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Wyszukujesz frazę "Lee, T.-H." wg kryterium: Autor


Tytuł:
Subjective Perception of Load Heaviness
Autorzy:
Lee, T. H.
Powiązania:
https://bibliotekanauki.pl/articles/89678.pdf
Data publikacji:
2014
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
psychophysics
weight discrimination
sense of force
różnica płci
czynniki psychofizyczne
dźwiganie ciężarów
noszenie ciężarów
Opis:
This study examined human subjective perception of load heaviness. Forty-two (3 boxes × 14 weights) and 27 (3 boxes × 9 weights) experimental conditions were randomly presented to male and female participants, respectively. The results showed that the participants were not able to discriminate the effect of the box on perceived weight. The participants underestimated the weight for low weights and overestimated it for high weights. The females perceived a greater increase in weight than the males for the same increase in weight. The participants’ linguistic term for perceived weight was positively correlated to the magnitude of weight. Approximately 50% of the males perceived a weight of 20 kg or over as risky, while ~60% of the females perceived a weight of 14 kg or over as risky. This study supposes that the gender difference in muscular capability is responsible for the effect of gender on the risk perception of weight.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2014, 20, 3; 421-427
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Range and Mode on Lifting Capability and Lifting Time
Autorzy:
Lee, T. H.
Powiązania:
https://bibliotekanauki.pl/articles/90247.pdf
Data publikacji:
2012
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
lifting
strength
manual materials handling
Opis:
This study examined the effects of 3 lifting ranges and 3 lifting modes on maximum lifting capability and total lifting time. The results demonstrated that the maximum lifting capability for FK (from floor to knuckle height)was greater than that for KS (from knuckle height to shoulder height) or FS (from floor to shoulder height. Additionally, asymmetric lifting with initial trunk rotation decreased maximum lifting capability compared with symmetric lifting or asymmetric lifting with final trunk rotation. The difference in total lifting time between KS and FS was not significant, while FK increased total lifting time by ~20% compared with FS even though the travel distance was 50% shorter.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2012, 18, 3; 387-391
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Postural and Muscular Responses While Viewing Different Heights of Screen
Autorzy:
Lee, T. H.
Liu, T. Y.
Powiązania:
https://bibliotekanauki.pl/articles/90519.pdf
Data publikacji:
2013
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
visual display terminal
posture
viewing angle
pozycja przy pracy
kąt widzenia
ekran
praca przy komputerze
Opis:
This study aimed to examine the effects of visual display terminal (VDT) viewing angle on human postural angle and muscular activity. The participants’ neck, thoracic bending, and trunk inclination angles; and the activity of sternocleidomastoid, trapezius, splenius capitis, and erector spinae at 5 viewing angles (+400, +200, 00, –200, and –400) of a VDT screen were collected for 1 min. This study showed that neck and thoracic bending angles increased with viewing angle, while viewing angle did not significantly affect trunk inclination angle. In addition, the activity of trapezius and erector spinae increased when viewing a higher or lower VDT screen height compared with viewing a horizontal VDT screen height; however, the activity of splenius capitis decreased with viewing angle.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2013, 19, 2; 251-258
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Hand Posture, Breathing Type, Arm Posture and Body Posture on Hand Errors
Autorzy:
Lee, T. H.
Cheng, T. S.
Powiązania:
https://bibliotekanauki.pl/articles/90970.pdf
Data publikacji:
2012
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
aiming
fine manipulation
hand tremor
pointing
Opis:
This study consisted of 2 experiments. Experiment 1 examined the effects of hand posture, arm posture and body posture on hand error, while experiment 2 examined the effects of hand posture, breathing type and body posture on hand error. This study showed that more hand errors occurred in the nondominant hand, extended arm, normal breathing and standing compared with errors in the dominant hand, flexed arm, inspire–hold and sitting, respectively. This study advised people to use their dominant hand, flex their arm, inspire and hold the breath and support their body while performing fine manipulation tasks. Finally, hand error varied dramatically across the participants, indicating the need to screen individuals for fine manual manipulation tasks.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2012, 18, 3; 393-398
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymmetric Lifting Capabilities for Different Container Dimensions
Autorzy:
Lee, T. H.
Cheng, T. S.
Powiązania:
https://bibliotekanauki.pl/articles/91162.pdf
Data publikacji:
2011
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
lifting capacity
asymmetric lifting
container
Opis:
This study recruited 14 young male participants to examine human 4-h maximum acceptable weight of lifting (MAWL) and maximum weight of lifting (MWL) for different modes of asymmetric lifting and containers. The results showed that asymmetric lifting with trunk rotation decreased MAWL and MWL by 9.1 and 17.3%, respectively, and asymmetric lifting with body turn decreased MAWL and MWL by 6.1%, when compared with the symmetric lifting. The decreasing effects of container width and MAWL and MWL were greater than those of container length. Participants selected MAWL of ~33–37% of their MWL capability.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2011, 17, 2; 187-193
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Working Postures at a Construction Site Using the OWAS Method
Autorzy:
Lee, T. H.
