RESUMO-O trabalho foi realizado em uma área particular de tabuleiro de ocorrência natural no lito... more RESUMO-O trabalho foi realizado em uma área particular de tabuleiro de ocorrência natural no litoral norte do município de Maceió, bairro de Garça Torta Estado de Alagoas. As observações foram realizadas durante o período de floração da espécie vegetal, compreendendo os meses de novembro e dezembro de 2008. O visitante floral observado na espécie foi exclusivamente abelhas pertencentes à família Apidae representante da tribo Centridini destacando papel fundamental no processo reprodutivo do muricizeiro. Palavras-Chave: Abelhas solitárias, abelhas de óleo, Byrsonima verbascifolia. OCORÊNCIA DE ABEJAS DA LA TRIBO CENTRIDINI COMO AGENTE POLINIZADOR DEL MURICIZEIRO (Byrsonima verbascifolia) EN EL TABULEIRO COSTERO DE ALAGOAS. RESUMEN-El trabajo ha sido realizado en una área particular del tabuleiro de ocorência natural en el litoral norte del sitio em el Maceió, bairo de la Garça Torta en el Estado de Alagoas Brazil. Las observaciones fueran realizadas en el período de la floracion da la espécie vegetal, compreendendo los meses de novienbro e decienbro de 2008. El visitante floral observado en la espécie fue exclusivamente abejas pertencentes la familia Apidae representante da la tribo Centridini destacando el papel fundamentale en el proceso reproductivo del muricizeiro.
We consider the synthesis of a reactive module with input x and output y, which is specified by t... more We consider the synthesis of a reactive module with input x and output y, which is specified by the linear temporal formula ~(2, y). We show that there exists a program satisfying 'P iff the branching time formula (Vx)(Zly)A~(z, y) is valid over all tree models. For the restricted case that all variables range over finite domains, the validity problem is decidable, and we present an algorithm for constructing the program whenever it exists. The algorithm is based on a new procedure for checking the emptiness of Rabin automata on infinite trees in time exponential in the number of pairs, but only polynomial in the number of states. This leads to a synthesis algorithm whose complexity is double exponential in the length of the given specification.
International Symposium on Code Generation and Optimization, 2004. CGO 2004., 2004
We study several major characteristics of dynamic optimization within the PARROT power-aware, tra... more We study several major characteristics of dynamic optimization within the PARROT power-aware, trace-cachebased microarchitectural framework. We investigate the benefit of providing optimizations which although tightly coupled with the microarchitecture in substance are decoupled in time.
We consider the synthesis of a reactive module with input x and output y, which is specified by t... more We consider the synthesis of a reactive module with input x and output y, which is specified by the linear temporal formula (x, y). We show that there exists a program satisfying iff the branching time formula (x)(y)A(x, y) is valid over all tree models.
We present the PARROT concept aimed at both higher performance and power-awareness. The PARROT mi... more We present the PARROT concept aimed at both higher performance and power-awareness. The PARROT microarchitectural framework integrates trace caching, dynamic optimizations and pipeline decoupling. We employ a gradual and selective approach for applying complex mechanisms only for the most frequently used traces to maximize the performance gain at any given power constraint, thus attaining finer control of tradeoffs between performance and power awareness. We show that the PARROT microarchitecture delivers performance increases comparable to those available through conventional doubling of execution resources (average 16% IPC improvement). This improvement comes through better utilization of all available resources with the combination of a trace cache and selective trace optimization. On the other hand, performance advantage of a trace cache alone is limited to wide-machine configurations. No less critical, however, is power awareness. The PARROT microarchitecture delivers the performance increase at a comparable energy level, whereas the conventional path to higher performance consumes an average 70% more energy. Meanwhile, for those designs which can tolerate a higher power budget, PARROT gracefully scales up to use additional execution resources in a uniformly efficient manner. In particular, a PARROT-style doubly-wide machine delivers an average 45% IPC improvement while actually improving the Cubic-MIPS-per-WATT power awareness metric by over 50%.
