• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.32-43
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• 1999

In this paper, the transformed QMSA to load a capacitor without limitation of the electric force on QMSA(Quarter-wavelength Microstrip Antenna) is designed. Bandwidth of the designed and manufactured antenna is 5.7% at the resonant frequency of 2.0 GHz and the resonant frequency and bandwidth versus change of any arbitrary feed point is observed. Since the size of wide slot width between the left and right parallel plate to load a capacitor is very wide bandwidth, will be suitable for very wide bandwidth communication. The radiation pattern characteristics of the designed antenna based on the dipole structure and the aperture structure analysis method. As calculation results, relative backward radation is - 5 dB.

• Journal of Plant Biology
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• v.28 no.1
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• pp.1-8
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• 1985

To verify the cause of high productivity in Typha stand, leaf area index(LAI), leaf orientation and inclination, specific leaf area (SLA), and radiation interception profiles were determined in a natural Typha$\times$glauca stand. Throughout the growing season, the leaf inclination has been kept at near-right angle and leaf orientation has been random. These chracteristics were responsible for an uniform spatial arrangement of the leaves within the canopy and could be explained by the SLA value, which increased in their higher strata. The extinction coefficient (K) of the canopy, 0.12 to 0.20, was one of the smallest value out of terrestrial plant communities. At least more than 25% of full radiation penetrated into the lowest stratum of the canopy. High productivity of the Typha would be attributed to efficient penetration of the radiation in virtue of the stiff and straight leaves even though rather small LAI.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.1-7
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• 2003

Anatomical and physical characteristics of damaged wood by forest fire and sound wood of Pinus densiflora were examined. Granular substances were found in resin canals, epithelial cells and ray parenchyma cells of damaged wood, but the other distinctive marks of wood structure in damaged wood were not observed. Damaged wood showed slightly higher relative crystallinity in outermost growth ring than sound wood. Green moisture content and water absorptions both in tangential and radial sections of damaged wood were lower than those of sound wood. There were no significant differences in shrinkage, swelling and basic density between damaged and sound woods.

• Tunnel and Underground Space
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• v.11 no.2
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• pp.132-145
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• 2001

The purpose and need of the study is to quantify the advantage or disadvantage of the environmental friendliness of the partitioning of nuclear fuel cycle. To this end, a preliminary study on the quantitative effect of the partition on the permanent disposal of spent PWR and CANDU fuel (HLW) was carried out. Before any analysis, the so-called reference radionuclide release scenario from a potential repository embedded into a crystalline rock was developed. Firstly, the feature, event and processes (FEPs) which lead to the release of nuclides from waste disposed of in a repository and the transport to and through the biosphere were identified. Based on the selected FEPs, the ‘Well Scenario’which might be the worst case scenario was set up. For the given scenario, annual individual doses to a local resident exposed to radioactive hazard were estimated and compared to that from direct disposal. Even though partitioning and transmutation could be an ideal solution to reduce the inventory which eventually decreases the release time as well as the peaks in the annual dose and also minimize the repository area through the proper handling of nuclides, it should overcome major disadvantages such as echnical issues on the partitioning and transmutation system, cost, and public acceptance, and environment friendly issues. In this regard, some relevant issues are also discussed to show the direction for further studies.

• Analytical Science and Technology
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• v.13 no.4
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• pp.474-483
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• 2000

An inductively coupled plasma atomic emission spectrometer/shielding system was specially designed and built for the analysis of radioactive materials. Both of an inductively coupled plasma source and a sample transfer system to be contacted with radioactive materials was installed in a stainless steel glove box. In terms of analytical capability and radiation safety, characteristic feature of the system was investigated. Its applicability to the determination of fission products and corrosion products in the radioactive materials such as spent fuel dissolver solution and the primary coolant of nuclear power reactors was evaluated. In the concentration range $0.01-0.1mgL^{-1}$, the relative standard deviation was found to be less than 5%.

• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.1-8
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• 2007

Japanese larch specimens with dimension of 2.5 (radial direction) ${\times}$ 2.5 (tangential direction) ${\times}$ 2.5 cm (longitudinal direction) were prepared to determine 3 different directional internal moisture movement coefficients and surface emission coefficients along the radial-, the tangential-, and the tangential-direction. 4 sides of each cubic specimen were wrapped with paraffin tape and rubber tape, leaving open the 2 opposite surfaces of interest, to provide one dimensional moisture movement during drying. The coefficients were determined at three different temperatures, 70, 50 and $30^{\circ}C$ and at two different relative humidities, 30 and 60%. Internal moisture movement coefficients inclusive of flow of free water and diffusion of bound water and water vapor were increased in the high temperature condition. The internal moisture movement coefficient in the longitudinal direction was about six times of those in transverse directions with radial value being 20% greater than the tangential. Surface emission coefficients were increased with temperature and decreased with surface moisture content. Using this results, moisture content (MC) profile and quantities of moisture evaporating in Japanese larch lumber could be predicted in dynamic drying situations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.22-27
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• 1995

본 연구로부터 얻어진 결론은 다음과 같다. 1. 본 연구에서는 TBM에 의한 파이롯트 터널의 효율성을 극대화한 이방향 천공 발파공법을 개발, 현장실험을 통하여 그 효용성을 입증하였다. 2. NATM 공법에 의한 발파보다 TBM을 이용하여 파이롯트 터널을 굴착하여 확대발파할 경우 상당한 지반진동 경감효과를 얻을 수 있을 것으로 판단된다. 3. 이방향 천공 발파공법의 현장시험 결과, 측정된 지반 진동치는 20% 이상의 진동 경감효과가 있는 것으로 분석되었다. 4. 기존공법과 신공법의 상대비교를 위한 수치해석 결과, 신공법의 방사상 방향 발파는 기존공법의 종방향 발파에 비하여 관심의 대상이 되는 발파공 직상부에서 진동치가 크게 경감되었다.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.1-6
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• 1998

손가락결합부재에 대한 정적휨시험 및 초음파 비파괴시험을 실시하였다. 발신 및 수신 변환기의 상대 위치와 두 변환기 사이의 거리에 따른 음전달속도의 변화를 분석하였으며 정적 휨시험으로 부터 구한 MOE 및 MOR과 비교하였다. MOR과 음전달속도는 손가락의 경사가 증가할수록 감소하였다. MOR은 음전달속도와 매우 밀접한 상관관계를 보였으나 MOE는 손가락의 경사도나 음전달속도에 큰 영향을 받지 않는 것으로 나타났다. 음전달속도는 섬유방향이 방사방향이나 접선방향에 비하여 더 높은 값을 나타내었다. 발신 및 수선 변환기를 동일면에 부착한 경우에 직각면 또는 반대면에 부착한 경우보다 더 높은 음전달속도를 나타내었다. 변환기 사이의 거리가 증가할수록 음전달속도는 양끝면에 변환기를 부착한 경우의 속도에 수렴하는 경향을 나타내었다.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.277-278
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• 2003

키틴은 셀룰로오스와 더불어 자연계에 가장 많이 존재하는 천연고분자(선형다당)로서 $\beta$(1$\longrightarrow$4)-2-deoxy-2-acetamido-D-glucopyranose를 기본단위로 하고, 키토산(chitosan)은 천연적으로는 몇몇 미생물에서 발견되며, 키틴의 탈아세틸화반응(deacetylation)에 의해 생성되는 유도체로서 $\beta$(1$\longrightarrow$4)-2-deoxy-2-amino-D-glucopyranose를 기본단위로 한다는 점에서 상이하다. 하지만 키틴과 키토산은 각 기본단위가 반복된 homopolymer가 아니고 서로 일정 정도의 상대 기본단위를 함유하므로 일종의 공중합체 또는 heteropolymer라고 할 수 있으며, 그 조성비 즉 탈아세틸화도 (degree of deacetylation, 이하 DD)에 따라 키틴과 키티산으로 나누어진다.[1] (중략)

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.875-881
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• 1995

원자력 연구소는 국제원자력기구(IAEA/RCA) 주관하에 1990년부터 1993년 사이 3차에 걸쳐 실시한 개인선량계에 대한 국제상호비교에 참여하였다. 국제 상호비교에 참여하여 사용된 개인선량계는 방사선작업종사자에 대한 외부방사선으로부터 피폭관리를 위하여 기 사용중인 Taedyne Isotope 사의 PB-3타입의 열형광선량계이며 선량계판독용으로 Tdedyne 9150자동판독기를 사용하였다. 본 논문에는 3차에 걸쳐 국제상호비교결과를 요약하였으며 저 에너지의 엑스선에 경우를 제외하고 모든 조사방사선에 대해 0.78에서 1.07사이에 상대비율로 결과를 나타내었다. 또한 미국기준 ANSI Nl 3.11에 의해 성능을 시험한 결과 모든 조사방사선장에 대해서 허용기준 0.5이하를 나타내었다.