Architectural Constraints Research Articles

Investigation of building integrated photovoltaics potential in achieving the zero energy building target

Since the photovoltaic (PV) scientific community started exploring innovative ways of incorporating solar electricity into buildings, a whole new vernacular of solar electric architecture emerged. Currently, there is a growing consensus that building integrated photovoltaics (BIPV) systems will be the backbone of the zero energy building (ZEB) European target by 2020, through their widespread commercialization. BIPV systems often produce however less energy than conventional PV systems due to architectural constraints in the design of BIPV arrays. This paper presents a conceptual study regarding the energy yield and feasibility of BIPVs in several locations in Europe. Specific conclusions on the energy yield and economic feasibility of BIPVs with regard to the implemented PV module technology, the climatic zone, the orientation of the building and the mounting disposition are drawn. The findings of this work that were also validated using hourly time step computational analysis, reveal the necessary conditions under which BIPVs could have a major contribution to fulfilling the European 2020 targets by enabling the achievement of the ZEB goal.

Semi-automated architectural abstraction specifications for supporting software evolution

In this paper we present an approach for supporting the semi-automated architectural abstraction of architectural models throughout the software life-cycle. It addresses the problem that the design and implementation of a software system often drift apart as software systems evolve, leading to architectural knowledge evaporation. Our approach provides concepts and tool support for the semi-automatic abstraction of architecture component and connector views from implemented systems and keeping the abstracted architecture models up-to-date during software evolution. In particular, we propose architecture abstraction concepts that are supported through a domain-specific language (DSL). Our main focus is on providing architectural abstraction specifications in the DSL that only need to be changed, if the architecture changes, but can tolerate non-architectural changes in the underlying source code. Once the software architect has defined an architectural abstraction in the DSL, we can automatically generate architectural component views from the source code using model-driven development (MDD) techniques and check whether architectural design constraints are fulfilled by these models. Our approach supports the automatic generation of traceability links between source code elements and architectural abstractions using MDD techniques to enable software architects to easily link between components and the source code elements that realize them. It enables software architects to compare different versions of the generated architectural component view with each other. We evaluate our research results by studying the evolution of architectural abstractions in different consecutive versions of five open source systems and by analyzing the performance of our approach in these cases.

Is the NZEB Benchmarking Approach Suitable for Assessing Energy Retrofit Design?

Currently, many effort have been done to enable energy saving issues in building design and many definitions have been introduced for most performing constructions based on energy balance between energy demand and supply. Recently, the Net Zero Energy Building theory has bypassed old Passive House concept but many questions still remain open. Present work aims to estimate how NZEB requirements matching could be affected by the choice of their definition and the choice of weighting factor system, to be count in the energy balance. NZEB concept is mainly referred to new buildings design. Its application to existing buildings is for sure an hard task provided the architecture and physical constraints are often problematic. Nevertheless, the benchmarking approach able to assess the building performance according to the NZEB objective can be utilized for other two purposes. The first one is to assess how an existing building is far from the performances of a NZEB. The second one is to assess the contribution of a conventional retrofit in improving its energy balance.

Seismic Behavior of a Modern Concrete Coupled Wall

AbstractRC core walls are used commonly in modern building construction as the primary lateral load–resisting system. To meet architectural constraints, including elevator, stair, and doorway openings, common configurations include walls coupled together with heavily reinforced, low-aspect-ratio coupling beams. Numerous studies have focused on coupling beams and improved seismic performance and design of coupling beams. However, far fewer research programs have studied the seismic behavior of the coupled wall system. Coupled walls are typically used in mid- to high-rise construction, and understanding their seismic response requires simulation beyond the coupling beam and must include all important yielding components of the system. A research project was undertaken to investigate the response of a midrise coupled wall designed to meet current codes. The advanced testing capabilities of the University of Illinois at Urbana-Champaign George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES)...

