• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.481-482
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• 2022

본 논문은 MOSFET 트랜지스터로 구성된 monolithic 3D 인버터의 구조에서 하부 MOSFET 게이트 전압의 변화에 따라서 상부 MOSFET 트랜지스터의 random dopant fluctuation(RDF) 영향을 3차원 소자 시뮬레이션을 통하여 조사하였다. RDF 영향 조사를 위한 표본화는 kinetic monte carlo 방식을 통하여 진행하였으며, RDF 영향이 트랜지스터의 임계전압 변동에 영향을 주는 것을 확인하였고, 상부 트랜지스터와 하부 트랜지스터 사이에 전기적 커플링을 조사하였다.

• 한국기계가공학회지
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• 제8권3호
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• pp.98-104
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• 2009

The objective of this paper is to investigate the effect of factors on the dynamic stiffness variation of boring bar. The experiment was carried out by Taguchi Method and Orthogonal array table. The results indicate that overhang was found out to be dominant factor with 95% confident intervals and feed rate and depth of cut were insignificant. In addition, analysis of loss function shows that loss value increased sharply from 3D to 4D(D is a shank diameter). Consequently, there is critical point which changes property of dynamic stiffness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.159-161
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• 1997

This paper presents a method of reducing cogging torque and improving average torque by changing the dead zone angle of trapezoidal magnetization distribution of rotor magnet in ring type. Because brushless d.c. motor has 3D shape of overhang, 3D analysis should be used for computation of its magnet field. In this paper, Three Dimensional Equivalent Magnetic Circuit Network method (3DEMCN) which can calculate an accurate 3D magnetic field has been introduced. The method has an advantage that nonlinear magnetic phenomena can be considered and the cogging torque analyses requesting the rotation of the rotor can be performed by the variation of magnetization distribution without remesh.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.477-480
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• 1989

In this paper, we introduce the three-dimensional Korean character display by using 2D fonts and character depth. Character segments are designed by the set of vertex at run time. Character depth is applied for 3D visualization. And, the variation of eye-point and distance of object is used for 3D character animation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.53-55
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• 2005

The signals of the eddy current testing(ECT) for the examination of the steam generator(SG) tubes in the nuclear power plant(NPP) determine the existence, size, and kind of defects using the variation of impedance signals when a testing coil, driven by alternating current, passes through the SG tube contains defects. The aim of this paper is building a database of the RPC probe signals on the basis of the sizes variation of defects and frequency variation of probe. In this paper 3-D numerical analysis of the ECT signals using the finite element method is performed. Through this study, it is shown variation of magnitude and phase of impedance according to variation of defect size and frequency. From the result of this paper, we can obtain the information which is useful in defect discrimination of SG tube in nuclear power plant.

• 대한전자공학회논문지SD
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• 제40권4호
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• pp.65-73
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• 2003

본 논문은 진동형 각속도 검출 센서로부터 각속도 신호를 검출하는 애널로그 신호처리 ASIC의 구현에 관한 것이다. 각속도 검출 센서의 출력은 구조적으로 콘덴서의 용량변화로 나타나므로 이를 검출하기 위하여 전하 증폭기를 이용하였으며, 센서의 구동에 필요한 자체발진회로는 각속도 검출 센서의 공진 특성을 이용한 정현파 발진회로로 구현하였다. 특히 센서의 제조 공정으로 인한 특성 변화나 온도 변화와 같은 외부 요인에 의한 자체발진특성의 열화를 방지하기 위하여 자동이득조절회로를 사용하였다. 진동형 각속도 검출 센서의 동작특성에 의하여 진폭변조 형태로 나타나는 각속도 신호를 검출하기 위하여 동기검파회로를 사용하였다. 동기검파회로에서는 반송파의 크기에 따라 검파신호의 크기가 달라지는 현상을 방지하기 위하여 스위칭 방식의 곱셈회로를 사용하였다. 설계된 칩은 0.5㎛ CMOS 공정으로 구현하였으며, 1.2㎜×1㎜의 칩 크기로 제작되었다. 실험 결과 3V의 전원전압에서 3.6mA의 전류를 소비하였으며, 칩과 각속도 센서를 결합한 정상동작상태에서 직류에서 50㎐까지 잡음 스펙트럼 밀도는 -95 dBrms/√㎐에서 -100 dBrms/√㎐ 사이에 존재하였다.

