Architectural Constraints Research Articles

A study on the energy performance of a ground source heat pump utilized in the refurbishment of an historical building: comparison of different design options

The European construction sector is facing a major challenge due to the actual impact on long-term energy consumption, caused by the large number of existing buildings. In order to achieve the 2012 energy efficiency directive (2012-27-EU) each European country must draw-up long-term national building renovation strategies. Furthermore, existing buildings, subject to major renovation, also have to meet the European minimum energy performance requirements, in term of energy needs and system efficiency, requested by the 2010/31/EU and 2009/28/CE directives. The aim of the European Commission is to reduce by 27% the actual energy building consumption and to increase the total amount of renewable energy used by 27% by 2030. In Italy, national and regional laws have already implemented these strategies in order to achieve the national energy goals.The design phase in refurbishment projects is often problematic. The decisions taken in the early stages of the design determine the final result; however, the assessment of the environmental performance only happens at the end of the design process. Moreover, historical buildings present many artistic and architectural constraints that make the process more difficult, especially in the application of envelope refurbishment measures. Therefore, even more than in modern buildings, it is necessary to focus efforts on plant efficiency and exploitation of renewable sources. Currently the application of alternative energy supply systems in common retrofit has not generally been fully explored, in particular for historical buildings. In this context, geothermal energy is becoming all around Europe one of the most interesting sources of renewable energy for heating and cooling by ground-coupled heat pumps.The aim of this work is to compare different system solutions in terms of economic impact and energy needs during a building’s operating phase and to evaluate the sustainability of ground-coupled heat pump technology for heating and cooling.The test case is an historical single-family dwelling located in Northern Italy and built in 1800 with relevant architectural and artistic features. A range of generation system retrofit options are analyzed in order to evaluate the building’s primary energy needs, renewable energy exploitation and actualized return costs in each case. The heating and cooling generation systems compared are heat pumps with different renewable sources (geothermal and external-air) and different control systems (on/off and variable-capacity). Results can be applied in comparable case studies to support refurbishment strategies design.

Energy retrofitting of dwellings from the 40’s in Borgata Trullo - Rome

Buildings with architectural constraints and recognized historical values entail careful design process, especially, when the aim is to improve the energy efficiency. Foreseeable interventions consist of preservation and improvement of building envelope energy performance as well as the adaptation of the built environment to modern use and its accessibility. The compatibility between the aforementioned constraints and its future more sustainable use represents the crucial challenge. In this paper, feasible interventions on the dwellings from the 40’s in Borgata Trullo, Rome were designed and analyzed. Public housing asset is an interesting environment to test a sustainable holistic approach due to its homogeneity in terms of building technology solutions and typologies. Furthermore, the absence of public funding made more difficult the ordinary and extra-ordinary maintenance processes. So, the approach accounts for the age of the building along with the subsequent reduced energy performance as well as the architectural values to preserve. The proposed energy retrofitting measures are related to the building envelope, in the installation of insulation layers, the substitution of windows and improvement of HVAC systems to enhance energy efficiency. Besides the case study, design guidelines were presented to help the stakeholders in compatible and sustainable interventions. New HVAC solutions showed high gains in energy saving even if building envelope modifications were limited by the willing to preserve the cultural heritage values. Therefore, a virtuous restoration can address effectively current energy efficiency targets.

The Polyvalent heat pumps technology in retrofit of existing HVAC systems

In terms of existing buildings’ retrofit, historical and non-residential buildings clearly represent two challenging categories. In historical buildings, due to architectural constraints, acting on the technical side is often the only way to reduce consumptions, while non-residential buildings usually require simultaneous production of hot and chilled water. In these cases, Polyvalent heat pumps represent an interesting solution, able to guarantee significant reductions of primary energy consumptions.In detail, a Reference Building for an historical office was simulated in three Mediterranean cities, using EnergyPlus software and some evaluation tools specifically set to emulate the energy performances of the examined HVAC technologies.

