• Water for future
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• v.15 no.1
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• pp.57-62
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• 1982

In order to make a numerical modeling for the one dimensional unsteady flow which expressed by Saint Venant partial differential equations, Preissman's implicit schem was used, and it's stability and accuracy was investigated. By introducing recurrence relations make it possible to use double sweep algorithm. Effective parameters to the result were the values of the C$$ and the Chezy coefticient. In order to get numerical solutions whith enough accuracy, C$$ should not be far from the value of1, and when the criteria of the $\theta$ was 0.6<$\theta$<1.0, the rewult was always stable for any condition. This model should be calibrated by real field data, and expected to be developed for the simulation of the river system and to the long wave analysis for one dimensional coastal zone problem.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.171-179
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• 2003

In this paper a neural network-based fault tolerant control system for aircraft sensor and actuator failures is considered. By exploiting flight dynamic relations a set of neural networks is constructed to detect sensor failure and give alternative signal for the faulty sensor. For actuator failures another set of neural networks is designed to perform fault detection, identification, and accomodation which returns the aircraft to a new stable trim. Integrated system is simulated to show the performance of the system with sensor and control surface failures.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.2
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• pp.27-34
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• 1995

In this paper, an X-band TDRO(transistor dielectric resonator oscillator) is designed and experimented with the oscillator constructed. Design of the TDRO is carried out by deriving analycally the coupling parameters between a microstrip line and a dielectric resonator. The coupling parameters take account of the relations among substrate material, ground plane, metallic boundaries surrounding the resonator, distance between a microstrip line and a resonator. Two criteria, external quality factor and coupling coefficient, have been chosen in order to evaluate the performance of the TDRO designed. TDRO studed in this paper may be useful for the application of a microwave system requiring a stable and effective oscillator frequency.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.2 s.109
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• pp.48-59
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• 2005

The purpose of this study was to examine the ecological characteristics of herbaceous communities by systematic and scientific analysis of their structure and diversity in the Midongsan Arboretum and to offer raw data for a long-tenn monitoring study. The importance value and diversity index of species appearing in twenty plots from July to September, 2004 were analyzed and a management plan for these communities is presented. Vascular plants were represented by 60 taxa of 23 families, 51 genera, 50 species and 10 varieties. Based on the results of importance value analysis, the most dominant species was Artemisia princeps var. orientalis, followed by Setaria viridis and Erigeron canadensis. The diversity index analysis showed that plot no. 5 had the highest H' and H'_{max}$(2.0135 and 2.6391). It's species composition was comparatively more diverse and it's structure more stable than other plots. Artemisia montana and Dactylis glomerata showed the highest correlation between species. Because herbaceous communities are important biological habitats and provide important function in environmental conservation, it is important to properly preserve these communities. At the same time, in order to preserve genetic resources and improve spatial function, it may be necessary to consider removing herbaceous communities in certain areas. In the future, the relations between physicochemical soil properties and herbaceous communities should be examined and community movement should be studied.

• Journal of Families and Better Life
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• v.28 no.5
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• pp.67-74
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• 2010

This study investigates the effects of adult attachment on parenting stress using marital conflict as a mediating variable for mothers of preschoolers. The subjects were 370 mothers who lived with at least one preschooler in Daegu or Gyeongbuk Province. The collected data were analyzed by Pearson's correlation as well as single and multiple regressions that used SPSS Win 15.0. The results were as follows: (1) The adult attachment by mothers was negatively associated with parenting stress. The adult attachment level of mothers becomes lower as the perception of parenting stress increases. (2) The adult attachment by mothers was negatively associated with marital conflict. That is, the adult attachment level of mothers becomes lower as the perception of marital conflict increases. (3) The effects of adult attachment in parenting stress by mothers was reducing explanation when controlled for the marital conflict. Adult attachment which influenced the parenting stress of mothers was partially mediated by marital conflict. The results of the study imply that to reduce the parenting stress of mothers, there is a need to improve spousal relationships, in addition, there is a need for more active support to improve conjugal relations for mothers whose adult attachment was not stable.

