• 제목/요약/키워드: Halo effect

검색결과 94건 처리시간 0.047초

SOC를 위한 Digital CMOS 소자의 Analog Performance 개선 (Analog Performance Enhancement of Digital CMOS for SOC Application)

  • 지희환;김용구;왕진석;박성형;이희승;강영석;김대병;이희덕
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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    • pp.1003-1006
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    • 2003
  • 본 논문에서는 sub-micron 소자에서 SCE(Short Channel Effect) 억제를 위한 Halo 와 SSR(Super Steep Retrograde Well) 적용에 따른 analog 특성의 열화를 석하고 이를 개선하기 위해 Twist 이온주입과 In, Sb Halo 를 채택하였다. Analog 특성은 CMOS 의 amplifier 과 Comparator 로의 사용을 고려해 Drain Rout과 Early voltage를 이용해 나타내었으며 Digital 성능을 함께 고려하였다. 실험결과 NMOS 의 경우 45 twist Halo 조건에서, PMOS의 경우 As보다 Sb를 Halo 로 적용하는 경우 더 우수한 analog 특성을 나타내었다.

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Single image dehazing by segmenting dark channel prior

  • ;김원하
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송∙미디어공학회 2016년도 추계학술대회
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    • pp.172-175
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    • 2016
  • In image dehazing, the existing transmission estimators bring out the halo artifact at boundaries unless they adopt a refinement process with the high computational complexity. We analyze how the existing transmission estimation methods suffer from the halo artifact at the boundaries and observed that the elaborate, high computational refinement processes to remove the halo effect are excessive for dehazing. On the basis of the analysis and observation, we embed a simple segmentation logic in an existing transmission estimator, which is sufficiently accurate for dehazing. The experiment verifies that the proposed method significantly reduces the halo artifact without requiring any refinement process.

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The Effect of Massive Neutrinos on the Merging Rates of the First Objects

  • Song, Hyun-Mi;Lee, Joung-Hun
    • 천문학회보
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    • 제35권2호
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    • pp.44-44
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    • 2010
  • We study the effect of massive neutrinos on the evolution of the early mini-halos ($M\sim10^6h^{-1}M{\odot}at$ z~20) where the first stars may have formed. In the framework of the extended Press-Schechter formalism, we evaluate analytically the rates of merging of the mini-halos into zero-dimensional larger halos and one-dimensional mini-filaments. It is shown that the halo-to-filament merging rate increases with the neutrino mass fraction $f_v$ while the halo-to-halo merging rate decreases. Comparing the cases of $f_v$=0 and 0.10, the halo-to-filament merging rate for $f_v$=0.10 is 3 times larger than the other. The distribution of the epochs of the longest-axis collapse of these first filaments is also derived and found to reach a sharp maximum at z~8-9. Once the first mini-filaments form, they would provide bridges along which the matter and gas more rapidly accrete onto the constituent halos, causing the early formation of the first galaxies and rapid growth of their central blackholes. Furthermore, the longest axis collapse of these first mini-filaments would spur the supermassive blackholes to power the ultra-luminous high-z quasars.

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아유르베다 오일의 항균성에 관한 연구 (A Study of the Antibiosis in Ayurvedic Oils)

  • 최정명
    • 한국산학기술학회논문지
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    • 제11권3호
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    • pp.1139-1145
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    • 2010
  • 본 연구는 아유르베다의 모발과 두피 프로그램을 적용하고 그 효과를 분석하고자 한다. 아유르베딕(Ayurvedic) 처치는 자연치유력에 의해 면역력을 강화시킨다. 아유르베딕 베이스 오일과 에센셜 오일을 모발과 두피에 사용했을 때, 두피에 상주하는 균에 대한 항균효과를 알아보기 위해 MIC test 와 Halo test를 통해 측정하였다. 그 결과는 다음과 같다. 9종류의 베이스 오일과 18종류의 에센셜 오일을 이용하여 Bacillus subtilis, Propionibacterium acnes균에 대한 베이스 오일과 에센셜 오일의 항균효과를 MIC test를 통해 조사하였다. 실험 결과, 베이스 오일에서는 모두 균에 대한 항균효과가 없는 것으로 나타났으며, 에센셜 오일은 Chamomile, Clary sage, Jasmine, Neroli, Rose오일에서 두 균에 대해 모두 5% 이하에서 항균효과가 없는 것으로 나타났다. 두 균주에 대해 Thyme, Geranium, Lavender, Tea tree가 모두 효과가 높은 것으로 조사되었다. Geranium, Lavender, Thyme 에센셜 오일과 Sesame and Coconut 베이스 오일을 이용하여 7가지 공시균주에 대한 Halo test결과 베이스 오일에서는 항균효과가 없는 것으로 나타났다. 에센셜 오일은 7가지 공시균주에 대해 모두 항균성이 있는 것으로 조사되었다. Thyme은 MIC test 와 Halo test 결과 항균력이 가장 높은 것으로 나타났다.

