• Title/Summary/Keyword: light guide

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Vibration Analysis of Separation Screen in a Recycling Plant of Moisturized Construction Wastes (고함수율의 건설폐기물 폐 토속에 포함된 이물질 선별을 위한 분리스크린의 진동해석)

  • Moon, Byung-Young;Bae, Hyo-Dong;Kwag, Kwang-Hun;Bae, Kee-Sun;Song, Ha-Young
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.8
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    • pp.526-533
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    • 2008
  • In this study, theoretical super screen vibration analysis has been carried out to predict the dynamic characteristics of interactive waste particles. In order to approach these problems, it is necessary to have a fundamental understanding the screening process and the process of both the remaining and the passed material on a screen with several interacting screen planes based on Soldinger(1999) was discussed. Here, the vibrating screen is composed of three assemblies such as screen, wastes guide, and supported screen as shown in Fig. 1. This model is regarded vibrator as the system of screen fixed tilt plates. Then materials(or particles) of different size is to be separated by using the eccentric vibrator and classifying tilt plates. As well moisturized construction wastes is more efficient to separate than moisture-less it. In processing separate mechanism, the more materials is light, the more staying time is long. Thus much lighter construction wastes(wood, Styrofoam, etc) and heavier materials are separated by staying time delay in a super screen. The design results, separation screen were able to know that small and larger particles are conspicuous difference each motion character according to trajectory particles, and small particles raise the probability in classifying tilt plates.

Feasibility study on the development of Liquid crystal-optical fiber temperature sensor for minimal invasive laserthermia (LC(Liquid crystal)-광섬유를 이용한 최소 침습적 레이저 온열 치료용 온도 측정 센서의 개발을 위한 기초 연구)

  • Lee, Bong-Soo;Hwang, Young-Muk;Chung, Soon-Cheol
    • Journal of Sensor Science and Technology
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    • v.12 no.5
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    • pp.225-230
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    • 2003
  • Nowadays, laserthermia is widely used to treat malignant tumors with generating heat as the one of minimal invasive surgeries. Generally, the laserthermia probe system consists of the fiber-optic laser and light guides, image guide and temperature sensor. It is very important to measure the temperature of treating tumor and make a stable temperature ($42{\sim}43^{\circ}C$) during the treating time. Therefore, laserthermia probe needs temperature sensor which can measure it exactly and fast. In this study, to develop a new type of temperature sensor with LC(liquid crystal) and optical fiber, the reflectivity of LC according to the temperature changes are measured. Also, the relationships are derived from the results.

Colour Interpolation of Tongue Image in Digital Tongue Image System Blocking Out External Light (디지털 설진 시스템의 색상 보정)

  • Kim, Ji-Hye;Nam, Dong-Hyun
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.16 no.1
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    • pp.9-18
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    • 2012
  • Objectives The aim of this study is to propose an optimized tongue colour interpolation method to achieve accurate tongue image rendering. Methods We selected 60 colour chips in the chips of DIC color guide selector, and then divided randomly the colour chips into two groups. The colour chips of a group (Gr I) were used for finding the optimized colour correction factor of error and those of the other group (Gr II) were used for verifying the correction factor. We measured colour value of the Gr I colour chips with spectrophotometer, and took the colour chips image with a digital tongue image system (DTIS). We adjusted colour correction factor of error to equal the chip colour from each method. Through that process, we obtained the optimized colour correction factor. To verify the correction factor, we measured colour value of the Gr II colour chips with a spectrophotometer, and took the colour chips image with the DTIS in the two types of colour interpolation mode (auto white balance mode and optimized colour correction factor mode). And then we calculated the CIE-$L^*ab$ colour difference (${\Delta}E$) between colour values measured with the spectrophotometer and those from images taken with the DTIS. Results In auto white balance mode, The mean ${\Delta}E$ between colour values measured with the spectrophotometer and those from images taken with the DTIS was 13.95. On the other hand, in optimized colour correction factor mode, The mean ${\Delta}E$ was 9.55. The correction rate was over 30%. Conclusions In case of interpolating colour of images taken with the DTIS, we suggest that procedure to search the optimized colour correction factor of error should be done first.

A Basic Study on How to Improve the Management and Operation of Maritime or Coastal National Parks as Based on the Analysis of the Basic Statistical Data on National Parks (국립공원 기초통계자료분석을 기반으로 한 해상·해안형 국립공원 관리운영개선에 대한 기초 연구)

