• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.271-271
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• 2019

Estimating ship motion is difficult because it take place in complex environments.. Estimating ship motion is an important factor in ensuring the safety of ship, so accurate estimates are needed. Existing motion-related studies compare the apparent motion of the model acquired and the reference model by experimenting with the ship motion on a particular alignment, making it difficult to intuitively estimate the hull motion. This study introduces the concept of estimating the characteristics of ship motion as a transfer function through pole-zero interpretation and frequency response analysis by applying the method of transfer function of Linear-Time Invariant system. Ship motion analysis model using Linear-Time Invariant system is consist with 1) wave as input signal 2) ship motion as output signal 3) hull defined as black box. This model can be defined by numericalizing the ship motion as a transfer function and is expected to facilitate the characterization of the ship motion through pole-zero analysis and frequency response analysis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.12
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• pp.3315-3337
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• 2012

Crowded scenes analysis is a challenging topic in computer vision field. How to detect diverse motion patterns in crowded scenarios from videos is the critical yet hard part of this problem. In this paper, we propose a novel approach to mining motion patterns by utilizing motion information during both long-term period and short interval simultaneously. To capture long-term motions effectively, we introduce Motion History Image (MHI) representation to access to the global perspective about the crowd motion. The combination of MHI and optical flow, which is used to get instant motion information, gives rise to discriminative spatial-temporal motion features. Benefitting from the robustness and efficiency of the novel motion representation, the following motion pattern mining is implemented in a completely unsupervised way. The motion vectors are clustered hierarchically through automatic hierarchical clustering algorithm building on the basis of graphic model. This method overcomes the instability of optical flow in dealing with time continuity in crowded scenes. The results of clustering reveal the situations of motion pattern distribution in current crowded videos. To validate the performance of the proposed approach, we conduct experimental evaluations on some challenging videos including vehicles and pedestrians. The reliable detection results demonstrate the effectiveness of our approach.

• International Journal of Aeronautical and Space Sciences
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• v.2 no.1
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• pp.28-43
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• 2001

Developed in these two series of paper is a complex dynamic model representing the motion of aircraft on the ground and a computer program for numerical simulation. The first part of paper presents the theoretical derivation of equations of motion of the landing gear system based on the physical principle. Developed model is 'structured' in the sense that the undercarriage system is regarded as an assembly of strut, tire, and wheel, where each component is modeled by a separate module. These modules are linked with two external modules-the aircraft and the runway characteristics-to carry out dynamic analysis and numerical simulation of the aircraft motion on the ground. Three sets of coordinate system associated with strut, wheel/tire and runway are defined, and external loads to each component and response characteristics are examined. Lagrangian formulation is used to derive the undercarriage equations of motion relative to the moving aircraft, and the resultant forces and moments from the undercarriage are transformed to aircraft body axes.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.453-460
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• 2010

For high quality image acquisition, compensating air-vehicle motion is essential for airborne SAR system. This paper describes a timing control based motion compensation method for airborne SAR system. Efficient timing control is critical for SAR system since it maintains many timing signals and timing setting for the signals should be updated frequently. This paper proposes Timing Cluster method as an efficient means for timing control of SAR system. Moreover, this paper suggests a simple and efficient method to compensate air-vehicle motion based on the Timing Cluster method. Timing Cluster method enables SAR system to control the timing in a timing noncritical way just maintaining little amount of information.

• Journal of the Korean Society for Railway
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• v.8 no.1
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• pp.27-33
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• 2005

This paper presents a development of 6DOF motion platform far a tilting train simulator. The tilting train simulator will be used to verify the tilting electronics and tilting control algorithm which are to be applied the Korean 180km/h tilting train. The tilting train simulator is composed of a 6-axis motion platform, a track generation system, a graphic user interface, and a visualization system with 1600mm-diameter dome screen. In this study, the 6DOF motion platform for a tilting train simulator has been designed and manufactured. The motion platform developed is a motion platform of Stewart type. The inverse kinematic analysis has been performed to determine the length of the links of the platform. Furthermore, the specification of the motors have been evaluated by the equation of motion of the platform.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.61-75
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• 2023

