38 research outputs found
A Latent Dirichlet Allocation and Fuzzy Clustering Based Machine Learning Model for Text Thesaurus
It is not quite possible to use manual methods to process the huge amount of structured and semi-structured data. This study aims to solve the problem of processing huge data through machine learning algorithms. We collected the text data of the company’s public opinion through crawlers, and use Latent Dirichlet Allocation (LDA) algorithm to extract the keywords of the text, and uses fuzzy clustering to cluster the keywords to form different topics. The topic keywords will be used as a seed dictionary for new word discovery. In order to verify the efficiency of machine learning in new word discovery, algorithms based on association rules, N-Gram, PMI, andWord2vec were used for comparative testing of new word discovery. The experimental results show that the Word2vec algorithm based on machine learning model has the highest accuracy, recall and F-value indicators
Intensive Livestock Farming on New Zealand Hill Country Farms Creates Critical Source Areas of Potential Pollution
Oral Session
Intensive Livestock Farming on New Zealand Hill Country Farms Creates Critical Source Areas of Potential Pollution
Oral Session
Imaging of the Atomic Structure of All-Inorganic Halide Perovskites
All-inorganic halide perovskites are promising materials for optoelectronic applications. The surface or interface structure of the perovskites plays a crucial role in determining the optoelectronic conversion efficiency, as well as the material stability. A thorough understanding of surface atomic structures of the inorganic perovskites and their contributions to their optoelectronic properties and stability is lacking. Here we show a scanning tunneling microscopy investigation on the atomic and electronic structure of CsPbBr3 perovskite. Two different surface structures with a stripe and an armchair domain are identified, which originates from a complex interplay between Cs cations and Br anions. Our findings are further supported and correlated with density functional theory calculations and photoemission spectroscopy measurements. The stability evaluation of photovoltaic devices indicates a higher stability for CsPbBr3 in comparison with MAPbBr3, which is closely related to the low volatility of Cs from the perovskite surface
On the geometry of generalized linear models : submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Massey University, Palmerston North, New Zealand
The perspective afforded by Euclidean geometry led to the rapid development of linear models in the early stages of the twentieth century: Fisher saw the data as a point in finite-dimensional Euclidean space, the model as a subspace and least squares fitting as projection of the observation vector onto the model space. From the late 1960s to early 1970s, Fienberg revealed geometry underlying loglinear models for two-way tables, while Haberman discussed geometry for the log-transformed case. Generalized linear models, however, have largely eluded geometers until recently. In 1997 an extension of Fisher's view to generalized linear models was given by Kass and Vos, using the language of differential geometry. The aim of this work is to develop a simple, general geometric framework for generalized linear models, closely related to the thinking of Fienberg and Haberman. Whereas Kass and Vos developed a geometric view which leads to the usual scoring method, we develop geometry which leads to a new algorithm. A linearization of this new algorithm yields the scoring method. The geometry discussed by Kass and Vos is based on the log-likelihood function whereas the geometry developed here depends on sufficiency. In the geometry of generalized linear models, developed through chapters 1 to 3, an observation with n values is viewed as a vector in Euclidian space Rn. This Euclidian space Rn is partitioned into two orthogonal spaces, the sufficiency space S and the auxiliary space A, with respect to a new basis. We focus on two mean sets relating to generalized linear models, one for the untransformed model space and another for the link-transformed model space. There are two critical properties of the maximum likelihood estimate of the parameters of a generalized linear model with canonical link. The first property is that the coefficients of the basis of the sufficiency space, the sufficient statistics, are preserved in the untransformed model space in the fitting process. The second property is that the coefficients of the basis of the auxiliary space are zeroed in the link-transformed model space in the fitting process. Linear models and loglinear models serve as special cases of generalized linear models with identity and log link respectively. Based on the geometric framework discussed in the thesis, a new algorithm is constructed for fitting generalized linear models with canonical link in Chapter 4. This algorithm, which relies on sufficient statistics for the parameters in the model rather than the likelihood function, takes