Routing Stage Research Articles

A Two-stage Learning-based method for Large-scale On-demand pickup and delivery services with soft time windows

With the rapid growth of the on-demand logistics industry, large-scale pickup and delivery with soft time windows has become widespread in various time-critical scenarios. This problem has proven to be an NP-hard problem. Hence, the computation time and resources required to solve it increase exponentially with the growth of size. As a result, it is burdensome for the exact algorithm and heuristic method to generate a high-quality solution instantly. Machine learning seems to be a possible option due to the advantage of offline training. However, it is difficult to solve large-scale problems due to the lengthy training time, heavy computational cost, and training instability. Thus, this paper proposes the two-stage learning-based method composed of the clustering stage and the routing stage to tackle this problem. The clustering stage builds upon the attention mechanism by introducing graph convolutional network to the input, which can keep the match of pickup and paired delivery customers and classify them into different vehicles, while the routing stage adopts a well-trained model to generate a route for each capacitated vehicle. Furthermore, the well-trained model is utilized to train another problem inspired by transfer learning. Experiments show that the model, trained on small-scale problems, generalizes well to larger-scale problems, and achieves superior performance compared with the heuristic method and Google OR-Tools, with an extremely short computing time. In addition, the favorable transferability of this model is verified through contrast experiment, which can save a significant amount of training time.

Beneš Network-Based Efficient Data Concentrator for Triggerless Data Acquisition Systems

The concentration of data from multiple links to a single output is an essential task performed by High-Energy Physics (HEP) Data Acquisition Systems (DAQs). At high and varying data rates combined with the large width of the concentrator’s output interface, this task is non-trivial. A high-speed dense packing of data from possibly non-continuous streams with preserving their time order requires complex and real-time adjustable routing. This paper presents a concentrator based on the Beneš network, which provides efficient concentration without using a high-frequency clock internally. It warrants that empty data are eliminated and does not disturb the data time-ordering if the data rates significantly differ between inputs. The concentrator uses simple data-routing primitives resulting in low resource consumption. If necessary, the pipeline registers may be added after each routing stage, shortening the critical path and increasing the maximum acceptable clock frequency. These features render the design well-suited to FPGA implementation.

How diverse are residents’ perceptions of wine tourism impacts in three Portuguese wine routes? The role of involvement with tourism, wine production and destination life-cycle stage

Purpose Wine tourism has been growing considerably over the past decades. The literature highlights its relevance in the social, economic and cultural development of the regions where wine routes are located. However, few studies examine residents’ tourism impact perceptions and even fewer analyse the diversity of these perceptions. This study aims to fill this gap, examining this diversity according to the life-cycle stage of the wine route and residents’ involvement with wine and with tourism activities. Design/methodology/approach Data obtained from a questionnaire-based survey (N = 882) of residents from three wine routes of the Central Region of Portugal – Bairrada, Dão and Beira Interior – were used, with dimensions of perceived impacts tested for internal consistency via Cronbach’s α. T-tests and ANOVA tests were used to compare residents’ perceptions of wine tourism impacts according to the life-cycle stage of the wine route and residents’ involvement with wine and with tourism activities. Findings Generally, residents perceived that wine tourism generates more benefits than costs, with positive economic and socio cultural impacts standing out, while negative environmental and social impacts were perceived less. Some differences are observed according to the life-cycle stage of the wine route, with both the most and the least developed routes presenting more pronounced both positive and negative impact impressions in diverse dimensions. Also, a moderating effect (however not as pronounced) of working in tourism and (even less visible) of working in the wine sector is observed. Possible explanations of these findings and implications on wine route development are discussed. Originality/value This article analyses a subject of great relevance for the sustainable development of wine tourism destinations that has been little studied in the literature. Thus, relevant theoretical and empirical contributions are identified.

