• 제목/요약/키워드: fundamental solution.

검색결과 733건 처리시간 0.03초

빅데이터 분석 시스템을 활용한 자동차 부품 비전 검사 시스템 (An Automotive Industry Vision Inspection System using Big Data Analytic System)

  • 권대호;이정석;유남현
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2019년도 춘계학술대회
    • /
    • pp.220-222
    • /
    • 2019
  • 국내 자동차 시장은 2016년 이후 생산 및 수출이 지속적으로 둔화되고 있다. 이를 극복하기 위한 가장 근본적인 해결책은 경쟁력 있는 부품을 개발해야 한다. 경쟁력 있는 부품을 개발하기 위해서는 두 가지 중요한 요소가 있다. 가장 중요한 것은 제품 설계 기술이며, 두 번째로 중요한 것이 바로 생산 기술이다. 생산기술이 중요한 이유는 재료비를 제외한 생산 단가를 낮추어야 하며, 품질의 지속성을 가지고 있어야하기 때문이다. 본 논문에서는 생산기술을 확보하기 위하여 C사의 자동차 회사 부품을 검사하기 위한 설계한 지능형 스마트 검사 시스템의 기본 구조를 설계하였다. 현재 본 시스템은 기본 및 상세설계가 마무리 되고 현재 개발 진행 단계에 있다. 본 시스템이 성공적으로 개발된다면 C사의 품질 검사 단계의 자동화와 불량률을 감소시킬 수 있을 것을 예상하고 있다.

  • PDF

블록체인 기반의 전파 공유 기술과 전파 정책 (Technology and Policy for Blockchain-based Spectrum Sharing)

  • 신나연;남지현;최예진;이일구
    • 디지털융복합연구
    • /
    • 제17권10호
    • /
    • pp.13-21
    • /
    • 2019
  • 제한된 네트워크 자원과 불균등한 전파 자원 분배로 인해 전파자원 부족 문제와 서비스 품질 열화가 발생하고 있다. 또한, 기존 중앙집중식 전파 공유 방식은 전파 공유 활성화를 위한 근본적인 해결책이 되지 못하고 있으며 비용, 편의성, 보안성 관점에서 비효율적이다. 본 논문에서는 전파자원을 분배하고 공유할 수 있는 저비용, 고신뢰, 고효율 플랫폼으로서 블록체인 기반의 스펙트럼 쉐어링 플랫폼을 제안하고 이를 실현하기 위한 법적 쟁점을 분석하였다. 스펙트럼 쉐어링 플랫폼에서는 와이파이 AP 전파 정보와 LTE 모바일 핫스팟 전파 정보를 블록체인에 등록하고, 전파 공유자와 전파 사용자가 스마트 컨트랙트 통해 개인 간 (P2P) 전파 공유 계약을 빠르고 효율적으로 체결한다. 전파 공유에 대한 대가와 품질 관리에 대한 보상인 암호화폐는 선순환적인 전파 공유 오픈 플랫폼 생태계를 활성화할 것이며, 스펙트럼 쉐어링 플랫폼을 통해 편리하고 효율적인 공공 무선 인프라를 제공할 수 있다.

귀에트 주택에 나타난 르 꼬르뷔지에의 건축개념 및 제5원칙에 관한 고찰 (A Study on the Features of Architectural Concept Applied in Maison Guiette and Le Corbusier's 'Five Points of a New Architecture')

  • 김종성
    • 대한건축학회논문집:계획계
    • /
    • 제35권7호
    • /
    • pp.89-99
    • /
    • 2019
  • The purpose of this study is to reveal the meaning of Le Corbusier's works focused on Maison Guiette. This House was completed in 1926, 4 year later than the work of the Citrohan and also, this house is the only remaining mixed use Dwelling in Belgium. It offers a fine example of the early architectural concepts of Le Corbusier's. Despite these important facts, the meanings of the ideas of this house have not been paid attention as much as other houses constructed at the same period, such as Maison La Roche, Maison Stein de Monzie, Villa Savoye, etc. In his book, 'Oeuvre Complete 1910-1929', Le Corbusier mentioned as follows: "A special solution imposed by Belgian housing developments characterized by a dimension of 6 meters of frontage and a very great depth. The staircase serving the various floors is like the ladder of Jacob climbs Charlie Chaplin in the "Kid" and This house is an architectural experiments of his ideas. And this study aims at analysing the relationship between Maison Guiette and spaces on the basic of Le Corbusier's 'Five Points of a New Architecture' which had a great effects on architectural history and became a fundamental elements for the change into the Modern housing. By analysing the points in regard with the Features of Architectural Concept Applied in Maison Guiette, The Five Points are the background of the interpenetration of the interior and the exterior. To attain this, this research appraises each points in detail in regards with Maison Guiette. The study of Maison Guiette will be an important architectural subject to clarify the meaning of his later works and ideas.

