• 제목/요약/키워드: fundamental principles

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선형 가변 차동 변압기를 이용한 강유전 세라믹의 전기장 인가에 따른 변형 측정 (Electric-Field-Induced Strain Measurement of Ferroelectric Ceramics Using a Linear Variable Differential Transducer )

  • 한형수;안창원
    • 한국전기전자재료학회논문지
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    • 제37권2호
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    • pp.141-147
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    • 2024
  • 강유전체, 압전체 및 전왜 재료의 전기-기계적 반응의 기본 원리를 이해하기 위해 전기장 인가에 따른 변형 측정법은 널리 사용되고 있다. 특히, 전기 자극에 반응하는 압전 재료의 변형 특성을 이해하는 것은 압전 액츄에이터, 음향 장치, 초음파 발생기와 같은 부품을 연구하고 개발하는 데 중요하다. 이 튜토리얼 논문에서는 다양한 산업 분야에서 널리 사용되는 변위 측정 장치인 선형 가변 차동 변환기(linear variable differential transducer, LVDT)의 구성 요소와 작동 원리를 소개한다. 또한 전기장을 인가하여 강유전체, 압전체 또는 전왜 재료의 변형 특성을 측정하기 위해 LVDT를 사용하는 실험 장치의 구성을 소개한다. 그리고 이 논문에는 LVDT 실험 장치를 통해 얻은 간단한 측정 결과와 분석이 포함되어 있어서 다양한 재료의 전기-기계 상호 작용 연구 방법에 대해 유용한 정보를 제공한다.

Key Principles of Clinical Validation, Device Approval, and Insurance Coverage Decisions of Artificial Intelligence

  • Seong Ho Park;Jaesoon Choi;Jeong-Sik Byeon
    • Korean Journal of Radiology
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    • 제22권3호
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    • pp.442-453
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    • 2021
  • Artificial intelligence (AI) will likely affect various fields of medicine. This article aims to explain the fundamental principles of clinical validation, device approval, and insurance coverage decisions of AI algorithms for medical diagnosis and prediction. Discrimination accuracy of AI algorithms is often evaluated with the Dice similarity coefficient, sensitivity, specificity, and traditional or free-response receiver operating characteristic curves. Calibration accuracy should also be assessed, especially for algorithms that provide probabilities to users. As current AI algorithms have limited generalizability to real-world practice, clinical validation of AI should put it to proper external testing and assisting roles. External testing could adopt diagnostic case-control or diagnostic cohort designs. A diagnostic case-control study evaluates the technical validity/accuracy of AI while the latter tests the clinical validity/accuracy of AI in samples representing target patients in real-world clinical scenarios. Ultimate clinical validation of AI requires evaluations of its impact on patient outcomes, referred to as clinical utility, and for which randomized clinical trials are ideal. Device approval of AI is typically granted with proof of technical validity/accuracy and thus does not intend to directly indicate if AI is beneficial for patient care or if it improves patient outcomes. Neither can it categorically address the issue of limited generalizability of AI. After achieving device approval, it is up to medical professionals to determine if the approved AI algorithms are beneficial for real-world patient care. Insurance coverage decisions generally require a demonstration of clinical utility that the use of AI has improved patient outcomes.

지역사회 치매환자 사정도구 개발을 위한 일 고찰 (A Study on the Assessment of Dementia Patients in Community)

