• 제목/요약/키워드: View synthesis

검색결과 237건 처리시간 0.028초

실감형 화상 회의를 위해 깊이정보 혼합을 사용한 시선 맞춤 시스템 (Eye Contact System Using Depth Fusion for Immersive Videoconferencing)

  • 장우석;이미숙;호요성
    • 전자공학회논문지
    • /
    • 제52권7호
    • /
    • pp.93-99
    • /
    • 2015
  • 본 논문에서는 실감형 원격 영상회의를 위한 시스템을 제안한다. 원격 영상회의에서 카메라는 보통 디스플레이의 중앙이 아닌 측면에 설치가 된다. 이는 시선 불일치를 만들고, 사용자들의 몰입도를 떨어뜨린다. 따라서 실감형 영상회의에 있어서 시선 맞춤은 중요한 부분을 차지한다. 제안하는 방법은 스테레오 카메라와 깊이 카메라를 사용하여 시선 맞춤을 시도한다. 깊이 카메라는 비교적 적은 비용으로 효율적으로 깊이 정보를 생성할 수 있는 키넥트 카메라를 선택하였다. 하지만 키넥트 카메라는 비용적인 장점에도 불구하고 단독으로 사용하기에는 내제하는 단점이 많다. 따라서 스테레오 카메라를 더하여 각 깊이 센서 간의 단점을 보완하는 방법을 개발하였고, 이는 각 깊이 정보 간의 혼합 및 정제 과정을 통해서 실현된다. 시선 맞춤 영상 생성은 후처리를 통한 보완된 깊이 정보를 이용하여 3차원 워핑 기술을 이용하여 구현된다. 실험결과를 보면 제안한 시스템이 자연스러운 시선 맞춤 영상을 제공하는 것을 알 수 있다.

A cost-effective method to prepare size-controlled nanoscale zero-valent iron for nitrate reduction

  • Ruiz-Torres, Claudio Adrian;Araujo-Martinez, Rene Fernando;Martinez-Castanon, Gabriel Alejandro;Morales-Sanchez, J. Elpidio;Lee, Tae-Jin;Shin, Hyun-Sang;Hwang, Yuhoon;Hurtado-Macias, Abel;Ruiz, Facundo
    • Environmental Engineering Research
    • /
    • 제24권3호
    • /
    • pp.463-473
    • /
    • 2019
  • Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 nm), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 nm and the predominance (> 90%) of particles with sizes < 6.10 nm. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.

한국인삼론(韓國人蔘論) (Current Status of Korean Ginseng Research)

