• STI Policy Review
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• 제1권1호
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• pp.1-21
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• 2010

To achieve the "low carbon green growth" vision, the first step is securing core technologies. Therefore, S&T policy direction for green technology development is urgently needed. As of 2008, investment in green technology (GT) development hovered around 10% of the government's total R&D budget. Thus, the Korean government developed a plan to increase that percentage to 15%, by 2013. To develop reasonable investment strategies for green technology development, targeted strategies that reflect technology and market changes by green technology area are needed. However, the overall planning and coordination of national GT development is currently split among, approximately, 10 government ministries. To establish an efficient green technology development system, the so-called "Green Technology R&D Council" should be launched in collaboration with the Presidential Committee on Green Growth and the National Science and Technology Council. Furthermore, to build a solid foundation for commercializing the outcomes of GT development projects and promote GT transfer, the government should undertake two initiatives. First, the government should reinforce GT R&D performance management, by establishing a GT R&D performance management and evaluation system. Second, the government should implement the "customized packaged support for promoting green technology business rights and commercialization" and present "e-marketplace for market-oriented green technologies". Creating a pan-ministerial policy for GT development policy would necessitate restructuring the HR(Human Resources) development system, which is currently separated by technology area. Based upon mid/long-term HR supply and demand forecasts, the government should design differentiated HR development projects, continuously evaluate those projects, and reflect the evaluation results in future policy development. Finally, to create new GT-related industries, the "Green TCS (Testing, Certification, and Standards) System" needs to be implemented. For objective evaluation and diffusion of R&D results by green technology area, a common standardization plan for testing, analysis, and measurement, like the "Green TCS", should be developed and integrated.

• 한국수산과학회지
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• 제10권4호
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• pp.227-235
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• 1977

1976년 8월 16일 (북위 $34^{\circ}27'30'$ 동경 $128^{\circ}23'15'$)과 1977넌 7월 28일(북위 $34^{\circ}47'$ 동경 $128^{\circ}53'$)에 관악산호의 선박소음이 r.p.m에 따라 항해시와 정선시 (기관의 공회전)의 소음압이 해중에 분포하는 것을 조사 연구한 결과를 요약하면 다음과 같다. 1. 기관의 r.p.m.과 음압관계 r.p.m.과 음압의 증가비는 100 : 1이었으며 r.p.m. 600에서 104dB로 peak를 이루었다. 2. 외현주변의 해중해압분포 A. 정선시의 기관소음압 100,102,103,104,104 dB일때 관측점 No.1에서 69,70,72,74,75 dB No.3은 No. 1에 비해 $2\~3\;dB$ 증가해 peak를 이루었고 No.5는 No.3에 비해 $10\~15\;dB$씩 감쇠되었다. 기관소음압이 최대 일때 관측점 $No.1\~No.5$에서의 음압이 투과된 백분율은 약 $78,79,80,73,70\%$였다. B. 항해시의 선박수중소음압 정선시와 같은 기관회전 조건하에서 No.2에서 69,72,75,77,78 dB로 peak를 이고 No. 1보다 $2\~3\;dB$씩 감쇠되었다. 기관 최고소음압에 대한 $No1.\~No.5$에서의 음압투과 백분율은 약 $78,81,79,77,71\%$ 였다. 3. 항해시와 정선시의 외현해중 음압 peak점에서의 음압을 비교하면 항해시가 1 dB 높았다. 4. 선박이 멀어질 때 0 m(관측점 통과시)에서 67 dB, 1,400 m에서 56 dB였다. 5. 선박이 가까워질 때 거리 0 m에서 72 dB, 1,400 m에서 57 dB로서 멀어 질때와 비교하면 0m에서 5 dB, 600 m에서 2 pB씩 증가한 도플러 효과가 일어남을 알 수 있다. 6. r.p.m.을 600으로 하여놓고 스크류를 돌리지 않고 기관만 공회전 시킬 때 수평거리 20 m인 곳의 No.7에서 수심 10 m마다 50 m까지의 음압은 68,75,62,59,55,51 dB였다.

• Ocean Systems Engineering
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• 제6권1호
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• pp.61-97
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• 2016

