• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.961-968
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• 2015

As BIM has been increasingly applied to building project recently, its application to civil engineering project is also on the rise. As construction structures have been expanded and complicated in a size and type, the information for handling maintenance process has also increased. Thus, to actively utilize the BIM information created at the design stage, this study has been carried out to establish a maintenance system using a marker-less based augmented reality method, by presenting a maintenance system for the construction structures using augmented reality. A SURF algorithm is used to link the 3D objects in the design and construction phases to the maintenance phase. The presented method in this study can increase the utilization of 3D information created at the design stage, by offering an augmented reality technology at the maintenance stage. The method could also improve the efficiency of visual inspection on construction structures by augmenting 3D model of a bridge structure.

• Journal of the Semiconductor & Display Technology
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• v.7 no.4
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• pp.23-28
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• 2008

A high speed automated pitch variation unit (HAPU) related to semiconductor category sorting movement of the test handler system was developed. In the design process, 'DMADOV' step of 6-Sigma method has been applied. The design result for the desirable pitch variation was a 3:1 reduction rack-pinion and a linkage which are operated by servomotors. The realization and reliability of the mechanism was obtained at the design stage by FEM analysis, and by robust design using Taguchi orthogonal array against weight and deformation. Finally, the validity of the high speed variation mechanism was confirmed via inspection using a high speed camera while performing pitch variation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.930-933
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• 2005

Non-destructive inspection techniques using laser have been breading their application areas as well as growing their measurement skills together with the rapid development of circumferential technology like fiber optics. computer and image processing The ESPI technique is already on the stage of on-line testing with commercial products in developed country nations. Especially, this technique is expected to be applied to the nuclear industry, automobile and aerospace because it is proper for the vibration measurement and it can be applied to objects of a high temperature. This paper describes the use of the ESPI system for measuring vibration patterns on the reflecting objects. Using this system, high-quality Jo fringes for identifying mode shapes are displayed. A bias vibration is introduced into the reference beam to shift the Jo fringes so that fringe shift algorithms can be used to determine vibration amplitude. Using this method. amplitude fields for vibrating objects were obtained directly from the time-average interferometer recorded by the ESPI system.

• Journal of IKEEE
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• v.22 no.2
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• pp.242-249
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• 2018

In this paper, we identify the code vulnerabilities that can be automatically detected through Visual Studio (VS) compiler and code analyzer based on a secure coding rule set which is optimized for development of battlefield information system. Then we describe a weak point item that can be dealt with at the implementation stage without depending on the understanding or ability of the individual programmer's secure coding through the implementation of the secure coding library. Using VS compiler and the code analyzer, the developers can detect only about 38% of security weaknesses. But with the help of the proposed secure coding library, about 48% of security weaknesses can be detected and prevented in the proactive diagnosis in the development stage.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.3
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• pp.163-171
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• 1998

Near/far field length and directivity of transducers were investigated for the improvement and evaluation of the detectability of flaws in a disc. The reference block is fabricated for the disc of stage 6 in Yonggwang unit 1. The near/far field and directivity of an ultrasonic transducer with the center frequency of 5MHz were calculated for the inspection of the disc. These values showed good agreements with the experimental results. In the system composed of a wedge and a disc, those are evaluated theoretically and experimentally for the specimen with the artificial flaws of the size 2mm and 4mm and an ultrasonic transducer with the center frequency 5MHz and diameter 0.5inch. The detectability of keyway-flaw and detectable region for inspection were evaluated by using both tangential $45^{\circ}$ and $90^{\circ}$ transducers located at the distance of 53mm and 75mm from the disc hub, respectively.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.277-280
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• 2006

Most real world design evaluation and risk-based decision support combine quantitative and qualitative (linguistic) variables. Decision-making based on conventional mathematics that combines qualitative and quantitative concepts always exhibit difficulty in modelling actual problems. The successful selection process for choosing a design/procurement proposal is based on a high degree of technical integrity, safety levels and low costs in construction, corrective measures, maintenance, operation, inspection and preventive measures. However, the objectives of maximising the degree of technical performance, maximising the safety levels and minimising the costs incurred are usually in conflict, and the evaluation of the technical performance, safety and costs is always associated with uncertainties, especially for a novel system at the initial concept design stage. In this paper, a design-decision support framework using a composite structure methodology grounded in approximate reasoning approach and evidential reasoning method is suggested for design evaluation of machinery space of a ship engine room at the initial stages. It is a Multiple Attribute Decision-Making (MADM) or Multiple Criteria Decision Making (MCDM) framework, which provides a juxtaposition of cost, safety and technical performance of a system during evaluation to assist decision makers in selecting the winning design/procurement proposal that best satisfies the requirement in hand. An illustrative example is used to demonstrate the application of the proposed framework.

• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1083-1095
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• 2016

The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodiumshowed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.457-461
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• 2007

Laser slide marking systems are being considered by the staffs of clinical laboratories in hospitals as the main potential substituent for the conventional manual processes of the laboratory works. Many of the processes in domestic hospitals such as operations of test equipments in clinical laboratories and physical distributions in hospitals are being computerized due to the recent development of information technologies. The clinical laboratories in charge of inspection processes are putting their efforts on the computerization and automation of the test equipments, which increases the demand for the usage of laser marking slide systems which is the main component of the inspection works. The domestic market size of the laser slide marking systems is expected to be 250 million won in 2008, which is believed to increase to 1.75 billion won in 2012. The laser slide marking system was first introduced to domestic hospitals in 2005. It's product life cycle is currently on the early stage, and it is believed to have a very high growth potential in the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.144-150
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• 2020

This study examined the current status of ATE in the development stage of the domestic guided weapons field, including the re-establishment of automatic test equipment (ATE), and attempted to develop methods to verify the validity of ATE in the defense sector. This study includes methods for confirming the repeatability and reproducibility of newly manufactured or replaced ATE. An error injection test is required for validation in the development phase. And pre-inspection steps are required for validation. When developing ATE, the use of an international standard testing script language ensures efficient validation and SW reliability. This ensures interoperability between the main and test equipment, and the tester can secure a test system platform that supports standardized testing methods, which is considered to be effective in validating specific ATE for each weapon system.

• Wind and Structures
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• v.16 no.2
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• pp.157-178
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• 2013

Output-only modal parameter identification is based on the assumption that external forces on a linear structure are white noise. However, harmonic excitations are also often present in real structural vibrations. In particular, it has been realized that the use of forced acceleration responses without knowledge of external forces can pose a problem in the modal parameter identification, because an external force is imparted to its impulse acceleration response function. This paper provides a three-stage identification procedure as a solution to the problem of harmonic and white noise excitations in the acceleration responses of a linear dynamic system. This procedure combines the uses of the mode indicator function, the complex mode indication function, the enhanced frequency response function, an iterative rational fraction polynomial method and mode shape inspection for the correlation-related functions of the force-embedded acceleration responses. The procedure is verified via numerical simulation of a five-floor shear building and a two-dimensional frame and also applied to ambient vibration data of a large-span roof structure. Results show that the modal parameters of these dynamic systems can be satisfactorily identified under the requirement of wide separation between vibration modes and harmonic excitations.