• Electronics and Telecommunications Trends
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• v.16 no.2 s.68
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• pp.10-30
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• 2001

본 고에서는 차세대 인터넷 구축을 위한 요소 기술에 대하여 전반적으로 살펴본다. 우리는 현재보다 1,000배 빠른 차세대 인터넷의 구축을 목표로 하고 있다. 따라서 과연 그만큼 빠른 인터넷의 구축이 필요할 것인가를 검증하는 차원에서 향후 5년 정도의 가까운 시일 내에 있을 인터넷 트래픽의 증대에 대한 수요를 서비스 측면에서 살펴본다. 차세대 인터넷은 풍부한 전송대역폭의 제공과 QoS를 기반으로 한 신뢰성 있는 데이터의 전달을 특징으로 하며, 이를 위해서 광스위칭 기반의 전송 하부구조 위에 MPLS 기술이 사용될 것으로 예상된다. 이를 위한 요소기술로 DWDM 전송기술, MEMS 기반의 광스위칭 소자기술과 함께 광스위칭 기술에 지능을 부여하기 위한 표준화 동향에 대하여 살펴본다. 현재의 IP 기반 인터넷에서 제공하지 못하는 QoS 기능은 MPLS에서 가능하게 될 것이다. MPLS에서의 중요한 응용인 트래픽 엔지니어링과 VPN 서비스는 망이 보다 안정적으로 유지될 수 있도록 지원하면서 기업들이 MPLS 망을 이용하여 자신의 망을 구축할 수 있도록 지원할 것이다. MPLS 기술은 IETF에서 표준화가 진행되고 있으며 라우터 개발업체 및 ISP의 큰 지원을 받고 있다. 차세대 인터넷을 위해서는 전달망의 구축도 필요하지만 이와 함께 차세대 인터넷 응용을 위한 컴퓨팅 인프라도 균형있게 개발되어야 한다. 따라서 현재 그 윤곽을 드러내고 있는 차세대 인터넷 응용 인프라 환경에 대하여 그 등장 배경과 관련 기술에 대하여 조망한다. 차세대 인터넷의 개발을 위해서는 광처리 관련 원천 기술, 프로세서 개발 기술, 라우터 설계 기술 및 서버 개발 기술, 어플리케이션 기반 기술 및 사용자 인터페이스 기술들이 전략적으로 이음새 없이 매끄럽게 통합되어야 한다. 이러한 관점에서 필요한 요소기술들을 다수 보유하고 있는 ETRI의 역할은 매우 중요하리라 생각된다.

• Journal of Internet Computing and Services
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• v.16 no.3
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• pp.1-11
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• 2015

WBAN(Wireless Body Area Network) operating around the human body aims at medical and non-medical service at the same time. and it is the short-range communication technology requiring low-power, various data rate and high reliability. Various studies is performing for IEEE 802.15.4, because IEEE 802.15.4 can provide high compatibility for operate WBAN among communication standard satisfiable these requirements. Meanwhile, in the case of coexisting many IEEE 802.15.4-based WBAN, signal interference and collision are the main cause that is decreasing data reliability. but IEEE 802.15.4 Standard does not consider about coexistence of many networks. so it needs improvement. In this paper, To solve about this problem, identify coexistence problem of IEEE 802.15.4-based WBAN by preliminary experiments. and propose a scheme to mitigate the reliability decrease at multiple coexistence WBAN. The proposed scheme can be classified in two steps. The first step is avoidance to collision on the CFP through improving data transmission. The second step is mitigation collision through converting channel access method. Proposed scheme is verified the performance by performing comparison experiment with Standard-based WBAN.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.716-723
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• 2016

A computerized information management system of road bridges as a national key infrastructure is needed to effectively collect data of the current status, improve the reliability of data, and use the results from the analysis of the accumulated data as fundamental resources for supporting the establishment of policies. The Internet-based Bridge Information System (BIS), including a database and geographic information systems (GIS), was designed, and the data items were comprised of essential information, such as GIS-based location coordinates, bridge condition grade information and so on. The BIS was developed to be connected with a related information system, and it is possible to make the current information of traffic volume, address and so on by adopting the GIS. To enhance the reliability of the information of current bridge status, it is also possible to improve the accuracy of data through an information verifying function to prevent entry errors. In addition, the BIS can easily support the establishment of policies offering various types of knowledge information that were available in the past based on an analysis of the accumulated data. The intuitive identification and analysis of the current status is to be feasible through a GIS screen. Improvement of the business efficiency and data accuracy and time-series information analysis are available by managing the information of current status through BIS. In the future, it is expected that BIS can be used effectively for the establishment of reasonable maintenance policies of the nation.

• Journal of KIISE
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• v.44 no.11
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• pp.1219-1230
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• 2017

Real-time streaming services over the Internet have increased with the explosive growth of the various mobile platforms, with a focus on smart phones, and the demand for them is growing. In addition, the bandwidth occupied by the streaming services over the Internet had already surpassed 50% in 2010. Because of the shortage of network bandwidth for multimedia services traffic, restrictions on quality and capacity will become more and more serious. CCN is a future Internet architecture that improves how existing host-based Internet architecture handles content-oriented structure, but it is designed for the transmission of general contents and is not suitable for transmitting real-time streaming contents. In this paper, we focus on the inefficient aspects of CCN and propose a hierarchical grade-based scheme for real-time service for a more efficient environment in real-time streaming services. Experiments have shown better performance in terms of bandwidth, network load, and reliability.

