Incorporating legacy soil data to minimize errors in salinity change detection: a case study of Darab Plain,Iran

The results of a 1990 soil survey of a salinized region in Darab Plain, southern Iran, were combined with soil sampling data taken in 2002 from the same locations and employed as a basis for salinity change detection in the region. New preprocessing of satellite imagery was used, along with statistical analysis of the digital number (DN)?salinity relationship, in order to determine salinization of the area. Removal of outliers on the basis of interfering land uses improved the correlations. Nonlinear regression (NLR) in the form y?=?a +?bx ^α provided a suitable predictor of salinity (y, dS m^?1) for both 1990 and 2002 based on DNs (x). Among the 12 tested methods of salinity classification in this study, the six salinity class method with intervals 0–4, 4–10, 10–32, 32–64, 64–80 and >80 dS m^–1 was selected. A series of accuracy assessments through a trial-and-error procedure was the basis of the selection of the best method and led to a final accuracy of 91%. About 42% of the lands located on ‘no saline’ and ‘low salinity’ classes in 1990 had changed to the ‘medium’, ‘very high’ and ‘new agricultural land’ classes in 2002.     

Comparison and assessment of coarse resolution land cover maps for Northern Eurasia

Information on land cover at global and continental scales is critical for addressing a range of ecological, socioeconomic and policy questions. Global land cover maps have evolved rapidly in the last decade, but efforts to evaluate map uncertainties have been limited, especially in remote areas like Northern Eurasia. Northern Eurasia comprises a particularly diverse region covering a wide range of climate zones and ecosystems: from arctic deserts, tundra, boreal forest, and wetlands, to semi-arid steppes and the deserts of Central Asia. In this study, we assessed four of the most recent global land cover datasets: GLC-2000, GLOBCOVER, and the MODIS Collection 4 and Collection 5 Land Cover Product using cross-comparison analyses and Landsat-based reference maps distributed throughout the region. A consistent comparison of these maps was challenging because of disparities in class definitions, thematic detail, and spatial resolution. We found that the choice of sampling unit significantly influenced accuracy estimates, which indicates that comparisons of reported global map accuracies might be misleading. To minimize classification ambiguities, we devised a generalized legend based on dominant life form types (LFT) (tree, shrub, and herbaceous vegetation, barren land and water). LFT served as a necessary common denominator in the analyzed map legends, but significantly decreased the thematic detail. We found significant differences in the spatial representation of LFT's between global maps with high spatial agreement (above 0.8) concentrated in the forest belt of Northern Eurasia and low agreement (below 0.5) concentrated in the northern taiga-tundra zone, and the southern dry lands. Total pixel-level agreement between global maps and six test sites was moderate to fair (overall agreement: 0.67-0.74, Kappa: 0.41-0.52) and increased by 0.09-0.45 when only homogenous land cover types were analyzed. Low map accuracies at our tundra test site confirmed regional disagreements and difficulties of current global maps in accurately mapping shrub and herbaceous vegetation types at the biome borders of Northern Eurasia. In comparison, tree dominated vegetation classes in the forest belt of the region were accurately mapped, but were slightly overestimated (10%-20%), in all maps. Low agreement of global maps in the northern and southern vegetation transition zones of Northern Eurasia is likely to have important implications for global change research, as those areas are vulnerable to both climate and socio-economic changes.     

Impact of Lean Production on Perceived Job Autonomy and Job Satisfaction: An Experimental Study

Previous studies have indicated positive and negative effects of lean production on employees’ perceived work characteristics and job attitudes. The most detrimental consequence of lean production is a decrease in the perceived job autonomy of workshop employees. To reduce these negative consequences, we propose human resource practices for integration with lean production. Drawing on the job characteristics model, we hypothesized that the implementation of lean production combined with human resource practices would enhance perceived job autonomy, job satisfaction, and operational performance. To evaluate our hypotheses, we used an experimental design consisting of a simulation game that mimics a manufacturing company. We implemented lean production combined with human resource practices in this simulated company. The results indicated a significant increase in perceived job autonomy, job satisfaction, and operational performance. Moreover, the results revealed a positive relationship between job satisfaction and operational performance.     

