One-way Path Research Articles

Improvement path, the improvement potential and the dynamic evolution of regional energy efficiency in China: Based on an improved nonradial multidirectional efficiency analysis

As a globally important energy-using country, China's energy efficiency improvement is crucial to achieving its energy-saving goals and economic transformation. This paper explores the improvement path, the improvement potential and the dynamic evolution of regional energy efficiency in China from 2005 to 2016 with an improved multidirectional efficiency analysis and the Markov model. The results indicate that (1) China's provincial energy efficiency is olive-shaped, and there is a significant spatial imbalance. (2) Most central provinces and a small number of eastern and western provinces need to adopt a one-way breakthrough path for their weak links. Most western provinces should adopt a step-by-step progressive or leap-forward path to improve energy efficiency. (3) The energy saving potential of the eastern and western regions is relatively large, and the potential value of CO2 emission reduction in the central region are relatively large. (4) In the short run, the comprehensive energy efficiency of different provinces aren't highly fluid between different levels; In the long run, the equilibrium state of energy efficiency in China will be at a mid-low level. Accordingly, it is recommended to strengthen exchanges between different regions, give full play to the resource advantages of each region, and differentiated and targeted energy efficiency policies should be carried out in different provinces.

Valley Hall phases in kagome lattices

We report the finding of the analogous valley Hall effect in phononic systems arising from mirror symmetry breaking, in addition to spatial inversion symmetry breaking. We study topological phases of plates and spring-mass models in Kagome and modified Kagome arrangements. By breaking the inversion symmetry it is well known that a defined valley Chern number arises. We also show that effectively, breaking the mirror symmetry leads to the same topological invariant. Based on the bulk-edge correspondence principle, protected edge states appear at interfaces between two lattices of different valley Chern numbers. By means a plane wave expansion method and the multiple scattering theory for periodic and finite systems respectively, we computed the Berry curvature, the band inversion, mode shapes and edge modes in plate systems. We also find that appropriate multi-point excitations in finite system gives rise to propagating waves along a one-way path only.

Smart Tour Route Planning Algorithm Based on Clustering Center Motive Iteration Search

Tour route planning is hot research issue of smart tourism and tourism GIS. Reasonable tour route can help tourists get best motive benefit satisfaction. According to common tour route planning method and existing problems, smart tour route planning algorithm based on clustering center motive iteration search is brought forward in the study. Tourist sight data set and subset are set up and interest tourist sight empty vector is formed to store optimal interest tourist sight. Based on individual needs, tourist’s temporary accommodation in the downtown is set as clustering center to build optimal tourist sight extracting algorithm. Motive iteration interval and sub-interval are defined to build one-way shortest path algorithm to output shortest path between clustering center and tourist sight and between two tourist sights. Combining with positive and negative motive benefit impact factors, sub motive iteration values and motive iteration values are formed by iteration functions. Then descending order complete binary tree is generated to output and store motive iteration values and the optimal closed-loop structure with tour route, meanwhile, sub-optimal closed-loop structures with tour routes are also output. Experiment is designed and performed, sample tourists are selected to provide interest needs, and optimal tourist sight generation tree, all closed-loop structures and motive iteration values are obtained. Experiment indicates that the algorithm can solve problems of common tour route planning, meet the individual needs of tourists and provide them with optimal tourist sights and route to get best motive benefits.

