title: NIR technologies for high speed fruit grading

authors: Fraser, Daniel Grant

abstract: Today’s consumers seek information about food products so they can purchase with confidence, even if it translates to higher priced items. It is the aim of this thesis to improve the instruments available for the prediction of food quality, in particular, to advance the technology used for the rapid, low cost, non-destructive analysis of the internal quality of fruit. This thesis contains both experimental and theoretical work covering two main areas of research: the first deals with issues related to the practical grading of fruit, the second with the NIR light penetration and distribution within a fruit. 

A ‘rotary grader’ has been built to enable the rapid, non-destructive assessment of fruit. Up to twenty fruit can be placed on a rotating disk, which can be spun at a controlled speed or moved to fixed positions for stationary studies. A variety of optical arrangements can be mounted to enable the acquisition of spectra from individual fruit in different ‘modes’ of operation. A comparison between the different optical arrangements is presented. It was found that transmission mode (where the light passes right through the fruit) performs better than reflectance mode (where the detected light comes primarily from near the surface of the fruit). This result has been previously predicted and has now been demonstrated with the equipment used in this work. Different angles of transmission are compared as well as different fruit orientations for their influence on fruit quality predictions. It was found that 90° transmission (where the light is detected at right angles to the illumination of the fruit) might work best for randomly orientated kiwifruit; if they are hand placed then 180° or 150° may be more effective. A study of mandarins suggested that the acid content cannot be assessed directly, but it can be inferred from surface properties such as colour and chlorophyll content. This is contrary to several published reports and questions the ability of NIR spectroscopy to measure low concentrations of acid in fruit. A third experiment showed that soluble solids content (SSC) and dry matter (DM) can be assessed from moving apples with a prediction error of 0.54 ± 0.07 °Brix (R²ₚ  = 0.65) and 0.66 ± 0.08 % (R²ₚ  = 0.80) respectively. A unique perspective is presented showing where the useful information is attained from the continuously moving fruit. Transmission and reflectance spectra from apples moving at speeds of up to 3 fruit/s have been recorded, and the optimal spectra from the sequence were combined for improved predictions. 

To investigate the NIR light distribution and penetration in fruit a fibre optic probe was built to take direct measurements of the light levels inside fruit. This enabled, for the first time, the degree of light penetration to be assessed without altering the optical boundaries of the fruit (for example cutting away sections of the fruit). Corresponding simulations using Monte Carlo photon tracing, match the experimental measurements. It was found that fruit such as mandarin exhibit strong internal reflection from the skin, a result that has not previously been reported. The influence of the core and other features in the fruit on the light penetration and distribution is also studied showing perturbations in the internal light levels mapping out these features.

text: NIR technologies for high speed fruit grading Today’s consumers seek information about food products so they can purchase with confidence, even if it translates to higher priced items. It is the aim of this thesis to improve the instruments available for the prediction of food quality, in particular, to advance the technology used for the rapid, low cost, non-destructive analysis of the internal quality of fruit. This thesis contains both experimental and theoretical work covering two main areas of research: the first deals with issues related to the practical grading of fruit, the second with the NIR light penetration and distribution within a fruit. 

A ‘rotary grader’ has been built to enable the rapid, non-destructive assessment of fruit. Up to twenty fruit can be placed on a rotating disk, which can be spun at a controlled speed or moved to fixed positions for stationary studies. A variety of optical arrangements can be mounted to enable the acquisition of spectra from individual fruit in different ‘modes’ of operation. A comparison between the different optical arrangements is presented. It was found that transmission mode (where the light passes right through the fruit) performs better than reflectance mode (where the detected light comes primarily from near the surface of the fruit). This result has been previously predicted and has now been demonstrated with the equipment used in this work. Different angles of transmission are compared as well as different fruit orientations for their influence on fruit quality predictions. It was found that 90° transmission (where the light is detected at right angles to the illumination of the fruit) might work best for randomly orientated kiwifruit; if they are hand placed then 180° or 150° may be more effective. A study of mandarins suggested that the acid content cannot be assessed directly, but it can be inferred from surface properties such as colour and chlorophyll content. This is contrary to several published reports and questions the ability of NIR spectroscopy to measure low concentrations of acid in fruit. A third experiment showed that soluble solids content (SSC) and dry matter (DM) can be assessed from moving apples with a prediction error of 0.54 ± 0.07 °Brix (R²ₚ  = 0.65) and 0.66 ± 0.08 % (R²ₚ  = 0.80) respectively. A unique perspective is presented showing where the useful information is attained from the continuously moving fruit. Transmission and reflectance spectra from apples moving at speeds of up to 3 fruit/s have been recorded, and the optimal spectra from the sequence were combined for improved predictions. 

