• 대한기계학회논문집B
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• 제27권8호
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• pp.1174-1181
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• 2003

The flow around a circular cylinder was controlled by attaching O-rings to reduce drag force acting on the cylinder. Four experimental models were tested in this study; one smooth cylinder of diameter D (D=60mm) and three cylinders fitted with O-rings of diameters d=0.0167 D, 0.05D and 0.067 D with pitches of PPD=2D, 1D, 0.5D and 0.25D. The drag force, mean velocity and turbulence Intensity profiles in the near wake behind the cylinders were measured for Reynolds numbers based on the cylinder diameter in the range of Re$_{D}$=7.8$\times$10$^3$~1.2$\times$10$^{5}$ . At Re$_{D}$=1.2$\times$10$^{5}$ , the cylinder fitted with O-rings of d=0.0167D in a pitch interval of 0.25D shows the maximum drag reduction of about 5.4%, compared that with the smooth cylinder. The drag reduction effect of O-rings of d=0.067D is not so high. For O-ring circulars, as the Reynolds number increases, the peak location of turbulence intensity shifts downstream and the peak magnitude is decreased. Flow field around the cylinders was visualized using a smoke-wire technique to see the flow structure qualitatively. The size of vortices and vortex formation region formed behind the O-ring cylinders are smaller, compared with the smooth cylinder.der.

• 한국전자통신학회논문지
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• 제9권1호
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• pp.11-16
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• 2014

본 논문에서는 가늘어진 아크릴 원통이 광 결합 및 광 분배 작용을 하는 $1{\times}7$ 형태의 플라스틱 광섬유 커플러를 제안하고 구현하였다. 제작된 소자는 광 결합기로 동작 시 2.27~3.31 dB의 삽입손실과 광분배기로 동작 시 8.67~11.27dB의 삽입손실을 보였다.

• The Plant Pathology Journal
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• 제35권3호
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• pp.243-256
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• 2019

Field surveys for Plum pox virus (PPV) infection were conducted in stone fruit orchards all over Bulgaria. In total, 1168 out of 3020 leaf samples from cultivated Prunus spp. and wildly growing P. cerasifera trees reacted positive for PPV in DASI-ELISA with the universal monoclonal antibody (MAb) 5B. Further ELISA analyses showed that 987 and 127 isolates belonged to PPV-M and PPV-D serotypes, respectively. The plum and P. cerasifera showed 82.0% and 50.5% levels of infection, respectively followed by the peach (40.0%) and the apricot (32.0%). Five hundred fifty one PPV isolates were further typed by IC-RT-PCR with PPV-Rec, -M and -D-specific primers, targeting (Cter)NIb-(Nter) CP genome region, as 125 isolates were sequenced. The results revealed the presence of PPV-Rec, PPV-M and PPV-D and mixed infections of these strains. PPV-Rec was the most prevalent strain (49.0%), followed by PPV-M (40.1%), while PPV-D was the less spread strain (8.2%). PPV-Rec was the most common strain in plums, including the eight "old-aged" trees from the region of the first Sharka discovery. PPV-M was the most prevalent strain in peach and apricot. Phylogenetic analyses on (Cter)NIb-(Nter)CP of the isolates were performed. PPV-Rec isolates formed a homogeneous group, while PPV-M isolates split into PPV-Ma and PPV-Mb subgroups. Five separated clades were formed by the analyzed PPV-D isolates. Nucleotide sequences of the partial CP coding region of the analyzed isolates revealed a slightly higher intra-strain genetic variability in PPV-Rec and PPV-M isolates, while that of PPV-D strain isolates was higher from the reported for these strains.

• 한국전기전자재료학회논문지
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• 제25권1호
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• pp.6-14
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• 2012

For integrated complementary metal oxide semiconductor (CMOS) circuits, the lateral spread for two-dimensional (2-D) impurity distributions are very important for the analyzing the devices. The measured two-dimensional SEM data obtained using the chemical etching-method matched very well with the results of the Gauss model for boron implanted samples. But the profiles in boron implanted silicon were deviated from the Gauss model. The profiles in boron implanted silicon were shown a little bit steep profile in the deep region due to backscattering effect on the near surface from the bombardments of light boron ions. From the simulated 3-D data obtained using an analytical model, the 1-D and 2-D data were compared with the experimental data and could be verified the justification from the experimental data. The data of 3-D model were also shown good agreements with the experimental and the simulated data. It can be used in the 3-D chip design and the analysis of microelectro-mecanical system (MEMS) and special devices.

• 복식문화연구
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• 제24권3호
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• pp.315-323
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• 2016

The present study is intended to study sole types necessary for shoe designs for elementary school students that are in age groups in growth periods, and 3D midsole design utilizing 3D printing technology. This study analyzed data from the 3D measurement of the feet of 1,227 elementary school students aged 7-13 years residing in the capital region conducted as part of the 6th Anthropometry of Size Korea. In addition, 3D midsoles by sole type were designed utilizing a Rhino CAD, and midsole prototypes were output utilizing a Zortrax-M200 3D Printer. Through a cluster analysis of sole shapes by type, sole shapes were classified into three types. Type 1 has small values of foot lengths and foot breadths, with large toe 1 angles and high arch heights. Type 2 has intermediate values of foot lengths and foot breadths, with small toe 1 angles and high arch heights. Type 3 has large values of foot lengths and foot breadths with small toe 1 angles and low arch heights. On reviewing the results of design of 3D midsoles by sole type, it can be seen that the midsoles were designed according to characteristics by sole type. The results of the sole type analysis in the present study are expected to be meaningful as basic data for the development of shoe insoles for elementary school students.

