Mass Market Entry of Wireless Telecommunications

Although cellular wireless telecommunication is now availableworldwide, it still constitutes only a small percentage of overalltelecommunications traffic. Even in advanced countries suchas the USA, wireless service still remains somewhat élitist,with no more than 16% of the population having cellular phonesin 1996. As various national governments make new spectrum availablefor wireless personal communications services (PCS), and existingcellular service transforms itself into PCS, the public is demandingubiquitous, affordable high-quality wireless service. PCS willbe defined not only by its advanced technological capabilities,but also by its universal affordability. This paper describessome of the strategies new PCS service-providers are adoptingto meet this challenge. While the penetration of wireless telecommunicationin any market depends on many factors, price is a fundamentalfactor. We analyze the trends in the US and Israeli marketsusing principles of marketing science to illustrate this point.Specifically, we analyze the Israeli wireless market, with itsrevolutionary low tariff structure and project the effect asimilar tariff would have on the US cellular market. But lowerprices would also create a highly competitive, low-revenue per-minute-of-useenvironment for the operator. In the rest of the paper, we discusschanges in traffic patterns, new marketing strategies, wirelessdigital technologies, advanced planning techniques, and innovativenetwork management systems that enable companies to succeedin this new environment.     

CLASSIFICATION OF AVOCADO BY FIRMNESS AND MATURITY

Table-ripe soft avocado cannot be shipped or stored for more than a few days. Thus, it is common practice to store and ship firm, tree-ripe avocado, while the consumer may soften the fruit as required. A human sorter cannot distinguish between a freshly picked firm avocado and a somewhat softer semiripe fruit, yet the accelerated evolution of ethylene by even several ripe fruits, may prematurely ripen a whole shipment. A sensor system, for nondestructive sensing of avocado firmness is presented, based on vibrationally exciting one side of the fruit, while measuring the transmitted vibration energy on its other side. Special signal processing hardware and software was developed for computing several alternative firmness indexes, highly correlated to the standard piercing force, destructive, test method. Optimal classification algorithms were developed, whereby the fruit may be classified into two or three firmness grades. In both cases, the actual contamination of the firm fruit class by soft fruits was only 3.3%, while the overall classification accuracy was about 90%.     

SYNTAX AND LEXICAL STATISTICS IN ANAPHORA RESOLUTION

We describe a syntactically based salience algorithm for pronominal anaphora resolution and a procedure for reevaluating the decisions of the algorithm on the basis of statistically modeled lexical semantic/pragmatic preferences. We report the results of an extensive blind test of both systems on computer manual text. We discuss the implications of these results for the comparative roles of syntactically defined salience and statistically measured lexical preference in determining the references of pronouns in text.     

FREQUENCY DEPENDENCE IN DIELECTROPHORESIS: TRAJECTORIES AND PARTICLE BUILDUP

A study of the effect of frequency of a sinusoidal field on dielectrophoretic capture is presented, using numerical analysis to compute particle trajectories. It is shown that at certain critical frequencies the trapping efficiency drops sharply due to weakening of the dielectrophoretic pull. Experiments in which the capture performance was visually recorded by photographing the particle buildup on a single rod at increasing frequencies are reported. Results are discussed in the light of the numerical analysis.     

Storage Stability of Orange Juice Concentrate Packaged Aseptically

Orange juice concentrates were packaged aseptically by a “Dole” aseptic canning machine using 6 oz metal cans. The final juice products (11°, 34°, 44°, 58° Brix) were stored between ?18° and 36°C and tested periodically for nonenzymatic browning, ascorbic acid destruction, furfural and sensory changes. Nonenzymatic browning, the main deterioration phenomena in these products, was satisfactorily retarded at 12°C or lower. Ascorbic acid destruction rate constant was dependent on temperatures between 5 and 25°C, and was affected by degree of juice concentration. Furfural accumulation in juice was higher than that in 58° Brix concentrate. Orange juice concentrate of 58° Brix did not show flavor changes after storage at 5°C or 12°C for 17 or 10 months, respectively, when evaluated after reconstitution to 11° Brix.     

EFFECT OF KOJIC ACID ON THE HYDROXYLATION OF L-TYROSINE AND TYRAMINE BY MUSHROOM TYROSINASE1

Kojic acid inhibits effectively the rate of L-tyrosine and tyramine hydroxylation by mushroom tyrosinase. It also affects the spectrum of product (s) formed, this being due to the ability of dopaquinone and dopamine-o-quinone to oxidize kojic acid to a yellow product(s). Kojic acid prevents the conversion of these o-quinones to their corresponding melanins. An insoluble yellow product(s) is formed when tyramine, but not L-tyrosine, is incubated with tyrosinase for 20 h in the presence of excess kojic acid.