The Adaptive Nature of Eye Movements in Linguistic Tasks: How Payoff and Architecture Shape Speed‐Accuracy Trade‐Offs

We explore the idea that eye-movement strategies in reading are precisely adapted to the joint constraints of task structure, task payoff, and processing architecture. We present a model of saccadic control that separates a parametric control policy space from a parametric machine architecture, the latter based on a small set of assumptions derived from research on eye movements in reading (Engbert, Nuthmann, Richter, & Kliegl, 2005; Reichle, Warren, & McConnell, 2009). The eye-control model is embedded in a decision architecture (a machine and policy space) that is capable of performing a simple linguistic task integrating information across saccades. Model predictions are derived by jointly optimizing the control of eye movements and task decisions under payoffs that quantitatively express different desired speed-accuracy trade-offs. The model yields distinct eye-movement predictions for the same task under different payoffs, including single-fixation durations, frequency effects, accuracy effects, and list position effects, and their modulation by task payoff. The predictions are compared to-and found to accord with-eye-movement data obtained from human participants performing the same task under the same payoffs, but they are found not to accord as well when the assumptions concerning payoff optimization and processing architecture are varied. These results extend work on rational analysis of oculomotor control and adaptation of reading strategy (Bicknell & Levy, ; McConkie, Rayner, & Wilson, 1973; Norris, 2009; Wotschack, 2009) by providing evidence for adaptation at low levels of saccadic control that is shaped by quantitatively varying task demands and the dynamics of processing architecture.

Spike-Based Probabilistic Inference in Analog Graphical Models Using Interspike-Interval Coding

Temporal spike codes play a crucial role in neural information processing. In particular, there is strong experimental evidence that interspike intervals (ISIs) are used for stimulus representation in neural systems. However, very few algorithmic principles exploit the benefits of such temporal codes for probabilistic inference of stimuli or decisions. Here, we describe and rigorously prove the functional properties of a spike-based processor that uses ISI distributions to perform probabilistic inference. The abstract processor architecture serves as a building block for more concrete, neural implementations of the belief-propagation (BP) algorithm in arbitrary graphical models (e.g., Bayesian networks and factor graphs). The distributed nature of graphical models matches well with the architectural and functional constraints imposed by biology. In our model, ISI distributions represent the BP messages exchanged between factor nodes, leading to the interpretation of a single spike as a random sample that follows such a distribution. We verify the abstract processor model by numerical simulation in full graphs, and demonstrate that it can be applied even in the presence of analog variables. As a particular example, we also show results of a concrete, neural implementation of the processor, although in principle our approach is more flexible and allows different neurobiological interpretations. Furthermore, electrophysiological data from area LIP during behavioral experiments are assessed in light of ISI coding, leading to concrete testable, quantitative predictions and a more accurate description of these data compared to hitherto existing models.

Andromonoecy and developmental plasticity in Chaerophyllum bulbosum (Apiaceae-Apioideae).

Andromonoecy, the presence of hermaphrodite and male flowers in the same individual, is genetically fixed or induced, e.g. by fruit set. Little is known about the forces triggering andromonoecy in the Apiaceae. In the present study, a natural population of the protandrous Chaerophyllum bulbosum was investigated to elucidate architectural constraints and effects of resource reallocation. Three sets of plants (each n = 15) were treated by hand pollination, pollinator exclusion and removal of low-order inflorescences. Fifteen untreated plants were left as controls. Untreated plants produce umbels up to the third branch order, with increasing proportions of male flowers from 15 % (terminal umbel) to 100 % (third-order umbels). Fruit set correspondingly decreases from 70% (terminal umbel) to <10 % (second-order umbels). Insignificant differences from hand-pollinated plants do not reveal any sign of pollinator limitation at the study site. Bagged individuals show the same increase in male flowers with age as untreated plants, indicating that the presence of andromonoecy is not induced by fruit set. After umbel removal, individuals tend to present a higher number of hermaphrodite flowers and fruits in the umbels of second and third order. Three plants (25 %) produced an additional branch order composed of 100 % male umbels. Inherited andromonoecy and the plastic response to environmental conditions are interpreted as a self-regulating system saving investment costs and optimizing fruit set at the same time.

“A framework for development of secure software”

To design, build and deploy secure systems, we must integrate security into our application development life cycle and adapt current software engineering practices and methodologies to include specific security-related activities. Developers enforces security measures during design phase of software development processes which may end up in specifying security related architecture constraints that are not really necessary. To eliminate this problem, we propose a Framework for Security Engineering Process that involves converting security requirements and threats into design decisions to mitigate the identified security threats. The identified design attributes are prioritized and a security design template is prepared. We have stored various cryptographic techniques and their analytic attributes in the repository to find out the specific cryptographic technique that would eventually help in the later stages of the design process by eliminating unnecessary design constraints in a particular scenario.

