• 제목/요약/키워드: Analysis by modeling objectives

검색결과 103건 처리시간 0.027초

환경유래 식품오염물질의 범부처 통합 저감화 플랫폼 설계 (Design of Integrated Reduction Platform for Food Contaminants Derived from the Environment through Interagency Collaboration in Korea)

  • 고아라;허지영;강영운;강길진;정명섭;이헌주
    • 한국환경보건학회지
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    • 제43권4호
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    • pp.307-313
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    • 2017
  • Objectives: Chemicals derived from various environment media contaminates food across the food supply chain. In Korea, levels of contaminants in food have been sporadically measured by monitoring programs of different government agencies. There is difficulty with data compilation and integrated analysis across media. Therefore, the aim of this study was to propose an overall integrated database and analytical platform design for the 'ECO-FOOD NET (Environmental COntaminant reduction platform for FOOD through an interagency collaboration NETwork)', a tool to support the reduction of environmental contaminants in food. Methods: We developed a new data structure and standardized protocols for the compilation of integrated data. In addition, we conducted subject-oriented logical and physical relational database modeling and created the architecture design of the platform. Results: We established a standardized code system related to exposure media and route, analysis method and food matrix. In addition, we designed the seven software modules of 'About the System', 'Introduction to Interagency Work', 'Media-Chemicals Profiles', 'Method Bank', 'Monitoring Data Base', 'Integrated Media Analysis', and 'Risk-Benefit Analysis'. Conclusions: This study will contribute to decision-making as a tool for executing risk management, such as sustainable reduction policies of contaminants in food.

Moderating effect of self-esteem and depression on the correlation between the frequency of community volunteer activities and job consciousness in dental hygiene students

  • Lorentzen, Marcia H.;Lee, Young-Soo;Jang, Jong-Hwa
    • 한국치위생학회지
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    • 제18권6호
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    • pp.1025-1035
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    • 2018
  • Objectives: This study examined dental hygiene students' frequency of participation in community volunteer activities, job consciousness, depression, and self-esteem, and then identified the correlation among them. We also analyzed the moderating effect of depression and self-esteem on the correlation between participation in community volunteer activities and job consciousness. Methods: We surveyed 312 dental hygiene students attending four universities in South Chungcheong Province, Korea, from May 2 to June 15, 2016, through direct visits. They were given structured questionnaires containing four items on community volunteer activities, three on job consciousness, ten on self-esteem, and 13 on depression. To examine the moderating effect of depression and self-esteem, we performed analysis of variance, correlation analysis, and structural equation modeling analysis (based on the path analysis model and by inserting interaction terms) using SPSS and AMOS. Results: We observed a negative correlation between self-esteem and depression (r=-0.062) but a positive correlation between self-esteem and job consciousness (r=0.125). Depression and job consciousness had a negative correlation (r=-0.176). Depression had a statistically significant impact on job consciousness (r=-0.519, p<0.01). The interaction term between depression and frequency of community volunteer activities also had a statistically significant influence on job consciousness (r=0.090, p<0.05). These findings indicate that depression moderates the correlation between frequency of community volunteer activities and job consciousness at a statistically significant level. Conclusions: More frequent participation in volunteer activities enhances dental hygiene students' self-esteem, reduces depression, and raises job consciousness. The positive impact of volunteering on self-esteem, depression, and job consciousness warrants encouraging students' participation in community volunteer activities, creating supportive structures, and developing various volunteer programs relevant to the students' area of study.

