A scale-adjusted measure of “Urban sprawl” using nighttime satellite imagery

“Urban Sprawl” is a growing concern of citizens, environmental organizations, and governments. Negative impacts often attributed to urban sprawl are traffic congestion, loss of open space, and increased pollutant runoff into natural waterways. Definitions of “Urban Sprawl” range from local patterns of land use and development to aggregate measures of per capita land consumption for given contiguous urban areas (UA). This research creates a measure of per capita land use consumption as an aggregate index for the spatially contiguous urban areas of the conterminous United States with population of 50,000 or greater. Nighttime satellite imagery obtained by the Defense Meteorological Satellite Program's Operational Linescan System (DMSP OLS) is used as a proxy measure of urban extent. The corresponding population of these urban areas is derived from a grid of the block group level data from the 1990 U.S. Census. These numbers are used to develop a regression equation between Ln(Urban Area) and Ln(Urban Population). The ‘scale-adjustment’ mentioned in the title characterizes the “Urban Sprawl” of each of the urban areas by how far above or below they are on the “Sprawl Line” determined by this regression. This “Sprawl Line” allows for a more fair comparison of “Urban Sprawl” between larger and smaller metropolitan areas because a simple measure of per capita land consumption or population density does not account for the natural increase in aggregate population density that occurs as cities grow in population. Cities that have more “Urban Sprawl” by this measure tended to be inland and Midwestern cities such as Minneapolis-St. Paul, Atlanta, Dallas-Ft. Worth, St. Louis, and Kansas City. Surprisingly, west coast cities including Los Angeles had some of the lowest levels of “Urban Sprawl” by this measure. There were many low light levels seen in the nighttime imagery around these major urban areas that were not included in either of the two definitions of urban extent used in this study. These areas may represent a growing commuter-shed of urban workers who do not live in the urban core but nonetheless contribute to many of the impacts typically attributed to “Urban Sprawl”. “Urban Sprawl” is difficult to define precisely partly because public perception of sprawl is likely derived from local land use planning decisions, spatio-demographic change in growing urban areas, and changing values and social mores resulting from differential rates of international migration to the urban areas of the United States. Nonetheless, the aggregate measures derived here are somewhat different than similar previously used measures in that they are ‘scale-adjusted’; also, the spatial patterns of “Urban Sprawl” shown here shed some insight and raise interesting questions about how the dynamics of “Urban Sprawl” are changing.     

Simultaneous performance achievement via compensator blending

In this paper we consider the problem of designing a state-feedback controller that simultaneously achieves different optimality criteria defined on different input-output pairs. Precisely, if r “optimal” target transfer functions are given (as the result of local “optimal” controllers), it is shown that (under mild assumptions) there exists a unique controller capable of replicating these transfer functions in the closed-loop system, so simultaneously achieving the performances inherited by the chosen local transfer functions. An explicit and constructive procedure (we refer to such procedure as “compensator blending”) is provided. The possibility of designing a stable blending compensator or the generalization to dynamic local controllers or time varying systems are also discussed. We finally consider the dual version of the problem, precisely, we show how to achieve simultaneous optimality by filter blending.     

Landslide identification and classification by object-based image analysis and fuzzy logic: An example from the Azdavay region (Kastamonu, Turkey)

This study presents a data-driven and semiautomatic classification system carried out by object-based image analysis and fuzzy logic in a selected landslide-prone area in the Western Black Sea region of Turkey. In the first stage, a multiresolution segmentation process was performed using Landsat ETM+ satellite images of the study area. The model was established on 5235 image objects obtained by the segmentation process. A total of 70 landslide locations and 10 input parameters including normalized difference vegetation index, slope angle, curvature, brightness, mean band blue, asymmetry, shape index, length/width ratio, gray level co-occurrence matrix, and mean difference to infrared band were considered in the analyses. Membership functions were used to classify the study area by five fuzzy operators such as “and”, “or”, “mean arithmetic”, “mean geometric”, and “algebraic product”. In order to assess the performances of the so-produced maps, 700 image objects, which were not used in the model, were taken into consideration. Based on the results, the map produced by “fuzzy and” operator performed better than those classified by the other fuzzy operators. The proposed methodology applied in this study may be useful for decision makers, local administrations, and scientists interested in landslides. It may also be useful in landslide-prone areas for planning, management, and regional development purposes.     