We present the PARROT concept that seeks to achieve higher performance with reduced energy consum... more We present the PARROT concept that seeks to achieve higher performance with reduced energy consumption through gradual optimization of frequently executed code traces. The PARROT microarchitectural framework integrates trace caching, dynamic optimizations and pipeline decoupling. We employ a selective approach for applying complex mechanisms only upon the most frequently used traces to maximize the performance gain at any given power constraint, thus attaining finer control of tradeoffs between performance and power awareness.
Proceedings of the 17th annual international conference on Supercomputing - ICS '03, 2003
This paper performs a comprehensive investigation of dynamic selection for long atomic traces. It... more This paper performs a comprehensive investigation of dynamic selection for long atomic traces. It introduces a classification of trace selection methods and discusses existing and novel dynamic selection approaches -including loop unrolling, procedure inlining and incremental merging of traces based on dynamic bias. The paper empirically analyzes a number of selection schemes in an idealized framework.
The trace cache is becoming an important building block of modern, wide-issue, processors. So far... more The trace cache is becoming an important building block of modern, wide-issue, processors. So far, trace cache related research has been focused on increasing fetch bandwidth. Trace-caches have been shown to effectively increase the number of "useful" instructions that can be fetched into the machine, thus enabling more instructions to be executed each cycle. However, trace cache has another important benefit that got less attention in recent research: especially for variable length ISA, such as Intel's IA-32 architecture (X86), reducing instruction decoding power is particularly attractive. Keeping the instruction traces in decoded format, implies the decoding power is only paid upon the build of a trace, thus reducing the overall power consumption of the system. This paper has three main contributions: it indicates that trace cache optimizations directed to reducing power consumption are do not necessarily coincide with optimizations directed to increasing fetch bandwidth; it extends our understanding on how well the trace cache utilizes its resources and introduces a new trace-cache organization based on filtering techniques. The knowledge obtained from the analysis of the traces' behavioral patterns motivates the use of filtering techniques. The new trace-cache organization increases the effective instruction-fetch bandwidth in conjunction with reducing the power consumption of the trace-cache system. We observe that (1) the majority of traces that are inserted into the trace-cache are rarely used again before being replaced; (2) the majority of the instructions delivered for execution originate from the fewer traces that are heavily and repeatedly used; and that (3) techniques that aim to improve instruction-fetch bandwidth may increase the number of traces built during program execution. Based on these observations, we propose splitting the trace cache into two components: the filter trace-cache (FTC) and the main trace-cache (MTC). Traces are first inserted into the FTC that is used to filter out the infrequently used traces; traces that prove "useful" are later moved into the MTC itself. The FTC/MTC organization exhibits an important benefit: it decreases the number of traces built, thus reducing power consumption while improving overall performance. For medium-size applications, the FTC/MTC pair reduces the number of trace builds by 16% in average. An extension of the filtering concept involves adding a second level (L2) trace-cache that stores less frequent traces that are replaced in the FTC or the MTC. The extra level of caching allows for order-of-magnitude reduction in the number of trace builds. Second level trace cache proves particularly useful for applications with large instruction footprints.
This paper considers the problem of synthesizing a finite-state distributed reactive system. Give... more This paper considers the problem of synthesizing a finite-state distributed reactive system. Given a distributed architecture A, identifying several processors 9 , . . . , 9, and their interconnection scheme, and a propositional temporal specification 'P, a solution to the synthesis problem consists of finite-state programs II1, . . . , I I k (one for each processor), whose joint (synchronous) behavior maintains ' P against all possible inputs from the environment. We refer to such a solution as the realization of the specification ' P over the architecture A. The work reported here extends the finite-state reactive synthesis studies reported in [PR88, PR89aI and also in [ALW89], that did not impose a given architecture, and hence standardly yielded a solution based on the easiest architecture, that of a single processor.
