Guided search

Complexity Engineering Specific applications of CA to physical problems typically involve enormous efforts spent on obtaining just the right set of rules appropriate for a given problem. By succinctly suinniarizing the statistical behavior of a well-defined class of rules for a variety of lattice structures, the LST equations may be used to effectively guide searches for particular rules displaying the set of desired statistical behaviors. 

The reverse search starts from a set of desired properties and asks for substances that possess them. Theoretical knowledge and past experience should be relied upon to suggest where to look, since it is the fastest and least expensive approach. When theoretical knowledge and past experience have been exhausted, then random searches may be the only way to make progress, if the problem is sufficiently important and there is enough budget and patience. Table 7.1 compares some of the requirements and the pros and cons of the guided search and the random search... 

National Cancer Institute. URL http //www.cancer.gov/clini-caltrials (accessed October 2005). The U.S. National Cancer Institute s PDQ database of cancer clinical trials. Uses search forms for guiding search with drop-down boxes listing all types of cancer. Can also select type and location of trial. Advanced search form allows limiting by cancer stage or sub-type, type of treatment or intervention (drop-down box lists options), drug/s used in the trial, and active or closed trials. The treatment/intervention choices allow you to select... 

A careful and balanced parametrization is clearly important in exploring the limits of a given semiempirical model, but it cannot replace the theoretically guided search for better models, which offer the most... 

The heuristic search is a guided search and it does not guarantee an optimal solution. However, it can often find satisfactory solutions (Abbass et al. 2002). 

Fig. 12 a Examples for color popout-effect. b Example for conjunction-search where shape and color have to be combined. Following the Guided Search Model, red objects are searched first... 

In this situation, computer simulations have several prospects to offer. One can design simple models that reproduce the experimental phenomenology and can then be analyzed in far more microscopic detail. The models themselves can be simplified to such an extent that one can identify the molecular properties indispensable for defining a glass-forming substance. This and the complete microscopic information available allow for a guided search for possible order parameters needed to address the question of a possible underlying phase transition. Furthermore, a detailed simultaneous study of the temperature dependence of the structural and conformational relaxation in polymer melts is possible. 

New user interface in Guided Search (including the ability to perform multiple searching and chemistry crossover searching to all STN files that support Registry Numbers). 

The combination of the guided search on the Internet with the ball bearing proved to be an interesting and motivating method. The method helped the students to become clear about what they have to do. Although the evaluation of information is not an easy task and students sometimes feel uncertain... 

Pauser, S., Reszka, R., Wagner, S., Wolf, K. J., Buhr, H. L, and Berger, G. 1997. Liposome-encapsulated superparamagnetic iron oxide particles as markers in an MRI-guided search for tumor-specific drug carriers. Anficancer Drag Des. 12 125-135. 

STN Express (the Chemical Abstracts Service approved front-end to CAS ONLINE) is touched upon in Chapters 6 and 7. It, also, allows the user to formulate queries offline and provides help with special difflculties such as tautomerism. In addition it has a Guided Search module for novices in the STN Command Language and Boolean logic. Structure drawing is compatible with PsiGen. 

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