Space-time Relationship Research Articles

Research on modelling of spatial dynamic structural mechanics and spatio-temporal evolution of coal mine stopes

Original scientific paper Major hazardous accidents in coal mines are basically attributable to a lack of understanding of or the failure to establish a complete spatial structural mechanical model of the stope during the course of exploitation, as well as of the spatial movement over time caused by the mining itself, mining at the wrong time, as well as improper roadway maintenance and advance of the work face. To efficiently study and analyze the mechanism behind major stope disasters, a method based on monitoring the stress and displacement of stopes was adopted to deduce the process whereby the overlying strata fracture, and a method of ascertaining stope stability based on qualitative identification of the dynamics was further proposed. The study found that the stability of stopes during the process of mining the face can be divided into two stages: (1) Unstable stage: i.e. the distance the work face has advanced Lx width of work face L0. These research results provide a basis for reasonable determination of a space-time relationship for the mining process.

Determination of Levels of Use of Basic Process Skills of High School Students

It aims to determine the abilities of use of basic process skills of the students and the levels of conceptual learning of the students as oriented to general chemistry topics. The sampling comprises 160 students whose were studying at 10th and 11th grades of seven different high schools in Turkey. The study design is based on Survey model. The questionnaire prepared by considering the levels of conceptualization of chemistry topics of the students aims to measure their ability of use of science process skills. The questions and items were selected in the manner that it covers basic skills such as observation, classification, measurement, the sensing of space-time relationship and communicating, and also classified on the Bloom Taxonomy of cognitive development which consist of knowledge, comprehension, application, analysis, synthesis, and evaluation. The results from analysis of variance (ANOVA) show that. The differences between students’ grade levels, score and order of admission to high school and the type of school have a significantly effect on the potential of use of basic process skills.

Measuring equipment and test bench to control evolution of acoustic-deformation and heat fields induced in solids under failure by fluids

The authors have developed a procedure and a test bench for studying evolution of various nature physical fields in modeling geomedium fracture by fluids. The test bench performs synchronous recording of macro- and micro-deformation, heat and acoustic emission induced in physical models of geomedium under loading to discontinuity. The experimental procedure has been trialed. The analysis of the synchronized test data allows a conclusion on the existence of time–space relationship between different nature physical fields induced during failure of solids.

Mikhail Bakhtin e Manoel de Barros: entre o cronotopo e a infância

RESUMONeste artigo aproximamos a infância, o espaço e o tempo através da literatura e da filosofia. Partimos da leitura que Bakhtin faz das obras de François Rabelais, no contexto do realismos grotesco, e do conceito de cronotopo aí formulado. Bakhtin constrói uma perspectiva filosófica de espaço-tempo aberto e coletivo, de liberdade e criação. A literatura de Manoel de Barros, por sua vez, materializa um cronotopo, afirmando uma visão de mundo e de homem no embate entre sentidos e valores. Chegamos ao entendimento de que os poemas de Barros possuem uma estética particular que se aproxima daquela analisada por Bakhtin. É regida por uma relação espaço-temporal que trabalha com a infância associada à criação, envolvendo o espaço-tempo do inútil e da contemplação, o rebaixamento do olhar, o renascimento e a produção de vizinhanças entre elementos heterogêneos.

Kachchh Mesozoic Domes, Western India: Study of Morphotectono Character and Evolution

Kachchh domes are recognized by the oval to elliptical- shaped outcrop patterns marked by outlines of bedding surfaces which invariably dip in the outward directions. The occurrence of domes in rows without having corresponding basin-like features implies that these are not superposed folds resulting due to constriction- type tectonic forces. Further, in spite of the close time-space relationship, the occurrence of domes is exclusively in the Mesozoic rocks on the uplifted block of the fault. The absence of any such rock formation on the other side of the fault rules out the possibility that these are 'drape folds' developed during the adjustment of the sedimentary blanket over the faulted-up edges of the basement blocks. Hinging on the evidence of intrusive plutonic (mafic) masses in the core of some of the domes, we suggest that the structures evolved through diapiric rise of magma bodies causing dome-shaped up-warping (bending) of the pre-existing (Mesozoic) flat-lying sedimentary formations. Linear disposition of domes is explained as due to channellization of magma along the fractures that developed around large-scale crustal doming during the early phase of the Reunion Plume impingement under the Indian Lithosphere.