Large-Scale Environmental Effects on the Mass Assembly of Dark Matter Halos

  • 정인태;이재현;이석영
    • 천문학회보
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    • 제38권1호
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    • pp.32.2-32.2
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    • 2013
  • We examine large-scale environmental effects on the formation and the mass growth of dark matter halos. To facilitate this, we constructed dark matter halo merger trees from a cosmological N-body simulation, which enabled us to trace the merger information and the assembly history of individual halos. In fact, since the massive halos are more likely to be distributed in denser regions than in less dense regions (Mo & White, 1996), the large-scale environment dependence of the properties of halos can be partly originated from the halo mass effect. In order to avoid such contamination, caused by the mass dependence of halo properties, we carefully measured the local overdensity as the indicator of large-scale environment, which was calculated to be as independent of halo mass as possible. Small halos (${\sim}10^{11-12}M_{\odot}$), which usually host isolated single galaxies, show a notable difference on the formation time of galaxies depending on their large-scale environments, which reconfirms halo assembly bias (Gao & White, 2007). Furthermore, we investigate how this environmental effect on small halos is correlated with the mass assembly history of galaxies by using our semi-analytic model. We found that assembly bias in small halos does not have significant effects on the formation time or on the star formation history of galaxies residing in those halos except for the individual stellar mass of galaxies at z = 0. On average, isolated galaxies in high-density regions tend to be slightly more massive than those in low-density regions. Although the observational data from the current galaxy surveys is not yet sufficient for testing this prediction, future galaxy surveys will be able to explore these small galaxies more thoroughly.

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항균제에 의한 기저귀 발진을 일으키는 Candida albicans 억제 효과 (The Effect of Antibacterial Agent for Candida albicans Inhibition of Diaper Rash)

  • 박준호;윤병호;이명구;조욱기
    • 펄프종이기술
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    • 제33권3호
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    • pp.69-74
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    • 2001
  • Diaper rash is found on the skin inside of babys diaper area. Most diaper rashes are caused by prolonged contact with the moisture, germs, and ammonia of the stool and urine. Some diaper rashes are caused by fungi infection such as candida albicans and Preteus vulgaris. In this study, Candida albicans was used as a test microorganism and experiment was carried out to inhibit diaper rash. Handsheets were treated with chitosan oligosaccharide, bamboo extractives, as well as mixture of monolaurin as an emulsifier and bamboo extractives. Both shake flask method and halo test were applied in order to examine the antimicrobial activity of each sample. It was found from both results of the halo test and shake flask method that handsheets treated with chitisan oligosaccharide or bamboo extractives showed antimicrobial property. In the treatment of bamboo extractives without emulsifier, no distinct difference in antimicrobial effect was found between bamboo branch and bamboo leaves extractives. In case of mixture of bamboo extractives and emulsifier, the result also suggested that bamboo branch showed better syngergistic effect than bamboo leaves. Both chitosan oligosaccharide and bamboo extractive can be used as antifungal agents against Candida albicans for making diaper.

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영상 선명화를 위한 개선된 Retinex 알고리즘 (Advanced Retinex Algorithm for Image Enhancement)