A conceptually simple algorithm for the capacitated location-routing problem

Location-routing problems (LRPs) jointly optimize the location of depots and the routing of vehicles. The most studied LRP variant, the capacitated LRP (CLRP), has been addressed by a large number of metaheuristic approaches. These methods often decompose the problem into a location stage to determine a promising depot configuration and a routing stage, in which a vehicle-routing problem is solved to assess the quality of the previously determined depot configuration. Unfortunately, the CLRP literature does not shed much light on the important question which algorithmic features have the biggest influence on the solution quality and runtime of such heuristics. The purpose of this paper is to propose a conceptually simple (yet reasonably effective) heuristic for the CLRP and to provide some insights on the design of successful metaheuristics for this problem. Our algorithm is a hybrid combining (i) a GRASP phase that uses a variable neighborhood descent for local improvement in the location stage, and (ii) a variable neighborhood search in the routing stage. We analyze the impact of the algorithmic components on solution quality and runtime. In addition, we find that the suboptimal routing solutions used to assess the quality of the investigated depot configurations in tendency lead to depot configurations with too many open depots. We propose a depot configuration refinement phase that alleviates this drawback, and we show that this algorithmic component significantly contributes to the solution quality of our method, enabling it to provide reasonable results in comparison to the state-of-the-art methods from the literature.

Проблемы организации поликлинической помощи пациентам с синдромом карпального канала.

Peripheral nerve diseases occupy an important place in the structure of morbidity, accompanied by temporary disability and invalidation of the population. In addition, these diseases lead to an increase in the citizens’ and state’s expenditure for maintaining health and active lifestyle. P u r p o s e of the study is to analyze and evaluate the routing of patients with carpal tunnel syndrome, formulate proposals for its improvement. M a t e r i a l s a n d m e t h o d s . The study used the following methods: analytical, expert assessments of medical organization employees who provide care to patients with diseases of the peripheral nervous system. The analysis of medical documentation of S. P. Botkin City Clinical Hospital have been carried out. The object of the study were patients treated in this hospital from 2007 to 2021. R e s u l t s . Analyzing the routing stages of a patient with carpal tunnel syndrome, attention is drawn to the violation of the priority of the patient’s interests not only within the rational use of his time, but also the duration of neuropathic pain syndrome. The timeframes of medical care are violated. In addition, in conditions of limited resources and lean production, budgetary funds are unreasonably spent on the examination of the patient. F i n d i n g s . Optimization of routing of patients with this pathology will contribute to the timely provision of high-quality medical care, which will reduce the time of temporary disability and avoid invalidation of population.

VLSI Placement Optimization Algorithms

Placement is a fundamental optimization step to compute cell locations. The quality of results in Clock Tree Synthesis (CTS) and routing stages is impacted by the placement solution. The placement optimization flow is split into (1)global placement, (2) legalization, and (3) detailed placement. In global placement, cell locations are computed to minimize total wire length subject to a maximum cell density threshold. The cell overlapping and cell alignment to site row boundaries are relaxed. In legalization, cells are placed in locations free of overlapping and aligned to site row boundaries. Legalization algorithms compute cell locations with minimized cell displacement. In detailed placement, objectives are optimized locally. Detailed placement algorithms iterate over one cell or a small set of cells. The traditional optimization objective is total wire length. Placement algorithms also address timing violations, routability, design rules, and so forth. The placement algorithms rely on heuristics and formal methods to compute optimized cell locations. Moreover, placement algorithms require models to address signal delay propagation, area density, routing congestion, hyper-edge nets, and so forth. In the literature, several algorithms have been presented to improve placement solutions. On the other hand, placement is a really challenging problem that continues to have space for further improvement and for innovative algorithms.

Technique proposal and application for risk assessment in collective basic sanitation system in rural areas

Nowadays, apply risk assessment processes, from health perspective in all basic sanitation components (water supply, sanitary sewage, solid waste and rainwater management), in order to follow the Resolution 64/292 it is a reality. In this context, this article aimed to propose a risk assessment process (RAP) for collective basic sanitation structures and apply it on a riverside community in Goiás state of Brazil. The steps used included scope definition, technique selection for risk assessment and RAP approach and application. The community studied was Arraial da Ponte, which has collective systems for water supply, solid waste and rainwater management. The selected technique was the probability/consequence matrix, according to the criteria established in NBR IEC/ISO 31010:2021 and proposal included identification stages of RAP risk factors, hazards, contamination route and hazardous events, as well as characterization and risk prioritization. It was based on the components of risk management process of NBR ISO 31000 and on World Health Organization recommendations described for water and sanitary sewage safety plan manuals. As result, health risks were identified in all basic sanitation components, with levels ranging from moderate to unacceptable. The risks showed need for greater attention from managers, as effective public policies implementation. Finally, the RAP managed to prioritize hazardous events and their associated risks, being able to help in the construction of plans and investments in the evaluated community.