We consider the synthesis of a reactive module with input x and output y, which is specified by t... more We consider the synthesis of a reactive module with input x and output y, which is specified by the lin-ear temporal formula ~(2, y). We show that there exists a program satisfying 'P iff the branching time formula (Vx)(Zly)A~(z, y) is valid over all tree mod-els. For the restricted case that all ...
Proceedings - Symposium on Logic in Computer Science, 1990
In this paper we continue the study of the inherent power of bounded cooperative concurrency, whe... more In this paper we continue the study of the inherent power of bounded cooperative concurrency, whereby an automaton can be in some bounded number of states that cooperate in accepting the input. The present paper addresses the difficulty of reasoning about programs. Specifically, we consider the question of whether the additional succinctness that bounded concurrency provides influences the complexity of reasoning about regulzr computation sequences on the propositional level. Our results concern dynamic, temporal, and process logics, and supply a strongly affirmative answer. In particular, we prove triple-exponential time upper and lower bounds on deciding the validity of proppositional dynamic logic with alternating automata enriched with bounded cooperative concurrency, and quadruple-exponential time bounds for deciding validity of branhcing-time and process logics with such automata. In addition to constituting further evidence for the inherent exponential nature of bounded concurrency, the results appear to provide the first examples of natural decision problems that are ele-*mentary yet have lower bounds that are higher than double-exponential time.
Reprogramming to pluripotency is a low-efficiency process at the population level. Despite notabl... more Reprogramming to pluripotency is a low-efficiency process at the population level. Despite notable advances to molecularly characterize key steps, several fundamental aspects remain poorly understood, including when the potential to reprogram is first established. Here, we apply live-cell imaging combined with a novel statistical approach to infer when somatic cells become fated to generate downstream pluripotent progeny. By tracing cell lineages from several divisions before factor induction through to pluripotent colony formation, we find that pre-induction sister cells acquire similar outcomes. Namely, if one daughter cell contributes to a lineage that generates induced pluripotent stem cells (iPSCs), its paired sibling will as well. This result suggests that the potential to reprogram is predetermined within a select subpopulation of cells and heritable, at least over the short term. We also find that expanding cells over several divisions prior to factor induction does not incr...
Luca Aceto Peter Aczel Fabio Alessi Thorsten Altenkirch Rajeev Alur André Arnold Eugene Asarin Al... more Luca Aceto Peter Aczel Fabio Alessi Thorsten Altenkirch Rajeev Alur André Arnold Eugene Asarin Albert Atserias Reinhard Bündgen Matthias Baaz Eric Badouel Patrick Baillot Richard Banach Sharon Barner Jules Bean Oleg Belegradek Steve Bellantoni Josh Berdine Lorenzo Bettini Gavin Bierman Howard Blair Bruno Blanchet Achim Blumensath Michele Boreale Gerhard Brewka Harry Buhrman Sam Buss Doron Bustan Luis Caires Cristiano Calcagno Diego Calvanese Luca Cardelli Paul Caspi Iliano Cervesato Gang Chen Juliusz Chroboczek Dmitri Chubarov ...
Developmental processes in cells require a series of complex steps. Often only a single master re... more Developmental processes in cells require a series of complex steps. Often only a single master regulator activates genes in these different steps. This poses several challenges: some targets need to be ordered temporally, while co-functional targets may need to be synchronized in both time and expression level. Here we study in single cells the dynamic activation patterns of early meiosis genes in budding yeast, targets of the meiosis master regulator Ime1. We quantify the individual roles of the promoter and protein levels in expression pattern control, as well as the roles of individual promoter elements. We find a consistent expression pattern difference between a non-cofunctional pair of genes, and a highly synchronized activation of a co-functional pair. We show that dynamic control leading to these patterns is distributed between promoter, gene and external regions. Through specific reciprocal changes to the promoters of pairs of genes, we show that different genes can use different promoter elements to reach near identical activation patterns.
