• Mycobiology
• /
• 제37권3호
• /
• pp.240-242
• /
• 2009

An improved procedure for preparing PCR cloning vectors was developed. This procedure includes the incorporation of adapters to create XcmI restriction enzyme sites in pBluescript II SK(+) vectors, digestion with XcmI followed by further digestion of the small fragment produced by XcmI digestion with additional enzymes, and purification with PCR purification kits. Using this procedure, PCR cloning vectors with high ligation efficiencies and low blue or false-positive colonies were obtained.

• The Korean Journal of Ecology
• /
• 제15권2호
• /
• pp.117-125
• /
• 1992

TWINSPAN(two-way indicator species analysis), DCCA(detrended canonical correspondence analysis) and polar ordination method wee used so as to analyze the the relation between forest vegetation and hibitat of mudungsan(1, 187m) located in kwangju area. Vegetationsurvey consulted 1:25, 000 topographical map, set up 41 quadrats and analyzed from April, 1990 to August, 1991. Forest vegetation of mudungsan was classifild to quercus acutissima community, fraxinus mandshurica community, quercus mongolica community, quercus serrata community, quercus dentata community, quercus variabilis community, and pinus densiflora community by TWINSPANmethod, and this almost coincide with the result of plar ordination. according to DCCA analysis, P. densiflora community was formed in xeric and low altitude region which soil nutrient was poor, compared with other communities. q. variabilis and q. acutissima community wee distributed in the region that low altitude and organic matter content was comparatively low, but q. acutissima community was formed in a damp region while q. variabilis community in a xeric region. q. mongolica and f. mandshurica formed the communities in a high altitude region, especially f. mandshurica cmmunity was distributed in a high humidity region. According to polar ordination analysis, the forest vegetation was classified to 7 communities by means of environmental gradient such as humidity, organic matter, ph, temperature, c.e.c and P2O5.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권5호
• /
• pp.550-556
• /
• 2016

Polar codes are one of the most favorable capacity-achieving codes due to their simple structure and low decoding complexity. However, because of the disappointing decoding performance realized using conventional successive cancellation (SC) decoders, polar codes cannot be used directly in practical applications. In contrast to conventional SC decoders, list SC (SCL) decoders with large list sizes (e.g. 32) achieve performances very close to those of maximum-likelihood (ML) decoders. In SCL decoders with large list sizes, however, hardware increase is a severe problem because an SCL decoder with list size L consists of L copies of an SC decoder. In this paper, we present a low-area SCL decoder architecture that applies the proposed merged processing element-sharing (MPES) algorithm. A merged processing element (MPE) is the basic processing unit in SC decoders, and the required number of MPEs is L(N-1) in conventional SCL decoders. Using the proposed algorithm reduces the number of MPEs by about 70% compared with conventional SCL decoders when the list size is larger than 32.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
• /
• pp.25.2-25.2
• /
• 2008

Polar rain is a spatially uniform precipitation of electrons with energies around 100eV that penetrate into the polar cap region where geomagnetic field lines are connected to the Interplanetary Magnetic Fields (IMF). Since their occurrences depend on the IMF sector polarity, they are believed to originate from the field aligned component of the solar wind. However, statistically direct correlation between polar rain and solar wind has not been shown. In this presentation, we examined specifically the IMF strength influence on the polar rain flux variation by classifying of IMF sector polarities. For this study, we employed the polar rain flux data measured by STSAT-1 and compared them with the solar wind parameters obtained from the WIND and ACE satellites. We found the direct mutuality between polar rain flux and IMF strength with correlation coefficient above 0.5. This proportional tendency appears stronger when the northern hemisphere is in the away sector of the IMF, which could be associated with a favorable geometry for magnetic reconnection. Simple particle trajectory simulation clearly shows why polar rain intensity depends on the IMF sector polarity. These results are consistent with the direct entry model of Fairfield et al.(1985), while low correlation coefficient with solar wind density, the similarity between slops of both energy spectra shows that transport process occur without acceleration.

• 한국측량학회:학술대회논문집
• /
• 한국측량학회 2009년도 춘계학술발표회 논문집
• /
• pp.95-100
• /
• 2009

Global warming melts polar ice, changes ocean currents, creates variation of local climate, and inundates low-altitude regions resulting in disasters to mankind. Accordingly, developed countries including U.S.A. and U.K. spend great amounts of efforts and money to plan and manage research activities on polar ice which is regarded as a key indicator of climate change. The proposed research aims to provide basic information for chasing and monitoring the melting phenomena of polar ice through multiple GPS to enhance the GPS quality.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
• /
• pp.23-26
• /
• 2003

The vector field histogram(VFH) uses a two-dimensional Cartesian histogram grid as a world model. The VFH method subsequently employs a two-stage data-reduction process in order to compute the desired control commands for the vehicle. In the first stage the histogram grid is reduced to a one dimensional polar histogram that is constructed around the robot's momentary location. Each sector in the polar histogram contains a value representing the polar obstacle density in that direction. In the second stage, the algorithm selects the most suitable sector from among all polar histogram sectors with a low polar obstacle density, and the steering of the robot is aligned with that direction. We applied this algorithm to our four-legged robot.

