Delta Model Research Articles

DELTA MODEL OF THE EDUCATIONAL ENVIRONMENT

В статье представлена метафорическая модель образовательного пространства – Дельта-модель, разработанная в целях проектирования образовательных сред. Условия и механизмы образования личности рассматриваются на образе дельты реки. Рассмотрены механизмы развития личности в образовательном Дельта-пространстве: образовательные ресурсы, внешняя учебная мотивация и пространство возможностей субъектной активности личности.

Object-based 3D geomodel with multiple constraints for early Pliocene fan delta in the south of Lake Albert Basin, Uganda

The early Pliocene fan delta complex developed in the south of Lake Albert Basin which is located at the northern end of the western branch in the East African Rift System. The stratigraphy of this succession is composed of distributary channels, overbank, mouthbar and lacustrine shales. Limited by the poor seismic quality and few wells, it is full of challenge to delineate the distribution area and patterns of reservoir sands. Sedimentary forward simulation and basin analogue were applied to analyze the spatial distribution of facies configuration and then a conceptual sedimentary model was constructed by combining with core, heavy mineral and palynology evidences.A 3D geological model of a 120 m thick stratigraphic succession was built using well logs and seismic surfaces based on the established sedimentary model. The facies modeling followed a hierarchical object-based approach conditioned to multiple trend constraints like channel intensity, channel azimuth and channel width. Lacustrine shales were modeled as background facies and then in turn eroded by distribute channels, overbank and mouthbar respectively. At the same time a body facies parameter was created to indicate the connectivity of the reservoir sands. The resultant 3D facies distributions showed that the distributary channels flowed from east bounding fault to west flank and overbank was adhered to the fringe of channels while mouthbar located at the end of channels. Furthermore, porosity and permeability were modeled using sequential Gaussian simulation (SGS) honoring core observations and petrophysical interpretation results.Despite the poor seismic is not supported to give enough information for fan delta sand distribution, creating a truly representative 3D geomodel is still able to be achieved. This paper highlights the integration of various data and comprehensive steps of building a consistent representative 3D geocellular fan delta model used for numeral simulation studies and field development plan.

Tidal intrusion within a mega delta: An unstructured grid modelling approach

The finite volume community ocean model (FVCOM) has been applied to the Ganges-Brahmaputra-Meghna (GBM) delta in the northern part of the Bay of Bengal in order to simulate tidal hydrodynamics and freshwater flow in a complex river system. The delta region is data-poor in observations of both bathymetry and water level; making it a challenge for accurate hydrodynamic models be configured for and validated in this area. This is the first 3D baroclinic model covering the whole GBM delta from deep water beyond the shelf break to 250 km inland, the limit of tidal penetration.This paper examines what controls tidal penetration from the open coast into an intricate system of river channels. A modelling approach is used to improve understanding of the hydrodynamics of the GBM delta system. Tidal penetration is controlled by a combination of bathymetry, channel geometry, bottom friction, and river flow. The simulated tides must be validated before this delta model is used further to investigate baroclinic processes, river salinity and future change in this area. The performance of FVCOM tidal model configuration is evaluated at a range of sites in order to assess its ability to capture water levels which vary over both a tidal and seasonal cycle.FVCOM is seen to capture the leading tidal constituents well at coastal tide gauge stations, with small root-mean-squared errors of 10 cm on average. Inland, the model compares favourably with twice daily observed water levels at thirteen stations where it is able to capture both tidal and annual timescales in the estuarine system. When the river discharge is particularly strong, the tidal range can be reduced as the tide and river are in direct competition.The bathymetry is found to be the most influential control on water levels within the delta, though tidal penetration can be significantly affected by the model's bottom roughness, and the inclusion of large river discharge. We discuss the generic problem of implementing a model in a data-poor region and the challenge of validating a hydrodynamic model from the open coast to narrow river channels.

