• 제목/요약/키워드: history of science and technology

검색결과 921건 처리시간 0.029초

Impact Force Reconstruction of Composite materials based on Improved Regularization Technology

  • Sun, Yajie;Yin, Tao;Yang, Jian;Cai, Zhiyu;Wu, Shaoen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제15권8호
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    • pp.2718-2731
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    • 2021
  • In the structural health monitoring of composite materials, in order to solve the ill-posed problem of impact force reconstruction, regularization techniques are often used to deal with it. Due to the poor convergence of the traditional Tikhonov regularization method, in order to accurately reconstruct the time history of the impact force, this paper improves Tikhonov regularization method and constructs homotopy function with strong convergence. Since the optimal regularization parameters need to be found in the homotopy function, the Newton downhill method is used to find the optimal parameters and the homotopy function can be calculated, which can accurately reconstruct the time history of the impact force. In order to verify the universality of the method in this paper, impact hammers of different materials were used in the experiment in this paper to study and compare the reconstruction effect of impact time history of different impact hammers.

과학체험학습에 관한 선행연구 및 경기도 지역 초등학교 운영실태 분석을 통한 다양한 과학체험학습장의 활용방안 모색 (Classification of Place for Experiential Learning through Analysis of Previous Study and Actual Status of Elementary Schools in Gyeonggi-do about Science Experience Learning)

  • 권난주;권혁재
    • 한국초등과학교육학회지:초등과학교육
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    • 제38권1호
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    • pp.43-54
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    • 2019
  • In order to organize various places for science experience study, this study gathered and analyzed prior research on science experience study and various science experience perated in school. To that end, a total of 162 relevant prior studies of literature published from 2000 to 2016 were collected and 2,201 cases of science experience study conducted in 2015 were collected and analyzed. The place where the science experiential learning was done is divided into three areas of natural ecology, cultural history, facility experiential learning study, and the characteristics of participating subjects are examined. In terms of the number of articles published in the field of science-related experiential learning areas, 83 ecological experience study sites (51.2%), facilities institution experience study sites 56 (34.6%), and cultural history experience study books 23 (14.2%). Through this study, it was found out that research tendency to analyze science - related attitudes became prominent by setting study subjects using natural objects around and learning to play while playing and playing in nature. There was also an analysis by subjects of participation in science related experience learning centers. Cultural history experiential learning field was significantly lower than previous studies. In the lower grades, nature ecological experience learning was mainly performed. Combining the above findings, it can provide implications for the development of science-related experience activities. First, it is necessary to develop a technology-related experience learning center using local community resources. Second, it is necessary to expand the culture and history experience learning center related to science. Third, we need an education support center to support the expansion and operation of such a technology-related cultural history learning center.

기술적 관점에서 바라본 사진사에 대한 고찰 (Historical Meaning through Technological Issues on Photography)

  • 김상기;김유진
    • 한국콘텐츠학회논문지
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    • 제12권10호
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    • pp.93-105
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    • 2012
  • 사진이 발명된 계기에는 과학과 기술이 뿌리 깊게 자리 잡고 있다. 인간의 손이 아닌 기계와 과학적 처리과정을 통해 생성된 이미지는 사실 그대로의 정교한 이미지로만 그치지 않았다. 사진은 대중문화, 예술, 광고, 과학연구 등 정확한 기록성과 사실적 묘사가 필요한 곳이면 어디든지 사용되었으며, 하나의 인류문화로 자리를 잡았다. 그러나 현재 사진교육에서 다루는 사진사는 사진가의 사진성향, 예술적 패러다임의 시대적 변화와 전쟁과 같은 사회적 변화를 중심으로 사진의 흐름을 다루고 있을 뿐 기술적 관점과 같은 다양한 관점에서 바라본 사진사 연구는 부족하다. 본 연구에서는 사진의 과학 기술적 탄생 배경을 중심으로 사진의 기술사를 살펴보았고 중요한 기술적 성취단계에서 사진은 어떤 영향을 받고 변화했는지 각각의 사례를 통해 분석 및 논의하였다. 이러한 관점의 논의는 빠르게 변화하고 있는 현대사진을 이해하는데 도움이 되며 앞으로의 사진 변화를 예측하는데 참고가 될 수 있기에 적지 않은 의미를 가진다. 또한 사진이 기술에 의존적이라는 사실을 이해함으로써 사진전공자들에게 사진기술 및 관련이론을 습득하는 것이 무슨 의미를 가지는지를 깨우쳐 줄 수 있을 것이다.

A Brief History of Architectural Acoustics in China.: Yesterday and Tomorrow.

  • Yan, Xiang
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2010년도 춘계학술대회 논문집
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    • pp.461-461
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    • 2010
  • The history of architectural acoustics is a part of history of human being getting together for both politics and entertainments, is also a part of the history of nobility pursuing hearing enjoyments, is still a part history of scientists deeply understanding the concept of "just for people", and as well as is a part history ceaselessly driven by the musicians to find their real hearts through music. The history of architectural acoustics explains not only the acoustic knowledge developments in architectural design, but also the unity on contradictory of both the science and the arts, both the technology and the culture, both the sense and sense organ. The history of architectural acoustics prints the interactions between the mankind and the nature, between the mankind and themselves, between the mankind and their souls, in which course people understand their feelings more deeply and deeply. This paper discusses the brief history of architectural acoustic in China from the ancient drama stages to grand theaters in 20 century, even up to nowadays, including some most important buildings and events as well.

