• 환경위생공학
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• 제11권3호
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• pp.9-12
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• 1996

Polychlorinated biphenyl (PCBs) is one of major toxic pollutants in marine environments, This artificial chlorinated compound has been found in freshwater, seawater, soil, sediments and organismes living in various environments. Because of its toxicity and degradability, its uses in industrial processes have been banned after 1984 in Korea. Coastal area is an important environment for agriculture, industry, transportation, reduction of pollution loads through biogeochemical processes, cycling of nutrients and recreation. Input of pollutants from land and freshwater has been occurring through runoff, rivers and estuaries. Concentrations of PCBs were determined with GC-ECD. Concentrations of PCBs were in the range of 1.0 - 19.2 ng/g-dry weight of sediment(g-d.w.) at Ulsan, 4.5 -8,2 ng/g-d.w. at Onsan, 2.7 - 33.5 ng/g-d.w. at Masan and 4.0 - 60.7 ng/g-d.w. in Kwangyang, In Inchon area, PCBs were not detected in sediments. In sediments of Nakdong estuary, the distribution of PCBs' concentrations was 0.19 - 303 ng/g-d.w.

• Journal of Ginseng Research
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• 제39권4호
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• pp.384-391
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• 2015

It has been reported that Korean Red Ginseng has been manufactured for 1,123 y as described in the GoRyeoDoGyeong record. The Korean Red Ginseng manufactured by the traditional preparation method has its own chemical component characteristics. The ginsenoside content of the red ginseng is shown as Rg1: 3.3 mg/g, Re: 2.0 mg/g, Rb1: 5.8 mg/g, Rc:1.7 mg/g, Rb2: 2.3 mg/g, and Rd: 0.4 mg/g, respectively. It is known that Korean ginseng generally consists of the main root and the lateral or fine roots at a ratio of about 75:25. Therefore, the red ginseng extract is prepared by using this same ratio of the main root and lateral or fine roots and processed by the historical traditional medicine prescription. The red ginseng extract is prepared through a water extraction ($90^{\circ}C$ for 14-16 h) and concentration process (until its final concentration is 70-73 Brix at $50-60^{\circ}C$). The ginsenoside contents of the red ginseng extract are shown as Rg1: 1.3 mg/g, Re: 1.3 mg/g, Rb1: 6.4 mg/g, Rc:2.5 mg/g, Rb2: 2.3 mg/g, and Rd: 0.9 mg/g, respectively. Arginine-fructose-glucose (AFG) is a specific amino-sugar that can be produced by chemical reaction of the process when the fresh ginseng is converted to red ginseng. The content of AFG is 1.0-1.5% in red ginseng. Acidic polysaccharide, which has been known as an immune activator, is at levels of 4.5-7.5% in red ginseng. Therefore, we recommended that the chemical profiles of Korean Red Ginseng made through the defined traditional method should be well preserved and it has had its own chemical characteristics since its traditional development.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.140-143
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• 2005

This study was concerned with the optimization of liquid culture conditions for mycelial growth and polysaccharide production and its physicochemical properties in Cordyceps militaris. The one factor at a time method was adopted to investigate the effects of medium composition, environmental factors and C/N ratio. Among the these varialbles, glucose 80g/L, yeast extract 10g/L, $MgSO_4{\cdot}7H_{2}O\;0.5g/L$, $KH_{2}PO_4\;0.5g/L$ were proved to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature, initial pH, working volume were identified to be $24^{\circ}C$, 7.0 and 100ml, respectively. Under the optimal conditions, the strategies in shake flask culture and 5L jar fermentor led to mycelial growth of 29.43 g/L, 28.88g/L and polysaccharide production of 2.53g/L, 6.38 g/L, respectively. Among the phisicochemical properties, relative concentrations(w/v) of total sugar, uronic acid, protein and hexoseamine were identified to be 74.07%, 1.13%, 0.91%, and 0.46%, respectively. The fraction of neutral and acidic polysaccharide were identified to be 81.9% and 18.1%, respectively.

