4,175 research outputs found
Army reserve prior service market profile
Only about 28 percent of the 177,023 enlisted losses to the Active Army in FY 1993 either transferred to the Reserve Components (RC) or had completed all of their obligated service and were eligible for reserve service (RE). Of these 48,000 RC and RE losses, 41,000 were in paygrades E4 and E5, the target pool for USAR Troop Program Unit (TPU) prior service recruiting. Only 28 percent of RC and RE E4--E5s had an occupation considered a priority for TPU readiness. A typical Active Army loss to the RC was a single white male E4 from the South census region with almost four years of service. He was a high school graduate in mental group category I-IIIA and had initially entered the Army for a four year term. A typical RE loss was a white male E5 with nine years of service. He was older and more likely to be married with dependents, but was similar in other respects to his RC counterpart. Neither was in a reserve priority occupation. Women made up less than 20 percent of both groups. Blacks were more strongly represented and Hispanics less strongly represented among RC and RE losses than among the comparable civilian population.Fund number: MIPR 7UNPSRSApproved for public release; distribution is unlimited
Space shuttle electromagnetic environment experiment. Phase A: Definition study
Methods for carrying out measurements of earth electromagnetic environment using the space shuttle as a measurement system platform are herein reported. The goal is to provide means for mapping intentional and nonintentional emitters on earth in the frequency range 0.4 to 40 GHz. A survey was made of known emitters using available data from national and international regulatory agencies, and from industry sources. The spatial distribution of sources, power levels, frequencies, degree of frequency re-use, etc., found in the survey, are here presented. A concept is developed for scanning the earth using a directive antenna whose beam is made to rotate at a fixed angle relative to the nadir; the illuminated area swept by the beam is of the form of cycloidal annulus over a sphere. During the beam's sojourn over a point, the receiver sweeps in frequency over ranges in the order of octave width using sweeping filter bandwidths sufficient to give stable readings
Asymptotic information leakage under one-try attacks
We study the asymptotic behaviour of (a) information leakage and (b) adversary’s error probability in information hiding systems modelled as noisy channels. Specifically, we assume the attacker can make a single guess after observing n independent executions of the system, throughout which the secret information is kept fixed. We show that the asymptotic behaviour of quantities (a) and (b) can be determined in a simple way from the channel matrix. Moreover, simple and tight bounds on them as functions of n show that the convergence is exponential. We also discuss feasible methods to evaluate the rate of convergence. Our results cover both the Bayesian case, where a prior probability distribution on the secrets is assumed known to the attacker, and the maximum-likelihood case, where the attacker does not know such distribution. In the Bayesian case, we identify the distributions that maximize the leakage. We consider both the min-entropy setting studied by Smith and the additive form recently proposed by Braun et al., and show the two forms do agree asymptotically. Next, we extend these results to a more sophisticated eavesdropping scenario, where the attacker can perform a (noisy) observation at each state of the computation and the systems are modelled as hidden Markov models
Toward a Broader View of Security Protocols
Computer and network security researchers usually focus on the security of computers and networks. Although it might seem as if there is more than enough insecurity here to keep all of us fully occupied for the foreseeable future, this narrow view of our domain may actually be contributing to the very problems that we are trying to solve. We miss important insights from, and opportunities to make contributions to, a larger world that has been grappling with security since long before the computer was invented
Space shuttle electromagnetic environment experiment. Phase A: Definition study
A program is discussed which develops a concept for measuring the electromagnetic environment on earth with equipment on board an orbiting space shuttle. Earlier work on spaceborne measuring experiments is reviewed, and emissions to be expected are estimated using, in part, previously gathered data. General relations among system parameters are presented, followed by a proposal on spatial and frequency scanning concepts. The methods proposed include a nadir looking measurement with small lateral scan and a circularly scanned measurement looking tangent to the earth's surface at the horizon. Antenna requirements are given, assuming frequency coverage from 400 MHz to 40 GHz. For the low frequency range, 400-1000 MHz, a processed, thinned array is proposed which will be more fully analyzed in the next phase of the program. Preliminary hardware and data processing requirements are presented
Quantitative information flow, with a view