  • 오진주
    • 한국보건간호학회지
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    • 제11권2호
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    • pp.141-151
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    • 1997
  • As concerns about dementia patients increase gradually in society, the nursing of them becomes more and more important. For intervening in dementia patients effectively, the most fundamental thing is to understand their characteristics and to increase the ability of assessing them. The assessment data supply us with the foundations of Nursing diagnosis and nursing plan. The reaseons why the assessment data are especially important to dementia patients are as follows; First, dementia patients have great differences among them in intellectual, physical ability. And their condition varies from time to time. Second, the intervention without planning results in the deficiency of consistence, and it rather embarrasses and makes dementia patients uneasy. Third, nursing of dementia patients requires participation of multi-disciplinary team because of characteristics of that disease. The development of an unitary assessment tool is essential for all members of the team to have close relations between them and care for dementia patients. Fully understanding the importance of assessment data, this study investigate the content to be included in the assessment before developing assessment tools to be used in community. It points out that the assessment should include the informations about patients, their family, and main care-giver. And it sets up items that can supply with detailed information on each person. In the future it is necessary to transform the contents of this study to more concrete items and develope the assessment tools for dementia patients. And recording paper for follow up should be supplemented to check any changes in family caring for dementia patients and describe the changes in detail. To make assessment tools is one of the fundamental works in controlling dementia patients. Therefore the official assessment tools should be provided as soon as possible. This study aimed at presenting the guiding principles for developing that assessment tools.

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Genomic and Proteomic Databases: Foundations, Current Status and Future Applications

  • Navathe, Shamkant B.;Patil, Upen;Guan, Wei
    • Journal of Computing Science and Engineering
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    • 제1권1호
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    • pp.1-30
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    • 2007
  • In this paper we have provided an extensive survey of the databases and other resources related to the current research in bioinformatics and the issues that confront the database researcher in helping the biologists. Initially we give an overview of the concepts and principles that are fundamental in understanding the basis of the data that has been captured in these databases. We briefly trace the evolution of biological advances and point out the importance of capturing data about genes, the fundamental building blocks that encode the characteristics of life and proteins that are the essential ingredients for sustaining life. The study of genes and proteins is becoming extremely important and is being known as genomics and proteomics, respectively. Whereas there are numerous databases related to various subfields of biology, we have maintained a focus on genomic and proteomic databases which are the crucial stepping stones for other fields and are expected to play an important role in the future applications of biology and medicine. A detailed listing of these databases with information about their sizes, formats and current status is presented. Related databases like molecular pathways and interconnection network databases are mentioned, but their full coverage would be beyond the scope of a single paper. We comment on the peculiar nature of the data in biology that presents special problems in organizing and accessing these databases. We also discuss the capabilities needed for database development and information management in the bioinformatics arena with particular attention to ontology development. Two research case studies based on our own research are summarized dealing with the development of a new genome database called Mitomap and the creation of a framework for discovery of relationships among genes from the biomedical literature. The paper concludes with an overview of the applications that will be driven from these databases in medicine and healthcare. A glossary of important terms is provided at the end of the paper.

텐서그러티 모듈의 변형 및 응용에 관한 연구 (A Study on Reformability and Application of Tensegrity Modules)

  • 최선영;박선우;박찬수
    • 한국공간구조학회논문집
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    • 제5권2호
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    • pp.73-79
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    • 2005
  • 텐서그러티는 연속인장-불연속압축 구성요소에 기반한 상대적으로 새로운 구조시스템이다. 좀 더 상세한 구조적 고찰이 필요하지만, 연구목적에 접근하기 위해서는 최소한 텐서그러티의 구조원리와 근본적인 역학관계를 파악하는 것이 필수적이다. 일단 이점을 확인하고 난 후에, 이러한 구조물의 특성뿐만 아니라 건축에서의 적용성을 다룬다. 그리고 이런 시스템을 규정하는 정의에 이견이 없지는 않으나, 경량구조물로써 텐서그러티의 가능성을 설명하기 위하여 구조디자인연구소(iESD)에서 제작한 텐서그러티 모듈(기본형)의 몇 가지 예를 제시한다. 따라서, 본 연구에서는 기본 정의(규정)뿐 아니라 기본 모듈의 유형을 소개하고, 건축에서 텐서그러티 모듈의 변형성과 응용성을 탐색한다.

