• 대한방사선기술학회지:방사선기술과학
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• 제44권6호
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• pp.599-605
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• 2021

The International Electrotechnical Commission (IEC) 62494-1 has defined the exposure index (EI) that have a proportional relationship with the dose incident on the image receptor, and target exposure index (EI_T), deviation index (DI). In this study, an appropriate EI_T for skull radiography was established through the diagnostic reference level (DRL) and changes in DI were confirmed. Entrance surface dose (ESD) and EI were obtained using the computed radiography system displayed the EI as per IEC on console and skull phantom by experiment based on the national average exposure conditions announced in 2012 and 2019. And appropriate EI_T was established by applying the DRL in 2012 and 2019. As a results, the EI_T is changed according to the change in the DRL, and the exposure condition that becomes the ideal DI according to the change in the EI_T also has a difference of about 1.41 times. DRL is recommended to optimize the patient dose, however it is difficult to measure in real time at medical institutions whereas EI and DI are displayed on the console at the same time as exposure. When the EI_T is set based on the DRL and the DI is closed to an ideal value, it is useful as a patient dose management tool. Therefore, when the EI_T is periodically managed along with the revision of the DRLs, the patient dose can be optimized through the EI, EI_T and DI.

• 디지털융복합연구
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• 제20권4호
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• pp.309-319
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• 2022

선행연구에서는 정보통신기술(ICT) 근무환경의 스트레스가 조직 구성원들의 정서에 부정적인 영향을 줌으로써 업무성과를 저하시키는 것에 대한 연구가 진행 되어왔다. 그러나 현재 코로나 팬데믹 시대를 맞아서 조직 구성원들이 스마트 환경하에 재택근무하는 비율이 높아짐에 따라 긍정적 스트레스와 부정적 스트레스가 업무성과에 미치는 영향에 대한 연구의 필요성이 제기되고 있다. 이에 따라 본 연구는 정서적 사건 반응이론을 토대로 직원들이 인지하는 긍정적, 부정적 ICT 스트레스가 긍정적 감정과 부정적 감정으로 구분되는 정서적 영향을 통해 업무성과에 미치는 영향을 분석하였다. 또한 스마트워크가 업무 성과에 미치는 영향도 분석하였다. 본 설문은 리서치 전문회사에 의뢰하여 조사 하였고 Smart PLS 3.0 툴로 분석하였다. 따라서 본 연구결과를 바탕으로 스트레스가 직원들의 정서에 부정적인 영향만을 주는 것이 아니며, 목표를 달성하고자 하는 마음에서 나타나는 도전적 스트레스가 직원들의 정서에 긍정적 감정을 유발시켜 업무성과 향상에 도움이 된다는 시사점을 제시하였다.

• 한국전자통신학회논문지
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• 제17권1호
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• pp.161-166
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• 2022

본 논문에서는 데이터 분석 도구인 R을 이용하여 빅데이터 분석을 수행할 때 발생하는 문제점을 분석하고, 빅데이터의 분산 처리를 효과적으로 지원하는 스파크와 R을 연계한 SparkR을 이용한 분석의 유용성을 제시하고자 한다. 먼저, 대량의 데이터를 로딩하고 연산을 수행할 때 발생하는 R의 메모리 할당 문제점과 R과 비교한 SparkR의 특징 및 프로그래밍 환경을 분석한다. 그리고, 선형 회귀 분석을 각각의 환경에서 수행할 때의 실행 성능을 비교 분석한다. 분석 결과 SparkR을 통해 추가적인 언어 학습 없이도 R을 그대로 이용하여 데이터 분석에 활용할 수 있음을 보였으며, SparkR을 이용하여 R로 작성된 코드를 클러스터 내 노드 수의 증가에 따라 효과적으로 분산 처리할 수 있었다.