Energy retrofit of historic buildings in the Mediterranean area: the case of the Palaeontology Museum of Naples

This paper aims to identify some optimal system solutions for the energy refurbishment of a specific historic building, through energy simulations in dynamic conditions performed with a suitable software. The analysis is carried out by the evaluation of energy requirements of the building, in terms of both primary and electric energy. The hypotheses of intervention regard only the air conditioning system components and take into account the existing architectural constraints. The case study refers to the Palaeontology Museum of Naples (Southern Italy), whose rooms are currently in a historic building located in the ancient centre of the city.

Toward Cognitively Constrained Models of Language Processing: A Review

Language processing is not an isolated capacity, but is embedded in other aspects of our cognition. However, it is still largely unexplored to what extent and how language processing interacts with general cognitive resources. This question can be investigated with cognitively constrained computational models, which simulate the cognitive processes involved in language processing. The theoretical claims implemented in cognitive models interact with general architectural constraints such as memory limitations. This way, it generates new predictions that can be tested in experiments, thus generating new data that can give rise to new theoretical insights. This theory-model-experiment cycle is a promising method for investigating aspects of language processing that are difficult to investigate with more traditional experimental techniques. This review specifically examines the language processing models of Lewis and Vasishth (2005), Reitter, Keller, and Moore (2011), and Van Rij, Van Rijn, and Hendriks (2010), all implemented in the cognitive architecture ACT-R (Anderson, Bothell, Byrne, Douglass, Lebiere, & Qin, 2004). These models are all limited by the assumptions about cognitive capacities provided by the cognitive architecture, but use different linguistic approaches. Because of this, their comparison provides insight into the extent to which assumptions about general cognitive resources influence concretely implemented models of linguistic competence. For example, the sheer speed and accuracy of human language processing is a current challenge in the field of cognitive modeling, as it does not seem to adhere to the same memory and processing capacities that have been found in other cognitive processes. Architecture-based cognitive models of language processing may be able to make explicit which language-specific resources are needed to acquire and process natural language. The review sheds light on cognitively constrained models of language processing from two angles: we discuss 1) whether currently adopted cognitive assumptions meet the requirements for language processing, and 2) how validated cognitive architectures can constrain linguistically motivated models, which, all other things being equal, will increase the cognitive plausibility of these models. Overall, the evaluation of cognitively constrained models of language processing will allow for a better understanding of the relation between data, linguistic theory, cognitive assumptions, and explanation.

WIRELESS BODY AREA NETWORK (WBAN) FOR HEALTH MONITORING SYSTEM USING GENETIC ALGORITHM AND FUZZY LOGIC

WBAN (Wireless Body Area Network) is one of the mostly used real time networks can be explained by certain limitations and constraints. The difficulties of the network occur because of the environmental constraints, device restrictions and architectural constraints. These problems also lift up various issues associated to network life, reliability and security. It is an automatic system utilized for the supervision of patients in circle condition. In the research, we have designed a network area with length and width of size 1000×1000 and 50 numbers of sensor nodes and the procedure is being iterated for almost six times. The research is being simulated in MATLAB environment. Parameters, namely, energy Consumption and Throughput have been used for checking the performance of the research. Optimization algorithm that is Genetic Algorithm is utilized for improving the performance of the parameters. The extraneous data is being removed by using Fuzzy logic classifier.

Improving entity linking with ontology alignment for semantic microservices composition

PurposeThis paper aims to propose a method based on Linked Data and Semantic Web principles for composing microservices through data integration. Two frameworks that provide support for the proposed composition method are also described in this paper: Linkedator, which is responsible for connecting entities managed by microservices, and Alignator, which aligns semantic concepts defined by heterogeneous ontologies.Design/methodology/approachThe proposed method is based on entity linking principles and uses individual matching techniques considering a formal notion of identity. This method imposes two major constraints that must be taken into account by its implementation: architectural constraints and resource design constraints.FindingsExperiments were performed in a real-world scenario, using public government data. The obtained results show the effectiveness of the proposed method and that, it leverages the independence of development and composability of microservices. Thereby, the data provided by microservices that adopt heterogeneous ontologies can now be linked together.Research limitations/implicationsThis work only considers microservices designed as data providers. Microservices designed to execute functionalities in a given application domain are out of the scope of this work.Originality/valueThe proposed composition method exploits the potential data intersection observed in resource-oriented microservice descriptions, providing a navigable view of data provided by a set of interrelated microservices. Furthermore, this study explores the applicability of ontology alignments for composing microservices.

