• 한국차세대컴퓨팅학회논문지
• /
• 제15권1호
• /
• pp.86-98
• /
• 2019

최근 컨테이너 기반의 PaaS (Platform-as-a-Service)를 구축하는 트렌드가 확대되고 있다. 컨테이너 기반 플랫폼 기술은 클라우드 컴퓨팅을 구축하기 위한 하나의 주요 기술로써, 컨테이너는 가상 머신에 비해 구동 오버헤드가 적다는 장점이 있어 수백, 수천 대의 컨테이너가 한 대의 물리적 머신에서 구동될 수 있다. 하지만 이러한 클라우드 컴퓨팅 환경에서 구동되는 다수의 컨테이너에 대한 스토리지 로그를 기록하고 모니터링하는 것은 상당한 오버헤드가 발생한다. 따라서 본 논문에서는 클라우드 컴퓨팅 환경에서 구동되는 컨테이너의 파일 시스템 변경 이벤트를 탐지할 때 발생하는 두 가지 문제점을 도출하고, 이를 해결하여 PaaS 형태의 클라우드 컴퓨팅 환경에서 컨테이너 파일 시스템 이벤트 탐지를 위한 시스템을 제안하였다. 성능 평가에서는 본 논문에서 제안한 시스템의 성능에 대한 세가지 실험을 수행하였고, 본 논문에서 제안한 모니터링 시스템은 컨테이너의 CPU, 메모리 읽기 및 쓰기, 디스크 읽기 및 쓰기 속도에 아주 미세한 영향만을 발생시킨다는 것이 실험을 통해 도출되었다.

• 한국콘텐츠학회논문지
• /
• 제4권1호
• /
• pp.83-89
• /
• 2004

인스턴트 메시징(Instant Messaging:IM) 서비스는 인터넷상에서 사용자들 간에 간단한 메시지를 주고 받을 수 있는 유용한 통신 수단의 하나이다. 통상적으로 인스턴트 메시징 서비스는 Presence 서비스를 통하여 상호간에 온라인 상태를 제공받아 메시지를 직접 송수신하는 방식을 사용하는데 이는 사용자가 오프라인 상태일 경우에는 메시지의 송수신이 불가능함을 의미한다. 따라서 본 논문에서는 SIP(Session Initiation Protocol) 기반의 인스턴트 메시징 시스템을 구현함에 있어 메시지 서버를 이용하여 메시지를 보관 및 관리함으로써 상대방의 상태에 무관하게 메시지를 전송할 수 있도록 보완하였다. 또한 In working group에서 제안하고 있는 message waiting indication event package를 메시지 서버에 포함시켜 메시지의 정보 및 상태들을 제공받을 수 있도록 하였으며 사용자들이 메시지 서버의 사용을 명시할 수 있는 Caller Preference 기능을 시스템에 포함시켰다.

• 한국응급구조학회지
• /
• 제9권2호
• /
• pp.137-146
• /
• 2005

This research focused on studying the phenomena of activity injuries occurred in military service, the object of which is soldiering soldiers in army. I made a inquiry paper including 6 items such as injury frequency, athletic event when you are injured, injury pattern, injury part in body and injury time according to military classes, and distributed it to elected 421 soldiers, the number of which is the total number of injured soldiers having time for physical activities in a year(last 2002 year). The results were as follows ; First, Injury frequency was according to private middle classes, private second classes, private last classes, private first classes. Second, Athletic event when you are injured was according to soccer, basketball, running and Martial Art(Taekwondo). 1) An abrasion was the most injury pattern when playing soccer. 2) A sprain was the most injury pattern when playing basketball. Third, Most causes of injuries dued to his / her carelessness, which is his / her excessive greed to win. Fourth, The most injury pattern was a skin abrasion. Fifth, The most injury part in body was a leg. Sixth, There was the most injury in summer. Wednesday on week, especially afternoon when you have time for physical to improve your battle-power.

• 대한산업공학회지
• /
• 제33권2호
• /
• pp.191-200
• /
• 2007

We propose the QoS (Quality of Service) assurance model for AMR (Adaptive MultiRate) voice users considering the capacity and service quality jointly in downlink WCDMA system. For this purpose, we introduce a new system performance measure and the number-based AMR mode allocation scheme. The proposed number-based AMR mode allocation can be operated only with the information of total number of ongoing users. Therefore, it can be more simply implemented than the existing power-based allocation. The proposed system performance measure considers the stochastic variations of AMR modes of ongoing users and can be analytically obtained using CTMC (Continuous Time Markov Chain) modeling. In order to validate the proposed analytical model, a discrete event-based simulation model is also developed. The performance measure obtained from the analytical model is in agreement with the simulation results and is expected to be useful for parameter optimization.

