title: Case studies

authors: Weyers, Benjamin

subjects: Computer science

abstract: This chapter introduces a set of case studies that are used in the rest of the book. They encompass well known problem domains in Human-Computer Interaction research and provide a practical focus for the approaches presented in this book. The set of case studies includes case studies concerned with: the controller interface to a (semi-automated) nuclear power plant; a partly-autonomous arrival management interactive system in the domain of air-traffic control; a user interface for new interactive cockpits and an interactive system used in rural and urban areas to maintain wind turbines. The final case study brings an interesting perspective for formal techniques, namely interactive public displays.

text: Case studies This chapter introduces a set of case studies that are used in the rest of the book. They encompass well known problem domains in Human-Computer Interaction research and provide a practical focus for the approaches presented in this book. The set of case studies includes case studies concerned with: the controller interface to a (semi-automated) nuclear power plant; a partly-autonomous arrival management interactive system in the domain of air-traffic control; a user interface for new interactive cockpits and an interactive system used in rural and urban areas to maintain wind turbines. The final case study brings an interesting perspective for formal techniques, namely interactive public displays.

year: 2017

title: A sedimentological study of three saline lakes in the Dry Valleys of Victoria Land, Antarctica

authors: Gumbley, John Watson

subjects: Sediments

abstract: The Dry Valley region of Victoria Land is the largest ice-free area in Antarctica. Within the frigid arid environment of the Dry Valleys, where the mean annual air temperature is -20℃, there are several permanently ice-covered, amictic, saline lakes occupying undrained bedrock depressions. Three of these lakes, namely Lakes Vanda, Bonney and Joyce, have been studied with the aim of determining the nature of their bottom sediments and relating the stratigraphy of bottom sediment cores to Holocene climatic fluctuations. These lakes have an area of 0.8 to 5.2 km², are from 35 to 68m in maximum depth and have an ice-cover 3 to 4m thick. The lakes are chemically and thermally stratified and receive their water from meltwater streams draining the local glaciers.

The bottom sediments consist of detrital sands and silts, chemical precipitates and organic material. The detrital sediments consist of feldspar and quartz with smaller quantities of hornblende, augite, hypersthene and mica that are derived locally from the rocks exposed on the adjacent valley sides. These sediments are mainly wind-transported or, to a lesser extent, river-transported into the lakes. The wind derived sediments are either blown onto the lake-ice, where they eventually sink to the lake-floor, or they are blown into the moat developed about the shores of the lake in summer. The chemical precipitates consist mainly of gypsum, halite, aragonite and calcite whose constituent elements were derived from meltwater streams discharging into the lakes; however Lake Bonney also received dissolved solids of marine origin about 300,000 years B.P. and 1,200 years B.P.

From the sequence of chemical precipitate - rich bands and grain-size cycles in cores from Lakes Vanda and Joyce, together with the stratigraphy in the Lake Bonney cores, a sequence of climatic fluctuations is inferred. Colder climatic phases are most probably associated with periods of low lake-level during which chemical precipitates formed following the concentration of brines under frigid evaporitic conditions. At these times the sediment input from meltwater streams was low because of the locking-up of water in valley glaciers, and the main source of sediment would probably then be wind-derived. 

U/Th dating of the chemical precipitates has provided an absolute record of past climatic changes which indicate that the major glacier systems in the Dry Valley region were nonsynchronous. Low lake levels occurred in Lake Vanda some 2,000 and 5,500 years B.P. and on at least four earlier occasions. Sediment cores from Lake Joyce indicate a period of low lake-level about 3,000 years B.P. The Lake Bonney cores suggest periods of low lake-level occurred following each of the marine incursions into the valley (300,000 and 1,200 years B.P.) and that the advance of the Taylor Glacier into the Bonney Basin at least 10,000 years B.P. probably coincided with the Taylor I Glaciation. Frigid evaporitic conditions have continued to operate in Lake Bonney since 1,200 years B.P. with halite crystals forming on the lake-floor. However, the lake-level has been steadily rising over the last 500 years.

text: A sedimentological study of three saline lakes in the Dry Valleys of Victoria Land, Antarctica The Dry Valley region of Victoria Land is the largest ice-free area in Antarctica. Within the frigid arid environment of the Dry Valleys, where the mean annual air temperature is -20℃, there are several permanently ice-covered, amictic, saline lakes occupying undrained bedrock depressions. Three of these lakes, namely Lakes Vanda, Bonney and Joyce, have been studied with the aim of determining the nature of their bottom sediments and relating the stratigraphy of bottom sediment cores to Holocene climatic fluctuations. These lakes have an area of 0.8 to 5.2 km², are from 35 to 68m in maximum depth and have an ice-cover 3 to 4m thick. The lakes are chemically and thermally stratified and receive their water from meltwater streams draining the local glaciers.