Sulfosulfuron Persistence in Soil Under Different Cultivation Systems of Wheat (Triticum aestivum)

Many sulfonylurea herbicides have been used under a wide variety of agronomic conditions in numerous crops. An understanding of dissipation rate of herbicide is fundamental for predicting the fate of herbicide in soil. In order to study the sulfosulfuron persistence under different cultivation systems of wheat, a four replicated experiment was carried out in the Hashemabad Reaserch Center of Gorgan, Iran in 2010 in a split plot design with two factors. Cultivation system as the main factor consisted of six levels, including conservation tillage by Combinate, no-tillage by Baldan grain drill, conservation tillage by Chizelpacker, conservation tillage by Delta Model, surface tillage by heavy disk, and conventional tillage by moldboard plow and twice disk. Secondary factor included two levels of sulfosulfuron application (with and without sulfosulfuron). Soil samples were taken at 6 stages and soil microbial respiration and soil pH were measured as factors affecting sulfosulfuron persistence. Results showed the least time of sulfosulfuron persistence belonged to the cultivation system of no-tillage by Baldan grain drill with a half-life of 4.62 d. Then, conservation tillage by Combinate and conventional tillage with a half-life of 6.30 d and conservation tillage by Delta Model with a half-life of 9.90 d were ordered. The most time of sulfosulfuron persistence (11.55 d) was related to conservation tillage by Chizelpacker. Ninety percent reduction of sulfosulfuron concentration occurred 15.34, 20.92, 32.88, and 36.38 d after sulfosulfuron application, respectively, for no-tillage system, conservation tillage by Combinate and conventional tillage, conservation tillage by Delta Model and surface tillage, and conservation tillage by Chizelpacker. In all the cultivation systems, toxicity symptoms were not observed 40 d after spraying sulfosulfuron onto the tomato plants which were used as test plant. Effects of different cultivation systems on soil microbial respiration were also significant.

3-D Simulations of the San Francisco Estuary with Subgrid Bathymetry to Explore Long-Term Trends in Salinity Distribution and Fish Abundance

doi: http://dx.doi.org/10.15447/sfews.2016v14iss2art3 The UnTRIM hydrodynamic model was applied to San Francisco Bay and the Sacramento–San Joaquin Delta (Delta) using a coarse-resolution model grid with bathymetry represented at a finer subgrid scale. We simulated a 35-year period, spanning from January 1, 1980 through December 31, 2014. This simulation was used to develop salinity distribution maps to facilitate visualization of fish distribution and abundance data. We compared predicted salinity from the coarse-grid UnTRIM Bay–Delta model to continuous salinity monitoring observations as well to the measured surface salinity from San Pablo Bay through the Delta at a total of 5,542 times and locations where surface salinity was observed as part of several long-term fish monitoring programs: the Fall Midwater Trawl, Summer Townet Survey, and San Francisco Bay Study. The coarse-grid UnTRIM Bay–Delta model was shown to accurately predict hydrodynamics and the spatial distribution of salinity over both a 3-year detailed validation period and over the full 35-year analysis period. The predicted salinity was used to calculate the daily position of X2 and the daily-averaged area of the Low Salinity Zone (LSZ) for each day during the 35-year simulation. Our analysis highlights the influence of multi-year climate patterns, shorter-duration weather patterns, and Delta outflow on salinity distribution. We used the predicted salinity to develop maps of salinity distribution over seven periods for six fish species, and combined the salinity maps with historic fish sampling data to allow for visualization of fish abundance and distribution for 33 years between 1980 and 2012. These maps can be used to explore how different species respond to annual differences in salinity distributions in the San Francisco Estuary, and to expand the understanding of the relationships among salinity and fish abundance, distribution, and population resiliency.

Delta Rhapsody

AbstractModel Based System Engineering (MBSE) has become the pre‐eminent paradigm used to improve the development of complex systems. Additionally, Delta Modelling provides an incremental approach to the design and maintenance of models when there is variability in the system. In this context, the market leading IBM Rhapsody® provides a professional and wide range of functionalities. Nevertheless, there is not support for Delta Modelling in IBM Rhapsody®. To meet this need, the Delta Rhapsody solution has been developed. With the tool a new variant model can be automatically generated applying deltas to a core model. The application of the solution in an industrial case study has been undertaken. From this, it was concluded that the Delta Rhapsody solution notably reduces the required time to develop a variant model. To further improve the Delta Rhapsody solution, some future works have also been identified.

Whether We are Still Immature to Assess the Environmental KPIs!

