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A Study on the Qualification Development of 3D Printing Operation Expert and 3D Printing Development Specialist (3D프린팅전문운용사 및 3D프린터개발산업기사 국가기술 자격종목 개발에 관한 연구)

  • Kang, Seok Joo;Woo, Mi Hye
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.34-38
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    • 2016
  • This study aims to develop qualification criteria for training and establishing an expert pool of 3D printing operation experts and 3D printing development specialists in the emerging 3D printing industry. We investigate the domestic and international 3D printing industry, as well as 3D printing- related training institutions and quantity of test examinees. Utilizing competency analysis, this study examines the competencies and educational content of both 3D printing operation expert as well as 3D printing development specialists. In addition, a survey was conducted on the issue of institutionalization of qualification criteria for 3D printing operation expert and 3D printer development specialists. This study further proposes evaluation methods for qualification criteria for both 3D printing operation expert and 3D printer development specialists based on simulations of both written and performance tests. Based on the findings, this study proposes instructional program outlines as well as comprehensive guidelines for training and qualification processes for 3D printing operation expert and 3D printer development specialists.

ON THE CARDINALITY OF SEMISTAR OPERATIONS OF FINITE CHARACTER ON INTEGRAL DOMAINS

  • Chang, Gyu Whan
    • Korean Journal of Mathematics
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    • v.22 no.3
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    • pp.455-462
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    • 2014
  • Let D be an integral domain with Spec(D) finite, K the quotient field of D, [D,K] the set of rings between D and K, and SFc(D) the set of semistar operations of finite character on D. It is well known that |Spec(D)| ${\leq}$ |SFc(D)|. In this paper, we prove that |Spec(D)| = |SFc(D)| if and only if D is a valuation domain, if and only if |Spec(D)| = |[D,K]|. We also study integral domains D such that |Spec(D)|+1 = |SFc(D)|.

Drosophilid Survey of Mt. Sul-Ak (Kang-Won Province) (설악산의 초파리 분포조사)

  • 정용재;노분조
    • The Korean Journal of Zoology
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    • v.2 no.2
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    • pp.1-6
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    • 1959
  • 1. 저자들이 1959년 7월 14일부터 22일까지에 강원도 설악산의 9개소 즉 장수태, 십이탕골, 백담사, 오세암, 수강동, 봉정암, 가야동, 마등령, 및 신흥사에서 주로 복숭아 trap 법과 sweeping 법으로 채집한 Drosophilidae 는 4 촉 4 아촉 22종 512 개체였다. 2. D.auraria, D. testacea, D.brachynephros, D.sexivitata, D.unispina, D.bifasciata, Amiota variegata, D.angularis 및 D. histrio가 다수 채집되었으며 Mycodrosophilachr과 Chymomyza 촉의 종은 본 채집에서 볼 수 없었고 다른곳에서 흔히 잡히는 D.bizohnata D.bizonnata, D.nigrmaculata 도 채집되어지지 않았다. 3. D.sexivittata, D.testacea 의 Polymorphism, D.brachynephros, D. angularis,D. unispina의 구별, D. lacertosa 와 Amiota variegata 의 crossvein, A. alboguttata 의 genitalia , D, histrio의 abominal band 및 crossvein , A. alboguttata 의 genitalia, D.histrio의 abominal band 및 crossvein $C_3$ bristle 문제를 검토했다. 4. D.kuntzeisms 한국산 Drosophilidae 목록에 새로 첨가할 미기록종이며 미지종 3 종 즉 A(A.) sp., d.(D.) sp., D.(S.) sp like helvetica BURLA 의 검토를 예의 진행중에 있다.

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Advertisement Coverage Analysis of Social Commerce Service with D2D Communications (D2D 통신을 이용한 소셜커머스 광고 커버리지 분석)

  • Kim, Jun-Seon;Lee, Howon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.7
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    • pp.1547-1556
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    • 2014
  • In this paper, we propose cost-effective device-to-device (D2D) advertisement scenario with properties of proximity and timeliness through the convergence of D2D communications and social commerce service. We numerically analyze advertisement dissemination effect of the proposed scenario according to the number of sectors, and demonstrate the performance of the normalized D2D coverage, the average number of D2D users, and the average D2D coverage per user via intensive simulations. We verify the accuracy of the results for our numerical analysis compared with the simulation results.

2D-3D Conversion Method Based on Scene Space Reconstruction (장면의 공간 재구성 기법을 이용한 2D-3D 변환 방법)

  • Kim, Myungha;Hong, Hyunki
    • The Journal of the Korea Contents Association
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    • v.14 no.7
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    • pp.1-9
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    • 2014
  • Previous 2D-3D conversion methods to generate 3D stereo images from 2D sequence consist of labor-intensive procedures in their production pipelines. This paper presents an efficient 2D-3D conversion system based on scene structure reconstruction from image sequence. The proposed system reconstructs a scene space and produces 3D stereo images with texture re-projection. Experimental results show that the proposed method can generate precise 3D contents based on scene structure information. By using the proposed reconstruction tool, the stereographer can collaborate efficiently with workers in production pipeline for 3D contents production.

