• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4C
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• pp.290-296
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• 2012

In this paper, we propose a practical authentication system based on Wireless Body Area Networks(WBAN) for U-healthcare medical information environments. The proposed authentication system is based on symmetric cryptosystem such as AES and is designed to not only provide security such as data secrecy, data authentication, data integrity, but also prevent replay attack by adopting timestamp technique and perform secure authentication between sensor node, master node, base-station, and medical server.

• Proceedings of the Korea Society for Simulation Conference
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• 1997.04a
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• pp.75-80
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• 1997

본 연구에서는 대용량의 데이터를 고속으로 입출력할 수 있는 데이터 저장 시스템 이 가져야할 요구사항을 분석하고, 그것을 만족하는 시스템을 설계하였다. 본 논문에서는 우선 고속 대용량, 랜덤 억세스의 조건을 만족시키기 위해 여러 대의 하드 디스크를 병렬로 연결하여 입력되는 데이터들을 나누어 저장하도록 하였다. 그러나 하드 디스크의 성능은 디 스크 아암의 탐색동작에 의해 크게 영향을 받으므로 실시간 요구 조건을 만족시키기 위해선 단순히 디스크의 수를 늘이는 것 외에 디스크 아암의 탐색 동작을 효율적으로 제어할 수 있 는 방법이 필요하다. 그래서 본 논문에서 설계된 시스템에서는 시스템을 MCU(Master Control Unit), DDU(Data Distribution Unit), SCU(Slave Control Unit), DSU(Data Storage Unit)의 4부분으로 나누고, 각 디스크의 디스크 아암 탐색 동작을 독립된 SCU에서 제어하 도록 하였다. 설계된 내용이 주어진 요구사항들을 만족하는 것을 확인하기 위해, 본 논문에 서는 이산사건 시스템을 기술하는 수학적인 언어인 DEVS 형식론을 이용하여 제안된 시스 템을 기술하고 시뮬레이션하였다. 그리고 시뮬레이션되는 과정에서 생산되는 사건들의 궤적 을 분석하였다. 분석결과 제안된 시스템은 앞에서 제시한 여러 요구사항들을 잘 수용함을 보았다.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.750-753
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• 2003

In this paper, we have developed the web-based management system for greenhouse teleoperation. The remote control system consists of database, web-server, controller in greenhouse, and clients. The database in the server stores user informations and greenhouse conditions, and is used to manage user login and conditioning data. The management system developed by using Java applet, which is a client program for effective and easy management of greenhouse, monitors the greenhouse in real time. Master and driver boards installed in greenhouse control unit. Database on flowering to collect and analyze data exchanges data with the server. The greenhouse can be managed effectively by timer routine, repeat control within setting time, and algorithm of setting points. Also, the greenhouse conditions can be controlled by manual or remote controller (PC) through web browser in internet. Furthermore, all of the control devices of the greenhouse are managed by remote control using PC and checked via camera installed in greenhouse.

• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.4
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• pp.29-42
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• 2020

SCADA (Supervisory Control and Data Acquisition) systems for remote monitoring, data acquisition and control are applied to major industrial infrastructures including power, water and railroad. Recently, there are many researches on key management scheme for secure communication due to change to the open network environment. These systems are located at far distances and are connected to the main control center through various types of communication methods. Due to the nature of these systems, they are becoming the significant targets of cyber attack. We propose an efficient key management scheme which is established on ID-based cryptosystem without an expensive computation on MTU (Master Terminal Unit), Sub-MTU, and RTU (Remote Terminal Unit). The proposed method is secure and effective in key management among multiple legitimate devices.

