• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.63-68
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• 2017

To reduce the exposure dose in head CT, the use of low tube voltage is required. However, increasing noise may cause errors in the second data processing. In this study, we proposed a method to reduce noise by using low tube voltage. Experimental results show that the noise level is high at 100kVp and lowest at 140 kVp. The dose was lower at 100 kVp and higher at 140 kVp. As a result of applying the wavelet according to the threshold value, the noise value in the wavelet Th30 decreased to 4.51. Using the parameter condition(100 kVp, rotation time 0.5 sec, dose: 40.64 mGy) and the wavelet Th 30, the dose reduction of 65.3% was possible. We believe that applying the proposed method to head CT images will help to patient safety and interpret accurate information.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.261-264
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• 2014

In this study, $Gd_2O_2S:Tb^{3+}$ was used as the component of the intensifying screen, and this study aims at analysis of fluorescent feature depending on the increase of tube voltage using spectrometer. When the released fluorescence was measured according to the increase of tube voltage, blue, green and red was observed, among which, $^5D_4-^7F_5$ which is applicable to green, was strongest. In addition, when the fluorescent of 50 kVp and 120 kVp were compared, 50 kVp was proved to release only 9.56% fluorescence of 120 kVp. In case when tube voltage which is higher than 100 kVp is used for the X-ray using $Gd_2O_2S:Tb^{3+}$ intensifying screen, the amount and strength of the fluorescence reaching the film increase drastically, so attention is demanded to get images of proper concentration.

• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.7-12
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• 2006

We have studied pharmacokinetics of a new anti-human immunodeficiency virus (HIV) agent VP-0501 and its amino acid prodrug VP-0501AL which is designed to improve oral bioavailability. After oral administration at 100 mg/kg dose in rats (n = 4), VP-0501 was not detectable in plasma (<50 ng/ml), while after the administration of VP-0501AL, VP-0501 was quantitatively detected, at least for 8 hrs, with Cmax of ca. $2.5{\mu}g/ml$ and AUC of $8hr^{\ast}{\mu}g/ml$. When VP-0501 was intravenously administered at 50mg/kg, this compound appeared at a marginal level in plasma with AUC of $2hr^{\ast}{\mu}g/ml$, $t_{1/2}$ of 2 hr, $C_0$ of $0.7{\mu}g/ml$, and MRT of 3 hr. On the other hand, with intravenous VP-0501AL at the same dose, both the prodrug VP-0501AL and its metabolite VP-0501 appeared comparatively at higher level in the plasma: pharmacokinetic parameters of VP-0501AL including $Vd_{\beta}$, AUC, $t_{1/2,{\beta}}$, $C_0$, $CL_{tot}$, and MRT were ca. 2 L/kg, $70hr^{\ast}{\mu}g/ml$, 2 hr, $180{\mu}g/ml$, 0.7 L/hr/kg, and 1 hr, respectively. These results demonstrate that attachment of amino acid alanine to VP-0501 is an effective approach for improvement of its oral bioavailability. Therefore, VP-0501AL is expected to become a new highly bioavailable and potent anti-AIDS drug candidate/lead compound.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.8
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• pp.949-956
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• 1999

