• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.13-19
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• 2016

Purpose In order to calculate the left ventricular ejection fraction (LVEF) accurately, it is important to acquire the best septal view of left ventricle in the multi-gated cardiac blood pool scan (GBP). This study aims to acquire the best septal view by measuring angle of ventricular septal wall (${\theta}$) using enhanced CT scan and compare with conventional method using left anterior oblique (LAO) 45 view. Materials and Methods From March to July in 2015, we analyzed the 253 patients who underwent both enhanced chest CT and GBP scan in the department of nuclear medicine at National Cancer Center. Angle (${\theta}$) between ventricular septum and imaginary midline was measured in transverse image of enhanced chest CT scan, and the patients whose difference between the angle of ${\theta}$ and 45 degree was more than 10 degrees were included. GBP scan was acquired using both LAO 45 and LAO ${\theta}$ views, and LVEFs measured by automated and manual region of interest (Auto-ROI and Manual-ROI) modes respectively were analyzed. Results $Mean{\pm}SD$ of ${\theta}$ on total 253 patients was $37.0{\pm}8.5^{\circ}$. Among them, the patients whose difference between 45 and ${\theta}$ degrees were more than ${\pm}10$ degrees were 88 patients ($29.3{\pm}6.1^{\circ}$). In Auto-ROI mode, there was statistically significant difference between LAO 45 and LAO ${\theta}$ (LVEF $45=62.0{\pm}6.6%$ vs. LVEF ${\theta}=64.0{\pm}5.6%$; P = 0.001). In Manual-ROI mode, there was also statistically significant difference between LAO 45 and LAO ${\theta}$ (LVEF $45=66.7{\pm}7.2%$ vs. LVEF ${\theta}=69.0{\pm}6.4%$; P < 0.001). Intraclass correlation coefficients of both methods were more than 95%. In case of comparison between Auto-ROI and Manual ROI of each LAO 45 and LAO ${\theta}$, there was no significant difference statistically. Conclusion We could measure the angle of ventricular septal wall accurately by using transverse image of enhanced chest CT and applied to LAO acquisition in the GBP scan. It might be the alternative method to acquire the best septal view of LAO effectively. We could notify significant difference between conventional LAO 45 and LAO ${\theta}$ view.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1860-1865
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• 2008

40Gbps WDMSystems have been studied by numerical simulation to optimize their performance. Standard single mode fiber is assumed, and the most popular modulation format, NRZ, is used for the study. These assumptions are valid when existing WDM systems are required to upgrade their performance to 40Gbps. It is shown that the standard single mode fiber can transmit optical signals over 4800 (BER < 10-15) by optimizing optical and electrical filter characteristics at the receiver and by compensation of dispersion. In addition, when the system performance is mainly limited by ASE noise of EDFAs, it is found that flattop-shaped optical filter at the receiver gives a better result than Gaussian-shaped filter unless the insertion loss of the optical filter is larger than 5dB.

• 한국정보통신설비학회:학술대회논문집
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• 2002.08a
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• pp.127-129
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• 2002

ADSL, Metro Ethernet등 가입자에게 넓은 대역폭을 할당하는 기술이 서비스 영역에 적용되고 있음에 따라 이를 원활히 수용할 수 있는 초고속 대용량 기간망 구축기술이 필요하다. 현재 사용되는 기술로는 2.5Gbps 또는 10Gbps의 전송속도를 갖는 수 십 채널을 각각 파장이 다른 광반송파(optical carrier)에 실어 광학적으로 다중화한 뒤 한 가닥의 광섬유를 통해 전송시키는 파장분할 다중화(Wavelength Division Multiplexing: WDM) 기술이 있다. 본 논문에서는 채널 당 전송 속도를 40Gbps로 증가시키거나, 증폭기 이득 대역폭을 확장시켜 채널 수를 증가시켜 수 THz의 전송용량을 수 천 km 전송시키는데 필요한 라만 광증폭기 기술, FEC 기술, 변조포맷, 분산관리(Dispersion management)기술 등의 핵심기술을 소개한다.

