• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.27-36
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• 2018

This is qualitative research using grounded theory to examine the experiences that mothers of children with epilepsy can have. Data were collected through in-depth interviews, observation, and memo-taking with a total of 13 participants in this study-10 mothers taking care of children with epilepsy and 3 principal informants-and the data were analyzed using the method developed by Strauss and Corbin (1998). As a result of data analysis, 163 concepts, 26 subcategories and 8 categories were formed through open coding. Such categories were analyzed by the paradigm of the grounded theory, and as a result the experiences of the mothers of epileptic children were based on a causal condition of 'confrontation' and the central phenomenon of 'Wandering around the forest under a yoke'. The contextual conditions, which exerted influence on phenomena, were 'stigma cognition', 'personality traits' and 'health of children.' The action/interaction strategy selected by participants was 'Quietly pulling through: Bracing myself, Getting to know my enemy and myself, Taking care while hiding, Putting out one step at a time, Establishing a foothold. The intervening condition affecting action/interaction was 'the support system', and its result was 'watching.'

• Smart Structures and Systems
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• v.19 no.5
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• pp.523-538
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• 2017

A series of field vibration tests are conducted on the Runyang Suspension Bridge during both the construction and operational stages. The purpose of this study is devoted to the analysis of the dynamic characteristics of the suspension tower. After the tower was erected, an array of accelerometers was deployed to study the evolution of its modal parameters during the construction process. Dynamic tests were first performed under the freestanding tower condition and then under the tower-cable condition after the superstructure was installed. Based on the identified modal parameters, the effect of the pile-soil-structure interaction on dynamic characteristics of the suspension tower is investigated. Moreover, the stiffness of the pile foundation is successfully identified using a probabilistic finite model updating method. Furthermore, challenges of identifying the dynamic properties of the tower from the coupled responses of the tower-cable system are discussed in detail. It's found that compared with the identified results from the freestanding tower, the longitudinal and torsional natural frequencies of the tower in the tower-cable system have changed significantly, while the lateral mode frequencies change slightly. The identified modal results from measurements by the structural health monitoring system further confirmed that the vibrations of the bridge subsystems (i.e., the tower, the suspended deck and the main cable) are strongly coupled with one another.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.6
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• pp.758-766
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• 2006

A two-stage bioreactor, which consists of a biotrickling filter module and a biofilter module in series, was investigated for the enhanced treatment of a VOC mixture, toluene and methyl ethyl ketone (MEK). Throughout the experiments, the overall inlet loading rate was maintained at approximately $43g/m^3/hr$, but the inlet ratios of the VOCs were modified. The experimental results showed that the different ratios of the VOC mixture resulted in changes of overall removal efficiencies, elimination capacities (ECs) and microbial accumulation on the surface of each packing material. The ratio of inlet toluene to MEK at 50 : 150 was found to be most effective in terms of the overall removal efficiency, because, at this condition, MEK (i.e., the hydrophilic compound) was mostly removed in the biotrickling filter module and the following biofilter module was used to remove toluene. It was also found that when the inlet loading rate of the VOC mixture was serially increased stepwise within short-term periods, the ECs for toluene dropped significantly but the ECs for MEK increased at the ratio of the VOC mixture. These results implied that substrate interaction and/or substrate preferable utilization might have an effect on the biological removal of each compound in the two-stage bioreactor; therefore, the bioreactor should be operated in the condition where the substrate interaction could be minimized in order to maximize overall performance of the two-stage bioreactor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1073-1078
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• 2003

This paper presents the vibration characteristics of a cantilever beam in contact with a fluid using a PZT actuator and PVDF film. dynamic behaviors of a flexible beam-water interaction system are examined. The effect of the liquid level on free vibration of the composite beam in a partially liquid-filled circular cylinder is investigated. The coupled system is subject to an undisturbed boundary condition un the fluid domain. In the vibration analysis of a wetted beam. the decoupled analyses between beam and fluid have been conventionally employed by considering first the composite beam vibration in the all and secondly Performing the correction taking account for surrounding fluid effects. That is, this investigation was to look at how natural frequencies, mode shapes. and damping are affected by liquid level variations. The signals from the sensor according to the applied input voltage are digitalized and filtered in order to obtain the dynamic characteristics of the composite beam in contact with fluid. It was found that the coupled natural frequencies decreased with the fluid level for the identical composite beam due to added mass effect. In case of the free-free boundary condition, the natural frequency gently decreased at fluid water level between 20% and 80% in the first tending mode and we found out the bends of stair shape for added mass effect of the fluid.