• 한국자동차공학회논문집
• /
• 제23권6호
• /
• pp.615-622
• /
• 2015

Recently Digital-TachoGraph(DTG) was mounted mandatorily in commercial vehicles(Taxi, Bus, etc.). DTG records accurate and detailed information of the running state of vehicles related to traffic accident, such as Time, Distance, Velocity, RPM, Brake ON/OFF, GPS, Azimuth, Acceleration. Thus those standardized data can play an important role in traffic accident investigation and reconstruction. To develope the accurate and objective method using the DTG data for the reconstruction of traffic accident, we had conducted several tests such as driving test, high speed circuit test, braking test, slalom test at Korea Automobile Testing & Research Institute(KATRI), and collision test at Korea Automobile insurance repair Research and Training center(KART) with the vehicle equipped with several DTG. Development of the program which enables the reading and analysis of the DTG data was followed. In the experiments, we have found velocity error, RPM error, brake signal error and azimuth error in several products, and also non-continuous event data. The cause of these errors was deduced to be related to the correction factor, the durability of electronic parts and the algorithm.

• 한국시뮬레이션학회논문지
• /
• 제19권1호
• /
• pp.33-39
• /
• 2010

미래 전장환경이 네트워크 중심으로 변해감에 따라, 워게임 시뮬레이터는 네트워크에 분산된 모듈간의 높은 상호운영성과 전장 이벤트에 따른 동적구성의 필요성이 높아지고 있다. 본 논문에서는 이벤트 기반의 워게임 시뮬레이터 개발방법론을 제안한다. 워게임 시뮬레이터의 페더레이트들은 이벤트 기반의 웹서비스로 개발되며, 각 페더레이트는 전장 이벤트를 감지하고, 관계있는 이벤트가 발생할 경우에만 워게임에 반응하게 된다. 이러한 감지-반응 방법과 비동기적 이벤트 처리방법을 이용하여 시뮬레이션 수행 시간을 줄일 수 있다. 본 논문에서는 간단한 수상전 시뮬레이터를 구성하여, 제안된 방법이 전장 장비 및 네트워크상에서 모델러 및 운영자를 통해 발생되는 다양한 이벤트를 처리해야 하는 미래 전장환경 시뮬레이션 수행시 효과적임을 보이도록 한다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
• /
• pp.276-279
• /
• 2004

The location-based service is one of the most powerful services in the mobile area. The location-based service provides information service for moving user's location information and information service using wire / wireless communication. In this paper, we propose a model for personalized recommendation system which includes location information and personalized recommendation system for location-based service. For this service system, we consider mobile clients that have a limited resource and low bandwidth. Because it is difficult to input the words at mobile device, we must deliberate it when we design the interface of system. We design and implement the personalized recommendation system for location-based services(advertisement, discount news, and event information) that support user's needs and location information. As a result, it can be used to design the other location-based service systems related to user's location information in mobile environment. In this case, we need to establish formal definition of moving objects and their temporal pattern.

• Journal of the Korean Data and Information Science Society
• /
• 제19권4호
• /
• pp.1123-1131
• /
• 2008

A considerable amount of research has focused on the dimensionality of service failure and recovery construct. This paper is focused on service failure and recovery in the Korean native cattle and imported beef restaurant industry in the Korea. So, this paper has adapted Kau and Loh's Service recovery measurement scale so that restaurant managers can use it to determine how customers perceive the service quality in Korean native cattle beef restaurant and imported beef restaurant. The purpose of this research is to test the difference in pre-purchase expectation and post-purchase actual performance of 4 dimensions between the restaurants that sell the beef of Korean native cattle and imported cattle. The paired t -test is used to test difference of pre-purchase expectation and post-purchase actual performance for service recovery measurement scale's 4 dimensions of the 2 restaurant types. But, there is significant difference between pre-purchase expectation and post-purchase actual performance in the 2 restaurant types.

• 한국멀티미디어학회논문지
• /
• 제23권1호
• /
• pp.24-30
• /
• 2020

As the number of internet-connected appliances and the variety of IoT services are rapidly increasing, it is hard to protect IT assets with traditional network security techniques. Most traditional network log analysis systems use rule based mechanisms to reduce the raw logs. But using predefined rules can't detect new attack patterns. So, there is a need for a mechanism to reduce congested raw logs and detect new attack patterns. This paper suggests enterprise security management for IoT services using graph and network measures. We model an event network based on a graph of interconnected logs between network devices and IoT gateways. And we suggest a network clustering algorithm that estimates the attack probability of log clusters and detects new attack patterns.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.617-621
• /
• 2003

The purpose of this paper is to analyze piping failure trend of safety pipings In domestic nuclear power plants. First, database for the piping failure was constructed with 105 data fields. The database includes plant population data, event data, and service history data. 7 kinds of piping failures in domestic NPPs were investigated. Among the 7 cases, detailed root causes were investigated for 3 cases. The first one is pipe wall thinning in main feedwater pipings of Westinghouse 3 loop type plants. The root cause of the wall thinning was flow accelerated corrosion near welding area. The next one is leak event in chemical and volume control system(CVCS) due to vibration. Some cracks occurred in socket welding area. The events showed that the integrity or socket weld is very vulnerable to vibration. The last one is also a leak event in primary sampling line in Korean standard reactor due to thermal fatigue. Although the structural integrity was not maintained by the events, there was no effect on nuclear safety in the above 3 piping failure eases.