Type Synthesis of Walking Robot Legs

Walking robots use leg structures to overcome obstacles or move on complicated terrains. Most robots of current researches are equipped with legs of simple structure. The specific design method of walking robot legs is seldom studied. Based on the generalized-function(GF) set theory, a systematic type synthesis process of designing robot legs is introduced. The specific mobility of robot legs is analyzed to obtain two main leg types as the goal of design.Number synthesis problem is decomposed into two stages, actuation and constraint synthesis by name,corresponding to the combinatorics results of linear Diophantine equations. Additional restrictions are discussed to narrow the search range to propose practical limb expressions and kinematic-pair designs. Finally, all the fifty-one leg structures of four subtypes are carried out, some of which are chosen to make up robot prototypes, demonstrating the validity of the method. This paper proposed a novel type synthesis methodology, which could be used to systematically design various practical robot legs and the derived robots.

Parametric Vibration Analysis of Submerged Floating Tunnel Tension Legs

According to the characteristics of submerged floating tunnel anchored by tension legs,simplifying the tube as point mass and assuming that the tension leg is a nonlinear beam model hinged at both ends,the nonlinear vibration equation of the tension leg is derived.The equation is solved by the Galerkin method and Runge Kutta method.Subsequently,numerical analysis of typical submerged floating tunnel tension leg is carried out.It is shown that,the parametric vibration response of the submerged floating tunnel tension leg is related to the amplitude and frequency of the end excitation.Without considering axial resonance and transverse resonance,it is reasonable that higher order modes are abandoned and only the first three modes are considered.The axial resonance amplitude of the second or third order mode is equivalent to the first order mode axial resonance amplitude,which should not be ignored.

Finite Element Analysis of Deformed Legs of Offshore Platform Structures

The element stiffness matrix of the equivalent beam or pipe element of the deformed leg of the platform is derived by the finite element method. The stresses and displacements of some damaged components are calculated, and the numerical solutions agree well with those obtained by the fine mesh finite element method. Finally, as an application of this method, the stresses of some platform structures are calculated and analyzed.

The Calculating Model of Structural Analysis for Jack-Up Rig Legs

The selection or establishment of structural calculating model is a matter of primary importance in structural analysis. By analysing the irrationality of the calculating models used by some research organizations at home and abroad in structural analyses for truss jack-up rig legs, this paper introduces a new calculation model which is more reasonable. This model can simulate better the load situation of a rig reflecting more precisely the effects of the leg loads caused by the spring support of gearboxes of the jacking system and the secondary bending moment raised by hull displacement under extreme conditions. The rig conversion was completed in 1989. In July 1991 the rig safely stood the frontal hitting of Typhoon with the wind speed of 52 m / s, which shows that the checking on the structure is correct.

Management of restless legs syndrome in chronic liver disease:A challenge for the correct diagnosis and therapy

AIM To investigate the association between restless legs syndrome(RLS) and well-defined chronic liver disease, and the possible therapeutic options. METHODS Two hundred and eleven patients with chronic liver disease, complaining of sleep disturbances, painful leg sensation and daily sleepiness, were included. Patients with persistent alcohol intake, recent worsening of clinical conditions, or hepatitis C virus were excluded. Diagnosis of RLS was suggested by the Johns Hopkins questionnaire and verified by fulfilling the diagnostic criteria by Allen. All patients were tested, both at baseline and during follow-up, with the Hamilton rating scale for depression, sleep quality assessment(PSQI), Epworth sleepiness scale(ESS), International Restless Legs Syndrome Study Group evaluation, and international RLS severity(IRLS) scoring system. Ironfree level, ferritin, folate, vitamin B12 and D-OH25 were detected. Neurological examinations and blood testoccurred at the beginning of the therapy, after 2 wk, and at the 28^(th), 75 th, 105 th, 135 th, 165 th and 205 th day. Regarding therapy, pramipexole or gabapentin were used.RESULTS Patients were moderately depressed, with evident nocturnal sleep problems and concomitant daily sleepiness. Sleep problems and involuntary leg movements had been underestimated, and RLS s yndrome had not be e n c ons ide re d be fore t he neurological visit. All(211/211) patients fulfilled the RLS diagnostic criteria. Twenty-two patients considered their symptoms as mild, according to IRSL, but 189 found them moderate to very severe. No correlation was found between ammonium level and ESS or PSQI. Augmentation was rather precocious in our patients(135 th day), and more frequent(35%) than previous data(8.3%-9.1%). The dosage of dopamine agonists was found to be associated with augmentation and appears in range with the literature. Previous intake of alcohol and lower levels of vitamins have been related to the phenomenon in our study.CONCLUSION RLS is a common disorder, requiring rapid diagnosis and treatment. Further research is therefore fundamental.