중고 명품 거래 플랫폼의 속성이 지각된 유용성, 유희성 및 지속사용의도에 미치는 영향 (The Effects of the Attributes of Second-Hand Luxury Goods Trading Platforms on Perceived Usefulness, Perceived Enjoyment, and Continuance Intention to Use)

  • 강천시;김미숙
    • 한국의류산업학회지
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    • 제24권6호
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    • pp.731-743
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    • 2022
  • This study examined the effects of platforms' attributes(economy, convenience, ease of use, and security) on perceived usefulness, perceived enjoyment, trust, and the continuance intention to use. Data were collected through a survey conducted with 327 users of second-hand luxury goods trading platforms in their twenties and thirties; 300 were used for statistical analysis using SPSS26.0 for exploratory factor analysis and correlation analysis, and AMOS 26.0 for confirmatory factor analysis and structural equation modeling. For the attributes of second-hand luxury goods trading platforms, four factors were extracted: economy, convenience, ease of use and security. The results showed that only the security of second-hand luxury goods platforms had a positive effect on the perceived usefulness of the platform, but other attributes did not influence perceived usefulness. In contrast, all attributes of the platform showed positive effects on perceived enjoyment. Perceived enjoyment had a strong effect on trust; however, perceived usefulness did not affect trust. The continuance intention to use the platforms was most influenced by perceived usefulness, trust, and perceived enjoyment, in that order. The current findings can help marketers of second-hand luxury goods platforms optimize the platforms' attributes based on the marketing objectives and develop strategies to build perceived usefulness and enjoyment first, and in turn, trust and intention to use.

SysML 기반 모델링 및 시뮬레이션 기법을 통한 기능안전 설계 대안들의 평가 및 결정 방법 (Evaluation and Determination of System Design Alternatives Utilizing a SysML-Based M&S Method for Achieving Functional Safety)

  • 정호전;이재천
    • 한국산학기술학회논문지
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    • 제19권11호
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    • pp.574-582
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    • 2018
  • 철도, 자동차, 항공 등의 시스템에서는 시스템의 고장이 사고로 이어져 심각한 인명피해와 경제적 손실로 직결되는 경우가 많기 때문에 시스템 안전의 확보가 매우 중요하다. 기존 연구들에서는 구성품 수준의 정보를 활용해서 고장 분석 및 안전조치를 도출하고 이를 통해 고장이 발생했을 때 피해를 경감시키기 위한 안전설계가 주로 수행되었다. 그러나 기능안전 개념에 의한 설계는 위험원 식별 및 평가 그리고 안전기능을 생성한 후 안전 설계를 통해 안전 목표를 달성하고자 하는 것이다. 따라서 시스템의 기능수준에서 고장의 현재 빈도를 수용 가능한 목표수준으로 빈도를 낮출 수 있는 안전기능을 결정하고 이를 설계에 반영하기 위한 방법에 대한 연구가 필요하다. 이를 달성하기 위하여 본 연구에서는 먼저 시스템모델링 언어인 SysML을 활용하여 안전기능 들에 대해 고장빈도를 반영하기 위한 고장 모델링 방법을 연구하였다. 그리고 나서 생성된 SysML 고장모델 대안들의 시뮬레이션을 통해 각 안전기능 들이 달성할 수 있는 고장빈도의 감축능력을 평가해서 안전목표를 충족하는 대안을 결정하는 방법을 제시하였다. 사례 연구로서 대표적인 안전중시 시스템인 철도신호시스템에 적용하여 유용성을 확인하였다. 철도신호시스템의 안전기능 형태의 설계 대안들에 대해 안전 목표를 충족하는 지를 M&S를 통해 비교평가 하였다. 본 연구의 결과는 시스템의 개념설계 단계에서부터 적용 가능한 방법으로 안전기능을 수행하기 위한 다양한 설계대안 들 중에서 적절한 것을 선택함으로써 안전 목표를 충족하는 시스템의 안전 설계에 유용하게 활용될 수 있을 것이다.

