• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.741-748
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• 2021

In this study, we evaluated image quality by changing collimator length and detector thickness using the Geant4 Application for Tomographic Emission (GATE) simulation tool. The gamma camera based on the Cadimium Zinc Telluride (CZT) and NaI detectors is modeled. In addition the images were acquired by setting 1, 2, 3, 4, 5, and 6 cm collimator length and 1, 3, 5, and 7 mm detector thickness using point source and phantom, which is designed by each diameter (4.45, 3.80, 3.15, 2.55 mm) with 447, 382, 317, and 256 Bq. The sensitivity (cps/MBq) for point source, and signal to noise ratio (SNR) and profile for phantom at the 4.45 mm by drwan the region of interests were used for quantitative analysis. Based on the results, the sensitivity according to collimator length is 2.3 ~ 48.6 cps/MBq for CZT detector, and 1.8 ~ 43.9 cps/MBq for NaI detector. The SNR using phantom is 3.6~9.8 for CZT detector, and 2.9~9.5 for NaI detector. As the collimator length is increased, the image resolution is also improved according to profile results based on the CZT and NaI detector. In addition, the senistivity for detector thickness is 0.04 ~ 0.12 cps/MBq for CZT detector, and 0.03 ~ 0.11 cps/MBq. The SNR using phnatom is 7.3~9.8 count for CZT detector, and 5.9~9.5 for NaI detector. As the detector thickness is increased, the image resolution is decreased according to profile results based on the CZT and NaI detector due to scatter ray. In conclusion, we need to set the geometric material such as detector and collimator to acuquire suitable image quality in nuclear medicine.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.352-352
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• 2021

가뭄은 강수량의 부족으로 인한 기상학적 가뭄과 지표수 및 지하수의 부족으로 인한 수문학적 가뭄, 토양의 건조 상태로 인한 농업적 가뭄, 용수 및 전력공급의 제한으로 인한 사회·경제적 가뭄으로 분류될 수 있으며, 일반적으로는 어느 지역의 인간생활 및 사회 경제 활동이나 동식물 생육에 피해를 가져올 정도로 강수량 부족이 장기화되는 비정상적인 현상으로 정의할 수 있다. 메가가뭄의 선제적인 대비를 위한 메가가뭄의 사전감지를 위해 본 연구에서는 매년 가뭄 발생 및 확산 여부 판단을 통해 메가가뭄 예방/대비 목적의 년 단위 가뭄 전주기 분석을 위한 메가가뭄상태 판단 절차 방법론을 제시하였다. 메가가뭄 상태 판단 절차 방법론은 메가가뭄 확산 유무에 따라 6단계의 절차로 진행된다. 1단계로 전년도의 가뭄상태(Carry over의 유무)와 가뭄피해 실적자료(통합가뭄위험도 활용 )를 분석하여 확산여부를 판단하며, 2단계로 당해연도에 가뭄이 발생할 것인지를 장기예보와 더불어 MODIS 위성자료를 이용한 평년대비 토양건조상태로 감지한다. 3단계로 1개월 및 10일 예보자료를 이용해 기상학적 가뭄의 발생 여부를 가뭄지수로 판단하고, 4단계로 기상학적 가뭄 하에서 농업 및 수문학적 가뭄의 진행여부를 저수율, 지하수위, 현장대응 정보의 신속한 수집을 통해 확산여부를 판단한다. 5단계는 가뭄 관련 인터넷 뉴스데이터기반의 농작물 피해, 식수제한, 녹조발생 등의 피해상황을 통해 가뭄 피해발생지역을 도출하여 확산여부를 판단하며, 6단계는 기상, 농업, 수문, 사회 경제적 가뭄을 평가함과 더불어 다음년도 가뭄확산에 대비하는 순으로 메가가뭄 상태 판단 절차 방법론이 진행된다.

• Journal of Information Management
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• v.38 no.2
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• pp.153-173
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• 2007

[ $OntoFrame^{(R)}$ ] system provides information dissemination service and inference service, based on Semantic Web framework to fully support R&D activities. Although it is one of state-of-the-art systems in the viewpoint of functionality, we are not able to declare whether it has satisfiable usability because of the omission of usability test in development process. Thus, this research tries to reveal the usability level of the $OntoFrame^{(R)}$, and further to find ways to achieve a user-center system. Both 'theory-based assessment' by a software ergonomics expert and 'user test' by four users are used for evaluating the usability of the $OntoFrame^{(R)}$. We look forward this research to being a basic reference for practical systems aiming at satisfiable usability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.115-120
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• 1997

Environmental Product Life Cycle Management is an activity for defining and describing the product, process or activity environmentally. Especially, the main responsibility for the environmental impact of products lies in the design phase of product. Designers cany a heavy responsibility to determine technical, economic and ecological properties of the product. So in order to help designers, structured understanding and application of treating large amount of data and infonnation should be considered. This paper presents a methodological approach for decision supporting to build Product Life Cycle Management system and show a set of database modeling. Additionally, a key issue for databases is the quality of the provided information.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.795-802
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• 2022

Korea is showing its appearance as a leading country in the hydrogen economy by establishing policies for revitalizing the hydrogen economy and enacting the 「Hydrogen Economy Promotion and Hydrogen Safety Management Act」 for the first time in the world. In addition, domestic hydrogen facilities are using hydrogen energy safely through world-class safety management compared to overseas advanced countries. However, in order to enhance the safety of the rapidly diversifying hydrogen industry and rapid technology development, such as the introduction of liquefied hydrogen, some institutional improvements are needed. In this regard, this paper intends to analyze the results of safety inspections on 13 representative facilities and prepare safety improvement plans to establish preemptive safety measures.

