• Title/Summary/Keyword: two-action problem

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Optimal Convergence Rate of Empirical Bayes Tests for Uniform Distributions

  • Liang, Ta-Chen
    • Journal of the Korean Statistical Society
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    • v.31 no.1
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    • pp.33-43
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    • 2002
  • The empirical Bayes linear loss two-action problem is studied. An empirical Bayes test $\delta$$_{n}$ $^{*}$ is proposed. It is shown that $\delta$$_{n}$ $^{*}$ is asymptotically optimal in the sense that its regret converges to zero at a rate $n^{-1}$ over a class of priors and the rate $n^{-1}$ is the optimal rate of convergence of empirical Bayes tests.sts.

Strategy for Insecticide Resistance Management Approach to IPM

  • Motoyama, Naoki;Dauterman, W.C.
    • Korean journal of applied entomology
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    • v.31 no.3
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    • pp.314-327
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    • 1992
  • Insecticide resistance is a serious is a serious threat to IPM, resulting in various adverse effects not to mention the loss of yield in agriculture. One approach to counter the problem is the disruption of resistance mechanisms. This can be achieved by (1) compounds which show a negative correlation with resistance at the site of action, (2) specific metabolic inhibitors which serve as synergists, or (3) a certain combination of two insecticides producing a joint action. This approach, however, requires certain precautions for the side effects may cause an increase in toxicity to mammals. Owing to the recent advances in theoretical studies on resistance management employing computer simulation and mathematical models, a few principles to reduce the risk of development of resistance have been clarified. They are helpful in designing operational strategies with regard to, for instance, insecticide doses to be applied, mode of application, and choice and nature of the insecticide(s) to be used. For restoration of insecticide susceptibility of a resistant population, reintroduction of susceptible individuals to the resistant population is feasible when certain conditions are met. Natural enemies which developed resistance to insecticides can be an important component of IPM as has been shown in the pest management in apple orchards. After all, the implementation of a successful resistance management program depends upon cooperation between different sigments of the agricutural community. Although resistance is a preadaptive phenomenon, in some cases spontaneous loss of resistance does occur without contamination by susceptible individuals. The instability of resistance in these insects implies the possible existence of a switch machanism controlling the expression of resistance gene(s). Elucidation of such a mechanism may eventually provide us with a new technical approach with which we can combat the problem of insecticide resistance.

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A Study of Gameplay based on Affordance (행동유도성 기반의 게임플레이에 관한 연구)

  • Song, Seung-Keun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.170-171
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    • 2013
  • In aspect of HCI(Human Computer Interaction) gameplay is the procedure to solve the problem that gamers encounter in order to generate or discover a new rule to achieve gamers' goal. The goal of this research is to investigate the structure and understand the gameplay in aspect of affordance from ecological psychology rather than the traditional problem solving theory. This research selects 'World of Warcraft' as MMORPG(Massively Multiplayer Online Role Playing Game). Five expert gamers participated in this experiment. We record all gameplay using audio and video device. We conducted protocol analysis as qualitative method based on the verbal report and action protocol during game playing. As result, gameplay based on affordance includes selection and relation. We found that subjects selected one thing at once with attention. Moreover, we found that there were two behaviors : exploratory action and performatory action. We believe that learning, utilization, and transformation for affordance appear. The result of this research imply to suggest design guideline for game design methodology when designers develop game.

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A Systematic Review and Meta-Analysis of the Effects of Action Learning-Based Education Program on Nursing Students (간호대학생의 액션러닝 기반 교육프로그램 효과에 대한 체계적 문헌고찰 및 메타분석)

  • Mi-Hyeon Park;Yong-Joo Cho
    • Journal of Practical Engineering Education
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    • v.16 no.4
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    • pp.587-598
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    • 2024
  • This study aimed to evaluate the effectiveness of an action learning-based educational program for domestic nursing students. A systematic review and meta-analysis were conducted following PRISMA guidelines. Limited to the period from January 2013 to December 2023, a search conducted across the electronic databases DBpia, RISS, KCI, KISS, and SCIENCE ON identified a total of 779 documents. From these, 13 documents that met the established selection criteria were ultimately included. Thirteen documents meeting the selection criteria were identified, and quality evaluation was independently performed by two researchers using ROBINS-I. The effect size of the action learning-based education program was analyzed using the 'Meta package' in the R program. The effect size for problem-solving was ESr=.68 (95% CI=.30 to 1.06). For communication skills, the effect size was ESr=.39 (95% CI=-.08 to .85), and for critical thinking, the effect size was ESr=.26 (95% CI=.02 to .50). Action learning-based educational programs have been shown to be an effective method for enhancing problem-solving skills and critical thinking among nursing students. Therefore, there is a need for the active implementation of action learning techniques to further develop nursing students' clinical practice capabilities within nursing education.

A Study for Improved Human Action Recognition using Multi-classifiers (비디오 행동 인식을 위하여 다중 판별 결과 융합을 통한 성능 개선에 관한 연구)

  • Kim, Semin;Ro, Yong Man
    • Journal of Broadcast Engineering
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    • v.19 no.2
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    • pp.166-173
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    • 2014
  • Recently, human action recognition have been developed for various broadcasting and video process. Since a video can consist of various scenes, keypoint approaches have been more attracted than template based methods for real application. Keypoint approahces tried to find regions having motion in video, and made 3-dimensional patches. Then, descriptors using histograms were computed from the patches, and a classifier based on machine learning method was applied to detect actions in video. However, a single classifier was difficult to handle various human actions. In order to improve this problem, approaches using multi classifiers were used to detect and to recognize objects. Thus, we propose a new human action recognition using decision-level fusion with support vector machine and sparse representation. The proposed method extracted descriptors based on keypoint approach from a video, and acquired results from each classifier for human action recognition. Then, we applied weights which were acquired by training stage to fuse each results from two classifiers. The experiment results in this paper show better result than a previous fusion method.

