• 제목/요약/키워드: Technical precision

검색결과 407건 처리시간 0.028초

Evaluation of two interforaminal implants and implant-assisted removable dentures on stress distribution: an in vitro study

  • Bilhan, Selda Arat;Geckili, Onur;Cilingir, Altug;Bozdag, Ergun;Bilhan, Hakan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제45권4호
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    • pp.199-206
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    • 2019
  • Objectives: In mandibular edentulism, the treatment option with a two-interforaminal implant-retained bridge and a removable partial denture is rarely evaluated in literature. The aim of this in vitro study was to evaluate the stress distribution of this treatment option by comparing it with traditional treatment options with interforaminal implants in the edentulous mandible. Materials and Methods: Two interforaminal implants were placed in a formalin-fixed cadaver mandible, and overdentures with three different types of attachments were fabricated: (1) two ball attachments and an overdenture, (2) a Dolder bar and an overdenture, and (3) screw-retained two-implant inter-canine porcelain fused to a metal bridge and an implant-assisted removable denture (IARD) with precision attachments. Three biting conditions were generated for each denture type, and the strains were documented under vertical loading of 100 N. Results: The calculated strain values from measured strains in all measurement sites and loading conditions for the screw-retained two-implant intercanine porcelain fused to a metal bridge and a cast framework partial denture with precision attachments situation were lower than in the other scenarios (P<0.05). Conclusion: Within the limitations of the present study, it can be concluded that an IARD may be a reasonable and valuable alternative to ball attachments or a bar in two interforaminal implants, especially when the patients prefer to be able to show their teeth even when they take out their removable dentures.

가상현실 기반 실전적 정밀사격훈련 구현 연구 (A study on the actual precision shooting training based on virtual reality)

  • 이병학;김종환;신규용;김동욱;이원우;김남혁
    • 융합보안논문지
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    • 제18권4호
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    • pp.62-71
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    • 2018
  • 4차 산업혁명 시대에 가상현실 기술의 급속한 성장은 국방 분야에서도 ICT 융합과 더불어 군사훈련체계의 과학화를 가속 시키고 있다. 최근 육군에서는 사격장 소음문제에 따른 민원증가, 사격장 안전사고 예방, 그리고 훈련비용 절감과 같은 민감한 사안을 해결하기 위해 모의 사격훈련 시뮬레이터 연구개발이 활발하게 진행되고 있다. 본 논문에서는 기존의 사격훈련시뮬레이터의 기술적 한계점을 살펴보고 이를 극복하기 위해 훈련자 중심의 공간 동기화 기법과 미소각 근사 수정질점탄도모델을 제안한다. 자체 개발한 정밀사격 시뮬레이터 MARS(medium range assault rifle shooting simulator)에 조성된 혼합현실(mixed reality) 환경에서 반응조끼(haptic vest)를 착용한 훈련자는 가상적군과 양방향 교전간 실시간 피격을 경험할 뿐만 아니라 실제 탄도궤도가 적용된 정밀사격훈련을 수행하게 되어 훈련 결과에 따른 신뢰 높은 훈련평가를 받을 수 있게 되었다.

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다이아몬드 피복공구에 의한 SiC 강화 복합재료의 절삭특성 (Machining Characteristics of SiC reinforced Composite by multiple diamond-coated drills)

  • M. Chen;Lee, Y. M.;S. H. Yang;S. I. Jang
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.533-537
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    • 2003
  • Compared to sintered polycrystalline diamond (PCD), the deposited thin film diamond has a great advantage on the fabrication of cutting tools with complex geometries such as drills. Because of high performance in high speed machining non-ferrous difficult-to-cut materials in the field of automobiles industry, aeronautics and astronautics industry, diamond-coated drills find large potentialities in commercial applications. However, the poor adhesion of the diamond film on the substrate and high surface roughness of the drill flute adversely affect the tool lift and machining quality and they become the main technical barriers for the successful development and commercialization of diamond-coated drills. In this paper, diamond thin films were deposited on the commercial WC-Co based drills by the electron aided hot filament chemical vapor deposition (EACVD). A new multiple coating technology based on changing gas pressure in different process stages was developed. The large triangular faceted diamond grains may have great contribution to the adhesive strength between the film and the substrate, and the overlapping ball like blocks consisted of nanometer sized diamond crystals may contribute much to the very low roughness of diamond film. Adhesive strength and quality of diamond film were evaluated by scanning electron microscope (SEM), atomic force microscope (AFM), Raman spectrum and drilling experiments. The ring-block tribological experiments were also conducted and the results revealed that the friction coefficient increased with the surface roughness of the diamond film. From a practical viewpoint, the cutting performances of diamond-coated drills were studied by drilling the SiC particles reinforced aluminum-matrix composite. The good adhesive strength and low surface roughness of flute were proved to be beneficial to the good chip evacuation and the decrease of thrust and consequently led to a prolonged tool lift and an improved machining quality. The wear mechanism of diamond-coated drills is the abrasive mechanical attrition.

