A Simplified Min-Sum Decoding Algorithm for Non-Binary LDPC Codes

Non-binary low-density parity-check codes are robust to various channel impairments. However, based on the existing decoding algorithms, the decoder implementations are expensive because of their excessive computational complexity and memory usage. Based on the combinatorial optimization, we present an approximation method for the check node processing. The simulation results demonstrate that our scheme has small performance loss over the additive white Gaussian noise channel and independent Rayleigh fading channel. Furthermore, the proposed reduced-complexity realization provides significant savings on hardware, so it yields a good performance-complexity tradeoff and can be efficiently implemented.Comment: Partially presented in ICNC 2012, International Conference on Computing, Networking and Communications. Accepted by IEEE Transactions on Communication

Non-iterative RGB-D-inertial Odometry

This paper presents a non-iterative solution to RGB-D-inertial odometry system. Traditional odometry methods resort to iterative algorithms which are usually computationally expensive or require well-designed initialization. To overcome this problem, this paper proposes to combine a non-iterative front-end (odometry) with an iterative back-end (loop closure) for the RGB-D-inertial SLAM system. The main contribution lies in the novel non-iterative front-end, which leverages on inertial fusion and kernel cross-correlators (KCC) to match point clouds in frequency domain. Dominated by the fast Fourier transform (FFT), our method is only of complexity $\mathcal{O}(n\log{n})$, where $n$ is the number of points. Map fusion is conducted by element-wise operations, so that both time and space complexity are further reduced. Extensive experiments show that, due to the lightweight of the proposed front-end, the framework is able to run at a much faster speed yet still with comparable accuracy with the state-of-the-arts

Does PPP hold for Big Mac price or consumer price index? Evidence from panel cointegration

This paper examines the validity of purchasing power parity (PPP) using CPI and Big Mac prices. The benchmark model, i.e., the OLS method, which does not take nonstationarity into account, rejects the hypothesis of PPP regardless of prices used. We next use the panel cointegration method to consider the nonstationary nature of variables. Estimated results for CPI are mixed. The PPP is rejected when the nominal exchange rate is employed as the dependent variable but is not rejected when the price ratio is used as the dependent variable. By contrast, the PPP is overwhelmingly not rejected when the Big Mac price is used. Last, we remove the production bias and re-examine the same issue by using panel cointegration. The PPP is again decisively rejected when CPI price is used but not for Big Mac price. Accordingly, Big Mac price is more supportive to the validity of PPP than CPI price.Big Mac

Type-Directed Weaving of Aspects for Polymorphically Typed Functional Languages

Incorporating aspect-oriented paradigm to a polymorphically typed functional language enables the declaration of type-scoped advice, in which the effect of an aspect can be harnessed by introducing possibly polymorphic type constraints to the aspect. The amalgamation of aspect orientation and functional programming enables quick behavioral adaption of functions, clear separation of concerns and expressive type-directed programming. However, proper static weaving of aspects in polymorphic languages with a type-erasure semantics remains a challenge. In this paper, we describe a type-directed static weaving strategy, as well as its implementation, that supports static type inference and static weaving of programs written in an aspect-oriented polymorphically typed functional language, AspectFun. We show examples of type-scoped advice, identify the challenges faced with compile-time weaving in the presence of type-scoped advice, and demonstrate how various advanced aspect features can be handled by our techniques. Lastly, we prove the correctness of the static weaving strategy with respect to the operational semantics of AspectFun

The value of D-dimer in the detection of early deep-vein thrombosis after total knee arthroplasty in Asian patients: a cohort study

<p>Abstract</p> <p>Background and purpose</p> <p>The relationship of D-dimer and deep-vein thrombosis (DVT) after total knee arthroplasty (TKA) remains controversial. The purpose of this study was to assess the value of D-dimer in the detection of early DVT after TKA.</p> <p>Methods</p> <p>The measurements of plasma D-dimer level were obtained preoperatively and at day 7 postoperatively in 78 patients undergoing TKA. Ascending venography was performed in 7 to 10 days after surgery. The plasma D-dimer levels were correlated statistically with the venographic DVT.</p> <p>Results</p> <p>Venographic DVT was identified in 40% of patients. High plasma D-dimer level >2.0 μg/ml was found in 68% of patients with DVT and 45% without DVT (P < 0.05). Therefore, high D-dimer level greater than 2.0 μg/ml showed 68% sensitivity, 55% specificity, 60% accuracy, 50% positive predictive rate and 72% negative predictive rate in the detection of early DVT after TKA.</p> <p>Conclusion</p> <p>High plasma D-dimer level is a moderately sensitive, but less specific marker in the detection of early of DVT after TKA. Measurement of serum D-dimer alone is not accurate enough to detect DVT after TKA. Venography is recommended in patients with elevated D-dimer and clinically suspected but asymptomatic DVT after TKA.</p

Managing voiding dysfunction in young men

AbstractVoiding dysfunction is an uncommon condition in young men. With increased understanding of the etiology of chronic lower urinary tract dysfunction, there has been significant improvement in the management of the condition. We have reviewed the current literature and make suggestions about diagnosis, treatment, and further research on this topic. We searched the PubMed database for the management of voiding dysfunction in young men using the following terms: voiding dysfunction, lower urinary tract symptoms, young men, risk factor, urodynamics study, uroflowmetry, magnetic resonance imaging, primary bladder neck obstruction/bladder neck dysfunction, dysfunctional voiding/pseudodyssynergia, impaired detrusor contractility/detrusor underactivity, adrenergic antagonist, transurethral incision, urotherapy, baclofen, and botulinum toxin. Uroflowmetry is an important noninvasive examination for screening young men for possible voiding dysfunction. A videourodynamic study is recommended for patients with low urine flow. Primary bladder neck obstruction and dysfunctional voiding are the two most common diagnoses. α-Adrenergic antagonists and urotherapy are widely used for treating bladder neck obstruction and dysfunctional voiding, respectively. Botulinum toxin A may become a potential therapeutic option in the future. Although the published reports usually included a small number of patients and lacked randomization and a placebo-controlled group, these clinical studies still provide great advances in managing voiding dysfunction in young men. Further well-designed studies are warranted to support optimal management of these conditions

Missions for Executives in Developing an E-Management Platform

Under the impact of internet, many promises of e-management are provided. However, so far, executives are still skeptical in developing e-management platform, the anxieties come from the fact that too many IT developing projects failed. In practice, IT is a specialty which is quite heterogeneous to business management, to achieve e-management makes the issue of integration of these two domains can not be neglected any more. A failed project is by no means the duty of IT team only; it would be the reason that the interaction between IT team and executives is too weak. To reduce the gaps in platform developing, executives have some missions are offered, they are: a. Let IT group understand executives’ business affairs; b. Review architecture of platform; c. Involve to system test. It deserves to assert that, in developing an e-management platform, executives are not just the users, but also a part of developing members