• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.5
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• pp.35-44
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• 2011

PGA (Peak Ground Acceleration) is the parameter which indicates the peak value for strong ground motion and is mainly due to the intensity of the seismic wave. Usually, seismic waves can consist of different characteristics and can have different effects on structures. Therefore, it may be undesirable that the effects of a seismic wave are evaluated only based on the PGA. In this study, time history analysis was executed with a single degree of freedom model for inelastic seismic analysis. The numerical model was assumed to be a perfect elasto-plastic model. Input accelerations were made with El Centro NS (1940), other earthquake records and artificial earthquakes. The displacement ductility demand and cumulative dissipated energy, which were calculated from other artificial earthquakes, were compared. As a result, different responses from other seismic waves which have the same PGA were identified. Therefore, an index which could reflect both seismic and structural characteristics is needed. The SI (Spectrum Intensity) scale which could be obtained from integration by parts of the velocity response spectrum could be an index reflecting the inelastic seismic response of structures. It can be possible to identify from correlation analysis among the SI scale, displacement ductility demand and cumulative dissipated energy that the SI scale is sufficient to be an index for the inelastic response of structures under seismic conditions.

• Culinary science and hospitality research
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• v.22 no.7
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• pp.158-172
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• 2016

This study engaged food-service industry workers in Busan (casual dining restaurants and buffets) to investigate the moderating effect of job satisfaction on the influence of emotional labor on turnover intention and job burnout. To accomplish the goal of this study, the statistical programs SPSS 21.0 and AMOS 21.0 were employed for frequency analysis, factor analysis, reliability, and confirmatory factor analysis of responses from f 278 respondents. An examination was conducted to prove the hypothesis based on a structural equation model. There are two sub factors of emotional labor, surface acting and deep acting. According to the result of this study, surface acting has a positive influence (+) on job burnout (exhaustion) while deep acting has a negative influence(-). In addition, job burnout showed a positive influence (+) on turnover intention. It has been revealed that job satisfaction has a moderating effect on the path from deep acting to job burnout. Having considered that job burnout of food-service workers in Busan was related to deep acting, one of sub factors of emotional labors, promoting deep acting appears to be the way of reducing both job burnout and the number of people with turnover intention. Therefore, it is necessary for restaurant owners and CEOs to implement employee training and improve employee benefits in order to promote the deep acting of their employees.

• Journal of Environmental Science International
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• v.5 no.6
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• pp.813-826
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• 1996

The toxic effects of aluminium (Al) on growth, chlorophyll content, $\delta-aminolevulinic$ acid dehydratase (ALAD) activity and anatomy of root and shoot were investigated in 7-day-old azuki bean (Vigna angularis) seedlings. Significant depressions in root elongation was observed in the low concentrations of Al (50, 100 $\muM)$ and increasing Al concentrations caused a sharp decline of root and shoot growth. The degree of inhibition was dependent upon Al supply. Exposure to 50 $\muM$ Al or more inhibited root elongation within 1 day. In the 50 $\muM$ Al treatments, a recovery of root growth was seen after 7 days exposure. In contrast, lateral root initials was little affected by Al exposure. Al toxicity symptoms and growth responses were more well developed in the roots than in the shoots. Analysis of Al localization in root cells by hematoxylin stAlning showed that Al entered root apices and accumulated in the epidermal and cortical cells immeadiately below the epidermis. There was a good positive correlation between the level of chlorophyll and ALAD activity. Increasing Al concentrations caused a decrease in total chlorophyll contents, accompanied by proportional changes in ALAD activity, suggesting a cootr-dinated reduction of a photosynthetic machinery. Al exerted specific influence on the morphology of root ann shoot. At higher concentrations of Al the roots induced drastic anatomical changes. The epidermal cells were disorganized or destructed while the cortical cells exhibited distortion of cell shape and/or disintegration. The diameter of root and transectional area of cortical cells decreased considerably with Al treatment. In the shoot Al also enhanced reduction of diameter of shoot and cell size. Gross anatomy of leaves treated with Al did not differ significantly from the controls, except for fewer and smaller chloroplast. Our results indicate that toxic effect of Al appear to be manifested primarily in roots and secondarily on shoots, and changes in root morphology are related to changes in the root growth patterns. Results are further discussed in re181ion to the findings in other plant species, and it is concluded that Al causes morphological, structural and, presumably, functional damage to the roots of the species investigated.

