• 자원환경지질
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• 제55권4호
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• pp.339-352
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• 2022

환경 기준 항목이 증가하거나 강화되면서 지질기원에 의한 중금속 오염사례가 증가하고 있으며, 토양이나 지하수의 기준치 초과양상에서 자연적 기원인지 인위적 기원인지 구분해야 할 필요성이 높아지고 있다. 본 연구에서는 전국 지화학도 자료에 대한 통계적 처리와 높은 지질축적지수 분포 지역의 지화학적 특성을 평가하여 중금속 원소들의 지질기원 발생요인을 규명하였다. 지화학도가 작성된 Co, Cr, Cu, Ni, Pb, V, Zn 등을 대상으로 하였으며, 초염기성암 또는 초고철질암에서 기원한 Co, Cr, Ni, V이 요인 1로, 비철금속 황화광물에 기인한 Cu, Pb, Zn가 요인 2로 구분되어졌다. 특히 충청지역의 사문암체 분포지역에서 요인 1에 의한 중금속 지질기원 부화현상이 주로 나타나며 이를 포함한 인근지역에서도 오염 위험이 있다. 요인 2의 경우 태백산 및 경남 광화대 등지의 비철금속 광화지역 뿐만 아니라 국내의 전반적인 금-은 광화대 지역에서도 지질기원 부화현상이 우려된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.47-50
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• 2003

Hot-forging Process and die design was made for a large-scale compressor wheel of Ti-6Al-4V alloy with 2-D FE analysis. The design integrated the geometry-controlled approach and dynamic materials modelling(DMM). In order to obtain the processing contour map of Ti-6Al-4V alloy based on DMM, compression tests were carried out in the temperature range of 915$^{\circ}C$ to 1015$^{\circ}C$ and the strain range of 10$\^$-3/s$\^$-1/ to 10s$\^$-1/. In the die design of the compressor wheel using the rigid-plastic FE analysis, forging dimensional accuracy, the capacity of the forging machine and defect-free forging were considered as main design factors. The microstructure of hot forged wheel using the designed die showed a typical alpha-beta structure without forging-defects.

• 대한수학회보
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• 제49권2호
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• pp.395-409
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• 2012

In the study of homology cobordisms, knot concordance and link concordance, the following technical problem arises frequently: let ${\pi}$ be a group and let M ${\rightarrow}$ N be a homomorphism between projective $\mathbb{Z}[{\pi}]$-modules such that $\mathbb{Z}_p\;{\otimes}_{\mathbb{Z}[{\pi}]}M{\rightarrow}\mathbb{Z}_p{\otimes}_{\mathbb{Z}[{\pi}]}\;N$ is injective; for which other right $\mathbb{Z}[{\pi}]$-modules V is the induced map $V{\otimes}_{\mathbb{Z}[{\pi}]}\;M{\rightarrow}\;V{\otimes}_{\mathbb{Z}[{\pi}]}\;N$ also injective? Our main theorem gives a new criterion which combines and generalizes many previous results.

• Journal of applied mathematics & informatics
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• 제36권5_6호
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• pp.359-368
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• 2018

In this paper, we investigate quasi-cyclic codes over the ring $R={\mathbb{F}}_2+v{\mathbb{F}}_2$, where $v^2=v$. We investigate the structure of generators for one-generator quasi-cyclic codes over R and their minimal spanning sets. Moreover, we find the rank and a lower bound on minimum distances of free quasi-cyclic codes over R. Further, we find a relationship between cyclic codes over a different ring and quasi-cyclic codes of index 2 over R.

• Journal of Information Processing Systems
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• 제11권4호
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• pp.495-508
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• 2015

In this paper, a novel robust medical images watermarking scheme is proposed. In traditional methods, the added watermark may alter the host medical image in an irreversible manner and may mask subtle details. Consequently, we propose a method for medical image copyright protection that may remedy this problem by embedding the watermark without modifying the original host image. The proposed method is based on the visual cryptography concept and the dominant blocks of wavelet coefficients. The logic in using the blocks dominants map is that local features, such as contours or edges, are unique to each image. The experimental results show that the proposed method can withstand several image processing attacks such as cropping, filtering, compression, etc.