DCL 2.0: modular and reusable specification of architectural constraints

BackgroundDue to the abstract nature of software architecture concepts, ensuring the correct implementation of architectural decisions is not a trivial task. Divergences between the planned architecture and source code may occur in the early stages of the software development, which denotes a phenomenon known as software architecture erosion. Architectural conformance checking techniques have been proposed to tackle the problem of divergences between the planned architecture and source code. Among such techniques, we can note the DCL (dependency constraint language), which is a domain-specific language that has interesting results in architectural conformance contexts. However, the current version of DCL has some limitations, such as lack of modularity and low degree of reuse, which may prevent its adoption in real software development scenarios. In this article, we extend DCL with a reusable, modular, and hierarchical specification.MethodWe propose and evaluate DCL 2.0—an extension of the original DCL—and its tool in a real-world development scenario of a large system used by a government branch of Minas Gerais, Brazil.ResultWe were able to detect 771 architectural violations where 74% of them could only be detected due to the new violation types proposed in DCL 2.0.ConclusionBy using DCL 2.0 herein presented, it was possible to conclude the following: (i) DCL 2.0 proved importance in helping the development team consistently address violations, and (ii) after using DCL 2.0 for months, the number of architectural violations being committed into the system branches was reduced to zero. Therefore, we argue that DCL 2.0 can have a positive impact on the architectural conformance of systems.

Facing herbivory on the climb up: Lost opportunities as the main cost of herbivory in the wild yam Dioscorea praehensilis.

Plants with simple architecture and strong constraints on their growth may offer critical insights into how growth strategies affect the tolerance of plants to herbivory. Although Dioscorea praehensilis, a wild yam of African forests, is perennial, both aerial apparatus and tuber are annually renewed. Each year, the tuber produces a single stem that climbs from the ground to the forest canopy. This stem bears no leaves and no branches until it reaches optimal light conditions. Once in the canopy, the plant's production fuels the filling of a new tuber before the plant dies back to the ground. We hypothesized that if deprived of ant defense, the leafless growth phase is a vulnerable part of the cycle, during which a small amount of herbivory entails a high cost in terms of loss of opportunity. We compared the growth of stems bearing ants or not as well as of intact stems and stems subjected to simulated or natural herbivory. Ants reduce herbivory; herbivory delays arrival to the canopy and shortens the season of production. Artificially prolonging the stem growth to the canopy increased plant mortality in the following year and, in surviving plants, reduced the stem diameter and likely the underground reserves produced. Tuber size is a key variable in plant performance as it affects both the size of the aerial apparatus and the duration of its single season of production. Aerial apparatus and tuber are thus locked into a cycle of reciprocal annual renewal. Costs due to loss of opportunity may play a major role in plant tolerance to herbivory, especially when architectural constraints interact with ecological conditions to shape the plant's growth strategy.

Spike propagation path planning on IBM TrueNorth neurosynaptic system

The authors report on the implementation of a path planning algorithm on the TrueNorth neurosynaptic system. Their implementation exploits processing in the temporal domain within the architectural constraints of the TrueNorth chip to deduce the optimal path. The optimal path is computed on the TrueNorth chip for grid maps with dimensions as large as 173 × 168 nodes consuming ∼70 mW at an operating voltage of 0.8 V.

Improved multi-objective model and analysis of the coordinated operation of a hydro-wind-photovoltaic system

The coordinated operation of a hydro-wind-photovoltaic system can mitigate the conflict between power generation and output fluctuations and overcome the bottleneck of new energy development. Because of the lack of available research on the coordination mechanism for analysing the relationship between power generation and output fluctuations, depicting the grid architecture and allocating power curtailment, this study establishes a multi-objective model for the coordinated operation of a hydro-wind-photovoltaic power system. The model seeks to maximize power generation and minimize output fluctuations under the constraints of multilayer architecture of the power network and balanced allocation of power curtailment. In a case study of a prefectural-level power grid in southwest China, three schemes are compared: independent operation with a single objective, coordinated operation with a single objective, and coordinated operation with multiple objectives. The complementary role of hydropower for increasing power generation and mitigating output fluctuations is explored; the effects of coordinated operation on transmission utilization and the hydrological regime are analysed; and the Pareto frontier of power generation and output fluctuations is obtained and the interaction of these factors is discussed. This study refines the model of a hydro-wind-photovoltaic system and investigates the complementary mechanism underlying multi-energy systems.

