首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Ground stability is a major concern for land use planning and both natural and anthropogenic risk assessment, especially in urbanized areas. Space‐borne differential radar interferometry provides a unique tool able to give a synoptic view of ground deformation with centimetric to millimetric vertical precision. Approaches for combining a wide range of radar images such as the permanent scatterers (PS) technique allow the estimation of the deformation history of single buildings. The PS approach has been exploited to investigate a test site particularly exposed to ground deformation hazards, namely the iron mining basin in Lorraine (France). In this Letter, a specific focus was set on the case of Roncourt, where precursor signs of a collapse affecting an area of ~300×300?m2 have been identified.  相似文献   

2.
Abstract

This study aims to evaluate the accuracy of location (x, y and z) using a Magellan GPS NAV 1000 receiver. The position of a known reference point was compared with 50 fix points measured in two-dimensional (2D) mode (x, y) and with 50 fix points measured in three-dimensional (3D) mode (x, y and z).

The mean errors and the root mean square errors (RMSE) in the Euclidian distances between the reference point and the measured fix points were 17·9?m and 20·0?m respectively for the 2D measurements, and 25·7?m and 34·8?m respectively for the 3D measurements. The mean error in elevation was 0·2?m and the corresponding RMSE was 39·1?m. The study indicates a significant difference in the total error (Euclidian distance) between points obtained with different signal qualities and different geometric qualities. The error in the Euclidian distance never exceeded 44·0?m using 2D mode, which suggests that the Magellan GPS NAV 1000 receiver should be a useful supportive tool for many remote sensing applications.  相似文献   

3.
Most empirical studies of open source software repositories focus on the analysis of isolated projects, or restrict themselves to the study of the relationships between technical artifacts. In contrast, we have carried out a case study that focuses on the actual contributors to software ecosystems, being collections of software projects that are maintained by the same community. To this aim, we defined a new series of workload and involvement metrics, as well as a novel approach— $\widetilde{\mathbf{T}}$ -graphs—for reporting the results of comparing multiple distributions. We used these techniques to statistically study how workload and involvement of ecosystem contributors varies across projects and across activity types, and we explored to which extent projects and contributors specialise in particular activity types. Using Gnome as a case study we observed that, next to coding, the activities of localization, development documentation and building are prevalent throughout the ecosystem. We also observed notable differences between frequent and occasional contributors in terms of the activity types they are involved in and the number of projects they contribute to. Occasional contributors and contributors that are involved in many different projects tend to be more involved in the localization activity, while frequent contributors tend to be more involved in the coding activity in a limited number of projects.  相似文献   

4.
This study investigates connections between usability efforts and organizational factors. This is an important field of research which so far appears to be insufficiently studied and discussed. It illustrates problems when working with software engineering tasks and usability requirements. It deals with a large company that manufactures industrial robots with an advanced user interface, which wanted to introduce usability KPIs, to improve product quality. The situation in the company makes this difficult, due to a combination of organizational and behavioural factors that led to a “wicked problem” that caused conflicts, breakdowns and barriers. Addressing these problems requires a holistic view that places context in the foreground and technological solutions in the background. Developing the right product requires communication and collaboration between multiple stakeholders. The inclusion of end users, who fully understand their own work context, is vital. Achieving this is dependent on organizational change, and management commitment. One step to beginning this change process may be through studying ways to introduce user-centred design processes.  相似文献   

5.
Abstract

While the potentially crucial role of information technology in the development of Third World countries has been widely prescribed, the evolving interaction between IT and the organization during the process of IT implementation and its implications for managers in these environments, has received little attention. This paper argues for more fieldwork to better analyze the dynamic interweaving between the new technology and the social/organizational setting in which it is being embedded.  相似文献   