• 방송공학회논문지
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• 제26권6호
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• pp.692-703
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• 2021

최근 컴퓨터 그래픽 기술의 발전으로 현실의 객체를 더욱 사실적인 가상의 그래픽으로 표현하는 기술의 연구가 활발히 진행되고 있다. 포인트 클라우드는 3차원 공간 좌표와 색 정보 등을 포함하는 수많은 점을 사용해 3차원 객체를 표현하는 기술로 기존의 2차원 영상보다 많은 데이터를 사용하고 데이터 처리에 더욱 복잡한 연산이 필요하므로 포인트 클라우드를 사용한 서비스를 제공하기 위해서는 거대한 데이터 저장 공간과 높은 성능의 연산 장치가 필요하다. 현재 국제 표준기구인 MPEG에서 포인트 클라우드를 2차원 평면에 투영한 다음 비디오 코덱을 사용해 압축하는 Video-based Point Cloud Compression (V-PCC) 기술이 연구되고 있다. V-PCC 기술은 포인트 클라우드를 점유 맵 (Occupancy map), 기하 영상 (Geometry image), 속성 영상 (Attribute image) 등의 2차원 영상과 2차원 영상과 3차원 공간 사이의 관계를 알려주는 보조 정보를 사용해 압축한다. 복호화된 포인트 클라우드의 밀도를 높이거나 객체를 확대할 때, 일반적으로 3차원 연산을 사용하지만 연산 방식이 복잡하고 많은 시간을 소모하며 새로운 포인트의 정확한 생성 위치를 결정하기 힘들다는 한계가 존재한다. 이에 본 논문은 V-PCC의 포인트 클라우드가 투영된 영상에 2차원 보간 (Interpolation) 기술을 적용해 적은 연산으로 보다 정확한 추가 포인트 클라우드를 생성하는 방안을 제안한다.

• 한국식품저장유통학회지
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• 제14권5호
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• pp.457-461
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• 2007

영주산 '후지' 사과의 전처리 및 포장방법별 저장기간 동안 품질변호를 알아보기 위하여 사과를 5% $CaCl_2$ 용액에 15분 동안 침지한 후 완전히 건조시켜 $25\;{\mu}m$ 두께의 LDPE 필름으로 박스단위로 포장하여 $0^{\circ}C$의 농협 현지저온저장고에서 21주간 중량감소율, 경도, 적정산도, 가용성 고형분함량, 비타민 C함량, 부패율 조사하였다. 중량감모율, 경도변화, Vitamin C 변화, 부패율 등에서 칼슘처리과 필름포장을 병행한 처리구(Ca-MA)가 다른 처리구에 비해 저장 중 품질변화가 가정 적은 것으로 나타나 영주산 '후지' 사과 저장시 선도유지에 효과적인 것으로 사료된다.

• The Korean Journal of Physiology
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• 제29권1호
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• pp.91-102
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• 1995

