Appropriate Level Of Detail Research Articles

Influence of high fidelity structural models on the predicted mass of aircraft wing using design optimization

This paper explores the necessary and appropriate level of detail that is required to describe the structural geometry of aircraft wings accurately enough to predict the mass of the main load-carrying wing structure to an acceptable level of accuracy. Four different models of increasing structural fidelity are used to describe the wingbox structure of a realistic real-world aircraft wing. The wingbox of the NASA Common Research Model served as a test model for exploring and analyzing the trade-off between the granularity level of the wingbox geometry description under consideration and the computational resources necessary to achieve the required degree of accuracy. The mass of metallic and composite wingbox configurations was calculated via finite element analysis and design optimization techniques. The results provided an insight into the competence of certain wingbox models in predicting the mass of the metallic and composite primary wing structures to an acceptable level of accuracy, and in demonstrating the relative merits of the wingbox structural complexity and the computational time and input efforts for achieving the required level of accuracy.

Building an active semantic data warehouse for precision dairy farming

ABSTRACTDigitalization of agricultural technology has led to the emergence of precision dairy farming, which strives for the simultaneous improvement of productivity as well as animal well-being in dairy farming through advanced use of technology such as movement sensors and milking parlors to monitor, control, and improve dairy production processes. The data warehouse serves as the appropriate technology for effective and efficient data management, which is paramount to the success of precision dairy farming. This paper presents a joint effort between industry and academia on the experimental development of an active semantic data warehouse to support business intelligence and business analytics in precision dairy farming. The research follows an action research approach, deriving lessons for theory and practice from a set of actions taken in the course of the project. Among these actions are the development of a loading stage to facilitate data integration, the definition of an analysis view as well as the introduction of semantic OLAP patterns to facilitate analysis, and analysis rules to automate periodic analyses. The large volumes of generated sensor data in precision dairy farming required careful decision-making concerning the appropriate level of detail of the data stored in the data warehouse. Semantic technologies played a key role in rendering analysis accessible to end users.

Integrating retention soil filters into urban hydrologic models – Relevant processes and important parameters

Retention Soil Filters (RSFs), a form of vertical flow constructed wetlands specifically designed for combined sewer overflow (CSO) treatment, have proven to be an effective tool to mitigate negative impacts of CSOs on receiving water bodies. Long-term hydrologic simulations are used to predict the emissions from urban drainage systems during planning of stormwater management measures. So far no universally accepted model for RSF simulation exists. When simulating hydraulics and water quality in RSFs, an appropriate level of detail must be chosen for reasonable balancing between model complexity and model handling, considering the model input’s level of uncertainty.The most crucial parameters determining the resultant uncertainties of the integrated sewer system and filter bed model were identified by evaluating a virtual drainage system with a Retention Soil Filter for CSO treatment. To determine reasonable parameter ranges for RSF simulations, data of 207 events from six full-scale RSF plants in Germany were analyzed.Data evaluation shows that even though different plants with varying loading and operation modes were examined, a simple model is sufficient to assess relevant suspended solids (SS), chemical oxygen demand (COD) and NH4 emissions from RSFs. Two conceptual RSF models with different degrees of complexity were assessed. These models were developed based on evaluation of data from full scale RSF plants and column experiments. Incorporated model processes are ammonium adsorption in the filter layer and degradation during subsequent dry weather period, filtration of SS and particulate COD (XCOD) to a constant background concentration and removal of solute COD (SCOD) by a constant removal rate during filter passage as well as sedimentation of SS and XCOD in the filter overflow.XCOD, SS and ammonium loads as well as ammonium concentration peaks are discharged primarily via RSF overflow not passing through the filter bed. Uncertainties of the integrated simulation of the sewer system and RSF model mainly originate from the model parameters of the hydrologic sewer system model.

