• 천문학회지
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• 제33권1호
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• pp.47-55
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• 2000

Nonpotential characteristics of magnetic fields in AR 5747 are examined using Mees Solar Observatory magnetograms taken on Oct. 20, 1989 to Oct. 22, 1989. The active region showed such violent flaring activities during the observational span that strong X-ray flares took place including a 2B/X3 flare. The magnetogram data were obtained by the Haleakala Stokes Polarimeter which provides simultaneous Stokes profiles of the Fe I doublet 6301.5 and 6302.5. A nonlinear least square method was adopted to derive the magnetic field vectors from the observed Stokes profiles and a multi-step ambiguity solution method was employed to resolve the $180^{\circ}$ ambiguity. From the ambiguity-resolved vector magnetograms, we have derived a set of physical quantities characterizing the field configuration, which are magnetic flux, vertical current density, magnetic shear angle, angular shear, magnetic free energy density, a measure of magnetic field discontinuity MAD and linear force-free coefficient. Our results show that (1) magnetic nonpotentiality is concentrated near the inversion line in the flaring sites, (2) all the physical parameters decreased with time, which may imply that the active region was in a relaxation stage of its evolution, (3) 2-D MAD has similar patterns with other nonpotential parameters, demonstrating that it can be utilized as an useful parameter of flare producing active region, and (4) the linear force-free coefficient could be a evolutionary indicator with a merit as a global nonpotential parameter.

• Structural Engineering and Mechanics
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• 제5권6호
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• pp.803-815
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• 1997

It is well understood that concentrated forces applied in the plane of a beam or panel (such as a wall or slab) lead to splitting forces developing within a disturbed region forming beyond the bearing zone. In a linearly elastic material the length of the disturbed region is approximately equal to the depth of the member. In concrete structures, however, the length of the disturbed region is a function of the orthotropic properties of the concrete-steel composite. In the detailing of steel reinforcement within the disturbed regions two limit states must be satisfied; strength and serviceability (in this case the serviceability requirement being acceptable crack widths). If the design requires large redistribution of stresses, the member may perform poorly at service and/or overload. In this paper the results of a plane stress finite element investigation of concentrated loads on reinforced concrete panels are presented. Two cases are examined (i) panels loaded concentrically, and (ii) panels loaded eccentrically. The numerical investigation suggests that the bursting force distribution is substantially different from that calculated using elastic design methods currently used in some codes of practice. The optimum solution for a uniformly reinforced bursting region was found to be with the reinforcement distributed from approximately 0.2 times the effective depth of the member ($0.2D_e$) to between $1.2D_e$ and $1.6D_e$. Strut and tie models based on the finite element analyses are proposed herein.

• 한국해양학회지
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• 제5권1호
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• pp.6-13
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• 1970

Ten days and monthly mean temperatures were analysed daily data observed during July, 1916 to March, 1970 statistically. Periodic characters were calculated by Δn, new method of approximate solution of Schuster Method. According to ten days mean temperatures, annual variation function is F($\theta_d$)=16.29-5.27 cos $\theta_d$+0.75 cos2 $\theta_d$-3.14 sin $\theta_d$+1.16 sin2 $\theta_d$-0.63 sin $\3{theta}_d$, where $\theta_d$=$-\frac{\pi}{18}$(d-3), d is the order of ten days period, 1 to 36. Annual mean water temperature is 16.3$^{\circ}C$, minimum in the last ten days of February 10.9$^{\circ}C$, maximum in the last ten days of August 24.5$^{\circ}C$. Periodic character of secular variation shows 11 year and its curve is F($\theta_y$)=16.29+0.53 cos $\theta_y$ -0.16cos $2{\theta}_y$+0.10 cos$3{\theta}_y$-0.10 sin $\theta_y$, where $\theta_y$=2$-\frac{2\pi}{11}$(y-1920), y is calendar year. And the relation between air temperature x and water temprature y is following. y=9.67 1.035$\^x$

• 농업과학연구
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• 제40권1호
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• pp.27-34
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• 2013

