title: The evolution of hog production and potential sources for future growth in China

authors: Xiao, Hongbo

subjects: China

abstract: Following reforms to the market, China’s hog industry has developed rapidly, however, with social and economic transitions, China’s hog industry is facing challenges which might restrict long-term growth in production. This paper analyzes the changes in regional scale, organization, input factors, and technological progress for China’s hog production over the last few decades. The paper seeks to reveal the sources of hog production growth and provide some suggestions for future development of the hog industry. To achieve these aims, the paper uses stochastic frontier production functions and the Malmquist index to measure total factor productivity (TFP) in the hog industry and decompose TFP into technical efficiency; technological progress; scale efficiency; and allocative efficiency using data for 25 provinces from 1980 to 2008. The results show firstly that; the TFP of hog production increased by 64.3% from 1980 to 2008, and allocative efficiency and scale efficiency improvements played a key role in this TFP growth. In contrast, technical efficiency and technical progress have changed little over this period. Secondly, TFP’s contribution to output was 39.7%, it being less than that of factor inputs to output. Thirdly, the results suggest that the growth of China’s pork production depends mostly on the increase in the quantity of factor inputs, especially feed. As a consequence, the key to ensuring long-term and stable development of China’s hog production would seem to involve focusing on enhancing total factor productivity and changing the pattern of production growth.

text: The evolution of hog production and potential sources for future growth in China Following reforms to the market, China’s hog industry has developed rapidly, however, with social and economic transitions, China’s hog industry is facing challenges which might restrict long-term growth in production. This paper analyzes the changes in regional scale, organization, input factors, and technological progress for China’s hog production over the last few decades. The paper seeks to reveal the sources of hog production growth and provide some suggestions for future development of the hog industry. To achieve these aims, the paper uses stochastic frontier production functions and the Malmquist index to measure total factor productivity (TFP) in the hog industry and decompose TFP into technical efficiency; technological progress; scale efficiency; and allocative efficiency using data for 25 provinces from 1980 to 2008. The results show firstly that; the TFP of hog production increased by 64.3% from 1980 to 2008, and allocative efficiency and scale efficiency improvements played a key role in this TFP growth. In contrast, technical efficiency and technical progress have changed little over this period. Secondly, TFP’s contribution to output was 39.7%, it being less than that of factor inputs to output. Thirdly, the results suggest that the growth of China’s pork production depends mostly on the increase in the quantity of factor inputs, especially feed. As a consequence, the key to ensuring long-term and stable development of China’s hog production would seem to involve focusing on enhancing total factor productivity and changing the pattern of production growth.

year: 2012

title: Compression and explanation using hierarchical grammars

authors: Nevill-Manning, Craig G.

subjects: computer science

abstract: Data compression is an eminently pragmatic pursuit: by removing redundancy, storage can be utilised more efficiently. Identifying redundancy also serves a less prosaic purpose-it provides cues for detecting structure, and the recognition of structure coincides with one of the goals of artificial intelligence: to make sense of the world by algorithmic means. This paper describes an algorithm that excels at both data compression and structural inference. This algorithm is implemented in a system call SEQUITUR that efficiently deals with sequences containing millions of symbols.

text: Compression and explanation using hierarchical grammars Data compression is an eminently pragmatic pursuit: by removing redundancy, storage can be utilised more efficiently. Identifying redundancy also serves a less prosaic purpose-it provides cues for detecting structure, and the recognition of structure coincides with one of the goals of artificial intelligence: to make sense of the world by algorithmic means. This paper describes an algorithm that excels at both data compression and structural inference. This algorithm is implemented in a system call SEQUITUR that efficiently deals with sequences containing millions of symbols.

year: 1996-07

title: Water Quality Modelling of Te Waihora/Lake Ellesmere

authors: Hamilton, David P.

abstract: As a component of work to contribute towards the management of water quality of Te Waihora/Lake Ellesmere, the University of Waikato was subcontracted by University of Otago to apply a coupled hydrodynamic-water quality model to the lake. The primary funder for this work was Environment Canterbury (ECAN), Whakaora Te Waihora and the Central Government Freshwater Cleanup Fund. The main modelling tool used in the study to simulate the dynamics of Te Waihora/Lake Ellesmere was the one‐dimensional (1‐D) hydrodynamic-water quality model DYRESM-CAEDYM. The model was used to reproduce observed water column data for a mid-lake station over the period 2011 to 2015. Once a satisfactory level of reproduction of these data had been achieved, an assessment was carried out with the model to examine the impact of various management scenarios on lake water quality. These scenarios involved: (i) projected changes to external nutrient loads to the lake that could be associated with future land management in the catchment and (ii) different lake water level management regimes based around opening of the barrier separating the lake from the ocean. The scenarios are intended here to be a catalyst for further hui and consultations that may adapt and refine additional scenarios, some of which may involve testing of multiple management options. The quantitative output from the model provides a component of the input required to inform strategies for lake management, alongside historical and expert knowledge, as well as analysis of measured data.

text: Water Quality Modelling of Te Waihora/Lake Ellesmere As a component of work to contribute towards the management of water quality of Te Waihora/Lake Ellesmere, the University of Waikato was subcontracted by University of Otago to apply a coupled hydrodynamic-water quality model to the lake. The primary funder for this work was Environment Canterbury (ECAN), Whakaora Te Waihora and the Central Government Freshwater Cleanup Fund. The main modelling tool used in the study to simulate the dynamics of Te Waihora/Lake Ellesmere was the one‐dimensional (1‐D) hydrodynamic-water quality model DYRESM-CAEDYM. The model was used to reproduce observed water column data for a mid-lake station over the period 2011 to 2015. Once a satisfactory level of reproduction of these data had been achieved, an assessment was carried out with the model to examine the impact of various management scenarios on lake water quality. These scenarios involved: (i) projected changes to external nutrient loads to the lake that could be associated with future land management in the catchment and (ii) different lake water level management regimes based around opening of the barrier separating the lake from the ocean. The scenarios are intended here to be a catalyst for further hui and consultations that may adapt and refine additional scenarios, some of which may involve testing of multiple management options. The quantitative output from the model provides a component of the input required to inform strategies for lake management, alongside historical and expert knowledge, as well as analysis of measured data.

year: 2017