The Optimal Configuration of Feeder Switches in DAS Based on Pareto Optimality Solution

In urban radial networks, the feeder is often complex with a main line, branches and even sub-branches. It is necessary to optimize the configuration of automation switching devices in distribution automation system (DAS) to reduce the impact range of power outage and improve the power supply reliability. The interruption frequency and the space-time relationship among the switching devices were ignored in the most of researches. This paper presents a new reliability planning scheme of switching devices in DAS which involves three types of circuit breakers and three types of load switches. The model which target is to get the minimal cost, the lowest average annual interruption frequency and the least interruption duration is built thereby. The constraint is the availability rate of electricity supply of load node. Based on the Pareto optimality theory, the multi-objective differential evolution algorithm is adopted to solve the Pareto front efficiently. The proposed algorithm can provide many optional choices and the final scheme can be chosen based on the situation. Finally, a practical example is used to illustrate the developed scheme.

Using Web Crawler Technology for Geo-Events Analysis: A Case Study of the Huangyan Island Incident

Social networking and network socialization provide abundant text information and social relationships into our daily lives. Making full use of these data in the big data era is of great significance for us to better understand the changing world and the information-based society. Though politics have been integrally involved in the hyperlinked world issues since the 1990s, the text analysis and data visualization of geo-events faced the bottleneck of traditional manual analysis. Though automatic assembly of different geospatial web and distributed geospatial information systems utilizing service chaining have been explored and built recently, the data mining and information collection are not comprehensive enough because of the sensibility, complexity, relativity, timeliness, and unexpected characteristics of political events. Based on the framework of Heritrix and the analysis of web-based text, word frequency, sentiment tendency, and dissemination path of the Huangyan Island incident were studied by using web crawler technology and the text analysis. The results indicate that tag cloud, frequency map, attitudes pie, individual mention ratios, and dissemination flow graph, based on the crawled information and data processing not only highlight the characteristics of geo-event itself, but also implicate many interesting phenomenon and deep-seated problems behind it, such as related topics, theme vocabularies, subject contents, hot countries, event bodies, opinion leaders, high-frequency vocabularies, information sources, semantic structure, propagation paths, distribution of different attitudes, and regional difference of net citizens’ response in the Huangyan Island incident. Furthermore, the text analysis of network information with the help of focused web crawler is able to express the time-space relationship of crawled information and the information characteristic of semantic network to the geo-events. Therefore, it is a useful tool to collect information for understanding the formation and diffusion of web-based public opinions in political events.

Quo Vadis Civitas? – Thoughts on the European Conception of the City Today

The article deals with the change of paradigms in European urban thinking through time. The principles of Modern City Planning of the first half of the 20th century, which despised the classical ideals of the European city and of historical urban environments, as well as the subsequent advent of their counterplot, i.e. the approach of integrated conservation and preservation planning, are seen as the two main opposing tendencies of city development in the last 100 years. They have preceded and prepared the way for a new urban consciousness which puts emphasis on the principles of sustainable development in both global and local terms. While the pressing demands for sustainability have been taken into consideration and even recorded in the law on a certain level in most European countries at the turn of this century, there are still many other new-type urban phenomena which express the present-day tendencies of change in our city-life. The breaking of the traditional space-time relationship due to the arrival of the Internet and the multicultural post-modern urban nomadism, which both go together with a tremendous worldwide economic, social, and environmental restructuration, are among them. As a result, the concept of place has lost its former meaning as an explicitly physical scene. At the same time, mentally, socially and culturally processed issues, such as the identity of a place, have become more and more important putting emphasis on the type of interaction between different people and the places of their lives. Thus the question of dwelling and the expression of multi-cultural identities have become fundamental urban issues. Today in Europe city planning is often less concerned with building new environments than with transforming extant environments and creating interaction and synergy between old and new. Multicultural and tolerant living environments with different historical, social and cultural layers function as magnets for creative people and for inspiring city-life. CV: Kaisa Broner-Bauer is an architect D.Sc. (Tech./Arch.), and professor emerita of Architecture at the University of Oulu, Finland. She has studied and worked in Finland, France, the United States, and Japan and is the author of numerous publications on architecture, historic preservation, and urban studies. Her present research interests include the questions of identity and transcendence in architecture and the built environment.