• Journal of the Korea Fashion and Costume Design Association
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• v.10 no.3
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• pp.1-13
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• 2008

The purpose of this research is to study the cause of obstruction in various knit pattern structures by understanding the needs of the customers, and to develop knitted fabric goods that satisfy the individual taste of consumers and that reflecting the latest fashions. Actual conditions of the manufacturer's designing processes must be examined. In addition, a comparison analysis of fashion sensibilities and preferences between producers and consumers had been made in order to study developing knit pattern structures. Questionnaires and interviews had been used as research methods. The research involved two groups: one group consisted of 57 producers, which included designers, programmers, and merchandisers working for a knit manufacturer in Seoul, while the other group consisted of 74 consumers, which included students with knitted fabric design as their major and those who have working knowledge of knitted fabrics. For a more accurate evaluation, 28 out of 150 patterns have been selected through a preliminary study conducted by 24 designers. On the 28 knit patterns, a sensibility evaluation had been made through the use of the sense of sight and sense of touch, which was followed by a frequency analysis, cluster analysis, and t-test using SPSS 12.0. The results are as follows: the fashion sensibility evaluation on knit patterns showed that structures, such as racking II or lace II, are typically elegant ('elegance'), while structures, such as links I or racking I, are typically 'active.' Furthermore, a 'country' image was displayed in structures such as cable I, cable II, and miss II. Links I appeared as 'sophisticated'. Miss I and milano were said to have 'modem' images. Lace II was regarded as 'ethnic', while racking II was said to have a 'romantic' image. 2:1 rib and milano were generally thought to be manly ('manish'). The fashion sensibility scale for each knit pattern has been made based on the above results. Based on producer and consumer responses, the sensibility evaluation on knit pattern structures showed that the two groups had similar preferences in knit pattern structures. Therefore, the fashion sensibility scale developed in this study can be used as a basic data for structure development when designing knitted fabric goods.

• Culinary science and hospitality research
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• v.22 no.8
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• pp.1-16
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• 2016

The purpose of this study is to verify the effects of team trust and cooperative behavior on the food-service employees' perceived service performance as well as the moderating effects of team competency and other department support in the relationship among the team trust, cooperative behavior, and service performance of food-service employees. We conducted a survey of 1,080 food-service employees working in 8 hotels and 4 food-service stores located in Seoul, Gyeonggi, Song-do, Gyeongju, and Busan, and 841 food-service employees were employed for statistical analysis except unreliable responses. As a result of a SEM (structural equation modeling) analysis to confirm hypotheses, it was found that team trust (leader trust and co-worker trust) had a positive effect on the cooperative behavior. In addition, the cooperative behavior had a positive influence on the food-service employees' perceived service performance. Also found was the moderating effect of other department support in the relationship between the cooperative behavior and food-service employees' perceived service performance. Based on the research findings, we discussed its academic and practical implications, and suggestions on the future research.

• Interaction and multiscale mechanics
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• v.2 no.1
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• pp.69-89
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• 2009