Han, C. S.
Powiązania:
https://bibliotekanauki.pl/articles/90807.pdf
Data publikacji:
2013
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
construction
posture
occupational injury
OWAS
budownictwo
pozycja przy pracy
analiza bezpieczeństwa
Opis:
This study used OWAS to analyze the working postures of construction workers on building the foundations of a log cabin. Three construction workers, with an average work experience of 40 years, participated in this study. Eight elementary jobs of building the foundations of a log cabin were videotaped at a construction site and analyzed later in the laboratory. For an overall distribution of trunk postures, OWAS identified that a bent and twisted trunk posture (34%), which fell into action category 3, was the major poor posture for construction workers. This study also identified that tying beams with steel bars, assembling column templates, and cement grouting of the ground were the 3 principal jobs in which workers building the foundations exhibited poor working posture. This article suggests ways to reduce and evaluate poor posture in a dynamic construction site.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2013, 19, 2; 245-250
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grip Force and Heart Rate Responses to Manual Carrying Tasks: Effects of Material, Weight, and Base Area of the Container
Autorzy:
Lee, T. H.
Tseng, C. Y.
Powiązania:
https://bibliotekanauki.pl/articles/91134.pdf
Data publikacji:
2014
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
liquid
solid
carriage
manual materials handling
pracownik fizyczny
chwyt
transport ręczny
Opis:
This study recruited 16 industrial workers to examine the effects of material, weight, and base area of container on reduction of grip force (ΔGF) and heart rate for a 100-m manual carrying task. This study examined 2 carrying materials (iron and water), 4 carrying weights (4.4, 8.9, 13.3, 17.8 kg), and 2 base areas of container (24 ´ 24 cm, 35 ´ 24 cm). This study showed that carrying water significantly increased ΔGF and heart rate as compared with carrying iron. Also, ΔGF and heart rate significantly increased with carrying weight and base area of container. The effects of base area of container on ΔGF and heart rate were greater in carrying water condition than in carrying iron condition. The maximum dynamic effect of water on ΔGF and heart rate occurred when water occupied ~60%–80% of full volume of the container.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2014, 20, 3; 377-383
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Economic statistical design of variable sampling interval X̅ control chart based on surrogate variable using genetic algorithms
Autorzy:
Lee, T.-H.
Hong, S.-H.
Kwon, H.-M.
Lee, M.
Powiązania:
https://bibliotekanauki.pl/articles/406970.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
economic design
surrogate variable
variable sampling interval
TRISO Fuel
genetic algorithms
Opis:
In many cases, a X̅ control chart based on a performance variable is used in industrial fields. Typically, the control chart monitors the measurements of a performance variable itself. However, if the performance variable is too costly or impossible to measure, and a less expensive surrogate variable is available, the process may be more efficiently controlled using surrogate variables. In this paper, we present a model for the economic statistical design of a VSI (Variable Sampling Interval) X̅ control chart using a surrogate variable that is linearly correlated with the performance variable. We derive the total average profit model from an economic viewpoint and apply the model to a Very High Temperature Reactor (VHTR) nuclear fuel measurement system and derive the optimal result using genetic algorithms. Compared with the control chart based on a performance variable, the proposed model gives a larger expected net income per unit of time in the long-run if the correlation between the performance variable and the surrogate variable is relatively high. The proposed model was confined to the sample mean control chart under the assumption that a single assignable cause occurs according to the Poisson process. However, the model may also be extended to other types of control charts using a single or multiple assignable cause assumptions such as VSS (Variable Sample Size) X̅ control chart, EWMA, CUSUM charts and so on.
Źródło:
Management and Production Engineering Review; 2016, 7, 4; 54-64
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of Cu and Ni Nano-Fluids Synthesized by Pulsed Wire Evaporation Method
Autorzy:
Kim, H.-S.
Yilmaz, F.
Dharmaiah, P.
Lee, D.-J
Lee, T.-H.
Hong, S.-J.
