• 한국농공학회논문집
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• 제58권2호
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• pp.73-82
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• 2016

This study is about development of personal disaster shelters for minimization of the casualties caused by the landslide and steep slope collapse. The objectives of present research is the selection of disaster evacuation facilities utilizing FRP (Fiber Reinforced Plastic) material. For the proper assessment of FRP member, several layers by strength test and the three-dimensional numerical analysis of these FRR member was carried out. As a result, the personal disaster evacuation facility utilizing FRP materials, was found to be of a material that is able to protect the weak person at the time of the collapse of the landslides and steep slopes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권10호
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• pp.2844-2861
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• 2023

Internet is the most prevailing word being used nowadays. Over the years, people are becoming more dependent on the internet as it makes their job easier. This became a part of everyone's life as a means of communication in almost every area like financial transactions, education, and personal-health operations. A lot of data is being converted to digital and made online. Many researchers have proposed different authentication factors - biometric and/or non-biometric authentication factors - as the first line of defense to secure online data. Among all those factors, passwords and passphrases are being used by many users around the world. However, the usability of these factors is low. Also, the passwords are easily susceptible to brute force and dictionary attacks. This paper proposes the generation of a novel passcode from the hybrid authentication factor - sound. The proposed passcode is evaluated for its strength to resist brute-force and dictionary attacks using the Shannon entropy and Passcode (or password) entropy formulae. Also, the passcode is evaluated for its usability. The entropy value of the proposed is 658.2. This is higher than that of other authentication factors. Like, for a 6-digit pin - the entropy value was 13.2, 101.4 for Password with Passphrase combined with Keystroke dynamics and 193 for fingerprint, and 30 for voice biometrics. The proposed novel passcode is far much better than other authentication factors when compared with their corresponding strength and usability values.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.1180-1200
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• 2017

Currently, automated payment services provide intuitive user interfaces by adapting various wireless communication devices with mobile services. For example, companies like Samsung, Google, and Apple have selected the NFC payment method to service payments of existing credit cards. An electronic payment standard has been released for NFC activation within Korea and will strengthen the safety of payment service communications. However, there are various security risks regarding the NFC-based electronic payment method. In particular, the NFC payment service using the recently released lightweight devices cannot provide the cryptographic strength that is supported by many financial transaction services. This is largely due to its computational complexity and large storage resource requirements. The chaotic map introduced in this study can generate a highly complicated code as it is sensitive to the initial conditions. As the lightweight study using the chaotic map has been actively carried out in recent years, associated authentication techniques of the lightweight environment have been released. If applied with a chaotic map, a high level of cryptographic strength can be achieved that can provide more functions than simple XOR operations or HASH functions. Further, this technique can be used by financial transaction services. This study proposes a mutual authentication technique for NFC-PCM to support an NFC payment service environment based on the chaotic map.

• 시큐리티연구
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• 제24호
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• pp.1-31
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• 2010

본 논문은 미국 연방정부에 있어서 정보 자유법의 시행이 정부 기구의 재정, 집행자의 자질 및 관료 문화를 포함한 제반 조직적 요인들에 미치는 정책 효과를 경험적으로 검증하는데 그 목적이 있다. 실상 정보자유법의 기본 취지는 정부의 정보에 접근할 수 있는 국민의 알 권리를 보호하는 동시에 국가안보를 위한 민주적 책임을 신장하기 위하여 제정되어졌지만, 실제로 시행과정상에 있어서 각 정부 기구들의 불복종과 잦은 정보 누설 등의 다양한 요인들에 의해 본래의 목적이 훼손되면서 많은 문제점을 야기하고 있는 실정이다. 더욱이 9/11 테러를 비롯한 심각한 테러 위협에 대처할 수 있는 정보 자유법의 지속적 수정은 많은 논란을 불러 오고 있지만 이 법의 시행변수와 조직적 변수간의 인과관계를 밝히는 연구들은 소수에 그치고 있다. 따라서 본 논문은 정보자유법 시행의 주요 결정요인, 그 효과의 실태, 그리고 정책적 효과의 상대적 강점을 규명함으로써 공공조직의 정책 집행에 대한 이론적 발전에 기여함은 물론 정보 자유법의 효율성을 높이는 실천적 방안을 모색하고자 한다. 특히 본 논문은 최근 핵 문제를 둘러싼 남 북한의 첨예한 군사적, 외교적 대립속에서 국민의 알권리와 국가안보라는 상반된 가치 사이에 국 내외적으로 분열된 대립과 갈등을 빚고 있는 현 상황을 미국 정보자유법의 고찰을 통해 조명해 봄으로서 앞으로 발생할 수 있는 더욱 심각한 사태에 대처할 수 있는 시사점을 제공할 것이다.