RESUMO-O trabalho foi realizado em uma área particular de tabuleiro de ocorrência natural no lito... more RESUMO-O trabalho foi realizado em uma área particular de tabuleiro de ocorrência natural no litoral norte do município de Maceió, bairro de Garça Torta Estado de Alagoas. As observações foram realizadas durante o período de floração da espécie vegetal, compreendendo os meses de novembro e dezembro de 2008. O visitante floral observado na espécie foi exclusivamente abelhas pertencentes à família Apidae representante da tribo Centridini destacando papel fundamental no processo reprodutivo do muricizeiro. Palavras-Chave: Abelhas solitárias, abelhas de óleo, Byrsonima verbascifolia. OCORÊNCIA DE ABEJAS DA LA TRIBO CENTRIDINI COMO AGENTE POLINIZADOR DEL MURICIZEIRO (Byrsonima verbascifolia) EN EL TABULEIRO COSTERO DE ALAGOAS. RESUMEN-El trabajo ha sido realizado en una área particular del tabuleiro de ocorência natural en el litoral norte del sitio em el Maceió, bairo de la Garça Torta en el Estado de Alagoas Brazil. Las observaciones fueran realizadas en el período de la floracion da la espécie vegetal, compreendendo los meses de novienbro e decienbro de 2008. El visitante floral observado en la espécie fue exclusivamente abejas pertencentes la familia Apidae representante da la tribo Centridini destacando el papel fundamentale en el proceso reproductivo del muricizeiro.
We consider the synthesis of a reactive module with input x and output y, which is specified by t... more We consider the synthesis of a reactive module with input x and output y, which is specified by the linear temporal formula ~(2, y). We show that there exists a program satisfying 'P iff the branching time formula (Vx)(Zly)A~(z, y) is valid over all tree models. For the restricted case that all variables range over finite domains, the validity problem is decidable, and we present an algorithm for constructing the program whenever it exists. The algorithm is based on a new procedure for checking the emptiness of Rabin automata on infinite trees in time exponential in the number of pairs, but only polynomial in the number of states. This leads to a synthesis algorithm whose complexity is double exponential in the length of the given specification.
International Symposium on Code Generation and Optimization, 2004. CGO 2004., 2004
We study several major characteristics of dynamic optimization within the PARROT power-aware, tra... more We study several major characteristics of dynamic optimization within the PARROT power-aware, trace-cachebased microarchitectural framework. We investigate the benefit of providing optimizations which although tightly coupled with the microarchitecture in substance are decoupled in time.
We consider the synthesis of a reactive module with input x and output y, which is specified by t... more We consider the synthesis of a reactive module with input x and output y, which is specified by the linear temporal formula (x, y). We show that there exists a program satisfying iff the branching time formula (x)(y)A(x, y) is valid over all tree models.
We present the PARROT concept aimed at both higher performance and power-awareness. The PARROT mi... more We present the PARROT concept aimed at both higher performance and power-awareness. The PARROT microarchitectural framework integrates trace caching, dynamic optimizations and pipeline decoupling. We employ a gradual and selective approach for applying complex mechanisms only for the most frequently used traces to maximize the performance gain at any given power constraint, thus attaining finer control of tradeoffs between performance and power awareness. We show that the PARROT microarchitecture delivers performance increases comparable to those available through conventional doubling of execution resources (average 16% IPC improvement). This improvement comes through better utilization of all available resources with the combination of a trace cache and selective trace optimization. On the other hand, performance advantage of a trace cache alone is limited to wide-machine configurations. No less critical, however, is power awareness. The PARROT microarchitecture delivers the performance increase at a comparable energy level, whereas the conventional path to higher performance consumes an average 70% more energy. Meanwhile, for those designs which can tolerate a higher power budget, PARROT gracefully scales up to use additional execution resources in a uniformly efficient manner. In particular, a PARROT-style doubly-wide machine delivers an average 45% IPC improvement while actually improving the Cubic-MIPS-per-WATT power awareness metric by over 50%.
