Informational and entropic - metabolic aspects are strictly intertwined in organisms. An overview of bacterial chemotaxis is presented as a good and simple model to study these issues. In particular, the paper shall f...Informational and entropic - metabolic aspects are strictly intertwined in organisms. An overview of bacterial chemotaxis is presented as a good and simple model to study these issues. In particular, the paper shall focus on the ability of the organism to restore its homeostasis not only from a metabolic point of view but also from an informational point of view. The organism cannot accomplish this task without a good “model” of the environment and without undertaking appropriate actions that will somehow modify it or at least the relation “organism - environment”. Subsequently, the concept of teleonomy is developed as a dynamical trade - off between segregation and openness of the organism both from a thermodynamic and informational point of view.展开更多
A large number of crashes occur on curves even though they account for only a small percentage of a system’s mileage. Excessive speed has been identified as a primary factor in both lane departure and curve-related c...A large number of crashes occur on curves even though they account for only a small percentage of a system’s mileage. Excessive speed has been identified as a primary factor in both lane departure and curve-related crashes. A number of countermeasures have been proposed to reduce driver speeds on curves, which ideally result in successful curve negotiation and fewer crashes. Dynamic speed feedback sign (DSFS) systems are traffic control devices that have been used to reduce vehicle speeds successfully and, subsequently, crashes in applications such as traffic calming on urban roads. DSFS systems show promise, but they have not been fully evaluated for rural curves. To better understand the effectiveness of DSFS systems in reducing crashes on curves, a national field evaluation of DSFS systems on curves on rural two lane roadways was conducted. Two different DSFS systems were selected and placed at 22 sites in seven states. Control sites were also identified. A full Bayes modeling methodology was utilized to develop crash modification factors (CMFs) for several scenarios including total crashes for both directions, total crashes in the direction of the sign, total single-vehicle crashes, and single-vehicle crashes in the direction of the sign. Using quarterly crash frequency as the response variable, crash modification factors were developed and results showed that crashes were 5% to 7% lower after installation of the signs depending on the model.展开更多
基于贝叶斯(Bayesian)理论的相关反馈技术是可有效提高图像检索性能的重要手段之一.然而,当前大多数的Bayesian反馈算法普遍受到小样本问题和训练样本不对称问题的制约.本文提出一种新的相关反馈算法,该算法将查询点移动(query point mo...基于贝叶斯(Bayesian)理论的相关反馈技术是可有效提高图像检索性能的重要手段之一.然而,当前大多数的Bayesian反馈算法普遍受到小样本问题和训练样本不对称问题的制约.本文提出一种新的相关反馈算法,该算法将查询点移动(query point movement,QPM)技术嵌入Bayesian框架中,并采用不对称的学习策略处理正、负反馈信息,故而称之为不对称Bayesian学习(asymmetry Bayesianlearning,ABL).对于正例样本,该算法同时考虑用户提供的正、负反馈信息,并借助QPM技术估计相关语义类图像的概率分布.对于负例样本,采用一种半监督学习机制以应对负例样本稀缺问题.首先,通过随机采样从数据库中选取一组无标记图像,然后,利用QPM技术对其进行数据审计.最后,将审计后的无标记图像作为额外的负例样本,并与用户标记的负反馈信息一起用于估计不相关语义类图像的概率分布.仿真实验及对比结果表明,不对称Bayesian学习策略可显著提高相关反馈的效率,且本文算法的检索性能明显优于当前其它的相关反馈算法.展开更多
文摘Informational and entropic - metabolic aspects are strictly intertwined in organisms. An overview of bacterial chemotaxis is presented as a good and simple model to study these issues. In particular, the paper shall focus on the ability of the organism to restore its homeostasis not only from a metabolic point of view but also from an informational point of view. The organism cannot accomplish this task without a good “model” of the environment and without undertaking appropriate actions that will somehow modify it or at least the relation “organism - environment”. Subsequently, the concept of teleonomy is developed as a dynamical trade - off between segregation and openness of the organism both from a thermodynamic and informational point of view.
文摘A large number of crashes occur on curves even though they account for only a small percentage of a system’s mileage. Excessive speed has been identified as a primary factor in both lane departure and curve-related crashes. A number of countermeasures have been proposed to reduce driver speeds on curves, which ideally result in successful curve negotiation and fewer crashes. Dynamic speed feedback sign (DSFS) systems are traffic control devices that have been used to reduce vehicle speeds successfully and, subsequently, crashes in applications such as traffic calming on urban roads. DSFS systems show promise, but they have not been fully evaluated for rural curves. To better understand the effectiveness of DSFS systems in reducing crashes on curves, a national field evaluation of DSFS systems on curves on rural two lane roadways was conducted. Two different DSFS systems were selected and placed at 22 sites in seven states. Control sites were also identified. A full Bayes modeling methodology was utilized to develop crash modification factors (CMFs) for several scenarios including total crashes for both directions, total crashes in the direction of the sign, total single-vehicle crashes, and single-vehicle crashes in the direction of the sign. Using quarterly crash frequency as the response variable, crash modification factors were developed and results showed that crashes were 5% to 7% lower after installation of the signs depending on the model.
文摘基于贝叶斯(Bayesian)理论的相关反馈技术是可有效提高图像检索性能的重要手段之一.然而,当前大多数的Bayesian反馈算法普遍受到小样本问题和训练样本不对称问题的制约.本文提出一种新的相关反馈算法,该算法将查询点移动(query point movement,QPM)技术嵌入Bayesian框架中,并采用不对称的学习策略处理正、负反馈信息,故而称之为不对称Bayesian学习(asymmetry Bayesianlearning,ABL).对于正例样本,该算法同时考虑用户提供的正、负反馈信息,并借助QPM技术估计相关语义类图像的概率分布.对于负例样本,采用一种半监督学习机制以应对负例样本稀缺问题.首先,通过随机采样从数据库中选取一组无标记图像,然后,利用QPM技术对其进行数据审计.最后,将审计后的无标记图像作为额外的负例样本,并与用户标记的负反馈信息一起用于估计不相关语义类图像的概率分布.仿真实验及对比结果表明,不对称Bayesian学习策略可显著提高相关反馈的效率,且本文算法的检索性能明显优于当前其它的相关反馈算法.
