• The KIPS Transactions:PartC
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• 제19C권2호
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• pp.83-90
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• 2012

MANET(Mobile Ad-Hoc Network) has a weakness from a security aspect because it operates where no wired network is built, which causes the exposed media, dynamic topology, and the lack of both central monitoring and management. It is especially difficult to detect and mitigate a malicious node because there is not a mediator which controls the network. This kind of malicious node is closely connected to the routing in the field of study of Ad-Hoc security. Accordingly this paper proposes the method on how to enhance the security for the safe and effective routing by detecting the malicious node. We propose MBC(Identification technition of Malicious Behavior node based on Collaboration in MANET) that can effectively cope with malicious behavior though double detecting the node executing the malicious behavior by the collaboration between individual node and the neighbor, and also managing the individual nodes in accordance with the trust level obtained. The simulation test results show that MBC can find the malicious nodes more accurately and promptly that leads to the more effectively secure routing than the existing method.

• Journal of Internet Computing and Services
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• 제4권5호
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• pp.77-86
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• 2003

This paper introduces the extension of SIP protocol for Multiparty Conference and the implementation of IP-based Multi-Conference. SIP protocol is a signaling protocol for initiating, modifying and terminating interactive sessions (voice, video, text, application). Multiparty conference system is implemented by RTP protocol for real time transmission and by H.323 for call setup. As H.323 fits into PSTN, it has some problems (call setup delay, hard implementation) for IP applications. IETF developed SIP protocol used for signaling in IP networks. However this SIP protocol doesn't explain signal protocol about multimedia conference, which is different from the existing H.323. So this paper describes the extension of SIP according to SIP Specification and case study for the multimedia conference.

• Journal of the Institute of Convergence Signal Processing
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• 제19권4호
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• pp.147-152
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• 2018

Underwater transient signals are complex, variable and nonlinear, resulting in a difficulty in accurate modeling with reference patterns. We analyze one type of underwater transient signals, in the form of whale sounds, using the MFCC(Mel-Frequency Cepstral Constant) and synthesize them from the MFCC and the weighted $L_2$-norm minimization techniques. The whales in this experiments are Humpback whales, Right whales, Blue whales, Gray whales, Minke whales. The 20th MFCC coefficients are extracted from the original signals using the MATLAB programming and reconstructed using the weighted $L_2$-norm minimization with the inverse MFCC. Finally, we could find the optimum weighted factor, 3~4 for reconstruction of whale sounds.

• Journal of the Korea Institute of Information Security & Cryptology
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• 제20권1호
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• pp.73-83
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• 2010

Recently, as IT technologies developed, communication technologies of a various forms that satisfied convenience of user are being researched. Among various research, unlike traditional forms of communication, M2M communication is getting attention that without any control or involvement of people to establish communication between devices. However, the M2M communication could more easily be exposed to many security problems such as data exposure, data theft, unauthorized change and delete and privacy. Therefore, in this paper, we derive security requirements and propose the M2M communication architecture that provide a secure M2M communication environment. Also, we propose a secure mutual authentication and key establishment protocol between a M2M device or gateway domain and a M2M network domain. The proposed protocol is secure against replay attack, impersonation attack and protect a user privacy and tracing.

• Journal of the Korean Society for information Management
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• 제38권2호
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• pp.113-127
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• 2021

The purpose of this study is to propose a personalized book recommendation system to promote the use of university libraries. In particular, unlike many recommended services that are based on existing users' preferences, this study proposes a method that derive evaluation metrics using individual users' book rental history and tendencies, which can be an effective alternative when users' preferences are not available. This study suggests models using two matrix decomposition methods: Singular Value Decomposition(SVD) and Stochastic Gradient Descent(SGD) that recommend books to users in a way that yields an expected preference score for books that have not yet been read by them. In addition, the model was implemented using a user-based collaborative filtering algorithm by referring to book rental history of other users that have high similarities with the target user. Finally, user evaluation was conducted for the three models using the derived evaluation metrics. Each of the three models recommended five books to users who can either accept or reject the recommendations as the way to evaluate the models.

• The Korea Journal of Herbology
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• 제29권4호
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• pp.77-82
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• 2014

Objectives : The effects of ethanol extract of Plantago asiatica L. were investgated on adipocyte differentiation, lipopogenesis, lipolysis and apoptosis using differnentiated 3T3-L1 adipocytes. Methods : Plantago asiatica L. was extracted with ethanol (CCE). We carried on MTT assay for cell proliferation, Oil Red O staining for determination of cell differentiation and intracelluar adipogenesis. TUNEL staining assay for cell apoptosis, and Western blot analysis for measurement of pAMPK and pACC, $C/EBP{\alpha}$, $PPAR{\gamma}$ protein expressions were performed. Results : The addition of CCE up to 0.2 mg/ml into cell culture media showed no cytotoxicity. Treatment of 0.2 mg/ml CCE significantly inhibited differentiation in 3T3-L1 preadipocytes. Lipid accumulation of the CCE treated cells was decreased compared with that of control. Induction of cell apoptosis was increased in CCE treated cells compared with that of control. AMPK and ACC levels of the cells with 0.2 mg/ml CCE were led to phosphorylation and also expressions of $C/EBP{\alpha}$ and $PPAR{\gamma}$, as adipogenic transcription factors, were suppressed compared with those of control. Conclusions : Taken together, these results provide evidence that CCE has a regulatory role in lipid metabolism that is related to differentiation into adipocytes, adipogenesis and apoptosis.

