• Title/Summary/Keyword: measured size

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Comparison of different measuring methods for the determination of the particle size of powders for plasma spraying

  • 석한길
    • Proceedings of the KWS Conference
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    • 2001.10a
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    • pp.220-222
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    • 2001
  • The average grain size, the grain-size distribution, the morphology and the microstructure are fundamental characteristics of a spraying powder. Now that the significance of the grain size for the pattern of properties of the powder has been recognised, greater consideration is also being given to it in standards and regulations. However, unfortunately, the processes according to which the grain size and the grain-size distribution must be determined are specified in the rarest of cases. The contribution therefore dealt with the comparison of different particle-size measuring techniques, such as diffraction spectroscopy, sedimentation, sieving and microscopic measurement. The comparability of the measured results was investigated on twelve plasma spraying powders with different compositions, nominal sizes and morphologies.

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The Suitability of the Size Classification of Dress Shirts on the Market (시판 드레스셔츠의 치수 구분 적합성)

  • Han, Eun Joo;Kweon, Soo Ae;Choi, Jong Myoung;Song, Jae Min;Lim, Bo Youn
    • Journal of the Korean Society of Clothing and Textiles
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    • v.39 no.5
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    • pp.695-702
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    • 2015
  • This study provides basic data that are helpful to prepare a sizing system for dress shirts that improves the wearer's size fitness. The 16 different parts of the dress shirts were measured for 24 pieces of dress shirts with three kinds of size (95, 100 and 105) among the eight different brands on the market. The measurement sizes of the dress shirts analyzed the accuracy of the size information, size classification by size designation, and differences of size by brand. The results of the study were: 1. The size information of dress shirts differed from customer demand. 2. The size increments between size designations differed from each other even though measurement sizes of the dress shirts increased as the size designation increase. 3. Measurement sizes of the dress shirts were different between brands even for dress shirts of the same size designation. It is necessary that manufacturers secure an accurate and standardized sizing system and provide accurate information for the measurement sizes of dress shirts on an online shopping mall.

Measurement of Size Distributions of Submicron Electrosprays Using a Freezing Method and an Image Processing Technique (냉각법 및 영상 처리기법을 이용한 서브마이크론 정전분무 액적의 크기분포 측정)

  • Ku, Bon-Ki;Kim, Sang-Soo;Kim, Yu-Dong
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.100-106
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    • 2001
  • The size distributions of electrospray droplets from the Taylor cone in cone-jet mode are directly measured by using a freezing method and a transmission electron microscope (TEM) image processing technique. These results are compared with the data obtained by an aerodynamic size spectrometer (TSI Aerosizer DSP). The use of glycerol seeded with NaI and a freezing method make it possible to sample droplets with their original sizes preserved. Since pictures of droplets are taken with TEM with very low vapor pressure of the solution, evaporation is suppressed by freezing. For liquid flow rates below 1 nl/sec, the measured droplet diameters by the TEM image processing technique and the aerosizer are in the range of 0.25 to $0.32{\mu}m$ and 0.30 to $0.40{\mu}m$, respectively. Comparing the TEM data with the aerosizer measurements, it has been revealed that the TEM image processing technique can afford more accurate values of droplet size distributions in the submicron range of 0.1 to $0.4{\mu}m$.

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The Construction of Solid State Detector System Using Commercially Available Diode and Its Application (정류기형 다이오드를 이용한 반도체 방사선 검출 장치의 제작과 그 응용에 관한 연구)

  • 신동오;홍성언;이병용;이명자
    • Progress in Medical Physics
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    • v.1 no.1
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    • pp.91-95
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    • 1990
  • The solid state detector system was constructed using commercially available rectifier diode for the assessment of quality assurance in radiotherapy. Dosimetry system which consists of the electrometer and the water phanton was used for measuring small field size scanning. The measured results, which had linearity in accordance with variation of radiation dose for gamma-ray of Co- 60 and 6 and 10MV photons of linear accelerator, showed quite linear characteristics within 1% error. The percent depth dose of 10MV photon of Mevatron KD linear accelerator was measured in small field size using diode, and the results were compared with that of using ion chambers. The results show that the difference of percent depth dose between the value of diode and that of ion chamber was negligible in large field size. However, in small size less than 4$\times$4cm, the difference of percent depth dose estimated by diode and ion chamber was 4.7% by extrapolation to 0$\times$0cm. Considering the smaller volume of diode than that of ion chamber, it might be more reliable to use diode for estimating percent depth dose. Above results suggest that diode can be used for routine check such as beam profile, flatness, symmetry and energy