Reinforced and prestressed concrete (RC and PC) thin walls are crucial to the safety and serviceability of structures subjected to shear. The shear strengths of elements in walls depend strongly on the softening of concrete struts in the principal compression direction due to the principal tension in the perpendicular direction. The past three decades have seen a rapid development of knowledge in shear of reinforced concrete structures. Various rational models have been proposed that are based on the smeared-crack concept and can satisfy Navier's three principles of mechanics of materials (i.e., stress equilibrium, strain compatibility and constitutive laws). The Cyclic Softened Membrane Model (CSMM) is one such rational model developed at the University of Houston, which is being efficiently used to predict the behavior of RC/PC structures critical in shear. CSMM for RC has already been implemented into finite element framework of OpenSees (Fenves 2005) to come up with a finite element program called Simulation of Reinforced Concrete Structures (SRCS) (Zhong 2005, Mo et al. 2008). CSMM for PC is being currently implemented into SRCS to make the program applicable to reinforced as well as prestressed concrete. The generalized program is called Simulation of Concrete Structures (SCS). In this paper, the CSMM for RC/PC in material scale is first introduced. Basically, the constitutive relationships of the materials, including uniaxial constitutive relationship of concrete, uniaxial constitutive relationships of reinforcements embedded in concrete and constitutive relationship of concrete in shear, are determined by testing RC/PC full-scale panels in a Universal Panel Tester available at the University of Houston. The formulation in element scale is then derived, including equilibrium and compatibility equations, relationship between biaxial strains and uniaxial strains, material stiffness matrix and RC plane stress element. Finally the formulated results with RC/PC plane stress elements are implemented in structure scale into a finite element program based on the framework of OpenSees to predict the structural behavior of RC/PC thin-walled structures subjected to earthquake-type loading. The accuracy of the multiscale modeling technique is validated by comparing the simulated responses of RC shear walls subjected to reversed cyclic loading and shake table excitations with test data. The response of a post tensioned precast column under reversed cyclic loads has also been simulated to check the accuracy of SCS which is currently under development. This multiscale modeling technique greatly improves the simulation capability of RC thin-walled structures available to researchers and engineers.

• 모자간호학회지
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• v.2 no.1
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• pp.70-86
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• 1992

What is the meaning of menopause experienced by urban Korean women? Nurses need an under standing of menopause as it is experienced by women themselves. Nursing needs to build knowledge of womens' health experiences. This phenomenological study examined what menopause means to modern Korean woman to build a structure of knowledge useful for practice to enhance the quality of life of women throughout this experience. Traditional definition of menopause according to physiological changes, as illness and more recently as psychosociocultural phenomena were examined along with the folk lore information generally available in the society A review of the research and scientific literature was done from the perspectives of four models including the medical model of menopause as disease, the psychosocial model as positive and negative behavioral responses to menopause, a feminist model of menopause as a time of rebirth and a nursing model of the changing patterns of meaning, rythms and transformation women experience through menopause. Van Kaam's method was used to analyse data audio-recorded during interviews by the investigator with 65 women, 40 to 60 years of agey whose confidentility was assured. Interpretation of the data was enhanced luther by consultation with professional colleugues and with informants. Four rhythmical patterns of process emerged : from suffering to comfort, from oppression to freedom from being a good wife and wise mother to becoming a woman and from a hard life to an abundant life. The detailed common elements making up each of the four patterns and definitions of each pattern were presented. Each pattern was discussed critically from the point of view of medical, psychosociocultural, womens' and nursing models. The structural definition of the synthesis of the four process patterns was stated as : in spite of suffering the middle-aged urban Korean woman find she is able to help herself to feel comfortable and to realize release as she moves from oppression to liberation and freedom from being a good wife and wise mother she experiences rebirth as a woman : she begins to live a profitable and valuable life : her life becomes one of transformed abundant living. The definition transcends the medical and phychosociocultural model to embody a nursing model. The analysis was critiqued by using Parse' Human Becomming theory of nursing because the emerging themes were process patterns. Parse' theory provides and explanation of the experience of menopause consistant with the data which enhances nursing understanding of womens' experience of menopause. Parse' practice methodology provide guidance for promoting womens' quality of life throughout the experience of menopause. Feminist analysis contributes valuable critique to nursing research, richly expanding the perspective from traditional approaches to promote understanding of the meaning of womens' health experiences.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.6 s.46
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• pp.13-19
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• 2005

Floor response spectra for dynamic response of subsystem such as equipment, or piping in nuclear power plants are usually generated without considering dynamic interaction between main structure and subsystem. This study describes the analytic method in which equipment response spectra can be obtained through dynamic analysis considering equipment-structure Interaction(ESI). In this method, dynamic response of the equipment by this method is based on a dynamic substructure method in which the equipment-structure system is partitioned into the single-degree-ol-freedom system(SDOF) representing the equipment and the equipment support impedance representing the dynamic charactenstics of the structure ai the equipment support. A family of equipment response spectra is developed by applying this method to calculate the maximum responses of a family of SDOF equipment systems with wide banded equipment frequency, damping ratio, and mass. The method is validated by comparing the floor response spectrum from this method with the floor response spectrum generated from the rigorous analysis including equipments on the containment building of a prototypical nuclear power plant. in order to Investigate ESI effect in the response of equipment, response values from the method and the conventional approach without considering ESI are compared for the equipment having the mass less than 1% of the total structural mass. Response spectra from the method showed lower spectral amplitudes than those of the conventional floor response spectra around controlling frequencies.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.198-210
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• 2016