The role of neurohumoral mechanisms in the regulation of cardiovascular functions and the effects of ethanol (EOH) on these mechanisms were examined in hemorrhaged conscious Wistar rats. The rats were bled at a constant rate (2 ml/kg/min) through the femoral artery until mean arterial pressure (MAP) was reduced by 30 mmHg. We studied the responses to hemorrhage 1) under normal conditions (Normal), and after pretreatments with 2) neural blockade (NB), pentolinium, 3) arginine vasopressin V1-receptor antagonist (AVPX) + NB, 4) angiotensin II ATI-receptor antagonist (AngIIX) + NB, 5) combined humoral blockade (HB), and 6) neurohumoral blockade. Intravenous administration of 30% EOH (6.3 ml/kg) attenuated the baroreceptor reflex sensitivity, and enhanced the depressor action of AngIIX. During hemorrhage, NB produced a faster fall ill MAP than Normal both in the saline and EOH groups. However, HB accelerated the rate of fall in MAP only in the EOH group. The recovery from hemorrhagic hypotension was not different between NB and Normal rats, but was attenuated in HB rats in the saline group. Under NB, AngIIX, but not AVPX, retarded the recovery rate compared with NB alone. EOH attenuated the recovery of MAP after hemorrhage in Normal rats, but completely abolished the recovery in HB rats. We conclude that 1) the maintenance of MAP during hemorrhage is mediated almost entirely by the autonomic functions, 2) angiotensin II plays an important role in the recovery from hemorrhagic hypotension, but AVP assumes little importance, 3) AVP release largely depends on the changes in blood volume, whereas renin release depends on the changes in blood pressure rather than blood volume, and 4) EOH increases the dependence of cardiovascular regulation on angiotensin II and impairs the recovery from hemorrhagic hypotension through the attenuation of autonomic functions.

• 대한약침학회지
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• 제22권2호
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• pp.95-101
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• 2019

Objectives: Angiotensin II (AngII), a major product of renin-angiotensin system (RAS) has important role in induction of hypertension and antihypertensive effect of several medicinal plant was mediated by effect on this agent. Therefore, this study examined the possible effect of hydroalcoholic extract of Crocus sativus (C. sativus) on hypertension induced by AngII. Methods: Six groups (n = 6) of rats were used as follow: 1) Control, 2) AngII (300 ng/kg), 3) Losartan (Los, 10 mg/kg) + AngII and 4-6) C. sativus extract (10, 20 & 40 mg/kg,) + AngII. The femoral artery and vein were cannulated for recording cardiovascular parameters and drugs administration, respectively. All drugs were injected intravenously (i.v). Los and all doses of C. sativus injected 10 min before AngII. Systolic blood pressure (SBP), mean arterial blood pressure (MAP) and heart rate (HR) were recorded throughout the experiment and those peak changes (${\Delta}$) were calculated and compared to control and AngII. Results: AngII significantly increased ${\Delta}MAP$, ${\Delta}SBP$ and ${\Delta}HR$ than control (P < 0. 01 to P < 0.001) and these increments were significantly attenuated by Los. All doses of C. sativus significantly reduced peak ${\Delta}MAP$, ${\Delta}SBP$, and ${\Delta}HR$ than AngII group (P < 0. 05 to P < 0.001). In addition, peak ${\Delta}MAP$, ${\Delta}SBP$ in doses 10 and 20 were significant than Los + AngII group (P<0.05 to P< 0.01) but in dose 40 only MAP was significant (P<0.05). Peak ${\Delta}HR$ in all doses of C sativus was not significant than Los+ AngII. Conclusion: Regarding the improving effect of the C. sativus extract on AngII induced hypertension, it seems that this ameliorating effect partly mediated through inhibition of RAS.

• 한국환경복원기술학회지
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• 제25권6호
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• pp.13-24
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• 2022

The purpose of this study is to evaluate the applicability of Ecosystem Service Matrix method in Songnisan and Hannamgeumbukjeongmaek Boeun-gun area. The assessment was carried out with 25 land cover types by 7 ecosystem values. The research area was divided by 30m x 30m cell unit and the each cell value was classified into 5 grades. The total number of cell under the investigation was 433,910 units in Songnisan and 84,975 in Boeun-gun. Class I and II area were widely spread and Class V area is narrowly distributed inside of Class III area in Songnisan. I area, II area and separately managed zone belong to Ecological Zoning map and Environmental Conservation Value Assessment Map(Environment + Ecology) were assessed Class I in Ecosystem service matrix. In conclusion, Ecosystem Service Matrix assessment based on land cover map is a rapid assessment methodology which reflecting ecosystem functions in a larger area. If it is supported with more ecosystem functions, the more precise nature value can be calculated.