Via-Based Redistribution Layer Routing for InFO Packages With Irregular Pad Structures

The integrated fan-out (InFO) wafer-level chip-scale package (WLCSP) is introduced for modern system-in-package designs with larger I/O counts, higher interconnection density, and small form factors. A redistribution layer (RDL) in an InFO package is an extra metal layer for interchip connections, and RDL routing is crucial for achieving desired interchip connections. In a high-density InFO package, multiple RDLs with flexible vias are often adopted. To integrate chips of different technology nodes into one package, irregular pad structures need to be considered; however, no published RDL routing work considers flexible vias or irregular pad structures. This article formulates a new RDL routing problem with unified-assigned pad pairs on a via-based multilayer multichip InFO package with irregular pad structures and presents the first algorithm for this problem. The algorithm consists of a preprocessing stage, three routing stages, and a layout optimization stage. The preprocessing stage analyzes routing resources and potential routing congestion. The first routing stage performs layer assignment based on a weighted maximum planar subset of chords algorithm to route interchip nets concurrently. The second routing stage constructs a 3-D routing graph based on partitioned octagonal tiles to handle the irregular layout structure and applies A*-search to route remaining interchip nets. The third routing stage transforms a routing graph into a network-flow model to perform concurrent routing for chip-to-board nets by applying the minimum-cost maximum-flow algorithm. Finally, we develop an efficient linear-programming-based layout optimization algorithm to find desired solutions. Experimental results show that our router can achieve 100% routablility for all benchmarks under limited RDLs, while the previous state-of-the-art work cannot.

Pathfinder Algorithm Modification for FPGA Routing Stage

Pathfinder Algorithm Modification for FPGA Routing Stage

Dislocation density evolution in cold-rolled Zr-2.5%Nb pressure tubes under thermal treatments by high energy XRD and neutron TOF diffraction peak profile analysis

Diffraction line profile analysis was done to characterize the change in the dislocation density at different stages of the processing route of a Zr-2.5%Nb pressure tube. Two diffraction experiments were carried out: High Energy X-Ray Diffraction (HE-XRD) and Neutron Time of Flight Diffraction (TOF-ND). On samples in the extruded, cold-rolled and post-annealed conditions, the HE-XRD experiment in transmission geometry allows a detailed characterization of the dependence of the line shape on the direction of the scattering vector. Important variations of the FWHM (Full Width at Half Maximum) were observed, which was interpreted as the non-uniform distribution of dislocations among grains with different orientations. Average values of the dislocation density and subgrain size were obtained after applying the Warren-Averbach method.The effect of post deformation annealing for soaking temperatures from 400° to 450°C was studied using TOF-ND. Peak profile analysis was performed on in-situ neutron time-of-flight diffractograms to obtain peak positions and widths to calculate residual stresses and dislocation densities. The results show that the dislocation density decreases largely at early times and it is followed by a slow diminution over time. Dislocation density decreases from ∼8 × 1014 m−2 for the cold-rolled sample to values close or under 2 × 1014 m−2. A remnant dislocation density after long annealing times was detected, with a value that decreases as the soaking temperature increases. Dislocation type was also characterized. It was found that dislocations with 〈a〉 Burgers vectors represent approximately 90% of the population, while the other 10% are 〈c+a〉. An empirical recovery kinetics model was proposed where dislocation mobility is assumed as a thermally activated mechanism. This model can be used as a processing tool to estimate the dislocation density expected for different soaking temperatures and times. The effect of residual stresses on peak broadening was also discussed. It was estimated that this contribution represents around 10–20% to the observed physical line broadening.

