Medial Longitudinal Arch Pad Influences Landing Control of the Lower Limbs during Single-Leg Jump-Landing

Background: Arch support has the effect of maintaining arch and correcting alignment, and it is broadly used for the prevention of sports impediment and treatment of athletes with lowered MLA and foot problems. The fact that the morphological change of MLA damages balance sense and postural control, it was reported that the insole supporting the arch of MLA improved postural balance. There are several studies regarding the effects of arch support;however, its effects on landing control have not been clarified. Therefore, in our research, we discussed the effect of MLA support for landing control, using lower limb dynamic alignment and the moment during landing as indexes. Methods: This study measured the landing motion to be evaluated was to jump from a platform with a height of 30 cm by taking-off with a single foot, and landing on a single foot on a floor reaction force gauge placed ahead and stay still for three seconds for the subjects were 13 healthy females. A soft 6 mm Boron sheet cut in the size of 9 × 3.5 cm, applied with double-sided tape (MLA pad) was used for arch support (hereafter referred to as “pad”). For the lower limb evaluation, an 8-camera with a three-dimensional behavioral analyzer (CORTEX, NAC product, sampling frequency: 120 Hz) and a floor reaction force gauge (AMTI product, sampling frequency: 1000 Hz) were used. Ten successful jump-landing tests for each limb were used for further analyses using Visual 3D software (Cmotion Inc., Kingston, Canada). Analysis objects were knee joint bending angle and valgus angle during landing;knee joint maximum bending angle;bending knee joint valgus angle, hip joint bending angle, adduction angle, ankle joint plantar flexion angle, varus angle at the time of knee joint maximum bending angle;and each joint moment. For statistical processing, the average value of three trials out of five trials was regarded as a representative value. Results: Regarding joint angles, significant differences were observed in maximum knee joint bending angle, knee joint bending angle during maximum valgus knee joint and ankle joint varus angle during knee joint maximum bending angle between before and after intervention. No significant differences were observed in other joint angles. Regarding joint moments, no significant difference was observed in each joint moment before and after the intervention. Significance: The decrease of knee joint valgus angle during landing by the use of MLA pad suggests the possibility of decreasing the risk of ACL injury. As the incidence of ACL injury in females is higher than that of males, and the evaluation for females had proceeded, it can be useful information for the prevention of ACL injury.

Spatiotemporal variations in ecosystem services and their trade-offs and synergies against the background of the gully control and land consolidation project on the Loess Plateau,China

Studying the spatiotemporal variations in ecosystem services and their interrelationships on the Loess Plateau against the background of the gully control and land consolidation(GCLC)project has significant implications for ecological protection and quality development of the Yellow River Basin.Therefore,in this study,we took Yan'an City,Shaanxi Province of China,as the study area,selected four typical ecosystem services,including soil conservation service,water yield service,carbon storage service,and habitat quality service,and quantitatively evaluated the spatiotemporal variation characteristics and trade-offs and synergies of ecosystem services from 2010 to 2018 using the Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model.We also analysed the relationship between the GCLC project and regional ecosystem service changes in various regions(including 1 city,2 districts,and 10 counties)of Yan'an City and proposed a coordinated development strategy between the GCLC project and the ecological environment.The results showed that,from 2010 to 2018,soil conservation service decreased by 7.76%,while the other three ecosystem services changed relatively little,with water yield service increasing by 0.56% and carbon storage service and habitat quality service decreasing by 0.16% and 0.14%,respectively.The ecological environment of Yan'an City developed in a balanced way between 2010 and 2018,and the four ecosystem services showed synergistic relationships,among which the synergistic relationships between soil conservation service and water yield service and between carbon storage service and habitat quality service were significant.The GCLC project had a negative impact on the ecosystem services of Yan'an City,and the impact on carbon storage service was more significant.This study provides a theoretical basis for the scientific evaluation of the ecological benefits of the GCLC project and the realization of a win-win situation between food security and ecological security.

