• 제목/요약/키워드: self-alignment

검색결과 143건 처리시간 0.027초

플립칩 솔더링의 자기정렬 효과에 관한 모델링 (Modeling of Self-Aligning Effect in Flip Chip Soldering)

  • 정용진;안도현;유중돈;김용석
    • Journal of Welding and Joining
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    • 제20권6호
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    • pp.789-795
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    • 2002
  • The self-aligning effect is useful in the electronic packaging because it compensates the positional errors occurred in flip chip placement. The solder shapes are predicted in this work either by minimizing the energy of the solder profile using the second-order polynomials or by the Surface Evolver program. The restoring forces and spring constants in vertical and horizontal directions are calculated to estimate the self-aligning effect. The calculated results using the second-order polynomial are similar to those using the Surface Evolver in the vertical direction. However, significant discrepancy between the results using the polynomial and Surface Evolver occurs in the horizontal direction. The assumption of the circular cross-section of the solder joint appears to cause the discrepancy. As the horizontal restoring force and spring constant are smaller than those in the vertical direction, larger aligning error can be resulted in the horizontal direction.

Quantitative Determination of the Chromophore Alignment Induced by Electrode Contact Poling in Self-Assembled NLO Materials

  • Kim, Tae-Dong;Luo, Jingdong;Jen, Alex K.-Y.
    • Bulletin of the Korean Chemical Society
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    • 제30권4호
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    • pp.882-886
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    • 2009
  • The electrode contact poling is one of the efficient tools to induce a stable polar order of nonlinear optical (NLO) chromophores in the solid film. Self-assembled NLO chromophores with high electro-optic (E-O) activities were utilized for quantitative determination of the chromophore order induced under contact poling by spectroscopic changes. We found that NLO chromophores rarely decompose under the high electric field during contact poling. The absorption spectra were de-convoluted into a sum of Gaussian components to separate energy transitions for a binary composite system which contains a secondary guest chromophore AJC146 in the self-assembled chromophore HDFD. Poling efficiency was significantly improved in the binary system compared to the individual components.

도로선형의 결정에서 토공량 산정에 관한 연구 (A Study on the Earth-work Volume Calculation for Route Alignment of Highway)

  • 최재화;이석배;심정민
    • 한국측량학회지
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    • 제11권2호
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    • pp.89-100
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    • 1993
  • 본 연구는 CAD와 LISP(LIST Processing)을 이용한 도로노선 결정에 있어서의 토공량 산정에 관한 연구이다. 컴퓨터의 비약적인 발전과 산업분야에서의 이용증대는 CAD/CAM/CAE 기술의 발전으로 이어져 자동설계 및 자동제작을 가능케 하고 있으며 또한 토목설계의 자동화도 꾸준히 추진되어 오고 있는 실정이다. 이러한 자동화 작업의 일환으로 본 연구에서는 도로노선 결정시 각 노선의 토공량 산정을 자동화하여 토목설계업무의 효율성을 높이고자 하였다. 연구의 방법으로 지형도에 DTM(Digital Terrain Model) 개념을 도입하여 지형정보를 자동독취할 수 있도록 프로그램화 한 후 이 데이타를 가지고 LISP 언어를 이용하여 체계적인 알고리즘을 만든 후 CAD 시스템과 접목시켜 종·횡단 면적과 토공량을 산정해서 유토곡선을 출력하는 자동설계 시스템을 시험적으로 구축하는 데 그 목적을 두고 있다.

