• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.6
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• pp.35-40
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• 2015

An IP-2 type container is used for the transport of low-level radioactive materials. An IP-2 type metal container was modeled and analyzed for the dropping conditions in normal transport conditions required by NSSC Notice 2014-50, "Regulations on the packaging and transport of radioactive materials." Structural analyses were performed by finite element method, and the acceptability was reviewed by comparing the results with technical standards and maximum allowable stresses of each material. Structural members of the container were modeled as 3D solid elements, and the possible dropping directions were considered in these analyses. Results show that maximum stresses, maximum deformed gaps in the cover, and maximum estimated thickness reduction in structural members were well below the allowable limits; thus, the structural integrity of the container was confirmed.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.213-216
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• 2001

극자외선영역의 빛에대한 Mo/Si 반사형 다층 박막 미러를 스퍼터링 시스템으로 증착하여, 특성을 평가한 결과 3mTorr의 낮은 공정 압력에서 최적의 구조인자를 가진 다층 박막을 증착할 수 있었다. TEM, low angle XRD peak, 반사도 그래프로부터 다층 박막의 구조인자를 분석하였으며, 특히 low angle XRD peak로부터 다층박막의 d-spacing, 층간 두께 uniformity에 대한 정보 및 광학적 정보를 간접적으로 분석할 수 있었다. 최대 반사도는 12.7nm 파장에서 약 53%였으며, low angle XRD에서 추출한 d-spacing 값이 TEM 이미지에서 측정한 값보다 더 정확한 값을 얻을 수 있었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.595-600
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• 2007

This paper presents a new jetting dispenser driven by a piezoelectric actuator at high operating frequency to provide very small dispensing dot size of adhesive in modern semiconductor packaging processes. After describing the mechanism and operational principle of the dispenser, a mathematical model of the structured system is derived by considering behavior of each component such as piezostack and dispensing needle. In the fluid modeling, a lumped parameter method is applied to model the adhesive whose rheological property is expressed by Bingham model. The governing equations are then derived by integrating the structural model with the fluid model. Based on the proposed model, dispensing performances such as dispensing amount are investigated with respect to various input trajectories.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.4
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• pp.432-438
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• 2008

This paper presents a new jetting dispenser driven by a piezoelectric actuator at high operating frequency to provide very small dispensing dot size of adhesive in modern semiconductor packaging processes. After describing the mechanism and operational principle of the dispenser, a mathematical model of the structured system is derived by considering behavior of each component such as piezostack and dispensing needle. In the fluid modeling, a lumped parameter method is applied to model the adhesive whose rheological property is expressed by Bingham model. The governing equations are then derived by integrating the structural model with the fluid model. Based on the proposed model, dispensing performances such as dispensing amount are investigated with respect to various input trajectories.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.1
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• pp.29-34
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• 2000

In this paper, the damping characteristics for electrostatically driven micro mirror which have deep grooves on their driving electrodes were investigated. A coupled simulation of gas flow and structural displacement of the micro mirror using the Finite-Element-Method is applied to this. The damping farce is caused by squeeze action of the gas film between a moving mirror plate and the electrodes. The grooves decrease the damping force and enable the moving plate to be driven at high speed and low driving voltage.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.39-45
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• 2020

The Cu/Cu2O/CuO photoelectrode has been successfully fabricated by Rapid Thermal Annealing technique. The structural characterization of fabricated photoelectrode was performed using X-Ray diffraction, while elemental composition of the prepared material has been checked with X-Ray Photoelectron Spectroscopy. The synthesis parameters are optimized on the basis of photoelectrochemical performance. The best photoelectrochemical performance has been observed for the Cu/Cu2O/CuO photoelectrode fabricated at 550 ℃ oxidation temperature and oxidation time of 50 seconds with highest photocurrent density of -3 mA/㎠ at -0.13 V vs. RHE.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.2938-2956
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• 2020

Objective image quality assessment (IQA) models have been developed by effective features to imitate the characteristics of human visual system (HVS). Actually, HVS is extremely sensitive to color degradation and complex texture changes. In this paper, we firstly reveal that many existing full reference image quality assessment (FR-IQA) methods can hardly measure the image quality with contrast and masking texture changes. To solve this problem, considering texture masking effect, we proposed a novel FR-IQA method, called Texture and Color Quality Index (TCQI). The proposed method considers both in the masking effect texture and color visual perceptual threshold, which adopts three kinds of features to reflect masking texture, color difference and structural information. Furthermore, random forest (RF) is used to address the drawbacks of existing pooling technologies. Compared with other traditional learning-based tools (support vector regression and neural network), RF can achieve the better prediction performance. Experiments conducted on five large-scale databases demonstrate that our approach is highly consistent with subjective perception, outperforms twelve the state-of-the-art IQA models in terms of prediction accuracy and keeps a moderate computational complexity. The cross database validation also validates our approach achieves the ability to maintain high robustness.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.143-149
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• 2022

PCS needs to freely switch AC and DC to connect the battery, external AC loads and renewable energy in both directions for energy efficiency. Whenever converting happens, power loss inevitably occurs. Minimization of the power loss to save electricity and convert it for usage is a very critical function in PCS. PCS plays an important role in the ESS(Energy Storage System) but the importance of stabilizing semiconductors on PCB(Printed Circuit Board) should be empathized with a risk of failure such as a fire explosion. In this study, the temperature variation inside PCS was reviewed by cooling fan on top of PCS, and the vibration characteristics of PCS were analyzed during truck transportation for reliability of the product. In most cases, a cooling fan is mounted to control the inner temperature at the upper part of the PCS and components generating the heat placed on the internal aluminum cooling plate to apply the primary cooling and the secondary cooling system with inlet fans for the external air. Results of CFD showed slightly lack of circulating capacity but simulated temperatures were durable for components. The resonance points of PCS were various due to the complexity of components. Although they were less than 40 Hz which mostly occurs breakage, it was analyzed that the vibration displacement in the resonance frequency band was very insufficient. As a result of random-vibration simulation, the lower part was analyzed as the stress-concentrated point but no breakage was shown. The steel sheet could be stable for now, but for long-term domestic transportation, structural coupling may occur due to accumulation of fatigue strength. After the test completed, output voltage of the product had lost so that extra packaging such as bubble wrap should be considered.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.417-423
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• 2007

This paper describes how using the XPS Document technologies of Windows Vista support and enhances interactions with the structural design and construction process. It illustrates the document workflows and the document life cycle in a typical construction base knowledge system. It provides engineers and decision makers and implementers with information about this new technology and how they can apply it to their design and construction models. The paper also highlights opportunities for the new format of data exchange in the recent efforts to develop National Management System Standards for Transportation Applications to benefit from these emerging technologies.

• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.448-453
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• 2012

Nitrogen-incorporated $SnO_2$ thin films were deposited by rf magnetron sputtering. Comparative structural, electrical and optical studies of thin films deposited by sputtering of the Sn metallic target and sputtering of the $SnO_2$ ceramic target were conducted. The $SnO_2$ thin films deposited by sputtering of the Sn metallic target had a higher electrical conductivity due to a higher carrier concentration than those by sputtering of the $SnO_2$ ceramic target. Structurally the $SnO_2$ thin films deposited by sputtering of the $SnO_2$ ceramic target had a better crystallinity and a larger grain size. This study confirmed that there were distinct and clear differences in electrical, structural, and optical characteristics between $SnO_2$ thin films deposited by reactive sputtering of the Sn metallic target and by direct sputtering of the $SnO_2$ ceramic target.