A novel MLSD receiver architecture for nonlinear channels

A new architecture for maximum likelihood sequence detec- tion (MLSD) in nonlinear dispersive channels (NLCs) is presented, and its robustness to inaccurate channel knowledge is analyzed. This architecture is developed by considering a novel orthogonal representation of the NLC, which is exploited to develop a front-end capable of obtaining uncorrelated symbol rate samples, representing a sufficient statistic for information decoding. This front-end is a special form of space-time whitened matched filter (ST-WMF), and the MLSD obtained by using this front-end (ST-WMF-MLSD) requires simple branch metrics due to the signal whitening. The ST-WMF also allows for space-time compression of the equivalent channel, which is exploited for further complexity reduction of the ST-WMF-MLSD. Simulation results show the good trade-off in performance and complexity obtained with the ST-WMF- MLSD, even in the presence of inaccurate channel knowledge.Sociedad Argentina de Informática e Investigación Operativa (SADIO

A novel MLSD receiver architecture for nonlinear channels

A new architecture for maximum likelihood sequence detec- tion (MLSD) in nonlinear dispersive channels (NLCs) is presented, and its robustness to inaccurate channel knowledge is analyzed. This architecture is developed by considering a novel orthogonal representation of the NLC, which is exploited to develop a front-end capable of obtaining uncorrelated symbol rate samples, representing a sufficient statistic for information decoding. This front-end is a special form of space-time whitened matched filter (ST-WMF), and the MLSD obtained by using this front-end (ST-WMF-MLSD) requires simple branch metrics due to the signal whitening. The ST-WMF also allows for space-time compression of the equivalent channel, which is exploited for further complexity reduction of the ST-WMF-MLSD. Simulation results show the good trade-off in performance and complexity obtained with the ST-WMF- MLSD, even in the presence of inaccurate channel knowledge.Sociedad Argentina de Informática e Investigación Operativa (SADIO

A novel MLSD receiver architecture for nonlinear channels

A new architecture for maximum likelihood sequence detec- tion (MLSD) in nonlinear dispersive channels (NLCs) is presented, and its robustness to inaccurate channel knowledge is analyzed. This architecture is developed by considering a novel orthogonal representation of the NLC, which is exploited to develop a front-end capable of obtaining uncorrelated symbol rate samples, representing a sufficient statistic for information decoding. This front-end is a special form of space-time whitened matched filter (ST-WMF), and the MLSD obtained by using this front-end (ST-WMF-MLSD) requires simple branch metrics due to the signal whitening. The ST-WMF also allows for space-time compression of the equivalent channel, which is exploited for further complexity reduction of the ST-WMF-MLSD. Simulation results show the good trade-off in performance and complexity obtained with the ST-WMF- MLSD, even in the presence of inaccurate channel knowledge.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Principios de econometría

Es un texto basado en la experiencia docente en el programa de Ingeniería Financiera y de Negocios del Instituto Tecnológico Metropolitano. Busca de manera amigable dar mayor comprensión a los temas ofrecidos en la mayoría de cursos de econometría, porque proporciona un repaso por el modelo clásico de regresión lineal, la bondad de ajuste de los modelos, variables dummy y modelos probabilísticos.Based on the teaching experience of a professor in the Business and Finance Engineering program at Instituto Tecnológico Metropolitano, this volume aims to provide insight on the topics that are taught in most econometrics courses in a friendly way by reviewing the classical linear regression model, the goodness of fit of models, dummy variables and probabilistic models

Fisheries-based approach to disentangle mackerel (Scomber scombrus) migration in the Cantabrian Sea

Mackerel is an important commercial pelagic species present in the western and eastern North Atlantic. The Northeast Atlantic Mackerel (NEAM) stock has its southernmost spawning area mainly located western Iberian Peninsula and southern Biscay. This species performs extensive annual migrations. The present study is focused on the distribution of this species along the Cantabrian Sea, an essential area of the South Spawning Component (SSC), and the environmental drivers that can affect its migration phenology. We have used data from Vessel Monitoring System and Logbooks of the hand line fishery to estimate the catch per unit of effort (CPUE) as a proxy of its distribution and abundance. CPUEs data of fisheries targeting NEAM provided us with a tool to discriminate the most important predictors for both its prespawning and the postspawning behavior. Among the drivers that can affect mackerel migration, we have analyzed wind speed and direction, temperature at surface (SST) and at 200 m depth, chlorophyll a, mixed layer depth, upwelling intensity, and the most representative geographical variables: depth, slope of the seafloor, and distance to coast. We used generalize additive models to highlight the predictors most closely related to the phenology of the species and to shape the spatial–temporal abundance of NEAM in the southern Bay of Biscay waters. Temperature and wind speed and direction are the most important factors that affect prespawning and postspawning migration of NEAM SSC and shape its niche tracking leading to a gradual advance of the spawning season.Postprint2,04

