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Density-Based Opportunistic Broadcasting Protocol for Emergency Situations in V2X Networks

  • Park, Hyunhee;Singh, Kamal Deep;Piamrat, Kandaraj
    • Journal of information and communication convergence engineering
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    • v.12 no.1
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    • pp.26-32
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    • 2014
  • Vehicular-to-anything (V2X) technology is attractive for wireless vehicular ad-hoc networks (VANETs) because it allows for opportunistic choice of a vehicular protocol between vehicular-to-vehicular (V2V) and vehicular-to-infrastructure (V2I) communications. In particular, achieving seamless connectivity in a VANET with nearby network infrastructure is challenging. In this paper, we propose a density-based opportunistic broadcasting (DOB) protocol, in which opportunistic connectivity is carried out by using the nearby infrastructure and opposite vehicles for solving the problems of disconnection and long end-to-end delay times. The performance evaluation results indicate that the proposed DOB protocol outperforms the considered comparative conventional schemes, i.e., the shortest path protocol and standard mobile WiMAX, in terms of the average end-to-end delay, packet delivery ratio, handover latency, and number of lost packets.

전자상거래 분쟁해결제도의 개선방안에 관한 연구

  • Kim, Seok-Cheol
    • Journal of Arbitration Studies
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    • v.10 no.1
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    • pp.68-90
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    • 2000
  • This paper disscusses about the e-commerce and the various types of e-commerce disputes. Through empirical examination on the dispute consiliation system and by comparative analysis it is derived out of the weakness of current system and finally some suggestions for improvement. First, it is recommended that the more sophisticated knowledge concerning e-commerce should be proliferated through the existing institutions. For example, disputes for B2C could be managed by the consiliation system of consumer dispute consiliation in Consumer Protecion Board of Korea, while B2B by the arbitration system of the Korean Commercial Arbitraion Board. Second, the role of Korea Institute for Electronic Commerce established for the purpose of consiliation of e-commerce disputes is much emphasized. For successful achievement, it is necessarily required to reinforce the related laws, systems, institutions and human resources. Finally, it is also suggested that the the Korean Commercial Arbitraion Board and Consummer Protection Board of Korea fully cover consiliation and arbitration, while Korea Institute for Electronic Commerce activates its proper role of consulting and ad hoc arbitration by using electronic information. The paper points out the last one as the most desired practice.

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A Study on Hierarchy-based Secure Encryption Protocol for Trust Improvement on Multicast Environment of MANET (MANET의 멀티캐스트 환경에서 신뢰성 향상을 위한 계층기반 암호 프로토콜 기법 연구)

  • Yang, Hwanseok
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.3
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    • pp.43-51
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    • 2017
  • MANET consists of only wireless nodes having limited processing capability. It processes routing and data transmission through cooperation among each other. And it is exposed to many attack threats due to the dynamic topology by movement of nodes and multi-hop communication. Therefore, the reliability of transmitted data between nodes must be improved and security of integrity must be high. In this paper, we propose a method to increase the reliability of transmitted data by providing a secure cryptography protocol. The proposed method used a hierarchical structure to provide smooth cryptographic services. The cluster authentication node issues the cluster authentication key pair and unique key to the nodes. The nodes performs the encryption through two steps of encryption using cluster public key and block encryption using unique key. Because of this, the robustness against data forgery attacks was heightened. The superior performance of the proposed method can be confirmed through comparative experiment with the existing security routing method.

수학과 실재

  • 정계섭
    • Journal for History of Mathematics
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    • v.14 no.1
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    • pp.47-60
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    • 2001
  • The present study develops the given theme “Mathematics and Reality” along two lines. First, we explore the answers, in its various facets, to the following question: How is it possible that mathematics shows such wondrous efficiency when explaining nature\ulcorner In addition to a comparative analysis between empiricism and rationalism, constructivism as a function of idealism is compared with realism within the frame provided by rationalism. The second step involves limiting our discussion to realism. We attempt to explain the various stages of mathematical realism and their points of difficulty. Postulate of parallels, Godel's theorem, continuum hypothesis and choice axiom are typical examples used in demonstrating undecidable propositions. They clearly show that it is necessary to mitigate the mathematical realism which depends on bivalent logic based on an objective exterior world. Lowenheim-Skolem theorem, which states that reality is composed not of one block but rather of diverse domains, also reinforces this line of thought. As we can see the existence of undecidable propositions requires limiting the use of reductio ad absurdum proof which depends on the concept of excluded middle. Consequently, it becomes obvious that bivalent logic must inevitably cede to a trivalent logic since there are three values involved: true, false, and undecidable.

