scholarly journals Time series livestock diet optimization: cost-effective broiler feed substitution using the commodity price spread approach

2017 ◽  
Vol 5 (1) ◽  
Author(s):  
Othman Alqaisi ◽  
Oghaiki Asaah Ndambi ◽  
Ryan Blake Williams
Keyword(s):  
Time Series ◽  
Cost Effective ◽  
Commodity Price ◽  
Price Spread ◽  
Broiler Feed ◽  
Diet Optimization

scholarly journals Effectiveness and cost-effectiveness of implementing HIV testing in primary care in East London: protocol for an interrupted time series analysis

BMJ Open ◽  
2017 ◽  
Vol 7 (12) ◽  
pp. e018163 ◽  
Author(s):  
Werner Leber ◽  
Lee Beresford ◽  
Claire Nightingale ◽  
Estela Capelas Barbosa ◽  
Stephen Morris ◽  
...  
Keyword(s):  
Primary Care ◽  
Time Series ◽  
General Practice ◽  
Cost Effectiveness ◽  
Hiv Testing ◽  
Cost Effective ◽  
Interrupted Time Series ◽  
Rapid Hiv Testing ◽  
Post Trial ◽  
Implementation Programme

IntroductionHIV remains underdiagnosed. Guidelines recommend routine HIV testing in primary care, but evidence on implementing testing is lacking. In a previous study, the Rapid HIV Assessment 2 (RHIVA2) cluster randomised controlled trial, we showed that providing training and rapid point-of-care HIV testing at general practice registration (RHIVA2 intervention) in Hackney led to cost-effective, increased and earlier diagnosis of HIV. However, interventions effective in a trial context may be less so when implemented in routine practice. We describe the protocol for an MRC phase IV implementation programme, evaluating the impact of rolling out the RHIVA2 intervention in a post-trial setting. We will use a longitudinal study to examine if the post-trial implementation in Hackney practices is effective and cost-effective, and a cross-sectional study to compare Hackney with two adjacent boroughs providing usual primary care (Newham) and an enhanced service promoting HIV testing in primary care (Tower Hamlets).Methods and analysisService evaluation using interrupted time series and cost-effectiveness analyses. We will include all general practices in three contiguous high HIV prevalence East London boroughs. All adults aged 16 and above registered with the practices will be included. The interventions to be examined are: a post-trial RHIVA2 implementation programme (including practice-based education and training, external quality assurance, incentive payments for rapid HIV testing and incorporation of rapid HIV testing in the sexual health Local Enhanced Service) in Hackney; the general practice sexual health Network Improved Service in Tower Hamlets and usual care in Newham. Coprimary outcomes are rates of HIV testing and new HIV diagnoses.Ethics and disseminationThe chair of the Camden and Islington NHS Research Ethics Committee, London, has endorsed this programme as an evaluation of routine care. Study results will be published in peer-reviewed journals and reported to commissioners.

Automatic fault detection for Building Integrated Photovoltaic (BIPV) systems using time series methods

2018 ◽  
Vol 8 (2) ◽  
pp. 160-170 ◽  
Author(s):  
Mohsen Shahandashti ◽  
Baabak Ashuri ◽  
Kia Mostaan
Keyword(s):  
Time Series ◽  
Automatic Detection ◽  
Cost Effective ◽  
Performance Ratio ◽  
Solar Irradiation ◽  
Short Term ◽  
Content Type ◽  
Structure Changes ◽  
Cost Effective Approach ◽  
Building Integrated Photovoltaic

