Avoiding Knotty Structures in Design: Schematic Functional Programming

Designers in general have used diagrams and sketches to help in the process of creation. This is particularly so for system designers whose output is a set of programs. It would seem reasonable that the conversion of diagrams directly into a program would be desirable and yet the work of Green and Petre [3–4, 13] and Citrin [2] has placed doubt on the viability of graphical programming notations. Some of this work is reviewed in this paper. The use of secondary notation and the matc–mismatch hypothesis is reconsidered in the light of functional programming. It is proposed that much of the criticism of graphical notation is due to the imperative (or process orientated) nature of programming. Many of the limitations observed in using graphical notation are lifted when functional programming is used. Eight engineering dimensions and four engineering relationships (coherences) are proposed to describe programming environments (including notation). The source of ‘knotty structures’ is identified as embedded ‘if then else’ or ‘if’ statements. On analysing both imperative and functional programs it was found that imperative programs used an order of magnitude larger number of ‘if’s than functional programs. The key to the success of a functional language as a general representation as well as its coherence with a graphical notation comes from its unique extensibility. Support for these arguments is drawn from examples of a schematic programming language used for industrial scale projects. It is concluded that the marriage between a functional language and its graphical representation overcomes most of the original criticisms of graphical programming. It is demonstrated that this combination makes a viable and expressive tool for industrial-sized applications.     

HPLC Determination of Carotenoids in Fruits and Vegetables in the United States

A study was conducted to determine alpha- and beta-carotene and beta-cryptoxanthin in twenty-two fruits and vegetables. Foods were obtained from wholesale distributors from five locations throughout the United States (Los Angeles, Dallas, Chicago, Miami, and Boston) three times during a year (November, March, and July). Mean vitamin A activity in retinol equivalents (RE) of each food along with average values for the individual carotenoids (μg/100g) are given. beta-Carotene was the most prevalent carotenoid. Carrots, beet greens, spinach, swiss chard and sweet potatoes had the most vitamin A activity. Analysis of variance indicated that there were no significant differences among either locations or time of analysis. A comparison was made between the new values and the ones listed in USDA Handbook No. 8 and revised Handbook No. 8–9. There were differences between the old and new values in 14 of the 22 fruits and vegetables analyzed.     

Interactions of Citrus Flavor Compounds with Polypropylene Films of Varying Crystallinities

Equilibrium sorption levels at 23°C were determined individually for two citrus flavor components (d-limonene and 1-carvone) into ground and unground polypropylene films of different crystallinities. Sorption levels at equilibrium were also determined for a mixture of the two flavor compounds. Aqueous solutions of the flavor compounds (200 ppm carvone and 1000 ppm limonene) were employed. Concentrations of flavors remaining in solution before and after exposure were measured by high performance liquid chromatography (HPLC). Results indicated flavor compound polarity, polymer crystallinity and the presence of other flavor compounds in a mixture influenced sorption behavior.     

SENSORY FIRMNESS SCALE BASED ON GELATIN GELS

A series of gelatin gels was produced and scaled to resemble the firmness of typical meat samples used in texture evaluation. The maximum force required to cut through the gel sample was determined with a Warner-Bratzler instrument and a TA. TX2 Model Texture Analyzer. Samples were scaled depending on the shear force required to force a blade through the material. An untrained sensory panel of 30 people, and a trained panel of 12, confirmed the sensory scale using a triangle test and unstructured scales. Untrained panelists were able to distinguish a difference between gels in three tenderness categories (P ≤ 0.001) in three consecutive tests. Trained panelists detected significant differences between scaled standards. Results suggest that scaled firmness standards based on gelatin gels provide a good model for meat tenderness sensory training.     

CONSUMER PERCEPTIONS OF QUALITY: APRICOTS, CANTALOUPES, PEACHES, PEARS, STRAWBERRIES, AND TOMATOES

Consumers are increasing their produce consumption; however, complaints of inconsistent produce quality and improper consumer handling practices could reduce consumer satisfaction with and demand for specific produce items. Seventy to eighty percent of consumers buy cantaloupes, peaches, pears, strawberries and tomatoes at the supermarket; only about half buy apricots at the supermarket. Apricots are not purchased at any location by almost 30% of consumers. Satisfaction with quality is highest for cantaloupes, lowest for tomatoes and apricots. Consumer complaints center around flavor and textural changes which develop in ripening. Both consumer handling practices and fresh product quality contribute to dissatisfaction.     

Alpha-Chaconine and Alpha-Solanine Content of Potato Peels and Potato Peel Products

Twelve samples of raw and cooked potato peels from commercial potato varieties were analyzed for their α-chaconine and α-solanine content by high-performance liquid chromatography (HPLC). Raw peels contained 1.30–56.67 mg/100g peel (wet weight) α-chaconine and 0.5–50.16 mg/100g peel (wet weight) α-solanine. Raw flesh from the same potatoes contained 0.02–2.32 mg/100g flesh (wet weight) α-chaconine and 0.01–2.18 mg/100g flesh (wet weight) of α-solanine. Peels were cooked by baking, frying and baking-frying. The two types of fried peels contained more α-chaconine (2.18–92.82 mg/100g cooked peel) and α-solanine (1.09–72.09 mg/100g cooked peel). Four commercial potato peel products – wedges, slices, fried peels and baked-fried peels – contained 3.60–13.71 mg α-chaconine/100g cooked product and 1.60–10.48 mg α-solanine/100g cooked product.     

β-Robust scheduling for single-machine systems with uncertain processing times

In scheduling environments with processing time uncertainty, system performance is determined by both the sequence in which jobs are ordered and the actual processing times of jobs. For these situations, the risk of achieving substandard system performance can be an important measure of scheduling effectiveness. To hedge this risk requires an explicit consideration of both the mean and the variance of system performance associated with alternative schedules, and motivates a β-robustness objective to capture the likelihood that a schedule yields actual performance no worse than a given target level. In this paper we focus on β-robust scheduling issues in single-stage production environments with uncertain processing times. We define a general β-robust scheduling objective, formulate the β-robust scheduling problem that results when job processing times are independent random variables and the performance measure of interest is the total flow time across all jobs, establish problem complexity, and develop exact and heuristic solution approaches. We then extend the 0-robust scheduling model to consider situations where the uncertainty associated with individual job processing times can be selectively controlled through resource allocation. Computational results are reported to demonstrate the efficiency and effectiveness of the solution procedures.