Fractal advection-dispersion equation for groundwater transport in fractured aquifers with self-similarities

.Groundwater transport within a fractured aquifer with a fractal nature exhibiting self-similarity cannot be accurately simulated by the classical Fickian advection-dispersion transport equation without a detailed characterisation of the fracture network and heterogeneity of the system. Because the information to characterise such a system to an appropriate level of detail is often not available, most applications fail to accurately simulate the observed contaminant transport. In response to the current limitations of transport modelling using the advection-dispersion equation, especially in fractured media, a fractal advection-dispersion groundwater transport equation is developed. Fractal differentiation is discussed in terms of the fractal derivative and the fractal integral. The fractal derivative is commonly applied and known, yet the fractal integral is developed in this paper along with the appropriate theorem and proof. The numerical approximation of the fractal derivative and integral are given, where Simpson’s 3/8Rule and Boole’s Rule for numerical integration are applied for the fractal integral, and the forward and Crank-Nicolson finite difference schemes are applied for the fractal derivative. Upon the given foundation, the fractal advection-dispersion transport equation is formulated to develop a new groundwater transport model. The qualitative properties of the fractal advection-dispersion equation are investigated to determine boundedness, existence and uniqueness of the solution. To validate the developed fractal advection-dispersion equation, a numerical simulation is performed with different fractal dimensions to demonstrate the applicability of the model to fractal groundwater systems. The numerical simulations found that anomalous diffusion could be better modelled by incorporating a fractal dimension, especially where limited information is available on preferential pathways.

Opinion–Aspect Relations in Cognizing Customer Feelings via Reviews

Determining a consensus opinion on a product sold online is no longer easy, because assessments have become more and more numerous on the Internet. To address this problem, researchers have used various approaches, such as looking for feelings expressed in the documents and exploring the appearance and syntax of reviews. Aspect-based evaluation is the most important aspect of opinion mining, and researchers are becoming more interested in product aspect extraction; however, more complex algorithms are needed to address this issue precisely with large data sets. This paper introduces a method to extract and summarize product aspects and corresponding opinions from a large number of product reviews in a specific domain. We maximize the accuracy and usefulness of the review summaries by leveraging knowledge about product aspect extraction and providing both an appropriate level of detail and rich representation capabilities. The results show that the proposed system achieves F1-scores of 0.714 for camera reviews and 0.774 for laptop reviews.

Finite element study of deep excavation construction processes

Excavations for deep basements in urban areas present complex design questions, e.g. related to the selection of retaining systems and the specification of construction processes. Consideration must be given to the design of structural systems to support the excavation and the mitigation of any impact that the construction might have on any nearby infrastructure. The finite element analysis is routinely used (in design and research) for the analysis of this type of complex soil-structure interaction problem. Care is needed to ensure that representations of the construction processes, soil and structural behaviour are incorporated in the finite element model at an appropriate level of detail. This paper addresses the implementation of construction procedures in a finite element analysis of a deep excavation in Shanghai. Initially, an analysis is developed to model the construction processes actually employed in the project. The results of this model compare favourably with data measured during construction. The model is then developed to investigate the influence of certain aspects of the construction processes on the computed results. The results indicate the following: (i) the construction sequence for the floor slabs does not have a significant influence on the computed deformations in the retaining walls or the nearby ground at the end of construction; (ii) earth beams (used as temporary supports) are effective in reducing the computed wall and ground movements, and (iii) neglecting the presence of openings in the floor slabs may lead to unconservative calculations of the retaining wall and ground movements.

Determination of appropriate level of detail of a three-dimensional computer-aided design model from a permissible dissimilarity for fully automated simplification

The level of detail required for a three-dimensional computer-aided design model varies according to its purpose. Thus, it is necessary to develop an automated method for controlling the level of detail of three-dimensional computer-aided design models to facilitate the use of three-dimensional computer-aided design models in different application areas. When multiple three-dimensional computer-aided design models need to be simplified in a batch mode without user intervention, it would be advantageous if the appropriate level of details for the models were automatically determined. This study proposes a new and automated method to determine the appropriate level of detail of each three-dimensional computer-aided design model during the simplification phase. To achieve this goal, the concept of an “appropriate level of detail for simplification” was defined from the viewpoint of shape dissimilarity. After that, an algorithm was developed to determine the appropriate level of detail of a model by adopting the feature-based simplification method and the shape distribution–based comparison method. Finally, a prototype system was invented to verify the proposed method through experiments, in which the appropriate level of details for test cases were determined by the system.