Performance and energy consumptions of split type air conditioning units for different arrangements of outdoor units in confined building shafts

Architectural constraints always recommend placing the outdoor units of split type air-conditioning (AC) systems in building shafts. This leads to high on-coil temperature, high electric consumption of and low performance of the units. In the present study, a CFD simulations of this problem are conducted for different installation arrangements of the outdoor units in two different situations of building shafts: the shaft is closed from the bottom by a basement slab, and the shaft is open from the bottom on the basement floor. The study aims to put installation guidelines for optimum arrangements of the outdoor units in building shafts. The results show that (i) the performance of the AC units dramatically getting bad when the building shaft is closed from the bottom, (ii) for open-bottom shaft, the performance of the units decreases as the installation floor level of the unit increases, (iii) for open-bottom shafts, it is preferable to install all outdoor units at one wall except for upper floors units where it preferred to be installed on two adjacent walls, (iv) for closed bottom shafts, it is not recommended to install outdoor units in lower levels of the shafts but can be installed at upper levels.

Routing and Fault Tolerance in Z-Fat Tree

Fat tree topologies have been extensively used as interconnection networks for high performance computing, cluster and data center systems, with their most recent variants able to fairly extend and scale to accommodate higher processing power. While each progressive and evolved fat-tree topology includes some extra advancements, these networks do not fully address all the issues of large scale HPC. We propose a topology called Zoned-Fat tree ( Z -Fat tree,) which is a further extension to the fat trees. The extension relates to the provision of extra degree of connectivity to utilize the extra ports per switches (routing nodes), that are, in some cases, not utilized by the architectural constraints of other variants of fat trees, and hence increases the bisection bandwidth, reduces the latency and supplies additional paths for fault tolerance. To support and profit from the extra links, we propose an adaptive low latency routing for up traffic which is based on a series of leading direction bits predefined at the source; furthermore we suggest a deterministic routing by implementing a dynamic round robin algorithm that overtakes D-mod-K in same cases and guarantees the utilization of all the extra links. We also propose a fault tolerance algorithm, named recoil-and-reroute which makes use of the extra links to ensure higher message delivery even in the presence of faulty links and switches.

Practice increases procedural errors after task interruption.

Positive effects of practice are ubiquitous in human performance, but a finding from memory research suggests that negative effects are possible also. The finding is that memory for items on a list depends on the time interval between item presentations. This finding predicts a negative effect of practice on procedural performance under conditions of task interruption. As steps of a procedure are performed more quickly, memory for past performance should become less accurate, increasing the rate of skipped or repeated steps after an interruption. We found this effect, with practice generally improving speed and accuracy, but impairing accuracy after interruptions. The results show that positive effects of practice can interact with architectural constraints on episodic memory to have negative effects on performance. In practical terms, the results suggest that practice can be a risk factor for procedural errors in task environments with a high incidence of task interruption. (PsycINFO Database Record

A Novel LWCSO-PKM-Based Feature Optimization and Classification of Attack Types in SCADA Network