  • 한병훈
    • 생약학회지
    • /
    • 제3권3호
    • /
    • pp.151-160
    • /
    • 1972
  • Recent achievements of scientific research on the pharmacologic activities and the chemical problems of dammalene glycosides, which are considered to be effective principles of Korean ginseng, are reviewed and analyzed in view of structure-activity relationship. 1) S. Shibata and his co-workers detected 12 glycoside spots of dammalene series on the two dimensional T.L.C. of total glycoside fraction from Japanese ginseng, and designated them Ginsenoside Rx(x=a, b, c, g, h, etc.) in the order of increasing Rf-value. The aglycones of those glycosides were characterized to be protopanaxadiol for the Ginsenoside $Rx(x=a,\;b_{1},\;b_{2},\;c,\;d,\;e,\;f)$ and protopanaxatriol for the Ginsenoside $Rx(x=g_{1},\;g_{2},\;g_{3},\;h_{1}\;'h_{2})$. Using Korean ginseng as the material for our study, the author and his coworkers isolated a new dammalene glycoside(Panax Saponin C), which comes under the category of protopanaxadiol glycosides based on the classification of S. Shibata et al., and characterized this saponin to be the glycoside of protopanaxatriol series. Furthermore, Panax Saponin C dissociated into $two\;components(C_{1}\;and\;C_{2}-acetate)$ by acetylation, both of which returned to original Panax Saponin C by deacetylation. Based on this result, more than 13 glycoside components of dammalene series will be expected in the Korean ginseng. 2) The structures of protopanaxadiol and protopanaxatriol, the genuine aglycones of dammalene glycosides, are fully established to be structural analogues by S. Shibata and his co-workers, therefore antagonistic and/or analogical activities will be expected for the pharmacologic activities of these glycoside series of structural analogues. K. Takaki and his co-workers found central nervous system (CNS) stimmulant activity from the glycosides of protopanaxatriol series and CNS-depressant activity from the glycosides of protopanaxadiol series. On the other hand, the author and his co-workers found stimmulating activity on the protein synthesis from both the series of dammalene glycosides with delayed and long-lasting characteristics. This delayed and long-lasting characteristics were also observed in the anti-inflammatory activity of glycosides of protopanaxatriol series on their time course tendency. For the convenience's sake of argument, pluralistic pharmacologic activities of dammalene glycosides, which were observed by many workers at various pharmacologic site, may be classified into two main categories; one is pan-cellular activity and the other is organ specific activity to the certain tissue which is a mass of cells differentiated to a certain direction for their special functions in the body. Based on the data of K. Takaki and those of the authors, following assumption will be probable; Pharmacologic activities of both series of glycosides of protopanaxadiol and protopanaxatriol aglycones may be antagonistic on their tissue-specific activities and analogic on their pan-cellular activities. Therefore, the mixture of these two series of glycosides in an appropriate ratio, as the case of total extract of Korean ginseng, will be probably beneficial to the host by increasing the synthesis of some functional proteins, due to the additive action of pan-cellular activity, and with the disappearance of any significant behavioral symptoms due to the antagonism of tissue specific activity. This fact will probably be the main reason why classical trials of pharmacologists failed in re-discovering the efficacy of Korean ginseng with their behavioral test. 3) The author and his co-workers achieved the synthesis of $C^{14}-labelled\;Panax\;Saponin\;A\;on\;C_{25}-C_{27}\;position\;of\;aglycone$ in the interest of tracer studies in vivo. The method will be applicable to other dammalene glycosides regardless of their chemical structure. 4) The author and his co-workers converted chemically betulafolienetriol, a triterpene component of Betula platyphylla, to the protopanaxadiol, one of genuine aglycone of dammalene glycosides.