Access(ing), habits, attitudes, and engagements: Re-thinking access as practice

Government efforts to universalize access have resulted in narrow constructions of access as ownership of technology. This article posits a more substantive dialogue of access, one that goes beyond connectivity issues, to consider how the “practice of access” influences technology-use, examining attitudes and ideas about communication and computing technologies. Looking at one effort to address the digital divide in a technology camp for middle school students, I argue that access is practice and that if we examine the “practice of access” in our classrooms and in our research, we look not at the technology but at the practices—what gets reinforced, valued, and rewarded by local communities. The “practice of access” is a more useful way of understanding how social and economic infrastructures mediate access. In this way, access is re-cast as a mutable practice that is influenced by real, everyday practices.     

Manifold topological multi-resolution analysis method

In this paper, two significant weaknesses of locally linear embedding (LLE) applied to computer vision are addressed: “intrinsic dimension” and “eigenvector meanings”. “Topological embedding” and “multi-resolution nonlinearity capture” are introduced based on mathematical analysis of topological manifolds and LLE. The manifold topological analysis (MTA) method is described and is based on “topological embedding”. MTA is a more robust method to determine the “intrinsic dimension” of a manifold with typical topology, which is important for tracking and perception understanding. The manifold multi-resolution analysis (MMA) method is based on “multi-resolution nonlinearity capture”. MMA defines LLE eigenvectors as features for pattern recognition and dimension reduction. Both MTA and MMA are proved mathematically, and several examples are provided. Applications in 3D object recognition and 3D object viewpoint space partitioning are also described.     

Fast estimation of slopes of linear and quasi-linear structures in noisy background, using Fourier methods

We present a fast algorithm for slope detection on gray scale images, based on 2D Fourier transform and standard filters; this may be used for line or edge detection. Our approach is based on the calculation of “energy” per direction of the image, thus obtaining the “energy spectrum on slope” (θ). This exhibits local maxima at the points where θ equals the slopes of linear or quasi-linear segments within the image, yet it is not affected by their position within it. The process thus outlined has certain advantages as regards its efficiency of linear structure detection, compared to the Radon and Hough transforms. It was motivated by the study of astrophysical images (solar dynamic radio spectra) which necessitated the introduction of a method for fast extraction of “drifting structures”, since they appear as linear or quasi-linear segments on these spectra.     

How to predict very large and complex crystal structures

Evolutionary crystal structure prediction proved to be a powerful approach in discovering new materials. Certain limitations are encountered for systems with a large number of degrees of freedom (“large systems”) and complex energy landscapes (“complex systems”). We explore the nature of these limitations and address them with a number of newly developed tools.For large systems a major problem is the lack of diversity: any randomly produced population consists predominantly of high-energy disordered structures, offering virtually no routes toward the ordered ground state. We offer two solutions: first, modified variation operators that favor atoms with higher local order (a function we introduce here), and, second, construction of the first generation non-randomly, using pseudo-subcells with, in general, fractional atomic occupancies. This enhances order and diversity and improves energies of the structures. We introduce an additional variation operator, coordinate mutation, which applies preferentially to low-order (“badly placed”) atoms. Biasing other variation operators by local order is also found to produce improved results. One promising version of coordinate mutation, explored here, displaces atoms along the eigenvector of the lowest-frequency vibrational mode. For complex energy landscapes, the key problem is the possible existence of several energy funnels - in this situation it is possible to get trapped in one funnel (not necessarily containing the ground state). To address this problem, we develop an algorithm incorporating the ideas of abstract “distance” between structures. These new ingredients improve the performance of the evolutionary algorithm USPEX, in terms of efficiency and reliability, for large and complex systems.     

