• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.428-433
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• 1999

전자해도는 각국의 수로국이 자국의 영해에 대해 책임 생산하는 기존 종이해도의 디지틀 형태이며 국제수로기구가 제정한 표준에 의해 제작된 데이터이다. 전자해도는 기본적으로 항해에 사용하도록 제작되었으나 데이터의 정화도와 유용성 때문에 다양한 분야에 사용될 것이 확실하다. 이에 본 논문에서는 항해분야 뿐만 아니라 기타 GIS 분야에 사용될 국내 전자해도에 대해 개발한 ENC Converter를 이용하여 Text 형태로의 변환 및 DB에 저장하고 이를 이용하여 데이터에 대한 고찰을 수행하였다. 데이터의 변환은 여러 가지 GIS 데이터 형식으로의 변환에 대한 요구를 충족시키기 위한 것의 중간 단계로써의 의미를 갖고 있으며 국내 데이터에 대한 각종 분석 및 고찰은 데이터에 대한 여러 가지 정보를 제공할 것이다. 이를 위해 ENC Converter의 기본 알고리즘과 프로그램을 소개하고 변환된 데이터를 이용한 각종 통계 및 간단한 분석을 수행하였다. 이러한 분석 및 고찰은 데이터 제작자에게 더 좋은 질의 데이터를 생산하도록 함과 동시에 사용자로 하여금 자신에게 맞는 형태의 데이터를 추출하여 사용하도록 하기 위한 것이다.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.334-340
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• 2012

This project defines Tiled-SENC format for S-57 ENC data usage of the mobile platforms and low-end terminals which are not included in ECDIS carriage requirements of SOLAS Chapter V. Also, the architecture modeling and converting technology of Tiled-SENC have been developed and the performance has been compared with ENC Format.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.66-71
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• 2018

Purpose: Performance recovered from SCR through cleaning was studied, measuring differential pressure, NOx reduction efficiency, fuel consumption and engine power before and after cleaning. Ideal cleaning intervals are proposed based on SCR mileage and differential pressure. SCR endurance and reliability improvements through cleaning were studied through physicochemical testing of SCR durability at 43,000km 50,000km, and 110,000km respectively. Methods: Engine power, fuel consumption and exhaust gas were measured using engine full load tests and ND-13 MODE by installing the SCR before cleaned at total engine mileages of 400,000 km, 300,000km and 200,000km. The same tests were performed after cleaning the SCR catalytic converter. Endurance and reliability of the SCR cleaning was studied through the same test by SCR catalyst after each 43,000km 50,000km, 110,000km, durability test on SCR cleaning. Conclusion: We confirmed the low-performance of the SCR due to clogging is restored by SCR cleaning technology. The NOx reduction efficiency was restored to 82%, 86% and 88% from 69%, 72% and 79%. As well as the NOx reduction efficiency, it was confirmed that the engine power, fuel consumption and back pressure was restored to fresh SCR levels. As a result of the durability and reliability achieved through SCR cleaning, we confined the appearance and reduction efficiency through visual inspection and ND-13 MODE are similar to new SCR catalysts. Finally, it was judged that there was no change in performance even when driving the SCR without cleaning throughout the 100,000 km mileage warranty.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.81-86
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• 2016

Background: For positron emission tomography (PET) application, cadmium zinc telluride (CZT) has been investigated by several institutes to replace detectors from a conventional system using photomultipliers or Silicon-photomultipliers (SiPMs). The spatial and energy resolution in using CZT can be superior to current scintillator-based state-of-the-art PET detectors. CZT has been under development for several years at the Korea Atomic Energy Research Institute (KAERI) to provide a high performance gamma ray detection, which needs a single crystallinity, a good uniformity, a high stopping power, and a wide band gap. Materials and Methods: Before applying our own grown CZT detectors in the prototype PET system, we investigated preliminary research with a developed discrete type data acquisition (DAQ) system for coincident events at 128 anode pixels and two common cathodes of two CZT detectors from Redlen. Each detector has a $19.4{\times}19.4{\times}6mm^3$ volume size with a 2.2 mm anode pixel pitch. Discrete amplifiers consist of a preamplifier with a gain of $8mV{\cdot}fC^{-1}$ and noise of 55 equivalent noise charge (ENC), a $CR-RC^4$ shaping amplifier with a $5{\mu}s$ peak time, and an analog-to-digital converter (ADC) driver. The DAQ system has 65 mega-sample per second flash ADC, a self and external trigger, and a USB 3.0 interface. Results and Discussion: Characteristics such as the current-to-voltage curve, energy resolution, and electron mobility life-time products for CZT detectors are investigated. In addition, preliminary results of gamma ray imaging using 511 keV of a $^{22}Na$ gamma ray source were obtained. Conclusion: In this study, the DAQ system with a CZT radiation sensor was successfully developed and a PET image was acquired by two sets of the developed DAQ system.