• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.7
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• pp.2205-2212
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• 1996

In order to move the body of a walking robot translationally, and step over the obstacles, the walking robot must have at least 3 degrees of freedom for each leg. Therefore each leg of the general walking robots can be composed of 3-link system with 3 revolute joints. In this paper, the colsed form of inverse kinimatic solutions is shown for this general 3R linkage. Moreover, in order to have efficient walking volume in rough terrain, the workspace of each log is obtained considering the twist angles and the offsets in D-H parameters. When we design a walking robot, the information of the walking volume is needed for planning desired trajectories of the feet effectively. Appropriate knowledge of the walking volume can also be used to maximize linear or angular velocity of minimize power of stress. However, since it is impossible to obrain the information of walking volume in 3-D space directly from the kinematic equations, the walking volume can be searched through the edge detection algorithm using the triangle tracer with closed from inverse kinematic solutions. In this study, we present the closed form inverse kinematic solutions for 3R linkage model, and the walking volume of 6 legged walking robot which is modeled after the darking bettle, Eleodes obscura sulcipennis, through the method of edge detection for an arbitrary 2 dimensional shape using triangle tracer.

• Journal of the Korean Society of Safety
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• v.29 no.5
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• pp.146-153
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• 2014

This study looks at the impact of psychological and physical factors of the working conditions on the health of workers depending on whether technology is used by such workers. The data used for the study is the third work environment survey. Out of 50,032 respondents, a total of 29,711 paid workers were used as analysis subjects. Although it was anticipated that the use of technology was a factor that hindered job autonomy and teamwork autonomy. However, the analysis results showed low levels of job autonomy and teamwork autonomy in the group that did not use technology. The study assumes a regression analysis model about work environment and work organizational practices of workspaces that have an impact on musculoskeletal complaints, stress symptoms and level of work satisfaction by controlling the social demographic variable that represents the level of individual sensitivity. As a result of the study, ergonomic risk had a significant effect on both groups that did or did not use technology with respect to stress symptoms, musculoskeletal complaints and level of work satisfaction. In particular, as workspace practices and work environment had an effect on the development of musculoskeletal complaints in the group that used machines, there is a need to improve such situation. The autonomous team work or level of job autonomy within the group that used technology may act as a risk factor to the health and welfare of workers. However, because it may also act as a buffer factor, there is a need for a change to reduce stress symptoms and increase the level of work satisfaction by improving autonomous team work and the level of job autonomy.

• Journal of Internet Computing and Services
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• v.5 no.4
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• pp.11-22
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• 2004

Works that improve the process and notify the improved process, the product and the change of tasks to all users are essential in achieving project. Existent project management tools support the definition and the change of project activities, and configuration management tools support version check, workspace management. build management. etc. It costs too much to buy each tool. as well as, it is burdensome to learn usage for various tools. Therefore the web-based integrated tool is proposed to manage the process and artifacts at a time in this paper. The proposed tool defines component based development process model. and achieves recording of process progression, processing the request of change, reporting the progression of each task, product registering and change, version recording, artifact or form search, etc. using ebXML. Furthermore, the stakeholders get the systematic management and standardization by sharing information that are necessary in process achievement and configuration management in distributed environment using the integrated management tool.

• The KIPS Transactions:PartB
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• v.12B no.1 s.97
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• pp.1-8
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• 2005

The importance of software is getting high in development of the digital device (digital camcoder, digital camera, mp3 player, ....). And because the sire of software becomes larger and complicated, the necessity of software configuration management (to solves a software crisis) is increased. The general software configuration management system shows lack of the property and features of software development environment for image processing algorithm due to its wide range to be covered. Image processing algorithm development environment has properties like repetitive analysis and simulation using visual programming environment where, beside support of elementary development functions. component(or library) can be combined and tested interactively. Moreover, the method to look fast and effectively for component having similar function is required. In this paper, we present the system which supports the software configuration management method for a simulation tool and the property in the visual programming environment. And we relate our system to real simulation tool so as to check its ability as the software configuration management system for image processing algorithm development environment.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.296-301
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• 2005

This paper describes the kinematics, dynamics and control of a 6-DOF shaking table with a bell crank structure, which converts the direction of reciprocating movements. In this shaking table, the bell crank mechanism is used to reduce the amount of space needed to install the shaking table and create horizontal displacement of the platform. In kinematics, joint design is performed using $Gr{\ddot{u}}bler's$ formula. The inverse kinematics of the shaking table is discussed. The derivation of the Jacobian matrix is presented to evaluate singularity conditions. Considering the maximum stroke of the hydraulic actuator, collision between links and singularity, workspace is computed. In dynamics, computations are based on the Newton-Euler formulation. To derive parallel algorithms, each of the contact forces is decomposed into one acting in the direction of the leg and the other acting in the plane orthogonal to the direction of the leg. Applying the Newton-Euler approach, the solution of inverse dynamics is almost completely parallel. Only one of the steps-the application of the Newton-Euler equations to the platform-must be performed on one single processor. Finally, the efficient control scheme is proposed for the tracking control of the motion platform.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2042-2047
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• 2005

