• 한국국방경영분석학회지
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• 제17권1호
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• pp.159-176
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• 1991

The probability of target survival is the most important factor in the target assignment, Most of the studies about it have assumed the case of one target and ane weapon type. Therefore, they can not be applied to the real situation. In this paper. the quantity and type of enemy assets of the friendly force are considered simultaneously. Considered defense type is the coordinated defense with no impact point prediction. The objective function is to minimize the expected total survival value of targets which are scattered in the defense area. The rules of aircraft assignment are as follows : first, classify targets into several groups, each of those has the same desired damage level secondly. select the critical group which has the least survival value in accordance with the additional aircraft assignment, and finally. assign the same number of attack assets against each target in the critical group. In this paper, the attack assets, the escort assets, and the defense assets are considered. The model is useful to not only the simple aircraft assignment problem but also the complicated wargame models.

• 농촌의학ㆍ지역보건
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• 제6권1호
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• pp.33-41
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• 1981

To investigate the status of medical accident attack rate and medicare utilization during last 27months from 1st Oct., 1977 to 31st Dec. 1979 in the area under Sam Wha Medicare Insurance Union, the study was carried out through analyzing the medicare records of patients who were enrolled. "The medical accident" in this study was used as the meaning of the state that the people who have been treated morbid condition with insurance money. For the study, 2 doctors and one nurse were mobilized and the results are as follows: 1) The total number of the Medicare Insurance Union members among the 37,044 total population of the study area, (Hea-mi, Unsan, Eumam Myun) were 57, 35 composed of 3,000 males (52.3%) and 27, 35 females (47.7%) in 1977, 3,383 composed of 2,006 males (59.3%) 1,377 females (40.7%) in 1978, 2,573 composed of 1,437 males and 1,336 females (44.2%) in 1979. 2) Total number of medical accident attack cases were 6,774 case (partially overlapped the number of the 1977 with that of the 1978) and average annual medical accident attack rate per 1,000 population was 700.9. 3) Five major disease group in the past three years were disease of the respiratory system (177.7), disease of the digestive system (165.8), disease of the skin and subcutaneous(64.9), symptoms, signs and ill-defined conditions (64.6), any injury and poisoning (51.9). Mental disorders (32.6) was the 6th order disease group. 4) The order of the medical accident attack rate of age group per 1,000 population per year was the year group of 0~4(877.8), 45~64(832.6), 25~44(810.3), 5~14(495.1) 15~24(494.7) 65 and over (460.7). 5) Medical accident attack rate of age group per 1,000 population in the 5 major disease groups were the year group of 45~64 (100.0) in the mental disorders 0~4(525.1) in the disease of the respiratory system 45~64 (328.5) in the disease of the digestive system 0~4 (202.8) in the disease of the skin and subcutanous tissue, 25~44 (98.3) in the accidents and poisoning. 6) Monthly medical accidents attack rate were 87.0 in the winter (Dsc., Jan., Feb.) and 86.2 in the summer (Jun., July, Aug.). So the trend of the medical accidents attack rate during the year was bimount figure. 7) Monthly medical accidents attack rate in the major disease group were highest in Jan., Apr., (31.1) in the disease of the respiratory system, in Jan., Feb., Mar. (24.9) in the disease of the digestive system, in Jan., Jun., Aug. (9.8) in the injury and poisoning. 8) Duration of the treatment of the 93.1% of the total cases were within 5 days. 9) 299 cases (4.5%) of the total number of cases, 6,587 cases were referred to secondary and tertiary medicare facilities. 10) The order of the major 10 kinds of diagnosis of the disease, 6,587 cases during 27 months, were URI and chillness (1,063 cases, 16.1%), gastritis(830 cases, 12. 6%) dermatitis(360 cases, 5.5%), bronchitis(291 cases, 4.4%), neurosis (284 cases, 4.3%), contusion (165 cases, 2.5%), tooth extraction (157 cases, 2.4%), tonsillitis (109 cases, 0.7%), laceration (107 cases, 1.6%), neuralgia (105 cases, 1.6%), arthritis (104 cases, 1.6%), otitis media and mastoiditis (103 cases, 1.6%), so total case were 3,678 cases (55.9%).

