• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.7-13
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• 2008

This paper suggests a Path-planning algorithm for mobile agents. While there are a lot of studies on the path-planning for mobile agents, mathematical modeling of complex environment which constrained by spatio-temporally is very difficult and it is impossible to obtain the optimal solutions. In this paper, an optimal path-planning algorithm based on the graphic technique is presented. The working environment is divided into two areas, the one is free movable area and the other is not permissible area in which there exist obstacles and spatio-temporally constrained, and an optimal solution is obtained by using a new algorithm which is based on the well known ACO algorithm.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.4
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• pp.38-45
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• 1998

It is a tedious and excessive time consuming process to model the local area of crack tip part of structures in calculation of stress intensity factors by FEM. So, in this paper, the hybrid method of FEM and BEM approach was formulated to overcome this type of problems. The multi-domained BEM was adopted to simplify the modelling process of complex geometry and singularity characteristics of crack tip part and the ordinary FEM modelling was used in the rest part. The example calculations shows very good results compared with analytic solutions and other numerical method.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.973-976
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• 2010

제안요청서(RFP)는 사업목적 달성을 위해 발주자가 공급자의 제안을 받기 위한 요구사항을 정의한 문서로 프로젝트 목표 수행의 중요한 요소이고, 불명확한 요구사항과 요구의 변경, 외부 수행 작업의 문제, 일정과 예산의 비현실성 등은 프로젝트의 성공적인 수행을 저해하는 위험요인이다. 본 논문에서는 2005년부터 2009년까지 공공 SI(System Integration) 프로젝트의 RFP를 대상으로 첫째, 미국 프로젝트 표준규격인 PMBOK(Project Management Body of Knowleage) 지식 및 관리 프로세스 영역을 적용하여 현황을 분석하였고 둘째, Core와 Support 프로세스 영역을 비교분석하고, 셋째, Core 프로세스의 범위, 일정, 비용 영역에 대해 분석하였다. 연구결과로 공공 SI RFP의 범위, 일정, 비용을 의미한 항목에서 분명한 차이를 보여 보완이 요구되었다. 향후 본 연구를 통해 공공 SI 프로젝트의 RFP 작성시 명확성을 제고하여 프로젝트 성공 수행에 도움이 되도록 하고자 한다.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.1-11
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• 2006

Many research demonstrations and commercial applications have been tried to develop face detection and recognition systems. Human face detection plays an important role in applications such as access control and video surveillance, human computer interface, identity authentication, etc. There are some special problems such as a face connected with background, faces connected via the skin color, and a face divided into several small parts after skin region segmentation in generally. It can be allowed many face detection techniques to solve the first and second problems. However, it is not easy to detect a face divided into several parts of regions for reason of different illumination conditions in the third problem. Therefore, we propose an efficient modified skin segmentation algorithm to solve this problem because the typical region segmentation algorithm can not be used to. Our algorithm detects skin regions over the entire image, and then generates face candidate regions using our skin segmentation algorithm For each face candidate, we implement the procedure of region merging for divided regions in order to make a region using adjacency between homogeneous regions. We utilize various different searching window sizes to detect different size faces and a face detection classifier based on a back-propagation algorithm in order to verify whether the searching window contains a face or not.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1901-1907
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• 2010

A hydraulic cylinder is a primary component of an excavator and is used for activating attachments such as boom, arm, and bucket. Generally, the cylinder is prone to structural problems such as buckling and fatigue failure caused by cyclic high pressure. Therefore, the safety margin for fatigue, yield, and buckling during the design lifetime should be evaluated at the durability-design stage. The durability design includes basic and detailed stages. In the basic design, the principal dimensions of the rod and tube are determined by considering the working force, speed, and range with respect to yield and buckling. In the detailed design, the dimensions of the rod notch, welds, tube end, gland, orifice, and cushion ring are determined by considering the fatigue safety. We present and discuss the overall procedure for durability design and the related analysis techniques.