효율적인 코로나19 진단을 위한 그룹검사 체계 (Group Testing Scheme for Effective Diagnosis of COVID-19)

  • 성진택
    • 한국정보전자통신기술학회논문지
    • /
    • 제14권6호
    • /
    • pp.445-451
    • /
    • 2021
  • 최근 코로나19 확산과 피해가 늘어나는 가운데 감염을 차단하기 위해 가장 중요한 것은 감염자를 조기에 찾아내는 것이다. 지난 반세기 전에 등장한 그룹검사(group testing)가 최근 코로나19 진단 방법으로써 활용 가능하며 매우 효율적인 방법으로 자리 잡고 있다. 본 논문에서는 기존의 그룹검사 알고리즘들의 동작원리를 살펴본다. 그리고 압축센싱(compressed sensing)에서 제안한 희소 신호 복원 방법을 개선하여 그룹검사의 해법으로 제시한다. 압축센싱과 그룹검사는 연산 방법에서 차이가 있지만 희소 신호를 찾는다는 점에서 유사하다. 시뮬레이션 결과를 통해 제안하는 희소 신호 복원 방법의 성능 우수성을 보여준다. 주목할 점은 모든 결함 샘플을 정확히 찾고자 하는 그룹검사 시스템에서는 제안하는 방법이 다른 알고리즘보다 월등한 성능 향상을 보여준 것이다. 또한 결함 샘플 수가 적을 때보다는 많을 때 그 성능이 크게 개선된다.

Crossover from weak anti-localization to weak localization in inkjet-printed Ti3C2Tx MXene thin-film

  • Jin, Mi-Jin;Um, Doo-Seung;Ogbeide, Osarenkhoe;Kim, Chang-Il;Yoo, Jung-Woo;Robinson, J. W. A.
    • Advances in nano research
    • /
    • 제13권3호
    • /
    • pp.259-267
    • /
    • 2022
  • Two-dimensional (2D) transition metal carbides/nitrides or "MXenes" belong to a diverse-class of layered compounds, which offer composition- and electric-field-tunable electrical and physical properties. Although the majority of the MXenes, including Ti3C2Tx, are metallic, they typically show semiconductor-like behaviour in their percolated thin-film structure; this is also the most common structure used for fundamental studies and prototype device development of MXene. Magnetoconductance studies of thin-film MXenes are central to understanding their electronic transport properties and charge carrier dynamics, and also to evaluate their potential for spin-tronics and magnetoelectronics. Since MXenes are produced through solution processing, it is desirable to develop deposition strategies such as inkjet-printing to enable scale-up production with intricate structures/networks. Here, we systematically investigate the extrinsic negative magnetoconductance of inkjetprinted Ti3C2Tx MXene thin-films and report a crossover from weak anti-localization (WAL) to weak localization (WL) near 2.5K. The crossover from WAL to WL is consistent with strong, extrinsic, spin-orbit coupling, a key property for active control of spin currents in spin-orbitronic devices. From WAL/WL magnetoconductance analysis, we estimate that the printed MXene thin-film has a spin orbit coupling field of up to 0.84 T at 1.9 K. Our results and analyses offer a deeper understanding into microscopic charge carrier transport in Ti3C2Tx, revealing promising properties for printed, flexible, electronic and spinorbitronic device applications.