Étude des relations entre la morphologie cranio-faciale et l’occlusion en denture temporaire : remodelages occipitaux et singularités basicrâniennes déterminantes pour l’occlusion

Before performing any procedure or initiating early intervention on children in lacteal dentition, it is crucial to closely investigate a few key elements of the cranial base of the child. A first step of diagnostics is needed - the classification of the dysharmony ie its squelettal and/or functional element - before we prescribe a major orthopedic treatment or just stop dysfunctions using simple functional appliances. To confront these constraints of diagnostic, a set of 243 children in the lacteal dentition was examined. Our clinical expertise made it possible to select cephalometric measurements that would be supposedly linked with the type of skeletal dysharmony (based on cranial and facial osseous landmarks located on the profile-view of a digital tele-X-ray). The occlusal classification takes into account occlusal criteria and the design of the masticatory function. Statistical analysis (namely linear discriminant analysis of cephalometric variables) indicates that in lacteal dentition, some cranial architectural features have preferred links with specific occlusions. We noticed that the amplitude of basicranial "flexure" (hence the sphenoidal angle) is influenced by the occipital remodeling: the ontogenic process of flexion of the base and the amplitude of closure of the sphenoid angle are under controlled by the remodeling of the occipital bone in three main modalities. Correlations exist between these groups and the facial equilibrium, like a forward or backward position of the chin. The important clinical deduction is that the masticatory function in lacteal dentition is organized by architectural constraints that arise from the remodeling of the cranial base; the squelettal effect of dysfunctions is certainly specific to each type of dysfunction, nonetheless it also depends on the architectural uniqueness of the cranial base.

FPGA-aware techniques for rapid generation of profitable custom instructions

Instruction set extension of FPGA based reconfigurable processors provides an effective means to meet the increasingly strict design constraints of embedded systems. We have shown in our previous works [20,21] that the usage of FPGA architectural constraints for pruning the design space during enumeration of custom instructions/patterns not only leads to notable reduction in the time taken to identify custom instructions but can also result in the selection of profitable custom instructions when the area is highly constrained. However when area constraint is relaxed, the previously proposed methods failed to perform better than traditional methods. In this paper, we propose a heuristic to identify profitable custom instructions for designs with arbitrary area constraints. The proposed heuristic relies on a new pruning criterion to enumerate patterns with high size-to-hardware-area ratio. We also proposed a suitable algorithm to select profitable custom instructions from the enumerated patterns. The proposed template selection algorithm takes advantage of the FPGA area-time measures of the enumerated patterns, which can be easily inferred from the FPGA-aware enumeration strategy. Experimental results show that the proposed methods in this paper result in custom instructions that achieve an average performance gain of 76.23% over current state-of-the-art approaches.

Mitochondrial dynamics in the adult cardiomyocytes: which roles for a highly specialized cell?

Mitochondrial dynamics is a recent topic of research in the field of cardiac physiology. The study of mechanisms involved in the morphological changes and in the mobility of mitochondria is legitimate since the adult cardiomyocytes possess numerous mitochondria which occupy at least 30% of cell volume. However, architectural constraints exist in the cardiomyocyte that limit mitochondrial movements and communication between adjacent mitochondria. Still, the proteins involved in mitochondrial fusion and fission are highly expressed in these cells and could be involved in different processes important for the cardiac function. For example, they are required for mitochondrial biogenesis to synthesize new mitochondria and for the quality-control of the organelles. They are also involved in inner membrane organization and may play a role in apoptosis. More generally, change in mitochondrial morphology can have consequences in the functioning of the respiratory chain, in the regulation of the mitochondrial permeability transition pore (MPTP), and in the interactions with other organelles. Furthermore, the proteins involved in fusion and fission of mitochondria are altered in cardiac pathologies such as ischemia/reperfusion or heart failure (HF), and appear to be valuable targets for pharmacological therapies. Thus, mitochondrial dynamics deserves particular attention in cardiac research. The present review draws up a report of our knowledge on these phenomena.

A systems approach defining constraints of the genome architecture on lineage selection and evolvability during somatic cancer evolution