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Effects of Manual Intervention and Self-Corrective Exercise Models of the General Coordinative Manipulation on Balance Restoration of Spine and Extremities Joints

  • Moon, Sang Eun;Kim, Mi Hwa
    • 국제물리치료학회지
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    • 제4권2호
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    • pp.573-587
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    • 2013
  • The purpose of this study was conducted in order to analyze the effects of the manual intervention and self-corrective exercise models of general coordinative manipulation(GCM) on the balance restoration of spine & extremities joints with distortions and mal-alignment areas. The subjects were the members who visited GCM Musculoskeletal Prevent Exercise Center from March 1 2012 to December 31 2013 because of spine & extremities joints distortion and mal-alignments, poor posture, and body type correction. All subjects were diagnosed with the four types of the GBT diagnosis. And according to the standards of the mobility vs stability types of the upper & lower body, they were classified into Group 1(40 persons) and Group 2(24 persons). For every other day for three times a week, GCM intervention models were applied to all subjects for four weeks, adding up to 12 times in total. Then the balance restoration effects were re-evaluated with the same methods. The results are as follows. 1) Balance restoration effects of VASdp(Visual analysis scale pain & discomfort) and ER(Equilibrium reaction: ER) came out higher in GCM body type(GBT) II III IV of Group 1. 2) In case of balance restoration effects in Moire and postural evaluation areas, Group 1 was higher and cervical and scapular girdle were higher in Group 2. The balance restoration of the four GBT types was significant in all regions(p<.05), and the scapular girdle came out as high in the order of GBTII IV I. 3) In case of thoracic-lumbar scoliosis and head rotation facial asymmetric cervical scoliosis ribcage forward, the balance restoration effects of the upper body postural evaluation areas came out the highest in Group 1 and Group 2, respectively. The balance restoration effects of the four GBT types were significant in all regions(p<.05), and came out the highest in lumbar scoliosis GBTIII I, ribcage forward and thoracic scoliosis GBTII IV. 4) The balance restoration effects of the lower body postural evaluation areas came out higher in Group 1 and Group 2 for pelvis girdle deviation patella high umbilicus tilt and hallux valgus foot longitudinal arch: FLA patella direction, respectively. The balance restoration effects of the four GBT types were significant in all regions(p<.05), and came out the highest in pelvis girdle deviation GBTIII I and patella high-direction GBTIV II I. 5) The balance restoration effects between the same GBT came out significant (p<.05) in all evaluation areas and items. The conclusions of this study was the manual intervention and self-corrective exercise models of the GCM about the mal-alignment of the spine & extremities joints across the whole body indicated high balance restoration effects(p<.05) in spine & extremities joints in all evaluation areas.

A distance perception model for AVG based on a moving camera

  • Ant io Cunha;Jo Barroso;Cruz, Jos-Bulas;Jo L. Monteiro
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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    • pp.248-251
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    • 2003
  • This paper presents a distance perception model based around a moving camera, in the context of driving a self-guidance vehicle. Aligned images, by escape points, and acquired by a moving camera, present objects at different positions depending on its relative distance to camera. The objects that are farthest from the observer(the camera) gradually lose their alignment as the distance diminishes. With the current setup, this lack of alignment is noticeable up to a distance of 10 meters. In the paper, the results of real imagery tests are presented and discussed.

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Multimode Configuration Doped with a Chiral Agent for Transflective Liquid Crystal Display with a Single Cell Gap

  • Yu, Chang-Jae;Kim, Jin-Yool;Kim, Dong-Woo;Lee, Sin-Doo
    • Journal of Information Display
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    • 제5권3호
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    • pp.8-13
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    • 2004
  • We demonstrate a transflective liquid crystal display (LCD), doped with a chiral agent to produce a low helical twisting power, in a multimode configuration consisting of the homogeneous alignment and the hybrid alignment. The multimode transflective LCD with a single cell gap was fabricated using a single-step photoalignment technique with a self-masking process of an array of metal reflectors in the reflective region. In our configuration, the electro-optical disparity between the transmissive region and the reflective region was found to be significantly reduced by the low helical twisting power of the chiral dopant.