  • PDF

ATHEROSCLEROSIS, CHOLESTEROL AND EGG - REVIEW -

  • Paik, I.K.;Blair, R.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제9권1호
    • /
    • pp.1-25
    • /
    • 1996
  • The pathogenesis of atherosclerosis can not be summarized as a single process. Lipid infiltration hypothesis and endothelial injury hypothesis have been proposed and investigated. Recent developments show that there are many points of potential interactions between them and that they can actually be regarded as two phases of a single, unifying hypothesis. Among the many risk factors of atherosclerosis, plasma homocysteine and lipoprotein(a) draw a considerable interest because they are independent indicators of atherogenicity. Triglyceride (TG)-rich lipoproteins (chylomicron and VLDL) are not considered to be atherogenic but they are related to the metabolism of HDL cholesterol and indirectly related to coronary heart disease (CHD). LDL can of itself be atherogenic but the oxidative products of this lipoprotein are more detrimental. HDL cholesterol has been considered to be a favorable cholesterol. The so-called 'causalist view' claims that HDL traps excess cholesterol from cellular membranes and transfers it to TG-rich lipoproteins that are subsequently removed by hepatic receptors. In the so-called 'noncausalist view', HDL does not interfere directly with cholesterol deposition in the arterial wall but instead reflects he metabolism of TG-rich lipoproteins and their conversion to atherogenic remnants. Approximately 70-80% of the human population shows an effective feedback control mechanism in cholesterol homeostasis. Type of dietary fat has a significant effect on the lipoprotein cholesterol metabolism and atherosclerosis. Generally, saturated fatty acids elevate and PUFA lower serum cholesterol, whereas MUFA have no specific effect. EPA and DHA inhibit the synthesis of TG, VLDL and LDL, and may have favourable effects on some of the risk factors. Phospholipids, particularly lecithin, have an antiatherosclerotic effect. Essential phospholipids (EPL) may enhance the formation of polyunsaturated cholesteryl ester (CE) which is less sclerotic and more easily dispersed via enhanced hydrolysis of CE in the arterial wall. Also, neutral fecal steroid elimination may be enhanced and cholesterol absorption reduced following EPL treatment. Antioxidants protect lipoproteins from oxidation, and cells from the injury of toxic, oxidized LDL. The rationale for lowering of serum cholesterol is the strong association between elevation of plasma or serum cholesterol and CHD. Cholesterol-lowing, especially LDL cholesterol, to the target level could be achieved using diet and combination of drug therapy. Information on the link between cholesterol and CHD has decreased egg consumption by 16-25%. Some clinical studies have indicated that dietary cholesterol and egg have a significant hypercholesterolemic effect, while others have indicated no effect. These studies differed in the use of purified cholesterol or cholesterol in eggs, in the range of baseline and challenge cholesterol levels, in the quality and quantity of concomitant dietary fat, in the study population demographics and initial serum cholesterol levels, and clinical settings. Cholesterol content of eggs varies to a certain extent depending on the age, breed and diet of hens. However, egg yolk cholesterol level is very resistant to change because of the particular mechanism involved in yolk formation. Egg yolk contains a factor of factors responsible for accelerated cholesterol metabolism and excretion compared with crystalline cholesterol. One of these factors could be egg lecithin. Egg lecithin may not be as effective as soybean lecithin in lowering serum cholesterol level due probably to the differences of fatty acid composition. However, egg lecithin may have positive effects in hypercholesterolemia by increasing serum HDL level and excretion of fecal cholesterol. The association of serum cholesterol with egg consumption has been widely studied. When the basal or control diet contained little or no cholesterol, consumption of 1 or 2 eggs daily increased the concentration of plasma cholesterol, whereas that of the normolipemic persons on a normal diet was not significantly influenced by consuming 2 to 3 eggs daily. At higher levels of egg consumption, the concentration of HDL tends to increase as well as LDL. There exist hyper-and hypo-responders to dietary (egg) cholesterol. Identifying individuals in both categories would be useful from the point of view of nutrition guidelines. Dietary modification of fatty acid composition has been pursued as a viable method of modifying fat composition of eggs and adding value to eggs. In many cases beneficial effects of PUFA enriched eggs have been demonstrated. Generally, consumption of n-3 fatty acids enriched eggs lowered the concentration of plasma TG and total cholesterol compared to the consumption of regular eggs. Due to the highly oxidative nature of PUFA, stability of this fat is essential. The implication of hepatic lipid accumulation which was observed in hens fed on fish oils should be explored. Nutritional manipulations, such as supplementation with iodine, inhibitors of cholesterol biosynthesis, garlic products, amino acids and high fibre ingredients, have met a limited success in lowering egg cholesterol.

내비성(耐肥性)에 관(關)한 질소대사적(窒素代謝的) 개념(槪念) -II. 질소환경(窒素環境) 변화(變化)에 따른 질소대사(窒素代謝) (Cencept of adaptability for heavy nitrogen in view of nitrogen metabolism -II. Nitrogen metabolism under the change of itrogen nenvironment)