HISTORIC BIM: A NEW REPOSITORY FOR STRUCTURAL HEALTH MONITORING

Abstract. Recent developments in Building Information Modelling (BIM) technologies are facilitating the management of historic complex structures using new applications. This paper proposes a generative method combining the morphological and typological aspects of the historic buildings (H-BIM), with a set of monitoring information. This combination of 3D digital survey, parametric modelling and monitoring datasets allows for the development of a system for archiving and visualizing structural health monitoring (SHM) data (Fig. 1). The availability of a BIM database allows one to integrate a different kind of data stored in different ways (e.g. reports, tables, graphs, etc.) with a representation directly connected to the 3D model of the structure with appropriate levels of detail (LoD). Data can be interactively accessed by selecting specific objects of the BIM, i.e. connecting the 3D position of the sensors installed with additional digital documentation. Such innovative BIM objects, which form a new BIM family for SHM, can be then reused in other projects, facilitating data archiving and exploitation of data acquired and processed. The application of advanced modeling techniques allows for the reduction of time and costs of the generation process, and support cooperation between different disciplines using a central workspace. However, it also reveals new challenges for parametric software and exchange formats. The case study presented is the medieval bridge Azzone Visconti in Lecco (Italy), in which multi-temporal vertical movements during load testing were integrated into H-BIM.

Megastructures: use of CFD turbulence models for the evaluation of wind-induced fatigue loads

Abstract: The determination of time dependent wind actions on large civil steel structures by means of turbulence models for CFD allows an improved evaluation of the fatigue load spectrum. The purpose of this paper is to identify, from literature review, the flow characteristics required to conduct a proper assessment of a fatigue load spectrum, given that practical cases determine which are the properties of the flow to be relevant. Subsequently, some CFD turbulence models are presented in order to investigate their ability to provide the required outputs with an appropriate level of detail. The computational cost of the models is also considered.

Global resilience analysis of water distribution systems

Evaluating and enhancing resilience in water infrastructure is a crucial step towards more sustainable urban water management. As a prerequisite to enhancing resilience, a detailed understanding is required of the inherent resilience of the underlying system. Differing from traditional risk analysis, here we propose a global resilience analysis (GRA) approach that shifts the objective from analysing multiple and unknown threats to analysing the more identifiable and measurable system responses to extreme conditions, i.e. potential failure modes. GRA aims to evaluate a system's resilience to a possible failure mode regardless of the causal threat(s) (known or unknown, external or internal). The method is applied to test the resilience of four water distribution systems (WDSs) with various features to three typical failure modes (pipe failure, excess demand, and substance intrusion). The study reveals GRA provides an overview of a water system's resilience to various failure modes. For each failure mode, it identifies the range of corresponding failure impacts and reveals extreme scenarios (e.g. the complete loss of water supply with only 5% pipe failure, or still meeting 80% of demand despite over 70% of pipes failing). GRA also reveals that increased resilience to one failure mode may decrease resilience to another and increasing system capacity may delay the system's recovery in some situations. It is also shown that selecting an appropriate level of detail for hydraulic models is of great importance in resilience analysis. The method can be used as a comprehensive diagnostic framework to evaluate a range of interventions for improving system resilience in future studies.

Desafíos para PISA

El Programa para la Evaluación Internacional de Alumnos (PISA) proporciona un marco en el que más de 80 países colaboran para construir métricas globales avanzadas para explorar los conocimientos, habilidades y atributos del estudiantado. El diseño de las evaluaciones plantea importantes desafíos conceptuales y técnicos, como el éxito del aprendizaje. Más allá de una base conceptual sólida, PISA necesita cumplir una serie de exigencias a veces contradictorios. Los/as administradores de escuelas, autoridades normativas y los docentes deben ser capaces de utilizar esta información de la evaluación para determinar cómo crear mejores oportunidades para el aprendizaje de los estudiantes. Las evaluaciones también deben proporcionar retroalimentación productiva, con niveles apropiados de detalle, para potenciar las decisiones de mejora y rendición de cuentas, en todos los niveles educativos. De hecho, además de evaluar la lectura, las matemáticas y la ciencia como competencias clave, PISA va incorporando progresivamente también algunas de las competencias cognitivas más amplias, sociales y emocionales.

Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion

Abstract Surface plasmons provide a pathway to efficiently absorb and confine light in metallic nanostructures, thereby bridging photonics to the nano scale. The decay of surface plasmons generates energetic ‘hot’ carriers, which can drive chemical reactions or be injected into semiconductors for nano-scale photochemical or photovoltaic energy conversion. Novel plasmonic hot carrier devices and architectures continue to be demonstrated, but the complexity of the underlying processes make a complete microscopic understanding of all the mechanisms and design considerations for such devices extremely challenging.Here,we review the theoretical and computational efforts to understand and model plasmonic hot carrier devices.We split the problem into three steps: hot carrier generation, transport and collection, and review theoretical approaches with the appropriate level of detail for each step along with their predictions.We identify the key advances necessary to complete the microscopic mechanistic picture and facilitate the design of the next generation of devices and materials for plasmonic energy conversion.

A differentiated description of building-stocks for a georeferenced urban bottom-up building-stock model

Several building-stock modelling techniques have been employed to investigate the impact of energy efficiency measures (EEM), where the description of the building-stock generally consists of an age-type classification to specify building characteristics for groups of buildings. Such descriptions lack the appropriate level of detail to differentiate the potential for EEM within age groups. This paper proposes a methodology for building-stock description using building-specific data and measured energy use to augment an age-type building-stock classification. By integrating building characteristics from energy performance certificates, measured energy use and envelope areas from a 2.5D GIS model, the building-stock description reflects the heterogeneity of the building-stock. The proposed method is validated using a local building portfolio (N=433) in the city of Gothenburg, where modelled results for space heating and domestic hot water are compared to data from measurements, both on an individual building level and for the entire portfolio. Calculated energy use based on the building-stock description of the portfolio differ less than 3% from measured values, with 42% of the individual buildings being within a 20% margin of measured energy use indicating further work is needed to reduce or quantify the uncertainty on a building level.

Non-Operating Room Anesthesia

Non-Operating Room Anesthesia

Finite-element analysis of a deep excavation case history

The design of deep excavations requires careful consideration of the influence of various soil/structure interaction mechanisms and detailed issues relating to the construction processes and the mechanics of the soil. Finite-element analysis provides a useful design tool for deep excavations, but care needs to be taken to ensure that an appropriate level of detail is included in the model. This paper describes a three-dimensional finite-element analysis of a deep excavation supported by a diaphragm wall, recently constructed in Shanghai. The principal purpose of the study is to investigate the level of detail that is required in the finite-element model to obtain results that provide a realistic representation of the wall and ground movements measured during the construction process. Studies are conducted on (a) the influence of the soil constitutive model on the quality of the results; (b) procedures to model the effect of post-cure shrinkage in the concrete floor slabs; (c) procedures to model the construction joints in the diaphragm wall; (d) the relative merits of using shell and solid elements to model the diaphragm wall; and (e) the sensitivity of the analysis to the assumed initial horizontal stresses in the soil.

Memory‐Efficient Interactive Online Reconstruction From Depth Image Streams

AbstractWe describe how the pipeline for 3D online reconstruction using commodity depth and image scanning hardware can be made scalable for large spatial extents and high scanning resolutions. Our modified pipeline requires less than 10% of the memory that is required by previous approaches at similar speed and resolution. To achieve this, we avoid storing a 3D distance field and weight map during online scene reconstruction. Instead, surface samples are binned into a high‐resolution binary voxel grid. This grid is used in combination with caching and deferred processing of depth images to reconstruct the scene geometry. For pose estimation, GPU ray‐casting is performed on the binary voxel grid. A one‐to‐one comparison to level‐set ray‐casting in a distance volume indicates slightly lower pose accuracy. To enable unlimited spatial extents and store acquired samples at the appropriate level of detail, we combine a hash map with a hierarchical tree representation.

