Spatiotemporal Path Research Articles

The Appraisal of Low-Carbon Development to Cities along the Yangtze River

The 28 cities in the upper, middle and lower reaches of the Yangtze River can be regarded as an epitome of the cities in eastern, central and western China. Therefore, the low-carbon development level of the cities along the Yangtze River objectively reflects the overall development degree and regional difference of Chinese low-carbon cities. On the basis of analyzing and understanding the connotation of low-carbon cities, this thesis sets up the appraisal index system of low-carbon cities, puts forward the concept of low-carbon index, and conducts a cluster analysis and appraisal to the low-carbon indexes of 28 cities along the Yangtze River through a spatio-temporal path.

Inferring Infection-Spreading Links in an Air Traffic Network

The objective of this paper is to present a network-based optimization method for identifying links in an air traffic network responsible for carrying infected passengers into previously unexposed regions. The required data include individual infection reports (i.e., when the disease was first reported in a region), travel pattern data, and other geographic properties. The network structure is defined by nodes and links, which represent regions (cities, states, countries) and travel routes, respectively. The proposed methodology is novel in its attempt to replicate an outbreak pattern atop a transportation network by exploiting regional infection data. The problem parallels a related problem in phylodynamics, which uses genetic sequencing data to reconstruct the most likely spatiotemporal path of infection.

Dynamic expression patterns of ECM molecules in the developing mouse olfactory pathway

Olfactory sensory neuron (OSN) axons follow stereotypic spatio-temporal paths in the establishment of the olfactory pathway. Extracellular matrix (ECM) molecules are expressed early in the developing pathway and are proposed to have a role in its initial establishment. During later embryonic development, OSNs sort out and target specific glomeruli to form precise, complex topographic projections. We hypothesized that ECM cues may help to establish this complex topography. The aim of this study was to characterize expression of ECM molecules during the period of glomerulogenesis, when synaptic contacts are forming. We examined expression of laminin-1, perlecan, tenascin-C, and CSPGs and found a coordinated pattern of expression of these cues in the pathway. These appear to restrict axons to the pathway while promoting axon outgrowth within. Thus, ECM molecules are present in dynamic spatio-temporal positions to affect OSN axons as they navigate to the olfactory bulb and establish synapses.

ラオス首都近郊農村におけるＧＰＳ・ＧＩＳを利用した村落住民の生活行動調査

Many time-allocation studies have adopted questionnaires (activity diaries) or direct observation of informants. However, it is difficult to use questionnaires in rural areas of developing countries due to problems such as illiteracy, the fact that few people possess a watch, and the lack of place names in many rural and wild areas. Direct observation also has limitations because it is not possible to obtain information from many informants simultaneously. We developed a new survey method combining interviews with the use of GPS and GIS. The procedures are as follows. (1) Each informant is asked to carry a wristband GPS receiver for an entire day. The GPS unit records information related to the spatio-temporal aspects of the informant's activities. (2) After 24 hours of GPS, recording is completed; then the data are stored and represented visually using GIS software (ArcView 9.1). The investigator works out the shape of the spatio-temporal path of each informant by mapping tracking points with time information. (3) Subsequently, as GPS data reveals almost nothing about the content of activities, the investigator interviews each informant to clarify details of activities: what activity was carried out, at what time, where, and with whom. We conducted the survey in Dongkhuwaai Village, which is located about 30km from Vientiane, the capital of Laos. The daily activities of villagers consist mainly of a combination of subsistence agriculture, fishing, hunting, and gathering. By carrying out this survey, in which 138 villagers participated, it was verified that the new survey method has the following merits. (1) Using GPS improves the accuracy of spatio-temporal data. (2) GPS data can be easily correlated with satellite images and map data, which enables us to consider people's daily activities in combination with various geographical phenomena. (3) Investigators can obtain information outlining an informant's activities from GPS data before conducting interviews, thereby improving the efficiency of interviews.

A GIS Framework for Spatio-temporal Analysis and Visualization of Laboratory Mice Tracking Data

Knowing the locations and spatio-temporal paths of individual mice is an essential prerequisite for behavioral analysis of large groups of laboratory mice. Traditional observations have been carried out by trained humans who are able to distinguish more than fifty behavioral patterns. This is a tedious labor limited with respect to length of observation time. In this paper we propose a tracking solution based on the integration of GIS and RFID (Radio Frequency Identification) technology to automatically collect 24h/7days of movement data. Appropriate cage design and antenna placement are discussed. A software solution is presented to facilitate the recording (JerryTS), visualization, and analysis (TOM) of mice movements.

