A comparison of two neural network schemes for navigation

Neural networks have been applied to tasks in several areas of artificial intelligence, including vision, speech, and language. Relatively little work has been done in the area of problem solving. Two approaches to path-finding are presented, both using neural network techniques. Both techniques require a training period. Training under the back propagation (BPL) method was accomplished by presenting representations of current position, goal position pairs as input and appropriate actions as output. The Hebbian/interactive activation (HIA) method uses the Hebbian rule to associate points that are nearby. A path to a goal is found by activating a representation of the goal in the network and processing until the current position is activated above some threshold level. BPL, using back-propagation learning, failed to learn, except in a very trivial fashion, that is equivalent to table lookup techniques. HIA, performed much better, and required storage of fewer weights. In drawing a comparison, it is important to note that back propagation techniques depend critically upon the forms of representation used, and can be sensitive to parameters in the simulations; hence the BPL technique may yet yield strong results

A comparison of two neural network schemes for navigation

Neural networks have been applied to tasks in several areas of artificial intelligence, including vision, speech, and language. Relatively little work has been done in the area of problem solving. Two approaches to path-finding are presented, both using neural network techniques. Both techniques require a training period. Training under the back propagation (BPL) method was accomplished by presenting representations of (current position, goal position) pairs as input and appropriate actions as output. The Hebbian/interactive activation (HIA) method uses the Hebbian rule to associate points that are nearby. A path to a goal is found by activating a representation of the goal in the network and processing until the current position is activated above some threshold level. BPL, using back-propagation learning, failed to learn, except in a very trivial fashion, that is equivalent to table lookup techniques. HIA, performed much better, and required storage of fewer weights. In drawing a comparison, it is important to note that back propagation techniques depend critically upon the forms of representation used, and can be sensitive to parameters in the simulations; hence the BPL technique may yet yield strong results

A preliminary investigation into the use of alginates for the lifting and enhancement of fingermarks in blood

Recent studies have reported the use of alginate in the lifting and subsequent enhancement of footwear marks in blood. A study was set up to assess the use of such a method in the treatment of fingermarks in blood on a variety of porous, non-porous and semi-porous surfaces. Other variables included ageing of the fingermarks in blood and the application of chemicals prior to or post-alginate lifting. All different variations were compared to direct chemical treatment of the substrate. The results demonstrated that alginate is not compatible with certain substrates (e.g. glass and tile). On substrates that were compatible with alginate (e.g. fabric and paper), the enhanced fingermarks on the alginate cast and the enhanced fingermarks on the post-alginate substrates appeared, overall, inferior compared to direct chemical enhancement without the use of alginate. A further variation using water-based protein stains directly mixed with the alginate appeared to provide enhancement directly on the substrate as well as simultaneous lifting and enhancing the fingermarks in blood on the alginate cast

Colonial Wildlife Conservation and National Parks in Sub-Saharan Africa

Colonial wildlife conservation initiatives in Africa emerged during the late 19th century, with the creation of different laws to restrict hunting as well as with the setting up of game reserves by colonial governments. Key influential figures behind this emergence were aristocratic European hunters who had a desire to preserve African game populations—ostensibly protecting them from settler and African populations—so that elite sports hunting could persevere on the continent. These wildlife conservation measures became more consolidated at the turn of the 20th century, notably due to the 1900 Convention for the Preservation of Animals, Birds and Fish in Africa—an agreement between European imperial powers and their colonial possessions in Africa to improve wildlife preservation measures—and with the establishment of the Society for the Preservation of the Wild Fauna of the Empire in 1903. This Society, made up of aristocrats, hunter-naturalists, and former government officials, used the influence of its members to advocate for greater wildlife conservation measures in Africa. The wildlife preservation agenda of the Society was largely geared around restricting hunting praxis (and land access) for African populations, while elite European hunting was defended and promoted as an imperial privilege compatible with environmental outcomes. Starting in the 1920s, members from the Society played a key role in setting up Africa’s early national parks, establishing a key conservation praxis that would continue into the late colonial and postcolonial periods. After World War II, colonial wildlife conservation influence reached its zenith. African populations were displaced as national parks were established across the continent

Analogical mapping and inference in overlapping networks.

A method for training overlapping feed-forward networks on analogous tasks is extended and analyzed. The learning dynamics of simultaneous (interlaced) training of similar tasks interact at the shared connections of the networks. The output of one network in re-sponse to a stimulus to the other network can be interpreted as an analogical inference. In a similar fashion, the networks can be explicitly trained to map specific items in one domain to specifc items in the other domain. The method has been applied to spatial tasks in a simple environments and to tree structures

The Ambit of Private Arbitration: Limits on Determination under Agreed Dispute Settlement Procedures in Federal Awards and Agreements

Dissertação de Mestrado em Psicologia, área de Psicologia Clínica (Psicopatologia e Psicoterapias Dinâmicas), apresentada à Faculdade de Psicologia e de Ciências da Educação da Universidade de CoimbraO presente estudo visa explorar a relação entre os sintomas de stress pós-traumático e a lesão medular, considerando a eventual influência de variáveis sociodemográficas (sexo, idade, escolaridade, rendimentos), clínicas (quadro clínico, classificação neurológica, tempo de lesão, causa da lesão), psicopatológicas (somatização, obsessões-compulsões, sensibilidade interpessoal, depressão, ansiedade, hostilidade, ansiedade fóbica, ideação paranoide, psicoticismo), das experiências peritraumáticas, do suporte social e do locus de controlo na reabilitação. A amostra é composta por 22 sujeitos com lesão medular em regime de internamento no Centro de Medicina e Reabilitação da Região Centro – Rovisco Pais (CMRRC-RP). Os resultados evidenciam que a idade, a escolaridade, a satisfação com o suporte social (Escala de Satisfação com o Suporte Social) e o locus de controlo (Escala de Locus de Controlo na Reabilitação) funcionam como variáveis dimensionais, com um contributo significativo no desenvolvimento da Perturbação de Stress Pós-traumático.This study aims to explore the relationship between the symptoms of post-traumatic stress and spinal cord injury, considering the possible influence of sociodemographic variables (gender, age, education, income), clinical (clinical, neurological classification, injury time, cause the injury), psychopathology (somatization, obsession-compulsion, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, psychoticism), the peritraumatic experiences, social support and locus of control in rehabilitation. The sample consists of 22 individuals with spinal cord injured that are inpatient at the Centro de Medicina e Reabilitação da Região Centro – Rovisco Pais (CMRRC-RP). The results showed that age, education, satisfaction with social support (Satisfaction with Social Support Scale) and the control locus (Locus of Control in Rehabilitation Scale) work as dimensional variables, with a significant contribution in the development of Posttraumatic Stress Disorder

Deviations in Representations Induced by Adversarial Attacks

Deep learning has been a popular topic and has achieved success in many areas. It has drawn the attention of researchers and machine learning practitioners alike, with developed models deployed to a variety of settings. Along with its achievements, research has shown that deep learning models are vulnerable to adversarial attacks. This finding brought about a new direction in research, whereby algorithms were developed to attack and defend vulnerable networks. Our interest is in understanding how these attacks effect change on the intermediate representations of deep learning models. We present a method for measuring and analyzing the deviations in representations induced by adversarial attacks, progressively across a selected set of layers. Experiments are conducted using an assortment of attack algorithms, on the CIFAR-10 dataset, with plots created to visualize the impact of adversarial attacks across different layers in a network