• 한국정보통신설비학회:학술대회논문집
• /
• 2008.08a
• /
• pp.491-494
• /
• 2008

과거 CDMA 시스템에서 이동단말과 PSTN 및 PSDN간의 통신이 가능하게 하기 위해서는 망간의 정합기능을 수행하는 연동장치(IWF Inter-Working Function)가 필요로 되는데, 이때 이동단말과 BSC/MSC간의 무선 데이터를 IWF로 HDLC 프레임 형태로 구동하고 반대로 IWF로부터 수신된 데이터 프레임을 이동 단말측으로 전달하기 위하여 HDLC frame driver의 역할이 필요하다. 또한 교환기와 IWF간의 데이터 통신은 Frame-relay 프로토콜을 이용하며 정합기능을 수행해 주어야 한다. 본 논문에서 구현된 기능은 과거 CDMA 의 MSC 내에 구현된 본 기능이 HDLC 정합, Frame-Relay 정합, IPC, Datapath 등의 기능들로 구분되어 분리되어 있는 구조를 통합하여 하나의 기능 Board로 통합하였고 이러한 기능을 MG(Media Gateway) System에 기반하여 구현하여 적용하였다.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.15 no.6
• /
• pp.761-769
• /
• 2012

In this paper, we propose a low-power design strategy to minimize energy-consumption for surveillance and reconnaissance sensor networks. The sensor network consists of many different nodes with various operations such as target detection, packet relay, video monitoring, changing protocols, and etc. Each sensor node consists of sensing, computing, communication, and power components. These components are integrated on a single or multiple boards. Therefore, the power consumption of each component can be different on various operation types. First, we identified the list of components and measured power consumption for them from the first prototype nodes. Next, we focus on which components are the main sources of energy consumption. We propose many energy-efficient approaches to reduce energy consumption for each operation type.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.04d
• /
• pp.325-327
• /
• 2003

현재, IEEE 802.11 WG(Working Group)중에는 AP(Access Point)간의 표준화된 프로토콜을 개발하는 TGf(Task Group F)가 있다. 이 그룹에서는 서로 다른 제조업체에서 생산한 AP 간의 상호연동을 보장하기 위한 IAPP(Inter Access Point Protocol)를 제안하였는데. 이는 동일 서브네트워크 내의 서로 다른 AP 간에 이동성을 보장하기 위한 프로토콜로. STA(Station)들이 이동할 때 재인증 과정을 거치지 않고 AP 간의 Security Context 정보나 Layer 2 forwarding 정보를 공유함으로서 STA간의 seamless connectivity를 제공한다. 본 논문에서는 위의 AP간의 메시지 전달시 발생할 수 있는 키 유출을 막기 위해서 메시지의 전달 경로를 바꾸고. 좀 더 높은 보안성을 제공하기 위해 공개키를 이용한 방안을 제시하고자 한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10a
• /
• pp.721-723
• /
• 2001

익스트라넷 환경에서는 인트라넷 환경에서 고려되는 보안 문제는 물론이고, 이와 함께 익스트라넷 환경 내의 여러조직사이에 공유되는 자원의 관리 및 사용자에 대한 접근 제어에 있어 많은 문제를 가지고 있다. 본 논문에서는 익스트라넷 환경에서의 보안 문제를 해결하기 위해 익스트라넷 내부의 여러 도메인을 PKI(Public Key Infrastructure)를 기반으로 상호 연동하는 방안을 제안한다. 또한 상호 연동된 여러 도메인 사이의 상호 인증을 통해 익스트라넷 사용자에 대한 단일 인증 서비스를 제공하는 방안을 제안한다. 각 도메인 내부에는 도메인의 사용자 정보를 가지고 있는 사용자 관리 서버를 두고, 이 사용자 관리 서버에서는 사용자에 대한 인증과 응용 서버에 접근하여 응용 서비스를 제공받을 수 있는 서비스 티켓을 발급한다. 사용자 관리 서버에서 부여된 권한 정보가 담긴 서비스 티켓을 통하여 각 응용 서버는 응용 서버 자신의 보안 정책에 맞는 권한 속성을 접근하는 사용자에게 부여한다. 따라서 사용자의 인증은 PKI 기반으로 상호 연동되어 있는 도메인내의 사용자 관리 서버에서 한번 이루어지며 이때 발급한 서비스 티켓의 권한 정보를 통하여 사용자는 권한에 맞는 권한 속성에 따라 응용 서비스를 각 응용 서버에서 독립적으로 제공받을 수 있다.

