• Title/Summary/Keyword: SPIT

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SPIT Prevention Framework using Expanded White List (확장 화이트리스트 기법을 이용한 SPIT 대응 프레임워크)

  • Bae, Kwang-Yong;Chae, Kang-Suk;Kim, Young-Beom
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.2
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    • pp.95-102
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    • 2010
  • This paper proposes a SPIT(Spam over IP Telephony) prevention framework which is using expanded white-list in real-time VoIP environment. The existing schemes are vulnerable to attack from spammers since they can continue to transfer SPIT upon changing their ID. And existing frameworks have experienced the time delay and overload as session initiates due to real-time operation. To solve these problems, the proposed scheme expands the scope of white lists by forming social networks using the white list, but it is to decide quickly whether pass a caller ID without searching the entire database. The proposed framework takes the three-stage architecture and the fast scoring system. The proposed framework minimize user's inconvenience and time delay for initiation of session, therefore, it is proper for real-time VoIP environment.

Evolution and Sediment Facies of the Namdaecheon Spit, Yang-Yan Coast East Sea of korea (강원도 동해안 양양읍 남대천 하고 Spit Beach에 관한 연구)

  • 박용안
    • The Korean Journal of Quaternary Research
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    • v.12 no.1
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    • pp.1-8
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    • 1998
  • 동해안의 강원도 양양읍 남대천 하구에 발달한 spit beach의 지형적변화(1979∼ 1996) 는 outlet의 위치변화와 해안선 모습의 변화로 규명되었는바 일차적인 변화는 해안에 평행한 spit의 성장이며 이차적인 변화는 spit폭의 변화(overwash across sedimentation)라 고 밝혀졌다. 해빈환경의 소환경(subenvironment)으로서 swash zone과 berm crest는 각각 의 특징적 퇴적상(조직매개변수)으로 구분되는바 이에 관한 분석결과가 기술되었다.

A Study on Prediction Reputation System Improvement for Prevention of SPIT (SPIT 차단을 위한 예측 평판도 기법 개선에 대한 연구)

  • Bae, Kwang-yong;Jo, Hwa;Yoon, Oh-jun;Jang, Sung-jin;Shin, Yongtae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.7
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    • pp.1568-1576
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    • 2015
  • This paper proposes a prediction reputation system for the anti-SPIT solution in real-time VoIP environment. Increased accuracy of the determination as to whether spam or not by deriving a threshold based on SPIT presence in the existing paper. The existing schemes need to get the user's feedback and/or have experienced the time delay and overload as session initiates due to real-time operation. To solve these problems, the proposed scheme predicts the reputation through the statistical analysis based on the period of session initiation of each caller and the call duration of each receiver. As per the second mentioned problem, this scheme performs the prediction before session initiation, therefore, it's proper for real-time VoIP environment.

An Experimental Basic Study of Water Purification Function due to Spit in Small Estuary (하구에 형성된 소규모 모래톱의 수질정화 기능에 관한 기초적 연구)

  • Park, Sang-Kil;Kim, Byung-Dal;Jeong, Seong-Il
    • Journal of Ocean Engineering and Technology
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    • v.21 no.3 s.76
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    • pp.8-15
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    • 2007
  • This study is intended to examine the relationship between the magnitude of sand spit in the estuary of the stream and improvement of the quality of water that flaws into the sea, by means of hydraulic experimentation. In order to determine the effect of improvements of water quality when river flow is stagnant, the estuary flows into the sea through the small sand spit, and a two-dimensional physical model experiment was carried out. Distribution of concentration was decreased in response to an increase in length of sand spit and time. The experimental results are compared with theoretical results, based on the solution of the equation. Also, there are functions of influx prevention of salt wedge and purification of pollution water due to sand spit in small estuary.

Analysis on Static Characteristics for Greylist-based SPIT Level Decision of VoIP SPAM Calls (VoIP 스팸 Call의 Grey List 기반 SPIT 레벨 결정을 위한 정적 속성 분석 연구*)

  • Chang, Eun-Shil;Kim, Hyoug-Jong;Kang, Seung-Seok;Cho, Young-Duk;Kim, Myuhng-Joo
    • Convergence Security Journal
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    • v.7 no.3
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    • pp.109-120
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    • 2007
  • VoIP service provides various functions that PSTN phone service hasn't been able to provide. Since it also has superiority in service charge, the number of user is increasing these days. When we think of the other side in cost aspect, the spam caller can also send his/her commercial message over phone line using more economic way. This paper presents the characteristics that should be considered to detect the spam call using greylisting method. We have explored static and dynamic characteristics in VoIP calls, and analyzed the relation among them. Especially, we have surveyed the authentication and charging method of Korean VoIP service provider. We have analyzed each charging method using our spam call simulation result, and derived the charging method that can be favored by spam caller. The contribution of the work is in analysis result of static aspect for SPIT Level calculation in greylisting method.

