Heuristic Expanding Disconnected Graph:A Rapid Path Planning Method for Mobile Robots

Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality.

The expanding amyloid family:Structure,stability,function,and pathogenesis

The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack into unbranched fibrils.Stranger still,a single protein sequence can adopt wildly different two-dimensional conformations,yielding distinct fibril polymorphs.

Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures

BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures.

Even Closer China-Philippines Relations China and the Philippines have shown commitment to managing differences and expanding cooperation,which fosters more confidence in the ongoing stability of bilateral relations over the next six years

On January 3,2023,China welcomed the first visit in the new year by a foreign head of state,Philippine President Ferdinand Marcos Jr.The visit was also the president’s first official state visit to a country outside ASEAN since he took office in June 2022,which demonstrated the great importance the two countries attach to their bilateral relations.The three-day visit was fruitful despite a tight schedule.

Expanding Food Security

China and FAO assist Uganda to become self-sufficent in food production, and serve as the food basket of the region Eighty percent of Uganda’s economy depends on agriculture, according to the Uganda Bureau of Statistics. For this reason, Frank Tumwebaze, Uganda’s minister of agriculture, animal industry and fisheries, said in an interview recently that since the majority of the country’s population is involved in agriculture.

Effects of expanding zone parameters of vacuum dust suction mouth on flow simulation results

Based on the parametric analysis of the expanding zone of the vacuum dust suction mouth,the flow in the vacuum dust suction mouth was simulated by computational fluid dynamics(CFD)software,Fluent.The effects of the expanding zone parameters on flow simulation were analyzed.The results show that simulation effects depend on threshold values of the expanding zone parameters of the dust suction mouth,and the threshold values of the expanding zone can be obtained according to the different structures of the vacuum dust suction mouth and be selected as the geometric parameters in calculating,and also corners of the expanding zone make unobvious difference in calculation accuracy and in computational efficiency compared with no corner.The simulation results provide practical guidance to the flow simulation on the dust suction mouth.

Strain rate dependency and fragmentation pattern of expanding warheads

For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testing produces the uniform stress and strain rates but the testing is expensive. The Taylor test is relatively inexpensive but produces non-uniform stress and strain fields, and the results are not so easily inferred for material modeling. In the split-Hopkinson bar(SHB), which may be used in compression, tension and torsion testing, the strain rates never exceeds 103/s. In the present work, we use the expanding ring test where the strain rate is 104e105/s. A streak camera is used to examine the expanding ring velocity, and a water tank is used to collect the fragments. The experimental results are compared with the numerical simulations using the hydrocodes AUTODYN, IMPETUS Afea and a regularized smooth particle(RSPH) software. The number of fragments increases with the increase in the expansion velocity of the rings. The number of fragments is similar to the experimental results. The RSPH software shows much the same results as the AUTODYN where the Lagrangian solver is used for the ring. The IMPETUS Afea solver shows a somewhat different fragmentation characteristic due to the node splitting algorithm that induces pronounced tensile splitting.

Hybrid enzyme catalysts synthesized by a de novo approach for expanding biocatalysis

The two major challenges in industrial enzymatic catalysis are the limited number of chemical reaction types that are catalyzed by enzymes and the instability of enzymes under harsh conditions in industrial catalysis.Expanding enzyme catalysis to a larger substrate scope and greater variety of chemical reactions and tuning the microenvironment surrounding enzyme molecules to achieve high enzyme performance are urgently needed.In this account,we focus on our efforts using the de novo approach to synthesis hybrid enzyme catalysts that can address these two challenges and the structure-function relationship is discussed to reveal the principles of designing hybrid enzyme catalysts.We hope that this account will promote further efforts toward fundamental research and wide applications of designed enzyme hybrid catalysts for expanding biocatalysis.

Native Expanding <i>Merremia boisiana</i>Is Not More Allelopathic than Its Non-Expanding Congener <i>M. vitifolia</i>in the Expanded Range in Hainan

Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During range expansion, native species also encounter many new plant competitors. Thus, allelochemicals from native expanding species may also be more novel and allelopathic than those from non-expanding species to other plant competitors in the expanded range. We test this hypothesis using the native expanding Merremia boisiana and its non-expanding congener M. vitifolia in year 2012 inthe expanded range inHainan. In petridish bioassays, we found that aqueous extracts of M. boisiana leaves were often less inhibitory or more stimulatory to seed germination and seedling growth of five vegetable species than those of M. vitifolia leaves. In pot culture, we also found that aqueous leaf extracts of the two congeners could both inhibit the growth of a naturally co-occurring plant Paederia scanden, but their effects did not differ from each other. These results indicate that while allelopathy may contribute to the competitive ability of M. boisiana, it may not act as a novel weapon explaining its success in the expanded range in Hainan.

