• Title/Summary/Keyword: mass physical properties

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Worker-Centered Design for Working Area in the Electronic Industry

  • Baik, Sung Wan;Jeong, Byung Yong;Shin, Dong Seok
    • Journal of the Ergonomics Society of Korea
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    • v.33 no.3
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    • pp.229-239
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    • 2014
  • Objective: This research provides a guideline for working area design in the electronic industry, considering gender differences of physical characteristics. Background: Co-work in the electronic industry requires workers of various physical properties to work cohesively in the conveyor line for mass production. This stresses the need for a worker-centered design of the workplace convenient for all the workers. Method: In this research, the $6^{th}$ Size Korea (National Anthropometric Survey in Korea) report is referred to obtain the design measurements according to age and gender varieties. This information is used to provide the working area guideline concerning conveyor line workers of both genders aged 20 to 40. Results: Physical properties of workers and workplace design principles were obtained for application in the assembly, inspection, and material handling process in the electronic industry. Conclusion: Applying ergonomic design principles can provide safe and comfortable workplace for both genders. Application: This research can be fundamentally used in designing worker-centered workplaces.

CORE AND GLOBAL PROPERTIES OF EARLY-TYPE GALAXIES AND THEIR GLOBULAR CLUSTER SYSTEMS

  • Cote, Patrick;The Acs Virgo And Fornax Cluster Survey Teams, The Acs Virgo And Fornax Cluster Survey Teams
    • Publications of The Korean Astronomical Society
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    • v.25 no.3
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    • pp.59-64
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    • 2010
  • The core and global properties of the early-type ("red sequence") galaxies in the Virgo and Fornax clusters are examined using high-quality HST/ACS imaging for 143 galaxies. Rather than dividing neatly into disparate populations having distinct formation and/or evolution histories, many of the core and global properties of these galaxies show smooth and systematic variations along the galaxy luminosity function. The few examples of the rare class of compact elliptical galaxies in our sample all show properties that are strongly suggestive of tidal stripping by massive galaxies; if so, then these systems should not be viewed as populating the low-luminosity extension of so-called "normal" elliptical sequences. These results demonstrate that complete and/or unbiased samples are a pre-requisite for identifying the physical mechanisms that gave rise to the early-type galaxies we observe locally, and how these mechanisms varied with mass and environment.

Modeling Techniques for Geoenvironmental Engineering Problems

  • Singh, D.N.;Rao, B. Hanumantha
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.542-557
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    • 2007
  • Contamination of subsurface results in degradation of geomaterials (i.e., soils and rock mass), in the long run. This is mainly due to the presence of chemical and/or radiological materials in undesirable concentrations and at elevated temperatures. However, as contaminant-geomaterial interaction is an extremely slow and complex process, which primarily depends on their physical, chemical and mineralogical properties, it is quite difficult to study this interaction under laboratory or in situ conditions. In such a situation, accelerated physical modeling, using a geotechnical centrifuge, and finite element/difference based numerical modeling techniques are found to be quite useful. This paper presents details of various modeling techniques developed by the researchers at the Indian Institute of Technology Bombay, Mumbai, India, for studying heat migration, flow and interaction (fate) of reactive and non-reactive contaminants in the geoenvironment, under saturated and unsaturated conditions. In addition, paper presents details of the technique that can be employed for determining susceptibility of a material to undergo physico-chemico-mineralogical alterations due to its interaction with contaminants.

