• 한국지리정보학회지
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• 제11권4호
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• pp.122-138
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• 2008

도시의 삶의 질 분석에 대한 화소기반 기법은 복잡성이라는 조건 하에서의 공간의사결정문제로 간주될 수 있다. 왜냐하면, 도시의 삶의 질 분석은 상이한 가중치가 부여된 여러 개의 평가기준에 기반을 두고 높은 혹은 낮은 수준의 삶의 질을 가진 지역을 도시공간에서 탐색하기 때문이다. 이러한 도시의 삶의 질 분석에는 측정단위가 다른 여러 개의 평가기준들의 부적절한 스케일링, 평가자의 판단에 있어서 비구조적인 주관성 그리고 래스터 GIS환경에서 대량의 데이타 처리 등과 같은 어려움이 있다. 도시의 삶의 질 분석에 있어서 이러한 비구조적 문제를 해결하기 위한 대안적인 접근방법의 개발이 필요하다. 이러한 점에서, 본 연구는 래스터 GIS 환경에서 도시의 삶의 질을 평가하기 위한 공간적 다기준평가 기법을 제안하고자 한다. 이러한 방법론은 애틀란타 대도시권을 사례로 예시되어진다. 본 연구에서 사용된 방법론은 도시의 삶의 질을 평가하는데 있어서 새로운 대안적인 접근방법으로 제시된다.

• Progress in Superconductivity
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• 제3권2호
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• pp.241-246
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• 2002

We have performed the current and voltage loading tests of resistive superconducting fault current limiters (SFCLS) based on $YBa_2$$Cu_3$$O_{7}$(YBCO) films with the diameter of 2 inch. The SFCL consists of meander-type YBCO stripes covered with 200 nm Au layer grown in situ for current shunt and heat dispersion at hot spots. The minimum quench current of an SFCL unit was about 25 Apeak. Seven SFCL units were connected in parallel fur the current load ing tests at power source of 100 $V_{rms}$ $/2,000A_{rms}$. This SFCL units had maximum limiting current of 170 Apeak during the fault instant and then successfully controlled the fault current below 100 Apeak within 1~2 msec after short circuit. Increased short current also reduced the quench completion time with little change of current limiting characterization. We connected six SFCL units in series fur the voltage loading tests at power source of $1,200 V_{rms}$/170 $A_{rms}$ at this time. The shunt resistors were inserted into each SFCL unit to eliminate power imbalance originated from serial connection of SFCL units. Each SFCL unit was quenched simultaneously during the fault condition. The current increased up to 40 $A_{peak}$ and decreased to 14 $A_{peak}$ after 3 cycles. Quench was completed within 1 msec after the fault. We confirmed operating characteristics of 140 kVA($120 A_{rms}$ $\times$ 1,200 $V_{rms}$) SFCL and presented the manufacturing possibility of 3.3 kV SFCL using 4 inch YBCO films.BCO films.lms.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.46-54
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• 1996

This study was carried out to investigate the vacuum drying characteristics of 50mm- and 75mm- thick tree disks of some domestic softwoods for substituting the conventional hardwoods as the materials for wood crafts. Though the elapsed drying times from green to in-use moisture content(MC) were largely shortened by vacuum drying, the tree disks treated by EWS couldn't be dried to in-use MC, and so sapwood stains also were occurred severely. We suggest EWS treatment is undesirable for the species with very high sapwood portion or vacuum drying with hot water circulation heating system. Heart checks were slight, but sapwood checks, which have never been trouble in drying process of tree disks, were severe. For the reasonable explanation it is suggested MC differences between sapwood and heartwood were large and most of tree disks had already no barks before drying test. Ginkgo was vacuum-dried with very slight drying defects such as heart checks, sapwood checks. V-cracks and sapwood stains. In Korean red pine and pitch pine V-cracks were severely occurred. And it was found the special feature that most of these defected tree disks contained several V-cracks within one tree disk. It can be considered as the causes that the region of sapwood was defected by the several checks at the early drying stage because of the steep MC gradient along the radial direction, and then at the later drying stage the drying stresses due to differential shrinkage were concentrated on these brittle spots.

