• Title/Summary/Keyword: 이물질

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A Study on Low Power Energy Transfer Circuits of the Non Contact Method by means of Solar Generation (태양광 발전에 의한 비접촉 방식 저 전력 에너지 전송회로에 관한 연구)

  • Hwang, Lark-Hoon;Na, Seung-Kwon;Kim, Jong-Rae;Choi, Gi-Ho;Kim, Jin-Seon
    • Journal of Advanced Navigation Technology
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    • v.18 no.1
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    • pp.35-43
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    • 2014
  • In this paper, it is about to non-contact wireless power transmission according to various conditions of self induction principle between the two planar coils at a transmission unit and a receiving unit based on the theory of wireless power transmission. The experiments are occurred in order to power transfer of noncontact method from designed wireless circuits in the primely coil and secondary coil, and the applying to Half Bridge Resonant converter transmission unit and receiving unit. and that were able to prepared circumstance to calculate of the output voltage and power source. The main power of the inductive coupling the resonant converter at the transmission unit is converted electrical energy using the solar cell module and artificial light source (halogen lamp) as a replace light and received 24 V power supply from solar power was used a input power source for the wireless power transmission device. Experimental results, to received of power is used to illuminate the lighting and to charge the battery in receiving circuit.And the wireless power transmission efficiency measured at the output side of the transmission unit is obtained about 70% to 89% compared to input power of receiving unit.In addition, efficiency were tested through ID verification method and comparing the phase difference between the voltage when foreign substances interfere with wireless power transmission.

Analysis on Spatial Variability of Rainfall in a Small Area (소규모 지역에 대한 강우의 공간변화도 분석)

  • Kim, Jong Pil;Kim, Won;Kim, Dong-Gu;Lee, Chanjoo
    • Journal of Korea Water Resources Association
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    • v.48 no.11
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    • pp.905-913
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    • 2015
  • This study deployed six rain gauges in a small area for a dense network observing rainfall and analyzed the spatial variability of rainfall. They were arranged in a $2{\times}3$ rectangular grid with equal space of 60 m. The rainfall measurements from five gauges were analyzed during the period of 50 days because one was seriously affected by alien substance. The maximum difference in cumulative rainfall from them is approximately 38.5 mm. The correlation coefficients from hourly rainfall time series differ from each other while daily rainfall coincide. The coefficient of variation in hourly rainfall varies up to 224% and that in daily rainfall up to 91%. The results from uncertainty analysis show that with only four rain gauges areal mean rainfall cannot be estimated over 95% accuracy. For reliable flood prediction and effective water management it is required to develop a new technique for the estimation of areal rainfall.

Comparative Study of the Formal Features and Production Techniques of the Two Ridge-end Tiles Excavated the Geumgangsa Temple Site (금강사지 치미의 형태적 특징 및 제작기법 비교 연구)

  • Shin, Yeonhong;Hwang, Hyunsung;Shin, Myeonghee;Huh, Ilkwon
    • Conservation Science in Museum
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    • v.20
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    • pp.31-48
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    • 2018
  • The Geumganasa Temple site two Ridege-end tiles at the Buyeo National Museum(The Buyeo2150-1 and 2150-2, hereinafter referred to as 2150-1 and 2150-2) were excavated the Geumgangsa Temple site. They provide important materials for investigating the shapes and production techniques of the ridge-end tiles of the time since their lower portions remain relatively intact. This study is intended to examine whether the two ridge-end tiles were identical. Conservation treatment, including removal of foreign substances, was conducted in preparation for observation with the naked eye to compare the formal features and production techniques of the two examples. The study revealed that these ridge-end tiles shared formal features such as surface color, clay composition, shape, size, and decoration; however, they differed in terms of production technique. The 2150-1 tile was made by assembling a separately-made body and wing and has no hole through the back, while the 2150-2 tile had its body and wing made as a single unit using long clay plates and features circular holes in the back. It was revealed that one portion of the body of both tiles was intentionally tilted during the production process.

An Experimental Study on the Quality Variation by the Number of Production of Recycled Sand and Mechanics Properties of Mortar using Sand Flux Apparatus (샌드플럭스 장치를 이용한 순환모래의 생산횟수별 품질변화 및 모르타르의 역학특성에 관한 실험적 연구)

  • Lee, Sang-Soo;Song, Ha-Young;Kim, Joon-Seok;Kim, Jae-Hwan;Lee, Jong-Suk
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.1
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    • pp.81-88
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    • 2009
  • This study has shown the tendency to enhance Sand Flux, a device of separating screening the foreign matter, for the recycling of construction waste possible to improve the quality of wet type production system meaningfully as part of research. As a result of experiment on the basic material properties, this study had a tendency to improve the quality and performance significantly in case of absolute surface dried density, 0.08mm sieve throughput, volume of clay lumps, and content of organic foreign matter. In addition, as a result of examining the quality characteristics of mortar, this study has shown the tendency that the flow and compressive strength more increased than the mortar using RS-II by utilizing RS-VI recycled sand produced finally through the device Sand Flux. As for the shrinkage properties, this study has shown the character the generation rate of crack of mortar using RS-IV recycled sand produced finally through the device Sand Flux.