Powiązania:
https://bibliotekanauki.pl/articles/356475.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pulsed wire evaporation
nanofluid
Cu
Ni
suspension stability
dispersibility
Opis:
In the present work, Cu and Ni nanofluids were synthesized using the pulsed wire evaporation (PWE) method in the different aqueous medias, namely (ethanol and ethylene glycol), and the effects of the aqueous media on the dispersion state, stability, and particle size of nanoparticles were studied. The size and morphology of synthesized nano-particles were investigated by transmission electron microscopy (TEM). Also, the dispersion stability of the nanofluids was evaluated by turbiscan analysis. The TEM results showed that the nano-particles were spherical in shape, and the average particle size was below 100 nm. The average particle size of the Cu nano-particles was smaller than that of Ni, which was attributed to a difference in the specific sublimation energy of the elements. Moreover, ethylene glycol (EG) exhibited higher suspension stability than ethanol. Finally, the dispersion stability of Cu@EG displayed the highest value due to lower particle size and greater viscosity.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 999-1004
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect Of Different Mechanical Milling Processes On Morphology And Microstructural Changes Of Nano And Micron Al-Powders
Wpływ różnych procesów mielenia na morfologię i mikrostrukturę nanometrycznych i mikronowych proszków Al
Autorzy:
Kim, H.-S.
Madavali, B.
Eom, T.-J.
Kim, C.- M.
Koo, J.-M.
Lee, T. H.
Hong, S.-J.
Powiązania:
https://bibliotekanauki.pl/articles/355715.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al alloys
high-energy ball milling
low energy ball milling
plastic deformation
stopy Al
wysokoenergetyczne mielenie kulkowe
mielenie energooszczędne
odkształcenia plastyczne
Opis:
In this research, effect of the various mechanical milling process on morphology and microstructural changes of nano and micron Al-powders was studied. The milling of Al-powders was performed by both high energy and low energy ball milling process. The influence of milling (pulverizing) energy on the structural changes of Al-powders was studied. Al-nanoparticles were agglomerated during the MA and its size was increased with increasing milling while micron Al-powder gets flattened shape during high energy ball milling due to severe plastic deformation. Meanwhile, structural evolution during high energy ball milling of the nano powder occurred faster than that of the micron powder. A slight shift in the position of X-ray diffraction peaks was observed in nano Al-powders but it was un-altered in macro Al-powders. The variation in lattice parameters was observed only for nano Al powders during the high energy ball milling due to lattice distortion.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1235-1239
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reaction Kinetics and Morphological Study of TiNb2O7 Synthesized by Solid-State Reaction
Autorzy:
Choi, S. H.
Ali, B.
Choi, K. S.
Hyun, S. K.
Sim, J. J.
Choi, W. J.
Joo, W.
Lim, J. H.
Lee, T. H.
Kim, T. S.
Park, K. T.
Powiązania:
https://bibliotekanauki.pl/articles/355326.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
solid state reaction
kinetic analysis
quantitative phase analysis
TiNb2O7 synthesis
Opis:
Although TiNb2O7 is regarded as a material with high application potential in lithium-ion batteries (LIBs) and solid-oxide fuel cells (SOFCs), it has been difficult to find suitable cost-effective conditions for synthesizing it on a commercial scale. In this study, TiNb2O7 compounds were synthesized by a solid state synthesis process. For stoichiometrically precise synthesis of the TiNb2O7 phase, the starting materials, TiO2 and Nb2O5 were taken in a 1:1 molar ratio. Activation energy and reaction kinetics of the system were investigated at various synthesis temperatures (800,1000,1200, and 1400°C) and for various holding durations (1,5,10, and 20 h). Furthermore, change in the product morphology and particle size distribution were also evaluated as a function of synthesis temperature and duration. Additionally, quantitative phase analysis was conducted using the Rietveld refinement method. It was found that increases in the synthesis temperature and holding time lead to increase in the mean particle size from 1 to 4.5 μm. The reaction rate constant for the synthesis reaction was also calculated.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1051-1056
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Immobilization of rambutan (Nephelium lappaceum) peel as a sorbent for Basic Fuchsin removal
Autorzy:
Lee, H.-J.
Ong, S.-T.
Powiązania:
https://bibliotekanauki.pl/articles/207651.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fuchsin
Fourier transform infrared spectrophotometry
FTIR
Nephelium lappaceum
fuksyna
spektroskopia w podczerwieni z transformatą Fouriera
Opis:
The potential of rambutan (Nephelium lappaceum) peel as a low-cost adsorbent in an immobilized condition to remove Basic Fuchsin from aqueous solution was studied. The effect of initial dye concentration, contact time, pH and adsorbent dosage for the dye removal was studied at room temperature (26±2 °C). Infrared spectrum of rambutan peel indicates the presence of C–O, –OH and C=C functional groups. The adsorption rate was found to be high at the first 30 min and the process reached equilibrium after 3 h with more than 80% of dye being removed. The uptake of Basic Fuchsin was more promising at pH slightly above 7. The study of sorption model and kinetic model showed that the adsorption of Basic Fuchsin on rambutan peel conformed to the Freundlich isotherm and pseudo-second order kinetics with a high correlation coefficient, R,sup>2 > 0.98. This indicates the Basic Fuchsin adsorbs chemically on the heterogeneous surface of rambutan peel. The maximum adsorption capacity determined from the Langmuir isotherm was 108.696 mg/g. It seems that rambutan peel has the potential to substitute activated carbon as an alternative low-cost adsorbent in the treatment of the dye effluent.
