• International Journal of Control, Automation, and Systems
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• 제3권4호
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• pp.509-523
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• 2005

We are developing a novel framework, PRIDE (PRediction In Dynamic Environments), to perform moving object prediction (MOP) for autonomous ground vehicles. The underlying concept is based upon a multi-resolutional, hierarchical approach which incorporates multiple prediction algorithms into a single, unifying framework. The lower levels of the framework utilize estimation-theoretic short-term predictions while the upper levels utilize a probabilistic prediction approach based on situation recognition with an underlying cost model. The estimation-theoretic short-term prediction is via an extended Kalman filter-based algorithm using sensor data to predict the future location of moving objects with an associated confidence measure. The proposed estimation-theoretic approach does not incorporate a priori knowledge such as road networks and traffic signage and assumes uninfluenced constant trajectory and is thus suited for short-term prediction in both on-road and off-road driving. In this article, we analyze the complementary role played by vehicle kinematic models in such short-term prediction of moving objects. In particular, the importance of vehicle process models and their effect on predicting the positions and orientations of moving objects for autonomous ground vehicle navigation are examined. We present results using field data obtained from different autonomous ground vehicles operating in outdoor environments.

• Journal of Contemporary Eastern Asia
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• 제18권2호
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• pp.1-8
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• 2019

The blockchain is still new and unfamiliar. But blockchain appears to shake an entire technology innovation system. Blockchain is rapidly drawing attention in that it will be able to fundamentally revolutionize industry ecosystem. While cryptocurrency transactions and market capitalization have been popular in mass media, several platform operators in non-cryptocurrency areas such as jewelry, social networks, and entertainment, are also moving to introduce blockchain technology in full swing. In this brief note, we intend to present integrated theoretical strands to summarize various prospects for blockchain technology. Further, we want to provide a reflection as to whether this new technology gives opportunities, challenges, or risks to future society. Particularly, we point out one of its alternative and promising adoption that gives way to new forms of decentralized and autonomous organizations (DAOs).

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.758-771
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• 2021

This paper presents a novel control scheme for the three-dimensional (3D) path following of underactuated Autonomous Underwater Vehicle (AUVs) subject to unknown internal and external disturbances, in term of the time scale decomposition method. As illustration, two-time scale motions are first artificially forced into the closed-loop control system, by appropriately selecting the control gain of the integrator. Using the singular perturbation theory, the integrator is considered as a fast dynamical control law that designed to shape the space configuration of fast variable. And then the stabilizing controller is designed in the reduced model independently, based on the time scale decomposition method, leading to a relatively simple control law. The stability of the resultant closed-loop system is demonstrated by constructing a composite Lyapunov function. Finally, simulation results are provided to prove the efficacy of the proposed controller for path following of underactuated AUVs under internal and external disturbances.

• International journal of advanced smart convergence
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• 제13권2호
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• pp.7-15
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• 2024

6G network technology represents the next generation of communications, supporting high-speed connectivity, ultra-low latency, and integration with cutting-edge technologies, such as the Internet of Things (IoT), virtual reality, and autonomous vehicles. These advancements promise to drive transformative changes in digital society. However, as technology progresses, the demand for efficient data transmission and energy management between smart devices and network equipment also intensifies. A significant challenge within 6G networks is the optimization of interactions between satellites and smart devices. This study addresses this issue by introducing a new game theory-based technique aimed at minimizing system-wide energy consumption and latency. The proposed technique reduces the processing load on smart devices and optimizes the offloading decision ratio to effectively utilize the resources of Low-Earth Orbit (LEO) satellites. Simulation results demonstrate that the proposed technique achieves a 30% reduction in energy consumption and a 40% improvement in latency compared to existing methods, thereby significantly enhancing performance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1060-1065
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• 2005

An Independent Administrative Corporation Japan Agency for Marine-Earth Science and Technology (JAMSTEC) is developing light-and-small Autonomous Underwater Vehicles (AUV)$^{1)}$, named 'MR-X1' (Marine Robot Experimental 1), which can cruise, investigate and observe by itself without human's help. In this paper, we consider the motion control problem of 'MR-X1' and derive a controller. Since the dynamic property of 'MR-X1' is changed by the influence of the speed, the mathematical model of 'MR-X1' becomes the nonlinear model. In order to design a controller for 'MR-X1', we generally apply nonlinear control theories or linear control theories with some constant speed situation. If we design a controller by applying Linear Quadratic (LQ) optimal control theory, the obtained controller only compensates t e optimality at the designed speed situation, and does not compensate the stability at another speed situations. This paper proposes a controller design method using Linear Matrix Inequalities (LMIs)$^{2),3),4)}$, which can adapt the speed variation of 'MR-X1'. And examples of numerical analysis using our designed controller are shown.

