ppxscal/embedding_network huggingface dataset:
Reflectance spectroscopy for the assessment of soil salt content in soils of the Yellow River Delta of China
Authors: Yongling Weng, Peng Gong, Zhiliang Zhu
Venue: International Journal of Remote Sensing (2008)

There has been growing interest in the use of reflectance spectroscopy as a rapid and inexpensive tool for soil characterization. In this study, we collected 95 soil samples from the Yellow River Delta of China to investigate the level of soil salinity in relation to soil spectra. Sample plots were selected based on a field investigation and the corresponding soil salinity classification map to maximize variations of saline characteristics in the soil. Spectral reflectances of air-dried soil samples were measured using an Analytical Spectral Device (ASD) spectrometer (350-2500 nm) with an artificial light source. In the Yellow River Delta, the dominant chemical in the saline soil was NaCl and MgCl2. Soil spectra were analysed using two-thirds of the available samples, with the remaining one-third withheld for validation purposes. The analysis indicated that with some preprocessing, the reflectance at 1931-2123 nm and 2153-2254 nm was highly correlated with soil salt content (S SC). In the spectral region of 1931-2123 nm, the correlation R ranged from -0.80 to -0.87. In the region of 2153-2254 nm, the S SC was positively correlated with preprocessed reflectance (0.79-0.88). The preprocessing was done by fitting a convex hull to the reflectance curve and dividing the spectral reflectance by the value of the corresponding convex hull band by band. This process is called continuum removal, and the resulting ratio is called continuum removed reflectance (CR reflectance). However, the S SC did not have a high correlation with the unprocessed reflectance, and the correlation was always negative in the entire spectrum (350-2500 nm) with the strongest negative correlation at 1981 nm (R = -0.63). Moreover, we found a strong correlation (R = 0.91) between a soil salinity index (S SI: constructed using CR reflectance at 2052 nm and 2203 nm) and S SC. We estimated S SC as a function of S SI and S SI' (S SI': constructed using unprocessed reflectance at 2052 nm and 2203 nm) using univariate regression. Validation of the estimation of S SC was conducted by comparing the estimated S SC with the holdout sample points. The comparison produced an estimated root mean squared error (RMSE) of 0.986 (S SC ranging from 0.06 to 12.30 g kg-1) and R 2 of 0.873 for S SC with S SI as independent variable and RMSE of 1.248 and R 2 of 0.8 for S SC with S SI' as independent variable. This study showed that a soil salinity index developed for CR reflectance at 2052 nm and 2203 nm on the basis of spectral absorption features of saline soil can be used as a quick and inexpensive method for soil salt-content estimation.
MINS2
Authors: Yungki Park, Volkhard Helms
Venue: Bioinformatics (2008)

Summary: To be fully functional, membrane proteins should not only fold, but also get inserted into the membrane, which is mediated by the Sec61 translocon. Recent experimental studies have attempted to elucidate how the Sec61 translocon accomplishes this delicate task by measuring the translocon-mediated membrane insertion free energies of 357 systematically designed peptides. On the basis of this data set, we have developed MINS2, a novel sequence-based computational method for predicting the membrane insertion free energies of protein sequences. A benchmark analysis of MINS2 shows that MINS2 signi.cantly outperforms previously proposed methods. Importantly, the application of MINS2 to known membrane protein structures shows that a better prediction of membrane insertion free energies does not lead to a better prediction of transmembrane segments of polytopic membrane proteins. Availability: A web server for MINS2 is publicly available at http://service.bioinformatik.uni-saarland.de/mins. Contact: volkhard.helms@bioinformatik.uni-saarland.de Supplementary information:Supplementary data are available at Bioinformatics online.
Zone-based virtual backbone formation in wireless ad hoc networks
Authors: Bo Han
Venue: Ad Hoc Networks (2009)

Efficient protocol for clustering and backbone formation is one of the most important issues in wireless ad hoc networks. Connected dominating set (CDS) formation is a promising approach for constructing virtual backbone. However, finding the minimum CDS in an arbitrary graph is a NP-Hard problem. In this paper, we present a novel zone-based distributed algorithm for CDS formation in wireless ad hoc networks. In this Zone algorithm, we combine the zone and level concepts to sparsify the CDS constructed by previous well-known approaches. Therefore, this proposed algorithm can significantly reduce the CDS size. Particularly, we partition the wireless network into different zones, construct a dominating tree for each zone and connect adjacent zones by inserting additional connectors into the final CDS (at the zone borders). Our comprehensive simulation study using a custom simulator shows that this zone-based algorithm is more effective than previous approaches. The number of nodes in the CDS formed by this Zone algorithm is up to around 66% less than that constructed by others. Moreover, we also compare the performance of Zone algorithm with some recently proposed CDS formation protocols in ns2 simulator.
Affect in computer-mediated communication: an experiment in synchronous terminal-to-terminal discussion
Authors: Sara Kiesler, David Zubrow, Anne Marie Moses, Valerie Geller
Venue: Human-computer interaction (1985)