• 한국의류학회지
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• 제38권1호
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• pp.97-109
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• 2014

This study developed a functional dress shirt for adult males that reflected the body surface variation of a human body section by motion. This study conducted a 3D body scan for 8 subjects in their 40's based on the Size Korea 2010 database. Data recorded the proper posture change value and body surface change value to develop functional dress shirts for adult males. We scanned the subjects with a 3D body scanner for five primarily male wearing dress shirts and operating postures, right standing, arms raised to $90^{\circ}$ horizontal forward position, arms raised $90^{\circ}$ to the horizontal position side, lift up the arm $180^{\circ}$, and arm forward $90^{\circ}$ in a bent posture. We analyzed the 3D scan data from those motions to examine change of length using 3D software Rapidform XOS. The results indicated that the body surface sections with contraction were the front and rear shoulder area, armpit and central length as well the width of arms at more than 10%. The increased body section included the body and armpit back length; in addition, the rear arm vibration girth and under arm girth were more than 10%. In order to reflect the size variation of for each motion, the ease amount of the front and rear shoulder length and width needs to be reduced 20% because it affects the shoulder length during the right standing. The results suggest that the ease amount of the shoulder length should be minimal. The ease amount of the back size needs to be 0.5-2cm bigger and set 0.5-1.5cm longer than the dress shirt length side drooping to compensate for the side length shortage of each motion. The sleeve length needs to be 0-0.5cm shorter, and ease amount of the girth of sleeve bottom needs to be reduced 0-0.7cm due to the size variation of arms. However, the girth of the rear arms is suggested to be 0-0.6cm longer in the ease amount to the rear arm girth as the extension is more than 10% over the width and length of each motion.

• 대한방사선기술학회지:방사선기술과학
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• 제46권1호
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• pp.1-8
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• 2023

As the demand for bone mineral density testing increases in Korea, which is close to an aging society, it is necessary to evaluate the repeatability of equipment such as femur phantom other than l-spine for more accurate diagnosis. However, in clinical practice, it is often not possible to proceed such evaluation due to insufficient quality control conditions. Therefore, this study is to evaluate the usefulness of the femur phantom after fabricating the same using 3D printing technology. The femur phantom was output using GlowFill filament and FDM 3D printing type. Each phantom was repeatedly scaned 20 times to compare whether the existing l-spine phantom and the fabricated femur phantom were suitable as a phantom for quality control. Each time the seven researchers took three times, the location of the femur phantom was readjusted, and then scanned to confirm the error between the researchers. As a result of conducting repeatability evaluation using femur phantom, the coefficient of variation rate was 2%, which was within the minimum precision tolerance of 2.5%. The reproducibility between the researcher was also found to be suitable as the average coefficient of variation was 0.031 and the coefficient of variation rate was 3.1%, which was within the minimum precision error range of 5%. In conclusion, it is considered that the prospective attitude and usefulness of the femur phantom fabricated by 3D printing in clinical practice will be sufficient.

• 수산해양기술연구
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• 제53권4호
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• pp.337-348
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• 2017

The tension of warp from trawler and sea-floor contact can generate tilt and wake turbulence around otter boards. Preliminary measurements of otter board tilt and 3-D flow velocity during bottom trawl operations were taken using a vector instrument to investigate the effects of wake turbulence at the trailing edge of the otter board. Tilt data (i.e., yaw, pitch, and roll) at 1 Hz and flow data (velocities in the towing, lateral, and vertical directions) at 16 Hz were analyzed to determine their periods and amplitudes using global wavelet and peak event analyses. The mean period (${\pm}standard$ deviation) of the tilt from the peak event analysis ($5{\pm}2s$) was longer or double than that of flow velocity ($3{\pm}2s$). The two periods also had a significant linear relationship. The turbulence rate of flow was 30-50% at the trailing edge and was closely related to roll deviation. The frequency of phase difference ratios (i.e., peak time differences between tilts and flow periods) was significantly different from random occurrence in two trials, possibly due to side tidal effects. However, in the other trials, flow peaks were random, as shown by the even peak times between tilts and flows. Future studies should focus on reducing tilt variation, wake turbulence, and bottom contact to stabilize otter board motion.

• 한국방재학회 논문집
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• 제3권2호
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• pp.147-154
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• 2003

본 연구에서는 수리모형실험을 통하여 원환 설치 전 후 교각 주위의 수리특성을 분석하였다. 하천 흐름에서 교각 전 후의 수위 변화를 분석한 결과, 교각 전면부에서 원환 설치 전 후의 수위차는 약 0.2cm, 교각 후면부에서 원환 설치 전 후의 수위차는 약 0.1cm로 거의 변화가 없었다. 따라서, 원환이 하천 흐름에 장애가 되지 않는 것으로 판단되었다. 또한, 교각 전 후의 유속 변화를 분석한 결과, 교각 전 후면부에서 원환 설치 전 후의 흐름방향 유속(u)과 횡방향 유속(v)은 변화를 보이지 않았으며, 교각 전면부에서 연직방향 유속(w)은 수심비(y/D)가 0.33인 지점에서 약 16.72% 최대감소효과를 나타냈으며, 교각 후면부에서 연직방향 유속(w)은 수심비(y/D)가 0.67인 지점에서 약 15.83% 최대감소효과를 나타내었다. 원환을 설치했을 경우 교각 주위에서 세굴을 일으키는 하강류의 발생을 억제함으로써 국부세굴심을 감소시킬 수 있을 것으로 판단되었다.