• 전자통신동향분석
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• 제37권4호
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• pp.46-59
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• 2022

The 5G MEC (Multi-access Edge Computing) technology offers network and computing functionalities that allow application services to improve in terms of network delay, bandwidth, and security, by locating the application servers closer to the users at the edge nodes within the 5G network. To offer its interoperability within various networks and user equipment, standardization of the 5G MEC technology has been advanced in ETSI, 3GPP, and ITU-T, primarily for the MEC platform, transport support, and MEC federation. This article offers a brief review of the standardization activities for 5G MEC technology and the details about the system architecture and functionalities developed accordingly.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.163-169
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• 2020

Synthesis of Fe-Co/meso-HZSM5 catalyst, intended to be applied in Fischer-Tropsch (FT) reaction was investigated. The study emphasized the effect of desilication agents, NaOH and KOH, on the catalyst materials properties. Impregnation composition of active metal (Fe and Co) was also examined. HZSM-5, converted from ammonium ZSM-5 through calcination, was treated with NaOH and KOH for desilication, followed by impregnation with 10% metal loading. Fe composition in the initial mixture was varied at 10-50% from total composition. After impregnation, reduction was applied by flowing hydrogen gas at 400 ℃ for 10 hours. The use of KOH solution induced greater mesoporous volumes; however, it had a detrimental effect on zeolite crystal structure. NaOH solutions, on the other hand, increased mesopore area as high as 100%, indicated from surface area increase from 266.28 m²/g of HZSM-5, to 526.03 m²/g of NaOH-desilicated HZSM-5. In addition, the application of NaOH solution increased pore volume from 0.14 cc/g to 0.486 cc/g. Further, more Fe-Co alloys and less oxide of iron (Fe₂O₃) as well cobalt (Co₃O₄) had been commonly observed in the produced catalysts. The largest Fe-Co alloys could be found in 50Fe-50Co/HZSM-5

• 식물분류학회지
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• 제44권1호
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• pp.22-32
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• 2014

꿀풀과에 속하는 긴병꽃풀속(Glechoma)내 5종에 대한 화판과 악편의 미세 구조를 관찰하여 기재하고 그 분류학적 유용성을 판단하였으며, 분자계통학적 유연관계를 확인하기 위하여 핵 리보솜 DNA의 ITS 염기서열에 기초한 연구를 수행하였다. 기공복합체는 조사된 모든 분류군의 악편에서 분포하였으며, 공변세포의 길이는 분류군마다 다소 차이를 보였다. 긴병꽃풀속 분류군들의 화판과 악에 분포하는 모용은 5 종류(단세포 비선모, 다세포 비선모, 짧은 자루 두상 선모, 긴 자루 두상 선모, 방패형 선모)로 나타났으며, 모용의 종류, 분포, 밀도가 분류군마다 다르게 나타났다. 핵 리보솜 DNA의 ITS 염기서열에 의한 분자계통학적 연구 결과 긴병꽃풀속은 분포지역에 따라 3개의 분계조(유럽-미국, 중국-한국, 일본)로 분리되었다. 한국과 중국에 분포하는 G. longituba는 단계통군을 이루었고, 이탈리아의 특산종인 G. sardoa와 미국 및 유럽에 분포하는 G. hederacea는 단계통군을 형성하였다. G. hirsuta는 유럽의 분계조와 자매군 관계를 이루었으나, 일본에 분포하는 G. grandis는 나머지 분류군들의 상호 유연관계에서 통계적 지지를 얻지 못하였다. 본 연구 결과에서 긴병꽃풀속내의 종간 한계 설정에 있어 화판 및 악의 미세형태형질의 연구보다 핵 리보솜 DNA의 ITS 염기서열에 기초한 분자 계통학적인 연구가 유용한 방법임이 판명되었다. 그러나 구체적인 본 속내 계통 분류학적인 논의를 위해서는 외부 형태학적 형질에 대한 분석을 동시에 수행할 필요가 있으며, 계통학적 유용성이 보다 높은 DNA 구간을 추가로 분석할 필요가 있다.

• 생명과학회지
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• 제25권2호
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• pp.206-213
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• 2015

