• 반도체디스플레이기술학회지
• /
• 제10권4호
• /
• pp.53-59
• /
• 2011

Recently there have been considerable attentions on nanoimprint lithography (NIL) by the display device and semiconductor industry due to its potential abilities that enable cost-effective and high-throughput nanofabrication. Although one of the current major research trends of NIL is large-area patterning, the technical difficulties to keep the uniformity of the residual layer become severer as the imprinting area increases more and more. In this paper we focused on the deformation of the $2^{nd}$ generation TFT-LCD sized ($370{\times}470mm^2$) large-area soft mold in the UV imprinting process. A mold was fabricated with PDMS(Poly-dimethyl Siloxane) layered glass back plate(t0.5). Besides, the mold includes large surrounding wall type protrusions of 1.9 mm width and the via-hole(7 ${\mu}m$ diameter) patterend area. The large surrounding wall type protrusions cause the proximity effect which severely degrades the uniformity of residual layer in the via-hole patterend area. Therefore the deformation of the mold was calculated by finite element analysis to assess the effect of large surrounding wall type protrusions and the flexiblity of the mold. The deformation of soft mold was verified by the measurements qualitatively.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제7권4호
• /
• pp.691-698
• /
• 2015

The hydrodynamic interaction forces and moments induced by the vicinity of bank on a passing vessel are known as wall effects. In this paper, the characteristics of interaction acting on a passing vessel in the proximity of a semi-circle bank wall are described and illustrated, and the effects of ship velocity, water depth and the lateral distance between vessel and semi-circle bank wall are discussed. For spacing between ship and semi-circle bank wall (SP) less than about 0.2 L and depth to ship's draft ratio (h/d) less than around 2.0, the ship-bank interaction effects increase steeply as h/d decreases. However, for spacing between ship and semi-circle bank wall (SP) more than about 0.3 L, the ship-bank interaction effects increase slowly as h/d decreases, regardless of the water depth. Also, for spacing between ship and semi-circle bank wall (SP) less than about 0.2 L, the hydrodynamic interaction effects acting on large vessel increase largely as ship velocity increases. In the meantime, for spacing between ship and semi-circle bank wall ($S_P$) more than 0.3 L, the interaction effects increase slowly as ship velocity increases.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제4권1호
• /
• pp.1-8
• /
• 2012

The hydrodynamic interaction between ship and bank can't be neglected when a vessel is app- roached toward the tip of a wedge-shaped bank in restricted waterways, such as in a harbor, near some fixed obstacles, or in a narrow channel. In this paper, the characteristic features of the hydrodynamic interaction acting on a slowly moving vessel in the proximity of a wedge-shaped bank are described and illustrated, and the effects of water depth and the spacing between ship and wedge-shaped bank are summarized and discussed based on the slender body theory. From the theoretical results, it indicated that the hydrodynamic interactions decrease as wedge-shaped bank of angle ${\beta}$ in-creases. For water depth to draft ratio less than about 2.0, the hydrodynamic interactions between ship and bank in-crease sharply as h/d decreases, regardless of the wedge-shaped bank of angle ${\beta}$. Also, for lateral separation more than about 0.2L between ship and wedge-shaped bank, it can be concluded that the bank effects decrease largely as the separation increases.

• International Journal of Contents
• /
• 제15권1호
• /
• pp.32-38
• /
• 2019

In an environment where a large number of weapons are operated compared to a large number of ground targets, it is important to monitor and manage the targets to set up a fire plan, and through their multilateral analysis, to equip them with a priority order process for targets having a high threat level through the quantitative calculation of the threat level. Existing studies consider the anti-aircraft and anti-ship targets only, hence, it is impossible to apply the existing algorithm to ground weapon system development. Therefore, we proposed an effective threat evaluation algorithm for multiple ground targets in multi-target and multi-weapon environments. Our algorithm optimizes to multiple ground targets by use of unique ground target features such as proximity degree, sorts of weapons and protected assets, target types, relative importance of the weapons and protected assets, etc. Therefore, it is possible to maximize an engagement effect by deducing an effective threat evaluation model by considering the characteristics of ground targets comprehensively. We carried out performance evaluation and verification through simulations and visualizations, and confirmed high utility and effect of our algorithm.