To investigate the NIR light distribution and penetration in fruit a fibre optic probe was built to take direct measurements of the light levels inside fruit. This enabled, for the first time, the degree of light penetration to be assessed without altering the optical boundaries of the fruit (for example cutting away sections of the fruit). Corresponding simulations using Monte Carlo photon tracing, match the experimental measurements. It was found that fruit such as mandarin exhibit strong internal reflection from the skin, a result that has not previously been reported. The influence of the core and other features in the fruit on the light penetration and distribution is also studied showing perturbations in the internal light levels mapping out these features.

year: 2001

title: Measures of Dosage for Spinal-Cord Electrical Stimulation: Review and Proposal

authors: Single, Peter S.

abstract: This manuscript proposes an electrical definition of therapeutic dose for spinal cord systems used for the treatment of chronic pain, analogous to the pharmacological definition. Dose-response relationships are fundamental to pharmacology, radiotherapy, and other treatments, but have never been properly established for neuromodulation. This manuscript offers a robust measure of dose, pre-requisite to establishing a reliable and repeatable dose-response relationship. The new definition, enabled by the system transresistance obtained from measurement of evoked action potentials, recognizes the mechanism of action of spinal cord stimulation (SCS), and should improve acceptance of the therapy as compared to pharmacological treatments which are currently used more frequently for the treatment of chronic pain. The new definition suggests methods for personalization and standardization of the dose in SCS, and is potentially generalizable to all neuromodulation therapies in which nervous tissue is excited including sacral nerve stimulation (SNS), vagal nerve stimulation (VNS), and deep-brain stimulation (DBS). Formulas are provided, and applied using patient data. Powerful conclusions are drawn from application of the new measure.

text: Measures of Dosage for Spinal-Cord Electrical Stimulation: Review and Proposal This manuscript proposes an electrical definition of therapeutic dose for spinal cord systems used for the treatment of chronic pain, analogous to the pharmacological definition. Dose-response relationships are fundamental to pharmacology, radiotherapy, and other treatments, but have never been properly established for neuromodulation. This manuscript offers a robust measure of dose, pre-requisite to establishing a reliable and repeatable dose-response relationship. The new definition, enabled by the system transresistance obtained from measurement of evoked action potentials, recognizes the mechanism of action of spinal cord stimulation (SCS), and should improve acceptance of the therapy as compared to pharmacological treatments which are currently used more frequently for the treatment of chronic pain. The new definition suggests methods for personalization and standardization of the dose in SCS, and is potentially generalizable to all neuromodulation therapies in which nervous tissue is excited including sacral nerve stimulation (SNS), vagal nerve stimulation (VNS), and deep-brain stimulation (DBS). Formulas are provided, and applied using patient data. Powerful conclusions are drawn from application of the new measure.

year: 2023

title: Using a digital library as a Māori language learning resource: Issues and possibilities

authors: Mato, Paora James

subjects: Digital Library

abstract: The development of electronic language learning resources, founded on digital library technology, is a capability that, to date, is largely unrealised. The Flexible Language Acquisition (FLAX) project is a digital library initiative at the University of Waikato in New Zealand. The current FLAX activities provide practice for students who are learning English as an additional language. The prospect of extending this resource to include te reo Māori is as exciting as it is groundbreaking. The outcomes of this research inform the issues and possibilities involved in creating such resources.