two projections alternately, orthogonal projection onto a sufficiency affine plane and non-orthogonal projection onto the transformed model space. In the process, we match the model space and sufficient statistics iteratively until convergence. Linearization of the new algorithm induces the scoring method. In Chapter 5 we pay special attention to a subset of loglinear models, graphical loglinear models, those which are the intersection of a finite set of conditional independence statements. The model space of one conditional independence statement is described through the notions of "corresponding point convex hull" and "set convex hull". The fitting of one conditional independence statement is considered geometrically using a direct fitting method and the familiar iterative proportional fitting method
Enhancing vehicle utilization via a mobile application within the courier industry in New Zealand : a thesis presented in partial fulfilment of the requirement for the degree of Master of Supply Change Management at Massey University, College of Sciences, School of Engineering and Advanced Technology, Manawatu, New Zealand
In the New Zealand transport sector, the Owner-Operator is an indispensable part of
Logistics industry. Most couriers and road freight companies Owner-Operators as
independent contractors for delivery service. Hence, the vehicle utilization of
Owner-Operators might directly influence the profitability and service quality of
couriers companies as well as their personal incomes. With respect to the inefficient
vehicle utilization, it normally represents as underutilized capacities of part-load
shipments, empty movements or idle time.
In conducting the qualitative research, the researcher has interviewed thirty respondents
who consist of Owner-Operators and Operations team staff. According to the relevant
qualitative data, the research found that the inefficient activities, such as empty run,
unpaired shipments and part load shipments are principally caused by unsteady delivery
frequency, lack of business acquisition opportunities and small time window. These
causes provide mobile technology with a significant potential to enhance the vehicle
efficiency. A Logistical Mobile Application, which is installed in a smart phone or
portable electronic devices, offers a cost-effective and real-time information exchange
platform between customers and service providers.
From the perspectives of respondents, Owner-Operators believe that the mobile app is a
new trend of integrating the functions of scanner, GPS and pager. Furthermore, around
ninety percent of them perceive that it is a useful tool for improving the vehicle
utilization and incomes. However, although the respondents have relatively positive
attitudes on this new technology and business model, there are some constraints of its
practical effect, due to the boundary and policy of the companies, as well as the
population density of New Zealand.
KEYWORDS:Mobile Commerce, Mobile App, Owner-Operators, Vehicle Utilization,
Logistics Managemen
A structural model with interventions for new Zealand sawn timber production
Timber production in New Zealand was privatized in 1987. We examine
the effects of this change on the level of New Zealand sawn timber production,
and changes in the seasonal pattern, using a state-space model with intervention
variables. We describe the formulation and estimation of the state-space model,
and show how it can be used to examine both the structural changes around the
time of privatization and the gradually evolving seasonal pattern in production. We
also show how the model can be used to forecast future production
Sheep Rumen Fermentation Characteristics Affected by Feeding Frequency and Feeding Level When Fed Fresh Forage
Feeding frequency and feeding level are two important factors affecting rumen fermentation characteristics, but few studies on these have been conducted on fresh forage. Eight rumen-fistulated sheep were fed either fresh chicory or perennial ryegrass hourly in the first period (d 14 to 21) of the experiment and twice-daily in the second period (d 22 to 27) at 1.3 or 2.2 times the requirement of metabolizable energy for maintenance. When fed hourly, but not twice-daily, rumen fluid pH value was affected by forage species and feeding level. The total concentrations of short-chain fatty acid (SCFA) were similar at both feeding levels when fed chicory hourly, but they were greater at the higher feeding level in comparison with the lower feeding level when fed perennial ryegrass. However, forage species and feeding level did not affect rumen fluid total SCFA concentration when sheep were fed twice-daily. Therefore, rumen fermentation characteristics were affected by forage species, feeding frequency, feeding level and their interactions and the differences in fermentation characteristics were more apparent when feeding was performed hourly rather than twice-daily. This study highlighted the importance of feeding frequency on manipulating sheep ruminal metabolism when fed fresh forage