Optimal spatial patterns of fuel management and timber harvest with fire risk

2010 ◽  
Vol 40 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Masashi Konoshima ◽  
Heidi J. Albers ◽  
Claire A. Montgomery ◽  
Jeffrey L. Arthur
Keyword(s):  
Spatial Configuration ◽  
Fire Risk ◽  
Timber Harvest ◽  
Fire Spread ◽  
Fuel Management ◽  
Fuel Treatment ◽  
Trade Offs ◽  
Dynamic Optimization Model ◽  
Cost Efficient ◽  
The Cost

The stochastic and spatial nature of fire poses challenges for the cost-efficient allocation of fuel treatment over the landscape. A model that addresses complex but important components of fuel management decisions, spatial and dynamic aspects of fire risk, and a carefully designed framework that allows us to draw general insight into the optimal spatial pattern of management are necessary to provide a basis for developing efficient fuel treatment plans. For this purpose, we combine a physical fire model and a spatial-dynamic optimization model to explore harvest and fuel treatment across a hypothetical landscape under risk of a moving fire over a range of physical and economic conditions. Our model is able to describe spatial trade-offs involved in decision process, namely trade-offs between protection of on-site values and protection against fire spread. We found that the spatial configuration of management units can lead to heterogeneity in management across seemingly homogeneous units.

scholarly journals Spatial-Endogenous Fire Risk and Efficient Fuel Management and Timber Harvest

2008 ◽  
Vol 84 (3) ◽  
pp. 449-468 ◽  
Author(s):  
M. Konoshima ◽  
C. A. Montgomery ◽  
H. J. Albers ◽  
J. L. Arthur
Keyword(s):  
Fire Risk ◽  
Timber Harvest ◽  
Fuel Management ◽  
Endogenous Fire

scholarly journals Estimation of wildfire size and risk changes due to fuels treatments

2012 ◽  
Vol 21 (4) ◽  
pp. 357 ◽  
Author(s):  
M. A. Cochrane ◽  
C. J. Moran ◽  
M. C. Wimberly ◽  
A. D. Baer ◽  
M. A. Finney ◽  
...  
Keyword(s):  
Wildland Fire ◽  
Fire Severity ◽  
Fire Risk ◽  
Fire Spread ◽  
Prescribed Fires ◽  
Fuel Treatments ◽  
Human Land Use ◽  
Trade Offs ◽  
Management Policies ◽  
Fuels Treatments

Human land use practices, altered climates, and shifting forest and fire management policies have increased the frequency of large wildfires several-fold. Mitigation of potential fire behaviour and fire severity have increasingly been attempted through pre-fire alteration of wildland fuels using mechanical treatments and prescribed fires. Despite annual treatment of more than a million hectares of land, quantitative assessments of the effectiveness of existing fuel treatments at reducing the size of actual wildfires or how they might alter the risk of burning across landscapes are currently lacking. Here, we present a method for estimating spatial probabilities of burning as a function of extant fuels treatments for any wildland fire-affected landscape. We examined the landscape effects of more than 72 000 ha of wildland fuel treatments involved in 14 large wildfires that burned 314 000 ha of forests in nine US states between 2002 and 2010. Fuels treatments altered the probability of fire occurrence both positively and negatively across landscapes, effectively redistributing fire risk by changing surface fire spread rates and reducing the likelihood of crowning behaviour. Trade offs are created between formation of large areas with low probabilities of increased burning and smaller, well-defined regions with reduced fire risk.

scholarly journals Comparison of LPWAN Technologies: Cost Structure and Scalability

2021 ◽  
Author(s):  
Mohammad Istiak Hossain ◽  
Jan I. Markendahl
Keyword(s):  
Communication Technology ◽  
Service Providers ◽  
Communication Technologies ◽  
Cost Structure ◽  
Small Scale ◽  
Area Network ◽  
Wide Area Network ◽  
Generic Framework ◽  
Cost Efficient ◽  
The Cost

AbstractSmall-scale commercial rollouts of Cellular-IoT (C-IoT) networks have started globally since last year. However, among the plethora of low power wide area network (LPWAN) technologies, the cost-effectiveness of C-IoT is not certain for IoT service providers, small and greenfield operators. Today, there is no known public framework for the feasibility analysis of IoT communication technologies. Hence, this paper first presents a generic framework to assess the cost structure of cellular and non-cellular LPWAN technologies. Then, we applied the framework in eight deployment scenarios to analyze the prospect of LPWAN technologies like Sigfox, LoRaWAN, NB-IoT, LTE-M, and EC-GSM. We consider the inter-technology interference impact on LoRaWAN and Sigfox scalability. Our results validate that a large rollout with a single technology is not cost-efficient. Also, our analysis suggests the rollout possibility of an IoT communication Technology may not be linear to cost-efficiency.

scholarly journals A framework for reducing the overhead of the quantum oracle for use with Grover’s algorithm with applications to cryptanalysis of SIKE