Analysis of IR Drop, Signal Electromigration and Self-Heating Effect using Flat and Hierarchical Method in FinFET Technology

VLSI industry has been rapidly growing where multiple processors can be implemented on a single chip. In physical design of a chip main factors to be considered are timing closure, congestion, and power. Compare to 180nm and 90nm designs were not much complicated due to less transistor density as going to lower technology nodes chip size, area, length will decrease that impact on packaging and cooling issues, so it is necessary to estimate the power at the early stage of design. Power analysis is done immediately after placement and routing stage of the chip. Power analysis can be performed in two methods one is flat method and other is hierarchical method. In flat method of analysis, the data of both top level and block level is given as input data to calculate the results whereas in hierarchical method of analysis the Power Grid View (PGV) of hierarchical block is designed which is then given as input. In hierarchical runs the sub-blocks are black boxed. The simulation is carried out using the Voltus IC Integrity Solution tool from cadence for a chip designed in 16nm FinFET technology. The results obtained from the flat method of analysis takes 2X the runtime compared to hierarchical method which would be unfavorable for very much larger circuits. The IR drop in VDD and VSS are 11.69 mW and 11.02mW respectively in flat method and 12.32 mW and 13.26 mW for VDD and VSS in hierarchical method of analysis. The accuracy is more obtained in flat run due to its transparency in logic functions.

Emergency resources scheduling in distribution system: From cyber-physical-social system perspective

With the frequently happened aging electrical grid and extreme weather events, outage management and service restoration face the challenges of flexible scheduling multiple resources for different kinds of objectives. Previous research mainly focuses on the single restoration objective or single emergency resource management. This paper proposes a new emergency scheduling framework under the cyber-physical-social system (CPSS) perspective, which includes the scheduling of multiple components from CPSS, i.e., crew, mobile distributed generators, and resources. Under the framework, a novel co-scheduling model with the goal of minimizing time-consuming, cost, and shedding load are also built as a mixed-integer non-linear optimization model. Then we formulate this problem as advanced multiple salesmen traveling problem with a routing stage and a scheduling stage, and design a solution algorithm based on the genetic algorithm to solve this problem. In the solving algorithm, the optimal routing solutions are got at first, then the emergency scheduling solutions are optimized in the second stage based on the routing results. Finally, a numerical case study on the IEEE 123-bus network shows the effectiveness of the co-optimization process, which can provide a routing solution for each depot, and the corresponding optimization objective results will increase 25.75% and 73.92% when compared with time-consuming optimization and load-shedding optimization.

Even in predictable orthographies: Surface dyslexia in Turkish

ABSTRACT Purpose We report here, for the first time, on developmental surface dyslexia in Turkish, a very transparent orthography. surface dyslexia is a deficit in the lexical route, which forces the reader to read words via the sublexical route, leading to regularization errors. Methods To detect surface dyslexia, we used reading aloud of loanwords with irregular conversion of vowel length or consonant allophone, and analysed regularization errors. We also tested the properties of this dyslexia using lexical decision on pseudohomophones, repetition and reading of nonwords, and analyses of reading of different types of words. The children with surface dyslexia were identified out of 175 9–10-year-olds who were tested using a reading aloud screening task and tasks that were designed to detect sublexical (rather than lexical) reading of existing words. Results We identified 45 fourth-graders with surface dyslexia. Reading speed was less sensitive to surface dyslexia than regularization errors, as only one-third of the children we diagnosed with surface dyslexia according to their reading errors also showed slower reading than controls. A task of lexical decision of pseudohomophones indicated that 31 of the participants had impairment in the orthographic input lexicon, whereas for 14 others the orthographic input lexicon was intact and the deficit is probably at a later stage in the lexical route – the phonological output lexicon or the connection between the lexica. Nonword reading was intact for the majority of surface dyslexia participants (35 of the 45). None of the surface dyslexia participants showed phonological deficits. Conclusions Surface dyslexia can be identified even in transparent orthographies once the relevant stimuli and error analyses are used.