• Imaging Science in Dentistry
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• 제52권2호
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• pp.209-217
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• 2022

Purpose: The aim of this study was, firstly, to determine the concordance of ultrasonographic and histopathological diagnoses in patients in whom apical resection was already indicated. Secondly, this study aimed to determine whether lesions were periapical granulomas or cysts, and to compare them after root canal treatment using ultrasonography and periapical radiographs. Materials and Methods: In the first stage of the study, ultrasonographic and histopathologic diagnoses of 10 lesions were compared. Secondly, the periapical radiographs and ultrasonographic images of 44 lesions were measured. The presence of internal vascularity was determined by ultrasonographic color and power Doppler modes. Follow-up examinations of healing after root canal treatment were performed using ultrasonography and periapical radiographs, and these modalities were compared. Results: In the periapical granuloma and cyst groups, the measurement values decreased for all variables. There was no significant difference in the dimensional changes of lesions between the 2 groups, and ultrasonography and periapical radiographs were compatible. The pre-diagnoses were compared with histopathological diagnoses and were found to be compatible. Conclusion: The ultrasonographic color and power Doppler techniques could be an effective method for diagnosing periapical lesions as cysts or granulomas. After root canal treatment of granulomas and cysts, the dimensional shrinkage and healing patterns appear to be similar. Ultrasonography and periapical radiographs were consistent in terms of dimensional comparisons, and ultrasonography may be an alternative method for follow-up of the healing of periapical lesions.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.102-114
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• 2021

Biofouling represents an important problem in the shipping industry since it causes the increase in surface roughness. The most of ships in the current world fleet do not have good coating condition which represents an important problem due to strict rules regarding ship energy efficiency. Therefore, the importance of the control and management of the hull and propeller fouling is highlighted by the International Maritime Organization and the maintenance schedule optimization became valuable energy saving measure. For adequate implementation of this measure, the accurate prediction of the effects of biofouling on the hydrodynamic characteristics is required. Although computational fluid dynamics approach, based on the modified wall function approach, has imposed itself as one of the most promising tools for this prediction, it requires significant computational time. However, during the maintenance schedule optimization, it is important to rapidly predict the effect of biofouling on the ship hydrodynamic performance. In this paper, the effect of biofilm on the ship hydrodynamic performance is studied using the proposed performance prediction method for three merchant ships. The applicability of this method in the assessment of the effect of biofilm on the ship hydrodynamic performance is demonstrated by comparison of the obtained results using the proposed performance prediction method and computational fluid dynamics approach. The comparison has shown that the highest relative deviation is lower than 4.2% for all propulsion characteristics, lower than 1.5% for propeller rotation rate and lower than 5.2% for delivered power. Thus, a practical tool for the estimation of the effect of biofouling with lower fouling severity on the ship hydrodynamic performance is developed.

• 한국BIM학회 논문집
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• 제11권4호
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• pp.31-41
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• 2021

Digital twins between "BIM Digital Model-Physical Prototype Model" will be built for Noise Barrier tunnel(NBT) that meet the definition of N.G smart city facilities derived from previous studies to build a data flow that connects data at each stage of design, construction, and operation. In this process, BIM design automation tools are created and utilized, and consistent transmission of member and attribute data is performed by converting them into IFC format. Through this, the purpose is to improve the labor-intensive environment required from the design stage of the NBT and to consistently maintain the information required for subsequent production and construction. This includes achieving changes in the construction industry based on digital transformation by unifying various data formats used differently for each industry from design to operation. In addition, it demonstrates that information exchange in the maintenance and management stages is possible based on the data exchange of the established digital twin and aims to improve the existing labor-intensive environment and expand operability between digital and physical information. As suggested in previous studies, the implementation of digital twins in these N.G smart city facilities includes the possibility of building an environment that adds to the possibility of high value-added product platforms as well as the function of big data platforms targeting existing smart cities.

• Journal of Ecology and Environment
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• 제45권4호
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• pp.255-263
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• 2021

Background: Ecosystem service mapping is an important tool for decision-making in landscape planning and natural resource management. Today, pollination service mapping is based on the Lonsdorf model (InVEST software) that determines the availability of nesting and floral resources for each land cover and estimates pollination according to the foraging range of the desired species. However, it is argued that the Lonsdorf model has significant limitations in estimating pollination in a landscape that can affect the results of this model. Results: This paper presents a free software, named PollMap, that does not have the limitations of the Lonsdorf model. PollMap estimates the pollination service according to a modified version of the Lonsdorf model and assumes that only cells within the flight range of bees are important in the pollination mapping. This software is produced for estimating and mapping crop pollination in agricultural landscapes. The main assumption of this software is that in the agricultural landscapes, which are dominated by forest and agriculture ecosystems, forest patches serve only as a nesting habitat for wild bees and the surrounding fields provide floral resources. Conclusion: The present study provided new software for mapping crop pollination in agricultural landscapes that does not have the limitations of the Lonsdorf model. We showed that the use of the Lonsdorf model for pollination mapping requires attention to the limitations of this model, and by removing these limitations, we will need new software to obtain a reliable mapping of pollination in agricultural landscapes.