6.
Abstract

Towns and cities in India are facing complex problems regarding the provision and maintenance of services and infrastructure in the face of the rapid growth of pupulation, caused both by natural increase and migration. In order to meet such challenges a planner needs to have fairly accurate and up-to-date information, especially about physical structures and related land parameters. A study of their trends generally helps in the understanding of the emerging growth pattern and in formulating policies to guide or redirect it. Recent advances in the field of remote sensing technology and computer based Geographical Information Systems (GIS) provide very useful tools in undertaking such analysis. The results from a study about growth trends of the urban areas in the Bombay Metropolitan Region using multi-date remote sensing data and ARC/INFO GIS package are described here. The period under consideration is from 1968 to 1989. It should be noted that the major growth in the region is confined to Greater Bombay between 1968 to 1975. After the year 1975, a distinct outward growth along the rail corridors is visible. Growth after 1975 is mainly in the Kalyan, Bhiwandi, New Bombay and Panvel areas and in the area around Manori creek (Charkop area). The growth rate is found to be higher after the year 1975 compared to the prior growth rate. The spatial growth trends are examined in relation to the population and the population density has been computed for different periods. Based upon these densities, the extent of land required for urban development for the year 2001 has been calculated. Suitability of land for urbanisation has been carried out based upon physical characteristics of the land and environmental parameters. The priority areas of urban development to meet the additional requirement in 2001 have been identified on the basis of this suitability analysis. A map on a 1:250000 scale has been prepared to show the areas for urbanisation which will meet the demands for the year 2001. This study demonstrates the potential offered by the integration of the tools of remote sensing and GIS for urban and regional planning.  相似文献   

7.
When services providing real-time information are accessible from mobile devices, functionality is often restricted and no adaptation of the user interface to the mobile device is attempted. Mobile access to real-time information requires designs for multi-device access and automated facilities for the adaptation of user interfaces. We present TapBroker, a push update service that provides mobile and stationary access to information on autonomous agents trading stocks. TapBroker is developed for the Ubiquitous Interactor system and is accessible from Java Swing user interfaces and Web user interfaces on desktop computers, and from a Java Awt user interface on mobile phones. New user interfaces can easily be added without changes in the service logic.  相似文献   

8.
The selection of the software development tool for the development of an expert system is a difficult and often disputed decision. This paper describes a comparison of a knowledge engineering tool, Kee, and a general purpose language, Prolog, on concrete and real life example from AGATHA, an electronic circuit board diagnosis expert system.Prolog is a high-level programming language with flexible and powerful inference mechanisms. Kee is a big tool that supports a frame-based knowledge representation, an object-oriented programming style and a built-in rule system. It also offers a window environment suitable for rapid development of user-interface prototypes.Prolog's representation is more succinct, implicit and uses problem specific predicates and therefore leaves more room for personal programming styles. Kee is more verbose, explicit and uses standard templates. The maintainability of a Prolog implementation relies heavily on good documentation. In Kee, the unavoidable ‘escapes to Lisp’ require a maintainer to be fluent in Kee and Lisp.Both Prolog and Kee require a considerable investment in learning time.  相似文献   

9.
Depleted marine resources and increased threats by man-made pollutants are forcing many countries to increase law enforcement and begin offshore planning. Accurate, useable, and accessible digital boundaries, with defined territorial claims, are becoming essential for daily business in the ocean. The term cadastre has not often been used in the context of the marine environment, though many (and some may argue all) of the cadastral components such as adjudication, survey, and owner rights have a parallel condition in the ocean. This paper discusses some of the framework issues that must be considered in the development of marine cadastral data and the use of these data in a marine information system for the United States. The unique features of coastal and marine data, the policy framework that surrounds the development of these data, and the implications to state1, national, and international policy are discussed. In addition, a specific case study, the Ocean Planning Information System is outlined as a “real world” application where these cadastral data have been applied toward integrated ocean planning and governance.  相似文献   

10.
The core spirit for web 2.0 is collective wisdom (i.e., the contribution of users, and the creation of value through the interaction between users). Social bookmarking sites integrate all kind of contents on the Internet (especially those generated by users), and play the role of pivot between content production and consumption. This paper mainly investigates how the positive/negative feedbacks would impact the quality of the collective wisdom within the autonomous service environments (i.e., the social bookmarking sites). Our research findings show that the performance of social bookmarking sites has a tradeoff between collective filtering (i.e., results of positive feedbacks) and front page update frequency that should be carefully managed for ensuring the good quality in collective wisdom and service performance. Moreover, the negative feedback could also shape the collective wisdom and stabilize the system performance. The research findings are believed to provide some managerial guidelines for web 2.0 sites design and operations.  相似文献   