PurposeFaults in the actual outdoor performance of Building Integrated Photovoltaic (BIPV) systems can go unnoticed for several months since the energy productions are subject to significant variations that could mask faulty behaviors. Even large BIPV energy deficits could be hard to detect. The purpose of this paper is to develop a cost-effective approach to automatically detect faults in the energy productions of BIPV systems using historical BIPV energy productions as the only source of information that is typically collected in all BIPV systems.Design/methodology/approachEnergy productions of BIPV systems are time series in nature. Therefore, time series methods are used to automatically detect two categories of faults (outliers and structure changes) in the monthly energy productions of BIPV systems. The research methodology consists of the automatic detection of outliers in energy productions, and automatic detection of structure changes in energy productions.FindingsThe proposed approach is applied to detect faults in the monthly energy productions of 89 BIPV systems. The results confirm that outliers and structure changes can be automatically detected in the monthly energy productions of BIPV systems using time series methods in presence of short-term variations, monthly seasonality, and long-term degradation in performance.Originality/valueUnlike existing methods, the proposed approach does not require performance ratio calculation, operating condition data, such as solar irradiation, or the output of neighboring BIPV systems. It only uses the historical information about the BIPV energy productions to distinguish between faults and other time series properties including seasonality, short-term variations, and degradation trends.

scholarly journals Characterization of Pathogen Airborne Inoculum Density by Information Theoretic Analysis of Spore Trap Time Series Data

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1343 ◽  
Author(s):  
Robin A. Choudhury ◽  
Neil McRoberts
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
Complex Dynamics ◽  
Cost Effective ◽  
Series Data ◽  
Spore Trap ◽  
Abundance Data ◽  
Airborne Inoculum ◽  
Pathogen Dna ◽  
Low Dimensional

In a previous study, air sampling using vortex air samplers combined with species-specific amplification of pathogen DNA was carried out over two years in four or five locations in the Salinas Valley of California. The resulting time series data for the abundance of pathogen DNA trapped per day displayed complex dynamics with features of both deterministic (chaotic) and stochastic uncertainty. Methods of nonlinear time series analysis developed for the reconstruction of low dimensional attractors provided new insights into the complexity of pathogen abundance data. In particular, the analyses suggested that the length of time series data that it is practical or cost-effective to collect may limit the ability to definitively classify the uncertainty in the data. Over the two years of the study, five location/year combinations were classified as having stochastic linear dynamics and four were not. Calculation of entropy values for either the number of pathogen DNA copies or for a binary string indicating whether the pathogen abundance data were increasing revealed (1) some robust differences in the dynamics between seasons that were not obvious in the time series data themselves and (2) that the series were almost all at their theoretical maximum entropy value when considered from the simple perspective of whether instantaneous change along the sequence was positive.

scholarly journals Fog and Low Stratus Obstruction of Wind Lidar Observations in Germany—A Remote Sensing-Based Data Set for Wind Energy Planning

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3859
Author(s):  
Benjamin Rösner ◽  
Sebastian Egli ◽  
Boris Thies ◽  
Tina Beyer ◽  
Doron Callies ◽  
...  
Keyword(s):  
Time Series ◽  
Planning Process ◽  
Negative Impact ◽  
Cost Effective ◽  
Data Availability ◽  
Cloud Base ◽  
Radiation Fog ◽  
Data Set ◽  
Weather Types ◽  
Lidar Measurements

Coherent wind doppler lidar (CWDL) is a cost-effective way to estimate wind power potential at hub height without the need to build a meteorological tower. However, fog and low stratus (FLS) can have a negative impact on the availability of lidar measurements. Information about such reductions in wind data availability for a prospective lidar deployment site in advance is beneficial in the planning process for a measurement strategy. In this paper, we show that availability reductions by FLS can be estimated by comparing time series of lidar measurements, conducted with WindCubes v1 and v2, with time series of cloud base altitude (CBA) derived from satellite data. This enables us to compute average maps (2006–2017) of estimated availability, including FLS-induced data losses for Germany which can be used for planning purposes. These maps show that the lower mountain ranges and the Alpine regions in Germany often reach the critical data availability threshold of 80% or below. Especially during the winter time special care must be taken when using lidar in southern and central regions of Germany. If only shorter lidar campaigns are planned (3–6 months) the representativeness of weather types should be considered as well, because in individual years and under persistent weather types, lowland areas might also be temporally affected by higher rates of data losses. This is shown by different examples, e.g., during radiation fog under anticyclonic weather types.