Plasma activation of methane for hydrogen production in a N2 rotating gliding arc warm plasma: A chemical kinetics study

In this work, a chemical kinetics study on methane activation for hydrogen production in a warm plasma, i.e., N2 rotating gliding arc (RGA), was performed for the first time to get new insights into the underlying reaction mechanisms and pathways. A zero-dimensional chemical kinetics model was developed, which showed a good agreement with the experimental results in terms of the conversion of CH4 and product selectivities, allowing us to get a better understanding of the relative significance of various important species and their related reactions to the formation and loss of CH4, H2, and C2H2 etc. An overall reaction scheme was obtained to provide a realistic picture of the plasma chemistry. The results reveal that the electrons and excited nitrogen species (mainly N2(A)) play a dominant role in the initial dissociation of CH4. However, the H atom induced reaction CH4 + H → CH3 + H2, which has an enhanced reaction rate due to the high gas temperature (over 1200 K), is the major contributor to both the conversion of CH4 and H2 production, with its relative contributions of >90% and >85%, respectively, when only considering the forward reactions. The coexistence and interaction of thermochemical and plasma chemical processes in the rotating gliding arc warm plasma significantly enhance the process performance. The formation of C2 hydrocarbons follows a nearly one-way path of C2H6 → C2H4 → C2H2, explaining why the selectivities of C2 products decreased in the order of C2H2 > C2H4 > C2H6.

Anatomical Repair Conversion After Bidirectional Cavopulmonary Shunt for Complex Cardiac Anomalies: Palliation is Not a One-Way Path.

Complex cardiac anomalies are sometimes channeled toward Fontan palliation for various reasons. Nevertheless, anatomical repair after bidirectional cavopulmonary shunt may be another option with theoretical benefits. In this study, we report our experience with anatomical repair conversion in challenging patients who had been palliated with bidirectional cavopulmonary shunt. Retrospective review was conducted in patients who underwent anatomical repair conversion from prior bidirectional cavopulmonary shunt palliation between January 2008 and March 2016. Patients who underwent a planned staged 1½-ventricular repair were excluded. Twenty-three patients underwent anatomical repair conversion at a median age of 6.5years (range 2.7-20.0years). The interval time between palliation and conversion was 4.6 ± 2.4years (range 0.9-12.4). Indications for conversion were high-risk Fontan candidates (n = 11) and preference for biventricular anatomy (n = 12). In eight of the patients, bidirectional cavopulmonary shunts were taken down and superior vena cava was reconnected to the right atrium with Gore-Tex tube or bovine jugular venous tube. Mean cardiopulmonary bypass and aortic cross-clamp times were 225.6 ± 107.0 and 138.3 ± 76.6min, respectively. After a mean follow-up of 2.7 ± 2.2years, there was no mortality and reoperation. No patients presented sinoatrial node dysfunction and superior venous cave stenosis. All the patients were in the New York Heart Association functional class I or II. Patients with previous bidirectional cavopulmonary shunt should be re-evaluated before completion of Fontan and, if cardiac anatomy allows, anatomical repair conversion may be considered, especially in patients with high-risk Fontan completion. Initial bidirectional cavopulmonary shunt palliation should not be considered as a one-way path to Fontan. Although technically challenging, early- and mid-term clinical results of anatomical repair conversion were satisfactory.

Finishing of freeform surfaces with an optimized Z-Constant machining strategy

Freeform surfaces used in molds and dies industries…etc. are machined on multi-axis CNC milling machines with the objective to achieve a good surface finish and a minimum machining time. For the finishing operation, Parallel Plane, Isoparametric, Z-Constant, etc. machining strategies are used. Z-Constant machining strategy is suitable for machining vertical or slant surfaces and deep cavities. In this strategy, cutting tool removes material on consecutive horizontal parallel planes which increases tool clearances and engagements and hence air cuts and machining times. Commonly, tool path is generated using a linear interpolation which makes tool movements discontinuous which creates vibrations that affect surface finish. To improve surface finish and to reduce machining programs sizes, tool path must be generated using continuous curves. In this paper, for finishing freeform NURBS surfaces on 3-axis CNC milling machines using ball cutters and Z-Constant machining strategy, an approach is proposed for determining the optimum tool avoiding interferences, optimizing the tool path by considering machining and geometric constraints. Finally, generation of One-Way or Zig-Zag tool path in terms of B-Spline curves by finding the minimum control points number producing the best tool positions approximation to achieve a good surface finish and a reduced machining program. This approach reduces the product development cycle, decreases machining times and costs and increases productivity.