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마리안 무어의 시적 기교와 도덕성 (The Poetic Techniques and Morality of Marianne Moore)

  • 최태숙
    • 영어영문학
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    • 제56권2호
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    • pp.219-236
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    • 2010
  • As a poet, a reviewer of books, and an editor of a major literary journal, Marianne Moore participated in aesthetic revolution which invented the American poetry of the twentieth century. Of all the modernists, she was one of the few truly technical originals, and became an endearing mascot of poetry. Innately attentive to detail, Moore wrote a myriad of poems about animal and plant subjects, and set out to develope and secure her own particular paradigm for modernist poetic and the poetry of objective and scientific description. Foregrounding a mind scientifically trained, Moore used her verse to demonstrate a means by which to see the reality beyond the obvious. Ironically enough, however, a central difficulty with understanding Moore's poetry lies with her concern for such scientific or surface description and precision. In order to understand Moore's poetry fully, it is of special necessity to appreciate relativity among the seemingly disparate entities such as science and literature, as Moore herself did. This paper explores the way in which the poetic techniques of Moore substantiate her sense of morality that underlies the creation of her poetry. Rather than merely addressing her artistic genius or craftsmanship as a modernist poet, Moore's methods engage the power of imagination, magic, lifting the human spirit and eschewing anthropocentric perspectives. For Moore, the poet's magic comes by diligence. In so doing, as I would argue here, Moore draws on the nature of language, especially what Bakhtin insisted with his notions of polyphony and carnival. By introducing openness to various perspectives and meanings in her verse, Moore succeeds in maintaining her own sense of creativity while continuing to acknowledge morality. In a similar skein, her use of active verbs in animal poems and the kaleidoscopic descriptions demonstrate how Moore accommodates imagination and reality, and form and content.

이차구순열 결손의 치료 (THE CORRECTION OF SECONDARY CLEFT LIP DEFORMITIES)

  • 박인순;여환호;김영균;김수관;지재휴;임석균
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제19권2호
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    • pp.135-142
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    • 1997
  • Despite the current accomplishments with the repair of cleft lips, the surgical management of the nasal deformity remains a functional and aesthetic dilemma for patients, their families, and reconstructive surgeons. Recent improvements in the understanding and technical execution of te primary cleft lip repair have significantly reduced secondary sequelae and the consequent need for secondary surgical correction. But, secondary surgical corrections are necessary according to numerous factors. Such factors include the secondary surgical corrections are necessary according to numerous factors. Such factors include the severity of the initial deformity, the surgical plan, precision of execution of the primary repair, and success of the postoperative management. We preformed the secondary correction of cleft lip and palate in 11 patients via various methods. In conclusion, primary repair of cleft lip and palate patients is the most important to prevent the secondary deformities, and most of cleft lip and palate with secondary deformities must be treated with combined cheiloplasty and rhinoplasty.

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대용량 이차전지 관리 시스템용 전력형 션트저항의 열기전력 안정화 (Stabilization of Thermo Electromotive Force of Power Type Shunt Resistor for Mass Storage Secondary Battery Management System)

  • 김은민;이선우
    • 한국전기전자재료학회논문지
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    • 제30권6호
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    • pp.376-380
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    • 2017
  • In this paper, we prepared a metal alloy resistor with stable thermal electro motive force (thermal EMF) as well as a low temperature coefficient of resistance (TCR) by adjusting the manganese proportion from 3 to 12 wt% in the Cu-Mn-Ni alloy. Composition of the fabricated metal alloy was investigated using energy dispersive X-ray (EDX) analysis. The TCR of each sample was measured as 44.56, 40.54, 35.60, and 31.56 ppm for Cu-3Mn-2Ni, Cu-5Mn-2Ni, Cu-10Mn-2Ni, and Cu-12Mn-2Ni, respectively. All the resistor samples were available for the F grade (${\pm}1%$ of the allowable error of resistance) high-precision resistor. All the samples satisfied the baseline of high thermal EMF (under 3 mV at $60^{\circ}C$); however, Cu-3Mn-2Ni and Cu-5Mn-2Ni satisfied the baseline of low thermal EMF (under 0.3 mV at $25^{\circ}C$). We were thus able to design and fabricate the metal alloy resistor of Cu-3Mn-2Ni and Cu-5Mn-2Ni to have low TCR and stable thermal EMF at the same time.

