• Journal of the Microelectronics and Packaging Society
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• v.26 no.1
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• pp.9-15
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• 2019

Here, we present a facile route to fabricate a vertically stacked 3D porous structure-based triboelectric nanogenerator (TENG) that can be used to harvest energy from the friction in a repetitive contact-separation mode. The unit component of TENG consists of thin Al foil electrodes integrated with microstructured 3D foams such as Ni, Cu, and polyurethane (PU), which provide advantageous tribo-surfaces specifically to increase the friction area to the elastomeric counter contact surfaces (i.e., polydimethylsiloxane, PDMS). The periodic contact/separation-induced triboelectric power generation from a single unit of the 3D porous structure-based TENG was up to $0.74mW/m^2$ under a mild condition. To demonstrate the potential applications of our approach, we applied our TENGs to small-scale devices, operating 48 LEDs and capacitors. We envision that this energy harvesting technology can be expanded to the applications of sustainably operating portable electronic devices in a simple and cost-effective manner by effectively harvesting wasted energy resources from the environment.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.260-261
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• 2007

본 논문에서는 800MHz와 1.9GHz 대역의 시스템에 적용할 수 있는 20dB 방향성 결합기를 8층 PCB 기판에 내장하여 소형화 및 저가화 할 수 있도록 설계하였다. 방향성 결합기는 4층과 6층에 coupled line으로 적층함으로써, 다층 PCB기판을 최대한 활용하여 공간을 최소화하였다. 또한, 고유전율을 가진 필름을 이용하여, coupled line의 끝에 내장형 고용량 커패시터를 연결하여 설계하였다. 6 $\times$ 6 $\times$ 0.7 (height)$mm^3$ 크기로 설계된 방향성 800MHz 결합기의 경우 -20dB의 coupling 특성, -0.6dB의 transmission 특성, -25dB의 isolation 특성을 나타내었다. 패키징 기판에 내장된 방향성 결합기는 단말기 및 통신시스템의 소형화에 크게 기여할 수 있을 것이다.

• Food Science of Animal Resources
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• v.43 no.4
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• pp.580-593
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• 2023

The purpose of this study was to analyze whether seawater has positive effects on appearance characteristics, such as CIE a^*, and to determine the gas composition concentration that is suitable for maintaining it. Pork hind meat was cured with four types of curing agent for 5 d at 4℃. The different curing agents comprised the control salt, control nitrite pickling salt (CN), treatment brine, and treatment bittern (BT). The cured hams were cooked at 65℃ for 4 h and packaged at O₂:N₂ gas ratios of 7:3, 8:2, and 9:1 for 3 wk. The physicochemical properties were assessed immediately after heating the sample, and the color properties were measured after a 3 wk storage period. Based on the correlation results of the physicochemical properties, BT had a higher curing and cooking yield than the other treatments, owing to its high salinity. Results of color properties for BT (7:3) and CN (8:2) showed similar color CIE L^*, CIE a^* chroma, and hue angle values. Therefore, BT can be said to be a sous-vide curing agent suitable for preserving the color of ham, and a high nitrogen concentration of 30% helps to maintain the appearance of seawater sous-vide ham.

• Journal of Information Technology Services
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• v.15 no.3
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• pp.71-95
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• 2016

In recent years, text mining has been used to extract meaningful insights from the large volume of unstructured text data sets of various domains. As one of the most representative text mining applications, topic modeling has been widely used to extract main topics in the form of a set of keywords extracted from a large collection of documents. In general, topic modeling is performed according to the weighted frequency of words in a document corpus. However, general topic modeling cannot discover the relation between documents if the documents share only a few terms, although the documents are in fact strongly related from a particular perspective. For instance, a document about "sexual offense" and another document about "silver industry for aged persons" might not be classified into the same topic because they may not share many key terms. However, these two documents can be strongly related from the R&D perspective because some technologies, such as "RF Tag," "CCTV," and "Heart Rate Sensor," are core components of both "sexual offense" and "silver industry." Thus, in this study, we attempted to discover the differences between the results of general topic modeling and R&D perspective topic modeling. Furthermore, we package social issues from the R&D perspective and present a prototype system, which provides a package of news articles for each R&D issue. Finally, we analyze the quality of R&D perspective topic modeling and provide the results of inter- and intra-topic analysis.

