• Bulletin of the Korean Mathematical Society
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• v.40 no.1
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• pp.77-83
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• 2003

In this paper, we study the strong Perron integral, and show that the strong Perron integral is equivalent to the McShane integral.

• Communications of the Korean Mathematical Society
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• v.20 no.2
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• pp.291-297
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• 2005

In this paper, we introduce the SP-integral and the $SP_\alpha-integral$ defined on an interval in the n-dimensional Euclidean space $\mathbb{R}^n$. We also investigate the relationship between these two integrals.

• Journal of the Chungcheong Mathematical Society
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• v.15 no.2
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• pp.41-46
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• 2003

In this paper, we investigate the $SP_{\alpha}$-integral and the $M_{\alpha}$-integral defined on an interval of the n-dimensional Euclidean space $\mathbb{R}^n$. In particular, we show that these two integrals are equivalent.

• East Asian mathematical journal
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• v.27 no.5
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• pp.539-543
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• 2011

In this paper, we consider an optimization problem which consists a nonconvex quadratic objective function and two nonconvex quadratic constraint functions. We formulate its dual problem with semidefinite constraints, and we establish weak and strong duality theorems which hold between these two problems. And we give an example to illustrate our duality results. It is worth while noticing that our weak and strong duality theorems hold without convexity assumptions.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.2
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• pp.59-65
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• 2020

The empirical Green's function method is applied to the foreshock and the mainshock of the 2016 Gyeongju earthquake to simulate strong ground motions of the mainshock and scenario earthquake at seismic stations of seven metropolises in South Korea, respectively. To identify the applicability of the method in advance, the mainshock is simulated, assuming the foreshock as the empirical Green's function. As a result of the simulation, the overall shape, the amplitude of PGA, and the duration and response spectra of the simulated seismic waveforms are similar with those of the observed seismic waveforms. Based on this result, a scenario earthquake on the causative fault of Gyeongju earthquake with a moment magnitude 6.5 is simulated, assuming that the mainshock serves as the empirical Green's function. As a result, the amplitude of PGA and the duration of simulated seismic waveforms are significantly increased and extended, and the spectral amplitude of the low frequency band is relatively increased compared with that of the high frequency band. If the empirical Green's function method is applied to several recent well-recorded moderate earthquakes, the simulated seismic waveforms can be used as not only input data for developing ground motion prediction equations, but also input data for creating the design response spectra of major facilities in South Korea.

• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.6
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• pp.233-240
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• 2021

The stochastic method is applied to simulate strong ground motions at seismic stations of seven metropolises in South Korea, creating an earthquake scenario based on the causative fault of the 2016 Gyeongju earthquake. Input parameters are established according to what has been revealed so far for the causative fault of the Gyeongju earthquake, while the ratio of differences in response spectra between observed and simulated strong ground motions is assumed to be an adjustment factor. The calculations confirm the applicability and reproducibility of strong ground motion simulations based on the relatively small bias in response spectra between observed and simulated strong ground motions. Based on this result, strong ground motions by a scenario earthquake on the causative fault of the Gyeongju earthquake with moment magnitude 6.5 are simulated, assuming that the ratios of its fault length to width are 2:1, 3:1, and 4:1. The results are similar to those of the empirical Green's function method. Although actual site response factors of seismic stations should be supplemented later, the simulated strong ground motions can be used as input data for developing ground motion prediction equations and input data for calculating the design response spectra of major facilities in South Korea.

• Journal of Digital Convergence
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• v.6 no.1
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• pp.53-61
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• 2008

For the domestic digital contents, a proactive cooperation system or framework between the government, the businesses and research institutions, which would allow for free flow of interaction among these players, can play that role. We have proposed and realized the Dynamic Coordinating Framework(DCF) to bridge these gaps among the major players in the industry. The the Dynamic Coordinating Framework rests on the following major functions. The first major function of the DCF is to decipher any ambiguity that may be embedded in external inputs by stratified role and bias. The second function is to create cooperative groups that will deal with the ambiguities based on its consequent situation. The third is a feedback function that will draw out a new cooperative way by re-feeding the capacities and the conflicts that stem from the existing organizations and strategies into cooperation and adjustment process. Our DCF has compared and evaluated with England and Australia digital content industry models under AHP(Analytic Hierarchy Process) method. DCF has turned out to be well designed and have strong points based on OECD innovation and cooperation criteria.

