title: Compositional synthesis of maximally permissive supervisors using supervision equivalence

authors: Flordal, Hugo

subjects: computer science

abstract: This paper presents a general framework for efficient synthesis of supervisors for discrete event systems. The approach is based on compositional minimisation, using concepts of process equivalence. In this context, a large number of ways are suggested how a finite-state automaton can be simplified such that the results of supervisor synthesis are preserved. The proposed approach yields a compact representation of a least restrictive supervisor that ensures controllability and nonblocking. The method is demonstrated on a simple manufacturing example to significantly reduce the number of states constructed for supervisor synthesis.

text: Compositional synthesis of maximally permissive supervisors using supervision equivalence This paper presents a general framework for efficient synthesis of supervisors for discrete event systems. The approach is based on compositional minimisation, using concepts of process equivalence. In this context, a large number of ways are suggested how a finite-state automaton can be simplified such that the results of supervisor synthesis are preserved. The proposed approach yields a compact representation of a least restrictive supervisor that ensures controllability and nonblocking. The method is demonstrated on a simple manufacturing example to significantly reduce the number of states constructed for supervisor synthesis.

year: 2007

title: Interfacial modification of hemp fiber reinforced composites using fungal and alkali treatment

authors: Pickering, Kim L.

subjects: natural fibers

abstract: Increasing worldwide environmental awareness is encouraging scientific research into developing cheaper, more sustainable materials. Industrial hemp fiber is one of the strongest and stiffest available natural fibers [K. L. Pickering, M. Priest, T. Watts, G. Beckermann, and S. N. Alam, J. Adv. Mater. 37, 15 (2005)] and therefore has great potential in composite materials. Incorporated into a thermoplastic matrix, it gives a structural material that is cheap, lightweight, and recyclable. However, natural fibers are commonly incompatible with common molding thermoplastics such as polypropylene, which limits the performance of the composites produced. The main objective of the current work was to investigate the use of fungi to treat hemp fiber to create better bonding characteristics in natural fiber reinforced polypropylene composites. X-ray diffraction (XRD), ζ-potential, lignin testing, thermal analysis, and scanning electron microscopy (SEM) were used to characterize the effect of treatment on hemp fibers. A combined alkali and fungi treated fiber composite produced the highest tensile strength of 48.3 MPa, an increase of 32% compared to composites with untreated fiber.

text: Interfacial modification of hemp fiber reinforced composites using fungal and alkali treatment Increasing worldwide environmental awareness is encouraging scientific research into developing cheaper, more sustainable materials. Industrial hemp fiber is one of the strongest and stiffest available natural fibers [K. L. Pickering, M. Priest, T. Watts, G. Beckermann, and S. N. Alam, J. Adv. Mater. 37, 15 (2005)] and therefore has great potential in composite materials. Incorporated into a thermoplastic matrix, it gives a structural material that is cheap, lightweight, and recyclable. However, natural fibers are commonly incompatible with common molding thermoplastics such as polypropylene, which limits the performance of the composites produced. The main objective of the current work was to investigate the use of fungi to treat hemp fiber to create better bonding characteristics in natural fiber reinforced polypropylene composites. X-ray diffraction (XRD), ζ-potential, lignin testing, thermal analysis, and scanning electron microscopy (SEM) were used to characterize the effect of treatment on hemp fibers. A combined alkali and fungi treated fiber composite produced the highest tensile strength of 48.3 MPa, an increase of 32% compared to composites with untreated fiber.

year: 2007

title: Introduction to tephra-derived soils, North Island, New Zealand: University of Waikato and University of Wisconsin-Platteville post-conference Andisol excursion, 21-23 December, 2016

authors: Lowe, David J.

abstract: Provisional itinerary DAY 1 Wednesday 21 December: Mamaku Plateau-Rerewhakaaitu-Lake Tarawera: 1 Goodwin Farm, Tapapa Rd, Tapapa: welded ignimbrite, tephras, loess, buried soils (Tirau soil) - stratigraphy of sequence (230 ka and younger) and upbuilding pedogenesis - Tirau silt loam 2 Brett Rd, Rerewhakaaitu: Holocene tephras and buried soil (Rotomahana soil) - Volcanic landscape, historical importance of area for NZ soil survey - Stratigraphy of sequence (~9.5 cal ka to 10 June 1886 Tarawera eruption) and upbuilding pedogenesis - Rotomahana sandy loam, 3 Ash Pit Rd, Rerewhakaaitu: tephras and buried soils (Matahina soil) - Matahina gravel - buried spodic/podzol soil features, 4 Okareka Loop Rd tephra section with proximal Rotorua Tephra and buried soils, loess, Buried Village Museum, Te Wairoa, Lake Tarawera (Stoney Point). DAY 2 Thursday 22 December: Otorohanga-Waitomo Caves -Pirongia Mountain: 1 Raynes Road section: Ultisol in composite tephra sequence (Kainui soil), 2 Otorohanga Kiwi House, 3 Waitomo Caves,, 4 Pirongia Mountain: Mangakara forest walk, 5 Evening meal on an Andisol. DAY 3 Friday 23 December: Hobbiton, Hamilton gardens including Te Parapara (ancient Maori garden): 1. Hobbiton tour 10.15 am (2 hrs), 2. Hamilton Gardens incl. Te Parapara Garden and human-modified soils (Tamahere soil).

text: Introduction to tephra-derived soils, North Island, New Zealand: University of Waikato and University of Wisconsin-Platteville post-conference Andisol excursion, 21-23 December, 2016 Provisional itinerary DAY 1 Wednesday 21 December: Mamaku Plateau-Rerewhakaaitu-Lake Tarawera: 1 Goodwin Farm, Tapapa Rd, Tapapa: welded ignimbrite, tephras, loess, buried soils (Tirau soil) - stratigraphy of sequence (230 ka and younger) and upbuilding pedogenesis - Tirau silt loam 2 Brett Rd, Rerewhakaaitu: Holocene tephras and buried soil (Rotomahana soil) - Volcanic landscape, historical importance of area for NZ soil survey - Stratigraphy of sequence (~9.5 cal ka to 10 June 1886 Tarawera eruption) and upbuilding pedogenesis - Rotomahana sandy loam, 3 Ash Pit Rd, Rerewhakaaitu: tephras and buried soils (Matahina soil) - Matahina gravel - buried spodic/podzol soil features, 4 Okareka Loop Rd tephra section with proximal Rotorua Tephra and buried soils, loess, Buried Village Museum, Te Wairoa, Lake Tarawera (Stoney Point). DAY 2 Thursday 22 December: Otorohanga-Waitomo Caves -Pirongia Mountain: 1 Raynes Road section: Ultisol in composite tephra sequence (Kainui soil), 2 Otorohanga Kiwi House, 3 Waitomo Caves,, 4 Pirongia Mountain: Mangakara forest walk, 5 Evening meal on an Andisol. DAY 3 Friday 23 December: Hobbiton, Hamilton gardens including Te Parapara (ancient Maori garden): 1. Hobbiton tour 10.15 am (2 hrs), 2. Hamilton Gardens incl. Te Parapara Garden and human-modified soils (Tamahere soil).

year: 2016-12-21