Currently, Supervisory Control and Data Acquisition (SCADA) systems are widely used in the remote monitoring and control of the large-scale manufacturing plants and power grids. The development of high-security SCADA is the major requirement due to their vulnerability to attacks based on the architectural constraints. The decision making regarding the controlling of power flows and the replacement of faulty devices is based on the two stages normal or attacked. The observations from the sensor play the major role in the classification of normal and abnormal patterns. With the increase in a number of observations, the dimensionality of features is high and thus there is a chance of misleading results during the classification progress. Various classification and the intrusion detection (ID) algorithms are available to reduce the dimensionality of features for better classification. This paper proposes a novel approach for feature optimization and classification of the attack types in the SCADA network with better performance than the existing algorithms. The Linear Weighted Cuckoo Search Optimization (LWCSO) algorithm in proposed work selects the best features from the overall features. A Probabilistic Kernel Model (PKM) updates the weight function of each node to form the clusters representing the optimal features. The label is applied to each cluster based on the difference between the set of labeled training features with the testing feature set. Based on this label, the features are applied to detect the anomaly node in the network area. From the classification result, if the attack type is already known, then appropriate action is taken immediately. If the attack type is unknown, its type is added to the database. The periodical discovery of the type of attack and the database update with the unknown attacks increases the detection ability effectively. From the performance analysis, it is observed that the proposed LWCSO-PKM approach achieves better performance than the existing classification techniques and IDS algorithms.

Aspects of gorgonopsian paleobiology and evolution: insights from the basicranium, occiput, osseous labyrinth, vasculature, and neuroanatomy.

Synapsida, the clade including therapsids and thus also mammals, is one of the two major branches of amniotes. Organismal design, with modularity as a concept, offers insights into the evolution of therapsids, a group that experienced profound anatomical transformations throughout the past 270 Ma, eventually leading to the evolution of the mammalian bauplan. However, the anatomy of some therapsid groups remains obscure. Gorgonopsian braincase anatomy is poorly known and many anatomical aspects of the brain, cranial nerves, vasculature, and osseous labyrinth, remain unclear. We analyzed two gorgonopsian specimens, GPIT/RE/7124 and GPIT/RE/7119, using propagation phase contrast synchrotron micro-computed tomography. The lack of fusion between many basicranial and occipital bones in GPIT/RE/7124, which is an immature specimen, allowed us to reconstruct its anatomy and ontogenetic sequence, in comparison with the mature GPIT/RE/7119, in great detail. We explored the braincase and rendered various skull cavities. Notably, we found that there is a separate ossification between what was previously referred to as the “parasphenoid” and the basioccipital. We reinterpreted this element as a posterior ossification of the basisphenoid: the basipostsphenoid. Moreover, we show that the previously called “parasphenoid” is in fact the co-ossification of the dermal parasphenoid and the endochondral basipresphenoid. In line with previous descriptions, the anatomy of the osseous labyrinth is rendered in detail, revealing a unique discoid morphology of the horizontal semicircular canal, rather than toroidal, probably due to architectural constraints of the ossification of the opisthotic and supraoccipital. In addition, the orientation of the horizontal semicircular canal suggests that gorgonopsians had an anteriorly tilted alert head posture. The morphology of the brain endocast is in accordance with the more reptilian endocast shape of other non-mammaliaform neotherapsids.

Secondary Flow Control in Low Aspect Ratio Vanes Using Splitters

Low aspect ratio vanes, often the result of overall engine architecture constraints, create strong secondary flows and high end-wall loss. In this paper, a splitter concept is demonstrated that reduces secondary flow strength and improves stage performance. An analytic conceptual study, corroborated by inviscid computations, shows that the total secondary kinetic energy (SKE) of the secondary flow vortices is reduced when the number of passages is increased and, for a given number of vanes, when the inlet end-wall boundary layer is evenly distributed between the passages. Viscous computations show that, for this to be achieved in a splitter configuration, the pressure-side leg of the low aspect ratio vane horseshoe vortex, must enter the adjacent passage (and not “jump” in front of the splitter leading edge). For a target turbine application, four vane designs were produced using a multi-objective optimization approach. These designs represent current practice for a low aspect ratio vane, a design exempt from thickness constraints, and two designs incorporating splitter vanes. Each geometry is tested experimentally, as a sector, within a low-speed turbine stage. The vane designs with splitter geometries were found to reduce the measured secondary kinetic energy, by up to 85%, to a value similar to the design exempt from thickness constraints. The resulting flow field was also more uniform in both the circumferential and radial directions. One splitter design was selected for a full annulus test where a mixed-out loss reduction, compared to the current practice design, of 15.3% was measured and the stage efficiency increased by 0.88%.