In this paper, we design and experiment a 5G-based metaverse motion synchronization system with configuration of a mobile motion capture studio that has not been commercialized at home and abroad. As a result of the experiment, the average value of the latency test measurement using Wi-Fi is 0.134 seconds faster than the average latency test measurement value using the 5G network. Existing motion capture studios have spatial limitations as the motion capture range is limited to the Wi-Fi communication range. However, the 5G-based metaverse motion synchronization system configures a mobile motion capture studio so that motion performers can solve the spatial limitations by expanding the motion capture communication range indefinitely regardless of time and place. Therefore, it is possible to implement realistic metaverse contents by displaying a realistic and natural digital human because it is free from spatial constraints. The system which was tested in this paper can create a new business model by converging next-generation technologies that are receiving attention related to the digital virtual world, such as motion capture + 5G + digital human twin + metaverse. And it allows for research and develop a next-generation metaverse-based broadcasting solution at a recent time when the business value of digital human and metaverse technologies and functions has been proven and related sales are growing in earnest.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1191-1194
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• 2004

We describe the development of an interactive aerobic training system using vision-based motion capture and multimedia technology. Unlike the traditional one-way aerobic training on TV, the proposed system allows the virtual trainer to observe and interact with the user in real-time. The system is composed of a web camera connected to a PC watching the user moves. First, the animated character on the screen makes a move, and then instructs the user to follow its movement. The system applies a robust statistical background subtraction method to extract a silhouette of the moving user from the captured video. Subsequently, principal body parts of the extracted silhouette are located using model-based approach. The motion of these body parts is then analyzed and compared with the motion of the animated character. The system provides audio feedback to the user according to the result of the motion comparison. All the animation and video processing run in real-time on a PC-based system with consumer-type camera. This proposed system is a good example of applying vision algorithms and multimedia technology for intelligent interactive home entertainment systems.

• The Research Journal of the Costume Culture
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• v.8 no.5
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• pp.741-753
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• 2000

The purpose of this study : 1. The total 24 range measurements of active dynamic motion of 40 subjects(20's and 30's, and 40's∼60's) using previous studies. The results were compared with the other studies in the aspects of age. In this study, The 3-D motion analysis system consists of VICON 140, data acquisition system, and data analysis program called by KRISSMAS. VICON 140 is dynamic motion analyzer, and KRISSMAS is a program developed for analysis of the data captured from the VICON. The results of this study were as follows : 1. Comparing 20's∼30's and 40's∼60's the result shows that 40's∼60's have smaller ROM at the most joints(Thoratic and Lumber, Hip Joint, Knee Joint, Ankle Joint), which is inconsistent with the previous result. The reason is that most investigations were carried out using traditional measurement equipments, which have encountered difficulty in quantifying the exact motion of the body. 2. There are no significant mean difference between the right and the left side. Most of the significances were not high(〉0.05).

• International conference on construction engineering and project management
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• 2015.10a
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• pp.321-323
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• 2015

Monitoring crane motion in real time is the first step to identifying and mitigating crane-related hazards on construction sites. However, no accurate and reliable crane motion capturing technique is available to serve this purpose. The objective of this research is to explore a method for real-time crane motion capturing and investigate an approach for assisting hazard detection. To achieve this goal, this research employed various techniques including: 1) a sensor-based method that accurately, reliably, and comprehensively captures crane motions in real-time; 2) computationally efficient algorithms for fusing and processing sensing data (e.g., distance, angle, acceleration) from different types of sensors; 3) an approach that integrates crane motion data with known as-is environment data to detect hazards associated with lifting tasks; and 4) a strategy that effectively presents crane operator with crane motion information and warn them with potential hazards. A prototype system was developed and tested on a real crane in a field environment. The results show that the system is able to continuously and accurately monitor crane motion in real-time.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.5
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• pp.599-605
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• 2011

A 3-D rehabilitation robot system is developed. The robot system is for the rehabilitation of upper extremities, especially the shoulder and elbow joints, and has 3-D workspace for occupational therapy to recover physical functions in activities of daily living(ADL). The rehabilitation robot system has 1 DOF in horizontal rotational motion and 2 DOF in vertical rotational motion, where all actuators are set on the ground. Parallelogram linkage mechanisms lower the equivalent inertia of the control elements as well as control forces. Also the mechanisms have high mechanical rigidity for the end effector and the handle. In this paper, a hybrid position/force controller is used for controlling positions and forces simultaneously The controller is tuned according to the robot posture. The active motion modes for rehabilitation program consist of active-resisted motion mode and active-free motion mode. The results of the experiments show that the proposed motion modes provide the intended forces effectively.