• Fire Science and Engineering
• /
• v.16 no.2
• /
• pp.51-58
• /
• 2002

For Halon-1301 regulated by Montreal Protocol and $CO_2$as its alternatives, the empirical equations of density, viscosity, and enthalpy were correlated in terms of temperature. They were obtained by regression analysis from the experimental data in the literature. The empirical equation of density was expressed as compressibility factor by the second- order function of temperature. The empirical equation of viscosity was formulated as a power function, and a correction factor was considered to cover the wider range of temperature. Finally, heat capacity as well as enthalpy were well fitted by empirical form of the second-order temperature. The correlation coefficients of the empirical equations in this work were more than 0.99.

• Hwankyungkyoyuk
• /
• v.10 no.2
• /
• pp.157-174
• /
• 1997

The purpose of this thesis is to study recognition and attitude between teachers and students about school environmental education. The data for this study were collected by administering interviews with seven hundred sixty three teachers and one thousand six hundred fifty six students, and make comparison between these teachers and students recognition and attitude for the environmental education by use of research are as follows. The conclusion of this research are as follows. First, In the study of teachers and students recognition and attitudes about environmental education, though they are interested in it, they lack in knowledge and ability to solve real environmental problems. Also, environmental education tends to be dealt with indifferently and formally because of the burden of entrance examination and lack of material concerned. Second, the recognition and attitude of the teacher-student group about the school environmental education have meaningful difference in each region. The suggestions for the improvement of the environmental education based on these conclusions are as follows. First, the more efficient methods and materials of the school environmental education must be developed in order that students may understand the complex property of the environment and at the same time have the ability to improve the environmental quality. Second, the cooperating system of environmental education including the teacher- student- student's parents' should be established in order to develop the recognition and attitudes for the environment. And also for teachers group to get the more professional leadership about environmental education, government' support is needed.

• Structural Engineering and Mechanics
• /
• v.20 no.3
• /
• pp.293-312
• /
• 2005

In this paper, free vibration of rotating beam with random properties is studied. The cross-sectional area, elasticity modulus, moment of inertia, shear modulus and density are modeled as random fields and the rotational speed as a random variable. To study uncertainty, stochastic finite element method based on second order perturbation method is applied. To discretize random fields, the three methods of midpoint, interpolation and local average are applied and compared. The effects of rotational speed, setting angle, random property variances, discretization scheme, number of elements, correlation of random fields, correlation function form and correlation length on "Coefficient of Variation" (C.O.V.) of first mode eigenvalue are investigated completely. To determine the significant random properties on the variation of first mode eigenvalue the sensitivity analysis is performed. The results are studied for both Timoshenko and Bernoulli-Euler rotating beam. It is shown that the C.O.V. of first mode eigenvalue of Timoshenko and Bernoulli-Euler rotating beams are approximately identical. Also, compared to uncorrelated random fields, the correlated case has larger C.O.V. value. Another important result is, where correlation length is small, the convergence rate is lower and more number of elements are necessary for convergence of final response.

• Fire Science and Engineering
• /
• v.16 no.3
• /
• pp.16-25
• /
• 2002

For Freon-23, a conventional extinguished agent regulated by Montreal Protocol and HFC-227ea, its alternative, the empirical equations were correlated in terms of saturated pressure, density, viscosity, enthalpy and surface tension. They were obtained by regression analysis from the experimental data in the literature. The empirical equations of saturated pressure were expressed as the second and third order function of temperature. The empirical equation of density was expressed as compressibility factor and saturated pressure by a function of temperature. The empirical equation of viscosity was formulated as a power function. Heat capacities as well as enthalpies were well fitted by empirical form of the second-order temperature. Finally, surface tension simply has linear function form in terms of temperature.

• Journal of Korean Society of Water and Wastewater
• /
• v.33 no.3
• /
• pp.205-213
• /
• 2019

Batch adsorption tests were performed to evaluate the applicability of adsorption kinetic model by using hydrogel chitosan bead crosslinked with glutaraldehyde (HCB-G) for Cu(II) as cation and/or phosphate as anion. Pseudo first and second order model were applied to determine the sorption kinetic property and intraparticle and Boyd equation were used to predict the diffusion of Cu(II) and phosphate at pore and boundary-layer, respectively. According to the value of theoretical and experimental uptake of Cu(II) and phosphate, pseudo second order is more suitable. On comparison with the value of adsorption rate constant (k), phosphate kinetic was 2-4 times faster than that of Cu(II) at any experimental condition indicating the electrostatic interaction between ${NH_3}^+$ and phosphate is dominated at the presence of single component. However, when Cu(II) and phosphate simultaneously exist, the value of k for phosphate was sharply decreased and then the difference was not significant. Both diffusion models confirmed that the sorption rate was controlled by film mass transfer at the beginning time (t < 3 hr) and pore diffusion at next time section (t > 6 hr).