SummaryMost clinically distinguishable malignant tumors are characterized by specific mutations, specific patterns of chromosomal rearrangements and a predominant mechanism of genetic instability but it remains unsolved whether modifications of cancer genomes can be explained solely by mutations and selection through the cancer microenvironment.It has been suggested that internal dynamics of genomic modifications as opposed to the external evolutionary forces have a significant and complex impact on Darwinian species evolution. A similar situation can be expected for somatic cancer evolution as molecular key mechanisms encountered in species evolution also constitute prevalent mutation mechanisms in human cancers. This assumption is developed into a systems approach of carcinogenesis which focuses on possible inner constraints of the genome architecture on lineage selection during somatic cancer evolution. The proposed systems approach can be considered an analogy to the concept of evolvability in species evolution.The principal hypothesis is that permissive or restrictive effects of the genome architecture on lineage selection during somatic cancer evolution exist and have a measurable impact. The systems approach postulates three classes of lineage selection effects of the genome architecture on somatic cancer evolution: i) effects mediated by changes of fitness of cells of cancer lineage, ii) effects mediated by changes of mutation probabilities and iii) effects mediated by changes of gene designation and physical and functional genome redundancy. Physical genome redundancy is the copy number of identical genetic sequences. Functional genome redundancy of a gene or a regulatory element is defined as the number of different genetic elements, regardless of copy number, coding for the same specific biological function within a cancer cell. Complex interactions of the genome architecture on lineage selection may be expected when modifications of the genome architecture have multiple and possibly opposed effects which manifest themselves at disparate times and progression stages.Dissection of putative mechanisms mediating constraints exerted by the genome architecture on somatic cancer evolution may provide an algorithm for understanding and predicting as well as modifying somatic cancer evolution in individual patients.

Scaling digital walls: Everyday practices of consent and adaptation to digital architectural control

Users of mobile phones, computers and other digital media devices are increasingly confronted with what Lessig calls ‘architectural control’. This article presents results from a study which reveals that users adopt four tactics in negotiating architectural control: modifying use, modifying the technology, decreasing use and acceptance. Users consent in two ways: by internalizing control through incorporating architectural constraints into their embodied practice, and by responding to the convenience of architectural controls and the complexity of far-flung collective digital systems. Thus it is argued that modification and adaptation in everyday practices of digital media and information communication technologies (ICTs) is a type of consent rather than resistance to digital control.

China's Macro‐Planning Policies: Architectural Catalyst or Constraint?

AbstractChina is undergoing one of the most intense and rapid processes of urbanisation in the world today. It also has one of the most centralised planning systems, which is driven by a Soviet‐style, five‐year plan. Edward Denison looks at the relationship between China's highly systematised planning process and the high‐density, standardised form that urban development typically takes. Amidst this formal context, he locates a ‘whisper’ of change afoot for architects.

Designing an information technology system in public health: observations from India

The use of information technology in healthcare has seen varying success across states, due to differing institutional capacities. Despite isolated successes and partial gains, public health information technology systems in the country are unable to support integrated decision making at either district or state levels. An emphasis on technological advancements without significant attention to systems design has limited the potential gains from applications of information technology. This paper is an effort to describe the level of public health information technology systems development over the eleventh plan period and examine the architectural constraints that constitute a common problem across systems.

Disjoint out-of-order execution processor

High-performance superscalar architectures used to exploit instruction level parallelism in single-thread applications have become too complex and power hungry for the multicore processors era. We propose a new architecture that uses multiple small latency-tolerant out-of-order cores to improve single-thread performance. Improving single-thread performance with multiple small out-of-order cores allows designers to place more of these cores on the same die. Consequently, emerging highly parallel applications can take full advantage of the multicore parallel hardware without sacrificing performance of inherently serial and hard to parallelize applications. Our architecture combines speculative multithreading (SpMT) with checkpoint recovery and continual flow pipeline architectures. It splits single-thread program execution into disjoint control and data threads that execute concurrently on multiple cooperating small and latency-tolerant out-of-order cores. Hence we call this style of execution Disjoint Out-of-Order Execution (DOE). DOE uses latency tolerance to overcome performance issues of SpMT caused by interthread data dependences. To evaluate this architecture, we have developed a microarchitecture performance model of DOE based on PTLSim, a simulation infrastructure of the x86 instruction set architecture. We evaluate the potential performance of DOE processor architecture using a simple heuristic to fork control independent threads in hardware at the target addresses of future procedure return instructions. Using applications from SpecInt 2000, we study DOE under ideal as well as realistic architectural constraints. We discuss the performance impact of key DOE architecture and application variables such as number of cores, interthread data dependences, intercore data communication delay, buffers capacity, and branch mispredictions. Without any DOE specific compiler optimizations, our results show that DOE outperforms conventional SpMT architectures by 15%, on average. We also show that DOE with four small cores can perform on average equally well to a large superscalar core, consuming about the same power. Most importantly, DOE improves throughput performance by a significant amount over a large superscalar core, up to 2.5 times, when running multitasking applications.

