Multi-Sensor Context-Awareness in Mobile Devices and Smart Artefacts

The use of context in mobile devices is receiving increasing attention in mobile and ubiquitous computing research. In this article we consider how to augment mobile devices with awareness of their environment and situation as context. Most work to date has been based on integration of generic context sensors, in particular for location and visual context. We propose a different approach based on integration of multiple diverse sensors for awareness of situational context that can not be inferred from location, and targeted at mobile device platforms that typically do not permit processing of visual context. We have investigated multi-sensor context-awareness in a series of projects, and report experience from development of a number of device prototypes. These include development of an awareness module for augmentation of a mobile phone, of the Mediacup exemplifying context-enabled everyday artifacts, and of the Smart-Its platform for aware mobile devices. The prototypes have been explored in various applications to validate the multi-sensor approach to awareness, and to develop new perspectives of how embedded context-awareness can be applied in mobile and ubiquitous computing

Investigation of Thermal Comfort for A Naturally Ventilated House: Correlation between Climatic Design Strategy and Thermal Data Analysis

One of the main factors contributing to climate change and global warming is architecture, which accounts for about 50% of the country's greenhouse emissions due to construction and the energy needed to keep buildings operational. Sustainable architecture is believed to reduce emissions, and this approach has been practised with traditional buildings. In Malaysia, a traditional Malay house (TMH) is one of the traditional buildings, and it is initially naturally ventilated with occupant-controlled air ventilation to condition the space. Numerous experimental studies claimed that TMH has demonstrated a good model for contemporary designers to understand climatic and environmental design, building systems, and design adaptability. One of the approaches is to practise climatic design strategies. However, there is a lack of study to determine if TMH is still relevant as a sustainable design that can adapt to current climate conditions. Thus, the study aims to investigate the adaptive indoor thermal comfort of a Negeri Sembilan Malay house in a hot-humid climate determined by the correlation between climatic design strategy and thermal data analysis. This study employed the Predictive Adaptive model by executing two stages of fieldwork: i) local climate background and ii) physical measurement (case study description and environmental data). The data were then analysed using the ACS of ASHRAE 55 and MS 2680:2017. The primary results revealed that 62% of the hourly indoor operative temperature of the case study house was within 80 to 90 % of the acceptability limit. The optimal comfort hourly indoor operative temperature was between 25.5 to 29.5 °C with a prevailing mean outdoor air temperature between 23 to 30 °C, which represents 90% of the acceptability limit range. Moreover, the results also complied with the standards of ACS, where the average hourly indoor operative temperature was less than 31 °C, with a prevailing mean outdoor air temperature less than 32 °C, which was an acceptable indoor state for occupants' comfort. The findings complied with RMK 12 Theme 3, which aims to be a carbon-neutral country by practising sustainable architecture and construction. The design of naturally ventilated houses, such as Negeri Sembilan Malay houses in hot-humid climates, can be a model reference for modern housing design development

Quadruple glazing panel filled with PCM and its influence on the sound insulation of building facades

The long-term pressure on a properly functioning modern infrastructure is the main reason for the development of new construction elements and technological processes. In the case of buildings, this development can offer original and significant improvements in aesthetic, functional and economical terms. Then the implemented structural elements and technological systems have a major impact on the overall of building quality, and comfort for occupants. Recently, when building structures are becoming lighter and lighter in weight, problems with heat accumulation and poor sound insulation occur. To improve the accumulation properties, production and implementation companies implementing accumulation materials into the buildings most frequently in the form of panels that can be incorporated into the peripheral walls or directly replace them. A subject of this paper is to study the effect of implementation one type of facade system into the perimeter walls on the airborne sound insulation of building facades. The research is dedicated to the quadruple glazing panel which is a translucent wall element without any mechanical components or electronic devices. © 2017, World Scientific and Engineering Academy and Society. All rights reserved.MSMT-7778/2014, MŠMT, Ministerstvo Školství, Mládeže a Tělovýchov

