This paper presents a methodology for image-to-space path planning of a SCARA manipulator with a single static color camera. The method proposes a two step algorithm for estimating object position on the image plane and then mapping into space to find required angular values of the manipulator joints. Tests were carried with a computational routine to estimate position on the image plane of a set of different fruits under natural light conditions. Finally the method was tested using a robotic arm and similarly structured objects. Hardware and software implementation of the present method is of low cost when compared to current commercial technology, and operational results are promising but dependent on environmental illumination control and camera calibration accuracy. The methodology is intended to be applied in the automatic classification of fruits.

This paper presents new low-cost systems for the automation of some fish farm operations. Particularly, computer vision is applied to non-contact fish weight estimation. Stereo vision systems with synchronised convergent cameras are employed to perform fish 3-D segmentation in tanks and sea cages. Several pre-processing algorithms are applied to compensate for illumination local variations. The approach applied for fish 3-D segmentation consists in detecting in both images certain fish features. Once these points have been detected and validated in both images, the fish are 3-D segmented by applying stereo vision matching considerations. Fish weight is estimated by using simple length-weight relations well known in the aquaculture domain. The paper also briefly describes robotics systems for fish feeding and underwater pond cleaning, which can be also used to implement the above mentioned computer vision techniques for the fish estimation.

In this paper, development and implementation are presented of a client software package for remote process control. The proposed software is based on a client-server model under an Intranet architecture. The architecture is proposed for a telecontrol system of a real process, which includes the possibility of integrating I/O devices with data networks based on open protocols such as TCP/IP. This protocol allows the implementation of control systems using a low-cost alternative. Also, the Smith predictor is revised for remote control applications over an Ethernet network. Some experiences on a laboratory pasteurization plant are addressed to show both developed controllers and architecture performance.

Functional languages are particularly well-suited to the interpretive implementations of Domain-Specific Embedded Languages (DSELs). We describe an implemented technique for producing optimizing compilers for DSELs, based on Kamin's idea of DSELs for program generation. The technique uses a data type of syntax for basic types, a set of smart constructors that perform rewriting over those types, some code motion transformations, and a back-end code generator. Domain-specific optimization results from chains of domain-independent rewrites on basic types. New DSELs are defined directly in terms of the basic syntactic types, plus host language functions and tuples. This definition style makes compilers easy to write and, in fact, almost identical to the simplest embedded interpreters. We illustrate this technique with a language Pan for the computationally intensive domain of image synthesis and manipulation.

We show that database schema validation and update processing problems such as view updating, materialized view maintenance, integrity constraint checking, integrity constraint maintenance or condition monitoring can be classified as problems of either abductive or deductive nature, according to the reasoning paradigm that inherently suites them. This is done by performing abductive and deductive reasoning on the event rules (Olivé 1991), a set of rules that define the difference between consecutive database states. In this way, we show that it is possible to provide methods able to deal with all these problems as a whole. We also show how some existing general deductive and abductive procedures may be used to reason on the event rules. In this way, we show that these procedures can deal with all database schema validation and update processing problems considered in this paper.

Smart devices used in continuous system, benefit from the addition of microelectronics and software that runs inside the device to perform control and diagnostic functions. Very small components, such as inputs/outputs blocks and overload relays, are too small to integrate data processing for technical-economic reason. However, it's possible to develop embedded intelligence and control for the smallest factory floor devices. In the paper, a generic model of smart equipment with reconfiguration functions is proposed. The interest of this functional model is that it can be used for smart devices but it can also be developed in modules for the nearest possible of the inputs and outputs in manufacturing equipment. This solution is economic for a great number of applications because it allows one to realise modular design and to standardise part of system in order to re-use it.

We present a formal and general specification of lambda lifting and prove its correctness with respect to a call-by-name operational semantics. We use this specification to prove the correctness of a lambda lifting algorithm similar to the one proposed by Johnsson. Lambda lifting is a program transformation that eliminates free variables from functions by introducing additional formal parameters to function definitions and additional actual parameters to function calls. This operation supports the transformation from a lexically-structured functional program into a set of recursive equations. Existing results provide specific algorithms and only limited correctness results. Our work provides a more general specification of lambda lifting (and related operations) that supports flexible translation strategies, which may result in new implementation techniques. Our work also supports a simple framework in which the interaction of lambda lifting and other optimizations can be studied and from which new algorithms might be obtained.

