Context aware building energy management system with heterogeneous wireless network architecture

Energy wastage in buildings is to be minimized to reduce the carbon footprint of electricity. Wireless sensor and actor networks (WSAN) have been providing solutions for effective energy management within buildings. In this paper, we present a decisive server based context aware energy management system for smart buildings through Cyber Physical System (CPS) models. A layered architecture for building energy management is proposed to enhance scalability of the system. Heterogeneous wireless network based multiple radio gateway is proposed and implemented to make the system more adaptive to different applications catering to variable data rates. A smart room test bed is deployed in the IIT Hyderabad campus, where the decisive server collects various physical parameters through sensors, and based on the context generates wireless control messages to power electronics based actuators. Integrating context awareness into the system increases the efficiency in terms of energy savings and was observed to be significant, around 30%. The paper also presents a detailed analysis on the turnaround time required to realise the real saving after recovering investments. Applications are developed to integrate smart phones and tabloids providing web enablement to the end user. In this paper, each of the sensors and actuators in the smart room are associated with a state machine, which enables modelling of the system using Hybrid automata for future scope of applications

Classical open lumbar laminectomy and discectomy for disc herniations among manual labourers in India

Background: Lumbar disc herniations are most common at L4/5 and L5/S1 levels and this is most prevalent condition among manual laborers. The aim of the study to analyze the clinical presentation, age and sex distribution, immediate postoperative complications and long-term complications/recurrence of symptoms and to formulate recommendations to avoid complications and recurrence of symptoms.Methods: This is a retrospective study which includes 250 patients operated for lumbar disc herniations at L4/5 and L5/S1 levels. A detailed history of presenting complaints, clinical examination and corresponding findings on imaging are correlated. In all these patients, there was severe symptomatology with failed conservative management which necessitated classical open lumbar laminectomy and discectomy. These patients were followed for a period of 5 to 10 years.Results: Assessment of outcome was done using the modified Macnab criteria. The overall success rate was 96% in our series. Post operatively, 9.2% of them experienced localized low back pain which is mild to moderate and being treated with NSAIDS and exercises. 2.4% developed residual disc herniation or hypertrophic fibrotic scar at the operated site which needed surgical intervention. 2% developed spondylolysis and spondylolesthesis at the level of previous surgery, and 4.4% developed adjacent disc herniations.Conclusions: The overall success rate was 96% in our series. In addition to removal of herniated disc other compressing elements like hypertrophied Ligamentumflavum, facet arthropathy and narrowed spinal canal diameter are also addressed with open procedure. To prevent later complications, these patients are supposed to avoid strenuous work, lifting weights, torsion and jerky movements, faulty posture at work and rest, gait training, crouching, sitting on the floor and haunches

Analytical Model of Relay Node Integrating IEEE 802.15.4 MAC and Energy Conserving State Behaviour

Accurate relay node model for a generic topology of multi-hop networks is still unsolved problem in the Wireless Sensor Networks (WSN) arena. Even though there are lot of multi-hop models in the literature, there is still a lot of scope for improvement in these relay node models to achieve endto-end reliability and delay optimizing energy. In this paper a state behavioural relay node model is developed integrating IEEE 802.5.4 MAC and energy conserving states like Sleep, Idle-Listen and Active-Tx using three dimensional Markov chain framework. Novel window of reference is introduced into relay nodes to decide the wake up strategies and to improve performance of the network. Hence developed model is a combination of asynchronous and periodic protocols which is first in it’s kind of nature. Developed emulation model of the MAC confirms the performance improvement with 95% confidence level. Analysis proves that random anycast routing with proposed duty cycle model extends network lifetime with efficient load sharing among all relay nodes and reduce overall active duration of a node

Real Time Wireless Air Pollution Monitoring system

Air pollution has significant influence on the concentration of constituents in the atmosphere leading to effects like global warming and acid rains. To avoid such adverse imbalances in the nature, an air pollution monitoring system is utmost important. This paper attempts to develop an effective solution for pollution monitoring using wireless sensor networks (WSN) on a real time basis namely real time wireless air pollution monitoring system. Commercially available discrete gas sensors for sensing concentration of gases l ike CO 2 , NO 2, CO and O 2 are calibrated using appropriate calibration technologies. These pre - calibrated gas sensors are then integrated with the wireless sensor motes for field deployment at the campus and the Hyderabad city using multi hop data aggregatio n algorithm. A light weight middleware and a web interface to view the live pollution data in the form of numbers and charts from the test beds was developed and made available from anywhere on the internet. Other parameters like temperature and humidity w ere also sensed along with gas concentrations to enable data analysis through data fusion techniques. Experimentation carried out using the developed wireless air pollution monitoring system under different physical conditions show that the system collects reliable source of real time fine - grain pollution data

Modified IEEE 802.15.4 MAC with Integrated State Behaviour Model for High Density Traffic IoT Applications

The IEEE 802.15.4 standard has received considerable attention as low data rate and low power protocol for wireless sensor network (WSN) applications. The applications include industry, control, home automation, health-care, and smart grids thereby en- abling Internet of Things (IoT). Applications like IoT can deliver better performance by utilizing the scalable multi-hop networks. Multi-hop networks for above applica- tions demand reliable, timely and energy efficient communications. IEEE 802.15.4 have poor performance in terms of power consumption, reliability and delay. This performance can be improved by closely coupling medium access control (MAC) with network parameters in real time. It is instrumental to tune the IEEE 802.15.4 param- eters to enhance the network lifetime and improve the quality of service experienced by the applications running on top of the network. There is scope of improvement for the existing IEEE 802.15.4 multi-hop network models in the literature for below men- tioned aspects in realizing an accurate generalized multi-hop model that can greatly enhance the performance of the dense traffic