Public transit route planning through lightweight linked data interfaces

While some public transit data publishers only provide a data dump – which only few reusers can afford to integrate within their applications – others provide a use case limiting origin-destination route planning api. The Linked Connections framework instead introduces a hypermedia api, over which the extendable base route planning algorithm “Connections Scan Algorithm” can be implemented. We compare the cpu usage and query execution time of a traditional server-side route planner with the cpu time and query execution time of a Linked Connections interface by evaluating query mixes with increasing load. We found that, at the expense of a higher bandwidth consumption, more queries can be answered using the same hardware with the Linked Connections server interface than with an origin-destination api, thanks to an average cache hit rate of 78%. The findings from this research show a cost-efficient way of publishing transport data that can bring federated public transit route planning at the fingertips of anyone

Continuous client-side query evaluation over dynamic linked data

Existing solutions to query dynamic Linked Data sources extend the SPARQL language, and require continuous server processing for each query. Traditional SPARQL endpoints already accept highly expressive queries, so extending these endpoints for time-sensitive queries increases the server cost even further. To make continuous querying over dynamic Linked Data more affordable, we extend the low-cost Triple Pattern Fragments (TPF) interface with support for time-sensitive queries. In this paper, we introduce the TPF Query Streamer that allows clients to evaluate SPARQL queries with continuously updating results. Our experiments indicate that this extension significantly lowers the server complexity, at the expense of an increase in the execution time per query. We prove that by moving the complexity of continuously evaluating queries over dynamic Linked Data to the clients and thus increasing bandwidth usage, the cost at the server side is significantly reduced. Our results show that this solution makes real-time querying more scalable for a large amount of concurrent clients when compared to the alternatives

The human prerogative: a critical analysis of evidence-based and other paradigms of care in substance abuse treatment

Present-day substance abuse treatment is characterized by a compelling demand for applying evidence-based interventions. Vehement discussions between policymakers, practitioners and researchers illustrate this clash of differing paradigms. The aim of this article is to situate evidence-based practice among the leading paradigms of care and to elucidate its implicit assumptions and potential implications. Evidence-based practice is inherent in the empirical-analytical paradigm of care and science, founded upon randomized and controlled studies. This paradigm is compared with the phenomenological-existential and the critical post-structural paradigm, which focus on elaborating the human potential and exploring individuals' subjective interpretations, and on criticizing social inequalities and striving for compliance with human rights, respectively. Evidence-based practice and the methodological rigidity in each paradigm are analyzed critically. We conclude that through the dialectical integration of these diverse approaches, evidence, existence/humanism and social emancipation can be combined for the benefit of the human prerogative of care

Order batching in multi-server pick-and-sort warehouses.

In many warehouses, customer orders are batched to profit from a reduction in the order picking effort. This reduction has to be offset against an increase in sorting effort. This paper studies the impact of the order batching policy on average customer order throughput time, in warehouses where the picking and sorting functions are executed separately by either a single operator or multiple parallel operators. We present a throughput time estimation model based on Whitt's queuing network approach, assuming that the number of order lines per customer order follows a discrete probability distribution and that the warehouse uses a random storage strategy. We show that the model is adequate in approximating the optimal pick batch size, minimizing average customer order throughput time. Next, we use the model to explore the different factors influencing optimal batch size, the optimal allocation of workers to picking and sorting, and the impact of different order picking strategies such as sort-while-pick (SWP) versus pick-and-sort (PAS)Order batching; Order picking and sorting; Queueing; Warehousing;

Partial generalization in pigeons trained to discriminate morphine from saline: Applications of receptor theory

In pigeons trained to discriminate 5.6 mg/kg of morphine from saline, cyclazocine, l-N-allyl-normetazocine (l-NANM, l-SKF10,047), and ketamine, but not U50,488, produced partial generalization, i.e., a maximum level of drug-appropriate responding between the levels produced by saline and by the training drug. The generalization gradient of cyclazocine and of l-NANM, but not that of ketamine, was less steep than the gradient of morphine. Cyclazocine and l-NANM, but not U50,488 and ketamine, antagonized partially the discriminative stimulus (DS) effects of morphine. Naltrexone antagonized the DS effects of morphine, cyclazocine, and l-NANM, but not ketamine. Increasing the training dose of morphine shifted the morphine gradient to the right, increased the antagonist effects of cyclazocine and of l-NANM, and decreased their agonist effects, but did not alter the effects of ketamine. Decreasing the training dose of morphine shifted the morphine gradient to the left and increased the agonist effects of cyclazocine, but did not alter the effects of l-NANM and ketamine. The full generalization produced by cyclazocine when the training dose of morphine was lowered could be blocked completely by naltrexone and l-NANM, but not by ketamine. These results suggest that cyclazocine and l-NANM, but not ketamine, produced partial generalization because of their low efficacy at the receptor that underlies the DS effects of morphine. However, the results obtained with ketamine suggest that partial generalization may also be produced through other mechanisms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50214/1/430160211_ftp.pd

Hypermedia-based discovery for source selection using low-cost linked data interfaces

Evaluating federated Linked Data queries requires consulting multiple sources on the Web. Before a client can execute queries, it must discover data sources, and determine which ones are relevant. Federated query execution research focuses on the actual execution, while data source discovery is often marginally discussed-even though it has a strong impact on selecting sources that contribute to the query results. Therefore, the authors introduce a discovery approach for Linked Data interfaces based on hypermedia links and controls, and apply it to federated query execution with Triple Pattern Fragments. In addition, the authors identify quantitative metrics to evaluate this discovery approach. This article describes generic evaluation measures and results for their concrete approach. With low-cost data summaries as seed, interfaces to eight large real-world datasets can discover each other within 7 minutes. Hypermedia-based client-side querying shows a promising gain of up to 50% in execution time, but demands algorithms that visit a higher number of interfaces to improve result completeness