• Journal of the Korean Home Economics Association
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• v.25 no.2
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• pp.79-87
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• 1987

Paeksolgi is a typical Korean rice cake made by steaming rice powder added sugar, water and salt. This study attempted to clarify the factors which affect the textural characteristics, and to examine the effects of various steaming time and volume of adding water on sensory characteristics and Instron measurement on textures of Paeksolgi. Evaluation was conducted through sensory evaluation and objective evaluation. The results were summarized as follows. 1. In the preparation, the significant factors were soaking time, volume of sugar, and the interaction between soaking time and volume of adding water. And, Kind of sweetener, volume of adding water, steaming time, condition of powder, and the interaction between soaking time and steaming time, and between soaking time and volume of adding water, and between kind of sweetener and condition of powder, and between steaming time and volume of sugar were the significant factors which affected the textural characteristics of Paeksolgi. 2. In sensory evaluation on the various steaming time and volume of adding water, Paeksolgi made by steaming rice powder added water of 10% for 30 min. showed the most favorite tendency on the overall quality. The results of Instron measurement indicated that hardness, gumminess and chewiness tended to decrease as volume of adding water increased in same steaming time.

• Journal of the Korean Ceramic Society
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• v.30 no.12
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• pp.1071-1079
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• 1993

Interaction of alkali oxides and SO3 and C3S formation and microstructure was studied using K2CO3 and Na2CO3 as alkali sources and (NH4)2SO4 for SO3. When SO3/K2O=1.43 as mole ratio, K2O and SO3 react to form K2SO4, this phase is immiscible with other oxide melt and thus could not affect C3S formation as well as its microstructure. In a condition of SO3/K2O 1, C3S crystals were round and grown in a much larger size. With addition of Na2O and SO3 by only 1wt% each, C3S formation was strongly hindered. Since C2S was stabilized by Na+ and SO4-2, it could not react to give C3S formation. However in the condition of SO3/Na2O=1.43, a little amount of C3S was formed. It is considered that small amount of Na2SO4 was formed, this phase was immiscible with clinker liquid, and the C3S crystals were formed locally in the liquid part of relatively low Na2O and SO3 compositions. These crystals had irregular and rough surfaces and contained more inclusions than those grown from K2O.SO3 system.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.5
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• pp.421-430
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• 2018

The shape of a yacht sail made of thin fabric materials is easily deformed by wind speed and direction and it is affected by the deformation of the standing rig such as mast, boom, shrouds, stays and spreaders. This deformed sail shape changes the air flow over the sail, it makes the deformation of the sail and the rig again. To get a sail performance accurately these interactive behavior of sail system should be studied in aspects of the aerodynamics and the fluid-structure interaction. In this study aerodynamic analysis for the sail system of a 30 feet sloop is carried out and the obtained dynamic pressure on the sail surface is applied as the loading condition of the calculation to get the deformations of the sail shape and the rig. Supporting forces by rig are applied as boundary condition of the structure deformation calculations. And the characteristics of the air flow and the dynamic pressure over the deformed sail shape is investigated repeatedly including the lift force and the location of CE.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.99-107
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• 2008

There are being a lot of studies for achievement of high speed Dehydration, high-strength and Lightweight of washing machine in the latest washing machine business. It is essential that strength of mechanical press-Joining (MPJ) for spin drum is improved to attain that target. MPJ of spin drum is composed of seaming and caulking process. Because Seaming process of MPJ has various design factors such as thickness, bending radius, seaming width, caulking press width and the dynamic factor such as multistage plastic working, elastic recovery, residual stress, the optimum conditions can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor during drum MPJ and proposed optimum condition using center composition method among response surface derived from regression equation of simulation-based DOE.

• Journal of Fashion Business
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• v.13 no.4
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• pp.51-59
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• 2009

The purpose of this research is to investigate the influences of service experience and brand reputation on intention by word of mouth(WOM) when consumers get experiences at beauty salon. We made 2(valence of service experience: positive/negative) ${\times}$ 2(brand reputation level: high/low) subjects experimental design in order to find reason that there is a significant difference of intention by word of the mouth between positive experience condition and negative experience condition. Also we tried to find the interaction of two factors. To test our hypothesis, an experiment was performed on 68 university students in seoul area. Specifically, we used 2-way ANOVA and planned contrast method through SPSS 12.0 procedure. As a result, a two-way ANOVA demonstrated a significant main effect of service experience, which means that people more intend to make WOM when they experience a negative service than a positive service. Also the ANOVA showed a significant interaction effect between service experience and brand reputation, which represents that people more intend to make WOM for high-reputed(low-reputed) brand than low-reputed(high-reputed) brand when they encounter negative(positive) services.

• Earthquakes and Structures
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• v.3 no.3_4
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• pp.203-230
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• 2012

This paper presents results for impedance (and compliance) functions and input motions of foundations in a layered half-space computed on the basis of a procedure that combines a consistent transmitting boundary with continued-fraction absorbing boundary conditions which are accurate and effective in modeling wave propagation in various unbounded domains. The effects of obliquely incident seismic waves in a layered half-space are taken into account in the formulation of the transmitting boundary. Using the numerical model, impedance (and compliance) functions and input motions of rigid circular foundations on the surface of or embedded in a homogeneous half-space are computed and compared with available published results for verification of the procedure. Extrapolation methods are proposed to improve the performance in the very-low-frequency range and for the static condition. It is concluded from the applications that accurate analysis of foundation dynamics and soil-structure interaction in a layered half-space can be carried out using the enhanced consistent transmitting boundary and the proposed extrapolations.