• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2007년도 Proceedings of The Convention of The Korean Society of Applied Pharmacology
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• pp.115-121
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• 2007

Opuntia ficus-indica var. saboten (Cactaceae) is widely cultivated in Jeju Island (South Korea) for use in the manufacture of health foods such as tea, jam and juice. Its fruit and stem have been traditionally used as oriental folk medicine to treat diabetes, hypertension, asthma, burns, edema and indigestion. During the search for naturally occurring antioxidative neuroprotective agents, it was found that the ethyl acetate fraction of the stems and fruits of Opuntia ficus-indica var. saboten exhibited potent antioxidant effect. Using a chromatographic fractionation method, several constituents were isolated from this fraction. Among isolates, KYS50182 showed the most potent in vitro and in vivo neuroprotective activities, suggesting that the flavonoid can serve as a lead structure for the development of neuroprotective agents by providing neuroprotection against oxidative and focal ischemic neuronal injuries.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.88-89
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• 2000

Chitosan is derived from chitin by deacetylation in the presence of alkali, which is a copolymer consisting of $\beta$-(1longrightarrow4)-2-acetamido-D-glucose and $\beta$-(1longrightarrow4)-2-amino-D-glucose units with the latter usually exceeding 80% (Arvanitoyannis et al., 1998). Chitosan has been developed as new physiological material since it possesses antibacterial activity, hypocholesterolemic activity and antihypertensive action. However, even though chitosan has very strong functional properties in many areas, its high molecular weight and high viscosity may restrict the use in vivo. In addition, there is little doubt that such properties will influence absorption in the human intestine. Recently, studies on chitosan have attracted interest for converted chitosan to oligosaccharide, because the oligosaccharide possesses not only water-soluble property but also versatile functional properties such as antitumor activity, immune-enhancing effects, enhancement of protective effects against infection with some pathogens in mice, antifungal activity, calcium absorption accelerating effect (Jeon et al., 1999) and antimicrobial activity. There is, however, little information on the toxicity of chitosan oligosaccharide. (omitted)

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.90-91
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• 2000

The physiological systems that control blood fluidity are both complex and elegant. Blood must remain fluid within the vasculature and yet clot quickly when exposed to nonendothelial surfaces at sites of vascular injury. There are two principle mechanisms to control a delicate balance in higher organisms (Davie & Ratnoff, 1964). Present evidence suggests that the intrinsic pathway play an important role in the growth and maintenance of fibrin formation in the coagulation cascade while a second overlapping mechanism, called the extrinsic pathway, is critical in the initiation of fibrin formation. Coagulation factors is in two mechanisms, and in order to clot blood, they are activated by a cooperation with $Ca^{2+}$, phospholipid and vitamin K etc. For example, the human placental anticoagulant protein (PAP of PAP- I), which is a $Ca^{2+}$ -dependent phospholipid binding protein (Funakoshi et al., 1987) inhibited the activity of factor Xa, so that it prolonged fibrin formation. We wondered whether any other protein was involved in regulation of the coagulant system as an anticoagulant protein from natural organisms. Natural agents would have not harmful side-effects in comparision with chemically synthesized materials such as warfarin, aspirin, phenindione, etc.. But anticoagulant agents from natural, especially marine organisms have hardly been researched except for polysaccharides from marine algae. (omitted)

• 환경영향평가
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• 제20권2호
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• pp.217-226
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• 2011

This paper was inspired by the fact that Real-time Traffic Information Service could play a key role in reducing incomplete combustion time remarkably since it can provide traffic jam information in real-time basis. Emission characteristics of experimental engines were studied with variable travel distances and speed of car in terms of traffic information provided. 12 Km distance road of Susung district in Daegu is taken as an experimental area to examine this new approach. The emission was tested while the driving was done at 8 AM, 3 PM, 6 PM which represents various traffic conditions. The reduced emission has been measured for a travel distance running at different loads (conventional shortest route and Real-time Traffic Information) and various loads (CO, VOC and NOx) are all inventoried and calculated in terms of existing emission factors. The emission has been shown to reduce linearly with travel distance : carbon monoxide (20.56%), VOC (29.21%), NOx(8.86%).

• 한국화재소방학회논문지
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• 제20권2호
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• pp.72-79
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• 2006

본 연구에서는 부분배연설비의 배연효율을 분석하고, 화재시 운영방안을 제시하기 위하여 수치해석을 실시하였다. 해석결과 선행된 실험을 통하여 얻었던 균일댐퍼의 배연효율 및 연기의 단면분포에 의한 성층화 결과는 서로 일치하는 경향을 얻을 수 있었다. 균일댐퍼의 운영방안은 화재시 화재 근방의 댐퍼만을 개방하였을 경우가 터널내 모든 댐퍼를 개방하였을 경우에 비하여 약 7%의 배연효율이 증가됨을 보였다. 또한, 터널내 차량이 정체시 화재가 발생할 경우 승객의 안전한 대피를 위한 부분배연설비의 정량적인 운전방안을 제안하였다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권2호
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• pp.89-94
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• 2002