The study of tactile feeling and It's expressing vocabulary

Tactile feeling is an important sense of people's use of products in our daily life. However, how people express and verbalize their tactile feeling has hardly been systematically studied. Thus, the purpose of this study is to investigate how people describe their tactile feeling and how this expression will be affected by visual experience. To achieve the purpose a focus interview was conducted for this study. A set of 51 samples of various textures based on a literature review and a pilot study was prepared as reference stimuli in the interview to evoke respondents' tactile feeling and experience. Six blind and 5 blindfolded respondents were recruited for the interview. In each interview session the respondent was guided and encouraged by the interviewer to exhaustively describe his/her tactile feeling on freely touching the reference samples only, without the aid of vision. The Kawakita Jiro method (KJ method) then was used to sort, classify and analyze the collected vocabularies of tactile feeling. The results showed that the expressed vocabularies of tactile feeling can be classified into five dimensions: “objective/measurable”, “evaluative/aesthetic”, “social status and positions”, “emotional” and “interface quality”. Among them, vocabularies of “objective/measurable” and “interface quality” were the most frequently mentioned by respondents, while those of the “evaluative/aesthetic” were the least. The expressed vocabularies between the blind and the blindfolded respondents were also found to be significantly different in the five dimensions.     

Robotic vocabulary building using extension inference and implicit contrast

TWIG (“Transportable Word Intension Generator”) is a system that allows a robot to learn compositional meanings for new words that are grounded in its sensory capabilities. The system is novel in its use of logical semantics to infer which entities in the environment are the referents (extensions) of unfamiliar words; its ability to learn the meanings of deictic (“I,” “this”) pronouns in a real sensory environment; its use of decision trees to implicitly contrast new word definitions with existing ones, thereby creating more complex definitions than if each word were treated as a separate learning problem; and its ability to use words learned in an unsupervised manner in complete grammatical sentences for production, comprehension, or referent inference. In an experiment with a physically embodied robot, TWIG learns grounded meanings for the words “I” and “you,” learns that “this” and “that” refer to objects of varying proximity, that “he” is someone talked about in the third person, and that “above” and “below” refer to height differences between objects. Follow-up experiments demonstrate the system's ability to learn different conjugations of “to be”; show that removing either the extension inference or implicit contrast components of the system results in worse definitions; and demonstrate how decision trees can be used to model shifts in meaning based on context in the case of color words.     

Applying the technology acceptance model in a study of the factors affecting usage of the Taiwan digital archives system

The rapid development of information and communication technology and the popularization of the Internet have given a boost to digitization technologies. Since 2001, The National Science Council (NSC) of Taiwan has invested a large amount of funding in the National Digital Archives Program (NDAP) to develop digital content. Some studies have indicated that most respondents had no confidence in particular digital archive websites. Thus, with the Technology Acceptance Model (TAM) as a theoretical basis, the focus of the present study was to identify the factors influencing usage. Extension of the roles of perceived playfulness and interface design was also explored to identify the reasons that digital archives might not be accepted by some users. The present study used a random sampling method to distribute questionnaires to digital archive users via e-mail. The Structural Equation Modeling (SEM) method was used to verify the appropriateness of the study model and whether the hypotheses were confirmed. Study results indicated that the “interface design” is an important factor that influences people to use the digital archives, and that it is separate from the “human factor” and the “human–computer interface” (HCI). Moreover, the results showed that HCI had a significant impact on the “perceived ease of use” and on “usage intentions.” However, the human factor interface showed a significant impact only on “perceived ease of use.” With respect to the hypotheses regarding “usage intentions,” the “perceived usefulness,” “perceived ease of use,” “attitude,” and “perceived playfulness” were not related to “usage intentions.” Therefore, it is necessary to consider the quality of interface design in the development of digital archives in order to promote usage.     

