Improving Grading and Feedback of Programming Assignments Using Version Control: An Experience Report

Leaving meaningful, actionable feedback that students will read and, most importantly, follow-up on, is essential for strengthening their programming skills. In addition, being capable with version control platforms, such as git, is a desired skill in industry. Could a marriage between the two, leaving meaningful feedback for student submissions in a version control system, lead them to be better programmers while improving the time and quality of instructors’ feedback? This experience report describes how we used GitHub Classroom for programming assignment submission and assessment in CS2. We provide examples of typical feedback using various assessment mechanisms, describe the process of assignment submission for students, the assessment process for instructors, and reflect on students’ reception towards the process and the value, in terms of time and quality, for the instructor

THE SPECIAL SAFEGUARD MECHANISM IN THE DOHA DEVELOPMENT AGENDA: A CASE STUDY OF SOYBEANS

The Special Safeguard Mechanism (SSM) proposed for developing countries has become a thorny issue in the Doha Development Agenda’s (DDA) agricultural negotiations. Proponents of the mechanism argue that it is a necessary compromise to counter sharp price declines or rapid import surges in staple commodity markets of developing nations. Opponents of the SSM, which include many developed exporters, contend that the policy flexibility contained in current SSM proposals would severely limit market access if the mechanism is triggered. The impact of the SSM depends on a number of parameters: the number of times the SSM is triggered, whether the price or volume SSM is triggered, the size of current tariffs, the magnitude with which tariffs are reduced in the DDA, and the number of times a developing country will actually make use of the SSM. This study introduces a static, synthetic, global, partial equilibrium model of the world soybean complex to assess the preliminary aspects of the DDA’s proposed tariff cuts. Future work on this project will extend the model to a stochastic framework from which to simulate the effects of an SSM combined with the DDA tariff cutting formulas for developing nations.Agribusiness,

The Effect of Wavelet Families on Watermarking

With the advance of technologies such as the Internet, Wi-Fi Internet availability and mobile access, it is becoming harder than ever to safeguard intellectual property in a digital form. Digital watermarking is a steganographic technique that is used to protect creative content. Copyrighted work can be accessed from many different computing platforms; the same image can exist on a handheld personal digital assistant, as well as a laptop and desktop server computer. For those who want to pirate, it is simple to copy, modify and redistribute digital media. Because this impacts business profits adversely, this is a highly researched field in recent years. This paper examines a technique for digital watermarking which utilizes properties of the Discrete Wavelet Transform (DWT). The digital watermarking algorithm is explained. This algorithm uses a database of 40 images that are of different types. These images, including greyscale, black and white, and color, were chosen for their diverse characteristics. Eight families of wavelets, both orthogonal and biorthogonal, are compared for their effectiveness. Three distinct watermarks are tested. Since compressing an image is a common occurrence, the images are compacted to determine the significance of such an action. Different types of noise are also added. The PSNR for each image and each wavelet family is used to measure the efficacy of the algorithm. This objective measure is also used to determine the influence of the mother wavelet. The paper asks the question: “Is the wavelet family chosen to implement the algorithm of consequence?” In summary, the results support the concept that the simpler wavelet transforms, e.g. the Haar wavelet, consistently outperform the more complex ones when using a non-colored watermark

An Autonomous Onboard Targeting Algorithm Using Finite Thrust Maneuvers

In earlier investigations, the adaptation and implementation of a modified two-level corrections process as the onboard targeting algorithm for the Trans-Earth Injection phase of Orion is presented. The objective of that targeting algorithm is to generate the times of ignition and magnitudes of the required maneuvers such that the desired state at entry interface is achieved. In an actual onboard flight software implementation, these times of ignition and maneuvers are relayed onto Flight Control for command and execution. Although this process works well when the burn durations or burn arcs are small, this might not be the case during a contingency situation when lower thrust engines are employed to perform the maneuvers. Therefore, a new version of the modified two-level corrections process is formulated to handle the case of finite burn arcs. This paper presents the development and formulation of that finite burn modified two-level corrections process which can again be used as an onboard targeting algorithm for the Trans-Earth Injection phase of Orion. Additionally, performance results and a comparison between the two methods are presented. The finite burn two-level corrector formulation presented here ensures the entry constraints at entry interface are still met without violating the available fuel budget, while still accounting for much longer burn times in its design

Wireless Sensor Networks for Condition Monitoring in the Railway Industry : a Survey

In recent years, the range of sensing technologies has expanded rapidly, whereas sensor devices have become cheaper. This has led to a rapid expansion in condition monitoring of systems, structures, vehicles, and machinery using sensors. Key factors are the recent advances in networking technologies such as wireless communication and mobile adhoc networking coupled with the technology to integrate devices. Wireless sensor networks (WSNs) can be used for monitoring the railway infrastructure such as bridges, rail tracks, track beds, and track equipment along with vehicle health monitoring such as chassis, bogies, wheels, and wagons. Condition monitoring reduces human inspection requirements through automated monitoring, reduces maintenance through detecting faults before they escalate, and improves safety and reliability. This is vital for the development, upgrading, and expansion of railway networks. This paper surveys these wireless sensors network technology for monitoring in the railway industry for analyzing systems, structures, vehicles, and machinery. This paper focuses on practical engineering solutions, principally,which sensor devices are used and what they are used for; and the identification of sensor configurations and network topologies. It identifies their respective motivations and distinguishes their advantages and disadvantages in a comparative review

In Extremis Leadership: A Study of the Effects in Different Contexts

When lives are at stake, astutely reading a situation (situation awareness) and belief in one’s ability to manage it (self-efficacy) are crucial leadership skills. Fire fighters, law enforcement officers and military leaders routinely enter dangerous, in extremis, situations. Data from these environments is difficult to capture, so there is a gap in the literature looking at the distinctness of these professions. We report on a survey of 514 military, firefighting, and law enforcement leaders examining their experiences during in extremis conditions. This study examines the moderating effect of four human qualities identified in that study (self-esteem, self-sacrifice, mental flexibility and altruism) on situation awareness and self-efficacy as they relate to performance in life threatening situations. We theorize and show in our research that differing priorities among the organizational missions give rise to disparities among the groups. Instead of routinely looking at all in extremis occupations as one population with identical roles, research into these differences should be explored further. Results thus seem relevant to most organizations facing lifethreatening situations, and each distinct group may benefit from different criteria for hiring, recruiting and training of personnel. The results may also be of interest to individuals facing tense, ambiguous, albeit less acute, circumstances