• Title/Summary/Keyword: size effect model

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Effects of Cognitive level of HACCP on Customer Satisfaction factor for Bakeries (HACCP 인식수준이 베이커리의 고객만족 요인에 미치는 영향)

  • Eom, Gi-Su;Im, Chung-Muk
    • Proceedings of the Safety Management and Science Conference
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    • 2012.04a
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    • pp.23-35
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    • 2012
  • The purpose of this study is to present HACCP management method for improving customer satisfaction in bakery industry. As a study method, literature review on HACCP and customer satisfaction and developing questionnaires through model design were done. Then, a survey was done to 209 customers who had experiences of visiting small size bakeries in Seoul or the national capital region. It was then statistically analyzed and examined. In conclusion, even though the respondents showed positive expectation that the certification of HACCP will have an effect on the factors of customer satisfaction like brand image, quality of product and service, facility and physical environment and so on, but as we proved in the course of study model's hypothesis confirmation, actually, current promoting efforts and strategies of the government or related institutions to spread recognition of HACCP don't have an meaningful effect on the factors of customer satisfaction.

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IMPLEMENTATION OF VELOCITY SLIP MODELS IN A FINITE ELEMENT NUMERICAL CODE FOR MICROSCALE FLUID SIMULATIONS (속도 슬립모델 적용을 통한 마이크로 유체 시뮬레이션용 FEM 수치 코드 개발)

  • Hoang, A.D.;Myong, R.S.
    • Journal of computational fluids engineering
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    • v.14 no.2
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    • pp.46-51
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    • 2009
  • The slip effect from the molecular interaction between fluid particles and solid surface atoms plays a key role in microscale fluid transport and heat transfer since the relative importance of surface forces increases as the size of the system decreases to the microscale. There exist two models to describe the slip effect: the Maxwell slip model in which the slip correction is made on the basis of the degree of shear stress near the wall surface and the Langmuir slip model based on a theory of adsorption of gases on solids. In this study, as the first step towards developing a general purpose numerical code of the compressible Navier-Stokes equations for computational simulations of microscale fluid flow and heat transfer, two slip models are implemented into a finite element numerical code of a simplified equation. In addition, a pressure-driven gas flow in a microchannel is investigated by the numerical code in order to validate numerical results.

Scale effect of mechanical properties of jointed rock mass: A numerical study based on particle flow code

  • Wang, Xiao;Yuan, Wei;Yan, Yatao;Zhang, Xue
    • Geomechanics and Engineering
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    • v.21 no.3
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    • pp.259-268
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    • 2020
  • The synthetic rock mass (SRM) were used to investigate the influence of specimen size on the mechanical properties of jointed rock mass. The SRM were established based on parallel bond model (PBM) and smooth joint model (SJM) and the scaled rock specimens were sampled in two SRMs considering three sampling locations. The research results show that the smaller the initial fracture density is, the greater the uniaxial compressive strength (UCS), elastic modulus (E) is when compared with the same sampling location. The mechanical properties of rock specimens obtained by different sampling methods in different SRMs have different scale effects. The strength of rock specimens with more new cracks is not necessarily less than that of rock specimens with fewer new cracks and the failure of rock is caused by the formation of macro-fracture surface.

Solvent Effect on Stress Relaxation of PET Filament Fibers and Self Diffusion of Crystallites

  • Nam Jeong Kim;Eung Ryul Kim;Sang Joon Hahn
    • Bulletin of the Korean Chemical Society
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    • v.12 no.5
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    • pp.468-473
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    • 1991
  • Viscoelastic properties of PET filament fibers on stress relaxation were investigated in the solvents of $H_2$O, 0.05% NaOH and 50% DMF using an Instron (UTM4-100 Tensilon) with solvent chamber. The theoretical stress relaxation equation derived by applying the Ree-Eyring's hyperbolic sine law to dashpot of three element non-Newtonian model was applied to the experimental stress relaxation curves, and the model parameters $G_1,G_2$, ${\alpha}$ and ${\beta}$ were obtained. By analyzing temperature dependency of the relaxation time, the values of activation entropy, activation enthalpy and activation free energy for flow in PET filament fiber were evaluated, the activation free energy being about 25.7 kcal/mol. The self diffusion coefficient and hole distance were obtained from parameters ${\alpha}$, ${\beta}$ and crystallite size in order to study the self diffusion and the orientation of crystallites in amorphous region and the effect of solvent.

