• 전자공학회논문지C
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• 제36C권8호
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• pp.10-21
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• 1999

본 논문에서는 12비트의 해상도와 65MHz의 변환속도를 가지면서 단일 3.3V의 공급전압으로 동작하는 전류 셀 매트릭스 구조의 CMOS D/A 변환기를 제안하였다. 설계된 CMOS D/A 변환기는 우수한 단조증가성과 빠른 정착시간을 가지는 전류 셀 매트릭스 구조의 장점을 이용하면서 기존의 D/A 변환기의 전류셀 간의 문턱전압의 부정합과 접지선의 전압 강하에 의한 오차를 감소시키기 위해 트리 구조 바이어스 회로, 대칭적 접지선 연결, 캐스코드 전류 스위치를 사용하여 구현되었다. 설계된 전류 셀 매트릭스 12비트 D/A 변환기를 $0.6{\mu}m$ CMOS n-well 공정을 이용하여 제작하였다. 제작된 DAC칩을 +3.3V 단일 공급전원을 이용하여 측정한 결과, 정착시간이 20nsec로써 50MHz의 변환속도와 35.6mW의 전력소모를 나타내었다. 또한 측정된 SNR, DNL은 각각 55 dB, ${\pm}0.5LSB$,${\pm}2LSB$를 나타내었다.

• 전자공학회논문지
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• 제50권10호
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• pp.91-97
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• 2013

본 논문에서는 NTSC/PAL 아날로그 TV를 구동하기 위한 10-bit current steering D/A 변환기를 제안하였다. 제안하는 D/A 변환기는 50MS/s 의 동작속도를 가지며, 6+4 분할 구조로 설계되었다. 또한 새로운 개념의 자가보정 바이어스 기법을 적용하여 칩 내부의 종단저항을 사용하고도 공정오차를 최소화 하였다. 제안하는 D/A 변환기는 3.3V 0.11um 1-poly 6-metal CMOS 공정을 사용하여 제작되었다. 제작된 칩의 유효 면적은 $0.35mm^2$, 3.3V 전원전압 상에서 약 88mW의 전력소모를 나타내었다. 실험 결과는 변환 속도 50MS/s, 입력 주파수 1MHz에서 SFDR 63.1dB의 특성을 나타내었다.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.407-412
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• 2018

Background: We conducted this study to determine the optimal length of patellar and tibial bone blocks for the modified transtibial (TT) technique in anterior cruciate ligament (ACL) reconstruction using the bone-patellar tendon-bone (BPTB) graft. Methods: The current single-center, retrospective study was conducted in a total of 64 patients with an ACL tear who underwent surgery at our medical institution between March 2015 and February 2016. After harvesting the BPTB graft, we measured its length and that of the patellar tendon, patellar bone block, and tibial bone block using the arthroscopic ruler and double-checked measurements using a length gauge. Outcome measures included the length of tibial and femoral tunnels, inter-tunnel distance, length of the BPTB graft, patellar tendon, patellar bone block, and tibial bone block and graft-tunnel length mismatch. The total length of tunnels was defined as the sum of the length of the tibial tunnel, inter-tunnel distance and length of the femoral tunnel. Furthermore, the optimal length of the bone block was calculated as (the total length of tunnels - the length of the patellar tendon) / 2. We analyzed correlations of outcome measures with the height and body mass index of the patients. Results: There were 44 males (68.7%) and 20 females (31.3%) with a mean age of 31.8 years (range, 17 to 65 years). ACL reconstruction was performed on the left knee in 34 patients (53%) and on the right knee in 30 patients (47%). The optimal length of bone block was 21.7 mm (range, 19.5 to 23.5 mm). When the length of femoral tunnel was assumed as 25 mm and 30 mm, the optimal length of bone block was calculated as 19.6 mm (range, 17 to 21.5 mm) and 22.1 mm (range, 19.5 to 24 mm), respectively. On linear regression analysis, patients' height had a significant correlation with the length of tibial tunnel (p = 0.003), inter-tunnel distance (p = 0.014), and length of patellar tendon (p < 0.001). Conclusions: Our results indicate that it would be mandatory to determine the optimal length of tibial tunnel in the modified TT technique for ACL reconstruction using the BPTB graft. Further large-scale, multi-center studies are warranted to establish our results.

• Journal of Yeungnam Medical Science
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• 제39권2호
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• pp.141-149
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• 2022

Background: The present study evaluated the clinical implications of adjuvant chemotherapy according to the mismatch repair (MMR) status and clinicopathologic features of patients with intermediate- and high-risk stage II colon cancer (CC). Methods: This study retrospectively reviewed 5,774 patients who were diagnosed with CC and underwent curative surgical resection at Kyungpook National University Chilgok Hospital. The patients were enrolled according to the following criteria: (1) pathologically diagnosed with primary CC; (2) stage II CC classified based on the 7th edition of the American Joint Committee on Cancer staging system; (3) intermediate- and high-risk features; and (4) available test results for MMR status. A total of 286 patients met these criteria and were included in the study. Results: Among the 286 patients, 54 (18.9%) were identified as microsatellite instability-high (MSI-H) or deficient MMR (dMMR). Although all the patients identified as MSI-H/dMMR showed better survival outcomes, T4 tumors and adjuvant chemotherapy were identified as independent prognostic factors for survival. For the intermediate-risk patients identified as MSI-low (MSI-L)/microsatellite stable (MSS) or proficient MMR (pMMR), adjuvant chemotherapy exhibited a significantly better disease-free survival (DFS) but had no impact on overall survival (OS). Oxaliplatin-containing regimens showed no association with DFS or OS. Adjuvant chemotherapy was not associated with DFS in intermediate-risk patients identified as MSI-H/dMMR. Conclusion: The current study found that the use of adjuvant chemotherapy was correlated with better DFS in MSI-L/MSS or pMMR intermediate-risk stage II CC patients.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권2호
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• pp.106-113
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• 2006

