• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권4호
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• pp.1307-1323
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• 2014

With the exhaustion of global IPv4 addresses, IPv6 technologies have attracted increasing attentions, and have been deployed widely. Meanwhile, new applications running over IPv6 networks will change the traditional traffic characteristics obtained from IPv4 networks. Traditional models obtained from IPv4 cannot be used for IPv6 network monitoring directly and there is a need to investigate those changes. In this paper, we explore the flow features of IPv6 traffic and compare its difference with that of IPv4 traffic from flow level. Firstly, we analyze the differences of the general flow statistical characteristics and users' behavior between IPv4 and IPv6 networks. We find that there are more elephant flows in IPv6, which is critical for traffic engineering. Secondly, we find that there exist many one-way flows both in the IPv4 and IPv6 traffic, which are important information sources for abnormal behavior detection. Finally, in light of the challenges of analyzing massive data of large-scale network monitoring, we propose a group flow model which can greatly reduce the number of flows while capturing the primary traffic features, and perform a comparative measurement analysis of group users' behavior dynamic characteristics. We find there are less sharp changes caused by abnormity compared with IPv4, which shows there are less large-scale malicious activities in IPv6 currently. All the evaluation experiments are carried out based on the traffic traces collected from the Northwest Regional Center of CERNET (China Education and Research Network), and the results reveal the detailed flow characteristics of IPv6, which are useful for traffic management and anomaly detection in IPv6.

• 한국통신학회논문지
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• 제41권6호
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• pp.663-671
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• 2016

인터넷 트래픽양의 급증에 따라 고속 라우터의 수요가 많아졌다. 트래픽 통계 또는 보안 등의 목적으로 라우터에서 패킷을 측정해야 하는데 고속 라우터의 특성상 메모리공간이 제한적이다. RCC는 적은 메모리로 트래픽을 정확하고 효율적으로 측정하는 방법을 제시했다. RCC에서는 트래픽을 측정하는데 큰 Flow를 추가적인 Quadratic Probing 기반 해시 테이블에 누적하는 방법 사용한다. 그런데 Quadratic Probing은 적은 메모리 또는 메모리 사용률이 많은 상황에서 연산량이 많으며, 특히 갱신 또는 실시간 조회가 자주 발생하는 시스템에서 오버헤드가 크다. 이 논문에서는 RCC의 특성을 분석하고 실험을 통해 Quadratic Probing의 문제점을 증명하며 갱신 또는 조회에 효율적인 Cuckoo Hashing을 사용하여 RCC의 성능을 개선한다. 실험 결과에 따르면 RCC에서 Cuckoo Hashing을 사용할 때 메모리 사용률이 높은 상황에서도 높은 정확도를 보여주었고, 효율적으로 트래픽을 측정할 수 있었다.

• 한국습지학회지
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• 제17권2호
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• pp.113-117
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• 2015

최근 멸종위기식물인 조름나물의 보전과 복원을 위한 연구가 진행되지만, 조름나물의 위해인자에 대한 연구는 진행되지 않고 있다. 본 연구에서는 국내 최초로 실험 결과를 통해 조름나물에 대한 위해인자로서 주홍박각시의 생육 및 섭식 특성을 밝혔다. 6마리의 주홍박각시 애벌레를 대상으로 실험을 실시하였으며, 이들의 성장에 따른 몸무게 변화와 먹이 선호도, 조름나물 섭식량을 조사하였다. 주홍박각시 애벌레가 번데기로 용화하는 데는 약 27일이 소요되며, 그때의 몸무게는 4-7.5g이었다. 주홍박각시 애벌레의 먹이 선호도는 조름나물, 봉선화, 개머루, 담쟁이덩굴 순으로 나타났다. 애벌레 동안의 총 섭식량을 모델을 이용해 계산한 결과 11-30g으로 나타났다. 이는 조름나물 순군집 면적 $0.03-0.08m^2$에 해당한다. 본 연구를 통해 주홍박각시는 멸종위기종인 조름나물에 대한 잠재적인 위해인자임이 확인되었으며, 주홍박각시의 분포 범위를 고려할 때 멸종위기종인 조름나물의 보전과 복원 계획에 주홍박각시의 선제적 관리가 포함되어야 함을 제안한다.

