Position control of a four link hyper redundant robotic manipulator

Hyper-Redundant robotic manipulators like Serial robots, Snake robots, Tentacle robots or Continuum robots have very large number of degrees of kinematics redundancy. Position control of such a robotic manipulator comprising of more than three links and articulated joints is a big challenge due to the involvement of large number of trigonometric terms in its inverse kinematics equations. In this paper, a simple algorithm for the inverse kinematics solution (IKS) of a four-link serial robotic manipulator has been proposed, which is then validated experimentally. The proposed method divides the robot into two two-link virtual sub-robot and solves the inverse kinematics analytically for joint variables of each sub-robot successively. A validation experiment was conducted on a 4-link prototype to check the validity of the proposed algorithm. The experimental results showed satisfactory results with good repeatability

Iterative Design and Prototyping of Computer Vision Mediated Remote Sighted Assistance

Remote sighted assistance (RSA) is an emerging navigational aid for people with visual impairments (PVI). Using scenario-based design to illustrate our ideas, we developed a prototype showcasing potential applications for computer vision to support RSA interactions. We reviewed the prototype demonstrating real-world navigation scenarios with an RSA expert, and then iteratively refined the prototype based on feedback. We reviewed the refined prototype with 12 RSA professionals to evaluate the desirability and feasibility of the prototyped computer vision concepts. The RSA expert and professionals were engaged by, and reacted insightfully and constructively to the proposed design ideas. We discuss what we learned about key resources, goals, and challenges of the RSA prosthetic practice through our iterative prototype review, as well as implications for the design of RSA systems and the integration of computer vision technologies into RSA

Motion investigation of a snake robot with different scale geometry and coefficient of friction

Most snakes in nature have scales at their ventral sides. The anisotropic frictional coefficient of the ventral side of the snakes, as well as snake robots, is considered to be responsible for their serpentine kind of locomotion. However, little work has been done on snake scales so far to make any guidelines for designing snake robots. This paper presents an experimental investigation on the effects of artificial scale geometry on the motion of snake robots that move in a serpentine manner. The motion of a snake robot equipped with artificial scales with different geometries was recorded using a Kinect camera under different speeds of the actuating motors attached to the links of the robot. The results of the investigation showed that the portion of the scales along the central line of the robot did not contributed to the locomotion of the robot, rather, it is the parts of the scales along the lateral edges of the robot that contributed to the motion. It was also found that the lower frictional ratio at low slithering speeds made the snake robot motion unpredictable. The scales with ridges along the direction of the snake body gave better and more stable motion. However, to get the peg effect, the scales needed to have a very high lateral to forward friction ratio, otherwise, significant side slipping occurred, resulting in unpredictable motio

Riverbank erosion and rural food security in Bangladesh

The erosion of riverbanks has a negative impact on many nations across the world, costing them land, buildings, food, fish, and other living things, which forces people to relocate. Both the frequency and severity of riverbank erosion are alarming in Bangladesh. In Zajira Upazila, a baseline investigation was carried out to evaluate the effects of river erosion on the local availability of food. The results show how erosion threatens the majority of residents in the research territory. Additionally, as a consequence of the depletion of farmland brought on by the disaster and its effects, crop production is steadily dropping. Occasionally, people lose whole properties, leaving them with few employment options and little spending power. As a result, they are always in danger of experiencing a shortage of food. The suffering people use various coping strategies to deal with these challenging circumstances, such as shifting to cheaper or less appealing eating options. Despite the fact that local governing bodies have put in place various programs to help them, including food assistance and social protection programs, these are inadequate because of the government’s constrained organizational assets and competence The study’s findings will aid scientists and decision-makers in Bangladesh and abroad in better comprehending the requirements of vulnerable riverine populations and in designing programs that would increase those societies’ food safety Therefore, these results imply that developing and implementing efficient rural development strategies could increase the food security of those residing in Bangladeshi regions threatened by riverbank erosion