  • 차효상;홍성훈
    • 한국멀티미디어학회논문지
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    • 제16권1호
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    • pp.29-41
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    • 2013
  • 디지털 카메라는 제한된 크기의 다이내믹레인지를 갖는 이미지 센서의 한계로 인하여 인간의 눈으로 보는 것과 동일한 화질의 영상을 얻을 수 없기 때문에 이를 개선해야 할 필요성이 있다. 기존의 화질개선방법으로는 Land의 인간의 시각적 모델을 바탕으로 한 Retinex 알고리즘이 대표적이다. Retinex 알고리즘은 칼라의 일관성과 시각적인 개선을 제공하지만, 전역적인 contrast 감소와 후광효과 및 색왜곡 문제를 발생시키기도 한다. 이러한 문제를 개선하기 위해 본 논문에서는 YCbCr 색공간에서 휘도성분의 주파수성분에 대한 처리를 통해 전역적 contrast를 향상시키고, 색차성분에 대한 처리를 통해 칼라 선명도를 향상시키는 방법을 제안한다. 실험 결과영상의 비교를 통해 제안된 알고리즘이 기존의 알고리즘에 비해 연산량 감소효과가 뛰어나며 전역적 contrast 향상과 색상 보전 성능이 우수하고 후광효과를 효과적으로 제거함을 확인하였다.

EFFECTS OF SOURCE POSITION ON THE DH-TYPE II CME PROPERTIES

  • Shanmugarju, A.;Moon, Y.J.;Cho, K.S.;Umapathy, S.
    • 천문학회지
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    • 제42권3호
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    • pp.55-60
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    • 2009
  • The properties of SOHO/LASCO CMEs are subjected to projection effects. Their dependence on the source position is important to be studied. Our main aim is to study the dependence of CME properties on helio-longitude and latitude using the CMEs associated with type IIs observed by Wind/WAVES spacecraft (Deca-hecta metric type IIs - DH type IIs). These CMEs were identified as a separate population of geo-effective CMEs. We considered the CMEs associated with the Wind/WAVE type IIs observed during the period January 1997 - December 2005. The source locations of these CMEs were identified using their associated GOES X-ray flares and listed online. Using their locations and the cataloged properties of CMEs, we carried out a study on the dependence of CME properties on source location. We studied the above for three groups of CMEs: (i) all CMEs, (ii) halo and non-halo CMEs, and (iii) limb and non-limb CMEs. Major results from this study can be summarized as follows. (i) There is a clear dependence of speed on both the longitude and latitude; while there is an increasing trend with respect to longitude, it is opposite in the case of latitude. Our investigations show that the longitudinal dependence is caused by the projection effect and the latitudinal effect by the solar cycle effect. (ii) In the case of width, the disc centered events are observed with more width than those occurred at higher longitudes, and this result seems to be the same for latitude. (iii) The dependency of speed is confirmed on the angular distance between the sun-center and source location determined using both the longitude and latitude. (iv) There is no dependency found in the case of acceleration. (v) Among all the three groups of CMEs, the speeds of halo CMEs show more dependency on longitude. The speed of non-halo and non-limb CMEs show more dependency on latitude. The above results may be taken into account in correcting the projection effects of geo-effective CMEs.

Cytotoxic Activities of 6-Arylamino-7-halo-5,8-quinolinediones against Human Tumor Cell Lines

  • Ryu, Chung-Kyu;Kang, Hye-Yung;Yi, Yu-Jini;Lee, Chong-Ock
    • Archives of Pharmacal Research
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    • 제23권1호
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    • pp.42-45
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    • 2000
  • 6-Arylamino-7-halo-5,8-quinolinediones (4a-4k, 5a-5b) were tested for in vitro cytotoxicity against human solid tumor cell lines such as A 549 (non-small cell lung). SK-OV-3 (ovarian), SK-MEL-2 (melanoma), HCT-15 (colon) and XF 498 (CNS) by SRB assay. The arylamino-7-chloro-5,8-quinolinediones 4 were also evaluated for cyclin-dependent kinase (CDK2 and CDK4) inhibitory effect. Among them, the 5,8-quinolinediones 4a and 5a with 7-(4-fluorophenyl) amino group were found to be potent cytotoxic against HCT 15, SKOV-3 and XF 498, and the compounds 4f and 4i showed inhibitory activities for the CDK4.

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Advanced Frame Rate Conversion without Halo and judder effect for 120Hz LCD Displays

  • Lim, Kyoung-Won;Kim, Han-Soo;Noh, Hyun-Chul;Shin, Hyun-Chul;Jung, Woo-Chul;Koo, Gun-Jae;Park, Ryuk
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1397-1400
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    • 2008
  • Frame rate conversion became key technology due to recent advances in LCD panel refresh rates. Although many FRC algorithms have been developed and applied for LCD TV sets, they still suffer from well-known halo artifact. This paper discusses about the artifacts and method to handle them.

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