This paper explores the relationship between company maturity level and environmental key performance indicator (KPI) assessment. A cross-sectional approach was taken to examine differences among low and high maturity organizations, measuring the level of environmental KPIs importance assessed by 51 project portfolio managers. The assessment has been prepared according to Regulation (EC) No 1221/2009 of the European Parliament and the Council 2009, and IPMA Delta model for maturity assessment (individual, project and organizational level assessment). Differences between environmental KPIs and individual, project and organizational maturity were observed. Data analysis was prepared using SPSS 20.0 software and Rapid Miner Studio 6.0. The initial step was related to the determination of the relationship between environmental KPIs areas (Material Efficiency, Energy Efficiency, Water Management, Waste Management, Biodiversity, Emissions into the air). K-means algorithm was performed in order to identify group characteristics. Man Whitney test was used for group comparison to determine environmental KPIs differences that are related to organizational, project and individual maturity level. The research findings are described by mean and standard deviation. Analyzing individual, organizational and project factors, influential maturity components were identified using linear regression analysis method. Project portfolio managers’ demographics have taken into account in this analysis. The study showed a significant difference between high mature and low mature organizations in environmental KPIs assessment according to project and individual level, but there is no difference according to the organizational level. Theoretical and practical implications are discussed.

Aerodynamic Flow Characteristics of Utilizing Delta Wing Configurations in Supersonic and Subsonic Flight Regimes

Computational fluid dynamic tests are performed on delta wing models at different heights and speeds in order to achieve lift and drag coefficient values. Primarily, testing was done at supersonic speeds to reveal the advantages of these wing configurations at supersonic flight regimes at a cruise speed and altitude. The low speed characteristics are also examined, important for take-off and landing regimes where the distinctive vortices become prominent. Throughout the two flight conditions tested, a simple delta wing model (with a straight swept wing) is compared to a delta wing model that exhibited a ‘LERX’ (leading edge root extension). Provided literature describes how the performance of delta wings can be improved through this inclusion. Results obtained from the tests show that the model with the LERX has a small, but significant, performance improvement over the simple delta model, in respect to the maximum achievable lift coefficient and maximum stall angle. Lift to drag ratio is not improved however, due to the large vortices creating pressure drag. Generally, the delta wing models produce relatively small amounts of drag, and slightly less lower lift, when at low angles of attack. This is primarily due to the geometry of the models that have thin leading edges and also low thickness to chord ratios.

How does business analytics contribute to business value?

AbstractThis paper presents a model, synthesized from the literature, of factors that explain how business analytics contributes to business value. It also reports results from a preliminary assessment of that model. The model consists of two parts: a process and a variance model. The process model depicts the analyze‐insight‐decision‐action process through which use of an organization's business analytic capabilities is intended to create business value. The variance model proposes that the five factors in Davenport et al.'s DELTA model of business analytics success factors, six from Watson & Wixom and three from Seddon et al.'s model of organizational benefits from enterprise systems, assist a firm to gain business value from business analytics. A preliminary assessment of the model was conducted using data from 100 customer success stories from vendors such as IBM, SAP and Teradata. Our conclusion is that the business analytics success model is likely to be a useful basis for future research.

Incremental Consistency Checking in Delta-oriented UML-Models for Automation Systems

Automation systems exist in many variants and may evolve over time in order to deal with different environment contexts or to fulfill changing customer requirements. This induces an increased complexity during design-time as well as tedious maintenance efforts. We already proposed a multi-perspective modeling approach to improve the development of such systems. It operates on different levels of abstraction by using well-known UML-models with activity, composite structure and state chart models. Each perspective was enriched with delta modeling to manage variability and evolution. As an extension, we now focus on the development of an efficient consistency checking method at several levels to ensure valid variants of the automation system. Consistency checking must be provided for each perspective in isolation, in-between the perspectives as well as after the application of a delta.

