• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.288-294
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• 2009

The purpose of this study is manufacturing of monolithic housing for modularization of steering gear. Monolithic housing is difficult to weld with only rotation and linear motion. It is for this reason that housing of joining parts have a slope of 76.3 degrees. For this reason, welding trajectory was measured by the cooperative controled robot system, and then allowing for measured results, we developed the dedicated system. The developed system can be welded by using only 3 axises in contrast with robot system using 8 axises in housing welding. In addition, we applied CMT and laser welding device to dedicated system and as a result of experiment, sound bead and excellent roundness could be obtained.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.93-96
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• 2003

Korea Multi-Purpose SATellite (KOMPSAT) uses software-controlled unregulated bus system In which the main bus is directly connected to a battery and the duty-ratio for PWM switch is generated by the on-board satellite software algorithm. In this paper, we propose a new power-stage circuit that can be available for modularization of a solar array regulator(SAR) which is used in the KOMPSAT. The operations at each mode and current sharing characteristics of the power-stage are analyzed and verified by simulation and experiments on a prototype converter.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.38-47
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• 2014

This paper describes the application of discrete event systems theory to the design of an automated laboratory system. Current automated laboratory systems typically consist of several interacting processes that must be carefully sequenced to avoid any possible process conflicts. Discrete Event Systems (DES) theory and Supervisory Control Theory (SCT) can be applied together as effective methods of modeling the system dynamics and designing supervisory controllers to precisely sequence the many processes that such systems might involve. Classical approaches to supervisory controller design tend to result in complex controller structures that are difficult to implement, maintain, and upgrade. In this paper, a new approach to designing supervisory controllers for automated laboratory systems is introduced. This new approach uses a modular controller structure that is easier to implement, maintain, and upgrade, and deals with "state explosion" issues in a novel and efficient way.

• 한국경영정보학회:학술대회논문집
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• 2008.06a
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• pp.232-237
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• 2008

Korea is one of the most advanced countries in terms of nation-wide readiness for conducting complex trade processes in an electronic way. Since various trade processes are well-known for their complexity and cost as well as time consuming characteristics due to required collaborations with involving parties, automation and efficiency are always the main concern of trade-related practitioners. Using information technology can be a possible solution to this problem and Korea has developed the national e-trade infrastructure called "u-Trade Hub." In this paper, we propose the framework to enhance the national integrated e-trade system called "u-Trade Hub," which is ready to be released for commercial use in near future. We propose the framework to upgrade u-Trade Hub in four directions: (1) opening, (2) strengthening community feature, (3) modularization, (4) seeking profitability. In this paper, we study and compare national e-trade environment of other countries such as Singapore and Japan. Then, we analyze and design the enhanced e-trade infrastructure based on Web 2.0.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2393-2405
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• 2015

This paper considers a decentralized multiple faults detection and isolation (FDI) scheme for reconfigurable manipulators. Inspired by their modularization property, a global sliding mode (GSM) based stable adaptive fuzzy decentralized controller is investigated for the system in fault free, while for the system suffering from multiple faults (actuator fault and sensor fault), the decentralized sliding mode observer (DSMO) is employed to detect their occurrence. Hereafter, the time and location of faults can be determined by a fault isolation scheme via a bank of DSMOs. Finally, the effectiveness of the proposed schemes in controlling, detecting and isolating faults is illustrated by the simulations of two 3-DOF reconfigurable manipulators with different configurations successfully.

• Journal of Korea Multimedia Society
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• v.22 no.11
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• pp.1259-1268
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• 2019

Recently, Communication media have been developed for the underwater communication in underwater environments where the underwater communication failures occur frequently. Although the underwater communication by one medium is not stable due to the influence of the underwater environment, the use of various communication media can complement each other and so this makes the underwater communication more stable. For this reason, this paper proposes approaches to the design and implementation of integrated MAC for complementing individual unstable underwater communications. In addition this paper presents the comparison and analysis on each of the proposed approaches so to be able to provide guidelines to designers and implementers of integrated MAC.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.535-537
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• 2008

This paper proposes a modularized two-stage charge equalization converter for a series-connected lithium-ion battery string. In this paper, the series-connected battery sting is modularized into M modules, and each module has K cells in series. With this modularization, low voltage stress on the electronic devices can be achieved. A two-stage dc-dc converter with cell selection switches is employed. The first stage dc-dc converter steps down the high bus voltage to about 10 V. The second stage dc-dc converter integrated with selection switches equalizes the cell voltages. A prototype for 88 lithium-ion battery cells is optimally designed and implemented. Experimental results verify that the proposed equalization method has good cell balancing performance showing low voltage stress, small size, and low cost.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.201-211
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• 1998

The fundamental object of work measurement is to precisely establish the time standards, which are the indices of labor productivity. This study discussed the development of robot work measurement method that could establish the time standard effectively. In manufacturing industries the various robot tasks are generally classified and standardized by the unit motions. The Robot Modularization of the Unit Motion (ROMUM) was realized by the module of two steps GET and PUT unit motions. This method reduced time and effort of analysis, and could be done with ease. Therefore, ROMUM will increase the convenience of use for the unskilled worker and decrease the time required, cost and errors. And, it will contribute to reduce the unnecessary motion by robot motion analysis.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.9
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• pp.816-824
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• 2004

In this paper, the framework for accelerating the development of personal robots is presented, which includes the technology such as modularization with its own processing and standardization open to the other developers. Its basic elements are Module-D(Module of DRP I) characterized functionally and VM-D(Virtual Machine of DRP I) arbitrating Module-Ds. They can suggest the effective ways for integrating various robotic components and interfacing among them. Based on this framework, we developed a fully modularized personal robot called DRP I(Dynamically Reconfigurable Personal robot). Its hardware components are easily attached to and detached from the whole system. In addition, each software of the components is functionally distributed. For the materialization of the proposed idea, we mainly focus on the dynamically reconfigurable feature of DRP I.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.589-594
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• 1997

We have already presented the constraint satisfaction algorithm which could solve the losed loop problem in constraint network by using local constraint propagation, variable elimination and constraint modularization. With this algorithm, we have implemented a knowledge-based system (intelligent CAD) for supporting machine design interactively. In this paper, we present newer constraint satisfaction algorithm which can solve inequalities or under-constrained problems in constraint network, interactively and efficiently. This algorithm is a hybrid type of using both declarative description (constraint represention) and optimization algorithm (Simulated Annealing), simultaneously. The under-constrained problems are represented by constraint networks and satisfied completely with this algorithm. The usefulness of our algorithm will be illustrated by the application to a gear design.