ppxscal/embedding_network huggingface dataset:
Multi-resolution extension for transmission of geodata in a mobile context
Authors: Jean-Michel Follin, Alain Bouju, Frédéric Bertrand, Patrice Boursier
Venue: Computers Geosciences (2005)

A solution is proposed for the management of multi-resolution vector data in a mobile spatial information visualization system. The client-server architecture and the models of data and transfer of the system are presented first. The aim of this system is to reduce data exchanged between client and server by reusing data already present on the client side. Then, an extension of this system to multi-resolution data is proposed. Our solution is based on the use of increments in a multi-scale database. A database architecture where data sets for different predefined scales are precomputed and stored on the server side is adopted. In this model, each object representing the same real world entities at different levels of detail has to be linked beforehand. Increments correspond to the difference between two datasets with different levels of detail. They are transmitted in order to increase (or decrease) the detail to the client upon request. They include generalization and refinement operators allowing transitions between the different levels. Finally, a framework suited to the transfer of multi-resolution data in a mobile context is presented. This allows reuse of data locally available at different levels of detail and, in this way, reduces the amount of data transferred between client and server.
Stopping criterion for complexity reduction of sphere decoding
Authors: Zheng Ma, Bahram Honary, Pingzhi Fan, Erik G. Larsson
Venue: IEEE Communications Letters (2009)

Maximum-likelihood detection in MIMO communications amounts to solving a least-squares problem with a constellation (alphabet) constraint. One popular method that can be used to solve this problem is sphere decoding. We show in this letter that by employing a simple stopping criterion, it is possible to significantly reduce the complexity of sphere decoding over a wide range of SNRs, without a noticeable performance degradation. Specifically, simulation results demonstrate that a 10%-90% reduction of the average complexity could be achieved.
Weakly supervised techniques for domain-independent sentiment classification
Authors: Jonathon Read, John Carroll
Venue: Proceeding of the 1st international CIKM workshop on Topic-sentiment analysis for mass opinion (2009)

An important sub-task of sentiment analysis is polarity classification, in which text is classified as being positive or negative. Supervised machine learning techniques can perform this task very effectively. However, they require a large corpus of training data, and a number of studies have demonstrated that the good performance of supervised models is dependent on a good match between the training and testing data with respect to the domain, topic and time-period. Weakly-supervised techniques use a large collection of unlabelled text to determine sentiment, and so their performance may be less dependent on the domain, topic and time-period represented by the testing data. This paper presents experiments that investigate the effectiveness of word similarity techniques when performing weakly-supervised sentiment classification. It also considers the extent to which the performance of each method is independent from the domain, topic and time-period of the testing data. The results indicate that the word similarity techniques are suitable for applications that require sentiment classification across several domains.
A semi-dynamic approach for valuing and hedging options on two assets with continuous payout
Authors: Shi-Jie Deng
Venue: Proceedings of the Fourth IASTED International Conference on Financial Engineering and Applications (2007)

A central problem in risk management is how to develop effective and accurate hedging strategies for financial and physical assets which are usually not liquidly traded in the market. We consider the problem of replicating the payoffs of options on two assets with a fixed finite maturity which continuously pay out cash flows. We propose an alternative approach for pricing and hedging these options, which combines dynamic trading in the underlying assets with static positions in a set of basket options of one single maturity. In markets where the amount of financial instruments required for implementing effective hedging strategies is large but the number of liquidly traded instruments is small such as the case with electricity markets, this approach presents a promising alternative for hedging long-term financial/physical assets with underlying commodities and a set of standardized options of one or several maturity times. It helps in identifying a standardized set of hedging instruments, which reduces the need for trading with a large variety of financial instruments and focuses the trading in the chosen set of securities, thus increasing the trading liquidity of the chosen instruments as well as the hedging efficiency.
A robust ranging scheme for OFDMA-based networks
Authors: Michele Morelli, Luca Sanguinetti, H. Vincent Poor
Venue: IEEE Transactions on Communications (2009)

Uplink synchronization in orthogonal frequency-division multiple-access (OFDMA) systems is a challenging task. In IEEE 802.16-based networks, users that intend to establish a communication link with the base station must go through a synchronization procedure called Initial Ranging (IR). Existing IR schemes aim at estimating the timing offsets and power levels of ranging subscriber stations (RSSs) without considering possible frequency misalignments between the received uplink signals and the base station local reference. In this work, a novel IR scheme is presented for OFDMA systems where carrier frequency offsets, timing errors and power levels are estimated for all RSSs in a decoupled fashion. The proposed frequency estimator is based on a subspace decomposition approach, while timing recovery is accomplished by measuring the phase shift between the users' channel responses over adjacent subcarriers. Computer simulations are employed to assess the effectiveness of the proposed solution and to make comparisons with existing alternatives.
Event Feature and Personality-Event - Ontology Based for Classifying Chinese Web Pages
Authors: Li Wang, Zong-Tian Liu, YanHua Wang, Rong Sun, H. F. Liu
Venue: Proceedings of the 2009 Second International Workshop on Computer Science and Engineering - Volume 02 (2009)

