• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.9
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• pp.97-103
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• 2006

This paper described the design and performance evaluation of fiber optic gyro using digital closed-loop processing. For the feedback to null the gyro input rate, digital serrodyne modulation was employed, and for scale factor stabilization, the control circuits of modulation amplitude and optical power are implemented. Performance tests show that prototype fiber optic gyro has bias stability of 0.34 deg/hr, scale factor non-lineality of about 100ppm, and maximum measurement range of ${\pm}500$ deg/sec.

• Journal of Korea Multimedia Society
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• v.14 no.5
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• pp.622-631
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• 2011

Corners play an important role in describing object features for pattern recognition and identification. This paper proposed a fast and adaptive corner detector in both coarse and fine scale, followed by the framework of the curvature scale space (CSS). An adaptive curvature threshold and evaluating of angles of corner candidates are added to original CSS to remove round corners and false corners in the detecting process. The efficiency of proposed method is compared to other popular detectors in both accuracy criteria, stability and time consuming. Results illustrate that the proposed method performs extremely surpass in both areas.

• Journal of Korean Foot and Ankle Society
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• v.11 no.2
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• pp.192-197
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• 2007

Purpose: The purpose of this study is to present our clinical results after surgical treatment in tarsal tunnel syndrome due to space occupying lesions. Material and Methods: We performed surgical decompression for tarsal tunnel syndrome in 20 patients from July 2004 to February 2007. Out of them, thirteen cases were due to space occupying lesions around the tarsal tunnel. The average age at operation was 51.3 years old and the duration from symptom onset to surgery was 16.5 months. The operation included removal of space occupying lesions and tarsal tunnel decompression. The clinical parameters were pain visual analogue scale (VAS), AOFAS scale, and subjective satisfaction. Results: The ganglion cysts were the most frequent causes (ten cases) and synovial chondromatosis in 1 case, neurofibroma in 1 case, talocalcaneal coalition in 1 case. The average follow-up duration was 14.5 months. The AOFAS scale showed significant improvement from 77.8 to 92.7. The average VAS decreased from 6.4 to 2.2. Seven out of thirteen patients were satisfied with the results. The excellent results were shown in six patients, the good results in one patient, the fair result in three patients and the unsatisfactory results in three patients. Conclusion: Favorable results could be obtained in patients with known etiology. But not all cases with surgical decompression of space occupying lesions showed satisfactory results. We assume that the clinical results were related to the multiple factors, not only well performed surgery but also age, size lesions and duration of symptoms, ect.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.445-452
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• 2014

This paper discusses the multifrontal direct solution method with out of core storage for large scale structural analysis in a limited computing resource. Large scale structural analysis requires huge amount of memory space and computation, so out of core solution method is needed in limited computing resource. In this research, out of core multifrontal solution algorithm which utilize the small size of physical memory and minimize the amount of access of low speed out of core storage is introduced. Three ideas, which are stack space in lower trianglar part of square factorization matrix, inverse stack data structure and selective data caching and recovery by data block size, are proposed.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.527-534
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• 2005

Rotation and scale variations make it difficult to solve the problem of shape description and recognition because these variations change the location of points composing the shape. However, some geometric Invariant points and the relations among them are not changed by these variations. Therefore, if points in image space depicted with the r-y coordinates system can be transformed into a new coordinates system that are invariant to rotation and scale, the problem of shape description and recognition becomes easier. This paper presents a shape description method via transformation from the image space into the invariant feature space having two axes: representing relative distance from a centroid and contour segment curvature(CSC). The relative distance describes how far a point departs from the centroid, and the CSC represents the degree of fluctuation in a contour segment. After transformation, mesh features were used to describe the shape mapped onto the feature space. Experimental results show that the proposed method is robust to rotation and scale variations.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.159-162
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• 2012

Combustion in a narrow space has been interested as a model of meso-scale combustors (or micro-combustors). Premixed flames have been used to overcome flame quenching in a narrow space and non-premixed flames have been used to improve flame stabilization. In this study, overall characteristics of premixed flame and non-premixed flame in narrow combustion spaces were reviewed. Various effects such as the flow velocity distribution, thermal interaction, enhanced mass diffusion were discussed and an eventual structure of the flame at the extinction limit was introduced.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2008.05a
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• pp.169-172
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• 2008

Nationally large scale of festival is common in these days, the space for a space be party-able such as an event space or an performance space is more necessary. Accordingly applied the balloon art which utilizes a balloon material, to interior and exterior space design can maximize space design for the nonce and renovate space with flexible materials which is the balloon art. This research provides the balloon art is able to be a new research field in interior and exterior design study with three types of way to apply the balloon art to interior and exterior design. First type is an applied interior design with the balloon art, second type is an applied party space design with the balloon art, and third type is practical examples of applied interior design with mixing materials of the balloon and another materials.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.74.2-74.2
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• 2010

We investigate driven magnetohydrodynamic (MHD) turbulence by including the effects of expansion and collapse of background medium. The main goal is to quantify the evolution and saturation of strength and characteristic lengths of magnetic fields in expanding and collapsing media. Our findings are as follows. First, with expansion and collapse of background medium, the magnetic energy density per comoving volume does not saturate; either it keeps decreasing or increasing with time. The magnetic energy density relative to the kinetic energy density strongly depends on the expanding or collapsing rate. Second, at scales close to the energy injection (or driving) scale, the slope of magnetic field power spectrum shallows with expansion but steepens with collapse. Third, various characteristic lengths, relative to the energy injection scale, decrease with expansion but increase with collapse. We discuss the astrophysical implications of our findings.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.57.2-57.2
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• 2011

To study the formation and evolution of sub-galactic scale structures, we have added SPH (Smoothed Particle Hydrodynamics) method into an existing cosmological PMTree code, GOTPM. To follow the evolution of gas particles, we consider heating/cooling processes, star formation, and energy & metal feedback by supernova explosion. We have performed various tests for the new code and found that the results reproduce observed quantities or follow the known analytic solutions. We present a test simulation of isolated disk galaxy with a focus on whether the star formation reproduces the observed features.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.107-110
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• 2008

This study is aimed to develop fundamental technology on the smoke control method by simulation model and scale model simulation technique in underground space. Thereby, this research aimed to establish design elements and technologies required for smoke control system that is suitable to underground spaces of the high-rise residential-commercial and office buildings in order to minimize the loss of lives and property damage in case of fire.