PCODE: an efficient and reliable collective communication protocol for unreliable broadcast domain

Existing programming environments for clusters are typically built on top of a point-to-point communication layer (send and receive) over local area networks (LANs) and, as a result, suffer from poor performance in the collective communication part. For example, a broadcast that is implemented using a TCP/IP protocol (which is a point-to-point protocol) over a LAN is obviously inefficient as it is not utilizing the fact that the LAN is a broadcast medium. We have observed that the main difference between a distributed computing paradigm and a message passing parallel computing paradigm is that, in a distributed environment the activity of every processor is independent while in a parallel environment the collection of the user-communication layers in the processors can be modeled as a single global program. We have formalized the requirements by defining the notion of a correct global program. This notion provides a precise specification of the interface between the transport layer and the user-communication layer. We have developed PCODE, a new communication protocol that is driven by a global program and proved its correctness. We have implemented the PCODE protocol on a collection of IBM RS/6000 workstations and on a collection of Silicon Graphics Indigo workstations, both communicating via UDP broadcast. The experimental results we obtained indicate that the performance advantage of PCODE over the current point-to-point approach (TCP) can be as high as an order of magnitude on a cluster of 16 workstations

Voice and Choice: Learning Expression Choice Boards for Learning Reflection

Learner variability can provide a barrier for educators to provide meaningful learning experiences. With consideration for universal design for learning, the learning expression choice board was tested in an undergraduate preservice teacher course (n=56) to provide opportunities for students to reflect on their learning in a way that was meaningful to them. Students in the course were asked at the end of the semester if they would try learning expression boards in their classroom, and 90% agreed/strongly agreed. An ANOVA test showed no significant difference (>.05) in the variables of GPA, class standing, high school dual enrollment participation, intended student teaching date, gender association or transfer student status. Given the appeal to all students, and the intention to try the universal design strategy, practitioners should continue to explore the learning expression choice board in their courses as a method to foster meaningful reflection

Association between personality characteristics and an orientation to conflict resolution with a general systems interpretation

Purpose of the Study Redacted for Privacy J. Richard Connelly This study was to look at: (1) the orientation subjects' had toward the resolution of conflict situations, and (2) associations between personality traits, selected demographic characteristics and subjects' orientation to conflict resolution. Procedures Eighty-seven subjects, 23 male and 64 female college students, were given a pre- and post-assessment on their orientation to conflict resolution via the Modified Conflict Resolution Inventory (MCRI). They were administered two personality scales: Edwards Personal Preference Schedule (general need traits) and Taylor-Johnson Temperament Analysis (socially oriented traits); they filled out a demographic data questionnaire and responded to a Relevance of Conflict Resolution instrument. An intervening variable of training in a Need approach to conflict resolution was given to assure subjects had an exposure to this approach. Training was not assessed as to its effectiveness. Subjects were classified on the dependent variable, their orientation to conflict resolution, as Issue or Need oriented. The Need orientation followed after the work of William Glasser (1967), who defines two basic psycho-social needs of man as: (1) the need to love and be loved, and (2) the need to feel worthwhile to oneself and others. Two sets of judges were used to rate subjects on the dependent variable classifications. Three regular judges' ratings were used as the subjects' classifications, the other set of judges' ratings were used for reliability assessment. Findings All 87 subjects were rated as Issue oriented on the pre-MCRI; 31 of the subjects shifted to the Need orientation on the post-MCRI. Independent variable scores were associated with the post-MCRI assessments through a step-wise discriminant analysis. Two independent variables--heterosexuality from EPPS and activation from RCR--were significant in the discriminant function, but each represented so many mis-classifications as to have relatively little value as discriminators. Significance in the discriminant function is based only on a difference between groups' means and not on the amount of variance accounted for. Interpretation The General Systems Theory perspective was used to interpret the findings. The 31 subjects who changed from an Issue to a Need orientation were ones who had received and processed information that allowed the Need selection on the posttest. None of the subjects had the prerequisite information to make a pre-test Need selection- - training was essential. The General Systems perspective is that substantive differences, i.e. , scores on personality traits, are not important in looking at behaviors. Subjects' goals and purposes are important as they fit in the environmental melieu. It is the purpose of the subject and not a score on a trait that must be looked at for understanding behavior. Processing of information is what determines the goals or purposes as they change in time. The independent variable of activation was seen as the most valuable, though it needs refinement, because it started to look at information about the subjects' purposes vis-a-vis conflict situations. Conclusions 1. There were no personality traits or demographic characteristics which had substantive differences that gave good discrimination between Issue and Need orientation to resolution of conflicts by the subjects. 2. A behavioral selection can only be made when the prerequisite information is present for the selection. In looking at behaviors, it is far more economical to look at information processed, which is used by the individual to set and modify goals and purposes, than to look for cause and effect relationships. 3. Further development of the MCRI and RCR would help refine these instruments for greater use in research and training or therapy