A Structured Hardware/Software Architecture for Embedded Sensor Nodes

Owing to the limited requirement for sensor processing in early networked sensor nodes, embedded software was generally built around the communication stack. Modern sensor nodes have evolved to contain significant on-board functionality in addition to communications, including sensor processing, energy management, actuation and locationing. The embedded software for this functionality, however, is often implemented in the application layer of the communications stack, resulting in an unstructured, top-heavy and complex stack. In this paper, we propose an embedded system architecture to formally specify multiple interfaces on a sensor node. This architecture differs from existing solutions by providing a sensor node with multiple stacks (each stack implements a separate node function), all linked by a shared application layer. This establishes a structured platform for the formal design, specification and implementation of modern sensor and wireless sensor nodes. We describe a practical prototype of an intelligent sensing, energy-aware, sensor node that has been developed using this architecture, implementing stacks for communications, sensing and energy management. The structure and operation of the intelligent sensing and energy management stacks are described in detail. The proposed architecture promotes structured and modular design, allowing for efficient code reuse and being suitable for future generations of sensor nodes featuring interchangeable components

Thermal Analysis of a New Sliding Smart Window Integrated with Vacuum Insulation, Photovoltaic, and Phase Change Material

A zero-energy building (ZEB) requires an innovative integration of technologies, in which windows play a paramount role in energy reduction, storage, and generation. This study contributes to four innovative designs of sliding smart windows. It integrates air-gap (AG), phase change material (PCM), photovoltaic (PV), and vacuum glazing (VG) technologies. These smart sliding windows are proposed to generate electricity along with achieving efficient thermal insulations and heat storage simultaneously. A two-dimensional multiphysics thermal model that couples the PCM melting and solidification model, PV model, natural convection in the cavity, and the surface-to-surface radiation model in the vacuum gap are developed for the first time. The model is validated with data in the literature. The transient simulations were carried out to investigate the thermo-electrical performance of a window with an area of 1 m by 1 m for the meteorological conditions of Kuwait city on the 10th of June 2018, where the window was oriented to south direction. The results showed that the total solar heat energy gain per unit window area is 2.6 kWh, 0.02 kWh, 0.22 kWh, 1.48 kWh, and 0.2 kWh for the double AG, AG + PV + PCM + VG, PV + PCM + VG, AG + PV + PCM, and the ventilated AG + PV + PCM + VG, respectively. The results elucidate the advantages of the integration of VG in this integrated sliding smart window. The daily generated PV electrical energy in these systems is around 1.3 kWh, 1.43 kWh, and 1.38 kWh for the base case with double AG, PV + PCM + VG, and the ventilated AG + PV + PCM + VG respectively per unit window area

An Environmental Skin: Enhancing Thermal Performance with Double-Skin Facades in Hawaii's Climate

Highly glazed commercial buildings in Hawai`i present overheating challenges due to high outside temperatures combined with solar gains. In order to optimize thermal performance and reduce excessive cooling loads, the thermal behavior of this type of building requires careful investigation. As an increasing interest in double‐skin facades as a successful methodology for controlling building performance continues to be explored in Europe , its feasibility within Hawai`i’s climate has yet to be discovered. In this study, double‐skin façade design strategies are examined in Hawai`i’s climate focusing on enhancing thermal performance on an existing building model. This research adopts a CFD simulation approach to model heat and air flow transfers in various double‐skin façade design scenarios. The impact of solar radiation, surface temperature, cavity height and air flow rate on temperature and velocity fields inside the channel of the double‐skin facade is analyzed. This research focuses on the investigation of context based design for double‐skin facades, particularly focusing on design considerations during the design process. In conclusion, this investigation will help to identify the potential of this specific system within Hawai`i’s climate and its ability to improve thermal performance within existing buildings

Antennas And Wave Propagation In Wireless Body Area Networks: Design And Evaluation Techniques