• Venture DIGEST
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• no.1 s.126
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• pp.16-18
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• 2009

구리는 가라. 빛을 통한 신호 전송이 PCB에서도 구현된다.' 구리가 아닌 광 회로를 통해 신호를 전달할 수 있는 광PCB 기술이 한창 개발되고 있다. 광PCB의 전송속도인 2.5Gbps보다 수십 배 빠른 속도를 구현함으로써 고속 데이터 전송 및 처리를 필요로 하는 컴퓨터, 휴대폰, 게임기 등 각종 첨단 분야에 폭넓게 응용되고 있다. 초고속 스피드 시대를 열어 갈 전기-광PCB 기술을 소개한다.

• Information and Communications Magazine
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• v.33 no.6
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• pp.27-32
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• 2016

본고에서는 5G 포럼 네트워크 위원회에서 진행하고 있는 기술백서의 내용을 중심으로 5G 네트워크에 대한 고찰을 통해서 다가올 5G 네트워크에 대한 진화를 예측해 보고자 한다. 5G, 즉 IMT-2020은 홀로그램, 8K UHD와 같은 진화된 비디오 서비스를 안정적으로 사용하기 위하여 기존 대비 20배 증가된 20Gbps의 최고 전송 속도, 기존 대비 10배 향상된 100Mbps 이상의 이용자 체감 전송 속도 제공을 기본 목표로 하고 있다. 이런 5G 네트워크의 요구 사항을 기능, 구조, 운영 관점에서 살펴보고, 코어네트워크에서 필요한 요구 사항과 고려되고 있는 기술에 대한 고찰을 통해 5G에서의 코어 네트워크에 대한 이해를 돕고자 한다.

• Clinical and Experimental Pediatrics
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• v.63 no.7
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• pp.265-271
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• 2020

Background: Pneumococcal diseases among children aged <5 years worldwide are associated with high annual mortality rates. Purpose: This study aimed to evaluate the immunogenicity and safety of GBP411, a 12-valent pneumococcal conjugant vaccine, with a dosing schedule of 2 primary doses plus 1 booster dose (2p+1) in healthy infants. Methods: This randomized active-controlled (Prevnar 13) double-blind phase 2 trial enrolled healthy subjects aged 6-10 weeks. Three serum concentrations of pneumococcal serotype-specific immunoglobulin G (IgG) were evaluated using the pneumococcal serotype-specific pneumonia polysaccharide enzyme-linked immunosorbent assay at 1 month after the primary doses and before and 1 month after the booster dose. The pneumococcal serotype-specific IgG titer was evaluated using a multiplex opsonophagocytic assay in a subset of 15 subjects per group. Results: After administration of the primary doses, the proportion of subjects who achieved pneumococcal serotype-specific IgG concentrations of >0.35 ㎍/mL was lower for some serotypes in the GBP411 group than in the comparator group (6B: 20.83% vs. 39.22%, P=0.047 and 19A: 58.33% vs. 90.20%, P<0.001). However, after administration of the booster dose, >97% of the subjects in each group achieved IgG concentrations of ≥0.35 ㎍/mL for all 12 serotypes. Increased immunogenicity was observed for some serotypes that showed significant intergroup differences after administration of the primary doses but not after the booster dose. We also found no significant intergroup difference in the overall incidence of solicited local adverse events. Furthermore, the overall incidence of solicited systemic adverse events was significantly lower in the GBP411 group than in the comparator vaccine group (79.59% vs. 98.04%; P=0.003). Conclusion: The GBP411 vaccine with a dosing schedule of 2p+1 may be immunogenic and safe for healthy infants.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.46-55
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• 2014

PCB design technology for high-speed transmission line has been developed continuously. Adapting to the high capacity of the communication system, switch fabric interface used for backplane is being standardized to accommodate more than 10Gbps serial interface. In this paper, various computer simulations are performed to compare the performance of each transmission line per length according to PCB material, and also to analyze the effect from via stub length and crosstalk, for the purpose of applying 11.5Gbps serial interface as a switch fabric interface in tera-bit switching system. As a result of the simulation, important design issues, such as PCB material of each board supporting 8dB improvement in transmission loss using low loss PCB, maximum available stub length on transmission line via, whether or not to apply the backdrill process to the via, and the clearance of the differential pair between transmission lines, are determined. The most efficient system architecture which could be applied 11.5Gbps serial interface in all switch fabric interfaces is defined from the simulation results.