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기계공학에서의 PBL적용 교과과정 개발: 제품해체 설계추론 (Development of a New Design Course to Apply Problem Based Learning in Mechanical Engineering: Product Dissection and Design Reasoning)

  • 황성호;권오채;김용세
    • 공학교육연구
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    • 제8권1호
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    • pp.20-30
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    • 2005
  • 최근 들어 '학습자 중심의 자기주도 학습' 이라는 새로운 교육패러다임에 대한 관심이 집중되면서, 문제중심학습(Problem-Based Learning; PBL)이 학생의 과학적 사고능력 및 지식의 확장, 적용력, 비판적 지식창출 능력, 창의적 문제해결 능력을 향상시킬 수 있는 방법으로 주목받고 있다. 기계공학 분야에서도 이러한 PBL교육기법을 적용한 교과과정 개발에 대한 노력들이 활발히 전개되고 있으며, 본 논문에서 제시하는 '제품해체 설계추론'교과목도 그러한 교육방법을 적용한 한 예시라 할 수 있다. 제품해체 설계추론은 제품개발에 있어서 그 기여도가 가장 높은 기초물리학이 실제 제품에 어떻게 응용되고 있는가를 학생들이 직접 참여하여 체험할 수 있게 하는 제품해체 학습법 (product dissection)을 도입하여, 설계추론(design reasoning)에 있어서 기초물리학의 중요성을 인식시키는 한편, 다양한 기초과학에 대한 흥미를 유발할 수 있는 실습위주의 교과목이라 할 수 있다. 이러한 교과목을 통하여 창의적 설계 인력 양성에 큰 역할을 할 수 있을 것으로 기대한다.

ISO 9001:2015 인증을 위한 리스크 기반 사고의 개념과 리스크 관리 (A Fundamental Concept of Risk-Based Thinking and Risk Management for ISO 9001:2015 Certification)

  • 김호균;강병환;박동준
    • 산업경영시스템학회지
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    • 제40권3호
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    • pp.38-48
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    • 2017
  • ISO 9001 Quality Management Systems-Requirements has been revised in 2015. It has been updated four times since its publication in 1987. It is the most widely used International Standard in the world. There are over one million companies and organizations in over 170 countries certified to ISO 9001 from an ISO survey. Organizations are supposed to be certified to this new version by late 2018. The key changes in ISO 9001:2015 are to establish a High Level Structure (HLS) and focus on Risk-Based Thinking (RBT). Risk-Based Thinking means the process approach to decide how risk is addressed in establishing the processes to improve process outputs and prevent undesirable results. It pursues process planning and controls based on risks so that organizations can improve the effectiveness of the quality management system. It maintains and manages a Quality Management System that inherently addresses risks and meets objectives. In this article we firstly attempt to explain how to understand the fundamental concept of Risk-Based Thinking which is a systematic approach to consider risks rather than treating prevention as a separate component of a Quality Management System. We comment on the detailed requirements that contain risks in ISO 9001:2015 clauses. We also summarize recent advances on the risk assessment and management in line with ISO 31000:2009 Risk Management-Principles and Guidelines. We finally propose the practical risk management procedures for implementing ISO 9001:2015 with an emphasis on RBT. This article would contribute to help quality managers and practitioners convert to ISO 9001:2015.

선체고유횡진동해석(船體固有橫振動解析)에 있어서의 계산정도(計算精度) (On the Accuracy of Calculation in the Analysis of Natural Transverse Vibrations of a Ship's Hull)

  • 김극천;이호섭
    • 대한조선학회지
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    • 제13권1호
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    • pp.1-9
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    • 1976
  • Using the computer programs for calculation of natural vibrations of ship's hull developed by the authors et al., an investigation into influences of various parameters on the accuracy of calculation was done through example calculations of a 30,000 DWT petroleum products carrier M/S Sweet Brier built by Korea Shipbuilding and Engineering Corporation. The methodical principles employed for the computer program development are as follows; (a) the ship system is reduced to an equivalent discrete elements system conforming to Myklestad-Prohl model, (b) the problem formulation is of transfer matrix method, and (c) to obtain solutions an extended $G\ddot{u}mbel's$ initial value method is introduced. The scope of the investigation is influences of number of discrete elements, choice of significant system parameters such as rotary inertia, bending stiffness and shear stiffness, and simplification of distributions of added mass and stiffness as trapezoidal ones referred to those of midship section on the calculation accuracy. From the investigation the followings are found out; (1) To obtain good results for the modes up to the seven-noded thirty or more divisions of the hull is desirable. For fundamental mode fifteen divisions may give fairly good results. (2) The influence of rotary inertia is negligibly small at least for the modes up to the 5- or 6- noded. (3) In the case of assuming either bending modes or shear modes the calculation results in considerably higher frequencies as compared with those based on Timoshenko beam theory. However, the calculation base on the slender beam theory surprisingly gives frequencies within 10% error for fundamental modes. (4) It is proved that to simplify distributions of added mass and stiffness as trapezoidal ones referred to those of midship section is a promising approach for the prediction of natural frequencies at preliminary design stage; provided good accumulation of data from similar type ships, we may expect to obtain natural frequencies within 5% error.

