title: Enhancement of the Hooghoudt Drain-Spacing Equation

authors: Shokri, Ali

subjects: Science & Technology

abstract: The Hooghoudt equation is widely used as a simple means of specifying drain spacing when designing networks of parallel drains in drainage systems, based on estimating the maximum water table height between two drains. It is shown via comparison with a numerical model that the Hooghoudt equation can overestimate water table height and therefore yield drain spacings that may be too wide. This is because the Hooghoudt drain-spacing equation in fact has a concealed dependency on Van Genuchten soil-water retention curve parameters, which can bias the water table estimates unless adjustments are made explicitly. A modification of the Hooghoudt equation is presented that incorporates two new dimensionless coefficients to make allowance for this dependency. The modified expression yields improved accuracy as measured against the numerical reference model.

text: Enhancement of the Hooghoudt Drain-Spacing Equation The Hooghoudt equation is widely used as a simple means of specifying drain spacing when designing networks of parallel drains in drainage systems, based on estimating the maximum water table height between two drains. It is shown via comparison with a numerical model that the Hooghoudt equation can overestimate water table height and therefore yield drain spacings that may be too wide. This is because the Hooghoudt drain-spacing equation in fact has a concealed dependency on Van Genuchten soil-water retention curve parameters, which can bias the water table estimates unless adjustments are made explicitly. A modification of the Hooghoudt equation is presented that incorporates two new dimensionless coefficients to make allowance for this dependency. The modified expression yields improved accuracy as measured against the numerical reference model.

year: 2015-06-01

title: Full model selection in the space of data mining operators

authors: Sun, Quan

subjects: genetic algorithm

abstract: We propose a framework and a novel algorithm for the full model selection (FMS) problem. The proposed algorithm, combining both genetic algorithms (GA) and particle swarm optimization (PSO), is named GPS (which stands for GAPSO-FMS), in which a GA is used for searching the optimal structure of a data mining solution, and PSO is used for searching the optimal parameter set for a particular structure instance. Given a classification or regression problem, GPS outputs a FMS solution as a directed acyclic graph consisting of diverse data mining operators that are applicable to the problem, including data cleansing, data sampling, feature transformation/selection and algorithm operators. The solution can also be represented graphically in a human readable form. Experimental results demonstrate the benefit of the algorithm.

text: Full model selection in the space of data mining operators We propose a framework and a novel algorithm for the full model selection (FMS) problem. The proposed algorithm, combining both genetic algorithms (GA) and particle swarm optimization (PSO), is named GPS (which stands for GAPSO-FMS), in which a GA is used for searching the optimal structure of a data mining solution, and PSO is used for searching the optimal parameter set for a particular structure instance. Given a classification or regression problem, GPS outputs a FMS solution as a directed acyclic graph consisting of diverse data mining operators that are applicable to the problem, including data cleansing, data sampling, feature transformation/selection and algorithm operators. The solution can also be represented graphically in a human readable form. Experimental results demonstrate the benefit of the algorithm.

year: 2012

title: Alice Grey Nicholls, daughter of William, and her husband, Charles John Dearle

authors: Hart, Philip

abstract: Alice Grey Nicholls was the ‘half-caste’ daughter of a Pakeha Maori, William Nicholls. She would marry a Pakeha and have several children, losing her only son but bringing up a family of daughters, who all received a Pakeha education. Having a moko emphasized her Maori heritage, and she was on good terms with many Maori.
Charles John Dearle, a Londoner, after some involvement in gold mining spent most of his life working for the government. At the request of Maori landowners, from 1883 until 1895 he allocated goldfields revenue amongst them, a challenging task. He was also involved in land purchases both on behalf of the government and for personal gain. 
They farmed her land at Mangaiti, near Te Aroha, Alice continuing to farm it profitably after his early death, assisted for a time by her daughters. She purchased more land, and to enable her to sell some portions of it she had it declared European land, an illustration of her astuteness in business; her family obtained a good financial position from her farming and land dealings. When she died, aged 81, her Pakeha friends fondly remembered her.

text: Alice Grey Nicholls, daughter of William, and her husband, Charles John Dearle Alice Grey Nicholls was the ‘half-caste’ daughter of a Pakeha Maori, William Nicholls. She would marry a Pakeha and have several children, losing her only son but bringing up a family of daughters, who all received a Pakeha education. Having a moko emphasized her Maori heritage, and she was on good terms with many Maori.
Charles John Dearle, a Londoner, after some involvement in gold mining spent most of his life working for the government. At the request of Maori landowners, from 1883 until 1895 he allocated goldfields revenue amongst them, a challenging task. He was also involved in land purchases both on behalf of the government and for personal gain. 
They farmed her land at Mangaiti, near Te Aroha, Alice continuing to farm it profitably after his early death, assisted for a time by her daughters. She purchased more land, and to enable her to sell some portions of it she had it declared European land, an illustration of her astuteness in business; her family obtained a good financial position from her farming and land dealings. When she died, aged 81, her Pakeha friends fondly remembered her.

year: 2016