We put forward a general model intended for assessment of system security against passive eavesdroppers, both quantitatively ( how much information is leaked) and qualitatively ( what properties are leaked). To this purpose, we extend information hiding systems ( ihs ), a model where the secret-observable relation is represented as a noisy channel, with views : basically, partitions of the state-space. Given a view W and n independent observations of the system, one is interested in the probability that a Bayesian adversary wrongly predicts the class of W the underlying secret belongs to. We offer results that allow one to easily characterise the behaviour of this error probability as a function of the number of observations, in terms of the channel matrices defining the ihs and the view W . In particular, we provide expressions for the limit value as n → ∞, show by tight bounds that convergence is exponential, and also characterise the rate of convergence to predefined error thresholds. We then show a few instances of statistical attacks that can be assessed by a direct application of our model: attacks against modular exponentiation that exploit timing leaks, against anonymity in mix-nets and against privacy in sparse datasets
Stellenwert der endoskopischen Axilladissektion beim invasiven Mammakarzinom
Zusammenfassung: Grundlagen: Die Axilladissektion liefert zuverlässige prognostische Information, bestimmt mehrheitlich die adjuvante Therapie und reduziert die axillären Tumorrezidive. Die Morbidität nach Axilladissektion kann jedoch nicht vernachlässigt werden (sensible Störungen, Schmerzen, motorische Schwäche, Lymphödem). Patientinnen mit kleinen Tumoren (pT1a, b, c) könnten von neueren weniger invasiven Verfahren (endoskopische Axilladissektion) oder von selektiveren Methoden (Sentinel-lymph-node-Procedere) profitieren. In dieser prospektiven Studie wurde die axilloskopische Lymphadenektomie evaluiert. Methodik: 55 klinisch nodal negative Patientinnen (Durchschnittsalter: 60 Jahre [30 bis 86 Jahre]) wurden von einem Chirurgen endoskopisch operiert (Januar 1996 bis Juni 1998). Nach Liposuktion des axillären Fettkörpers wurden die Lymphknoten von Level I+II identifiziert und unter direkter endoskopischer Sicht reseziert (erfolgreiches Verfahren in 95 %: n=52). Die Patientinnen wurden entsprechend dem Nachsorgeschema alle 4 Monate kontrolliert. Nach einer mittleren Beobachtungszeit von 22 Monaten (7 bis 37 Monate; n=51 [eine Patientin verweigerte die Nachsorge]) wurden die Patientinnen mit einem Evaluationsfragebogen, einem Interview und einer klinischen Untersuchung (inklusiv Schultergelenksfunktion, Zirkumferenzmessungen der oberen Extremität) nachkontrolliert. Ergebnisse: Durchschnittlich wurden 13,3 (5 bis 25) Lymphknoten endoskopisch entfernt. Nodal positive Lymphknoten wurden in 31 % (n=16) beobachtet. Der Durchschnittswert der positiven Lymphknoten/Patientin betrug 3,1 (1 bis 10). Acht Serome (15 %) mußten in der frühpostoperativen Phase punktiert werden. Es traten keine Hämatome, jedoch ein Infekt in der Axilla nach Chemotherapie auf (2 %). Nach einer mittleren Beobachtungszeit von 22 Monaten (7 bis 37 Monate) konnten keine axillären Rezidive nachgewiesen werden. Eine subkutane Implantationsmetastase in der Narbe eines Trokarkanals (1/55, 2 %) wurde diagnostiziert und reseziert. Klinisch traten keine Lymphödeme auf. Die frühe Mobilisation des Schultergelenkes war subjektiv und objektiv gut. Schlußfolgerungen: Die durchschnittlich 13 axilloskopisch entfernten Lymphknoten entsprechen der Anzahl resezierter Lymphknoten bei offener Axilladissektion. Die Morbidität dieses in Evaluation begriffenen Verfahrens ist niedrig. Nach einer mittleren Beobachtungszeit von 22 Monaten wurde ein Implantationsrezidiv im subkutanen Kanal des anterioren Arbeitstrokar nachgewiesen. Eine längere Beobachtungszeit ist nötig, um die Technik empfehlen zu können. Es zeichnet sich ab, daß die endoskopische, axilläre Lymphknotendissektion durch das selektivere Sentinel-lymph-node-Verfahren abgelöst wir
Performance of Solar-Assisted Modified-Open-Front Swine Nurseries
Performance data of two modified-open-front non-mechanically ventilated swine nurseries have shown that solar energy can be effectively utilized to maintain a productive environment within the animal space during cold weather (temperatures as low as -26°C ( - 15 °F). The nurseries feature a monoslope roof design and passive collector panels that also function as warm weather ventilation panels. An active solar-heating system uses a ground-level collector operated in conjunction with an in-floor solar heat distribution and storage system. The nurseries were designed to handle pigs weighing from 7 to 23 kg (15 to 50 lb). An average of 19% of the solar energy incident on the collector was transferred to the floor surface during the heating seasons from October 1980 to January 1982. Season heating costs were approximately 1.0% of the estimated cost to heat the nursery by conventional means
Reviews
Unfinished Tales of Numenor and Middle-earth. J. R. R. Tolkien. Ed. by Christopher Tolkien. Reviewed by Paul H. Kocher.
The Achievement of C.S. Lewis. Thomas Howard. Reviewed by Nancy-Lou Patterson.
The Silmarillion. J.R.R. Tolkien. Ed. by Christopher Tolkien. Reviewed by Thomas M. Egan
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