Statistical Scattering Model in Urban Propagation Environment

A statistical scattering model for mobile radio channels that has the following three features is proposed: 1) the effective scattering area (ESA) is expressed by an ellipse, the center of which is the mobile station (MS) location; 2) the major axis of the ellipse runs parallel along the street where the MS is located; and 3) the scattering power density function around the MS is expressed by a combination of two Laplacian distributions in which the standard deviations are different. To verify the proposed model and obtain realistic values for the model parameters, the spatiotemporal path data observed at a base station (BS) were measured using a 2.2-GHz band in a macrocell scenario (BS antenna height is 60 m) in a typical urban area. The scattering positions are detected from the path information such as the azimuth arrival angle and path length, assuming a single bounce. The spatial distribution of the scattering power is analyzed using principal component analysis. The results showed the ESA to be the anticipated ellipse with the major and minor axes of approximately 210 and 120 m, respectively (axis ratio: approximately 1.7). Furthermore, the power profiles that are projected for each axis of the ellipse can be approximated as Laplacian distributions. Finally, simplification of the proposed model is discussed

Neuronal Networks: Flip-Flops in theBrain

Neuronal activity can rapidly flip-flop between stable states. Although these semi-stable states can be generated through interactions of neuronal networks, it is now known that they can also occur in vivo through intrinsic ionic currents.

The resonant retina: Exploiting vibration noise to optimally detect edges in an image

We show that, far from being a drawback, the ubiquitous presence of random vibrations in vision systems operating from mobile devices can advantageously be used as a fundamental tool for edge detection. Directly inspired by biology, the concept of dynamic retina uses the random spatiotemporal path, traced by a moving receptor that samples the image over time, as the basis for the edge detection operation. We propose a simple mathematical formalization of the dynamic retina concept that shows that the relevant information needed for edge detection is contained in the modulation of the variance of the output signal delivered by the retina. Based on a sequence of observations, we then use a variance estimator to determine the presence of the image edges. Following again a biological inspiration, more specifically focusing on neuron dynamics, we introduce a threshold type estimator and use its local asymptotic normality to optimize, via the Cramer-Rao relation, the value of the threshold. The optimal threshold value coincides with a maximum of the associated Fisher information and the overall process can therefore be directly interpreted as a stochastic resonance. We end our contribution by reporting some simple experimental illustrations.

Identity, Survival, and Sortal Concepts

In cases of purported identity through time for members of natural kinds, the orthodox viewpoint is that there must be a principle whereby 'a' and 'b' can be located on a single continuous spatio-temporal path, and thereby be identified as stages of the same continuant particular. In addition, it is commonly assumed that the identification of 'a' and 'b' must be 'sortalcovered' i.e., they must be identified not just as stages of 'the same thing', but of'the samef' where 'f' is the appropriate natural kind concept. Following from this, it is assumed that a particular cannot change from being a member of one natural kind to being a member of another, without contravening the conditions under which its identity holds. In this article, I will challenge each of these claims, but firstly I will elaborate on the dominant theory by considering it in its most explicit form, as described by David Wiggins

Identification of Spatiotemporal Paths of Spread and Backwash

Geographical AnalysisVolume 15, Issue 4 p. 318-329 Free Access Identification of Spatiotemporal Paths of Spread and Backwash Shaul Krakover, Shaul Krakover I wish to express my thanks to Derek Thompson and Avinoam Meir for their help and comments. Shaul Krakover is lecturer in geography, Ben-Gurion University, Israel.Search for more papers by this author Shaul Krakover, Shaul Krakover I wish to express my thanks to Derek Thompson and Avinoam Meir for their help and comments. Shaul Krakover is lecturer in geography, Ben-Gurion University, Israel.Search for more papers by this author First published: October 1983 https://doi.org/10.1111/j.1538-4632.1983.tb00790.xCitations: 23 Shaul Krakover is lecturer in geography, Ben-Gurion University, Israel. I wish to express my thanks to Derek Thompson and Avinoam Meir for their help and comments. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume15, Issue4October 1983Pages 318-329 ReferencesRelatedInformation