The bottom sediments consist of detrital sands and silts, chemical precipitates and organic material. The detrital sediments consist of feldspar and quartz with smaller quantities of hornblende, augite, hypersthene and mica that are derived locally from the rocks exposed on the adjacent valley sides. These sediments are mainly wind-transported or, to a lesser extent, river-transported into the lakes. The wind derived sediments are either blown onto the lake-ice, where they eventually sink to the lake-floor, or they are blown into the moat developed about the shores of the lake in summer. The chemical precipitates consist mainly of gypsum, halite, aragonite and calcite whose constituent elements were derived from meltwater streams discharging into the lakes; however Lake Bonney also received dissolved solids of marine origin about 300,000 years B.P. and 1,200 years B.P.

From the sequence of chemical precipitate - rich bands and grain-size cycles in cores from Lakes Vanda and Joyce, together with the stratigraphy in the Lake Bonney cores, a sequence of climatic fluctuations is inferred. Colder climatic phases are most probably associated with periods of low lake-level during which chemical precipitates formed following the concentration of brines under frigid evaporitic conditions. At these times the sediment input from meltwater streams was low because of the locking-up of water in valley glaciers, and the main source of sediment would probably then be wind-derived. 

U/Th dating of the chemical precipitates has provided an absolute record of past climatic changes which indicate that the major glacier systems in the Dry Valley region were nonsynchronous. Low lake levels occurred in Lake Vanda some 2,000 and 5,500 years B.P. and on at least four earlier occasions. Sediment cores from Lake Joyce indicate a period of low lake-level about 3,000 years B.P. The Lake Bonney cores suggest periods of low lake-level occurred following each of the marine incursions into the valley (300,000 and 1,200 years B.P.) and that the advance of the Taylor Glacier into the Bonney Basin at least 10,000 years B.P. probably coincided with the Taylor I Glaciation. Frigid evaporitic conditions have continued to operate in Lake Bonney since 1,200 years B.P. with halite crystals forming on the lake-floor. However, the lake-level has been steadily rising over the last 500 years.

year: 1975

title: Is there evidence that traditional mōteatea (Māori laments) were composed from a common stock of oral formulae?

authors: Roa, Raukura

subjects: New Zealand

abstract: Oral formulaic composition, which involves the use of communally owned formulae of various kinds, is a common feature of verbal arts produced in many different languages. It is particularly associated with pre-literate cultures and tends to be gradually replaced by more individualistic verbal art forms when societies become literate. There are very few publications in which the analysis of mōteatea (Māori laments) is linked explicitly to oral formulaic theory. Nevertheless, there is sufficient evidence in published sources to indicate that traditional mōteatea (defined here as mōteatea that are not fundamentally influenced by European cultural beliefs and practices) exhibit evidence of regularly recurring, conventional themes (such as death, separation, loss and travel) and motifs (such as the setting sun, the presence of rain or mist and sleeplessness). The research reported here set out to test the hypothesis that traditional mōteatea were made up of verbal formulae, that is, of the same or very similar groups of words derived from a common store of poetic resources. Based on the analysis of the mōteatea included in Ngā mōteatea, a collection initially established by Sir Apirana Ngata, I conclude that this hypothesis must be rejected.

text: Is there evidence that traditional mōteatea (Māori laments) were composed from a common stock of oral formulae? Oral formulaic composition, which involves the use of communally owned formulae of various kinds, is a common feature of verbal arts produced in many different languages. It is particularly associated with pre-literate cultures and tends to be gradually replaced by more individualistic verbal art forms when societies become literate. There are very few publications in which the analysis of mōteatea (Māori laments) is linked explicitly to oral formulaic theory. Nevertheless, there is sufficient evidence in published sources to indicate that traditional mōteatea (defined here as mōteatea that are not fundamentally influenced by European cultural beliefs and practices) exhibit evidence of regularly recurring, conventional themes (such as death, separation, loss and travel) and motifs (such as the setting sun, the presence of rain or mist and sleeplessness). The research reported here set out to test the hypothesis that traditional mōteatea were made up of verbal formulae, that is, of the same or very similar groups of words derived from a common store of poetic resources. Based on the analysis of the mōteatea included in Ngā mōteatea, a collection initially established by Sir Apirana Ngata, I conclude that this hypothesis must be rejected.

year: 2007