• Proceedings of the Korea Information Processing Society Conference
• /
• 2018.10a
• /
• pp.736-738
• /
• 2018

최근 딥러닝의 발전에 따라 무인감시, CCTV 등 영상감시 시스템도 지능화되고 있다. 하지만 쓰레기 무단투기 감시는 여전히 관리자가 실시간으로 CCTV 영상을 관제하는 형태로 이루어지고 있다. 이러한 문제를 해결하기 위해 본 논문에서는 CCTV 영상에서 쓰레기 무단투기를 검출하는 방법을 제안하며 검출 방법으로 차 영상과 합성곱 신경망을 이용한다. 실험은 합성곱 신경망에서의 쓰레기봉투 분류 문제 위주로 진행하였다. 합성곱 신경망의 네트워크는 Inception v3를 사용하였으며 실험 결과, 약 99.52%의 쓰레기봉투 분류율을 얻을 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.331-334
• /
• 1999

본 논문에서는 경남산 고령토를 이용하여 고 실리카 제올라이트인 ZSM-5를 조제하는 방법에 대하여 검토한다. KOH를 알칼리 종으로 하여 ZSM-5를 합성하였다. 또한 수열합성을 위한 장치를 제작하여 회전속도 및 반응온도를 제어하였다. Si$_2$/Al$_2$O$_3$의 몰비와 $K_2$O/SiO$_2$의 몰비에 따른 결정생성물의 영역을 밝혔다. 또한, 생성된 ZSM-5를 SEM 및 X선 회절장치로 확인하였다. 또한, 반응시간에 따른 고체회수율 및 ZSM-5의 펴크강도를 관찰하였다. 또한, ZSM-5의 생성을 위한 반응시간을 알았고, ZSM-5가 소멸되기 시작하는 시간을 알았다. 또한 ZSM-5는 SiO$_2$/A1$_2$O$_3$의 몰비의 증가 및 반응시간의 증가에 의해 $\alpha$-Quartz로 전환되어짐을 알았다.

• Clean Technology
• /
• v.26 no.4
• /
• pp.263-269
• /
• 2020

Zeolite was synthesized hydrothermally using the water-treatment sludge, and the effects of various synthesis parameters like reaction temperature, reaction time, and Na2O/SiO2 molar ratio on the crystallization of zeolite were investigated. Crystal structure, physical property, and thermal stability of zeolite crystals were characterized by X-ray powder diffraction, FTIR spectroscopy, BET nitrogen adsorption, and TGA measurements. The removal efficiencies of nitrogen in ammonia, heavy metal ions, and TOC were calculated to evaluate zeolite's adsorption capacity. The primary chemical composition of water-treatment sludge was 28.79% Al2O3 and 27.06% SiO2. The zeolites were synthesized by merely employing the water-treatment sludge as silica and alumina sources without additional chemicals. Zeolite crystals synthesized through the water-treatment sludge were confirmed as an A-type zeolite structure. Zeolite A had the highest crystallinity obtained from a gel with the molar composition 2.1Na2O-Al2O3-1.6SiO2-65H2O after 5 h at a temperature of 90 ℃. The specific surface area of zeolite obtained was 55 ㎡ g-1, which was higher than commercial zeolite A. The removal efficiency of nitrogen in ammonia was 68% after 3 h of reaction time, while the removal efficiencies of Pb2+ and Cd2+ ions were 99.1% and 99.3%, respectively. These results indicate active ion exchange between Pb2+ or Cd2+ ion and Na+ ion in the zeolite framework. The adsorption experiments on the different zeolite addition conditions were performed for 3 h with 300 ppm humic acid. Based on the results, TOC's highest efficiency was 83% when 5 g of zeolite was added.

• Journal of Biomedical Engineering Research
• /
• v.23 no.6
• /
• pp.419-430
• /
• 2002

In this paper. we propose an efficient method for implementing hi-directional pixel-based focusing(BiPBF) based on a sparse array imaging technique. The proposed method can improve spatial resolution and frame rate of ultrasound imaging with reduced hardware complexity by synthesizing transmit apertures with a small number of sparsely distributed subapertures. As the distance between adjacent subapertures increases, however. the image resolution tends to decrease due to the elevation of grating lobes. Such grating lobes can be eliminated in conventional synthetic aperture imaging techniques. On the contrary, grating lobes arisen from employing sparse synthetic transmit apertures can not be eliminated, which has been shown analytically in this paper. We also propose the condition and method for suppressing the grating lobes below -40dB, which is generally required in practical imaging. by placing the transmit focal depth at a near depth and properly selecting the subaperture distance in Proportion to receive aperture size. The results of both the Phantom and in vivo experiments show that the proposed method implements two-wav dynamic focusing using a smaller number of subapertures, resulting in reduced system complexity and increased frame rate.