Axisymmetric vibration analysis of a sandwich porous plate in thermal environment rested on Kerr foundation

  • Zhang, Zhe;Yang, Qijian;Jin, Cong
    • Steel and Composite Structures
    • /
    • 제43권5호
    • /
    • pp.581-601
    • /
    • 2022
  • The main objective of this research work is to investigate the free vibration behavior of annular sandwich plates resting on the Kerr foundation at thermal conditions. This sandwich configuration is composed of two FGM face sheets as coating layer and a porous GPLRC (GPL reinforced composite) core. It is supposed that the GPL nanofillers and the porosity coefficient vary continuously along the core thickness direction. To model closed-cell FG porous material reinforced with GPLs, Halpin-Tsai micromechanical modeling in conjunction with Gaussian-Random field scheme is used, while the Poisson's ratio and density are computed by the rule of mixtures. Besides, the material properties of two FGM face sheets change continuously through the thickness according to the power-law distribution. To capture fundamental frequencies of the annular sandwich plate resting on the Kerr foundation in a thermal environment, the analysis procedure is with the aid of Reddy's shear-deformation plate theory based high-order shear deformation plate theory (HSDT) to derive and solve the equations of motion and boundary conditions. The governing equations together with related boundary conditions are discretized using the generalized differential quadrature (GDQ) method in the spatial domain. Numerical results are compared with those published in the literature to examine the accuracy and validity of the present approach. A parametric solution for temperature variation across the thickness of the sandwich plate is employed taking into account the thermal conductivity, the inhomogeneity parameter, and the sandwich schemes. The numerical results indicate the influence of volume fraction index, GPLs volume fraction, porosity coefficient, three independent coefficients of Kerr elastic foundation, and temperature difference on the free vibration behavior of annular sandwich plate. This study provides essential information to engineers seeking innovative ways to promote composite structures in a practical way.

Peracetic Acid Treatment as an Effective Method to Protect Wood Discoloration by UV Light

  • PARK, Kyoung-Chan;KIM, Byeongho;PARK, Hanna;PARK, Se-Yeong
    • Journal of the Korean Wood Science and Technology
    • /
    • 제50권4호
    • /
    • pp.283-298
    • /
    • 2022
  • Wood has always been used for various day-to-day applications such as interior or exterior construction materials, and household products. However, it can undergo photodegradation and discoloration by environmental factors including ultraviolet (UV) light, and thus has shortened its service life. Bleaching or delignification of wood surfaces is a suitable solution to stabilize wood against weathering by UV because these techniques can alter or remove the chromophores in lignin, which is a main factor of wood discoloration. To improve the color stability of wood surface according to the lifespan, surface delignification was conducted using peracetic acid (PAA) and hydrogen peroxide (HP) on the woods of Larix kaempferi and Quercus mongolica. After the PAA treatment, L* increased considerably from 60-70 to 90-95. Furthermore, wood surface color did not change significantly after UV exposure. The color differences (𝜟E*) between before and after PPA treatment of wood showed the 4.8-12.2 of L. kaempferi, and 1.7-3.7 of Q. mongolica, respectively. The lignin-related peaks in Fourier transform infrared spectroscopy (FT-IR) spectra disappeared with increased duration of PAA treatment. These results confirmed that the lignin component was partially or completely removed after the PAA treatment; the color differences (𝜟E*) clearly showed that there was a reduction in redness (a*) and yellowness (b*), and an increase in lightness (L*) owing to the removal of lignin. Based on these results, this study demonstrated that the partial removal of lignin from wood surfaces is a fundamental method for resolving photo-degradation.

Pest Prediction in Rice using IoT and Feed Forward Neural Network

  • Latif, Muhammad Salman;Kazmi, Rafaqat;Khan, Nadia;Majeed, Rizwan;Ikram, Sunnia;Ali-Shahid, Malik Muhammad
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제16권1호
    • /
    • pp.133-152
    • /
    • 2022
  • Rice is a fundamental staple food commodity all around the world. Globally, it is grown over 167 million hectares and occupies almost 1/5th of total cultivated land under cereals. With a total production of 782 million metric tons in 2018. In Pakistan, it is the 2nd largest crop being produced and 3rd largest food commodity after sugarcane and rice. The stem borers a type of pest in rice and other crops, Scirpophaga incertulas or the yellow stem borer is very serious pest and a major cause of yield loss, more than 90% damage is recorded in Pakistan on rice crop. Yellow stem borer population of rice could be stimulated with various environmental factors which includes relative humidity, light, and environmental temperature. Focus of this study is to find the environmental factors changes i.e., temperature, relative humidity and rainfall that can lead to cause outbreaks of yellow stem borers. this study helps to find out the hot spots of insect pest in rice field with a control of farmer's palm. Proposed system uses temperature, relative humidity, and rain sensor along with artificial neural network to predict yellow stem borer attack and generate warning to take necessary precautions. result shows 85.6% accuracy and accuracy gradually increased after repeating several training rounds. This system can be good IoT based solution for pest attack prediction which is cost effective and accurate.