Identifying Emerging Researchers using Social Network Analysis

Finding rising stars in academia early in their careers has many implications when hiring new faculty, applying for promotion, and/or requesting grants. Typically, the impact and productivity of a researcher are assessed by a popular measurement called the h-index that grows linearly with the academic age of a researcher. Therefore, h-indices of researchers in the early stages of their careers are almost uniformly low, making it difficult to identify those who will, in future, emerge as influential leaders in their field. To overcome this problem, we make use of Social network analysis to identify young researchers most likely to become successful. We assume that the co-authorship graph reveals a great deal of information about the potential of young researchers. We built a Social network of 62,886 researchers using the data available in CiteSeerx. We then designed and trained SVM and Naïve Bayes classifiers to learn how to identify emerging authors based on the personal and Social aspects of a set of 3,200 young researchers, who had an h-index of less than or equal to four in 2005. We concluded that the success of young researchers largely depends on the number of their early citations, the number of their collaborators, and the impact and recent research activity of their collaborators

Design and development of mopping robot-‘HotBot’

To have a healthy, comfortable, and fresh civilized life we need to do some unhealthy households. Cleaning the dirty floor with a mop is one of the most disgusting and scary house hold jobs. Mopping robots are a solution of such problem. However, these robots are still on the way to be smart enough. Many points limit their efficiency, i.e. cleaning sticky dirt, having dry floor after cleaning, monitoring, cost etc. ‘HotBot’ is a mopping robot that can clean dirty floor with nice efficiency leaving no sticky dirt. Hot water can be used for heavy stains or normal water for usual situation and economy. It needs neither to be monitored during mopping nor to wipe the floor after it. ‘HotBot’ has sensors to detect obstacles and a control mechanism to avoid those. Moreover, it cleans sequentially and equipped with several accident-protection-systems. Moreover, it is also cost effective compared to the robots available so far

Accessible Data Representation with Natural Sound

Sonification translates data into non-speech audio. Such auditory representations can make data visualization accessible to people who are blind or have low vision (BLV). This paper presents a sonification method for translating common data visualization into a blend of natural sounds. We hypothesize that people’s familiarity with sounds drawn from nature, such as birds singing in a forest, and their ability to listen to these sounds in parallel, will enable BLV users to perceive multiple data points being sonified at the same time. Informed by an extensive literature review and a preliminary study with 5 BLV participants, we designed an accessible data representation tool, Susurrus, that combines our sonification method with other accessibility features, such as keyboard interaction and text-to-speech feedback. Finally, we conducted a user study with 12 BLV participants and report the potential and application of natural sounds for sonification compared to existing sonification tools.https://doi.org/10.1145/3544548.358108

Dietary phytate intake inhibits the bioavailability of iron and calcium in the diets of pregnant women in rural Bangladesh: a cross-sectional study

BACKGROUND: Phytate, a potent inhibitor of calcium, iron, and zinc absorption, may hamper the bioavailability of these micronutrients at the time of pregnancy. This study assessed dietary phytate intake and its inhibitory effect on the bioavailability of calcium, iron, and zinc from the diets of pregnant women in rural Bangladesh. The study also explored significant determinants that predicted the absorption of these minerals from the diet. METHODS: A multiple pass recall (MPR) approach was used for this study, with in-depth probing interview covering 24-h dietary recall conducted among 717 pregnant women who were in either their second or third trimester. RESULTS: The mean daily phytate, calcium, iron and zinc intake of the pregnant women were found to be 695.1, 192.2, 5.1, and 5.7 mg respectively. The mean molar ratios of phytate to calcium, iron, zinc and (phytate x calcium)/zinc were 0.27, 12.8, 11.2, and 54.8 respectively. All the molar ratios were found to be significantly higher in a group with the highest phytate intake compared to other intake groups. Phytate inhibited iron absorption from the diet of all the pregnant women sampled, and inhibited calcium absorption among 52 % of the women while inhibition of zinc absorption was not found in a notable number (12 %) of the pregnant women. When using multivariate models, phytate intake, inadequate micronutrient intake, gestational age, and energy intake significantly predicted the variance in phytate to mineral molar ratios. The predicting models calculated about 92 %, 88 %, and 89 % variance in phytate to calcium, iron, and zinc molar ratios respectively. Phytate to calcium, iron, and zinc molar ratios would be expected to be respectively 0.05, 2.48, and 1.96 points higher for every 100 mg increment in daily phytate intake. CONCLUSIONS: Phytate intake was found to inhibit the bioavailability of iron and calcium from the diets of pregnant women. Moreover, phytate was one of the strongest inhibitory predictors of calcium, iron and zinc bioavailability