• Advances in Computational Design
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• v.9 no.1
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• pp.39-52
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• 2024

If the governing differential equation arising from engineering problems is treated as an analytic, continuous and derivable function, it can be expanded by one point as a series of finite numbers. For the function to be zero for each value of its domain, the coefficients of each term of the same power must be zero. This results in a recursive relationship which, after applying the natural conditions or the boundary conditions, makes it possible to obtain the values of the derivatives of the function with acceptable accuracy. The elastoplastic analysis of an inhomogeneous thick sphere of metallic materials with linear variation of the modulus of elasticity, yield stress and Poisson's ratio as a function of radius subjected to internal pressure is presented. The Beltrami-Michell equation is established by combining equilibrium, compatibility and constitutive equations. Assuming axisymmetric conditions, the spherical coordinate parameters can be used as principal stress axes. Since there is no analytical solution, the natural boundary conditions are applied and the governing equations are solved using a proposed new method. The maximum effective stress of the von Mises yield criterion occurs at the inner surface; therefore, the negative sign of the linear yield stress gradation parameter should be considered to calculate the optimal yield pressure. The numerical examples are performed and the plots of the numerical results are presented. The validation of the numerical results is observed by modeling the elastoplastic heterogeneous thick sphere as a pressurized multilayer composite reservoir in Abaqus software. The subroutine USDFLD was additionally written to model the continuous gradation of the material.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.2
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• pp.505-509
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• 2012

Background: Matrix metalloproteinases (MMP) are proteolytic enzymes that are essentially involved in turnover of the extracellular matrix (ECM). The aim was to investigate the diagnostic value of MMP-7 and MMP-10 as tumor markers in pleural effusion (PE) and evaluate the value of combining MMP-7, MMP-10 and carcinoembryonic antigen (CEA) assays as diagnostic aids for malignant cells. Materials and Methods: A total of 179 patients with PE (87 malignant and 92 benign) were included in this study. The levels of MMP-7 and MMP-10 were measured using ELISA. Results: Values for MMP-7 and MMP-10 were significantly higher in malignant PE than those in benign PE (P<0.01). Among all variables evaluated, logistic regression found that MMP-7 and MMP-10 were significantly correlated with the presence of malignant disease (P<0.01). Analysis of receiver operating characteristics (ROC) curves showed that the area under the curve of MMP-10 (0.806) was significantly larger than that of MMP-7 (0.771) and CEA (0.789) (P<0.01). With parallel interpretation, the combination of MMP-10 and CEA achieved the higher sensitivity of 94.6%. The combination of MMP-7 and CEA in serial interpretation was able to boost the specificity to 95.7%. The combination of MMP-7, MMP-10 and CEA produced better sensitivity, specificity, PPV and NPV than MMP-7 and MMP-10 alone. Conclusion: MMP-7 and MMP-10 in PE may represent helpful adjuncts to conventional diagnostic tools in ruling out malignancy as a probable diagnosis, thus guiding the selection of patients who might benefit from further invasive procedures.

• Geomechanics and Engineering
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• v.20 no.1
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• pp.1-7
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• 2020

In structures excavated in rock mass, load progressively increases to a level and remains constant during the construction. Rocks display different elastic properties such as E_i and ʋ under different loading conditions and this requires to use the true values of elastic properties for the design of safe structures in rock. Also, rocks will undergo horizontal and vertical deformations depending on the amount of load applied. However, under constant loads, values of E_i and ʋ will vary in time and induce variations in the behavior of the rock mass. In some empirical equations in which deformation modulus of the rock mass is taken into consideration, elastic parameters of intact rock become functions in the equation. Hence, the use of time dependent elastic properties determined under constant loading will yield more reliable results than when only constant elastic properties are used. As well known, rock material will play an important role in the deformation mechanism since the discontinuities will be closed due to the load. In this study, E_i and ʋ values of intact rocks were investigated under different constant loads for certain rocks with high deformation capabilities. The results indicated significant time dependent variations in elastic properties under constant loading conditions. E_i value obtained from deformability test was found to be higher than the E_i value obtained from the constant loading test. This implies that when static values of elastic properties are used, the material is defined as more elastic than the rock material itself. In fact, E_i and ʋ values embedded in empirical equations are not static. Hence, this workattempts to emerge a new understanding in designing of safer structures in rock mass by numerical methods. The use of time-dependent values of E_i and ʋ under different constant loads will yield more accurate results in numerical modeling analysis.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.190-206
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• 2016

