• Korean Parent-Child Health Journal
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• v.7 no.2
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• pp.182-200
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• 2004

Purpose: This study is to explore the essence of those lives who have been living with their mothers- in- law for more than 10years since their marriage by applying Van Manen's hermeneutic phenomenological methodology. It consists of four steps such as concentration on the nature of lived experience, existential research, hermeneutic phenomenological reflection and hermeneutic phenomenological writing. Method: Six middle aged participants who have been living with mothers- in- law in middle size of cities were interviewed and observed with their written consent for one month from 20, April. 2000 to 20 May 2000. To expand insight by analyzing sayings, folks stories, writings, etymology of sigipsalee relevant to it were collected and reviewed. Result: Five essential themes were derived by repeated reviewing the transcription of those interview such as difficulty living with endless heart distress, feeling oppressed, feeling deeply lonely, having a stronger backing as time passes, in turn harmonizing with each other. On the basis of the five essential theme hermeneutic phenomenological writing was done as follow. Participants lived lives filled with uneasy feeling from the newly formed relationship among in laws but especially with mothers- in- law. Participants did their best to be acknowledged found that at a significant moment during family event they would be treated as strangers so that they felt isolated and alone. Mothers in laws played a dominant role in most of family decision even buying their children's clothes. Mother in laws rarely complemented them so that they felt inferior as a person. As time passes. Mothers-in-law and daughters-in-law become adjusted to this lifestyle with each other and assumed a more mature relationship which includes a mutual respect thus better harmony. Participants become to have stronger backing so that they express their opinion to mothers-inlaw. With time both of them are getting old, participants show form of pity to their mothers-in- law. Sometimes participant surprise themselves by noticing a change in their behavior to the same pattern Mothers-in-law have showed them. Conclusion: Although generalizations have limitations, findings resulting from the study will enrich family nursing knowledge and understanding the problems when living with mothers-in- law in the same house. It will give a cleared view of problems faced by middle aged korean women in the Korean patriarchal culture. Researchers have recommended to study experiences of married young adult korean women's generation and the findings compared with this study to show trends and changes.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.199-207
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• 2018

Experimental programs were performed to evaluate the flexural performance of fiber reinforced concrete(FRC) beams using a hybrid double-layer arrangement of steel bars and fiber reinforced polymer(FRP) bars or using FRP bars only. A total of seven beam specimens were produced with type of tensile reinforcing bar(CFRP bar, GFRP bar, steel bar) and the poly vinyl alcohol(PVA) fiber mixing ratio(0.5%, 0%) as variable. An analysis method for predicting the flexural behaviors of FRC beams with hybrid arrangement of heterogeneous reinforcing bars through finite element analysis was proposed and verified. In case of the specimens with the double-layer reinforcing bars, the test results showed that the first cracking load of specimen with a double-layer arrangement of steel bars was greater by 26-34% than specimens with a hybrid double-layer arrangement of steel and FRP bars. In maximum flexural strengths, the specimen that used CFRP bars as bottom tensile reinforcing bar showed the greatest strength among the specimens with the double-layer reinforcing bars. When the maximum moment value obtained through experiments was compared with that obtained through analysis, the ratio was 1.2 on average, the standard deviation was 0.085, and the maximum error rate was 22% or less. Based on these results, the finite element analysis model proposed in this study can effectively simulate the actual behavior of the beams with hybrid double-layer reinforcing bars.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.5
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• pp.495-503
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• 1997

In this paper, the E-polarized electromagnetic scattering problems by a resistive strip grating with tapered resistivity on 3 dielectric layers are analyzed to find out the effects for the tapered resistivity of resistive strip and the relative permittivity and thickness of 3 die- lectric layers by applying the Fourier-Galerkin moment methods. The induced surface current density is expanded in a series of Jacobi-polynomial ${P^{(\chi,\beta)}}_p$(.) of the order $\alpha$= 0 and $\beta$=1 as a kind of orthogonal polyomians, and the tapered resistivity assumes to vary linearly from 0 at one edge to finite resistivity at the other edge. The normalized reflected and transmitted powers are obtained by varying the tapered resistivity and the relative permittivity and thickness of dielectric layers. The sharp variation points are observed when the higher order modes are transferred between propagating and evanescent modes, and in general the local minimum positions occur at less grating period for the more relative permittivity of dielectric layers. It should be noted that the patterns of the normalized reflected and transmitted powers for the tapered resistivity are very much different from those of the uniform resistivity and perfectly conducting cases. The proposed method of this paper cna solve the scattering problems for the tapered resistive, uniform resistive, and PEC strip cases.