이 논문에서는 ATM (Asynchronous Transfer Mode) 방식의 초고속망의 장애 발생 시 이용자 연결의 QoS (Quality of Service)를 고려하여 복구할 수 있게 하는 보호 망 설계 방안을 제시한다. 제시한 설계 방안에 기초한 비용과 복구 특성을 분석과 모의 실험을 통해 알아본다. 제안하는 망에서의 복구는 분리 VP 그룹 (Disjoint Virtual Path Group, DVPG) 을 사용하는 상태 독립적 (State- independent) 방식으로 복구된다. ATM 망의 운용 및 보호 VP 할당과 용량 배정 문제를 정의하고 이를 바탕으로 최소의 비용을 갖는 VP 망을 설계한다. 망의 고장 시 기존 노드간의 VP 연결은 미리 할당된 링크 또는 노드 분리 보호 VP 경로를 따라 간단한 복구 알고리즘에 의해 빠르게 복구된다. QoS의 고려는 추가 비용을 필요로 하지만 정확한 이용자 연결의 복구를 실현하며, 분리 VP 그룹의 적용은 비용을 상승시키지만, 빠른 복구와 복수의 고장에 대처할 수 있는 방안이 된다.Abstract A cost evaluation of protection scheme for VP-based ATM network is presented here and its related characteristics are evaluated. The proposed and evaluated scheme is a state-independent restoration scheme using a disjoint path group. For fast and simple restoration of failed connections, link disjoint or node disjoint VP groups (DVPG) were utilized in this paper. A VP assignment and capacity planning problem is formulated. When failure occurs, the failed working VPs are switched to the protection VPs of disjoint path groups with a simple restoration scheme. And, cost evaluation and restoration characteristics are presented. The consideration of multiple QoS (Quality of Service) levels and disjoint path group protection scheme require additional network cost but acquire fit and fast restoration.

• Development and Reproduction
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• v.20 no.4
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• pp.283-288
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• 2016

The purpose of the present study was to investigate the morphological characteristics of the developing vallate papillae (VP) of Korean native goats using scanning electron microscopy. In prenatal development of the VP, primordia of the VP were observed and the moat was shallowly spread in 60-day-old fetuses. The moat of the vallate papillae was shallowly spread and still undifferentiated in 90-day-old fetuses. The trench wall of the moat of the VP was well developed in 120-day- old fetuses. In neonates, the moat of the VP was more widely and deeply engraved and VP were developed as completely as those of adults. In postnatal development, VP were observed to have continually increased in size with slight morphological changes until 90-days after birth. Taste pores of the VP were shaped like flower leaves in 120-days after birth. The microridges and microplicaes were well developed on the epithelial surface of the VP in goats ranging from 120-day-old fetuses to 120-day-old postnatal animals. These results suppose that the sensing ability for gestation of VP was already well developed by the time of its birth and VP were differentiated into a variety of different shape and size during development.

• BMB Reports
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• v.37 no.6
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• pp.726-734
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• 2004

White spot disease (WSD) is caused by the white spot syndrome virus (WSSV), which results in devastating losses to the shrimp farming industry around the world. However, the mechanism of virus entry and spread into the shrimp cells is unknown. A binding assay in vitro demonstrated VP28-EGFP (envelope protein VP28 fused with enhanced green fluorescence protein) binding to shrimp cells. This provides direct evidence that VP28-EGFP can bind to shrimp cells at pH 6.0 within 0.5 h. However, the protein was observed to enter the cytoplasm 3 h post-adsorption. Meanwhile, the plaque inhibition test showed that the polyclonal antibody against VP28 (a major envelope protein of WSSV) could neutralize the WSSV and block an infection with the virus. The result of competition ELISA further confirmed that the envelope protein VP28 could compete with WSSV to bind to shrimp cells. Overall, VP28 of the WSSV can bind to shrimp cells as an attachment protein, and can help the virus enter the cytoplasm.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.417-422
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• 2014

In this study, the influence degree of the scattering of the line depending on the incident energy of the radiation objective was to evaluate a new method of quantitative methods of PSNR is provided.Value of MSE and PSNR of the DR and the Target is placed at the left when there was no change in CR Target, the change appeared to ttaran MSE and PSNR value in tube voltage. Both CR and DR seen that there is a variation of the MSE and PSNR depending on the tube voltage change Computon showed that the scattered radiation effects. If the CR and DR 80 The changes in the MSE and PSNR experience the symptoms suddenly occur in areas kVp was found to affect the optoelectronic Computon E, and at the same time, the scattered radiation detector Computon Computon by scattering due to the photoelectric effect. CR and DR of the imaging device in the future on the basis of the energy bands of the photoelectric effect of 60 kVp 70 kVp, 80 kVp, 90 kVp, compares the value of the PSNR and MSE 100 kVp in accordance with the change of the tube voltage of the CR and device DR proposes jigil scattering study of the degradation of the line quality is achieved.