In recent years, more and more experts find that events have more semantic means than any other features, such as, characters, terms and concepts. This paper described a method which used event features to classify Chinese web pages talking about personality in SVM classifier. Firstly, we explained how to represent Chinese documents by event features. Secondly, we constructed event ontology about personality information. We called this event ontology as Personality Event Ontology (PEOnt). Finally, an experiment was presented. This experiment showed that our approach results had an improved classification in terms of precision and recall. This improvement, however, come at a cost in a low features vector space’s dimensionality due to the event features and event ontology used.
On pairwise shift-invariant protocol sequences
Authors: Yijin Zhang, Kenneth W. Shum, Wing Shing Wong
Venue: IEEE Communications Letters (2009)

Protocol sequences offer an approach to implement random-access channel without feedback. For these sequences, it is desirable that their cross-correlation should be as low as possible and that the length of their period should not be short. Completely shift-invariant sequences form an important class of protocol sequences which have perfect cross-correlation property but exponential growth period as a function of the number of users. We investigate in this paper a broader class of protocol sequences which are only pairwise shift-invariant. Results on minimum period and bit-pattern structure are presented.
An effective method for 3D geological modeling with multi-source data integration
Authors: Qiang Wu, Hua Xu, Xukai Zou
Venue: Computers Geosciences (2005)

The existing 3D geological modeling systems rely heavily on large numbers of borehole and cross-section data. However, it is well known that the available geological data are generally sparse and undersampled. In this paper, we propose a stepwise refinement method for 3D modeling with multi-source data integration. The method can naturally simulate geological structures no matter whether the available geological data are sufficient or not. By stepwise refinement on multiple data, the method increases the accuracy of 3D models gradually and effectively. In addition, the mechanisms used in the method for organizing and manipulating information can have an equally important impact upon geologists' thought, the interpretation of geological data, and 3D modeling methodology. A concrete example of using the method to Huai Bei fault and fold belt shows that the method can be applied to broad and complex geological areas.
Exposing digital forgeries from JPEG ghosts
Authors: Hany Farid
Venue: IEEE Transactions on Information Forensics and Security (2009)

When creating a digital forgery, it is often necessary to combine several images, for example, when compositing one person's head onto another person's body. If these images were originally of different JPEG compression quality, then the digital composite may contain a trace of the original compression qualities. To this end, we describe a tfchnique to detect whether the part of an image was initially compressed at a lower quality than the rest of the image. This approach is applicable to images of high and low quality as well as resolution.
Performance evaluation for widely linear demodulation of PAM/QAM signals in the Presence of rayleigh fading and Co-channel interference
Authors: Kiran Kuchi, Vasant K. Prabhu
Venue: IEEE Transactions on Communications (2009)

In this paper, widely linear filtering (WLF) techniques are applied to the demodulation of both pulse amplitude modulation (PAM) and quadrature amplitude modulation (QAM) systems with multiple receiver antennas and multiple co-channel interferers. In the proposed implementation, the existing correlations between the real (I) and imaginary (Q) parts of the complex-valued baseband received signal are exploited using a widely linear (WL) maximum likelihood (ML) receiver. Several bounds and approximations are developed to analyze the average symbol error rate (SER) performance, and to analyze the tradeoff between the diversity advantage and interference cancellation (IC) gain in a flat Rayleigh fading channel. Two new results are shown. First, we show that the IC ability of WL receivers is independent of the modulation type used by the desired signal but the gain depends mainly on the modulation type employed by the individual interferers and the total number of antennas. Secondly, assuming that the system uses a mixture of PAM and QAM signals, we show that a WL receiver with N antennas can reject any combination of M1 PAM, M2 QAM interferers satisfying the constraint: M1 + 2M2 < 2N with an asymptotic diversity order N - M1/2 - M2. In contrast, a conventional receiver whose performance is independent of the modulation characteristics of the individual interferers can reject only up to M1 + M2 interferers, where M1 + M2 < N with an asymptotic diversity order N - M1 - M2. When the system contains either PAM, or a mixture of PAM and QAM type CCI, it is shown that WL processing offers a significant performance advantage with a moderate increase in the receiver complexity.
A Minimum Time to Release Job Scheduling Algorithm in Computational Grid Environment
Authors: N. Malarvizhi, V. Rhymend Uthariaraj
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. However, a number of major technical hurdles must be overcome before this potential can be realized. One problem that is critical to effective utilization of computational grids is the efficient scheduling of jobs. This work addresses this problem by describing and evaluating a grid scheduling architecture and a job-scheduling algorithm. The architecture is scalable and does not assume control of local site resources. In our algorithm Grid Resource Manager or Grid Scheduler performs resource brokering and job scheduling. The scheduler selects computational resources based on job requirements, job characteristics and information provided by the resources. The main aim of these schedulers is to minimize the total time to release for the individual application. The Time To Release (TTR) includes the processing time of the program, waiting time in the queue, transfer of input and output data to and from the resource. Since grid resources are heterogeneous and distributed over many areas the transmission time is very important criteria. In this paper, an algorithm for minimum time to release is proposed. The proposed scheduling algorithm has been compared with other scheduling schemes such as First Come First Served (FCFS) and Min-Min. These existing algorithms does not consider the transmission time (in time and out time) when scheduling jobs to resources. The proposed algorithm has been verified through the GridSim simulation toolkit and the simulation results confirm that the proposed algorithm produce schedules where the execution time of the application is minimized. The average weighted response times of all submitted jobs decrease up to about 19.79%. The results have been verified using different workloads and Grid configurations.
Multivariate analysis of full-term neonatal polysomnographic data
Authors: V. Gerla, K. Paul, L. Lhotska, V. Krajca
Venue: IEEE Transactions on Information Technology in Biomedicine (2009)

