title: Selection of dispatching rules in simulation-based scheduling of flexible manufacturing

authors: Basnet, Chuda

subjects: flexible manufacturing systems

abstract: Discrete-event simulation has been proposed as a tool for the real-time selection of dispatching rules in the scheduling of flexible manufacturing systems (FMS). In this approach, a look-ahead simulation is used to predict the trajectory of the system under different dispatching rules. Then a rule is selected for use in the FMS, based on the performance criterion associated with each trajectory. However, this raises the issue of the criterion to be used for the selection of the rules. A simulation model of an FMS was used to test the effect of rule selection procedure on two performance measures. This simulator was run using four scheduling policies and the performance of the FMS was measured. The main finding of this research is that the use of global criteria gives better results than the use of local criteria.

text: Selection of dispatching rules in simulation-based scheduling of flexible manufacturing Discrete-event simulation has been proposed as a tool for the real-time selection of dispatching rules in the scheduling of flexible manufacturing systems (FMS). In this approach, a look-ahead simulation is used to predict the trajectory of the system under different dispatching rules. Then a rule is selected for use in the FMS, based on the performance criterion associated with each trajectory. However, this raises the issue of the criterion to be used for the selection of the rules. A simulation model of an FMS was used to test the effect of rule selection procedure on two performance measures. This simulator was run using four scheduling policies and the performance of the FMS was measured. The main finding of this research is that the use of global criteria gives better results than the use of local criteria.

year: 2011

title: The Formulation of Titanium - based Metal Feedstocks and the Fabrication of Parts using the Powder Injection Moulding Process

authors: Ewart, Paul Douglas

subjects: Binder

abstract: Development of a profitable titanium industry for New Zealand will not come about without innovative technologies. Plastic injection moulding has long held a place in NZ manufacturing to produce large quantities of complex parts and holds the key to such innovation.
Titanium metal parts were fabricated by injection moulding titanium based metal powder feedstock followed by a debinding process and subsequent sintering. The fabrication process in its entirety was investigated in four distinct steps. Feedstock formulation involved combining the metal powders with various carrier components. Injection moulding enabled the shaping of the feedstock into geometries approximating the final part. Debinding being the process whereby the carrier/binder system is removed from the part to create a powder compact retaining the required geometry. Sintering being the final step where the metal powders are consolidated into a fully dense metal part of net shape.
The feedstock binder consisted of water soluble polyethylene glycol that reduced feedstock viscosity, improved particle wetting, aided greenpart shape retention and eliminated toxic solvents in debinding. Carnauba wax and bees wax aided dispersion, lubricated particles, were safe to handle and better for the environment (than petroleum waxes). Their low melt temperatures aided removal during thermal debinding and supported residue elimination.
By optimising the ratio of water soluble, wax and polyolefin binder components (3: 2: 1 respectively) for melt flow and pellet formation, greenparts defect free with uniform particle distribution were made. The optimal binder system proved suitable for titanium alloy and irregular shape pure titanium powders (hydride-de-hydride). Increasing powder loading (wP = (0.60 to 0.65)) had no appreciable effect on viscosity while enabling feedstock with good uniformity and pellet formation. Dimensional change was not affected by uniformity of the feedstock however molecular weight, volume and dispersion of binder components affected interparticular distances. Low processing temperatures reduced disruption to part geometry, benefitted particle bonding and helped retain handling strength.
The use of low temperatures for thermal debinding (t = 250 °C) enabled removal of the binder below the temperatures that facilitate interstitial diffusion and oxide/carbide formation, although part thickness, mass and overall volume effected the processing time. A strong correlation was seen between handling strength of the greenparts and defects, such as non-uniform density distribution and cracking after sintering.
Sintering was essential to produce the final part and showed that a binder free brownpart was not the only criteria for eliminating impurities. The furnace atmosphere must remain free from contamination to eliminate transfer back to the parts. This was addressed using an argon sweep gas, however, the design and efficacy of the system was considered inadequate. Decomposition products need to be removed quickly from the furnace as they evolve before impurities from the sweep gas diffuse back into the parts during the extended duration at sinter temperatures (t = 1300 °C).
The combination of an optimised titanium feedstock and the use of a low temperature thermal debinding technique produced a consolidated MIM part of relatively large dimensions. The parts were seen to have uniform microstructure throughout the cross-section with density comparable to that of MIM standards. In difference to the literature, a high powder loading (φp = 0.65) of HDH powders was used and shown to be readily mouldable. The higher powder loading also eliminate separation defects and shape distortions evident using lower amounts of powder.

