• Title/Summary/Keyword: manufacturing tolerance

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Development of a machine vision system for automotive part car seat frame inspection (자동차 부품 카시트 프레임 검사를 위한 머신비전 개발)

  • Andres, Nelson S.;Jang, Bong-Choon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.4
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    • pp.1559-1564
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    • 2011
  • This study presents the development of a machine vision inspection system(MVIS) purposely for car seat frames as an alternative for human inspection. The proposed MVIS is designed to meet the demands, features and specifications of car seat frame manufacturing companies in striving for increased throughput of better quality. This computer-based MVIS is designed to perform quality measures by detecting holes, nuts and welding spots on every car seat frame in real time. In this study, the NI Vision Builder software for Automatic Inspection was used as a solution in configuring the aimed quality measurements. The techniques for visual inspection are optimized through qualitative analysis and simulation of human tolerance on inspecting car seat frames. Furthermore, this study exemplifies the incorporation of the optimized vision inspection environment to the pre-inspection and post-inspection subsystems. The system built on this proposed MVIS for car seat frames has successfully found the possible detections.

Physicochemical and Microbiological Characterization of Protected Designation of Origin Ezine Cheese: Assessment of Non-starter Lactic Acid Bacterial Diversity with Antimicrobial Activity

  • Uymaz, Basar;Akcelik, Nefise;Yuksel, Zerrin
    • Food Science of Animal Resources
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    • v.39 no.5
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    • pp.804-819
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    • 2019
  • Ezine cheese is a non-starter and long-ripened cheese produced in the Mount of Ida region of Canakkale, Turkey, with a protected designation of origin status. Non-starter lactic acid bacteria (NSLAB) have a substantial effect on the quality and final sensorial characteristics of long-ripened cheeses. The dominance of NSLAB can be attributed to their high tolerance to the hostile environment in cheese during ripening relative to many other microbial groups and to its ability to inhibit undesired microorganisms. These qualities promote the microbiological stability of long-ripened cheeses. In this study, 144 samples were collected from three dairies during the ripening period of Ezine cheese. Physicochemical composition and NSLAB identification analyses were performed using both conventional and molecular methods. According to the results of a 16S rRNA gene sequence analysis, 13 different species belonging to seven genera were identified. Enterococcus faecium (38.42%) and E. faecalis (18.94%) were dominant species during the cheese manufacturing process, surviving 12 months of ripening together with Lactobacillus paracasei (13.68%) and Lb. plantarum (11.05%). The results indicate that NSLAB contributes to the microbiological stability of Ezine cheese over 12 months of ripening. The isolation of NSLAB with antimicrobial activity, potential bacteriocin producers, yielded defined collections of natural NSLAB isolates from Ezine cheese that can be used to generate specific starter cultures for the production of Ezine cheese (PDO).

Potential Evaluation and Health Fostering Intrinsic Traits of Novel Probiotic Strain Enterococcus durans F3 Isolated from the Gut of Fresh Water Fish Catla catla

  • Alshammari, Eyad;Patel, Mitesh;Sachidanandan, Manojkumar;Kumar, Prashant;Adnan, Mohd
    • Food Science of Animal Resources
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    • v.39 no.5
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    • pp.844-861
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    • 2019
  • Over the last few years, marine environment was found to be a source of surplus natural products and microorganisms with new bioactive secondary metabolites of interest which can divulge nutritional and biological impact on the host. This study aims to assess the possible, inherent and functional probiotic properties of a novel probiotic strain Enterococcus durans F3 (E. durans F3) isolated from the gut of fresh water fish Catla catla. Parameters for evaluating and describing the probiotics described in FAD/WHO guidelines were followed. E. durans F3 demonstrated affirmative results including simulated bile, acid and gastric juice tolerance with exhibited significant bactericidal effect against pathogens Staphylococcus aureus, Salmonella Typhi, Escherichia coli and Pseudomonas aeruginosa. This can be due to the enterocin produced by E. durans F3 strain, which was resolute by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) gel with amplification of the anticipated fragment of a structural gene; enterocin A, followed by antibiotic susceptibility assessment. Effective antioxidant potentiality against ${\alpha}$-diphenyl-${\alpha}$-picrylhydrazyl free radicals including lipase, bile salt hydrolase activity with auto-aggregation and cell surface hydrophobicity was similarly observed. Results are proving the potentiality of E. durans F3, which can also be used as probiotic starter culture in dairy industries for manufacturing new products that imparts health benefits to the host. Finding the potent and novel probiotic strains will also satisfy the current developing market demand for probiotics.