Introduction. Polysomnography (PSG) is one of the most important noninvasive methods for studying maturation of the child brain. Sleep in infants is significantly different from sleep in adults. This paper addresses the problem of computer analysis of neonatal polygraphic signals. Methods. We applied methods designed for differentiating three important neonatal behavioral states: quiet sleep, active sleep, and wakefulness. The proportion of these states is a significant indicator of the maturity of the newborn brain in clinical practice. In this study, we used data provided by the Institute for Care of Mother and Child, Prague (12 newborn infants of similar postconceptional age). The data were scored by an experienced physician to four states (wake, quiet sleep, active sleep, movement artifact). For accurate classification, it was necessary to determine the most informative features. We used a method based on power spectral density (PSD) applied to each EEG channel. We also used features derived from electrooculogram (EOG), electromyogram (EMG), ECG, and respiration [pneumogram (PNG)] signals. The most informative feature was the measure of regularity of respiration from the PNG signal. We designed an algorithm for interpreting these characteristics. This algorithm was based on Markov models. Results. The results of automatic detection of sleep states were compared to the "sleep profiles" determined visually. We evaluated both the success rate and the true positive rate of the classification, and statistically significant agreement of the two scorings was found. Two variants, for learning and for testing, were applied, namely learning from the data of all 12 newborns and tenfold cross-validation, and learning fromthe data of 11 newborns and testing on the data from the 12th newborn. We utilized information obtained from several biological signals (EEG, ECG, PNG, EMG, EOG) for our final classification.We reached the final success rate of 82.5%. The true positive rate was 81.8% and the false positive rate was 6.1%. Discussion. The most important step in the whole process is feature extraction and feature selection. In this process, we used visualization as an additional tool that helped us to decide which features to select. Proper selection of features may significantly influence the success rate of the classification. We made a visual comparison of the computed features with the manual scoring provided by the expert. A hidden Markov model was used for classification. The advantage of this model is that it determines the future behavior of the process by its present state. In this way, it preserves information about temporal development.
Call Taking, Dispatch Decision Supporting, Vehicle Tracing: Emergency Response Systems under Location Based Services
Authors: Feng Yang, Lifeng Jiao, Zhizheng Zhou, Cuiju Li
Venue: Proceedings of the 2009 Third International Conference on Multimedia and Ubiquitous Engineering (2009)

Emergency response is a time critical work that needs rapid response time and system reliability. With the development of the location based services, it has been utilized in emergency response system and improved its every activity.We introduced the position of call incoming improved the process of call taking, the location of incident make the dispatch decision progress, and the location make it convenient to dispatching and tracing the vehicle in this paper. And then a vehicle tracing model based location has been provided to improve dispatching and tracing, which make the system optimized for rapid response.
A Mixed-Encoding Genetic Algorithm for Nonlinear Bilevel Programming Problems
Authors: Hecheng Li, Yuping Wang
Venue: Proceedings of the 2009 Fifth International Joint Conference on INC, IMS and IDC (2009)

