Pipelines [Unix programming]

One of the underlying philosophies of the Unix command shell is the idea of the pipeline: take a set of small, specialized programs and let them interact by feeding the output of one into the input of the next. By stringing simple programs together in this way, rich behavior can emerge. Pipelines can let you replace complex program logic with a chain of far simpler discrete steps.     

Delaying commitment [programming strategy]

A programming strategy of delaying design commitment is advocated. It is argued that such an approach retains flexibility and provides an opportunity for new insights and creative design further on in the process. In the context of programming, delaying commitment corresponds to lazy evaluation. Tactics for delaying commitment are discussed     

Fugue for MMX [parallel programming]

When I was an undergraduate in a hardware architecture course, one of my instructors compared programming for parallel processors with writing a symphony. At the time parallel processors were largely theoretical, and there were none around for me to play with. Now MMX adds more instruments to the orchestra. This article documents some of my early experiences with programming a simple compositing routine for MMX and the lessons I've learned from it. The program deals with pixels comprised of red, green, blue, and alpha (coverage) components, and with the assumption that the RGB components have already been multiplied by their own alpha component. I implement the most common image compositing operation, the Porter-Duff over operator     

When to make a type [programming]

When I started programming computers, I began with fairly primitive languages, such as Fortran 4 and various early flavors of Basic. One of the first things you learn using such languages - indeed, even using more up-to-date languages - is which types your language supports. Being oriented toward number crunching, Fortran supported integer and real types, with the interesting rule that any variable whose name started with the letters I through N was an integer, and all other variables were floats. I'm glad that convention hasn't caught on, although Perl is close. Furthermore, using object-oriented languages, you can define your own types and in the best languages, they act just as well as built-in ones.     

Dear editor [programming tools of the trade]

In this article, we give some advices for the programmers for an efficient software design. Programmers are advised not to type what they can automate in the editor environment and don't use the editor feature where they can code.     

It's the programming, stupid [semantic Web]

We discuss the virtues of the semantic Web services in terms of e-commerce. We've collectively defined a set of problem levels as well as processes for adding problems and for evaluating how well the technologies solve them. A RosettaNet PO is a complex XML specification as well as a simple protocol for exchanging messages about its processing. The main challenge facing modern enterprises is how to scale programming costs in the face of rapid change and the increasing requirement for interoperation with other enterprises. Some researchers have posed the problem of the Semantic Web, and services, as an interoperability issue.     

Temporal logic programming for assembly sequence planning

A temporal-constraint logic programming framework for the specification and automatic verification and synthesis of assembly sequences is developed. The implemented tool is based on the formulated and derived precedence properties for a general mechanical assembly. This tool, called the Mechanical Assembly Sequence Satisfiability Checker (MASS-C), supports the use of a subset of temporal logic for assembly constraint specification. MASS-C provides the logic programming framework by which the designer can be relieved of the tedium of finding the assembly sequences, and the assembly sequence planning process manifests itself in the implicit modelling of assembly sequences by acquiring and formulating the set of correct and complete assembly constraints as a logic program. MASS-C implements a class of temporal expressions as predicates for logic programming of assembly constraints. It provides facilities to either verify an assembly sequence or synthesise all assembly sequences that satisfy the specified constraints composed as a logic program. Two examples illustrate the use of MASS-C for such verification and synthesis.     

C — an alternative to assembly programming

The recent increase in popularity of the programming language c is explained, and similarities between c and both high- and low-level languages are pointed out. In particular, a comparison is drawn with assembly language programming. Advantages and disadvantages of programming in c are highlighted. The c compiler written by Whitesmiths is treated in some detail. Various examples of its use are given.     

