scholarly journals Space profiling for parallel functional programs

2010 ◽  
Vol 20 (5-6) ◽  
pp. 417-461 ◽  
Author(s):  
DANIEL SPOONHOWER ◽  
GUY E. BLELLOCH ◽  
ROBERT HARPER ◽  
PHILLIP B. GIBBONS
Keyword(s):  
Resource Use ◽  
Source Code ◽  
Semantic Space ◽  
Runtime System ◽  
Scheduling Policies ◽  
Use Patterns ◽  
Scheduling Policy ◽  
Standard Ml ◽  
Cost Semantics ◽  
The Impact

AbstractWe present a semantic space profiler for parallel functional programs. Building on previous work in sequential profiling, our tools help programmers to relate runtime resource use back to program source code. Unlike many profiling tools, our profiler is based on a cost semantics. This provides a means to reason about performance without requiring a detailed understanding of the compiler or runtime system. It also provides a specification for language implementers. This is critical in that it enables us to separate cleanly the performance of the application from that of the language implementation. Some aspects of the implementation can have significant effects on performance. Our cost semantics enables programmers to understand the impact of different scheduling policies while hiding many of the details of their implementations. We show applications where the choice of scheduling policy has asymptotic effects on space use. We explain these use patterns through a demonstration of our tools. We also validate our methodology by observing similar performance in our implementation of a parallel extension of Standard ML.

A Debugger for Standard ML

1995 ◽  
Vol 5 (2) ◽  
pp. 155-200 ◽  
Author(s):  
Andrew Tolmach ◽  
Andrew W. Appel
Keyword(s):  
New Jersey ◽  
Compiler Optimization ◽  
Source Code ◽  
Runtime System ◽  
Portable Instrumentation ◽  
Standard Ml ◽  
Internal Mechanism ◽  
Source Level

AbstractWe have built a portable, instrumentation-based, replay debugger for the Standard ML of New Jersey compiler. Traditional ‘source-level’ debuggers for compiled languages actually operate at machine level, which makes them complex, difficult to port, and intolerant of compiler optimization. For secure languages like ML, however, debugging support can be provided without reference to the underlying machine, by adding instrumentation to program source code before compilation. Because instrumented code is (almost) ordinary source, it can be processed by the ordinary compiler. Our debugger is thus independent from the underlying hardware and runtime system, and from the optimization strategies used by the compiler. The debugger also provides reverse execution, both as a user feature and an internal mechanism. Reverse execution is implemented using a checkpoint and replay system; checkpoints are represented primarily by first-class continuations.

scholarly journals Climate shock effects and mediation in fisheries

2021 ◽  
Vol 118 (2) ◽  
pp. e2014379117 ◽  
Author(s):  
Mary C. Fisher ◽  
Stephanie K. Moore ◽  
Sunny L. Jardine ◽  
James R. Watson ◽  
Jameal F. Samhouri
Keyword(s):  
Resource Use ◽  
Food Systems ◽  
Food System ◽  
Fishing Communities ◽  
Dungeness Crab ◽  
Spatial Mobility ◽  
Use Patterns ◽  
The Social ◽  
Climate Shocks ◽  
The Impact

Climate shocks can reorganize the social–ecological linkages in food-producing communities, leading to a sudden loss of key products in food systems. The extent and persistence of this reorganization are difficult to observe and summarize, but are critical aspects of predicting and rapidly assessing community vulnerability to extreme events. We apply network analysis to evaluate the impact of a climate shock—an unprecedented marine heatwave—on patterns of resource use in California fishing communities, which were severely affected through closures of the Dungeness crab fishery. The climate shock significantly modified flows of users between fishery resources during the closures. These modifications were predicted by pre-shock patterns of resource use and were associated with three strategies used by fishing community member vessels to respond to the closures: temporary exit from the food system, spillover of effort from the Dungeness crab fishery into other fisheries, and spatial shifts in where crab were landed. Regional differences in resource use patterns and vessel-level responses highlighted the Dungeness crab fishery as a seasonal “gilded trap” for northern California fishing communities. We also detected disparities in climate shock response based on vessel size, with larger vessels more likely to display spatial mobility. Our study demonstrates the importance of highly connected and decentralized networks of resource use in reducing the vulnerability of human communities to climate shocks.

