• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07a
• /
• pp.424-427
• /
• 2003

We have investigated the microstructural analysis of epitaxial lateral overgrowth (ELO), pendeoepitaxy (PE), and superlattice structures used as technology for the reduction of structural defects like dislocation in nitride semiconductors using transmission electron microscopy. We confirmed that the regrowth process such as ELO and PE is very effective technique on the reduction of threading dislocation (less than $10^6/cm^2$) in the specific area. However, to decrease the defect density in the whole nitride films and the suppress the generation of defect by regrowth, we should find the optimized conditions. Besides, the process using double PE and AlGaN/GaN superlattice structure showed no effect on the defect reduction up to now.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.2
• /
• pp.109-115
• /
• 2005

The study of Oxygen Vacancy on SnO$_2$ thin films grown by thermal chemical vapor deposition were investigated with different substrate temperature. X-ray diffraction showed that the crystallinity of the grown thin films increased with increasing substrate temperature. Two narrow peaks and two broad peaks were observed from the photoluminescence measurements at 6 K. The intensity and shape of the broad peaks were changed with increasing substrate temperature. It was concluded that the origin of the broad peak at 2.4 eV was due to oxygen vacancies and that of peak at 3.1 eV was related to structural defects. Hall effect measurements showed that the carrier density was decreased as increasing deposition time from 10 to 30 min., but increased for the deposition of 60 min.

• Transactions of the Society of Information Storage Systems
• /
• v.2 no.4
• /
• pp.230-235
• /
• 2006

The machine locking system is an important device for the safety of persons using the machine. In this study, a locking system using electromagnetic fields is proposed to decrease the defects and the cost for repairing and maintenance of the existing locking system using structural mechanism. We analyze the electromagnetic locking system and calculate the generated force considering direction by the finite element method. Also, we set up two design domains for the topology optimization; first domain is optimized to reduce the volume and the other is optimized to maximize the generated force keeping the volume, especially. The optimal design is obtained by integration of the two optimized results. An improved design is obtained by the optimal topology and it is confirmed by comparison with the initial locking system.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.176-177
• /
• 2014

The new algorithm was proposed to quantify symmetry recorded in convergent beam electron diffraction (CBED) patterns and symmetry mapping. The proposed algorithm is based on the normalized cross-correlation coefficient (${\gamma}$) for quantifying the amount of symmetry in a CBED pattern. The quantification and mapping procedures are automatically controlled by the script implemented in Gatan Digital Micrograph$^{(c)}$. We apply the quantitative CBED measurement to a strained Si sample to test the sensitivity to defects.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2019-2021
• /
• 1999

In this paper, the AC-PDP's structural defects with a gap between front and rear glass are investigated. Breakdown voltage, sustain voltage, current and brightness have been measured for various gaps between two plates under various gas pressures. The experimental results show that the firing voltage, sustain voltage and brightness were decreased whereas the discharge current was increased as the gap increased. When the gap is over $40{\mu}m$, it was impossible to drive cells separately.

• Proceedings of the Safety Management and Science Conference
• /
• 2012.04a
• /
• pp.313-323
• /
• 2012

Single PPM Quality Innovation Program is to pursuit of defects below 10ppm in outgoing quality for strengthen the small and medium enterprise's competitiveness. This study aims to find that whether quality innovation promotion is significant or not in the ISO 9001 certification enterprises. To perform this research, we surveyed CEOs, managers and workers working for manufacturing business, we distributed 250 sheets totally and withdrew 171 sheets. We analyzed 135 sheets that we could use for this research using SPSS 15.0 and AMOS 18.0 program.

• Journal of the Korea Safety Management & Science
• /
• v.14 no.2
• /
• pp.213-220
• /
• 2012

Single PPM Quality Innovation Program is to pursuit of defects below 10ppm in outgoing quality for strengthen the small and medium enterprise's competitiveness. This study aims to find that whether quality innovation promotion is significant or not in the ISO 9001 certification enterprises. To perform this research, we surveyed CEOs, managers and workers working for manufacturing business, we distributed 250 sheets totally and withdrew 171 sheets. We analyzed 135 sheets that we could use for this research using SPSS 15.0 and AMOS 18.0 program.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.11
• /
• pp.3340-3344
• /
• 2013

The fabrication of polymer field-effect transistors with good electrical properties requires the minimization of molecular defects caused by low molecular weight (MW) fractions of a conjugated polymer. Here we report that the electrical properties of a narrow bandgap conjugated polymer could be dramatically improved as a result of dipping a thin film into a poor solvent. The dipping time in hexanes was controlled to efficiently eliminate the low molecular weight fractions and concomitantly improve the molecular ordering of the conjugated polymer. The correlation between the structural order and the electrical properties was used to optimize the dipping time and investigate the effects of the low MW fraction on the electrical properties of the resulting thin film.

• Korean Journal of Bronchoesophagology
• /
• v.1 no.1
• /
• pp.64-68
• /
• 1995

Vocal folds injury from vocal abuse is important topics of phonosurgery. Recent advances in diagnostic equipment, phonosurgery and speech analysis equipment have provided a lot of Information about fine movement of the vocal folds. However, predicting the reaction of the vocal folds to phonatory trauma remains difficult. The vocal folds need to withstand great vibratory and shearing stress and anchoring fibers of basement membrane Bone play a role in maintaining structural integrity of histologically different epidermis and superficial layer of lamina propria(cover of vocal folds). The purpose of this study is to demonstrate the changes of anchoring fibers in vocal polyp using transmission electron microscope. Various defects were observed : a irregular thickening of basement membrane, a near absence of normal anchoring fiber, a lot of electron dense material in superficial layer of lamina propria, a destruction of hemidesmosome and many vesicles carrying electron dense material In basal keratinocyte. These observations were suggestive of a hyperactivity of basal keratinocyte of vocal folds epithelium in response to vibratory stress.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1996.10a
• /
• pp.526-531
• /
• 1996

Most of existing tunnels in Korea have structural and material defects, such as lack of the thickness in the crown and presence of an opening behind thie lining as a result of its construction. In Japan, it is said that carbon fiver sheet is very attractive for the upgrading damaged tunnel due to its good tensile strength, handability and resistance to corrosion. This report is the summary of the applicability of continous carbon fiber sheet for a repair and reiforcement of existing tummel located in Masan. It is the aim of this study to analyze the site data related to consturcion method used carbon fiber sheet.