This work presents a new method to compute the GHASH function involved in the Galois/Counter Mode of operation for block ciphers. If X = X1 . . . Xn is a bit string made of n blocks of 128 bits each, then the GHASH function effectively computes X1H n +X2H n−1 + . . . XnH, where H is an element of the binary field F2128 . This operation is usually computed by using n successive multiply-add oper...

Refrigerant leakage from failed braze joints is a multi-billion dollar problem for the global HVAC&R industry. Leaks are typically caused due to mechanical fatigue from extreme pressure cycling, temperature cycling including exposure to freeze/thaw cycles, or vibrational wear induced from rotating electrical machinery. Three tests to accelerate mechanical fatigue were devised to simulate real w...

In this study, a complete evaluation procedure of energy-saving and efficiency improvement for a large-scale hospital retrofit project has been established and successfully validated in Taiwan. The retrofit scheme, in integrating the alternative hot water system, namely, a water source heat pump (WSHP), with the existing HVAC (Heating, Ventilating, and Air-Conditioning) system, enables the capa...

This paper investigates the interaction between supermarket heating, ventilation and air conditioning and refrigeration systems through simulation in EnergyPlus. This interaction has been studied by modelling a generic UK supermarket. The impact on the sum of HVAC and refrigeration energy consumption due to changes in a range of operating conditions was studied. These include the effect of alte...

Faulty operations of Heating, Ventilation and Air Conditioning (HVAC) chiller systems can lead to discomfort for the occupants, energy wastage, unreliability and shorter equipment life. Such faults need to be detected early to prevent further escalation and energy losses. Commonly, data regarding unforeseen phenomena and abnormalities are rare or are not available at the moment for HVAC install...

In this paper, we report, for the first time, experimental results on channel capacity of heating, ventilation, and air-conditioning (HVAC) ducts based on multi-carrier transmission technique and measured channel frequency responses in the 2.4 GHz Industrial, Scientific, and Medical (ISM) band. Experiments using actual synthesized signals through a building HVAC duct system demonstrate the abil...

Even though many approaches have been proposed for automated fault detection and diagnosis of Heating Ventilation and Air Conditioning (HVAC) systems, and advanced maintenance programs, such as preventive and predictive maintenance have been applied for the systems, issuing work orders for corrective maintenance is still a reality. Currently corrective maintenance still accounts for more than 5...

a gas permeation model (coupling model) has been developed which has the flexibility to be used for different membrane module configurations. the aim of this work is to predict the performance of a single stage gas separation process using membranes and provide a comprehensive description of process parameters like flow rates, composition, stage cut and stream pressure. the significant feature ...