Range Of Historical Data Research Articles

Development of high-precision wind, wave and current forecast system for offshore wind energy industry in Taiwan: a two-stage method of numerical simulation and AI correction

ABSTRACT At the Changhwa Fuhai wind farm, the high-resolution numerical models for wind, wave and current simulations are crucial to provide daily forecasts as a decision-support system for Taiwan’s offshore wind energy industry. In this study, the two-stage method, consisting of numerical simulation and deep-learning correction based on the observed data at Fuhai wind farm site, is implemented to further improve the meteorological and marine forecast accuracy. The recurrent neural network-long short-term memory (RNN-LSTM) model is adopted in the deep learning analytics. Currently, this system is capable of daily providing the next 4-day wind field forecast and the next 7-day wave and current field forecast. Through the testing, it is found that the error correction of wind simulations can reduce root mean square error (RMSE) by up to 36.7%. Furthermore, through adopting the SQL and HBase hybrid database system, a wide range of historical data as well as daily forecast data can be quickly queried and displayed on the web interface to provide important decision support to the relevant wind power companies in scheduling offshore construction plans, forecasting wind energy production, and arranging wind turbines’ shutdown and maintenance sequence.

Population dynamics of the Taimyr wild reindeer herd

The paper analyses with a range of historical data the dynamics of the Taimyr wild reindeer population. Its first period is a pre-commercial hunting period (1959–1971). The second is the period of intensive organised commercial hunting (1972–1993). The third is a post-commercial hunting period (1994–2007). Finally, there is the period of barbarity (2008 – present time). The analysis covers the dynamics of the size, sex and age structure of the population (according to the data of aerial census survey and commercial hunting samples), female barrenness, animals’ natural mortality, commercial hunting and productivity of the population. It has been demonstrated that the predominance of males in the sex and age structure of the population begins mainly at the beginning of animals’ lives. The analysis of the data on reindeer’s fertility and mortality (both natural and from commercial hunting) lead us to the conclusion that the most productive indices of the population were reached in the period of intensive organised commercial hunting. It has been demonstrated through the latest data that uncontrolled poaching might very soon lead to the destruction of this unique biological resource.

A Phase 2 Study of 5-Fluorouracil (5-FU), Ziv-Aflibercept, and Radiation for the Preoperative and Adjuvant Treatment of Patients with Stage II/III Rectal Cancer

ABSTRACTBackground: This phase II study combined aflibercept with preoperative chemoradiation for patients with stage II/III rectal cancer, followed by mFOLFOX6/aflibercept. Methods: Patients received preoperative 5-FU (days 1–43), radiation (weeks 1–6), and aflibercept (days 1–15) each 28 day cycle for 6 weeks. Six weeks following the last aflibercept dose, patients underwent surgical resection. Four cycles of mFOLFOX6 plus aflibercept began 8 weeks after surgery. Results: Common treatment-related toxicities included diarrhea, fatigue, and mucositis. The pCR rate was 23%. Discussion: Afilbercept plus 5-FU-based chemoradiation was tolerated in patients with localized rectal cancer and showed a pCR rate within range of historical data.

Integrated Monitoring Software for Application Service Managers

In today's data centers, many application services share the same physical/virtual devices and affect each other. Therefore, application service managers need to spend a lot of time monitoring the application services by investigating a wide range of historical data about the shared devices. In this paper, integrated monitoring software for a wide range of historical data, which shortens the transition time (i.e., the time to switch from one historical data to another) by collecting and processing the historical data, is proposed and evaluated. Five basic historical data formats for automatically creating both well-organized historical data and relation data for the historical data are also proposed. The formats help application service managers by eliminating the need for the additional software development, which was otherwise required for each application service. Surveys on application service managers in a SaaS provider for over 50 000 companies show that about 98.6% of monitoring tasks can be covered by the five basic data formats and that the integrated monitoring software reduces the transition times for switching between historical data by about 54.7% compared to those with conventional monitoring software. These results suggest that the proposed integrated monitoring software is effective not only for reducing the time required for monitoring application services, but also for enhancing the overall service availability of SaaS providers' systems.

