A deep learning-based home safety perception system for household service robot
In 2016, the population of people over the age of 65 in Macau was 11.2%. This means that Macau has already become an aging society. As such, more younger generations are needed to look after the elderly. According to statistics, falls are the primary cause of injury or death for the elderly over 65 years old. About 30% of the elderly over 65 years old fall every year. Along with the increase in the elderly population, it is urgent to find a fast and effective way to ensure the safety of the elderly. As there is a lot more danger besides falling in an elderly life, we aim to build a robot collocated with its danger detection system to ensure the safety of the elderly at home. The reason we decided to use robots is that we want to have larger flexibility and mobility, for example, we can give elderly rescue materials when they need help. Moreover, more home robots will be used in the future, they can just apply our system to theirs and ensure the safety of elderlies. In this research, we mainly used cameras with the Openpose model to detect dangers such as falling, potential human action danger, and environmental danger. Innovative ways are used to detect fall action, collocated with our home robot, it is a foreseeing project that could ensure the safety of the elderly in a home environment.
m×n圖改造成一座森林的探討
本研究試圖找出一些策略，以了解在mxn的格狀街道中，最少應該放入幾個吸螞蟻的裝置，便保證能抓到所有螞蟻。這問題等價於在圖G(m,n)中，最少應放入幾個紅點後，便能使G中的所有環都能碰到至少一個紅點。更等價於在圖G(m,n)中，最少應扣除幾個點後，便可形成一森林。 我們將這些點數記作k(m,n)。特別地，當m=n時記作k(n) 。本文推得：k(m,n)≧[mn+1/3]，並將等號成立時的k(m,n) 稱為完美的。經過構造後發現k(2n)、k(3,n)、 k(3n,m)、k(2+6m,2+6n),k(4+6m,4+6n) , 亦為完美的，並且將k(m,n)壓到只剩兩種可能。也得知了在無限擴張的格子圖中被移除點的密度為1/3。
Development of a neurointerface glove with tactile feedback
Research Question or Engineering Problem A stroke continues to be the most important medical and social problem of the modern world. Stroke is a type of acute cerebrovascular accident (ACVA) and is characterised by a sudden (within minutes, less often - hours) appearance of focal neurological symptoms (motor, speech, sensory, coordinating, visual and other disorders) and / or general brain disorders (depression of consciousness, headache, vomiting, etc.) that persist for more than 24 hours or lead to death of the patient in a short period of time due to a cause of cerebrovascular origin. There are two clinical and pathogenetic forms of stroke: ishemic stroke (cerebral infarction) is caused by acute focal cerebral ischemia, leading to infarction (zone of ischemic necrosis) of the brain; hemorrhagic stroke (non-traumatic intracerebral hemorrhage) is caused by rupture of an intracerebral vessel and blood penetration into the brain parenchyma or rupture of an arterial aneurysm with subarachnoid hemorrhage (SAH). ACVA also includes transient disorders of cerebral circulation, characterised by the sudden occurrence of focal neurological symptoms that develop in a patient with cardiovascular disease (arterial hypertension, atherosclerosis, atrial fibrillation, vasculitis, etc.), last for several minutes, less often hours, but no more than 24 hours, and ends with a full restoration of the impaired brain functions. Transient disorders of cerebral circulation include: transient ischemic attack (TIA), which develops as a result of short-term local cerebral ischemia and is characterised by sudden transient neurological disorders with focal symptoms; hypertensive cerebral emergency, which is a condition associated with an acute (usually significant) rise in blood pressure (BP) and accompanied by the appearance of general cerebral (less often focal) neurological symptoms secondary to hypertension. The most severe form of hypertensive crisis is acute hypertensive encephalopathy, the basis of pathogenesis of which is cerebral edema. Cerebral infarction generally is the result of the interaction of many etiopathogenetic factors, which can be subdivided into local and systemic ones. Local factors include: morphological changes in the brachiocephalic or intracerebral arteries (pathological tortuosity, etc.), atherosclerotic lesions of the vessels of the aortic arch and cerebral arteries, cardiac lesions as a source of thromboembolic cerebral infarctions, fibromuscular dysplasias of the walls of the brachiocephalic and cerebral arteries, brachiocephalic artery dissection, vasculitis (arteritis), changes in the cervical spine with the formation of extravasal compression of the vertebral arteries, anomalies in the structure of the vessels of the neck and brain (hypoplasia of the vertebral artery, trifurcation of the internal carotid artery), etc. Systemic factors include: disorders of central and cerebral hemodynamics (a sharp change in BP or a decrease in cardiac output, etc.), hereditary and acquired coagulopathies, polycythemia, certain forms of leukemia, hypovolemia, psychoemotional stress / distress, etc., hypercoagulative / hyperaggregatory side effects of a number of medications (oral contraceptives, etc.). In the 俄羅斯n Federation, more than 500 thousand people have a stroke every year. About 25,000 new cases of stroke occur in St. Petersburg every year. The incidence of stroke in the 俄羅斯n Federation is 3.48 ± 0.21 cases per 1000 people. The incidence of various types of ACVA varies widely, in particular, cerebral