This study explores the meaning of life insurance planner's job experiences achieving job security, high performance and high income. After 6 of life insurance planners working in the field were chosen as the study participants, we use narrative approach to studying the meaning of their job experiences. The study shows that perception about job competency of planners depends on the level of experience: candidates who had no experience at all feel that anyone can perform planner's job, new employees after introduction training program see planners can do with product knowledge and consulting competency, and experienced people admit they can perform successfully only when they have good attitude towards customers and do all their work in a conscientious manner. Also, the meaning of planner's job experiences is identified as awareness of work value and serving customers with their commitment. The anticipated factors that make planner's job performed successfully are playing a role as a teacher, doctor, and angel, being regarded as happiness preacher for economic stability of individuals and families, and displaying their performance as experts.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.430-440
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• 2021

We analyzed research trends of 288 Korean academic dissertations and articles regarding platform work, using topic modeling and keyword network analysis method. Research disciplines of many studies were laws, business administration, and economics fields. Thigh frequent themes were platform labor protection measures and direct or indirect effects of the sharing economy. The main keywords were digital, value, industry, and labor in terms of infrastructure and structural change. Besides, the main topics were the protection of platform workers, the values of sharing services, digital paradigm, and platform regulations. Based on the results of the analysis, we derived four implications and suggestions such as researching structural frames in macroscopic contexts, generalizing case analysis, and technology supplementation by applying average and quantitative analysis methods, researching individual competency development to realize the essential symbiotic value of sustainability, and developing customized vocational education and training programs.

• Geomechanics and Engineering
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• v.29 no.4
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• pp.421-434
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• 2022

In the present study, reference samples were prepared using ore preparation facility tailings taken from the copper mine (Kure, Kastamonu), Portland cement (PC) in certain proportions (3 wt%, 5 wt%, 7 wt%, 9wt% and 11 wt%), and water. Then natural zeolite taken from the Bigadic Region was mixed in certain proportions (10 wt%, 20 wt%, 30 wt% and 40 wt%) for each cement ratio, instead of the PC, to prepare zeolite-substituted CPB samples. Thus, the effect of using Zeolite instead of PC on CPB's strength was investigated. The obtained CPB samples were kept in the curing cabinet at a temperature of 25℃ and at least 80% humidity, and they were subjected to the Uniaxial Compressive Strength (UCS) test at the end of the curing periods of 3, 7, 14, 28, 56, and 90 days. Except for the 3 wt% cement ratio, zeolite substitution was observed to increase the compressive strength in all mixtures. Also, the liquefaction risk limit for paste backfill was achieved for all mixtures, and the desired strength limit value (0.7 MPa) was achieved for all mixtures with 28 days of curing time and 7 wt%, 9 wt%, 11 wt% cement ratios and 5% cement - 10% zeolite substituted mixture. Moreover, the limit value (4 MPa) required for use as roof support was obtained only for mixtures with 11% cement - 10% and 20% zeolite content. Generally, zeolite substitution seems to be more effective in early strength (up to 28th day). It has been determined that the long-term strength losses of zeolite-substituted paste backfill mixtures were caused by the reaction of sulfate and hydration products to form secondary gypsum, ettringite, and iron sulfate.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.187-198
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• 1975

Although considerable research has been done on the blood chemistry of domestic animals, little work has been made of the changes associated with age. Moreover, the records about physiology of the goat were not much available in Korea, and a comprehensive survey of the blood values of the Korean native goat has not been made. The object of the present investigation was to make good this deficiency and to suggest standards for the blood chemical values of Korean native goats from birth to maturity. The goats were kept under average farming conditions in Korea. Blood samples were collected from the jugular vein at birth, at one and four days, at one, two, three and four weeks, and at two, three, six, nine and twelve months of age. The results obtained in this work were summarized as follows: 1. The highest concentration of serum glucose was observed at birth and it decreased gradually until three months of age, showing a steady state thereafter. 2. The concentration of total serum protein was a little higher at one day of age than at birth and showed a steady state until seven days of age; then it decreased slightly at two weeks of age and recovered at three weeks of age and showed a steady state until twelve months of age. The concentration of serum albumin was increased a little at one day of age and revealed a steady state thereafter. The concentration of serum globulin showed three phases - a fall during the first two weeks to reach minimum, a rise to the fourth week, and a fall at two months of age, showing a steady state thereafter. The lowest value of albumin fraction was observed at birth, then the value increased gradually until three months of age and revealed a stealer state thereafter. The highest value of globulin fraction was observed at birth, then the gradual decrease of the value was seen until three months of age; thereafter the value showed a steady state. 3. Albumin/globulin ratio was the minimum at birth, then it increased to reach a maximum at two weeks of age and decreased a little thereafter. 4. The concentration of total serum cholesterol showed a gradual increase during the first three months and fell to reach adult revel at six months of age. 5. Urea nitrogen in serum decreased during the first week to reach a minimum, then it increased at three months of age, and showed a fell to mature level at six mouths of age. 6. The concentration of serum creatinine was not affected by age. 7. The concentration of total serum calcium was a little higher during the first two weeks than the other period during the first year of life. 8. The concentration of serum inorganic phosphorus showed a gradual rise to reach a maximum and a gradual fall to reach adult level at nine months of age. 9. No significant sex differences of serum chemical values were recognized.

