• Journal of Applied and Pure Mathematics
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• v.4 no.1_2
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• pp.9-26
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• 2022

The purpose of this work is to study the existence and continuous dependence on neutral stochastic partial integrodifferential equations with impulsive effects, perturbed by a fractional Brownian motion with Hurst parameter $H{\in}({\frac{1}{2}},\;1)$. We use the theory of resolvent operators developed in Grimmer [19] to show the existence of mild solutions. Further, we establish a new impulsive-integral inequality to prove the exponential stability of mild solutions in the mean square moment. Finally, an example is presented to illustrate our obtained results.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.58-59
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• 2015

As the business environment for construction enterprises has been worse, the level of their dependence on public projects increases. Under these circumstances, the public owners should pursue more efficient management process and make continuous efforts to establish strategic project-oriented organizations. There are growing concerns on owners' role with the recognition that the public owners are the key stakeholders to improve effectiveness in public sectors and reinforce competitiveness of entire industry. This study reviewed the characteristics of public construction projects with the concept of program, evaluated the current status of program management capabilities, and discussed the requirement for effective program management.

• Journal of the Korean Mathematical Society
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• v.61 no.4
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• pp.797-836
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• 2024

We consider the following strongly damped wave equation on ℝ³ with memory u_tt - αΔu_t - βΔu + λu - ∫₀^∞ κ'(s)∆u(t - s)ds + f(x, u) + g(x, u_t) = h, where a quite general memory kernel and the nonlinearity f exhibit a critical growth. Existence, uniqueness and continuous dependence results are provided as well as the existence of regular global and exponential attractors of finite fractal dimension.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.9-14
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• 1996

The dependence of microstructural and optical properties of Ag-In-Sb-Te thin films on annealing heat-treatments was studied. It was found from the present work that the increase of reflectance after annealing heat-treatment is related with phase change of Ag-In-Sb-Te thin film from amorphous state to crystalline phases which involve Sb crystalline phase and AgInTe$_2$ stoichiometric phase. On the other hand, the reflectance is decreased after high temperature annealing (above 450$^{\circ}C$), due to the morphology .mange of film surface. For the purpose of practical application(erasable optical disk), we fabricated quadrilayered Ag-In-Sb-Te alloy disk, and annealed it with continuous laser beam. As result of this laser\ulcorner annealing treatment, we found that the increment of reflectance is 9.3% at 780nm wavelength. It might be considered that Ag-In-Sb-Te alloy optical disk is the big promising candidate for the erasable optical memory medium.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.941-945
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• 2006

In the development of electricity generating wind turbines for wind farm application, only two types have survived as the methods of power regulation; stall regulation and fun span pitch control. The sound measurement procedures of IEC 61400-11 are applied to field test and evaluation of noise emission from each of 1.5 MW and 660 kW wind turbine generators (WTG) utilizing the stall regulation and the pitch control for the power regulation, respectively. Apparent sound power level, wind speed dependence and third-octave band levels are evaluated for both of WTGs. It is found that while 1.5 MW WTG using the stall control is found to emit lower sound power than 660 kW one using the pitch control at low wind speed (below 8 m/s), sound power from the former becomes greater than that of the latter in the higher wind speed. Equivalent continuous sound pressure levels (ECSPL) of the stall control type of WTG vary more widely with wind speed than those of the pitch control type of WTG These characteristics are believed to be strongly dependent on the basic difference of the airflow around the blade between the stall regulation and the pitch control types of WTG. These characteristics according to the methods of power regulation lead to the very different noise emission characteristics of WTG depending on the seasons because the average wind speed in summer is lower than the critical velocity over which the airflow on the suction side of blade in the stall types of WT are separated. These results propose that, in view of environmental noise regulation, the developer of wind farm should give enough considerations to the choice of power regulation of their WTG based on the weather conditions of potential wind farm locations.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.8 s.113
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• pp.864-871
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• 2006

In the development of electricity generating wind turbines for wind farm application, only two types have survived as the methods of power regulation; stall regulation and full span pitch control. The main purpose of this paper is to experimentally identify the characteristics of noise emission of wind turbines according to the power regulation types. The sound measurement procedures of IEC 61400-11 are applied to field test and evaluation of noise emission from each of 1.5 MW and 660 kW wind turbines (WT) utilizing the stall regulation and the pitch control for the power regulation, respectively. Apparent sound power level, wind speed dependence, third-octave band levels and tonality are evaluated for both of WTs. It is observed that equivalent continuous sound pressure levels (ECSPL) of the stall control type of WT continue to increase with increasing wind speed whereas those of the pitch control type of WT show less correlation with wind speed. These observed characteristics are believed to be due to the different airflow patterns around the blade between the stall regulation and the pitch control types of WT; the airflow on the suction side of blade in the stall types of WT are separated at the high wind speed. It is also found that the 1.5 MW WT using the stall control emits lower sound power than 660 kW one using the pitch control at wind speeds below 8m/s, whereas sound power of the former becomes higher than that of the latter in the wind speed over 8m/s. This wind-speed dependence of sound power leads to the very different noise omission characteristics of WTs depending on the seasons because the average wind speed in summer is lower than 8m/s whereas that in summer is higher. Based on these experimental observations, it is proposed that, in view of environmental noise regulation, the developer of wind farm should give enough considerations to the choice of power regulation of their WTG based on the weather conditions of potential wind farm locations.