  • 윤종혁;박훈;조성진
    • 한국토양비료학회지
    • /
    • 제7권1호
    • /
    • pp.49-53
    • /
    • 1974
  • 장려품종이며 온대형질(溫帶形質)인 진흥(振興)과 열대형질(熱帶形質)인 다수성(多收性) 신품종(新品種) IR 667을 사용(使用)하여 수경(水耕)에서 고(高)(50 또는 80ppm) 저(低)(10 또는 40ppm)의 질소수준(窒素水準) 또는 2주간질소(二週間窒素) 결제(缺除)(최분기(最分期)와 출수기(出穗期))에 의(依)한 질소대사상(窒素代謝上)의 차이(差異)를 비교(比較) 검토(檢討)한 결과(結果) 다음과 같다. 1. 수경(水耕)에서 진흥(振興)은 고농도(高濃度)에서 수량(收量)이 크고 IR 667은 저농도(低濃度)에서 크다. 2. IR 667은 고농도(高濃度)에서 암모늄 독작용(毒作用)을 받아 감수(減收)된 것 같고 이것은 질소결제(窒素缺除)로 방지(防止)었다. 3. IR 667은 진흥(振興)보다 질소환경(窒素環境)의 변화(變化)에 감수성(感受性)이 크다. 4. 진흥(振興)은 고농도(高濃度)에서 질소흡수력(室素吸收力)과 단백합성력(蛋白合成力)이 IR 667 보다 우열(優熱)하나 저농도(低濃度)에서는 이와 반대(反對)였다. 5. 이상(以上)의 결과(結果)로 진흥(振興)은 대사적내비성(代謝的耐肥性) 크고 IR667은 구조적내비성(構造的耐肥性)이 큰 것으로 보이며 이상적(理想的) 생산적(生産的) 내비성(耐肥性)은 이 두 품종(品種)의 내비성(耐肥性)의 결합형(結合型)으로 보인다.

  • PDF

호장으로부터 분리한 Polydatin의 미백 및 주름억제 효능에 대한 연구 (The Effects of Polydatin Isolated from Polygonum cuspidatum on Melanogenesis and Wrinkle Formation)

  • 진무현;정의택;김미선;송혜진;곽택종;박선규;이상민
    • 대한화장품학회지
    • /
    • 제37권4호
    • /
    • pp.327-335
    • /
    • 2011
  • 5,4'-dihydroxystilbene-3-O-D-glucopyranoside (polydatin)는 호장(Polygonum cuspidatum)에 존재하는 stilbenes류의 하나로 지금까지 피부에서의 효능이 잘 알려지지 않았다. 우리는 호장으로부터 Polydatin을 분리하여 얻었으며, 피부유래의 멜라노사이트와 fibroblast를 이용하여 효능을 검증하였다. 실험결과 멜라노사이트에서 polydatin은 타이로시네이즈 활성과 멜라닌 생성을 억제하였고, 멜라닌 생합성 과정에 관여하는 타이로시네이즈와 전사인자인 microphthalmia-associated transcription factor (MITF)의 발현을 억제하는 것을 확인하였다. 미백효과가 확인된 polydatin에 대하여 human fibroblast를 대상으로 type I procollagen 생합성에 미치는 영향을 분석한 결과 polydatin은 농도 의존적 으로 콜라젠 합성을 촉진함을 알 수 있었다. 또한 polydatin의 피부에서의 효능을 검증하기 위해 인체효력시험을 통해 주름개선과 미백개선 효능을 검증하였으며 이를 통해 주름과 미백기능에 있어 유의한 효과를 확인하였다. 이상의 결과로부터 polydatin은 안전한 피부 미백 개선제 및 주름개선제로 사용될 수 있는 후보물질임을 제안하며, 상업적으로 활용하기 위해 원료화를 성공하였다.

Low-temperature synthesis of nc-Si/a-SiNx: H quantum dot thin films using RF/UHF high density PECVD plasmas