• Journal of Korean society of Dental Hygiene
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• v.9 no.3
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• pp.456-467
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• 2009

For this study, self-completion survey for 149 implant patients of dental clinics and hospitals in Seoul and Kyunggi areahas been executed in order to provide basic data for increasing patient satisfaction level by effective consultation and various information for the patients who want dental implantation. The conclusion of the study is like below. 1. In terms of demographics of the study, sample size of female patients(n=85) was more than that of male patients(n=64) and patients in their 50s were major age group. When it comes to the educational level, university graduates were 85 and high school graduates were 44. And 132 were married and 6 were single. In the income level, monthly income between KRW 2~4 million was major group(n=59). 2. In the study, patients' most concern was complication or adverse events(n=41), and price(n=39) & annual dental check-up(n=49) were following it. And 80 patients responded that dental health is the most valuable(n=80) and whole body health was following(n=37). In terms of knowledge on dental implant, 100 patients responded 'know just a little', 31 and 13 answered 'generally know' and 'well know' each. 3. As a result of analyzing implant patients' satisfaction level by segment, general satisfaction rate was highest as 4.20, social satisfaction rate was 4.20, psychological function was 4.06 and masticatory function was 3.90. 4. Based on the result of comparing patient satisfaction level by general characters of dental implant patient, chewing function was the highest in the age group of 60s with score of 4.21 and in terms of social function, the group with over KRW 8 million of monthly income showed highest score with 4.54. When it comes to the psychological function, patients in their 70s showed highest satisfaction level with 4.52. In the end, patients in their 70s showed highest score with 4.81 in the overall satisfaction and it was also statistically significant. 5. In the overall satisfaction level by interest in dental health, appearance showed highest score with 4.57 and it was also significantly higher than that of whole body. In the variance by dental knowledge, 'well know' group showed highest score with 4.58, and that of 'just a little' group was 4.33. That means there are correlations between dental knowledge and satisfaction level. 6. As a result of analyzing correlations amongst variances of the study, there were strong positive correlations among them. And there were very significantly positive correlations especially between social and psychological function and between psychological and overall satisfaction level. In conclusion, higher psychological function has strong relations with both social function and overall satisfaction level(p<.001).

• Journal of the Chungcheong Mathematical Society
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• v.26 no.4
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• pp.723-734
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• 2013

A robust optimization problem, which has a maximum function of continuously differentiable functions as its objective function, continuously differentiable functions as its constraint functions and a geometric constraint, is considered. We prove a necessary optimality theorem and a sufficient optimality theorem for the robust optimization problem. We formulate a Wolfe type dual problem for the robust optimization problem, which has a differentiable Lagrangean function, and establish the weak duality theorem and the strong duality theorem which hold between the robust optimization problem and its Wolfe type dual problem. Moreover, saddle point theorems for the robust optimization problem are given under convexity assumptions.

• Geomechanics and Engineering
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• v.37 no.3
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• pp.279-291
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• 2024

The "Korea Institute of Geoscience and Mineral (KIGAM) Quake" is a web-based open platform developed for publicly serving seismological data from 61 stations operated by KIGAM in Korea. The service provides meta-information related to observatory sites, sensors, and recorders necessary for utilizing the seismological data, as well as mainly observed continuous and strong-motion waveforms. The data is available through both the web and International Federation of Digital Seismograph Networks (FDSN) web services (open API), a unified data-providing interface in seismology. The platform aims to strengthen its open nature by offering a signal processing function for strong ground motions that can be controlled by user requests. The processed results can be downloaded in ASCII format, designed to meet the increased demands and accessibility in the earthquake engineering field. The platform also offers earthquake research information produced by KIGAM, such as recent major earthquake source information and academic annual report of earthquakes. Additionally, a site flat file was constructed for the geotechnical characteristics of 61 KIGAM station (KGNET) sites based on direct investigations and estimations.