Self assembly of rectangular shapes on concentration programming and probabilistic tile assembly models

Efficient tile sets for self assembling rectilinear shapes is of critical importance in algorithmic self assembly. A lower bound on the tile complexity of any deterministic self assembly system for an n?×?n square is $\Upomega(\frac{\log(n)}{\log(\log(n))})$ (inferred from the Kolmogrov complexity). Deterministic self assembly systems with an optimal tile complexity have been designed for squares and related shapes in the past. However designing $\Uptheta(\frac{\log(n)}{\log(\log(n))})$ unique tiles specific to a shape is still an intensive task in the laboratory. On the other hand copies of a tile can be made rapidly using PCR (polymerase chain reaction) experiments. This led to the study of self assembly on tile concentration programming models. We present two major results in this paper on the concentration programming model. First we show how to self assemble rectangles with a fixed aspect ratio (??:??), with high probability, using $\Uptheta(\alpha+\beta)$ tiles. This result is much stronger than the existing results by Kao et?al. (Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008) and Doty (Randomized self-assembly for exact shapes. In: proceedings of the 50th annual IEEE symposium on foundations of computer science (FOCS), IEEE, Atlanta. pp 85?C94, 2009)??which can only self assembly squares and rely on tiles which perform binary arithmetic. On the other hand, our result is based on a technique called staircase sampling. This technique eliminates the need for sub-tiles which perform binary arithmetic, reduces the constant in the asymptotic bound, and eliminates the need for approximate frames (Kao et?al. Randomized self-assembly for approximate shapes, LNCS, vol 5125. Springer, Heidelberg, 2008) . Our second result applies staircase sampling on the equimolar concentration programming model (The tile complexity of linear assemblies. In: proceedings of the 36th international colloquium automata, languages and programming: Part I on ICALP ??09, Springer-Verlag, pp 235?C253, 2009), to self assemble rectangles (of fixed aspect ratio) with high probability. The tile complexity of our algorithm is $\Uptheta(\log(n))$ and is optimal on the probabilistic tile assembly model (PTAM)??n being an upper bound on the dimensions of a rectangle.     

结合罚函数与序列二次规划的[lp]范数优化方法

结合罚函数法与序列二次规划（SQP）方法研究了[lp]范数优化的求解算法。分析了基于SQP方法的[lp]范数优化算法,探讨了初值选取对算法收敛性的影响;针对SQP方法受迭代初值的限制,引入罚函数优化方法对迭代初值作预估计,使其进入可行域,采用SQP方法求解计算。实验结果表明,结合罚函数与SQP方法的[lp]范数优化算法对稀疏信号有较优的重构效果。     

TL-10: A programming language for assembly robots

TL-10, Toyoto Robot Language-10, is a BASIC-like robot language. It has functions that define locations and subroutine parameters, which are useful in the accumulation and the transference of robot applied technology. It also has functions to communicate with other computers such as those for vision systems. The important features are described and illustrated by examples.     

Robot programming system for assembly: Conceptual graph-based approach

This work develops a method for robot program synthesis. Currently, the programming task is one of the major hurdles of robotic application. Progress towards automatic synthesis of robot programs will ease industrial robot application. The proposed system provides a means towards automated (guided by knowledge) conversion of a user's request, expressed in natural language, to the appropriate conceptual model of the required task. This model incorporates the information necessary for understanding, planning, and sensory-guided performance of the required robotic task.First, we state the problem of robotic assembly and recognize its hierarchic structure as the structure of a system that builds a predesigned assembly. Next, we present and analyze the requirements of the robotic assembly domain. This analysis enables us to draw conclusions concerning the most suitable methodology for the development of a support system for assembly program synthesis and interpretation. It is the conceptual graph-based approach. Then we present the algorithm of the proposed conceptual graph-based system and show how the system synthesizes robotic assembly operations, such as valid assembly sequences and sequences of special treatments for the assembled components (including the determination of the required resources). Finally, a case study illustrates the approach developed here on a large family of multi-axisymmetric components. We also present illustrative examples of working sessions with the current implementation of the system.     

Comments on `Dynamic programming approach to optimal weightselection in multilayer neural networks' [with reply]

The commenter claims that in the above-titled paper (ibid., vol.2, p.465-467, July 1991), which presents an efficient algorithm using dynamic programming to find weights which load a set of examples into a feedforward neural network with minimal error, a contradiction lies buried in the paper's notation. In reply, the author maintains that the comments are due to some misunderstandings about the implementation of dynamic-programming-based algorithms and clarifies the work