The Effects of Geometrical Imperfections on the Dynamic Characteristics of a Tapered Roller Bearing Cage (테이퍼 롤러 베어링 케이지의 불완전성이 통특성에 미치는 영향)

  • Ahn, Tae-Kil;Park, Jang-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.464-469
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    • 2019
  • Tapered roller bearings are used widely in vans, trucks, and trains because they can support the vehicle in a stable manner even under a heavy load. The cage of a tapered roller bearing maintains the gap between the rollers, which prevents friction wear and suppresses heating. If the cage is severely deformed due to resonance, the roller may not be able to roll smoothly and even leave the cage. Consequently, it is very important to analyze the dynamic characteristics of the cage for reliable performance of a bearing. The cage essentially has geometrical tolerance in the manufacturing process. In this paper, the effects of those geometrical imperfections on the dynamic characteristics of the cage were investigated. As a result, natural frequency separation occurred near the natural frequency of the ideal cage due to geometrical imperfections. In addition, the interval was proportional to the magnitude of the geometric error, and the interval increased with increasing mode number.

Evaluation of electromechanical properties in REBCO CC tapes under transverse compression using anvil test method

  • Diaz, Mark Angelo;Shin, Hyung-Seop
    • Progress in Superconductivity and Cryogenics
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    • v.24 no.3
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    • pp.57-61
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    • 2022
  • One of the major applications of REBCO coated conductor (CC) tapes is in superconducting magnets or coils that are designed for high magnet fields. For such applications, the CC tapes were exposed to a high level of stresses which includes uniaxial tensile or transverse compressive stresses resulting from a large magnetic field. Thus, CC tapes should endure such mechanical load or deformation that can influence their electromechanical performance during manufacturing, cool-down, and operation. It has been reported that the main cause of critical current (Ic) degradation in CC tapes utilized in coil windings for superconducting magnets was the delamination due to transversely applied stresses. In most high-magnetic-field applications, the operating limits of the CC tapes will likely be imposed by the electromechanical properties together with its Ic dependence on temperature and magnetic field. In this study, we examined the influence of the transverse compressive stress on the Ic degradation behaviors in various commercially available CC tapes which is important for magnet design Four differently processed REBCO CC tapes were adopted to examine their Ic degradation behaviors under transverse compression using an anvil test method and a newly developed instantaneous Ic measurement system. As a result, all REBCO CC tapes adopted showed robustness against transverse compressive stresses for REBCO coils, notably at transverse compressive stresses until 250 MPa. When the applied stress further increased, different Ic degradation behaviors were observed depending on the sample. Among them, the one that was fabricated by the IBAD/MOCVD process showed the highest compressive stress tolerance.

Design and Performance Analysis of an Off-Axis Three-Mirror Telescope for Remote Sensing of Coastal Water (연안 원격탐사를 위한 비축 삼반사경 설계와 성능 분석)

  • Oh, Eunsong;Kang, Hyukmo;Hyun, Sangwon;Kim, Geon-Hee;Park, YoungJe;Choi, Jong-Kuk;Kim, Sug-Whan
    • Korean Journal of Optics and Photonics
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    • v.26 no.3
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    • pp.155-161
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    • 2015
  • We report the design and performance analysis of an off-axis three-mirror telescope as the fore optics for a new hyperspectral sensor aboard a small unmanned aerial vehicle (UAV), for low-altitude coastal remote sensing. The sensor needs to have at least 4 cm of spatial resolution at an operating altitude of 500 m, $4^{\circ}$ field of view (FOV), and a signal to noise ratio (SNR) of 100 at 660 nm. For these performance requirements, the sensor's optical design has an entrance pupil diameter of 70 mm and an F-ratio of 5.0. The fore optics is a three-mirror system, including aspheric primary and secondary mirrors. The optical performance is expected to reach $1/15{\lambda}$ in RMS wavefront error and 0.75 in MTF value at 660 nm. Considering the manufacturing and assembling phase, we determined the alignment compensation due to the tertiary mirror from the sensitivity, and derived the tilt-tolerance range to be 0.17 mrad. The off-axis three-mirror telescope, which has better performance than the fore optics of other hyperspectral sensors and is fitted for a small UAV, will contribute to ocean remote-sensing research.

Development of Mold for Coupling Parts for Drum Washing Machine (드럼세탁기용 커플링 부품 다이캐스팅 금형개발)

  • Park, Jong-Nam;Noh, Seung-Hee;Lee, Dong-Gil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.6
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    • pp.482-489
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    • 2020
  • This study conducted a prototype development and evaluation by performing die-casting mold design, mold manufacturing, and injection condition optimization based on flow and solidification analysis to meet the needs of the coupling parts produced by die casting. Through flow analysis, the injection conditions suitable for 100% filling in the cavity were found to be a molten metal temperature of 670 ℃, injection speed of 1.164 m/s, and filling pressure of 6.324~18.77 MPa. In addition, solidification close to 100 % occurred in all four cavities when the solidification rate was 69.47 %. A defect inspection on the surface and inside the product revealed defects, such as poor molding and pores. In addition, the dimensions of the injected product were within the target tolerance and showed good results. Through the feedback of the results of flow and solidification analysis, it was possible to optimize the mold design, and the injection optimization conditions were confirmed to be a total cycle time of approximately 6.5 seconds. Good quality carrier parts with an average surface hardness of approximately 45 mm from the gate measured at 97.48(Hv) could be produced.