Eagle Vision-Based Coordinate Landing Control Framework of Unmanned Aerial Vehicles on an Unmanned Surface Vehicle

The coordinate landing control of the unmanned aerial vehicles(UAVs)is a key technology to expand the cooperation between the UAVs and the unmanned surface vehicle(USV).This paper provides an eagle vision-based coordinate landing control framework for the UAV swarm landing on a USV.Back-stepping controller is designed to guarantee that the tracking errors in both of the approaching stage and the landing stage converge to zero.Eagle vision is applied in the visual navigation to improve the landing accuracy.The experiment verified the feasibility of the proposed method.

Dynamically Adapt to Uneven Terrain Walking Control for Humanoid Robot

Dynamically adapt to uneven ground locomotion is a crucial ability for humanoid robots utilized in human environments.However,because of the effect of current pattern generation method,adapting to unknown rough ground is limited.Moreover,to maintain large support region by four-point contact during the landing phase is usually a key problem.In order to solve these problems,a landing phase control and online pattern generation in three dimensional environments is proposed.On the basis of robot-environment non-planar interactive modes,a method of landing control based on optimal support region is put forward to realize stable four-point contact by flexible foot,and a controller is employed to adapt to the changes of ground without using prior knowledge.Furthermore,an adaptable foothold planning is put forward to the online pattern generation considering walking speed,uneven terrain,and the effect of lateral movement to the locomotion stability.Finally,the effectiveness of landing control and online pattern generation is demonstrated by dynamic simulations and real robot walking experiments on outdoor uneven ground.The results indicate that the robot kept its balance even though the ground is unknown and irregular.The proposed methods lay a foundation for studies of humanoid robots performing tasks in complex environments.

Assessing the Effect of Natural Controls and Land Use Change on Sediment Yield in a Major Andean River:The Magdalena Drainage Basin,Colombia

马格达莱纳河是哥伦比亚安第斯山区的一个世界级的河流网络，该河流年产沙量约为150Mt，是全世界10大主要产沙河流之一。在本研究中，我们探讨主要自然因子和人类活动对马格达莱纳河流域产沙模式的影响，重建该区森林砍伐和农业活动时空模式，探讨土地利用变化与产沙趋势的关系。我们的研究结果表明，整个马格达莱纳河流域的产沙量可以用自然变量（包括径流量和最大河水流量）来解释。这两个因子解释了产沙量58％的变化。含沙率和土地利用的时间分析表明，在过去10～20年里流域侵蚀呈现增加的趋势。许多人类活动的影响，包括森林覆被在20年里减小了近40％．农业和牧场增加了65％、土壤保持差、开矿活动，以及城市化的加速，都促进了该地区域尺度上产沙量的增加。

Development and Prospect of Zoning Mode in the Three Rounds of Overall Land Use Planning of China

Zoning system is the basic mode of establishment of overall land use planning. In this study,the zoning mode and practice in the three rounds of overall land use planning that have been carried out in China were analyzed and summarized firstly,and then some obvious problems existing in the implementation of the zoning mode were analyzed. Finally,countermeasures and suggestions were put forward to provide necessary reference for further development and improvement of the zoning mode and the development of overall land use planning at all levels in China.

Analysis on Green Development Strategy of Xinjiang Cotton

Through on-the-spot investigation and survey in Xinjiang cotton region and relevant data( containing statistical data,online information and government documents,etc.),the characteristics of water resource,wind-sand disaster,soil salinization,cotton diseases,insect pests and weeds in Xinjiang are studied. It is proposed reasons and specific programmes of green development strategy of Xinjiang cotton,and specific strategies contain ecological water supply,land desertification control,soil improvement,and ecological control of diseases,insect pests and weeds,thereby providing the support for sustainable development of Xinjiang cotton.