2020 ◽  
Vol 15 (1) ◽  
pp. 143-156
Author(s):  
Jean-François Biasse ◽  
Benjamin Pring
Keyword(s):  
Search Algorithm ◽  
Circuit Complexity ◽  
Quantum Circuit ◽  
Grover’S Algorithm ◽  
Search Problems ◽  
Trade Offs ◽  
Single Target ◽  
Grover's Algorithm ◽  
Quantum Oracle ◽  
The Cost

AbstractIn this paper we provide a framework for applying classical search and preprocessing to quantum oracles for use with Grover’s quantum search algorithm in order to lower the quantum circuit-complexity of Grover’s algorithm for single-target search problems. This has the effect (for certain problems) of reducing a portion of the polynomial overhead contributed by the implementation cost of quantum oracles and can be used to provide either strict improvements or advantageous trade-offs in circuit-complexity. Our results indicate that it is possible for quantum oracles for certain single-target preimage search problems to reduce the quantum circuit-size from $O\left(2^{n/2}\cdot mC\right)$ (where C originates from the cost of implementing the quantum oracle) to $O(2^{n/2} \cdot m\sqrt{C})$ without the use of quantum ram, whilst also slightly reducing the number of required qubits.This framework captures a previous optimisation of Grover’s algorithm using preprocessing [21] applied to cryptanalysis, providing new asymptotic analysis. We additionally provide insights and asymptotic improvements on recent cryptanalysis [16] of SIKE [14] via Grover’s algorithm, demonstrating that the speedup applies to this attack and impacting upon quantum security estimates [16] incorporated into the SIKE specification [14].

scholarly journals Determination of Critical Separation Distance Between Dwellings in Informal Settlements Fire

2021 ◽  
Author(s):  
Yu Wang ◽  
Lesley Gibson ◽  
Mohamed Beshir ◽  
David Rush
Keyword(s):  
Heat Flux ◽  
Informal Settlement ◽  
Informal Settlements ◽  
Fire Risk ◽  
Fire Spread ◽  
Separation Distance ◽  
Flame Length ◽  
Critical Distance ◽  
Fire Disaster ◽  
Critical Separation

AbstractApproximately one billion people across the globe are living in informal settlements with a large potential fire risk. Due to the high dwelling density, a single informal settlement dwelling fire may result in a very serious fire disaster leaving thousands of people homeless. In this work, a simple physics-based theoretical model was employed to assess the critical fire separation distance between dwellings. The heat flux and ejected flame length were obtained from a full-scale dwelling tests with ISO 9705 dimension (3.6 m × 2.4 m × 2.4 m) to estimate the radiation decay coefficient of the radiation heat flux away from the open door. The ignition potential of combustible materials in adjacent dwellings are analyzed based on the critical heat flux from cone calorimeter tests. To verify the critical distance in real informal settlement fire, a parallel method using aerial photography within geographic information systems (GIS), was employed to determine the critical separation distances in four real informal settlement fires of 2014–2015 in Masiphumelele, Cape Town, South Africa. The fire-spread distances were obtained as well through the real fires. The probabilistic analysis was conducted by Weibull distribution and logistic regression, and the corresponding separation distances were given with different fire spread probabilities. From the experiments with the assumption of no interventions and open doors and windows, it was established that the heat flux would decay from around 36 kW/m2 within a distance of 1.0 m to a value smaller than 5 kW/m2 at a distance of 4.0 m. Both experiments and GIS results agree well and suggest the ignition probabilities at distances of 1.0 m, 2.0 m and 3.0 m are 97%, 52% and 5% respectively. While wind is not explicitly considered in the work, it is implicit within the GIS analyses of fire spread risk, therefore, it is reasonable to say that there is a relatively low fire spread risk at distances greater than 3 m. The distance of 1.0 m in GIS is verified to well and conservatively predict the fire spread risk in the informal settlements.

scholarly journals Wideband Rectangular Foldable and Non-foldable Antenna for Internet of Things Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Steve W. Y. Mung ◽  
Cheuk Yin Cheung ◽  
Ka Ming Wu ◽  
Joseph S. M. Yuen
Keyword(s):  
Internet Of Things ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Design Parameters ◽  
Multiple Frequency ◽  
Wireless Applications ◽  
Printed Circuit ◽  
Iot Applications ◽  
Trade Offs ◽  
The Cost

This article presents a simple wideband rectangular antenna in foldable and non-foldable (printed circuit board (PCB)) structures for Internet of Things (IoT) applications. Both are simple structures with two similar rectangular metal planes which cover multiple frequency bands such as GPS, WCDMA/LTE, and 2.4 GHz industrial, scientific, and medical (ISM) bands. This wideband antenna is suitable to integrate into the short- and long-range wireless applications such as the short-range 2.4 GHz ISM band and standard cellular bands. This lowers the overall size of the product as well as the cost in the applications. In this article, the configuration and operation principle are presented as well as its trade-offs on the design parameters. Simulated and experimental results of foldable and non-foldable (PCB) structures show that the antenna is suited for IoT applications.

scholarly journals Cost Analysis of a Novel Method for Ecological Compensation—A Study of the Translocation of Dead Wood