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Comparative study of OFDMA cooperative relaying methods in Rayleigh fading channel (레일레이 퍼이딩 채널에서 OFDMA 협동 릴레이 방식에 따른 성능비교)

  • Kim, Nam-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.3
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    • pp.109-115
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    • 2009
  • Recently, the relay communication is focused for the power saving and coverage extension of ad-hoc networks. For the high date rate transmission, it is proposed to adapt OFDMA relays. In this paper, we assume the 2 hop cooperative OFDMA relays between the source and the destination. The performance of 3 different relaying methods are derived and compared. We noticed that the selective OFDMA relaying method has the best performance followed by opportunistic OFDMA relaying and repetition-based OFDMA relaying method under the same threshold mutual information rate.

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A Study on the Simcho of Wooden Pagodas in Baekjae (백제의 심초 및 사리봉안)

  • Jung, Ja Young
    • Korean Journal of Heritage: History & Science
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    • v.41 no.1
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    • pp.109-125
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    • 2008
  • Recently, there has been an increase in excavation studies of wood pagodas from the Three Kingdoms and Unified Shilla periods and new data related to wood pagoda erection are being found bringing about progress in research on this field. In other words, studies on wooden pagodas in Korea were composed mainly of flat, axis construction techniques and sarijangeomgu, but by acquiring new data, it has now become possible to study not only the stylobate construction procedure and transition, but also studies on restoring wooden pagodas. Furthermore, pagoda sites similar to this were found in China and Japan as well, making it possible to make comparative studies among ancient wooden pagodas possible. In this paper, the main remains were set as Baekjae wooden pagodas, which were the most frequently studied and among the wooden pagodas, the simcho (central base stone) and sarira housing locations. In result, simcho can be found changing its position from underground ${\rightarrow}$ halfway underground ${\rightarrow}$ above ground. Baekjae wooden pagodas up until the mid sixth century located at Neungsan-ri saji (AD 567) and Wangheungsaji (AD 577) had its simcho located underground and later it was constructed halfway underground and then above ground. It was confirmed that in the 7th century, it became customary to place above ground as seen in the Jaeseoksaji (AD639) and Hwangnyongsaji (AD645) wooden pagoda sites. The sarira was usually located on the south side of the simcho, but gradually changed to the center. In particular, sarira were combined in the simcho in the mid sixth century at the Wangheungsaji. This is approximately 11 years earlier than the Bijosa (AD 588) simcho found in Japan and this was not found even in the simcho of wooden pagodas in Yeongnyeongsa (AD 516) and Jopaengseong temple (AD 535~561) of China showing that the Wangheungsaji simcho was the earliest of its kind.

The Effects of Sa-am Acupuncture on Radial Pulse in Healthy Human Subjects: A Comparative Study on Tonifications of Kidney and Urinary Bladder (신정격 및 방광정격 자침이 정상 성인의 맥파 변화에 대한 비교 연구)

  • Kwak, Kyu In;Kang, Jae Hui;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.32 no.2
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    • pp.105-121
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    • 2015
  • Objectives : The purpose of this study is to observe the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse in healthy subjects. Methods : Sixty healthy subjects participated in this study, and were divided into a kidney tonifying acupuncture group(KI group), urinary bladder tonifying acupuncture group(BL group) and control group. Radial pulse was measured by 3 dimensional pulse imaging system(DMP-3000) before, immediately after, 30 minutes after, and 60 minutes after acupuncture at Cun, Guan, and Chi in each time. Results : 1. BL group exhibited significantly reduced T1 / T, T4 / T, T4 / (T-T4), T5 / T and increased(T-T4) / T compared to KI group. 2. BL group showed increase of radial augmentation index / heart rate(RAI / HR) in left Cun, H5, Ad / Ap in left Chi, H1, As / Ap in right Chi compared to KI group. BL group showed decrease of As / Ap, Aw / Ap in left Chi, H1, pulse depth, Ad / Ap in right Chi compared to KI group. 3. KI group showed increase of Aw / Ap, H1, H2, H4, pulse area in right Guan, pulse depth in right Chi compared to BL group. KI group showed decrease of RAI in left Cun, applied pressure, pulse depth in left Guan, Aw / Ap in right Chi compared to BL group. Conclusions : The effects of Sa-am acupuncture with tonifications of kidney and urinary bladder in healthy humans have been observed on various parameters. The parameters analysed in this study can be used to differentiate the effects of Sa-am acupuncture with tonifications of kidney and urinary bladder on radial pulse.