• Applied Chemistry for Engineering
• /
• v.21 no.3
• /
• pp.333-336
• /
• 2010

Fe/$Al_2O_3$ granules with various compositions were prepared by combining sol-gel with oil drop method for Fishcer-Tropsh reaction to produce light olefin from synthesis gas. The granules was characterized and employed as a catalyst in the reaction. The surface area of granules was decreased with increasing Fe concentration. Especially, granule with 1.5 of Al/Fe ratios showed the highest CO conversion. However, the olefin selectivity was hardly affected by Al/Fe ratio. K concentration of granule gave a significant effect on catalytic performance. Initial CO conversion and olefin selectivity were increased with K concentration. However, the catalyst with higher K concentration was deactivated rapidly.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.2
• /
• pp.134-142
• /
• 2016

In this paper, a method synthesizing speech signal using the 40 kHz ultrasonic signals reflected from the articulatory muscles was introduced and performance was evaluated. When the ultrasound signals are radiated to articulating face, the Doppler effects caused by movements of lips, jaw, and chin observed. The signals that have different frequencies from that of the transmitted signals are found in the received signals. These ADS (Acoustic-Doppler Signals) were used for estimating of the speech parameters in this study. Prior to synthesizing speech signal, a quantitative correlation analysis between ADS and speech signals was carried out on each frequency bin. According to the results, the feasibility of the ADS-based speech synthesis was validated. ADS-to-speech transformation was achieved by the joint Gaussian mixture model-based conversion rules. The experimental results from the 5 subjects showed that filter bank energy and LPC (Linear Predictive Coefficient) cepstrum coefficients are the optimal features for ADS, and speech, respectively. In the subjective evaluation where synthesized speech signals were obtained using the excitation sources extracted from original speech signals, it was confirmed that the ADS-to-speech conversion method yielded 72.2 % average recognition rates.

• Korean Journal of Materials Research
• /
• v.8 no.1
• /
• pp.27-32
• /
• 1998

In-Sit반응소결에의해 Si과 AI금속분말을 이용하여 Si$_{3}$N$_{4}$-AIN 복합세라믹스를 합성하였다. 합성된 Si$_{3}$N$_{4}$-AIN복합세라믹스의 미세조직과 결정구조를 해석하기 위해, OM, TEM, XRD및 EDX를 이용하였으며, Si$_{3}$N$_{4}$-AIN -20wt.%AIN복합세라믹스에서 Si의 질화율은 97%로 가장 높았다. Si$_{3}$N$_{4}$-AIN 복합세라믹스에서 Si의 질화율은 AI첨가량 증가에 따라 감소하였다. 대부분의 AI입자들은 다결정 AI입자들은 다결정 AIN(4-H구조)로 완전질화되었으며, 따라서 잔류 AI상은 반응소결체내에서 관찰되지 않았다. Si$_{3}$N$_{4}$의 결정구조는 $\alpha$와 $\beta$구조가 혼재된 상태이며, 잔류 Si입자내에서는 미소균열 및 전위가 관찰되었다. AI/Si$_{3}$N$_{4}$와 Si$_{3}$N$_{4}$ 두계면에서 이들은 거친 형상을 보이지만, 계면반응상은 관찰되지 않았다.

• Journal of Korean Ophthalmic Optics Society
• /
• v.11 no.2
• /
• pp.143-149
• /
• 2006

The purpose of this study is synthesizing silicone polymer which is used the material of contact lens and solving the problems of water content and light transmittance for gas permeable contact lens. We used NVP, MMA, HEMA monomer for polymerization and EGDMA as cross linking regent. Also, we polymerized with a several formulation arrangement for the best condition as contact lens. After that. we measured water content and light transmittance by each sample which was polymerized. We polymerized the silicone polymer which is simultaneously pursued by the transparent and water content of the material and measured their physical nature of each sample on this study.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.1
• /
• pp.93-101
• /
• 2010

When doing underground excavation works for the purpose of constructing large underground structures for a building in the limited space in downtown area, the stability of the adjacent ground must be top priority, and to accomplish this, it is essential to review the retaining wall construction carefully. H-Pile, which has been mainly used as a stress-carrying material in temporary earth-retaining structures, is most likely to be abandoned after completion of the works for the basement exterior wall in relation to contiguous bored piles, so it will result in a waste of material. To improve this situation, Basement Composite Wall where H-Pile and basement wall are compounded, has been developed. This wall is being used most frequently in many local construction sites. In this study, five specimens are made in order to evaluate the shear resistance of the basement composite wall and tested. Test parameter is the composition ratio and wall thickness according to shear connectors. Test result shows that the shear strength is improved when the composite ratio is increased but the magnitude is not much. A formula, which considers the contribution of concrete, web of H-pile as well as flange' effect in calculation of shear strength of composite basement wall, is suggested and used to calculation of the strength of specimens. It is found that there is a good co-relation between test result and the calculated one by the formula.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.1
• /
• pp.456-461
• /
• 2012

The glycerol carbonate was synthesized by glycerol and urea using metal oxide catalysts. The physical properties of the prepared metal oxide catalysts were investigated by X-ray diffraction (XRD), specific surface area analysis (BET), field emission scanning electron microscopy (FE-SEM) and temperature programmed desorption (TPD). In addition, we confirmed the conversion of the glycerol and the yield of the glycerol carbonate according to characteristics of metal oxide catalysts. From XRD and FE-SEM analysis, the crystallite size and crystallinity of metal oxide catalysts decrease with addition of Al. In addition, the Zn-Al mixed metal oxide had higher catalytic activity than the pure ZnO due to decreased side reaction in the synthesis of glycerol carbonate.