인공지능 문장 분류 모델 Sentence-BERT 기반 학교 맞춤형 고등학교 통합과학 질문-답변 챗봇 -개발 및 1년간 사용 분석- (A School-tailored High School Integrated Science Q&A Chatbot with Sentence-BERT: Development and One-Year Usage Analysis)

  • 민경모;유준희
    • 한국과학교육학회지
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    • 제44권3호
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    • pp.231-248
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    • 2024
  • 본 연구에서는 오픈소스 소프트웨어와 인공지능 문서 분류 모델인 한국어 Sentence-BERT로 고등학교 1학년 통합과학 질문-답변 챗봇을 제작하고 2023학년도 1년 동안 독립형 서버에서 운영했다. 챗봇은 Sentence-BERT 모델로 학생의 질문과 가장 유사한 질문-답변 쌍 6개를 찾아 캐러셀 형태로 출력한다. 질문-답변 데이터셋은 인터넷에 공개된 자료를 수집하여 초기 버전을 구축하였고, 챗봇을 1년 동안 운영하면서 학생의 의견과 사용성을 고려하여 자료를 정제하고 새로운 질문-답변 쌍을 추가했다. 2023학년도 말에는 총 30,819개의 데이터셋을 챗봇에 통합하였다. 학생은 챗봇을 1년 동안 총 3,457건 이용했다. 챗봇 사용 기록을 빈도분석 및 시계열 분석한 결과 학생은 수업 중 교사가 챗봇 사용을 유도할 때 챗봇을 이용했고 평소에는 방과 후에 자습하면서 챗봇을 활용했다. 학생은 챗봇에 한 번 접속하여 평균적으로 2.1~2.2회 정도 질문했고, 주로 사용한 기기는 휴대폰이었다. 학생이 챗봇에 입력한 용어를 추출하고자 한국어 형태소 분석기로 명사와 용언을 추출하여 텍스트 마이닝을 진행한 결과 학생은 과학 질문 외에도 시험 범위 등의 학교생활과 관련된 용어를 자주 입력했다. 학생이 챗봇에 자주 물어본 주제를 추출하고자 Sentence-BERT 기반의 BERTopic으로 학생의 질문을 두 차례 범주화하여 토픽 모델링을 진행했다. 전체 질문 중 88%가 35가지 주제로 수렴되었고, 학생이 챗봇에 주로 물어보는 주제를 추출할 수 있었다. 학년말에 학생을 대상으로 한 설문에서 챗봇이 캐러셀 형태로 결과를 출력하는 형태가 학습에 효과적이었고, 통합과학 학습과 학습 목적 이외의 궁금증이나 학교생활과 관련된 물음에 답해주는 역할을 수행했음을 확인할 수 있었다. 본 연구는 공교육 현장에서 학생이 실제로 활용하기에 적합한 챗봇을 개발하여 학생이 장기간에 걸쳐 챗봇을 사용하는 과정에서 얻은 데이터를 분석함으로써 학생의 요구를 충족할 수 있는 챗봇의 교육적 활용 가능성을 확인했다는 점에 의의가 있다.

비료제조공장 인근 지역의 담배특이니트로사민 환경 노출 (Environmental Exposure to Tobacco-specific Nitrosamines in an Area Near a Fertilizer Plant)

  • 하재나;윤미라;장준영;고도현;신호상;김수향;이철우;이보은;김정수
    • 한국환경보건학회지
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    • 제46권4호
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    • pp.398-409
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    • 2020
  • Objectives: This study aimed to evaluate environmental exposure to tobacco-specific nitrosamines (TSNAs) by conducting an analysis of the concentration of TSNAs in deposited dust collected from a fertilizer plant and the surrounding village, a simulation of high-temperature drying of tobacco waste, and CALPUFF modeling. Methods: The raw materials of the products, deposited dust (inside and outside the plant and residential area), soil, and wastewater were sampled and the TSNA concentrations were analyzed by LC-MS/MS. As the plant was closed down before the investigation, simulation tests were conducted to confirm the substances discharged during high-temperature (300℃) drying of tobacco waste. CALPUFF modeling was performed to identify the area of influence due to exposure to TSNAs. Results: TSNAs were detected in organic fertilizers estimated to contain tobacco waste, deposited dust, and soil collected from inside and outside the plant. N'-nitrosonornicotine (NNN), 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), and N'-nitrosoanatabine (NAT) components were detected in five of 15 deposited dust samples collected from the residential area around the plant, while TSNAs were not detected in the five sampling points in the control area. Also, the simulation test for the high temperature drying of tobacco waste found emissions of TSNAs. The CALPUFF modeling results showed that the survey area was likely to be included in the area of influence of TSNA emissions from the plant. Conclusions: It is estimated that harmful tobacco ingredients such as TSNAs were dispersed in nearby areas due to the illegal use of tobacco waste as a raw material to produce organic fertilizers at the plant. These findings assume that the residents have been exposed to TSNAs and suggest that the need for the establishment of measures to manage environmental health.