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On the Contrast of Aerosol Size Distribution and Cloud Condensation Nuclei Concentrations between the East and the West of the Korean Peninsula (대관령과 영종도에서 측정한 에어러솔 크기분포 및 CCN 수농도에 관한 연구)

  • Kim, Jong Hwan;Park, Min-Su;Shim, Sungbo;Yum, Seong Soo
    • Atmosphere
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    • v.22 no.1
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    • pp.87-96
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    • 2012
  • Aerosol number concentration ($N_{CN}$), size distribution and cloud condensation nuclei (CCN) concentration ($N_{CCN}$) were measured during 16-21 August 2008 at Daegwallyeong (DG) located in the eastern rural region of the Korean Peninsula. In the very next week (22-29 August 2008) the same aerosol properties were measured at Yeongjong Island (YJ) in the Yellow Sea. $N_{CN}$ for all 3 size cuts (above 3, 6 and 10 nm) was significantly higher at DG than YJ, but $N_{CCN}$ was significantly lower at the former and resulted in the $N_{CCN}/N_{CN}$ ratio more than twice higher at YJ ($0.94{\pm}0.09$ vs. $0.35{\pm}0.15$ at 0.53% supersaturation). The geometric mean diameter at DG, $53{\pm}15nm$, was much smaller than that at YJ, $91{\pm}6nm$, due to the particle formation events that were likely to have occurred continuously at DG. For given mean diameter, aerosols were more likely to act as CCN at YG compared to those at DG.

Vocabulary Coverage Improvement for Embedded Continuous Speech Recognition Using Part-of-Speech Tagged Corpus (품사 부착 말뭉치를 이용한 임베디드용 연속음성인식의 어휘 적용률 개선)

  • Lim, Min-Kyu;Kim, Kwang-Ho;Kim, Ji-Hwan
    • MALSORI
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    • no.67
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    • pp.181-193
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    • 2008
  • In this paper, we propose a vocabulary coverage improvement method for embedded continuous speech recognition (CSR) using a part-of-speech (POS) tagged corpus. We investigate 152 POS tags defined in Lancaster-Oslo-Bergen (LOB) corpus and word-POS tag pairs. We derive a new vocabulary through word addition. Words paired with some POS tags have to be included in vocabularies with any size, but the vocabulary inclusion of words paired with other POS tags varies based on the target size of vocabulary. The 152 POS tags are categorized according to whether the word addition is dependent of the size of the vocabulary. Using expert knowledge, we classify POS tags first, and then apply different ways of word addition based on the POS tags paired with the words. The performance of the proposed method is measured in terms of coverage and is compared with those of vocabularies with the same size (5,000 words) derived from frequency lists. The coverage of the proposed method is measured as 95.18% for the test short message service (SMS) text corpus, while those of the conventional vocabularies cover only 93.19% and 91.82% of words appeared in the same SMS text corpus.

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Comparison of Dynamic Behavior of Droplet Mean Diameter with 2holes-2sprays and 4holes-2sprays Types Injector for Gasoline Engine (가솔린 엔진용 2홀 2분류와 4홀 2분류 타입 인젝터의 액적 평균 직경의 동적 거동 비교)

  • Kim, Beom-Jun;Cho, Dae-Jin;Yoon, Suck-Ju
    • Journal of ILASS-Korea
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    • v.11 no.1
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    • pp.17-23
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    • 2006
  • The influence of fuel spray characteristics on engine performance has been known as one of the major concerns to Improve fuel economy and to reduce exhaust emissions. In general, the UBHC(Unburned Hydrocarbon) emission could be reduced by decreasing the droplet size of the fuel sprays. In PFI (Port Fuel Injection) gasoline engines, the mixture of air and fuel would not be uniform under a certain condition, because the breakup and production of spray droplets are made in a short distance between the fuel injector and intake valve sheat. In this study, were investigated the transient spray characteristics and dynamic behavior of droplets from 2holes-2sprays and 4holes-2sprays type injectors used in PFI gasoline engine. Mean droplet size and optical concentration were measured by LDPA (Laser Diffraction Particle size Analyzer). The variation of droplet mean diameter and optical concentration were measured for understanding the behavior of unsteady spray.