We present the PARROT concept that seeks to achieve higher performance with reduced energy consum... more We present the PARROT concept that seeks to achieve higher performance with reduced energy consumption through gradual optimization of frequently executed code traces. The PARROT microarchitectural framework integrates trace caching, dynamic optimizations and pipeline decoupling. We employ a selective approach for applying complex mechanisms only upon the most frequently used traces to maximize the performance gain at any given power constraint, thus attaining finer control of tradeoffs between performance and power awareness.
Proceedings of the 17th annual international conference on Supercomputing - ICS '03, 2003
This paper performs a comprehensive investigation of dynamic selection for long atomic traces. It... more This paper performs a comprehensive investigation of dynamic selection for long atomic traces. It introduces a classification of trace selection methods and discusses existing and novel dynamic selection approaches -including loop unrolling, procedure inlining and incremental merging of traces based on dynamic bias. The paper empirically analyzes a number of selection schemes in an idealized framework.
The trace cache is becoming an important building block of modern, wide-issue, processors. So far... more The trace cache is becoming an important building block of modern, wide-issue, processors. So far, trace cache related research has been focused on increasing fetch bandwidth. Trace-caches have been shown to effectively increase the number of "useful" instructions that can be fetched into the machine, thus enabling more instructions to be executed each cycle. However, trace cache has another important benefit that got less attention in recent research: especially for variable length ISA, such as Intel's IA-32 architecture (X86), reducing instruction decoding power is particularly attractive. Keeping the instruction traces in decoded format, implies the decoding power is only paid upon the build of a trace, thus reducing the overall power consumption of the system. This paper has three main contributions: it indicates that trace cache optimizations directed to reducing power consumption are do not necessarily coincide with optimizations directed to increasing fetch bandwidth; it extends our understanding on how well the trace cache utilizes its resources and introduces a new trace-cache organization based on filtering techniques. The knowledge obtained from the analysis of the traces' behavioral patterns motivates the use of filtering techniques. The new trace-cache organization increases the effective instruction-fetch bandwidth in conjunction with reducing the power consumption of the trace-cache system. We observe that (1) the majority of traces that are inserted into the trace-cache are rarely used again before being replaced; (2) the majority of the instructions delivered for execution originate from the fewer traces that are heavily and repeatedly used; and that (3) techniques that aim to improve instruction-fetch bandwidth may increase the number of traces built during program execution. Based on these observations, we propose splitting the trace cache into two components: the filter trace-cache (FTC) and the main trace-cache (MTC). Traces are first inserted into the FTC that is used to filter out the infrequently used traces; traces that prove "useful" are later moved into the MTC itself. The FTC/MTC organization exhibits an important benefit: it decreases the number of traces built, thus reducing power consumption while improving overall performance. For medium-size applications, the FTC/MTC pair reduces the number of trace builds by 16% in average. An extension of the filtering concept involves adding a second level (L2) trace-cache that stores less frequent traces that are replaced in the FTC or the MTC. The extra level of caching allows for order-of-magnitude reduction in the number of trace builds. Second level trace cache proves particularly useful for applications with large instruction footprints.
This paper considers the problem of synthesizing a finite-state distributed reactive system. Give... more This paper considers the problem of synthesizing a finite-state distributed reactive system. Given a distributed architecture A, identifying several processors 9 , . . . , 9, and their interconnection scheme, and a propositional temporal specification 'P, a solution to the synthesis problem consists of finite-state programs II1, . . . , I I k (one for each processor), whose joint (synchronous) behavior maintains ' P against all possible inputs from the environment. We refer to such a solution as the realization of the specification ' P over the architecture A. The work reported here extends the finite-state reactive synthesis studies reported in [PR88, PR89aI and also in [ALW89], that did not impose a given architecture, and hence standardly yielded a solution based on the easiest architecture, that of a single processor.
