Experiences with Scala Across the College-Level Curriculum

Various hybrid-functional languages, designed to balance compile-time error detection, conciseness, and performance, have emerged. Scala, e.g., is interoperable with Java and has become an early leader in adoption, especially in the start-up and open-source spaces. As educators, we have recognized Scala’s value as a teaching language across the CS curriculum. In CS1, the read-eval-print loop and simple, uniform syntax aid programming in the small. In CS2, higher-order methods allow concise, efficient manipulation of collections. In a programming languages course, advanced constructs facilitate the separation of concerns, program representation and interpretation, and concurrent programming. In advanced applied courses, language mechanisms and suitable libraries support the development of mobile apps, web apps, and web services. Based on our own experiences in the classroom, we discuss what works and what needs improvement, and hope to discuss the best ways for industry and higher education to partner in an effort to meet the growing demand for Scala talent

Flash-Flood Monitoring and Modeling in Kentucky

This research project focused on the evaluation of hydrologic issue of flash-flooding in the state of Kentucky. The primary objectives of this project were the following:(1) to initiate the establishment of a hydrologic database archive necessary for characterizing rainfall and runoff associated with flash-flooding; (2) identification of appropriate modeling approaches for evaluating site-specific flash-flood runoff behavior. Specific tasks accomplished to meet the objectives include the following:(1) development of a rainfall and streamflow data archive using existing measurement gages and identification of the rain gage data from two sources for preliminary quality control; (2) identification of the spatial and temporal characteristics of rainfall at daily, seasonal, and annual time scales; (3) definition of the characteristics of runoff associated with flash-flooding; and (4) initiation of a review of flash-flood runoff modeling approaches for small watersheds. Flash-flooding is one of the most costly natural hazards nationally each year. In 1990, it resulted in I 09 deaths and damages of $625 million (Kentucky Engineer, 1992) in the United States. In 1992, a single flash-flood event in Bar-Creek, Kentucky resulted in four deaths and displaced approximately 54 families (National Weather Service, 1992). Due to the short response time associated with the watersheds prone to flash flooding, rainfall data must be collected rapidly in real-time and flood estimates computed accurately in order that adequate and timely warnings may be issued. Accurate estimates of flash-flood water levels require site-specific information describing the hydrometeorologic conditions and physiographic characteristics of the watershed for use of high resolution runoff modeling approaches. Monitoring rainfall events that lead to or cause flash-flooding is necessary to identify the rainfall characteristics associated with flooding and flash-flooding. The ultimate objective in a flash-flood warning system is to provide increased warning time to residents to allow them to escape the rapidly rising water. National-level agencies are only beginning to address the issue of real time, high resolution flood forecasts meeting the needs of state agencies and local-area residents. Other issues, beyond the scope of this work, must be addressed and resolved before such a system can be significantly mitigate flash-flood losses. This project addresses the initial step toward establishing such a system by compiling a flash-flood precipitation and runoff database for Kentucky from existing gage networks, and quantitatively defining the behavior of precipitation and runoff

Criterios espaciales de diseño de un restaurante de estilo minimalista para la remodelación de casonas miraflorinas

El presente proyecto de investigación, responde a una problemática que se evidencia a través de una serie de debilidades como la antigüedad de edificación de las casonas ,las cuales se pueden encontrar en mal estado de conservación lo que significa un aumento en el costo de las remodelaciones ya que estas no solo se centrarían en transformar la vivienda a un restaurante sino en reparar y reforzar las estructuras que se encuentren en mal estado, la falta de planos y también contribuye a elevar estos costos de remodelación

A Two-Player Game of Life

We present a new extension of Conway's game of life for two players, which we call p2life. P2life allows one of two types of token, black or white, to inhabit a cell, and adds competitive elements into the birth and survival rules of the original game. We solve the mean-field equation for p2life and determine by simulation that the asymptotic density of p2life approaches 0.0362.Comment: 7 pages, 3 figure

Autonomous Information Unit for Fine-Grain Data Access Control and Information Protection in a Net-Centric System