• The Journal of Korean Academy of Sensory Integration
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• v.20 no.1
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• pp.1-13
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• 2022

Objective : The purpose of this study was to investigate the effects of group Cognitive Orientation to daily Occupational Performance (CO-OP) on the occupational performance and social interaction skills of children with Cerebral Palsy (CP). Methods : A single-case experimental study with an ABA design was conducted from April to June 2021, targeting three children with cerebral palsy who met the study selection criteria. The baseline period consisted of 3 intervention sessions until the data were stabilized, and the intervention period consisted of 10 sessions (once a week, 60 minutes/session). For comparison before and after the intervention, motor development, visual perception, and daily life behavior were evaluated. To evaluate the quality of each session, a performance quality evaluation scale was used. Results : In all 3 subjects, the quality of work performance in the three common goal activities improved. The evaluation scores for visual perception, large and small movements, and daily activities were also improved. Conclusion : This study provided evidence that group CO-OP can improve the pre-academic skills and occupational performance of children with CP.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06b
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• pp.411-413
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• 2012

R&D 기획은 연구 개발 전주기에 있어 수행, 평가에 앞서 필수적으로 선행되어야 하는 행위이다. 그렇지만, 아직까지 R&D 기획에서 무엇을 다루어야 하는지에 대한 원칙, 사례만 존재하고 이를 통합 시스템화하지 못하고 있어, 대부분의 연구자들은 논문, 특허, 웹을 포함한 다양한 자원들로부터 정보를 수집, 취합, 분석하는 데 많은 시간을 뺏기고 있는 형편이다. 이 문제를 해결하기 위해서 본 연구 이전에 시맨틱 기술과 텍스트 마이닝 기술을 이용하여 R&D 전략 수립을 지원하고자 InSciTe, InSciTe Advanced 등이 개발되었지만, R&D 기획이라는 궁극적 목적 내에서도 사용자마다 다양한 시나리오들을 분별하여 지원하기에는 어려움이 많았다. 이에 본 연구는 사용자 적응적 가이드 방식을 통합적으로 적용하여 실시간으로 변화하는 사용자 관심을 파악하고, 대표적 시나리오들에 맞추어 사용자가 목적을 효과적으로 달성할 수 있도록 지원하는 데 초점을 맞추고자 한다. 먼저 사용자 적응적 가이드 방식의 R&D 기획 시스템 구축을 위해 필요한 요구 사항들과 이들을 효과적으로 시스템에 반영하기 위한 온톨로지, 웹 서비스 중심의 설계 원칙들을 제시함으로써 R&D 기획뿐만 아니라 타 분야에서도 유연하게 적용할 수 있는 기반을 제공한다.

• Clean Technology
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• v.26 no.3
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• pp.228-236
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• 2020

Korea has an economy based on manufacturing industrial fields, which produce high amounts of hazardous wastes, in spite of few landfill candidates, and a significant concern for fine airborne particulates; therefore, traditional waste management is difficult to apply in this country. Moreover, waste collection and accumulation have recently been intensified by the waste import prohibitions or regulations in developing nations, the universalization of delivery services in Korea, and the global COVID-19 crisis. This study thus presents a domestic waste management strategy that aims to address the recent issues on waste. The contents of the strategy as the main results of the study include the (1) improvement of the compatibility of the classification codes between the domestic hazardous waste and the international ones such as those of the Basel Convention; (2) consideration of the mixed hazard indices to represent toxicity from low-content components such as rare earth metals often contained in electrical and electronic equipment waste; (3) management application based on risks throughout the life cycles of waste; (4) establishment of detailed material flow information of waste by integrating the Albaro system, Pollutant Release and Transfer Register (PRTR) system, and online trade databases; (5) real-time monitoring and prediction of the waste movement or discharge using positional sensors and geographic information systems, among others; and (6) selection and implementation of optimal treatment or recycling practices through Life Cycle Assessment (LCA) and clean technologies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.12-28
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• 2017

The core of the transportation service, so-called Mobility 4.0 is the flexibility of the entire mobility and its implementation. By doing so, the most essential element is to build a platform to link a supply and a demand simultaneously. In other word, a comprehensive analytical framework is to be set with a data repository which can be periodically updated. With such circumstances, the entire trip chain including pedestrian movements is required to be thoroughly investigated and constructed at the viewpoint of the intermodal transit station. A few studies, however, have been attempted. In this study, the comprehensive analytical framework with the integrated mobility at intermodal transit station was proposed, which consisted of the three modules; 1) Data Repository Extracting from Smart Card DB, 2) Framework of Analyzing Integrated Mobility, and 3) Interpretation of the Integrated Mobility with GIS information and the other factors. A case study with the seven railway stations (Sadang, Sindorom, Samseong, Gwanghwanoon, Gangnam, Jamsil, Seoul Nat'l Univ. of Education) was conducted. The stations of the case study were clustered by the three groups with the statistical ground, and it is most likely to understand the effect of a variety of factors and a comprehensive data-driven analyses with the entire trip stages.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.477-490
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• 2015

In this study, we investigated the restoration possibility of the old streams by enhancing the rainwater infiltration in the watershed of Deokjin Park, Jeonju City. This study was performed by modeling groundwater discharge to the streams under various conditions. We assessed the amount and location of groundwater recharge enhancement to restore the streams and evaluated whether the baseflows of the restored streams are sufficient to keep the water ecosystem of the Deokjin Pond. The results show that the baseflow of the streams can persist for a longer time even during the dry season when the rainwater drainage system is recovered similarly to the those before development using low impact development (LID) techniques. The enhancements of recharge in the headwater area, which is the area around the zoo and Daeji Village in the Deokjin Park watershed, is useful to increase the baseflows of the downstream reaches. Furthermore, spreaded recharge over a widespread area is better to prevent the streams from drying than the intensive recharge at a few sites.