11.
《Information & Management》2014,51(8):1005-1016
This study aims to examine whether and how national culture affects e-government diffusion. To explore the possible relationship, we analyze two sets of international-level indexes: (1) the indexes of five of the societal cultural practices of the GLOBE project [35]; and (2) the e-government development and participation indexes from the most recent United Nations e-government survey [71]. Because economic development reportedly plays an important role in both e-government diffusion and cultural dynamics, we also examine the relationships between GNI per capita, culture, and e-government diffusion. A sample of 55 countries was studied. We find that culture does have an effect on e-government diffusion in various ways, and that economic development in the form of GNI per capita has a moderating effect on the relationship between culture and e-government diffusion. We discuss the implications of these findings for e-government strategy. In addition, we identify the limitations of the study and propose areas for future research. This study is among the first to use the GLOBE approach to study cultural effects on e-government diffusion while endeavoring to explore the relationship between culture and e-government diffusion.  相似文献   

12.
In this paper, we address a university-timetabling problem and present a methodology that relies on Benders’ partitioning for its solution. This partitioning results from the special nature of the underlying integer programming formulation for this problem. We have used our methodology to schedule courses offered by the College of Engineering as well as to those offered university-wide at Virginia Tech. The results clearly depict an improvement in the quality of course schedules obtained by our methodology over those currently used, when the performance of a timetable is measured by the total distance traveled by the faculty members from their offices in respective departments to the classrooms, where the courses are offered.  相似文献   

13.
With the continuous increase of traffic volume in recent years, inland waterway transportation suffers more and more from congestion problems, which form a major impediment to its development. Thus, it is of great significance for the stakeholders and decision makers to address these congestion issues properly. Fuzzy Techniques for Order Preference by Similarity to an Ideal Solution (TOPSIS) is widely used for solving Multiple Criteria Decision Making (MCDM) problems with ambiguity. When taking into account fuzzy TOPSIS, decisions are made in a static scenario with fixed weights assigned to the criteria. However, risk conditions usually vary in real-life cases, which will inevitably affect the preference ranking of the alternatives. To make flexible decisions according to the dynamics of congestion risks and to achieve a rational risk analysis for prioritising congestion risk control options (RCOs), the cost-benefit ratio (CBR) is used in this paper to reflect the change of risk conditions. The hybrid of CBR and fuzzy TOPSIS is illustrated by investigating the congestion risks of the Yangtze River. The ranking of RCOs varies depending on the scenarios with different congestion risk conditions. The research findings indicate that some RCOs (e.g. “Channel dredging and maintenance”, and “Prohibition of navigation”) are more cost effective in the situation of a high level of congestion risk, while the other RCOs (e.g. “Loading restriction”, and “Crew management and training”) are more beneficial in a relatively low congestion risk condition. The proposed methods and the evaluation results provide useful insights for effective safety management of the inland waterway congestions under dynamic risk conditions.  相似文献   

14.

Microfluidic analytical devices manufactured on paper and similar inexpensive substrates (µ-PADs) have shown considerable promise for disease diagnostics in resource-limited regions. However, current commercialization approaches can be improved substantially by addressing existing technical challenges associated with µ-PADs. Among these, off-device plasma separation from whole blood is a critical challenge in µ-PAD technology that limits commercialization. Existing µ-PADs made by combining multiple components require extra fabrication steps and manufacturing material. Our approach utilizes a two-step plasma process to fabricate single-layer semi-enclosed µ-PADs directly on a commercially available blood plasma separation membrane to incorporate blood plasma separation functionality into the device. The semi-enclosed µ-PADs are bonded with low-cost adhesive plastic tape to provide mechanical support to the device and make it more mechanically robust for field applications. Detection zones of the µ-PADs have also been modified with a cellulose nanocrystal (CNC) to increase colorimetric signal homogeneity, thus enhancing signal quality. The CNC-modified µ-PADs have been used for colorimetric detection of two model analytes (glucose and albumin) in whole blood. Colorimetric signals for both glucose and albumin from whole blood samples were consistent with the calibration curves generated using stock solutions.

