Nest excavation in social insects is an integral part of a colony’s life cycle. Soil-dwelling colonies build complex systems of narrow underground chambers and tunnels spanning thousands of insect body lengths below the ground. The nest excavation is performed by multiple animals simultaneously and is governed by local interactions of the workers with environment and other workers. The challeng...

This paper introduces a Cartesian impedance control framework in which reaction forces exceeding control authority directly reshape bucket motion during successive excavation passes. This novel approach to excavation results in an iterative process that does not require explicit prediction of terrain forces. This is in contrast to most excavation control approaches that are based on the generat...

BACKGROUND To describe the clinical and optical coherence tomography (OCT) features of focal choroidal excavation in Chinese patients. METHODS Retrospectively, thirty-seven eyes (in 31 patients) that demonstrated focal choroidal excavation on spectral-domain OCT were collected. Their clinical characteristics and other features were also collected and analyzed. RESULTS In total, 42 focal cho...

Bioretention cells are incorporated as part of low impact development LID because of their ability to release influent runoff as exfiltration to the soil or evapotranspiration to the atmosphere. However, little care is taken as to the techniques used to excavate bioretention cells, and there is little concern as to the soil-moisture condition during excavation. Certain excavation techniques and...

Underground utility lines being struck by mechanize d excavators during construction or maintenance operations is a long standing problem. Besides the disruptions to public services, daily life, and commerce, utility strike accidents lead to injuries, fatalities, and property damages that cause significant financial loss. Utility strikes by excavation occur mainly because of the lack of an effe...

Background: Retinal vein pulsation is often absent in glaucoma, but can be induced by applying a graded ophthalmodynamometric force (ODF) to the eye, which is elevated in glaucoma. Aim: To assess whether ODF has a predictive value in determining glaucoma progression. Methods: 75 patients with glaucoma and suspected glaucoma were examined prospectively in 1996, and then re-examined at a mean of ...

This thesis describes an approach to synthesizing plans for robotic excavators. Excavation tasks range from loading a pile of soil to cutting a geometrically described volume of earth— for a trench or foundation footing. The excavation task can be stated in terms familiar to researchers in robotics and artificial intelligence: Transform the world from its current state to another state. Two imp...

Porencephaly was observed in a female cynomolgus monkey (Macaca fascicularis) aged 5 years and 7 months. The cerebral hemisphere exhibited diffuse brownish excavation with partial defects of the full thickness of the hemispheric wall, and it constituted open channels between the lateral ventricular system and arachnoid space. In addition, the bilateral occipital lobe was slightly atrophied. His...

During a typical excavation operation, there is a high risk of inadvertently damaging the existing subsurface utilities. Such incidents cause significant financial loss to the project and can delay or abruptly halt ongoing construction. In many cases, they also pose a life threat and often result in accidental deaths. As a result, constructors are required to protect utility systems during exca...