The continuous production of citric acid from dairy wastewater was investigated using calcium-alginate immobilized Asrergillus niger ATCC 9142. The citric acid productivity and yield were strongly affected by the culture conditions. The optimal pH, temperature, and dilution rate were 3.0, 30$^{\circ}C$, and 0.025 h$\^$-1/, respectively. Under optimal culture conditions, the maximum productivity, concentration, and yield of citric acid produced by the calcium-alginate immobilized Aspergillus niger were 160 mg L$\^$-1/ h$\^$-1/, 4.5 g/L, and 70.3%, respectively, The culture was continuously perfored for 20 days without any apparent loss in citric acid productivity. Conversely, under the same conditions with a batch shake-flask culture, the maximum productivity, citric acid concentration, and yield were only 63.3 mg L$\^$-1/h$\^$-1/, 4.7 g/L and 51.4%, respectively, Therefore, the results suggest that the bioreactor used in this study could be potentially used for continuous citric acid production from dairy wastewater by applying calcium-alginate immobilized Aspergillus niger.

• Journal of Communications and Networks
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• 제17권3호
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• pp.275-285
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• 2015

To improve the efficiency of carrier sense multiple access (CSMA)-based medium access control (MAC) protocols, CSMA with collision resolution (CSMA/CR) has been proposed. In the CSMA/CR, a transmitting station can detect a collision by employing additional sensing after the start of a data transmission and then resolve the next collision that might occur by broadcasting a jam signal during a collision detection (CD) period. In this paper, we analyze the delay of a CSMA/CR based on a generic p- persistent CSMA model and obtain the minimum achievable delay of the CSMA/CR by finding the optimal length of the CD period according to the number of contending stations. Through this delay analysis, we also investigate the throughput-delay characteristics of the CSMA/CR protocol according to various parameters. Analysis and simulation results show that the CSMA/CR has a considerably lower delay and its throughput-delay characteristic is significantly improved than the conventional CSMA/CA and wireless CSMA/CD protocols.

• 한국약용작물학회지
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• 제16권2호
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• pp.100-105
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• 2008

We previously examined extracts, isolated from Scutellaria baicalensis (SB), chemical mediators, and IgE by mesenteric lymph node (MLN) lymphocytes in rats. The present study was to evaluate the effects of extracts of SB on the MLN lymphocytes function of mice given orally by 20 mg/kg for 2 weeks with dextran sulfate sodium (DS)-induced colitis. Results show that IgE levels in MLN lymphocytes was low, while IgA was high, in mice given SB compared to that fed water. Concentrations of $Inteferon-{\gamma}$ and interleukin (IL)-2 of T cells by concanavalin A treatment was significantly higher in the SB fed group than the normal group. Activation-induced IL-4 and IL-10 secretion was lower in SB fed mice compared control mice after DS-induced colitis. These results suggested that SB suppresses the inflammation in DS-induced colitis through the modulation of Th1/Th2 balance to down-regulate $Th_2$ response in MLN lymphocytes.

• 한국인터넷방송통신학회논문지
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• 제17권2호
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• pp.127-134
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• 2017

본 논문은 LTE 사용단말 증가에 따른 주파수 부족현상 개선과 기존의 비효율적인 WiFi의 접속방법으로 인한 트래픽 몰림 현상을 해결하고자 한다. 제안한 LTE-WIFI Vertical Handover 방식은 LTE를 통하여 AP의 사전인증 방법과 RADIUS 서버를 이용하여 단말의 접속 AP를 통제하는 방법이 사용되었다. 제안한 방법은 모의실험을 통하여 기존연결방식대비 AP의 접속속도가 95%가량 향상된 것을 확인할 수 있었고 연결 속도는 기존대비 18%가량 개선된 것을 확인할 수 있었다. 사전인증시스템을 통한 끊김 없는 AP제공과 AP접속 분배를 통한 무선네트워크 속도 향상으로 LTE주파수 부족 문제 해결과 무선네트워크 이용 만족도를 향상시킬 수 있다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.586-589
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• 2018

도로 교통 시스템에 빅데이터 기술이 융합되면서 운전자와 보행자에게 편리하고 도움이 되는 새로운 서비스들이 생겨나고 있다. 다양한 교통 데이터를 수집하고 분석함으로써 교통 시스템에서 흔히 발생할 수 있는 정체 현상 또는 교통량 등을 예측하는 모델이 개발되고 있다. 본 논문에서는 대구시에서 수집한 택시 경로 데이터를 이용하여 대구시의 지도 위에 해당 데이터를 시각화한다. 그 다음으로 대구 시 내의 도로 구간을 설정하고, 택시 데이터의 위치와 속도 데이터, 그리고 도로 구간 정보를 이용하여 해당 구간의 교통량과 구간에서의 차량 평균 속도를 구한다. 이 결과를 이용하여 특정 도로 구간에 대한 교통 시스템 문제 파악에 도움을 주고자 한다.