• Journal of the Korean Magnetics Society
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• v.16 no.1
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• pp.45-50
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• 2006

Oxygen-deficient anatase and rutile titanium dioxide $(TiO_{2-\delta})$ thin films were prepared by a sol-gel method and their structural, electronic, and magnetic properties were investigated. Both anatase and rutile $TiO_{2-\delta}:Fe$ Fe films exhibited ferromagnetism at room temperature for a limited range of Fe doping. For the same amount of Fe doping, the anatase sample exhibited a higher magnetic moment than the rutile one. Result of conversion electron Mossbauer spectroscopy measurements indicates that $Fe^{3+}$ ions substituting the octahedral $Ti^{4+}$ sites mainly contribute to the room-temperature ferromagnetism. Some of the anatase $TiO_{2-\delta}:Fe$ films exhibited p-type character but the observed feromagnetism turns out to be independent of the hole concentration. The room-temperature ferromagnetism can be explained in terms of a direct ferromagnetic coupling between two neighboring $Fe^{3+}$ ions via an electron trapped in oxygen vacancy in $TiO_{2-\delta}:Fe$.

• Composites Research
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• v.32 no.5
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• pp.284-289
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• 2019

In the present paper, the dynamic force-moment equilibrium equations, driving power and energy equations are analyzed to formulate the equation for fuel economy(km/liter) equivalent to the driving distance (km) divided by the fuel volume (liter) of the vehicle, a selected model of gasoline powered KIA K3 (1.6v). In addition, the effects of the dynamic parameters such as speed of vehicle (V), vehicle total weight(M), rolling resistance ($C_r$) between tires and road surface, inclined angle of road (${\theta}$), as well as the aerodynamic parameters such as drag coefficient ($C_d$) of vehicle, air density(${\rho}$), cross-sectional area (A) of vehicle, wind speed ($V_w$) have been analyzed. And the possibility of alternative materials such as lightweight metal alloys, fiber reinforced plastic composite materials to replace the conventional steel and casting iron materials and to reduce the weight of the vehicle has been investigated by Ashby's material index method. Through studies, the following results were obtained. The most influencing parameters on the fuel economy at high speed zone (100 km/h) were V, the aerodynamic parameters such as $C_d$, A, ${\rho}$, and $C_r$ and M. While at low speed zone (60 km/h), they are, in magnitude order, dynamic parameters such as V, M, $C_r$ and aerodynamic ones such as $C_d$, A, and ${\rho}$, respectively.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.181-186
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• 2022

This study examines the effect of parenting stress on children's social competence in relation to parenting stress, children's social competence, and parents' self-esteem, The purpose of this study is to investigate whether parental self-esteem mediates the relationship between parenting stress and children's social competence. Frequency analysis and descriptive statistical analysis were performed on the data of the 7th year of 2014 Panel Study of Korean Children(PSKC), and Pearson's moment correlation coefficient was calculated for correlation analysis between variables. In addition, in order to verify the mediating effect of parental self-esteem in the relationship between parenting stress and the child's social competence, Process Macro Model 4 was applied to verify the mediating effect, The significance of the indirect effect was verified by the bootstrapping method. As a result of this study, first, the correlations between all latent variables showed significant correlations. Second, it was confirmed that mother and father self-esteem had a mediating effect in the effect of father and mother's stress on infants' social competence. These results suggest that in order to improve children's social competence, parents should be able to increase their self-esteem so that they can have faith and confidence in themselves and control their emotions well in parenting stressful situations.

