University of Malaya

About: University of Malaya is a education organization based out in Kuala Lumpur, Malaysia. It is known for research contribution in the topics: Population & Fiber laser. The organization has 25087 authors who have published 51491 publications receiving 1036791 citations. The organization is also known as: UM & Universiti Malaya.

Stock Return Predictability and the Adaptive Markets Hypothesis: Evidence from Century Long U.S. Data

Abstract: We study return predictability of the Dow Jones Industrial Average indices from 1900 to 2009. We find strong evidence that time-varying return predictability is driven by changing market conditions, consistent with the implications of the adaptive markets hypothesis. During market crashes, no return predictability is observed, but an extreme degree of uncertainty is associated with return predictability. During fundamental economic or political crises, stock returns have been highly predictable with a moderate degree of uncertainty. During economic bubbles, return predictability and its uncertainty have been smaller than normal times.

A review on the performance of nanoparticles suspended with refrigerants and lubricating oils in refrigeration systems

Abstract: Recently scientists used nanoparticles in refrigeration systems because of theirs remarkable improvement in thermo-physical, and heat transfer capabilities to enhance the efficiency and reliability of refrigeration and air conditioning system. In this paper thermal–physical properties of nanoparticles suspended in refrigerant and lubricating oil of refrigerating systems were reviewed. Heat transfer performance of different nanorefrigerants with varying concentrations was reviewed and review results are presented as well. Pressure drop and pumping power of a refrigeration system with nanorefrigerants were obtained from different sources and reported in this review. Along with these, pool boiling heat transfer performance of CNT refrigerant was reported. Moreover, challenges and future direction of nanofluids/nanorefrigerants have been reviewed and presented in this paper. Based on results available in the literatures, it has been found that nanorefrigerants have a much higher and strongly temperature-dependent thermal conductivity at very low particle concentrations than conventional refrigerant. This can be considered as one of the key parameters for enhanced performance for refrigeration and air conditioning systems. Because of its superior thermal performances, latest upto date literatures on this property has been summarized and presented in this paper as well. The results indicate that HFC134a and mineral oil with TiO2 nanoparticles works normally and safely in the refrigerator with better performance. The energy consumption of the HFC134a refrigerant using mineral oil and nanoparticles mixture as lubricant saved 26.1% energy with 0.1% mass fraction TiO2 nanoparticles compared to the HFC134a and POE oil system. It was identified that fundamental properties (i.e. density, specific heat capacity, and surface tension) of nanorefrigerants were not experimentally determined yet. It may be noted as well that few barriers and challenges those have been identified in this review must be addressed carefully before it can be fully implemented in refrigeration and air conditioning systems.

The Association Between Training and Organizational Commitment Among White-Collar Workers in Malaysia

Abstract: The exploration of the relationship between organizational commitment and training is still in its early stages. Although there have been several studies reported on training and organizational commitment in Western countries, very little has been done in respect of the local professionals in Malaysia. This research investigates the association between five training variables (availability of training, support for training, motivation to learn, training environment and perceived benefits of training), and various aspects of organizational commitment (affective commitment, normative commitment, continuance commitment and overall organizational commitment). The availability of training, support for training, motivation to learn, training environment, perceived benefits of training were all significantly correlated with affective commitment, normative commitment and overall organizational commitment. The training environment and perceived benefits were also significantly correlated with continuance commitment. However the availability of training, support for training and motivation to learn were not significantly correlated with continuance commitment. This suggests that despite other forms of commitment, Malaysian workers do not feel that they need to remain in an organization that has made available the training, given support for the training and were motivated to learn. Otherwise, results suggest that on the whole, training does seem to have an influence on organizational commitment. The practical implication of this is that managers, who are so desirous of enhancing organizational commitment among their subordinates, should pay more attention to training. Annual income was found to correlate positively with affective commitment and overall commitment. Age and tenure were not significant predictors of overall organizational commitment contradicting studies in the West. This demonstrated that Malaysians might have different attitudes towards organizational commitment. The older they are and the longer they stay within an organization do not imply that they will be committed towards their organization. This phenomenon can be attributed to the uncertain business environment in Malaysia.