• 한국인터넷방송통신학회논문지
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• 제15권5호
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• pp.9-17
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• 2015

무선 통신 기술의 발전과 ICT 시장의 변화에 따라 M2M 서비스 활성화 및 기술은 지속적인 발전을 거듭하고 있다. 사람의 제어나 직접적인 개입 없이 사물과 사물간의 통신환경을 구축하는 M2M 환경이 주목받고 있다. 무선 통신 환경의 특성으로 데이터 노출, 위조, 변조, 삭제, 프라이버시 등의 문제에서 다양한 보안 위협에 노출 될 가능성과 안전한 통신 보안 기술이 중요 요구사항으로 이슈화되고 있다. 본 논문은 트랩도어 충돌 해쉬의 요구사항을 분석하고, 트랩도어의 특수성을 이용하여 M2M 환경에서 그룹간의 키를 생성하고, 이를 세션키로 교환하는 기법을 제안한다. 그리고 그룹키 생성에 이은 디바이스와 게이트웨이의 인증을 확인하는 기법을 제안한다. 제안하는 기법은 충돌 메시지와 충돌 해쉬의 특수성을 이용하여 그룹 통신 구간의 위장 공격, 중간자 공격, 재전송 공격 등의 공격 저항성을 가지는 안전한 기법임을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제32권10호
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• pp.3743-3747
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• 2011

Kinetic studies on the reactions of Y-S-aryl phenyl phosphonochloridothioates with X-pyridines have been carried out in MeCN at $55.0^{\circ}C$. The Hammett and Bronsted plots for substituent X variations in the nucleophiles are biphasic concave upwards with a break point at X = H. The Hammett plots for substituent Y variations in the substrates are biphasic concave upwards with a break point at Y = H, and the sign of ${\rho}_Y$ is changed from unusual negative (${\rho}_Y$ < 0) with the weaker electrophiles to positive (${\rho}_Y$ > 0) with the stronger electrophiles. The stepwise mechanism is proposed on the basis of the ${\rho}_X$, ${\beta}_X$, and ${\rho}_{XY}$ values as follows: a ratelimiting leaving group departure from the intermediate involving a frontside attack and product-like TS for the stronger nucleophiles and weaker electrophiles; a rate-limiting leaving group departure from the intermediate involving a backside attack and product-like TS for the weaker nucleophiles and electrophiles; a rate-limiting bond formation involving a frontside attack for the stronger nucleophiles and electrophiles; a rate-limiting bond formation involving a backside attack for the weaker nucleophiles and stronger electrophiles. The substituent effects of X and Y on the pyridinolysis mechanisms of $R_1R_2P$(=S)Cl-type substrates are discussed.

• Journal of information and communication convergence engineering
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• 제8권5호
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• pp.549-553
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• 2010

Lim et al. proposed a Hybrid Group Key Management scheme for Hierarchical Self-Organizing Sensor Network in 2008 to provide a secure way to pass down the group key for cluster-based communication. This paper presents two practical attacks on the scheme proposed by Lim et al. by tampering sensor nodes of a cluster to recover necessary secret keys and by exploiting the IDS employed by the scheme. The first attack enables a long-term but slow data fabrication while other attack causes more severe DoS on the access to cluster sensor nodes.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2012년도 제46차 하계학술발표논문집 20권2호
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• pp.373-375
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• 2012

최근 다양하고 전문적인 웹 서비스와 어플리케이션들이 사용자를 위해 제공되고 있다. 이러한 서비스들은 보통 사용자의 인증을 거친 뒤 검증된 사용자에 한해 서비스를 제공하기 때문에 사용자는 매번 서비스별로 회원가입을 해야 하는 불편함을 겪고 있다. 이러한 불편함을 해결하기 위해 제 3의 서비스가 사용자의 보호된 데이터에 접근할 수 있도록 허가하는 OAuth 프로토콜이 등장하게 되었다. 본 논문에서는 OAuth 프로토콜의 동작과정과 문제점을 분석하고 피싱 공격 방어를 위한 확장된 프로토콜을 제안한다. 본 논문에서 제안하는 프로토콜은 기존의 OAuth 프로토콜에 인증 절차를 추가한 것이다.

