• 동력기계공학회지
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• 제4권4호
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• pp.92-98
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• 2000

Modern manufacturing systems should cope with the frequent changes in a product model and disturbances in manufacturing process. The control system of such systems must cover a constant adaptation and high flexibility. Holonic Flexible Manufacturing Cell(HFMC) is introduced to handle these issues more successfully. It is based on the concept of autonomous co-operating agent, called 'Holon', which is a building block of a manufacturing system for transforming, transporting, storing and/or validating information and physical objects. In this paper the basic structure of the HFMC is represented by using Unified Modeling Language and Open architecture cell controller is developed for effective integration components of a manufacturing system. Also a new control model, called MuLOM(Multi-Layered Operation Model), is suggested to represent the control behaviour for a holonic flexible manufacturing cell control system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.983-988
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• 2001

Dynamic behaviors and stability of an optical disk drive coupled with an automatic ball balancer(ABB) are analyzed by a theoretical approach. The feeding system is modeled a rigid body with six degree-of-freedom. Using Lagrange's equation, we derive the nonlinear equations of motion for a non-autonomous system with respect to the rectangular coordinate. To investigate the dynamic stability of the system in the neighborhood of the equilibrium positions, the monodromy matrix technique is applied to the perturbed equations. On the other hand, time responses are computed by the Runge-Kutta method. We also investigate the effects of the damping coefficient and the position of ABB on the dynamic behaviors of the system.

• 소음진동
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• 제9권2호
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• pp.355-362
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• 1999

Vibration reduction of an optical disk drive is achieved by an automatic ball balancer and dynamic behaviors of the drive are studied by theoretical approaches. Using Lagrange's equation, we derive nonlinear equations of motion for a non-autonomous system with respect to the rectangular coordinate. To investigate the dynamic stability of the system in the neighborhood of equilibrium positions, the Floquet theory is applied to the perturbed equations. On the other hand, time responses are computed by an explicit time integration method. We also investigate the effects of mass center and the position of the ABB on the dynamic behaviors of the system.

• ETRI Journal
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• 제45권5호
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• pp.746-757
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• 2023

This study presents a novel safe landing algorithm for urban drone deliveries. The rapid advancement of drone technology has given rise to various delivery services for everyday necessities and emergency relief efforts. However, the reliability of drone delivery technology is still insufficient for application in urban environments. The proposed approach uses the "landing angle control" method to allow the drone to land vertically and a rapidly exploring random tree-based collision avoidance algorithm to generate safe and efficient vertical landing paths for drones while avoiding common urban obstacles like trees, street lights, utility poles, and wires; these methods allow for precise and reliable urban drone delivery. We verified the approach within a Gazebo simulation operated through ROS using a six-degree-of-freedom drone model and sensors with similar specifications to actual models. The performance of the algorithms was tested in various scenarios by comparing it with that of stateof-the-art 3D path planning algorithms.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2024년도 제69차 동계학술대회논문집 32권1호
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• pp.335-337
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• 2024

This paper presents a new open-world object detection method emphasizing uncertainty representation in machine learning models. The focus is on adapting to real-world uncertainties, incrementally updating the model's knowledge repository for dynamic scenarios. Applications like autonomous vehicles benefit from improved multi-class classification accuracy. The paper reviews challenges in existing methodologies, stressing the need for universal detectors capable of handling unknown classes. Future directions propose collaboration, integration of language models, to improve the adaptability and applicability of open-world object detection.

• 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.

• Advances in Computational Design
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• 제3권4호
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• pp.339-366
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• 2018

Parametric design systems serve as powerful assistive tools in the design process by providing a flexible approach for the generation of a vast number of design alternatives. However, contemporary parametric design systems focus primarily on low-level engineering and structural forms, without an explicit means to also take into account high-level, cognitively motivated people-centred design goals. We present a precedent-based parametric design method that integrates people-centred design "precedents" rooted in empirical evidence directly within state of the art parametric design systems. As a use-case, we illustrate the general method in the context of an empirical study focusing on the multi-modal analysis of wayfinding behaviour in two large-scale healthcare environments. With this use-case, we demonstrate the manner in which: (1). a range of empirically established design precedents -e.g., pertaining to visibility and navigation- may be articulated as design constraints to be embedded directly within state of the art parametric design tools (e.g., Grasshopper); and (2). embedded design precedents lead to the (parametric) generation of a number of morphologies that satisfy people-centred design criteria (in this case, pertaining to wayfinding). Our research presents an exemplar for the integration of cognitively motivated design goals with parametric design-space exploration methods. We posit that this opens-up a range of technological challenges for the engineering and development of next-generation computer aided architecture design systems.

