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IM(Instant Messenger) chatting service can carry user's various information including life style, geographical position, and psychology & crime history and thus forensic analys is on the IM service is desirable. But, forensic analysis for KakaoTalk's chatting service is not well studied yet. For this reason, we study KakaoTalk's forensic analysis focusing on chatting service. This paper first details a general method of IM forensics investigating the previous articles about IM forensics although there are not many articles. Seco nd, we discuss methodologies for IM forensics wherein we present analysis of table structure and method for reconstruction of chatting message. These result in the basic element of forensic tools of KakaoTalk chatting message. Last, we compare artifacts of KakaoTalk with that of WhatsApp. We conclude that these applications are, at least, different in that table structures and the ways to reconstruct chatting messages are not same and therefore digital evidences or artifacts are not same and somewhat distinct.

This paper explains a web session management system for mobile web environment with BYOD(Bring Your Own Device). This system operates by enhanced secure session token. This system consists of an unique identifier, time stamp, and encryption algorithm. The Unique identifier in this system classifies each mobile device for web security based on mobile environment with BYOD. And the Time stamp in this system that determine session effectiveness for web security. Also the Cipher algorithm in this system that protects session token information for web security. This paper analysis a security of session management system running on mobile web environment using the simulation techniques. The proposed method is more suitable than the other methods under enviroment mobile web environment with BYOD.

IEEE 802.15.6 표준인 무선 Body Area Networks (WBAN) 은 여러 디지털 장비들을 가지고 있는 사람과 사람간의 통신규약이다. WBAN 에서는 하나의 주 디바이스와 여러 개의 부 디바이스들을 가진 한 사람 단위로 피코넷이 구성 되며, 이 피코넷은 사람의 움직임에 따라 이동하게 되며, 다른 사람과 근처에 있게 되면 피코넷간의 충돌이 일어나게 된다. 따라서 이와 같은 충돌을 감지하고 간섭을 회피하는 일이 피코넷 내부 통신을 위하여 필요하게 된다. 이 논문에서는 피코넷 충돌에 관하여 논하며, 간단하며 유용한 로컬 오프셋을 이용한 분산시간 분리 피코넷 충돌회피 방법을 제시한다. 이 제시된 방법은 여러 응용(동영상, 보안, 의료 등)을 위하여 응용마다 다른 수준의 서비스를 제공하는 하게 되는 기능을 갖게 되며, 수행된 실험 결과는 전통적인 CSMA 에 비교하여 성능이 뒤지지 않음을 보인다.

Although there were many activities to provide FMC (Fixed Mobile Convergence) service by several foreign countries such as United States, FMC service could not make a good success for a number of reasons for example, customers indifference and lack of needs. On the other hand, recently FMC is showing its good progress at B2B market in foreign government such as in Germany and US satisfying e-government and BYOD (Bring Your Own Device) needs. This paper studies FMC service of foreign countries and as a result makes a analysis presenting issues for Korean e-government service. Also, we make several suggestions to energize FMC service success.

This paper investigates the dynamic response in case of cable loss with focus on dynamic amplification through case studies on an actual cable-stayed bridge. Cable-stayed bridges are designed to accommodate cable replacement as well as the abrupt loss of a stay cable and design recommendations are providing simplified method of the cable loss verification, which replaces the dynamic effect by factored static load. It is not unusual for cable loss to govern the design of the superstructure due to inadequate or overestimated dynamic amplification factors. This paper intends to derive proper load factor for cable-stayed bridges through adequate simulation of the instantaneous or progressive rupture of a stay cable as well as the use of appropriate model in the time history analysis. Accordingly, a process by which reasonable values of DAF can be derived for cable stayed bridges according to the stress of considered structural element or section is proposed. The proposed process applied to Seohae Bridge is seen to produce reasonable values of the DAFs according to the structural element with values below 1.5 for the critical sections.

In this paper, we develop an improved optimization algorithm based on genetic algorithm (GA) approach for the bandwidth allocation of ATM networks. The ATM switches can be connected with multiples of DS3 trunks via digital cross connect systems (DCS). One of the advantages of DCS is its ability to reconfigure a customer network dynamically. We utilize this advantage in the design and dynamic reconfiguration of ATM networks. The problem is formulated as a network optimization problem where a congestion measure based on the average packet delay is minimized, subject to capacity constraints posed by the underlying facility trunks. We choose the traffic routing on the express pipes and the allocation of the bandwidth on these pipes as the variables in this problem. The previous GA algorithm is not practical because (1) the number of the traffic distribution patterns is huge, and (2) the values of offered traffic are continuous. A new representation of the chromosome, Net- Chro, and the reproduction operator are presented. We show that the previous algorithm cannot guarantee full usage of trunk capacities in the solutions it generates. We also discuss open-loop control to overcome the congestion caused by a trunk failure.