As communication and networking technologies advance, networks will become highly complex and heterogeneous, interconnecting different network domains. There is a need to provide user authentication and data protection in order to further facilitate critical mission operations, especially in the tactical and mission-critical net-centric networking environment. The Autonomous Information Unit (AIU) technology was designed to provide the fine-grain data access and user control in a net-centric system-testing environment to meet these objectives. The AIU is a fundamental capability designed to enable fine-grain data access and user control in the cross-domain networking environments, where an AIU is composed of the mission data, metadata, and policy. An AIU provides a mechanism to establish trust among deployed AIUs based on recombining shared secrets, authentication and verify users with a username, X.509 certificate, enclave information, and classification level. AIU achieves data protection through (1) splitting data into multiple information pieces using the Shamir's secret sharing algorithm, (2) encrypting each individual information piece using military-grade AES-256 encryption, and (3) randomizing the position of the encrypted data based on the unbiased and memory efficient in-place Fisher-Yates shuffle method. Therefore, it becomes virtually impossible for attackers to compromise data since attackers need to obtain all distributed information as well as the encryption key and the random seeds to properly arrange the data. In addition, since policy can be associated with data in the AIU, different user access and data control strategies can be included. The AIU technology can greatly enhance information assurance and security management in the bandwidth-limited and ad hoc net-centric environments. In addition, AIU technology can be applicable to general complex network domains and applications where distributed user authentication and data protection are necessary. AIU achieves fine-grain data access and user control, reducing the security risk significantly, simplifying the complexity of various security operations, and providing the high information assurance across different network domains

Comparison of different culture media and storage temperatures for the long-term preservation of Streptococcus pneumoniae in the tropics

Objective: The preservation of Streptococcus pneumoniae by standard freezing methods for subsequent tests- such as serotyping and antibiotic susceptibility-is not possible or is difficult in many developing countries because of the high cost of equipment, inadequate equipment maintenance, and irregular power supply. We evaluated alternative low-cost methods, by comparing different culture media and storage temperatures. Methods: Clinical isolates of five capsular types (1, 5, 7, 19, and 23) of S. pneumoniae were preserved in rabbit blood, sheep blood, skimmed milk, or glycerol-chocolate broth, and stored at -20 °C or -70 °C. The cultures were also preserved by lyophilization or sand desiccation, followed by storage at room temperature and 4 °C. The viability of the preserved cultures was determined by making serial colony counts on day 0 and after 1 week, 4 weeks, 4 months and 16 months. The viability of cultures preserved by sand desiccation and storage at 4 °C was also determined every 6 months for up to 68 months. Findings: Irrespective of the media used, cultures maintained at -20 °C became nonviable by the fourth month, while those maintained at -70 °C were still viable at 16 months. Cultures preserved by lyophilization or sand desiccation lost their viability by the fourth month when maintained at local room temperature (30-42 °C), but remained viable when stored at 4 °C for up to 68 months. Conclusions: Our results confirm that freezing at -70 °C, or lyophilization and storage at 4 °C are the ideal methods for the preservation of S. pneumoniae. In laboratories where lyophilization is not feasible, sand desiccation and storage at 4 °C offers an alternative low-cost method for the long-term preservation of S. pneumoniae

Supporting the Dynamic Careers of Licensed Practical Nurses: A Strategy to Bolster the Long-Term Care Nurse Workforce

As the U.S. population ages and the demand for long-term care increases, an insufficient number of licensed practical nurses (LPNs) is expected in the nursing workforce. Understanding the characteristics of LPN participation in the workforce is essential to address this challenge. Drawing on the theory of boundaryless careers, the authors examined longitudinal employment data from LPNs in North Carolina and described patterns in LPN licensure and career transitions. Two career patterns were identified: (a) the continuous career, in which LPNs were licensed in 75% or more of the years they were eligible to be licensed and (b) the intermittent career, in which lapses in licensure occurred. Findings indicated that LPNs who made job transitions were more likely to demonstrate continuous careers, as were Black LPNs. These findings suggest the importance of organizational support for LPN career transitions and support for diversity in the LPN workforce

The contribution of normal modes in the bottom to the acoustic field in the ocean

Also published as: Journal of the Acoustical Society of America 68 (1980): 602-612The effects of normal modes in the bottom on the acoustic field in the ocean are examined. The ocean bottom model consists of a slow isovelocity layer overlying an isovelocity half-space to simulate the characteristic sound velocity drop at the water-bottom interface. Attention is focused on the perfectly trapped modes which are excited in the layer by inhomogeneous waves emitted by a point source in the water column. The relative normal mode contribution to the total acoustic field in the water is calculated analytically for a near-bottom source/receiver geometry and evaluated for representative ocean bottom examples. It is shown that, for combined source/receiver heights less than a wavelength, the field is dominated by the leaky mode contribution at short ranges ( $ 2 km) and the trapped mode contribution at long ranges ( ~ 2 km). For fixed bottom parameters, the trapped mode contribution increases exponentially with decreasing combined source/receiver height. It is also shown that, for a fixed layer wavenumber-thickness product and fixed layer sound speed, the leaky mode fields at different frequencies are approximately range-scaled versions of the same field.Prepared for the Office of Naval Research under Contract N000 14-77-C-0196