Recently, fabrication of miniature electronic devices that can be used for wireless connectivity becomes of great interest in many applications. This has resulted in many small and compact wireless devices that are either implantable or wearable. As these devices are small, the space for the antenna is limited. An antenna is the part of the wireless device that receives and transmits a wireless signal. Implantable and wearable antennas are very susceptible to harmful performance degradation caused by the human body and very difficult to integrate, if not designed properly. A designer need to minimize unwanted radiation absorption by the human body to avoid potential health issues. Moreover, a wearable antenna will be inevitably exposed to user movements and has to deal with influences such as crumpling and bending. These deformations can cause degraded performance or a shifted frequency response, which might render the antenna less effective. The existing wearable and implantable antennas’ topologies and designs under discussion still suffer from many challenges such as unstable antenna behavior, low bandwidth, considerable power generation, less biocompatibility, and comparatively bigger size. The work presented in this thesis focused on two main aspects. Part one of the work presents the design, realization, and performance evaluation of two wearable antennas based on flexible and textile materials. In order to achieve high body-antenna isolation, hence, minimal coupling between human body and antenna and to achieve performance enhancement artificial magnetic conductor is integrated with the antenna. The proposed wearable antennas feature a small footprint and low profile characteristics and achieved a wider -10 dB input impedance bandwidth compared to wearable antennas reported in literature. In addition, using new materials in wearable antenna design such as flexible magneto-dielectric and dielectric/magnetic layered substrates is investigated. Effectiveness of using such materials revealed to achieve further improvements in antenna radiation characteristics and bandwidth and to stabilize antenna performance under bending and on body conditions compared to artificial magnetic conductor based antenna. The design of a wideband biocompatible implantable antenna is presented. The antenna features small size (i.e., the antenna size in planar form is 2.52 mm3), wide -10 dB input impedance bandwidth of 7.31 GHz, and low coupling to human tissues. In part two, an overview of investigations done for two wireless body area network applications is presented. The applications are: (a) respiratory rate measurement using ultra-wide band radar system and (b) an accurate phase-based localization method of radio frequency identification tag. The ultimate goal is to study how the antenna design can affect the overall system performance and define its limitations and capabilities. In the first studied application, results indicate that the proposed sensing system is less affected and shows less error when an antenna with directive radiation pattern, low cross-polarization, and stable phase center is used. In the second studied application, results indicate that effects of mutual coupling between the array elements on the phase values are negligible. Thus, the phase of the reflected waves from the tag is mainly determined by the distance between the tag and each antenna element, and is not affected by the induced currents on the other elements

EVALUATION OF DIGITAL TWIN APPROACHES FOR THERMAL MODELING AND ENERGY OPTIMIZATION FOR EXISTING BUILDINGS

Residential, commercial, and industrial building sectors in the United States were responsible for 42% of the nation’s consumption of 100.2 quadrillion BTUs of energy in 2019 [1]. 80% of the nation’s energy is sourced from fossil fuels, including coal, natural gas, and petroleum. Fossil fuels are known contributors to carbon emissions and climate change, making energy reduction vital. Consequently, New Jersey Department of Military and Veterans Affairs (NJDMAVA) is tasked with evaluating energy consumption and efficiency in all New Jersey Army National Guard (NJARNG) facilities, as mandated by TAG Policy Letter 18-5, Executive Order 13990, and the Energy Independence and Security Act of 2007. This research investigates three building energy consumption modeling (BEM) approaches for colder weather: eQUEST, degree-day modeling, and resistance-capacitance (RC) modeling. Each method has distinct advantages and limitations, but BEM holds promise in identifying cost-effective energy-saving measures, aligning with the goals of government entities like NJDMAVA. Specifically, eQUEST proves valuable for experienced users in energy modeling. Degree-day modeling excels at detecting operational shifts and benchmarking similar facilities. The RC model was able to accurately predict energy savings as a result of changes to thermostat setting