• 한국항행학회논문지
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• 제19권3호
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• pp.257-263
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• 2015

DoS 공격 및 DDoS 공격에 대한 다양한 대비 방안이 제시되고 있지만, 네트워크 및 프로토콜이 가지는 취약점으로 인해 여전히 악용되고 있다. 특히, 언제 어디서나 인터넷을 사용할 수 있는 환경이 구축되었고, 사물인터넷 시대의 진입을 앞둔 현 시점에서는 기존의 컴퓨터뿐만 아니라 가전기기 등도 DoS 공격 대상 또는 공격자 역할을 수행할 가능성이 높아지고 있다. 본 논문에서는 DoS 공격의 유형 및 특징에 대해 알아보고, 공개용 운영체제인 리눅스에 기본 탑재된 패킷필터링 도구이자 방화벽 프로그램인 iptables를 이용하여 빈번하게 발생되는 DoS 공격에 대비하는 정책 설정에 대해 기술하였다.

• Journal of Communications and Networks
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• 제5권3호
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• pp.240-248
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• 2003

This paper analyzes mobile agent performance in network management compared to the client-server model used in the Simple Network Management Protocol (SNMP). Prototypes of an application that gathers MIB-II (Management Information Base-II) variables have been created and tested on a LAN. After acquiring implementation parameters related to network management and to the mobile agent infrastructure, simulation results have been obtained on large topologies similar in shape to the Internet. Response time results show that mobile agents perform better than SNMP when the number of managed elements ranges between two specific limits, an inferior bound and a superior one, determined by the number of messages that pass through a backbone and by the mobile agent size which grows along with MIB-II variables collected on network elements. The results also show that a significant improvement is achieved when the mobile agent returns or sends data to the management station after visiting a fixed number of nodes.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.267-273
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• 2020

With the strong growth of social networking sites such as Facebook in recent years, the potential of exploiting customers on Facebook is increasing. Presently, trading activities on Facebook is rapidly developing. Therefore, businesses have become increasingly competitive when selling products on Facebook, so as to retain customers as well as to satisfy customer, which is of paramount importance. This study was conducted to assess the factors affecting the satisfaction of individual customers in Vietnam when buying goods on Facebook. This study uses multivariate analysis techniques (Confirmatory Factor Analysis, Structural Equation Modeling) to determine the factors affecting customer satisfaction when buying goods on Facebook. Research results from 268 individual customers in Vietnam indicated trust and convenience are the two important factors related to customer satisfaction when buying goods on Facebook. Customer satisfaction is the result of consumer experience throughout the different stages of purchase. The more the shopping experience, the more the customers are satisfied when buying products. The price and products do not affect customer satisfaction (prices are easy to compare and products are easily understood on the Internet; hence, these two factors are not considered as determinants of customer satisfaction). Furthermore, this study provides recommendations to improve customer satisfaction.

• 복식
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• 제59권7호
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• pp.1-16
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• 2009

This study is on the children's clothing in Seoul Gyeonggi-do, Chungcheong-do and Gangwon-do between the $1920s{\sim}1950s$, by comparing positive data collected from pictures and literatures, remains and interviews. A baenaet jeogori was made of soft white cotton fabrics and was used as a charm when the baby had grown and had an test or a big occasion. A dureong chima and pungcha trousers were clothes for both boys and girls from their birth to the age of $4{\sim}5$ when they could have bowel movements by themselves. Occasions for celebrating a baby's growth were the one-hundredth day and the first birthday. In general, ordinary families had their babies' one-hundredth day in a simple way without special clothes. On the first birthday, however, even ordinary families prepared new clothes for their babies, and read their fortune and prayed for their well being and long life through events such as doljabi. In the age when medicine was poor and the infant mortality was high, the meaning of such a ceremony was to congratulate on the baby's safe growth through dangerous moments.

• 영미문화
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• 제14권1호
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• pp.1-26
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• 2014

Multicultural theories fully fledged around the 1980s and the early 1990s. Emerging in the 1960s thanks to the Civil Rights movement, multiculturalism has become the grand American national narratives, whose tenets recognize and respect people with diverse racial and cultural backgrounds. This period, however, witnessed the eruption of violent and destructive rebellions or uprisings involving racial minorities. Racial conflicts and tensions exploded at the moment when multiculturalism was widely practiced in areas including education and public policy revealing that complicated problems are embedded in the urban ghettos. American popular culture, specifically addresses antagonisms among different races or ethnicities in Bed-Stuy in New York. Although the film is mainly concerned with the collision among races, it lets ambivalent and cacophonous values and ideologies be present in the black community. On the other hand, Ice Cube's "Black Korea" empowers the black community when it deals with the turbulent relationship between black residents and Korean American merchants. Simultaneously, it denigrates Korean Americans as gasta raps often target the institution like government or police. In short, while attempts to search the ideas of coexistence and juxtaposition through polyphonic features embodied in the film "Black Korea" seems to depend on the dualistic system when it deals with the black-Korean conflicts and as a result it just reveals the chasm between two communities.

