• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.247-248
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• 2008

The etching characteristics of Titanium Nitride (TiN) and etch selectivity of TiN to $SiO_2$ and $HfO_2$ in $CH_4$/Ar plasma were investigated. It was found that TiN etch rate shows a non-monotonic behavior with increasing both Ar fraction in $CH_4$ plasma, RF power, and gas pressure. The maximum TiN etch rate of nm/min was obtained for $CH_4$ (80%)/Ar(20%) gas mixture. The plasmas were characterized using optical emission spectroscopy (OES) analysis measurements. From these data, the suggestions on the TiN etch characteristics were made.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.45-45
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• 2008

$SrTiO_3$/Organic composites 는 Inorganic/organic 복합재료로, 유전 특성이 우수하고, 저온하여 제조단가의 감소가 가능하다. 이를 바탕으로 $SrTiO_3$/Organic composites 복합재를 이용한 가능성을 확인하기 위해 Multilayer 구조의 Coupler를 설계, 제작 후 특성을 분석하였다. Coupler 는 RF signal을 분기하기 위한 목적으로 평행한 한 쌍의 Conductor line 구조를 가진다. 2개의 Line 의 길이를 특정주파수 $f_0$의 wavelength $\lambda$/4 로 설계하여 서로 근접 시켰을 때 $f_0$를 중심으로 RF 신호 분기 현상이 나타난다. 보다 넓은 대역에 걸쳐서 신호분기를 하기 위해서는 두 line 간의 간격을 좁혀 Signal coupling 효과를 증가 시킨다. single layer conductor 구조에서는 물리적인 한계가 있으므로, multilayer 구조를 사용하면 보다 넓은 대역의 Coupled line coupler 로서 기능하게 된다.

• Journal of Communications and Networks
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• v.9 no.2
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• pp.159-166
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• 2007

In this paper, we propose an efficient and robust interference mitigation technique based on a nullsteering multi-user multiple-input multiple-output (MU-MIMO) spatial division multiple access (SDMA) scheme for frequency sharing between IMT-advanced and fixed satellite service (FSS) in the 3400-4200 and 4500-4800 MHz bands. In the proposed scheme, the pre-existing precoding matrix for SDMA unitary precoded (UPC) MIMO proposed by the authors is modified to construct nulls in the spatial spectrum corresponding to the direction angles of the victim FSS earth station (ES). Furthermore, a numerical formula to calculate the power of the interference signal received at the FSS ES when IMT-Advanced base stations (BS) are operated with the interference mitigation technique is presented. This formula can be derived in closed form and is simply implemented with the help of simulation, resulting in significantly reduced time to obtain the solution. Finally, the frequency sharing results are analyzed in the co-channel and adjacent channel with respect to minimum separation distance and direction of FSS earth station (DOE). Simulation results indicate that the proposed mitigation scheme is highly efficient in terms of reducing the separation distance as well as robust against DOE estimation errors.

• Journal of Environmental Impact Assessment
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• v.20 no.3
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• pp.411-424
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• 2011

Over the past three decades, Korea has undertaken a series of reforms to improve development policy, plans and programs, including measures to mainstream the environment across all major sectors. Despite of these efforts, there has been still the lack of capacity to fully assess the environmental impacts as well as sustainable implications of development projects and strategies. At the level of regional and sectoral development plans, the development of strategic environmental assessment SEA systems continues to remain at a relatively early stage in the region with fewer examples of fully operational processes or effective practice. This study shows a further information to our understanding of the EIA and SEA systems and their implementation in Korea. It affords a number of insights into strengths and weaknesses of the current action in different countries, and identifies an agenda of needs and options for capacity building for implementing the EIA enactment.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.05a
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• pp.214-223
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• 2005

In order to recover valuable metals from fine-grained electronic waste, bioleaching of Cu, Zn, Al, Co, Ni, Sn and Pb were carried out using Aspergillus niger as a leaching microorganism in a shaking flask. Aspergillus niger was able to grow in tile presence of electronic scrap. The formation of organic acids(citric and oxalic acid) from Aspergillus niger caused the mobilization of metals from waste electronic scrap. In a preliminary study, in order to obtain the data on the leaching of Cu, Zn, Al, Co and Ni, the metal leaching behaviours were accomplished using Organic acid(Citric acid and Oxalic acid) instead of Aspergillus niger. At the electronic scrap concentration of 50g/L, Aspergillus niger were able to leach more than 95% of the available Cu, Co. But Al, Zn, Pband Sn were able to leach about 15-35%. Ni and Fe were detected in the leachate less than 10%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.17-18
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• 2007

The etching characteristics of Zinc Oxide (ZnO) and etch selectivity of ZnO to $SiO_2\;in\;BCl_3$/Ar plasma were investigated. It was found that ZnO etch rate shows a non-monotonic behavior with increasing both Ar fraction in $BCl_3$ plasma, RF power, and gas pressure. The maximum ZnO etch rate of 50.3 nm/min was obtained for $BCl_3$ (80%)/Ar(20%) gas mixture. The plasmas were characterized using optical emission spectroscopy (OES) analysis measurements while chemical state of etched surfaces was investigated with X-ray photoelectron spectroscopy (XPS). From these data the suggestions on the ZnO etch mechanism were made.