• Korean Security Journal
• /
• no.14
• /
• pp.69-87
• /
• 2007

Study results on the perception of organization justice and organization member behavior of private security are as below. Primarily, organization justice showed variation according to socio-demographic characteristics which include age, the period the person has stayed in the current workplace, total period of working and monthly income. As for age, in aspect of the perception of distribution justice, the 36 or older age group prevailed, and the 31 to 35 age group prevailed in the perception of procedure justice. So, perception of organization justice increased accordingly with age. According to the period the person has stayed in the current workplace category, showed high levels in the perception of distribution justice and perception of procedure justice in the $3\;{\sim}\;5$ years group. As for total period of working, both perception of distribution justice and the perception of procedure justice proved greatest in the 5 years or more group and according to monthly income, the KRW 1800,000 or more group showed high levels of perception of distribution justice and the perception of procedure justice. Secondly, organization member behavior showed variation according to sociodemographic characteristics. In organization member behavior, loyal behavior increased along with age and inter-personal relationship behavior and altruistic behavior prevailed in the age group 31-35 According to period the person has worked at the current workplace and in case of total period of working, loyal behavior, inter-personal relationship behavior and altruistic behavior proved to be high. As for monthly income, an increase in monthly income resulted in a high figure in loyal behavior, inter-personal relationship behavior and altruistic behavior. Thirdly, after regression analysis of the relationship of the perception of organization justice and organization member behavior, perception of procedure justice was analyzed to have relatively high influence. Therefore, the hypothesis presented in this study was all chosen after the regression analysis results. This shows that the enhancement of organization member behavior can be improved. by enhancing the perception of organization justice. Thus, it can be concluded that if a private guard recognizes his justice, organization member behavior can be enhanced.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.1
• /
• pp.45-52
• /
• 2009

Currently broadcasting and telecommunication has integrated, And IPTV Service has appeared who called TPS(Triple Play Service) which integrated with broadcasting, telecommunication and Phone Service. IPTV provide broadcasting service and VOD(Video on Demand) service, and it must be satisfied digital content security. For this condition, IPTV Forum working on standardization of interface for digital content security. The Security solution for broadcasting and VOD are CAS (Conditional Access System) and DRM(Digital Rights Management). But these solutions manufactured by many vendors, so there is no inter-operability. And after finished standardization of interface for CAS and DRM system, the problem of inter-operability with them will be issued. For this reason, Rights management system which possible to operate independently with platform is necessary. In this paper, To protect multimedia digital content, we designed and implemented Conditional Access Management System.

• Imaging Science in Dentistry
• /
• v.47 no.4
• /
• pp.233-239
• /
• 2017

Purpose: This study was performed to quantify the repeat rate of imaging acquisitions based on different clinical examinations, and to assess the prevalence of error types in intraoral bitewing and periapical imaging using a digital complementary metal-oxide-semiconductor(CMOS) intraoral sensor. Materials and Methods: A total of 8,030 intraoral images were retrospectively collected from 3 groups of undergraduate clinical dental students. The type of examination, stage of the procedure, and reasons for repetition were analysed and recorded. The repeat rate was calculated as the total number of repeated images divided by the total number of examinations. The weighted Cohen's kappa for inter- and intra-observer agreement was used after calibration and prior to image analysis. Results: The overall repeat rate on intraoral periapical images was 34.4%. A total of 1,978 repeated periapical images were from endodontic assessment, which included working length estimation (WLE), trial gutta-percha (tGP), obturation, and removal of gutta-percha (rGP). In the endodontic imaging, the highest repeat rate was from WLE (51.9%) followed by tGP (48.5%), obturation (42.2%), and rGP (35.6%). In bitewing images, the repeat rate was 15.1% and poor angulation was identified as the most common cause of error. A substantial level of intra- and inter-observer agreement was achieved. Conclusion: The repeat rates in this study were relatively high, especially for certain clinical procedures, warranting training in optimization techniques and radiation protection. Repeat analysis should be performed from time to time to enhance quality assurance and hence deliver high-quality health services to patients

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.5
• /
• pp.61-66
• /
• 2012

We propose a traffic information service system for which traffic data are transmitted over vehicle ad-hoc network from neighbor vehicles, and eventually provided to the traffic information center through a few gateway vehicles which are capable of inter-working with the infrastructure network like 3G. The center broadcasts the traffic information through the FM radio. The proposed scheme allows collecting and analyzing traffic status of large areas without incorporating separated monitoring systems, e.g., probe cars and enables to provide accurate traffic information to drivers in timely manner. We also evaluate its performance by ns-3 simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.516-519
• /
• 2008

Currently broadcasting and telecommunication has integrated, And IPTV Service has appeared who called TPS(Triple Play Service) which integrated with broadcasting, telecommunication and Phone Service. IPTV provide broadcasting service and VOD(Video on Demand) service, and it must be satisfied digital content security. For this condition, IPTV Forum working on standardization of interface for digital content security. The Security solution for broadcasting and VOD are CAS(Conditional Access System) and DRM(Digital Rights Management). But these solutions manufactured by many vendors, so there is no inter-operablity. And after finished standardization of interface for CAS and DRM system, the problem of inter-operability with them will be issued. For this reason, Rights management system which possible to operate independently with platform is necessary. In this paper, To protect multimedia digital content, we designed and implemented Conditional Access Management System.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.2A
• /
• pp.174-185
• /
• 2010

A seamless handover between the 3G LTE and legacy 3G system is required for the smooth deployment of the 3G LTE system which is the next generation cellular network system. Especially on voice call handover, the service interruption time is very sensitive for user's satisfaction and therefore, a seamless voice call handover scheme is necessarily required. However, handover between the 3G LTE and the 3G CS system is hard to be achieved due to the lack of interface between two systems and the restriction of radio resource. In this paper, a new network entity called SCSE is proposed and inter-working between the 3G LTE and the 3G CS systems is enabled. Also contributed to the feature of the SCSE, the handover procedure is simplified and the service interruption time is minimized as a consequence. The evaluation result shows that the proposed SCSE scheme exclusively meets the service interruption time requirement which is smaller than 300 ms.