Research on Collision Avoidance Strategy of AGV

In order to avoid the phenomenon of collision between automatic guidance in unidirectional guidance route network, an automatic guided vehicle system based on one-way guidance path network is proposed to avoid the problem of automatic navigation touch strategy.

How cognitive engagement fluctuates during a team-based learning session and how it predicts academic achievement

The objective of the paper is to report findings of two studies that attempted to find answers to the following questions: (1) What are the levels of cognitive engagement in TBL? (2) Are there differences between students who were more exposed to TBL than students who were less exposed to TBL? (3) To which extent does cognitive engagement fluctuate as a function of the different activities involved in TBL? And (4) How do cognitive engagement scores collected over time correlate with each other and with academic achievement? The studies were conducted with Year-1 and -2 medical students enrolled in a TBL curriculum (N=175, 62 female). In both studies, six measurements of cognitive engagement were taken during the distinct TBL activities (preparation phase, individual/team readiness assurance test, burning questions, and application exercises). Data were analysed by means of one-way repeated-measures ANOVAs and path modelling. The results of the repeated-measures ANOVA revealed that cognitive engagement systematically fluctuated as a function of the distinct TBL activities. In addition, Year-1 students reported significantly higher levels of cognitive engagement compared to Year-2 students. Finally, cognitive engagement was a significant predictor of performance (β=.35). The studies presented in this paper are a first attempt to relate the different activities undertaken in TBL with the extent to which they arouse cognitive engagement with the task at hand. Implications of these findings for TBL are discussed.

Is subterranean lifestyle reversible? Independent and recent large-scale dispersal into surface waters by two species of the groundwater amphipod genus Niphargus

Groundwater is an extreme environment due to its absence of light, resource scarcity and highly fragmentary nature. Successful groundwater colonizers underwent major evolutionary changes and exhibit eye and pigment loss (troglomorphies). Consequently, their chances of dispersal and survival in the well-connected surface waters are greatly decreased, resulting in significant endemism. The West Palaearctic subterranean amphipod genus Niphargus comprises hundreds of narrowly endemic and troglomorphic species. Nevertheless, a few are known to occur in surface waters, two of which, N. hrabei and N. valachicus, have extremely large ranges that even exceed those of many surface-water amphipods. We tested if this pattern results from a secondary colonization of the relatively well-connected epigean environment, and whether this ecological shift promoted the large-scale dispersal of these species. Results showed that despite their ecological and zoogeographic similarities, N. hrabei and N. valachicus are not closely related and independently colonized surface waters. Their phylogeographic patterns indicate Middle to Late Pleistocene dispersal episodes throughout the Danube lowlands, and relatively modest yet significant genetic differentiation among populations. Clustering based on morphology revealed that the two species are phenotypically closer to each other than they are to most other epigean congeners. We presume that the ecological shift to surface environments was facilitated by their ability to thrive in hypoxic waters where rheophilic competitors from the family Gammaridae cannot survive. In conclusion, our results indicate that adaptation to groundwater is not a one-way evolutionary path and that troglomorphic species can occasionally recolonize and widely disperse in surface waters.

Statistics of an autoregressive correlated random walk along a return path

A closed-form analytical solution is derived for the statistical outcome of a random walk along a return path. The random walk is generated from the cumulative sum of correlated samples in a Gaussian-distributed autoregressive sequence. The outcome exhibits a smaller variance compared with a one-way path of equivalent length due to cancellation of correlated steps along the return leg. Furthermore, the variance decreases towards zero as the correlation coefficient approaches unity. An example application for this general result is the modelling of cumulative errors in dead-reckoning navigation systems, e.g. Doppler velocity log-aided inertial navigation systems used commonly on underwater vehicles. In this particular application, it can be used to express and quantify the natural cancellation of correlated error components between subsequent opposing legs in a typical ‘lawnmower’ survey pattern.