An affordable surround‐screen virtual reality display

Abstract— Building a projection‐based virtual reality display is a time‐, cost‐, and resource‐intensive enterprise, and many details contribute to the final display quality. This is especially true for surround‐ screen displays where most of them are one‐of‐a‐kind systems or custom‐made installations with specialized projectors, framing, and projection screens. In general, the costs of acquiring these types of systems have been in the hundreds and even millions of dollars, specifically for those supporting synchronized stereoscopic projection across multiple screens. Furthermore, the maintenance of such systems adds an additional recurrent cost, which makes them hard to afford for general introduction in a wider range of industry, academic, and research communities. A low‐cost easy‐to‐maintain surround‐screen design based on off‐the‐shelf affordable components for the projection screens, framing, and display systems is presented. The resulting system quality is comparableto significantly more expensive commercially available solutions. Additionally, users with average knowledge can implement this design, and it has the added advantage that single components can be individually upgraded based on necessity as well as available funds.     

Discontinuities in continuous scatter plots

The concept of continuous scatterplot (CSP) is a modern visualization technique. The idea is to define a scalar density value based on the map between an n-dimensional spatial domain and an m-dimensional data domain, which describe the CSP space. Usually the data domain is two-dimensional to visually convey the underlying, density coded, data. In this paper we investigate kinds of map-based discontinuities, especially for the practical cases n = m = 2 and n = 3 | m = 2, and we depict relations between them and attributes of the resulting CSP itself. Additionally, we show that discontinuities build critical line structures, and we introduce algorithms to detect them. Further, we introduce a discontinuity-based visualization approach—called contribution map (CM)—which establishes a relationship between the CSP's data domain and the number of connected components in the spatial domain. We show that CMs enhance the CSP-based linking & brushing interaction. Finally, we apply our approaches to a number of synthetic as well as real data sets.     

Dual stream speech recognition using articulatory syllable models

Recent theoretical developments in neuroscience suggest that sublexical speech processing occurs via two parallel processing pathways. According to this Dual Stream Model of Speech Processing speech is processed both as sequences of speech sounds and articulations. We attempt to revise the “beads-on-a-string” paradigm of Hidden Markov Models in Automatic Speech Recognition (ASR) by implementing a system for dual stream speech recognition. A baseline recognition system is enhanced by modeling of articulations as sequences of syllables. An efficient and complementary model to HMMs is developed by formulating Dynamic Time Warping (DTW) as a probabilistic model. The DTW Model (DTWM) is improved by enriching syllable templates with constrained covariance matrices, data imputation, clustering and mixture modeling. The resulting dual stream system is evaluated on the N-Best Southern Dutch Broadcast News benchmark. Promising results are obtained for DTWM classification and ASR tests. We provide a discussion on the remaining problems in implementing dual stream speech recognition.     

Pricing combinatorial auctions by a set of linear price vectors

In combinatorial auctions, items are sold simultaneously. A substantial component of an auction mechanism is the pricing scheme. Prices determine the auctioneer’s revenue and, ideally, justify the outcome of the auction to the bidders. Each bidder should be able to see why he won or lost a certain bundle by comparing the determined price of a bundle and his bid’s value. In this paper, we pick up a non-linear anonymous pricing scheme from the literature that consists of a set of linear price vectors. We investigate whether this scheme can guarantee to find prices that support the winner allocation. Furthermore, we refine the pricing scheme by suggesting various objectives in order to evaluate different prices. We consider the computational complexity of the corresponding optimization problems and compare different objectives by means of a computational study using a well-established combinatorial auction test suite.     

A Framework for Commercial Grids—Economic and Technical Challenges

This paper argues that the technology of Grid computing has not yet been adopted in commercial settings due to the lack of viable business models. While in academia Grid technology has already been taken up, the sharing approach among non for-profit organizations is not suitable for enterprises. In this paper, the idea of a Grid market is taken up to overcome this Grid adoption gap. We propose a framework for building up a Grid market and identifies the associated economic and technical challenges. Based on this framework, we identify a catalogue of possible market mechanisms which offer a promising fit to the Grid environment’s characteristics and which may thus help to carry the idea of Grid markets from theory to practice.