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A Study on Prediction Reputation System for Prevention of SPIT (SPIT 차단을 위한 예측 평판도 기법에 대한 연구)

  • Bae, Kwang-Yong;Lee, Jae-Eun;Kim, Young-Beom
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.2
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    • pp.152-160
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    • 2013
  • This paper proposes a prediction reputation system for the anti-SPIT solution in real-time VoIP environment. The existing schemes need to get the user's feedback and/or have experienced the time delay and overload as session initiates due to real-time operation. To solve these problems, the proposed scheme predicts the reputation through the statistical analysis based on the period of session initiation of each caller and the call duration of each receiver. As per the second mentioned problem, this scheme performs the prediction before session initiation, therefore, it's proper for real-time VoIP environment.

Modeling and Simulation for Performance Evaluation of VoIP Spam Detection Mechanism (VoIP 스팸 탐지 기술의 성능 평가를 위한 모델링 및 시물레이션)

  • Kim, Ji-Yeon;Kim, Hyung-Jong;Kim, Myuhng-Joo;Jeong, Jong-Il
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.3
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    • pp.95-105
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    • 2009
  • Spam call is one of the main security threat in VoIP services. In this paper, we have designed simulation model for performance evaluation of VoIP spam defense mechanism. The simulation model has functions for performance evaluation such as calls generation and input/output comparison. Four representative caller models have been developed for performance evaluation and each model has its own characteristics as statistical parameters. The target mechanism of performance evaluation is SPIT(Spam over Internet Telephony) level decision algorithm, and we have derived SPIT levels of caller models. The performance evaluation model is designed using the DEVS formalism and DEVSJAVA$^{TM}$ is exploited for development and execution of simulation models.

A Session Key Exchange Scheme for Authentication and SDP Encryption to Protect P2P SPIT in SIP (SIP P2P 스팸 방지를 위한 인증 및 SDP 암호화 키 교환 기법)

  • Jang, Yu-Jung;Choi, Jae-Sic;Choi, Jae-Duck;Won, Yoo-Jae;Cho, Young-Duk;Jung, Sou-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12B
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    • pp.750-757
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    • 2007
  • This paper analyzes spam threats and proposes key exchange scheme for user authentication and SDP encryption to protect potential spam threats in SIP-based VoIP services. The existing HTTP digest authentication scheme exchanges many message because challenge is sent for every establishment of the session and doesn't provide a confidentiality of SDP. To protect SPIT, our scheme exchanges initial nonce and a session master key for authentication and SDP encryption during registration. In our scheme, the challenge and response procedure is not necessary and the communication overhead is much less than applying S/MIME or TLS.

A Research on the ORyungJinAekByeol of the Young Chu(靈樞) (영추(靈樞).오륭진액별에 대한 연구(硏究))

  • Sin, Yeong-Il;Jeong, Jong-Guk
    • Journal of Korean Medical classics
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    • v.13 no.2 s.17
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    • pp.156-171
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    • 2000
  • Body fluid(津液) is a general term for normal mucus in human body, including saliva, gastric juice, intestinal juice and articular fluid in joints as well as tear, running nose, sweat, etc.. The formation of Body fluid goes through two phases. First phase is digestion of food at stomach, and then evaporation and classification of energy at Triple warmer(三焦). More technically speaking, Body fluid is divided into the Jin(津) & the Aek(液). Aek is a very mild and water-like fluid, runs deep into the internal organs. Jin is a thick and sticky liquid, running shallow under the skin or in the joints of limbs. Major roles of body fluid over the body are to moisturize the internal organs, flesh, skin, etc., to soften the joints, to fill the bone marrow, and to balance Yin and Yang. This article deals with the role of body fluid and how to differentiate them, the liquid metabolism in the human body, and the formation and change of sweat, urine, tear, spit, bone marrow, etc.. The imbalance of Yin and Yang and disturbance of Triple warmer's evaporation lead into lumbago, leg weakness and edema is also explained here.

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A Study on the Morphological Characteristics of the River Mouth in the East Coast and Analysis of It's Causes (동해안 하구 형태의 특성과 그 요인 분석에 관한 연구)

  • 이원환;송재우
    • Water for future
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    • v.8 no.2
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    • pp.65-74
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    • 1975
  • The east coast seems to have remarkably different features from the west and south coast in the geographical, geomorphological, and oceanographical senses. In this paper the auther wishes to introduce some results of investigation morphological characteristics of the river mouth in the east coast an of analysis of it's causes. There are various closing form in river mouth by many causes, but the east coast hs the same closing form(the ratio of closing; roughly 0.18), as well known, by the sand spit, and has not hydrological but littoral drift background. The river of the east coast is proved mature age from hypsometric analysis. The wave and longshore current must be principal factor to be considered, in the analysis of the closing phenomenon owing to littoral drift. The research of the blown sand is considered valuable for the next study of this subject.

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