The effect of an information ethics course on the information ethics values of students - A Chinese guanxi culture perspective

The development of information technology has a significant influence on social structure and norms, and also impacts upon human behavior. In order to achieve stability and social harmony, people need to respect various norms, and have their rights protected. Students’ information ethics values are of critical and radical importance in achieving this goal. Using qualitative approach, the present study utilizes Kohlberg’s CMD model to measure improvement in students’ “information ethics values” through “technology mediated learning (TML)” models, and to assess the extent to which it is influenced by gender and Chinese guanxi culture. We find that while e-learning improves female students’ “respect rules,” “privacy,” “accessibility” and “intellectual property” values more than male students, the percentages relating to “intellectual property” for females in the higher stages remain lower than for males. Moreover, these results are interpreted from a Chinese guanxi culture perspective. In light of these results, educators should take account of such improvements when designing effective teaching methods and incentives.     

Monte Carlo simulations of the 2d-Ising model in the geometry of a long stripe

The two-dimensional Ising model in the geometry of a long stripe can be regarded as a model system for the study of nanopores. As a quasi-one-dimensional system, it also exhibits a rather interesting “phase behavior”: At low temperatures the stripe is either filled with “liquid” or “gas” and “densities” are similar to those in the bulk. When we approach a “pseudo-critical point” (below the critical point of the bulk) at which the correlation length becomes comparable to the length of the stripe, several interfaces emerge and the systems contains multiple “liquid” and “gas” domains. The transition depends on the size of the stripe and occurs at lower temperatures for larger stripes. Our results are corroborated by simulations of the three-dimensional Asakura–Oosawa model in cylindrical geometry, which displays qualitatively similar behavior. Thus our simulations explain the physical basis for the occurrence of “hysteresis critical points” in corresponding experiments.     

Feminism asks the “Who” questions in HCI

In this brief personal essay, I describe some of the ways that feminism has influenced my life as a researcher and practitioner in HCI and CSCW - in the creation of work to be read by others, in the critical reading of works that were created by others, and in the planning and framing of practical work in enterprise workplaces. I discuss three variations of “Who” questions that feminism helps us to ask in HCI: The “who” of the identity of the user; the “who” of the identity of organizational actors; and the “who” of the practitioner or researcher.     

Investigation of effects of virtual reality environments on learning performance of technical skills

Practical training is what brings imagination and creativity to fruition, which relies significantly on the relevant technical skills needed. Thus, the current study has placed its emphasis on strengthening the learning of technical skills with emerging innovations in technology, while studying the effects of employing such technologies at the same time. As for the students who participated in the study, technical skills had been cultivated in the five dimensions of knowledge, comprehension, simulation, application, and creativity, in accordance to the set teaching objectives and the taxonomy for students learning outcome, while the virtual reality learning environment (VRLE) has also been developed to meet different goals as the various technical skills were being examined. In terms of the nature of technology, operation of machines, selection of process parameters, and process planning in technical skills, VRLE has also designed the six modules of “learning resource”, “digital content”, “collaborative learning”, “formative evaluation”, “simulation of manufacturing process”, and “practical exercise” in particular for providing students with assistance in the development on their technical skills on a specific, gradual basis. After assessing the technical skills that have been developed for the time period of one semester, the students have reported finding VRLE to be a significantly effective method when considering the three dimensions of “operation of machines”, “selection of process parameter”, and “process planning”, though not so much so when it came to the dimension of “nature of technology”. Among the six modules, “simulation of manufacturing process” and “practical exercise” were the two that were most preferred by students for the three dimensions considered.     

Volume discounting coordinates a supply chain effectively when demand is sensitive to both price and sales effort

In this paper, we use a simple and parsimonious model to investigate the performance of volume discounting schemes (hereafter “[VD]”) in a supply chain where the market demand is sensitive to both retail price “p” and sales effort “e” — hereafter called a “(p,e)-channel.” The problem is analyzed as a manufacturer-leading Stackelberg game. We first present, for the deterministic-system-parameter situation, contract-designing procedures under two contract formats; namely, a “regular” version of [VD] (hereafter “[RVD]”) and a “continuous” version of [VD] (hereafter “[CVD]”). Our solutions show that [RVD] cannot perfectly coordinate this (p,e)-sensitive channel; moreover, very often [RVD] leads to a lower channel efficiency than the simple price-only contract. In contrast, we show that [CVD] leads to perfect channel coordination — a significant result since most contract formats have been shown in the literature to be unable to coordinate a (p,e)-channel. Next, we consider the more realistic situations in which the manufacturer is uncertain about one of the system parameters — specifically, either the market size “a” or the effort cost “η”. Our results show that, if Manu is uncertain about a, [RVD] becomes useless but the manufacturer can still use [CVD] to benefit himself. When the manufacturer is uncertain about η, [CVD] remains useful (as expected); however, surprisingly, [RVD] can outperform [CVD] when both the mean value and the uncertainty of η are sufficient high. These results underline the necessity of evaluating a contract format under various forms of system-parameter uncertainties — often at the expense of analytical tractability.     