Optical Compensation in a Vertical Alignment Liquid Crystal Cell for Elimination of the Off-Axis Light Leakage

  • Ji, Seung-Hoon;Choi, Jung-Min;Lee, Gi-Dong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1580-1583
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    • 2008
  • We propose an optical configuration for a vertical alignment (VA) liquid crystal (LC) cell to eliminate the off-axis light leakage in the dark state. The proposed compensation configuration consists of a positive A-film, a positive C-film and a negative C-film. The optical design is performed on a Poincar$\acute{e}$ sphere. This configuration has a better tolerance to the wavelength dispersion, as the polarization trace could self-compensate it. From calculations, we show that the proposed VA LC cell can improve the viewing angle characteristics by compensating for the light leakage in the diagonal direction.

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A Quantitative Self Alignment Method in Incremental Printing: Coalescent Bar Alignment

  • Chun, Y.;Kim, T.Y.
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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    • pp.106-109
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    • 2003
  • The repeatability error creeps in every corner of mechanical design as mechanical design becomes diverse and complicated. Inkjet printing has inherent repeatability error problem due to its nature of seamless incremental image synthesis of partial images. Without the calibration for the repeatability error realization of high print quality or enhancement of other printing performance could be impaired. Printer designers have met this recurrent problem even before the inception of inkjet print device and contrived various solutions as their own intelectual proprietary. Also, it is a trend to perform necessary calibration without painstaking human intervention. To come up with another useful and proprietary solution has become an important ingredient in inkjet printer design. This paper presents such a solution developed at Digital Printing Division of Samsung Electronics Company.

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고성능 $I^2L$을 위한 새로운 제작공정 (A New Process for a High Performance $I^2L$)

  • 한철희;김충기;서광석
    • 대한전자공학회논문지
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    • 제18권1호
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    • pp.51-56
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    • 1981
  • 양호한 특성의 I2L 구조를 구현하기 위한 새로운 공정을 제안하였다. 이 구조에서는, extrinsic base 의 불순물 농도가 높으며, 또한 collector는 불순물 농도가 낮은 intrinsic base와 self align된다. 제안한 공정에서는 spin-on source를 확산원으로 사용하였고, mask 단계를 줄이기 위하여 열처리로 단단해진 spin-on source를 확산 mask로 사용하였다. 이 공정에 의하여 13단 ring oscil-lator를 포함한 시험소자를 6.5μm의 epi 충을 갖는 n/n+ silicon wafer 상에 제작하였다. 제작한 시험소자의 특성은, collector가 세 개인 I2L의 경우 npn transistor의 상향 전류이득은 최대치가 8이었으며, collector가 하나인 I2L의 속도전력적과 최소 전달 지연시간은 각각3.5 pJ과 50ns 이었다.

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Effects of Combination Patterns of Proprioceptive Neuromuscular Facilitation on Cervical Alignment, Self-Awareness and Physique in Patients with Forward Head Posture

  • Oh, Dong Gun;Han, Sang Jin;Yoo, Kyung Tae
    • 국제물리치료학회지
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    • 제7권2호
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    • pp.1018-1024
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    • 2016
  • The purpose of this study was to identify the effects of cervical alignment, pain, and physique to apply proprioceptive neuromuscular facilitation(PNF) techniques in patients with forward head posture (FHP). The subjects of this study were 24 patients diagnosed with FHP. They were randomly divided into two groups: a PNF group(n=12) and a control group(n=12). The intervention was performed a total of 24 times, 30 min a day, six times a week for four weeks. Data on cervical alignment(forward head displacement, FHD), pain(visual analog scale, VAS), and physique(height, weight, and body mass index) were obtained pre- and post-intervention. Two-way repeated measures ANOVA was used to compare the groups and time. For FHD, the VAS, and physique(height and BMI), there was an interaction effect for the groups and time(p<.001, BMI: p<.05) and main effects for time(p<.001, BMI: p<.05). For weight, there were main effects of time(p<.01). For FHD(p<.01) and the VAS(p<.05), there were main effects for the groups. In the PNF group, there were significant improvements in FHD, VAS, and physique. In the control group, there was a significant increase in FHD. The results of this study indicated that PNF intervention using scapular and upper extremity patterns effective in FHP positively. The use of a therapeutic intervention on physique changes may also be effective in improving poor posture and help to better patients' quality of life.