An adaptive hierarchical matrix on point iterative Poisson solver

In this paper, an adaptive hierarchical matrix (H-matrix) points iterative method based solution was proposed to solve two-dimensional Poisson problem with Dirichlet boundary condition. The finite difference approximation was used to discretize the problem, which led to a system of linear equation. Two types of admissibility conditions, standard and weak, produces two different H-matrix structures, HS- and HW- respectively. The adaption of the H-matrices to a linear system leads to the saving of memory utilization. An experiment was conducted which compares the proposed HW-matrix with the benchmarked HS-matrix. The results showed the superiority of the proposed method when comparing both H-matrix structures

Asymptotic Loss in Privacy due to Dependency in Gaussian Traces

The rapid growth of the Internet of Things (IoT) necessitates employing privacy-preserving techniques to protect users' sensitive information. Even when user traces are anonymized, statistical matching can be employed to infer sensitive information. In our previous work, we have established the privacy requirements for the case that the user traces are instantiations of discrete random variables and the adversary knows only the structure of the dependency graph, i.e., whether each pair of users is connected. In this paper, we consider the case where data traces are instantiations of Gaussian random variables and the adversary knows not only the structure of the graph but also the pairwise correlation coefficients. We establish the requirements on anonymization to thwart such statistical matching, which demonstrate the significant degree to which knowledge of the pairwise correlation coefficients further significantly aids the adversary in breaking user anonymity.Comment: IEEE Wireless Communications and Networking Conferenc

A Potentially Disastrous Life -Threatening Complication of Emergency Tube Thoracostomy in A Simple Case of Spontaneous Pneumothorax

Emergency tube thoracostomy carries risks of infective and technical complications. The aseptic technique is essential to prevent infections, while blunt dissection method can minimise the associated technical complications. Preparation and adherence to protocols as well as appropriate knowledge and skills, however, are of utmost importance to reduce risks of complications. Physicians must have adequate knowledge of anatomy and the procedure to ensure for accurate site tube placement without any complication. This case illustrates how a failure to appropriately use the instrument resulted in a displaced scalpel blade inside the thoracic cavity. It caused an unnecessary thoracotomy for blade retrieval. The mishap escalated a simple procedure to the potentially disastrous life-threatening event

Lifetime Analysis on Centrifugal ID Fan Foundation in Cement Plants

The dynamic behavior of centrifugal ID fan foundation of cement plants to perform the lifetime analysis was investigated in this study. To this end, a three-dimensional (3D) finite-element model (FEM) of this foundation was proposed and the analyses under static and dynamic loads for various modulus of elasticity of concrete (Ec= 20, 25, 28 and 30 GPa) and reinforcement (Es= 200, 250, 300 GPa) and rotor speeds of 400, 800, 1200, and 1800 rounds per minute (rpm) were conducted.The results show that the stress and deflection for a certain ID fan is around 2.5 and 10 times more under dynamic loading compared to static loading. Therefore, the excessive vibrations induced by increased speed of ID fan can result in reduced lifetime and fatigue of the foundation. Comparison of FEM results with laboratory-based evidence verified the accuracy of simulations made by the FEM. The proposed model can thus be applied to determine the critical points in foundation structure in order to obtain optimum results of design parameters

The Effects of Zeolite X and Y on Cancer Cell Lines

Zeolites are hydrated silicates of aluminium that have been very useful in many industry because of its microporous property, absorbance ability and ion exchange capacity. It is currently viewed as a potential adjuvant in cancer therapy due to its ability to inhibit the proliferation of cancer cells. Research on natural zeolite clinoptilolite application as anticancer agent has been proven by others. However, the effect of other types of zeolite on cancer cells is still uncertain. This study is performed to determine the effects of zeolite X and Y on cancer cell lines proliferation in vitro. Cancer cell lines HeLa, AsPC-1 and 911 cells were cultured in designated medium treated with zeolite X and zeolite Y at the concentration of 5 mg/ml and 50 mg/ml. Fetal Bovine Serum (FBS) concentrations were modified to 5%, 10%, 15% and 20%. After 72 hours incubation, the efficacy of zeolite to treat cancer cell lines were measured by means of cell viability test via MTT assay. Overall results showed that cancer cell lines cultivated in the medium treated with 50 mg/ml of zeolite X and 5% FBS exhibited the highest inhibition of cell proliferation and decrease in cell viability. This finding provides preliminary information in the study of determining the potential use of zeolite as anticancer agent for alternative or complementary therapy