With the spread of computer networks, communication via computer conferences, electronic mail, and computer bulletin boards will become more common in society, but little is known about the social psychological implications of these technologies. One possibility is a change in physiological arousal, feelings, and expressive behavior-that is, affect. These computermediated communication technologies focus attention on the message, transmit social information poorly, and do not have a well-developed social etiquette. Therefore, these technologies might be associated with less attention to others, less social feedback, and depersonalization of the communication setting. In the present study we examined what would happen to feelings and interpersonal behavior in an experiment in which two people met for the first time and discussed a series of questions in order to get to know one another. We measured physiological arousal (pulse and palmar sweat), subjective affect (emotional state and evaluations), and expressive behavior (self-disclosure and uninhibited behavior) in both synchronous computer-mediated and faceto-face discussions. (For comparison purposes, we also examined these effects under high- and low-evaluation anxiety). Communicating by computer did not influence physiological arousal, and it did not change emotions or selfevaluations. However, people who communicated by computer evaluated each other less favorably than did people who communicated face-to-face, they felt and acted as though the setting was more impersonal, and their behavior was more uninhibited. These findings suggest that computer-mediated communication, rather than provoking emotionality per se, elicits asocial or unregulated behavior. Of course, our data are based on a laboratory experiment using just one type of computer-mediated communication, but the results are generally consistent with anecdotal evidence and new field research on how people use computers to communicate in organizations.
Quantifying the operational status of the DNSSEC deployment
Authors: Eric Osterweil, Michael Ryan, Dan Massey, Lixia Zhang
Venue: Proceedings of the 8th ACM SIGCOMM conference on Internet measurement (2008)

This paper examines the deployment of the DNS Security Extensions (DNSSEC), which adds cryptographic protection to DNS, one of the core components in the Internet infrastructure. We analyze the data collected from the initial DNSSEC deployment which started over 2 years ago, and identify three critical metrics to gauge the deployment: availability, verifiability, and validity. Our results provide the first comprehensive look at DNSSEC's deployment and reveal a number of challenges that were not anticipated in the design but have become evident in the deployment. First, obstacles such as middle-boxes (firewalls, NATs, etc.) that exist in today's Internet infrastructure have proven to be problematic and have resulted in unforeseen availability problems. Second, the public-key delegation system of DNSSEC has not evolved as it was hoped and it currently leaves over 97% of DNSSEC zones isolated and unverifiable, unless some external key authentication mechanism is added. Furthermore, our results show that cryptographic verification is not equivalent to validation; a piece of verified data can still contain the wrong value. Finally, our results demonstrate the essential role of monitoring and measurement in the DNSSEC deployment. We believe that the observations and lessons from the DNSSEC deployment can provide insights into measuring future Internet-scale cryptographic systems.
Analysis of co-occurrence and discrete wavelet transform textures for differentiation of forest and non-forest vegetation in very-high-resolution optical-sensor imagery
Authors: Yashon O. Ouma, J. Tetuko, R. Tateishi
Venue: International Journal of Remote Sensing (2008)

The extraction of texture features from high-resolution remote sensing imagery provides a complementary source of data for those applications in which the spectral information is not sufficient for identification or classification of spectrally similar landscape features. This study presents the results of grey-level co-occurrence matrix (GLCM) and wavelet transform (WT) texture analysis for forest and non-forest vegetation types differentiation in QuickBird imagery. Using semivariogram fitting, the optimal GLCM windows for the land cover classes within the scene were determined. These optimal window sizes were then applied to eight GLCM texture measures (mean, variance, homogeneity, dissimilarity, contrast, entropy, angular second moment, and correlation) for the scene classification. Using wavelet transformation, up to five levels of macro-texture were computed and tested in the classification process. Comparing the classification results, (1) the spectral-only bands classification gave an overall accuracy of 58.69%; (2) the statistically derived 21×21 optimal mean texture combined with spectral information gave the best results among the GLCM optimal windows with an accuracy of 73.70%; and (3) the combined optimal WT-texture levels 4 and 5 gave an accuracy of 63.56%. The combined classification of these three optimal results gave an overall accuracy of 77.93%. The results indicate that even though vegetation texture was generally measured better by the GLCM-mean texture (micro-textures) than by WT-derived texture (macro-textures), the results show that the micro-macro texture combination would improve the differentiation and classification of the overall vegetation types. Overall, the results suggests that computer-assisted classification of high-spatial-resolution remotely sensed imagery has a good potential to augment the present ground-based forest inventory methods.
Structural optimization of a full-text n-gram index using relational normalization
Authors: Min-Soo Kim, Kyu-Young Whang, Jae-Gil Lee, Min-Jae Lee
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2008)