• Culinary science and hospitality research
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• v.16 no.3
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• pp.130-146
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• 2010

This research examines difference in learning motivation and self-regulated learning according to the general characteristics of the students in hotel and food service related departments at vocational colleges, and subsequently identifies correlation between the two attributes. The research conducted a survey for 300 students in hotel and food service related departments at three vocational colleges in Daegu region, and 267 copies were used for the final analysis. In terms of learning motivation, students in the age between 20 and 24 indicated 'employment after graduation' as the strongest motivation while relatively older students indicated 'joy of learning' as their motivation. It turned out that students who showed strong motivation in terms of 'employment after graduation' and 'fun of college life' acquired more professional certificates. Next, regarding self-regulated learning, female students showed higher ability than male students. Students in higher grade, with older age, and with field practice experience showed more strength in self-regulated learning. Students with higher levels of a cognitive strategy, meta cognition and achievement value acquired more professional certificates. Learning motivation and self-regulated learning showed positive correlation with an exception of 'amotivation' among learning motivations. 'Amotivation' demonstrated negative correlation with all the factors of self-regulated learning ability.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.678-688
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• 2020

Occupational ethical awareness is a system of norms and standards of behavior and an important component of professionalism that affects organizational performance and commitment. The purpose of this study is to examine the mediating effect of professionalism on the relationship between job ethics and organizational commitment of civil servants. A survey was conducted on 300 central government officials with more than one year of employment. 261 copies were used for the final analysis. The results are as follows. First, the vocational ethics of civil servants had a significant effect on professionalism. The higher the years of service, the higher the level of ethics. Second, the work ethic of public officials had a significant effect on organizational commitment. These results can be interpreted as the internal commitment of civil servants to the state of work ethic. Third, the mediating effect of professionalism was verified in the relationship between public morality and organizational commitment. Based on these results, the public ethics of public servants are the basis for accepting public values and goals. Vocational expertise with embedded codes of conduct and value systems influences organizational commitment. As a practical implication for improving the ethical ethics of public officials, education programs for improving ethical consciousness according to job titles and duties were provided, and the ethical ethical competence was presented.

• Journal of vocational education research
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• v.36 no.4
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• pp.79-102
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• 2017

The purpose of this study was to develop curriculum framework for entrepreneurship development for adolescents. In order to achieve this goal, we studied and developed entrepreneurship semantics, entrepreneurship education, entrepreneurship education, entrepreneurship education contents. This study was developed through Delphi survey. The results of this study were as follows. First, the meaning of entrepreneurship is Innovative mind-set to create true value by experience into life in order to pursue 'self full-filling life' as the organizer of life. Second, the nature of entrepreneurship education for youth is that entrepreneurship education aims to find and solve new problems through self-management to young people who will lead the future, and to create dynamic challenges and creative changes to create innovative values. Leadership skills, challenging spirit, and ability to solve practical problems'. Third, we developed a general goal for youth and elementary, middle and high school goal for entrepreneurship education. Fourth, as a domain of entrepreneurship education, we have developed 'core discovery', 'entrepreneurial skills', 'becoming an entrepreneur' and developed key themes. Based on the results of this study, we developed a systematic entrepreneurship education linkage and educational condition creation for young people outside schools; entrepreneurship program application and educational condition development according to the operation of the free-learning semester system; the strengthening of business start-up support for youth in late adolescence, the establishment of measures to utilize related institutions in local communities and others.