Adaptive low-priority congestion control for high bandwidth-delay product and wireless networks

The low-priority service is an exciting and attractive choice for networking applications (e.g. automatic update, backup, peer-to-peer file share) which create traffic that is considered less urgent than that of others and become a renewed interest at the Internet Engineering Task Force (IETF). A low-priority protocol, which provides the low-priority service, can exploit the residual bandwidth of the bottleneck link and achieve the high throughput, low-latency data delivery in traditional networks. However, due to the conservative and inappropriate congestion control mechanisms, the existing low-priority protocols (e.g. LEDBAT) cannot effectively utilize the residual bandwidth of the bottleneck link in high bandwidth-delay product (HBDP) and wireless networks. In this paper, we propose an adaptive Congestion level-based Low-Priority congestion Control (CLPC) protocol to improve the efficiency of low-priority protocols and maintain the low-priority features. Specifically, the CLPC sender adopts an one-way path delay to estimate the congestion level and adjust the aggressiveness of congestion control mechanisms. Different from other low-priority protocols, the CLPC protocol is more aggressive when the bottleneck link of HBDP and wireless networks has residual bandwidth. This makes a faster convergence of link utilization in HBDP networks. Combining the random loss detection, CLPC can achieve the high throughput in wireless networks. The extensive simulations in NS-2 show that CLPC can improve the transmission performance significantly as compared to other low-priority protocols in HBDP and wireless networks. Furthermore, we implement the CLPC protocol in the Linux kernel (3.13) and setup a testbed to measure it. The results also indicate the feasibility and effectiveness of CLPC.

Perceptual shrinkage of a one-way motion path with high-speed motion.

Back-and-forth motion induces perceptual shrinkage of the motion path, but such shrinkage is hardly perceived for one-way motion. If the shrinkage is caused by temporal averaging of stimulus position around the endpoints, it should also be induced for one-way motion at higher motion speeds. In psychophysical experiments with a high-speed projector, we tested this conjecture for a one-way motion stimulus at various speeds (4–100 deg/s) along a straight path. Results showed that perceptual shrinkage of the motion path was robustly observed in higher-speed motion (faster than 66.7 deg/s). In addition, the amount of the forwards shift at the onset position was larger than that of the backwards shift at the offset position. These results demonstrate that high-speed motion can induce shrinkage, even for a one-way motion path. This can be explained by the view that perceptual position is represented by the integration of the temporal average of instantaneous position and the motion representation.

Research of AGV Scheduling and Path Planning of Automatic Transport System

This paper focuses on AGV scheduling and path planning of automatic transport system. Using the topological modeling method to build an electronic map; based on A* (A-Star) algorithm and complex scheduling strategies to solve single AGV path planning, this paper presents a one-way graph path based planning algorithm which solves the problem of multi-AGV path planning, avoids system conflicts and enhances system stability. And the algorithm is verified by the AGV automatic transport management system, which is based on VC++6.0 and SQL Server.

Metáfora e metonímia segundo a abordagem funcionalista: estudo da gramaticalização do É QUE

É crescente o uso falado e escrito da expressão é que dita “expletiva” tanto no português brasileiro quanto no português europeu. Este trabalho consiste num relato dos resultados de uma investigação empírica da emergência da expressão é que. Objetiva apresentar os processo(s)/mecanismos que caracterizam a emergência do uso do é que como relativos a um processo de gramaticalização. No paradigma funcionalista em que se abriga o estudo da gramaticalização, este estudo analisa, diacronicamente, dados amostrais escritos desde o português antigo. Os resultados empíricos parecem comprovar a hipótese de que a trajetória unidirecional de mudança do é que teve, nos estágios iniciais de gramaticalização, uma motivação semântico-pragmática da metáfora OBJETO/ESPAÇO > TEXTO; além de um mecanismo metonímico, por meio de uma reanálise do uso original trecentista é o que em é que.