• Clinical and Experimental Otorhinolaryngology
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• 제11권4호
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• pp.250-258
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• 2018

Objectives. To compare narrative skills between fourth and fifth grades of Persian-speaking students with hearing impairments and typical hearing students of the same grade and also to evaluate the effects of group, sex, hearing age, and educational grade of the students on their spoken/written narrative performance. Methods. The subjects were 174 students aged 10-13 years, 54 of whom wore cochlear implants, 60 suffered from moderate to severe hearing losses and wore hearing aids, with the remaining 60 students being typical hearing in terms of the sense of hearing. The micro- and macrostructure components of spoken and written narrative were elicited from a pictorial story (The Playful Little Elephant) and then scored by raters. Results. Compared to the typical hearing, the students with hearing impairments had significantly lower scores in all of the microstructure components of narratives. However, the findings showed no significant difference among different groups in macrostructure components of narratives. It was also revealed that the students had equal performance in spoken and written narrative. Finally, factor analysis manifested that group, sex, hearing age, and educational level of children might alter the outcome measures in various interactions. Conclusion. Although cochlear implantation was more effective than hearing aid on spoken and written narrative skills, the Persian-speaking students with hearing impairments were seen to need additional trainings on microstructure components of spoken/written narrative.

• 한국식생활문화학회지
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• 제25권1호
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• pp.25-35
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• 2010

This article examines the types of tteok (Korean rice cake) recorded in 21 old literatures of the Joseon dynasty (1392-1909) according to its main ingredients. Tteok varieties of the Joseon dynasty were categorized into jjin-tteok, chin-tteok, jijin-tteok, salmeun-tteok and guun-tteok and their changes in cooking method were discussed from the early to late eras of the Joseon dynasty. These can be summarized as follows. In the early, middle and late eras of the Joseon dynasty, there were 1, 15 and 84 kinds of tteok using non-glutinous rice as the main ingredient, and 6, 24 and 120 kinds using glutinous rice, respectively. Tteok using wheat flour was not found in the early Joseon dynasty, whereas 6 and 32 kinds were found in the middle and late eras, respectively. There were 1, 4 and 5 kinds of tteoks using buckwheat, and 5, 11 and 19 kinds using other ingredients such as yam, barley, elephant's ear, oat, and arrowroot flour, in the early, middle and late eras, respectively. The frequency of the main ingredient increased in the order of glutinous rice>non-glutinous rice>wheat flour>other ingredient>buckwheat flour during the Joseon dynasty and the ratio of tteoks using non-glutinous and glutinous rice flours was 1:1.5. The number and types of tteok were noted to increase abruptly throughout the Joseon dynasty. This may be associated with the commercial industrial development that prevailed in the late Joseon dynasty. Further study will be conducted on their recipes and ingredients recorded in these old literatures to develop a standardized recipe for the globalization of tteok.

• Computers and Concrete
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• 제32권2호
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• pp.217-232
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• 2023

Numerous studies have been performed on the behavior of pile foundations in cold regions. This study first attempted to employ artificial neural networks (ANN) to predict pile-bearing capacity focusing on pile data recorded primarily on cold regions. As the ANN technique has disadvantages such as finding global minima or slower convergence rates, this study in the second phase deals with the development of an ANN-based predictive model improved with an Elephant herding optimizer (EHO), Dragonfly Algorithm (DA), Genetic Algorithm (GA), and Evolution Strategy (ES) methods for predicting the piles' bearing capacity. The network inputs included the pile geometrical features, pile area (m²), pile length (m), internal friction angle along the pile body and pile tip (Ø°), and effective vertical stress. The MLP model pile's output was the ultimate bearing capacity. A sensitivity analysis was performed to determine the optimum parameters to select the best predictive model. A trial-and-error technique was also used to find the optimum network architecture and the number of hidden nodes. According to the results, there is a good consistency between the pile-bearing DA-MLP-predicted capacities and the measured bearing capacities. Based on the R2 and determination coefficient as 0.90364 and 0.8643 for testing and training datasets, respectively, it is suggested that the DA-MLP model can be effectively implemented with higher reliability, efficiency, and practicability to predict the bearing capacity of piles.