  • Yin, Yongyi;Sahu, B.B.;Lee, J.S.;Kim, H.R.;Han, Jeon G.
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
    • /
    • pp.341-341
    • /
    • 2016
  • The discovery of light emission in nanostructured silicon has opened up new avenues of research in nano-silicon based devices. One such pathway is the application of silicon quantum dots in advanced photovoltaic and light emitting devices. Recently, there is increasing interest on the silicon quantum dots (c-Si QDs) films embedded in amorphous hydrogenated silicon-nitride dielectric matrix (a-SiNx: H), which are familiar as c-Si/a-SiNx:H QDs thin films. However, due to the limitation of the requirement of a very high deposition temperature along with post annealing and a low growth rate, extensive research are being undertaken to elevate these issues, for the point of view of applications, using plasma assisted deposition methods by using different plasma concepts. This work addresses about rapid growth and single step development of c-Si/a-SiNx:H QDs thin films deposited by RF (13.56 MHz) and ultra-high frequency (UHF ~ 320 MHz) low-pressure plasma processing of a mixture of silane (SiH4) and ammonia (NH3) gases diluted in hydrogen (H2) at a low growth temperature ($230^{\circ}C$). In the films the c-Si QDs of varying size, with an overall crystallinity of 60-80 %, are embedded in an a-SiNx: H matrix. The important result includes the formation of the tunable QD size of ~ 5-20 nm, having a thermodynamically favorable <220> crystallographic orientation, along with distinct signatures of the growth of ${\alpha}$-Si3N4 and ${\beta}$-Si3N4 components. Also, the roles of different plasma characteristics on the film properties are investigated using various plasma diagnostics and film analysis tools.

  • PDF

(TBMA)Macromer를 그라프트시킨 음이온성 아크릴 공중합체의 합성과 물성 (The Synthesis and Characterization of (TBMA)Macromer Grafted Anionic Acrylic Copolymer)

  • 김형욱;노시태;강신춘
    • 공업화학
    • /
    • 제4권3호
    • /
    • pp.627-636
    • /
    • 1993
  • 마크로머를 이용한 음이온성 아크릴 수지를 제조하기 위하여 음이온 리빙 중합법으로 TBMA를 합성하였고 이들을 다시 MMA와 공중합 시켜 아크릴계 그라프트 공중합체를 제조하였다. 그라프트 공중합체의 음이온 site 함량을 제어하기 위하여 (TBMA)마크로머의 MMA의 weight 비율을 7/93, 10/90, 15/85, 20/80, 30/70, 40/60, 50/50가지 변화시켜 합성하였다. (TBMA)마크로머의 음이온 리빙 중합과정에서는 반응온도를 $-78^{\circ}C$로 유지하면서 n-butyllithium-diphenylethylene계 개시제 시스템을 사용하였으며 정지반응 단계에서는 말단에 이중결합을 도입하기 위하여 capping material로 benzaldehyde를 사용한 후, methacryloyl chloride와 반응시켰으나, 넓은 분자량 분포(1.4~1.5)가 나타났다. 또한 그라프트 공중합체 내의 TBMA는 p-toluenesufonic acid인 촉매로 가수분해하였고 중화제로 triethylamine을 사용한 중화 반응은 아크릴 수지의 음이온성을 부여하였다. (TBMA)마크로머의 분자량과 분자량 분포에 대한 측정은 GPC를 이용하였으며 TBMA의 가수분해 반응과 더불어 아크릴 수지의 이온화 반응을 IR과 NMR을 이용하여 분석하였다. (TBMA)수분산성 및 분산 안정성의 관점에서 그라프트 공중합체내의 (TBMA)마크로머 분자량에 대한 가지(branch)의 길이와 TBMA함량을 관련지어 검토한 결과 분자량이 작은(TBMA) 마크로머에서는 적은 TBMA 함량으로도 안정된 수분산화 현상이 일어남을 알았다.

  • PDF

기술수용모델 개념 간의 관계에 대한 메타분석: 우리나라 학회지에 게재된 스마트폰 연구 중심으로 (A Meta-analysis of Relationship between Constructs of the Technology Acceptance Model: Focusing on the Research Papers Published for Smartphone in Korea Journals)