JAVASCRIPT ASYNCHRONOUS PROGRAMMING

2019 ◽  
Vol 128 (2B) ◽  
pp. 5-16
Author(s):  
Tran Thanh Luong ◽  
Le My Canh
Keyword(s):  
Design Patterns ◽  
Source Code ◽  
Object Oriented ◽  
Exception Handling ◽  
Code Smells ◽  
Asynchronous Programming ◽  
Event Driven ◽  
Programming Patterns ◽  
The Impact

JavaScript has become more and more popular in recent years because its wealthy features as being dynamic, interpreted and object-oriented with first-class functions. Furthermore, JavaScript is designed with event-driven and I/O non-blocking model that boosts the performance of overall application especially in the case of Node.js. To take advantage of these characteristics, many design patterns that implement asynchronous programming for JavaScript were proposed. However, choosing a right pattern and implementing a good asynchronous source code is a challenge and thus easily lead into less robust application and low quality source code. Extended from our previous works on exception handling code smells in JavaScript and exception handling code smells in JavaScript asynchronous programming with promise, this research aims at studying the impact of three JavaScript asynchronous programming patterns on quality of source code and application.

scholarly journals From hunters to nature observers: a record of 53 years of diver attitudes towards sharks and rays and marine protected areas

2011 ◽  
Vol 62 (6) ◽  
pp. 755 ◽  
Author(s):  
Sally Whatmough ◽  
Ingrid Van Putten ◽  
Andrew Chin
Keyword(s):  
Protected Areas ◽  
Marine Protected Areas ◽  
Resource Use ◽  
Scientific Data ◽  
Attitudinal Change ◽  
Use Patterns ◽  
Positive Effects ◽  
Economic Information ◽  
Perceptions And Attitudes ◽  
Conservation Awareness

Human values, perceptions, attitudes and interactions with the natural environment have been found to change over time, with social and economic information used to inform management decisions and actions. Content analysis is applied here to a 53-year long collection of the popular dive magazine, SportDiving, to identify recreational divers’ experiences with regard to sharks and rays, the Great Barrier Reef (GBR) and marine protected areas (MPAs). This analysis suggests there has been a diversification of diver activities with the emergence of passive-observational activities such as SCUBA diving. Attitudes towards sharks and rays have changed significantly, with recreational divers changing from a group that could be described as adventure-seeking hunters to a group that can be described as nature-appreciating observers, suggesting an increase in conservation awareness. The GBR continues to be a highly regarded dive destination, with divers perceiving positive effects of protection within MPAs. However, declines in the abundance of large fish and sharks and rays were occasionally reported throughout the 53 year period. Collectively, these types of data can show changes in resource-use patterns, perceptions and attitudes and provide information that supplements scientific monitoring data. These data may be valuable where scientific data is scarce, historical records difficult to obtain, and where attitudinal change can significantly affect future resource use.

scholarly journals Modeling Community-Scale Natural Resource Use in a Transboundary Southern African Landscape: Integrating Remote Sensing and Participatory Mapping

2021 ◽  
Vol 13 (4) ◽  
pp. 631
Author(s):  
Kyle D. Woodward ◽  
Narcisa G. Pricope ◽  
Forrest R. Stevens ◽  
Andrea E. Gaughan ◽  
Nicholas E. Kolarik ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Resource Use ◽  
Training Data ◽  
Systems Science ◽  
Participatory Mapping ◽  
Land Use Patterns ◽  
Modeling Framework ◽  
Use Patterns ◽  
Human Habitation