We consider the synthesis of a reactive module with input x and output y, which is specified by t... more We consider the synthesis of a reactive module with input x and output y, which is specified by the lin-ear temporal formula ~(2, y). We show that there exists a program satisfying 'P iff the branching time formula (Vx)(Zly)A~(z, y) is valid over all tree mod-els. For the restricted case that all ...
Proceedings - Symposium on Logic in Computer Science, 1990
In this paper we continue the study of the inherent power of bounded cooperative concurrency, whe... more In this paper we continue the study of the inherent power of bounded cooperative concurrency, whereby an automaton can be in some bounded number of states that cooperate in accepting the input. The present paper addresses the difficulty of reasoning about programs. Specifically, we consider the question of whether the additional succinctness that bounded concurrency provides influences the complexity of reasoning about regulzr computation sequences on the propositional level. Our results concern dynamic, temporal, and process logics, and supply a strongly affirmative answer. In particular, we prove triple-exponential time upper and lower bounds on deciding the validity of proppositional dynamic logic with alternating automata enriched with bounded cooperative concurrency, and quadruple-exponential time bounds for deciding validity of branhcing-time and process logics with such automata. In addition to constituting further evidence for the inherent exponential nature of bounded concurrency, the results appear to provide the first examples of natural decision problems that are ele-*mentary yet have lower bounds that are higher than double-exponential time.
Reprogramming to pluripotency is a low-efficiency process at the population level. Despite notabl... more Reprogramming to pluripotency is a low-efficiency process at the population level. Despite notable advances to molecularly characterize key steps, several fundamental aspects remain poorly understood, including when the potential to reprogram is first established. Here, we apply live-cell imaging combined with a novel statistical approach to infer when somatic cells become fated to generate downstream pluripotent progeny. By tracing cell lineages from several divisions before factor induction through to pluripotent colony formation, we find that pre-induction sister cells acquire similar outcomes. Namely, if one daughter cell contributes to a lineage that generates induced pluripotent stem cells (iPSCs), its paired sibling will as well. This result suggests that the potential to reprogram is predetermined within a select subpopulation of cells and heritable, at least over the short term. We also find that expanding cells over several divisions prior to factor induction does not incr...
Luca Aceto Peter Aczel Fabio Alessi Thorsten Altenkirch Rajeev Alur André Arnold Eugene Asarin Al... more Luca Aceto Peter Aczel Fabio Alessi Thorsten Altenkirch Rajeev Alur André Arnold Eugene Asarin Albert Atserias Reinhard Bündgen Matthias Baaz Eric Badouel Patrick Baillot Richard Banach Sharon Barner Jules Bean Oleg Belegradek Steve Bellantoni Josh Berdine Lorenzo Bettini Gavin Bierman Howard Blair Bruno Blanchet Achim Blumensath Michele Boreale Gerhard Brewka Harry Buhrman Sam Buss Doron Bustan Luis Caires Cristiano Calcagno Diego Calvanese Luca Cardelli Paul Caspi Iliano Cervesato Gang Chen Juliusz Chroboczek Dmitri Chubarov ...
Developmental processes in cells require a series of complex steps. Often only a single master re... more Developmental processes in cells require a series of complex steps. Often only a single master regulator activates genes in these different steps. This poses several challenges: some targets need to be ordered temporally, while co-functional targets may need to be synchronized in both time and expression level. Here we study in single cells the dynamic activation patterns of early meiosis genes in budding yeast, targets of the meiosis master regulator Ime1. We quantify the individual roles of the promoter and protein levels in expression pattern control, as well as the roles of individual promoter elements. We find a consistent expression pattern difference between a non-cofunctional pair of genes, and a highly synchronized activation of a co-functional pair. We show that dynamic control leading to these patterns is distributed between promoter, gene and external regions. Through specific reciprocal changes to the promoters of pairs of genes, we show that different genes can use different promoter elements to reach near identical activation patterns.
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Papers by Roni Rosner