scholarly journals Quantifying acoustic damping using flame chemiluminescence

2016 ◽  
Vol 808 ◽  
pp. 245-257 ◽  
Author(s):  
E. Boujo ◽  
A. Denisov ◽  
B. Schuermans ◽  
N. Noiray
Keyword(s):  
Growth Rate ◽  
Time Series ◽  
Gas Turbines ◽  
Linear Growth ◽  
Dynamic Pressure ◽  
Cost Effective ◽  
Operating Conditions ◽  
Linear Growth Rate ◽  
Acoustic Damping ◽  
Output Only

Thermoacoustic instabilities in gas turbines and aeroengine combustors fall within the category of complex systems. They can be described phenomenologically using nonlinear stochastic differential equations, which constitute the grounds for output-only model-based system identification. It has been shown recently that one can extract the governing parameters of the instabilities, namely the linear growth rate and the nonlinear component of the thermoacoustic feedback, using dynamic pressure time series only. This is highly relevant for practical systems, which cannot be actively controlled due to a lack of cost-effective actuators. The thermoacoustic stability is given by the linear growth rate, which results from the combination of the acoustic damping and the coherent feedback from the flame. In this paper, it is shown that it is possible to quantify the acoustic damping of the system, and thus to separate its contribution to the linear growth rate from the one of the flame. This is achieved by postprocessing in a simple way simultaneously acquired chemiluminescence and acoustic pressure data. It provides an additional approach to further unravel from observed time series the key mechanisms governing the system dynamics. This straightforward method is illustrated here using experimental data from a combustion chamber operated at several linearly stable and unstable operating conditions.

Co-movement of major energy, agricultural, and food commodity price returns: A time-series assessment

2016 ◽  
Vol 57 ◽  
pp. 28-41 ◽  
Author(s):  
Francesca de Nicola ◽  
Pierangelo De Pace ◽  
Manuel A. Hernandez
Keyword(s):  
Time Series ◽  
Commodity Price ◽  
Food Commodity

scholarly journals Efficiency of Contractual Arrangements in Private Agricultural Product Markets

2000 ◽  
Vol 31 (4) ◽  
pp. 813
Author(s):  
Haleigh Boyd ◽  
Lewis Evans ◽  
Neil Quigley
Keyword(s):  
Vertical Integration ◽  
Social Life ◽  
Cost Effective ◽  
Commodity Price ◽  
Agricultural Product ◽  
Product Markets ◽  
Firm Level ◽  
Contractual Arrangements ◽  
Production Variability ◽  
The Individual

The electronic and information revolution is changing virtually all aspects of economic and social life, no more so than in the ability of firms of all sizes to make their mark in production and exporting. The ready access to vast information and the lower costs that now attend dealing with other firms have opened opportunities that never before would have been cost-effective at the individual firm level. These firms have to contract with other firms for all sorts of purposes. Because of the small size of agricultural and horticultural producers and special problems of seasonal production, variability in production and price, and product perishability, some of the most challenging contracts are in this sector.Co-operatives provide a vehicle for the vertical integration of production and processing in agriculture. The producers provide capital for and control the processing entity so that their interests are aligned. Returns to producers bundle together the commodity price and the return from the capital invested in processing.Many of the agricultural product markets in New Zealand operate within this co-operative structure, and in the case of the dairy industry, it is supported by statute. The forestry, wine and processed vegetable industries are notable exceptions in that these industries employ contracts between producers and processors as an alternative to vertical integration via co-operatives.In this article, we use examples of contracts between producers and processors in the forestry, wine and processed vegetable markets to consider the extent to which contracts may provide efficient vehicles for the alignment of interests between producers and processors in agricultural markets. We consider the ways in which these contracts:•Minimise transaction costs;•Use incentive mechanisms and monitoring to limit opportunism;•Allocate risk;•Facilitate investment in specific assets; and•Allocate property rights.We assess the implications of the annual crop cycles and perishability of grapes and vegetables with the longer crop cycles of forestry. We conclude that contracts appear to be viable alternatives to co-operative structures, even in the market for perishable agricultural products.

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