Electrical properties of $Si_{0.88}Ge_{0.12}(C)$ p-MOSFETs have been exploited in an effort to investigate $Si_{0.88}Ge_{0.12}(C)$ channel structures designed especially to suppress diffusion of dopants during epitaxial growth and subsequent fabrication processes. The incorporation of 0.1 percent of carbon in $Si_{0.88}Ge_{0.12}$ channel layer could accomodate stress due to lattice mismatch and adjust bandgap energy slightly, but resulted in deteriorated current-voltage properties in a broad range of operation conditions with depressed gain, high subthreshold current level and many weak breakdown electric field in gateoxide. $Si_{0.88}Ge_{0.12}(C)$ channel structures with boron delta-doping represented increased conductance and feasible use of modulation doped device of $Si_{0.88}Ge_{0.12}(C)$ heterostructures.

• 한국초전도ㆍ저온공학회논문지
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• 제16권4호
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• pp.49-52
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• 2014

REBCO coated conductor (CC) tapes with superior mechanical and electromechanical properties are preferable in applications such as superconducting coils and magnets. The CC tapes should withstand factors that can affect their performance during fabrication and operation of its applications. In coil applications, CC tapes experience different mechanical constraints such as tensile or compressive stresses. Recently, the critical current ($I_c$) degradation of CC tapes used in coil applications due to delamination were already reported. Thermal cycling, coefficient of thermal expansion mismatch among constituent layers, screening current, etc. can induce excessive transverse tensile stresses that might lead to the degradation of $I_c$ in the CC tapes. Also, CC tapes might be subjected to very high magnetic fields that induce strong Lorentz force which possibly affects its performance in coil applications. Hence, investigation on the delamination mechanism of the CC tapes is very important in coiling, cooling, operation and design of prospect applications. In this study, the electromechanical properties of REBCO CC tapes fabricated by reactive co-evaporation by deposition and reaction (RCE-DR) under transversely applied loading were investigated. Delamination strength of the CC tape was determined using the anvil test. The $I_c$ degraded earlier under transverse tensile stress as compared to that under compressive one.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.499-500
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• 2006

This paper presents a fast switching CMOS frequency synthesizer with a new coarse tuning method for PHS applications. To achieve the fast lock-time and the low phase noise performance, an efficient bandwidth control scheme is proposed. Charge pump up/down current mismatches are compensated with the current mismatch compensation block. Also, the proposed coarse tuning method selects the optimal tuning capacitances of the LC-VCO to optimize the phase noise and the lock-time. The measured lock-time is about $20{\mu}s$. This chip is fabricated with $0.25{\mu}m$ CMOS technology, and the die area is $0.7mm{\times}2.1mm$. The power consumption is 54mW at 2.7V supply voltage.

• 한국자기학회지
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• 제17권6호
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• pp.246-252
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• 2007

본 논문에서는 출발원료 배합비 및 육성 파라미터가 LPE(Liquid Phase Epitaxy)법으로 육성된 자성 가넷 막의 특성에 미치는 영향을 조사하며, 광 CT의 페러데이 회전자용으로서 적합한 막의 육성 조건을 제시한다. 막을 평가하기 위하여 조사한 특성은 막후, 표면 모폴로지, X선 회절, 격자상수, 막과 기판(단결정 비자성 가넷 웨이퍼)사이의 격자상수의 부정합, 페러데이 회전각 등이었다. 또한, 육성된 자성 가넷 막을 이용하여 광 CT를 제작하고, 성능을 평가했다.

• 환경영향평가
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• 제23권1호
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• pp.1-9
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• 2014

This study, focusing on the area expansion of limestone mines, identifies the problems of Environmental Impact Assessment(EIA) and what impact the current problems exert on another mines developing process. The legal relations analysis reveals that the Management of Mountainous Districts Act and other related laws effect on EIA process, especially the case of area expansion of limestone mines excluded from EIA. However, these problems can create mismatch with the policy goal of EIA system and have a negative impact on the environment in the future. A series of indepth interviews with managers in related agencies found that those agencies have been unaware of the seriousness of the problem. Without any strategy, negative result made by development activities would get more serious and sustainable development may not be possible at all. In order to solve these problems, government should modify the current interdependent legal provision and create the incentive structure to participate actively related agency in the EIA system.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권3호
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• pp.370-377
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• 2017

This paper presents a simple noise margin (NM) model of MOS current mode logic (MCML) gates especially in CMOS processes where a large device mismatch deteriorates logic reliability. Trade-offs between speed and logic reliability are discussed, and a simple yet accurate NM equation to capture process-dependent degradation is proposed. The proposed NM equation is verified for 130-nm, 110-nm, 65-nm, and 40-nm CMOS processes and has errors less than 4% for all cases.