height control
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2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xingzheng Chen ◽  
Congbo Li ◽  
Rui Hu ◽  
Ning Liu ◽  
Chi Zhang

AbstractVertical picking method is a predominate method used to harvest cotton crop. However, a vertical picking method may cause spindle bending of the cotton picker if spindles collide with stones on the cotton field. Thus, how to realize a precise height control of the cotton picker is a crucial issue to be solved. The objective of this study is to design a height control system to avoid the collision. To design it, the mathematical models are established first. Then a multi-objective optimization model represented by structure parameters and control parameters is proposed to take the pressure of chamber without piston, response time and displacement error of the height control system as the optimization objectives. An integrated optimization approach that combines optimization via simulation, particle swarm optimization and simulated annealing is proposed to solve the model. Simulation and experimental test results show that the proposed integrated optimization approach can not only reduce the pressure of chamber without piston, but also decrease the response time and displacement error of the height control system.


2021 ◽  
Vol 941 (1) ◽  
pp. 012011
Author(s):  
Aleksandr Gurin ◽  
Svetlana Rezvyakova ◽  
Nikolay Revin

Abstract The studies were carried out in the apple orchard planted in 1987. The layout of trees was 7x5 m, the stock was vigorous (seedlings of cultivated varieties). In the first experiment, the influence of the crown cut on fruit yield was studied. The object of research was an apple tree of the Sinap Orlovsky variety. The following options were considered: 1. Without reduction in the crown height (control); 2. Cutting the tree height to 5.0-5.5 m; 3. Cutting the tree height to 4.0-4.5 m; 4. Cutting the tree height to 3.0-3.5 m. The trees were pruned in the spring of 2015. In the second experiment, perennial wood was removed and the yield was compared. The object of the study was an apple tree of the Antonovka Ordinary variety. The following options were considered: 1. Sanitary pruning (control); 2. Pruning for 3-4 year old wood; 3. Pruning for 5-6 year old wood; 4. Pruning for 7-8 year old wood. The trees were pruned in the spring of 2016. The experiments were repeated 4 times, each option used 6 trees, the placement of the plots was randomized. In the first experiment, on the sixth year, the highest yield (15.8 t/ha) was observed for the option with a crown cut to 4.0-4.5 m. This option also showed the highest total yield for 6 years (55.1 t/ha). In the second experiment for options with rejuvenation pruning, the total yield over 5 years exceeded the control option by 9.9-36.3%. The highest yield (52.2 t/ha) was obtained for the option with pruning for 5-6 year old wood.


2021 ◽  
Vol 12 ◽  
Author(s):  
Sung Eun Kim ◽  
Dong-Yun Lee ◽  
Min-Sun Kim ◽  
Sung Yoon Cho ◽  
Dong-Kyu Jin ◽  
...  

ObjectiveThis study aimed to determine the most appropriate age for height control treatment in patients with Marfan syndrome (MFS).Materials and MethodsThis retrospective study included patients with MFS who underwent height control treatment with estradiol valerate. The estrogen dose was increased according to the height change. The cut-off age for the maximum difference between the expected height and actual final height was evaluated.ResultsSeventeen patients were included in this study. The difference between the height predicted by the growth curve and the final height (gcHtD) and that predicted by the bone age and the final height (baHtD) was the largest in the 10.5 years age group (p=0.0045 and p=0.0237, respectively). The gcHtD was 10.6 (10.2, 13.5) cm for patients aged ≤10.5 years, whereas it was 0.6 (−3.65, 5.85) cm for patients aged >10.5 years. The baHtD was 10.1 (7.31, 11.42) cm for patients aged ≤10.5 years, while it was 3.83 (0.84, 6.4) cm for patients aged >10.5 years. When height change was observed for a minimum of 6 months after completion of estrogen treatment, the average growth was 0.6 (0.2, 2.1) cm.ConclusionInitiating height control treatment before the age of 10.5 years is effective in female patients with MFS.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rana El-Dabaa ◽  
Islam Salem