• Journal of Internet Computing and Services
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• v.7 no.5
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• pp.135-145
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• 2006

This paper presents a novel approach to real-time recognition of 3D environment and objects for intelligent robots. First. we establish the three fundamental principles that humans use for recognizing and interacting with the environment. These principles have led to the development of an integrated approach to real-time 3D recognition and modeling, as follows: 1) It starts with a rapid but approximate characterization of the geometric configuration of workspace by identifying global plane features. 2) It quickly recognizes known objects in environment and replaces them by their models in database based on 3D registration. 3) It models the geometric details on the fly adaptively to the need of the given task based on a multi-resolution octree representation. SIFT features with their 3D position data, referred to here as stereo-sis SIFT, are used extensively, together with point clouds, for fast extraction of global plane features, for fast recognition of objects, for fast registration of scenes, as well as for overcoming incomplete and noisy nature of point clouds. The experimental results show the feasibility of real-time and behavior-oriented 3D modeling of workspace for robotic manipulative tasks.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.388-394
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• 2003

To handle the high level radioactive materials such a spent fuel, the master-slave manipulators (MSM) are widely used as a remote handling device in nuclear facilities such as the hot cell with sealed and shielded space. In this paper, the Digital Mockup which simulates the remote operation of the Advanced Conditioning Process(ACP) is developed. Also, the workspace and the motion of the slave manipulator, as well as, the remote operation task should be analyzed. The process equipment of ACP and Maintenance/Handling Device are drawn in 3D CAD models using IGRIP. Modeling device of manipulator is assigned with various mobile attributes such as a relative position, kinematics constraints, and a range of mobility, The 3D graphic simulator using the external input device of space ball displays the movement of manipulator. To connect the external input device to the graphic simulator, the interface program of external input device with 6 DOF is deigned using the Low Level Tele-operation Interface(LLTI). The experimental result shows that the developed simulation system gives much-improved human interface characteristics and shows satisfactory response characteristics in terms of synchronization speed. This should be useful for the development of work's education system in the virtual environment.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.439-446
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• 2019

Poststroke depression can have a secondary effect on social cognition, and this can lead to behavioral problems. The purpose of this study was to verify the effects of a Cognitive Stimulation Circulative Program(CSCP) based on occupational therapy. The participants of this study were 12 stroke patients. The CSCP was organized in such a way to promote the cognitive process. This program were carried out as a circuit program(16 sessions). As a result of this study, the depression scale of the subjects had statistically significant benefit(p<.05). Also, the evaluation results verified partial improvement in quality of life, and the relationship change scale which was used to evaluate role of physical and social cognitive function ability had statistically significant benefit(p<.05). The above results of this study verified that the CSCP was an efficient intervention program that reduces the depression of stroke patients and improve their social cognitive function ability, thus enhancing the quality of life.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.111-116
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• 2019

Recently, GPU expands application domains from graphic processing to various kinds of parallel workloads. However, current GPU systems focus on the maximization of each workload's parallelism through simplified control rather than considering various workload characteristics. This paper classifies the resource usage characteristics of GPU workloads into computing-bound, memory-bound, and dependency-latency-bound, and quantifies the fine-grained bottleneck for efficient workload allocation. For example, we identify the exact bottleneck resources such as single function unit, double function unit, or special function unit even for the same computing-bound workloads. Our analysis implies that workloads can be allocated together if fine-grained bottleneck resources are different even for the same computing-bound workloads, which can eventually contribute to efficient workload allocation in GPU.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.507-514
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• 2022

Mobile manipulators are getting lime light in the field of home automation due to their mobility and manipulation capabilities. In this paper, we developed a small size manipulator system that can be mounted on a mobile robot as a preliminary study to develop a mobile manipulator. The developed manipulator has four degree-of-freedom. At the end-effector of manipulator, there are a camera and a gripper to recognize and manipulate the object. One of four degree-of-freedom is linear motion in vertical direction for better interaction with human hands which are located higher than the mobile manipulator. The developed manipulator was designed to dispose the four actuators close to the base of the manipulator to reduce rotational inertia of the manipulator, which improves stability of manipulation and reduces the risk of rollover. The developed manipulator repeatedly performed a pick and place task and successfully manipulate the object within the workspace of manipulator.