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A new method for safety classification of structures, systems and components by reflecting nuclear reactor operating history into importance measures

  • Cheng, Jie;Liu, Jie;Chen, Shanqi;Li, Yazhou;Wang, Jin;Wang, Fang
    • Nuclear Engineering and Technology
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    • 제54권4호
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    • pp.1336-1342
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    • 2022
  • Risk-informed safety classification of structures, systems and components (SSCs) is very important for ensuring the safety and economic efficiency of nuclear power plants (NPPs). However, previous methods for safety classification of SSCs do not take the plant operating modes or the operational process of SSCs into consideration, thus cannot concentrate on the safety and economic efficiency accurately. In this contribution, a new method for safety classification of SSCs based on the categorization of plant operating modes is proposed, which considers the NPPs operating history to improve the economic efficiencies while maintaining the safety. According to the time duration of plant configurations in plant operating modes, average importances of SSCs are accessed for an NPP considering the operational process, and then safety classification of SSCs is performed for plant operating modes. The correctness and effectiveness of the proposed method is demonstrated by application in an NPP's safety classification of SSCs.

수산 발효식품 산업 발전 (The history of the fermented fisheries industry)

  • 송호수;김상무
    • 식품과학과 산업
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    • 제55권3호
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    • pp.284-300
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    • 2022
  • Indigenous fermented foods have played a vital role in human history, and continue to offer a multitude of diverse sensory characteristics. According to earthenware relic, the fermented fisheries products might be consumed in Korean peninsula from Paleolithic period. The traditional Korean fermented fish products are classified into four groups; Jeot-gal (sik-hae), Aek-jeot, Seasoned Jeot-gal, and Seasoned Aek-jeot. Jeot-gal is a fermented fishery with salt. Aek-jeot is a liquid part of Jeot-gal. Sik-hae is manufactured by fementing fishery with salt, cereal, malt powder, etc. Seasoned Jeot-gal is a salt-seasoned fish with red pepper powder, garlic, onion, etc. Seasoned Aek-jeot is a seasoned product by adding "salt-water" or "condiment" to Aek-jeot. The fermented fisheries industry has traditionally been succeeded mainly in a cottage scale to the middle of 20th century. Thereafter, together with the development of pelagic fishery, the fermented fisheries industry also developed constantly to an enterprise size.

MODEL TESTS ON LEVEES REINFORCED WITH SHEET PILES UNDER HIGH WATER CONDITIONS WITH/WITHOUT SEISMIC LOADING HISTORY

  • Koseki, Junichi;Tanaka, Hiroyuki;Otsushi, Kazutaka;Nagao, Naoya;Kaneko, Masaru
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회 3차
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    • pp.49-54
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    • 2010
  • In order to study the performance of levees reinforced with steel sheet piles under high water condition, a series of model tests was conducted by simulating the high water condition before and after applying severe seismic loading history. As a result, the seepage behavior through the subsoil layers underlying the levee was not significantly affected by the seismic loading history. It was also verified that, irrespective of the seismic loading history, the sheet piles installed at the levee crest or shoulder are effective in preventing the breakage of levees caused by overflow. In addition, applicability of drainage works at the foot of the levee in preventing the seepage failure was confirmed.

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박판성형 공정 설계 및 해석의 발전 (Research History and Recent Trends in the Development of Sheet Metal-Forming Processes)

  • 김종봉;이성욱;양동열;정완진
    • 한국정밀공학회지
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    • 제33권4호
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    • pp.247-255
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    • 2016
  • Sheet metal-forming processes such as stamping, deep drawing, bending, shearing, hydroforming, hydromechanical deep drawing, rubber forming, and incremental forming have been widely used in the automotive, aircraft, and ship-building industries. With the expansion of the automotive industry, research on these processes has been remarkably developed in Korea since the 1980s. Here, we review the history of this research as well as recent trends in sheet metal-forming processes. This overview focuses specifically on the results of research in Korea and on the works of Professor D.Y. Yang, in honor of his retirement.

A Simple Proposal For Ain Makkah Almukkarmah An Application Using Augmented Reality Technology

  • Taghreed Alotaibi;Laila Alkabkabi;Rana Alzahrani;Eman Almalki;Ghosson Banjar;Kholod Alshareef;Olfat M. Mirza
    • International Journal of Computer Science & Network Security
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    • 제23권12호
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    • pp.115-122
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    • 2023
  • Makkah Al-Mukarramah is the capital of Islamic world. It receives special attention from the Saudi government's rulers to transform it into a smart city for the benefit of millions of pilgrims. One of the 2030 vision objectives is to transform specific cities to smart ones with advanced technological facilitation, Makkah is one of these cities. The history of Makkah is not well known for some Muslims. As a result, we built the concepts of our application "Ain Makkah" to enable visitors of Makkah to know the history of Makkah by using technology. In particular "Ain Makkah" uses Augmented Reality to view the history of Al-Kaaba. A 3D model will overlay Al-Kaaba to show it in the last years. Our project will use Augmented Reality to build a 3D model to overlay Al-Kaaba. Future work will expand the number of historical landmarks of Makkah.