Daylighting Performance of Solar Control Films for Hospital Buildings in a Mediterranean Climate

One of the main retrofitting strategies in warm climates is the reduction of the effects of solar radiation. Cooling loads, and in turn, cooling consumption, can be reduced through the implementation of reflective materials such as solar control films. However, these devices may also negatively affect daylight illuminance conditions and the electric consumption of artificial lighting systems. In a hospital building, it is crucial to meet daylighting requirements as well as indoor illuminance levels and visibility from the inside, as these have a significant impact on health outcomes. The aim of this paper is to evaluate the influence on natural illuminance conditions of a solar control film installed on the windows of a public hospital building in a Mediterranean climate. To this end, a hospital room, with and without solar film, was monitored for a whole year. A descriptive statistical analysis was conducted on the use of artificial lighting, illuminance levels and rolling shutter aperture levels, as well as an analysis of natural illuminance and electric consumption of the artificial lighting system. The addition of a solar control film to the external surface of the window, in combination with the user-controlled rolling shutter aperture levels, has reduced the electric consumption of the artificial lighting system by 12.2%. Likewise, the solar control film has increased the percentage of annual hours with natural illuminance levels by 100–300 lux

CMOS design of adaptive fuzzy ASICs using mixed-signal circuits

Analog circuits are natural candidates to design fuzzy chips with optimum speed/power figures for precision up to about 1%. This paper presents a methodology and circuit blocks to realize fuzzy controllers in the form of analog CMOS chips. These chips can be made to adapt their function through electrical control. The proposed design methodology emphasizes modularity and simplicity at the circuit level - prerequisites to increasing processor complexity and operation speed. The paper include measurements from a silicon prototype of a fuzzy controller chip in CMOS 1.5 /spl mu/m single-poly technology

A modular CMOS analog fuzzy controller

The low/medium precision required for many fuzzy applications makes analog circuits natural candidates to design fuzzy chips with optimum speed/power figures. This paper presents a sixteen rules-two inputs analog fuzzy controller in a CMOS 1 /spl mu/m single-poly technology based on building blocks implementations previously proposed by the authors (1995). However, such building blocks are rearranged here to get a highly modular architecture organized from two high level blocks: the label block and the rule block. In addition, sharing of membership function circuits allows a compact design with low area and power consumption and its highly modular architecture will permit to increase the number of inputs and rules in future chips with hardly design effort. The paper includes measurements from a silicon prototype of the controller

A multiplexed mixed-signal fuzzy architecture

Analog circuits provide better area/power efficiency than their digital counterparts for low-medium precision requirements. This limit in precision as well as the lack of design tools when compared to the digital approach, imposes a limit of complexity, hence fuzzy analog controllers are usually oriented to fast low-power systems with low-medium complexity. The paper presents a strategy to preserve most of the advantages of an analog implementation, while allowing a notorious increment of the system complexity. Such strategy consists in implementing a reduced number of rules, those that really determine the output in a lattice controller, which we call analog core, then this core is dynamically programmed to perform the computation related to a specific rule set. The data to program the analog core are stored in a memory, and constitutes the whole knowledge base in a kind of virtual rule set. HSPICE simulations from an exemplary controller are shown to illustrate the viability of the proposal

Neuro-fuzzy chip to handle complex tasks with analog performance

This Paper presents a mixed-signal neuro-fuzzy controller chip which, in terms of power consumption, input-output delay and precision performs as a fully analog implementation. However, it has much larger complexity than its purely analog counterparts. This combination of performance and complexity is achieved through the use of a mixed-signal architecture consisting of a programmable analog core of reduced complexity, and a strategy, and the associated mixed-signal circuitry, to cover the whole input space through the dynamic programming of this core [1]. Since errors and delays are proportional to the reduced number of fuzzy rules included in the analog core, they are much smaller than in the case where the whole rule set is implemented by analog circuitry. Also, the area and the power consumption of the new architecture are smaller than those of its purely analog counterparts simply because most rules are implemented through programming. The Paper presents a set of building blocks associated to this architecture, and gives results for an exemplary prototype. This prototype, called MFCON, has been realized in a CMOS 0.7μm standard technology. It has two inputs, implements 64 rules and features 500ns of input to output delay with 16mW of power consumption. Results from the chip in a control application with a DC motor are also provided

