title: Video observations of beach cusp morphodynamics

authors: Almar, Rafael

subjects: beach cusps

abstract: Beach cusps are a common feature of steep reflective and intermediate beaches. Although many observations of beach cusp spacing exist, there are few observations quantifying the incipient formation, evolution and eventual destruction of these features. Beach cusp morphodynamics were analyzed using a 3-year dataset of video images collected at Tairua Beach (New Zealand). Twenty-four beach cusp episodes were selected to monitor the cycle of beach face changes, from planar to the appearance of the cusp patterns and back to planar again. Observations show that beach cusp disappearance can be ascribed not only to the erosive influence of storms but also to the persistence of accretionary conditions leading to the infilling of beach cusp bays and the development of an alongshore continuous berm. We also report observations of changes in beach cusp spacing over time which can be attributed to the merging of adjacent cusps within the cusp field, with the overall cusp spacing re-adjusting to accommodate the disappearance of a horn. Although the self-organization theory provides a better fit to the data and theory, we were unable to conclusively refute any of the mechanisms causing beach cusp formation since both existing theories, subharmonic standing edge wave and self-organization, can predict the trend in the observed beach cusp spacing. These observations show that initial beach cusp formation primarily occurs (around 70% of the episodes analyzed) under mildly accretionary conditions and, when accretion persists, the pattern disappearance is likely to occur as a result of bay infilling to form a featureless berm.

text: Video observations of beach cusp morphodynamics Beach cusps are a common feature of steep reflective and intermediate beaches. Although many observations of beach cusp spacing exist, there are few observations quantifying the incipient formation, evolution and eventual destruction of these features. Beach cusp morphodynamics were analyzed using a 3-year dataset of video images collected at Tairua Beach (New Zealand). Twenty-four beach cusp episodes were selected to monitor the cycle of beach face changes, from planar to the appearance of the cusp patterns and back to planar again. Observations show that beach cusp disappearance can be ascribed not only to the erosive influence of storms but also to the persistence of accretionary conditions leading to the infilling of beach cusp bays and the development of an alongshore continuous berm. We also report observations of changes in beach cusp spacing over time which can be attributed to the merging of adjacent cusps within the cusp field, with the overall cusp spacing re-adjusting to accommodate the disappearance of a horn. Although the self-organization theory provides a better fit to the data and theory, we were unable to conclusively refute any of the mechanisms causing beach cusp formation since both existing theories, subharmonic standing edge wave and self-organization, can predict the trend in the observed beach cusp spacing. These observations show that initial beach cusp formation primarily occurs (around 70% of the episodes analyzed) under mildly accretionary conditions and, when accretion persists, the pattern disappearance is likely to occur as a result of bay infilling to form a featureless berm.

year: 2008

title: Instruction systolic arrays for exact parallel linear algebraic computation

authors: Krishnamurthy, V.

abstract: This thesis develops new computational algorithms for parallel/distributed error-free (exact) rational (real and complex) computing and its applications to exact linear algebraic computing. 
The practical realization of these parallel algorithms in VLSI systems using a new concept known as Instruction Systolic Arrays (ISA) is considered.
Thus, the thesis represents the author’s contribution to the theory, design, and implementation of parallel/distributed algorithms for exact rational/linear algebraic computing using ISA processors.
This thesis consists of six chapters with the following contents.

CHAPTER 1
INSTRUCTION SYSTOLIC ARRAYS - A PROGRAMMABLE PARALLEL ARCHITECTURE
Chapter 1 introduces the concept of Instruction Systolic arrays (ISA). The ISA is a new versatile programmable parallel architecture that retains all the advantages of systolic arrays. In the ISA, instructions and boolean selectors are pumped through the processing array. The ISA has tremendous potential for VLSI computing because of its ability to execute different types of programs on the same processing array. We also introduce a variant of the ISA known as the Single Instruction Systolic Array (SISA). In the SISA, single instructions and selectors are pumped through the processing array.