A cohesive model for concrete mesostructure considering friction effect between cracks

  • Huang, Yi-qun;Hu, Shao-wei
    • Computers and Concrete
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    • v.24 no.1
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    • pp.51-61
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    • 2019
  • Compressive ability is one of the most important mechanical properties of concrete material. The compressive failure process of concrete is pretty complex with internal tension, shear damage and friction between cracks. To simulate the complex fracture process of concrete at meso level, methodology for meso-structural analysis of concrete specimens is developed; the zero thickness cohesive elements are pre-inserted to simulate the crack initiation and propagation; the constitutive applied in cohesive element is established to describe the mechanism of crack separation, closure and friction behavior between the fracture surfaces. A series of simulations were carried out based on the model proposed in this paper. The results reproduced the main fracture and mechanical feature of concrete under compression condition. The effect of key material parameters, structure size, and aggregate content on the concrete fracture pattern and loading carrying capacities was investigated. It is found that the inner friction coefficient has a significant influence on the compression character of concrete, the compression strength raises linearly with the increase of the inner friction coefficient, and the fracture pattern is sensitive to the mesostructure of concrete.

An Analysis of Cutting Force in Micromachining (미소절삭에서의 절삭력 해석)

  • Kim, Dong Sik;Kahng, C.H.;Kwak, Yoon Keun
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.12
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    • pp.72-80
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    • 1995
  • Ultraprecision machining technology has been playing a rapidly increasing and important role in manufacturing. However, the physics of the micromachining process at very small depth of cut, which is typically 1 .mu. m or less is not well understool. Shear along the shear plane and friction at the rake face dominate in conventional machining range. But sliding along the flank face of the tool due to the elastic recovery of the workpiece material and the effects of plowing due to the large effective negative rake angle resultant from the tool edge radius may become important in micromachining range. This paper suggests an orthogonal cutting model considering the cutting edge radius and then quantifies the effect of plowing due to the large effective negative rake angle.

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Analysis of the Impact of Trade Facilitation on China's Trade - Focused on APEC countries - (무역원활화가 중국 수출입에 미치는 영향 분석 - APEC 국가 중심으로 -)

  • Xuan Zhou;Chang-Hwan Choi
    • Korea Trade Review
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    • v.47 no.4
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    • pp.1-14
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    • 2022
  • This study examines the impact of trade facilitation on China's trade for the period 2010-2017 using a gravity model with a measurement of APEC trade facilitation through principal component analysis. The empirical results confirmed that trade facilitation was a key factor to have a positive effect on Chinese exports and that the higher the level of trade facilitation in APEC countries, the more positive the increase in exports and quantities with China. Further, the size of the economy, the total population, and the border between the trading partner had a positive effect on Chinese trade volume. To promote economic growth through increase in trade volume, countries should actively improve trade facilitation and participate in global trade facilitation reform through continuous cooperation with trading partners.

Analysis of Employment Creation Effect Model for SW Industry (SW산업 일자리 창출효과 모델분석)

  • Lim, Gyoo Gun;Lee, Ji Yoon
    • Journal of Information Technology Services
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    • v.18 no.1
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    • pp.63-78
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    • 2019
  • Despite the government's efforts, the jobs in SW industry are not easily created and only many problems of unemployment have been pointed out, failing to solve the basic problem. Sustainable decent jobs were recognized as a national task. Emotional connection between things and people is the SW industry, which is a core industry of the 4th industrial revolution. In order to be globally competitive, SW job creation, manpower planning for generating core human resources and highly educated manpower is a necessary issue. Basic estimation of job creation using the Input Output Table by Bank of Korea has some limitations and did not consider the SW industry characteristics. This study proposes an assessment model of SW policies and the practices a case of assessment of 113 projects supported by the Korean government. We propose a flowchart that can divide the government budgets according to the portion of the direct investment for SW industry by introducing investment types. We use an adjusted Input Output Table for SW industry and the model also considers the effect of SW promotions and regulations effects. This model can be used practically and flexibly by adjusting the SW fusion areas portions. It also considers the characteristics of the project, supporting areas, project size, short-term and long-term types. 113 projects of 'MSIT', 'SMBA' and 'NIPA' were analyzed and classified into 'policy' and 'business' to reflect SW job creation effect model considering domestic SW characteristics. By analyzing the practical data, 47,254 jobs are expected to be created within five years in optimistic cases and 27,211 jobs would be created in pessimistic cases.

