Process capability indices for skewed populations

This paper proposes a new method of constructing process capability indices (PCIs) for skewed populations. It is based on a weighted standard deviation method which decomposes the standard deviation of a quality characteristic into upper and lower deviations and adjusts the value of the PCI using decomposed deviations in accordance with the skewness estimated from sample data. For symmetric populations, the proposed PCIs reduce to standard PCIs. The performance of the proposed PCIs is compared with those of standard and other PCIs, and finite sample properties of the estimates are investigated using Monte Carlo simulation. Numerical studies indicate that considerable improvements over existing methods can be achieved by the use of the weighted standard deviation method when the underlying distribution is skewed. Copyright © 2002 John Wiley & Sons, Ltd.     

An analysis of a fracture specimen for rough crack in shear

In this paper, a BEM formulation predicting the reduced mode II and the enhanced mode I stress intensity factors of the mode II test specimen caused by fracture surface roughness is presented. The dilatant boundary conditions (DBC) are based on the assumptions of idealized uniform sawtooth crack surfaces and an effective Coulomb sliding law. They are obtained by relating the crack opening displacement and crack sliding displacement through the assumption of rigid body asperity sliding as in Young (1999). Three different types of crack, i.e. (1) non-interfering flat closed crack; (2) DBC with elastic crack tip; and (3) DBC with plastic crack tip are discussed. The results show a good approximation of the present BEM model. This study also shows the potential application of the present method determining the effect of crack face roughness in a realistic experimental specimen.     

Mergers and Acquisitions in the Telecommunications Industry: Myths and Reality

This paper investigates how market participants react to mergers and acquisitions (M&As) involving telecommunications companies. The empirical evidence suggests that such activities convey bad news to the market. This is consistent with the synergy trap hypothesis and extant empirical findings of value‐reducing diversification strategies in recent literature. The evidence also indicates that a cross‐border, rather than a domestic M&A deal, is the main driver of the negative market reaction. Further, our evidence of negative impacts on the bidder's business after an M&A reinforces our main finding that market participants, on average, perceive M&A activities to be detrimental to shareholder value. This suggests that value creation or synergy through an M&A deal is not warranted even though it can generate an increase in size of the firm.     

Couple communication and female problem drinking: A behavioral observation study.

Couples with alcohol and relationship problems often report poor communication, yet little is known about the communication of maritally distressed couples in which the woman abuses alcohol (MDWA couples). Compared with maritally distressed couples without alcohol problems (MDNA) and couples with neither problem (NDNA), MDWA couples showed a distinctive pattern of negative communication. Similar to MDNA men, MDWA men spoke negatively to their partners but listened positively to their partners much like NDNA men. MDWA women listened negatively, much as MDNA women did, but spoke positively, like NDNA women did. The interactions of MDWA couples can be characterized as a male-demand-female-withdraw pattern, which is a gender reversal of the female-demand-male-withdraw pattern often observed in MDNA couples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fabrication of excimer laser annealed poly-Si thin film transistor by using an elevated temperature ion shower doping

We have investigated the effect of an ion shower doping of laser annealed poly-Si films at elevated substrate temperatures. The substrate temperature was varied from room temperature to 300°C when the poly-Si film was doped with phosphorus by a non-mass-separated ion shower. Optical, structural, and electrical characterizations have been performed in order to study the effect of the ion shower doping. The sheet resistance of the doped poly-Si films was decreased from 7 × 10⁶ Ω/sq to 700 Ω/sq when the substrate temperature was increased from room temperature to 300°C. This large change in sheet resistance is due to the fact that the doped films do not become amorphous but remain in the polycrystallinephase. The mildly elevated substrate heating appears to contribute mainly to reduction of ion damages incurred in the poly-Si films in addition to the activation of dopants during the ion shower doping. From the fabricated n-channel poly-Si TFTs, the current crowding effect do not occur because of the low contact source-drain resistance and the field effect mobility of 120 cm²/(V s) has been obtained.     

Phase behaviors of polymer blend(PEO–PPO) electrolyte/LiCF3SO3 systems in lithium battery

Polymer blend (poly(ethylene oxide) (PEO)–poly(propylene oxide) (PPO)) systems with two different mole ratios, complexed with LiCF₃SO₃ salt, have been characterized at various temperatures and compositions using a thermo‐optical analysis (TOA) technique. We also developed a new melting point depression theory based on the modified perturbed hard sphere chain model to interpret phase behavior of polymer blend electrolyte systems. The obtained results show that the eutectic points move toward higher T_m and lower weight fraction of salt with decreasing PEO mole ratio and also indicate that the mole ratio of PEO–PPO for each polymer blend plays an important role in determining the eutectic point of the polymer blend system. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2314–2319, 2005     

Selective Oxidation and Sub-surface Phase Transformations in Chromium-bearing Austenitic Steels

A series of Fe–15Cr–(2–3)Mo–(0.7–2.5)C (compositions in weight percent) steels was oxidised at 850°C and P_{O_2} = 5.8 × 10^–20 atm, where iron oxide is unstable. All grew external Cr₂O₃ scales according to parabolic kinetics. Depletion of chromium from alloy subsurface regions led to dissolution of chromium-rich carbides if the original alloy carbon level was less than 1.2%. Simultaneous decarburisation caused a transformation of the original austenitic or austenoferritic structure into single-phase ferrite, stabilised by the molybdenum. Diffusion analysis of the concentration profiles within this transformed zone led to satisfactory agreement with the known diffusion coefficient for chromium in ferrite. At high carbon levels, decarburisation was slow, resulting in low chromium concentrations at the internal alloy–carbide interfaces. In these cases, the carbide dissolution did not proceed and chromia scaling rates were slowed.