Tubing the Future: Participatory Pedagogy and YouTube U in 2020

Our vision for the future of composition focuses on the “tube” and the culture inspired by online video sharing. Understanding composition in 2020 requires further theorizing about the participatory practices occurring in online video culture. Based on practices found on the platform YouTube, we turn to the term “tubing” to explain phenomena taking place there, and we put forward the concept of “participatory pedagogy” that we see emerging in 21st century classrooms. The ubiquitous and historically loaded “tube” (noun) and its YouTube-specific counterpart “tubing” (verb), explain many of the shifts taking place as acts of writing expand to include participation in online video sharing. Other scholars have forwarded the notion of “postpedagogy” (Vitanza, 1991; Davis, 2000; Arroyo, 2003, 2005; Rickert, 2007), which places a high value on invention, encourages the playful, yet serious linking of disparate historical figures, and opens up new pathways that we see as working in tandem with what George Siemens (2005) called a “pedagogy of participation,” an offshoot of what Henry Jenkins named “participatory culture” (2009). Using tubing as a guiding metaphor, we develop our version of “participatory pedagogy” for 2020 by focusing on the propagation of Internet memes and the inventional possibilities found in the everyday practices of video culture, which create an historical archive, an untapped repository of cultural patterns, and a light yet ruthlessly public demand for participation.     

The relative effects of positive interdependence and group processing on student achievement and attitude in online cooperative learning

This study investigated the effects of positive interdependence and group processing on student achievement and attitude in online learning. Students in three university courses received initial instruction about teamwork skills and cooperative learning and were randomly assigned to one of three treatment groups in each course. The “positive interdependence” and the “group processing” groups received subsequent associated skills training. The “no structure” control group received no additional training. Following the treatment, the “positive interdependence” groups had significantly higher achievement than the “group processing” or the “no structure” groups. There was no significant difference among any of the three groups on student attitude.     

Contending with Terms: “Multimodal” and “Multimedia” in the Academic and Public Spheres

Scholars have begun naming and defining terms that describe the multifaceted kinds of composing practices occurring in their classrooms and scholarship. This paper analyzes the terms “multimedia” and “multimodal,” examining how each term has been defined and presenting examples of documents, surveys, web sites and others to show when and how each term is used in both academic and non-academic/industry contexts. This paper shows that rather than the use of these terms being driven by any difference in their definitions, their use is more contingent upon the context and the audience to whom a particular discussion is being directed. While “multimedia” is used more frequently in public/industry contexts, “multimodal” is preferred in the field of composition and rhetoric. This preference for terms can be best explained by understanding the differences in how texts are valued and evaluated in these contexts. “Multimodal” is a term valued by instructors because of its emphasis on design and process, whereas “multimedia” is valued in the public sphere because of its emphasis on the production of a deliverable text. Ultimately, instructors need to continue using both terms in their teaching and scholarship because although “multimodal” is a term that is more theoretically accurate to describe the cognitive and socially situated choices students are making in their compositions, “multimedia” works as a gateway term for instructors and scholars to interface with those outside of academia in familiar and important ways.     

A test for determining systems with “mixed” small gain and passivity properties

“Mixedness” is a property that captures elements of the notions of passivity and small gain. In the frequency domain, a linear, time-invariant system is called “mixed” if, over some frequency bands, it is strictly passive and, over the remaining frequencies, it has a gain of less than one; there exist no frequencies over which the system has neither of the notions of these properties associated with it. In this paper, a test is developed for determining whether or not a linear, time-invariant system is “mixed”.