title: Latent class count models of total visitation demands: days out hiking in the eastern Alps

authors: Scarpa, Riccardo

subjects: travel cost method

abstract: We report preliminary results on the investigation of the hypothesis of the existence of latent classes in the total demand for days out in a vast section of the Italian Eastern Alps. Finite mixing is informed by socioeconomic variables and it is limited to the demand portion of a hurdle model of visitation. Gradually more flexible count models are estimated moving from the Poisson to the Negative Binomial -1 and -2, to the generalized negative binomial. The implications for expected consumers surplus, predicted visitation and choke prices are discussed for a plausible 2 class model where years of experience play an important role in class membership.

text: Latent class count models of total visitation demands: days out hiking in the eastern Alps We report preliminary results on the investigation of the hypothesis of the existence of latent classes in the total demand for days out in a vast section of the Italian Eastern Alps. Finite mixing is informed by socioeconomic variables and it is limited to the demand portion of a hurdle model of visitation. Gradually more flexible count models are estimated moving from the Poisson to the Negative Binomial -1 and -2, to the generalized negative binomial. The implications for expected consumers surplus, predicted visitation and choke prices are discussed for a plausible 2 class model where years of experience play an important role in class membership.

year: 2007

title: On the insecurity of arithmetic coding

authors: Cleary, John G.

subjects: computer science

abstract: Arithmetic coding is a technique which converts a given probability distribution into an optimal code and is commonly used in compression schemes. The use of arithmetic coding as an encryption scheme is considered. The simple case of a single binary probability distribution with a fixed (but unknown) probability is considered. We show that for a chosen plaintext attack w+ 2 characters is sufficient to uniquely determine a w-bit probability. For many known plaintexts w+ m+ O(log m) symbols where mis the length of an initial sequence containing just one of (the two possible) symbols is sufficient. It is noted that many extensions to this basic scheme are vulnerable to the same attack provided the arithmetic coder can be repeatedly reset to its initial state. If it cannot be reset then their vulnerability remains an open question.

text: On the insecurity of arithmetic coding Arithmetic coding is a technique which converts a given probability distribution into an optimal code and is commonly used in compression schemes. The use of arithmetic coding as an encryption scheme is considered. The simple case of a single binary probability distribution with a fixed (but unknown) probability is considered. We show that for a chosen plaintext attack w+ 2 characters is sufficient to uniquely determine a w-bit probability. For many known plaintexts w+ m+ O(log m) symbols where mis the length of an initial sequence containing just one of (the two possible) symbols is sufficient. It is noted that many extensions to this basic scheme are vulnerable to the same attack provided the arithmetic coder can be repeatedly reset to its initial state. If it cannot be reset then their vulnerability remains an open question.

year: 1994-06

title: Ngā kanohi hou – identifying and exploring the issues: Experiences of an intern

authors: Masters-Awatere, Bridgette

subjects: Maori

abstract: The current paper reflects upon the discovery of an intern from the post graduate diploma in community psychology programme (PGDipPsych (Com). The PGDipPsych (Com) is currently facilitated through the University of Waikato School of Arts and Social Sciences, Psychology Department. This journey of discovery is presented from the perspective of a Māori student who is employed in a mainstream public health organisation. The perspective of a person who is new to the workforce, and the “real world,” who views the surrounding environment with a pair of fresh eyes.

This paper highlights the importance of the internship period as it supports the student who moves from a structured environment with a strong emphasis on theory, towards a competitive, semi structured environment that is driven by deadlines, budgets and contracts.

Factors identified are the demands of Māori communities on Māori health researchers, supportive versus competitive environments, the benefits and drawbacks of being based in a mainstream health organisation, and the future direction of Māori health research. It is hoped that the current paper will encourage further discussion about the future direction of a diploma programme such as the PGDipPsychCom for Māori graduates of a New Zealand tertiary institution.

text: Ngā kanohi hou – identifying and exploring the issues: Experiences of an intern The current paper reflects upon the discovery of an intern from the post graduate diploma in community psychology programme (PGDipPsych (Com). The PGDipPsych (Com) is currently facilitated through the University of Waikato School of Arts and Social Sciences, Psychology Department. This journey of discovery is presented from the perspective of a Māori student who is employed in a mainstream public health organisation. The perspective of a person who is new to the workforce, and the “real world,” who views the surrounding environment with a pair of fresh eyes.

This paper highlights the importance of the internship period as it supports the student who moves from a structured environment with a strong emphasis on theory, towards a competitive, semi structured environment that is driven by deadlines, budgets and contracts.

Factors identified are the demands of Māori communities on Māori health researchers, supportive versus competitive environments, the benefits and drawbacks of being based in a mainstream health organisation, and the future direction of Māori health research. It is hoped that the current paper will encourage further discussion about the future direction of a diploma programme such as the PGDipPsychCom for Māori graduates of a New Zealand tertiary institution.

year: 1999