• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.637-640
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• 2023

This paper presents multimodal image fusion with human pose for detecting abnormal human behaviors in low illumination conditions. Detecting human behaviors in low illumination conditions is challenging due to its limited visibility of the objects of interest in the scene. Multimodal image fusion simultaneously combines visual information in the visible spectrum and thermal radiation information in the long-wave infrared spectrum. We propose an abnormal event detection scheme based on the multimodal fused image and the human poses using the keypoints to characterize the action of the human body. Our method assumes that human behaviors are well correlated to body keypoints such as shoulders, elbows, wrists, hips. In detail, we extracted the human keypoint coordinates from human targets in multimodal fused videos. The coordinate values are used as inputs to train a multilayer perceptron network to classify human behaviors as normal or abnormal. Our experiment demonstrates a significant result on multimodal imaging dataset. The proposed model can capture the complex distribution pattern for both normal and abnormal behaviors.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.1
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• pp.39-43
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• 2003

Thermal management is very important for the success of high density circuit design in LTCC. In this paper, LTCC substrates containing thermal via and pad were fabricated in order to study the influence of the thermal dissipation. To realize the accurate thermal analysis for structure design, a series of simple thermal conductivity measurement by laser flash method and parametric numerical analysis have been carried out. The LTCC substrate including via and Ag pad has good thermal conductivity over 103 W/mK which is 44% value of pure Ag material. Thermal behaviors with via arrays, size and density in the LTCC substrate were studied by numerical method.

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.25-31
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• 2017

This study investigates changes in the mechanical behaviors, especially hardness and indentation load-displacement curves, of thermal barrier coatings (TBCs) brought about by thermal shock. The TBCs on the Nickel-based bondcoat/superalloy was prepared with diameters of 25.4 mm and $600{\mu}m$ thickness. The results of thermal shock cycling test from $1100^{\circ}C$ of the highest temperature indicate that the thermal shock do not influence on the mechanical behavior, but a continuous decrease in porosity and increase in hardness were observed after 1200 thermal shock cycles; these changes are believed to be due to sintering of thermal barrier coating materials. The results that no degradation in the indentation load-displacement curves indicate that the coating shows good thermal shock resistance up to 1200 cycles at $1100^{\circ}C$ in air.

• Polymer(Korea)
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• v.24 no.3
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• pp.350-357
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• 2000

Curing behaviors of glass/epoxy prepreg for printed circuit boards (PCB) were studied by using dielectrometer and differential scanning calorimeter. This prepreg was showed the lowest ionic viscosity at about 115$^{\circ}C$, and then the ionic viscosity was gradully increased up to 15$0^{\circ}C$. This indicated that the curing reaction of this prepreg started at 115$^{\circ}C$ and the molecular weight was increased by the accelerated thermal cross-linking reaction. The loss factor and tan $\delta$ values were also measured and discussed. The dielectric behaviors of this prepreg system were also measured according to the cure cycle for PCB. This material was found to be thermally stable up to about 30$0^{\circ}C$ and then was showed an abrupt decomposition beyond this temperature.

• Tribology and Lubricants
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• v.19 no.5
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• pp.268-273
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• 2003

This paper presents hot spot behaviors on the rubbing surface of disk-pad type brake by using coupled thermal-mechanical analysis technique. The height of micro-asperity on the rubbing surface is usually 2∼3 ${\mu}$m in practical disk brakes. Non-uniform micro-contacts between the disk and the rigid friction pads lead to high local temperature distributions, which may cause the material degradation, and develop hot spots, thermal cracks, and brake system failure at the end for a braking period. The friction temperatures on the rubbing surface of disk brakes in which are strongly related to the hot spot and thermal related wears are rapidly concentrated on the micro-contact asperities during braking. The computed FEM results show that the contact stress, friction induced temperature and thermal strain are highly concentrated on the rubbing micro-contact asperities even though the braking speed and force are small during the braking period. This hot spot may directly produce the slippage and various thermal wears on the brake-rubbing surface.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.323-328
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• 2004

This study measured the thermal environment and residents' cooling behavior of the apartments' living rooms in summer in Seoul. The purpose of this study is to find out the present thermal environment of the living rooms and to find out the target figure of passive cooling system. The surveys and measurements took place in six apartments of Seoul for 60days(2004. 7. 3${\sim}$2004. 8. 31). The result were summarized as follows; The thermal environment of apartments' living rooms were almost neutral, and residents felt a little uncomfortable. Residents turned on the air conditioner at $27.31^{\circ}C$ of indoor temperature, and $28.89^{\circ}C$ of SET*. Therefore, cooling critical temperature of the passive cooling system can be figured out from this result.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.6
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• pp.800-808
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• 1998

In this study the thermal stress distribution and deformantion characteristics resulting from the nonuniform temperature fields of the cylinder block of a light 3-cylinder 4-stroke gasoline engine were analyzed using the 3-dimensional finite element method. The temperature distributions req-uisite for the thermoelastic behavior alalysis were obtained from the steady-state heat conduction analysis performed on the basis of experimental data. in order to examine the effect of a ceramic material the cylinder liner was replaced by the silicon nitride($Si_{3}N_{4}$) and its thermal behaviors were compared with those of the original block.

• Tribology and Lubricants
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• v.15 no.2
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• pp.199-205
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• 1999

Using a coupled thermal-mechanical analysis, the thermal distortion of the ventilated disk brakes has been investigated based on the air cooling effects during 15 braking operations. The FEM results show that the bendings and distortions of the disk toward the left side are decreased, but the sinusoidal distortion of the disk rubbing surface along the arc length of the vent hole is highly increased by increasing the convective air cooling effects, which is heavily related to the squeal, wear and micro-thermal crackings at the rubbing surfaces due to uneven dissipation rates of friction heatings.

• Journal of the Semiconductor & Display Technology
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• v.12 no.2
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• pp.93-98
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• 2013

Nanoimprint lithography (NIL) is a next generation technology for fabrication of micrometer and nanometer scale patterns. There have been considerable attentions on NIL due to its potential abilities that enable cost-effective and high-throughput nanofabrication to the display device and semiconductor industry. To successfully imprint a nanosized pattern with the thermal NIL, the process conditions such as temperature and pressure should be appropriately selected. This starts with a clear understanding of polymer material behavior during the thermal NIL process. In this paper, a filling process of the polymer resist into nanometer scale cavities during the thermal NIL at the temperature range, where the polymer resist shows the viscoelastic behaviors with consideration of stress relaxation effect of the polymer. In the simulation, the filling process and the residual layer formation are numerically investigated. And the effects of pressure and temperature on NIL process, specially the residual layer formation are discussed.

• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.396-403
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• 2011

In this study, we investigated the mechanical behaviors of layered thermal barrier coatings by indentations. Various single and double-layered thermal barrier coatings were deposited by air plasma spray process using different type of commercialized YSZ (Yttria stabilized zirconia) starting powders. Indentation stress-strain curve, load-displacement curve and hardness of the single and the double-layered thermal barrier coatings were obtained experimentally and analyzed. The indentation damages at the same loads were compared, and thus, the results depend on the structure of each coating. The result indicates improvement in damage resistances from tailoring of layered structures in the component of gas turbine system is expected.