Closed-Form Gibbs Sampling for Graphical Models with Algebraic Constraints

Probabilistic inference in many real-world problems requires graphical models with deterministic algebraic constraints between random variables (e.g., Newtonian mechanics, Pascal’s law, Ohm’s law) that are known to be problematic for many inference methods such as Monte Carlo sampling. Fortunately, when such constraintsare invertible, the model can be collapsed and the constraints eliminated through the well-known Jacobian-based change of variables. As our first contributionin this work, we show that a much broader classof algebraic constraints can be collapsed by leveraging the properties of a Dirac delta model of deterministic constraints. Unfortunately, the collapsing processcan lead to highly piecewise densities that pose challenges for existing probabilistic inference tools. Thus,our second contribution to address these challenges is to present a variation of Gibbs sampling that efficiently samples from these piecewise densities. The key insight to achieve this is to introduce a class of functions that (1) is sufficiently rich to approximate arbitrary models up to arbitrary precision, (2) is closed under dimension reduction (collapsing) for models with (non)linear algebraic constraints and (3) always permits one analytical integral sufficient to automatically derive closed-form conditionals for Gibbs sampling. Experiments demonstrate the proposed sampler converges at least an order of magnitude faster than existing Monte Carlo samplers.

Measuring the quality of diff algorithms: a formalization

The automatic detection of differences between documents is a very common task in several domains. This paper introduces a formal way to compare diff algorithms and to analyze the deltas they produce. There is no one-fits-all definition for the quality of a delta, because it is strongly related to the application domain and the final use of the detected changes. Researchers have historically focused on minimality: reducing the size of the produced edit scripts and/or taming the computational complexity of the algorithms. Recently they started giving more relevance to the human interpretability of the deltas, designing tools that produce more readable, usable and domain-oriented results. We propose a universal delta model and a set of metrics to characterize and compare effectively deltas produced by different algorithms, in order to highlight what are the most suitable ones for use in a given task and domain.

Comparison of Two Identification Models Used in Adaptive Control of Continuous-Stirred Tank Reactor

The goal of this paper is to compare two identification methods – continuous-time and discrete-time. The continuous-time identification model is more accurate but not very suitable for on-line identification. This disadvantage was overcome with the use of differential filters. On the other hand, discrete-time identification model has is more suitable for identification but less accurate. Compromise can be found in the delta model as a special type of the discrete-time model parameters of which are related to the sampling period. The adaptive approach is based on the choice of the External Linear Model, parameters of which are identified recursively which satisfies the adaptivity of this system. Proposed control strategy was applied on the mathematical model of the Continuous Stirred-Tank reactor as a typical nonlinear lumped-parameters system used in the industry.

Virtual Heterogeneous Model Integration Layer

The classic way of building a software today sim-plistically consists in connecting a piece of code calling a method with the piece of code implementing that method. We consider these piece of code (software systems) not calling anything, behaving in a non deterministic way and providing complex sets of services in different domains. In software engineering reusability is the holly grail, and specially the reusability of code from autonomus tools requires powerful compostion/integration mechanisms. These systems are developed by different developers and being modified inceremently. Integrating these autonomous tools generate various conflicts. To deal with these conflicts, current integration mechanisms defines specific set of rules to resolve these conflicts and accompalish integration. Indeed still there is a big chance that changes made by other developers, or they update their changes in order to make them compliant with other developers cancel the updates done by others. The approach presented here claims three contributions in the field of Hetrogeneous Software Integration. First, this approach eliminate the need of conflicts resolving mechanism. Secondly, it provides the mechanism to work in the presence of conflicts without resolving them. Finally, contribution is that the integration mechanism does not affect if either of the system evolves. We do this by introducing an intermediate virtual layer between two systems that introduce a delta models which consist of three parts; viability that share required elements, hiding that hide conflicting elements and aliasing that aliases same concepts in both systems.

