• 인터넷정보학회논문지
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• 제22권4호
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• pp.13-28
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• 2021

강화학습은 한 환경에서 에이전트가 정책에 따라 액션을 취하고 보상 함수를 통해 액션을 평가 및 정책 최적화 과정을 반복하는 Closed-Loop 구조로 이루어진 알고리즘이다. 이러한 강화학습의 주요 장점은 액션의 품질을 평가하고 정책을 지속적으로 최적화 하는 것이다. 따라서, 강화학습은 지능형 시스템, 자율제어 시스템 개발에 효과적으로 활용될 수 있다. 기존의 강화학습은, 단일 정책, 단일 보상함수 및 비교적 단순한 정책 업데이트 기법을 제한적인 문제에 대해 제시하고 적용하였다. 본 논문에서는 구성요소의 복수성을 지원하는 확장된 강화학습 모델을 제안한다. 제안되는 확정 강화학습의 주요 구성 요소들을 정의하고, 그들의 컴퓨팅 모델을 포함하는 정형 모델을 제시한다. 또한, 이 정형모델을 기반으로 시스템 개발을 위한 설계 기법을 제시한다. 제안한 모델을 기반으로 자율 최적화 자동차 내비게이터 시스템에 적용 및 실험을 진행한다. 제시된 정형 모델과 설계 기법을 적용한 사례연구로, 복수의 자동차들이 최적 목적지에 단 시간에 도착할 수 있는 진화된 내비게이터 시스템 설계 및 구현을 진행한다.

• 한국가축번식학회지
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• 제23권2호
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• pp.95-103
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• 1999

본 연구는 초산의 Wistar 계 rat를 이용하여 포유기간 중 제한포유시기와 이유시기를 조절하여 혈중 progesterone 수준을 검토하였다. 정상포유군 (NL)은 포유자의 수를 8 마리로 조절하였으며, 제한포유군 (RL)과 완전이유군 (W)은 RL0, RL5, RL10, RL15 및 RL20, 그리고 W0, W5, W10, W15 및 W20으로 각각 5 개 군으로 구분하여, 제한포유군은 각 개시일에 포유자의 수를 8마리에서 4마리로 조절하였으며, 완전이유군은 각 개시일에 포유자의 수를 완전히 이유시켰다. 1. 포유자의 발육상태는 제한포유군에서 정상포유군보다 성장이 유의적 (P＜0.05)으로 증가하였고, 또한 분만직후 (RL0) 와 포유 5(RL5), 10(RL10), 15(RLl5) 일에 제한포유를 실시한 군에서는 시간이 경과함에 따라 정상포유군에 비해 유의적 (P＜0.05) 으로 증가하였으나, 포유 20 일(RL20) 에 제한포유군에서는 정상포유군과 차이가 없었다 . 초산 rat 의 임신기간은 21.53$\pm$0.04일이었고 산자수는 13.75$\pm$0.07 마리였다. 2. 포유기간 중 모체의 성주기 변화는 정상포유군은 발정징후가 관찰되지 않았으나 분만직후 제한포유군은 20 일을 전후하여 불규칙적인 성주기가 관찰되었고, 분만직후 완전이유군은 10일을 전후하여 정상적인 성주기가 관찰되었다. 3. 정상포유군의 progesterone 농도는 포유 0 일에 33.16$\pm$2.64ng/$m\ell$에서 포유 10 일에 122.55$\pm$3.68ng/$m\ell$ 까지 증가하여 포유 20 일까지 높은 수준을 유지하다가 그 후 25 일에 97.30$\pm$3.21ng/$m\ell$ 까지 급속히 감소 (P＜0.05) 하였다. 포유초기 (RL0, RL5)와 포유중기 (RL10)의 제한포유군은 제한포유실시 이후 5일 까지는 정상포유군과 같은 수준을 유지하다가 그 후 급격히 (P＜0.05) 감소하였다. 결론적으로 흰쥐에 있어서 분만 후 포유자의 포유자극이 모체 난소의 기능에 중요하게 작용하는 것으로 사료된다.

