무선 센서 네트워크는 여러 지역에 퍼져 있는 다수의 센서 노드들이 무선 방식으로 연결 되어있는 그물망으로 전 세계에서 연구되고 있는 기술 중 하나이다. 그러나 자원의 제약성, 무선 통신 사용 등, 네트워크 자체적인 특성으로 인해 일반 네트워크에 비해서 보안이 매우 취약하다. 무선 센서 네트워크의 공격법은 크게 도청기반 공격, 위조기반 공격, 서비스 거부 기반 공격으로 나누어지며, 보안법으로 대개의 Sensor Network Application은 전송되는 정보의 도청 또는 수정, 잘못된 정보의 삽입 등 여러가지 공격으로부터 방어를 해야 할 필요가 있다. 이를 위한 기본적인 방법은 암호화 방법, 스위칭 기법 등을 서술 한다.

This study empirically investigated cultural differences in the amount of information provided by managerial accounting information systems as well as the differences in organizational performance according to variations in the amount of information. Through cluster analysis, I classified sample firms into five organizational cultural types: Semi-innovative, innovative, bureaucratic, semi-bureaucratic and supportive. The results showed that in the semi-innovative firms, a greater amount of the traditional and advanced types of information is produced, while in bureaucratic firms, traditional information is much more provided than in the innovative, semi-bureaucratic and supportive firms. These results confirmed cultural differences in the amount of information produced. According to the results of this study, it was found that in organizational performance, the rankings of semi-innovative firms, which have the highest scores in the amount of information, are also the highest, and the performance scores in innovative firms are generally next to those of semi-innovative firms. Hence it is concluded that there are cultural differences in the amount of information provided and theses differences affect organizational performance

스마트폰 개발의 발전으로 인하여 사용자의 스마트폰 사용율이 PC 사용율보다 점점 높아지고 있는 실정이다. 스마트폰 사용이 대중화되면서 스마트폰 사용자의 개인신상정보, 금융 정보와 같은 중요한 프라이버시 정보들을 보호하는 연구는 현재 미미한 상태이다. 본 논문에서는 현재까지 연구되었던 스마트폰의 다양한 취약점에 대해서 분석하고 스마트폰 보안 공격 방법에 대한 대응방법 및 스마트포 소비자 분쟁 해결 기준들을 제시한다. 특히, 스마트폰에서 발생하기 쉬운 보안 위협(네트워크, 악성코드, 훔쳐보기 공격 등)을 통해 사용자의 개인정보 유출이나 금전적 손실과 같은 직접적인 피해를 최소화하기 위한 방법들을 분석한다.

Group communication is becoming increasingly popular in Internet applications such as videoconferences, online chatting programs, games, and gambling. For secure communications, the integrity of messages, member authentication, and confidentiality must be provided among group members. To maintain message integrity, all group members use the Group Key (GK) for encrypting and decrypting messages while providing enough security to protect against passive attacks. Tree-based Group Diffie-Hellman (TGDH) is an efficient group key agreement protocol to generate the GK. TGDH assumes all members have an equal computing power. One of the characteristics of distributed computing and grid environments is heterogeneity; the member can be at a workstation, a laptop or even a mobile computer. Member reordering in the TDGH protocol could potentially lead to an improved protocol; such reordering should capture the heterogeneity of the network as well as latency. This research investigates dynamic reordering mechanisms to consider not only the overhead involved but also the scalability of the proposed protocol.

Security is a primary concern in group communication, and secure authentication is essential to establishing a secure group communication. Most conventional authentications consist of knowledge-based and token-based methods. One of the token-based methods is a X.509 certificate, which is used under a Public Key Infrastructure (PKI); it is the most well-known authentication system in a distributed network environment. However, it has a well-known weakness, which only proves the belonging of a certificate. PKI cannot assure identity of a person. The conventional knowledge-based and token-based methods do not really provide positive personal identification because they rely on surrogate representations of the person's identity. Therefore, I propose a secure X.509 certificate with biometric information to assure the identity of the person who uses the X.509 certificate in a distributed computing environment.

Recent advancement in Wireless Sensor Networks (WSNs) has paved the way for WSNs to enable in various environments in monitoring temperature, motion, sound, and vibration. These applications often include the detection of sensitive information from enemy movements in hostile areas or in locations of personnel in buildings. Due to characteristics of WSNs and dealing with sensitive information, wireless sensor nodes tend to be exposed to the enemy or in a hazard area, and security is a major concern in WSNs. Because WSNs pose unique challenges, traditional security techniques used in conventional networks cannot be applied directly, many researchers have developed various security protocols to fit into WSNs. To develop countermeasures of various attacks in WSNs, descriptions and analysis of current security attacks in the network layers must be developed by using a standard notation. However, there is no research paper describing and analyzing security models in WSNs by using a standard notation such as The Unified Modeling Language (UML). Using the UML helps security developers to understand security attacks and design secure WSNs. In this research, we provide standard models for security attacks by UML Sequence Diagrams to describe and analyze possible attacks in the three network layers.

본 논문에서는 가시광 통신 에서 시스템 성능에 주된 영향을 주는 요인들에 대해 분석하였다. 일반적으로 발표된 논문들은 가시광 통신 시스템의 전송속도, 전송거리의 증가, 변조 기법을 통한 성능향상 등에 초점을 맞춰 연구가 진행 되고 있다. 이에, 자세한 가시광 통신 시스템 환경을 분석하기 위해 통신 성능에 주된 영향을 주는 통신거리 및 입사각에 따른 성능 분석을 진행하였으며, 모의실험을 통해 성능 감쇄 정도를 확인하였으며, 향후 연구방향에 대해 고찰 하였다.