Probabilistic Flood Defence Assessment Tools

The WTI2017 project is responsible for the development of flood defence assessment tools for the 3600 km of Dutch primary flood defences, dikes/levees, dunes and hydraulic structures. These tools are necessary, as per January 1st 2017, the new flood risk management policy for the Netherlands will be implemented. Then, the seven decades old design practice (maximum water level methodology of 1958) and two decades old safety standards (and maximum hydraulic load methodology of 1996) will formally be replaced by a more risked based approach for the national policy in flood risk management. The formal flood defence assessment is an important part of this new policy, especially for flood defence managers, since national and regional funding for reinforcement is based on this assessment. This new flood defence policy is based on a maximum allowable probability of flooding. For this, a maximum acceptable individual risk was determined at 1/100 000 per year, this is the probability of life loss of for every protected area in the Netherlands. Safety standards of flood defences were then determined based on this acceptable individual risk. The results were adjusted based on information from cost -benefit analysis, societal risk and large scale societal disruption due to the failure of critical infrastructure e.g. power stations. The resulting riskbased flood defence safety standards range from a 300 to a 100 000 year return period for failure. Two policy studies, WV21 (Safety from floods in the 21st century) and VNK-2 (the National Flood Risk in 2010) provided the essential information to determine the new risk based safety standards for flood defences. The WTI2017 project will provide the safety assessment tools based on these new standards and is thus an essential element for the implementation of this policy change. A major issue to be tackled was the development of user-friendly tools, as the new assessment is to be carried out by personnel of the institutions managing flood the defences, and not by just a small number of experts in probabilistic assessment. Therefore, data management and use of software are main issues that have been covered in courses and training in 2016 and 2017. All in all, this is the largest change in the assessment of Dutch flood defences since 1996. In 1996 probabilistic techniques were first introduced to determine hydraulic boundary conditions (water levels and waves (wave height, wave period and direction for different return periods). To simplify the process, the assessment continues to consist of a three-step approach, moving from simple decision rules, to the methods for semi-probabilistic assessment, and finally to a fully probabilistic analysis to compare the strength of flood defences with the hydraulic loads. The formal assessment results are thus mainly based on the fully probabilistic analysis and the ultimate limit state of the strength of a flood defence. For complex flood defences, additional models and software were developed. The current Hydra software suite (for policy analysis, formal flood defence assessment and design) will be replaced by the model Ringtoets. New stand-alone software has been developed for revetments, geotechnical analysis and slope stability of the foreshore. Design software and policy analysis software, including the Delta model, will be updated in 2018. A fully probabilistic method results in more precise assessments and more transparency in the process of assessment and reconstruction of flood defences. This is of increasing importance, as large-scale infrastructural projects in a highly urbanized environment are increasingly subject to political and societal pressure to add additional features. For this reason, it is of increasing importance to be able to determine which new feature really adds to flood protection, to quantify how much its adds to the level of flood protection and to evaluate if it is really worthwhile. Please note: The Netherlands government policy is to develop open source models.

Sedimentary facies and depositional model of shallow water delta dominated by fluvial for Chang 8 oil-bearing group of Yanchang Formation in southwestern Ordos Basin, China

A systematic analysis of southwestern Ordos Basin’s sedimentary characteristics, internal architectural element association styles and depositional model was illustrated through core statistics, well logging data and outcrop observations in Chang 8 oil-bearing group. This analysis indicates that shallow water delta sediments dominated by a fluvial system is the primary sedimentary system of the Chang 8 oil-bearing group of the Yanchang Formation in southwestern Ordos Basin. Four microfacies with fine grain sizes are identified: distributary channels, sheet sandstone, mouth bar and interdistributary fines. According to the sandbody’s spatial distribution and internal architecture, two types of sandbody architectural element associations are identified: amalgamated distributary channels and thin-layer lobate sandstone. In this sedimentary system, net-like distributary channels at the delta with a narrow ribbon shape compose the skeleton of the sandbody that extends further into the delta front and shades into contiguous lobate distribution sheet sandstone in the distal delta front. The mouth bar is largely absent in this system. By analyzing the palaeogeomorphology, the palaeostructure background, sedimentary characteristics, sedimentary facies types and spatial distribution of sedimentary facies during the Chang 8 period, a distinctive depositional model of the Chang 8 shallow water fluvial-dominated delta was established, which primarily consists of straight multi-phase amalgamated distributary channels in the delta plain, net-like distributary channels frequently diverting and converging in the proximal delta front, sheet sandstones with dispersing contiguous lobate shapes in the distal delta front, and prodelta or shallow lake mudstones.

