• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.9-15
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• 2016

In this paper, we propose a smart HLS(HTTP Live Stream) platform with dynamic single buffering for the best transmission of adaptive video bit-rates. This smart HLS can optimizes the channel transition zapping-time with the monitoring of bandwidth between HLS server and OTT(Over The Top) client. This platform is designed through the control of video stream due to proper multi-bitrates and bandwidths. This proposed OTT can decode the live and VOD(Video On Demand) videos with the buffering of optimumal bitrate. And, the HLS can be cooperated with a smart OTT, and segmented for the m3u8 files of H.265 MPEG-2 TS(Transport Stream) videos. As a resullt, this single buffer based smart OTT can transmit optimal videos with the maximum data buffering according to the adaptive bit-rate depending on the network bandwidth efficiency and the decoded VOD video, too.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.3
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• pp.481-496
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• 2021

It is imperative to migrate the current public key cryptosystem to a quantum-resistance system ahead of the realization of large-scale quantum computing technology. The National Institute of Standards and Technology, NIST, is promoting a public standardization project for Post-Quantum Cryptography(PQC) and also many research efforts have been conducted to apply PQC to TLS(Transport Layer Security) protocols, which are used for Internet communication security. In this paper, we propose a scenario in which a server and multi-clients share session keys on TLS by using the parallelized NTRU which is PQC in the key exchange process. In addition, we propose a method of accelerating NTRU using GPU and analyze its efficiency in an environment where a server needs to process large-scale data simultaneously.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1670-1675
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• 2020

In this study, to provide the basis for establishing effective network based countermeasures against DRDoS(Distributed Reflection Denial of Service) attacks, we propose a new 'DRDoS attack multi-level detection method' that identifies the network based characteristics of DRDoS and applies probability and statistical techniques. The proposed method removes the limit to which normal traffic can be indiscriminately blocked by unlimited competition in network bandwidth by amplification of reflectors, which is characteristic of DRDoS. This means that by comparing 'Server to Server' and 'Outbound Session Incremental' for it, accurate DRDoS identification and detection is possible and only statistical and probabilistic thresholds are applied to traffic. Thus, network-based information security systems can take advantage of this to completely eliminate DRDoS attack frames. Therefore, it is expected that this study will contribute greatly to identifying and responding to DRDoS attacks.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.1-8
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• 2009

Learning user's preference is a key issue in intelligent system such as personalized service. The study on user preference model has adapted simple user preference model, which determines a set of preferred keywords or topic, and weights to each target. In this paper, we recommend multi-perspective user preference model that factors sentiment information in the model. Based on the topicality and sentimental information processed using natural language processing techniques, it learns a user's preference. To handle timc-variant nature of user preference, user preference is calculated by session, short-term and long term. User evaluation is used to validate the effect of user preference teaming and it shows 86.52%, 86.28%, 87.22% of accuracy for topic interest, keyword interest, and keyword favorableness.

• Journal of the Korea Society of Computer and Information
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• v.28 no.7
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• pp.67-75
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• 2023

In this paper, we analyze the problem of the user authentication scheme that provides dynamic ID in a multi-server environment proposed by Andola et al. and propose an improved authentication one to solve this problem. As a result of analyzing the authentication scheme of Andrea et al. in this paper, it is not safe for smart card loss attack, and this attack allows users to guess passwords, and eventually, the attacker was able to generate session key. This paper proposed an improved authentication scheme to solve these problems, and as a result of safety analysis, it was safe from various attacks such as smart card loss attack, password guess attack, and user impersonation attack. Also the improved authentication scheme not only provides a secure dynamic ID, but is also effective in terms of the computational complexity of the hash function. In addition, the improved authentication scheme does not significantly increase the amount of transmission, so it can be said to be an efficient authentication scheme in terms of transmission cost.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.2
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• pp.533-538
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• 2012

Background: Tobacco cessation would provide the most immediate benefits of tobacco control to prevent tobacco related disease morbidity and mortality. Methods: A tobacco cessation program involving individual and group behavior therapy was implemented in three stages at a worksite. Tobacco quit rates were assessed at the end of each contact session. Results: Out of the 291 tobacco users identified, 224 participated in the tobacco cessation interventions. At the end of three interventions, 38 (17%) users had successfully quit tobacco use. Presence of clinical oral pre-cancer lesion was found to be associated with quitting (p=0.02). Also tobacco users with oral pre-cancer lesions were around three times more likely to quit than those with no lesions (OR= 2.70 95% C.I= 1.20 - 6.05). Conclusion: Cost effective multi-pronged tobacco cessation approaches, inbuilt into other occupational health and welfare activities, are acceptable and feasible to achieve long term sustainable tobacco cessation programs at worksites.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.6
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• pp.2963-2978
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• 2017

