Monitoring of Deep Groove Ball Bearing Defects Using the Acoustic Emission Technology

One of the essential components in rotating machinery are Rolling element bearings and their failure proved to be one of the most common reasons behind machine breakdown. Acoustic Emission (AE), a passive listening technique, has evolved as a significant opportunity to diagnose and monitor the mechanical integrity of rolling element bearings. The investigation reported in this paper mainly focuses on the application of the AE technology for detecting the defect on a radially loaded bearing. In order to undertake this task, a special purpose test-rig was designed so that defect could be seeded onto the outer race of a test bearing using an electrical engraver. By applying varying rotating speed and radial load, twenty tests were carried out. The structure mechanism allows locating an AE sensor directly on the bearing outer race. The AE wave signal has been analyzed in time and frequency domain. It was concluded that the AE can provide good indications of bearing defects. Moreover, it has been noted that the amplitude, absolute energy, and RMS provided indications of bearing condition

State Control and the Effects of Foreign Relations on Bilateral Trade

Do states use trade to reward and punish partners? WTO rules and the pressures of globalization restrict states’ capacity to manipulate trade policies, but we argue that governments can link political goals with economic outcomes using less direct avenues of influence over firm behavior. Where governments intervene in markets, politicization of trade is likely to occur. In this paper, we examine one important form of government control: state ownership of firms. Taking China and India as examples, we use bilateral trade data by firm ownership type, as well as measures of bilateral political relations based on diplomatic events and UN voting to estimate the effect of political relations on import and export flows. Our results support the hypothesis that imports controlled by state-owned enterprises (SOEs) exhibit stronger responsiveness to political relations than imports controlled by private enterprises. A more nuanced picture emerges for exports; while India’s exports through SOEs are more responsive to political tensions than its flows through private entities, the opposite is true for China. This research holds broader implications for how we should think about the relationship between political and economic relations going forward, especially as a number of countries with partially state-controlled economies gain strength in the global economy

CDSIMEQ: A program to implement two-stage probit least squares

The cdsimeq command implements the two-stage probit least squares estimation method described in Maddala (1983) for simultaneous equations models in which one of the endogenous variables is continuous and the other endogenous variable is dichotomous. The cdsimeq command implements all the necessary procedures for obtaining consistent estimates for the coefficients, as well as their corrected standard errors

CDSIMEQ: A program to implement two-stage probit least squares

The cdsimeq command implements the two-stage probit least squares estimation method described in Maddala (1983) for simultaneous equations models in which one of the endogenous variables is continuous and the other endogenous variable is dichotomous. The cdsimeq command implements all the necessary procedures for obtaining consistent estimates for the coefficients, as well as their corrected standard errors. Copyright 2003 by Stata Corporation.simultaneous equations, Amemiya, Maddala, continuous endogenous, dichotomous endogenous, 2SPLS, 2SLS, instruments, standard errors

Trade and Conflict: Proximity, Country Size, and Measures

The effect of trade on military conflict is one of the most important questions in international relations. Liberals argue that trade brings peace, neo-realists and neo-Marxists reason that trade brings conflict, while classical realists contend that trade has no impact on conflict. This article investigates theoretically and empirically some of the most important issues that remain in this literature: the roles of geographical proximity, country size, the handling of the trade data, and the conceptualization of conflict. Employing a simultaneous equations model, we find that the claim that trade brings peace is not robust, but rather it is conflict that reduces trade.fatal disputes; liberal peace; militarized interstate disputes; missing trade data; realism; simultaneity; zero trade