A limit theorem for patch sizes in a selectively-neutral migration model

1979 ◽  
Vol 16 (3) ◽  
pp. 482-495 ◽  
Author(s):  
Stanley Sawyer
Keyword(s):  
Continuous Time ◽  
Equilibrium Distribution ◽  
Block Structure ◽  
Random Mating ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Random Size ◽  
Kinship Coefficients ◽  
Mating Model

Assume a population is distributed in an infinite lattice of colonies in a migration and random mating model in which all individuals are selectively equivalent. In one and two dimensions, the population tends in time to consolidate into larger and larger blocks, each composed of the descendants of a single initial individual. Let N(t) be the (random) size of a block intersecting a fixed colony at time t. Then E[N(t)] grows like √t in one dimension, t/log t in two, and t in three or more dimensions. On the other hand, each block by itself eventually becomes extinct. In two or more dimensions, we prove that N(t)/E[N(t)] has a limiting gamma distribution, and thus the mortality of blocks does not make the limiting distribution of N(t) singular. Results are proven for discrete time and sketched for continuous time.If a mutation rate u > 0 is imposed, the ‘block structure' has an equilibrium distribution. If N(u) is the size of a block intersecting a fixed colony at equilibrium, then as u → 0 N(u)/E[N(u)] has a limiting exponential distribution in two or more dimensions. In biological systems u ≈ 10–6 is usually quite small.The proofs are by using multiple kinship coefficients for a stepping stone population.

A limit theorem for patch sizes in a selectively-neutral migration model

1979 ◽  
Vol 16 (03) ◽  
pp. 482-495 ◽  
Author(s):  
Stanley Sawyer
Keyword(s):  
Continuous Time ◽  
Equilibrium Distribution ◽  
Block Structure ◽  
Random Mating ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Random Size ◽  
Kinship Coefficients ◽  
Mating Model

Assume a population is distributed in an infinite lattice of colonies in a migration and random mating model in which all individuals are selectively equivalent. In one and two dimensions, the population tends in time to consolidate into larger and larger blocks, each composed of the descendants of a single initial individual. Let N(t) be the (random) size of a block intersecting a fixed colony at time t. Then E[N(t)] grows like √t in one dimension, t/log t in two, and t in three or more dimensions. On the other hand, each block by itself eventually becomes extinct. In two or more dimensions, we prove that N(t)/E[N(t)] has a limiting gamma distribution, and thus the mortality of blocks does not make the limiting distribution of N(t) singular. Results are proven for discrete time and sketched for continuous time. If a mutation rate u > 0 is imposed, the ‘block structure' has an equilibrium distribution. If N(u) is the size of a block intersecting a fixed colony at equilibrium, then as u → 0 N(u)/E[N(u)] has a limiting exponential distribution in two or more dimensions. In biological systems u ≈ 10–6 is usually quite small. The proofs are by using multiple kinship coefficients for a stepping stone population.

scholarly journals Assessing a Linear Nanosystem's Limiting Reliability from its Components

2008 ◽  
Vol 45 (03) ◽  
pp. 879-887 ◽  
Author(s):  
Nader Ebrahimi
Keyword(s):  
Present State ◽  
Size Range ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Present Moment ◽  
One Dimensional ◽  
The One ◽  
Fixed Moment ◽  
Nanosized Systems

Nanosystems are devices that are in the size range of a billionth of a meter (1 x 10-9) and therefore are built necessarily from individual atoms. The one-dimensional nanosystems or linear nanosystems cover all the nanosized systems which possess one dimension that exceeds the other two dimensions, i.e. extension over one dimension is predominant over the other two dimensions. Here only two of the dimensions have to be on the nanoscale (less than 100 nanometers). In this paper we consider the structural relationship between a linear nanosystem and its atoms acting as components of the nanosystem. Using such information, we then assess the nanosystem's limiting reliability which is, of course, probabilistic in nature. We consider the linear nanosystem at a fixed moment of time, say the present moment, and we assume that the present state of the linear nanosystem depends only on the present states of its atoms.

Assessing the Validity of SWAT as a Workload Measurement Instrument

1983 ◽  
Vol 27 (2) ◽  
pp. 124-128 ◽  
Author(s):  
Stephen P. Boyd
Keyword(s):  
Mental Workload ◽  
Measurement Instrument ◽  
Two Dimensions ◽  
The Other ◽  
Three Dimensions ◽  
One Dimension ◽  
Implicit Assumption ◽  
Workload Measurement ◽  
Positive Correlations ◽  
High Level

The Subjective Workload Asssessment Technique (SWAT) carries with it the implicit assumption that people can accurately predict the amount of mental workload they would experience under various levels of three component dimensions. Research suggests that the perceptions of these dimensions may not be independent. This study was designed to measure the subjective interactions between the dimensions used in SKAT. Mental workload was generated using a text editing task in which the dimensions were manipulated independently. Results revealed significant positive correlations between the subjective levels of the three dimensions. That is, when a subject experienced a high level of one dimension, s/he also tended to rate the other two dimensions high. It may be unreasonable to assume that people can accurately predict the magnitude of these interactions when performing the ranking process which is used to derive the workload scale.