• Structural Engineering and Mechanics
• /
• 제91권1호
• /
• pp.103-121
• /
• 2024

The smoothed particle hydrodynamics (SPH) method is a numerical technique used in dynamic analysis to simulate the fluid-like behavior of materials under extreme conditions, such as those encountered in explosions or high velocity impacts. In SPH, fluid or solid materials are discretized into particles. These particles interact with each other based on certain smoothing kernels, allowing the simulation of fluid flows and predict the response of solid materials to shock waves, like deformation, cracking or failure. One of the main advantages of SPH is its ability to simulate these phenomena without a fixed grid, making it particularly suitable for analyzing complex geometries. In this study, the structural damage to a masonry arch bridge subjected to blast loading was investigated. A high-fidelity micro-model was created and the explosives were modeled using the SPH approach. The Johnson-Holmquist II damage model and the Mohr-Coulomb material model were considered to evaluate the masonry and backfill properties. Consistent with the principles of the JH-II model, the authors developed a VUMAT code. The explosive charges (50 kg, 168 kg, 425 kg and 1000 kg) were placed in close proximity to the deck and pier of a bridge. The results showed that the 50 kg charges, which could have been placed near the pier by a terrorist, had only a limited effect on the piers. Instead, this charge caused a vertical displacement of the deck due to the confinement effect. Conversely, a 1000 kg TNT charge placed 100 cm above the deck caused significant damage to the bridge.

• 한국경제지리학회지
• /
• 제18권3호
• /
• pp.267-280
• /
• 2015

시장규모와 기술력, 자본력이 작은 유럽 민간 항공산업이 세계시장을 정복하기 위해 채택한 생산논리는 참여국가의 부존자원을 결집시킨 국제합작 단일기업 형태의 공동개발 분업생산방식이었다. 전문화된 분업생산방식으로 각 생산입지는 지난 40년 동안 기술적 경험에 의한 학습효과와 상호작용을 촉진하는 지리적 근접성의 논리에 따라 관련 생산시설과 생산설비, 전문 협력업체와 하청업체, 관련 대학 및 연구소 등을 집적시키며 전문화를 강화해 왔다. 중 단거리 항공기 생산에서 전용 화물수송기를 이용한 물류연계체계는 지역간 시 공간을 단축시켜 분업화된 생산공정의 지리적 분산입지와 분산된 생산입지의 효율적인 물류연계를 가능하게 하였다. 그러나 부피와 무게로 전용 화물수송기에 의한 물류연계가 어려운 대형항공기 A380의 물류연계에는 전용 화물선이 선정되었다. 전용 화물선을 이용한 물류연계체계를 고려할 때, 최종조립공장의 입지로 내륙에 위치한 툴루즈의 선택은 해상과 육상이 연계된 복잡한 물류연계체계를 요구하기 때문에 입지측면에서 비합리적인 입지선택이었다. 이러한 입지선택은 유럽 민간 항공산업의 통합과정과 학습효과 및 지리적 근접성의 논리, 정부의 적극적인 유치지원정책에 의해 설명된다.

• 기술혁신학회지
• /
• 제21권1호
• /
• pp.354-384
• /
• 2018

본 연구는 사회적 자본의 관점에서 혁신중개인과 기업과의 관계가 흡수역량에 어떠한 영향을 미치는지 분석한다. 그리고 기업의 혁신환경요인은 이 과정에서 직 간접적으로 흡수역량에 어떠한 영향을 미치는지에 대해 연구한다. 이를 위해 국내 대표적인 혁신클러스터인 대덕연구개발특구 내 입주하고 있는 200여개 기업을 대상으로 실증분석을 수행함으로써 제시한 연구질문을 검증하고자 한다. 주요 연구결과는 기업이 활용하고 있는 혁신중개인의 관계와 혁신환경요인이 흡수역량과의 관계에서 전반적으로 유의한 정(+)의 효과가 있음을 보여준다. 세부적으로 혁신중개인의 관계 중에서 신뢰도 및 소통빈도는 흡수역량에 유의한 영향을 미치며, 반면에 지리적 근접성에 대해서는 유의하지 않은 것으로 분석되었다. 또한, 혁신중개인이 기업의 흡수역량에 미치는 영향에서 기업이 직면하고 있는 혁신환경요인은 정(+)의 조절역할을 하며, 하위차원에서는 사회적 요인이 뚜렷하고 긍정적인 영향을 미친다는 사실을 조명하고 있다. 본 연구는 기업의 기술혁신과정에서 혁신중개인의 역할과 흡수역량의 선행요인으로서의 혁신중개인의 중요성과 더불어 혁신환경요인의 중요성 대한 이해에 기여한다.

