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| Registros recuperados: 37 | |
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| David-grignot, Stephane; Lamlih, Achraf; Kerzerho, Vincent; Azaıs, Florence; Soulier, Fabien; Bernard, Serge; Rouyer, Tristan; Bonhommeau, Sylvain. |
| On-chip sine-wave signal generation is widely covered by literature for Built-In-Self Test (BIST) or biosensor applications. The objective is to generate pure and robust sinewave signal with minimal hardware resources. An attractive solution consists in combining several digital signals to built this analog sine-wave. The objective of this paper is to give an analytical study of various potential solutions based on digitalbased approaches. Thanks to this study, we prove that technique consisting in setting the phase shifts and various amplitude values of the square-wave signals is the most efficient approach. Moreover, this study allows the selection of the best solution in terms of parameters of the square-wave signals to cancel loworder harmonics of the... |
| Tipo: Text |
Palavras-chave: Harmonic cancellation; Sine-wave generation; On-chip signal generation. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00395/50608/55366.pdf |
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| Pierre, Maud; Rouyer, Tristan; Bonhommeau, Sylvain; Fromentin, Jean-marc. |
| Understanding whether recruitment fluctuations in fish stock arise from stochastic forcing (e.g. environmental variations) rather than deterministic forces (e.g. intrinsic dynamics) is a long standing question with important applied consequences for fisheries ecology. In particular, the relationship between recruitment, spawning stock biomass and environmental factors is still poorly understood, even though this aspect is crucial for fisheries management. Fisheries data are often short, but arise from complex dynamical systems with a high degree of stochastic forcing, which are difficult to capture through classic modelling approaches. In the present study, recent statistical approaches based on the approximation of the attractors of dynamical systems are... |
| Tipo: Text |
Palavras-chave: Causality; Forecasting models; Marine. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00408/51930/52555.pdf |
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| Rouyer, Tristan; Bonhommeau, Sylvain; Giordano, F; Wendling, B; Ellul, S; Ellul, G; Psaila, Ma; Deguara, S; Bernard, S; Kerzerho, V. |
| Tipo: Text |
Palavras-chave: Large atlantic bluefin tuna; Mediterranean; Malta; Electronic tagging; Farming cages; Purse seiners. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00484/59609/62626.pdf |
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| Rouyer, Tristan; Fromentin, Jean-marc; Menard, Felix; Calzelles, B; Briand, K; Pianet, R; Planque, Benjamin; Stenseth, N. |
| The patterns of variations in fisheries time series are known to result from a complex combination of species and fisheries dynamics all coupled with environmental forcing (including climate, trophic interactions, etc.). Disentangling the relative effects of these factors has been a major goal of fisheries science for both conceptual and management reasons. By examining the variability of 169 tuna and billfish time series of catch and catch per unit effort (CPUE) throughout the Atlantic as well as their linkage to the North Atlantic Oscillation (NAO), we find that the importance of these factors differed according to the spatial scale. At the scale of the entire Atlantic the patterns of variations are primarily spatially structured, whereas at a more... |
| Tipo: Text |
Palavras-chave: Time series analysis; North Atlantic Oscillation; Atlantic tuna. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3984.pdf |
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| Hidalgo, Manuel; Rouyer, Tristan; Bartolino, Valerio; Cervino, Santiago; Ciannelli, Lorenzo; Massuti, Enric; Jadaud, Angelique; Saborido-rey, Fran; Durant, Joel M.; Santurtun, Marina; Pineiro, Carmen; Stenseth, Nils C.. |
| Fisheries ecologists traditionally aimed at disentangling climate and fishing effects from the population dynamics of exploited marine fish stocks. However, recent studies have shown that internal characteristics and external forcing (climate and exploitation) have interactive rather than additive effects. Thought most of these studies explored how demographic truncation induced by exploitation affected the response of recruitment to climate, identifying a general pattern revealed to be difficult as interactions are often case-specific. Here we compared five exploited stocks of European hake Merluccius merluccius from the Atlantic Ocean and Mediterranean Sea to investigate how the interaction between internal characteristics and external forces affect the... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00079/19008/17561.pdf |
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| Casini, Michele; Rouyer, Tristan; Bartolino, Valerio; Larson, Niklas; Grygiel, Wlodzimierz. |
| Spatio-temporal density-dependent processes are crucial regulatory factors for natural populations. However, there is a lack of studies addressing spatial density-dependence in fish growth. A previous investigation has suggested spatio-temporal density-dependence in body condition of Baltic sprat. Here, we used different techniques, such as centre of gravity, distance, and homogeneity indices, to better characterize the spatial and temporal variations in sprat density and body condition in the Baltic Proper. Our results evidenced a negative spatio-temporal co-variation between the centres of gravity of density and maximum condition. In the 1980s-early 1990s both centres were located in the middle of the Baltic Proper. From the mid 1990s the centres... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00190/30091/28745.pdf |
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| Sardenne, Fany; Bodin, Nathalie; Metral, Luisa; Crottier, Anais; Le Grand, Fabienne; Bideau, Antoine; Brisset, Blandine; Bourjea, Jerome; Saraux, Claire; Bonhommeau, Sylvain; Kerzerho, Vincent; Bernard, Serge; Rouyer, Tristan. |