디지털 네이티브 세대를 위한 유튜브 리터러시 체크리스트 개발 연구 (Development of Youtube Literacy Checklist for Digital Natives)

  • 김형진;정효정;권보람
    • 한국콘텐츠학회논문지
    • /
    • 제22권3호
    • /
    • pp.273-284
    • /
    • 2022
  • 유튜브 사용량은 계속해서 증가하고 있으며, 유튜브를 가장 많은 시간 사용하는 연령대는 10대로 조사되고 있다. 어린이·청소년이 유해한 콘텐츠에 노출되는 것을 막는 것은 현실적으로 불가능하므로, 유튜브 콘텐츠를 건강하게 선택하고 활용하는 역량을 키워내는 것이 근본적인 해결책이 될 수 있다. 이에 본 연구에서는 디지털 네이티브 세대를 위한 유튜브 리터러시란 무엇인지 규명하고, 공통적으로 고려해야 할 기준을 마련하고자 하였다. 본 연구는 유튜브 리터러시 역량의 정의를 구체화하고, 어린이·청소년의 유튜브 플랫폼 활용 안내·지도 시 활용할 수 있는 체크리스트를 개발하는 것을 목적으로 한다. 이를 위하여 선행 연구와 해외사례 분석을 바탕으로 개념적 정의 및 체크리스트를 개발하였으며, 전문가 및 교육자 검토를 통하여 타당성을 확보하였다. 최종적으로 개발한 체크리스트는 미디어 접근, 비판적 이해, 미디어 참여, 윤리적 활용 4개 범주의 10개 역량, 23문항을 포함한다.

中国经济新常态下的 '新东北现象': 特征与含意 (Features and Implications of 'New Northeast Phenomenon' in China's New Normal Period)

  • 柳银河
    • 분석과 대안
    • /
    • 제6권1호
    • /
    • pp.259-282
    • /
    • 2022
  • 本文关注到与过去不同的新常态下 '新东北现象' 的复合特征,着重阐述最近 '新东北现象' 里的主要三个现象-经济现象, 人口现象, 财政现象。2014年以来东北地区经济增速减缓虽成大问题,同其间东北有关人口状况与财政支出结构变动也很突出。总之, 2014年以后在东北地区, 经济增长衰退, 人口减少与人才流失加剧, 老龄化提速, 财政收支缺口增加与社会保障支出激增, 这些现象都同时发生, 互相影响着产生恶性循环, 新常态下的 '新东北现象' 之难点就在这复合实质。那么, 新常态下的 '新东北现象' 之如此复合特征与难点给全中国何含意? 本文提出两点。第一, 基于近来中国一些有关状况变化趋势来看, 东北可以被视为中国的一个缩影, 新常态下的 '新东北现象' 不限于东北地区, 不久将来很可能扩散到中国其他区域, 会成为全中国现象。第二, 新常态下的 '新东北现象' 出现, 对于改革开发以来实行的西部大开发战略, 中部崛起战略, 东北振兴战略等一系列区域大开发战略的根本性效果, 要求深刻的反思且重新构想。这些区域发展战略, 虽有所成就, 中西部地区, 尤其是西部, 还仍然相对很落后, 中国区域差距一向没有缩小。振兴东北战略实行已有了20来年, 新常态下的 '新东北现象' 出现也显示长期以来困扰东北经济的深层次问题始终没有得到解决。近来习进平格外强调 '共同富裕', '新东北现象' 也成为本届中央政府最急切解决的问题之一, 如果成功了, 既能为重新构思和调整区域发展战略提出有效方向, 又能为对应未来中国经济社会变动成为一个重要标志。