Multiplexing architecture for mixed-signal CMOS fuzzy controllers

Limited precision imposes limits on the complexity of analogue circuits, and hence fuzzy analogue controllers are usually oriented to fast low-power systems with low-medium complexity. A strategy to preserve most of the advantages of an analogue implementation, while allowing a marked increment in system complexity, is presented.Comisión Interministerial de Ciencia y Tecnología TIC96-1392-C02-0

Indoor Air Quality Assessment: Comparison of Ventilation Scenarios for Retrofitting Classrooms in a Hot Climate

Current energy e ciency policies in buildings foster the promotion of energy retrofitting of the existing stock. In southern Spain, the most extensive public sector is that of educational buildings, which is especially subject to significant internal loads due to high occupancy. A large fraction of the energy retrofit strategies conducted to date have focused on energy aspects and indoor thermal comfort, repeatedly disregarding indoor air quality criteria. This research assesses indoor air quality in a school located in the Mediterranean area, with the objective of promoting di erent ventilation scenarios, based on occupancy patterns and carbon dioxide levels monitored on site. Results show that manual ventilation cannot guarantee minimum indoor quality levels following current standards. A constant ventilation based on CO2 levels allows 15% more thermal comfort hours a year to be reached, compared to CO2-based optimized demand-controlled ventilation. Nevertheless, the latter ensures 35% annual energy savings, compared to a constant CO2-based ventilation, and 37% more annual energy savings over that of a constant ventilation rate of outdoor air per person

A mixed-signal fuzzy controller and its application to soft start of DC motors

Presents a mixed-signal fuzzy controller chip and its application to control of DC motors. The controller is based on a multiplexed architecture presented by the authors (1998), where building blocks are also described. We focus here on showing experimental results from an example implementation of this architecture as well as on illustrating its performance in an application that has been proposed and developed. The presented chip implements 64 rules, much more than the reported pure analog monolithic fuzzy controllers, while preserving most of their advantages. Specifically, the measured input-output delay is around 500 ns for a power consumption of 16 mW and the chip area (without pads) is 2.65 mm/sup 2/. In the presented application, sensed motor speed and current are the controller input, while it determines the proper duty cycle to a PWM control circuit for the DC-DC converter that powers the motor drive. Experimental results of this application are also presented.Comisión Interministerial de Ciencia y Tecnología TIC99-082

A 16 [email protected] Mixed-Signal Programmable Fuzzy Controller CMOS-1μm Chip

We present a fuzzy inference chip capable to evaluate 16 programmable rules at a speed of 2.5Mflips (2.5 × 10 6 fuzzy inferences per second) with 8.6mW power consumption. It occupies 2.89mm 2 (including pads) in a CMOS 1μm single-poly technology. Measurements are given to demonstrate its performance. All the operations needed for fuzzy inference are realized on-chip using analog circuitry compatible with standard VLSI CMOS technologies. On-chip digital control and memory circuitry is also incorporated for programmability. The chip architecture and circuitry are based on our design methodology for neurofuzzy systems reported in [1]. A few architectural modifications are made to share circuitry among rules and, thus, obtain reduced area and power consumption. The chip parameters can be learned in situ, for operation in a changing environment, by using dedicated hardware-compatible learning algorithms [1][8

Distribution and Important Areas for the Conservation of Amphibians in the Province of Seville, Spain: Identifying Priorities

Amphibians are among the most threatened vertebrates in the world due to habitat destruction, emerging diseases, and climate change, and therefore, it is of critical importance to identify the risk and conservation measures for their populations. In this work, we aimed to identify the status of amphibian distribution in the province of Seville, in the south of Spain. We additionally wanted to identify critical conservation areas and propose measures of conservation for the whole community as well as specific taxa. To do this, we mapped the distribution of amphibians using our own data and bibliography and translated it into a 10 × 10 km2 UTM grid. Our work has allowed us to identify several areas of importance for amphibians in the province and populations of some species that need special attentio