• Korean Journal of Poultry Science
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• v.33 no.1
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• pp.7-14
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• 2006

The effects of aerobic and vacuum packaging of fresh duck meat on meat qualities including color, cooking loss, shear force, lipid oxidation and fatty acid composition during cold storage were investigated. The result showed that pH of the samples were decreased as increasing storage time, and leg meat showed significantly (p<0.05) higher than breast meat. Redness showed significantly (p<0.05) higher value in breast meat compared to leg meat as increasing the storage time. However, TBARS value showed significantly (p<0.05) higher in breast meat compared to leg meat as increasing storage time. This result suggested that the lower pH affected lipid oxidation and discoloration of the meat samples. However, fatty acid composition of 1 day storage time showed that aerobic packaging of leg meat had lower (p<0.05) ratio of palmitic acid and higher (p<0.05) ratio of linoliec acid, whereas vacuum packaging of leg meat showed higher (p<0.05) ratio of palmitic acid at 7 days storage time than other treatments. Therefore, this data speculated that saturated fatty acid like palmitic acid and unsaturated fatty acid like linoleic acid were affected by lipid oxidation at different storage time. Finally, aerobic packaging meat accelerated lipid oxidation compared to vacuum packaging meat, hence self life was no longer better than vacuum packaging meat without relation of different type of meat from duck.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.3
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• pp.7-11
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• 2017

In this paper, we have studied the characteristics of NAND Flash memory in SONOS Poly-Si Thin Film Transistor (Poly-Si TFT) device. Source/drain junctions(S/D) of cells were not implanted and selective transistors were located in the end of cells. We found the optimum conditions of process by means of the estimation for the doping concentration of channel and source/drain of selective transistor. As the doping concentration was increased, the channel current was increased and the characteristic of erase was improved. It was believed that the improvement of erase characteristic was probably due to the higher channel potential induced by GIDL current at the abrupt junction. In the condition of process optimum, program windows of threshold voltages were about 2.5V after writing and erasing. In addition, it was obtained that the swing value of poly Si TFT and the reliability by bake were enhanced by increasing process temperature of tunnel oxide.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.3
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• pp.89-93
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• 2020

Complex warpage behavior of the electronic packages causes internal stress so many kinds of mechanical failure occur such as delamination or crack. Efforts to predict the warpage behavior accurately in order to prevent the decrease in yield have been approached from various aspects. For warpage prediction, silicon is generally treated as a homogeneous material, therefore it is described as showing no warpage behavior due to thermal loading. However, it was reported that warpage is actually caused by residual stress accumulated during grinding and polishing in order to make silicon wafer thinner, which make silicon wafer inhomogeneous through thickness direction. In this paper, warpage behavior of the single-side polished wafer at solder reflow temperature, the highest temperature in packaging processes, was measured using 3D digital image correlation (DIC) method. Mechanism was verified by measuring coefficient of thermal expansion (CTE) of both mirror-polished surface and rough surface.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.3
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• pp.25-29
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• 2009

High temperature high humidity and thermal shock reliability tests were performed for the board level COB(chip-on-board) flip chip packages using self-formulated and commercial NCPs(non-conductive pastes) to ensure the performance of NCP flip chip packages. It was considered that the more smaller fused silica filler in prototype NCPs is more favorable for high temperature high humidity reliability. The failure of NCP interconnection was affected by the expansion of epoxy due to moisture absorption rather than the fatigue due to thermal stress. It was considered that the NCP having more higher adhesive strength seems to be more favorable to increase the thermal shock reliability.

• Polymer Science and Technology
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• v.24 no.3
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• pp.277-284
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• 2013

• Journal of the Microelectronics and Packaging Society
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• v.19 no.3
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• pp.43-48
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• 2012

Errors of relative permittivity calculation caused by the variation of sample aspect ratio (diameter/height) and measuring geometry were analyzed by computer simulation and measurement. Firstly, the $S_{21}$ spectrum of the sample (permittivity 38) was simulated in the post resonator measuring apparatus by HFSS simulation. Then, the relative permittivity was calculated from the $TE_{011}$ mode resonant frequency. The relative permittivity varied by ca. 0.3% with sample aspect ratio variation (D/H=0.8~1.6). The relative permittivity varied by ca. 1~10% when the 1~10% of air-gap was introduced in between the dielectric disk and upper conductor. All the simulation results showed consistent tendency with real measurement.