Pending Event Set Implementation

Táto práca sa zaoberá vytvorením knižnice v C++, ktorá implementuje rôzne varianty kalendára udalostí, ktorý sa používa na riadenia diskrétnych simulácií. Knižnica zahŕňa deväť rôznych implementácií kalendára udalostí, ktoré sú prístupné cez jednotné rozhranie. Toto rozhranie je navrhnuté tak, aby bolo jednoduché knižnicu rozšíriť o ďalšie implementácie. Okrem samotnej knižnice sa práca zaoberá aj návrhom a popisom testovacej aplikácie a zhodnotením časových zložitostí jednotlivých implementácií.This work aims to create a library in C++, which implements various variants of the pending event set, which is used in discrete simulations. The library includes nine different implementations of the pending event set, accessible through a single interface. This interface is designed to make it easy to extend the library with additional implementations. In addition to the library itself, the work also describes the design of the test application and evaluates the time complexity of individual implementations.

A Conflict-Resilient Lock-Free Calendar Queue for Scalable Share-Everything PDES Platforms

Emerging share-everything Parallel Discrete Event Simulation (PDES) platforms rely on worker threads fully sharing the workload of events to be processed. These platforms require efficient event pool data structures enabling high concurrency of extraction/insertion operations. Non-blocking event pool algorithms are raising as promising solutions for this problem. However, the classical non-blocking paradigm leads concurrent conflicting operations, acting on a same portion of the event pool data structure, to abort and then retry. In this article we present a conflict-resilient non-blocking calendar queue that enables conflicting dequeue operations, concurrently attempting to extract the minimum element, to survive, thus improving the level of scalability of accesses to the hot portion of the data structure---namely the bucket to which the current locality of the events to be processed is bound. We have integrated our solution within an open source share-everything PDES platform and report the results of an experimental analysis of the proposed concurrent data structure compared to some literature solutions

FlexQueue: Simple and Efficient Priority Queue for System Software

Existing studies of priority queue implementations often focus on improving canonical operations such as insert and deleteMin, while sacrificing design simplicity and pre- dictable worst-case latency. Design simplicity is sacrificed as the algorithm becomes more and more optimized, taking into account characteristics of the input workload distribution. Predictable worst-case latency is sacrificed when operations such as memory allocation and structural re-organization are deferred until absolutely necessary. While these techniques often yield performance improvement to some degree, it is possible to take a step back and ask a more basic question: is it possible to achieve similar performance while retaining a simple design? By combining techniques such as hierarchical bit-vector and dynamic horizon resizing, all of which are straight-forward in principle, this thesis presents a new priority queue design called FlexQueue, that answers this question with a definitive “yes”

URSIM reference manual

technical reportSimulation has emerged as an important method for evaluating new ideas in both uniprocessor and multiprocessor architecture. Compared to building real hardware, simulation provides at least two advantages. First, it provides the flexibility to modify various architectural parameters and components and to analyze the benefits of such modifications. Second, simulation allows detailed statistics collection, providing a better understanding of the tradcoffs involved and facilitating further performance tuning

