4,570 research outputs found
Improved Algorithms for Decremental Single-Source Reachability on Directed Graphs
Recently we presented the first algorithm for maintaining the set of nodes
reachable from a source node in a directed graph that is modified by edge
deletions with total update time, where is the number of edges and
is the number of nodes in the graph [Henzinger et al. STOC 2014]. The
algorithm is a combination of several different algorithms, each for a
different vs. trade-off. For the case of the
running time is , just barely below . In
this paper we simplify the previous algorithm using new algorithmic ideas and
achieve an improved running time of . This gives,
e.g., for the notorious case . We obtain the
same upper bounds for the problem of maintaining the strongly connected
components of a directed graph undergoing edge deletions. Our algorithms are
correct with high probabililty against an oblivious adversary.Comment: This paper was presented at the International Colloquium on Automata,
Languages and Programming (ICALP) 2015. A full version combining the findings
of this paper and its predecessor [Henzinger et al. STOC 2014] is available
at arXiv:1504.0795
On the Regular Behaviour of Orthogonal Polynomials
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135623/1/plms0119.pd
Building Machines That Learn and Think Like People
Recent progress in artificial intelligence (AI) has renewed interest in
building systems that learn and think like people. Many advances have come from
using deep neural networks trained end-to-end in tasks such as object
recognition, video games, and board games, achieving performance that equals or
even beats humans in some respects. Despite their biological inspiration and
performance achievements, these systems differ from human intelligence in
crucial ways. We review progress in cognitive science suggesting that truly
human-like learning and thinking machines will have to reach beyond current
engineering trends in both what they learn, and how they learn it.
Specifically, we argue that these machines should (a) build causal models of
the world that support explanation and understanding, rather than merely
solving pattern recognition problems; (b) ground learning in intuitive theories
of physics and psychology, to support and enrich the knowledge that is learned;
and (c) harness compositionality and learning-to-learn to rapidly acquire and
generalize knowledge to new tasks and situations. We suggest concrete
challenges and promising routes towards these goals that can combine the
strengths of recent neural network advances with more structured cognitive
models.Comment: In press at Behavioral and Brain Sciences. Open call for commentary
proposals (until Nov. 22, 2016).
https://www.cambridge.org/core/journals/behavioral-and-brain-sciences/information/calls-for-commentary/open-calls-for-commentar
Correlates of Serious Suicidal Ideation and Attempts in Female Adult Sexual Assault Survivors
Relations between (a) serious suicidal ideation and attempts and (b) demographics, trauma history, assault characteristics, post-assault outcomes, and psychosocial variables were examined among female adult sexual assault survivors. Younger, minority, and bisexual survivors reported greater ideation. More traumas, drug use, and assault disclosure related to greater attempts, whereas perceived control over recovery was related to fewer attempts. Child sexual abuse and some assault characteristics predicted suicidal behavior. Depression was related to suicidal behavior until psychosocial variables were accounted for. Specifically, using substances to cope and self-blame predicted greater ideation, whereas receiving aid/information support was related to less ideation. Implications for research and treatment are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved
TSD Symptoms and Self-Rated Recovery Among Adult Sexual Assault Survivors: The Effects of Traumatic Life Events and Psychosocial Variables
Prior research has demonstrated that self-blame is predictive of more PTSD symptoms and poorer recovery (Frazier, 2003; Koss, Figueredo, & Prince, 2002), and perceived control over recovery is associated with less distress (Frazier, 2003) in adult sexual assault (ASA) survivors. A structural equation model was tested to examine the role of traumatic events, self-blame, perceived control over recovery, and coping strategies on PTSD symptoms and self-rated recovery in women ASA survivors. Adaptive coping partially mediated the effects of other traumas, self-blame, and perceived control over recovery on PTSD symptoms, and showed a small positive association with increased PTSD symptoms. As hypothesized, maladaptive coping partially mediated the effects of other traumas, self-blame, and perceived control over recovery on both PTSD symptoms and self-rated recovery; greater maladaptive coping was associated with increased PTSD symptoms and lower self-rated recovery. Implications and directions for future research are discussed
Understanding Alcohol-Related Sexual Assaults: Characteristics and Consequences
Sexual assaults commonly involve alcohol use, but little is known about alcoholâs effects on many aspects of assaults and their aftermath. We investigated characteristics of victims, perpetrators, and assaults as a function of whether alcohol was involved in the assault, as well as differences in womenâs post-assault experiences. Assaults prior to which only perpetrators were drinking differed not only from non-alcohol-related assaults, but also from those prior to which both perpetrators and victims were drinking. Understanding the effects of alcohol-related assaults is important for identifying victims who should be targeted for mental health and substance use interventions
Prospective Effects of Sexual Victimization on PTSD and Problem Drinking
Posttraumatic stress disorder (PTSD) and problem drinking are common and often co-occurring sequelae experienced by women survivors of adult sexual assault, yet it remains unclear whether survivors drink to cope with PTSD symptoms or whether PTSD symptoms are exacerbated by drinking. Thus, we used a cross-lagged panel design with a large (N = 555), ethnically diverse sample of women assault survivors to determine whether PTSD prospectively led to problem drinking or vice versa. We also examined whether cumulative sexual victimization experiences related to greater PTSD and problem drinking. Structural equation modeling revealed that child sexual abuse was associated with greater symptoms of PTSD and problem drinking and intervening sexual victimization was associated with greater symptoms of PTSD and problem drinking 1 year later. We found no evidence, however, that PTSD directly influenced problem drinking over the long term, or vice versa. Rather, experiencing revictimization during the study predicted survivorsâ prospective PTSD and problem drinking symptoms. Implications and recommendations for future research are discussed
Vulnerability and Protective Factors for Sexual Assault
Approximately 1 in 5 women experience sexual assaults in adulthood during their lives (see Post, this volume, for review), including experiences of unwanted sexual contact, sexual coercion, attempted rape, and completed rape that result from threat, force, or incapacitation from alcohol or drugs (either willingly or unwillingly consumed)
Prospective Changes In Attributions Of Self-Blame And Social Reactions To Womenâs Disclosures Of Adult Sexual Assault
The present longitudinal study examined relations between self-blame attributions and social reactions to disclosure in a community sample of adult sexual assault victims (N = 555). Cross-lagged panel analyses showed that neither characterological self-blame nor behavioral self-blame related to negative social reactions over the 1-year follow-up period. In contrast, characterological but not behavioral self-blame predicted fewer positive reactions over time. Although positive reactions did not reduce self-blame, negative reactions led to greater characterological, but not behavioral, self-blame during the course of the study. Thus, relations between self-blame and social reactions were not reciprocal but rather quite complex. The effects of victimsâ coping strategies and sexual revictimization were also assessed. Implications for research, treatment, and intervention are discussed
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