An extrusion-shear-expanding process for manufacturing AZ31 magnesium alloy tube

A new severe plastic deformation method for manufacturing tubes made of AZ31 magnesium alloy with a large diameter was developed,which is called the TCESE(tube continuous extrusion−shear−expanding)process.The process combines direct extrusion with a two-step shear−expanding process.The influences of expanding ratios,extrusion temperatures on the deformation of finite element meshes,strain evolution and flow velocity of tube blanks during the TCESE process were researched based on numerical simulations by using DEFORM-3D software.Simulation results show that the maximum expanding ratio is 3.0 in the TCESE process.The deformation of finite element meshes of tube blanks is inhomogeneous in the shear−expanding zone,and the equivalent strains increase significantly during the TCESE process of the AZ31 magnesium alloy.A extrusion temperature of 380°C and expanding ratio of 2.0 were selected as the optimized process parameters from the numerical simulation results.The average grain size of tubes fabricated by the TCESE process is approximately 10μm.The TCESE process can refine grains of magnesium alloy tubes with the occurrence of dynamic recrystallization.The(0001)basal texture intensities of the magnesium alloy tube blanks decrease due to continuous plastic deformation during the TCESE process.The average hardness of the extruded tubes is approximately HV 75,which is obviously improved.

Efficacy and safety of standard and anti-reflux self-expanding metal stent: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer involving the gastroesophageal junction and the gastric cardia. Anti-reflux stents with valve have been designed to prevent the acid reflux. The superiority of anti-reflux stent over standard stent in preventing gastroesophageal reflux has not been established well. This study compares the anti-reflux stent and the standard stent in terms of their efficacy to prevent acid reflux.AIM To compare the standard and the anti-reflux stents in terms of their efficacy,safety, and complications.METHODS The meta-analysis included 8 randomized clinical trials(RCTs) to compare pooled outcomes of total 395 patients. Primary outcomes include improvement in reflux symptoms and dysphagia score. Secondary outcomes include complications of stent migration, occlusion, and bleeding.RESULTS A total of eight RCTs were included in the meta-analysis. Compared to the standard stent, the anti-reflux stent showed a trend towards reduction in the dysphagia score without reaching a statistical significance [Standardized mean difference(SMD):-0.33(-0.71, 0.05); P = 0.09, I2: 37%]. There was no statistical difference in the gastrointestinal reflux(GER) scores between the two types of stents [SMD:-0.17(-0.78, 0.45); P = 0.008, I2: 74%]. Compared to standard stent,anti-reflux stent showed no difference in the risk of stent migration [OR: 1.37(0.66, 2.83); P = 0.40, I2: 0 %], bleeding [OR: 1.43(0.40, 5.13); P = 0.59, I2: 0 %], and obstruction [OR: 1.66(0.60, 4.60); P = 0.33, I2: 0 %].CONCLUSION Traditional self-expanding standard esophageal stent and anti-reflux stent with valve are similar in terms of outcomes and complications.

Homotopy analysis solutions for the asymmetric laminar flow in a porous channel with expanding or contracting walls

In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homotopy analysis method （HAM） is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail.

Preventive Countermeasures for "Immiserizing Growth in Expanding Economies" in China's Rural Areas in the New Era

On the basis of defining the concept of "immiserizing growth in expanding economies",through analysing the status quo of economy in China's rural areas in the new era,this paper aims to find out the factors responsible for economic weakness of China's rural residents.It analyses the impact of market consuming economy on growth economy,and points out the phenomenon of "immiserizing growth in expanding economies" which may be triggered by China's rapid rural economic growth as follows:first,the income disparity between urban and rural residents increases ceaselessly,the commodity prices continuously soar,and the rural residents' market consuming capacity is short;second,the wealth concentrates highly and the majority of farmers' income is low.Thus we put forward the countermeasures and proposals for preventing "immiserizing growth in expanding economies" in rural areas as follows:we should reform household registration system so that the rural residents have the right to migrate freely,and farmers' status is promoted;we should coordinate urban-rural development,strengthen agriculture and rural infrastructure building and achieve impartial allocation of public resources;we should carry out redistribution on income scientifically and effectively,consolidate rural social security system,bridge urban-rural income gap,transform the comparative advantage into competitive advantage,so as to circumvent "immiserizing growth in expanding economies".

Theoretical Analysis on Thermal Choking in Expanding RBCC Duct

A one-dimensional theoretical model was adopted in this paper to describe and analyze the flow in an expanding RBCC(rocket based combined cycle)duct.It can be concluded that the expanding angle,heating amount and distribution of heating play crucial roles on the thermal choking.They mainly influence the acceleration of flow,the position of choking throat and the total pressure loss.In order to fulfill the transition of subsonic flow to supersonic flow in the expanding RBCC duct,the heating amount has to change from a bigger value to a smaller one along the duct.When the thermal choking occurs in the RBCC duct,the moderate expanding angle,proper heating amount and distribution of heating are necessary for the best performance of RBCC combustor.Adopting the RBCC duct with smaller expanding angles anterior and bigger expanding angles posterior has positive effects on the thermal choking and flexibility of selecting heating method,and can restrain the negative effect of the combustion on the inlet also.