선식은 웰빙식, 건강식으로 아시아인들에게는 인기있는 식품이지만 외국인들에게는 생소한 식품이다. 이에 본 연구는 외국인들의 선호도를 높이기 위하여 선식을 스무디 형태로 제조하고, 그의 특성을 연구하였다. 효소활성을 지니는 선식 제조를 위해서 흑미와 현미는 발아시켜 사용하였는데, 실온에서 24시간 침지시킨 후, 24시간 $30^{\circ}C$에서 발아시켰다. 알파아밀라아제 효소역가는 발아 전후로 약 13~15배 증가하였다. 현미는 발아 전 9.16 CU/g에서 152.63 CU/g로 증가하였고, 흑미는 7.47 CU/g에서 97.96 CU/g으로 증가하였다. 또한 발아현미분말을 엿기름으로 당화시킨 후, 토마토 30 g과 미강 1.5 g을 첨가하여 유산균을 배양하였다. 이때의 최고균체농도가 $1.1{\times}10^9CFU/ml$ 이었고, 이를 동결건조하여 선식에 첨가하였다. 선식음료제조 후 농도가 $1.3{\times}10^5CFU/ml$로 요구르트 스무디 제조를 위한 스타터 농도로 충분하였다. 이를 이용하여 배양한다면, 선식 요구르트 스무디를 제조가 가능하다. 관능평가결과, 선식 음료의 최적 조건으로는 우유 200 ml에 선식 30 g를 혼합한 것을 가장 선호하였다. 이때의 색도는 L 값 : $63.50{\pm}0.41$, a 값 : $-0.35{\pm}0.06$, b 값 : $8.85{\pm}0.19$로 나타났고, 점도는 $5.97{\pm}1.2$ centipoise 이었다.

• Journal of Information Processing Systems
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• 제20권1호
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• pp.38-52
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• 2024

The 5G is the 5th generation mobile network that provides enhanced mobile broadband, ultra-reliable & low latency communications, and massive machine-type communications. New services can be provided through multi-access edge computing, network function virtualization, and network slicing, which are key technologies in 5G mobile communication. However, these new technologies provide new attack paths and threats. In this paper, we analyzed the overall threats of 5G mobile communication through a literature review. First, defines 5G mobile communication, analyzes its features and technology architecture, and summarizes possible security issues. Addition, it presents security threats from the perspective of user devices, radio access network, multi-access edge computing, and core networks that constitute 5G mobile communication. After that, security requirements for threat factors were derived through literature analysis. The purpose of this study is to conduct a fundamental analysis to examine and assess the overall threat factors associated with 5G mobile communication. Through this, it will be possible to protect the information and assets of individuals and organizations that use 5G mobile communication technology, respond to various threat situations, and increase the overall level of 5G security.

• International Journal of Computer Science & Network Security
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• 제21권6호
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• pp.107-118
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• 2021

The deployment of 5G is in full swing, with a significant yearly growth in the data traffic expected to reach 26% by the year and data consumption to reach 122 EB per month by 2022 [10]. In parallel, the idea of smart cities has been implemented by various governments and private organizations. One of the main objectives of 5G deployment is to help develop and realize smart cities. 5G can support the enhanced data delivery requirements and the mass connection requirements of a smart city environment. However, for specific high-demanding applications like tactile Internet, transportation, and augmented reality, the cloud-based 5G infrastructure cannot deliver the required quality of services. We suggest using multi-access edge computing (MEC) technology for smart cities' environments to provide the necessary support. In cloud computing, the dependency on a central server for computation and storage adds extra cost in terms of higher latency. We present a few scenarios to demonstrate how the MEC, with its distributed architecture and closer proximity to the end nodes can significantly improve the quality of services by reducing the latency. This paper has surveyed the existing work in MEC for 5G and highlights various challenges and opportunities. Moreover, we propose a unique framework based on the use of MEC for 5G in a smart city environment. This framework works at multiple levels, where each level has its own defined functionalities. The proposed framework uses the MEC and introduces edge-sub levels to keep the computing infrastructure much closer to the end nodes.

• Natural Product Sciences
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• 제13권1호
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• pp.40-45
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• 2007

The methanol extract of Coscinium fenestratum, commonly own as tree turmeric, which is widely used in the indigenous system of medicine was studied for its in vitro scavenging activity in different methods viz DPPH scavenging, nitric oxide scavenging, iron chelation activity, superoxide scavenging, ABTS radical scavenging and lipid peroxidation. The results were analyzed statistically by regression method. Its antioxidant activity was estimated by $IC_{50}$ value and the values are $57.1\;{\mu}g/ml$ for DPPH radical scavenging, $36.5\;{\mu}g/ml$ for iron chelating activity, $51.7\;{\mu}g/ml$ for nitric oxide scavenging, $53.63\;{\mu}g/ml$ for ABTS scavenging, $44.2\;{\mu}g/ml$ for superoxide scavenging, and $40\;{\mu}g/ml$ for lipid peroxidation. In all the methods, the extract showed its ability to scavenge free radicals in a concentration dependent manner. The results indicate that C. fenestratum has potent antiofidant activity.