  相似文献   

15.
Abstract

Manufacturers of office automation equipment, in their design of ergonomic computer terminals and office furniture, are encountering needed design data which is sometimes weak, absent, erroneous or inapplicable to the office-worker situation under consideration. In some instances, office automation manufacturers simply follow standards. In others, manufacturers make assumptions as to the best design, and in others, design decisions were based on testing results and conclusions.This paper reviews the ergonomic tools and features incorporated into the design of one office automation manufacturer's terminals and workstations. The short fall of applicable design data relevant to comfort versus extremes of motion in biomechanics, to keyboard home row height and slope angle to viewing distance, as well as to reverse video and surface colour are presented, along with the design resolution of these parameters. Further, certain aspects of posture recently published are discussed.  相似文献   

16.
BackgroundIn Global Software Development (GSD), informal communication and knowledge sharing play an important role. Social Software (SoSo) has the potential to support and foster this key responsibility. Research on the use of SoSo in GSD is still at an early stage: although a number of empirical studies on the usage of SoSo are available in related fields, there exists no comprehensive overview of what has been investigated to date across them.ObjectiveThe aim of this review is to map empirical studies on the usage of SoSo in Software Engineering projects and in distributed teams, and to highlight the findings of research works which could prove to be beneficial for GSD researchers and practitioners.MethodA Systematic Mapping Study is conducted using a broad search string that allows identifying a variety of studies which can be beneficial for GSD. Papers have been retrieved through a combination of automatic search and snowballing, hence a wide quantitative map of the research area is provided. Additionally, text extracts from the studies are qualitatively synthesised to investigate benefits and challenges of the use of SoSo.ResultsSoSo is reported as being chiefly used as a support for collaborative work, fostering awareness, knowledge management and coordination among team members. Contrary to the evident high importance of the social aspects offered by SoSo, socialisation is not the most important usage reported.ConclusionsThis review reports how SoSo is used in GSD and how it is capable of supporting GSD teams. Four emerging themes in global software engineering were identified: the appropriation and development of usage structures; understanding how an ecology of communication channels and tools are used by teams; the role played by SoSo either as a subtext or as an explicit goal; and finally, the surprising low percentage of observational studies.  相似文献   

17.
One of the major areas of interest for deployment of blockchains is in the supply chain sector where decentralisation combined with immutability is expected to enhance the transparency and robustness of transaction processing drastically. In this work we contribute to a feasibility study for permissioned blockchains in the context of a major international retail company. First, we characterise the types, relationships, and volumes of events that are created in the life cycle of a product from creation to ownership transfer. We use the created event model and the data from the company operations to identify the load that such an event processing system would have to manage. Then we create a prototype based on Quorum that deals with a significant subset of the events and expose the blockchain-based prototype to variations in load to identify the maximum throughput and average transaction processing time. This system can then form the basis of understanding the bottlenecks, configuration settings and platform choices needed in future potential deployment.  相似文献   

18.
We present a comprehensive computational study on the effects of providing different forms of incomplete preference information in additive group decision models. We consider different types of information on individual preferences, and on weights of the group members, and study their effects on conclusiveness, efficiency and fairness of outcomes at the group level. Furthermore, we analyze possible violations of the axiom of independence of irrelevant alternatives (IIA) as well as the impact of problem characteristics, in particular initial agreement between group members. Our results indicate that providing information in the form of a ranking of differences between consecutive alternatives comes close to providing exact cardinal preference information in several outcome dimensions. However, group decision procedures based on incomplete preference information also show a significant amount of violations of the IIA axiom.  相似文献   

19.
LANDSAT data comprising eight scenes in the northern and central part of Orissa State, in eastern India were interpreted visually for delineation of target areas for mineral exploration, Even though this area has been mapped and studied in considerable detail LANDSAT data have been found to be very useful in redefining the tectonic structure, correlation of regional features and mapping of hitherto unmapped features. Subsequently one scene (path 152 row 047) was digitally analysed and enhanced for delineation of bauxitic lateritic plateaux and for comparison with visual interpretation.  相似文献   

20.
《Robotics and Computer》2000,16(2-3):161-167
This paper presents a case study on the reverse engineering of turbine blades used in nuclear power generators. Reverse engineering has been widely recognised as a crucial step in the product design cycle. However, major problems with current reverse engineering technology are the inefficient surface reconstruction process, lack of digitising accuracy control in the data digitisation process, and bottlenecks resulted from huge amounts of digitised surface points in the surface modeling process. Moreover, under this limitation, modern concurrent engineering concepts are difficult to implement to obtain optimal product design. This study applies a developed reverse engineering approach – the modified adaptive model-based digitizing process (MAMDP) to the 3D geometric design of turbine blades. The approach integrates surface digitising and modeling processes of turbine blades into a single surface reconstruction process. Using the approach, accurate product CAD models can be efficiently generated and the product design cycle of turbine blades can be successfully linked.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号