• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.777-780
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• 2005

The bench of cut-slope is necessary to stabilizing. But it is possible to be a weak zone in slope. When a small scale failure is occurred in a bench, it influence a large scale failure of slope. So when it is found out any unstable factor, weathering of rock, a direction of joint in a bench, if the bench is reinforced suitably, the holly failure is prevented in cut-slope

• Journal of electromagnetic engineering and science
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• 제15권4호
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• pp.258-265
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• 2015

A de-embedding method for multiport networks, especially for coupled odd interconnection lines, is presented in this paper. This method does not require a conversion from S-parameters to T-parameters, which is widely used in the de-embedding technique of multiport networks based on cascaded simple two-port relations, whereas here, we apply an operation to the S-matrix to generate all the uncoupled and coupled coefficients. The derivation of the method is based on the relations of incident and reflected waves between the input of the entire network and the input of the intrinsic device under test (DUT). The characteristics of the intrinsic DUT are eventually achieved and expressed as a function of the S-parameters of the whole network, which are easily obtained. The derived coefficients constitute ABCD-parameters for a convenient implementation of the method into cascaded multiport networks. A validation was performed based on a spice-like circuit simulator, and this verified the proposed method for both uncoupled and coupled cases.

• Imaging Science in Dentistry
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• 제36권4호
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• pp.227-231
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• 2006

Leiomyosarcoma of the oral cavity is a very rare tumor that is associated with aggressive clinical behavior and low survival. In this paper, we report a case of leiomyosarcoma presenting with a gingival exophytic mass that rapidly grew, causing facial asymmetry within 16 days, in a 9-year-old boy. After an excisional biopsy, microscopy revealed a spindle cell neoplasm that, on immunohistochemistry analysis, demonstrated reactivity for SMA. This established the diagnosis of leiomyosarcoma; subsequently, a marginal mandibulectomy and supraomohyoid neck dissection were performed.

• 한국표면공학회지
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• 제55권4호
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• pp.187-195
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• 2022

WO₃ thin films were synthesized by electrodeposition, and their electrochromic properties were investigated. The application of static voltage produced WO₃ films with a smooth, compact surface morphology, and the film thickness linearly increased with the application time. The thicker film showed a strong color contrast but a slow color-switching speed. High-temperature heat treatment exceeding 300 ℃ induced a phase transformation from an amorphous to a monoclinic structure and resulted in degraded electrochromic performance. Furthermore, the optimized WO₃ thin films demonstrated their potential application as electrochromic boards for writing and erasing letters using a simple modified 3D printer in a rapid, accurate process

• 전기학회논문지
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• 제56권6호
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• pp.1105-1110
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• 2007

This paper describes an equivalent circuit modeling of 4-port connector system. A coupled transmission line was designed and fabricated, mimicking a 4-port connector system, and then S-parameters were measured using 4 port VNA (Vector Network Analyzer). The S-parameters from measurement and from Full-wave simulator coincided quite nice. By using these S parameters, an equivalent circuit parameters for a 4-port system was obtained. The time domain response from the equivalent circuit model matched to the signals, which was measured using TDR(Time Domain Reflectometry) meter. We were also convinced that there should be enough bandwidth to get a meaningful time domain result from Fourier inverse transformation of the S parameters. In addition, we applied the conversion algorithm to the 4-port connector system, which calculates the S-parameters of a 4 port system using the data from a 2-port VNA with the other ports open. Comparison of the two data, one from measurement and the other one from the conversion algorithm, was made in this manuscript.

• 한국분말재료학회지
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• 제22권5호
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• pp.309-314
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• 2015

Tungsten trioxide thin films are successfully synthesized by a sol-gel method using tungsten hexachloride as precursors. The structural, chemical, and optical properties of the prepared films are characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-Vis spectrophotometry. The electrochemical and electrochromic properties of the films before and after heat treatment are also investigated by cyclic voltammetry, chronoamperometry, and in situ transmittance measurement system. Compared to as-prepared films, heat-treated tungsten trioxide thin films exhibit a higher electrochemical reversibility of 0.81 and superior coloration efficiency of $65.7cm^2/C$, which implies that heat treatment at an appropriate temperature is a crucial process in a sol-gel method for having a better electrochromic performance.

• ETRI Journal
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• 제34권1호
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• pp.110-113
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• 2012

We propose a very-low-complexity lattice-reduction (LR) algorithm for multi-input multi-output detection in time-varying channels. The proposed scheme reduces the complexity by performing LR in a block-wise manner. The proposed scheme takes advantage of the temporal correlation of the channel matrices in a block and its impact on the lattice transformation matrices during the LR process. From this, the proposed scheme can skip a number of redundant LR processes for consecutive channel matrices and performs a single LR in a block. As the Doppler frequency decreases, the complexity reduction efficiency becomes more significant.

• 대한기계학회논문집A
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• 제28권3호
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• pp.296-303
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• 2004

Recently, the ultra light metal structure with periodic and three dimensional truss elements takes attention because of its multi-functionality and substantial heat resistance. However, the complicated fabrication process leading to high cost has been a major obstacle to wide applications. In this paper, a new idea to construct an ultra light structure with periodic, three dimensional truss using metal wires is presented. To prove the practical validity, a Kagome-like structure was fabricated from stamped wires and punched face sheets. It was assembled by soldering. Through three-point bending and compression tests, the strength was evaluated and compared with the theory.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권4호
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• pp.158-163
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• 2001

Magnetization losses of a Bi-2223 tape in magnetic fields parallel to the tape surface were measured by a room temperature cancellation and a cryogenic temperature cancellation. The results indicate that the same loss data are observed for both methods. The magnetization losses are hysteretic because the measured losses agree well with calculated ones based on a critical state model. In the full field penetration cases the magnetization losses increase with the frequency but in the partial field penetration cases the influence of the frequency is opposite.

• Imaging Science in Dentistry
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• 제36권4호
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• pp.207-209
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• 2006

Necrotizing sialometaplasia (NS) was defined by Abrams et al. in 1973 as a reactive necrotizing inflammatory process involving minor salivary glands of the hard palate. Before that recognition, many patients with this condition had been improperly treated because of its clinical and histologic resemblance to malignancy such as mucoepidermoid carcinoma and squamous cell carcinoma. We report two cases of necrotizing sialometaplasia. One case involved a 58-year-old male who had an ulcerative palatal lesion exposing underlying bone which has the typical features of the above mentioned condition. Another case involved a 59-year-old male who developed a necrotizing sialometaplasia in association with a dome-shaped palatal swelling which was proved as an adenoid cystic carcinoma after operation biopsy.