• 제목/요약/키워드: Work Intensity

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The calculation of stress intensity factors by the surface integral method

  • Jin, Chi-Sub;Jang, Heui-Suk;Choi, Hyun-Tae
    • Structural Engineering and Mechanics
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    • v.3 no.6
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    • pp.541-553
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    • 1995
  • The determination of the stress intensity factors is investigated by using the surface integral defined around the crack tip of the structure. In this work, the integral method is derived naturally from the standard path integral J. But the use of the surface integral is also extended to the case where body forces act. Computer program for obtaining the stress intensity factors $K_I$ and $K_{II}$ is developed, which prepares input variables from the result of the conventional finite element analysis. This paper provides a parabolic smooth curve function. By the use of the function and conventional element meshes in which the aspect ratio (element length at the crack tip/crack length) is about 25 percent, relatively accurate $K_I$ and K_{II}$ values can be obtained for the outer integral radius ranging from 1/3 to 1 of the crack length and for inner one zero.

Determination of Stress Intensity Factors for Interface Cracks in Dissimilar Materials Using the RWCIM (상반일 등고선 적분법을 이용한 이종재 접합계면 균열의 응력강도계수 결정)

  • 조상봉;정휘원;김진광
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.5
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    • pp.180-185
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    • 2000
  • An interface V-notched crack problem can be formulated as a eigenvalue problem. there are the eigenvalues which give stress singularities at the V-notched crack tip. The RWCIM is a method of calculating the eigenvector coefficients associated with eigenvalues for a V-notched crack problem. Obtaining the stress intensity factors for an interface crack in dissimilar materials is examined by the RWCIM. The results of stress intensity factors for an interface crack are compared with those of the displacement extrapolation method by the BEM

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Analysis of Nursing Intensity Related to Nursing Activities in Operating Room using the Relative Value Scale For Nursing Cost (간호수가 산정을 위한 상대가치를 이용한 수술실 간호행위 간호강도 분석)

  • Ha, Ru Mee;Kwon, Kyoung Ja;Woo, Jin Ha;Kim, Jung A
    • Journal of Korean Clinical Nursing Research
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    • v.20 no.2
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    • pp.162-176
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    • 2014
  • Purpose: The purpose of this study was to perform an operating room nursing activities analysis and estimate nursing intensity of each nursing activity based on the Relative Value Scale (RVS). Methods: The methodology for this study of RVS was based on the work of Hsiao et al. The first stage was to identify nursing activities and the second to measure intensity of nursing activities including technical skill, mental effort, and stress. Results: Calculation of the RVS for 99 nursing practices showed a score range from 300.00 to 1337.78. CS operation assistant, OS operation assistant, and obtaining certification had high nursing intensity. Surgical hand washing, putting on surgical gowns, surgical gloves and surgical caps and mask had low nursing intensity. Conclusion: The activities of operating room are not compensated separately but reimbursement is usually included in physician fees. In the future, an estimation of nursing cost should show the nursing contribution rate to total operation revenue.

A Study on Energy Release Rate for Interface Cracks in Pseudo-isotropic Dissimilar Materials (유사등방성 이종재 접합계면 균열의 에너지해방률에 대한 연구)

  • 이원욱;김진광;조상봉
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.752-754
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    • 1997
  • The stress intensity factor for an interface crack in dissimilar materials has been obtained by many researchers. But research of the energy release rate for an interface crack in pseudo-isotropic dissimilar materials is insufficient yet. In this paper, the energy release rate for cracks in pseudo-isotropic dissimilar materials was obtained using eigenfunction expansion method and also analyzed numerically using the reciprocal work contour integral method. The results were verified by comparing with other worker's results.

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A study on the Pollution Emissions of the Ultrasonic Fuel Feeding System in Gasoline Injection Vehicle (초음파 연료공급장치용 가솔린 분사식 자동차의 저공해화 연구)

  • 최관호;김봉석;류정인
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.1
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    • pp.86-95
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    • 1996
  • This study was on the pollution emissions of the Ultrasonic fuel feeding system in gasoline injection vehicle. This work measured th SMD of the fuel, and compared the characteristics through chassis dynamometer and highway road test by the conventional vehicle. And this work measured vacuum degree, turbulence intensity and the rate of fuel consumption according to intake air velocity with swirler. The results are as followed; The effects of the vehicle installed the ultrasonic fuel feeding system are better than those of the conventional vehicle.