• 대순사상과 동아시아종교
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• 제3권2호
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• pp.71-92
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• 2024

The world we live in is becoming more convenient thanks to the inventions of science and technology. Still, the world is also becoming more and more unpredictable with the current situation of VUCA (Volatility, Uncertainty, Complexity, Ambiguity). The Covid-19 pandemic brought the biggest global disaster ever with 774,631,444 infected people and 7,031,216 deaths (WHO on February 11, 2024) but it seems that humanity is gradually forgetting this disaster. Meanwhile the economic stimulus packages worth trillions of dollars from governments after the pandemic have further caused the world debt bubble to swell. The bubble burst scenario is something that many economic experts fear. Apparently, in the transitional period of the early decades of the 21st century, the world's economic, cultural, political, social, natural, and environmental aspects have undergone profound transformations: from the real estate and finance crises in the United States since 2008; through the melting of the Arctic ice over the past several decades; to the double disaster of the earthquake and tsunami in Japan in 2011. Especially, in the context of the world economic crisis after the COVID-19 pandemic, the human achievements of the past thousands of years are in jeopardy of being wiped out in an instant. Many people are predicting a bad scenario for a chain collapse. Facing the signals of an imminent economic catastrophe based on the appearance of "the Gray Rhino, Black Swan and White Elephant," many drawn in by Eschatological thought declare that Doomsday will occur shortly. This is the time for many other people to hope for the incoming Messiah. The Messiah is said to appear when people feel despair or suffer a great disaster because faith in the Savior can help them overcome adversity mentally. This research will find out how adherents of Buddhism view and deal with civilizational crises by examining history via symbols associated with Maitreya as based upon the Buddhist Messiah, Maitreya.

• 미술자료
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• 제99권
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• pp.50-71
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• 2021

부여 동사리사지 오층석탑은 수도 개성 양식 계열의 남방한계선을 점하는 중요한 위치에 건립된 고려 전기 탑이다. 갑석 받침인 부연의 사선형 곡면 처리 등에서는 고려 개경 중심의 탑에서 보이는 고려중앙 양식의 특징을 잘 살펴볼 수 있었으며, 11세기 석탑과 양식을 공유하는 특징들도 뚜렷하게 관찰되었다. 하층기단의 안상문에서는 고려 1028년(현종 19)에 대대적으로 중수된 것으로 추정되는 부여 정림사지에 있는 석불좌상 대좌와, 천안의 천흥사지 당간지주에서 동일한 문양과 치석 수법이 조사되어, 동사리사지 오층석탑 건립 연대를 11세기로 추정했다. 부여 동사리사지는 금강 인근에 위치해 고려의 조운제도상 중요한 교통로이며, 고려 왕실의 원찰인개태사로 가는 길목에 자리잡고 있어 고려 현종대(1009~1031) 부여 정림사지가 크게 중수되고 동사리사지도 주요 거점으로 부각되면서 석탑이 조성되었을 것으로 짐작된다. 또한 동사리사지 석탑은 1021년(현종 12) 천안의 홍경사와 홍경원의 창건과 관련된 것으로 추정되는 인근의 천흥사지 석탑 및 당간지주와도 양식을 공유하고 있어 이를 통해 개경 양식의 유입 루트도 살펴볼 수 있었다. 부여 동사리사지 오층석탑은 고려 11세기 문화의 우수성을 보여주는 이 지역의 또 하나의 석조미술품이다. 수도 개경의 거대한 현화사 석등과 석탑과 비견되는 고려 초 논산 개태사나 관촉사, 부여 대조사 석조미륵보살입상 등의 거불(巨佛)과 함께 이 석탑 역시 고려 특유의 당당하고 자신감 있는 미감을 보이고 있다. 11세기 활발한 지역간 문화교류의 배경 아래 부여 동사리 지역은 고려 개경의 불교문화 영향권 아래 완숙한 문화 역량을 총 발휘해 경쾌하고 날렵하며, 엄정하면서도 세련된 이러한 석탑을 탄생하게 했을 것으로 추정된다.