An in vivo model of epithelial to mesenchymal transition reveals a mitogenic switch

The epithelial to mesenchymal transition (EMT) is a process by which differentiated epithelial cells transition to a mesenchymal phenotype. EMT enables the escape of epithelial cells from the rigid structural constraints of the tissue architecture to a phenotype more amenable to cell migration and, therefore, invasion and metastasis. We characterized an in vivo model of EMT and discovered that marked changes in mitogenic signaling occurred during this process. DNA microarray analysis revealed that the expression of a number of genes varied significantly between post-EMT and pre-EMT breast cancer cells. Post-EMT cancer cells upregulated mRNA encoding c-Met and the PDGF and LPA receptors, and acquired increased responsiveness to HGF, PDGF, and LPA. This rendered the post-EMT cells responsive to the growth inhibitory effects of HGF, PDGF, and LPA receptor inhibitors/antagonists. Furthermore, post-EMT cells exhibited decreased basal Raf and Erk phosphorylation, and in comparison to pre-EMT cells, their proliferation was poorly inhibited by a MEK inhibitor. These studies suggest that therapies need to be designed to target both pre-EMT and post-EMT cancer cells and that signaling changes in post-EMT cells may allow them to take advantage of paracrine signaling from the stroma in vivo.

An intelligent self-adjusting sensor for smart home services based on ZigBee communications

Wireless sensor networks (WSNs) have been becoming increasingly essential in recent years because of their ability to manage real-time situational information for various novel services. Recently, the scope of WSN technologies has been expanded to places such as the home, in order to provide the residents with various intelligent services, such as home automation services or home energy management services. However, due to their architectural constraints, such as the trade-off between the performance and cost, WSNs are not effectively implemented in home environments. Therefore, this paper proposes a ZigBee-based intelligent self-adjusting sensor (ZiSAS) in order to address these concerns. This paper presents a situation-based selfadjusting scheme, an event-based self-adjusting sensor network, and hardware and middleware implementation. We also introduce some smart home services using the proposed system. We implemented our system in real test bed and conducted an experiment. Our experiment shows that we reduce the system's energy consumption.

A Θ( √ n)-depth quantum adder on the 2D NTC quantum computer architecture

In this work, we propose an adder for the 2-Dimensional Nearest-Neighbor, Two-Qubit gate, Concurrent (2D NTC) architecture, designed to match the architectural constraints of many quantum computing technologies. The chosen architecture allows the layout of logical qubits in two dimensions with √ n columns where each column has √ n qubits and the concurrent execution of one- and two-qubit gates with nearest-neighbor interaction only. The proposed adder works in three phases. In the first phase, the first column generates the summation output and the other columns do the carry-lookahead operations. In the second phase, these intermediate values are propagated from column to column, preparing for computation of the final carry for each register position. In the last phase, each column, except the first one, generates the summation output using this column-level carry. The depth and the number of qubits of the proposed adder are Θ(√ n ) and O(n) , respectively. The proposed adder executes faster than the adders designed for the 1D NTC architecture when the length of the input registers n is larger than 51.

The role of epiphytism in architecture and evolutionary constraint within mycorrhizal networks of tropical orchids

Characterizing the architecture of bipartite networks is increasingly used as a framework to study biotic interactions within their ecological context and to assess the extent to which evolutionary constraint shape them. Orchid mycorrhizal symbioses are particularly interesting as they are viewed as more beneficial for plants than for fungi, a situation expected to result in an asymmetry of biological constraint. This study addressed the architecture and phylogenetic constraint in these associations in tropical context. We identified a bipartite network including 73 orchid species and 95 taxonomic units of mycorrhizal fungi across the natural habitats of Reunion Island. Unlike some recent evidence for nestedness in mycorrhizal symbioses, we found a highly modular architecture that largely reflected an ecological barrier between epiphytic and terrestrial subnetworks. By testing for phylogenetic signal, the overall signal was stronger for both partners in the epiphytic subnetwork. Moreover, in the subnetwork of epiphytic angraecoid orchids, the signal in orchid phylogeny was stronger than the signal in fungal phylogeny. Epiphytic associations are therefore more conservative and may co-evolve more than terrestrial ones. We suggest that such tighter phylogenetic specialization may have been driven by stressful life conditions in the epiphytic niches. In addition to paralleling recent insights into mycorrhizal networks, this study furthermore provides support for epiphytism as a major factor affecting ecological assemblage and evolutionary constraint in tropical mycorrhizal symbioses.