text: The Formulation of Titanium - based Metal Feedstocks and the Fabrication of Parts using the Powder Injection Moulding Process Development of a profitable titanium industry for New Zealand will not come about without innovative technologies. Plastic injection moulding has long held a place in NZ manufacturing to produce large quantities of complex parts and holds the key to such innovation.
Titanium metal parts were fabricated by injection moulding titanium based metal powder feedstock followed by a debinding process and subsequent sintering. The fabrication process in its entirety was investigated in four distinct steps. Feedstock formulation involved combining the metal powders with various carrier components. Injection moulding enabled the shaping of the feedstock into geometries approximating the final part. Debinding being the process whereby the carrier/binder system is removed from the part to create a powder compact retaining the required geometry. Sintering being the final step where the metal powders are consolidated into a fully dense metal part of net shape.
The feedstock binder consisted of water soluble polyethylene glycol that reduced feedstock viscosity, improved particle wetting, aided greenpart shape retention and eliminated toxic solvents in debinding. Carnauba wax and bees wax aided dispersion, lubricated particles, were safe to handle and better for the environment (than petroleum waxes). Their low melt temperatures aided removal during thermal debinding and supported residue elimination.
By optimising the ratio of water soluble, wax and polyolefin binder components (3: 2: 1 respectively) for melt flow and pellet formation, greenparts defect free with uniform particle distribution were made. The optimal binder system proved suitable for titanium alloy and irregular shape pure titanium powders (hydride-de-hydride). Increasing powder loading (wP = (0.60 to 0.65)) had no appreciable effect on viscosity while enabling feedstock with good uniformity and pellet formation. Dimensional change was not affected by uniformity of the feedstock however molecular weight, volume and dispersion of binder components affected interparticular distances. Low processing temperatures reduced disruption to part geometry, benefitted particle bonding and helped retain handling strength.
The use of low temperatures for thermal debinding (t = 250 °C) enabled removal of the binder below the temperatures that facilitate interstitial diffusion and oxide/carbide formation, although part thickness, mass and overall volume effected the processing time. A strong correlation was seen between handling strength of the greenparts and defects, such as non-uniform density distribution and cracking after sintering.
Sintering was essential to produce the final part and showed that a binder free brownpart was not the only criteria for eliminating impurities. The furnace atmosphere must remain free from contamination to eliminate transfer back to the parts. This was addressed using an argon sweep gas, however, the design and efficacy of the system was considered inadequate. Decomposition products need to be removed quickly from the furnace as they evolve before impurities from the sweep gas diffuse back into the parts during the extended duration at sinter temperatures (t = 1300 °C).
The combination of an optimised titanium feedstock and the use of a low temperature thermal debinding technique produced a consolidated MIM part of relatively large dimensions. The parts were seen to have uniform microstructure throughout the cross-section with density comparable to that of MIM standards. In difference to the literature, a high powder loading (φp = 0.65) of HDH powders was used and shown to be readily mouldable. The higher powder loading also eliminate separation defects and shape distortions evident using lower amounts of powder.

year: 2015

title: Kapa Haka Whakataetae Kua tini haere te kanohi o te mahi kapa haka i te ao hurihuri nei.

authors: Rollo, Te Manaaroha Pirihira

subjects: Kapa Haka

abstract: Tihei Haka! Mauriora Kapa haka (Rollo, 2006)
Ka tū te ihiihi, ka tū te wanawana o te hunga i ngā hui whakataetae kapa haka o te motu. He hui rongonui i te maramataka a te Māori ia tau ia tau, ā, he hui whakahirahira anō mō rātou mā i whakawhiti mai i tāwahi rā hoki. Mā te mahi a te kapa haka ka whakaari ngā rōpū haka i ngā mahi nō nehe rā me ngā mahi hou o te ao onāianei. Ahakoa te āhuatanga o te mahi, he taonga tuku iho nā rātou mā kua mene ki te pō.  Moe mai rā e te kāhui o ngā whetu i te pō, moe mai i te Ariki o te rangi. 