This is the second of two papers on the 3D numerical modeling of nearshore hydro- and morphodynamics. In Part I, the focus was on surf and swash zone hydrodynamics in the cross-shore and longshore directions. Here, we consider nearshore processes with an emphasis on the effects of oceanic forcing and beach characteristics on sediment transport in the cross- and longshore directions, as well as on foreshore bathymetry changes. The Delft3D and XBeach models were used with four turbulence closures (viz., ${\kappa}-{\varepsilon}$, ${\kappa}-L$, ATM and H-LES) to solve the 3D Navier-Stokes equations for incompressible flow as well as the beach morphology. The sediment transport module simulates both bed load and suspended load transport of non-cohesive sediments. Twenty sets of numerical experiments combining nine control parameters under a range of bed characteristics and incident wave and tidal conditions were simulated. For each case, the general morphological response in shore-normal and shore-parallel directions was presented. Numerical results showed that the ${\kappa}-{\varepsilon}$ and H-LES closure models yield similar results that are in better agreement with existing morphodynamic observations than the results of the other turbulence models. The simulations showed that wave forcing drives a sediment circulation pattern that results in bar and berm formation. However, together with wave forcing, tides modulate the predicted nearshore sediment dynamics. The combination of tides and wave action has a notable effect on longshore suspended sediment transport fluxes, relative to wave action alone. The model's ability to predict sediment transport under propagation of obliquely incident wave conditions underscores its potential for understanding the evolution of beach morphology at field scale. For example, the results of the model confirmed that the wave characteristics have a considerable effect on the cumulative erosion/deposition, cross-shore distribution of longshore sediment transport and transport rate across and along the beach face. In addition, for the same type of oceanic forcing, the beach morphology exhibits different erosive characteristics depending on grain size (e.g., foreshore profile evolution is erosive or accretive on fine or coarse sand beaches, respectively). Decreasing wave height increases the proportion of onshore to offshore fluxes, almost reaching a neutral net balance. The sediment movement increases with wave height, which is the dominant factor controlling the beach face shape.

• 한국전자파학회논문지
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• 제16권5호
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• pp.526-533
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• 2005

본 논문에서는 GPS 중심 주파수 1.575 GHz에서 마이크로스트립 안테나의 공진 길이 방향 양끝을 접거나 또는 네 방향 끝을 패치 아래로 모두 접어들이는 방법으로 선형 편파와 원형 편파 마이크로스트립 안테나의 소형화시키는 방법을 제시하고 설계, 제작하였다. 먼저 선형 편파의 경우, 마이크로스트립 안테나를 수직으로 내린 구조로써 안테나의 가시 길이를 $31.7\%(\varepsilon_r=1.06)$ 단축시켰으며, 이러한 접혀진 상태의 안테나를 다시 한번 안테나의 중심방향으로 접어 넣는 구조로 선형 편파 마이크로스트립 안테나를 구현하였다 그 결과 안테나의 가시 길이 단축율은 $73.6\%$이었으며 이득 5.12 dBd를 얻었다 -10 dB bandwidth는 $64MHz(4\%)$이고, E-plane과 H-plane의 HPBW는 각각 $151^{\circ},\;79.2^{\circ}$이었다. 또한 원형 편파의 경우, 네 방향 모두 선형 편파 안테나의 폴디드 구조를 적용시켰으며 접혀 넣어진 밑면의 면적 활용도를 높이기 위해 삼각형 구조로 설계하였다. 이때 안테나의 가시 면적 축소율은 $72.5\%$이었으며, 이득은 3.96 dBd이었다. -10 dB bandwidth는 $84 MHz(5.3\%)$, E-plane과 H-plane의 HPBW는 각각 $80.6^{\circ}$과 $82.1^{\circ}$이었다 이 결과들로부터, 선형 편파와 원형 편파의 폴디드 마이크로스트립 안테나가 일반적인 마이크로스트립 패치 안테나의 특성을 유지하면서 소형화되었기 때문에 본 논문에서 제안된 구조가 소형화에 적합함을 확인할 수 있었다.

• Journal of Yeungnam Medical Science
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• 제4권1호
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• pp.1-15
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• 1987

Magnetic Resonance (M.R.) is rapidly emerging technique that provides high quality images and potentially provides much more diagnostic information than do conventional imaging modalities. M.R.I. is conceptually quite different from currently used imaging methods. The complex nature of M.R.I. allows a great deal of flexibility in image product ion and available information, and key points are as follows. 1. M.R.I. offers a non-invasive technique with which to gene rate in vivo human images without ionizing radiation and with no known adverse biological effects. 2. Imaging mechanism of M.R.I. is quite different from conventional imaging modality and for more accurate diagnostic application, It is necessary for physician to understand imaging mechanism of M.R.I. 3. M.R. makes available basic chemical parameters that may provide to be useful for diagnostic medical imaging and more specific pathophysiologic information which are not available by alternate techniques. 4. M.R. can be produced by number of different methods. This flexibility allows the imaging technique to be applicated for particular clinical purpose. Multiplanar and three dimensional imaging may extend the imaging process beyond the single section available with current CT. 5. Future directions include efforts to; a. Further development of hard ware b. More fasternning scan time c. Respiratory and cardiac gated imaging d. Imaging of additional nuclei except hydrogen e. Further development of contrast media f. M.R. in vivo spectroscopy g. Real time M.R. imaging.