• Journal of The Korean Association of Information Education
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• v.21 no.1
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• pp.57-66
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• 2017

Lately, academic interests in big data analysis and social network has been prominently raised. Various academic fields are involved in this social network based research trend, which is, social network has been actively used as the research topic in social science field as well as in natural science field. Accordingly, this paper focuses on the text analysis and the following social network analysis with the Master's and Doctor's dissertations. The result indicates that certain words had a high frequency throughout the entire period and some words had fluctuating frequencies in different period. In detail, the words with a high frequency had a higher betweenness centrality and each period seems to have a distinctive research flow. Therefore, it was found that the subjects of the Master's and Doctor's dissertations were changed sensitively to the development of IT technology and changes in information curriculum of elementary, middle and high school. It is predicted that researches related to smart, mobile, smartphone, SNS, application, storytelling, multicultural, and STEAM, which had an increased frequency in period 4, would be continuously conducted. Moreover, the topics of robots, programming, coding, algorithms, creativity, interaction, and privacy will also be studied steadily.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.368-376
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• 2013

Fishing experiments were carried out in the adjacent sea of Yeongil Bay, the eastern cost of Korea from 2003 to 2004 using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3mm) in order to determine the size selectivity of pots for the whelk, Buccinum opisthoplectum. The catch species were composed of Buccinum opisthoplectum (45.4%), Buccinum striatissimum (30.1%), Pandalopsis japonica (9.3%), Chionoecetes opilio (8.9%), and so on. The shell height (l) of Buccinum opisthoplectum caught in the experimental fishing pots was measured. The SELECT (Share Each Length's Catch Total) analysis method was applied with fishing data to obtain master selection curve. The model with the estimated split parameter was found to fit the catch data best. The master selection curve was estimated to be s (R)〓exp (7.833R-10.871)/[1 + exp (7.833R-10.871], where R is the ratio of shell height to mesh size. The relative shell length for 50% retention was 1.388, and the selection range was 0.281. It means that the pots of larger mesh size allow more whelks of small size to escape.

• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.41-48
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• 2011

In order to detect driver's state in a driver safety system, both overt and covert measures such as driving performance, visual attention, physiological arousal and traffic situation should be collected and interpreted in the driving context. In this paper, we suggest a vehicle monitoring system that provides multimodal information on a broad set of measures simultaneously collected from multiple domains including driver, vehicle and road environment using an elaborate timer equipped as a soft synchronization mechanism. Using a master timer that records key values from various modules with the same master time of short and precise interval, the monitoring system provides more accurate context awareness through synchronized data at any given time. This paper also discusses the data collected from nine young drivers performing a cognitive secondary task through this system while driving.

• The Journal of Advanced Prosthodontics
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• v.7 no.1
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• pp.27-31
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• 2015

PURPOSE. The purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns. MATERIALS AND METHODS. A master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at $37^{\circ}C$ for 24 hours, and then they were thermocycled (TC, $5000{\times}$, $5-55^{\circ}C$) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (${\alpha}$=.05). RESULTS. Fmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01). CONCLUSION. Composite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CADCAM technique offers more advantages than the direct technique.

• Convergence Security Journal
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• v.20 no.2
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• pp.145-153
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• 2020

The aviation safety policy master plan is promoting the development of aviation safety management technology applying the 4th industrial revolution technology with the goal of establishing a flawless aviation safety management system and establishing a future aviation safety infrastructure. The master plan includes the establishment of various aviation safety management systems such as aircraft fault management using AI & Big data and flight training system using VR/AR. Currently, the Air Force is promoting a flight safety management system using new technology under the goal of building smart air force. Therefore, this study intends to apply the 4th Industrial Revolution technology to the aircraft condition check system that finally checks the safety of the aircraft before flight. The Air Force conducts airframe flaw checks and pre-flight aircraft check. In this study, we architect the airframe flaw check system using AI and drones, and the pre-flight aircraft condition check system using the IoT and big data for more precise and detailed check of aircraft condition and flawlessness check.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.151-158
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• 2010

The industrial foundation of the inside and outside of a country has brought significant damages due to attacks from hackers. Especially, if the national primary core infrastructures(like electric power, dam, railroad, atomic energy, etc.) has been significantly damaged, it can be directly linked not only to economic problems but also to people's lives. These national primary core infrastructures usually constitute SCADA system using Modbus RS486 communication. Because of this characteristic, SCADA system has RTU master and slave linked to RJ11 cables to directly pass commands. RJ11 is possible in data spoofing using physical connection because the transmission range of RJ11 has a wide bandwidth(almost 1km). Hence, this paper designed an idle-time measurement system for SCADA system for emerging security improvement in the national primary core infrastructures.