SMS-Builder: An adaptive software tool for building systematic mapping studies

A Systematic Mapping Study is an instrument frequently used to carry out a search process, identification, and classification of studies in different fields. Researchers in front of this type of process have a challenge while managing the data about these studies. This paper presents a software tool that has been created to help those who need to build a systematic mapping study. In addition, this work follows the evidence-based software engineering approach and extends it through a software tool by including different ways of adapting this process

Dental Non-Metric Traits in a Preconquest Sample from Tastil Region in Argentina, South America

Reconstruction of biological relationships between ancient human groups using teeth is an important research problem for South American bioarcheologist. The present study was carried out with a Tastil human pre-conquest sample from Northwest of Argentina, with the aim of exploring the dental morphology patterns in this population. The sample of this study is composed by 19 skulls with partial dentitions from Santa Rosa de Tastil ruins (Salta Province, Argentina). 12 dental non-mtetric traits were recorded using the ASU Dental Anthropology System. Percentages >70% was not found. Values between 0,1 and 70% was found in 12 traits of upper dentition only. In spite of the frequencies finding in Tastil sample can be influences by a low sample size, we can conclude that shovel shape of the incisors in the population of Tastil suggest a Mongoloid origin

Sensitivity of the g-mode frequencies to pulsation codes and their parameters

From the recent work of the Evolution and Seismic Tools Activity (ESTA, Lebreton et al. 2006; Monteiro et al. 2008), whose Task 2 is devoted to compare pulsational frequencies computed using most of the pulsational codes available in the asteroseismic community, the dependence of the theoretical frequencies with non-physical choices is now quite well fixed. To ensure that the accuracy of the computed frequencies is of the same order of magnitude or better than the observational errors, some requirements in the equilibrium models and the numerical resolutions of the pulsational equations must be followed. In particular, we have verified the numerical accuracy obtained with the Saclay seismic model, which is used to study the solar g-mode region (60 to 140$\mu$Hz). We have compared the results coming from the Aarhus adiabatic pulsation code (ADIPLS), with the frequencies computed with the Granada Code (GraCo) taking into account several possible choices. We have concluded that the present equilibrium models and the use of the Richardson extrapolation ensure an accuracy of the order of $0.01 \mu Hz$ in the determination of the frequencies, which is quite enough for our purposes.Comment: 10 pages, 5 figures, accepted in Solar Physic

Defense techniques for low-rate DoS attacks against application servers

a b s t r a c t Low-rate denial of service (DoS) attacks have recently emerged as new strategies for denying networking services. Such attacks are capable of discovering vulnerabilities in protocols or applications behavior to carry out a DoS with low-rate traffic. In this paper, we focus on a specific attack: the low-rate DoS attack against application servers, and address the task of finding an effective defense against this attack. Different approaches are explored and four alternatives to defeat these attacks are suggested. The techniques proposed are based on modifying the way in which an application server accepts incoming requests. They focus on protective measures aimed at (i) preventing an attacker from capturing all the positions in the incoming queues of applications, and (ii) randomizing the server operation to eliminate possible vulnerabilities due to predictable behaviors. We extensively describe the suggested techniques, discussing the benefits and drawbacks for each under two criteria: the attack efficiency reduction obtained, and the impact on the normal operation of the server. We evaluate the proposed solutions in a both a simulated and a real environment, and provide guidelines for their implementation in a production system

Gelatin–chitosan–PVA hydrogels and their application in agriculture

This work demonstrated the ability of a fabrication process in the preparation of gelatin-chitosan-PVA hydrogels for potential agricultural applications. The hydrogels showed a dense, tridimensional, interconnected and reticulated structure that was more evident in the hydrogel loaded with inulin. The hydrogels showed a water absorption capacity of ≤12 times its mass. FTIR and light microscopy demonstrated that the hydrogels were biodegradable. The percentage of degradation of hydrogels in inoculated soil was higher than in sterile soil using the soil burial test. Hydrogel loaded with inulin was found to be capable of inducing resistance in chili plants against Phytophthora capsici.ITESO, A.C