Mechanical analysis of cutout piezoelectric nonlocal nanobeam including surface energy effects

  • Eltaher, Mohamed A.;Omar, Fatema-Alzahraa;Abdalla, Waleed S.;Kabeel, Abdallah M.;Alshorbagy, Amal E.
    • Structural Engineering and Mechanics
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    • v.76 no.1
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    • pp.141-151
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    • 2020
  • This manuscript tends to investigate influences of nanoscale and surface energy on a static bending and free vibration of piezoelectric perforated nanobeam structural element, for the first time. Nonlocal differential elasticity theory of Eringen is manipulated to depict the long-range atoms interactions, by imposing length scale parameter. Surface energy dominated in nanoscale structure, is included in the proposed model by using Gurtin-Murdoch model. The coupling effect between nonlocal elasticity and surface energy is included in the proposed model. Constitutive and governing equations of nonlocal-surface perforated Euler-Bernoulli nanobeam are derived by Hamilton's principle. The distribution of electric potential for the piezoelectric nanobeam model is assumed to vary as a combination of a cosine and linear variation, which satisfies the Maxwell's equation. The proposed model is solved numerically by using the finite-element method (FEM). The present model is validated by comparing the obtained results with previously published works. The detailed parametric study is presented to examine effects of the number of holes, perforation size, nonlocal parameter, surface energy, boundary conditions, and external electric voltage on the electro-mechanical behaviors of piezoelectric perforated nanobeams. It is found that the effect of surface stresses becomes more significant as the thickness decreases in the range of nanometers. The effect of number of holes becomes significant in the region 0.2 ≤ α ≤ 0.8. The current model can be used in design of perforated nano-electro-mechanical systems (PNEMS).

Effects of the General Coordinative Manipulation Joint Intervention Model in Correcting Distort Leg with Imbalance of the Lower Extremity Joint, Pelvic and Shoulder Girdles, and Lumbar Spine (다리관절, 다리-팔 이음뼈, 허리뼈의 불균형을 가진 휜다리에 대한 전신조정술 관절중재모형의 교정효과)

  • Moon, Sangeun
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.3
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    • pp.1-10
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    • 2020
  • Purpose : The purpose of this study is to analyze the corrective effect of the general coordinative manipulation (GCM) joint intervention model on distort leg with imbalance of the lower extremity joints, pelvic and shoulder girdles, and lumbar spine. Methods : The study used a comparative analysis of the size of the distort leg and the imbalance of the lower extremity joints, pelvic and shoulder girdles, and lumbar spine before and after the application of the GCM joint intervention model. A total of 31 subjects from movement center G and the department of physical therapy at university M were selected as research subjects, and they were divided into two groups. The GCM joint intervention model was applied to 18 subjects in the bow knee group and 13 subjects in the knock knee group. The two groups received daily intervention three times a week for four weeks. The corrective effect of the GCM joint intervention model for each type of distort leg was compared and analyzed. Results : The effects of the GCM joint intervention model in correcting bow knee and knock knee with knee deformation and imbalance of the lower extremity joints, pelvic and shoulder girdles, and lumbar spine were significant in most domains (p<.05). The correlation between the bow knee and knock knee groups showed significance in most domains (p<.05). Conclusion : The GCM joint intervention model showed significant corrective effect in the bow knee and knock knee groups in terms of knee deformation, lower extremity joints, pelvic and shoulder girdles, and lumbar spine (p<.05).