Capturing Housing Market Segmentation: An Alternative Approach based on Neural Network Modelling

Various location specific attributes cause segmentation of the housing market into submarkets. The question is, whether the most relevant partitioning criteria are directly related to the transaction price or to other, socio-economic and physical, features of the location. On the empirical side, several methods have been proposed that might be able to capture this influence. This paper examines one of these methods: neural network modelling with an application to the housing market of Helsinki, Finland. The exercise shows how it is possible to identify various dimensions of housing submarket formation by uncovering patterns in the dataset, and also shows the classification abilities of two neural network techniques: the self-organising map (SOM) and the learning vector quantisation (LVQ). In Helsinki, submarket formation clearly depends on two factors: relative location and house type. Price-level clearly has a smaller role in this respect.     

Freeze-Texturized Maine Shrimp Protein Extract

Coagulated protein obtained from alkali extraction and acid precipitation from an abundant and inexpensive Maine Shrimp (Pandalus borealis) was packed in disc and cylindrical containers and freeze textured. A more pronounced fibrous formation was found at lower freezing rates, and the samples were harder. While disc samples exhibited randomized fibrous alignment, cylindrical samples had a continuous fiber development along their longitudinal axis which, at lower freezing rates, was similar to red meat muscle alignment; in case of higher freezing rate, the fiber simulated that of the poultry meat. Choosing a freezing rate would rely on the natural counterparts to be simulated. Morphological examination had depicted significant differences which contributed to the variations in texture, moisture, and color.     

Enzymatic Reduction of Phytate in Whole Wheat Breads

The presence of phytate in flour may be responsible for reduced bioavailability of iron, magnesium, zinc, and calcium from bread. The effect of various concentrations of commercial phytase or phosphatase added to whole wheat flour-yeast doughs on their phytate and nonphytate phosphorus content has been investigated. By using 2.0% (flour basis) of phytase and 0.11% phosphatase the initial phytate phosphorus concentration of the dough was reduced to 1/8 and 1/12 of its initial values, respectively. Storage of the whole wheat breads for up to 96 hr at room temperature showed further significant reduction of phytate phosphorus. The phytate phosphorus content of yeast leavened whole wheat breads decreased during 2 hours of dough fermentation, baking and the subsequent 48 hours of storage at room temperature from 24 mg/100g dough (dry matter) to 1.7 mg/100g bread (dry matter); the phytate phosphorus continued to decrease and after 96 hours storage it was 0.6 mg/100g bread.     

EFFECTS OF DIFFERENT AGING PROCEDURES ON THE PALATABILITY OF BEEF

Ten pairs of beef strip loins were obtained 48 h postmortem from ten good grade beef carcasses. Three steaks (2.5 cm thick) were cut from the loin end of each strip loin and the remaining portion retained as the subprimal. Steaks and subprimals were aged for 7 days at 2°C in the following treatments: polyvinyl chloride overwrapped steaks (PVC-ST), vacuum packaged steaks (VP-ST), vacuum packaged subprimals (VP-SP), and subprimals held in air (Air-SP). After aging of the subprimal, 3 additional steaks were cut for evaluation. The steaks from all treatments were evaluated for palatability and chemical characteristics. Palatability characteristics did not differ significantly (P > 0.05) between treatments with the exception of the off-flavor intensity of PVC-ST which was higher (P < 0.05) than other treatments. Warner-Bratzler shear values were similar for all treatments. No significant differences (P > 0.05) were observed between treatments for percent moisture, percent lipid, pH or TBA number. The results of this study indicate that aging method (air or vacuum) or type of cut (steaks or subprimals) had little effect on the palatability attributes or chemical characteristics of the beef strip loins.     

Herring Surimi During Low Temperature Setting, Physicochemical and Textural Properties

Herring surimi was held at 10°C for 0 to 24 hr, then heated at 90°C for 30 min. Rigidity, shear stress and shear strain at failure increased with holding time at 10°C, and the values of shear strain were 2.0 when setting time was > 3 hr. Electrophoresis revealed three types of protein-protein interactions involved in the formation of myosin polymers during setting at 10°C and/or subsequent heating at 90°C. The interactions included covalent, nondisulfide interactions; disulfide bonds and noncovalent interactions. The contributions of each type of protein-protein interaction to the formation of myosin polymers varied with setting time. Variations in the types of interactions were related to physical/chemical properties.     

Effect of Salt Reduction on the Yield, Breaking Force, and Sensory Characteristics of Emulsion-Coated Chunked and Formed Ham

The effect of a modified processing procedure (emulsion coating) on the characteristics of ham with reduced sodium chloride (salt) content was investigated. Emulsion coated (EC) and conventionally processed (CP) chunked and formed hams were prepared with 0.5, 1 and 2% added salt. When compared to CP hams, EC hams had increased cooking yield, breaking force, moisture retention, juiciness, texture, tenderness, and taste panel acceptability. The EC 1.0% salt treatment closely resembled the CP 2.0% salt treatment. The EC 0.5% salt product had many similarities to the CP 1.0% salt treatment but was significantly different in many attributes from the CP 2% salt product. Reducing salt in chunked and formed ham from 2.0% added salt addition to levels as low as 1.0% appears possible when combined with emulsion coating to minimize the effects of salt reduction.     

Measuring total productivity using production functions

This paper examines the role of the Frontier and Cobb-Douglas production functions in the measurement of company level productivity. The productivity of a typical British batch production company is measured using the production function concept. This approach utilizes the engineering concept of efficiency and this represents a major departure from the conventional measurement of company level productivity.     

Influence of Tomato Seed Addition on the Quality of Wheat Flour Breads

Tomato seed, an abundant tomato processing waste product, contains high amounts of crude fat and protein. The protein is especially high in lysine, the limiting amino acid of cereal products. Dried, ground tomato seeds were added at 5, 10, 15, and 20% wheat flour replacement levels. The influence of tomato seed addition on amino acid content, loaf volume, and staling rate were studied. A sensory evaluation based on odor only was conducted to identify consumer attitudes towards “tomato seed bread.” The addition of tomato seed at a replacement level of 20% to a bread formula with shortening resulted in no significant change (P < 0.05) in staling rate, but showed an increase in specific loaf volume of 20.4%. No significant differences in specific loaf volume were found between bread with 3% shortening and the 10% tomato seed supplemental bread without shortening. Addition of fat extracted tomato seeds at the 20% level decreased specific loaf volume by 72%. The supplementation of wheat flour bread at the 10% and 20% replacement levels increased lysine by 40.2% and 69.0% respectively.     

EXPLICIT CALCULATION OF WATER QUALITY PARAMETERS IN PIPE DISTRIBUTION SYSTEMS

Explicit algorithms have been developed for use in water quality studies and management of distribution networks with sources of dissimilar quality. The proposed algorithms can be effectively used for directly determining a variety of blended water quality parameters for a given set of network loading and operational conditions. The parameters include the spatial distribution of constituent concentrations, the flow influence characteristics of supply sources, and the water age distribution throughout the system. The developed algorithms are formulated analytically from mass balance relationships as contingent linear boundary value problems in conjunction with a topological sorting methodology. The resulting formulations yield coefficient matrices, of order equal to the number of junction nodes, that are triangular and positive definite. The parameter solutions sought are, thus, derived through a direct application of a one step substitution process. The proposed algorithms are both robust and efficient, and guaranteed to yield mathematically consistent solutions. Moreover, the algorithms are simple to understand and implement, and are well suited to the needs of those practicing engineers who wish to write and run their own programs. Two example applications are presented. Enhancement of distribution system water quality management is a principal benefit of the algorithms.