• Journal of Convergence Korean Medicine
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• 제5권1호
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• pp.5-23
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• 2023

Objectives: This study was conducted to evaluate the effect of combination treatment of herbal medicine for external use and western medicine for atopic dermatitis (AD). Methods: We searched randomized controlled trials (RCTs) which assess the effect of combination treatment of herbal and western medicine for AD through 8 electronic databases from the start to December 2022. The data synthesis was conducted by using Review Manager (RevMan, ver.5.4.1) and Cochrane risk-of-bias tool was used to evaluate the risk of bias. Results: 13 RCTs were included. The combination treatment group had significantly higher total efficacy rate(p<0.0001) and lower SCORAD score (p<0.00001) than the western medicine treatment group. The adverse event rate was also significantly lower in the combination treatment than the western medicine treatment group (p<0.0001). But there was no significant difference in recurrence rate (p=0.09). Conclusion: This study demonstrates that the combination treatment of herbal and western medicine could be safe and effective for AD. However, due to limits of included studies such as high heterogeneity between the literature and unclear risk of bias, further studies are warranted.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• 제36권3호
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• pp.74-98
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• 2023

Objectives : This study aims to evaluate the add-on effect of herbal bath combined with acitretin in patients with psoriasis. Methods : We searched randomized controlled trials(RCTs) reporting the effect of herbal bath and acitretin combined treatment for psoriasis in 10 electronic databases from their inception to January 2023. Study collection, data extraction, and risk of bias assessment were performed by two independent researchers. Data synthesis and risk of bias evaluation was conducted using Revman 5.4. Results : Ten RCTs with 1,008 subjects were included. Herbal bath and acitretin combined treatment group showed higher average total effective rate than acitretin alone group(RR 1.39; 95% CI: 1.15-1.68, P=0.0006, I² =0%). Herbal bath and additional treatments such as phototherapy(NB-UVB) and oral herbal medicine, combined with acitretin group also showed higher average total effective rate than acitretin alone group(RR 1.81; 95% CI: 1.47-2.22, P<0.00001, I² =43%). Herbal bath and phototherapy(NB-UVB) combined with acitretin group also showed higher average total effective rate than acitretin alone group(RR 1.51; 95% CI: 1.18-1.93, P=0.0009, I² =0%). The overall risk of bias of the included studies was unclear or of high risks. Conclusions : This review showed that the add-on of herbal bath combined with acitretin treatment could be more effective than acitretin alone treatment in patients with psoriasis. However, because of few included studies, heterogeneity between studies, and insufficient quality of included studies, further well-designed RCTs are needed to confirm the add-on effect of herbal bath on psoriasis.

• Journal of Powder Materials
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• 제30권6호
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• pp.463-469
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• 2023

Aluminum alloys, known for their high strength-to-weight ratios and impressive electrical and thermal conductivities, are extensively used in numerous engineering sectors, such as aerospace, automotive, and construction. Recently, significant efforts have been made to develop novel aluminum alloys specifically tailored for additive manufacturing. These new alloys aim to provide an optimal balance between mechanical properties and thermal/electrical conductivities. In this study, nine combinatorial samples with various alloy compositions were fabricated using direct energy deposition (DED) additive manufacturing by adjusting the feeding speeds of Al6061 alloy and Al-12Si alloy powders. The effects of the alloying elements on the microstructure, electrical conductivity, and hardness were investigated. Generally, as the Si and Cu contents decreased, electrical conductivity increased and hardness decreased, exhibiting trade-off characteristics. However, electrical conductivity and hardness showed an optimal combination when the Si content was adjusted to below 4.5 wt%, which can sufficiently suppress the grain boundary segregation of the α-Si precipitates, and the Cu content was controlled to induce the formation of Al₂Cu precipitates.

• Journal of Korean Medicine Rehabilitation
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• 제34권3호
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• pp.107-117
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• 2024

The objective of this study is to report the clinical effects of applying an integrated rehabilitation protocol to four patients with traumatic cervical spinal cord injuries. The treatments applied included acupuncture, cupping and moxibustion, chuna manual therapy, functional electrical stimulation, and other physical therapies. The evaluation methods included American Spinal Injury Association Impairment Scale, functional independence measure (FIM), modified Barthel index (MBI), numeric rating scale (NRS) and other scales. All patients presented marked improvements in FIM, MBI, NRS and other scales, along with increased muscle strength in the manual muscle test. The application of our protocol resulted in clear clinical benefits and enhanced the recovery and quality of life for the patients in this study.