Annual heating energy requirements of office buildings in a European climate

The concept of implementing energy savings to reduce greenhouse gas emissions has become a key element of energy policies of any industrialized country. In the civil sector and specifically, energy savings for office buildings, there are still opportunities for further enhancements related to correctly determining the air conditioning thermal requirements. However, there is a lack of simple correlations that allow a preliminary assessment for a single building or correlations that can be quickly applied at the district level. This paper proposes several simple correlations that determine the heating loads of a typical office building by only knowing the Degree-Days of a specific European location. The authors have developed a dynamic model of an office building, considering the different energy regulations in force in several European countries such that the building model is as energy-efficient as possible in each examined location. Furthermore, the standard requirements related to the employment rate, indoor ventilation and indoor gain have been included. The results from several simulations performed in the TRNSYS environment have enabled the development of mathematical relationships valid for seven European countries and three continental zones (northern, central and southern) with notably high correlation coefficients. The proposed equations can be useful for determining the heating load of non-residential buildings with an appropriate level of detail for a rough energy plan at the district level.

Reprint of PopGen: A virtual human population generator

The risk assessment of environmental chemicals and drugs is moving towards a paradigm shift in approach which seeks the full replacement animal testing with high throughput, mechanistic, in vitro systems. This new vision will be reliant on the measurement in vitro, of concentration-dependent responses where prolonged excessive perturbations of specific biochemical pathways are likely to lead to adverse health effects in an intact organism. Such an approach requires a framework, into which disparate data generated using in vitro, in silico and in chemico systems, can be integrated and utilised for quantitative in vitro-to-in vivo extrapolation (QIVIVE), ultimately to the human population level. Physiologically based pharmacokinetic (PBPK) models are ideally suited for this and are obligatory in order to translate in vitro concentration-response relationships to an exposure or dose, route and duration regime in people. In this report we describe PopGen a virtual human population generator which is a user friendly, open access web-based application for the prediction of realistic anatomical, physiological and phase 1 metabolic variation in a wide range of healthy human populations. We demonstrate how PopGen can be used for QIVIVE by providing input to a PBPK model, at an appropriate level of detail, to reconstruct exposure from human biomonitoring data. We discuss how the process of exposure reconstruction from blood biomarkers, in general, is analogous to exposure or dose reconstruction from concentration-response measurements made in proposed in vitro cell based systems which are assumed to be surrogates for target organs.

Applying the Domain-Mapping-Matrix to Identify the Appropriate Level of Detail of Simulation Models for Virtual Commissioning

Virtual commissioning (VC) as a method can be applied in many industries. The target of VC is to test control code as early as possible and enable thereby a smoother and faster execution of real commissioning. A crucial point in conducting simulation particularly within VC is that used simulation models must be sufficiently meaningful regarding the appropriate use case. An appropriate level of detail of used simulation models is therefore essential. A systematic classification of which parts of an automated plant should be simulated at what respective level of detail is, however, not available at present time. The following article follows the hypothesis that interactions between (production) processes and resources, emerged during the engineering process, allow for the identification of influence factors that play a key role in identifying the appropriate level of detail of simulation models. The Domain-Mapping-Matrix (DMM) and a rule-based approach can be used to analyse these interactions.

Levels of Detail and Appropriate Model Types for Virtual Commissioning in Manufacturing Engineering

Virtual commissioning is used to test control code deployed on Programmable Logical Controllers. Simulation models of a plant are the basis for simulation approaches covering virtual commissioning. However, it is often unclear what granularity these simulation models should have and how standardized levels of detail and particular model types should be defined. The approach presented herein identifies appropriate levels of detail and model types based on a hierarchical perception of automated manufacturing plants. The aim of this contribution is to systematize modelling approaches, especially the automatic generation of manufacturing plants' models.