Bone Marrow Cells Lymphocyte Activity of Pregnant Mice with Therapy of E. scaber and S. androgynus Post Infection Salmonella typhimurium

Pregnancy can cause immune system changes. It is characterized by a decrease in the activity of immunocompetent cells. The use of antibiotics was intended to combat pathogenic microorganisms, but antibiotics have negative effects on pregnant women. The use of antibiotics can be replaced with extracts of Elephantopus scaber and Sauropus androgynus because both plants have chemical compounds that act as immunomodulators. This study was aimed to determine the activity of lymphocytes B220 + , TER119 + , and GR-1 + on bone marrow pregnant mice given the combination of extracts of E lephantopus scaber and S auropus androgynus after infected with Salmonella typhimurium. This research uses seven treatment groups name: (K-) 0.05% NaCMC without bacterial infection; (K+) 0.05% NaCMC infected by bacteria; (P1) E. scaber 200 mg.kg -1 BW infected by bacteria; (P2) E. scaber 150 mg.kg -1 BW and S. androgynus 37.5 mg.kg -1 BW infected by bacteria; (P3) E. scaber 100 mg.kg -1 BW and S. androgynus 75 mg.kg -1 BW infected by bacteria; (P4) E. scaber 50 mg.kg -1 BW and S. androgynus 112.5 mg.kg -1 BW infected by bacteria; and (P5) S. androgynus 150 mg.kg -1 BW infected bacteria. The initial dose of E. scaber and S. androgynus was 50 mg.kg -1 . Each treatment has three repetitions, surgery performed on day 12 th and 18 th . Lymphocyte cells isolated from bone marrow, the obtained results were analyzed by flowcytometry and statistical analysis using SPSS 16.0 one-way ANOVA, Tukey test and path. Based on the results from ANOVA tables, the formulations on mice that can restore their normal conditions with B220 + cells is E. scaber 150 mg.kg -1 BW and S. androgynus 37.5 mg.kg -1 BW, TER119 + cells is S. androgynus 150 mg.kg -1 BW, while the GR-1 + cells affected by the surgery. Those three dose formulations can be used to obtain the optimum value which can increase the number of lymphocytes and not harmful to the developing fetus. Keywords: Bone marrow, Elephantopus scaber, Lymphocyte, Pregnant mice, Sauropus androgynus

Minimizing pocketing time by selecting most optimized chronology of tool passes

This study presents a way for optimizing material removal rate (MRR) simultaneously in terms of limiting axial depth of cut (w lim) and limiting radial immersion (ρ lim) considering the restrictions posed by tool and pocket dimensions. Both up-milling and down-milling along one-way tool path routine are considered. Analysis of production of pocket of arbitrary size allowed identification of two alternative routines of pocketing passes, namely, horizontal chronology (HC) of passes and vertical chronology (VC) of passes which are studied and compared in terms of machining time. The VC is seen to be more time saving than HC because it allows bivariate optimization while HC allows only univariate optimization. It is found that the coordinate of global maximum MRRlim on the curve ρ lim(w lim) and that of minimum pocketing time may not coincide for small pockets due to geometrical constraints, but this global optimum coordinate is expected to provide the shortest machining time if the pocket is so large that time gain from numerous passes at global optimum MRRlim overshadows time delay due to geometric constraints. This deduction is confirmed to hold more strongly the more the global optimum MRRlim is greater than the MRRlim at the coordinate of minimum machining time when the pocket is not large. A generalized five-point procedure for bivariate minimization of pocketing time along one-way toolpath is established and illustrated with four numerical cases that are seen to agree with the generic deductions of this work.

