• Proceedings of the KSME Conference
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• 2003.04a
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• pp.857-862
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• 2003

In this paper, we concern for development of precise measuement system for civil structure by using one chip microprocessor based on communication system. The datalogger is developed by using 80C196KC microprocessor. It has RF communication modul and data acquisition function for several kinds of sensors such as load cell, tilt-meter, strain gauge, tension meter, themocouple and so on. The data is acquisited by datalogger is sent to a main server which is located at central monitoring office. The server has a function suppervising several data points located at civil structures, it analyzes the data and shows the data graphically. The effectiveness of the developed system is proven through experimental results by an application for the bridge of Nakdong river edge in Busan, Korea.

• Transactions of Materials Processing
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• v.24 no.6
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• pp.400-404
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• 2015

For mass production of stamped parts, which require complicated in-press operations, it is always advisable to use a progressive die set. It is difficult to choose a progressive die set if the stamped parts need to be deep drawn and especially if they are unsymmetrical. Because unsymmetrical deep drawing parts are very sensitive to the effect of weight during moving to the next step, they are hard to exactly locate on the die face. An automotive seat side cushion panel is about 80mm high, unsymmetrical and its low edge needs hemming, so it is hard to produce even using a progressive die set. In the current paper a progressive stamping for seat side cushion panel was examined. Five strip bridges were considered to be strong enough to move to the next die as predicted by the CAE analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1635-1637
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• 2010

Simulation tools help creating a low cost and efficient development of embedded system. SID is an open source simulator software that consists library of components for modelling hardware and software components. A component can be written in C/C++ and Tcl/Tk. Currently, the SID simulation toolkit only provides support for C++ and Tcl/Tk. Tcl/Tk is used to write GUI-based components. However, we have observed that Tcl/Tk components cause slow simulation response because Tcl/Tk is a script language. It is not proper for developing the cutting-edge products with rich graphics. Therefore, in this paper, we suggest Java to a new language for GUI components in SID by developing a bridge module for SID to interworking with Java components.

• Journal of Power Electronics
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• v.2 no.3
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• pp.181-188
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• 2002

The utility interfaced sinewave modulation Inverter for the solar photovoltaic power conditioner with a high frequency transformer is presented for residential applications. As compared with the conventional full-bridge hard switching slnewave PWM inverter with a high frequency link, the simplest single-ended edge-resonant soft switching sinewave inverter with a sinewave duty cycle pulse control scheme is implemented, resulting in size and weight reduction, low cost and high efficiency This paper presents a prototype system of the sinewave zero voltage soft switching sinewave inverter for solar power conditioner, along with its operating principle and unique features. In addition to these, this paper discusses a control implementation to deliver high quality output current. Major design of each component and the power loss analysis under actual power processing is also discussed and evaluated from an experimental point of view A newly developed utility-connected sinewave power conditioning circuit which achieves 92.5% efficiency under 4kW output is demonstrated.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2514-2518
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• 2003

The KAERI Spent Fuel Remote Technology Development (SFRTD) Department is developing the remote maintenance and repair equipment, which is used in a hot cell in an intense radiation field, as part of a project to develop the Advanced spent fuel Conditioning Process (ACP). Although several mechanical master-slave manipulators (MSMs) is mounted on the hot cell wall, their reach will be limited and cannot access areas for all the ACP equipment maintenance. A Bridge Transported ServoManipulator (BTSM) has been designed to overcome the limitation of access areas that is a drawback of MSMs for the ACP equipment maintenance. The BTSM system consists of four components: a transporter with telescoping tubeset, a slave manipulator, a master manipulator, and a remote control system. The BTSM system has been designed by Solid Edge that is a 3D computer-aided design (CAD) software, except for the remote control system. The master manipulator and the slave manipulator are kinematically similar in design, except for the handle and the tong, respectively. The manipulators have 6 degrees of freedom (DOF) plus the jaws motion. The transporter has traveling, traverse, and hoisting motion to position the slave manipulator.