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Determination of Microfiltration Membrane Fouling Characteristics by Liquid Displacement Method (액체전이법을 이용한 정밀여과막 오염의 특성 평가)

  • 장규만
    • Membrane Journal
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    • v.9 no.4
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    • pp.221-229
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    • 1999
  • The nominal pore size 0.2 ${\mu}m polytetrafluroethylene(PTFE, Satorius Co,) membrane was used for the filtration of 0.1 wt% kaolin, bentonite, yeast, and starch solution, respectively. After filtration, the membrane was cleaned and the pore size was measured by liquid displacement method(LDMl using water/iso-butanol system. The pore size for new PTFE membrane evaluated by LDM was comparable with those of which were measured by mercury porosimetry and scanning electron microscope. The membrane pores were severely fouled, and constricted to below 0.3 ${\mu}m in the cases of bentonite and starch solution which contained smaller particles than pores. However, in the case of kaolin - solution, only some parts of membrane pores above 0.35 ${\mu}m were slightly fouled. Hence, the phenomena of membrane fouling could be identified quantitatively by the evaluation of pore size using LDM.

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High resolution size characterization of particulate contaminants for radioactive metal waste treatment

  • Lee, Min-Ho;Yang, Wonseok;Chae, Nakkyu;Choi, Sungyeol
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2277-2288
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    • 2021
  • To regulate the safety protocols in nuclear facilities, radioactive aerosols have been extensively researched to understand their health impacts. However, most measured particle-size distributions remain at low resolutions, with the particle sizes ranging from nanometer to micrometer. This study combines the high-resolution detection of 500 size classes, ranging from 6 nm to 10 ㎛, for aerodynamic diameter distributions, with a regional lung deposition calculation. We applied the new approach to characterize particle-size distributions of aerosols generated during the plasma arc cutting of simulated non-radioactive steel alloy wastes. The high-resolution measured data were used to calculate the deposition ratios of the aerosols in different lung regions. The deposition ratios in the alveolar sacs contained the dominant particle sizes ranging from 0.01 to 0.1 ㎛. We determined the distribution of various metals using different vapor pressures of the alloying components and analyzed the uncertainties of lung deposition calculations using the low-resolution aerodynamic diameter data simultaneously. In high-resolution data, the changes in aerosols that can penetrate the blood system were better captured, correcting their potential risks by a maximum of 42%. The combined calculations can aid the enhancement of high-resolution measuring equipment to effectively manage radiation safety in nuclear facilities.

Types and Characteristics of Digital Anthropometric Methods (디지털 인체 계측 방법의 유형 및 특성)

  • Kim, Rira
    • Journal of Fashion Business
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    • v.25 no.5
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    • pp.88-98
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    • 2021
  • In this study, the characteristics of digital anthropometric methods were determined with case studies. These methods were broadly classified into two categories: non-wearable and wearable. Then, these categories were further classified into four types: 3D Scanning, mobile app, smart clothing, and smart tool Among the non-wearable types, the "3D scanning" technique was based on the use of 3D hardware equipment. With this technique, the body shape was measured and the internal body information was obtained. Therefore, it is used in fields of healthcare and fitness. Among the wearable types, "Smart clothing" involves a special clothing that measures human body and a smartphone application. Both the components are linked to a fashion platform, which is based on the measured sizes that help shoppers. The "Smart tool" has the characteristic of measuring only with smart tools and smartphone applications; it does not involve the measurement of images. The common advantage of digital anthropometric methods are as follows: they reduce the time and cost of measurement by enabling self-measurement. Moreover, simple measurements are used to determine the size of anthropometry. Thereafter, it accumulates this data to track the continuous changes in size. From an industrial point of view, digital anthropometric technology should be used to increase sales. The on-demand market can be expanded as global consumers would throng the Korean fashion market. For the consumer, an avatar should be created to fit the user's size. This would provide a fun experience to the user.