• Journal for History of Mathematics
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• v.24 no.4
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• pp.97-118
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• 2011

This study aimed finding effective models for the teaching the concept of function. We selected two models. One is discrete model which focuses on the 'corresponding relation of the elements of the sets(domain and range). The other is continuous model which focuses on the dependent relationship of the two variables connected in variable phenomenon. A vending machine model was used as a discrete model, and a water bucket model was used as a continuous model in our study. We taught 2 times about the concept of function using two models to the 60 students (7th grade, 2 classes) living in Taebak city, and tested it twice, after class and about 3 months later. A vending machine model was helpful in understanding the definition of function in the 7th grade math textbook. Also, it was helpful to making concept image and to recalling it. On the other hand, students who used the water bucket model had a difficultly in understanding the all independent variables of the domain corresponding to the dependent variables. But they excelled in tasks making formula expression and understanding changing situations.

• Journal of Oriental Neuropsychiatry
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• v.26 no.2
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• pp.131-142
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• 2015

Objectives: The purpose of this study is to evaluate the personality traits and cognitive characteristics of the Sasang constitution by comparing the Eysenck Personality Questionnaire (EPQ), Temperament and Character Inventory (TCI), Continuous Performance Test (CPT) and Stroop Test. Methods: One hundred and six healthy subjects (age 20 to 40) were analyzed; 45 Taeeumin, 30 Soyangin and 31 Soeumin. The Sasang constitution was diagnosed by a sasang constitutional medicine specialist based on the results of a Two Step Questionnaire for Sasang Constitution Diagnosis (TS-QSCD), the external appearance, temperament and symptoms. The results of the EPQ, TCI, CPT and Stroop Test were compared between Sasang constitutions. Results: Among the seven dimensions of EPQ, Taeeumin and Soyangin scored significantly higher than Soeumin in Extraversion. Soyangin scored significantly higher than Soeumin in Impulsiveness. Among the four temperament dimensions of TCI, Taeeumin and Soyangin scored significantly higher than Soeumin in novelty seeking, reward dependence and persistence. Soeumin scored significantly higher than Taeeumin and Soyangin in harm avoidance. Among the three character dimensions of TCI, Soyangin scored significantly higher than Taeeumin in self transcendence. The results for CPT showed no significant differences between sasang constitutions. Taeeumin had a significantly higher color score in the stroop test than Soeumin. Conclusions: The personality tests showed significant differences between Sasang constitutions, but the neuropsychological test did not show any differences. Further studies should be performed to identify neuropsychological differences between Sasang constitutions.

• The Journal of Fisheries Business Administration
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• v.16 no.1
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• pp.31-54
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• 1985

The mutual credit of Fisheries Cooperatives is reciprocal financing bring overs and shorts to settlement themselves by filling each other's needs among feeble fishermen economically. The spread of mutual credit through Fisheries Cooperatives reduces private loan dependence and private loan interest rate at fishery village, and that fills up policy financing being restricted by working scale. And seeing movement side of Fisheries Cooperatives, it has done an under board to settle self-supporting foundation of primary fisheries cooperatives early. The mutual credit deposit shows about 53 times increase past an interval of a ten years. This increase rate is an epoch-making record being unparalleled in other banking facilities except Fisheries Cooperatives. Then being unparalleled increase rate, time and savings deposits increase has been contributed a great deal than demand deposits. Thinking important function factors as mutual credit growth, we can classify interior and exterior factors. The exterior factor is income of fishery household in some measure, interior factors are the high deposits interest rate and the enlargement of facilities organization. As these, they have been in a better factors, also have been a restriction factors. The restriction factors are conflict cancellation between mutual credit and them bring into existence a village vault, mutual savings and finance companies, private finance. For the sake of continuance growth rate in mutual credit as past, we should eliminate restricted factors in growth. On the other hand the better factors in growth should be act upon affirmation side continually. Consequently under circumstances not to an amicable settlement bring the fisheries fund demand as policy financing, we should do continuous and sound development of fisheries financing by means of putting in good order of fisheries cooperatives mutual credit. Surveying a problem from these viewpoints, when we study more deep and a full into a subject about growth project of mutual credit, we think to expect continuous growth in mutual credit of Fisheries Cooperatives.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.177-183
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• 2010

In continuous vocabulary recognition system by statistical method vocabulary recognition to be performed using probability distribution it also modeling using phoneme clustering for based sample probability parameter presume. When vocabulary search that low recognition rate problem happened in express vocabulary result from presumed probability parameter by not defined phoneme and insert phoneme and it has it's bad points of gaussian model the accuracy unsecure for one clustering modeling. To improve suggested probability distribution mixed gaussian model to optimized for based resemble Euclidean and Bhattacharyya distance measurement method mixed clustering modeling that system modeling for be searching phoneme probability model in clustered model. System performance as a result of represent vocabulary dependence recognition rate of 98.63%, vocabulary independence recognition rate of 97.91%.