For nonlinear bi-level programming problems in which the follower's problem is linear, the paper develops a genetic algorithm based on a mixed encoding technique. At first, each individual consists of two parts, the first part is the leader's variable values using real-encoding, whereas the second one is the sequence number of basic variables of the follower's programming, which are some integers. Then, a new fitness function is given, in which the optimality conditions of linear programming are incorporated into penalty term to guarantee the optimality of the follower's problem is satisfied. At last, based on the characteristic of individuals, new crossover and mutation operators are designed. The numerical results illustrate that the proposed algorithm is efficient and stable.
Removal of Trihalomethanes from Drinking Water by Air Stripping
Authors: Fangtong Wu, Shujuan Wu
Venue: Proceedings of the 2009 International Conference on Energy and Environment Technology - Volume 02 (2009)

This study investigated the effectiveness of packed tower to remove trihalomethanes (THMs) from drinking water. The results showed that the removal efficiency of total THMs generally exceeded 90% when temperature was 24 ℃, water temperature was 25 ℃, the hydraulic load was 20 m3/(m2•h) or lower, air-to-water ratio was 60 or greater. Among individual THMs species, the dichloromethane could be removed with the highest removal efficiency, while the tribromomethane with the lowest. Through the economic calculation, the operation cost was 0.0336 CNY/m3. The results of this study suggested that the air stripping was simple, highly efficient, cost-effective technology for removing THMs compounds. The volumetric mass transfer coefficients of individual THMs species were achieved according to dynamic analysis and experimental data under different hydraulic load and air-to-water ratio. The calculation of packed tower parameters was also discussed.
Performance of polar codes with the construction using density evolution
Authors: Ryuhei Mori, Toshiyuki Tanaka
Venue: IEEE Communications Letters (2009)

Polar coding, proposed by Arikan, makes it possible to construct capacity-achieving codes for symmetric binary-input discrete memoryless channels, with low encoding and decoding complexity. Complexity of the originally proposed code construction method, however, grows exponentially in the blocklength unless a channel is the binary erasure channel. Recently, the authors have proposed a new capacity-achieving code construction method with linear complexity in the blocklength for arbitrary symmetric binary-input memoryless channels. In this letter, we evaluate performance of polar codes designed with the new construction method, and compare it with that of the codes constructed with another heuristic method with linear complexity proposed by Arikan.
The role of self explanations in fostering reflection: multimedia communication training for preservice teachers
Authors: Michael Henninger, Christine Hörmann
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

One of the neglected aspects in preparing students for teaching is to train them in communicative behavior. Communicative behavior includes productive (e.g. speaking) and receptive (e.g. understanding) communicative patterns. To enable students to reflect on existing behavioral patterns, generate new ones and consciously deal with them needs time and specific learning possibilities. We created a learning scenario which is focused on the receptive part of communication. In this virtual teacher training video-sequences of teaching behavior are implemented into a web-based learning environment. In our study we examined to which extent self-explanations foster the ability to reflect receptive communicative behavior and lead to a differentiated understanding of utterances.
MIMO cooperative diversity with scalar-gain amplify-and-forward relaying
Authors: Youngpil Song, Hyundong Shin, Een-Kee Hong
Venue: IEEE Transactions on Communications (2009)

We analyze diversity performance of scalar fixed-gain amplify-and-forward (AF) cooperation in multiple-input multiple-output (MIMO) relay channels with nS source antennas, nR relay antennas, and nD destination antennas. We first derive the exact symbol error probability (SEP) for maximum likelihood decoding of orthogonal space-time block codes with M-ary phase-shift keying modulation over such channels and then characterize the effect of MIMO cooperative diversity on SEP behavior in a high signal-to-noise ratio regime. We show that the simple scalar-gain AF cooperation can create the diversity order dAF ≤ nSnD + nSnRnD/max {nS, nR, nD} with the equality if 2max {nS, nR, nD} ≥ nS + nR + nD - 1. This finding reveals that the number of relay antennas greater than or equal to nS+nD-1 is required to achieve the additional diversity order nSnD by scalar-gain AF relaying. We also present the asymptotic SEP as the number of relay antennas tends to infinity.
How to improve the retention rate in e-learning scenarios
Authors: Heinz-Dietrich Wuttke
Venue: Proceedings of the 10th IASTED International Conference on Computers and Advanced Technology in Education (2007)

Learning creativity in design is always a difficult task, independent from the subject to design. This may be an algorithm, a chip or a building. Much more complicate is to test someone's design and the level of knowledge he/she has reached in this learning process. Normally this is realized in hands-on laboratories and oral examinations. In an e-learning environment it is difficult to realize adequate scenarios. In this paper we describe a solution to couple an LMS with real experiments, so called "remote laboratories" as well as an integrated assessment system. Our teaching subject is computer engineering, especially digital control systems. The functionality of the LMS is extended with functions to realize real experiments and to asses the results of a design task. The students are forced to apply their knowledge to new situations and to synthesize own algorithms and control systems. Compared to Blooms taxonomy for measuring learning objectives our method is able to assess the highest levels of knowledge.