Using Web Crawler Technology for Text Analysis of Geo-Events: A Case Study of the Huangyan Island Incident

Abstract. With the social networking and network socialisation have brought more text information and social relationships into our daily lives, the question of whether big data can be fully used to study the phenomenon and discipline of natural sciences has prompted many specialists and scholars to innovate their research. Though politics were integrally involved in the hyperlinked word issues since 1990s, automatic assembly of different geospatial web and distributed geospatial information systems utilizing service chaining have explored and built recently, the information collection and data visualisation of geo-events have always faced the bottleneck of traditional manual analysis because of the sensibility, complexity, relativity, timeliness and unexpected characteristics of political events. Based on the framework of Heritrix and the analysis of web-based text, word frequency, sentiment tendency and dissemination path of the Huangyan Island incident is studied here by combining web crawler technology and the text analysis method. The results indicate that tag cloud, frequency map, attitudes pie, individual mention ratios and dissemination flow graph based on the data collection and processing not only highlight the subject and theme vocabularies of related topics but also certain issues and problems behind it. Being able to express the time-space relationship of text information and to disseminate the information regarding geo-events, the text analysis of network information based on focused web crawler technology can be a tool for understanding the formation and diffusion of web-based public opinions in political events.

Early Detection of Terrorism Outbreaks Using Prospective Space–Time Scan Statistics*

Terrorism is a complex phenomenon with high uncertainty involving a myriad of dynamic known and unknown factors. It is and will remain a challenge to predict or detect terrorism outbreaks at an early stage. This research presents an alternative approach for modeling terrorism activity, one that monitors and detects space–time clusters of terrorist incidents using prospective space–time scan statistics. Such clusters provide indicators of potential outbreaks of terrorist incidents. To evaluate the effectiveness of the approach, we analyze the terrorist incidents in the Consortium for the Study of Terrorism and Responses to Terrorism's (START) Global Terrorism Database (GTD) from 1998 to 2004. Clusters of terrorist events are detected at each time stamp and life trajectories of these clusters are constructed based on their space–time relationship to each other. Through the life trajectories and trends of clusters, we demonstrate how space–time scan statistics detect terrorism outbreaks at an early stage.

Application of the numerical manifold method for stress wave propagation across rock masses

SUMMARYIn this paper, the numerical manifold method (NMM) is extended to study wave propagation across rock masses. First, improvements to the system equations, contact treatment, and boundary conditions of the NMM are performed, where new system equations are derived based on the Newmark assumption of the space–time relationship, the edge‐to‐edge contact treatment is further developed for the NMM to handle stress wave propagation across discontinuities, and the viscous non‐reflection boundary condition is derived based on the energy minimisation principle. After the modification, numerical comparisons between the original and improved NMM are presented. The results show that the original system equations result in artificial numerical damping, which can be overcome by the Newmark system equations. Meanwhile, the original contact scheme suffers some calculation problems when modelling stress wave propagation across a discontinuity, which can be solved by the proposed edge‐to‐edge contact scheme. Subsequently, the influence of the mesh size and time step on the improved NMM for stress wave propagation is studied. Finally, 2D wave propagation is modelled, and the model's results are in good agreement with the analytical solution. Copyright © 2013 John Wiley & Sons, Ltd.

A Geospatial Analysis of Shark Attack Rates for the Coast of California: 1994–2010

The subject of this investigation was spatial and spatio-temporal shark attack clusters occurring along California’s coast between 1994 and 2010. Two hypotheses were postulated: (a) Shark attacks are proportionate to human beach activities. (b) No pronounced space-time relationship between human beach activity and shark attacks exists along this coast over time. The hypotheses were tested by using SaTScanTM version 9.1.1, a spatial scan statistic program. The results show that well-defined high- and low-risk areas have prevailed along the coast over the years. Because most attacks in California waters are attributed to white sharks, this animal was used as a model species to discuss the results.