• 설비공학논문집
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• 제14권2호
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• pp.175-183
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• 2002

Flow Condensation heat transfer coefficients (HTCs) of Rl2, R22, R32, Rl23, Rl25, R134a, R142b were measured experimentally on a horizontal plain tube. The experi- mental apparatus was composed of three main parts; a refrigerant loop, a water loop and a water-glycol loop. The test section in a refrigerant loop was made of a copper tube of 8.8 mm inner diameter and 1000 mm length respectively. The refrigerant was cooled by passing cold water through an annulus surrounding the test section. All tests were performed at a filed refrigerant saturation temperature of 4$0^{\circ}C$ with mass fluxes of 100, 200, 300 kg/$m^2$s. The experimental result showed that flow condensation HTCs increase as the quality, mass flux, and latent heat of condensation increase. At the same mass flux, the HTCs of R32 and R142b were higher than those of R22 by 35~45% and 7~14% respectively while HTCs of R134a and Rl23 were similar to those of R22. On the other hand, HTCs of Rl25 and Rl2 were lower than those of R22 by 28 ~30% and 15 ~25% respectively Finally, a new correlation for flow condensation HTCs was developed by modifying Dobson and Chato's correlation with the latent heat of condensation considered. The correlaton showed an average deviation of 13.1% for all pure fluids data indicating an excellent agreement.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.3653-3656
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• 2012

Background: A number of effective prevention measures have been introduced in attempts to substantially reduce both the incidence and mortality due to many kinds of cancer. The search for new anti-cancer compounds in foods or in plant medicines is one realistic and promising approach to prevention. Chinese medicines provide a rich pool of novel and efficacious agents for cancer prevention and treatment. Previously it was demonstratrated that hyperin extracted from the Manchurian rhododendron leaf reduces the proliferation of many cancer cells. The present study was carried out to evaluate its effects on human endometrial cancer cell viability and apoptosis and to investigate its mechanisms of action in RL952 cells. Methods: Cell viability was measured using the MTT assay. Intracellular calcium ions were detected using laser-scanning confocal microscopy. The effects of hyperin on apoptosis related proteins in RL952 cells were examined using Western blot analysis. Results: The growth of RL952 cells was inhibited by treatment with hyperin. OD values of caspase-3 and caspase-9 were increased and expression of bcl-2 was increased and bax was decreased in protein levels in RL952 cells after 24 h of hyperin treatment, Moreover, intracellular calcium accumulation occurred in hyperin-treated cells. Conclusion: These results suggest that hyperin may play an important role in tumor growth suppression by inducing apoptosis in human endometrial cells via a $Ca^{2+}$-related mitochondrion apoptotic pathway in RL952 cells.

• 수면정신생리
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• 제22권1호
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• pp.20-24
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• 2015

목 적 : 제 1형 당뇨병을 진단 받은 소아 청소년 환자들을 대상으로 RLS를 평가하고 RLS를 동반하는 환자군과 RLS를 동반하지 않은 환자군 간의 임상적 변인과 수면의 특성을 비교하고자 하였다. 방 법 : 소아 청소년과에서 제 1형 당뇨병으로 진단 받은 7세 이상 18세 이하의 소아 청소년 55명을 대상으로 면담, 설문조사, 임상학적 검사를 시행하였다. RLS 진단은 IRLSSG 진단기준을 따랐으며 설문은 Epworth sleepiness scale (ESS), International restless legs syndrome rating scale (IRLSRS)를 이용하였다. 결 과 : 55명의 대상자 중 RLS 빈도는 13명으로 23.6%였다. RLS 관련 변인으로 BMI, Hb, Iron, ferritin, TIBC, creatinine, GFR에서 두 군간에 유의한 차이는 없었다. RLS 환자 13명 중 RLS 가족력을 가진 환자는 7명으로, RLS가 없는 환자의 경우와 현저한 차이를 보였다. 수면의 특성을 조사한 결과 RLS를 동반한 환자군이 RLS를 동반하지 않은 군에 비해 ESS, IRLSRS 결과가 유의하게 높았다. 결 론 : 제 1형 당뇨병을 진단 받은 소아 청소년은 RLS가 흔히 동반되었다. 임상적으로 당뇨 소아 청소년의 RLS 동반여부와 수면의 질을 평가하여 치료하는 것이 필요하겠으며 향후 보다 많은 환자를 대상으로 보다 객관적인 방법을 이용한 연구가 진행되어야 할 것이다.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.69-79
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• 2012