infarctions account for 65–75%, hemorrhages (including subarachnoid hemorrhages) – 15–20%, transient cerebral circulation disorders account for 10–15%. The frequency of cerebral strokes in the population over 50–55 years old increases by 1.8–2 times in each subsequent decade of life. Medical and socio-economic consequences of ACVA are very significant, in particular, death in the acute period of stroke occurs in 34.6% cases, during the first year after the end of the acute period in 13.4% cases; severe disability with the need for constant care is present in 20.0% of stroke patients; 56.0% have limited working capacity and only 8.0% return to their previous work activity. Disability due to stroke (the national average is 56–81%) in our country ranks first among all causes of primary disability, amounting to 3.2 per 10 thousand people. Stroke mortality among working-age population has increased in the 俄羅斯n Federation by more than 30% over the past 10 years. The annual death rate from stroke in our country is 175 per 100 thousand people. Stroke annually becomes the main cause of disability: 85% of victims experience a decrease in strength or a complete lack of ability to control the muscles of half of the body and only half of them recover limb functions partially or completely; the rest of those who have suffered a stroke remain paralysed and require care, since they are not able to completely independent existence. In this regard, recently, in the process of rehabilitation, the technology of brain-computer interfaces (BCI) has begun to be actively used. on the basis of this technology exercise machines are created. These exercise machines are controlled directly by the patient himself. This feature of the technology increases the effect of the procedure by providing a direct connection between the patient's desire and effort with the work of the simulator. The greatest development of this technology is observed in the field of medicine, where BCIs are used as a means of communication or as one of the tools of neurorehabilitation. In this regard, it seems very promising to develop the most optimal brain-computer interfaces. The goal of our project was to create an automated training complex in the form of a neuro-controlled glove with tactile feedback, designed to simplify access to rehabilitation means.
HYBRID COMPOSITE FROM X-RAY WASTE
This study considered the tensile and flexural characterization of new lighter and cheaper hybrid composite materials to replace the existing insert panel for the currently available bulletproof vest. The materials chosen included a natural fibre, i.e., kenaf fibre, chemically treated with sodium hydroxide solution, and, as a means of recycling, used x-ray films with a surface treatment. Using the traditional hand lay-up method, the materials were fabricated into seven layers of different configurations, which were then subjected to tensile and flexural tests. The findings showed that one of the configurations that consisted of both treated materials had a tensile strength of 396.9M Pa, which is quite strong, and a flexural modulus of 6.24G Pa, which makes it flexible enough to be made into wearable equipment. This configuration was then chosen to be the base design for the specimen subjected to impact test. The interfacial bond between the two distinct materials proved to be a major issue, even with the help of fibre treatment. Therefore, some improvements need to be made for the material to be comparable to existing materials performance-wise hence making this configuration suitable for ballistic application.
Fabrication and Characterization of Biological Electrospinning Nanofiber Scaffold Based on Cellulose Diacetate-Gelatin-Green Tea for Tissue Engineering Applications
Tissue engineering has developed novel therapies such as many types of wound dressings, bio-pads, scaffolds and bandages, in order to reduce the effects of deep and extensive skin wounds. Here, we have produced an electrospun nanofiber scaffold, based on biodegradable materials such as gelatin (as a natural and hydrophilic polymer) and cellulose diacetate (with optimal biodegradability), in order to increase wound healing using nanotechnology. We also used green tea extract for its anti-oxidant and anti-bacterial effect, to improve the biological properties of the scaffold. In the fabrication process, two polymer solutions: 1. Gelatin (with acetic acid solvent) and 2. Cellulose Diacetate (with acetone solvent) mixed with green tea extract, were prepared. Then they were spun using a two-nozzle electrospinner to produce a hybrid nanofiber scaffold. SEM images showed enough finesse and uniformity of the produced scaffold to simulate the extracellular matrix. Further, measuring the contact angle of water droplet and the web surface, indicated optimal hydrophilicity of the nanofiber scaffold, which controls the level of scaffold degradability and cell adhesion. Also, the results of antibacterial tests for two bacterial strains (E. coli and S. aureus) showed the antibacterial characteristics of the extract-containing scaffold. In addition to previous tests, evaluation of fibroblast morphology on the nanofiber scaffolds, indicated appropriate cell adhesion and expansion, that confirms the biocompatibility of this produced scaffold.