  • Lee, Hee-Won;Yeom, Sung-Jin
    • Journal of Environmental Science International
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    • v.28 no.9
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    • pp.751-763
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    • 2019
  • National parks, which are preserved areas of $6,726.298km^2$($3,972.589km^2$ on land and $2,753.709km^2$, at sea), take up 6.71% of the national territory, and they are classified by type into 17 mountain parks, 4 maritime or coastal parks, and 1 historical site park. Of them all, the maritime or coastal national parks, which are preserved areas covering wide tracts of maritime, lately attract increasing numbers of visitors. In this light, this study identifies the issues with the maritime or coastal national parks such as the changes in the number of visitors and the unbalance involved in the budget execution, based on the visitors to the national parks and the specifics of budget executed for them. On this basis, the study has conducted the research with a view to suggesting improvements for more useful management and operation of the maritime or coastal national parks. As a result, the study has reached the following conclusions. First, to accommodate those who want to visit the maritime or coastal national parks, the tour infrastructure needs to be expanded to guide the visitors' use of the facilities by focusing on their touring behavior and characteristics. Second, budget should be acquired through diversifying revenue structure to eliminate hugely unbalanced budget. Third, visitors nowadays come to national parks for recreational experience or to tour nature, but the maritime or coastal national parks focus on cultural facilities. To accommodate the visitors' needs, the parks should get diversified visitor facilities that reflect the regional characteristics.

Simulation of Capillary Flow Along a Slot-die Head for Stripe Coatings (Stripe 코팅용 슬롯 다이 헤드 모세관 유동 전산모사)

  • Yoo, Su-Ho;Lee, Jin-Young;Park, Jong-Woon
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.1
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    • pp.92-96
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    • 2019
  • In the presence of ${\mu}-tip$ embedded in a slot-die head for stripe coatings, there arises the capillary flow that limits an increase of the stripe density, which is required for the potential applications in organic light-emitting diode displays. With an attempt to suppress it, we have employed a computational fluid dynamics software and performed simulations by varying the ${\mu}-tip$ length and the contact angles of the head lip and ${\mu}-tip$. We have first demonstrated that such a capillary flow phenomenon (a spread of solution along the head lip) observed experimentally can be reproduced by the computational fluid dynamics software. Through simulations, we have found that stronger capillary flow is observed in the hydrophilic head lip with a smaller contact angle and it is suppressed effectively as the contact angle increases. When the contact angle of the head lip increases from $16^{\circ}$ to $130^{\circ}$, the distance a solution can reach decreases sharply from $256{\mu}m$ to $44{\mu}m$. With increasing contact angle of the ${\mu}-tip$, however, the solution flow along the ${\mu}-tip$ is disturbed and thus the capillary flow phenomenon becomes more severe. If the ${\mu}-tip$ is long, the capillary flow also appears strong due to an increase of flow resistance (electronic-hydraulic analogy). It can be suppressed by reducing the ${\mu}-tip$ length, but not as effectively as reducing the contact angle of the head lip.

A Rapid Review of the Use of Appropriate Technology in Global Health

  • Park, Jayoung;Shin, Heesu;Choi, Hee Joon;Heo, Jongho;Kim, Woong-Han
    • Journal of Appropriate Technology
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    • v.7 no.2
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    • pp.235-247
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    • 2021
  • The need for appropriate technology in global health has expanded dramatically as the gap between industrialized and developing countries continues to expand. However, there is no collective knowledge of appropriate technology in global health. Thus, this study intends to provide light on the latest developments in the field of appropriate technology in global health and to speculate on future directions. A rapid review, or simplified technique, was used to systematically identify and summarize emerging papers. The search technique used the keywords "global health" and "appropriate technology." The total number of papers collected from PubMed and Scopus was 427, and 19 articles were thoroughly reviewed for the result section following the research. The study's conclusions included the following: 1) an assessment of appropriate technology adopted in developing countries; and 2) strategies for implementing appropriate technologies in global health. Additionally, we drew lessons and identified problems to serve as a useful guide for future research and development in appropriate technology. This review uncovered a small but valuable level of information about acceptable technology in global health.

Deep Learning based Vehicle AR Manual for Improving User Experience (사용자 경험 향상을 위한 딥러닝 기반 차량용 AR 매뉴얼)

  • Lee, Jeong-Min;Kim, Jun-Hak;Seok, Jung-Won;Park, Jinho
    • Journal of the Korea Computer Graphics Society
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    • v.28 no.3
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    • pp.125-134
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    • 2022
  • This paper implements an AR manual for a vehicle that can be used even in the vehicle interior space where it is difficult to apply the augmentation method of AR content, which is mainly used, and applies a deep learning model to improve the augmentation matching between real space and virtual objects. Through deep learning, the logo of the steering wheel is recognized regardless of the position, angle, and inclination, and 3D interior space coordinates are generated based on this, and the virtual button is precisely augmented on the actual vehicle parts. Based on the same learning model, the function to recognize the main warning light symbols of the vehicle is also implemented to increase the functionality and usability as an AR manual for vehicles.

How do diverse precipitation datasets perform in daily precipitation estimations over Africa?