  • 남수태;진찬용
    • 벤처창업연구
    • /
    • 제8권4호
    • /
    • pp.67-79
    • /
    • 2013
  • 메타분석은 여러 실증연구의 정량적인 결과를 통합과 분석을 통해 전체 결과를 조망할 수 있는 기회를 제공하는 통계적 통합 방법이다. 기술수용모델은 지난 20여 년 동안 경영정보시스템 연구에서 여러 가지 주제로 다루어지고 있으며, 지금도 여전히 계속 연구되어 오고 있다. 최근 정보통신기술과 지식정보사회의 융합은 정치, 경제 및 다양한 분야에 빠른 영향을 미치고 있다. 이러한 산업의 변화는 벤처기업 창업에 도움이 될 것이다. 따라서 기술수용모델을 기반으로 스마트폰 사용자들의 행동의도에 관한 연구들을 메타분석을 실시하였다. 또한, 본 연구는 2005년 이후 국내 학술지에 게재된 연구 중 기술수용모델의 개념간에 인과관계를 설정한 총 50편의 연구논문을 대상으로 하였다. 메타분석의 결과, 인지된 유용성에서 행위의도의 경로에 효과크기는 0.48을 보였으며, 인지된 사용 용이성에서 행위의도의 경로에 효과크기는 0.46으로 나타났다. 그리고 인지된 사용 용이성에서 인지된 유용성의 경로에 효과크기는 0.46으로 나타났다. 또한, 태도에서 행위의도의 경로에 효과크기는 0.61을 보였다. 분석결과를 바탕으로 선행연구와 비교분석을 통해 차이점을 논의하였다.

  • PDF

선양낭성암종(Adenoid Cystic Carcinoma)에서의 Glycosaminoglycan의 발현에 관한 연구 (STUDY ON EXPRESSION OF GLYCOSAMINOGLYCAN IN ADENOID CYSTIC CARCINOMA)

  • 손창원;김경욱;김철환
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제30권4호
    • /
    • pp.271-281
    • /
    • 2004
  • Adenoid cystic carcinoma is malignant tumor in salivary gland, and its behavior is very invasive. Of all malignant tumor adenoid cystic carcinoma is occured in frequency of 4.4% in major salivary gland, and 1.29% in minor salivary gland. Histopathologically, adenoid cystic carcinoma is characterized by a cribriform appearance, and tubular form and solid nest type tumor can be seen. The tumor cell structure composed of modified myoepithelial cell, and basaloid cell. Extracellular matrix of this tumor cell contains variable ground substance with basement membrane component. Basement membrane matrix composed of collagen fibers, glycoproteins, proteoglycans, and its function is well known that it participate in differentiation, proliferation, and growth of tumor cell. Basement membrane molecule is essential for invasion of peripheral nerve, blood vessel, skeletal muscle in tumor cell of adenoid cystic carcinoma. In many studies, the tumor cell of adenoid cystic carcinoma containing modified myoepithelial cell participate in synthesis of proteoglycan. In this study, tissue sample of adenoid cystic carcinoma of human salivary gland were obtained from 15 surgical specimen, and all specimen were routinely fixed in 10% formalin and embedded. Serial $4-{\mu}m$ thick sections were cut from paraffin blocks. the histopathologic evaluation was done with light microscopy. And, the immunohistochemical staining, characteristics of glycosaminoglycan were observed. For biochemical analysis of glycosaminoglycan, isolation of crude glycosaminoglycan from tumor tissue and Western bolt analysis were carried out. With transmission electomicroscopy, tumor cell were observed. Biologic behavior of adenoid cystic carcinoma was observed with distribution and expression of basement membrane of glycosaminoglycan in tumor cells, The results obtained were as follows: 1. In immunohistochemical study, chondroitin sulfate is postively stained in tumor cell and interstitial space, dermatan sulfate is weakly stained in ductal cell. But keratan sulfate is negatively stained. 2. In immunohistochemical study, heparan sulfate is strong positive stained in tumor cell and basement membrane, especially in invasion area to peripheral nerve tissue. 3. In transmission electromicroscpic view, the tumor cells are composed modifed myoepithelial cells, and contains many microvilli and rough endoplasmic reticulum. 4. In Western blot analysis, the expression of glycosaminoglycan is expressed mostly in heparan sulfate. From the results obtained in this study, tumor cell of adenoid cystic carcinoma is composed modified myoepithelial cell, and glycosaminoglycan of basement membrane molecule of heparan sulfate and chondroitin sulfate mostly participate in the development and invasiveness of adenoid cystic carcinoma by immunohistochemical study and western blot analysis.