Remote sensing analyses focused on non-timber forest product (NTFP) collection and grazing are current research priorities of land systems science. However, mapping these particular land use patterns in rural heterogeneous landscapes is challenging because their potential signatures on the landscape cannot be positively identified without fine-scale land use data for validation. Using field-mapped resource areas and household survey data from participatory mapping research, we combined various Landsat-derived indices with ancillary data associated with human habitation to model the intensity of grazing and NTFP collection activities at 100-m spatial resolution. The study area is situated centrally within a transboundary southern African landscape that encompasses community-based organization (CBO) areas across three countries. We conducted four iterations of pixel-based random forest models, modifying the variable set to determine which of the covariates are most informative, using the best fit predictions to summarize and compare resource use intensity by resource type and across communities. Pixels within georeferenced, field-mapped resource areas were used as training data. All models had overall accuracies above 60% but those using proxies for human habitation were more robust, with overall accuracies above 90%. The contribution of Landsat data as utilized in our modeling framework was negligible, and further research must be conducted to extract greater value from Landsat or other optical remote sensing platforms to map these land use patterns at moderate resolution. We conclude that similar population proxy covariates should be included in future studies attempting to characterize communal resource use when traditional spectral signatures do not adequately capture resource use intensity alone. This study provides insights into modeling resource use activity when leveraging both remotely sensed data and proxies for human habitation in heterogeneous, spectrally mixed rural land areas.

scholarly journals The impact of injuries on health service resource use and costs in primary and secondary care in the English NHS

2016 ◽  
Vol 38 (4) ◽  
pp. e464-e471 ◽  
Author(s):  
B. Kellezi ◽  
D.L. Baines ◽  
C. Coupland ◽  
K. Beckett ◽  
J. Barnes ◽  
...  
Keyword(s):  
Health Service ◽  
Resource Use ◽  
Secondary Care ◽  
Service Resource ◽  
The Impact ◽  
Health Service Resource

scholarly journals Optimality of index policies for stochastic scheduling with switching penalties

1992 ◽  
Vol 29 (04) ◽  
pp. 957-966 ◽  
Author(s):  
Mark P. Van Oyen ◽  
Dimitrios G. Pandelis ◽  
Demosthenis Teneketzis
Keyword(s):  
Optimal Policy ◽  
Time Delays ◽  
Stochastic Scheduling ◽  
Optimal Scheduling ◽  
Scheduling Policies ◽  
Parallel Queues ◽  
Lump Sum ◽  
Index Policies ◽  
Service Policy ◽  
The Impact

We investigate the impact of switching penalties on the nature of optimal scheduling policies for systems of parallel queues without arrivals. We study two types of switching penalties incurred when switching between queues: lump sum costs and time delays. Under the assumption that the service periods of jobs in a given queue possess the same distribution, we derive an index rule that defines an optimal policy. For switching penalties that depend on the particular nodes involved in a switch, we show that although an index rule is not optimal in general, there is an exhaustive service policy that is optimal.

scholarly journals Secondary use of electronic health record data for clinical workflow analysis

2017 ◽  
Vol 25 (1) ◽  
pp. 40-46 ◽  
Author(s):  
Michelle R Hribar ◽  
Sarah Read-Brown ◽  
Isaac H Goldstein ◽  
Leah G Reznick ◽  
Lorinna Lombardi ◽  
...  
Keyword(s):  
Simulation Models ◽  
Clinical Workflow ◽  
Electronic Health Record Data ◽  
Use Patterns ◽  
Secondary Use ◽  
Timing Data ◽  
Data Files ◽  
Electronic Health ◽  
Tracking Devices ◽  
The Impact

Abstract Objective Outpatient clinics lack guidance for tackling modern efficiency and productivity demands. Workflow studies require large amounts of timing data that are prohibitively expensive to collect through observation or tracking devices. Electronic health records (EHRs) contain a vast amount of timing data – timestamps collected during regular use – that can be mapped to workflow steps. This study validates using EHR timestamp data to predict outpatient ophthalmology clinic workflow timings at Oregon Health and Science University and demonstrates their usefulness in 3 different studies. Materials and Methods Four outpatient ophthalmology clinics were observed to determine their workflows and to time each workflow step. EHR timestamps were mapped to the workflow steps and validated against the observed timings. Results The EHR timestamp analysis produced times that were within 3 min of the observed times for >80% of the appointments. EHR use patterns affected the accuracy of using EHR timestamps to predict workflow times. Discussion EHR timestamps provided a reasonable approximation of workflow and can be used for workflow studies. They can be used to create simulation models, analyze EHR use, and quantify the impact of trainees on workflow. Conclusion The secondary use of EHR timestamp data is a valuable resource for clinical workflow studies. Sample timestamp data files and algorithms for processing them are provided and can be used as a template for more studies in other clinical specialties and settings.

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