An analytical procedure for multi-site, multi-season streamflow generation using maximum entropy bootstrapping

Stochastic time series models are very useful in many environmental domains. In this paper, an analytical procedure for multi-site, multi-season streamflow generation using maximum entropy bootstrap stochastic model (M3EB) is developed that can implicitly preserve both the spatial and temporal dependence structure, in addition to the other statistical characteristics present in the historical time series. The proposed model is computationally less demanding and simple in terms of modeling complexity. The maximum entropy bootstrap (MEB) generates random samples from the empirical cumulative distribution function (ECDF) and rearranges the random series based on the rank ordering of the historical time series. The modeling structure of MEB implicitly satisfies the ergodic theorem (preservation of summary statistics) and guarantees the reproduction of the time dependent structure of an underlying process. The orthogonal transformation is used with M3EB to capture the spatial dependence present in the multi-site collinear data. The performance of M3EB is verified by comparing the statistical characteristics between the observed and synthetically generated streamflows. Three case studies from Colorado River Basin, USA; Red River Basin, USA and Canada; and Cauvery River Basin, India; are used to demonstrate the advantages of M3EB. The statistical measures adopted for evaluation of M3EB performance include monthly statistics (mean, standard deviation and skewness), temporal and spatial correlation, smoothing (flows other than present in historical data) and extrapolation (flows outside the range of historical data). The M3EB model shows (i) a high level of accuracy in preserving the statistics; and (ii) a high computational efficiency. Since M3EB can be used for multiple variable problems, the model can be easily extended to other environmental or hydroclimatic time series data.

An improved energy‐dispersive X‐ray microanalysis method for analyzing simultaneously carbon, nitrogen, oxygen, phosphorus, sulfur, and other cation and anion concentrations in single natural marine microplankton cells

Electron‐probe X‐ray microanalysis (XRMA) is a technique that can be used to simultaneously quantify C, N, O, Na, Mg, Al, Si, P, S, Cl, K, and Ca present in single cells collected from the sea, with a minimal treatment of the samples. The technique has been used to determine elemental composition in plankton using scanning electron microscopes (SEM) or transmission electron microscopes (TEM). The methodologies used have shown some drawbacks. Here we present an improved methodology focusing on the analysis of the elemental concentration of marine microplankton cells, including light elements, based on the methodology of Norland et al. (1995). The most important modification is the use of a SEM microscope but reproducing TEM conditions by placing the sample grid at a distance from the holder bottom. This modification eliminates the interference of the SEM stub from the analysis of the cells, and improves the limit of detection of elements that are present in low concentrations. Experimental and theoretical data on the beam penetration depth using low incident beam energies (15 kV) are presented. The results show that a 15 kV accelerating voltage, invoked as a limitation in using XRMA for the analysis of samples thicker than 0.1 µm (Twining et al. 2008), is sufficient to analyze whole microplankton cells, and that there is no absorption of X‐rays during the analysis. The method has been applied to diatoms and dinoflagellates from the Western Mediterranean Sea. The cell elemental composition results fall within the range of historical data in the literature.

FORECASTING IN FUZZY SYSTEMS

Fuzzy regression has been applied to marketing, management, and sales forecasting for many years. In this paper, two types of forecasting methods within the framework of fuzzy regression analysis are discussed. The first type is a conventional forecasting method, which intends to find the value of a dependent variable when the given values of independent variables are beyond the range covered by historical data. The second type considers forecasting in which the necessary values of independent variables are desired when the given value of a dependent variable does not fall within the range of historical data. While the first type can be applied in planning, the second one is useful for control and management. Numerical examples are provided for illustration.

Feed demands and coproduct substitution in the biofuel era

The use of traditional feedstocks for biofuel production has brought about large changes to food and agricultural systems. As livestock producers adapt to rising feed costs, the prospect of incorporating dried distiller's grain with solubles (DDGS) at higher than traditional levels becomes an important consideration. Given prices for feedstuffs and supplies of DDGS that are outside the historical data range, forward-looking analyses of the agricultural economy (even those with explicit derived demands for livestock feed) are poorly equipped to represent the farm- and sector-level tradeoffs that will emerge. The authors' results indicate that DDGS demands are more responsive to price changes in energy-oriented feeds than protein, despite the predominant historic feeding use of DDGS as a protein supplement. They extend their empirical analysis to account for the role of heterogeneous DDGS feed quality, identifying this as a critical consideration for sector-level substitution patterns. The price elasticities they report from their two-stage farm-level feed mix simulation and sector-level cost function estimation offer a robust picture of feedstuffs substitution of the type necessary for understanding the livestock component of demand response in the biofuels era. [EconLit citations: D20; C61; C13]. © 2010 Wiley Periodicals, Inc.