I tēnei tuhinga, e āta titiro ana 'hau ki ngā mahi hou me te āhuatanga hou kei ngā rōpū haka i te whakataetae-a-motu, arā Te Matatini me ētahi atu momo whakataetae i Aotearoa, tāpiri mai hoki ērā kei Te Moana nui a Kiwa. Ko te ingoa matua o tēnei tuhinga,  KAPA HAKA WHAKATAETAE. Kua tīni haere te kanohi o te mahi kapa haka i te ao hurihuri nei .
No reira, ko te tino pātai kei tēnei rangahau ko tērā. He aha ngā mahi hou kei te kapa haka whakataetae? Nā he hua anō hoki kei reira? Ka hāngaia tonu e te tuhinga nei  ngā hui whakataetae kapa haka mai i te tau 1972 tae noa ki te tau 2006.

Ngā ūpoko o te tuhinga whakapae
E whā ngā wāhanga ūpoko o tēnei tuhinga whakapae. Mā ngā ūpoko katoa ka kitea ai ngā momo kaupapa ake e hāngai pū ana ki te kaupapa mō te whakataetae kapa haka me ōna āhuatanga hou. He mahi whakahirahira tāku ki te whakatakoto i ngā kōrero, i ngā whakaaro, i ngā mātauranga o tēnā tangata mōhio, o tēnā tangata mātau ki roto i ngā whare māramatanga, arā ngā  wāhanga wēnā,  hei mātauranga hou mō te ao katoa.

I te ūpoko tuatahi, ka anga te titiro ki ngā whakamāramatanga o ngā tikanga-a-iwi e pā ana ki te  tūturutanga me te ao o te kapa haka. Mā wēnei whakamāramatanga hei awhi i a 'hau i taku rangahau ki te mahi onāianei o te whakataetae kapa haka. Ka whai mātauranga 'hau mō ngā tikanga o ngā kupu e rua. Ko ēnei ko te kupu  haka  te tuatahi, ā, ko te kupu  kapa haka  te tuarua. He aha ngā rerekētanga me te ōritenga o wēnei kupu rongonui? Ka anga whakamua ki ngā tūmanako me ngā ritenga o te whakataetae kapa haka a te motu mai i te New Zealand Polynesian Festival tae atu ki Te Matatini. Ko te whāinga mutunga o tēnei wāhanga, ka hoki whakanui ki te whakataetae-a-motu mai i te tau 1972 tae noa atu ki te tau 2006.

Ko te ūpoko tuarua, ka whakatakoto e 'hau ngā whakautu o ngā patapātai mai i ngā rārangi kōrero me ngā whakaaro whānui i whakahokia mai e ngā tāngata o ngā rōpū haka e whā, arā, Te Rōpū Haka o Te Kotahitanga, Ngāti Poneke Young Māori Club, ko Te Waihīrere, ā, huri atu ki Te Pou a Mangatāwhiri hoki, he rōpū i whakatūhia anō i te tau 2005. I tēnei wāhanga ka kitea ngā kōrero ātaahua, ngā mātauranga tūturu me ngā whakaaro hōhonu o ngā kaiako me ngā tāngata e tautoko ana i taku mahi kimi mātauranga.  Nā rātou ka ohorere, ka mirimiri hoki i tōku hinengaro ki ngā māramatanga hou. He tika anō te kupu ā  Pā Henare Tate nō Ngapuhi nui tonu e kī ana,  Mā te whakaatu, ka mōhio, mā te mōhio, ka mārama, mā te mārama, ka mātau, mā te mātau, ka ora   (Barlow 1991)

