• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.32-35
• /
• 1997

A recent development in the Flat Panel Display(FPD) industry requires an auto-alignment system which is operated in high speed and high precision. In the FPD production process, aligning photo-mask with respect to guide mark printed in the glass should be accomplished in the accuracy of sub-micron order. So the system has high bandwidth and needs a dedicated control system which is fast and robust enough to control linear motors in precise manner. Proposed auto-alignment system structure in this presentation which consists of the master controller board, the DSP position controller board which controls 3 axis precision linear motors, the servo system and the man machine interface software. Designed and tuned under repeated experiments, the proposed system showed a reasonable performance in the aspect of rise time and steady state error.

• Transactions on Control, Automation and Systems Engineering
• /
• v.2 no.1
• /
• pp.62-68
• /
• 2000

Fixtures are used in almost all phases of machining and assembly to position and hold a part accurately. The class of fixture which consists of 3 locators and 1 clamp(3L/1C) is known as the minimal set that can provide form closure which is a kinematic constraint condition for preventing all planar motions. This type of fixtures has advantages in terms of the number of fixture elements required, the time for clamping, and so on. However it is not widely used in industry because reliable loading scheme has not been reported. In this paper, we propose a method to load the class of 3L/1C fixtures using compliant motions. The planner is developed for synthesizing compliant motions to achieve precise final fixture configuration in the presence of sensing and control uncertainties. A novel approach to eliminate uncertainty in part orientation by adding one extra fixture element called an aligning pin is proposed.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.10
• /
• pp.911-916
• /
• 2015

In the nano/micro scale, material properties are dependent on the size-scale of a structure. However, conventional micro-scale tensile tests have limitations to obtain reliable values of nano-scale material properties owing to residual stress and elastic slippage in the gripping/aligning process. The indenter-driven nano-scale tensile test provides prominent advantages simple testing device, high-quality nano-scale metallic specimen with negligible residual stress. In this paper, two-types of specimens (a specimen with multi-testing parts and a specimen with a single-testing part) are discussed. Focused ion beam (FIB) is employed to fabricate a nano-scale specimen from a thin nickel film. Using the specimen with a single-testing part, we obtained a nano-scale stress-strain curve of electroplated nickel film.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2002.02a
• /
• pp.123-126
• /
• 2002

Samples of Nb/Al-Al$O_{x}$/Nb tunnel junction with the size of 50$\mu$m $\times$ 50$\mu$m were fabricated by employing self-aligning and reactive ion etching technique. In the samples with high-quality, $V_{m}$ value (the product of the critical current and subgap resistance measured at 2 mV) was 34 mV at the critical current density $J_{c}$ = 500 A/$cm^{2}$ and $V_{g}$ value (the gap voltage) was 2.8 mV. In the higher $J_{c}$, voltage fluctuation in the current rising at the gap voltage was observed. The $V_{m}$ and $J_{c}$ value were 8 mV and 900 A/$cm^{2}$, respectively.

• Journal of Computing Science and Engineering
• /
• v.3 no.2
• /
• pp.109-126
• /
• 2009

Taxonomies are widely used to classify information, and multiple (possibly competing) taxonomies often exist for the same domain. Given a set of correspondences between two taxonomies, it is often necessary to "merge" the taxonomies, thereby creating a unied taxonomy (e.g., that can then be used by data integration and discovery applications). We present an algorithm for merging taxonomies that have been related using articulations given as RCC-5 constraints. Two taxa Nand M can be related using (disjunctions of) the ve base relations in RCC-5: M; N ${\subseteq}$M; N ${\supseteq}$; N ${\oplus}$M (partial overlap of Nand M); and N ! M (disjointness: N ${\cap}$M = ${\varnothing}$). RCC-5 is increasingly being adopted by scientists to specify mappings between large biological taxonomies. We discuss the properties of the proposed merge algorithm and evaluate our approach using real-world taxonomies.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.8 no.4
• /
• pp.194-201
• /
• 2000

It is called vehicle pull when a vehicle drifts in the lateral direction under the straight-ahead motion with no steering or external input. Recently vehicle pull draws attention as one of the critical evaluation items from the customers on the vehicle quality. It is generally recognized that the vehicle pull is complex phenomena due to internal and external factors. In this paper the relations between vehicle pull and ire were investigated through close survey on the road test results from the final inspection of car manufactures. Through this investigation the factors are identified which play an important role in causing vehicle pull problem.

• MALSORI
• /
• v.68
• /
• pp.95-114
• /
• 2008

The recent growing popularity of statistical methods in machine translation requires much more large parallel corpora. A Korean-English parallel corpus, however, is not yet enoughly available, little research on this subject is being conducted. In this paper we present a hybrid method of aligning sentences for Korean-English parallel corpora. We use bilingual news wire web pages, reading comprehension materials for English learners, computer-related technical documents and help files of localized software for building a Korean-English parallel corpus. Our hybrid method combines sentence-length based and word-correspondence based methods. We show the results of experimentation and evaluate them. Alignment results from using a full translation model are very encouraging, especially when we apply alignment results to an SMT system: 0.66% for BLEU score and 9.94% for NIST score improvement compared to the previous method.

• Journal of Welding and Joining
• /
• v.21 no.4
• /
• pp.87-91
• /
• 2003

Effects of the circular and non-circular pad shapes on self-alignment in BGA soldering are predicted using Surface Evolver, and the calculated results are compared with experimental data. While the pad shape has minor effects on self-alignment in the vertical direction, self-alignment in the lateral direction depends on the pad direction and length ratio of the non-circular pad. Larger restoring force is obtained in the minor-axis direction than the major-axis direction, which suggests a possibility of reducing misalignment in the specific direction. The restoring force of the circular pad is between those of the non-circular pad in the major and minor-axis directions. The calculated results of Surface Evolver show reasonably good agreements with experimental data using the shear loading system.

• Journal of Korea Multimedia Society
• /
• v.13 no.12
• /
• pp.1748-1759
• /
• 2010

We extend the octree subdivision process from Cartesian coordinates to spherical coordinates to develop more efficient space-partitioning structure for surface models. As an application of the proposed structure, we apply the octree subdivision in spherical coordinates ("S-Octree") to geometry compression in progressive mesh coding. Most previous researches on geometry-driven progressive mesh compression are devoted to improve predictability of geometry information. Unlike this, we focus on the efficient information storage for the space-partitioning structure. By eliminating void space at initial stage and aligning the R axis for the important components in geometry information, the S-Octree improves the efficiency in geometry information coding. Several meshes are tested in the progressive mesh coding based on the S-Octree and the results for performance parameters are presented.

• Proceedings of the KAIS Fall Conference
• /
• 2009.12a
• /
• pp.850-853
• /
• 2009

반도체 조립공정에서 사용되는 Pick and Placement장비는 반도체패키지를 컴퓨터 비젼을 이용하여 위치 정렬하고 Placement Tray에 적재하는 장비로서 고속,고정밀도가 요구된다. 다변량 통계적 분석방법인 주성분 분석법은 주어진 데이터에서 특징이 되는 일정한 패턴을 찾는 방법으로 영상의 차원감소를 위해 최근 많이 사용되어지고 있다. 본 논문에서는 반도체패키지의 기하학적 형태를 이용하여 위치정렬을 하도록 한 후 성능을 검증하도록 하였다. 패키지 원영상에서 밝기값의 차이에 따른 윤곽선을 인식한 후, 각 위치값들을 주성분 분석법을 이용해 직선을 추출한 방법으로 위치정렬한 결과 신뢰할만한 위치정렬 성능을 보였다.