• 정보보호학회논문지
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• 제19권5호
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• pp.59-69
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• 2009

사용자가 특정 태그를 찾기 위해 사용하는 RFID 태그 검색 시스템은 재고관리, 물류, 유통, 미아 찾기 등 다양한 환경에 사용될 수 있으며 이 기법은 RFID 시스템을 이용한 응용 분야 중 하나로 연구가 활발히 진행되고 있다. 기존의 RFID 시스템을 이용한 다른 기법들과는 달리 RFID 태그 검색 기법에서는 특히 특정 태그를 찾기 위해 리더의 이동성이 강조되어지는데, 만약 이동형 리더를 가지고 무선 통신이 불가능한 지역에 가게 되었을 경우 중앙 데이터베이스로부터 태그에 대한 정보를 얻어올 수 없어 실시간 검색이 불가능한 상황에서도 검색이 가능해야 한다. 또한 RFID 태그 검색 프로토콜에서는 사용자가 태그가 아닌 이동형 리더를 소지하기 때문에 이동형 리더 소지자에 대한 프라이버시가 고려되어야 한다. 리더의 신호는 태그의 신호보다 도청이 수백 배 더 쉽기 때문에 이동형 리더 소지자의 프라이버시 문제는 매우 중요하다. 최근 이러한 문제를 해결하기 위한 RFID 태그 검색 기법들이 제안되고 있으나 이 기법들은 모두 이동형 리더 소지자에 대한 프라이버시 문제를 고려하지 않음으로써 이동형 리더 소지자의 프라이버시 침해가 심각하다. 따라서 본 논문에서는 이러한 이동형 리더 소지자의 프라이버시 문제를 해결하면서도 수동형 태그에 적합한 안전한 태그 검색 프로토콜을 제안한다.

• 한국세라믹학회지
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• 제50권2호
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• pp.134-141
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• 2013

Pond ash produced from Seochun Power Station was quantitatively characterized to manufacture geopolymers with a range of Si/Al compositional ratios. Mix consistency was kept nearly constant for comparing the compressive strengths of geopolymers. The amorphous composition of coal ash was determined using XRF and quantitative X-ray diffraction. Different mix compositions were used in order to achieve Si/Al ratios of 2.0, 2.5 and 3.0 in the geopolymer binder. Geopolymers synthesized from coal ash with a Si/Al ratio of 3.0 exhibited the highest compressive strength in this study. It was found that geopolymers activated with aluminate produced different microstructure from that of geopolymers activated with silicate. High silica in alkali activators produced the fine-grained microstructure of geopolymer gel. It was also found that high compressive strength was related to low porosity and a dense, connected microstructure. The outcome of the reported experiment indicates that quantitative formulation method made it possible to choose suitable activators for achieving targeted compositions of geopolymers and to avoid efflorescence.

• 한국정보전자통신기술학회논문지
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• 제17권1호
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• pp.25-30
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• 2024

지능형 사물인터넷 (AIoT)의 핵심 응용 분야인 스마트시티는 안전, 보안, 의료 분야에서 위치 추적 및 위치 기반의 다양한 서비스를 제공한다. 위치 기반 서비스를 구현하기 위해서 실내 측위 시스템 (IPS)이 필요하며, WiFi, UWB, BLE 등의 무선통신 기술이 적용되고 있다. 저전력으로 데이터 송수신이 가능한 BLE는 저비용으로 센서, 비콘 등의 다양한 사물인터넷 소형 장치에 적용될 수 있어서 실내 측위를 위한 가장 적합한 무선통신 기술 중 하나이다. BLE는 RSSI(Received Signal Strength Indicator)를 이용하여 거리를 추정하는데, 다중 경로 페이딩(fading)의 영향으로 인한 신호 강도 변화로 인해서 수 미터 수준의 오차가 발생하게 된다. 본 논문에서는 근접 서비스를 제공하기 위한 BLE 실내 측위 시스템에 적용할 수 있는 경로 손실 모델을 연구하고, 자유공간 경로손실 계수의 최적화로 송·수신 장치 사이의 거리 오차를 줄일 수 있다는 것을 확인하였다.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.410-418
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• 2024