• Ocean Systems Engineering
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• 제3권3호
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• pp.219-236
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• 2013

The accurate prediction of motion in waves of a marine vehicle is essential to assess the maximum sea state vs. operational requirements. This is particularly true for small crafts, such as Autonomous Surface Vessels (ASV). Two different numerical methods to predict motions of a SWATH-ASV are considered: an inviscid strip theory initially developed at MIT for catamarans and then adapted for SWATHs and new a hybrid strip theory, based on the numerical solution of the radiation forces by an unsteady viscous, non-linear free surface flow solver. Motion predictions obtained by the viscous flow method are critically discussed against those obtained by potential flow strip theory. Effects of viscosity are analyzed by comparison of sectional added mass and damping calculated at different frequencies and for different sections, RAOs and motions response in irregular waves at zero speed. Some relevant conclusions can be drawn from this study: influence of viscosity is definitely non negligible for SWATH vessels like the one presented: amplitude of the pitch and heave motions predicted at the resonance frequency differ of 20% respectively and 50%; in this respect, the hybrid method with fully non-linear, viscous free surface calculation of the radiation forces turns out to be a very valuable tool to improve the accuracy of traditional strip theories, without the burden of long computational times requested by fully viscous time domain three dimensional simulations.

• 한국항공우주학회지
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• 제48권6호
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• pp.419-429
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• 2020

다수의 무인항공기를 이용하여 표적을 탐색 및 추적하는 임무를 수행하는데 있어서 무인항공기의 운용 대수, 비행고도 등 운용 조건뿐만 아니라, 각 비행체들이 어떤 알고리즘을 이용해 비행경로를 결정하느냐에 따라 그 임무에 대한 성과는 크게 달라질 수 있다. 다만 이러한 표적 탐색 임무에서 자율 비행 무인항공기의 운용 방법이 어떠할 때 가장 효과적이며 효율적인지에 대한 연구는 미흡한상태이다. 본 연구에서는 플로킹 이론을 기반을 둔 다양한 자율비행 알고리즘을 활용하여, 다수의 무인 항공기가 서로 충돌을 회피하면서 표적을 탐지하는 임무를 기반으로 비행 시뮬레이션을 수행하고 그 결과를 분석하여, 표적 탐지 임무에서의 다수의 무인항공기를 제어할 수 있는 보다 효율적/효과적인 방안을 제시하였다.

• Journal of Information Science Theory and Practice
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• 제7권2호
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• pp.54-64
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• 2019

A theory of public knowledge is offered for the purposes of defining more clearly its role in information systems and classification schemas. Public knowledge is knowledge intended to be available for use in a public system. It is knowledge accessible to the public or knowledge in the public arena as opposed to the other seemingly multitudinous ways to describe knowledge. Furthermore, there are many different public arenas or small worlds. Public knowledge, irrespective of these different arenas, has four important overlying characteristics: It is consensual, it does not imply complete truth or certainty, it is autonomous, and it has a constant renewal of old knowledge with new knowledge. Each of these attributes has been culled from a study of the works of Patrick Wilson, Karl Popper, and John Ziman.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1077-1081
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• 1990

Autonomous action, which corresponds actively to the change of conditions in complicated circumstances, is a fundamental function required to an intelligent robot. To develope a control system for a robot having the ability to adapt itself to complicated circumstances, it is necessary to establish self-tracing technology, which recognizes the corresponding position between peripheral objects and itself. So we need to manipulate the moving system with flexibility. It is effective for solving problem that fuzzy theory is adapted to algorithm on a complicated circumstances. We develope a method to generate a route-map which has not only a course from the present position to the destination but also useful information on surroundings.

• 대한간호학회지
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• 제52권2호
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• pp.157-172
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• 2022

Purpose: This study aimed to construct and test a hypothetical model to explain the predictive factors and causal pathways for exercise levels in patients with ankylosing spondylitis based on the self-determination theory. A conceptual framework was constructed assuming that autonomy support by health care providers would satisfy the three basic psychological needs of patients, which would increase their autonomous motivation for exercise, resulting in its initiation and continuation. Methods: This cross-sectional study included 221 patients with ankylosing spondylitis who were visiting rheumatology clinics in two tertiary hospitals. Health Care Climate Questionnaire-exercise regularly, Basic Psychological Needs Satisfaction scale, Behavior Regulation in Exercise Questionnaire-2, and exercise level were used to collect data. Results: The fitness of the hypothetical model met the recommended level (𝛘²/df ≤ 3, SRMR ≤ .08, RMSEA ≤ .08, GFI ≥ .90, AGFI ≥ .85, NFI ≥ .90, TLI ≥ .90, CFI ≥ .90). The model effect analysis revealed that autonomy support by health care providers had a positive effect on patients' autonomy, competence, relatedness, autonomous motivation, and exercise level. Competence and relatedness had positive effects on autonomous motivation and exercise level, respectively. Autonomous motivation had a positive effect on exercise level. Conclusion: The predictive factors of exercise level in patients with ankylosing spondylitis were autonomous motivation, health care providers' autonomy support, competence, and relatedness. Considering these factors, we recommend the development of an effective program for improving exercise levels in these patients.