Hybrid Simulation Safety: Limbos and Zero Crossings

Physical systems can be naturally modeled by combining continuous and discrete models. Such hybrid models may simplify the modeling task of complex system, as well as increase simulation performance. Moreover, modern simulation engines can often efficiently generate simulation traces, but how do we know that the simulation results are correct? If we detect an error, is the error in the model or in the simulation itself? This paper discusses the problem of simulation safety, with the focus on hybrid modeling and simulation. In particular, two key aspects are studied: safe zero-crossing detection and deterministic hybrid event handling. The problems and solutions are discussed and partially implemented in Modelica and Ptolemy II

Spontaneous Coherent Pulsations in Standing-Wave Laser Oscillators: Simplified Models

A series of simplifications and approximations is introduced into a recently described model for spontaneous pulsations in standing-wave laser oscillators. To the extent that these simplifications are valid they can lead to significant reductions in computation time and sometimes also to a better understanding of the relative importance of various physical effects. Of special interest is the number of spatial harmonics required to represent adequately the effects of longitudinal spatial hole burning. Other approximations investigated include neglect of spectral cross relaxation, neglect of multiple-energy-level equations, neglect of electric-field derivatives, and neglect of polarization derivatives. In addition, a detailed discussion is includede that concerns the most efficient numerical implementation of the model

Cumulate causes for the low contents of sulfide-loving elements in the continental crust

Despite the economic importance of chalcophile (sulfide-loving) and siderophile (metal-loving) elements (CSEs), it is unclear how they become enriched or depleted in the continental crust, compared with the oceanic crust. This is due in part to our limited understanding of the partitioning behaviour of the CSEs. Here I compile compositional data for mid-ocean ridge basalts and subduction-related volcanic rocks. I show that the mantle-derived melts that contribute to oceanic and continental crust formation rarely avoid sulfide saturation during cooling in the crust and, on average, subduction-zone magmas fractionate sulfide at the base of the continental crust prior to ascent. Differentiation of mantle-derived melts enriches lower crustal sulfide- and silicate-bearing cumulates in some CSEs compared with the upper crust. This storage predisposes the cumulate-hosted compatible CSEs (such as Cu and Au) to be recycled back into the mantle during subduction and delamination, resulting in their low contents in the bulk continental crust and potentially contributing to the scarcity of ore deposits in the upper continental crust. By contrast, differentiation causes the upper oceanic and continental crust to become enriched in incompatible CSEs (such as W) compared with the lower oceanic and continental crust. Consequently, incompatible CSEs are predisposed to become enriched in subduction-zone magmas that contribute to continental crust formation and are less susceptible to removal from the continental crust via delamination compared with the compatible CSEs

Human Infections with Plasmodium knowlesi, the Philippines.

Five human cases of infection with the simian malaria parasite Plasmodium knowlesi from Palawan, the Philippines, were confirmed by nested PCR. This study suggests that this zoonotic infection is found across a relatively wide area in Palawan and documents autochthonous cases in the country

An image-based visual strategy for working with color contrasts during design

acceptedVersio

Investigating the Relationship between Kadazandusun Beliefs about Paddy Spirits, Riddling in Harvest-time and Paddy-Related Sundait

During recent field trips to collect sundait (riddles) from Kadazandusun communities in Sabah, it was noted that many of the riddle answers relate to paddy farming: for example, rice planting activities and related paraphernalia are often mentioned. This paper analyzes collected Kadazandusun “paddyrelated” sundait based on their social context and background. In addition, it also examines traditional beliefs in paddy spirits and the origin of riddling at harvest-time. Some unique aspects of paddy-related sundait are highlighted and the relationship between the belief in paddy spirits and the ritual of harvest riddling is further explored

ARTICULATED DIFFICULTIES OF GRADE 11 STUDENTS AT TAYTAY SENIOR HIGH SCHOOL (TSHS) IN ENGLISH PROFICIENCY

English has been the medium of instruction since the beginning of the 20th century in the Philippines during the arrival of the Americans. This has been incorporated holistically in the society through the educational system, communication, mass media, publications and social media. It is given therefore that Filipino learners are bilingual-- i.e., speaking both Filipino (the native tongue) and English as Second Language (ESL). After a century though, proficiency in the language is still a difficulty and an anxiety, especially from public school learners. In Taytay Senior High School (a public senior high school), Grade 11 students were observed of certain levels of difficulties in reading, writing, speaking and listening. In this study, the researchers probed deeper into the following: a.) the difficulties experienced by grade 11 students b.) the factors that led to such difficulties and c.) the articulated ways to help them overcome such difficulties in English proficiency. As a descriptive study, the researchers used pre-survey, survey, FGD and extensive literature review as methodologies. The survey results revealed problematic stages on vocabulary, training and knowledge, confidence and self-esteem and interest. Articulated in the FGD furthermore were issues of generation, practice/articulation, and system as factors that led to difficulties in reading writing, speaking and listening. On the other hand, Grade 11 students underscored power of mind, the use of native language and practice as methodical solutions to the problem. Further directions of this study could include elaboration of the FGD results that pertain to issues of generation, practice/articulation and system. The use of native language could also be expounded on future studies

ARTICULATED DIFFICULTIES OF GRADE 11 STUDENTS AT TAYTAY SENIOR HIGH SCHOOL (TSHS) IN ENGLISH PROFICIENCY

English has been the medium of instruction since the beginning of the 20th century in the Philippines during the arrival of the Americans. This has been incorporated holistically in the society through the educational system, communication, mass media, publications and social media. It is given therefore that Filipino learners are bilingual-- i.e., speaking both Filipino (the native tongue) and English as Second Language (ESL). After a century though, proficiency in the language is still a difficulty and an anxiety, especially from public school learners. In Taytay Senior High School (a public senior high school), Grade 11 students were observed of certain levels of difficulties in reading, writing, speaking and listening. In this study, the researchers probed deeper into the following: a.) the difficulties experienced by grade 11 students b.) the factors that led to such difficulties and c.) the articulated ways to help them overcome such difficulties in English proficiency. As a descriptive study, the researchers used pre-survey, survey, FGD and extensive literature review as methodologies. The survey results revealed problematic stages on vocabulary, training and knowledge, confidence and self-esteem and interest. Articulated in the FGD furthermore were issues of generation, practice/articulation, and system as factors that led to difficulties in reading writing, speaking and listening. On the other hand, Grade 11 students underscored power of mind, the use of native language and practice as methodical solutions to the problem. Further directions of this study could include elaboration of the FGD results that pertain to issues of generation, practice/articulation and system. The use of native language could also be expounded on future studies