Restless legs syndrome is contributing to fatigue and low quality of life levels in hemodialysis patients

AIM To examine whether hemodialysis(HD) patients with restless legs syndrome(RLS) are subjects of greater fatigue and impaired quality of life(QoL) compared to HD patients without RLS.METHODS Eighty five stable HD patients participated in this study. According to their RLS status, the patients were dividedinto the RLS group(n = 23) and the non-RLS group(n = 62). QoL, fatigue, sleep quality, daily sleepiness and depression symptoms were assessed by using various questionnaires. Finally, biochemical parameters including iron, ferritin, hemoglobin, hematocrit and parathormone were assessed. RESULTS The HD patients with RLS scored worse in all the questionnaires used in the study(P < 0.05). The patients with RLS were more likely to receive the HD therapy on the morning shift, whilst 43.5% of the RLS patients reported to experience the RLS symptoms also during HD. The severity of RLS was correlated with fatigue, depression score and sleep quality(P < 0.05). CONCLUSION HD patients with RLS are subject to lower QoL related parameters and greater fatigue compared to HD patients without RLS. RLS should be successfully managed in order to improve the QoL of the sufferers.

Prevalence of restless legs syndrome in patients with irritable bowel syndrome

AIM:To determine the prevalence of restless legs syndrome(RLS)in patients with irritable bowel syndrome(IBS).METHODS:Patients with diarrhea-predominant IBS(n=30),constipation-predominant IBS(n=30),or mixed-symptom IBS(n=30)were recruited from the community between March 2008 and February 2009.Rifaximin 200 mg three times daily was administered empirically to alleviate small intestinal bowel over-growth in all patients.The presence of RLS was assessed via an RLS questionnaire and polysomnography.RESULTS:Twentysix patients with IBS(29%)were diagnosed with RLS using the RLS questionnaire.Twenty-four of the 26 patients(92%)underwent polysomnog-raphy,and all had confirmation of RLS.A greater percentage of patients with RLS had diarrhea-predominant IBS(62%)compared with patients with constipation-predominant IBS(4%)or mixed-symptom IBS(33%).CONCLUSION:Restless legs syndrome is prevalent in patients with IBS,especially those with diarrheal symptoms.Assessment of concomitant disorders may improve diagnosis and expand relevant treatment options for patients.

CLINICAL STUDY OF 108 RESTLESS LEGS CASES BY ACUPUNCTURE OR EAR ACUPUNCTURE

108 cases of restless legs syndrome were treated , out of which, 56 cases withacupuncture, 52 cases with ear acupuncture. The therapeutical effects of acupuncture are superior tothat of ear acupuncture.

Estimation of Standard Operation Time of Flight Legs Based on Clustering and Probability Analysis

A clustering algorithm and a probability statistics method were applied to different phases of a flight to analyze operation time during aircraft ground taxiing and airborne flight.And the clustering pattern,distribution characteristics and dynamically changing rules of the two phases were identified.Further,an estimate method was established to measure operation time of flight legs,with creative steps of calculating individual segment separately and then integrating them accordingly.The method can both objectively and dynamically measure operation time,and accurately reflect real situation.It helps to better utilize airport slot resources and provides a strong support for air traffic flow management when scheduling flight plan in strategic and pre-tactic phases.