Improvement of Computational Complexity of Device-to-Device (D2D) Resource Allocation Algorithm in LTE-Advanced Networks (LTE-Advanced 환경에서 D2D 자원 할당 알고리즘의 계산 복잡도 개선)

  • Lee, Han Na;Kim, Hyang-Mi;Kim, SangKyung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.4
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    • pp.762-768
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    • 2015
  • D2D communication as an underlaying LTE-Advanced network has proven to be efficient in improving the network performance and decreasing the traffic load of eNodeB(enhanced NodeB). However large amount of interference can be caused by sharing the resources between the cellular users and D2D pairs. So, a resource allocation for D2D communication to coordinate the interference is necessary. Related works for resource allocation that D2D can reuse the resources of more than one cellular user with best CQI(Channel Quality Indicator) have been proposed. D2D communications may still cause interference to the primary cellular network when radio resource are shared between them. To avoid this problem, we propose a radio resource allocation algorithm with low computational complexity for D2D communication in OFDM-based wireless cellular networks. Unlike the previous works, the proposed algorithm utilizes unused ones of the whole resource. The unused resource allocate to on D2D pair can be shared only with other D2D pairs. In other words, if the distance between the D2D pairs is sufficient, we allowed more than two D2D pairs to share the same resources. The simulation results have proven that the proposed algorithm has up to 11 times lower computational complexity than the compared one according to the number of D2D.

Producing the insoles for flat feet of senior men using 3D systems based on 3D scanning, 3D modeling, and 3D printing (3D 스캐닝, 3D 모델링, 3D 프린팅 기반의 3D 시스템에 의한 시니어 평발용 인솔 제작)

  • Oh, Seol Young;Suh, Dongae
    • The Research Journal of the Costume Culture
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    • v.25 no.3
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    • pp.270-284
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    • 2017
  • This study aimed to create 3D-printed insoles for flat-footed senior men using 3D systems. 3D systems are product-manufacturing systems that use 3-dimensional technologies like 3D scanning, 3D modeling, and 3D printing. This study used a 3D scanner (NexScan2), 3D CAD programs including Rapidform, AutoCAD, SolidWorks, Nauta+ compiling program, and a 3D printer. In order to create insoles for flat-footed senior men, we analyzed horizontal sections of 3D foot scans We selected 20 flat-footed and 20 normal-footed subjects. To make the 3D insole models, we sliced nine lines on the surface of the subjects' 3D foot scans, and plotted 144 points on the lines. We calculated the average of these 3D coordinates, then located this average within the 3D space of the AutoCAD program and created 3D sole models using the loft surface tools of the SolidWorks program. The sole models for flat feet differed from those of normal feet in the depth of the arch at the inner sideline and the big toe line. We placed the normal-footed sole model on a flat-footed sole model, and the combination of the two models resulted in the 3D insole for flat feet. We printed the 3D modeled insole using a 3D printer. The 3D printing material was an acrylic resin similar to rubber. This made the insole model flexible and wearable. This study utilized 3D systems to create 3D insoles for flat-footed seniors and this process can be applied to manufacture other items in the fashion industry as well.

THE CLASS GROUP OF D*/U FOR D AN INTEGRAL DOMAIN AND U A GROUP OF UNITS OF D

  • Chang, Gyu Whan
    • Korean Journal of Mathematics
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    • v.17 no.2
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    • pp.189-196
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    • 2009
  • Let D be an integral domain, and let U be a group of units of D. Let $D^*=D-\{0\}$ and ${\Gamma}=D^*/U$ be the commutative cancellative semigroup under aU+bU=abU. We prove that $Cl(D)=Cl({\Gamma})$ and that D is a PvMD (resp., GCD-domain, Mori domain, Krull domain, factorial domain) if and only if ${\Gamma}$ is a PvMS(resp., GCD-semigroup, Mori semigroup, Krull semigroup, factorial semigroup). Let U=U(D) be the group of units of D. We also show that if D is integrally closed, then $D[{\Gamma}]$, the semigroup ring of ${\Gamma}$ over D, is an integrally closed domain with $Cl(D[{\Gamma}])=Cl(D){\oplus}Cl(D)$; hence D is a PvMD (resp., GCD-domain, Krull domain, factorial domain) if and only if $D[{\Gamma}]$ is.

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A Study on the Stereoscopic 3D Filmmaking Curriculum in the Film and Image Major (영화 영상 전공에서의 스테레오스코픽 3D 제작 교육 과정 연구)

  • Lee, Chan-Bok
    • The Journal of the Korea Contents Association
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    • v.10 no.6
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    • pp.222-235
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    • 2010
  • After its remarkable success, "Avatar" brought another way of creating cinematic story; the stereoscopic 3-D cinema. Comparing conventional 2-D filmmaking, you need twice as much of budget and manpower in 3-D filmmaking because of the complicated process and slow production speed. The 3-D hardware like 3-D TV and 3-D projector are already showing at the retail stores while 3-D filmmaking is still in veil, and no major educational institution is yet to start 3-D related education. As 3-D movies get popular and demand more 3-D filmmaking professional crew, educating 3-D filmmaking to 2-D based film students will improve their hiring rate in the market. The successful result of the box office showing 3-D films like "Alice in Wonderland 3D" and "Titan 3D" forecasts that there will be more demand on 3-D related jobs very soon.

Fabrication and Characterization of Carbon Nanotube Field Emission Display for HD-TV Applications

  • Lee, Chun-Gyoo;Chi, Eung-Joon;Hwang, Sung-Yeon;Lee, Sang-Jo;Lee, Sang-Jin;Yoon, Tae-Ill;Lee, Byong-Gon;Nam, Joong-Woo;Ryu, Mee-Ae;Han, Ho-Su;Jin, Sung-Hwan;Ahn, Sang-Hyuck;Seo, Hyoung-Cheol;Choi, Jong-Sik;Oh, Tae-Sik;Kang, Sung-Kee;Kim, Jong-Min;Kim, Jung-Woo;Park, Young-Jun;Han, In-Taek;Jin, Yong-Wan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.191-192
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    • 2003
  • For the CNT-FED to be cost-effective, many efforts for the lower voltage operation have been made in the under-gate cathode structure. In this study, the effects of the frit proportion in the CNT paste, cathode electrode width, CNT-to-counter electrode gap, and the CNT length in the cathode structure were examined.

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