• Animal Systematics, Evolution and Diversity
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• v.36 no.3
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• pp.228-231
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• 2020

Pseudohelice subquadrata (Dana, 1851) is endangered due to its restricted habitat; hence, it has been designated as a marine protected species and endangered species by law in Korea. It has been recorded only Jeju-do and Geomun-do, Republic of Korea. The present study, is the first report on a cytochrome c oxidase subunit I DNA barcode for P. subquadrata. The maximum intra-specific genetic distance among all P. subquadrata individuals was found to be 0.5%, whereas inter-genetic distance within the same genus was 17.2-21.5% compared with Helice tientsinensis (Rathbun, 1931), H. tridens (De Haan, 1835), H. epicure (Ng et al., 2018), and Helicana wuana (Rathbun, 1931). Our barcoding data can thus be used as reference for restoration and conservation studies on P. subquadrata, which are designated as marine protected species.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.119-132
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• 2007

This study was performed to determine whether a pulse analyzer was useful 1) to characterize the variables of pulse wave of cerebral infarction patieno (CI), compared with those of healthy subjects, as well as 2) to determine Sasang Constitution in CI and healthy subjects. 1. Calibrated in Gwan, the amount of energy(Energy), height of main peak(H1), height of aorticvalley(H2), height of aortic peak(H3), total area of pulse wave(At), and area of main peak width(Aw) of the CI group were higher than those of the healthy group. 2. Calibrated in Cheek, Energy, H1, H2, H3, height of valve valley(H4), At, Aw, and main peak angle(MPA) of the CI group were higher than those of the healthy group. 3. Among the healthy (subjects) group, Taeumin showed the highest contact pressure(CP) and height of valve peak(H5) calibrated in Chon. The main peak width divided by whole time of pulse wave(MPW/T) calibrated in Gwan and Cheok, was highest in Soyangin and was lowest in Taeumin. The H3 divided by H1(H3/H1) and the time to valve valley minus the time to main peak and divided by T[(T4-T1)/T] calibrated in Cheek were highest in Soyangin. The time to main peak(T1) was longest in Soumin. 4. Among the CI group, At calibrated in Chon was widest in Taeumin and was narrowest in Soumin The time to aortic peak(T3) calibrated in Cheek was longest in Soumin and was shortest in Soyangin. The time to valve peak(T5) was shortest in Soyangin. 5. There were main effects of cerebral infarction in the area of systolic period(As) and area of diastolic period(Ad) calibrated in Chon, Energy calibrated in Cwan, and Energy, H1, H2, H3, (H4+H5)/Hl, and MPA calibrated in Cheek. 6. There were main effects of Sasang Constitution in (T4-T1)/T, area of systolic period(As), and Ad calibrated in Chon. 7. The interactions between the cerebral infarction and Sasang Constitution were observed in H5/H1 , T, At, As, Ad, and MPA calibrated in Chon, H4, T4, (T4-T1)/T, As, and Ad calibrated in Cwan, and 74,75, and MPW calibrated in Cheok. Therefore, we concluded that pulse analyzer was useful to determine the risk degree of cerebral infarction and Sasang Constitution.

• Journal of Life Science
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• v.22 no.2
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• pp.200-208
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• 2012

The characteristics of mycelium growth of Sparassis crispa KGFS08 and KFRI746 in liquid culture were investigated. The optimum growth of the mycelium of S. crispa was observed in the KTM medium. The best carbon source was starch. In terms of nitrogen sources, tryptone affected mycelial growth in the liquid culture. The optimal culture conditions were pH 4.0-5.0 in STK medium [3% (w/v) starch, 0.3% (w/v) tryptone, 0.1% (w/v) $KH_2PO_4$, and 0.1% (w/v) folic acid].

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.110-116
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• 2006

In this paper the algorithm of a methodology for the calculation of spectrum requirements was implemented. As well, the influence of traffic distribution ratio among radio access technology groups, spectral efficiency, and flexible spectrum usage(FSU) margin was analyzed in terms of the spectrum requirements, with a view toward for future development of IMT-2000 and systems beyond IMT-2000. The ratio of the spectrum requirement to the traffic distribution ratio is approximately $1\;GHz/20\;\%$, and the spectrum requirement varies from 5 to 9 GHz. As the FSU margin increases by 1.0 dB, the total spectrum requirement decreases by 0.9 dB. The required spectrum for the market input parameter, ${\rho}=0.5$ is 801.63 MHz, while the required spectrum for ${\rho}=1.0$ is 6295.4 MHz. It can be concluded that the market input parameter is the most effective parameter in the calculation of spectrum requirements.