• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.11
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• pp.5673-5691
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• 2019

Information centric mobile network can significantly improve the data retrieving efficiency by caching contents at mobile edge. However, the cache pollution attack can affect the data obtaining process severely by requiring unpopular contents deliberately. To tackle the problem, we design an algorithm of mitigating cache pollution attacks in information centric mobile network. Particularly, the content popularity distribution statistic is proposed to detect abnormal behavior. Then a probabilistic caching strategy based on abnormal behavior is applied to dynamically maintain the steady-state distribution for content visiting probability and achieve the purpose of defense. The experimental results show that the proposed scheme can achieve higher request hit ratio and smaller latency for false locality content pollution attack than the CacheShield approach and the baseline approach where no mitigation approach is applied.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.2
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• pp.173-184
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• 2017

The purpose of this study is to examine the effects of science classes using the geological materials of a locality on academic achievement and scientific attitude of elementary school students. For this study, the class unit is 'stratum and fossils', 2nd semester of 3rd grade, and the geological materials of a locality is applied for class. The geological materials used in teaching and learning of 'stratum and fossil' unit are photographs & video data relating to geological phenomenon, and rock & fossils samples collected in Jeollanam-do province. This study has been aimed at 2 classes 47 students of 3rd grade in G elementary school of G metropolitan. One class 23 students are the research group to apply science class using the geological materials in a locality, on the order hand another class 24 students are the comparison group to apply general science classes. The results of this study are follows. First, a positive relationship was identified between academic achievement and science class applying the geological materials in a locality in the research group. This shows that academic achievement was improved by science class applying the geological materials in a locality. Second, a positive relationship was identified between scientific attitude and science class applying the geological materials in a locality in the research group. This shows that scientific attitude was improved by science class applying the geological materials in a locality. Third, by the results of interview with students who was participated in science class applying the geological materials in a locality, it shows that they have interest and curiosity about local geology. Above results means that science class applying the geological materials in a locality help elementary schools students improve the educational effect about 'stratum and fossils' unit. Thus, it is needed to use the geological materials of a locality in science class relating to the geology units of elementary school science in order to improve academic achievement and scientific attitude of elementary school students.

• The KIPS Transactions:PartA
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• v.11A no.1
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• pp.11-20
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• 2004

Multimedia data processing in streaming pattern contains high spatial locality and low temporal locality. This paper has proposed a dynamic data prefetching scheme that fully exploits the regularity between memory addresses referred consecutively. Compared to the existing data Prefetching scheme, the Proposed scheme can reduce data Prefetching error when an application divides an way into smaller blocks and processes them block by block. Experimental results on various media benchmark programs show the proposed scheme predicts memory addresses more accurately and results in better performance than existing prefetching schemes.

• Animal Systematics, Evolution and Diversity
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• v.35 no.1
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• pp.33-36
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• 2019

The marine interstitial annelid Pharyngocirrus uchidai(Sasaki, 1981) has been only known from Japan. In this study, we report the occurrence of P. uchidai for the first time in four localities along the eastern coast of Korea: Bukmyeon, Gamchu, Gase, and Oeongchi. Species identification was confirmed by comparison of DNA barcoding sequences with morphological examination from the type locality, Oshoro, Japan. We generated a total of 25 sequences of a partial segment (580 bp) of the cytochrome c oxidase subunit I gene (COI), representing five specimens from each locality. Maximum intra-specific variation was 1.2% in terms of Kimura two-parameter (K2P) distance, observed between two individuals each from Gamchu (i.e., between two specimens from the single locality), Gamchu and Oeongchi, Gamchu and Oshoro, and Oeongchi and Oshoro. On the other hand, an identical haplotype was found in all the five localities, substantiating our species identification for the Korean populations. Inter-specific K2P distance between P. uchidai and an unidentified Saccocirrus sp. from Canada (based on public database entries) was 22.4-23.4%.