INFLUENCE OF CAPILLARITY AND ELASTICITY ON MICRO-CONTACTS

  • Zheng, J.;Streator, J.L.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.65-66
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    • 2002
  • One aspect of the stiction problem may be explained by the action of capillary forces in conjunction with surface elasticity. In the present work, the interaction between two elastic half-spaces separated by a small liquid bridge is investigated. By minimizing the total free energy stored in the interface (including elastic energy and surface energy), the equilibrium interface geometry is determined analytically in the case where there is no solid-solid contact. A non-dimensional number, $N_c=299\frac{{\gamma}^2_{LA}cos^2{\theta}V_o}{E^{'2}H^5}$ is found to govern the structure stability. When $N_c{\ge}1$, the two surfaces jump into solid-solid contact and, once this occurs, the contact area will continue to expand until the two surfaces are in full contact.

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EMPIRICAL BAYES TESTING FOR MEAN LIFE TIME OF RAYLEIGH DISTRIBUTION

  • Liang, TaChen
    • Journal of applied mathematics & informatics
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    • v.25 no.1_2
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    • pp.1-15
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    • 2007
  • Consider a Rayleigh distribution with $$pdf\;p(x/{\theta})\;=\;2x{\theta}^{-1}\;{\exp}\;({-x^2}/{\theta})$$ and mean lifetime ${\mu}\;=\;\sqrt{\pi\theta}/2$. We study the two-action problem of testing the hypotheses $H_{0}\;:\;{\mu}{\leq}{\mu}_{0}$ against $H_{1}\;:\;{\mu}\;>\;{\mu}_{0}$ using a linear error loss of ${\mid}{\mu}\;-\;{\mu}_{0}{\mid}$ via the empirical Bayes approach. We construct a monotone empirical Bayes test ${\delta}^{*}_{n}$ and study its associated asymptotic optimality. It is shown that the regret of ${\delta}^{*}_{n}$ converges to zero at a rate $\frac{{\ln}^{2}n}{n}$, where n is the number of past data available when the present testing problem is considered.

Elastodynamic Response of a Crack Perpendicular to the Graded Interfacial Zone in Bonded Dissimilar Materials Under Antiplane Shear Impact

  • Kim, Sung-Ho;Choi, Hyung-Jip
    • Journal of Mechanical Science and Technology
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    • v.18 no.8
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    • pp.1375-1387
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    • 2004
  • A solution is given for the elastodynamic problem of a crack perpendicular to the graded interfacial zone in bonded materials under the action of anti plane shear impact. The interfacial zone is modeled as a nonhomogeneous interlayer with the power-law variations of its shear modulus and mass density between the two dissimilar, homogeneous half-planes. Laplace and Fourier integral transforms are employed to reduce the transient problem to the solution of a Cauchy-type singular integral equation in the Laplace transform domain. Via the numerical inversion of the Laplace transforms, the values of the dynamic stress intensity factors are obtained as a function of time. As a result, the influences of material and geometric parameters of the bonded media on the overshoot characteristics of the dynamic stress intensities are discussed. A comparison is also made with the corresponding elastostatic solutions, addressing the inertia effect on the dynamic load transfer to the crack tips for various combinations of the physical properties.

Dynamic analysis of a magneto-electro-elastic material with a semi-infinite mode-III crack under point impact loads

  • Feng, Wenjie;Liu, Jinxi
    • Structural Engineering and Mechanics
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    • v.27 no.5
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    • pp.609-623
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    • 2007
  • The problem of a semi-infinite magneto-electro-elastically impermeable mode-III crack in a magneto-electro-elastic material is considered under the action of impact loads. For the case when a pair of concentrated anti-plane shear impacts, electric displacement and magnetic induction impacts are exerted symmetrically on the upper and lower surfaces of the crack, the magneto-electro-elastic field ahead of the crack tip is determined in explicit form. The dynamic intensity factors and dynamic energy density factor are obtained. The method adopted is to reduce the mixed initial-boundary value problem, by using the Laplace and Fourier transforms, into three simultaneous dual integral equations, one of which is converted into an Abel's integral equation and the others into a singular integral equation with Cauchy kernel. Based on the obtained fundamental solutions of point impact loads, the solutions of two kinds of different loading cases are evaluated by integration. For some particular cases, the present results reduce to the previous results.

Avoidance Behavior of Small Mobile Robots based on the Successive Q-Learning

  • Kim, Min-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.164.1-164
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    • 2001
  • Q-learning is a recent reinforcement learning algorithm that does not need a modeling of environment and it is a suitable approach to learn behaviors for autonomous agents. But when it is applied to multi-agent learning with many I/O states, it is usually too complex and slow. To overcome this problem in the multi-agent learning system, we propose the successive Q-learning algorithm. Successive Q-learning algorithm divides state-action pairs, which agents can have, into several Q-functions, so it can reduce complexity and calculation amounts. This algorithm is suitable for multi-agent learning in a dynamically changing environment. The proposed successive Q-learning algorithm is applied to the prey-predator problem with the one-prey and two-predators, and its effectiveness is verified from the efficient avoidance ability of the prey agent.

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