• 한국군사과학기술학회지
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• 제10권3호
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• pp.173-180
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• 2007

In this paper, we have proposed a simple finite element model for separation mode analysis on the roadwheel and track assembly of main battle tank and established a contact stress-based mechanism which could explain the initiation and growth of separation defect occurred during the test of padreplacable track. It was proved that the longitudinal contact shear stress component on the pin hole region of the track shoe body which is parallel to the driving direction is consistent with the crack initiation at the bonding surface between track shoe and wheel-side rubber. The longitudinal shear stress increased locally near the separated region after the separation initiated. So we could assume that the local stress concentration accelerates the separation growth according to the shear mode.

• 한국보육지원학회지
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• 제14권1호
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• pp.1-20
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• 2018

Objective: The purpose of this study was to examine the direct and indirect effects (through working mothers' overprotective parenting behavior) of working mothers' separation anxiety and job satisfaction on preschoolers' separation anxiety. Methods: A total of 251 working mothers with preschool-aged children participated in this study. Mothers completed a questionnaire concerning their separation anxiety, job satisfaction, overprotective parenting behavior, and preschoolers' separation anxiety. Data were analyzed using t-test, one-way ANOVAs, partial correlations and path analysis. Results: In terms of direct effects, working mothers' separation anxiety had a direct effect on preschoolers' separation anxiety. However, job satisfaction did not have a direct effect on preschoolers' separation anxiety. With respect to indirect effects, working mothers' separation anxiety indirectly influenced preschoolers' separation anxiety through their overprotective parenting behavior. However, mothers' job satisfaction did not have an indirect effect on preschoolers' separation anxiety. Conclusion/Implications: Findings from this study emphasize the importance of reducing mothers' separation anxiety in order to prevent preschoolers' separation anxiety.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.2006-2010
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• 2005

This study is concerned with the relation between steelbelt and belt edge separation. Belt edge separation causes tire burst and threatens passenger's safety. For that reason, it is important to predict durability caused by belt edge separation first in tire structure design step. In this study, to predict belt edge separation, we suggest the prediction method of belt edge separation and evaluate the effect of steelbelt width on the belt edge separation using FEM. We study on analysis parameter also to do exact estimation about the shear behaviour of belt edge area.

• 아동학회지
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• 제13권1호
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• pp.16-37
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• 1992

The purpose of this study was the development of a scale to assess maternal anxiety after mother-child separation. Subjects consisted of 384 mothers who had children from 6 to .36 months of age. A questionnaire consisting of eighty Likert-type items and Spielberger's(1970) State Anxiety Scale were administered to mothers and data were analyzed using item analysis. factor analysis. multiple regression. Cronbach's ${\alpha}$. Pearson's correlation and F-test. Sixty of the eighty items were significant and deemed acceptible through item discrimination method with indices ranging from. 32 to .95. Factor analytic procedures have selected 54 items of the 60-item scale and supported a 5-factor solution. The subscales labeled 'Maternal Separation Anxiety'. 'Perception of Separation Effects on the Child', 'Desire for Physical Cuddling and Closeness'. 'Attitudes toward the Value or Importance of Exclusive Maternal Care' and 'Employment-related Separation Concerns,' Finally. a multiple regression analysis conducted to reduce the length of the scale yielded a 39-item form for the Maternal Separation Anxiety Scale(MSAS). Internal consistency of the MSAS was high(Cronbach's ${\alpha}$ =.85). The correlation of the MSAS with the Spielberger's State Anxiety measure yielded a coefficient of .36, revealing a moderate and positive relationship.

• Structural Engineering and Mechanics
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• 제78권2호
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• pp.219-230
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• 2021

International seismic codes stipulate that adjacent buildings should be separated by a specified minimum distance, otherwise the pounding effect should be considered in the design. Recent researches proposed an alternative method (Double Difference Combination Rule) to estimate seismic gap between structures, as this method considers the cross relation of adjacent buildings behavior during earthquakes. Four different criteria were used to calculate the minimum separation distance using this method and results are compared to the international codes for five separation cases. These cases used four case study buildings classified by different heights, lateral load resisting systems and fundamental periods of vibrations to assess the consistency in results for the alternative methods. Non-linear analysis was performed to calculate the inelastic displacements of the four buildings, and the results were used to evaluate the relation between elastic and inelastic displacements due to the ductility of structural elements resisting seismic loads. A verification analysis was conducted to guarantee that the separation distance calculated is sufficient to avoid pounding. Results shows that the use of two out of the four studied methods yields separation distances smaller than that calculated by the code specified equations without under-estimating the minimum separation distance required to avoid pounding.