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Energy Expenditure of Male Blue Collar Workers (생산직 남성근로자의 작업 중 에너지 소모량)

  • Woo, Ji Hoon;Kang, Dongmug;Shin, Yong Chul;Kim, Myeong Ock;Son, Min Jung;Kim, Boo Wook;Cho, Byung Mann;Lee, Su Ill
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.16 no.2
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    • pp.183-192
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    • 2006
  • Predicting energy expenditure (EE) is important to prevent work-related musculoskeletal disorders (WMSDs). The problem to predict EE is that the standard of EE is based on western data. The authors checked average EE by job categories to provide basic data for suggesting proper work intensity for Korean workers. This study was conducted from 2003 to 2005. Study subjects were recruited from 4 car parts assembly plant, 2 car assembly plant, 2 Heavy machine manufacturing plant and 2 shipyards. Total study subjects were 515 male workers. To estimate VO2max, sub-maximal test was conducted to measure VO275%max by bicycle ergometer (Combi Co, Aerobike 75XL II). Heartbeats were recorded with heartbeat recorder (Polar Electro Co, Finland, S810) during work. EE of work was calculated by recorded heartbeat and individual regression equation which was derived from sub-maximal test. Subjects were classified into 4 industry and 8 work posture, 23 job task categories. Mean EEs (S.D.) according to industry classification (kcal/min) were 4.9 (0.7), 4.8 (0.7), 4.9 (0.7), 5.0 (0.9), and 4.0 (0.5) for Car Part manufacture, Car Assembly, Ship Building, Heavy Machinery Manufacture, and Hospital Office, respectively. The results suggest that Korean male workers of exceeding to the NIOSH criteria will be needed to plan for job rescheduling to maintain $worker^{\circ}$Øs health. Further study to establish Korean work intensity standard would be needed.

A Study on Determination of Stress Intensity Factor of Orthotropic Plates Using Crack Tip Singular Element (균열선단 특이요소를 이용한 직교이방성판의 응력확대계수 결정에 관한 연구)

  • 진치섭;최현태;이홍주
    • Proceedings of the Korea Concrete Institute Conference
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    • 1991.10a
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    • pp.124-128
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    • 1991
  • Wood, laminates, reinforced concrete, and some special types of metals systems with controlled grain orientation are often orthotropic and at least rectilinearly anisotropic from point to point, if regarded as homogeneous media. Orthotropic bodies where a crack is not associated with a plane of elastic symmetry may be conveniently treated as a crack problem in a generally anisotropic body. At this work, approach for the determination of the stress intensity factors (SIF) of anisotropic body using crack tip singular elements is presented. Caculated values are in good agreement with the others.

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Novel Design of Ultrashort Pulse Excimer Laser Amplifier System I (Energy Characteristics)

  • Lee, Young-Woo
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.39-43
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    • 2003
  • The technology required to advance the state of the art of ultra-high-intensity excimer amplifier construction to the 100 J/100fs output pulse level is identified. The preliminary design work for very large final amplifier pumped by electron beam module is described, and key design problems and approaches are presented and discussed in detail based on the recent experimental and theoretical results.

Inhomogeneous Poisson Intensity Estimation via Information Projections onto Wavelet Subspaces

  • Kim, Woo-Chul;Koo, Ja-Yong
    • Journal of the Korean Statistical Society
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    • v.31 no.3
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    • pp.343-357
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    • 2002
  • This paper proposes a method for producing smooth and positive estimates of the intensity function of an inhomogeneous Poisson process based on the shrinkage of wavelet coefficients of the observed counts. The information projection is used in conjunction with the level-dependent thresholds to yield smooth and positive estimates. This work is motivated by and demonstrated within the context of a problem involving gamma-ray burst data in astronomy. Simulation results are also presented in order to show the performance of the information projection estimators.

Servitization and Manufacturing Firms' Performance: Korean Firm-Level Data Evidence

  • Jae Wook Jung;Hyunsoo Kim
    • East Asian Economic Review
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    • v.26 no.4
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    • pp.257-277
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    • 2022
  • Does servitization improve manufacturing firms' performance, and in what condition? Following the seminal work of Crozet and Milet (2017), this study analyzes disaggregated firm-level data that covers 40,000 South Korean manufacturing firms surveyed by the Survey of Business Activities of Korea. We compute firm-level servitization intensity with available sales data of each firm by two-digit SIC sub-sectors. We find two novel empirical regularities: Korean servitization intensity distribution shows a very different shape from the French benchmark; Servitized firms tend to perform higher profitability and higher productivity than non-servitized firms.