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Using Tintinnid Distribution for Monitoring Water Mass Changes in the Northern East China Sea (북부 동중국해 수괴 변화 감시를 위한 유종섬모류 분포 적용)

  • Kim, Young-Ok;Noh, Jae-Hoon;Lee, Tae-Hee;Jang, Pung-Guk;Ju, Se-Jong;Choi, Dong-Lim
    • Ocean and Polar Research
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    • v.34 no.2
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    • pp.219-228
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    • 2012
  • Tintinnid species distribution has been monitored in the northern East China Sea (ECS) in the summer of 2006 through 2011. This is used to understand the water mass movements in the northern ECS. The warm oceanic tintinnid species had largely spread in 2007 in the area, indicating that there was greater warm water extension into the northern ECS. However the extension of neritic water within the Changjiang diluted water mass has strengthened in 2008 and 2010 because the neritic species distribution had relatively grown in both years. These annual results based on the biological indicators of tintinnid species are well matched with the salinity change in the area. The warm oceanic species, Dadayiella ganymedes had frequently occurred over the study years and had shown a significant relationship with the salinity change. This is valuable as a key stone species for monitoring the intrusion of the Kuroshio within the northern ECS. Information from tintinnid biological indicators can support physical oceanography data to confirm ambiguous water mass properties.

A Study of Engineering Properties and Deformation Behavior of Weathered Rock Mass (풍화 암반의 공학적 특성 및 변형거동에 관한 연구)

  • 강추원;박현식;김수로
    • Explosives and Blasting
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    • v.22 no.2
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    • pp.33-43
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    • 2004
  • The six grades weathering system is normally used in weathered rock classification. In this study. fresh and weathered rock block of grade I to V were sampled in Jang-soo ana but samples of the grade VI was omitted from this study. The variation quantities of chemical weathering indices with weathering degree are smaller than those of physical and mechanical properties. Increase of Weathering degree is well indicated by physical and mechanical properties such as strength, hardness, ultrasonic velocity and slake durability result. Especially, absorption and porosity ratio is a good indicator. As weathering proceeds. a number of the cracks affect the rock deformation. Therefore, stress-strain curves of weathered rocks in unconfined state are quite different from ones of fresh rocks.

Characteristics of wastewater from unit systems of automative process for manufacture of paper mulberry pulp fibers (닥 펄프 제조공정 자동화에 따른 단위공정 폐수의 특성)

  • Hwang, Ji-Hyun;Hwang, Sung-Jun;Kim, Hyoung-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.3
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    • pp.55-62
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    • 2015
  • Paper mulberry fibers have been used as fibrous raw materials for manufacturing traditional handmade paper, hanji for a long time. Compared to wood pulp fibers, pulp fibers from mulberry bast tissue have some benefits in physical and chemical properties due to their high D.P (degree of polymerization), M.W (molecule weight) and long fiber length. Specially, Korean handmade hanji shows outstanding characteristics in mechanical tensile strength, folding endurance, flexibility and long sustainable conservation properties. Therefore, hanji is widely applied to daily supplies, hygienic goods, medical supplies, clothing industries and so on. Recently, the potential demand of mulberry pulp fibers is more and more increased on the strength of high application fields. This study was focused on the possibility of wastewater recycling in unit operation systems for the development of automated mass production line. The properties and environmental loads of wastewater from debarking, cooking, bleaching and screening process were analyzed by means of COD, conductivity, turbidity and solid materials. The wastewater from debarking and cooking process was comparatively high in pollution load, and would be treated by additional approaches of chemico-physical method.

Characteristics Analysis of Highly Elastic Materials according to the Graphite Content and a Simulation Study of Physical Properties Prediction Using a Nonlinear Material Model (열팽창성 그래파이트 함량에 따른 고탄성 도료 소재의 특성 분석 및 비선형 재료모델을 활용한 물성 예측 시뮬레이션 연구)

  • Yu, Seong-Hun;Lee, Jong-Hyuk;Kim, Dae-cheol;Lee, Byung-Su;Sim, Jee-Hyun
    • Textile Coloration and Finishing
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    • v.34 no.4
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    • pp.250-260
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    • 2022
  • In this research, a high-elasticity acrylic emulsion binder with core-shell polymerization and self-crosslinking system is mixed with a flame-retardant water-dispersed polyurethane (PUD) binder. In addition, finite element analysis was conducted through virtual engineering software ANSYS by applying three representative nonlinear material models. The most suitable nonlinear material model was selected after the relative comparison between the actual experimental values and the predicted values of the properties derived from simulations. The selected nonlinear material model is intended to be used as a nonlinear material model for computational simulation analysis that simulates the experimental environment of the vibration test (ASTM E1399) and the actual fire safety test (ASTM E1966). When the mass fraction of thermally expandable graphite was 0.7%, the thermal and physical properties were the best. Among the nonlinear material models, the simulation result of the Ogden model showed the closest value to the actual result.