In an ongoing survey of the bioactive potential of microorganisms from Ladakh, India, the culture medium of a bacterial strain of a new Pseudomonas sp., strain ICTB-745, isolated from an alkaline soil sample collected from Leh, Ladakh, India, was found to contain metabolites that exhibited broad-spectrum antimicrobial and biosurfactant activities. Bioactivity-guided purification resulted in the isolation of four bioactive compounds. Their chemical structures were elucidated by $^1H$ and $^{13}C$ NMR, 2D-NMR (HMBC, HSQC, $^1H$,$^1H$-COSY, and DEPT-135), FT-IR, and mass spectroscopic methods, and were identified as 1-hydroxyphenazine, phenazine-1-carboxylic acid (PCA), rhamnolipid-1 (RL-1), and rhamnolipid-2 (RL-2). These metabolites exhibited various biological activities like antimicrobial and efficient cytotoxic potencies against different human tumor cell lines such as HeLa, HepG2, A549, and MDA MB 231. RL-1 and RL-2 exhibited a dose-dependent antifeedant activity against Spodoptera litura, producing about 82.06% and 73.66% antifeedant activity, whereas PCA showed a moderate antifeedant activity (63.67%) at 60 ${\mu}g/cm^2$ area of castor leaf. Furthermore, PCA, RL-1, and RL-2 exhibited about 65%, 52%, and 47% mortality, respectively, against Rhyzopertha dominica at 20 ${\mu}g/ml$. This is the first report of rhamnolipids as antifeedant metabolites against Spodoptera litura and as insecticidal metabolites against Rhyzopertha dominica. The metabolites from Pseudomonas sp. strain ICTB-745 have interesting potential for use as a biopesticide in pest control programs.

• 한국인터넷방송통신학회논문지
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• 제13권6호
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• pp.221-228
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• 2013

큰 반소수 n=pq의 소인수 p,q를 나눗셈 시행법으로 직접 찾는 것은 현실적으로 거의 불가능하다. 따라서 대부분의 소인수분해 알고리즘은$a^2{\equiv}b^2$ (mod n)의 제곱합동을 찾아 p=GCD(a-b, n), q=GCD(a+b, n)의 소인수를 찾는 간접 방법을 적용하고 있다. n = pq에 대해 p와 q를 선택한 영역은 $l(p)=l(q)=l(\sqrt{n})=0.5l(n)$의 [$10{\cdots}01$, $99{\cdots}9$] 범위에서 $\sqrt{n}$을 기준으로 $10{\cdots}00$ < p < $\sqrt{n}$과 $\sqrt{n}$ < q < $99{\cdots}9$에 존재한다는 사실만이 밝혀졌다. 본 논문은 n으로 부터 획득한 정보를 이용하여 p의 범위를 보다 축소시키는 방법을 제안한다. 제안 방법은 $n=n_{LR}+n_{RL}$, $l(n_{LR})=l(n_{RL})=l(\sqrt{n})$으로 분할하여 $p_{min}=n_{LR}$, $q_{min}=n_{RL}$로 설정하는 방법을 적용하였다. 본 논문에서 제안한 n의 정보로 p의 범위를 축소하는 방법은 $\sqrt{n}$의 정보로 p의 범위 축소 방법에 비해 최소 17.79%에서 최대 90.17%의 범위 축소 효과를 얻었다.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1800-1807
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• 2016