Sequence-Pair-Based Flow-Layer Physical Design Algorithm for Continuous-Flow Microfluidic Biochips

To address the problem that the two phases of flow-level physical design, i.e., component placement and routing, are usually considered separately and their interaction is neglected, resulting in the degradation of design quality and biochip execution efficiency, an effective sequence-pair-based flow-level physical design algorithm for continuous-flow microfluidic biochips is proposed. Firstly, based on the sequence-pair representation method which can quickly enumerate and calculate the placement solution, the component placement solution is obtained by the discrete particle swarm optimization algorithm with higher solving efficiency to further improve the quality of the placement solution. Then, the Manhattan distance between component pairs is considered as the basis for routing order in the routing stage, and the routing is performed by the negotiation-based routing algorithm to effectively reduce the number of crossings in the flow channel. Finally, the interaction between placement and routing is considered, and the placement is adjusted according to the feedback information of routing, thus bridging the component placement and routing phases. The benchmark test set of actual biochemical application reaction and synthesis is adopted, and the flow-level physical design algorithm based on simulated annealing placement and negotiated routing is reproduced as the comparison algorithm for the experiment. The experimental results show that the proposed algorithm optimizes the number of flow path intersections by 74.94%, the chip area by 5.04%, and the total flow path length by 16.88%, resulting in a high-quality flow path physical design solution.

Predictable Coupling Effect Model for Global Placement Using Generative Adversarial Networks With an Ordinary Differential Equation Solver

One of the most important issues in physical design is coupling capacitance. However, the issue is typically addressed during the routing stage, which necessitates the execution of a time-consuming algorithm. Based on the generative adversarial networks (GAN) model, we propose a coupling-free global placement (CFGP) model with different orders of ordinary differential equations (ODE) solver. Experiments on the ISPD’11/DAC’12 contest benchmark revealed that using the ODE-GAN architecture, our coupling effect estimator (CEE) model can achieve 0.91X similarity to the ground-truth image and a 50X speedup over traditional global routers such as NCTUgr. Compared to the original framework without the CEE model, the CFGP implemented using DREAMPlace results in a 41% reduction in coupling effect.

Multi-Strategy Layer Assignment Algorithm Considering Bus Timing Matching

Layer assignment stage affects the timing matching of the bus by controlling the level of bus net in the global routing stage. Therefore, a multi-strategy layer assignment algorithm considering bus timing matching is proposed. First, a network prioritization strategy based on wired network attributes is adopted to acquire a routing sequence that satisfies not only the wire lengths but also the bus deviation according to the different attribute characteristics of the network. Second, using the initial routing strategy based on the greedy strategy, every shortest route in the network being configured is selected from each routing process, which keeps networks inside similar buses to be of equal lengths whenever possible. Finally, a local adjustment strategy formulated based on the bus wire length is employed to rip and reroute the completed initial routing, so as to lengthen parts of the network to minimize the length discrepancy between the bus longest wired network. The algorithms run in a Linux environment with a 2.60 GHz CPU and 64 GB of RAM. The algorithm validation experiments use the test data from the ISPD competition, and the experimental results show the bus deviation generated by this algorithm is reduced by 23.5%, and it is possible to significantly optimize the bus timing matching effect.

Morphological Characterisation of Long Glass Fibre Composites for the Thermoforming Process

Abstract This paper lays out the main procedures for performing morphological characterisations of Long Glass Fibre (LGF) composites with particular reference to the sheet extrusion and thermoforming processes as they may be configured for production. The techniques used, including optical microscopy, scanning electron microscopy and image analysis, are described both with regard to their laboratory application to these materials and to their potential for monitoring the performance of the industrial manufacturing process. Results obtained from the different techniques at the three various stages of the manufacturing route are presented and discussed in terms of the structure property relationships obtained and the reinforcing fibre mat system typical of these types of material.

Clock-Latency-Aware Pre-CTS for better Timing Closure in VLSI Design

A common strategy for reducing the time jump due to a clock tree insertion is to add a clock uncertainty value. If a small clock uncertainty value is selected for the Pre-CTS optimization, then a significant timing jump is observed when the clock tree is inserted, and clock timings are propagated. On the other hand, if the clock uncertainty is large, then the place and route (PNR) flow does not converge. This approach has been proven to be insufficient as each timing path is affected differently by the creation of the clock tree. In this paper, we suggest a more targeted approach whereby all pins in the clock tree will be annotated with their estimated latency, and therefore clock arrival times under ideal clocks should closely model the post-CTS arrival times. This objective is achieved by introducing an accurate and fast clock prediction early in the flow at the pre-CTS stage. As a result, the transition from the pre-CTS stage to the post-CTS stage becomes easier without significant timing jumps. An experiment on nine commercial test cases led to a significant TNS timing improvement of up to 68%, with an average of 35% at the end of the route stage. The full PNR flow runtime is not impacted. We achieved a 3% average runtime reduction over all test cases. Keywords—Clock-latency estimation, Clock-tree Synthesis, Integrated circuit conception, Physical implementation, Static timing analysis, Static timing closure.