Preparation of Talc-Silica Composites by Controlling Surface Charge Behavior (표면전하 거동 조절을 이용한 탈크-실리카 복합체의 제조)

  • Yun, Ki-Hoon;Park, Min-Gyeong;Moon, Young-Jin;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.1
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    • pp.116-124
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    • 2017
  • A plate-type inorganic pigment complex was manufactured in a manner that treats the surface of the complex by adjusting zeta potential between talc, an inorganic pigment used as a material for color cosmetics, and hydrophobic silica. Talc, which is usually used in the prescription of color cosmetics, is a plate-type, white-colored inorganic substance with good application and spreadability to skin. Furthermore, it features excellent dispersibility and extensibility as well as outstanding heat tolerance, light stability, and chemical resistance. In general, silica contributes to durable makeup and stabilized formulation. This paper covers a process of manufacturing an inorganic pigment complex, where hydrophobic silica was applied to the surface of talc by using differences in zeta potential after the surface charges of talc and hydrophobic silica had been adjusted with cationic and anionic surfactants, respectively. The resulting inorganic pigment complex was composed of talc whose surface is coated hydrophobic silica to the thickness of $1{\mu}m$ or less, which developed an effective hydrophobic property. Zeta potential was measured to analyze the surface charge of an inorganic pigment, and FT-IR, used to check the functional group of a surfactant, was applied to treat the surface of the pigment. The surface of the inorganic pigment complex was observed employing SEM, EDS, and FIB, while its structure was confirmed with XRD and FT-IR.

Manufacturing of a Korean Hand Phantom with Human Electrical Properties at 835 MHz and 1,800 MHz Bands (835 MHz 및 1,800 MHz 대역에서 인체의 전기적 특성을 가지는 한국인 손 모양의 팬텀 제작)

  • Choi, Donggeun;Gimm, Yoonmyoung;Choi, Jaehoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.5
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    • pp.534-540
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    • 2013
  • Interest of the hand effect on the electromagnetic wave are internationally increasing with the increase of the use of the mobile phone. IEC TC106(International Electrotechnical Commission, Technical Committee 106) promotes international research exchange program in order to reflect the effect of human hands in the standard assessment method of human exposure dosimetry by the electromagnetic wave of mobile phones. Since current commercialized hand phantom is manufactured by taking into account the average size of westerners and provides only one grip posture, it imposes many restrictions on the accurate SAR measurement. Therefore, the development of proper hand phantom accounting for domestic situation and various grip posture capability is essential in order to analyze the accurate effect of human hand on the exposure estimation. In this paper, a jelly hand phantom suitable for Korean was manufactured with various grip posture capability at 835 MHz and 1,800 MHz bands. Although the tolerances of permittivity and conductivity of the manufactured hand phantom are with ${\pm}10%$ each, it was much less than CTIA(Cellular Telecommunication Industry Association) tolerance of ${\pm}20%$ at both bands. Its 3D CAD(3 Dimensional Computer Aided Design) file which was developed can be utilized for the simulation of human hand effect on SAR measurement of mobile phones. The findings in this study can be utilized for the analysis of human hand effect on SAR measurement of a mobile phone.

Analysis of the Spatial Distribution and Characteristics of Talented Labor Attraction in Korea - Focused on Talent Magnet Potential Index(TMPI) - (인재유인력의 지역분포와 특성분석 - 인재유인잠재력지수(TMPI) 산출을 중심으로 -)

  • Huh, Mungu
    • Journal of the Korean Regional Science Association
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    • v.31 no.4
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    • pp.47-69
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    • 2015
  • The purpose of this study is to analyze regional spatial distribution and characteristics with the Talent Magnet Potential Index(TMPI), which is calculated through the extra-regional talent attracting environment(Magnet factors) and intra-regional talent cultivating environment(Incubator factors) of each region. As a result, Seoul, Daejeon, Gyeonggi, Ulsan etc. ranked highest, and regions developed in knowledge-based services, R&D capability, and manufacturing turned out to have a higher TMPI. The regions were categorized into 4 types, and the regional type analysis showed that the cumulative effects of Type I(Talent comparative advantage type) and Type III(Talent absolute shortage type) contribute to widening the economic gap among these regions. In addition, although the metropolitan based Type IV(intra-regional talent dependant type) had excellent talent training capability, there seemed to be an outflow of talent into Type I or Type II(extra-regional talent dependant type). This paper has done a correlation analysis to test the validity of the TMPI. As a result, the correlation between talent by type and TMPI turned out to be very high. The correlation coefficient with 2T turned out to have the highest correlation, showing that tolerance contributes a much greater deal to talent attracting and training than expected. Finally, based on the main analytical results, implications for talent attraction & training policy projects and 7 improvement plans have been proposed.