| Various protocols are currently used to study marine lipids, but there is a growing interest in working on dry samples that are easier to transport. However, reference protocols are still lacking for dry samples. In order to make recommendations on this use, lipid classes and fatty acids (FA) obtained from six analytical protocols using two different tissue states (dry vs wet) and three extraction methods (automat vs manual potter vs leaving the solvent to work on tissue) were compared. Three dry storage modes of tissue (freezer vs gas nitrogen vs dry room) during one and three months were also compared. These comparisons were made on seven marine species with different lipid profiles, including fishes, crustaceans and mollusks. Lipid classes and FA... |
| Tipo: Text |
Palavras-chave: Degradation; Freeze-drying; Lyophilization; Lipid class; Marine animal; Protocol. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00467/57898/60189.pdf |
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| Rouyer, Tristan; Fromentin, Jean-marc; Stenseth, Nils Chr.. |
| Environmental variables affect many processes of fish biology and their fluctuations are thought to be one of the main factors in variability of fish stocks. Recent work has shown that the variability of the environment in the frequency domain (i.e., the environmental noise) can interact with endogenous processes (e.g., density dependence) and affect fluctuations of animal populations. In this study, we investigate whether fluctuations of large pelagics' time series are affected by environmental noise and whether life-history traits of species modulate this response. By analysing several environmental variables and a large dataset of tuna and billfish catch per unit effort (CPUE) time series from the Atlantic, we show that in environments dominated by... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12230/9083.pdf |
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| Chassot, E; Rouyer, Tristan; Trenkel, Verena; Gascuel, D. |
| The trophic level mean and variance, and the degree of omnivory for five Celtic Sea fish predators were estimated using a database of stomach content records characterized by a high level of taxonomic resolution. The predators occupied a high position in the food web, i.e. 4.75 for Atlantic cod Gadus morhua, 444 for haddock Melanogrammus aeglefinus, 4.88 for European hake Merluccius merluccius, 5.00 for megrim Lepidorhombus whiffiagonis and 5.27 for whiting Merlangius merlangus. The level of taxonomic resolution of the prey did not greatly affect mean T-L predator values; an effect on variance was evident, low resolution masking intra-population variability in T-L. Generalized additive models (GAM) were used to explain the variability of predator T-L... |
| Tipo: Text |
Palavras-chave: Trophic level; Predation; Omnivory; Indicator; GAM; Food web. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4699.pdf |
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| David-grignot, Stephane; Lamlih, Achraf; Belhaj, Mohamed Moez; Kerzerho, Vincent; Azais, Florence; Soulier, Fabien; Freitas, Philippe; Rouyer, Tristan; Bonhommeau, Sylvain; Bernard, Serge. |
| In the context of biosensor as much as Built-In-Self Test (BIST), on-chip sine-wave signal generation is a recurring research topic. Considering the implementation constraints, it implies a trade-off between the amount of resources and the signal quality. An attractive solution consists in combining several digital signals to build this analog sine-wave. The objective of this paper is to give an analytic study of various potential digital-based solutions. Thanks to this study, we prove that the technique consisting in setting the phase shifts and various amplitude values of the square-wave signals is the most efficient approach. This study allows the selection of the optimal square-wave signal parameters to cancel low-order harmonics of the generated... |
| Tipo: Text |
Palavras-chave: Harmonic cancelation; Sine-wave generation; On-chip signal generation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00425/53678/54609.pdf |
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| Imzilen, Taha; Bonhommeau, Sylvain; Rouyer, Tristan; Kell, Laurence T; Chassot, Emmanuel; Barde, Julien. |
| In this note, we present an approach which has been recently used to execute online the set of codes used for eastern blue_n tuna (BFT-E) stock assessment at ICCAT. We aim at discussing the possible interest of the approach to the IOTC Community for focusing on Indian ocean tuna and tuna-like stocks and running other assesment models such as Stock Synthesis 3 (SS3). In 2014, ICCAT BFT-E working group has been able to execute thousands of model runs by using parallelization of R and Fortran codes on a supercomputer. This approach has a lot of scienti_c bene_ts, in particular for better including the multiple sources of uncertainty in assessment results and associated scienti_c advice. However, very few participants would be able to reproduce it without... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00360/47135/47084.pdf |
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| Corbineau, A.; Rouyer, Tristan; Fromentin, Jean-marc; Cazelles, B.; Fonteneau, Alain; Menard, Frederic. |
| Catch data of large pelagic fish such as tuna, swordfish and billfish are highly variable ranging from short to long term. Based on fisheries data, these time series are noisy and reflect mixed information on exploitation (targeting, strategy, fishing power), population dynamics (recruitment, growth, mortality, migration, etc.), and environmental forcing (local conditions or dominant climate patterns). In this work, we investigated patterns of variation of large pelagic fish (i.e. yellowfin tuna, bigeye tuna, swordfish and blue marlin) in Japanese longliners catch data from 1960 to 2004. We performed wavelet analyses on the yearly time series of each fish species in each biogeographic province of the tropical Indian and Atlantic Oceans. In addition, we... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12231/9029.pdf |
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| Registros recuperados: 37 | |
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