Spartan Daily, May 7, 1991

Volume 96, Issue 63https://scholarworks.sjsu.edu/spartandaily/8131/thumbnail.jp

Up-to-date Key Retrieval for Information Centric Networking

Information Centric Networking (ICN) leverages in-network caching to provide efficient data distribution and better performance by replicating contents in multiple nodes to bring content nearer the users. Since contents are stored and replicated into node caches, the content validity must be assured end-to-end. Each content object carries a digital signature to provide a proof of its integrity, authenticity, and provenance. However, the use of digital signatures requires a key management infrastructure to manage the key life cycle. To perform a proper signature verification, a node needs to know whether the signing key is valid or it has been revoked. This paper discusses how to retrieve up-to-date signing keys in the ICN scenario. In the usual public key infrastructure, the Certificate Revocation Lists (CRL) or the Online Certificate Status Protocol (OCSP) enable applications to obtain the revocation status of a certificate. However, the push-based distribution of Certificate Revocation Lists and the request/response paradigm of Online Certificate Status Protocol should be fit in the mechanism of named-data. We consider three possible approaches to distribute up-to-date keys in a similar way to the current CRL and OCSP. Then, we suggest a fourth protocol leveraging a set of distributed notaries, which naturally fits the ICN scenario. Finally, we evaluate the number and size of exchanged messages of each solution, and then we compare the methods considering the perceived latency by the end nodes and the throughput on the network links

High-sensitivity troponin T: a potential safety predictive biomarker for discharge from the emergency department of patients with confirmed influenza

The purpose of the study was to analyze the relationship between the high-sensitivity troponin T levels in patients with confirmed influenza virus infection and its severity determined by mortality during the care process. In addition, a high-sensitivity troponin T cut-off value was sought to allow us to a safe discharge from the emergency department. An analytical retrospective observational study was designed in which high-sensitivity troponin T is determined as an exposure factor, patients are followed until the resolution of the clinical picture, and the frequency of mortality is analyzed. We included patients ? 16 years old with confirmed influenza virus infection and determination of high-sensitivity troponin T. One hundred twenty-eight patients were included (96.9% survivors, 3.1% deceased). Mean and median blood levels of high-sensitivity troponin T of survivors were 26.2 ± 58.3 ng/L and 14.5 ng/L (IQR 16 ng/L), respectively, and were statistically different when compared with those of the deceased patients, 120.5 ± 170.1 ng/L and 40.5 ng/L (IQR 266.5 ng/L), respectively, p = 0.012. The Youden index using mortality as the reference method was 0.76, and the cut-off value associated with this index was 24 ng/L (sensitivity 100%, specificity 76%, NPV 100%, PPV 4%) with AUC of 88,8% (95% CI: 79.8?92.2%), p < 0.001. We conclude that high-sensitivity troponin T levels in confirmed virus influenza infection are a good predictor of mortality in our population, and this predictor is useful for safely discharging patients from the emergency department

Performance Evaluation of Distributed Security Protocols Using Discrete Event Simulation

The Border Gateway Protocol (BGP) that manages inter-domain routing on the Internet lacks security. Protective measures using public key cryptography introduce complexities and costs. To support authentication and other security functionality in large networks, we need public key infrastructures (PKIs). Protocols that distribute and validate certificates introduce additional complexities and costs. The certification path building algorithm that helps users establish trust on certificates in the distributed network environment is particularly complicated. Neither routing security nor PKI come for free. Prior to this work, the research study on performance issues of these large-scale distributed security systems was minimal. In this thesis, we evaluate the performance of BGP security protocols and PKI systems. We answer the questions about how the performance affects protocol behaviors and how we can improve the efficiency of these distributed protocols to bring them one step closer to reality. The complexity of the Internet makes an analytical approach difficult; and the scale of Internet makes empirical approaches also unworkable. Consequently, we take the approach of simulation. We have built the simulation frameworks to model a number of BGP security protocols and the PKI system. We have identified performance problems of Secure BGP (S-BGP), a primary BGP security protocol, and proposed and evaluated Signature Amortization (S-A) and Aggregated Path Authentication (APA) schemes that significantly improve efficiency of S-BGP without compromising security. We have also built a simulation framework for general PKI systems and evaluated certification path building algorithms, a critical part of establishing trust in Internet-scale PKI, and used this framework to improve algorithm performance

ME-EM 2014-15 Annual Report

Table of Contents Human-centered Engineering Endowed Department Chair Enrollment & Degrees Graduates Department News Faculty & Staff Alumni Donors Contracts & Grants Patents & Publications Faculty & Staff Directoryhttps://digitalcommons.mtu.edu/mechanical-annualreports/1004/thumbnail.jp

The Fourth Amendment and the INS: An Update on Locating the Undocumented and a Discussion on Judicial Avoidance of Race-Based Investigative Targeting in Constitutional Analysis