From sprawl to compactness and back: population dynamics (1848–2011) and the economic structure of a Mediterranean city

In the recent decades southern European cities experienced morphological changes and a demographic transition towards zero (or negative) growth and aging. Population dynamics shifted from the impressive growth of the post-industrial period into recent de-concentration processes determining the spillover of commercial and residential settlements across the surrounding rural areas. Based on long-term demographic data, the present study hypothesizes that urban expansion did not follow a one-way linear path from compactness to dispersion while reflecting differentiated growth patterns based on the specific socioeconomic context at the local scale. Along a sufficiently long time period non-linear expansion waves alternating settlement densification and scattering are expected to be found especially in complex urban contexts such as those developed in the Mediterranean region. This hypothesis was tested for a paradigmatic case study in southern Europe (Athens, Greece) using demographic data covering 160 years (1848–2011). Urban growth in Athens was assessed through the analysis of long-term census data made available on a district level. These data provide information on the spatial distribution of resident population and characterize distinct expansion waves according to the dominant socioeconomic context. Results of the study were discussed in the light of the debate on future development of the Mediterranean cities and the (changing) economic relations with the surrounding region.

In-between coast and inland: a long-term assessment of demographic dynamics, agriculture and urban growth in Rome prefecture

Southern European urban areas have experienced a rapid transition from the impressive population growth typical of the post-industrial period to the most recent de-concentration patterns reflecting discontinuous expansion, land consumption and the abandonment of cultivated areas around the central city. Based on long-term demographic data, the present study investigates the long-term changes in population density (1871–2013) observed in Rome’s province focusing on the disparities growing between coastal and inland areas. Demographic dynamics at the local scale have been compared with the evolution of the primary sector (workers in agriculture, number of farms, cultivated land) along the study period. Our results indicate no linear, one-way path towards urbanization but a rather cyclic path alternating urbanization and suburbanization waves coinciding with the dispersed expansion of Rome and the consolidation of the gap in population density between coastal and internal areas. Results of this study were finally discussed in the light of the future development of the Mediterranean urban areas and the (changing) relationship with peri-urban agriculture and the conservation of coastal forests.

Ndido de las poblaciones ibéricas de Mercurialis annua?

Pannell, J.R ., Santos del Blanco, L. 2014 . Evolution of combined versus separate sexes: What have we learnt from the Iberian populations of Mercurialis annua ?. Ecosistemas 23(3): 13-22. Doi.: 10.7818/ECOS.2014.23-3.03 Most plant species are hermaphrodites, with both male and female functions performed by the same individuals. However, separate sexes (dioecy) have evolved on numerous independent occasions, probably either in response to selection for inbreeding avoidance, or because it pays individuals to specialize in one gender or the other. Although the evolution of dioecy from hermaphroditism tends to be thought of as a one-way path, dioecy has broken down to yield hermaphroditic populations on several occasions. One such case is found in the mainly dioecious genus Mercurialis ( Euphorbiaceae ). In the species complex M. annua , diploids are dioecious, but polyploid populations are variously monoecious or androdioecious (where males co-exist with functional hermaphrodites). This species complex offers rich material for addressing questions concerning the evolution and ecology of combined versus separate sexes, the evolution of secondary sexual dimorphism, which likely contributes to the stability of dioecy in the genus, and the evolution and genetics of sex determination and sex chromosomes. The species also offers itself as a valuable teaching tool for addressing topics ranging from sex-ratio selection to inter-sexual competition.

Simulation of Earthwork Load-and-Carry System Based on GPSS World

Focusing on the complexity and a large number of variable factors of earthworks, to simulate earthworks with discrete event system simulation method is very effective, on the basis of analyzing the current developed simulation software, GPSS World discrete event simulation system was used in the simulation; For the one-way path optimization in the Earthwork Load-and-Carry System, an optimization strategy was put forward and put into a series of recycling process including simulation, verification, modification, re-simulation and re-verification with the simulation system, to achieve the optimization of the simulation model. Finally, through the verification of simulation concrete example, the method is proved effective and feasible, and has a wide applicability and a strong guiding significance for actual projects.