Study of flow behavior within rod bundles has been an active topic. Surface modification technologies are important parts of the design of the fourth generation reactor, which can increase the strength of the secondary flow within the rod bundle lattices. Quasi-periodic large-scale vortex structure (QLVS) is introduced by arranging micro ribs on the surface of rod bundles, which enhanced the scale of the secondary flow between the rod bundle lattices. Using computational fluid dynamics (CFD) and water experiments, the flow field distribution and drag coefficient of the rod-bundle lattices are studied. The secondary flow between the micro-ribbed rod-bundle lattice is significantly enhanced compared to the standard rod-bundle lattice. The numerical simulation results agree well with the experimental results.

• 수산해양교육연구
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• 제26권4호
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• pp.769-788
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• 2014

Today, all the countries of the world newly recognize importance of sea on 70% area of the earth, which are focused on efforts for security of marine territory and fishes resources. On the security concerns of the ocean & fishes resources, Sea are very important on the ground of the importance of the ocean, thus international community has been trying to combat a maritime security threat and illegal fisheries. Coastal states need to have proper state's jurisdiction and exercise it's jurisdiction to response effectively to a maritime security threat and illegal fisheries. Here, many of the coastal states strengthened the rights in Exclusive Economic Zone(;EEZ) naturally, there are made cooperation activities and keen competition in the sea because deepening of complex understanding of the relationship between the surrounding countries with marine surveys & continental shelf development, island territorial sovereignty & marine jurisdiction in overlap of sea area on EEZ. In these circumstances, foreign fishing boats invaded to our territorial waters and EEZ many times. in addition, Chinese fishing boats are going to illegal fisheries naturally. On this point, a powerful crackdown of maritime enforcement organization had no effect on them. Also more and more their resistance gathered strength and tendency of a illegal activities became systematization, group action and atrocity little by little. So this thesis includes a study on the regal regulation, the system and formalities on the control of illegal fishing. And the author analyzed the details of the activities of illegal fishing and boats controlled by Korea Coast Guard(KCG), fishing patrol vessels of Ministry of Maritime Affaires and Fisheries(MOMAF) and Navy etc. from in adjacent sea area of Korea. In relation to this, the policy and activity plan were devised to crackdown to illegal fisheries of foreign fishing boats and then it was enforced every year. According to this, analyze the present conditions of illegal fisheries of a foreign fishing boats on this study, also analyze the present conditions of maritime enforcement organization & found out problems to compared it. protect the territorial waters, at the same time protection of marine mineral resources & fishes resources of EEZ including continental shelf, which has want to study for the role & response of maritime enforcement organization for the protection of fisheries resources and a proper, a realistic confrontation plan of maritime enforcement organization against illegal fisheries of foreign fishing boats.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.242-245
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• 2002

Authentication protocol as a part of security system has been growth rapidly since it was known that sending clear text password in the network is unsecured. Many protocols could be noted proposed to strengthen the authentication process. In 1985 an attempt to safeguard network services within Athena project resulting on the born of Kerberos 〔1〕〔8〕, one of the protocol that has a lot of attention from the research community. Several years later researchers were discovered some weaknesses carried by this protocol 〔2〕〔21〕. In 1992. EKE was introduced by Bellovin and Merrit. Since that time, many protocols introduced could be considered as its variant 〔5〕〔9〕〔13〕〔14〕. Some other protocols such as OKE〔5〕 and SRP〔18〕 although claimed different from EKE, they have the same basic mechanism in holding authentication process. Here, we explain the mechanism of those protocols, their strength and their weaknesses and shortcomings. Due to the limitations of the number of paper pages, only two types of authentication protocol can be explained here i.e EKE and SRP.