An Immersed Interface Method for the Incompressible Navier-Stokes Equations in Irregular Domains

We present an immersed interface method for the incompressible Navier Stokes equations capable of handling rigid immersed boundaries. The immersed boundary is represented by a set of Lagrangian control points. In order to guarantee that the no-slip condition on the boundary is satisfied, singular forces are applied on the fluid at the immersed boundary. The forces are related to the jumps in pressure and the jumps in the derivatives of both pressure and velocity, and are interpolated using cubic splines. The strength of singular forces is determined by solving a small system of equations at each time step. The Navier-Stokes equations are discretized on a staggered Cartesian grid by a second order accurate projection method for pressure and velocity.Singapore-MIT Alliance (SMA

An Immersed Interface Method for the Incompressible Navier-Stokes Equations

We present an immersed interface algorithm for the incompressible Navier Stokes equations. The interface is represented by cubic splines which are interpolated through a set of Lagrangian control points. The position of the control points is implicitly updated using the fluid velocity. The forces that the interface exerts on the fluid are computed from the constitutive relation of the interface and are applied to the fluid through jumps in the pressure and jumps in the derivatives of pressure and velocity. A projection method is used to time advance the Navier-Stokes equations on a uniform cartesian mesh. The Poisson-like equations required for the implicit solution of the diffusive and pressure terms are solved using a fast Fourier transform algorithm. The position of the interface is updated implicitly using a quasi-Newton method (BFGS) within each timestep. Several examples are presented to illustrate the flexibility of the presented approach.Singapore-MIT Alliance (SMA

Low-complexity transmit diversity scheme using moderate-sized signal constellations

In the conventional space-time coding technique [1], nT radio frequency (RF) chains are employed to transmit signals simultaneously from nT transmit antennas. In this Letter, a lowcomplexity transmit diversity scheme with nT = 2 transmit antennas is proposed. The proposed system employs only one RF chain as well as a low-complexity switch for transmission

Algebraic Differential Fault Analysis on SIMON block cipher

An algebraic differential fault attack (ADFA) is an attack in which an attacker combines a differential fault attack and an algebraic technique to break a targeted cipher. In this paper, we present three attacks using three different algebraic techniques combined with a differential fault attack in the bit-flip fault model to break the SIMON block cipher. First, we introduce a new analytic method that is based on a differential trail between the correct and faulty ciphertexts. This method is able to recover the entire master key of any member of the SIMON family by injecting faults into a single round of the cipher. In our second attack, we present a simplified Grobner basis algorithm to solve the faulty system. We show that this method could totally break SIMON ciphers with only 3 to 5 faults injected. Our third attack combines a fault attack with a modern SAT solver. By guessing some key bits and with only a single fault injected at the round T - 6, where T is the number of rounds of a SIMON cipher, this combined attack could manage to recover a master key of the cipher. For the last two attacks, we perform experiments to demonstrate the effectiveness of our attacks. These experiments are implemented on personal computers and run at very reasonable timin

Conceptualising personal resources on career adaptability

The literature on career adaptation is vast and based on a range of different measurement approaches. The present paper aims to understand the influence of personal resources on career adaptability in terms of concern, control, curiosity, and confidence among graduates. This study is based on an extensive review of past research on personal resources and career adaptability using the career construction theory. To conduct the literature review, we used keywords such as personal resources, emotional intelligence, self-esteem, self-efficacy, and career adaptability. From the literature reviewed, three predictors of career adaptability have been identified. They are emotional intelligence, self-esteem, and self-efficacy. The framework offers a number of propositions, which explain the proposed model of career adaptability among the graduates as predicted by personal resources. Further research is suggested to test and validate the framework provide empirical evidence. Upon model validation, the paper could offer stakeholders to assist and develop graduates’ personal resources in order to increases their career adaptability and then successful in their career path

The mediating role of career decision self-efficacy on the relationship of career emotional intelligence and self-esteem with career adaptability among university students

This study was undertaken to investigate whether career decision self-efficacy (CDSE) could mediate the relationships of career adaptability with emotional intelligence and with self-esteem among university students. Using cluster random sampling, a total of 205 university students aged 22 to 24 years (M age = 23.0, SD = .875) were selected as respondents. The strongest linear relationship was found between CDSE and career adaptability (r = .568, p = .001). Besides CDSE the main predictor of career adaptability (β = .354, p = .000), emotional intelligence (β = .282, p = .000) and self-esteem (β = .145, p = .019) also contributed significantly to career adaptability. CDSE was found to significantly mediate the influences of emotional intelligence and self-esteem on career adaptability. These results suggest that undergraduate students’ emotional intelligence, self-esteem and CDSE are substantially associated with career adaptability, which plays an important role in workforce efficiency and graduates’ employability

Sleeve gastrectomy causes weight-loss independent improvements in hepatic steatosis

Background and Aims: Sleeve gastrectomy (VSG) leads to improvement in hepatic steatosis, associated with weight loss. The aims of this study were to investigate whether VSG leads to weight-loss independent improvements in liver steatosis in mice with diet-induced obesity (DIO); and to metabolically and transcriptomically profile hepatic changes in mice undergoing VSG. Methods: Mice with DIO were treated with VSG, sham surgery with subsequent food restriction to weight-match to the VSG group (Sham-WM), or sham surgery with return to unrestricted diet (Sham-Ad lib). Hepatic steatosis, glucose tolerance, insulin and glucagon resistance, and hepatic transcriptomics were investigated at the end of the study period and treatment groups were compared with mice undergoing sham surgery only (Sham-Ad lib). Results: VSG led to much greater improvement in liver steatosis than Sham-WM (liver triglyceride mg/mg 2.5 ± 0.1, 2.1 ± 0.2, 1.6 ± 0.1 for Sham-AL, Sham-WM and VSG respectively; p = 0.003). Homeostatic model assessment of insulin resistance was improved following VSG only (51.2 ± 8.8, 36.3 ± 5.3, 22.3 ± 6.1 for Sham-AL, Sham-WM and VSG respectively; p = 0.03). The glucagon-alanine index, a measure of glucagon resistance, fell with VSG but was significantly increased in Sham-WM (9.8 ± 1.7, 25.8 ± 4.6 and 5.2 ± 1.2 in Sham Ad-lib, Sham-WM and VSG respectively; p = 0.0003). Genes downstream of glucagon receptor signalling which govern fatty acid synthesis (Acaca, Acacb, Me1, Acly, Fasn and Elovl6) were downregulated following VSG but upregulated in Sham-WM. Conclusions: Changes in glucagon sensitivity may contribute to weight-loss independent improvements in hepatic steatosis following VSG