional Chinese medicine) [95% CI (-2.05, -1.83), Z=34.91, P<0.00001]. Conclusion: the external treatment of granulomatous mastitis had a good clinical effect. It not only improved the clinical efficiency, but also effectively reduced the size of breast mass, which was worthy of clinical promotion. However, due to the low quality of clinical trials, further verification was needed.
Abstract: Objective: to systematically evaluate the clinical efficacy of external treatment of granulomatous mastitis (including clinical efficiency and the change of mass size). Methods: the computer was used to search CNKI, Wanfang database, VIP net, CBM, PubMed and Embase, and it was used to search and select the clinical randomized controlled trials of t...
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Investigation on Alternobaric Vertigo of Gradational Simulated Saturation Diving with the Deepest Saturation of 480m to -493m
Jianguang Zhou,
Changyun Liu,
Yingqi Zhou
Issue:
Volume 9, Issue 1, February 2021
Pages:
27-31
Received:
23 February 2021
Accepted:
Published:
12 March 2021
Abstract: Objective To provide medical support for deep helium-oxygen saturation diving. Methods According to the data, the diagnostic criteria of Alternobaric vertigo were established. Gradational simulated saturation diving at 65 m, 250 m and 480m helium-oxygen saturation -493 m (hereinafter referred to as 480 m) in 500m saturation system, questionnaire, physical examination, Nystagmus view detector and Magnetic resonance imaging were used to check divers before and after each pressure exposure. Results 1 person at 250m and 480 m after leaving the cabin each had hyposmia, and 1e person at 250m and 480 m after leaving the cabin each had knee reflex (+), but the two sides were symmetrical. 1 person at 250m and 480 m after leaving the cabin each had finger nose test (+), and 1 person at 480 m after leaving the cabin had heel-knee-tibia test (+). 1 person at 65m, 250m and 480 m after leaving the cabin each had hyperemia in the eardrum, and 1 person at 250m and 2 people at 480 m after leaving the cabin had caloric test (+), all on the right side. 2 people at 250m and 480m after leaving the cabin each were found to be impaired by electrical audiometry. All the abnormal people above were reexamined normal the next day. When the pressure changed, there were 5 person-times of dizziness (13s on average), 4 person-times of aural fullness (177.5s on average), 7 person-times of shaking sensation (337.14s on average), 5 person-times of nausea (312s on average), 3 person-times of dizziness (15min on average), 1 person-time of headache in total (20s), 6 person-times of Romberg and 2 person-times of Fukuda in total. Alternobaric vertigo was diagnosed 1 person-time and most likely 1 person-time at 65m, 2 person-times and most likely 2 person-times at 250m and 3 person-times at 480m. Conclusion Alternobaric vertigo occurs frequently in deep helium-oxygen saturated diving, which is characterized by short time, complete reversibility and no influence, but should be paid attention to.
Abstract: Objective To provide medical support for deep helium-oxygen saturation diving. Methods According to the data, the diagnostic criteria of Alternobaric vertigo were established. Gradational simulated saturation diving at 65 m, 250 m and 480m helium-oxygen saturation -493 m (hereinafter referred to as 480 m) in 500m saturation system, questionnaire, p...
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