• 정보보호학회논문지
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• 제17권2호
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• pp.3-17
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• 2007

본 논문에서는 IGMP(Internet group management protocol)를 부당하게 사용함으로써 발생하는 DoS(Denial-of Service) 공격으로부터 멀티캐스트 분배트리를 보호하기 위해 IGMP의 보안관련 기능을 확장시킴으로써 수신자 접근제어기법을 제안하였다. IP 멀티캐스트 애플리케이션의 상업적인 적용을 위해 채택된 특정 네트워크와 비즈니스 모델을 기반으로, CP(Content Provider), NSP(Network Service Provider), 그룹멤버(group member)에 대한 회계 및 청구와 함께 제안 접근제어기법의 부트스트래핑(bootstrapping)을 위해 키 관리기법 또한 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권10호
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• pp.4176-4197
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• 2020

Botnet is a type of dangerous malware. Botnet attack with a collection of bots attacking a similar target and activity pattern is called bot group activities. The detection of bot group activities using intrusion detection models can only detect single bot activities but cannot detect bots' behavioral relation on bot group attack. Detection of bot group activities could help network administrators isolate an activity or access a bot group attacks and determine the relations between bots that can measure the correlation. This paper proposed a new model to measure the similarity between bot activities using the intersections-probability concept to define bot group activities called as B-Corr Model. The B-Corr model consisted of several stages, such as extraction feature from bot activity flows, measurement of intersections between bots, and similarity value production. B-Corr model categorizes similar bots with a similar target to specify bot group activities. To achieve a more comprehensive view, the B-Corr model visualizes the similarity values between bots in the form of a similar bot graph. Furthermore, extensive experiments have been conducted using real botnet datasets with high detection accuracy in various scenarios.

• Journal of Communications and Networks
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• 제14권1호
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• pp.104-110
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• 2012

Group key agreement protocols allow a group of users, communicating over a public network, to establish a shared secret key to achieve a cryptographic goal. Protocols based on certificateless public key cryptography (CL-PKC) are preferred since CL-PKC does not need certificates to guarantee the authenticity of public keys and does not suffer from key escrow of identity-based cryptography. Most previous certificateless group key agreement protocols deploy signature schemes to achieve authentication and do not have constant rounds. No security model has been presented for group key agreement protocols based on CL-PKC. This paper presents a security model for a certificateless group key agreement protocol and proposes a constant-round group key agreement protocol based on CL-PKC. The proposed protocol does not involve any signature scheme, which increases the efficiency of the protocol. It is formally proven that the proposed protocol provides strong AKE-security and tolerates up to $n$-2 malicious insiders for weak MA-security. The protocol also resists key control attack under a weak corruption model.

• 정보처리학회논문지C
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• 제11C권4호
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• pp.409-418
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• 2004

인터넷상에서 멀티캐스트 서비스가 급속도로 증가하고 있으며 이에 따라 멀티캐스트 통신의 보안을 유지하는 것이 중요하다. 멤버의 탈퇴는 그룹키 관리의 확장성 문제와 밀접한 관계가 있다. 그룹의 한 멤버가 제거되면 새로운 그룹키를 생성하여 그룹의 나머지 모든 멤버들에게 전달되어야 한다. 새로운 키를 생성하여 분배하는 것은 많은 연산을 요구하므로 rekey하기 위하여 보내는 메시지의 수와 복합키를 생성하기 위한 연산비용을 최소화하는 것은 키 관리기법을 평가하는 중요한 기준이다. 일괄제거는 멤버를 순차적으로 1개씩 제거하는 것보다 rekey에 대한 메시지의 수와 복합키의 연산 비용을 줄일 수 있다. 본 논문에서는 그룹에서 제거될 멤버들간의 해밍거리가 임계치보다 작은 멤버들만 동시에 제거된다. 여러 개의 멤버를 제거할 때 라운드 조정 알고리즘을 수행하면 rekey를 위하여 메시지의 수와 복합키를 생성하기 위한 연산의 비용을 줄이며 공모공격의 가능성이 제거되는 이점이 있다.