Many service robots which is interacting with human at home and in buildings have been developed. Few of them are shown in of the United States and of Japan. These robots are supposed to have a powerful indoor navigation performance in places where human beings live and work. The overall capability of service robots to move around in this environment is called environment correspondence, in which localization problem to find the accurate position and orientation is the most critical problem. While users set up a proper or a best environment for industrial robots, but for services robots at home and in buildings, it is very difficult to change the environment for robots. The expanded workspace due to mobility is difficult to be covered by means of those used for industrial robots because the cost increases and human beings do not want their environment to be changed for robots. This fact has made many researchers study efficient and effective environment correspondence problems. Among these problems, localization is the most difficult. Goal of localization study includes (1) Accurate detection of position and orientation (2) Minimum cost of the additional devices (3) Minimum change of human environment. In this study, as a solution of the above, we propose "Artificial Stars" which are attached on room ceiling as landmarks. In addition, we solve an adoption problem raised when a robot is delivered to a customer site and before it can perform its full navigation capability. We call this as "Initialization Problem" of service robots. We solve the initialization problem for both cases of environment with the map and without map. The proposed system is experimented and has shown how well it handles the initialization problem.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.4
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• pp.320-328
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• 2007

This paper presents a stiffness modeling of a low-DOF parallel robot, which takes into account of elastic deformations of joints and links, A low-DOF parallel robot is defined as a spatial parallel robot which has less than six degrees of freedom. Differently from serial chains in a full 6-DOF parallel robot, some of those in a low-DOF parallel robot may be subject to constraint forces as well as actuation forces. The reaction forces due to actuations and constraints in each serial chain can be determined by making use of the theory of reciprocal screws. It is shown that the stiffness of an F-DOF parallel robot can be modeled such that the moving platform is supported by 6 springs related to the reciprocal screws of actuations (F) and constraints (6-F). A general $6{\times}6$ stiffness matrix is derived, which is the sum of the stiffness matrices of actuations and constraints, The compliance of each spring can be precisely determined by modeling the compliance of joints and links in a serial chain as follows; a link is modeled as an Euler beam and the compliance matrix of rotational or prismatic joint is modeled as a $6{\times}6$ diagonal matrix, where one diagonal element about the rotation axis or along the sliding direction is infinite. By summing joint and link compliance matrices with respect to a reference frame and applying unit reciprocal screw to the resulting compliance matrix of a serial chain, the compliance of a spring is determined by the resulting infinitesimal displacement. In order to illustrate this methodology, the stiffness of a Tricept parallel robot has been analyzed. Finally, a numerical example of the optimal design to maximize stiffness in a specified box-shape workspace is presented.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.2
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• pp.137-147
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• 2003

The fuzzy control and implementation of a new three-dimensional(3-D) inverted pendulum system are addressed. In comparison with conventional 1-D and 2-D systems, the 3-D inverted pendulum system is a proper benchmark system to simulate human's control action which includes the up and down motion to stabilize an inverted pendulum. To investigate the characteristics of the 3-D inverted pendulum system and to design of a fuzzy controller, we derive dynamic equations of the mechanism including a 3-axis cartesian robot and an inverted pendulum. We propose a design method of a fuzzy controller of the yaw and pitch angles of an inverted pendulum. In the design, the redundant degree-of-freedom(DOF) of the robot and the constrained workspace are taken into account. The performance of the proposed system is proved by experimental results using a developed PC-based Multi-Motion Control(MMC) board.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.1
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• pp.233-241
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• 2010

CoSlide is a collaborative system, extending the Jakarta Slide WebDAV server. The CoSlide server provides group workspaces for collaborators. CoSpace is a client which supports various collaborative authoring activities on the CoSlide server through the WebDAV protocol. CoSpace provides graphic user interfaces to support effective interaction among the collaborators, managing the shared resources for them. However, during collaboration, simultaneous modifications on the content of shared resources might cause conflicts among the content of the revisions made by the collaborators, leading to serious problems on project progress. In this paper, we describe an extension of the CoSpace client to solve the problem. The extended CoSpace client supports the remote version management facility through which the collaborators can manage the versions of the associated server resources in the distance. Also, to identify the changes of the text files such as program source codes, the extended client provides the facility for comparing two versions and displaying the differences in a visual manner. In addition, it provides the version management of a whole workspace and the removal of all the unnecessary versions of the designated resources.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.11-24
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• 2012

Recently, BIM (Building Information Modeling) technique is being considered as a critical delivery condition for the public projects according to the increase of best practices by practical application of BIM. However, since existing BIM studies are focused on the design and construction phases, those results are not considering the life cycle of a construction project. Therefore, this study suggests an integrated BIM operation process that enables an application of BIM for each phase of a construction project from planning to maintenance phases and develops an integrated BIM system based on the suggested methodologies. This study developed basic BIM functions and its application process by analyzing information systems in each project phase for a bridge construction project. Besides, this study performed case study and survey analysis for construction managers to verify a practical applicability of the developed system. Therefore, it is expected that the integrated BIM system is going to be utilized as a 3D-based integrated information management system considering life cycle of construction projects.