47527050
Approximability of Combinatorial Problems with Multi-agent Submodular Cost Functions
Abstract— Applications in complex systems such as the Internet have spawned recent interest in studying situations involving multiple agents with their individual cost or utility functions. In this paper, we introduce an algorithmic framework for studying combinatorial problems in the presence of multiple agents with submodular cost functions. We study several fundamental covering problems (Vertex Cover, Shortest Path, Perfect Matching, and Spanning Tree) in this setting and establish tight upper and lower bounds for the approximability of these problems
14475706
Efficiency, Fairness and Competitiveness in Nash Bargaining Games
Recently, [8] defined the class of Linear Nash Bargaining Games (LNB) and obtained combinatorial, polynomial time algorithms for several games in this class. [8] also defines two natural subclasses within LNB, UNB and SNB, which contain a number of natural Nash bargaining games. In this paper we define three basic game theoretic properties of Nash bargaining games: price of bargaining, fairness and full competitiveness. We show that for each of these properties, a game in UNB has this property iff it is in SNB.
16394212
A pharmacogenomic study on the polymorphic gene response to risperidone in schizophrenia patients
Risperidone is a widely used atypical antipsychotic medication, which has currently raised considerable interest in individual differences in patient response to it. Although risperidone is one of the major atypical anti-psychotics, there is a lack of pharmacogenetic studies on it, especially in Asian populations. This paper investigates the relationship between the -1438 A/G polymorphism of 5-HT2A and response to risperidone treatment. In this study, 130 schizophrenia patients were recruited, who were treated with risperidone monotherapy for eight weeks. Clinical response was assessed on the positive and negative syndrome scale (PANSS) on the day of admission and was subsequently assessed after eight weeks following the treatment. The -1438 A/G polymorphism was identified by direct sequencing. The confounding effects of nongenetic factors were estimated and the baseline symptom score was included as a covariate for adjustment. Association tests between genotype and percentage improvement in total PANSS scores, as well as positive symptom scores and negative symptom scores, were performed using analysis of variance (ANOVA). We find no significant differences in response to the treatment in terms of PANSS or subscore improvements among the subgroups according to different genotypes. Further studies on larger groups are planned to confirm the result.
3900881
HxH: a hop-by-hop transport protocol for multi-hop wireless networks
TCP can perform poorly in multi-hop wireless networks due to problems that arise with contention and mobility. Endto-end protocols are at an inherent disadvantage in trying to solve these problems because their feedback loop operates over multiple wireless hops, which makes it difficult to diagnose problems that occur several hops away and hinders their ability to adapt to changing network conditions. In this paper, we design HxH, a hop-by-hop transport protocol that uses credit-based congestion control and reverse ACKs to solve many of the problems observed with TCP. We use a simulation study to demonstrate that our hop-by-hop approach allows HxH to respond quickly to changing network conditions and to exploit the unique characteristics of wireless networks to reduce overhead. We show that HxH greatly increases throughput and improves fairness, as compared to several end-to-end protocols, in both mesh and mobile ad hoc networks.
8970759
Linux kernels as complex networks: A novel method to study evolution
In recent years, many graphs have turned out to be complex networks. This paper presents a novel method to study Linux kernel evolution — using complex networks to understand how Linux kernel modules evolve over time. After studying the node degree distribution and average path length of the call graphs corresponding to the kernel modules of 223 different versions (V1.1.0 to V2.4.35), we found that the call graphs of the file system and drivers module are scale-free small-world complex networks. In addition, both of the file system and drivers module exhibit very strong preferential attachment tendency. Finally, we proposed a generic method that could be used to find major structural changes that occur during the evolution of software systems.
12761861
A Robust Closed-Loop Control Algorithm for Mean Arterial Blood Pressure Regulation
This paper presents an expert body sensor network (BSN) algorithm for autonomous control of mean arterial blood pressure using vasoactive drugs. A robust Proportional Integral Differential (PID) control algorithm based on a statistics model was designated. Extensive simulation results indicated that the light-weighted expert BSN system is robust enough against sensitivity variations and various artificial disturbances.
16738561
Defect-tolerant digital filtering with unreliable molecular electronics
Molecular electronics such as silicon nanowires (NW) and carbon nanotubes (CNT) are considered to be the future computational substrates due to their ultra-high density and superior energy efficiency. However, excessive defects from bottom-up self-assembly fabrication pose a major technological barrier to achieving reliable computing at the molecular scale. Existing solutions targeting absolute correctness introduce high cost and complexity in post-fabrication testing and defect diagnosis. In this paper, we propose a new approach exploiting algorithm level enhancements for defect-insensitive signal processing. By deliberately allowing molecular-scale integrated systems to bear defects, the proposed design framework achieves reliable signal processing while significantly reduces the cost of defect tolerance.