• Journal of IKEEE
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• v.19 no.3
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• pp.392-399
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• 2015

This paper proposes a unified $4{\times}4$ transform architecture for HEVC and VP9 codec to reduce hardware size. It performs HEVC $4{\times}4$ IDCT, HEVC $4{\times}4$ IDST, VP9 $4{\times}4$ IDCT, and VP9 $4{\times}4$ IADST in a unified hardware. HEVC $4{\times}4$ IDCT and VP9 $4{\times}4$ IDCT have same IDCT computation except for the scales of coefficients. Similarly, HEVC $4{\times}4$ IDST and VP9 $4{\times}4$ IADST have same IDST computation except for the scales of coefficients. Furthermore, IDCT and IDST have quite a lot of similarity, so they can share some hardwares in common. So the proposed hardware performs all 4 operations in a unified hardware, where each operation has its own multiplication coefficients with shared butterfly adders. The synthesized block in 0.18 um technology is 6,679 gates, and the gate count is reduced by 25.3% in comparison with conventional designs.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.156-159
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• 2010

vp tree는 기준점(vantage point)과의 거리를 기준으로 데이터베이스 내의 자료를 색인하는 자료구조이다. 멀티미디어 자료 검색에서 비슷한 정도는 객체간의 거리를 바탕으로 비교하고, vp tree 색인 구조는 이 과정을 내포하고 있기 때문에 최근 멀티미디어 검색 연구에서 많이 사용되고 있다. 검색 방법에는 query와 가장 가까운 대상을 찾는 Nearest Neighbor Search, 또는 query와 가까운 k등까지를 검색하는 k-Nearest Neighbor Search가 있다. 본 논문에서는 Content-based retrieval에서 최근 자주 사용되는 vp tree에서 효과적인 k-NNS 방법을 제안하고, 기존의 전형적인 k-NNS 방법과의 비교 실험 결과를 보인다.

• Journal of the Korean Society of Radiology
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• v.16 no.2
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• pp.131-139
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• 2022

The purpose of this study was to insert a pedicle screw into a pig thoracic vertebrae, a general CT scan(Non MAR), and a thoracic axial image obtained with the Metallic Artifact Reduction for Orthopedic Implants (O-MAR) to reduce artifacts. The image obtained by reconstructing the algorithm (Standard, Soft, Bone, Detail) was used using the image J program. Signal to noise ratio(SNR) and contrast to noise ratio(CNR) were compared and analyzed by obtaining measured values based on the given equation. And this study was to investigate tube voltage and algorithm suitable for CT scan for thoracic pedicle screw insertion. As a result, when non-MAR was used, the soft algorithm showed the highest SNR and CNR at 80, 100, 120, and 140 kVp, On the other hand, when MAR was used, the standard algorithm showed the highest at 80 kVp, and the standard and soft algorithms showed similar values at 100 kVp. At 120 kVp, the Soft and Standard algorithms showed similar values, and at 140 kVp, the Soft algorithm showed the highest SNR and CNR. Therefore, when comparing Non-MAR and MAR, even if MAR was used, SNR and CNR did not increase in all algorithms according to the change in tube voltage. In conclusion, it is judged that it is advantageous to use the Soft algorithm at 80, 100, 120, and 140 kVp in Non MAR, the Standard algorithm at 80 and 100 kVp in MAR, and the Soft algorithm at 120 and 140 kVp. This study is expected to serve as an opportunity to further improve the quality of images by using selective tube voltage and algorithms as basic data to help evaluate images of pedicle screw CT scans in the future.