943,702 research outputs found
Contemporary developments in teaching and learning introductory programming: Towards a research proposal
The teaching and learning of introductory programming in tertiary institutions is problematic. Failure rates are high and the inability of students to complete small programming tasks at the completion of introductory units is not unusual. The literature on teaching programming contains many examples of changes in teaching strategies and curricula that have been implemented in an effort to reduce failure rates. This paper analyses contemporary research into the area, and summarises developments in the teaching of introductory programming. It also focuses on areas for future research which will potentially lead to improvements in both the teaching and learning of introductory programming. A graphical representation of the issues from the literature that are covered in the document is provided in the introduction
Finding largest small polygons with GloptiPoly
A small polygon is a convex polygon of unit diameter. We are interested in
small polygons which have the largest area for a given number of vertices .
Many instances are already solved in the literature, namely for all odd ,
and for and 8. Thus, for even , instances of this problem
remain open. Finding those largest small polygons can be formulated as
nonconvex quadratic programming problems which can challenge state-of-the-art
global optimization algorithms. We show that a recently developed technique for
global polynomial optimization, based on a semidefinite programming approach to
the generalized problem of moments and implemented in the public-domain Matlab
package GloptiPoly, can successfully find largest small polygons for and
. Therefore this significantly improves existing results in the domain.
When coupled with accurate convex conic solvers, GloptiPoly can provide
numerical guarantees of global optimality, as well as rigorous guarantees
relying on interval arithmetic
Linearized analysis versus optimization-based nonlinear analysis for nonlinear systems
For autonomous nonlinear systems stability and input-output properties in small enough (infinitesimally small) neighborhoods of (linearly) asymptotically stable equilibrium points can be inferred from the properties of the linearized dynamics. On the other hand, generalizations of the S-procedure and sum-of-squares programming promise a framework potentially capable of generating certificates valid over quantifiable, finite size neighborhoods of the equilibrium points. However, this procedure involves multiple relaxations (unidirectional implications). Therefore, it is not obvious if the sum-of-squares programming based nonlinear analysis can return a feasible answer whenever linearization based analysis does. Here, we prove that, for a restricted but practically useful class of systems, conditions in sum-of-squares programming based region-of-attraction, reachability, and input-output gain analyses are feasible whenever linearization based analysis is conclusive. Besides the theoretical interest, such results may lead to computationally less demanding, potentially more conservative nonlinear (compared to direct use of sum-of-squares formulations) analysis tools
Risk programming analysis with imperfect information
A Monte Carlo procedure is used to demonstrate the dangers of basing (farm) risk programming on only a few states of nature and to study the impact of applying alternative risk programming methods. Two risk programming formulations are considered, namely mean-variance (E,V) programming and utility efficient (UE) programming. For the particular example of a Norwegian mixed livestock and crop farm, the programming solution is unstable with few states, although the cost of picking a sub-optimal plan declines with increases in number of states. Comparing the E,V results with the UE results shows that there were few discrepancies between the two and the differences which do occur are mainly trivial, thus both methods gave unreliable results in cases with small samples
The C Object System: Using C as a High-Level Object-Oriented Language
The C Object System (Cos) is a small C library which implements high-level
concepts available in Clos, Objc and other object-oriented programming
languages: uniform object model (class, meta-class and property-metaclass),
generic functions, multi-methods, delegation, properties, exceptions, contracts
and closures. Cos relies on the programmable capabilities of the C programming
language to extend its syntax and to implement the aforementioned concepts as
first-class objects. Cos aims at satisfying several general principles like
simplicity, extensibility, reusability, efficiency and portability which are
rarely met in a single programming language. Its design is tuned to provide
efficient and portable implementation of message multi-dispatch and message
multi-forwarding which are the heart of code extensibility and reusability.
With COS features in hand, software should become as flexible and extensible as
with scripting languages and as efficient and portable as expected with C
programming. Likewise, Cos concepts should significantly simplify adaptive and
aspect-oriented programming as well as distributed and service-oriented
computingComment: 18
Optimality and uniqueness of the (4,10,1/6) spherical code
Linear programming bounds provide an elegant method to prove optimality and
uniqueness of an (n,N,t) spherical code. However, this method does not apply to
the parameters (4,10,1/6). We use semidefinite programming bounds instead to
show that the Petersen code, which consists of the midpoints of the edges of
the regular simplex in dimension 4, is the unique (4,10,1/6) spherical code.Comment: 12 pages, (v2) several small changes and corrections suggested by
referees, accepted in Journal of Combinatorial Theory, Series
Staff Engagement for Cohesion
This chapter in a book on small and rural libraries looks at issues around why staff engagement is a concern. We discuss the barriers to staff engagement and the role professional development plays in lowering the barriers. We look at events programming and the library's impact on other campus departments. Concludes with advice to other small academic libraries on developing a staff engagement plan.Ye
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