In view of the fact that most of the synthetic refrigerants, in case of leakage or release, are harmful to the environment by contributing in global warming or depleting stratospheric ozone layer, many research works have been done recently to find alternative refrigerants posing no or negligible threat to the environment.
Among alternative refrigerants, ammonia, a natural refrigerant with zero Global Warming Potential (GWP) and Ozone Depletion Potential (ODP), can be a sensible choice.Although ammonia has been used for many years in large industrial systems, its application in small units is rare.
In this project a small heat pump with about 7 kW heating capacity at -5 °C and +40 °C evaporation and condensation temperatures is designed and built to work with ammonia as refrigerant. The heat pump is expected to produce enough heat to keep a single-family house warm in Sweden and to provide tap hot water for the house.
After successful completion of this project, it is planned to install the heat pump in a house to test it throughout a heating season to study its performance in real working conditions. Since ammonia is flammable and toxic in high concentrations, the refrigerant charge is tried to be kept low in the heat pump to reduce the risk of fire or poisoning in case of unwanted release of refrigerant to the surroundings. The compact design of the heat pump helps reducing the refrigerant charge. Besides, considering the limited space normally reserved for installation of a heat pump in a house, the compact design of the heat pump is necessary.
Source: KTH
Author: A Monfared, Behzad
Source: KTH
Author: A Monfared, Behzad
Accurate measurements from sensors measuring the vehicle’s lateral behavior are vital in today’s vehicle dynamic control systems such as the Electronic Stability Program (ESP). This thesis concerns accurate plausibilisation of two of these sensors, namely the yaw rate sensor and the lateral acceleration sensor.
The estimation is based on Kalman filtering and culminates in the use of a 2 degree-of-freedom nonlinear two-track model describing the vehicle lateral dynamics. The unknown and time-varying cornering stiffnesses are adapted while the unknown yaw moment of inertia is estimated.
The Kalman filter transforms the measured signals into a sequence of residuals that are then investigated with the aid of various change detection methods such as the CuSum algorithm. An investigation into the area of adaptive thresholding has also been made.
The change detection methods investigated successfully detects faults in both the yaw rate and the lateral acceleration sensor. It it also shown that adaptive thresholding can be used to improve the diagnosis system. All of the results have been evaluated on-line in a prototype vehicle with real-time fault injection.
Source: Linköping University
Author: Wikström, Anders
Source: Linköping University
Author: Wikström, Anders
Speech Recognition is the process of converting spoken input to digital output, such as text. Speech recognition systems provide computers with the ability to listen to user speech and determine what is said.
The Speech Recognition process can be divided into these four steps:
- Speech is converted to digital signals.
- Actual speech sounds are extracted from the sounds (based on energy of the sounds).
- The extracted sounds are put together into ‘speech frames.’
- The speech frames are compared with words from the grammar file to determine the spoken word.
Project Description:
In this project, we will be designing a simple shopping mall using object oriented technology. The mall will provide a soothing shopping experience for customers, while at the same time allowing us to explore design patterns and other features object oriented technology.
In this project, we will be designing a simple shopping mall using object oriented technology. The mall will provide a soothing shopping experience for customers, while at the same time allowing us to explore design patterns and other features object oriented technology.
The requirements:
The system will allow more than one shop owner to set up different shops, to sell various products under one roof i.e. mall. The concept, at its very basic, provides for an environment that allows the following:
The system will allow more than one shop owner to set up different shops, to sell various products under one roof i.e. mall. The concept, at its very basic, provides for an environment that allows the following:
• Shop Owner:
o Any person wishing to setup shop in the mall can send a proposal to the mall owner.
o The mall owner approves the proposal and confirms the deal.
o Shop owners can then setup and maintain their own shop(s) in the Mall.
o Any person wishing to setup shop in the mall can send a proposal to the mall owner.
o The mall owner approves the proposal and confirms the deal.
o Shop owners can then setup and maintain their own shop(s) in the Mall.
• Customers:
o Customers when enter the mall have to authenticate themselves on a central server.
o After authentication, the customer is allocated a shopping cart and can enter a particular shop of his/her choice for shopping.
o After entering a shop, customer can brows through the products available in the shop, can select some of them and put into the shopping cart.
o Customer can anytime change the items in the cart either by adding new items or by removing existing items. Customer proceeds towards the payment counter. Finalize product list of items he finally wish to buy and make the final payment.
o He/She then leaves the shop and can either enter another shop or leave the mall.
o Customers when enter the mall have to authenticate themselves on a central server.
o After authentication, the customer is allocated a shopping cart and can enter a particular shop of his/her choice for shopping.
o After entering a shop, customer can brows through the products available in the shop, can select some of them and put into the shopping cart.
o Customer can anytime change the items in the cart either by adding new items or by removing existing items. Customer proceeds towards the payment counter. Finalize product list of items he finally wish to buy and make the final payment.
o He/She then leaves the shop and can either enter another shop or leave the mall.
• The prototype presented allows customers to purchase products from all the shops in the Mall
Source: IITB
Authors: Kamlesh Laddhad | Akshay Ukey
Source: IITB
Authors: Kamlesh Laddhad | Akshay Ukey
Thanks to advances in wide-area network technologies and the low cost of computing resources, Grid computing came into being and is currently an active research area. One motivation of Grid computing is to aggregate the power of widely distributed resources, and provide non-trivial services to users. To achieve this goal, an efficient Grid scheduling system is an essential part of the Grid. Rather than covering the whole Grid scheduling area, this survey provides a review of the subject mainly from the perspective of scheduling algorithms. In this review, the challenges for Grid scheduling are identified.
First, the architecture of components involved in scheduling is briefly introduced to provide an intuitive image of the Grid scheduling process. Then various Grid scheduling algorithms are discussed from different points of view, such as static vs. dynamic policies, objective functions, applications models, adaptation, QoS constraints, strategies dealing with dynamic behavior of resources, and so on. Based on a comprehensive understanding of the challenges and the state of the art of current research, some general issues worthy of further exploration are proposed.
Source: Queen’s University
Author: Fangpeng Dong and Selim G. Akl
Source: Queen’s University
Author: Fangpeng Dong and Selim G. Akl
In modern times mobile devices are a increasing technology and malicious users are increasing as well. On a mobile device it often exist valuable private information that a malicious user is interested in and it often has lower security features implemented compared to computers. It is therefore important to be aware of the security risks that exist when using a mobile device in order to stay protected.
In this study information about what security risks and attacks that are possible to execute towards a mobile device running Android will be presented. Possible attack scenarios are attacking the device itself, the communication between the device and a server and finally the server.
Source: Linnaeus University
Author: Andersson, Gustaf
Source: Linnaeus University
Author: Andersson, Gustaf
The main objective of this work is to collaborate with the Service Composition Tool investigation in the School of Mathematics and Systems Engineering technology at Växjö University.
The school is focusing its efforts in the software engineering technology. Presently one of the most promising ways to improve the software development is to look at various possible solutions to create advanced systems, based in adaptive code theory, that are able to make decisions without the aid of a human user.
These advanced systems will be able to change their behavior in function of several extern parameters or conditions. We will collaborate to that target, investigating the Aspect oriented Programming paradigm as a possible tool, implementing an adaptive code application using different technologies. We will then compare them so as to determine which one could help us create this kind of systems.
Source: Växjö University
Author: Galindo, Noel
Source: Växjö University
Author: Galindo, Noel