I te ūpoko tuatoru he whakaaturanga tēnei o āku tirohanga ki ngā āhua rerekē me ngā mahi hou i roto i ngā rōpū haka i runga i te ātamira o te whakataetae, i roto hoki i te mura o te ahi o te whakataetae. Kua tuhituhi au i ngā momo āhuatanga e pā ana ki  te taha o te kanikani, te mahi-a-korikori me ngā mahi katoa i runga i te atamira. Ahakoa iti ko tētahi atu wahanga o ērā kōrero e pā ana ki te pūoro me ōna mana kua puta i konei. Ka huri taku tuhinga ki te taha o te reo waiata, te toi whakaari me te whakaataata o ngā mahi a te Rēhia. I konei ka titiro ki te tāmoko, te pani kanohi me te pani tinana, arā he mahi hou katoa. Ko te wahanga mutunga e pā ana ki te reo Māori me te tito waiata hoki. Ahakoa he maha ngā āhuatanga, ko ngā tuhinga nei mō ia āhuatanga kia kitea ai ngā rerekēnga me ngā mahi hou i te whakataetae kapa haka o te ao Māori. No reira te nuinga engari ko wētahi i whakaurua mai i ētahi atu iwi ō tāwahi.       

Ko te ūpoko whakamutunga, ka hāngai taku titiro ki te ao o te whakataetae, arā, ki ngā whakaaro me te tā o te hinengaro me te ngākau o te tangata. Ka peka haere ki te whakatū o ngā rōpū whakataetae me te parakatihi o ngā waiata, ngā haka me ngā whakaritenga mo te whakataetae kapa haka. Ko te kōrero whakamutunga, ka huri ki wētahi atu o ngā whakataetae mai i Te Kuki Airani, i Tahiti me Hawaii hoki. Āe mārika, ka ora te ao o te whakataetae puta noa i te ao nui. Ki ahau, mā tēnei tuhinga hei whakapuare ngā hurihanga o te ao Māori me te ao o te kapa haka. Ka ea, he tika hoki te whakataukī rā,  ka pū te ruha, ka hao te rangatahi    (Ryan 1995), arā ka kimi i ērā e pīataata ai o rātou wairua, hinengaro, ngākau.

text: Kapa Haka Whakataetae Kua tini haere te kanohi o te mahi kapa haka i te ao hurihuri nei. Tihei Haka! Mauriora Kapa haka (Rollo, 2006)
Ka tū te ihiihi, ka tū te wanawana o te hunga i ngā hui whakataetae kapa haka o te motu. He hui rongonui i te maramataka a te Māori ia tau ia tau, ā, he hui whakahirahira anō mō rātou mā i whakawhiti mai i tāwahi rā hoki. Mā te mahi a te kapa haka ka whakaari ngā rōpū haka i ngā mahi nō nehe rā me ngā mahi hou o te ao onāianei. Ahakoa te āhuatanga o te mahi, he taonga tuku iho nā rātou mā kua mene ki te pō.  Moe mai rā e te kāhui o ngā whetu i te pō, moe mai i te Ariki o te rangi. 

I tēnei tuhinga, e āta titiro ana 'hau ki ngā mahi hou me te āhuatanga hou kei ngā rōpū haka i te whakataetae-a-motu, arā Te Matatini me ētahi atu momo whakataetae i Aotearoa, tāpiri mai hoki ērā kei Te Moana nui a Kiwa. Ko te ingoa matua o tēnei tuhinga,  KAPA HAKA WHAKATAETAE. Kua tīni haere te kanohi o te mahi kapa haka i te ao hurihuri nei .
No reira, ko te tino pātai kei tēnei rangahau ko tērā. He aha ngā mahi hou kei te kapa haka whakataetae? Nā he hua anō hoki kei reira? Ka hāngaia tonu e te tuhinga nei  ngā hui whakataetae kapa haka mai i te tau 1972 tae noa ki te tau 2006.

Ngā ūpoko o te tuhinga whakapae
E whā ngā wāhanga ūpoko o tēnei tuhinga whakapae. Mā ngā ūpoko katoa ka kitea ai ngā momo kaupapa ake e hāngai pū ana ki te kaupapa mō te whakataetae kapa haka me ōna āhuatanga hou. He mahi whakahirahira tāku ki te whakatakoto i ngā kōrero, i ngā whakaaro, i ngā mātauranga o tēnā tangata mōhio, o tēnā tangata mātau ki roto i ngā whare māramatanga, arā ngā  wāhanga wēnā,  hei mātauranga hou mō te ao katoa.

