On the Syntax of Logic and Set Theory

We introduce an extension of the propositional calculus to include abstracts of predicates and quantifiers, employing a single rule along with a novel comprehension schema and a principle of extensionality, which are substituted for the Bernays postulates for quantifiers and the comprehension schemata of ZF and other set theories. We prove that it is consistent in any finite Boolean subset lattice. We investigate the antinomies of Russell, Cantor, Burali-Forti, and others, and discuss the relationship of the system to other set theoretic systems ZF, NBG, and NF. We discuss two methods of axiomatizing higher order quantification and abstraction, and then very briefly discuss the application of one of these methods to areas of mathematics outside of logic.Comment: 34 pages, accepted, to appear in the Review of Symbolic Logi

Modeling canopy-induced turbulence in the Earth system: a unified parameterization of turbulent exchange within plant canopies and the roughness sublayer (CLM-ml v0)

Land surface models used in climate models neglect the roughness sublayer and parameterize within-canopy turbulence in an ad hoc manner. We implemented a roughness sublayer turbulence parameterization in a multilayer canopy model (CLM-ml v0) to test if this theory provides a tractable parameterization extending from the ground through the canopy and the roughness sublayer. We compared the canopy model with the Community Land Model (CLM4.5) at seven forest, two grassland, and three cropland AmeriFlux sites over a range of canopy heights, leaf area indexes, and climates. CLM4.5 has pronounced biases during summer months at forest sites in midday latent heat flux, sensible heat flux, gross primary production, nighttime friction velocity, and the radiative temperature diurnal range. The new canopy model reduces these biases by introducing new physics. Advances in modeling stomatal conductance and canopy physiology beyond what is in CLM4.5 substantially improve model performance at the forest sites. The signature of the roughness sublayer is most evident in nighttime friction velocity and the diurnal cycle of radiative temperature, but is also seen in sensible heat flux. Within-canopy temperature profiles are markedly different compared with profiles obtained using Monin–Obukhov similarity theory, and the roughness sublayer produces cooler daytime and warmer nighttime temperatures. The herbaceous sites also show model improvements, but the improvements are related less systematically to the roughness sublayer parameterization in these canopies. The multilayer canopy with the roughness sublayer turbulence improves simulations compared with CLM4.5 while also advancing the theoretical basis for surface flux parameterizations

Truth Degrees Theory and Approximate Reasoning in 3-Valued Propositional Pre-Rough Logic

By means of the function induced by a logical formula A, the concept of truth degree of the logical formula A is introduced in the 3-valued pre-rough logic in this paper. Moreover, similarity degrees among formulas are proposed and a pseudometric is defined on the set of formulas, and hence a possible framework suitable for developing approximate reasoning theory in 3-value logic pre-rough logic is established

Formalisation and evaluation of focus theories for requirements elicitation dialogues in natural language