As the amount of text data grows explosively, an efficient index structure for large text databases becomes ever important. The n-gram inverted index (simply, the n-gram index) has been widely used in information retrieval or in approximate string matching due to its two major advantages: language-neutral and error-tolerant. Nevertheless, the n-gram index also has drawbacks: the size tends to be very large, and the performance of queries tends to be bad. In this paper, we propose the two-level n-gram inverted index (simply, the n-gram/2L index) that significantly reduces the size and improves the query performance by using the relational normalization theory. We first identify that, in the (full-text) n-gram index, there exists redundancy in the position information caused by a non-trivial multivalued dependency. The proposed index eliminates such redundancy by constructing the index in two levels: the front-end index and the back-end index. We formally prove that this two-level construction is identical to the relational normalization process. We call this process structural optimization of the n-gram index. The n-gram/2L index has excellent properties: (1) it significantly reduces the size and improves the performance compared with the n-gram index with these improvements becoming more marked as the database size gets larger; (2) the query processing time increases only very slightly as the query length gets longer. Experimental results using real databases of 1 GB show that the size of the n-gram/2L index is reduced by up to 1.9---2.4 times and, at the same time, the query performance is improved by up to 13.1 times compared with those of the n-gram index. We also compare the n-gram/2L index with Makinen's compact suffix array (CSA) (Proc. 11th Annual Symposium on Combinatorial Pattern Matching pp. 305---319, 2000) stored in disk. Experimental results show that the n-gram/2L index outperforms the CSA when the query length is short (i.e., less than 15---20), and the CSA is similar to or better than the n-gram/2L index when the query length is long (i.e., more than 15---20).
An estimation of the optimum temporal resolution for monitoring vegetation condition on a nationwide scale using MODIS/Terra data
Authors: T. K. Alexandridis, I. Z. Gitas, N. G. Silleos
Venue: International Journal of Remote Sensing (2008)

Monitoring vegetation condition is an important issue in the Mediterranean region, in terms of both securing food and preventing fires. The recent abundance of remotely sensed data, such as the daily availability of MODIS imagery, raises the issue of appropriate temporal sampling when monitoring vegetation: under-sampling may not accurately describe the phenomenon under consideration, whilst over-sampling would increase the cost of the project without additional benefit. The aim of this work is to estimate the optimum temporal resolution for vegetation monitoring on a nationwide scale using 250 m MODIS/Terra daily images and composites. Specific objectives include: (i) an investigation into the optimum temporal resolution for monitoring vegetation condition during the dry season on a nationwide scale using time-series analysis of Normalized Difference Vegetation Index, NDVI, datasets, (ii) an investigation into whether this temporal resolution differs between the two major vegetation categories of natural and managed vegetation, and (iii) a quality assessment of multi-temporal NDVI composites following the proposed optimum temporal resolution. A time-series of daily NDVI data is developed for Greece using MODIS/Terra 250 m imagery. After smoothing to remove noise and cloud influence, it is subjected to temporal autocorrelation analysis, and its level of significance is the adopted objective function. In addition, NDVI composites are created at various temporal resolutions and compared using qualitative criteria. Results indicate that the proposed optimum temporal resolution is different for managed and natural vegetation. Finally, quality assessment of the multi-temporal NDVI composites reveals that compositing at the proposed optimum temporal resolution could derive products that are useful for operational monitoring of vegetation.
3D modeling using geognostic data: The case of the low valley of Foglia river (Italy)
Authors: G. Gallerini, M. De Donatis
Venue: Computers Geosciences (2009)

In specific geological contexts, such as alluvial environments, the lithology is highly heterogeneous and laterally variable. As a result, a large number of lithological data are collected (generally random and under sampled) for stratigraphic reconstruction. The integrated management of geo-lithologic data causes major methodological problems, because data obtained from geognostic investigations have to be normalized and correlated. Data are often affected by their degree of precision, a detail depending on the investigation technique and on the geologist's interpretation. This paper presents a methodological approach to organizing, integrating, and interpolating subsoil, mechanical (boreholes, penetration tests), and geophysical (seismic profiles, resistivity sounding) investigations for the construction of a three-dimensional geological model supported by geographical information systems and geostatistics. A practical application concerning the lower Foglia river alluvial deposits (Northern Marche, Italy) was carried out to investigate the geometry of these sedimentary bodies. This integrated approach offers many advantages for the understanding and in-depth visualization of the geometry of the deposits. Moreover, it allows for the acquisition of qualitative and quantitative information about hydrogeological settings, which is useful for water resources exploitation and protection. The achieved goals are the design of a data management workflow for geo-lithological data, the construction of a three-dimensional geological model of the lower Foglia river alluvial plain, a comparison between the geological sections obtained from the model and those made in a traditional manual fashion, and, in addition, new stratigraphic and hydrogeological considerations about the study area.
Monitoring the execution of robot plans using semantic knowledge
Authors: Abdelbaki Bouguerra, Lars Karlsson, Alessandro Saffiotti
Venue: Robotics and Autonomous Systems (2008)