CHAPTER 2
INSTRUCTION SYSTOLIC ARRAYS FOR DISTRIBUTED CHINESE REMAINDERING/ INTERPOLATION ALGORITHMS
We present a parallel/ distributed algorithm for a fundamental problem in Numerical Computing/algebraic computing, namely interpolation and the closely related Chinese remaindering. The ISA implementation of this algorithm is described. A generalization of the interpolation algorithm for multivariable is then presented. The multivariable interpolation algorithm can be realized in a ISA as well as in a pyramid architecture. The Occam simulation of a pyramid for multivariable interpolation is also described. We then present a parallel/ distributed algorithm for rational function interpolation and consider its ISA implementation.

CHAPTER 3
PARALLEL MATRIX COMPUTATION USING ISA
This chapter introduces a parallel algorithm for the generalized inversion (g-inversion) of matrices, which involves parallel matrix addition and multiplication operations. The ISA implementation of this algorithm is described. The solution of a homogeneous system of linear algebraic equations is based on g-inverse computation and we indicate its ISA implementation. The solution of such equations has important practical applications in finding Petri net invariants, chemical equation balancing and dimensional analysis. Two other important g-inversion algorithms - one iterative and the other direct - are also described.

CHAPTER 4
PARALLEL ERROR-FREE RATIONAL ARITHMETIC - ISA IMPLEMENTATION
This chapter introduces a new parallel error-free (exact) rational arithmetic system called Parallel Rational Hensel code arithmetic (Para-Hensel code or PHC). We introduce algorithms for parallel element-wise arithmetic operations, and for encoding and decoding PHC codes. We briefly indicate the ISA implementation of these algorithms. We also consider the application of PHC for exact parallel matrix g-inversion with systolic processors.

CHAPTER 5
PARALLEL COMPLEX RATIONAL AND MATRIX ARITHMETIC USING GAUSSIAN PRIME CODES
In this chapter, we introduce a new parallel exact complex rational arithmetic system based on Gaussian prime codes. Two closely related methods for constructing these codes are described. The first method uses several distinct (multiple) Gaussian primes to construct Gauss-Hensel codes (GHC). The second method uses the powers of one or more Gaussian primes to construct Gauss p-adic codes (GPC). Their practical applications and extension to parallel inversion of complex matrices are described. These systems are amenable for massively parallel realization. 

CHAPTER 6 
ISA - APPLICATIONS TO ARRAY PROCESSING AND REAL-TIME COMPUTING
This chapter considers the suitability of the ISA for vector/ array processing computers. We also consider the relationship of the ISA to wavefront processing and dataflow computing. We then describe a linear variant of the ISA known as the Linear ISA (LISA), which is an area efficient architecture. We then briefly indicate some possible application areas of the ISA: real-time robot control applications and high-speed vision systems.

text: Instruction systolic arrays for exact parallel linear algebraic computation This thesis develops new computational algorithms for parallel/distributed error-free (exact) rational (real and complex) computing and its applications to exact linear algebraic computing. 
The practical realization of these parallel algorithms in VLSI systems using a new concept known as Instruction Systolic Arrays (ISA) is considered.
Thus, the thesis represents the author’s contribution to the theory, design, and implementation of parallel/distributed algorithms for exact rational/linear algebraic computing using ISA processors.
This thesis consists of six chapters with the following contents.

CHAPTER 1
INSTRUCTION SYSTOLIC ARRAYS - A PROGRAMMABLE PARALLEL ARCHITECTURE
Chapter 1 introduces the concept of Instruction Systolic arrays (ISA). The ISA is a new versatile programmable parallel architecture that retains all the advantages of systolic arrays. In the ISA, instructions and boolean selectors are pumped through the processing array. The ISA has tremendous potential for VLSI computing because of its ability to execute different types of programs on the same processing array. We also introduce a variant of the ISA known as the Single Instruction Systolic Array (SISA). In the SISA, single instructions and selectors are pumped through the processing array.

