Harvey J. Miller

Learn More
Hägerstrand’s time geography is a powerful conceptual framework for understanding constraints on human activity participation in space and time. However, rigorous, analytical definitions of basic time geography entities and relationships do not exist. This limits abilities to make statements about error and uncertainty in time geographic measurement and(More)
A method based on acid digestion, hydride evolution atomic absorption spectrophotometry for estimating microgram and submicrogram quantities of As and Se in foods was developed and evaluated. Samples up to 3 g dry weight were digested with HNO3-HCIO4-H2SO4. As and Se in aliquots of the digests were reduced with NaBH4 to volatile hydrides, using(More)
Geographic information systems (GIS) are convenient and potentially powerful platforms for transportation and urban analysis. Most GIS-based tools for transportation and urban analysis continue a place-based representation that is increasingly ill-suited to answer important questions in theory, policy and practice. The increasing disconnection between(More)
Transportation systems exist to improve individual accessibility. However, emerging applications of GIS in transportation (GIS-T) and intelligent transportation system (ITS) focus on throughput (the amount of system flow) rather than accessibility. Throughput is related but not equivalent to accessibility. Sensitive transportation planning requires(More)
A common—perhaps modal—representation of geography in spatial analysis and geographic information systems is native (unexamined) objects interacting based on simple distance and connectivity relationships within an empty Euclidean space. This is only one possibility among a large set of geographic representations that can support quantitative analysis.(More)
Location-based services assist people in their decision-making during the performance of tasks in space. They do not consider the user’s individual preferences, time constraints, and possible subtasks to be performed. In order to account for these important aspects, a user centered spatio-temporal theory of location-based services is required. We propose(More)
The space-time prism (STP) and STP-based accessibility measures are powerful techniques for assessing the ability of individuals to travel and participate in activities at different locations and times in a given environment. However, traditional STPs and STP-based accessibility measures ignore spatial and temporal variations in travel times in an urban(More)
OBJECTIVE Obtaining the 'when, where and why' of healthy bouts of moderate-to-vigorous physical activity (MVPA) provides insights into natural PA. DESIGN In Salt Lake City, Utah, adults wore accelerometer and Global Positioning System (GPS) loggers for a week in a cross-sectional study to establish baseline travel and activity patterns near a planned(More)