Nitrogen and Phosphorus Rates’ Impact on Different Varieties of Alfalfa in Central Kansas

The United States is the largest producer of alfalfa (Medicago sativaL.) in the world, with a vast area grown under rainfed conditions. Under these conditions, and especially in a transition state such as Kansas, the alfalfa crop often suffers from water deficit stress. Environments under water-limited conditions promote a decrease in crop yield when inadequate water leads to an nitrogen deficiency and reduces crop biomass. This research aimed to investigate the production of different alfalfa varieties under different nitrogen and phosphorus rates in a rainfed environment. Three nitrogen application rates (0 lb/a; 200 lb/a; 400 lb/a) and three phosphorus application rates (0 lb/a; 100 lb/a; and 200 lb/a) provided nine combinations of application rates to four alfalfa varieties (54HVX41, Pioneer 54VR10, LOL 356HQRR, and DKA43-22RR). Five harvests were executed at 10% of flowering, and the whole plant biomass was collected to determine the dry matter in ton/a. Despite the statistically significant results of treatment interaction, there was no pattern in the average values of alfalfa production among different treatments and seasons. The collected weather data provided empirical evidence to support that precipitation and evapotranspiration (specifically under water stress) influenced alfalfa yield. The four genotypes used in this field study tended to be stable in their yield in response to fertilization

A Standardised Procedure for Evaluating Creative Systems: Computational Creativity Evaluation Based on What it is to be Creative

Computational creativity is a flourishing research area, with a variety of creative systems being produced and developed. Creativity evaluation has not kept pace with system development with an evident lack of systematic evaluation of the creativity of these systems in the literature. This is partially due to difficulties in defining what it means for a computer to be creative; indeed, there is no consensus on this for human creativity, let alone its computational equivalent. This paper proposes a Standardised Procedure for Evaluating Creative Systems (SPECS). SPECS is a three-step process: stating what it means for a particular computational system to be creative, deriving and performing tests based on these statements. To assist this process, the paper offers a collection of key components of creativity, identified empirically from discussions of human and computational creativity. Using this approach, the SPECS methodology is demonstrated through a comparative case study evaluating computational creativity systems that improvise music

Modelling creativity: identifying key components through a corpus-based approach

Creativity is a complex, multi-faceted concept encompassing a variety of related aspects, abilities, properties and behaviours. If we wish to study creativity scientifically, then a tractable and well-articulated model of creativity is required. Such a model would be of great value to researchers investigating the nature of creativity and in particular, those concerned with the evaluation of creative practice. This paper describes a unique approach to developing a suitable model of how creative behaviour emerges that is based on the words people use to describe the concept. Using techniques from the field of statistical natural language processing, we identify a collection of fourteen key components of creativity through an analysis of a corpus of academic papers on the topic. Words are identified which appear significantly often in connection with discussions of the concept. Using a measure of lexical similarity to help cluster these words, a number of distinct themes emerge, which collectively contribute to a comprehensive and multi-perspective model of creativity. The components provide an ontology of creativity: a set of building blocks which can be used to model creative practice in a variety of domains. The components have been employed in two case studies to evaluate the creativity of computational systems and have proven useful in articulating achievements of this work and directions for further research

Design by taking perspectives: How engineers explore problems

Background: Problem exploration includes identifying, framing, and defining design problems and bounding problem spaces. Intentional and unintentional changes in problem understanding naturally occur as designers explore design problems to create solutions. Through problem exploration, new perspectives on the problem can emerge along with new and diverse ideas for solutions. By considering multiple problem perspectives varying in scope and focus, designers position themselves to increase their understandings of the “real” problem and engage in more diverse idea generation processes leading to an increasing variety of potential solutions. Purpose/Hypothesis: The purpose of this study was to investigate systematic patterns in problem exploration in the early design phases of mechanical engineers. Design/Method: Thirty-five senior undergraduate students and experienced designers with mechanical engineering backgrounds worked individually following a think-aloud protocol. They explored problems and generated solutions for two of four randomly assigned design problems. After generating solutions, participants framed and rewrote problem statements to reflect their perspectives on the design problem their solutions addressed. Thematic analysis and a priori codes guided the identification of problem exploration patterns within and across problems. Results: The set of patterns in engineers\u27 problem exploration that emerged from the analysis documents alternative strategies in exploring problems to arrive at solutions. The results provide evidence that engineering designers, working individually, apply both problem-specific and more general strategies to explore design problems. Conclusions: Our study identified common patterns in the explorations of presented problems by individual engineering designers. The observed patterns, described as Problem Exploration Perspectives, capture alternative approaches to discovering problems and taking multiple problem perspectives during design. Learning about Problem Exploration Perspectives may be helpful in creating alternative perspectives on a design problem, potentially leading to more varied and innovative solutions. This paper concludes with an extended example illustrating the process of applying Problem Exploration Perspectives to move between problem perspectives to generate varied design outcomes

Global and Local Features of Semantic Networks: Evidence from the Hebrew Mental Lexicon

BACKGROUND: Semantic memory has generated much research. As such, the majority of investigations have focused on the English language, and much less on other languages, such as Hebrew. Furthermore, little research has been done on search processes within the semantic network, even though they are abundant within cognitive semantic phenomena. METHODOLOGY/PRINCIPAL FINDINGS: We examine a unique dataset of free association norms to a set of target words and make use of correlation and network theory methodologies to investigate the global and local features of the Hebrew lexicon. The global features of the lexicon are investigated through the use of association correlations--correlations between target words, based on their association responses similarity; the local features of the lexicon are investigated through the use of association dependencies--the influence words have in the network on other words. CONCLUSIONS/SIGNIFICANCE: Our investigation uncovered Small-World Network features of the Hebrew lexicon, specifically a high clustering coefficient and a scale-free distribution, and provides means to examine how words group together into semantically related 'free categories'. Our novel approach enables us to identify how words facilitate or inhibit the spread of activation within the network, and how these words influence each other. We discuss how these properties relate to classical research on spreading activation and suggest that these properties influence cognitive semantic search processes. A semantic search task, the Remote Association Test is discussed in light of our findings