• Journal of Korean Society of Archives and Records Management
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• v.20 no.2
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• pp.115-121
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• 2020

This article introduces the process of building Gongjuhak Archive that collects and databases data from various fields related to the region, enabling people to easily establish Gongju locality and lay the foundation for Gongju Studies. Gongjuhak Archive is built in accordance with the win-win development agreement between both Gongju City and Gongju University, and is proud to have played a pioneering role in the regional studies archive established by the local government. Therefore, we hope to share our concerns and experiences in building Gongjuhak Archive and to successfully develop it with regional studies archive building institutions across the country.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.175-183
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• 2008

This study reviewed and compared the measured value with the calculated sediment loads value by the existing theory equation, after actually measuring the suspended load, focusing on locality river in Gangwon province. Next, it suggested the application problems of the existing sediment loads calculation equation in case of rivers in Gangwon province, and suggested the proper sediment loads calculation equation to rivers in Gangwon province, after implementing the statistical regression analysis by using the measured data for 5 rears, 2003 ~ 2007.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.2
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• pp.82-102
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• 2008

Packet losses tend to occur during short error bursts separated by long periods of relatively error-free transmission. There is also a significant spatial correlation in loss among the receiver nodes in a multicast session. To recover packet transmission errors at the transport layer, tree-based protocols construct a logical tree for error recovery before data transmission is started. The current tree construction scheme does not scale well because it overloads the sender node. We propose a scalable recovery tree construction scheme considering these properties. Unlike the existing tree construction schemes, our scheme distributes some tasks normally handled by the sender node to specific nodes acting as repair node distributors. It also allows receiver nodes to adaptively re-select their repair node when they experience unacceptable error recovery delay. Simulation results show that our scheme constructs the logical tree with reduced message and time overhead. Our analysis also indicates that it provides fast error recovery, since it can reduce the number of additional retransmissions from its upstream repair nodes or sender node.

• Journal of Ubiquitous Convergence Technology
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• v.1 no.1
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• pp.28-34
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• 2007

Tree-based reliable multicast protocols provide scalability by distributing error-recovery tasks among several repair nodes. These repair nodes perform local error recovery for their receiver nodes using the data stored in their buffers. We propose a packet loss patterns adaptive feedback scheduling scheme to manage these buffers in an efficient manner. Under our scheme, receiver nodes send NAKs to repair nodes to request packet retransmissions only when the packet losses are independent events from other nodes. At dynamic and infrequent intervals, they also send ACKs to indicate which packets can be safely discarded from the repair node's buffer. Our scheme reduces delay in error recovery because the requested packets are almost always available in the repair node's buffers. It also reduces the repair node's workload because (a) each receiver node sends infrequent ACKs with non-fixed intervals and (b) their sending times are fairly distributed among all the receiver nodes.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.126-129
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• 2003

최근 대용량의 데이터베이스로부터 연관규칙을 발견하여 이를 활용하는 단계에서 이러한 연관규칙을 수량항목에도 적용할 수 있도록 확장하는 연구가 소개되고 있다. 본 논문에서는 수량 항목을 이진항목으로 변환하기 위하여 빈발구간 항목집합(Large Interval Itemsets)을 생성할 때 수량 항목이 특정 영역에 집중하여 발생하거나 골고루 분포되어 있지 않은 경우, 이러한 지역성(locality)을 고려하여 빈발구간 항목집합을 생성하는 방법을 제안한다. 이 방법은 기존의 방법보다 많은 수의 세밀한 빈발구간 항목들을 생성할 수 있을 뿐만 아니라 의미 있는 구간을 중심으로 빈발구간 항목들이 순서대로 생성되기 때문에 세밀도를 판단하여 활용할 수 있으며, 원 데이터가 가지고 있는 특성의 손실을 최소화할 수 있는 특징이 있다 또한 인구센서스등 실 데이터를 사용한 성능평가를 통하여 기존의 방법보다 우수함을 보였다.

• Journal of Sport and Applied Science
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• v.7 no.1
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• pp.1-10
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• 2023

Purpose: This paper analyzed the features of Winter Olympics mascots in chronological order by examining the evolution of mascots and presented the attributes of the Winter Olympics mascots from Innsbruck 1976 to Beijing 2022. Research design, data, and methodology: This paper conducted an exploratory study on the thinking to understand the characteristics of 13 Winter Olympics Mascots through literature review. Results: First, the mascot is a fictional character, usually an artificial character that represents the locality of the host city, including animals, human figures, and local inhabitants. Second, Schneemann, Innsbruck 1976 was known as the first official Winter Olympics mascot. Third, 19 mascots out of a total of 24 mascots were created using animals. Conclusions: The six attributes of the Winter Olympics mascots were identified: friendliness, symbolic meaning, originality, diversity, value, and identity of a special location. Above all, Winter Olympics has a locality that includes areas covered with ice and snow. From this point of view, the Olympics mascot highlights the image of snow and ice and the physical environment that includes it.