Źródło:
Environment Protection Engineering; 2017, 43, 1; 169-181
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery of HCL from chloride leach solution of spent HDS catalyst by solvent extraction
Autorzy:
Banda, R.
Nguyen, T.H.
Lee, M.S.
Powiązania:
https://bibliotekanauki.pl/articles/185588.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
HCl
extraction
stripping
recovery
TEHA
wydobycie
Opis:
In the present work, amine based extractant and its mixture with cationic and solvating extractants were tested for the extraction of HCl from chloride solution containing Al(III). The chloride feed solution resulted from the leaching of spent HDS (hydro-desulfurization) catalysts. For this purpose, amine extractants, such as TOA (trioctyl amine), Alamine 336 (a mixture of tri-octyl/decyl amine), Alamine 308 (tri-isooctyl amine), and TEHA (tri 2-ethylhexyl amine) were used and the extraction and stripping behavior of HCl was compared. The extracted HCl was easily stripped from loaded TEHA phase, when compared with the other tested tertiary amine system. Solvent extraction reaction of HCl by TEHA was determined from the extraction data. Unlike TOA and Alamine 336, adding cationic extractant to TEHA had negligible effect on the extraction and stripping of HCl. In our experimental ranges, no Al was extracted by amines and pure HCl was recovered. MaCabe-Thiele diagrams for the extraction and stripping of HCl by TEHA were constructed.
Źródło:
Chemical and Process Engineering; 2013, 34, 1; 153-163
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure and Magnetic Properties of NdFeB Sintered Magnets Diffusion-Treated with Cu/Al Mixed Dyco Alloy-Powder
Autorzy:
Lee, M.-W.
Bae, K.-H.
Lee, S.-R.
Kim, H.-J.
Jang, T.-S.
Powiązania:
https://bibliotekanauki.pl/articles/353351.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Nd-Fe-B sintered magnets
grain boundary diffusion process
low melting point element
DyCo alloy-powder diffusion
Opis:
We investigated the microstructural and magnetic property changes of DyCo, Cu + DyCo, and Al + DyCo diffusion-treated NdFeB sintered magnets. The coercivity of all diffusion treated magnet was increased at 880ºC of 1st post annealing(PA), by 6.1 kOe in Cu and 7.0 kOe in Al mixed DyCo coated magnets, whereas this increment was found to be relatively low (3.9 kOe) in the magnet coated with DyCo only. The diffusivity and diffusion depth of Dy were increased in those magnets which were treated with Cu or Al mixed DyCo, mainly due to comparatively easy diffusion path provided by Cu and Al because of their solubility with Ndrich grain boundary phase. The formation of Cu/Al-rich grain boundary phase might have enhanced the diffusivity of Dy-atoms. Moreover, relatively a large number of Dy atoms reached into the magnet and mostly segregated at the interface of Nd2 Fe14 B and grain boundary phases covering Nd2 Fe14 B grains so that the core-shell type structures were developed. The formation of highly anisotropic (Nd, Dy)2Fe14B phase layer, which acted as the shell in the core-shell type structure so as to prevent the reverse domain movement, was the cause of enhancing the coercivity of diffusion treated NdFeB magnets. Segregation of cobalt in Nd-rich TJP followed by the formation of Co-rich phase was beneficial for the coercivity enhancement, resulting in the stabilization of the metastable c-Nd2O3 phase.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1263-1266
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect Of DyMn Alloy-Powder Addition On Microstructure And Magnetic Properties Of NdFeB Sintered Magnets
Wpływ dodatku proszku DyMn na mikrostrukturę i właściwości magnetyczne spiekanych magnesów NdFeB
Autorzy:
Lee, M.-W.
Dhakal, D. R.
Kim, T. H.
Lee, S. R.
Kim, H. J.
Jang, T. S.
Powiązania:
https://bibliotekanauki.pl/articles/357010.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Nd-Fe-B sintered magnets
DyMn-alloy powder
coercivity
low melting point element
magnesy spiekane
proszek DyMn
koercja
elementy o niskiej temperaturze topnienia
Opis:
Micostructural change and corresponding effect on coercivity of a NdFeB sintered magnet mixed with small amount of DyMn powder was investigated. In the sintered magnet mixed with the DyMn alloy-powder Dy-rich shell was formed at outer layer of the main grains, while Mn was mostly concentrated at Nd-rich triple junction phase (TJP), lowering melting temperature of the Nd-rich phase that eventually improved the microstructural characteristics of the gain boundary phase. The coercivity of a magnet increased more than 3.5 kOe by the mixing of the DyMn alloy-powder.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1407-1409
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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