The World Wide Web has allowed an everyday access to the Internet, but finding and retrieving pertinent information is often a convoluted and time-consuming exercise. The normal outcome is that users are unable to take full advantage of the available resources. Digital libraries have an unprecedented power in terms of organising and storing vast amounts of information and, with built-in retrieval functionality, serve as ideal repositories. The ability to focus the information within these repositories is extremely significant because there is no longer the chaff that normally results from Internet searches. Purposeful learning activities can be presented exploiting an assortment of media and drawing on stored information that can be assembled in a range of formats. Such capacity, flexibility and diversity is normally only encountered at traditional, physical libraries.

The research includes an overview of digital libraries and some of the language learning resources that are currently available on the Internet. Since the target language is te reo Māori, a critical review on the features of kaupapa Māori theory, pedagogy and Māori pedagogy is undertaken. Using the concepts discussed in this review, the language learning activities associated with the FLAX project are analysed to determine their suitability for learning te reo Māori. Further feedback was provided by a sample group following their testing of a selection of activities that were based on text written in te reo Māori. 
 

The analysis suggests the current range of FLAX activities have more benefit to students as tools that allow practice of the learning that has been delivered in face-to-face classroom settings, rather than as a standalone language learning resource. In their present form, the main benefits of the activities predominantly rest in the way they were performed rather than in the activities themselves. Furthermore, commentary from the testing group regarded the activities as more beneficial for practicing sentence structures, grammar and punctuation, rather than actual language learning. The group generally agreed, however, that combining the activities with methods of oral and aural transmission, in te reo Māori, would certainly result in more effective language learning outcomes.

The legitimacy of digital library-based language learning activities lies in designs that promote learner-centred interaction that is consistent with best practice communicative learning theory. When the target language is te reo Māori, it is of the utmost importance that the activities are tailored to embrace a Māori world view in ways that promote the learning rather than the activity or the content.

text: Using a digital library as a Māori language learning resource: Issues and possibilities The development of electronic language learning resources, founded on digital library technology, is a capability that, to date, is largely unrealised. The Flexible Language Acquisition (FLAX) project is a digital library initiative at the University of Waikato in New Zealand. The current FLAX activities provide practice for students who are learning English as an additional language. The prospect of extending this resource to include te reo Māori is as exciting as it is groundbreaking. The outcomes of this research inform the issues and possibilities involved in creating such resources.

The World Wide Web has allowed an everyday access to the Internet, but finding and retrieving pertinent information is often a convoluted and time-consuming exercise. The normal outcome is that users are unable to take full advantage of the available resources. Digital libraries have an unprecedented power in terms of organising and storing vast amounts of information and, with built-in retrieval functionality, serve as ideal repositories. The ability to focus the information within these repositories is extremely significant because there is no longer the chaff that normally results from Internet searches. Purposeful learning activities can be presented exploiting an assortment of media and drawing on stored information that can be assembled in a range of formats. Such capacity, flexibility and diversity is normally only encountered at traditional, physical libraries.

The research includes an overview of digital libraries and some of the language learning resources that are currently available on the Internet. Since the target language is te reo Māori, a critical review on the features of kaupapa Māori theory, pedagogy and Māori pedagogy is undertaken. Using the concepts discussed in this review, the language learning activities associated with the FLAX project are analysed to determine their suitability for learning te reo Māori. Further feedback was provided by a sample group following their testing of a selection of activities that were based on text written in te reo Māori. 
 

The analysis suggests the current range of FLAX activities have more benefit to students as tools that allow practice of the learning that has been delivered in face-to-face classroom settings, rather than as a standalone language learning resource. In their present form, the main benefits of the activities predominantly rest in the way they were performed rather than in the activities themselves. Furthermore, commentary from the testing group regarded the activities as more beneficial for practicing sentence structures, grammar and punctuation, rather than actual language learning. The group generally agreed, however, that combining the activities with methods of oral and aural transmission, in te reo Māori, would certainly result in more effective language learning outcomes.

The legitimacy of digital library-based language learning activities lies in designs that promote learner-centred interaction that is consistent with best practice communicative learning theory. When the target language is te reo Māori, it is of the utmost importance that the activities are tailored to embrace a Māori world view in ways that promote the learning rather than the activity or the content.

year: 2009