scholarly journals A REJECTION MECHANISM IN 2D BOUNDED CONFIDENCE PROVIDES MORE CONFORMITY

2008 ◽  
Vol 11 (04) ◽  
pp. 529-549 ◽  
Author(s):  
S. HUET ◽  
G. DEFFUANT ◽  
W. JAGER
Keyword(s):  
Attitude Change ◽  
Large Range ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Two Dimensional ◽  
Number Of Clusters ◽  
Bounded Confidence ◽  
Rejection Mechanism ◽  
Model Apply

This paper explores the dynamics of attitude change in two dimensions resulting from social interaction. We add a rejection mechanism into the 2D bounded confidence (BC) model proposed by Deffuant et al. (2001). Individuals are characterized by two-dimensional continuous attitudes, each associated with an uncertainty u, supposed constant in this first study. Individuals interact through random pairs. If their attitudes are closer than u on both dimensions, or further than u on both dimensions, or closer than u on one dimension and not further than u + δ u on the other dimension, then the rules of the BC model apply. But if their attitudes are closer than u on one dimension and further than u + δ u on the other dimension, then the individuals are in a dissonant state. They tend to solve this problem by shifting away their close attitudes. The model shows metastable clusters, which maintain themselves through opposite influences of competitor clusters. Our analysis and first experiments support the hypothesis that, for a large range of uncertainty values, the number of clusters grows linearly with the inverse of the uncertainty, whereas this growth is quadratic in the BC model.

scholarly journals Commuting Double Sugeno Integrals

2019 ◽  
Vol 27 (Supp01) ◽  
pp. 1-38
Author(s):  
Didier Dubois ◽  
Hélène Fargier ◽  
Agnès Rico
Keyword(s):  
Expected Utility ◽  
Two Dimensions ◽  
The Other ◽  
Decision Problems ◽  
One Dimension ◽  
Two Dimensional ◽  
Conference Paper ◽  
The Relationship ◽  
Previous Conference

In decision problems involving two dimensions (like several agents in uncertainty) the properties of expected utility ensure that the result of a two-stepped procedure evaluation does not depend on the order with which the aggregations of local evaluations are performed (e.g., agents first, uncertainty next, or the converse). We say that the aggregations on each dimension commute. In a previous conference paper, Ben Amor, Essghaier and Fargier have shown that this property holds when using pessimistic possibilistic integrals on each dimension, or optimistic ones, while it fails when using a pessimistic possibilistic integral on one dimension and an optimistic one on the other. This paper studies and completely solves this problem when more general Sugeno integrals are used in place of possibilistic integrals, leading to double Sugeno integrals. The results show that there are capacities other than possibility and necessity measures that ensure commutation of Sugeno integrals. Moreover, the relationship between two-dimensional capacities and the commutation property for their projections is investigated.

scholarly journals Assessing a Linear Nanosystem's Limiting Reliability from its Components

2008 ◽  
Vol 45 (3) ◽  
pp. 879-887 ◽  
Author(s):  
Nader Ebrahimi
Keyword(s):  
Present State ◽  
Size Range ◽  
Two Dimensions ◽  
The Other ◽  
One Dimension ◽  
Present Moment ◽  
One Dimensional ◽  
The One ◽  
Fixed Moment ◽  
Nanosized Systems

Nanosystems are devices that are in the size range of a billionth of a meter (1 x 10-9) and therefore are built necessarily from individual atoms. The one-dimensional nanosystems or linear nanosystems cover all the nanosized systems which possess one dimension that exceeds the other two dimensions, i.e. extension over one dimension is predominant over the other two dimensions. Here only two of the dimensions have to be on the nanoscale (less than 100 nanometers). In this paper we consider the structural relationship between a linear nanosystem and its atoms acting as components of the nanosystem. Using such information, we then assess the nanosystem's limiting reliability which is, of course, probabilistic in nature. We consider the linear nanosystem at a fixed moment of time, say the present moment, and we assume that the present state of the linear nanosystem depends only on the present states of its atoms.