• 대한토목학회논문집
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• 제42권4호
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• pp.559-569
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• 2022

건설 엔지니어링은 과학기술과 지식을 접목하여 고부가가치와 일자리를 창출하는 대표적인 산업이지만 그 중요성이 저평가 되고 있다. 국토교통부의 자료에 의하면 엔지니어링 산업의 부가가치율(65.3 %)과 고용유발계수(14명 고용/10억 원)은 제조업의 3배 이상이다. 특히 시공 이전의 프로젝트 관리·기본설계 등 전방가치사슬은 총사업비의 10~15 % 미만임에도 불구하고 인프라 시설의 전체 가격과 품질을 좌우한다. 본 연구에서는 인프라 엔지니어링 플랫폼을 프로젝트 단위가 아니라 엔터프라이즈 수준의 플랫폼으로 개발하기 위하여 필요한 프레임워크, 도로 설계 업무 분류, 설계 지원 모듈 및 데이터베이스 구축 방향에 대하여 제시하고, 이를 바탕으로 클라우드 기반의 설계 플랫폼의 초기 버전을 개발하였다. 개발된 설계 플랫폼은 시간/공간 제약 없는 웹 기반 설계 업무환경을 제공하고, 해외사업 수주 및 경쟁력 확보에 크게 기여할 수 있을 것으로 기대된다.

• 대한치위생과학회지
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• 제4권2호
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• pp.1-7
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• 2021

Background: To identify the factors that affect the current status and satisfaction of people with disabilities at community oral care centers. Methods: A structured self-administered survey, including five questions on facility environment, five on usage procedure, four on medical skill, four on care cost, three on friendliness, and three on satisfaction, was administered to 218 residents of the G-disabled community care center. It comprised a Likert 5-point scale (strongly agree, 5 points; agree, 4 points; moderate, 3 points; disagree, 2 points; not at all, 1 point). The reliability of the measurement tool was 0.932 for Cronbach's α. Results: The evaluation of community oral care centers for the disabled showed that the environment was hygienic (4.42±0.73), reservation system was well maintained (4.18±0.95), and the dentist-in-charge was satisfied with the treatment (4.37±0.62). The participants agreed that the details were sufficiently explained (4.29±0.71). However, in terms of medical expenses, the score of "have fully heard the explanation of medical expenses and reductions" was 3.88±0.92. The factors affecting satisfaction were sex, final educational background in the facility environment, usage procedure, and medical skill. Conclusion: To increase the satisfaction of people with disabilities at community oral care centers, it is necessary to establish a facility environment and service according to the patients' need and increase the reduction or exemption benefits between different treatment cost categories. Oral health management policies for the disabled should be developed based on these factors, so that the oral care of vulnerable groups in blind spots can be maintained.

• 한국엔터테인먼트산업학회논문지
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• 제14권2호
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• pp.63-71
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• 2020

케이팝의 힘은 대단하다. 변방의 대중문화가 전 세계에 영향을 미치고 있음은 놀라운 일이다. 국내외 미디어들이 케이팝 성장의 비밀을 밝히려고 애쓰는 까닭이다. 하지만 케이팝의 괄목할 성장 이면에 감춰진, 아이돌 그룹(보이그룹, 걸그룹) 내부의 치열한 경쟁과 강제적인 멤버교체는 비판의 대상이 되고 있다. 대표적인 현상 가운데 하나가'졸업제도'이다. 르네 지라르는 욕망의 모방성과 폭력성, 그리고 이를 무마하기 위한 희생양 메커니즘을 주장했다. 본고는 걸그룹 <나인뮤지스>의 데뷔과정에서 벌어진 졸업제도를 기록한 다큐멘터리, 온라인 인터렉티브 사이트, 단행본 등 일련의 결과물을 바탕으로, 졸업제도에 희생양 메커니즘을 적용한 뒤 케이팝에서의 졸업제도를 정의하고자 하였다.