Unusual positional effects on flower sex in an andromonoecious tree: Resource competition, architectural constraints, or inhibition by the apical flower?

Two, nonmutually exclusive, mechanisms-competition for resources and architectural constraints-have been proposed to explain the proximal to distal decline in flower size, mass, and/or femaleness in indeterminate, elongate inflorescences. Whether these mechanisms also explain unusual positional effects such as distal to proximal declines of floral performance in determinate inflorescences, is understudied. We tested the relative influence of these mechanisms in the andromonoecious wild olive tree, where hermaphroditic flowers occur mainly on apical and the most proximal positions in determinate inflorescences. We experimentally increased the availability of resources for the inflorescences by removing half of the inflorescences per twig or reduced resource availability by removing leaves. We also removed the apical flower to test its inhibitory effect on subapical flowers. The apical flower had the highest probability of being hermaphroditic. Further down, however, the probability of finding a hermaphroditic flower decreased from the base to the tip of the inflorescences. An experimental increase of resources increased the probability of finding hermaphroditic flowers at each position, and vice versa. Removal of the apical flower increased the probability of producing hermaphroditic flowers in proximal positions but not in subapical positions. These results indicate an interaction between resource competition and architectural constraints in influencing the arrangement of the hermaphroditic and male flowers within the inflorescences of the wild olive tree. Subapical flowers did not seem to be hormonally suppressed by apical flowers. The study of these unusual positional effects is needed for a general understanding about the functional implications of inflorescence architecture.

The Role of Architectural and Learning Constraints in Neural Network Models: A Case Study on Visual Space Coding.

The recent “deep learning revolution” in artificial neural networks had strong impact and widespread deployment for engineering applications, but the use of deep learning for neurocomputational modeling has been so far limited. In this article we argue that unsupervised deep learning represents an important step forward for improving neurocomputational models of perception and cognition, because it emphasizes the role of generative learning as opposed to discriminative (supervised) learning. As a case study, we present a series of simulations investigating the emergence of neural coding of visual space for sensorimotor transformations. We compare different network architectures commonly used as building blocks for unsupervised deep learning by systematically testing the type of receptive fields and gain modulation developed by the hidden neurons. In particular, we compare Restricted Boltzmann Machines (RBMs), which are stochastic, generative networks with bidirectional connections trained using contrastive divergence, with autoencoders, which are deterministic networks trained using error backpropagation. For both learning architectures we also explore the role of sparse coding, which has been identified as a fundamental principle of neural computation. The unsupervised models are then compared with supervised, feed-forward networks that learn an explicit mapping between different spatial reference frames. Our simulations show that both architectural and learning constraints strongly influenced the emergent coding of visual space in terms of distribution of tuning functions at the level of single neurons. Unsupervised models, and particularly RBMs, were found to more closely adhere to neurophysiological data from single-cell recordings in the primate parietal cortex. These results provide new insights into how basic properties of artificial neural networks might be relevant for modeling neural information processing in biological systems.

Estimation of 3D Indoor Models with Constraint Propagation and Stochastic Reasoning in the Absence of Indoor Measurements

This paper presents a novel method for the prediction of building floor plans based on sparse observations in the absence of measurements. We derive the most likely hypothesis using a maximum a posteriori probability approach. Background knowledge consisting of probability density functions of room shape and location parameters is learned from training data. Relations between rooms and room substructures are represented by linear and bilinear constraints. We perform reasoning on different levels providing a problem solution that is optimal with regard to the given information. In a first step, the problem is modeled as a constraint satisfaction problem. Constraint Logic Programming derives a solution which is topologically correct but suboptimal with regard to the geometric parameters. The search space is reduced using architectural constraints and browsed by intelligent search strategies which use domain knowledge. In a second step, graphical models are used for updating the initial hypothesis and refining its continuous parameters. We make use of Gaussian mixtures for model parameters in order to represent background knowledge and to get access to established methods for efficient and exact stochastic reasoning. We demonstrate our approach on different illustrative examples. Initially, we assume that floor plans are rectangular and that rooms are rectangles and discuss more general shapes afterwards. In a similar spirit, we predict door locations providing further important components of 3D indoor models.