• The Journal of the Acoustical Society of Korea
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• v.35 no.6
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• pp.480-490
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• 2016

As wind turbines become larger and lighter, they are likely to respond sensitively by dynamic loads applied on them. Since the responses at resonances are particularly interested, it is required to be able to predict natural frequencies of wind turbines reliably at early design stage. To achieve this, the foundation-soil analysis is needed to be carried out and a finite element approach is adopted in general. However, the finite element approach would not be appropriate in early design stage because it demands heavy efforts in pile-soil modelling and computing facilities. On the contrary, theoretical approaches adopting linear approximations for soils are relatively simple and easy to handle. Therefore, they would be a useful tool in predicting a pile-soil interaction, particularly in early design stage. In this study an analysis for a pile inserted in soil is performed. The pile and soil are modelled as a beam and continuum medium, respectively, within an elastic range. In this analysis, influence factors at the pile head for lateral loads are predicted by means of this continuum approach for various length-diameter ratios of the pile. The influence factors predicted are validated with those reported in literature, proposed from a finite element analysis.

• Journal of the Korean Geosynthetics Society
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• v.23 no.2
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• pp.43-52
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• 2024

Recent abnormal climate conditions have increased the risk of slope collapses, which frequently result in significant loss of life and property due to the absence of early prediction and warning dissemination. In this paper, we develop a slope condition analysis system using IoT sensors and AI-based camera to assess the condition of slopes. To develop the system, we conducted hardware and firmware design for measurement sensors considering the ground conditions of slopes, designed AI-based image analysis algorithms, and developed prediction and warning solutions and systems. We aimed to minimize errors in sensor data through the integration of IoT sensor data and AI camera image analysis, ultimately enhancing the reliability of the data. Additionally, we evaluated the accuracy (reliability) by applying it to actual slopes. As a result, sensor measurement errors were maintained within 0.1°, and the data transmission rate exceeded 95%. Moreover, the AI-based image analysis system demonstrated nighttime partial recognition rates of over 99%, indicating excellent performance even in low-light conditions. Through this research, it is anticipated that the analysis of slope conditions and smart maintenance management in various fields of Social Overhead Capital (SOC) facilities can be applied.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.555-561
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• 1995

In this paper, the O-Ring Measurement System (O-R MS) has been designed to supplement such subectivity and apply to the diagnosis by constitution. A single chip microprocessor of Intel MCS-51 family has been used to control the O-R MS and process data with real time, and the O-R MS could measure the minute muscular strength, expanded width between fingers, and time of the measurement. Therefore the objective constitutional diagnosis is possible by the O-R MS. As a clinical testing for estimating credibility of O-R MS, the acupuncture points representing the constitution has been stimulated using a semiconductor laser stimulator and measure the muscular strength by the O-R MS. The result of clinical testing has been shown that the constitutional diagnosis with the O-R MS is proved highly precision of 96% and it is expected that the O-R MS can be used practically for the objective constitutional diagnosis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.343-350
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• 2010

In the existing design of web server architecture, data encryption technique is used to keep the reliability, stability, and safety of web service. But the use of data encryption technique wastes the work of cpu while decreasing throughput of web server and increasing average response time so that it shows negative effect on the capacity of web application server. Also, the latest web applications require security and safety for the safe internet communication. Therefore, this paper suggests the improved web server which uses thread pool and Non-blocking I/O adding new web service modules to the existing web server for the safe web service, provides reliability and safety to show the safe web service capacity. And we compare and evaluate the safety and capacity through experiment on the existing traditional Tomcat based web server and the proposed system to evaluate the safety and capacity of the proposed web server system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.143-146
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• 2009

The restaurants have been forced to inform the origin of ingredients to consumers due to the origin obligation policy enacted in 2008 October. However, it is difficult to trust the policy because the origin is represented by a manager's conscience. Therefore, in order to provide consumers with reliable information, we have designed, and embodied the agricultural management system using RFID and USN technology. By installing system on agricultural plantations this system not only manages environmental data such as temperature, illumination and humidity collected in real time but also offers consumers the information of fertilizers or pesticides sprayed on the crops. Before purchasing, consumers will be able to check raw flesh process and the fertilizer and agricultural chemical scattering scene of the crops as an image by using RFID tags with a leader, which more increase the reliability.

• The Journal of Korean Association of Computer Education
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• v.11 no.1
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• pp.1-10
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• 2008

Web-based Assessment System is needed for Process-Oriented Evaluation to integrate instructions into evaluation frequently in Informatics Education, and considered usability for supporting teachers to test more conveniently. First of all, we analyzed usability of traditional Web-based Assessment System, and proposed PBA(Paper-Based Assessment) model by extracting usability features of paper-pencil assessment in off-line. The evaluation system based on the PBA model controls the whole processes of tests; before-test, under-test, after-test. Especially, the system readily can change the target class, and control access to the test page during each step. Thus we can get high credibility about the test results. Moreover, students can login to the paper easily by using their grade, class, number and name. Finally, we designed and implemented the Web-based Assessment System for Informatics education on the basis of PBA model; PAS(PBA-based Assessment System).