title: A power-saving modulation technique for time-of-flight range imaging sensors

authors: Conroy, Richard M.

subjects: time of flight

abstract: Time-of-flight range imaging cameras measure distance and intensity simultaneously for every pixel in an image. With the continued advancement of the technology, a wide variety of new depth sensing applications are emerging; however a number of these potential applications have stringent electrical power constraints that are difficult to meet with the current state-of-the-art systems. Sensor gain modulation contributes a significant proportion of the total image sensor power consumption, and as higher spatial resolution range image sensors operating at higher modulation frequencies (to achieve better measurement precision) are developed, this proportion is likely to increase. The authors have developed a new sensor modulation technique using resonant circuit concepts that is more power efficient than the standard mode of operation. With a proof of principle system, a 93–96% reduction in modulation drive power was demonstrated across a range of modulation frequencies from 1–11 MHz. Finally, an evaluation of the range imaging performance revealed an improvement in measurement linearity in the resonant configuration due primarily to the more sinusoidal shape of the resonant electrical waveforms, while the average precision values were comparable between the standard and resonant operating modes.

text: A power-saving modulation technique for time-of-flight range imaging sensors Time-of-flight range imaging cameras measure distance and intensity simultaneously for every pixel in an image. With the continued advancement of the technology, a wide variety of new depth sensing applications are emerging; however a number of these potential applications have stringent electrical power constraints that are difficult to meet with the current state-of-the-art systems. Sensor gain modulation contributes a significant proportion of the total image sensor power consumption, and as higher spatial resolution range image sensors operating at higher modulation frequencies (to achieve better measurement precision) are developed, this proportion is likely to increase. The authors have developed a new sensor modulation technique using resonant circuit concepts that is more power efficient than the standard mode of operation. With a proof of principle system, a 93–96% reduction in modulation drive power was demonstrated across a range of modulation frequencies from 1–11 MHz. Finally, an evaluation of the range imaging performance revealed an improvement in measurement linearity in the resonant configuration due primarily to the more sinusoidal shape of the resonant electrical waveforms, while the average precision values were comparable between the standard and resonant operating modes.

year: 2011

title: Electrofishing survey of the fish community in the Whangamarino Wetland

authors: Hicks, Brendan J.

abstract: A previous fish community survey carried out in the Whangamarino Wetland system recorded 18 different fish species by netting, electrofishing, and interviews with local eel fishermen and reports from Acclimatisation Society staff (Strickland, 1980). Strickland reported that the most widespread and common species in the wetland were shortfinned eels, mosquitofish, goldfish and catfish. In August 2007 and March 2008, the Centre for Biodiversity and Ecology Research (CBER) were contracted to carry out an electric fishing survey of the fish community in the Whangamarino Wetland and its tributaries. Boat and backpack electrofishing caught a diverse range of native and introduced fish. A total of 1,491 fish comprising 8 native fish species and 5 introduced fish species were caught in a total fished area of 26,600 m2 or 2.66 ha from a total of 34 sites. Koi carp, shortfinned eels, goldfish and common smelt were the most widespread fish species throughout the wetland system. Fish distribution, density and biomass varied between sites throughout the Whangamarino Wetland as well as between the two different time periods (August 2007 and March 2008). Mean densities and biomasses of fish species at most sites increased substantially in March 2008 compared to August 2007.

text: Electrofishing survey of the fish community in the Whangamarino Wetland A previous fish community survey carried out in the Whangamarino Wetland system recorded 18 different fish species by netting, electrofishing, and interviews with local eel fishermen and reports from Acclimatisation Society staff (Strickland, 1980). Strickland reported that the most widespread and common species in the wetland were shortfinned eels, mosquitofish, goldfish and catfish. In August 2007 and March 2008, the Centre for Biodiversity and Ecology Research (CBER) were contracted to carry out an electric fishing survey of the fish community in the Whangamarino Wetland and its tributaries. Boat and backpack electrofishing caught a diverse range of native and introduced fish. A total of 1,491 fish comprising 8 native fish species and 5 introduced fish species were caught in a total fished area of 26,600 m2 or 2.66 ha from a total of 34 sites. Koi carp, shortfinned eels, goldfish and common smelt were the most widespread fish species throughout the wetland system. Fish distribution, density and biomass varied between sites throughout the Whangamarino Wetland as well as between the two different time periods (August 2007 and March 2008). Mean densities and biomasses of fish species at most sites increased substantially in March 2008 compared to August 2007.

