• 한국해양공학회지
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• 제19권6호통권67호
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• pp.78-85
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• 2005

Initial alignment and localization are important topics in inertial navigation systems, since misalignment and initial position error wholly propagate into the navigation systems and deteriorate the performance of the systems. This paper presents the error convergence characteristics of the hybrid navigation system for underwater vehicles initial position, which is based on an inertial measurement unit (IMU) accompanying a range sensor. This paper demonstrates the improvement on the navigational performance oj the hybrid system with the range information, especially focused on the convergence of the estimation of underwater vehicles initial position error. Simulations are performed with experimental data obtained from a rotating ann test with a fish model. The convergence speed and condition of the initial error removal for random initial position errors are examined with Monte Carlo simulation. In addition, numerical simulation is conducted with an AUV model in lawn-mowing survey mode to illustrate the error convergence of the hybrid navigation System for initial position error.

• 디지털융복합연구
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• 제13권5호
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• pp.251-257
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• 2015

침입방지시스템은 네트워크에서 공격 서명을 찾아내어 자동으로 조치를 취하여 비정상적인 트래픽을 중단시키는 보안시스템이다. 수동적인 방어를 하는 침입차단시스템이나 침입탐지시스템과 달리 침입경고 이전에 침입을 중단시키는 개념의 솔루션이다. 침입방지시스템의 보안성 성능은 보안감사, 사용자 데이터 보호, 보안 인증 등에 좌우되며 성능은 탐지시간, 처리량, 공격차단 성능 등에 좌우된다. 본 연구에서는 이러한 침입방지시스템의 보안성 성능평가를 위한 모델을 구축하기 위해 CC(Common Criteria : ISO/IEC 15408)와 소프트웨어 제품평가에 관한 ISO 국제표준을 근간으로 하여 융합 성능평가 모델을 구성하였다.

• 융합보안논문지
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• 제18권5_1호
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• pp.75-81
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• 2018

근래에 산업이 융합됨에 따라, 산업 간 융합 도구 활용이 조직 내 보안성에 미치는 영향이 증가하고 있다. 그러나, 조직구성원들은 기존의 시스템을 중심으로 비즈니스를 활동하기 때문에 새로운 시스템 도임에 대한 적응력이 부족하고, 이에 따라서, 보안에 대한 고려는 후 순위로 나타날 수 밖에 없는 환경이다. 본 연구에서는 의료융합산업에서 중소형 의료기관을 대상으로 보안 체계를 구축하기 위해 우선적으로 고려해야 할 요소들에 대한 비용 효율적인 선택방안에 대하여 연구하였다. 구체적으로 선행연구들을 통하여 현재의 법제도 체계를 고려하고 보안현황을 분석하였을 때, 중소형 의료기관에서 필요한 보안 솔루션/시스템/체계에 대하여 도출하였다. 그리고, 실제 비즈니스 환경에서 중소형 의료기관 관련자들을 대상으로 비용 효율적으로 보안 체계를 구축하기 위한 상대적 우선순위에 대하여 분석하고 전반적인 보안체계를 구축하기 위한 방안을 제시하였다.

• 한국해양공학회지
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• 제33권3호
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• pp.300-311
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• 2019

An ROV trencher is a type of heavy-duty work class ROV equipped with high-pressure water jet tools for cutting into the sea floor and burying cables. This kind of trencher is mostly used for PLIB operations. This paper introduces the development of this kind of ROV trencher, which has a 698 kW power system, with a 250 kW hydraulic system and two 224 kW water jet systems. The project was launched in January 2014. After four years of design, manufacturing, and system integration, we carried out two sea trials near the Yeongilman port (about 20-30 m in depth) in Pohang to evaluate the system performance in November 2017 and August 2018. Through tests, we found that most of specifications were satisfied, including a maximum bury depth of 3 m, maximum bury speed of 2 km/h, and maximum forward speed of 1.54 m/s.

• Journal of information and communication convergence engineering
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• 제18권1호
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• pp.16-21
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• 2020

Owing to the convergence of the communication network with the control system and public network, security threats, such as information leakage and falsification, have become possible through various routes. If we examine closely at the security type of the current control system, the operation of the security system focuses on the threats made from outside to inside, so the study on the detection system of the security threats conducted by insiders is inadequate. Thus, this study, based on "Spotting the Adversary with Windows Event Log Monitoring," published by the National Security Agency, found that event logs can be utilized for the detection and maneuver of threats conducted by insiders, by analyzing the validity of detecting insider threats to the control system with the list of important event logs.