2021 ◽  
Vol 13 (11) ◽  
pp. 6075
Author(s):  
Ola Lindroos ◽  
Malin Söderlind ◽  
Joel Jensen ◽  
Joakim Hjältén
Keyword(s):  
Cost Efficiency ◽  
Dead Wood ◽  
Road Transportation ◽  
Ecological Value ◽  
Ecological Compensation ◽  
Work Time ◽  
Delivery Times ◽  
Novel Method ◽  
Cost Efficient ◽  
The Cost

Translocation of dead wood is a novel method for ecological compensation and restoration that could, potentially, provide a new important tool for biodiversity conservation. With this method, substrates that normally have long delivery times are instantly created in a compensation area, and ideally many of the associated dead wood dwelling organisms are translocated together with the substrates. However, to a large extent, there is a lack of knowledge about the cost efficiency of different methods of ecological compensation. Therefore, the costs for different parts of a translocation process and its dependency on some influencing factors were studied. The observed cost was 465 SEK per translocated log for the actual compensation measure, with an additional 349 SEK/log for work to enable evaluation of the translocation’s ecological results. Based on time studies, models were developed to predict required work time and costs for different transportation distances and load sizes. Those models indicated that short extraction and insertion distances for logs should be prioritized over road transportation distances to minimize costs. They also highlighted a trade-off between costs and time until a given ecological value is reached in the compensation area. The methodology used can contribute to more cost-efficient operations and, by doing so, increase the use of ecological compensation and the benefits from a given input.

Demographic life history traits of reproductive natterjack toads (Bufo calamita) vary between northern and southern latitudes

2006 ◽  
Vol 27 (3) ◽  
pp. 365-375 ◽  
Author(s):  
Delfi Sanuy ◽  
Christoph Leskovar ◽  
Neus Oromi ◽  
Ulrich Sinsch
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Large Female ◽  
Breeding Period ◽  
Female Size ◽  
Data Set ◽  
Bufo Calamita ◽  
Trade Offs ◽  
Age Variation ◽  
The Cost

AbstractDemographic life history traits were investigated in three Bufo calamita populations in Germany (Rhineland-Palatinate: Urmitz, 50°N; 1998-2000) and Spain (Catalonia: Balaguer, Mas de Melons, 41°N; 2004). We used skeletochronology to estimate the age as number of lines of arrested growth in breeding adults collected during the spring breeding period (all localities) and during the summer breeding period (only Urmitz). A data set including the variables sex, age and size of 185 males and of 87 females was analyzed with respect to seven life history traits (age and size at maturity of the youngest first breeders, age variation in first breeders, longevity, potential reproductive lifespan, median lifespan, age-size relationship). Spring and summer cohorts at the German locality differed with respect to longevity and potential reproductive lifespan by one year in favour of the early breeders. The potential consequences on fitness and stability of cohorts are discussed. Latitudinal variation of life history traits was mainly limited to female natterjacks in which along a south-north gradient longevity and potential reproductive lifespan increased while size decreased. These results and a review of published information on natterjack demography suggest that lifetime number of offspring seem to be optimized by locally different trade-offs: large female size at the cost of longevity in southern populations and increased longevity at the cost of size in northern ones.

scholarly journals Visual multiple cross displacement amplification for the rapid identification of S. agalactiae immediately from vaginal and rectal swabs

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xueqin Cheng ◽  
Zhiqian Dou ◽  
Jing Yang ◽  
Dexi Liu ◽  
Yulong Gu ◽  
...  
Keyword(s):  
Pathogen Detection ◽  
Clinical Specimen ◽  
Rapid Identification ◽  
Sample Collection ◽  
Special Equipment ◽  
Multiple Cross ◽  
Rectal Swabs ◽  
Cost Efficient ◽  
The Cost ◽  
Positive Results

AbstractStreptococcus agalactiae (S. agalactiae) is an important pathogen that can lead to neonatus and mother infection. The current existing techniques for the identification of S. agalactiae are limited by accuracy, speed and high-cost. Therefore, a new multiple cross displacement amplification (MCDA) assay was developed for test of the target pathogen immediately from vaginal and rectal swabs. MCDA primers screening were conducted targeting S. agalactiae pcsB gene, and one set of MCDA primers with better rapidity and efficiency was selected for establishing the S. agalactiae-MCDA assay. As a result, the MCDA method could be completed at a constant temperature of 61 °C, without the requirement of special equipment. The detection limit is 250 fg (31.5 copies) per reaction, all S. agalactiae strains displayed positive results, but not for non-S. agalactiae strains. The visual MCDA assay detected 16 positive samples from 200 clinical specimen, which were also detected positive by enrichment/qPCR. While the CHROMagar culture detected 6 positive samples. Thus, the MCDA assay is prefer to enrichment/qPCR and culture for detecting S. agalactiae from clinical specimen. Particularly, the whole test of MCDA takes about 63.1 min, including sample collection (3 min), DNA preparation (15 min), MCDA reaction (45 min) and result reporting (6 s). In addition, the cost was very economic, with only US$ 4.9. These results indicated that our S. agalaciae-MCDA assay is a rapid, sensitive and cost-efficient technique for target pathogen detection, and is more suitable than conventional assays for an urgent detection, especially for 'on-site' laboratories and resource-constrained settings.

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