Three-section Model Research Articles

Determination of glass transitions in boiled candies by capacitance based thermal analysis (CTA) and genetic algorithm (GA)

The glass transition temperature (Tg) is an important property that influences the processing and textural characteristics of candy. Measurement of Tg is done by comparably expensive and complex instruments. In this study, we tested a new system which uses capacitance thermal analysis (CTA) of candy trapped between stainless plates, as the system is caused to heat at an uncontrolled rate. The data of capacitance as a function of temperature were processed by a genetic algorithm (GA), and fitted to a three-section model to determine Tg. Tg of the candies were independently measured by DSC as a reference. The results showed that when the Tg of the candy was below ∼15 °C, the measurement from the GA-CTA was higher (2–3 °C) than that from DSC. However, if Tg of the candy was higher than 15 °C, the two methods gave similar values. GA based CTA provides a feasible new way to measure phase transitions in candies with relatively inexpensive equipment, and with less need for user interpretation of data.

An improved static model for tool deflection in machining of Ti–6Al–4V acetabular shell produced by selective laser melting

Tool deflection during milling operation leads to dimensional error, decreasing surface quality and increasing rejection rate. In this study, tool deflection during the milling of the inner surfaces of Ti–6Al–4V prosthetic acetabular shell produced by selective laser melting (SLM) was modelled. The first purpose of this research is to provide a general static cutting tool deflection model for ball nose cutters where deviation of machine components and tool holder are so small as to be considered negligible. This is because the values of machine component and tool holder deflection were lower than standard tolerances (10 μm) and found to be lower than 1/15 of tool deflection. The second and third objectives of this work involve calculating contact surfaces by determining workpiece and tool geometry and choosing second moment of inertia using a novel cross section method (CSM). Static models for three quasi-analytical methods (QAM) that are simple cantilever beam model (SCBM), two-section model (TWSM) and our three section model (THSM) are presented. THSM showed high accuracy which was validated by 3D finite element method (FEM3D) and experimental measurements. The accuracy of tool deflection calculation using THSM by computing, shank, flute and ball head deflection and also utilizing CSM to determine second moment of inertia showed notable improvements.

基于功率转移函数的全光整形器性能评估

According to the linearized three-section model of input/output power transfer function(TF),the theoretical assessment method of all-optical reshapers' performance is investigated and verified by simulation of four-wave-mixing-based scheme.The performance of all-optical reshapers dependent on the input signal of Gaussian distribution is analyzed.The transfer function is divided into five regions from low to high power levels,and a larger improvement of quality factor or BER performance can be obtained for the cases that the average level of mark pulses exists in the fifth region.With the increase of the TF′s second-section slope for a desirable reshaper,the gain saturation of quality factor or BER performance will occur and the extinction ratio will be improved linearly.

BER Estimation in Optical Fiber Transmission Systems Employing All-Optical 2R Regenerators

A bit error rate estimation method for optical fiber transmission systems employing all-optical 2R regenerators is presented. The method is based on the linearization of the nonlinear transfer function of the regenerators in three sections. Using this linearized three-section model, the impact of 2R regeneration on the system performance as a function of the extinction ratio, the clamping factor, and the steepness of the transfer function is studied.

Optical multi-granularity crossconnect and its comparison with optical crossconnect

This paper obtains a formula for the calculation of the power penalty the optical channel suffers in the worst case when passing through the multi-granularity crossconnect (MG-OXC) by adopting a three-section model, analyzes performances of the MG-OXC and compares them with those of the conventional optical crossconnect based on the wavelength granularity. Conditions under which the power penalty of the MG-OXC is lower than that of the OXC are concluded.

Public Relations and the Production of News: A Critical Review and Theoretical Framework

Because the source-reporter relationship forms the focal point of news gathering, it is a significant topic in the media sociology literature. Most of the source-reporter literature, however, focuses on the routines and values of the reporter. In this chapter the authors argue that public relations often sets the agenda for news media simply because the source in source-reporter interaction is often either a public relations practitioner or a practitioner’s client. A three-section model explaining the role and impact of public relations in the news-gathering and news dissemination process is presented and used to organize a review of the literature. The source-reporter relationship section of the model includes studies of mutual assessments and power dynamics. The organizational section contains studies of practices and values in public relations, including ethics and professional values such as routines and news values. The societal section of the model covers studies pertaining to information subsidies and other influences on news media agendas, such as marketing pressures. A summary assessment of the source-reporter literature concludes that too much of the scholarly research has been merely descriptive. Theoretical directions are suggested to enrich public relations research and our understanding of public relations practice.

A three-section model for computing I-V characteristics of GaAs MESFET's

A new model of the GaAs MESFET is proposed by dividing the MESFET into three sections that may be replaced with the resistance (R2) and the voltage-dependent current sources I 1 and I 3 . In order to show the general fitness of this model, two different real devices with low and high pinchoff voltages, respectively, are simulated. The results obtained from the simulation are compared with those of the complete velocity saturation model and the square-law model, as well as experimental data. The results of this model agree better with the experimental data than those of the other two models, i.e., the complete velocity saturation model and the square-law model.