Currently, there is an intensive development of bipedal walking robots. The most known solutions are based on the use of the principles of human gait created in nature during evolution. Modernbipedal robots are also based on the locomotion manners of birds. This review presents the current state of the art of bipedal walking robots based on natural bipedal movements (human and bird) as well as on innovative synthetic solutions. Firstly, an overview of the scientific analysis of human gait is provided as a basis for the design of bipedal robots. The full human gait cycle that consists of two main phases is analysed and the attention is paid to the problem of balance and stability, especially in the single support phase when the bipedal movement is unstable. The influences of passive or active gait on energy demand are also discussed. Most studies are explored based on the zero moment. Furthermore, a review of the knowledge on the specific locomotor characteristics of birds, whose kinematics are derived from dinosaurs and provide them with both walking and running abilities, is presented. Secondly, many types of bipedal robot solutions are reviewed, which include nature-inspired robots (human-like and birdlike robots) and innovative robots using new heuristic, synthetic ideas for locomotion. Totally 45 robotic solutions are gathered by thebibliographic search method. Atlas was mentioned as one of the most perfect human-like robots, while the birdlike robot cases were Cassie and Digit. Innovative robots are presented, such asslider robot without knees, robots with rotating feet (3 and 4 degrees of freedom), and the hybrid robot Leo, which can walk on surfaces and fly. In particular, the paper describes in detail the robots’ propulsion systems (electric, hydraulic), the structure of the lower limb (serial, parallel, mixed mechanisms), the types and structures of control and sensor systems, and the energy efficiency of the robots. Terrain roughness recognition systems using different sensor systems based on light detection and ranging or multiple cameras are introduced. A comparison of performance, control and sensor systems, drive systems, and achievements of known human-like and birdlike robots is provided. Thirdly, for the first time, the review comments on the future of bipedal robots in relation to the concepts of conventional (natural bipedal) and synthetic unconventional gait. We critically assess and compare prospective directions for further research that involve the development of navigation systems, artificial intelligence, collaboration with humans, areas for the development of bipedal robot applications in everyday life, therapy, and industry.
raisin on mice in comparison with negative (phosphate buffer saline (PBS) and positive Mitomycin-C (MMC) controls. Moreover, the effect on fertility hormones (follicles stimulation hormone/FSH, lutenising hormone/LH) was also measured. The effect of the extracted samples were measured by employing cytogenetic analysis which included (the mitotic index (MI), chromosomal aberrations (CAs) and micronucleus (MN)) parameters. Results showed that significant increase in MI and significant reduction in both CAs and MN percentage were seen after treatment with both alcoholic and water extracts of the two raisins and alcoholic extracts was more effective than water extracts. On the other hand both the gold and black raisin enhanced the levels of the
... Show MoreThis study was done to compare the morphometric parameters of placentas in well controlled patients with preeclampsia, diabetes, and preeclampsia-diabetes with that of normal uncomplicated placentas. Patients & Methods: A total of Twenty four placentas were freshly collected. Six placentas for control group and eighteen placentas for complicated group (preeclamptic-diabetic and preeclamptic--diabetic subgroups). The placentas were grossly examined (shape, number of cotyledons, weight, and thickness). After suitable fixation, tissue processing and sectioning, the sections were stained by hematoxylin and eosin to study the general morphology and morphometry of the following parameters: number of terminal villi, number of syncytial knots, numb
... Show MoreWomen's rights in social studies and national textbooks in the secondary stage in the light of the international charters of women's rights and the cultural specificity of the Saudi society Abstract The current study focuses on exploring women rights that required to be involved in social studies and national textbooks in the secondary stage in the light of international conventions on women's rights and cultural specificity of the Saudi society, as well as to reveal the teachers and educational supervisors' estimation about the degree of importance of those components included in the books, and then build a matrix of the range and sequence of women's rights in the books of social studies and national in the secondary stage. The study us
... Show MoreSummary:
The A. H. 7th century had witnessed an obvious development
in the Yemeni scientific process. The most important reason
being the establishment of the Resooliy State (A. H. 626-858)
which had achieved economic and scientific prosperity in
various fields of knowledge. Its sultans had participated in
building schools, purchasing books, summoning of scientists,
presenting gifts, and encouraging scientific journeys in and out
of Yemen. Therefore, studies had thrived and authorship
widened, and there appeared not a few number of scientists..
In his life, a person engages in different types of verbal and actual dispositions that result in various effects, some of which are necessary and not valid, such as selling, and some are not necessary for one of the two contracting parties, such as a mortgage or both, such as lending and agency. However, there are some actions that are sometimes necessary and not necessary at other times, such as a gift that indicates in its simplest sense. Owning money for another without compensation, it is one of the doors of benevolence and benevolence, and it is one of the attributes of perfection with which God, may He be glorified and exalted be He, described Himself. - And if this analogy is the difference - and distanced himself from greed, the
... Show MoreAttention increased to the topic of academic accreditation by the university as a modern philosophy by which to improve its performance and provide high-quality education. Universities and colleges in general and Iraqi universities and colleges in particular have begun interest in accreditation and desire to get it. So starting from the pursuit of the Administration and Economics College / Baghdad University in obtaining accreditation of Association to Advance Collegiate Schools of Business (AACSB) The research is present which aims to determine the level of application (AACSB) International standards at the College of Administration and Economics / Baghdad University in preparation to get its accreditation in the future. Researc
... Show MoreSome have considered the dialectic in form and meaning from different points of view, and dismantled them from each other, and this view is correct if we adopt according to the logic of Aristotle when it comes to dialectic, the dialectic of form and meaning has different aspects and does not share a single line in terms of conceptual meaning, the form is the appearance What the recipient sees with the help of cognitive tools, the content or content is the mental meaning, which in turn depends on his own tools, and to this extent this view is correct, and the intellectual content or meaning of the artwork or the human message that the artist wants to convey to the viewer.
The research included four chapters. The first chapter included
Playing is the only common language among children in every place and time, to the fact that what distinguishes the children is their quest to play and fun way innate, not acquired, which is expressed with the child really is one of the rights. And play a key entrance to the growth of the child mentally, intellectually and cognitively and not for the child emotionally and socially just. In the play the child begins to identify and classify objects and learn concepts and circulate among themselves on a linguistic basis. Activity here and play a major role in leading the linguistic development of the child in the composition has the communication skills.
The Games (especially intellectual ones) Whatever the cause of the development
... Show MoreSome new heterocyclic compounds containing, cyclohexenone, indazole, isoxazoline, pyrmidine and pyrazoline ring system were prepared from chalcones (1a,b). The starting chalcones (1a,b) were obtained by a base catalyzed condensation of appropriately substituted benzaldehydes and 2-acetylbenzofuran. The reaction of the prepared chalcones with ethylacetoacetate/hydrazine hydrate, hydroxylamine hydrochloride, urea, thiourea, hydrazine hydrate, phenyl hydrazine or hydrazide derivatives gave the mentioned heterocycles. All synthesized compounds have been characterized by physical and spectral methods.