Scalable, Efficient and Optimal Discrete-Time Rebalancing Algorithms for Log-Optimal Investment Portfolio

Portfolio rebalancing decisions are crucial to today\u27s portfolio managers especially in high frequency algorithmic trading environment. These decisions must be made fast in dynamic market conditions. We develop computational algorithms to determine optimal rebalance frequency (ORF) of a class of investment portfolio for a finite investment horizon. We choose log-optimal investment portfolio which is deemed to be impractical and cost-prohibitive due to inherent need for continuous rebalancing and significant overhead of trading cost. Optimality of such portfolio is assured only when for very long term investor horizon. We study the question of how often a log-optimal portfolio be rebalanced for any given finite investment horizon. We develop an analytical framework to compute the expected log of portfolio value when a given discrete-time periodic rebalance frequency is used. For a certain class of portfolio assets, we compute the optimal rebalance frequency. We show that it is possible to improve investor log utility using this quasi-passive or hybrid rebalancing strategy. Under the assumptions of geometric Brownian motion for assets and log-normality for sum of log-normal random variables, we find that the ORF is a piecewise function of investment horizon. One can construct this rebalance strategy function, called ORF function, up to a specified investment horizon given a limited trajectory of expected log of portfolio value (ELPV) when the initial portfolio is never rebalanced. We develop the analytical framework to compute the optimal rebalance strategy in linear time, a significant improvement from the previously proposed search-based quadratic time algorithm. Simulation studies show that an investor can gain significantly by adopting a discrete-time rebalancing periodically using ORF in lieu of continuous rebalancing. Finally we investigate the computational efficiency of the proposed algorithms to develop optimized versions which are scalable to portfolios comprising of large number of assets

Political Ecology in Merbeel: A Power Play Around Past and Present Wetland Resource Management

The interrelationship between human society and nature is multifarious. Indeed, interrelationship involves different power plays either in explicit or implicit forms. In different indigenous societies of the world, different actors have been influencing the natural resource management process. With time, the power plays commenced by such actors have been altering their forms with different actors at the zenith of hierarchical man-environment relationship. This research is an attempt to explore a succession of such power plays around a historically famous wetland Merbeel and its island of Upper Assam. The research methods followed here is qualitative. A participatory research approach is used to explore different local dynamics. The research shows that the wetland and its island have perceivably been under a through hegemonic control of different groups, from time to time. Due to natural resource availability, Merbeel and its island have always been in the epicentre of these hegemonic power plays. This study provides a brief explanation of this succession process of these power plays dividing it into three periods

Impact of Flood on the Socio-Economic Conditions in the Southern Part of Kamrup District, Assam

Flood causes extreme loss of infrastructure and human life; besides it also propagates the condition of poverty and unceasing marginalisation of the affected region from development. This study elucidates how flood contributes to the socio-economic conditions of the rural people living in the Southern part of the Kamrup district of Assam. It focusses on flood hazard zoning and flood vulnerability analyses that are delineated based on the data collected from the Moderate Resolution Imaging Spectroradiometer (MODIS) Near Real-Time (NRT) Global Flood Mapping Product Portal. Flood hazard zoning of the study area is done using Multi-Criteria evaluation method based on rainfall distribution, slope, drainage density, population density, soil type, elevation, flow accumulation, roads, and embankment utilising Cartosat DEM and IRS P6 LISS III data. The zones are identified as actively flooded, chronically flooded, and occasionally flooded zones, which affects 39.4 per cent, 12.9 per cent and 26.1 per cent population respectively covering 1189.2 sq. km, that is, 56.5 per cent area of the study region.  The flood vulnerability assessment of the study area is done at village and ward level adapting geospatial assessment in a GIS environment. The findings of the research are generated through observations, key informant interviews with the rural population surveying 1420 number of households. It reveals that 200 villages are affected by floods every year that constitutes 76.6 per cent households and 78.4 per cent of the population of the study area

Ray skin- an emerging unconventional source of leather

Due to the ever-increasing demand for leather products, alternative sources are constantly being explored. Of late, a new trend in using fish skin is gaining momentum, which may become an important event in the development of leather industry. Fish leather has a good tensile strength as any other leather. The process is highly cost-effective, as the raw material generated is generally discarded at fish markets

Utilization of skin of 'Koth', Otolithoides biauritus - a new fish by-product

Dasyatis uarnak (banded whip-tail stingray)skin is being used as another alternative sources for leather.The skin of Koth and Ghol is used for this purpose and the finished product is used in the manufacture of purses,belts etc