I te ūpoko tuatahi, ka anga te titiro ki ngā whakamāramatanga o ngā tikanga-a-iwi e pā ana ki te  tūturutanga me te ao o te kapa haka. Mā wēnei whakamāramatanga hei awhi i a 'hau i taku rangahau ki te mahi onāianei o te whakataetae kapa haka. Ka whai mātauranga 'hau mō ngā tikanga o ngā kupu e rua. Ko ēnei ko te kupu  haka  te tuatahi, ā, ko te kupu  kapa haka  te tuarua. He aha ngā rerekētanga me te ōritenga o wēnei kupu rongonui? Ka anga whakamua ki ngā tūmanako me ngā ritenga o te whakataetae kapa haka a te motu mai i te New Zealand Polynesian Festival tae atu ki Te Matatini. Ko te whāinga mutunga o tēnei wāhanga, ka hoki whakanui ki te whakataetae-a-motu mai i te tau 1972 tae noa atu ki te tau 2006.

Ko te ūpoko tuarua, ka whakatakoto e 'hau ngā whakautu o ngā patapātai mai i ngā rārangi kōrero me ngā whakaaro whānui i whakahokia mai e ngā tāngata o ngā rōpū haka e whā, arā, Te Rōpū Haka o Te Kotahitanga, Ngāti Poneke Young Māori Club, ko Te Waihīrere, ā, huri atu ki Te Pou a Mangatāwhiri hoki, he rōpū i whakatūhia anō i te tau 2005. I tēnei wāhanga ka kitea ngā kōrero ātaahua, ngā mātauranga tūturu me ngā whakaaro hōhonu o ngā kaiako me ngā tāngata e tautoko ana i taku mahi kimi mātauranga.  Nā rātou ka ohorere, ka mirimiri hoki i tōku hinengaro ki ngā māramatanga hou. He tika anō te kupu ā  Pā Henare Tate nō Ngapuhi nui tonu e kī ana,  Mā te whakaatu, ka mōhio, mā te mōhio, ka mārama, mā te mārama, ka mātau, mā te mātau, ka ora   (Barlow 1991)

I te ūpoko tuatoru he whakaaturanga tēnei o āku tirohanga ki ngā āhua rerekē me ngā mahi hou i roto i ngā rōpū haka i runga i te ātamira o te whakataetae, i roto hoki i te mura o te ahi o te whakataetae. Kua tuhituhi au i ngā momo āhuatanga e pā ana ki  te taha o te kanikani, te mahi-a-korikori me ngā mahi katoa i runga i te atamira. Ahakoa iti ko tētahi atu wahanga o ērā kōrero e pā ana ki te pūoro me ōna mana kua puta i konei. Ka huri taku tuhinga ki te taha o te reo waiata, te toi whakaari me te whakaataata o ngā mahi a te Rēhia. I konei ka titiro ki te tāmoko, te pani kanohi me te pani tinana, arā he mahi hou katoa. Ko te wahanga mutunga e pā ana ki te reo Māori me te tito waiata hoki. Ahakoa he maha ngā āhuatanga, ko ngā tuhinga nei mō ia āhuatanga kia kitea ai ngā rerekēnga me ngā mahi hou i te whakataetae kapa haka o te ao Māori. No reira te nuinga engari ko wētahi i whakaurua mai i ētahi atu iwi ō tāwahi.       

Ko te ūpoko whakamutunga, ka hāngai taku titiro ki te ao o te whakataetae, arā, ki ngā whakaaro me te tā o te hinengaro me te ngākau o te tangata. Ka peka haere ki te whakatū o ngā rōpū whakataetae me te parakatihi o ngā waiata, ngā haka me ngā whakaritenga mo te whakataetae kapa haka. Ko te kōrero whakamutunga, ka huri ki wētahi atu o ngā whakataetae mai i Te Kuki Airani, i Tahiti me Hawaii hoki. Āe mārika, ka ora te ao o te whakataetae puta noa i te ao nui. Ki ahau, mā tēnei tuhinga hei whakapuare ngā hurihanga o te ao Māori me te ao o te kapa haka. Ka ea, he tika hoki te whakataukī rā,  ka pū te ruha, ka hao te rangatahi    (Ryan 1995), arā ka kimi i ērā e pīataata ai o rātou wairua, hinengaro, ngākau.

year: 2007