• International Journal of Aeronautical and Space Sciences
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• 제16권1호
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• pp.50-63
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• 2015

Explosive bolts are one of pyrotechnic release devices, which are highly reliable and efficient for a built-in release. Among them, ridge-cut explosive bolts which utilize shock wave generated by detonation to separate bolt body produce minimal fragments, little swelling and clean breaks. In this study, separation phenomena of ridge-cut explosive bolts or ridge-cut mechanism are computationally analyzed using Hydrocodes. To analyze separation mechanism of ridge-cut explosive bolts, fluid-structure interactions with complex material modeling are essential. For modeling of high explosives (RDX and PETN), Euler elements with Jones-Wilkins-Lee E.O.S. are utilized. For Lagrange elements of bolt body structures, shock E.O.S., Johnson-Cook strength model, and principal stress failure criteria are used. From the computational analysis of the author's explosive bolt model, computational analysis framework is verified and perfected with tuned failure criteria. Practical design improvements are also suggested based on a parametric study. Some design parameters, such as explosive weights, ridge angle, and ridge position, are chosen that might affect the separation reliability; and analysis is carried out for several designs. The results of this study provide useful information to avoid unnecessary separation experiments related with design parameters.

• Journal of Magnetics
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• 제15권2호
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• pp.91-98
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• 2010

The paper presents results of a study on the selective separation technology of ferrous and non-ferrous metals from broken light bulbs. The proposed method is to use magnetic fluids to obtain a magnetic fluid based- separation. [1] The study was conducted using three types of waste materials: regular light bulbs, auto light bulbs and neon tubes. In order to process the waste materials, a six stages technologic flow was developed: a) separation of light bulbs components; b) Physical and chemical analysis of raw materials; c) grain conditioning of the raw material; d) dry magnetic separation of ferrous components; e) magnetic fluid separation of non-magnetic material; f) recovery of the magnetic fluid adhered to the surface of the separated material grains. [2] This study shows that magnetic fluid separation is only profitable for regular and auto light bulbs and is not profitable in the case of neon tubes.

• 한국생산제조학회지
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• 제24권4호
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• pp.407-413
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• 2015

Research for renewable energy is being performed since it has the merits of little pollution of the environment and sustainable energy resources. Microalgae is attractive as a renewable energy resource. Biomass of the microalgae can be produced by mass culturing, and bulk harvest technology of is needed to produce biomass continuously. Recently, ultrasonic waves were used to harvest the cultivated microalgae continuously. In this study, the separation process using ultrasonic waves was performed to effectively harvest the microalgae. An ultrasonic wave separation resonator was designed and manufactured based on the acoustic field analysis. Separation experiments using design of experiment were carried out, and the influence of experimental variables from the ultrasonic wave separation process was investigated. Mixing conditions of variables were estimated to obtain high separation efficiency and a large microalgae harvest. Experimental results for suitable mixing conditions were compared with simulation results calculated from the state equation.

• 대한기계학회논문집A
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• 제30권11호
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• pp.1461-1471
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• 2006

This paper presents the mathematical model for rolling behaviors of a small regular polygonal part on an inclined plane. Throughout the numerical analysis performed with the simulation program which has been experimentally validated, it is shown that the number of edges of the rolling polygonal part can be a measure for the energy dissipation rather than the coefficient of friction. The appropriate slope angle has been found to be around 20 degree for roughness-separation as well as shape-separation of polygonal parts which have small number of edges. In additions, the vibratory motion applied to the inclined plane is able to cause mixed parts to be separated more effectively according to the shape or the roughness. Finally, a couple of parts separation methods based on the analysis results are presented, and are validated through the numerical simulation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.322-325
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• 2005

The separation mechanism is installed to separate a note one by one from the stacked notes and the overlap type, one of separation mechanism, has been used a lot in financial equipments like ATM. This paper has compared and estimated analysis results using finite element method with experimental results over various parameters such as conditions of note, overlap value, roller shapes, which affect the friction force (resistance) exerting on notes between rollers. Consequently, the effect of various parameters on the performance of overlap type separation mechanism can be known and optimal shape and overlap value can be obtained.