September 9, 2015

https://egrove.olemiss.edu/thedmonline/2194/thumbnail.jp

MALE REPRODUCTIVE STRATEGIES IN WILD NORTHERN PIG-TAILED MACAQUES (MACACA LEONINA): TESTING THE PRIORITY-OF-ACCESS MODEL

Among multi-male, multi-female primate groups, males engage in direct contest competition for access to mates. The priority-of-access model (PoA model) generally predicts that male reproductive success increases with male dominance rank, but the strength of this relationship is expected to decrease with increasing female reproductive synchrony, particularly in seasonally breeding primates. Genetic paternity studies support the model’s predictions, having found a positive relationship between male dominance rank and reproductive success. However, in addition to dominance status and female reproductive synchrony, a number of proximate factors also impact males’ ability to sire offspring, which have not been considered in studies of male reproductive strategies.By integrating behavioral, genetic, morphological, and hormonal analysis as more direct measures of reproductive success in individual males, this dissertation investigated the relationship between male dominance rank and reproductive success and including the proximate factors affecting this relationship in wild northern pig-tailed macaques (Macaca leonina). The main objectives of this study are: 1) to identify the relationships between male dominance rank, male mating success, and male reproductive success, and assess to what extent female synchrony affects these relationships; 2) to identify the proximate factors that may reduce the reproductive success of the top-ranking male and assess variation in male mating tactics related to dominance rank and migration status (i.e., resident males vs. extra-group males); and 3) to evaluate the function of males’ red ornaments that may be used to signal male dominance status (male-male competition) to attract females (female mate choice) or both. The study was conducted at Khao Yai National Park, northeastern Thailand. Systematic data collection on CH group occurred from September 2015-June 2017. The group composition was recorded daily as well as births, deaths, individual emigrations and immigrations, females’ parity status, and the presence of extra-group males (EGMs). Sociosexual data and male-female interactions (i.e., copulations, ejaculatory copulations, consortships, grooming, female proceptive behaviors and receptive behaviors) were recorded during females’ receptive periods. To assess male reproductive success, genetic paternity analyses were conducted on fecal DNA samples collected from 18 adult and subadult males, 22 adult females, and 25 juveniles and infants. To measure red skin coloration of males, hindquarter images were collected non-invasively for seven adult males. From those images, skin color and luminance were computationally quantified to assess variation in male anogenital reflectance. Lastly, fecal samples were collected from nine adult males to assess monthly levels of fecal testosterone by microtitreplate enzyme immunoassay. The distribution of births and matings suggested that northern pig-tailed macaques, at least in this group, are best categorized as moderate seasonal breeders. Indeed, 33-67% of births occurred within a three-month period. Copulation data revealed a positive relationship between male dominance rank and mating success, supporting the predictions of the PoA model. However, the distribution of male reproductive success indicated that: 1) high-ranking males controlled a proportion of paternity much lower than predicted by the PoA model; 2) middle-ranking males controlled a proportion of paternity higher than predicted by the model; and 3) EGMs, not considered in the PoA model, controlled a surprisingly large proportion of paternity despite a low observed mating success. When females were simultaneously receptive, lower-ranking and subadult males engaged in opportunistic and surreptitious copulation and avoided direct competition with higher-ranking males, and most females approached and mated with EGMs out of the resident adult males’ sight. However, one EGM also mated in full sight of resident adult males. This is the first study to report mating and successful paternity by EGMs in a moderately seasonally breeding species.Four male mating tactics were identified: 1) the top-ranking resident male tactic, in which the male competes for the alpha male position to control priority of access to receptive females through long consortships and copulations; 2) the lower-ranking resident male tactic, in which the male copulates opportunistically and surreptitiously out of sight of higher-ranking males mostly during the mating peak; 3) the subordinate EGM tactic, in which the male lives semi-solitarily and copulates opportunistically and surreptitiously, mostly during the mating peaks; and 4) the super-dominant EGM tactic, in which the EGM copulates irrespective of the presence of other males and in full sight of even the highest-ranking resident male. In addition, I found support for female mate choice. Darker and redder males had more mating partners, received more female proceptive behaviors, and were engaged in more consortships and grooming with receptive females. Furthermore, males became redder and darker as female reproductive synchrony increased. Together, these results suggest that male red ornaments exhibited in the male’s anogenital area is attractive to females. Furthermore, behavioral evidence of female mate choice towards EGMs was found. This dissertation provides a comprehensive picture of the complex male mating tactics of northern pig-tailed macaques. To achieve reproductive success, males engage in a diversity of mating tactics, strongly influenced by male dominance rank and the degree of female reproductive synchrony. However, mate-guarding costs, surreptitious copulations by lower-ranking males and EGMs, and female mate choice, need to be included in an extended version of the PoA model to provide stronger predictions of the distribution of male reproductive success in primates

Data Bandwidth Reduction Techniques For Distributed Embedded Simulatio

Maintaining coherence between the independent views of multiple participants at distributed locations is essential in an Embedded Simulation environment. Currently, the Distributed Interactive Simulation (DIS) protocol maintains coherence by broadcasting the entity state streams from each simulation station. In this dissertation, a novel alternative to DIS that replaces the transmitting sources with local sources is developed, validated, and assessed by analytical and experimental means. The proposed Concurrent Model approach reduces the communication burden to transmission of only synchronization and model-update messages. Necessary and sufficient conditions for the correctness of Concurrent Models in a discrete event simulation environment are established by developing Behavioral Congruence ¨B(EL, ER) and Temporal Congruence ¨T(t, ER) functions. They indicate model discrepancies with respect to the simulation time t, and the local and remote entity state streams EL and ER, respectively. Performance benefits were quantified in terms of the bandwidth reduction ratio BR=N/I obtained from the comparison of the OneSAF Testbed Semi-Automated Forces (OTBSAF) simulator under DIS requiring a total of N bits and a testbed modified for the Concurrent Model approach which required I bits. In the experiments conducted, a range of 100 d BR d 294 was obtained representing two orders of magnitude reduction in simulation traffic. Investigation showed that the models rely heavily on the priority data structure of the discrete event simulation and that performance of the overall simulation can be enhanced by an additional 6% by improving the queue management. A low run-time overhead, self-adapting storage policy called the Smart Priority Queue (SPQ) was developed and evaluated within the Concurrent Model. The proposed SPQ policies employ a lowcomplexity linear queue for near head activities and a rapid-indexing variable binwidth calendar queue for distant events. The SPQ configuration is determined by monitoring queue access behavior using cost scoring factors and then applying heuristics to adjust the organization of the underlying data structures. Results indicate that optimizing storage to the spatial distribution of queue access can decrease HOLD operation cost between 25% and 250% over existing algorithms such as calendar queues. Taken together, these techniques provide an entity state generation mechanism capable of overcoming the challenges of Embedded Simulation in harsh mobile communications environments with restricted bandwidth, increased message latency, and extended message drop-outs