Research on space-time coupling action laws of anchor-cable strengthening supporting for rock roadway in deep coal mine

In order to obtain space-time coupling relationship of anchor-cable to improve supporting effect for deep coal mine rock roadway, FLAC3D was used to investigate into mechanical characteristics of the roadway whose crosssection shape was vertical wall and semi-circular arch when the roadway was supported by bolts and metal mesh. The results show that the extent of stress concentrations, the range failure zone, and the deformation at the roof center and two spandrels of roadway are greater than those at other positions, except at the floor. The reasonable positions of anchor-cable supporting are the roof center and two spandrels of roadway. The anchor-cable should be installed at good time with bolts supporting after roadway driving because it can improve the stress states of deep surrounding rock around the roadway and control the roadway deformation effectively. The engineering practice has proven that the sustained deformation of deep surrounding rocks is effectively controlled when the anchor-cable supporting is adopted at reasonable positions of the roadway at good time.

Command and control cities in global space-economy before and after 2008 geo-economic transition

The global economic downturn caused primarily by the US sub-prime mortgage crisis in 2007 engendered revenue loss of the multinational corporations. Existing studies have yet to depict the detrimental impacts on city’s command and control functions induced by the sub-prime mortgage crisis together with its residual wave of global economic recession on the global spatial economy. Recent and previous studies have produced an ‘instant history’ of the global spatial economy before the global economic downturn undermines the global economy in late 2008. However, the waxes and wanes of major cities’ command and control functions on the global economic arena before and after the outbreak of financial crisis and its associated geo-economic transitions are still poorly understood. This paper attempts to contribute a new set of customized data to update and fill in the gap in the literature with the investigation of the command and control functions of cities around the world from 2005 to 2009. Particular attentions are paid to the time-space relationship of the geo-economic transition that can capture the recent historical images of the command and control situation of different cities in the world.

Application of length vernier in phase coincidence detection and precision frequency measurement

For comparison of arbitrary frequency signals, the paper proposed two levels of length vernier based on the time-space relationship are used in three levels of phase coincidence detecting circuits to extract the phase coincidence information by proper logic calculation. The length∕phase of each vernier is respectively corresponding to the accuracy and the resolution of detecting circuit. The time-space relationship is based on high-stability, high-accuracy, and high-speed of signal transmission. The method is effective to reduce the fuzzy region in the phase coincidence information and reach a higher measuring precision.

Holocene volcanic activity at Grímsvötn, Bárdarbunga and Kverkfjöll subglacial centres beneath Vatnajökull, Iceland

Assessment of potential future eruptive behaviour of volcanoes relies strongly on detailed knowledge of their activity in the past, such as eruption frequency, magnitude and repose time. The eruption history of three partly subglacial volcanic systems, Grimsvotn, Bardarbunga and Kverkfjoll, was studied by analysing tephra from soil profiles around the Vatnajokull ice-cap, which extend back to ~7.6 ka. Well known regional Holocene marker tephra (e.g. H3, H4, H5) were utilized to correlate profiles. Stratigraphic positions and geochemical compositions were used for fine-scale correlation of basaltic tephra. Around Vatnajokull ice-cap 345 tephra layers were identified, of which 70% originated from Grimsvotn, Bardarbunga or Kverkfjoll. The eruption frequency of each volcanic system was estimated; Grimsvotn has been the most active with an average of ~7 eruptions/100 years (range 4–14) during prehistoric time (before ~870 AD); Bardarbunga has been the second most active with ~5 eruptions/100 years (range 1–8); and Kverkfjoll has remained essentially calm with 0–3 eruptions/100 years but showing periodic activity with repose times of >1000 years. All three volcanic systems experienced lulls in activity from 5 ka to 2 ka, referred to as the “Mid-Holocene low”. This reduced eruption frequency appears to have resulted from a decrease in magma generation and delivery from the mantle plume rather than from changes in ice-load/glacier thickness. In prehistoric time, there was a time lag of 1000–3000 years between a peak of activity at volcanoes directly above the mantle plume versus at volcanoes located in the non-rifting part of the Eastern Volcanic Zone, closer to the periphery of the island. This time-space relationship suggests that a significant future increase in volcanism can be expected there, following increased levels of volcanism above the plume.