• 환경생물
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• 제20권4호
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• pp.316-324
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• 2002

To investigate the mutational spectrum of laccase (Lac) genes (lac -A and lac -B) involved in degrading lignin which is the recalcitrant cell wall polymer, the genes of the Pleurotus ostreatus mutants induced by gamma ray radiation were amplified by PCR and were cloned. All partial lac-A genes of 4 mutants (PO-6, -7, -14 and -15) consisted of 1763 base pairs due to the deletion of two bases (491-nt and 492-nt) and addition of one base (875-nt) in 1764 base pairs of lac -A gene of PO-1. Totally 36 mutational hot spots were detected and 32 positions were mutated in all of those 4 mutants simultaneously. These mutations were predominantly A : T -> G : C transitions (40%). Putative amino acid sequences of lac -A genes of mutants have one simultaneous mutated residue (from Thr-44 to Ala-44). The 1764 bp of partial lac -B gene was cloned only in PO -5 mutant and contained 19 mutated bases. These mutations were predominantly G : C->A : T transitions (45%). Lac-B protein of PO-5 has two mutated residues of Glu-290 and His-363 from Ala-290 and Phe-363, respectively. The hyper-mutational positions were concentrated in specific regions of between 50-nt and 900-nt in lac genes. These results suggested that the mutational hotspots responded to gamma radiation could be in some genes, at least lac -A and lac -B of p. ostreatus.

• 한국물환경학회지
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• 제31권5호
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• pp.543-555
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• 2015

The existing standard for soil erosion risk assessment has limitations in sustainable topsoil management since the fixed criteria are applied to determination of soil erosion risk areas regardless of land use types. It may not be necessary to apply soil erosion best management practices to agricultural areas with high potential of soil erosion because human or economic damage derived from soil erosion might be tiny in that region. Furthermore, the fixed criterion with absolute values can select too many hot spots of soil erosion to conduct efficient soil erosion management. Thus, objective of this study was to suggest the relative criteria using statistical analysis for efficient soil erosion management. In future, the relative indices for soil erosion prevention should be improved to provide a priority of soil erosion management considering economic damage from soil erosion or functional values of soil with quantitative soil erosion. Additional researches will be needed to reflect a regional characteristics and to consider various land use types and different criteria.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.636-636
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• 2013

Since first discovery of strong Raman spectrum of molecules adsorbed on rough noble metal, surface enhanced Raman scattering (SERS) has been widely used for detection of molecules with low concentration. Surface plasmons at noble metal can enhance Raman spectrum and using Au nanostructures as substrates of SERS has advantages due to it has chemical stability and biocompatibility. However, the photoluminescence (PL) background from Au remains a problem because of obtaining molecular vibration information. Recently, graphene, two-dimensional atomic layer of carbon atoms, is also well known as PL quenchers for electronic and vibrational excitation. In this study, we observed SERS of single layer graphene on or under monolayer of Au nanoparticles (NPs). Single layer graphene is grown by chemical vapor deposition and transferred onto or under the monolayer of Au NPs by using PMMA transfer method. Monolayer of Au NPs prepared using Langmuir-Blodgett method on or under graphene surface provides closed and well-packed monolayer of Au NPs. Scanning electron microscopy (SEM) and Raman spectroscopy (WItec, 532 nm) were performed in order to confirm effects of Au NPs on enhanced Raman spectrum. Highly enhanced Raman signal of graphene by Au NPs were observed due to many hot-spots at gap of closed well-packed Au NPs. The results showed that single layer graphene provides larger SERS effects compared to multilayer graphene and the enhancement of the G band was larger than that of 2D band. Moreover, we confirm the appearance of D band in this study that is not clear in normal Raman spectrum. In our study, D band appearance is ascribed to the SERS effect resulted from defects induced graphene on Au NPs. Monolayer film of Au NPs under the graphene provided more highly enhanced graphene Raman signal compared to that on the graphene. The Au NPs-graphene SERS substrate can be possibly applied to biochemical sensing applications requiring highly sensitive and selective assays.