본 연구는 원유의 내냉성 미생물의 계절별 분포에 관해 조사하기 위해서 수행하였다. 내냉성 미생물은 최적 생장온도가 $30^{\circ}C$ 근처이지만, $7^{\circ}C$ 이하에서도 생존가능한 균으로 Pseudomonas, Achromobacter, Aeromonas 속 등이 있다. 원유로부터 분리한 총 내냉성 미생물 균수는 다른 계절에 비해 겨울철 원유에서 $3.0{\times}10^4$ CFU/mL로 가장 높은 수준으로 검출되었고, 다른 지역에 비해 B 지역에서 $2.4{\times}10^5$ CFU/mL로 유의적으로 높은 균수가 측정되었다(p<0.05). 분리한 총 706개의 균을 동정한 결과는 Gamma-proteobacteria 강이 전체의 81.02%로 가장 우세하였고, 그 중 Pseudomonas 속이 32.34%로 가장 높은 검출 빈도수를 나타내었으며, 특히 Pseudomonas fluorescens가 39.46%로 가장 우세하였다. 동정된 내냉성 미생물의 지역별 분포는 A 지역은 12개의 Acinetobacter johnsonii, B 지역은 21개의 Pseudomonas fluorescens, C 지역은 13개의 Enterobacter amnigenus, D 지역은 19개의 Psychrobacter maritimus, E 지역은 19개의 Acinetobacter johnsonii, F 지역은 8개의 Acinetobacter haemolyticus, G 지역은 20개의 Pseudomonas fluorescens, H 지역은 9개의 Acinetobacter johnsonii, I 지역은 17개의 Pseudomonas mucidolens가 높은 검출 빈도수를 나타내었다.

• Journal of Animal Science and Technology
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• 제46권1호
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• pp.1-6
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• 2004

본 연구는 MCIR$^*$3 allele의 돼지에 있어서 유전적 변이를 관찰하기 위하여 수행하였다. 일반적으로 흑모색 바탕에 백색반점이나 백색띠를 갖고 있는 돼지의 MCIR 유전자의 유전자형은 E$^{D2}$로 나타낸다. 우성 백색계통의 E$^P$ 유전자형은 우성 흑모색 계통의 E$^{D2}$ 유전자와 frameshift mutation 관계가 있다. 돼지 MCIR 전체 번역지역을 증폭하기 위하여 oligonucleotide primer률 제작하여 PCR을 수행 하였다. 그 결과 길이가 963${\sim}$966 base pairs인 돼지 MCIR 유전자의 전체번역지역을 포함하는 산물을 얻었다. 이들 번역부위의 염기서열 결정하고 이들을 Clusta1 W 프로그램을 이용하여 정렬한 결과 23번 코돈{nt68)에서 Hampshire와 제주 재래혹돈은 염기 시토신(cytosine)이 3 개 그리고 Birl‘shire의 경우 염기 시토신(cytosine)이 2개 결실되어 있었다. 그 외에 3개의 missense mutations과 하나의 frameshift mutation이 발견되었다.

• ETRI Journal
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• 제31권1호
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• pp.68-70
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• 2009

In this letter, a parametric analysis of the Fresnel-field antenna measurement method is performed for a square aperture. As a result, the optimum number of Fresnel fields for one far-field point is guided as $M_{opt}=N_{opt}=D^2/{\lambda}R+5$, where D is the antenna diameter, ${\lambda}$ is the wavelength, and R is the distance between the source antenna and the antenna under test. For the aperture size 5 ${\leq}$ $L_x/{\lambda}$ ${\leq}$ 20, the tolerable distances for gain errors of 0.5 dB and 0.2 dB can be guided as $R_{0.5\;dB}$ ${\approx}$ $1.2Lx/{\lambda}$ and $R_{0.2\;dB}$ ${\approx}$ $2.0L_x/{\lambda}$, where $L_x$ is the lateral length of the square aperture. The tolerable distances for 20 ${\leq}$ $L_x/{\lambda}$ ${\leq}$ 200 are also proposed. This measurement guideline can be fully utilized when performing the Fresnel-field antenna measurement method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.168-171
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• 1988