종합병원에 근무하는 간호인력의 감성리더십과 조직성과 간의 관계 (The relationship between emotional intelligence in leadership and organizational performance of nurses in general hospitals)

  • 이보혜;최만규;문상식;정민수;김진희
    • 보건행정학회지
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    • 제21권2호
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    • pp.309-328
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    • 2011
  • In order to effectively attain the objectives of an organization, it is important for the leader to provide an environment where members can co-exist and mutually advance, and also to have an emotional impact on them. This study examines the structural relationship among emotional intelligence in leadership, organizational commitment, job satisfaction, turnover intention, and organizational performance effects of emotional leadership in the nursing profession of a general hospital. A structured questionnaire was sent to 550 nurses in 11 general hospitals in Seoul Metropolitan City, among which 350 responses were used in the analysis. The independent variable, emotional intelligence in leadership, was measured by 18 items, including self-awareness, self-regulation, social awareness and relationship management. The dependent variable, organizational effectiveness, consisted of 46 items, including 15 items regarding organizational commitment, 20 items on job satisfaction, 3 items on turnover intention and 8 items on organizational performance. The structural equation modeling technique was used to identify the impact of emotional intelligence in leadership on organizational effectiveness. The results of the analysis show that the emotional intelligence in leadership of superior nurses has a significant impact on the nurses'organizational commitment and job satisfaction. While the direct effect on turnover intention and organizational performance was not significantly high, organizational commitment and job satisfaction were parameters in low turnover intention and high job performance. In conclusion, emotional intelligence in leadership is critical as nursing services in hospitals are based on interpersonal relationships. Therefore, by developing appropriate programs and training, hospitals can anticipate improved self-awareness, self-regulation, social awareness and relationship management of nurses, and further improve the effectiveness of the nursing profession.

한약재의 연도·산지·업체별 가격변동 분석 연구 (Analysis of price variance of raw herbal medicines in Korea)

  • 김동수;임병묵;현은혜;이은경
    • 대한예방한의학회지
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    • 제23권2호
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    • pp.43-51
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    • 2019
  • Objectives : This study aimed to analyze price variance by year, region and company of raw herbal medicines to draw payment system for herbal medicine insurances in the National Health Insurance. Methods : To analyse price variance, we used 2015-2017 data of 'Quality test results of imported herbal medicines' provided by Korea Pharmaceutical Traders Association and 'Price data of 56 raw herbal medicines' that was surveyed by the Association of Korean Medicine. We analysed gap of highest price and lowest price those were compared with average price and coefficient of variation(CV) of prices by year, region and company of raw herbal medicines. Results : In analysing 3 years data, the highest price was 23.2% higher, and the lowest price was 19.1% lower than the average price. As of 2018, the average price of domestic produced herbal medicines was 1,8 times higher than that of imported herbal medicines. By companies, the highest price was 117.5% higher, and the lowest price was 57.3% lower than the average price. Conclusions : The price of herbal medicines varied by production year, region and company. This results suggest that comprehensive payment model needs to be considered in modeling the health insurance coverage for herbal medicine decoctions.