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Survey of Manager's Perception of Slaughter and Further Processed House for the Determination of Grading of Poultry Meat Cuts (닭고기 부분육 품질 등급 설정을 위한 도계 및 추가가공장 관리자 의식 조사)

  • Chae H. S.;Yoo Y. M.;Ahn C. N.;Ham J. S.;Jeong S. G.;Lee J. M.;Choi Y. I.
    • Korean Journal of Poultry Science
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    • v.32 no.3
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    • pp.179-186
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    • 2005
  • This study was conducted to establish a comprehensive guideline for grading system of poultry meat cuts. Slaughter and further processed houses were divided into large(>70,000 heads/day), middle($50,000\~25,000$ heads/day), and small scale(<25,000 heads/day), and the production managers were asked by the Questionnaire. Most poultry meat cuts produced by larger- and middle-slaughter house were consumed by dealers, franchisee and department store in increasing order, whereas further processed poultry meat cuts(small scale) provided meals for the students in the high amount. The packaging step was best f3r the determination of grading in the large slaughter house. This survey indicated that two or more grades were proper to determine the grading in the middle slaughter house, however only two grades were proper for the others. Freshness, bruise, wound, trimming and the inclusion of foreign materials affected to the grading. Poultry meat cuts were accepted for the grading in large-slaughter house, but whole poultry carcass was accepted for the grading in the others. Most managers agreed with that the grading system was only applied for the amounts requested. They also suggested that the grading system of poultry meat cuts were necessary in near future, even though it was not urgent to apply.

Fluidelastic Instability Analysis of the U-Tube Bundle of a Recirculating Type Steam Generator (재순환식 증기발생기 U-튜브군에 대한 유체탄성 불안정 해석)

  • 조종철;이상균;김웅식;신원기;은영수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.1
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    • pp.200-214
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    • 1993
  • This paper presents the results of fluidelastic instability analysis performed for the U-tube bundle of a Westinghouse model 51 steam generator, one of the recirculating types designed at an early stage, in which the principal region of external cross-flow is associated with the U-bend portion of tube. The prerequisites for this analysis are detailed informations of the secondary side flow conditions in the steam generator and the free vibration behaviours of the U-tubes. In this study, the three-dimensional two-phase flow field in the steam generator has been calculated employing the ATHOS3 steam generator two-phase flow code and the ANSYS engineering analysis code has been used to calculate the free vibration responses of specific U tubes under consideration. The assessment of the potential instability for the suspect U-tubes, which is the final analysis process of the present work, has been accomplished by combining the secondary side velocity and density distributions obtained from the ATHOS3 prediction with the relative modal displacement and natural frequency data calculated using the ANSYS code. The damping of tubes in two-phase flow has been deduced from the existing experimental data by taking into account the secondary side void fraction effect. In operation of the steam generator, the tube support conditions at the tube-to-tube support plate intersections due to either tube denting degradation or deposition of tube support plate corrosion products or ingression of dregs. Thus, various hypothetical cases regarding the tube support conditions at the tube-to-tube support plate intersections have been considered to investigate the clamped support effects on the forced vibration response of the tube. Also, the effect of anti-vibration bars support in the curved portion of tube has been examined.

CT Number Measurement of Residual Foreign Bodies in Face (안면부에 잔류된 다양한 이물질을 측정한 CT 계수)

  • Wee, Syeo Young;Choi, Hwan Jun;Kim, Mi Sun;Choi, Chang Yong
    • Archives of Plastic Surgery
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    • v.35 no.4
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    • pp.423-430
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    • 2008
  • Purpose: Computed tomography theoretically should improve detection of foreign bodies and provide more information of adjacent soft tissues. And the CT scanner and PACS program proved to be an excellent instrument for detection and localization of most facial foreign bodies above certain minimum levels of detectability. The severity of injury in penetrating trauma to the face, it is often underestimated by physical examination. Diagnosis of a retained foreign object is always critical. Methods: From March, 2005 to February 2008 a study was done with 200 patients who had facial trauma. Axial and coronal CT images were obtained with a General Electric(Milwaukee, Wis) 9800 CT scanner at 130 kV, 90 mA, with a 2-mm section thickness and a $512{\times}512$ matrix. Results: Axial and coronal CT images at various window widths should be used as the first imaging modality to detect facial foreign bodies. The attenuation coefficients for the metallic and nonmetallic foreign bodies ranged from -437 to +3071 HU. As a general rule, metallic foreign bodies produced more Hounsfield artifacts than nonmetallic foreign bodies, thus providing a clue to their composition. All of the metallic foreign bodies were represented by a single peak and had a maximum attenuation coefficient of +3071 HU. Of the nonmetallic foreign bodies, glass had an attenuation coefficient that ranged from +105 to +2039, while plastic had a much lower coefficient that ranged from -62 to -35. wood had the lowest range of attenuation coefficients: -491 to -437. Conclusion: The PACS program allows one to distinguish metallic from nonmetallic foreign bodies and to individually identify the specific composition of many nonmetallic foreign bodies. This program does not, however, allow identification of the specific composition of a metallic foreign body. We recommend this type of software program for CT scanning of any patient with an injury to the face in which a foreign body is suspected.