year: 2008-07-14

title: Ngaa tongikura o te Kiingitanga - He tongi takapou nui, he kura takapou roa

authors: Paki, Nga wai hono i te po

subjects: Tongikura

abstract: Mai anoo, mai anoo i te waa o ngoo taatou tuupuna, ko te iere o te reo, ko te tangi o te kupu te waka kawe i ngaa whakaaro me ngaa kare aa-roto o oo taatou tuupuna. Inaa hoki raa te hoohonu o te whakaaro me te huhua o ngaa kura huna kua rarau ki ngaa kupu tuku iho o oo taatou tuupuna. I roto i a maatou, o Tainui waka, o Waikato iwi, o te Kiingitanga, ko ngaa tongikura te ritenga.

Kei teenei tuhinga te whakamaaramatanga, te whakamahukitanga o teenei taonga te tongikura. Ahakoa, inaa raa ngaa tini tongikura o te Kiingitanga kua tongikuratia ko taa teenei tuhinga whakapae he tuuhura i ngaa kura huna e whakapaetia nei, he oranga kei roto i ngaa tongikura hei painga moo te tangata. Noo te orokohanganga mai o te Kiingitanga tatuu iho raa ki teenei rangi tonu kei ngeenei tongikura ngaa kupu taurangi, ngaa tohutohu nui aa te raangai upoko ariki o te Kiingitanga ki ngaa iwi. I roto i te whakapaparanga o te Kiingitanga kua kitea taatou i te nui o te whakamahinga o ngaa tongikura hei aarahi, hei takitaki i a taatou a Tainui waka, i a Tainui tangata.

Kua haoria ake raa ko ngeetehi kohinga tongikura hei whewheratanga maaku i roto i teenei tuhinga e kite ai taatou i te mauri ora o ngaa tongikura ki roto i te iwi o Waikato, ki roto anoo hoki i ngaa iwi o te Kiingitanga. E haangai mai ana ngeenei tongikura ki te ora o te iwi, e purutia ana hoki hei kura waananga maa ngaa reanga whakatupuranga o te inamata, ki te anamata. Tiikina ake raa ko te kupu wairua, kia tuu te tongikura, ko te aakinga te mea nui, tau ki runga ki teenei tuhikura. Haere, tomokia mai te whare tongikura, he tongi takapou kura, he kura takapou roa.

text: Ngaa tongikura o te Kiingitanga - He tongi takapou nui, he kura takapou roa Mai anoo, mai anoo i te waa o ngoo taatou tuupuna, ko te iere o te reo, ko te tangi o te kupu te waka kawe i ngaa whakaaro me ngaa kare aa-roto o oo taatou tuupuna. Inaa hoki raa te hoohonu o te whakaaro me te huhua o ngaa kura huna kua rarau ki ngaa kupu tuku iho o oo taatou tuupuna. I roto i a maatou, o Tainui waka, o Waikato iwi, o te Kiingitanga, ko ngaa tongikura te ritenga.

Kei teenei tuhinga te whakamaaramatanga, te whakamahukitanga o teenei taonga te tongikura. Ahakoa, inaa raa ngaa tini tongikura o te Kiingitanga kua tongikuratia ko taa teenei tuhinga whakapae he tuuhura i ngaa kura huna e whakapaetia nei, he oranga kei roto i ngaa tongikura hei painga moo te tangata. Noo te orokohanganga mai o te Kiingitanga tatuu iho raa ki teenei rangi tonu kei ngeenei tongikura ngaa kupu taurangi, ngaa tohutohu nui aa te raangai upoko ariki o te Kiingitanga ki ngaa iwi. I roto i te whakapaparanga o te Kiingitanga kua kitea taatou i te nui o te whakamahinga o ngaa tongikura hei aarahi, hei takitaki i a taatou a Tainui waka, i a Tainui tangata.

Kua haoria ake raa ko ngeetehi kohinga tongikura hei whewheratanga maaku i roto i teenei tuhinga e kite ai taatou i te mauri ora o ngaa tongikura ki roto i te iwi o Waikato, ki roto anoo hoki i ngaa iwi o te Kiingitanga. E haangai mai ana ngeenei tongikura ki te ora o te iwi, e purutia ana hoki hei kura waananga maa ngaa reanga whakatupuranga o te inamata, ki te anamata. Tiikina ake raa ko te kupu wairua, kia tuu te tongikura, ko te aakinga te mea nui, tau ki runga ki teenei tuhikura. Haere, tomokia mai te whare tongikura, he tongi takapou kura, he kura takapou roa.

year: 2022