Performance-based wind design of tall buildings: concepts, frameworks, and opportunities

  • Bezabeh, Matiyas A.;Bitsuamlak, Girma T.;Tesfamariam, Solomon
    • Wind and Structures
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    • 제31권2호
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    • pp.103-142
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    • 2020
  • One of the next frontiers in structural wind engineering is the design of tall buildings using performance-based approaches. Currently, tall buildings are being designed using provisions in the building codes and standards to meet an acceptable level of public safety and serviceability. However, recent studies in wind and earthquake engineering have highlighted the conceptual and practical limitations of the code-oriented design methods. Performance-based wind design (PBWD) is the logical extension of the current wind design approaches to overcome these limitations. Towards the development of PBWD, in this paper, we systematically review the advances made in this field, highlight the research gaps, and provide a basis for future research. Initially, the anatomy of the Wind Loading Chain is presented, in which emphasis was given to the early works of Alan G. Davenport. Next, the current state of practice to design tall buildings for wind load is presented, and its limitations are highlighted. Following this, we critically review the state of development of PBWD. Our review on PBWD covers the existing design frameworks and studies conducted on the nonlinear response of structures under wind loads. Thereafter, to provide a basis for future research, the nonlinear response of simple yielding systems under long-duration turbulent wind loads is studied in two phases. The first phase investigates the issue of damage accumulation in conventional structural systems characterized by elastic-plastic, bilinear, pinching, degrading, and deteriorating hysteretic models. The second phase introduces methods to develop new performance objectives for PBWD based on joint peak and residual deformation demands. In this context, the utility of multi-variate demand modeling using copulas and kernel density estimation techniques is presented. This paper also presents joined fragility curves based on the results of incremental dynamic analysis. Subsequently, the efficiency of tuned mass dampers and self-centering systems in controlling the accumulation of damage in wind-excited structural systems are investigated. The role and the need for explicit modeling of uncertainties in PBWD are also discussed with a case study example. Lastly, two unified PBWD frameworks are proposed by adapting and revisiting the Wind Loading Chain. This paper concludes with a summary and a proposal for future research.

GIS를 이용한 홍수위험지도 관리시스템 프로토타입 개발에 관한 연구 (Development of a Prototype for GIS-based Flood Risk Map Management System)

  • 김계현;윤천주;이상일
    • 한국수자원학회논문집
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    • 제35권4호
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    • pp.359-366
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    • 2002
  • 국토개발에 따른 자연 재해가 많아지고 있으며, 특히 홍수에 의한 피해가 나날이 증대되고 있는 실정이다. 따라서 국민의 안전과 복리를 증진하고 홍수에 의한 피해를 최소화할 수 있는 방안의 대책이 시급하다. 선진국에서는 홍수관리 및 효율적인 재난관리를 위하여 홍수위험지도를 제작 배포하여 홍수에 대한 지역 주민의 경각심을 고취하고, 홍수재난 관리 등에 널리 활용하고 있는 실정이다. 본 연구의 목적은 수문 모형과 입력 데이터의 연계를 바탕으로 홍수침수범위의 예측과 함께 결과물의 도식를 위한 홍수위험지도 관리시스템 프로토타입의 개발에 있다. 효율적인 시스템 개발을 위하여 사용자 요구분석을 통하여 종이지도형태의 홍수위험지도 및 관리시스템을 설계하였다. 본 연구와 병행으로 진행된 하천정보표준화 연구치 결과를 바탕으로 GIS 데이터베이스를 설계하였으며, 연구 대상 지역의 GIS 데이터베이스구축을 통하여 수리 수문 모델링을 위한 효율적인 지형정보의 구축방안을 제시하였다. 개발된 홍수위험지도 관리시스템은 하천정보 검색 모듈, 수리 수문 모델링 지원 모듈, 홍수위험지도 출력 모듈로 구성되었다. 각 모듈은 GIS 데이터베이스를 이용하여 도형 및 속성의 검색, 수리 수문 모델링의 분석 및 결과의 도식화 등을 지원할 수 있도록 개발되었다.