• 대한지역사회영양학회지
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• 제2권2호
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• pp.133-140
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• 1997

The serum concentrations of the major minerals(calcium, phosphorus, magnesium, sodium, potassium) and trace elements(iron, Zinc, copper manganese)were datermined in 23 breast fed infants living in Eumsung, Choong-buk region. The results obtained are summarized as follows: 1)The mean levels of calcium, phosphorus, magnesium, sodium and potassium of the serum of total subjects were 8.15$\pm$0.33mg/dI, 11.06$\pm$0.16mg/dI, 2.00$\pm$0.14mg/dI, 3.4476$\pm$17.99mg/dI and 9.06$\pm$2.04mg/dI respectively. 2)The serum concentrations of iron, zinc, copper and manganese in total subjects averaged 95.83$\pm$0.33mg/dI, 93.79$\pm$7.06$\mu$g/dI and 98.57$\pm$7.06 $\mu$g/dI and 4.93$\pm$0.62$\mu$g/dI respecitively. 3)Breast fed infants had significantly higher serum calcim, magnesium, sodium and iron concentrations than the formula fed groups. Otherwise, serum potassium, copper and manganese levels in breast milk fed infants were significantly lower than those in formula fed infants. 4) In formula fed infants, serum potassium and copper levels increased increased significantly with months after birth.

• 아시안잔디학회지
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• 제10권1호
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• pp.31-40
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• 1996

The mechanical expresion provides for the use of Soil property reserves and permanent protec-tion or improvement of soil resources in accordance with measurable standards. If the functions I (initial soil property), E (soil erosion), R (soil renewal), and M. (minimum allowable value) are assumed to be integrable in region A, erosion tolerance over a region is leaded to ${\int}_A{\int}I(m, cl, re, ch, b)dA-{\int}_A{\int}{\{\int}_{to}^{\infty}[E(w, re, c, re, ch, b, t)-R(m, ch, re, b, t)]dt}\dA{\geqq}{\int}_A{\int}M_i(m, cl, re, ch, b)dA$ were variable factors are m=parent material of soil, cl=climate, re=relief or topography, ch=soil characteristics, r=rain or water, w=wind, b=biota, and t=time.

• 한국균학회지
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• 제43권4호
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• pp.267-271
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• 2015

제주도 토양에 서식하는 야생효모들의 분포 특성을 조사하기 위해, 동부지역 7곳, 서부지역 5곳에서 토양을 채취하여 효모를 분리한 후, 콜로니 PCR에 의해 증폭된 26S rDNA D1/D2 지역의 염기서열을 결정하여 BLAST를 이용하여 효모를 동정하였다. 동부지역에서 채집한 토양에서 12종에 속하는 20균주를, 서부지역에서 6종에 속하는 13균주를 분리하였다. 분리되는 효모 종은 강수량 차이를 보이는 지역에 따라서 현저한 차이가 있는 것을 알 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제26권4호
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• pp.485-492
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• 2002

The present study is aimed to reveal macroscopic aerodynamic characteristics of two-dimensional rectangular prisms with three aspect ratios(D/H=1, 2 and 3) and six angles of attack($0^{circ}, 10^{circ}, 13.5^{circ}, 20^{circ}, 30^{circ} and 45^{\circ}$). The Reynolds number is fixed as $1\times10^4$. The SOLA-based revised finite difference method for the conservation form on irregular grid was adopted as a new numerical method. Instantaneous flow patterns at $45^{\circ}$ in case of D/H=2 and D/H=3 show larger asymmetric wake development which is closely related to the sharp decrease of drag coefficients at higher angles of attack range. Vorticity propagation into enlarged wake region is conjectured to be responsible for this phenomenon. The Strouhal number is found to be sensitive to the angle of attack at higher aspect ratios(D/H=2 and 3).

• 한국정보처리학회논문지
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• 제7권2호
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• pp.542-551
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• 2000

본 논문에서는 MR 영상의 3차원 가시화 및 분석을 위한 단일 채널 MR 영상의 자동 뇌영역 분할 방법을 제안한다. 이 방법은 4단계의 2차원 및 3차원 처리에 의하여 뇌윤곽을 찾아낸다. 1,2단계에서는 곡선 적합을 이용한 자동 문턱치화에 의하여 머리마스크와 초기 뇌마스크를 생성한다. 3단계에서 입방보간으로 초기 뇌마스크의 3차원 볼륨을 생성하여 형태학적 연산, 연결부위 레이블링에 의하여 중기 뇌마스크를 생성한다. 최종적으로 곡선 적합에 의한 자동 문턱치화를 이용하여 뇌마스크를 정련한다. 제안한 알고리즘은 영상의 슬라이스 방향을 고려할 필요가 없고 영상이 뇌 전체를 포함하지 않아도 되며, T1, T2, PD, SPGR등 다양한 종류의 MR 영상의 자동적인 뇌영역의 분할에 유용하다. 실험에서 20세트 MR 영상에 대하여 수동분할을 기준으로 0.97 이상의 유지도를 보였다.