Birth of an 'Asian cool' reference genome: AK1

  • Kim, Changhoon
    • BMB Reports
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    • 제49권12호
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    • pp.653-654
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    • 2016
  • The human reference genome, maintained by the Genome Reference Consortium, is conceivably the most complete genome assembly ever, since its first construction. It has continually been improved by incorporating corrections made to the previous assemblies, thanks to various technological advances. Many currently-ongoing population sequencing projects have been based on this reference genome, heightening hopes of the development of useful medical applications of genomic information, thanks to the recent maturation of high-throughput sequencing technologies. However, just one reference genome does not fit all the populations across the globe, because of the large diversity in genomic structures and technical limitations inherent to short read sequencing methods. The recent success in de novo construction of the highly contiguous Asian diploid genome AK1, by combining single molecule technologies with routine sequencing data without resorting to traditional clone-by-clone sequencing and physical mapping, reveals the nature of genomic structure variation by detecting thousands of novel structural variations and by finally filling in some of the prior gaps which had persistently remained in the current human reference genome. Now it is expected that the AK1 genome, soon to be paired with more upcoming de novo assembled genomes, will provide a chance to explore what it is really like to use ancestry-specific reference genomes instead of hg19/hg38 for population genomics. This is a major step towards the furthering of genetically-based precision medicine.

미용(美容)서비스품질(品質) 지각(知覺)이 구매행동(購買行動)에 미치는 영향 분석(影響 分析) (A Study on the Effect of the Perceived Beauty Service Quality on the Purchase Intention)

  • 김성남;김경인
    • 패션비즈니스
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    • 제10권1호
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    • pp.106-119
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    • 2006
  • The purpose of this study was to analysis how perceived beauty service quality, perceived value influenced on purchase intention of customers. Moreover, this study was suggested strategic solutions for beauty managers and employees to build efficient marketing strategies in order to maximize customer satisfaction. For research method, SPSS 12.0 program was used and for the accuracy of precision of a measuring instrument reliability test was applied. And then simple and multiple regression analysis were performed to examine the effects of independent variables to dependent variables to dependant variables. The results of this study were five folds: the higher perceived service quality of beauty service was, the higher perceived value, satisfaction, word-of-mouth, and intention of revisiting were; the higher perceived value was, the better satisfaction, word-of-mouth, and intention of revisiting were; technical service quality was single most important factor affecting influence on perceived value, satisfaction, word of mouth, intention of revisiting, and functional service quality and physical service quality were listed second and third.

자동차용 LPG 연료펌프의 윤활성 개선에 관한 연구 (A Study on the Improvement of Lubrication Characteristics for Fuel Pump in LPG Engine)

  • 김창업;최교남;강건용;박철웅
    • 한국분무공학회지
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    • 제16권1호
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    • pp.1-6
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    • 2011
  • In recent years, the need for more fuel-efficient and lower-emission vehicles has driven the technical development of alternative fuels such as LPG (Liquefied Petroleum Gas) which is able to meet the limits of better emission levels without many modifications to current engine design. LPG has a high vapor pressure and lower viscosity and surface tension than diesel and gasoline fuels. These different fuel characteristics make it difficult to directly apply the conventional gasoline or diesel fuel pump. Self acting lubricated groove design or coating can be used in high-speed and high precision spindle system like a roller-vane type fuel pump, because of its advantages such as low frictional loss, low heat generation, averaging effect leading better running accuracy and simplicity in manufacturing. Those design method can also affect the atomization of fuel from the injector and the formation of fuel film on the intake manifold. In this study, experiments are carried out to get performance characteristics of initial and steady state operation, The characteristics of vane type fuel pump were investigated to access the applicability on LPLi engine.

콜드호빙에 의한 냉간단조용 금형제작에 관한 연구 (A Study on the Manufacturing Cold Forging Dies by Cold Hobbing)

  • 유헌일;김세환;서희강
    • 대한기계학회논문집A
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    • 제20권2호
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    • pp.594-603
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    • 1996
  • It has been known that the life time of cold forging dies is shorten by the cracks and wear produced during the operation. Thus it is required to mak the same new one too often, At this time of making new ont the cutting work and electical discharge machining were mormally used. But the precision of product is declined in every times of making the mew dies due to the diffefence in dimensional accuracy arised from the electical discharge machining. Especially it can't meet the delivery date because the production was delayed for making another die. Furthemore it has the problem of increasing the production cost. Therfore inthis study we tried to solve these problems using the hobbing method instead of electical discharge machining.