108,168 research outputs found
An agent-based fuzzy cognitive map approach to the strategic marketing planning for industrial firms
This is the post-print version of the final paper published in Industrial Marketing Management. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2013 Elsevier B.V.Industrial marketing planning is a typical example of an unstructured decision making problem due to the large number of variables to consider and the uncertainty imposed on those variables. Although abundant studies identified barriers and facilitators of effective industrial marketing planning in practice, the literature still lacks practical tools and methods that marketing managers can use for the task. This paper applies fuzzy cognitive maps (FCM) to industrial marketing planning. In particular, agent based inference method is proposed to overcome dynamic relationships, time lags, and reusability issues of FCM evaluation. MACOM simulator also is developed to help marketing managers conduct what-if scenarios to see the impacts of possible changes on the variables defined in an FCM that represents industrial marketing planning problem. The simulator is applied to an industrial marketing planning problem for a global software service company in South Korea. This study has practical implication as it supports marketing managers for industrial marketing planning that has large number of variables and their cause–effect relationships. It also contributes to FCM theory by providing an agent based method for the inference of FCM. Finally, MACOM also provides academics in the industrial marketing management discipline with a tool for developing and pre-verifying a conceptual model based on qualitative knowledge of marketing practitioners.Ministry of Education, Science and Technology (Korea
Dynamical Models for the Formation of Elephant Trunks in H II Regions
The formation of pillars of dense gas at the boundaries of H II Regions is
investigated with hydrodynamical numerical simulations including ionising
radiation from a point source. We show that shadowing of ionising radiation by
an inhomogeneous density field is capable of forming so-called elephant trunks
(pillars of dense gas as in e.g. M16) without the assistance of self-gravity,
or of ionisation front and cooling instabilities. A large simulation of a
density field containing randomly generated clumps of gas is shown to naturally
generate elephant trunks with certain clump configurations. These
configurations are simulated in isolation and analysed in detail to show the
formation mechanism and determine possible observational signatures. Pillars
formed by the shadowing mechanism are shown to have rather different velocity
profiles depending on the initial gas configuration, but asymmetries mean that
the profiles also vary significantly with perspective, limiting their ability
to discriminate between formation scenarios. Neutral and molecular gas cooling
are shown to have a strong effect on these results.Comment: 17 pages, 11 figures, MNRAS. Minor revisions: typos corrected,
figures re-ordered to match published versio
Automatic generation of robot and manual assembly plans using octrees
This paper aims to investigate automatic assembly planning for robot and manual assembly. The octree decomposition technique is applied to approximate CAD models with an octree representation which are then used to generate robot and manual assembly plans. An assembly planning system able to generate assembly plans was developed to build these prototype models. Octree decomposition is an effective assembly planning tool. Assembly plans can automatically be generated for robot and manual assembly using octree models. Research limitations/implications - One disadvantage of the octree decomposition technique is that it approximates a part model with cubes instead of using the actual model. This limits its use and applications when complex assemblies must be planned, but in the context of prototyping can allow a rough component to be formed which can later be finished by hand. Assembly plans can be generated using octree decomposition, however, new algorithms must be developed to overcome its limitations
Convex relaxation of mixture regression with efficient algorithms
We develop a convex relaxation of maximum a posteriori estimation of a mixture of regression models. Although our relaxation involves a semidefinite matrix variable, we reformulate the problem to eliminate the need for general semidefinite programming. In particular, we provide two reformulations that admit fast algorithms. The first is a max-min spectral reformulation exploiting quasi-Newton descent. The second is a min-min reformulation consisting of fast alternating steps of closed-form updates. We evaluate the methods against Expectation-Maximization in a real problem of motion segmentation from video data
Non-linear Market Behavior: Events Detection in the Malaysian Stock Market
This paper advocates a reverse from of event studies that is data-dependent to determine endogeneously the events that trigger non-linear market behavior. Using the Malaysian stock market as our case study, coupled with the ‘windowing' approach proposed by Hinich and Patterson (1995), the present study is able to identify major political and economic events that contributed to the short bursts of non-linear behavior. The present framework can be extended to individual firm to examine the adjustment of its stock price to firm-specific events, which will provide deeper insight into issues on corporate finance.
Self-organizing, two-temperature Ising model describing human segregation
A two-temperature Ising-Schelling model is introduced and studied for
describing human segregation. The self-organized Ising model with Glauber
kinetics simulated by M\"uller et al. exhibits a phase transition between
segregated and mixed phases mimicking the change of tolerance (local
temperature) of individuals. The effect of external noise is considered here as
a second temperature added to the decision of individuals who consider change
of accommodation. A numerical evidence is presented for a discontinuous phase
transition of the magnetization.Comment: 5 pages, 4 page
Cross-temporal universality of non-linear dependencies in Asian stock markets
This study utilizes the Hinich portmanteau bicorrelation test in conjunction with the windowed testing procedure to examine the cross-temporal universality of non-linear dependencies in the returns series for Asian stock market indices. As a whole, the detected non-linear dependencies do not appear to be persistent or stable across time for all the stock markets. In particular, the underlying process is of a switching type, with the pure noise process from time to time switches to a non-linear dependent stochastic process for some unknown length of time, and then switches back to pure-noise. This provides a plausible explanation for the disappointing forecasting performance of many non-linear models, as these existing models do not take note of the episodic transient nature of the non-linear dependency structures.
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