The p-n homo junction diode of the III-V ternary alloy semiconductor $In_{1-x}Ga_xP$ : S grown by the temperature gradient solution (TGS) was fabricated by Zn-diffusion, and it's characteristics was investigated. The carrier concentration of $In_{1-x}Ga_xP$ doped with sulfur, 0.5 mol %, was $1{\times}10^{17}cm^{-3}$ and the mobility was varied with the composition. In the case that the diffusion time was constant as 30 minutes. The temperature dependence of diffusion coefficient was decreased from D= $4.2{\times}10^{-5}$ exp (-1.74/$k_{B}T$) to D= $2.5{\times}10^{-5}$ exp (-3.272/$k_{B}T$) with increasing of composition $\times$ from 0.43 to 0.98. The major peak of E.L spectrum was due to D-A pair recombination and the peak intensity was increased with the increasing of input current. And the E.L intensity was decreased with the increasing temperature, and shift to the long wavelength. The luminescence efficiencies measured at $5^{\circ}C$, atmosphere temperature, was decreased from $2.6{\times}10^{-4}$% to $9.49{\times}10^{-6}$ % with increasing of composition it from 0.39, direct transition region, to 0.98, indirect transition region.

• 한국임상보건과학회지
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• 제1권3호
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• pp.33-37
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• 2013

Purpose. In this study, we divided elementary school students into two investigated groups. The A group is the lower graders(boys 9, girls 18), and the B group is the higher graders(boys 10, girls 13). The myopia progression has been compared with to each group and it has been investigated for variable terms. Methods. We have analyzed the refraction inspection record of 50 students(boys 19, girls 31) who visited optical shops and more than two times in one year. Results. The subject of study were 50 students(boys 19, girls 31). 1. The distribution of spherical equivalent power with ages : boys A group -2.42D, girls A group -2.53D, boys B group -2.63D, girls B group -2.78D. boys B group -2.63D, girls B group -2.78D. 2. The monthly variation of spherical equivalent power : -0.055D(A), -0.04D(B) in boys, and -0.065D(A), -0.07D(B) in girls. Conclusions. Considering monthly variations and Supposing that the time of changing spectacles degrees were the time of refracting inspection. The result : 3.8 month for A group, 4.5 month for B group in boys, and 3.5 month for A group, 5.2 month for B group in girls.

• 한국전자통신학회논문지
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• 제7권4호
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• pp.867-871
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• 2012

본 논문에서는 폴리머 테이퍼링 도파로 영역을 포함하는 $1{\times}4$ 형태의 플라스틱 광섬유 커플러를 제안하고 구현하였다. 플라스틱 광섬유와 폴리머 사각 도파로의 접속면에서 광 누설 손실을 줄이기 위해 단면이 원형에서 구형으로 천천히 바뀐 플라스틱 광섬유를 도입하였다. 실리콘 고무로 만들어진 주형을 이용하여 소자를 제작하였다. 제작된 소자는 1.33 dB의 삽입손실과 2.2 dB의 평탄도를 보였다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권1호
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• pp.76-83
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• 2010

본 연구는 정렬배열 및 엇갈림배열 상태에 놓인 원주군 주위의 유동장 특성을 와법으로 수치계산한 것이다. 계산은 피치 비 Pt/D=1.25~2.0, 레이놀즈 수 Re=$4.0{\times}10^1{\sim}4.0{\times}10^4$의 범위 내에서 각 유동장의 순간 볼텍스 분포, 순간 속도분포를 계산하였다. 정렬배열 및 엇갈림 배열 모두 각 원주의 상방에서는 시계방향의, 하방에서는 반시계방향의 볼텍스가 발생하였다. 각 배열 모두 원주군 후방에서 역류의 발생여부는 피치 비와 레이놀즈 수에 기인하며, 같은 레이놀즈 수에서는 피치 비가 작을수록, 그리고 같은 피치 비에서는 레이놀즈 수가 클수록 원주군 후방에서 역류발생이 쉽게 일어났다. 그리고 그 경계영역은 정렬배열의 경우 피치 비 Pt/D=1.5, 레이놀즈 수 Re=400~4,000, 엇갈림 배열의 경우 피치 비 Pt/D=1.4, 레이놀즈 수 Re=40~400에 존재했다.