Efficient Message Passing Interface (MPI) for Parallel Computing on Clusters of Workstations

Parallel computing on clusters of workstations and personal computers has very high potential, since it leverages existing hardware and software. Parallel programming environments offer the user a convenient way to express parallel computation and communication. In fact, recently, a Message Passing Interface (MPI) has been proposed as an industrial standard for writing "portable" message-passing parallel programs. The communication part of MPI consists of the usual point-to-point communication as well as collective communication. However, existing implementations of programming environments for clusters are built on top of a point-to-point communication layer (send and receive) over local area networks (LANs) and, as a result, suffer from poor performance in the collective communication part. In this paper, we present an efficient design and implementation of the collective communication part in MPI that is optimized for clusters of workstations. Our system consists of two main components: the MPI-CCL layer that includes the collective communication functionality of MPI and a User-level Reliable Transport Protocol (URTP) that interfaces with the LAN Data-link layer and leverages the fact that the LAN is a broadcast medium. Our system is integrated with the operating system via an efficient kernel extension mechanism that we developed. The kernel extension significantly improves the performance of our implementation as it can handle part of the communication overhead without involving user space. We have implemented our system on a collection of IBM RS/6000 workstations con- nected via a lOMbit Ethernet LAN. Our performance measurements are taken from typical scientific programs that run in a parallel mode by means of the MPI. The hypothesis behind our design is that system's performance will be bounded by interactions between the kernel and user space rather than by the bandwidth delivered by the LAN Data-Link Layer. Our results indicate that the performance of our MPI Broadcast (on top of Ethernet) is about twice as fast as a recently published software implementation of broadcast on top of ATM

Likert Versus Cronbach's Psychometric Thresholds: Reducing Error and Maximizing Agricultural Education's Scholarship Impacts

Instrumentation is a critical function in measuring social and behavioral science impacts on stakeholders, teachers, and change agents. Internal validity and reliability have long been considered social sciences’ quality gatekeepers. A systematic review uses a comprehensive search based on explicit protocols to review existing literature with a synthesis of data focusing on key questions. Systematic reviews are five steps; identify the critical question, formulate search parameters, systematically search databases, analyze data, and data summary interpretation (Lee et al., 2021). Using the five steps, authors systematically reviewed all articles from Advancements in Agricultural Development (AAD), Journal of Agricultural Education (JAE), Journal of Extension (JOE), and The Journal of Agricultural Education and Extension (TJAEE) from 2018 to 2022. The authors reviewed eight hundred ninety-six (N = 896) articles from the four publications. Fewer items produced lower construct reliability coefficients and thus, produced higher levels of error. Much of agricultural education’s, broadly defined, published scholarship has not utilized instruments to collect data over the last five years; when they have, smaller numbers of items measured constructs. Likert’s convention in his quintessential work on measuring social variables suggested that for measurements to be reliable an alpha of .9 should be achieved. Researchers should include a maximum number of statements and questions and eliminate those that do not contribute to reliability and add additional questions when acceptable levels of reliability are not achieved.USDA NIFA Hatch Project 09890 “The Adoption Impact of Food and Agricultural Sciences Curricula on Public Health.

Preembryo Personhood: An Assessment of the President’s Council Arguments

The President’s Council on Bioethics has addressed the moral status of human preembryos in its reports on stem cell research and human therapeutic cloning. Although the Council has been criticized for being hand-picked to favor the right-to-life viewpoint concerning human preembryos, it has embraced the idea that the right-to-life position should be defended in secular terms. This is an important feature of the Council’s work, and it demonstrates a recognition of the need for genuine engagement between opposing sides in the debate over stem cell research. To promote this engagement, the Council has stated in secular terms several arguments for the personhood of human preembryos. This essay presents and critiques those arguments, and it concludes that they are unsuccessful. If the best arguments in support of the personhood of human preembryos have been presented by the Council, then there are no reasonable secular arguments in support of that view