FLECS: Planning with a Flexible Commitment Strategy

There has been evidence that least-commitment planners can efficiently handle planning problems that involve difficult goal interactions. This evidence has led to the common belief that delayed-commitment is the "best" possible planning strategy. However, we recently found evidence that eager-commitment planners can handle a variety of planning problems more efficiently, in particular those with difficult operator choices. Resigned to the futility of trying to find a universally successful planning strategy, we devised a planner that can be used to study which domains and problems are best for which planning strategies. In this article we introduce this new planning algorithm, FLECS, which uses a FLExible Commitment Strategy with respect to plan-step orderings. It is able to use any strategy from delayed-commitment to eager-commitment. The combination of delayed and eager operator-ordering commitments allows FLECS to take advantage of the benefits of explicitly using a simulated execution state and reasoning about planning constraints. FLECS can vary its commitment strategy across different problems and domains, and also during the course of a single planning problem. FLECS represents a novel contribution to planning in that it explicitly provides the choice of which commitment strategy to use while planning. FLECS provides a framework to investigate the mapping from planning domains and problems to efficient planning strategies.Comment: See http://www.jair.org/ for an online appendix and other files accompanying this articl

A KINEMATIC ANALYSIS OF ROWING PERFORMANCE DURING A 2000M ERGOMETER TEST

The aim of this study was to investigate how force, velocity and power change during a maximum 2000m-rowing test, and to examine the relationship between 2-D joint kinematics and performance. Ten male rowers performed a 2000m test, which was analysed in five periods, considering also the mean final results. One-way ANOVA for repeated measures showed that force, velocity and power changed significantly along the 2000m test. Hip, and elbow joint kinematic parameters remained unchanged throughout the test but knee’s angular displacement and angular position at the catch, changed significantly during the 2000m test. A stepwise multiple regression analysis evidenced that the knee angular position at the catch is in relationship with time to finish the 2000m rowing and remained the single predictor of performance

An integrated physical and cost-benefit approach to assess groins as a coastal erosion mitigation strategy

Future investments required for the construction and maintenance of coastal defense interventions are expected to increase, due to increasing coastal erosion issues along social, environmental and economically valuable coastal areas. The high costs related with coastal defense interventions require improved knowledge on their performance, considering impacts, costs and benefits. Despite the existence of several cost-benefit approaches applied to coastal zones, in this study a well-defined, sequential and integrated methodology supported by already existent numerical models is developed and applied to assess the effectiveness (shoreline evolution impacts), costs and benefits of different coastal defense interventions. This methodology encompasses three integrated modules, including a shoreline evolution module (to estimate areas of territory maintained, gained or lost over time), a coastal structure pre-design module (to estimate material volumes of coastal works) and a cost-benefit evaluation module (to assess cost-benefit evaluation criteria). The approach allows for the physical and economic comparison of different coastal defense intervention scenarios, helping coastal management and planning entities to define strategies. In this study, the proposed methodology was applied to evaluate the performance of different groin scenarios, based on a hypothetical case study. The case study allowed highlighting the importance of the physical and economic analysis of different scenarios. Results show that the definition of coastal defense interventions is complex where, on the one hand, best physical solutions are sometimes related to very high costs and, on the other hand, best economic scenarios lead to high territory losses. Thus, the innovative approach presented in this study shows that an integrated analysis of shoreline evolution, coastal intervention design and subsequent costs and benefits allows to improve the physical and economic performances of coastal defense interventions.publishe

A dynamic method for charging-up calculations: the case of GEM

The simulation of Micro Pattern Gaseous Detectors (MPGDs) signal response is an important and powerful tool for the design and optimization of such detectors. However, several attempts to simulate exactly the effective charge gain have not been completely successful. Namely, the gain stability over time has not been fully understood. Charging-up of the insulator surfaces have been pointed as one of the responsible for the difference between experimental and Monte Carlo results. This work describes two iterative methods to simulate the charging-up in one MPGD device, the Gas Electron Multiplier (GEM). The first method uses a constant step for avalanches time evolution, very detailed, but slower to compute. The second method uses a dynamic step that improves the computing time. Good agreement between both methods was reached. Despite of comparison with experimental results shows that charging-up plays an important role in detectors operation, should not be the only responsible for the difference between simulated and measured effective gain, but explains the time evolution in the effective gain.Comment: Minor changes in grammatical statements and inclusion of some important information about experimental setup at section "Comparison with experimental results

Ocorrencia da cigarrinha Molomea cincta (Signoret, 1854) em mangueira, na microrregiao de Teresina-PI.

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Caracterização físico-hídrica de um podzólico vermelho-amarelo textura arenosa/média sob diferentes usos, em Igarapé-Açu, Pará.

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Endoscopic Submucosal Dissection of Early Gastric Cancer Using the Insulated Tip Knife

AbstractEndoscopic submucosal dissection (ESD) is an endoscopic technique in which a gastrointestinal mucosal neoplasm can be excised by cutting through the submucosa with an endoscopic knife. It can be used with diagnostic or therapeutic intent and allows en bloc removal of the specimen. ESD usually begins with identification and evaluation of the lesion and assessment of the margin with chromo-endoscopy. The subsequent steps include marking, submucosal injection, and circumferential and submucosal dissection. Complications should be promptly recognized and dealt with immediately if necessary.This video demonstrates the main steps of the technique and management of complications. This article is part of an expert video encyclopedia

Simulation of gain stability of THGEM gas-avalanche particle detectors

Charging-up processes affecting gain stability in Thick Gas Electron Multipliers (THGEM) were studied with a dedicated simulation toolkit. Integrated with Garfield++, it provides an effective platform for systematic phenomenological studies of charging-up processes in MPGD detectors. We describe the simulation tool and the fine-tuning of the step-size required for the algorithm convergence, in relation to physical parameters. Simulation results of gain stability over time in THGEM detectors are presented, exploring the role of electrode-thickness and applied voltage on its evolution. The results show that the total amount of irradiated charge through electrode's hole needed for reaching gain stabilization is in the range of tens to hundreds of pC, depending on the detector geometry and operational voltage. These results are in agreement with experimental observations presented previously

A Benchmark dataset for predictive maintenance

The paper describes the MetroPT data set, an outcome of a eXplainable Predictive Maintenance (XPM) project with an urban metro public transportation service in Porto, Portugal. The data was collected in 2022 that aimed to evaluate machine learning methods for online anomaly detection and failure prediction. By capturing several analogic sensor signals (pressure, temperature, current consumption), digital signals (control signals, discrete signals), and GPS information (latitude, longitude, and speed), we provide a dataset that can be easily used to evaluate online machine learning methods. This dataset contains some interesting characteristics and can be a good benchmark for predictive maintenance models

Avaliação da matéria orgânica e de parâmetros físico-hídricos de um Latossolo Amarelo sob diferentes sistemas de manejo do dendezeiro, em Capitão Poço, Pará.

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