title: Solving complex retrofit problems using constraints and bridge analysis

authors: Lal, Nathan S.

abstract: The aim of this paper is to conduct retrofit analysis of large, complex industrial Heat Exchanger Networks using an automated Bridge Analysis. Large, complex networks have many different possible retrofit designs, or Retrofit Bridges, which requires both computational effort and user effort to evaluate. In this paper, constraints relating to the thermodynamic and economic performance of a retrofit design are proposed and applied to significantly reduce Retrofit Bridge options to a smaller, manageable number of design options. These constraints relate to capital costs, payback period, piping, and plant layout. The method is demonstrated with a Kraft pulp mill case study. The Kraft pulp mill currently has 54 heat exchangers and 73 hot and cold streams. Without constraints, the number of possible Retrofit Bridges is 1 x 10²⁰. After applying the constraints, this number is reduced to 15. The remaining Retrofit Bridges are considered to provide high thermodynamic and economic benefit and can be more easily assessed for the best projects. The use of constraints has allowed the complex case study to be solved quickly, and a single design can be selected for further development. The suggested design reduces the utility consumption by 9.2 MW and has an annual Total Retrofit Profit of NZD 2,140,000, requiring a single new exchanger.

text: Solving complex retrofit problems using constraints and bridge analysis The aim of this paper is to conduct retrofit analysis of large, complex industrial Heat Exchanger Networks using an automated Bridge Analysis. Large, complex networks have many different possible retrofit designs, or Retrofit Bridges, which requires both computational effort and user effort to evaluate. In this paper, constraints relating to the thermodynamic and economic performance of a retrofit design are proposed and applied to significantly reduce Retrofit Bridge options to a smaller, manageable number of design options. These constraints relate to capital costs, payback period, piping, and plant layout. The method is demonstrated with a Kraft pulp mill case study. The Kraft pulp mill currently has 54 heat exchangers and 73 hot and cold streams. Without constraints, the number of possible Retrofit Bridges is 1 x 10²⁰. After applying the constraints, this number is reduced to 15. The remaining Retrofit Bridges are considered to provide high thermodynamic and economic benefit and can be more easily assessed for the best projects. The use of constraints has allowed the complex case study to be solved quickly, and a single design can be selected for further development. The suggested design reduces the utility consumption by 9.2 MW and has an annual Total Retrofit Profit of NZD 2,140,000, requiring a single new exchanger.

year: 2018

title: Big brother is watching you - now in a doubleplusgood way

authors: Sterling, Corey

subjects: computer science

abstract: This paper reports on the progress made with our X Marks The Spot (XMTS) system. In XMTS we make a fundamental change to the compositing operation in a desktop manager, storing all text-display events and their related raster-draw events. This means we can provide the user with a search interface that allows them to go back in time and view how their desktop used to look. Because XMTS is aware of what text was drawn into which window and at what position, the provided snapshot is semi-interactive in that the user can bring individual windows forwards and backwards, and copy text from them. In previous work we demonstrated the approach is technically feasible. In this paper we detail infrastructural advances we have made and showcase its new search interface.

text: Big brother is watching you - now in a doubleplusgood way This paper reports on the progress made with our X Marks The Spot (XMTS) system. In XMTS we make a fundamental change to the compositing operation in a desktop manager, storing all text-display events and their related raster-draw events. This means we can provide the user with a search interface that allows them to go back in time and view how their desktop used to look. Because XMTS is aware of what text was drawn into which window and at what position, the provided snapshot is semi-interactive in that the user can bring individual windows forwards and backwards, and copy text from them. In previous work we demonstrated the approach is technically feasible. In this paper we detail infrastructural advances we have made and showcase its new search interface.

year: 2017

title: Māori Cultural Identity and Education

authors: Hawaikirangi-Pere, Charmaine

subjects: Identity

abstract: Underachievement of Māori students in mainstream schools has been a major topic of discussion by politicians and educational researchers in recent years. Research has shown that a secure cultural identity can enhance a person’s overall well-being and furthermore improve their chances of educational success. However, in reality, statistics show that a high percentage of the Māori population have little or no knowledge of their language and culture. The research question in this study will ask Māori whānau how they perceive cultural identity in relation to their children’s education.
Principles of Kaupapa Māori, Takepū and indigenous research and qualitative research methods have been used to ensure that participants were culturally and ethically respected. Participants interviewed in this study are members of my own whānau and some close friends. As an insider researcher I was committed to ensuring that my whānau were treated with respect and dignity throughout the research process. 
The interview data has exposed some unexpected issues specifically relating to their educational experiences and cultural identity. In the context of historical records and education for Māori, the findings of this study suggest that the educational experiences of Māori whānau have been, and continue to be, strongly influenced by government policies enforced before and during the period in which they attended school. All the whānau interviewed acknowledged their ethnic identity as Māori, however, most of them had little or no knowledge and understanding of Te Reo Māori nor had they taken part in cultural practices. Government policies restricted the use of the Māori language, disengaged them from their culture and curriculum provision limited expectations for both males and females. Mixed ethnicity and urbanisation were also identified as factors in the loss of their cultural identity. Data also shows that cultural identity loss has progressed on to future generations and influenced Māori whānau priorities and choice of school. 
The aim of this study is to provide educational policy makers with an in-depth understanding of the perspectives of Māori whānau determine their specific needs in education and propose some suggestions on how to improve achievement of Māori whānau in mainstream schools.

text: Māori Cultural Identity and Education Underachievement of Māori students in mainstream schools has been a major topic of discussion by politicians and educational researchers in recent years. Research has shown that a secure cultural identity can enhance a person’s overall well-being and furthermore improve their chances of educational success. However, in reality, statistics show that a high percentage of the Māori population have little or no knowledge of their language and culture. The research question in this study will ask Māori whānau how they perceive cultural identity in relation to their children’s education.
Principles of Kaupapa Māori, Takepū and indigenous research and qualitative research methods have been used to ensure that participants were culturally and ethically respected. Participants interviewed in this study are members of my own whānau and some close friends. As an insider researcher I was committed to ensuring that my whānau were treated with respect and dignity throughout the research process. 
The interview data has exposed some unexpected issues specifically relating to their educational experiences and cultural identity. In the context of historical records and education for Māori, the findings of this study suggest that the educational experiences of Māori whānau have been, and continue to be, strongly influenced by government policies enforced before and during the period in which they attended school. All the whānau interviewed acknowledged their ethnic identity as Māori, however, most of them had little or no knowledge and understanding of Te Reo Māori nor had they taken part in cultural practices. Government policies restricted the use of the Māori language, disengaged them from their culture and curriculum provision limited expectations for both males and females. Mixed ethnicity and urbanisation were also identified as factors in the loss of their cultural identity. Data also shows that cultural identity loss has progressed on to future generations and influenced Māori whānau priorities and choice of school. 
The aim of this study is to provide educational policy makers with an in-depth understanding of the perspectives of Māori whānau determine their specific needs in education and propose some suggestions on how to improve achievement of Māori whānau in mainstream schools.

year: 2013