This study firstly aims to estimate a leading-price of Jeju flounders with various price-classes by fish weight and secondly plans to provide policy implications of flounder purchase projects by understanding dynamic changes and interactions among flounder producer price-classes caused by price impulses in the market. This study applies an unit root test for stability of data, uses a Granger causality test to estimate the leading-price among producer prices by fish weight, employs the vector autoregressive model to analyze statistical impacts among t-1 variables used in models, and finally utilizes impulse response analyses and forecast error variance decomposition analyses to understand dynamic changes and interactions among change rates of the producer prices caused by price impulses in the market. The results of the study are as follows. Firstly, KPSS, PP, and ADF tests show that the change rate of Jeju flounder monthly producer prices by fish weight differentiated by logarithm is stable. Secondly, the Granger causality test presents that the change rate of the 1kg flounder producer price strongly leads it of 500g, 700g, and 2kg flounder producer prices respectively. Thirdly, the vector autoregressive model indicates that the change rate of the 1kg producer price in t-1 period statistically, significantly influences it of own weight in t period and also slightly affects price change rates of other weights in t period. Fourthly, the impulse response analysis indicates that impulse responses of structural shocks for the change rate of the 1kg producer price are relatively more powerful in its own weight and in other weights than shocks emanating from price change rates of other weights. Fifthly, the variance decomposition analysis points out that the change rate of the 1kg producer price is relatively more influential than it of 500g, 700g, and 2kg producer prices respectively. In conclusion, the change rate of the 1kg Jeju flounder producer price leads the change rates of other ones and Jeju purchase projects need to be targeted to the 1kg Jeju flounder producer price as the purchase project implemented in 2014.

• Earthquakes and Structures
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• v.11 no.6
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• pp.1101-1121
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• 2016

Base isolation, one of the popular seismic protection approaches proven to be effective in practical applications, has been widely applied worldwide during the past few decades. As the techniques mature, it has been recognised that, the biggest issue faced in base isolation technique is the challenge of great base displacement demand, which leads to the potential of overturning of the structure, instability and permanent damage of the isolators. Meanwhile, drain, ventilation and regular maintenance at the base isolation level are quite difficult and rather time- and fund- consuming, especially in the highly populated areas. To address these challenges, a number of efforts have been dedicated to propose new isolation systems, including segmental building, additional storey isolation (ASI) and mid-storey isolation system, etc. However, such techniques have their own flaws, among which whipping effect is the most obvious one. Moreover, due to their inherent passive nature, all these techniques, including traditional base isolation system, show incapability to cope with the unpredictable and diverse nature of earthquakes. The solution for the aforementioned challenge is to develop an innovative vibration isolation system to realise variable structural stiffness to maximise the adaptability and controllability of the system. Recently, advances on the development of an adaptive magneto-rheological elastomer (MRE) vibration isolator has enlightened the development of adaptive base isolation systems due to its ability to alter stiffness by changing applied electrical current. In this study, an innovative semi-active storey isolation system inserting such novel MRE isolators between each floor is proposed. The stiffness of each level in the proposed isolation system can thus be changed according to characteristics of the MRE isolators. Non-dominated sorting genetic algorithm type II (NSGA-II) with dynamic crowding distance (DCD) is utilised for the optimisation of the parameters at isolation level in the system. Extensive comparative simulation studies have been conducted using 5-storey benchmark model to evaluate the performance of the proposed isolation system under different earthquake excitations. Simulation results compare the seismic responses of bare building, building with passive controlled MRE base isolation system, building with passive-controlled MRE storey isolation system and building with optimised storey isolation system.