Prevalence of Restless Legs Syndrome in Patients Treated with Peritoneal Dialysis: Clinical and Biochemical Characteristics among Patients with and without Restless Legs Syndrome

Introduction and Aims:This is a prospective study identifying prevalence of Restless Legs Syndrome (RLS) in patients ongoing peritoneal dialysis (PD) due to end stage renal disease (ESRD) and comparing clinical and biochemical characteristics among patients with and without RLS. Methods: Two hundred ESRD patients who received PD at least six months assessed by neurologist and nephrologist with regards to presence of RLS. Also, clinical and biochemical features of these patients are determined. One hundred and forty four patients were excluded from study because they had other secondary causes of RLS except for ESRD. Results: Thirteen of 56 patients (23.2%) had RLS. The use of vitamin B + folic acid supplements was significantly lower in patients with RLS than in those without RLS (69.2% vs 97.7%;p = 0.008). There was no significant difference between patient groups with and without RLS in terms of age, gender, body mass index, cause of ESRD, peritoneal membrane transport characteristic, smoking, consuming alcohol, use of erythropoietin, duration of PD, hemoglobin, serum calcium, serum phosphorus, serum albumin, levels of serum iron, total iron binding capacity, ferritin, folic acid and vitamin B12, transferrin saturation, weekly Kt/V urea value, and amount of residual urine volume (p > 0.05). Conclusion: RLS is more common among PD patients than general population. Although essential cause is not exactly known, use of folic acid and vitamin B complex decrease the RLS prevalence in this particular patient group.

Restless Legs Syndrome in Liver Transplant Recipients

Background: The prevalence of restless legs syndrome (RLS) is approximately 10% in general population. This condition is more prevalent in certain diseases and we previously reported the prevalence of RLS in chronic liver disease population to be 62%. Objectives: Our aim was to assess the self-reported prevalence of RLS using an RLS symptom specific questionnaire in liver transplant patients. Methods: Subjects were a convenience sample in transplant clinic. They completed a validated survey for core RLS symptoms and if positive went on to completed a telephone survey using the validated International RLS Severity Scale Questionnaire (IRLS) and the Johns Hopkins RLS QoL survey to measure the effect of RLS symptoms on daily activities. Results: 40 patients surveyed, RLS was found in 16 subjects (40%) with moderate severity {17 (SD + 7.2, high score 31)}. Hepatitis C as indication for liver transplant was more likely associated with RLS (p = 0.05). Calcium channel blockers were protective (p = 0.032) while antidopaminergic agent use was statistically significant for RLS symptom (p = 0.005). On multiple linear regression analysis, diabetes (p = 0.024) and use of antidepressants/antihistamines (p = 0.049) were associated with RLS. Quality of Life (QoL) surveys specific to RLS suggested RLS symptoms resulted in significantly diminished QoL, with an average QoL score of 80 (SD + 11.7). Conclusion: There was a very high prevalence of RLS in our liver transplant patients with majority experiencing moderate or severe symptoms. The explanation for this higher prevalence is likely due to combination of comorbidites as well as medications that can trigger RLS.

OECD/NEA ROSA Project Experiment on Steam Condensation in PWR Horizontal Legs during Large-Break LOCA

Separate-effect experiment simulating steam direct-contact condensation on ECCS （emergency core cooling system） water in PWR （pressurized water reactor） cold legs during reflood phase of large-break LOCA （loss-of-coolant accident） was conducted in OECD/NEA ROSA Project using the LSTF （large scale test facility）. A new test section was furnished in the downstream of the LSTF break unit horizontally attached to the cold leg. Significant condensation of steam appeared in a short distance from the simulated ECCS injection point, and the steam temperature in the test section decreased immediately after the initiation of the ECCS water injection. Total steam condensation rate estimated from the difference between steam flow rates at the test section inlet and outlet was in proportion to the simulated ECCS water mass flux until the complete condensation of steam. Clear images of high-speed video camera were successfully obtained on droplet behaviors through the viewer of the test section, especially for annular mist flow.

RESEARCH OF KINEMATIC CHARAC－TERISTICS FOR QUADRUPED WALKING VEHICLE WITH LEGS OF DIFFERENT DISPOSITIONS OF DOFS

Systematic analyses have been made to three typical dispositions of walking vehicle leg,and their kinematic characteristics are obtained respectively. a reliable theoretical guidance for theselection of the form is provided.