Potential relationships between atmospheric particulate matter transported by winter monsoons and red tides in the East China Sea

Combining numerical diagnosis from atmospheric science with biogeochemical methods, a model of the potential correlation of monsoons with red tide emergence in the East China Sea is constructed. The model is designed based on an in-depth investigation of the time-space relationship of aerosol and red tide events in the East China Sea from 2005 to 2006, and a continuous monitoring of atmospheric particulates at two stations. The study shows that every red tide event investigated has a close relationship with aerosols coming from the northwest (wind direction in winter) along with subsidence flow. The elemental abundance of total suspended particulate in Hangzhou and Tiantai is different from that of soil background levels, indicating atmospheric particulates there are brought in by winter winds. There is a significant correlation between the content of iron and phosphorous in atmospheric particulates, which mainly exist in binding materials between particulates. In addition, the confined absorption of iron and phosphorous by red tides is related to the intensity of sunlight. These results provide new information regarding the mechanism for the high frequency of red tides in the East China Sea. The results also provide a scientific basis for establishing new pathways for pre-warning and forecasting of red tide disasters.

La globalización de las ciudades. Integración regional desde la gestión local

La globalización ha producido la modificación del espacio local a partir de una nueva articulación de la relación espacio tiempo. Por tanto ha generado espacios y relaciones diferentes a las conocidas, afectando más directamente a aquellas ciudades que por su ubicación geográfica relativa, tamaño y complejidad de sus funciones reciben un impacto más directo del fenómeno. Esta relocalización acarrea diversas consecuencias, pero en particular la instalación de un nuevo escenario con actores visibles y actores virtuales que cruzan con sus decisiones el espacio de la ciudad. Los problemas locales se convierten en problemas globales Como contrapartida, los gobiernos locales deben afrontar esta agenda globalizada con los mismos instrumentos y recursos que disponían cuando su acción se limitaba a los servicios públicos esenciales. En consecuencia aparecen modalidades de integración que suponen nuevos tipos de gestión e interacción construyendo redes sin fronteras, traspasando y rebasando los límites y las potestades institucionales establecidas. A partir de esta perspectiva se formulan las instancias de integración y las nuevas formas de gestión en la que se encuentra inserto el espacio ciudad del municipio de Mendoza en Argentina.

Research Foundation of Rock-Burst Hazard Control for Mining Pattern with No Pillar

In order to effectively prevent the rock burst occurrence for mining patter with no pillar, the reason and its realization condition of rock burst were studied; the stope structure mechanics model with working face mining was built; four phases of rock burst occurrence with mining were proposed; the relationship between rock burst occurrence and abutment pressure law of development was analyzed, time-space coupling relationship of rock burst and its relevant information for rock burst control were obtained.

A Reestruturação da cidade de Salvador: Conflitos e interesses na lógica da centralidade urbana

A partir da metade do século XX, ocorreram transformações políticas e econômicas que influenciaram a urbanização, consequentemente, a produção do espaço urbano em Salvador/BA. Essas mudanças provocaram alterações em sua estrutura urbana, sendo as mais importantes: a constituição de novas relações tempo-espaço, a implantação de hodiernos equipamentos e a redefinição na centralidade urbana, marcando o início do processo de reestruturação urbana e da cidade. Como consequência, atualmente, Salvador apresenta uma estrutura urbana poli(multi) nucleada. Por um lado, esse fenômeno revela a formação de novas áreas centrais, ou seja, “eclodiu” uma multiplicidade de centros e subcentros na cidade; por outro, percebe-se que esses espaços são bastante diferenciados entre si, mormente, no que tange às características sociais e econômicas, por isso também verificamos sua face poli. A constituição dessa nova lógica na centralidade soteropolitana revela nuances diferenciadas nos conflitos e interesses na cidade, que entendemos interferir no processo de produção e reprodução do espaço urbano, sobretudo no que tange à produção de espaços destinados ao consumo.
 
 Abstract 
 
 THE RESTRUCTURATION OF THE CITY OF SALVADOR: CONFLICTS AND INTERESTS IN THE URBAN CENTRALITY LOGIC
 
 After 1950 some economic and political transformations occurred, influencing in the urbanization process of the city of Salvador/BA. These changes provoked some important changes in the urban structure, such as the redefinition of the time-space relationship and the introduction of new equipments, marking the start of urban and city restructuration. The process was produced by the State, among with other agents, and its consequences demonstrate the formation of a new characteristic of the urban structure, understood as the multi(poly)centralité. The current centers are differentiated by the amount and by the interests of the social groups. The olds centers and oters centers had gone through a process of change in its characteristics. The new centers are related to the materiality of the current urban logic and its influences in the city. Due to the social inequality and the high value of the urban ground, the access to market spaces translates conflicts and group interests.