• 한국지반신소재학회논문집
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• 제17권1호
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• pp.111-118
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• 2018

단층 등 취약지반 조건에서의 터널굴착 시 터널천단 및 측벽변위의 억제를 목적으로 하는 각부보강공이 일반적으로 적용되고 있으며, 터널 단면증가 변화율에 따른 각부보강공 설치각도 및 길이를 고려한 지보안전성 확인을 위한 주요 인자로서 내공변위 천단침하 각부침하 각부축력 등의 여러 응력변위 특성 변수들이 있다. 이러한 굴착중 안전성확인을 위한 변수들에 대한 검토 결과, 우각부 침하영향성이 단면증가율 보다 더 큰 변위경향을 보이는 가장 중요한 중점관리 지배요소로 분석되었으며, 터널단면 증가 변화율에 대한 각 보강공 길이별 축력의 변화관점에서는 큰 연관성을 보여주지 못하는 터널단면 증가율 대비 작은 증가율을 나타냈다. 또한, 각부 보강공 축력의 발생경향은 터널 단면증가율보다 보강공 마찰지지 개념 메커니즘에 따른 거동 영향성을 보여주는 것으로 분석되었다. 본 연구결과, 일정한 길이의 각부 보강공이 선정될 경우 지반불량 구간에서의 터널 단면이 다소 대단면화하여도 무리하게 각부보강공의 길이를 연장시키지 않는 것이 시공성 및 경제성을 고려한 보다 더 합리적인 방법으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1233-1242
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• 2011

The in vivo digestibility of mulberry leaves (Morus alba) and the effects of the partial replacement of cotton seed with fresh mulberry leaf in rations on the performance of growing Vietnamese cattle was investigated. For the in vivo digestibility trial, twenty castrated rams of Phanrang breed (a local prolific breed) with an initial weight of 23-25 kg, were first assigned to four groups according to weight and then randomly assigned to one of four dietary treatments to determine digestibility of nutrients in mulberry leaves (M. alba), natural Bermuda grass (Cynodon dactylon), elephant grass (Pennisetum purpureum) and buffalo grass (Panicum maximum cv. TD 58). All forages were cut and chopped daily before being offered (at 120% maintenance) to the sheep. In the feeding trial, 20 Laisind (Vietnam yellow cows${\times}$Red Sindhy bulls) crossbred bulls averaged 18 month old and 184 kg were used to investigate the effect of partial replacement of cottonseed in the diet by mulberry leaves on live weight gain and feed conversion rate. The experiment was a randomized complete block design with four levels of fresh mulberry leaves which varied from 0 to 15% of total dietary dry mater and five animals per treatment over an 84 day period. The in vivo digestion trial showed the superior quality of mulberry leaves compared with the grasses. Chemical analysis indicated that mulberry leaves had the highest CP and the lowest NDF contents (22.3 and 31.1% DM, respectively) among the four forages tested. Digestibility of DM and OM of the mulberry leaf (66.4 and 71.8%, respectively) was also the highest but that of CP (58.2%) and NDF (58.4%) was the lowest of the four forages evaluated (p<0.05). Consequently, the ME value and therefore net energy (NE) and unit feed for lactation (UFL) values of the mulberry leaves, which was estimated from chemical composition and digestibility values, were the highest among the forages investigated in the present study. Results of the feeding trial showed no treatment effect on average daily gain (ADG) of the cattle. The values were 554, 583, 565 and 568 g/d for animals in the diets of 0, 5, 10, and 15% mulberry leaves inclusion, respectively. Total DM intake of the animal was not affected by the treatment when expressed as kg/animal/d. However, when adjusted for metabolic weight of the animal the DM intake was reduced (p<0.05) as whole cottonseed was replaced by mulberry leaves in the ration. When the level of mulberry leaves in the ration increased from 5 to 15% of dietary DM at the expense of whole cottonseed, CP and ME intakes of the cattle were significantly decreased (p<0.05) and the feed to gain ratio reduced by 8 to 14% as compared with the control diet (p<0.05). Mulberry leaf is a good feed ingredient for ruminants because of its high level of crude protein and high digestibility of nutrients and energy. Mulberry leaves can be efficiently used as a source of protein supplement to replace cottonseed, a more expensive animal feeds ingredient, in the diet for Vietnamese cattle.