• 콘크리트학회논문집
• /
• 제24권4호
• /
• pp.415-422
• /
• 2012

이 연구에서는 FRP 부재를 이용한 표면매입 보강에서, FRP의 부착강도를 평가하기 위하여 총 78개의 기존실험 결과를 분석하고, 기존 연구자들에 의해 제안된 식들을 평가하였다. 그 결과 FRP부재의 형상계수(폭-두께비)와 강성을 반영한 Seracino의 식이 부착내력을 가장 근사하게 예측하는 것으로 나타났다. 그러나 Seracino의 식은 실험 결과를 다소 과소평가하는 양상을 보이고 특히 부착길이가 작을수록 그 경향이 두드러진 것으로 나타났다. 이는 부착길이 증가에 따른 영향이 Seracino의 식에는 전혀 반영되어있지 않기 때문으로 볼 수 있다. 기존 실험 결과의 분석을 통하여 부착길이와 강도와의 상관관계를 찾고 또한 여러 개의 FRP부재를 인접하여 배치시 발생하는 무리효과를 고려하여 Seracino 식을 수정 제안하였다. 이 제시된 식을 이용하여 기존 실험체에 대한 내력을 계산하고 평가한 결과, 제안된 식으로서 표면매입 보강된 FRP의 부착강도를 매우 근사하게 예측할 수 있는 것으로 나타났다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제1권6호
• /
• pp.707-716
• /
• 1997

Recent reports revealed that the $Na^+-Ca^{2+}$ exchangers and feet structures of sarcoplasmic reticulum(SR) are located in close vicinity in the specific compartment. Therefore, we investigated the possibility that the $Na^+-Ca^{2+}$ exchanger may decrease the tension development by transporting the $Ca^{2+}$ out of the cell right after it released from SR, on the basis of this anatomical proximity. We exammined the negative force-frequency relationship of the developed tension in the electrically field stimulated left atria of postnatal developing rat(1, 3 day, 1 week and 4 week old after birth). Cyclopiazonic $acid(3{\times}10^{-5}\;M)$ treatment decreased the developed tension further according to postnatal age. $Monensin(3{\times}10^{-6}\;M)$ treatment did not increase the maximal tension in 4 week-old rat, preserving negative staircase, while the negative staircase in the younger rat were flattened. $Ca^{2+}$ depletion in the buffer elicited more suppression of the maximal tension according to the frequency in all groups except the 4 week-old group. The % decrease of the maximal developed tension of 4 week-old group at 1 Hz to that of 0.1 Hz after $Na^+$ and $Ca^{2+}$ depletion was only a half of those of the yonger groups. Taken together, it is concluded that the $Na^+-Ca^{2+}$ exchange transports more $Ca^{2+}$ released from SR out of the cell in proportion to the frequency, and this is responsible for the negative staircase effect of the rat heart.

• 유통과학연구
• /
• 제17권6호
• /
• pp.77-84
• /
• 2019

Purpose - Although an extensive body of research in psychology and marketing focuses on perceived waiting time, no research has examined the effect of the location of the waiting place on perceived waiting time. In particular, this study suggests that customers who are waiting in a restaurant may have different perceived waiting time depending on whether they are in close proximity to the service area (e.g., dining area) or farther from it. In particular, the author examines how and why the location of the waiting place affects the perceived waiting time of the consumer and reveals the mental simulation as its psychological mechanism. Research design, data, and methodology - This study conducted field surveys with customers waiting in real restaurants. Eighty-eight people participated under two conditions: a restaurant with a waiting place near the dining area and a restaurant with a waiting place far from the dining area. Participants responded to questions about perceived waiting time (the dependent variable), mental simulation (the mediator), and demographic variables. To verify the hypothesis, ANOVA and bootstrapping analysis were performed. Results - The major results from the field study are as follows. First, participants perceived wait time differently depending on the location of the restaurant's waiting place: participants in the restaurant with a waiting place close to the dining area perceived significantly shorter waiting times. Second, the effect of the location of the waiting place on the perceived waiting time was mediated by mental simulation: the closer the wait location is to the dining area, the more imagination the customer exercises about the meal, which in turn distracts attention from time flow and shortens the perceived wait time. Conclusion - This study has a theoretical implication in that it extends research on perceived waiting time as the first study of how and why the location of a waiting place affects a customer's perceived waiting time. It has a practical implication that can be used as a marketing tactics to improve the image of the service provider by changing the location of the waiting place.