  • Brian Odhiambo Ayugi;Eun-Sung Chung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.158-158
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    • 2023
  • Characterizing the performance of precipitation (hereafter PRE) products in estimating the uncertainties in daily PRE in the era of global warming is of great value to the ecosystem's sustainability and human survival. This study intercompares the performance of different PRE products (gauge-based, satellite and reanalysis) sourced from the Frequent Rainfall Observations on GridS (FROGS) database over diverse climate zones in Africa and identifies regions where they depict minimal uncertainties in order to build optimal maps as a guide for different climate users. This is achieved by utilizing various techniques, including the triple collection (TC) approach, to assess the capabilities and limitations of different PRE products over nine climatic zones over the continent. For daily scale analysis, the uncertainties in light PRE (0.1 5mm/day) are prevalent over most regions in Africa during the study duration (2001-2016). Estimating the occurrence of extreme PRE events based on daily PRE 90th percentile suggests that extreme PRE is mainly detected over central Africa (CAF) region and some coastal regions of west Africa (WAF) where the majority of uncorrected satellite products show good agreement. The detection of PRE days and non-PRE days based on categorical statistics suggests that a perfect POD/FAR score is unattainable irrespective of the product type. Daily PRE uncertainties determined based on quantitative metrics show that consistent, satisfactory performance is demonstrated by the IMERG products (uncorrected), ARCv2, CHIRPSv2, 3B42v7.0 and PERSIANN_CDRv1r1 (corrected), and GPCC, CPC_v1.0, and REGEN_ALL (gauge) during the study period. The optimal maps that show the classification of products in regions where they depict reliable performance can be recommended for various usage for different stakeholders.

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Formation and Inhibition of Cholesterol Oxidation Products (COPs) in Foods; An Overview (식품 내 콜레스테롤 산화 생성물(COPs)의 생성 및 억제; 개요)

  • Joo-Shin Kim
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.5
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    • pp.1163-1175
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    • 2023
  • Cholesterol is prone to oxidation, which results in the formation of cholesterol oxidation products (COPs). This occurs because it is a monounsaturated lipid with a double bond on C-5 position. Cholesterol in foods is mostly non-enzymatically oxidized by reactive oxygen species (ROS)-mediated auto-oxidative reaction. The COPs are found in many common foods of animal-origin and are formed during their manufacture process. The formation of COPs is mainly related to the temperature and the heating time the food is processed, storage condition, light exposure and level of activator present such as free radical. The level of COPs in processed foods could reach up to 1-10 % of the total cholesterol depending on the foods. The most predominant COPs in foods including meat, eggs, dairy products as well as other foods of animal origin were 7-ketocholesterol, 7 α-hydroxycholesterol (7α-OH), 7β-hydroxycholesterol (7β-OH), 5,6α-epoxycholesterol (5,6α-EP), 5,6β-epoxycholesterol (5,6β-EP), 25-hydoxycholesterol (25-OH), 20-hydroxycholesterol (20-OH) and cholestanetriol (triol). They are mainly formed non-enzymatically by cholesterol autoxidation. The COPs are known to be potentially more hazardous to human health than pure cholesterol. The procedure to block cholesterol oxidation in foods should be similar to that of lipid oxidation inhibition since both cholesterol and lipid oxidation go through the same free radical mechanism. The formation of COPs in foods can be stopped by decreasing heating time and temperature, controlling storage condition as well as adding antioxidants into food products. This review aims to present, discuss and respond to articles and studies published on the topics of the formation and inhibition of COPs in foods and key factors that might affect cholesterol oxidation. This review may be used as a basic guide to control the formation of COPs in the food industry.

The Role of MMA and EGDMA in Enhancing the Mechanical Properties of PMMA Composites (PMMA 복합재의 기계적 특성 향상을 위한 MMA 및 EGDMA의 역할 연구)

  • Aqila Che Ab Rahman;Shiyoung Yang;Sooman lim
    • Journal of Integrative Natural Science
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    • v.17 no.2
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    • pp.53-58
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    • 2024
  • This study explores the enhancement of mechanical properties in Polymethyl Methacrylate (PMMA) composites through the incorporation of Methyl Methacrylate (MMA) and Ethylene Glycol Dimethacrylate (EGDMA). Utilizing Digital Light Processing (DLP) technology, we conducted a series of experiments to analyze the impact of varying concentrations of MMA and EGDMA on PMMA. The results indicate that while MMA demonstrates non-linear and variable mechanical strength across different PMMA concentrations, EGDMA consistently improves mechanical strength as PMMA concentration increases. This consistent enhancement by EGDMA suggests a stable and predictable reinforcement effect, which is critical for applications requiring high mechanical strength. Our comparative analysis highlights that EGDMA is a more effective additive than MMA for optimizing the mechanical performance of PMMA composites. Specifically, EGDMA's ability to provide uniform reinforcement across various PMMA concentrations makes it ideal for high-strength applications. These findings are significant for material scientists and engineers focused on the design and development of advanced PMMA-based materials. In conclusion, this research underscores the importance of selecting appropriate additives to enhance the mechanical properties of PMMA composites. The superior performance of EGDMA in reinforcing PMMA suggests its potential for broader applications in fields such as automotive, construction, medical devices, and 3D printing. This study provides valuable insights that can guide future research and development in high-performance composite materials, paving the way for innovative applications and improved material efficiency.