PurposeConventional motion mechanisms in adaptive skins require rigid kinematic mechanical systems that require sensors and actuation devices, hence impeding the adoption of zero-energy buildings. This paper aims to exploit wooden responsive actuators as a passive approach for adaptive facades with dynamic shading configurations. Wooden passive actuators are introduced as a passive responsive mechanism with zero-energy consumption.Design/methodology/approachThe study encodes the embedded hygroscopic parameters of wood through 4D printing of wooden composites as a responsive wooden actuator. Several physical experiments focus on controlling the printed hygroscopic parameters based on the effect of 3D printing grain patterns and infill height on the wooden angle of curvature when exposed to variation in humidity. The printed hygroscopic parameters are applied on two types of wooden actuators with difference in the saturation percentage of wood in the wooden filaments specifically 20% and 40% for more control on the angle of curvature and response behavior.FindingsThe study presents the ability to print wooden grain patterns that result in single and double curved surfaces. Also, printing actuators with variation in infill height control each part of wooden actuator to response separately in a controlled passive behavior. The results show a passive programmed self-actuated mechanism that can enhance responsive façade design with zero-energy consumption through utilizing both material science and additive manufacturing mechanisms.Originality/valueThe study presents a set of controlled printed hygroscopic parameters that stretch the limits in controlling the response of printed wood to humidity instead of the typical natural properties of wood.


AGROFOR ◽  
2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Sevim DEMİR ◽  
Fisun Gürsel ÇELİKEL

In this study, effect of gibberellin inhibtors as preplant bulb soaks on plant height of Hyacinthus orientalis cv. ‘Jan Bos’ grown in pots were investigated. Bulbs of hyacints were soaked in flurprimidol at 0, 10, 20 ppm and paclobutrazol at 0, 100, 200 ppm before planting. Effect of gibberellin inhibitors on the flowering time, flower diameter and length, leaf length, plant height, flower life, chlorophyll content of leaves were determined. In addition, after hyacints grown in pots in the greenhouse arrived at the sales stage to determine the changes that occur in the plant height, plants were taken to the laboratory where temperature was held constant at 20 °C. The shortest plant height was obtained from the 200 ppm paclobutrazol and 20 ppm flurprimidol treatment as given bulb soaks. In this treatments, plant heihgt was 7.33 and 8.61 cm and were 49% , 41% shorter than untreated control. The lower dose of 10 ppm flurprimidol and 100 ppm paclobutrazol were also effective on height control with 9.11 and 9.71 cm plant height, respectively. Gibberellin inhibitors also shortened leaf lenght. Flurprimidol and paclobutrazol treatments resulted in higher chlorophyll content per unit area in the leaves than untreated controls. The highest chlorophyll contetnt was obtained from the plants treated 200 ppm paclobutrazol with 83.36 CCI (Chlorophyll content index), while the control was 50.56 CCI. The effects of treatments on plant height were maintained in lab conditions (home-office). The shortest plant height was obtained from 200 paclobutrazol treatment with 9.75 cm, while the control was 21.5 cm during post production period.


2021 ◽  
Author(s):  
Yulun Zhuang ◽  
Yuan Xu ◽  
Binxin Huang ◽  
Mandan Chao ◽  
Guowei Shi ◽  
...  

Author(s):  
L. Mitsevich ◽  
N. Zhukovskaya

Abstract. The article discusses methods for constructing and using digital photogrammetric and cartographic models as a basis for growing tree height control and plantation planning in aerodrome areas. Forests or gardens in the take-off and landing flight areas, exceeding special limitation surfaces, are dangerous obstacles and intended to cut down. Tree and bush vegetation should be under periodic monitoring because of their growth. The research was aimed to determine the maximum permissible obstacle height and tree age when it reaches the obstacle limitation surface altitude. For these purposes, it is proposed to use geospatial modeling and geoinformation analysis methods. As a basis for geospatial models, remote sensing optical stereo images were used. The allowable height is calculated as a difference between 3D obstacle limitation surface and the earth surface altitude values. The article presents the study results for a Belarus climatic zone, where the tree species predictive age in reaching the maximum permissible height is calculated. The main goal of the technology is to manage the aerodrome forest plantation growth without further labor-intensive monitoring, while ensuring the safety of aircraft flights.


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