• Journal of Microbiology
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• 제38권2호
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• pp.80-87
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• 2000

The nucleotide sequence of the luxC gene coding for lux-specific fatty acyl-CoA reductase and the upstream DNA (325bp)of the structural gene from bioluminescent bacterium, Photobacterium phosphoreum, has been deternubed. An open reading frame extending for more than 20 codons in 325 bp DNA upstream of luxC was not present in both directions. The lux gene can be translated into a polypeptide of 54 kDa and the amino acid sequences of lux specific reductases of P. phosphoreum shares 80, 65, 58, and 62% identity with those of the Photobacterium leiognathi, Vibrio fischeri, Vibrio harveyi, and Xehnorhabdus luminescenens reductases, respectively. Analyses of codon usage, showing that a high frequency (2.3%) of the isoleucine codon, AUA, in the luxC gene compared to that found in Escherichia coli genes (0.2%) and its absence in the luxA and B genes, suggested that the AUA codon may play a modulator role in the expression of lux gene in E. coli. The structural genes (luxC, D, A, B, E) of the P. phosphoreum coding for luciferase (${\alpha}$,${\beta}$) and fatty acid reductase (r, s, t) polypeptides can be expressed exclusively in E. coli under the T7 phage RNA polymerase/promoter system and identificationof the [35S]methionine labelled polypeptide products. The degree of expression of lux genes in analyses of codon usage. High expression of the luxC gene could only be accomplished in a mutant E. coli 43R. Even in crude extracts, the acylated acyl-CoA reductase intermediate as well as acyl-CoA reductrase activities could be readily detected.

• Journal of the Korean Statistical Society
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• 제30권2호
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• pp.193-217
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• 2001

Despite of the rich literature in discriminant analysis, this complicated subject remains much to be explored. In this article, we study the theoretical foundation that supports Fisher's linear discriminant analysis (LDA) by setting up the classification problem under the dimension reduction framework as in Li(1991) for introducing sliced inverse regression(SIR). Through the connection between SIR and LDA, our theory helps identify sources of strength and weakness in using CRIMCOORDS(Gnanadesikan 1977) as a graphical tool for displaying group separation patterns. This connection also leads to several ways of generalizing LDA for better exploration and exploitation of nonlinear data patterns.

• 응용통계연구
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• 제8권2호
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• pp.65-75
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• 1995

설명변수 축소방법들인 Sliced Inverse Regression과 Principal Hessian Directions에서는 효과적 차원축소공간의 차원을 결정하기 위하여 설명변수의 정규성과 충분한 수의 자료가 요구되는 점근적검정(asymptotic test)을 제시하고 있다. 본 연구에서는 Cook과 Weisberg(1991)가 제안하였던 순열검정통계량(permutation test statistic)을 개발하여 SIR과 PHD에서 제시된 점근적 검정 통계량과 검정력을 비교하기로 한다.

• 한국ITS학회 논문지
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• 제21권3호
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• pp.62-72
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• 2022

본 논문에서는 초소형 드론에 탑재가 가능하도록 소형화한 GPS 대역(L₁ 대역 중심 주파수 : 1.575 GHz) 안테나를 제안하였다. 소형화는 λ/4 마이크로스트립 안테나를 기저로 섭동법을 적용시키고, 패치 가장자리의 전류 길이를 길게 하는 개념으로 실현시켰다. 제안된 안테나는 10 mm × 9 mm × 10 mm(0.05 λ × 0.05 λ × 0.05 λ) 크기의 스티로폼(ε_r=1.06, 두께=10 mm) 표면에 장착 가능한 인쇄형으로 제작하였다. 임피던스 매칭을 위해 급전 선로의 두께 및 길이, 단락 스터브 간의 간격을 조절하였으며, 그 결과, 제작된 안테나는 중심주파수 1.575 GHz에서 S₁₁은 -38.6 dB를 얻었으며, 방사 패턴 측정 결과, 0° 방향에서 xz-plane의 E_θ 성분 이득 1.87 dBi, yz-plane의 Eθ 성분 이득 -1.7 dBi의 특성을 얻었다. 결과적으로, λ/2 마이크로스트립 패치 안테나와 비교하여 98.8 %의 체적 축소율을 확보함으로써, 초소형 드론에 탑재가 가능한 GPS 안테나로써 활용이 가능함을 제시하였다.

• Restorative Dentistry and Endodontics
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• 제29권5호
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• pp.413-422
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• 2004

Established microleakage tests have their own disadvantages. In this study, 3D reconstruction method was tried to overcome these disadvantages. Four types of microleakage tests were used and relationships among them were estimated: penetrated dye volume: marginal adaptability: degree of dye penetration and relative penetrated length to cavity wall. Twenty-four Class V cavities were bulk filled with composite (Esthet X) following surface treatments: N group (no treatment): E group (etching only): T group (etching + Prime & Bond NT). 50% silver nitrate was used as a dye solution after thermocycling ($5^{\circ}C{\;}&{\;}55^{\circ}C$, 1.000 times). Teeth were serially ground with a thickness of 0.2 mm. Volume of dye penetration was estimated from a three-dimensionally reconstructed image with a software (3D-DOCTOR). Percentage of margin without gap was estimated from SEM and degree of dye penetration and the relative length of dye penetration to overall cavity wall were also estimated. ANOVA and Scheffe test for dye volume, Kruskal-Wallis and Mann-Whitney test for marginal quality, Spearman's rho test for checking of relationships among methods were used. The results were as follows: 1. Dye penetration could be seen from several directions, furthermore, its volumetric estimation was possible. 2. Reverse relationship was found between dye volume and marginal quality (r = -0.881/ p = 0.004). 3. Very low relationship was seen between dye volume and two-dimensional tests (degree of dye penetration and relative length). However, 2D evaluation methods showed high relationship (p = 0.002-0.054) each other. 4. Three times vertical section could be recommended as a 2D test.