• 대한인간공학회지
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• 제35권4호
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• pp.193-204
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• 2016

Objective: This study carried out base research to build an agricultural safety monitoring system through ICT convergence to reduce safety accidents and enhance welfare in life in the agricultural field. Background: The functions and values of rural villages as the space of living are recognized anew, but occupational accident rate due to farm work accidents is on the rise each year. Therefore, the seriousness of such a problem emerges. The convergence technology combining ICT is recently applied to industries overall, and therefore better services are offered. However, studies on ICT convergence has not yet been applied to the agricultural safety field. Method: This study identified ICT convergence service technology trends and representative serious accident types mainly occurring in agricultural activities. This study defined the major factors of farm work accidents and ICT to solve those accident factors including the sensor technology, wired/wireless communication technology and location information service, and applied them to prototype PCB for the development of an agricultural safety monitoring system. Results: This study proposed an emergency monitoring system for farmers and a harmful environment monitoring system. The ICT technology to prevent farm work accidents can be summarized as sensing technology, ICT and network technology and user interface technology. This study also designed PCB module configuration and situation judgment algorithm as basic research for proposed monitoring system development. Conclusion: The ICT-based agricultural safety monitoring research proposed in this study is expected to become the basis to build a future real time monitoring system, and also is expected to contribute to social safety and welfare service improvement for farmers. Application: The ICT convergence farmer accident prevention system will make contributions to the prevention of serious farm work accidents.

• 한국안전학회지
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• 제36권5호
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• pp.71-78
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• 2021

There are regularly planned overhaul periods in thermal power plants, which involve the maintenance of the boiler of the power plants. However, thermal power plants workers are always exposed to risk during overhaul periods owing to the narrow space and significant dust inside the boiler. Therefore, it is essential to develop a safety monitoring system that is suitable for operating in this type of environment. In this study, we developed not only a worker three-dimensional (3D)-location monitoring system that can monitor and record the entry/exit of workers, their 3D-location, and fall accidents but also a method to secure the working environment and operation efficiency. This system comprises of a worker tag, which was equipped with an inertial measurement unit, a barometric pressure sensor, and a Bluetooth low energy (BLE), and the tags were given to each worker. In addition, the location of workers inside the boiler was measured using a pedestrian dead reckoning (PDR) method and BLE beacons. The location data of the workers tag were transmitted to the integrated database (DB) server through a gateway, and to the administrator monitoring system. The performance of the system was demonstrated inside an actual thermal power plant boiler, and the accuracy and reliability of the system were verified through a number of repeated tests. These results provide insights on designing a new system for monitoring enclosed spaces.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.1231-1234
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• 2017

이 논문은 실내 환경을 개선하기 위한 창문 자동제어 시스템을 제안한다. 현대인들은 하루에 약 70% 이상을 실내에서 생활하고 있다. 이로 인해 실내 환경의 질이 매우 중요한 요소로 부각되면서 사람들의 관심이 크게 증가하고 있다. 이 논문에서는 아두이노, 라즈베리 파이 및 다양한 센서를 이용하여 실내 환경을 적정수준으로 유지하고 개선할 수 있는 창문 자동제어 시스템을 제안한다. 제안 시스템 구현을 위해 온습도 센서, 미세먼지 센서, 공기 질 센서, 모터 등을 이용한다. 또한 3D프린팅을 이용하여 제작한 프로토타입을 보인다.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2646-2651
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• 2021

A rectangular-shaped PET system with an adjustable gantry (AGPET) has been developed for imaging small animals. The AGPET system employs a new depth of interaction (DOI) method using a depth dependent reflector patterns and a new digital time pickoff method based on the pulse reconstruction method. To evaluate the performance of the AGPET, timing resolution, intrinsic spatial resolution and point source images were acquired. The timing resolution and intrinsic spatial resolution were measured using two detector modules and Na-22 gamma source. The PET images were acquired in two field of view (FOV) sizes, 30 mm and 90 mm, to demonstrate the characteristic of the AGPET. As a result of in the experiment results, the timing resolution was 0.9 ns using the pulse reconstruction method based on the bi-exponential model. The intrinsic spatial resolution was an average of 1.7 mm and the spatial resolution of PET images after DOI correction was 2.08 mm and 2.25 mm at the centers of 30 mm and 90 mm FOV, respectively. The results show that the proposed AGPET system provided higher sensitivity and resolution for small animal imaging.

• Journal of Positioning, Navigation, and Timing
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• 제13권1호
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• pp.15-23
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• 2024

One of the core keywords in the fourth industrial revolution is convergence, and the convergence of the production, distribution, and consumption processes of services is particularly important. The convergence of user services is underway in various industrial fields including mobile communications, healthcare, mobility, artificial intelligence, etc. In order to offer these converged services efficiently, it is necessary to provide accurate user-centric location information, which can be obtained by employing the global navigation satellite system (GNSS). In addition, as we have entered the post-COVID era, the demand for various fields such as a healthcare, customized tourism services, and aviation services based on accurate location information is exploding. In this paper, we present the results of a case study on the current research trends of GNSS used in telemedicine services and AI & IoT fields, and also analyze these results.