• 한국지능시스템학회논문지
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• 제12권1호
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• pp.19-26
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• 2002

자율이동로봇의 센서-모터 제어기를 구축하는데 있어 로봇의 기계적인 부분과 제어기 부분을 조화시키는 것이나 외부환경과 로봇의 상호작용을 처리하는 것 등이 가장 큰 문제점이다. 이러한 문제점들을 해결하기 위해서 진화적 접근방법이 많이 사용되고 있다. 이전 연구에서는 이러한 연구선상에서 셀룰라 오토마타 기반 신경망인 CAM-Brain을 이동로봇 제어기로 진화시켰다. 그러나, 하나의 모듈로 이루어진 제어기로는 복잡한 행동을 하도록 만들기 어렵기 때문에 본 논문에서는 하위 수준의 간단한 행동을 하도록 진화된 모듈들을 결합하여 보다 상위 수준의 복잡한 행동을 하도록 하는 다중 모듈 결합방법을 제안한다. 실험결과, 간단한 행동들을 하도록 진화된 CAM-Brain 모듈들을 규칙기반 방법으로 결합하여 주어진 좀더 환경에 적응할 수 있는 제어기를 얻을 수 있었다.

• 대한간호학회지
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• 제48권6호
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• pp.692-707
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• 2018

Purpose: We aimed to examine the effects of an integrated physical activity (PA) program developed for physically inactive workers on the theoretical basis of the PRECEDE-PROCEED model. Methods: Participants were 268 workers in three departments of L manufacturing unit in South Korea. The three departments were randomly allocated into integration (n=86) (INT), education (n=94) (ED), and control (n=88) (CT) groups. The INT group received self-regulation, support, and policy-environmental strategies of a 12-week integrated PA program, the ED group received self-regulation strategies only, and the CT group did not receive any strategies. After 12 weeks, process evaluation was conducted by using the measures of self-regulation (autonomous vs. controlled regulation), autonomy support, and resource availability; impact evaluation by using PA measures of sitting time, PA expenditure, and compliance; and outcome evaluation by using the measures of cardiometabolic/musculoskeletal health and presenteeism. Results: Among process measures, autonomous regulation did not differ by group, but significantly decreased in the CT group (p=.006). Among impact measures, PA compliance significantly increased in the INT group compared to the CT group (p=.003). Among outcome measures, the changes in cardiometabolic/musculoskeletal health and presenteeism did not differ by group; however, systolic blood pressure (p=.012) and a presenteeism variable (p=.041) significantly decreased only in the INT group. Conclusion: The integrated PA program may have a significant effect on increases in PA compliance and significant tendencies toward improvements in a part of cardiometabolic health and presenteeism for physically inactive workers. Therefore, occupational health nurses may modify and use it as a workplace PA program.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.868-871
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• 2016

최근 IoT를 활용한 웨어러블 기기 및 무인 이동체에 관한 연구가 활발히 진행되고 있다. 그 중 무인 이동체는 IT 기술들의 집약체라고 할 수 있다. 로봇, 자율 주행, 장애물 회피, 데이터 통신, 전력, 영상 처리 등의 기술들이 합쳐진 것을 무인 이동체 또는 무인 로봇이라고 부른다. 무인 이동체의 최종 목표는 수동이 아닌 자율 주행을 하여 목적지까지 안전하고 신속하게 도달하는 것을 목표로 한다. 본 논문에서는 무인 이동체의 기술들 중 하나인 영상 처리 분야를 다루고자 한다. 현재 배터리의 기술로는 무인 이동체가 최대 1시간까지 주행할 수밖에 없다는 것을 감안하여, 전력 소비를 최소한으로 줄이기 위해 소형 컴퓨터인 라즈베리 파이3를 사용하여 영상 인식 시스템을 설계하고자 한다. 제안하고자 하는 시스템은 카메라로부터 받는 영상의 모든 것을 인식하는 시스템을 목표로 한다.