The Top-K query is currently played a key role in a wide range of road network, decision making and quantitative financial research. In this paper, a Top-K recommendation algorithm is proposed to solve the cold-start problem and a tag generating method is put forward to enhance the semantic understanding of the OLAP session. In addition, a recommendation system for OLAP sessions called "OLAP4R" is designed using collaborative filtering technique aiming at guiding the user to find the ultimate goals by interactive queries. OLAP4R utilizes a mixed system architecture consisting of multiple functional modules, which have a high extension capability to support additional functions. This system structure allows the user to configure multi-dimensional hierarchies and desirable measures to analyze the specific requirement and gives recommendations with forthright responses. Experimental results show that our method has raised 20% recall of the recommendations comparing the traditional collaborative filtering and a visualization tag of the recommended sessions will be provided with modified changes for the user to understand.

• Journal of Korean Academy of Nursing
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• v.47 no.2
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• pp.222-232
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• 2017

Purpose: This study was done to develop a children's sex education program for the parents of lower elementary grade students and to evaluate its effects on sexual knowledge, gender role attitude, parent efficacy for child's sex education, and marital consistency. Methods: A quasi-experimental with a non-equivalent control group pretest-posttest design was used. The participants were 29 couples (58 parents, experimental group=28, control group=30) from G city. The 5-week (5-session) program was developed based on 'A theory of protection: parents as sex educators' and used the case-based small group learning method. Data were collected during July and August 2015. The characteristics of the program developed in the present study were a theoretical-based, client-centered, multi-method. Results: After the intervention, the experimental group showed a significant improvement in sexual knowledge, gender role attitudes, parent efficacy for child's sex education, and marital consistency, compared to the control group. The effect sizes of the program were .64 (knowledge), .65 (gender role attitudes), and .68 (parent efficacy). Conclusion: The results of this study provided implications for the parents as effective sex educator and the role expansion of school health nurses.

• The KIPS Transactions:PartA
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• v.11A no.7 s.91
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• pp.511-520
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• 2004

A peer-to-peer model is very useful in solving the server link bottleneck problem of a client-server model. In this work, we discuss the problems of distributing multimedia content over peer-to-peer network. We focus on two problems in peer-to-peer media content distribution systems. The first is the transmission scheduling of the media data for a multi-source streaming session. We present a sophisticated scheduling scheme called fixed-length slotted scheduling, which results in minimum buffering delay. The second problem is on the fast distribution of media content in the peer-to-peer system that is self-growing. We propose a mechanism accelerating the speed at which the system's streaming ca-pacity increases, called FAST.

• Korean Journal of Organic Agriculture
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• v.8 no.3
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• pp.17-34
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• 2000

This paper is aim to report the core aspects of Codex guideline for organically grown food which is finalized by FAO/WHO Codex Alimentarius Commission on May 2000 in 28th session of the Codex committee on food labelling. The chapter of animal production had discussed for a long time before it was finalized in Ottawa/canada as well as use of GMO(Genetically modified organism), manure from factory farming, animal welfare, and fodder inputs consisting of at least 85% for ruminants and 80% for non-ruminants. As the guideline for Codex set out the several things which is very difficult for Asian country, Organic farmer in Korea should pay an attention to maintain/increase the fertility and biological activity by cultivation of legumes, green manures or deep-rooting plants in an appropriate multi-annual rotation programme, and incorporation in the soil of organic material from holding producing in accordance with the guidelines. Pest, diseases and weeds should be controlled by choice of appropriate varieties, appropriate rotation, mechanical cultivation, diversified ecosystems, flame weeding, animal weeding and steam sterilization. The use of plant growth hormone, GMO and manure from industrial management system are not allowed, and closed recycling system, rotation, resistant seeds again pest and disease should be practiced in organic farming. But these are not unfortunately practiced in the country. In the conclusion it was strongly suggested to enact the Basic Standard for Korean organic agriculture which contains the core principles of Codex guidelines, and to try the importation of the most advanced theory, skills and technology from leading country in organic farming.