This Article identifies and discusses various legal theories being used to avoid consideration of the fourth amendment in the use of arbitrary law enforcement methods, most notably the targeting of racial minorities as suspects. The Article discusses the concept of consensual encounters: the presumption that most law enforcement contacts are voluntary encounters with the targets of the inquiry freely answering questions or consenting to a search. This approach renders it legally unnecessary to determine whether race played an undue part in the encounter. The Article also examines the point at which a seizure occurs, which is often crucial in determining whether the fourth amendment has been observed. It also analyzes whether illegal aliens enjoy the same protections of the fourth amendment as U.S. citizens. The author concludes that under current legal theories, minority group members are disproportionately targeted by law enforcement for interrogation and investigation where there is no reasonable suspicion that they have committed a crime

Health state utilities for metastatic breast cancer

The aim of the study was to obtain United Kingdom-based societal preferences for distinct stages of metastatic breast cancer (MBC) and six common toxicities. Health states were developed based on literature review, iterative cycles of interviews and a focus group with clinical experts. They described the burden of progressive, responding and stable disease on treatment; and also febrile neutropenia, stomatitis; diarrhoea/vomiting; fatigue; hand-foot syndrome (grade 3/4 toxicities) and hair loss. One hundred members of the general public rated them using standard gamble to determine health state utility. Data were analysed with a mixed model analysis. The study sample was a good match to the general public of England and Wales by demographics and current quality of life. Stable disease on treatment had a utility value of 0.72, with a corresponding gain of +0.07 following a treatment response and a decline by 0.27 for disease progression. Toxicities lead to declines in utility between 0.10 (diarrhoea/vomiting) and 0.15 (febrile neutropenia). This study underlines the value that society place on the avoidance of disease progression and severe side effects in MBC. This may be the largest preference study in breast cancer designed to survey a representative general public sample

Desarrollo en Python de una plataforma para la revocación de certificados digitales en VANETs

El proyecto tiene como principal objetivo la implementación de un Servidor de Revocaciones de Certificados Digitales, el cual sea capaz de recibir principalmente peticiones de distintos clientes en las cuales se puede requerir: - La Revocación del Certificado digital de un cliente. - El envío de una CRL a un cliente específico, el cual contendrá la lista de certificados revocados en un momento dado.El otro objetivo fundamental de este proyecto es el estudio y evaluación del Riesgo, un nuevo mecanismo basado en el usuario que permite determinar la aceptación o rechazo de un certificado cuando el cliente se encuentra en estado de desconexión y su lista de certificados revocados está desactualizada. El objetivo en sí es preparar al servidor para ser capaz de tomar todas las estadísticas necesarias para poder calcular el riesgo real existente en el sistema

Chiral Separation of Racemic Mandelic Acid by the Coupling Crystallization Process and Simulated Moving Bed Technology

Chirality is a major concern in the modern pharmaceutical, food and agricultural industries. The importance of enantiopure drugs has risen dramatically in recent years due to FDA regulations requiring that all chiral bioactive molecules must be isolated and tested for the efficacy and safety, and have to be as pure as possible containing a single pure enantiomer. There are essentially three strategies that can be applied to obtain single pure isomers: (a) extraction from plants and animal materials (b) enantio-selective asymmetric synthesis so that only one isomer is formed in the first place, or (c) making a racemate and finding a method for separating the enantiomers. Only few enantiomers exist in nature and most of them are racemates. A highly efficient chiral asymmetric synthesis route would be the ideal situation, but it usually takes about 10-15 years to develop a synthesis recipe. Hence, the best strategy would be to synthesize the drug in racemate form and separate the isomers to produce single pure enantiomer. Among the variety of enantioseparation methods, chromatography and crystallization are the most dominant methods for the recovery of pure enantiomers. However, both methods have limitations. Crystallization cannot obtain enantiopure enantiomers from the racemic compound directly. In SMB, solvent consumption increases exponentially if desired purity requirement is close to 100%. In this work, the coupling of SMB for enrichment followed by direct crystallization is applied for the chiral resolution to circumvent limitations of each method. In order to take advantage of both the processes, SMB chromatography is used for partial enrichment thereby reducing solvent consumption followed by direct crystallization to obtain 100% pure enantiomers. Here, the chiral resolution of mandelic acid as racemic compound was considered to investigate the performance of the hybrid SMB-crystallization process theoretically as well as experimentally. The solubility and metastable zone limit of (R,S)-MA and (R)-MA in water and the crystallization kinetics parameters of (R,S)-mandelic acid and (R)-mandelic acid by optimization of the crystallization model based on the necessary experimental data collected in unseeded cooling batch crystallizers were determined. For the SMB part, the choice of mobile phase and determination of binary competitive equilibrium isotherms parameters of (R,S)-Mandelic acid and the experimental and modeling studies of SMB process have also been accomplished