• 사상체질의학회지
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• 제18권1호
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• pp.107-117
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• 2006

1. Objectives There are many studies on the ordinary symptoms based on Sasang constitution. But there. are not quite satisfactory between the types of Sasang constitution. So This study is for learning the characteristics of ordinary symptoms depending on Soyangin Soeumin and Taeyangin Taeumin of the Sasang constitution. 2. Methods One thousand and two hundred twenty nine subjects were included in Bundang Oriental Hospital of Dongguk University. We classified them into the each type of Sasang Constitutional Medicine(SCM) by the well-trained SCM specialist, and assessed their ordinary features by the questionnaire. Binary logistic regression analysis was applied to evaluate the influence of ordinary features to the diagnosis of SCM. 3. Results (1) Compared to Taeyangin Taeumin, Soyangin Soeumin do not sweat a lot. Even if Soyangin Soeumifl do sweat, one does not feel refreshed. Soyangin Soeumin do not sweat while sleeping at night nor eating meals, but discharges cold sweat if one does not feel well. (2) Compared to Taeyangin Taeumin, Soyangin Soeumin go to stool less frequently and have diarrhea when one does not feel well. Soyangin Soeumin do not feel irritated even though one is not able to go to stool for one day. (3) Compared to Taeyangin Taeumin, Soyangin Soeumin do not have foams in urine. (4) Compared to Taeyangin Taeumin, Soyangin Soeumin tend to eat slow, do not eat a lot normally, do not have a great appetite, have problems for digestion, and especially have difficulties in digestion when one is stressed. 4. Conclusions We found that Taeyangin Taeumin and Soyangin Soeumin have characteristics of ordinary symptoms, but partly there are not in accoradance with ones what Lee ]e-Ma said in his book. So in future we hope clinical studies are required steadily.

• 한국자원식물학회지
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• 제28권4호
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• pp.541-545
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• 2015

This study investigated the effect of planting density on growth and yield of elephant garlic. Three planting densities of 20 × 20, 20 × 15, and 20 × 10 ㎝ were tested with the furrow width fixed at 120 ㎝ for the evaluation of elephant galic growth and yield. The average date of emergence was middle and late November, requiring about 30 days for the all emergence. For the flowering, 221 days after sowing were required in all the treatments. Plant height and leaf growth were not significantly different according to the planting density. Flower stalk was shorter when planting density was narrow. The L/D ratio was decreased to form oval shape when planting density was narrow. The yield of elephant garlic was 1,811 ㎏ /10a in planting density 20 × 20 ㎝, 2,375 ㎏/10a in 20 × 15 ㎝, and 2,838 ㎏/10a in 20 × 10 ㎝ plot. The marketable garlic ratio was highest as 1,593 ㎏/10a in planting density of 20 × 15 ㎝.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.50.1-50.11
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• 2020

Objectives: In this study, we investigated the potential of amoxicillin-loaded polymeric microspheres to be delivered to tooth root infection sites via a bioactive reparative cement. Materials and Methods: Amoxicillin-loaded microspheres were synthesized by a spray-dray method and incorporated at 2.5% and 5% into a mineral trioxide aggregate cement clinically used to induce a mineralized barrier at the root tip of young permanent teeth with incomplete root development and necrotic pulp. The formulations were modified in liquid:powder ratios and in composition by the microspheres. The optimized formulations were evaluated in vitro for physical and mechanical eligibility. The morphology of microspheres was observed under scanning electron microscopy. Results: The optimized cement formulation containing microspheres at 5% exhibited a delayed-release response and maintained its fundamental functional properties. When mixed with amoxicillin-loaded microspheres, the setting times of both test materials significantly increased. The diametral tensile strength of cement containing microspheres at 5% was similar to control. However, phytic acid had no effect on this outcome (p > 0.05). When mixed with modified liquid:powder ratio, the setting time was significantly longer than that original liquid:powder ratio (p < 0.05). Conclusions: Lack of optimal concentrations of antibiotics at anatomical sites of the dental tissues is a hallmark of recurrent endodontic infections. Therefore, targeting the controlled release of broad-spectrum antibiotics may improve the therapeutic outcomes of current treatments. Overall, these results indicate that the carry of amoxicillin by microspheres could provide an alternative strategy for the local delivery of antibiotics for the management of tooth infections.

• Plant Resources
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• 제6권2호
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• pp.89-93
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• 2003

This study was conducted to develop the clonal propagation technique through in vitro culture using basal stem explants in Phalaenopsis hybrid grown in vitro. The highest frequency of protocorm-like body (PLB) formation was obtained when basal stem explants were cultured on VW medium containing 30g/L sucrose, 500 mg/L activated charcoal, 150 ml/L coconut water, 1 mg/L NAA, 5 mg/L 2iP and 2.5g/L gel rite. PLBs transferred to Hyponex medium were regenerated to plantlets. Plantlets transferred to plastic pots containing spagnum moss were developed and successfully acclimatized under greenhouse. The flower was bloomingly opened in plants regenerated from basal stem explants. The flower was not different from both mother plant and plant induced through clonal propagation of Phalaenopsis hybrid.

• 대한지리학회지
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• 제48권3호
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• pp.336-347
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• 2013

This paper presents an evaluation of stream restoration projects in Seoul with a focus on dissolved oxygen. Five test sites across four streams were measured for dissolved oxygen (DO) in late May to early June in 2012 and compared against a set of minimum and maximum thresholds. Only one test site, Hwarang-cheon, showed measurements below 6 mg/l DO. Towards the upper limit, the Hwarangcheon site was the only tested stream which was not at risk of DO supersaturation. The Danghyeon-cheon site had the highest probability of supersaturation, with DO saturation exceeding 130% expected 86.5% of the time. When measured every hour during daytime, DO levels showed diurnal variations, peaking in the afternoon. However, they showed inconsistent results along transects of the streams. Overall, the streams are rich in DO. To maintain the streams in good standing, nutrient loading should be addressed to prevent potential algal bloom induced hypoxic events down the line.