• Advances in environmental research
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• v.3 no.3
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• pp.231-251
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• 2014

The present study examines the phosphate adsorption potential and behavior of mixture of Ground Burnt Patties (GBP), a solid waste generated from cooking fuel used in earthen stoves and Red Soil (RS), a natural substance in fixed bed column mode operation. The characterization of adsorbent was done by Proton Induced X-ray Emission (PIXE), and Proton Induced ${\gamma}$-ray Emission (PIGE) methods. The FTIR spectroscopy of spent adsorbent reveals the presence of absorbance peak at $1127cm^{-1}$ which appears due to P = O stretching, thus confirming phosphate adsorption. The effects of bed height (10, 15 and 20 cm), flow rate (2.5, 5 and 7.5 mL/min) and initial phosphate concentration (5 and 15 mg/L) on breakthrough curves were explored. Both the breakthrough and exhaustion time increased with increase in bed depth, decrease in flow rate and influent concentration. Thomas model, Yoon-Nelson model and Modified Dose Response model were used to fit the column adsorption data using nonlinear regression analysis while Bed Depth Service Time model followed linear regression analysis under different experimental condition to evaluate model parameters that are useful in scale up of the process. The values of correlation coefficient ($R^2$) and the Sum of Square Error (SSE) revealed the Modified Dose Response model as the best fitted model to the experimental data. The adsorbent mixture responded effectively to the desorption and reusability experiment. The results of this finding advocated that mixture of GBP and RS can be used as a low cost, highly efficient adsorbent for phosphate removal from aqueous solution.

• Information and Communications Magazine
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• v.31 no.11
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• pp.87-94
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• 2014

본고에서는 스마트폰 도입 이후 전 세계적으로 급증하고 있는 무선 트래픽의 수요를 만족하기 위해 추가적으로 IMT 주파수를 확보하기 위한 국내외 동향을 고찰한다. ITU는 2015년 열릴 WRC-15에서 국제 공통의 IMT 주파수 지정을 논의할 예정이며 이를 위해 각 국에서 제안했던 잠정 후보대역 및 후보대역에서 운용중인 다른 업무들간 수행했던 공유연구 결과를 설명한다. 또한 1 Gbps의 체감 전송률을 목표로 하는 차세대 IMT(5G) 시스템의 주파수 요구사항을 만족하기 위해 초광대역폭의 이점이 있는 6 GHz 이상 대역의 동향을 살펴보고 향후 WRC-19 의제로 개발하기 위한 추진계획을 소개한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.812-820
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• 2006

Ethernet has been given a greater attention recently due to tendency of unifying most of transmission technique(not only LAN, but MAN and WAN) to ethernet. Performance evaluation was performed using C language for 10Gbps ethernet Data Link to design the optimum hardware, then internal FIFO size was evaluated. In this paper, MAC core for 10Gbps ethernet which contains high layer interface, transmit engine, flow control block, receive engine, reconciliation sublayer, configuration block, statistics block, and XGMII interface block was designed using VHDL language and Xilinx 6.2i tool and verified using Model_SIM 5.7G simulator. According to the specification of 10Gbps ethernet, MAC core with 64-bit data path should support 156.25MHz in order to support 10Gbps. The designed MAC core that process 64-bit data, operates at 168.549MHz and hence supports the maximum 10.78Gbps data processing. The designed MAC core is applicable to an area that needs a high-speed data processing of 10Gbps or more.