Regionalized multiple-point stochastic geological modeling: A case from braided delta sedimentary reservoirs in Qaidam Basin, NW China

Abstract Research on the depositional model of a braided delta in Kunbei oilfield, Qaidam Basin, was conducted with a fine geologic study in a dense well network area by combining sedimentary physical simulation to obtain statistical characteristic parameters and allocation relations of plane sedimentary facies units. On this basis, training images in different sedimentary regions of the braided delta were developed for reservoir modeling. In each sub-region, sequential conditional simulation in adjacent regions used different training images with angle revolving and scaling. This simulation succeeded in finely modeling the sedimentary microfacies of the braided delta. This method relaxed the requirement for a stationary training image in multipoint simulation and improved channel continuity as well as portability of the training image. In the fine reservoir description of the Kunbei oilfield, the model results were consistent with practical production and have the potential to guide effective water-flooding development. Effective application demonstrated the feasibility and practicability of the method. This paper presents a new method for accurately characterizing the braided delta using stochastic simulation.

Systematic synthesis of delta modeling languages

Delta modeling is a modular, yet flexible approach to capture variability by explicitly representing differences between system variants or versions. The conceptual idea of delta modeling is language-independent. But, to apply delta modeling to a concrete language, either a generic transformation language has to be used or the corresponding delta language has to be manually developed for each considered base language. Generic languages and their tool support often lack readability and specific context condition checking, since they are unrelated to the base language. In this paper, we present a process that allows synthesizing a delta language from the grammar of a given base language. Our method relies on an automatically generated language extension that can be manually adapted to meet domain-specific needs. We illustrate our method using delta modeling on a textual variant of architecture diagrams. Furthermore, we evaluate our method using a comparative case study. This case study covers an architectural, a structural, and a behavioral language and compares the preexisting handwritten grammars to the generated grammars as well as the manually tailored grammars. This paper is an extension of Haber et al. (Proceedings of the 17th international software product line conference (SPLC'13), pp 22---31, 2013).

The Sustainability Delta: Considering Sustainability Opportunities in Firm Valuation

In this paper we present the Sustainability Delta model as an improvement over existing environmental, social and governance (ESG) methodologies used in firm valuation. Starting from the question of how banks should integrate sustainability criteria into their valuation methods, we find that ESG methodologies currently do not consider the potential to generate higher future revenues due to sustainable innovations, and also lack consideration of different scenarios such as higher standards in legislation or consumer demand. To address these shortcomings the Sustainability Delta model is developed. Simulation results on the sugar manufacturing industry in Brazil demonstrate that by using the Sustainability Delta we estimate an improved firm value of 1.24%. The Sustainability Delta would allow for a more accurate valuation of firms as well as for the more effective allocation of capital for investors, which should bring market pressure to improve sustainability practices and thus contribute to sustainable development. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment

Three-Dimensional Modeling of Hydrodynamics and Salinity in the San Francisco Estuary: An Evaluation of Model Accuracy, X2, and the Low-Salinity Zone

doi: http://dx.doi.org/10.15447/sfews.2015v13iss1art2 The three-dimensional UnTRIM San Francisco Bay–Delta model was applied to simulate tidal hydrodynamics and salinity in the San Francisco Estuary (estuary) using an unstructured grid. We compared model predictions to observations of water level, tidal flow, current speed, and salinity collected at 137 locations throughout the estuary. A quantitative approach based on multiple model assessment metrics was used to evaluate the model's accuracy for each comparison. These comparisons demonstrate that the model accurately predicted water level, tidal flow, and salinity during a 3-year simulation period that spanned a large range of flow and salinity conditions. The model is therefore suitable for detailed investigation of circulation patterns and salinity distributions in the estuary. The model was used to investigate the location, and spatial and temporal extent of the low-salinity zone (LSZ), defined by salinity between 0.5 and 6 psu. We calculated X2, the distance up the axis of the estuary to the daily-averaged 2-psu near-bed salinity, and the spatial extent of the LSZ for each day during the 3-year simulation. The location, area, volume, and average depth of the low-salinity zone varied with X2; however this variation was not monotonic and was largely controlled by the geometry of the estuary. We used predicted daily X2 values and the corresponding daily Delta outflow for each day during the 3-year simulation to develop a new equation to relate X2 to Delta outflow. This equation provides a conceptual improvement over previous equations by allowing the time constant for daily changes in X2 to vary with flow conditions. This improvement resulted in a smaller average error in X2 prediction than previous equations. These analyses demonstrate that a well-calibrated three-dimensional (3-D) hydrodynamic model is a valuable tool for investigating the salinity distributions in the estuary, and their influence on the distribution and abundance of physical habitat.