• Computational Structural Engineering
• /
• v.5 no.3
• /
• pp.119-126
• /
• 1992

Most civil engineering structures such as bridges, power plants, and offshore platforms are apt to suffer structural damages over their service lives caused by adverse loadings, such as earthquakes, wind and wave forces. Accumulation of structural damages over a long period of time might cause catastrophic structural failure. Therefore, a methodology for monitoring the structural integrity is essential for assuring the safety of the existing structures. A method for the damage assessment of structures by the second order inverse modal perturbation technique is presented in this paper. Perturbation equation consists of a matrix equation involving matrices of structural changes(stiffness and mass matrix changes) and matrices of modal property changes(natural frequency and mode shape changes). The damages of a structure are represented as changes in the stiffness matrix. In this study, a second order perturbation equation is formulated for the damage assessment of structures, and solved by an iterative procedure. The effectiveness of the proposed method has been investigated through a series of example analysis. The estimated results for the structural damage indicated that the present method yields resonable estimates for the structural changes.

• Journal of Internet of Things and Convergence
• /
• v.9 no.6
• /
• pp.83-92
• /
• 2023

The purpose of this study is to provide a rational management strategy to improve the management performance of companies through intellectual property activities. Through this study, we aim to explore countermeasures to strengthen competitiveness in a changing global environment. A survey of 200 companies was conducted from September 1 to October 30, 2023. Statistical analysis was conducted using frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis, multiple regression analysis, and difference analysis. The conclusions are as follows. First, the impact of intellectual property activities on management performance was found to be creation and utilization. Second, the impact of management strategies on management performance was found to be differentiation strategy, cost advantage strategy, and concentration strategy. Third, cost advantage strategy has a partial mediation effect on the relationship between creation activities and managerial performance of intellectual property activities. Fourth, the differentiation strategy has a partial mediating effect on the relationship between the creation of intellectual property activities and managerial performance. In addition, differentiation strategy has a full mediating effect on the relationship between the utilization of intellectual property activities and performance. Fifth, concentration strategy has a partial mediating effect on the relationship between intellectual property activity utilization and management performance. Sixth, there is a difference between creation activities, protection activities, utilization activities, cost advantage strategy, differentiation strategy, financial performance, and non-financial performance based on venture certification status. As the importance of intellectual property is increasing in the era of technological hegemony, IoT companies will need to improve their management performance through venture certification and strategies utilizing intellectual property in order to secure future competitiveness. Based on this study, we hope that IoT companies will maximize their performance by implementing efficient strategies that consider IP activities.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.130-132
• /
• 1997

This paper proposes a reference model following control system using fuzzy logic controller and genetic algorithm. A fuzzy logic controller is designed such that plant output follows the output generated by a reference model. In this paper, First-order and second-order reference model with no overshoot and fast rise time is designed. Experiment results show the effectiveness of the proposed controller in tracking property and robustness.

• 대한공업교육학회지
• /
• v.45 no.2
• /
• pp.108-130
• /
• 2020

In order to cope with the rapid changes in science and technology and various societies and complex economies with the advent of the 4th Industrial Revolution, intellectual property education is essential above all. In this study, therefore, intellectual property and the required competences were derived and verified for each field. As for the research method, Delphi technique was used twice for literature review and experts, and the conclusions of the research are as follows. First, the field of intellectual property required in the era of the 4th Industrial Revolution was classified, through literature review and Delphi technique, in eleven sections such as IP-R & D consulting, IP information search analysis, IP entitlement, IP strategic planning, IP transaction, IP finance, IP value evaluation, IP management, global IP management, IP commercialization, and IP disputes, of which validity was verified. Second, It was analyzed that the validity of required competencies derived from each field of intellectual property was reliable. Third, it is generally appropriate to nurture manpower in each field of intellectual property in universities or graduate schools. In addition, it is judged that regular job training of industries such as enterprises and public institutions is necessary regardless of the field.

• Journal of Digital Convergence
• /
• v.12 no.6
• /
• pp.203-213
• /
• 2014

The purpose of this research is to deduce the effects factor of R&D output and outcome in the aspect of the researcher's intellectual property capacity, and conduct an empirical analysis to see if there is intermediated effect between cooperation of a patent attorney and output. I applied three step, input (researcher's intellectual property capacity and intellectual property environment), output (number of patent and SCI paper), outcome (number of technology transfer, profit), and analyzed the effects of researcher's intellectual property factors on output and outcome through structural equation model. The results are as follows. First, there's no cooperation between a researcher and patent attorney, the researcher's knowledge on patent specification had direct effect on the output. Second, a researcher and an patent attorney cooperate, the cooperative activities have complete mediation effect on the output, and the researcher's will to commercialize the technology has direct effects on the output. Third, the intellectual property environment of the research organization gives direct effects on the researcher's intellectual property capacity, and gives indirect effects on the outcome. this study suggest that it is important to cooperate with external experts in order to excellent R&D outcome.