• The Journal of the Acoustical Society of Korea
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• v.41 no.4
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• pp.435-445
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• 2022

In this study, the reverberation of a bistatic sonar operated in southeastern coast in the East Sea in July 2020 was analyzed. The reverberation sensor data were collected through an LFM sound source towed by a research vessel and a horizontal line array receiver 1 km to 5 km away from it. The reverberation sensor data was analyzed by various methods including geo-plot after signal processing. Through this, it was confirmed that the angle reflected from the sound source through the scatterer to the receiver has a dominant influence on the distribution of the reverberation sound, and the probability distribution characteristics of bistatic sonar reverberation varies for each beam. In addition, parametric factors of K distribution and Rayleigh distribution were estimated from the sample through moment method estimation. Using the Kolmogorov-Smirnov test at the confidence level of 0.05, the distribution probability of the data was analyzed. As a result, it could be observed that the reverberation follows a Rayleigh probability distribution, and it could be estimated that this was the effect of a low reverberation to noise ratio.

• Journal of IKEEE
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• v.26 no.3
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• pp.483-487
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• 2022

In this paper, we design a self-powered Arduino system for solar energy harvesting and explain its operation. To perform the operation, the Arduino system senses the amount of solar energy that changes every moment and adjusts the ratio of the active mode and sleep mode operation time according to a given solar light intensity. If the intensity of sunlight is strong enough, the Arduino system can be continuously driven in active mode and receive sufficient power from sunlight. If not, the system can run in sleep mode to minimize power consumption. As a result, it can be seen that energy consumption can be minimized by reducing power consumption by up to 81.7% when using sleep mode compared to continuously driving active mode. Also, when the light intensity is at an intermediate level, the ratio between the active mode and the sleep mode is appropriately adjusted according to the light intensity to operate. The method of self-control of the operating time ratio of active mode and sleep mode, proposed in this paper, is thought to be helpful in energy-efficient operation of the self-powered systems for wearables and bio-health applications.

• Journal of Korean Society of Steel Construction
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• v.22 no.5
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• pp.487-496
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• 2010

The structural damping ratios for seismic design of nuclear power plant structures are specified in Regulatory guide 1.61 of the United States NRC for RC structures of 4%(OBE) and 7%(SSE), and for steel structures of 3%(OBE) and 4%(SSE), but not for steel-plate concrete (SC) structures that have been developed recently. The objective of this study is to investigate the damping ratios of SC structures by identifying the relative differences in the damping ratios between RC and SC structures. An experimental study was performed on four specimens, RC-S, RC-M, SC-S and SC-M, where S stands for shear-governed and M for moment-governed. The conducted method was free vibration testing by rupturing a brittle steel plate that linked the actuator and the mass center. The test results were analyzed to determine fundamental frequencies and damping ratios at various load levels. By examining the relative differences in damping ratios of four specimens, it is proposed for SC structures to use the same damping ratio of 4% as RC one at OBE, but 1% less damping ratio than RC one resulting in 6% at SSE.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.1
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• pp.27-48
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• 1984

This study is conserned with the optimization of reinforced concrete frames using limit state design theory. Formulations of the optimal design for reinforced concrete frame based on the limit state theory turn out to be the nonlinear programming problems which have to deal with the required steel area, the width and effective height of the beam and column section and the moment reduction factor as the design variables. The objective function is formulated as the total construction cost which considers the costs of steel, concrete and forming for the reinforced concrete frames, and the basic constraints are imposed upon both ultimate and serviciability limit state concepts. Also, the stress blocks assumpted in CP110 and Hognestad et al. theory are applied to analysis an ultimate resistant section force for the ultimate limit state and only the criteria of CP110 are used for serviciability limit state. The optimized technique which is applied to solve the nonlinear programming problems for the optimization of reinforced concrete frames is SUMT utilizing the modified Newton-Raphson method. This algorithm is used to test for the two reinforced concrete frames, and then is compared and analysized with the numerical results of reference(10) to examine its convergence, applicability and stability under the same conditions. The results of this study are discussed about the economy comparision of the optimal values for CP110 and Hognestad et al., and the applicability, stability, convergence and validity of this algorithm used herein through the numerical analyses.