CHAPTER 2
INSTRUCTION SYSTOLIC ARRAYS FOR DISTRIBUTED CHINESE REMAINDERING/ INTERPOLATION ALGORITHMS
We present a parallel/ distributed algorithm for a fundamental problem in Numerical Computing/algebraic computing, namely interpolation and the closely related Chinese remaindering. The ISA implementation of this algorithm is described. A generalization of the interpolation algorithm for multivariable is then presented. The multivariable interpolation algorithm can be realized in a ISA as well as in a pyramid architecture. The Occam simulation of a pyramid for multivariable interpolation is also described. We then present a parallel/ distributed algorithm for rational function interpolation and consider its ISA implementation.

CHAPTER 3
PARALLEL MATRIX COMPUTATION USING ISA
This chapter introduces a parallel algorithm for the generalized inversion (g-inversion) of matrices, which involves parallel matrix addition and multiplication operations. The ISA implementation of this algorithm is described. The solution of a homogeneous system of linear algebraic equations is based on g-inverse computation and we indicate its ISA implementation. The solution of such equations has important practical applications in finding Petri net invariants, chemical equation balancing and dimensional analysis. Two other important g-inversion algorithms - one iterative and the other direct - are also described.

CHAPTER 4
PARALLEL ERROR-FREE RATIONAL ARITHMETIC - ISA IMPLEMENTATION
This chapter introduces a new parallel error-free (exact) rational arithmetic system called Parallel Rational Hensel code arithmetic (Para-Hensel code or PHC). We introduce algorithms for parallel element-wise arithmetic operations, and for encoding and decoding PHC codes. We briefly indicate the ISA implementation of these algorithms. We also consider the application of PHC for exact parallel matrix g-inversion with systolic processors.

CHAPTER 5
PARALLEL COMPLEX RATIONAL AND MATRIX ARITHMETIC USING GAUSSIAN PRIME CODES
In this chapter, we introduce a new parallel exact complex rational arithmetic system based on Gaussian prime codes. Two closely related methods for constructing these codes are described. The first method uses several distinct (multiple) Gaussian primes to construct Gauss-Hensel codes (GHC). The second method uses the powers of one or more Gaussian primes to construct Gauss p-adic codes (GPC). Their practical applications and extension to parallel inversion of complex matrices are described. These systems are amenable for massively parallel realization. 

CHAPTER 6 
ISA - APPLICATIONS TO ARRAY PROCESSING AND REAL-TIME COMPUTING
This chapter considers the suitability of the ISA for vector/ array processing computers. We also consider the relationship of the ISA to wavefront processing and dataflow computing. We then describe a linear variant of the ISA known as the Linear ISA (LISA), which is an area efficient architecture. We then briefly indicate some possible application areas of the ISA: real-time robot control applications and high-speed vision systems.

year: 1988

title: The enowning of thought and whakapapa: Heidegger's fourfold

authors: Mika, Carl Te Hira

subjects: Maori

abstract: Throughout colonization, Maori have been constantly urged to think of their terminology, and the objects it relates to, along constrained lines. In this practice, the self and other things are arguably restricted and impoverished. However, certain frequently used Maori terms – such as “whakapapa” and “whakaaro” – may be read alongside Heidegger’s “Ereignis,” revealing a completely other sense to them than their orthodox, respective translations of “genealogy” and “to think” allow. This kind of thinking in concert with an existential philosophy is an active process that allows for the “freeing up” of entities and a colonized group. With Heidegger’s assistance, the terms, and the original sources they refer to, reflect a kind of “Geviert”/Fourfold that ensures a continual strife and interplay between things in the world and self.

text: The enowning of thought and whakapapa: Heidegger's fourfold Throughout colonization, Maori have been constantly urged to think of their terminology, and the objects it relates to, along constrained lines. In this practice, the self and other things are arguably restricted and impoverished. However, certain frequently used Maori terms – such as “whakapapa” and “whakaaro” – may be read alongside Heidegger’s “Ereignis,” revealing a completely other sense to them than their orthodox, respective translations of “genealogy” and “to think” allow. This kind of thinking in concert with an existential philosophy is an active process that allows for the “freeing up” of entities and a colonized group. With Heidegger’s assistance, the terms, and the original sources they refer to, reflect a kind of “Geviert”/Fourfold that ensures a continual strife and interplay between things in the world and self.

year: 2014