Environmental Scanning for Organisational Effectiveness: A Study of Select MSMEs of Jammu and Kashmir, India

2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Vinay Chauhan ◽  
Sushma Kaushal
Keyword(s):  
Organizational Effectiveness ◽  
Business Environment ◽  
Two Dimensions ◽  
The State ◽  
The Other ◽  
Political Environment ◽  
Environmental Scanning ◽  
Jammu And Kashmir ◽  
Economic Dimension ◽  
The Impact

Environmental scanning yields greater anticipatory management that provides important inputs for aquitision and use of information for planning and designing organization strategies. Apart from this, effective environmental scanning activities are likely to deal with threats and grasp the opportunities to finally link with enhancing organizational effectiveness. In fact this relationship matrix has led the researchers to conduct an environmental scanning through an examination of the existing status the components of the macro-environment vis-a-vis their relationship with the organizational effectiveness. There are a number of approaches, which describe the macro-environment, of which PEST analysis is regarded as the most common approach for considering the external business environment. Thus, the present study applies PEST analysis to scan the existing business environment. Jammu and Kashmir due to its peculiar political, geographical, economic, and socio-cultural features, had led its cost mountain economy become a distinctive identity. Despite the fact that the state has rich endowments, international relations with its neighbours vis-a-vis its impact on political environment also pose developmental challenges for the business units operating in the state. This has provided valid rationale for conducting the present. The environmental scanning is done through the perception of the select entrepreneurs operating MSMEs in the state of J & K. An impact analysis of environmental factors (PEST) on the organizational effectiveness is also done in the study. The findings of the study show that the political environment of the state that is not favourable for entrepreneural development whereas the rest of the other drivers of PEST i.e. economic environment, socio-cultural environment, and technological environment show a favourable response of the entrepreneurs. In terms of cause and effect relationship, it is found that the first two drivers of the PEST i.e. political and economic dimension impacts OE positively whereas the other two dimensions namely socio-cultural and technological impacts OE negatively but it is pertinent to mention that the impact is very less and is insigninificant. The study also suggests some of strategic options for developing and creating an enabling environment for successful entrepreneurial development to achieve integrated development of the state.

Impact of Job Stress and Social Support on Job Satisfaction among Academic Staff

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Kumari Kumkum ◽  
R. N. Singh ◽  
Yogershi Rajpoot
Keyword(s):  
Social Support ◽  
Job Satisfaction ◽  
Job Stress ◽  
Positive Impact ◽  
Academic Staff ◽  
Two Dimensions ◽  
The Other ◽  
Human Beings ◽  
Negative Consequences ◽  
Four Dimensions

There may be so many negative consequences of stress for human beings and dissatisfaction among employees happens to be one of the major problems. It indicates negative feelings that individuals have regarding their jobs or its facets. On the other hand, social support is assumed to be mitigating the relationship between negative aspects of the work environment and job satisfaction. Job stress is said to be associated with job dissatisfaction as well as experience of strain. In view of the above, this study examined the role of job stress and social support in job satisfaction. The sample consisted of 30 school teachers from different school of Varanasi (U.P.). The job stress, job satisfaction and social support scales were administered on the participants. The responses of the participants were converted into scores for statistical analyses. The scores of participants on the scales were correlated. The findings revealed that job stress led to increased job satisfaction. It is against the proposed hypothesis and it appears as if the social support received by the participants is a factor behind it. Two of the four dimensions of social support were found to exert positive impact on job satisfaction but the other two dimensions were not found to be correlated with it. The findings are thoroughly discussed and interpreted.

Galilean Relativity

2018 ◽  
Author(s):  
David M. Wittman
Keyword(s):  
Inertial Frame ◽  
Vertical Component ◽  
Horizontal Component ◽  
The Other ◽  
One Dimension ◽  
Everyday Experience ◽  
Low Speed ◽  
Principle Of Relativity ◽  
Galilean Relativity ◽  
Laws Of Motion

Galilean relativity is a useful description of nature at low speed. Galileo found that the vertical component of a projectile’s velocity evolves independently of its horizontal component. In a frame that moves horizontally along with the projectile, for example, the projectile appears to go straight up and down exactly as if it had been launched vertically. The laws of motion in one dimension are independent of any motion in the other dimensions. This leads to the idea that the laws of motion (and all other laws of physics) are equally valid in any inertial frame: the principle of relativity. This principle implies that no inertial frame can be considered “really stationary” or “really moving.” There is no absolute standard of velocity (contrast this with acceleration where Newton’s first law provides an absolute standard). We discuss some apparent counterexamples in everyday experience, and show how everyday experience can be misleading.

Coping with longitudinal data in research on developmental psychopathology

2006 ◽  
Vol 30 (1) ◽  
pp. 20-25 ◽  
Author(s):  
David A. Cole
Keyword(s):  
Data Collection ◽  
Longitudinal Data ◽  
Developmental Psychopathology ◽  
Careful Consideration ◽  
Two Dimensions ◽  
The Other ◽  
Outcome Variable ◽  
The Third ◽  
Data Analytic ◽  
Over Time

Many outcome variables in developmental psychopathology research are highly stable over time. In conventional longitudinal data analytic approaches such as multiple regression, controlling for prior levels of the outcome variable often yields little (if any) reliable variance in the dependent variable for putative predictors to explain. Three strategies for coping with this problem are described. One involves focusing on developmental periods of transition, in which the outcome of interest may be less stable. A second is to give careful consideration to the amount of time allowed to elapse between waves of data collection. The third is to consider trait-state-occasion models that partition the outcome variable into two dimensions: one entirely stable and trait-like, the other less stable and subject to occasion-specific fluctuations.

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