To understand how human cytomegalovirus (HCMV) might change and evolve after reactivation, it is very important to understand how the nucleotide sequence of cultured HCMV changes after in vitro passaging in cell culture, and how these changes affect the genome of HCMV and the consequent variation in amino acid sequence. Strain JHC of HCMV was propagated in vitro for more than 40 passages and its biological and genetic changes were monitored. For each passage, real-time PCR was performed in order to determine the genome copy number, and a plaque assay was employed to get virus infection titers. The infectious virus titers gradually increased with passaging in cell culture, whereas the number of virus genome copies remained relatively unchanged. A linear correlation was observed between the passage number and the log₁₀ infectious virus titer per virus genome copy number. To understand the genetic basis underlying the increase in HCMV infectivity with increasing passage, the whole-genome DNA sequence of the high-passage strain was determined and compared with the genome sequence of the low-passage strain. Out of 100 mutations found in the high-passage strain, only two were located in an open reading frame. A G-T substitution in the RL13 gene resulted in a nonsense mutation and caused an early stop. A G-A substitution in the UL122 gene generated an S-F nonsynonymous mutation. The mutations in the RL13 and UL122 genes might be related to the increase in virus infectivity, although the role of the mutations found in noncoding regions could not be excluded.

• The Journal of Advanced Prosthodontics
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• 제13권4호
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• pp.246-257
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• 2021

PURPOSE. This study aimed to investigate the Vickers Hardness Number (VHN) of light- and dual cured resin cements cured through monolithic zirconia specimens (VITA YZ) of various translucencies: translucent (T); high translucent (HT); super translucent (ST); and extra translucent (XT) at 0, 24, and 48 h after curing. MATERIALS AND METHODS. Four zirconia specimens from each translucency were prepared. Two light-cured resin cements (Variolink N LC; VL and RelyX Veneer; RL) and two dual-cured resin cements (Variolink N DC; VD and RelyX U200; RD) were used. The cement was mixed and loaded in a mold and cured for 20 s through the zirconia specimen. The upper surface of cements was tested for VHN using a microhardness tester at 0, 24, and 48 h after curing. The VHN were analyzed using two-way repeated, Brown-Forsythe ANOVA with Games Howell post-hoc analysis and independent t-tests (P < .05). RESULTS. All cements showed significantly higher VHN from 0 h to 24 h (P < .001). At 48 h, the VHN of light-cured cements were significantly lower when cured under the T groups than under XT groups (P = .001 in VL, P = .014 in RL). At each post curing time of each translucency, VD showed higher VHN than VL (P < .05), and RD also showed higher VHN than RL (P < .05). CONCLUSION. The translucency of zirconia has an effect on the VHN for light-cured resin cements, but has no effect on dual-cured resin cements. Dual-cured resin cement exhibited higher VHN than the light-cured resin cement from the same manufacturer. All resin cements showed significantly higher VHN from 0 h to 24 h.

• ETRI Journal
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• 제35권6호
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• pp.990-1000
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• 2013

This paper describes the scalable extension of High Efficiency Video Coding (HEVC) to provide flexible high-quality digital video content services. The proposed scalable codec is designed on multi-loop decoding architecture to support inter-layer sample prediction and inter-layer motion parameter prediction. Inter-layer sample prediction is enabled by inserting the reconstructed picture of the reference layer (RL) into the decoded picture buffer of the enhancement layer (EL). To reduce the motion parameter redundancies between layers, the motion parameter of the RL is used as one of the candidates in merge mode and motion vector prediction in the EL. The proposed scalable extension can support scalabilities with minimum changes to the HEVC and provide average Bj${\o}$ntegaard delta bitrate gains of about 24% for spatial scalability and of about 21% for SNR scalability compared to simulcast coding with HEVC.