Challenges of Women Contributing to Food Security in Ghana： Perspectives of Women Farmers in Northern Ghana

Women contribution to all the four pillars of food security （food availability, accessibility, utilization, and sovereignty） has been well established in Ghana and many sub-Saharan African countries. However, the issue of sustainability of their contribution to the food security equation is still a dilemma. This study therefore examined the challenges and vulnerabilities associated with women farmers in accessing and controlling land for sustained agriculture in Northern Ghana. The study was mainly qualitative and utilized various participatory dialogue processes including focus group discussions and key informant interviews of selected women farmer groups, individual farmers, opinion leaders and traditional authorities in eight communities across four districts in three regions of Northern Ghana. The data was analysed thematically. Results of the study showed that women are disadvantaged in all the possible means of acquiring land for agricultural production-- inheritance, marriage, rent, shared cropping, outright purchase, and gift. It was evident that women have appreciable levels of access to land, but have low level of control of such lands for sustained food production. Several factors, such as low income, socio-cultural factors, climate change, mining, urbanization, low level of education, and low levels of awareness of property and inheritance rights, associate women＇s vulnerability to limited land in the study area. The findings of the study imply that any policy geared toward women empowerment in agriculture must not only target their access to land but also consider enhancing their control over agricultural land. The study therefore recommended that in order to increase food production and security in the study regions, there is the need to strengthen women＇s capacity to defend their land tenure rights and enhance their access and control over land within the context of natural resource management.

A Study of the Improvement of Planning Systems for Land Use Control in Agricultural Heritage Sites

The number of GIAHS sites is increasing these days and will continue to do so gradually in East Asian countries including Korea,China and Japan.As a result,conservation of heritage sites is more and more important,especially in Korea.Dealing with issues surrounding land use conflicts are important for conservation of heritages in order to harmonize between conservation and development to prevent reckless development.This study aims to identify measures for land use management and control to allow for sustainable development around agricultural heritage system sites.The results point to the importance of public-private partnerships and local ordinance systems or comprehensive planning of land use controls for agricultural heritage system sites.

Study of helicopter autorotation landing following engine failure based on a six-degree-of-freedom rigid-body dynamic model

This paper focuses on the prediction of the safe autorotation landing operations of a helicopter following engine failure.The autorotation landing procedure is formulated as a nonlinear optimal control problem based on an augmented six-degree-of-freedom rigid-body flight dynamic model.First,the cost function and constraints are properly selected.The direct transcription approach is then employed to solve the optimal control problem.For a UH-60 helicopter,the optimal solutions with the rigid-body model are compared with those obtained using a two-dimensional point-mass model.It is found that the optimal solutions using the two different models show reasonably good agreement,and furthermore the optimal solutions using the rigid-body model involve the time histories of angular rates and attitudes,lateral velocity and position,as well as pitch controls.Finally the optimal control formulations with different cost functions are proposed for taking account of 1-s time delay and minimum touchdown speed.The calculated control strategies and trajectories are realistic.

Approach and landing guidance design for reusable launch vehicle using multiple sliding surfaces technique

An autonomous approach and landing（A＆L） guidance law is presented in this paper for landing an unpowered reusable launch vehicle（RLV） at the designated runway touchdown. Considering the full nonlinear point-mass dynamics, a guidance scheme is developed in threedimensional space. In order to guarantee a successful A＆L movement, the multiple sliding surfaces guidance（MSSG） technique is applied to derive the closed-loop guidance law, which stems from higher order sliding mode control theory and has advantage in the finite time reaching property.The global stability of the proposed guidance approach is proved by the Lyapunov-based method.The designed guidance law can generate new trajectories on-line without any specific requirement on off-line analysis except for the information on the boundary conditions of the A＆L phase and instantaneous states of the RLV. Therefore, the designed guidance law is flexible enough to target different touchdown points on the runway and is capable of dealing with large initial condition errors resulted from the previous flight phase. Finally, simulation results show the effectiveness of the proposed guidance law in different scenarios.