• Steel and Composite Structures
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• v.28 no.3
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• pp.319-329
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• 2018

The field around additional cutout of the floor beam web in orthotropic bridge deck was subjected to high stress concentration, especially the weld toe between floor beam and U shaped rib and the free edge of the additional cutout. Based on different considerations, different geometrical parameters of additional cutout were proposed in European, American and Japanese specifications, and there remained remarkable differences among them. In this study, considering influence of out-of-plane deformation of floor beam web and U shaped rib, parameter analysis for additional cutout under typical load cases was performed by fine finite element method. The influence of additional cutout shape and height to the stress distribution around the additional cutout were investigated and analyzed. Meanwhile, the static and fatigue test on this structure details was carried out. The stress distribution was consistent with the finite element analysis results. The fatigue property for additional cutout height of 95mm was slightly better than that of 61.5 mm.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.205-213
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• 2008

The structure of PSC box girder with FRP strut has a form of supporting the cantilever part in the widened upper slab by modifying the existing PSC box girder efficiently, and it is able to build an economical and aesthetically pleasing bridge as it reduces the size of the lower structure by reducing the self-weight of the upper structure. In this research, loading test of PSC Box Girder using full-scale mock-up was conducted and FEM analysis was performed. By comparing results, structural safety of the FRP strut and the upper slab following application of the strut in the PSC Box Girder Bridge were evaluated.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.277-280
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• 2008

In this paper behavior of U-Channel Bridge (UCB) was studied, and a new analysis model was proposed. Most of the time, permanent and traffic load actions are directly transmitted to main beams located under the carriageway, one of the most distinctive features of UCB is that the edge beams that support the bridge are above the deck, in contrast with a conventional overpass system. In This study models used with the frame elements, the frame and plate elements, and the solid elements were constructed. Assuming that the results of solid models were similar to the real behavior of UCB, results of another models was compared. The results of the models used with the frame and plate elements were similar to the results of solid models, the model used with the frame and plate elements was proposed as an analysis model.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.3
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• pp.303-316
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• 1993

The purpose of this study was to analysis the stress distribution induced by three unit PFM bridges and various cantilever bridges replacing maxillary latersal incisor. The simplified two-dimensional photoelastic models used for this study was contructed in the folio- wing way. CR/R ratio was designed to be 1 : 1, 1 : 1.25 and 1 : 1.5. The pontics of cantilever bridge supported by maxillary canines consisted of wrap-around type, rest-extension type, and simple type. 3-unit PFM bridge was constructed with traditional method. 1kg vertical static load was applied on the center of the incisal edge of the pontic. The stress pattern was examined and recorded by photography. The results obtained were as follows ; 1. The magnitude of stress on the abutment root apex area of a traditional 3-unit bridge was the lowest. 2. The model of cantilevered pontic with a rest showed the relatively well distributed stress around the abutment tooth. The model with simple pontic generated the greatest stress concentration in the supporting structure of the abutment tooth. 3. As the height of bone level reduced, the rotational and vertical force increased around the abutment tooth. 4. The stress concentration of the 3-unit bridges occured on the root apex and stress concentration of the cantilever briage occured on the root apex and cervix area, 5. In the case of the cantilever bridge, stress concentrated distally on the root apex area of the abutment tooth and additional stress was observed mesially on the upper part of the root. Especially in the case of the simple pontic, was phenomenon was more apparent than the others. 6. Force applied to cantilevered pontic was transmitted to the adjacent central incisor through the contact surface. Stress was markedly observed on the mesial cervix area in the case of simple pontic and on the root apex area in the case of wrap-around type and rest-extension type.

• Smart Structures and Systems
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• v.15 no.1
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• pp.99-117
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• 2015

The Stonecutters Bridge (SCB) in Hong Kong is the third-longest cable-stayed bridge in the world with a main span stretching 1,018 m between two 298 m high single-leg tapering composite towers. A Wind and Structural Health Monitoring System (WASHMS) is being implemented on SCB by the Highways Department of The Hong Kong SAR Government, and the SCB-WASHMS is composed of more than 1,300 sensors in 15 types. In order to establish a linkage between structural health monitoring and maintenance management, a Structural Health Rating System (SHRS) with relevant rating tools and indices is devised. On the basis of a 3D space frame finite element model (FEM) of SCB and model updating, this paper presents the development of an SHR-oriented 3D multi-scale FEM for the purpose of load-resistance analysis and damage evaluation in structural element level, including modeling, refinement and validation of the multi-scale FEM. The refined 3D structural segments at deck and towers are established in critical segment positions corresponding to maximum cable forces. The components in the critical segment region are modeled as a full 3D FEM and fitted into the 3D space frame FEM. The boundary conditions between beam and shell elements are performed conforming to equivalent stiffness, effective mass and compatibility of deformation. The 3D multi-scale FEM is verified by the in-situ measured dynamic characteristics and static response. A good agreement between the FEM and measurement results indicates that the 3D multi-scale FEM is precise and efficient for WASHMS and SHRS of SCB. In addition, stress distribution and concentration of the critical segments in the 3D multi-scale FEM under temperature loads, static wind loads and equivalent seismic loads are investigated. Stress concentration elements under equivalent seismic loads exist in the anchor zone in steel/concrete beam and the anchor plate edge in steel anchor box of the towers.