• 대기
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• 제24권2호
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• pp.245-251
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• 2014

Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.

• 디지털융복합연구
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• 제18권1호
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• pp.111-119
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• 2020

본 연구에서는 한국을 방문한 개별 여행자들의 디지털 기록을 수집하여 정량적 통계 분석과 소셜 네트워크 분석(SNA)을 통해 한국을 방문하는 개별 중국 여행자들의 한국 관광 경로의 특징을 분석하였다. 연구결과 서울, 제주도, 부산 및 대구는 한국을 찾는 중국 여행자들의 주요 방문 장소이며, 중국의 청도, 천진, 심양, 홍콩, 포산 및 마카오는 한국을 찾는 중국 개별 여행자들의 주요 중계지 임을 알 수 있었다. 본 연구는 한국을 찾는 중국 개별 여행자들의 표본 특성과 각 여행 노드의 기능적 위치설정을 정확히 확인함으로써 정밀한 관광 마케팅과 관광 노선 개발에 활용할 수 있는데 의의가 있다. 향후 본 연구에 사용된 데이터의 추출 기간을 확대하고 더 많은 샘플을 확보하여 관광 경로의 연간 변동특성과 주요 방문지의 변동 특성을 분석할 필요가 있다.

• Journal of Forest and Environmental Science
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• 제25권3호
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• pp.177-185
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• 2009

Dryland species and ecosystems have developed unique strategies to cope with low and sporadic rainfall. They are highly resilient and recover quickly from prevailing disturbances such as fires, herbivore pressure and drought. Dryland people have engineered pastoral and farming systems, which are adapted to these conditions and have sustained the livelihoods of dryland people for centuries. In this article, we present the status of potentials and threats to dryland biodiversity and explore options for its conservation and sustainable use. Findings of the research can be summarized as follows: (i) The ecosystem goods and services are highly valued by the community but mechanism for wise use of the resources has disappeared, (ii) forests are under the ownership of the government but the local community is the realistic custodian of the forests through village leaderships and environmental committees; (iii) the immediate major threat to dryland biodiversity held in the forests appears to be the degradation of ecosystems and habitats caused by new and powerful forces of environmental degradation such as large scale irrigation of rice farms, poverty-induced overexploitation of natural resources, and disappearance and ignorance of traditional institutions for management of dryland biodiversity. These new forms of disturbances often overpower the legendary resilience of dryland ecosystems and constitute potentially serious threats to dryland biodiversity. Forests, wetlands and oases all of which are micro hot spots of dryland biodiversity, appear to be particularly vulnerable hence the need to set up some rules and regulations for sustainable utilization of these resources.

• 천문학회보
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• 제38권1호
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• pp.52.1-52.1
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• 2013

We present preliminary results of the photometric variability analysis in SDSS r, i and z bands for a newly confirmed FU Orionis-type object, HBC 722. We observed HBC 722 from 2011 April to 2012 November, with Camera for Quasars in Early uNiverse (CQUEAN) attached to the 2.1m Otto Struve telescope at McDonald Observatory, USA. The rapid cadence monitoring observations (minute timescale) were conducted in chosen photometric nights during observation campaigns to get adequate number of samples for short term period analysis. As this object is in active state, temperature at the inner disk/stellar surface can be characterized by the colors between r, i and z bands. Also, It is theorized that a sudden cataclysmic accretion associated with FU Orionis-type outburst can give rise to detectable "hot spots" on the central star and rotational asymmetries in the disk instability region. Thus the periodic variabilities of three bands would trace the stellar rotation or Keplerian rotation at the instability region of the inner accretion disk. Additionally, the range of instabilities could be estimated on the assumption of a temperature distribution for the HBC 722 disk. This analysis can provide a clue for understanding enhanced disk accretion of Class II young stellar object.