In this paper the use of inexpensive standard hardware and software is proposed in place of high-cost commercial solutions to set up real-time control experiments with a human in the control loop, including graphical and haptic virtual reality (VR). For this purpose a generic simulation environment for the implementation of control experiments using VR with haptic feedback and their evaluation, has been developed. As an example, setups of a car simulator with a human in the control loop and an inverted pendulum as an experiment for student laboratories are presented.

This paper addresses the issue of safely combining computational effects and multi-stage programming. We propose a type system which exploits a notion of closed type, to check statically that an imperative multi-stage program does not cause run-time errors. Our approach is demonstrated formally for a core language called $\hbox{\sf MiniML}^{\sf meta}_{\sf ref}$. This core language safely combines multi-stage constructs and ML-style references, and is a conservative extension of $\hbox{\sf MiniML}_{\sf ref}$, a simple imperative subset of SML. In previous work, we introduced a closed type constructor, which was enough to ensure the safe execution of dynamically generated code in the pure fragment of $\hbox{\sf MiniML}^{\sf meta}_{\sf ref}$.

This special issue of the Journal of Functional Programming follows up on the First International ACM SIGPLAN Workshop on the Semantics, Applications, and Implementation of Program Generators (SAIG 2000). The special issue contains eight full length papers, which were received based on an open call for papers. Six of these papers are substantially extended revisions of papers presented at the workshop itself.

A method is presented for generating the path that significantly reduces residual vibration of the redundant, flexible robot manipulator in the presence of obstacles. The desired path is optimally designed so that the system completes the required move with minimum residual vibration, avoiding obstacles. The dynamic model and optimal path are effectively formulated and computed by using a special moving coordinate, called VLCS, to represent the link flexibility. The path to be designed is developed by a combined Fourier series and polynomial function to satisfy both the convergence and boundary condition matching problems. The concept of correlation coefficients is used to select the minimum number of design variables. A planar three-link manipulator is used to evaluate this method. Results show that residual vibration can be drastically reduced by selecting an appropriate path, in the presence of obstacles.

The non-classical, nonmonotonic inference relation associated with the answer set semantics for logic programs gives rise to a relationship of strong equivalence between logical programs that can be verified in 3-valued Gödel logic, G3, the strongest non-classical intermediate propositional logic (Lifschitz et al., 2001). In this paper we will show that KC (the logic obtained by adding axiom $\neg A\vee\neg\neg A$ to intuitionistic logic), is the weakest intermediate logic for which strongly equivalent logic programs, in a language allowing negations, are logically equivalent.

Data analysis is an important scientific task which is required whenever information needs to be extracted from raw data. Statistical approaches to data analysis, which use methods from probability theory and numerical analysis, are well-founded but difficult to implement: the development of a statistical data analysis program for any given application is time-consuming and requires substantial knowledge and experience in several areas. In this paper, we describe AUTOBAYES, a program synthesis system for the generation of data analysis programs from statistical models. A statistical model specifies the properties for each problem variable (i.e. observation or parameter) and its dependencies in the form of a probability distribution. It is a fully declarative problem description, similar in spirit to a set of differential equations. From such a model, AUTOBAYES generates optimized and fully commented C/C++ code which can be linked dynamically into the Matlab and Octave environments. Code is produced by a schema-guided deductive synthesis process. A schema consists of a code template and applicability constraints which are checked against the model during synthesis using theorem proving technology. AUTOBAYES augments schema-guided synthesis by symbolic-algebraic computation and can thus derive closed form solutions for many problems. It is well-suited for tasks like estimating best-fitting model parameters for the given data. Here, we describe AUTOBAYES's system architecture, in particular the schema-guided synthesis kernel. Its capabilities are illustrated by a number of advanced textbook examples and benchmarks.