• Human Ecology Research
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• v.54 no.5
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• pp.551-564
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• 2016

This study examined the causal relationship between a mothers' depression and the emotional problems of their preschool-aged children as indicated by anxiety, depression and emotional reactivity. We analyzed data from 1,528 mothers and their children from the Panel Study of Korean Children (PSKC) collected when the children were 4 years old and 5 years old. Autoregressive cross-lagged modeling was conducted using AMOS ver. 23.0 to investigate the longitudinal reciprocal effects between mothers' depression and children's emotional problems. The results indicated that both mothers' depression and children's emotional problems were relatively stable between the ages of 4 to 5. There were significant cross-lagged effects from the mothers' depression to children's emotional problems and from children's emotional problems to mothers' depression. Mothers reported higher levels of depression when the children were 4 years old and the children showed more anxiety, depression and emotional reactivity when they were 5 years old. Emotional problems when the children were 4 predicted greater depression among mothers 1 year later. We also examined the group difference (between boys and girls) in the study model. Gender differences were not statistically supported. The results suggested that early assessment and intervention for mothers' depression and children's emotional problems are essential for a healthy mother-child relationship and later child outcomes.

• Architectural research
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• v.16 no.4
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• pp.149-156
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• 2014

This research is designed to identify factors that affect life satisfaction of the Korean elderly by studying residential environments and individual personalities as independent variables, and life satisfaction of the elderly as a dependent variable. It also includes emotional and instrumental support to describe relations between variables as mediating variables. It utilizes a questionnaire survey as its research method and studies those aged 65 and over living in urban, suburban and rural areas. In addition, regression and path analysis is used to identify casual links between different variables. The results are as follows: (1) Direct factors that impact emotional support are home ownership (direct effect= -.18) and transportation services (.15). That is, those who own their home and have easy access to public transpiration show increased levels of emotional support. (2) Direct factors that affect instrumental support are economic status (direct effect= .311) and living arrangement (.17). In other words, those who are financially stable and live with their children have more instrumental support. (3) Factors linked directly to life satisfaction of the elderly are their age (direct effect= -.10), health status (.19), economic status (.25), region of living (.22) and housing type (.19). (4) Among the mediating variables, emotional support has direct effect (.45) while instrumental support has indirect effect (.16).

• Proceedings of the Korea Water Resources Association Conference
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• 1982.07a
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• pp.27-32
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• 1982

In other to make a numerical modeling for the one dimensional unsteady flow which expressed by Saint Venant partial differential equations, Preissman's implicit scheme was used, and it's stability and accuracy was investigated. By introducing recurrence relations make it possible to use double sweep algorithm. Effective parameters to the result were the values df the $$ and the Chezy coefticient. In other to get numberical solutions with enough accuracy, $$ should not be far from the value of1, and when the criteria of the $$ was 0.6<$$<1.0, the result was alaways stable for any condition. This model should be calibrated by real fileld data, and expected to be developed for the simulation of the river system and to the long wave analysis for one dimensional coastal zone problem.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.3
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• pp.103-112
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• 1998

In this study, database schema which is capable of maintaining various design-knowledge and applicable to the structural designs has been presented. Futhermore, by utilizing the database system, RECODSS (REinforced COncrete Design Support System) was developed as well. Knowledge-base that were formulated from the document is constructed by applying the concrete standard specifications of Korea from 1989. The basic drawing was prepared by $AutoCAD^TM$. As an inference in the preliminary design, the certainty function and the interpolation function were presented. The certainty function is made by assuming linear relations between each data while referencing $MYCIN^TM$ (expert systems). Nevertheless, the interpolation function was made by utilizing the linear Lagrange interpolation. For the search of the design-knowledge, fast search algorithm and full-text search algorithm were used, however, the design engine was programmed with C language. RECODSS was applied for designing a slab and a beam member. And the results were compared with the existing results. In conclusion, RECODSS was able to efficiently manage various design knowledge and to introduce stable design results.

• Elastomers and Composites
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• v.47 no.3
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• pp.201-209
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• 2012

Grommet is one of the Automotive rubber components and is made from EPDM(Ethylene Propylene Diene monomer M-class) rubber and the nonlinear hyperelastic material properties of rubber are important to predict the behavior of rubber product. In this study, the stable stress-strain relations were obtained from the uni-axial tension test and the equi-biaxial tension test. Finite element analysis for grommet was carried out and heat aging test for the lifetime prediction of grommet was introduced.