Two-echelon vehicle routing problem with time windows and simultaneous pickup and delivery

This paper proposes a tabu search algorithm for the two-echelon vehicle routing problem with time windows and simultaneous pickup and delivery (2E-VRPTWSPD), which is a new variant of the two-echelon vehicle routing problem. 2E-VRPTWSPD involves three stages of routing: (1) the first-echelon vehicles start from the depot to deliver cargoes to satellites; (2) the second-echelon vehicles start from satellites to serve customers within time windows in a simultaneously pickup and delivery manner and finally return to their satellites with pickup cargoes; (3) the first-echelon vehicles start from the depot to collect cargoes on satellites. To solve this problem, we formulate it with a mathematical model. Then, we implement a variable neighborhood tabu search algorithm with a tailored solution representation to solve large-scale instances. Dummy satellites time windows are applied in our algorithm to speed up the search. Finally, we generate two benchmark instance sets to analyze the performance of our algorithm. Computational results show that our algorithm can obtain the optimal results for 10 out of 11 small-scale instances and produce promising solutions for 200-customer instances within a few minutes. Additional experiments indicate that the usage of dummy satellite time windows can save 19% computation time on average.

Two-step synthetic route towards Er3+/Yb3+ co-doped vernier yttrium oxyfluoride phosphor with high optical temperature sensing sensitivity

Exploring an up-conversion (UC) phosphor for the fluorescence intensity ratio (FIR) technique has been a great challenge in the field of optical temperature sensors. In this paper, a two-step synthetic route [Y(OH)CO 3 →Y(OH) 1.63 F 1.37 →Y 6 O 5 F 8 ] was designed to successfully synthesize Y 6 O 5 F 8 :Yb 3+ /Er 3+ UC phosphors for optical temperature sensing. The phase and morphology of the samples at various stages of the synthetic route were investigated. Under 980 nm excitation, two green emission bands centered at 522 nm and 547 nm and a red emission band centered at 670 nm were observed. Y 6 O 5 F 8 :10%Yb 3+ /1%Er 3+ exhibited the strongest UC emission under 980 nm excitation and was selected for further characterizations. The absorption and emission processes (a two-photon process) of photons in Y 6 O 5 F 8 :10%Yb 3+ /1%Er 3+ were elucidated based on the UC luminescence mechanism. Among them, the ET occupies a key position, which was also confirmed by the decay curves. In addition, the optical temperature sensing behavior of Y 6 O 5 F 8 :10%Yb 3+ /1%Er 3+ was explored using the FIR technique. The maximum absolute and relative sensitivities were determined to be 0.0074 K -1 (518 K) and 1.39% K −1 (293 K), respectively. The results show that Y 6 O 5 F 8 :10%Yb 3+ /1%Er 3+ phosphor has promising application potentials in optical temperature sensors with excellent sensitivity. A two-step synthetic route [Y(OH)CO 3 →Y(OH) 1.63 F 1.37 →Y 6 O 5 F 8 ] was designed to successfully synthesize Y 6 O 5 F 8 :Yb 3+ /Er 3+ UC phosphors. The optical temperature sensing performance of Y 6 O 5 F 8 :0.1Yb 3+ /0.01Er 3+ was evaluated based on the FIR technique, and its maximum absolute and relative sensitivities were determined to be 0.0074 K -1 (518 K) and 1.39% K −1 (293 K), respectively. • A two-step synthetic route was designed to successfully synthesize Y 6 O 5 F 8 . • The possible UC pathways of photons in Y 6 O 5 F 8 :0.1Yb 3+ /0.01Er 3+ were proposed. • High sensitivity for optical temperature sensing was found in this host material.