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수학과학통합교육의 설계 및 실행에 대한 연구 (A Study on the Design and Implementation of Mathematics and Science Integrated Instruction)

  • 이혜숙;임해미;문종은
    • 한국수학교육학회지시리즈A:수학교육
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    • 제49권2호
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    • pp.175-198
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    • 2010
  • To understand natural or social phenomena, we need various information, knowledge, and thought skills. In this context, mathematics and sciences provide us with excellent tools for that purpose. This explains the reasons why there is always significant emphasis on mathematics and sciences in school education; some of the general goals in school education today are to illustrate physical phenomena with mathematical tools based on scientific consideration, to encourage students understand the mathematical concepts implied in the phenomena, and provide them with ability to apply what they learned to the real world problems. For the mentioned goals, we extract six fundamental principles for the integrated mathematics and science education (IMSE) from literature review and suggest a instructional design model. This model forms a fundamental of a case study we performed to which the IMSE was applied and tested to collect insights for design and practice. The case study was done for 10 students (2 female students, 8 male ones) at a coeducational high school in Seoul, the first semester 2009. Educational tools including graphic calculator(Voyage200) and motion detector (CBR) were utilized in the class. The analysis result for the class show that the students have successfully developed various mathematical concepts including the rate of change, the instantaneous rate of change, and derivatives based on the physical concepts like velocity, accelerate, etc. In the class, they described the physical phenomena with mathematical expressions and understood the motion of objects based on the idea of derivatives. From this result, we conclude that the IMSE builds integrated knowledge for the students in a positive way.

가르치기 어려움에 대한 교육현상학적 검토 : 서양교육사에서 (A Study on Educational Difficulty in the History of Western Education)

  • 고요한
    • 교육철학
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    • 제46호
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    • pp.45-70
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    • 2012
  • The purpose of this study is researching on educational difficulty in the history of western education. In other words, the goal and significance of this paper lies in knowing the essential meaning of education based on the norms of difficulty. The major method for this study is hermeneutical-anthropological pedagogy. My fundamental claim is the following: the essential nature of teaching is difficulty at any instructional condition and situations. Such a discrete idea was clearly identified and confirmed in the process of pedagogical anthropology. That is, through the consciousness of educational difficulty and critical review for the history of western education, I can cleary define the concept of educational difficulty. Educational difficulty was various ways for understanding by all audiences. Namely, various formulars were developed for understanding it according to the age, cultures, nations, ideology, etc.. But there are continuous characters on the way for understanding on educational difficulty. The results on research are as followings. In the primitive age, fundamental difficulty of education lies in the initiation ceremony. At the classical ancient time, the purpose of education was 'Politai' with politike arete, in this educational conditions, instruction have a complex dimension politically as well as psychologically. At the medieval age, educational difficulty lies in the 'Askese' for instructional methods. In the modern and conventional age, educational difficulty is more and more complex and confused on goals, methods, evaluations, etc.. Most of all, the major or key concept of educational difficulty in this world is the conflict between the two instructional principles, that is, objectivism and constructivism in education. At now, the schoolworks for instruction over all educational situations and conditions have a difficulty of traditional as well conventional dilemma. In conclusion, educational difficulty have formal, natural, original attribute and it is general and universal phenomenon.