采用37.5■锦纶开发多功能弹力Legging面料

文章以37.5■锦纶科技纱线4.4 tex/34 f消光DTY为主纱,夹入2.2 tex黑氨纶材料,采用双面互锁的织造方式,开发出一款集抗菌、凉感、远红外、吸湿速干、防紫外线功能为一体的多功能弹力Legging针织面料。详细介绍该面料的原料选择、织造工艺以及染整工艺,并对面料的基本性能进行测试。结果表明,该面料具有较好的多项功能以及优良的包覆性能,可以满足女子多场景的运动与穿着舒适性的相关需求。

Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

An Analysis of Medication Rules of Chinese Medicine for Restless Legs Syndrome Based on Data Mining

Objective: Based on data mining, to explore the medication rules of Chinese medicine for the treatment of restless legs syndrome(RLS). Methods: The CNKI, WANFANG, and VIP were taken as data sources, and "restless legs syndrome, RLS" as the key words, and "Chinese medicine, Chinese materia medica, traditional Chinese medicine(TCM), traditional Chinese and Western medicine" as sub key words, the data was extracted from the journals and literature related to the treatment of RLS by TCM from the establishment of the database to 2020, and data mining techniques(frequency analysis, cluster analysis, association rules) were used to analyze the core drugs and drug pair(group) rules. Results: A total of 87 prescriptions met the requirements of this study, involving 142 Chinese herbal medicines. The top 5 Chinese herbal medicines with a higher frequency of use were Radix Paeoniae Alba, Radix Glycyrrhizae, Radix Angelicae Sinensis, Fructus Chaenomelis and Radix Astragali seu Hedysari. The four Qi(气) of the medicine were mainly warm and neutral, the five flavors were mainly sweet, bitter, and pungent. The main channels of the meridian were mainly the liver meridian, spleen meridian and heart meridian. The medication categories were mainly tonifying deficiency herbs, blood activating and removing blood stasis herbs, and eliminating wind and dampness herbs. The association rule analysis yielded 24 Chinese medicine combinations with high support, and the hierarchical cluster analysis yielded a total of 5 clusters. Conclusion: TCM treatment of RLS is based on tonifying deficiency herbs, especially to replenish Qi and blood throughout the course of the disease, supplemented by herbs for promoting blood circulation and removing blood stasis, and herbs for eliminating wind and dampness, as well as combined with herbs for reliving superficies and herbs for calming the liver to stop the wind.

Legs Are Back!

When I was in elementary school, my classmates made fun of me for always wearing leggings.'Why don’t you wear jeans?' They asked, pointing to their own denim-clad, prepubescent legs.

Picking Out Meat from Crab's Legs──The Jiangsu Oilfield

ＰｉｃｋｉｎｇＯｕｔＭｅａｔｆｒｏｍＣｒａｂ＇ｓＬｅｇｓ──ＴｈｅＪｉａｎｇｓｕＯｉｌｆｉｅｌｄ（Ｔｒｙｉｎｇｔｏｓｑｕｅｅｚｅｏｎｅｌａｓｔｂｏｎａｎｚａｆｒｏｍａｐａｔｃｈｏｆｓｏｉｌｔｈａｔ＇ｓａｌｒｅａｄｙｔｅｅｎｖｅｒｙｋｉｎｄｔｏＣｈｉｎ...

HAMS+LEGS

如果你想要煎炸你的股二头肌来作为早餐,那么稍等,请你先品尝一下这个股后肌群与大腿的组合训练。

“腿(leg)”隐喻在汉英表达中的认知语言学阐析

身体部位在人类认知体系中处于基础性地位,在获取身体体验的过程中具有独一无二的作用。身体部位之腿(leg)更是人们感知外部世界的重要工具之一。汉英表达中均广泛存在以腿(leg)为源域的腿(leg)隐喻表达。从认知层面的意象角度具体分析腿(leg)的隐喻可知,腿(leg)的意象分为两大类:一类是以腿(leg)的基本外形和功能为主的具体意象,另一类是由其基本外形和功能而衍生出来的抽象意象。汉英民族因为具有相同的身体结构和生理特征,产生了相近的身体体验,而趋近的体验也产生了对等的心理阐释和语言表述,因此汉英语言表达中存在众多相仿或趋同的腿(leg)隐喻。隐喻作为各民族典型的语言现象,势必与不同民族的文化意蕴密不可分。汉英表达中腿(leg)的隐喻义都颇为丰富,有相同之处,也存在典型差异,这主要是由各自的社会文化背景、思维方式、词法规则、词语搭配、主体指代关系和民族特色差异所造成的。