Study on Combination of External Gosamgamibang and Internal Chenggihaedok-san for the Treatment of Atopic Dermatitis (아토피피부염에 대한 고삼가미방(苦參加味方)과 청기해독산(淸肌解毒散)의 겸용 투여 효과)

  • Ko, Hong-Yun;Kim, Dong-Hee
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.6
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    • pp.1282-1291
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    • 2009
  • A combined prescription of GGB and CHS (G&C prescription group) was used to investigate its effects on immune related factors and histological changes in atopic dermatitis(AD) induced mice. Significant decrease of atopic dermatitis clinical index in G&C prescription group. In DLN, G&C prescription group significantly modulated the immune cells. G&C prescription group also showed significant effect on the immune cells of the dorsal skin as well as DLN. The group indicated significant decrease of the biosynthesis of IL-4, IL-5, IL-13, GM-CSF, cytokines in serum. On the other hand, the biosynthesis of TNF-$\alpha$ was decreased. G&C prescription group significantly decreased the immunoglobulin IgE levels in serum. The results suggest that G&C prescription significantly improves atopic dermatitis through regulation of immune cells and cytokines. Comparative studies with Protopic ointment also showed that G&C prescription showed significant effect in AD patients, and active application of the prescription in clinicals is anticipated. However, the reason for the results that oppose to those of previous studies should be investigated. Also, therapeutic effects of both internal and external applications should be studied individually as well as for any synergistic effects. Safety, toxicity, as well as stability studies should follow to develop G&C prescription into long-term external clinical product.

A Comparative Study of Parametric Methods for Significant Gene Set Identification Depending on Various Expression Metrics (유전자 발현 메트릭에 기반한 모수적 방식의 유의 유전자 집합 검출 비교 연구)

  • Kim, Jae-Young;Shin, Mi-Young
    • Journal of KIISE:Software and Applications
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    • v.37 no.1
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    • pp.1-8
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    • 2010
  • Recently lots of attention has been paid to gene set analysis for identifying differentially expressed gene-sets between two sample groups. Unlike earlier approaches, the gene set analysis enables us to find significant gene-sets along with their functional characteristics. For this reason, various novel approaches have been suggested lately for gene set analysis. As one of such, PAGE is a parametric approach that employs average difference (AD) as an expression metric to quantify expression differences between two sample groups and assumes that the distribution of gene scores is normal. This approach is preferred to non-parametric approach because of more effective performance. However, the metric AD does not reflect either gene expression intensities or variances over samples in calculating gene scores. Thus, in this paper, we investigate the usefulness of several other expression metrics for parametric gene-set analysis, which consider actual expression intensities of genes or their expression variances over samples. For this purpose, we examined three expression metrics, WAD (weighted average difference), FC (Fisher's criterion), and Abs_SNR (Absolute value of signal-to-noise ratio) for parametric gene set analysis and evaluated their experimental results.

Comparison and Analysis of Anomaly Detection Methods for Detecting Data Exfiltration (데이터 유출 탐지를 위한 이상 행위 탐지 방법의 비교 및 분석)

  • Lim, Wongi;Kwon, Koohyung;Kim, Jung-Jae;Lee, Jong-Eon;Cha, Si-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.440-446
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    • 2016
  • Military secrets or confidential data of any organization are extremely important assets. They must be discluded from outside. To do this, methods for detecting anomalous attacks and intrusions inside the network have been proposed. However, most anomaly-detection methods only cover aspects of intrusion from outside and do not deal with internal leakage of data, inflicting greater damage than intrusions and attacks from outside. In addition, applying conventional anomaly-detection methods to data exfiltration creates many problems, because the methods do not consider a number of variables or the internal network environment. In this paper, we describe issues considered in data exfiltration detection for anomaly detection (DEDfAD) to improve the accuracy of the methods, classify the methods as profile-based detection or machine learning-based detection, and analyze their advantages and disadvantages. We also suggest future research challenges through comparative analysis of the issues with classification of the detection methods.