• Ocean and Polar Research
• /
• 제25권1호
• /
• pp.53-62
• /
• 2003

Inductively coupled plasma mass spectrometry (ICP-MS) is useful instrument for determining abundance of rare earth elements, due to very low detection limits and rapid data acquisition. In this article, two methods are used for decomposition of alkaline rocks; close vessel acid digestion and $Na_2Co_3$ fusion. The two analytical results show good agreements. Considering total dissolved solids and detection limits, the most adequate dilution factor is 5,000 times. Polyatomic ion interferences during analysis can give rise to Inaccuracies. After correction from oxide and hydroxide interference, the analytical result show 20-30% decrease for Gd and Tm, 10-20% decrease for Tb and Er. In comparing the analytical results from KORDI with other institutes, most rare earth elements abundance show good agreements except Lu.

• Journal of Ecology and Environment
• /
• 제37권2호
• /
• pp.69-79
• /
• 2014

Soil organic carbon (SOC) in the Arctic is vulnerable to climate change. However, research on SOC stored in the high Arctic regions is currently very limited. Thus, this study was aimed at understanding the distribution and characteristics of SOC with respect to geomorphology and vegetation in Svalbard. In August 2011, soil samples were collected near the Vestre Lov$\acute{e}$nbreen moraine. Sampling sites were chosen according to altitude (High, Mid, and Low) and differences in levels of vegetation establishment. Vegetation coverage, aboveground biomass, and SOC contents were measured, and density-size fractionation of SOC was conducted. The SOC content was the highest in the Mid site ($126.9mg\;g^{-1}$) and the lowest in the High site ($32.1mg\;g^{-1}$), although aboveground biomass and vegetation coverage were not different between these two sites. The low SOC content measured at the High site could be related to a slower soil development following glacial retreat. On the other hand, the Low site contained a high amount of SOC despite having low vegetative cover and a high ratio of sand particles. These incompatible relationships between SOC and vegetation in the Low site might be associated with past site disturbances such as runoff from snow/glacier melting. This study showed that geomorphological features combined with glacier retreat or melting snow/glacier effects could have affected the SOC distribution and vegetation establishment in the high Arctic.

• Journal of Communications and Networks
• /
• 제17권4호
• /
• pp.328-338
• /
• 2015

Three areas of ongoing research in channel coding are surveyed, and recent developments are presented in each area: Spatially coupled low-density parity-check (LDPC) codes, nonbinary LDPC codes, and polar coding.

• 한국지구과학회지
• /
• 제42권6호
• /
• pp.734-751
• /
• 2021

이 연구는 극지 소양 교육을 학교 교육과정에 반영하기 위한 기초 자료를 마련하고자 수행되었다. 교육과정을 현장에서 구현하는 교사들이 지닌 극지 인식과 교수 경험, 극지 관련 인지적·정의적 특성을 조사했다. 대도시 및 중소도시 10개교의 초·중·고등학교 교사 56명을 대상으로 극지 관련 인식, 교수 현황, 극지 지식, 극지와 기후 변화에 대한 신념 및 태도를 포함한 설문을 실시했다. 그 결과, 교사들은 극지 정보에 대한 효능감은 낮은 편이나, 극지와 기후 변화 문제 해결에 있어 교육자의 위상을 긍정적으로 평가하고 있으며 세계 시민적 가치를 실용적 목적보다 우선했다. 학교에서 극지와 기후 변화 문제를 교수한 경험은 교과와 비교과에 걸쳐 다양했지만, 완성된 형태의 교수-학습 자료를 제공받기 원하는 등 교수 개발에 있어 수동적인 면모를 보였다. 인지적 측면에서 교사들은 극지 변화와 기후가 영향을 주고받는 작동 원리와 과정에 대해 다소 모호한 이해를 드러냈다. 정의적 측면에서 대부분 교사들은 학교급을 초월해서 극지 관련 문제에 대한 신념과 태도에서 높은 경향이 나타났지만, 행동 선택은 근소하게 낮았다. 이상의 결과를 바탕으로 극지 소양을 증진시키기 위한 기회 및 자료 제공, 가치 및 태도 형성을 위한 다양한 맥락의 교육 소재 발굴, 극지 연구 자료를 활용한 교육 자료 개발, 학생과 교사를 포함한 극지 지식에 대한 오개념 파악, 초등 교사의 극지 소양 강화, 정의적 태도와 가치관 함양 등의 시사점을 제안했다.