Artifacts in Digital Radiography (디지털 방사선 시스템에서 발생하는 Artifact)

  • Min, Jung-Whan;Kim, Jung-Min;Jeong, Hoi-Woun
    • Journal of radiological science and technology
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    • v.38 no.4
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    • pp.375-381
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    • 2015
  • Digital Radiography is a big part of diagnostic radiology. Because uncorrected digital radiography image supported false effect of Patient's health care. We must be manage the correct digital radiography image. Thus, the artifact images can have effect to make a wrong diagnosis. We report types of occurrence by analyzing the artifacts that occurs in digital radiography system. We had collected the artifacts occurred in digital radiography system of general hospital from 2007 to 2014. The collected data had analyzed and then had categorize as the occurred causes. The artifacts could be categorized by hardware artifacts, software artifacts, operating errors, system artifacts, and others. Hardware artifact from a Ghost artifact that is caused by lag effect occurred most frequently. The others cases are the artifacts caused by RF noise and foreign body in equipments. Software artifacts are many different types of reasons. The uncorrected processing artifacts and the image processing error artifacts occurred most frequently. Exposure data recognize (EDR) error artifacts, the processing error of commissural line, and etc., the software artifacts were caused by various reasons. Operating artifacts were caused when the user didn't have the full understanding of the digital medical image system. System artifacts had appeared the error due to DICOM header information and the compression algorithm. The obvious artifacts should be re-examined, and it could result in increasing the exposure dose of the patient. The unclear artifact leads to a wrong diagnosis and added examination. The ability to correctly determine artifact are required. We have to reduce the artifact occurrences by understanding its characteristic and providing sustainable education as well as the maintenance of the equipments.

Fire-fighting Pump Approval Standard for Fire-fighting Trucks with an Additional Positive Displacement Pump (용적형 펌프를 추가한 소방자동차용 소방펌프의 성능 인정기준에 관한 연구)

  • Han, Yong-Taek;Sung, Ki-Chan;Min, Se-Hong
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.104-110
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    • 2016
  • Positive displacement pumps with high pressure and water capacity are used large fires in various high-rise buildings. This study provides information for a performance approval standard of fire pumps for fire trucks based on centrifugal pump standards enacted in 2012. An experiment was conducted with a positive displacement pump for three levels of performance from the approval standard (V-1, 2, and 3). The efficiency of the pump was included in the reference, which requires the approval of 65% performance, the same as a centrifugal pump. The water pressure is between 1.5 and 2.5 MPa, and the required flow rate was established as at least $0.31m^3/min$ and up to $3.0m^3/min$. A relief valve was added to adjust the shut-off pressure due to the structural characteristics of the positive displacement pump. A strainer was also installed to prevent damage to the inside of the pump due to foreign matter. However, the strainer includes a difference from the positive displacement pump to operate without a vacuum pump and the centrifugal pump. This is due to the additional approval standard portion of the positive displacement pump, which is expected to be selected for more variety of fire-fighting equipment and proactive responses to fire suppression in a high-rise buildings and large fires. In conclusion, this approval standard was enacted in January 2016.

Physiology and Growth Properties of Halophilic Bacteria Isolated from Jeotgal (Salted Seafood) (젓갈(염장발효식품)에서 분리한 호염세균의 생리 및 성장특성)

  • Jung Yoo Jeong;Park Doo Hyun
    • Korean Journal of Microbiology
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    • v.40 no.4
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    • pp.263-268
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    • 2004
  • Two species of halophilic bacteria were isolated from five salted seafoods and identified by 16S rDNA sequenc­ing homology. One was identified as Halomonas subglaciescola and other four strains were belong to Halomo­nas marina. The identity of all isolates with standard organisms was above $95\%.$ H. subglaciescola, H. marina IN, and H. marina SH-2 grew in salinity condition from $3%\;to\;18\%$ NaCl but growth of H. marina SQ and H. marina SH-l grew in salinity environment from $8\%\;to\;17\%.$ Maximum biomass of H. subglaciescola, H. marina IN, H. marina SQ, H. marina SH-1, and H. marina SH-2 growing in LB medium containing $15\%$ NaCl were about 3.2, 4.5, 4.5, 5.7, and 4.2, however the maximum biomass in LB medium containing $5\%$ NaCl were about 2.2, 1.1, 0.7, 0.2, and 2.4 as optical density at 660 nm, respectively. In scanning electron micrograph, unknown material (mucus) attached to outer membrane of all isolates was observed. When mucus isolated from halophilic bacterial cell was added to culture of E. coli, E. coli grew in medium containing $15\%$ NaCl.