Even the best laid plans can fail, and robot plans executed in real world domains tend to do so often. The ability of a robot to reliably monitor the execution of plans and detect failures is essential to its performance and its autonomy. In this paper, we propose a technique to increase the reliability of monitoring symbolic robot plans. We use semantic domain knowledge to derive implicit expectations of the execution of actions in the plan, and then match these expectations against observations. We present two realizations of this approach: a crisp one, which assumes deterministic actions and reliable sensing, and uses a standard knowledge representation system (LOOM); and a probabilistic one, which takes into account uncertainty in action effects, in sensing, and in world states. We perform an extensive validation of these realizations through experiments performed both in simulation and on real robots.
Reasoning and identifying relevant matches for XML keyword search
Authors: Ziyang Liu, Yi Cher
Venue: Proceedings of the VLDB Endowment (2008)

Keyword search is a user-friendly mechanism for retrieving XML data in web and scientific applications. An intuitively compelling but vaguely defined goal is to identify matches to query keywords that are relevant to the user. However, it is hard to directly evaluate the relevance of query results due to the inherent ambiguity of search semantics. In this work, we investigate an axiomatic framework that includes two intuitive and non-trivial properties that an XML keyword search technique should ideally satisfy: monotonicity and consistency, with respect to data and query. This is the first work that reasons about keyword search strategies from a formal perspective. Then we propose a novel semantics for identifying relevant matches, which, to the best of our knowledge, is the only existing algorithm that satisfies both properties. An efficient algorithm is designed for realizing this semantics. Extensive experimental studies have verified the intuition of the properties and shown the effectiveness of the proposed algorithm.
The concept of interactivity -- revisited: four new typologies for a new media landscape
Authors: Jens F. Jensen
Venue: Proceeding of the 1st international conference on Designing interactive user experiences for TV and video (2008)

In this paper definitions, classifications and typologies of the concept of interactivity in the context of the new media landscape will be discussed. The paper takes its point of departure in the evaluation of two typologies of interactive media and interactivity introduced some 10 years ago. In the remainder of the paper, four new typologies or matrices concerning interactive media and the new media landscape are introduced. In this sense the paper can be seen as the concept of interactivity -- revisited.
Hyperspectral canopy measurements under artificial illumination
Authors: S. Delalieux, B. Somers, W. W. Verstraeten, W. Keulemans, P. Coppin
Venue: International Journal of Remote Sensing (2008)

Hyperspectral canopy reflectance measurements are usually obtained under ambient solar illumination. In some specific cases, however, the use of artificial light is preferred. This raises issues, since artificial light is usually non-parallel and non-homogeneous over the area and height profile of the target. This study therefore attempts to address the characteristics of artificial illumination and the consequences for remote sensing. A low-cost experimental setup is proposed to counter the main issues of using artificial light in hyperspectral research.
Anonymous Resolution of DNS Queries
Authors: Sergio Castillo-Perez, Joaquin Garcia-Alfaro
Venue: Proceedings of the OTM 2008 Confederated International Conferences, CoopIS, DOA, GADA, IS, and ODBASE 2008. Part II on On the Move to Meaningful Internet Systems (2008)

The use of the DNS as the underlying technology of new resolution name services can lead to privacy violations. The exchange of data between servers and clients flows without protection. Such an information can be captured by service providers and eventually sold with malicious purposes (i.e., spamming, phishing, etc.). A motivating example is the use of DNS on VoIP services for the translation of traditional telephone numbers into Internet URLs. We analyze in this paper the use of statistical noise for the construction of proper DNS queries. Our objective aims at reducing the risk that sensible data within DNS queries could be inferred by local and remote DNS servers. We evaluate the implementation of a proof-of-concept of our approach. We study the benefits and limitations of our proposal. A first limitation is the possibility of attacks against the integrity and authenticity of our queries by means of, for instance, man-in-the-middle or replay attacks. However, this limitation can be successfully solved combining our proposal together with the use of the DNSSEC (DNS Security extensions). We evaluate the impact of including this complementary countermeasure.