Expanding the selection criteria of laparoscopic hepatectomy for hepatocellular carcinoma

The introduction of laparoscopic procedures is one of the milestones of surgical innovation over the past few decades. The advantages of minimally invasive approach have been gradually accepted owing to its less postoperative pain, reduced morbidity and faster recovery. Also, since the introduction of laparoscopic approach of liver surgery in 1955 （1）, the benefit of the procedure had long been questioned but expected.

Homotopy analysis solution for micropolar fluid flow through porous channel with expanding or contracting walls of different permeabilities

The flow of a micropolar fluid through a porous channel with expanding or contracting walls of different permeabilities is investigated. Two cases are considered, in which opposing walls undergo either uniform or non-uniform motion. In the first case, the homotopy analysis method （HAM） is used＇to obtain the expressions for the velocity and micro-rotation fields. Graphs are sketched for some parameters. The results show that the expansion ratio and the different permeabilities have important effects on the dynamic characteristics of the fluid. Following Xu＇s model, in the second case which is more general, the wall expansion ratio varies with time. Under this assumption, the governing equations axe transformed into nonlinear partial differential equations that can also be solved analytically by the HAM. In the process, both algebraic and exponential models are considered to describe the evolution of α（t） from the initial state α0 to the final state al. As a result, the time-dependent solutions are found to approach the steady state very rapidly. The results show that the time-dependent variation of the wall expansion ratio can be ignored because of its limited effects.

A subspace expanding technique for global zero finding of multi-degree-of-freedom nonlinear systems

A subspace expanding technique(SET) is proposed to efficiently discover and find all zeros of nonlinear functions in multi-degree-of-freedom(MDOF) engineering systems by discretizing the space into smaller subdomains, which are called cells. The covering set of the cells is identified by parallel calculations with the root bracketing method. The covering set can be found first in a low-dimensional subspace, and then gradually extended to higher dimensional spaces with the introduction of more equations and variables into the calculations. The results show that the proposed SET is highlyefficient for finding zeros in high-dimensional spaces. The subdivision technique of the cell mapping method is further used to refine the covering set, and the obtained numerical results of zeros are accurate. Three examples are further carried out to verify the applicability of the proposed method, and very good results are achieved. It is believed that the proposed method will significantly enhance the ability to study the stability, bifurcation,and optimization problems in complex MDOF nonlinear dynamic systems.

Analytic solution to the micropolar-fluid flow through a semi-porous channel with an expanding or contracting wall

The flow of a micropolar fluid in a semi-porous channel with an expanding or contracting wall is investigated. The governing equations are reduced to ordinary ones by using similar transformations. To get the analytic solution to the problem, the homotopy analysis method （HAM） is employed to obtain the expressions for velocity fields. Graphs are sketched and discussed for various parameters, especially the effect of the expansion ratio on velocity and micro-rotation fields.

Slope stability of increasing height and expanding capacity of south dumping site of Hesgoula coal mine:a case study

This paper is devoted to improve the containment capacity of the Hesgoula south dumping site.The general geology of the dumping site was obtained through geological surveys.Physico-mechanical properties of silty clay and bedrock layers that have a large impact on the stability of the dump were measured by direct shear tests and triaxial tests in laboratory.Then ultimate bearing capacity of the substrate were analyzed and calculated.This paper proposed three capacity expansion and increase plans and used GeoStudio software for comparison.Through computation of the stability of the dump site slope after capacity expansion and increase for each plan,the capacity expansion plan was determined.The capacity expansion and increase plan will solve the problem of the current insufficient containment capacity of the Hesgoula south dumping site,which is of great significance for saving mine transportation costs,improving work efficiency,and reducing grassland occupation.

EQUAL INTERVAL RANGE APPROXIMATION AND EXPANDING LEARNING RULE FOR MULTI-LAYER PERCEPTRONS AND APPLICATIONS

In this paper,we propose an equal interval range approximation and expandinglearning rule for multi-layer perceptrons applied in pattern recognitions.Compared with tra-ditional BP algorithm,this learning rule requires the output activations interval between themaximum target output node and other nodes to exceed a given equal interval range for eachtraining input pattern,thus it can train networks faster in much lower calculation cost andmay avoid the occurrences ot reversed target output and overlearning,hence it can improve thenetwork’s generalization abilities in pattern recognitions.Through gradually expanding of theinterval range,this learning rule can also enable the network to learn its targets more accuratelyin less additional training iterations.Finally,we apply this algorithm in network training inEEG detection,and the experimental results have shown the above advantages of the proposedalgorithm.