Requirements engineering is an important part of software engineering. It consists in defining the needs of users when building a new system. These needs may be functional, i.e., what service should the system be able to provide, as well as non-functional, i.e., under which constraints should the system operate. Errors in requirements may have disastrous effects in the rest of the software engineering process (Brooks 1995, p.199), since they would lead to the construction of a system of little interest to its users or would require expensive modifications to correct. Because requirements documents may be very large, errors are usually hard to detect manually. Computer support is therefore often beneficial for their analysis. This is made easier if requirements are expressed formally. However, this support must also be adapted to and be usable by people who are expressing their requirements. These people are usually not computer specialists and are not accustomed to use formal languages. It is therefore necessary to help them express their requirements. Numerous approaches, have been suggested as aids to the acquisition of requirements (Reubenstein 1990). Much less attention has been paid to the control of the dialogue taking place between the users and the system whilst using such frameworks (Bubenko et al. 1994). Frameworks for requirements acquisition are not normally accompanied by theories of the types of dialogue which they support. Our ability to develop sophisticated formal frameworks to analyse requirements makes this deficiency more acutely felt, since increases in formality are often accompanied by greater difficulty in understanding and using the frameworks (Robertson et al. 1989).Users write their requirements in more or less natural language. This is then translated into a formal language that can be interpreted by the elicitation module. This module works on the requirements and provide feedback. The translation process is then applied to convert feedback into more or less natural language. Different systems put different emphasis on the parts of that general architecture. Some are very good at natural language interpretation while others put more emphasis on analysing the requirements and providing feedback.Natural language approaches to requirements elicitation, put an emphasis on natural language interpretation (see section 1.2.1). In these approaches, users write their specifica¬ tion in a subset of natural language. The system then translates it into a formal notation. The main benefit provided by these approaches is the improvement in the ease of use of the system: natural language is the main means of communication for human beings and does not need to be learned. However, most of these approaches do not provide a dialogue well suited for the requirements elicitation process. Because they translate the natural lan¬ guage specification into a formal notation but do not provide guidance on how to write the specification in the first place, users are left in charge of writing correct requirements. If a mistake is made while writing the specification, it will simply be translated into the formal notation.In order to actively help users in the process of writing the requirements, the elicit¬ ation system must interact with them. The emphasis, here, is no longer on translating requirements, but on actively extracting them through a dialogue with users. This is useful, since the requirements elicitation process is complex, and offering guidance is a big help for users. Unfortunately, most of the approaches providing guidance expose their formal underlying frameworks directly to users (see section 1.2.2). In order to benefit from the guidance provided, users have to learn the idiosyncrasies of the system they use. The task of providing guidance is complicated by the fact that there are numerous ways of carrying out the requirements elicitation. Very little research has been done on how to organise best the elicitation process to provide effective guidance. An arbitrary choice could be made, but forcing users to adopt a predefined method is usually not possible as it would make the elicitation process very difficult to follow and understand. The system must therefore be able to adapt itself to various elicitation methods. On the other hand, it is necessary for the system to make choices in order to provide active guidance. A "least-commitment" strategy, such as asking users at every choice point what to do next, is not a useful approach (Ferguson et al. 1996).One way of offering guidance without restricting users too much is by communicating with them in natural language, and by using natural language constraints to inform the choices made by the system to select a guidance strategy. These constraints ensure that the system adopts a strategy that will guide users in a natural and understandable manner, by taking into account the current state of the dialogue. In other words, the system takes into account the current state of the specification to help users complete it, but the current state of the dialogue is the principal factor constraining what will be spoken about next. Using such an approach reduces some of the problems discussed above. The specification does not need to be immediately correct as it will be checked and reworked by the system. The formal framework is hidden from users but is still there to ensure the correctness of the specifications. Guidance is continuously offered through dialogue, which is influenced by but does not directly follow the steps of construction of the specification.The natural language constraints we use in this thesis are theories of dialogue coherence, called "focus" theories. They define what can be spoken about next in a dialogue based on what has already been discussed and the subject under discussion. The theories take into account what participants in a dialogue pay attention to and try to ensure that the rest of the dialogue is related to it. The systems tries to help its users define how a research group WWW site should look like. The way the dialogue evolves from discussing the research group, to discussing the site and its associated home page, to discussing the set of publication can quite easily be followed. The use of pronouns helps in making the text fell natural. It would have been difficult to achieve the same result without using focus rules.Other techniques for organising dialogues, such as those based on the intentions under¬ lying the dialogue (Cohen et al. 1990), would require the dialogue manager to know what the elicitation system is trying to achieve and what its plan is. For some elicitation systems, this knowledge may not be available. Similarly, techniques based on the content of the communications exchanged and how they relate, e.g., based on RST (Mann and Thompson 1987), usually require a lot of domain knowledge. They are therefore time-consumming to code. Focus theories require less information from the elicitation module while enabling the dialogue manager to structure the dialogue. However, in some cases, focus theories are not sufficient to organise a dialogue. We use a theory based on speech act (see section 3.4.1) and some ideas from Grice's work on conversation (see section 5.2.1) to deal with these cases. More generally, although we tried to minimise the impact of other theories to study in detail focus theories, it would be interesting to know whether and how we can integrate them with the work presented in this thesis. In particular, the notion of dialog act and its application to dialog grammar could be of interest. General frameworks developped to study various aspects of dialogue, including dialog acts and focus, have started to appear but work is still at an early stage (C-Star Consortium 1998; Allen and Core 1997).Organising a dialogue based on attention requires a lot of domain knowledge in order to know how things mentioned in the dialogue relate to each other. Therefore, the amount of knowledge engineering needed to build natural language applications is also an important issue. We have tried to limit the engineering difficulties by clearly separating the domain knowledge needed by our dialogue manager from its management capabilities, and by provid¬ ing a way of re-using the existing domain knowledge as far as possible. This is done by using rules which enable us to re-use part of the domain knowledge already used by the elicitation module.The contribution of this thesis is therefore the formalisation and evaluation of focus theories for requirements elicitation dialogues in natural language. The main questions we deal with are the following: • Which focus theories should we use? • What are the relations between the constraints imposed by the focus theories and the constraints inherent to the requirements elicitation process? • Does this approach improve the perceived quality of the dialogue between the elicita¬ tion tool and its users?A prototype system has been developed. This system mainly operates in the WWW site design domain. It has also been applied in other domains as an initial demonstration of the range of problems that can be tackled by our approach

Radar systems for a polar mission, volume 3, appendices A-D, S, T

Success is reported in the radar monitoring of such features of sea ice as concentration, floe size, leads and other water openings, drift, topographic features such as pressure ridges and hummocks, fractures, and a qualitative indication of age and thickness. Scatterometer measurements made north of Alaska show a good correlation with a scattering coefficient with apparent thickness as deduced from ice type analysis of stereo aerial photography. Indications are that frequencies from 9 GHz upward seem to be better for sea ice radar purposes than the information gathered at 0.4 GHz by a scatterometer. Some information indicates that 1 GHz is useful, but not as useful as higher frequencies. Either form of like-polarization can be used and it appears that cross-polarization may be more useful for thickness measurement. Resolution requirements have not been fully established, but most of the systems in use have had poorer resolution than 20 meters. The radar return from sea ice is found to be much different than that from lake ice. Methods to decrease side lobe levels of the Fresnel zone-plate processor and to decrease the memory requirements of a synthetic radar processor are discussed

End-of-fabrication CMOS process monitor

A set of test 'modules' for verifying the quality of a complementary metal oxide semiconductor (CMOS) process at the end of the wafer fabrication is documented. By electrical testing of specific structures, over thirty parameters are collected characterizing interconnects, dielectrics, contacts, transistors, and inverters. Each test module contains a specification of its purpose, the layout of the test structure, the test procedures, the data reduction algorithms, and exemplary results obtained from 3-, 2-, or 1.6-micrometer CMOS/bulk processes. The document is intended to establish standard process qualification procedures for Application Specific Integrated Circuits (ASIC's)

Agricultural and hydrological applications of radar

Program objectives, covering a wide range of disciplines and activities in radar remote sensing, include radar systems development and analysis, data processing and display, and data interpretation in geology, geography and oceanography. Research was focused on the evaluation of radar remote sensing applications in hydrology and agriculture based on data acquired with the Microwave Active Spectrometer (MAS) system. The title, author(s) and abstract of each of the 62 technical reports generated under this contract are appended