A Comparative Study on the Injection Rate Characteristics of Conventional and F-T Synthetic Gasoline Under Various Fuel Temperatures (다양한 연료온도 조건에 있어서의 기존 가솔린과 F-T합성 가솔린의 분사율 특성 비교 연구)

  • Jihyun Son;Gyuhan Bae;Seoksu Moon
    • Journal of ILASS-Korea
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    • v.28 no.3
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    • pp.143-149
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    • 2023
  • Amidst the drive towards carbon neutrality, interest in renewable synthetic e-fuels is rising rapidly. These fuels, generated through the synthesis of atmospheric carbon and green hydrogen, offer a sustainable solution, showing advantages like high energy density and compatibility with existing infrastructure. The physical properties of e-fuels can be different from those of conventional gasoline based on manufacturing methods, which requires investigations into how the physical properties of e-fuels affect the fuel injection characteristics. This study performs a comparative analysis between conventional and Fischer-Tropsch (F-T) synthetic gasoline (e-gasoline) across various fuel temperatures, including the cold start condition. The fuel properties of F-T synthetic and conventional gasoline are analyzed using a gas chromatography-mass spectrometry technique and the injection rates are measured using a Bosch-tube injection rate meter. The F-T synthetic gasoline exhibited higher density and kinematic viscosity, but lower vapor pressure compared to the conventional gasoline. Both fuels showed an increase in injection rate as the fuel temperature decreased. The F-T synthetic gasoline showed higher injection rates compared to conventional gasoline regardless of the fuel temperature.

DEEP: KMTNet DEep Ecliptic Patrol

  • Moon, Hong-Kyu;Choi, Young-Jun;Kim, Myung-Jin;Ishiguro, Masateru;Thuillot, William
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.122.2-122.2
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    • 2011
  • For more than a decade, NEA (Near-Earth Asteroid) survey teams equipped with 1 meter-class telescopes discovered thousands of NEAs in the northern sky. As of August 2011, some 8,200 NEAs have been cataloged, yet only five percent of them has been investigated for their physical and chemical properties. In order to improve current situation, we propose a deep ecliptic survey utilizing KMTNet, for detection and characterization of NEAs in the southern sky. Thanks to the wide-field capability (four square degrees) of the telescopes, we will be able to considerably expand the search volume carrying out precision photometry down to 21.5th magnitude. We plan to focus our survey on opposition and two "sweet spots" in the ecliptic belt. Since SDSS colors characterize mineralogical properties of NEAs, g', r', i', z' filters will be employed. Based on the round-the-clock observation, we will study their rotational properties; for multiple systems, mass, density and other physical parameters can be obtained. We plan to maintain a dedicated database of the physical and mineralogical properties of NEAs. With this archive, it is expected that our understanding on the population will see a drastic change. We also plan to participate in the GAIA Follow-Up Network for ground based observation of the Solar System Objects (GAIA-FUN-SSO). The follow- up astrometry will be performed upon alerts issued by the GAIA-FUN-SSO Central Node in France.

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CENSUS AND ANALYSIS OF GALACTIC MOLECULAR CLOUDS

  • HOJAEV, A.S.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.107-108
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    • 2015
  • In this project, all available databases of molecular and gas-dust clouds in the Galaxy were cross-identified by taking into account available properties, including position, angular dimensions, velocity, density, temperature and mass. An initial list of about 7000 entries was condensed into a cross-identified all-sky catalogue containing molecular and gas-dust clouds. Some relationships were studied between the main physical features of clouds. Finally, we prepared a complex observing program and address future work for filling in the gaps.