• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.531-541
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• 1996

Periodontal disease is characterized by destruction of supporting tissues caused by invasion of plaque bacteria and defense mechanism of host. Many dentists are very interested in laser therapy on various intraoral soft tissue lesions including inflammatory periodontal pocket. In order to determine the therapeutic effect of intrapocket irradiation of a pulsed- Nd : YAG laser on the inflammatory periodontal pockets, bilateral 60 teeth with 4-6mm in probing pocket depth and gingival inflammation were selected and evaluated by sulcus bleeding index(SBI), and plaque index(pI) for baseline record. Intrapocket irradiation($300{\mu}m$ fiber optic, I.5W power, for 2 min.) of a pulsed-Nd : YAG laser(EL.EN.EN060, Italy) was applied on half of them. As the control group, the same procedure except power-off was repeated on the contralateral 30 teeth. At 1-, 2-, 3-, and 4-week after intrapocket manipulation, every tooth was reevaluated by the same clinical indices. And the difference between the lased group and control group was statistically analyzed by paired t-test and Chi-square test in Microstat program. Following results were obtained: 1. Until I-week and 2-week after intrapocket manipulation, SBI was lowered in both lased group and control group, compared to baseline SBI, but from 3-week after, the recovering tendency toward baseline was noted, and at only 2-week after, the number of teeth showing lowered SBI was significantly more in lased group than in control group(p<0.05). 2. PI of both lased group and control group was lowered through whole experimental period from I-week to 4-week after, compared to baseline PI(p<0.05), but there was no significant difference between lased group and control group(p>0.1). The results suggest that intrapocket irradiation of a pulsed-Nd:YAG laser may lead somewhat remission of gingival inflammation, but for more favorable therapeutic result the thorough root planing should be necessarily accompanied with gingival curettage.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.144-159
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• 2013

This study covers Namwoneupseong Fortress(南原邑城), Historic Site No. 298, which played a pivotal role in the urban development and military defense history of Namwon during the Joseon Dynasty. From the related historical records, Namwoneupseong Fortress was first constructed during the reign of King Seongjong. Discussion on the extension of Namwoneupseong Fortress, afterwards, was mainly guided by he traces of Yuingweseong Fortress(劉仁軌城). In other words, the original construction of the Fortress was in the original shape of the current Namwoneupseong Fortress, and Yuingweseong Fortress heavily impacted the extension works of Namwoneupseong Fortress. Although some studies covered Namwoneupseong Fortress and its overall construction process, no in-depth study exists on the original Namwoneupseong Fortress and Yuingweseong Fortress. This study covers the overall construction process of Namwoneupseong Fortress. At the same time, we tried to confirm inclusively and objectively the facts related to the relationship between Yuingweseong Fortress and Namwoneupseong Fortress, process and range of the expansion of Namwoneupseong Fortress among others through the location search of the originally built Namwoneupseong Fortress and Yuingweseong Fortress. The study discovered that Yuingweseong Fortress was built in A.D. 660~665 and that Namwoneupseong Fortress, which was built in the early stage of King Seongjong's reign, was extended along the traces of Yuingweseong Fortress towards the southeast. Furthermore, the study confirmed that Namwoneupseong Fortress is consisted of three sections - the section with Namwoneupseong Fortress's original walls preserved, newly constructed section, and the section following Yuingweseong Fortress's traces.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.29-38
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• 2024

The Matched Field Processing (MFP) is an estimation method for a source range and depth based on the prediction of sound propagation. However, as the frequency increases, the prediction inaccuracy of sound propagation increases, making it difficult to estimate the source position. Recently proposed, the Frequency-Difference Matched Field Processing (FD-MFP) is known to be robust even if there is a mismatch by applying a frequency-difference autoproduct extracted from the auto-correlation of a high frequency signal. In this paper, in order to evaluate the performance of the FD-MFP using a horizontal line array, simulations were conducted in the environment of the East Sea of Korea. In the area of Bottom Bounce (BB) and Convergence Zone (CZ) where detection of a sound source is possible at a long range, and the results of localization were analyzed. According to the the FD-MFP simulations of horizontal line array, the accuracy of localization is similar or degraded compared to the conventional MFP due to diffracted field and mismatch of sound speed. There was no clear result from the simulations conforming that the FD-MFP was more robust to mismatch than the conventional MFP.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.55-65
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• 2016

Detecting an object which is located at seabed is an important issue for various areas. This paper presents an approach to detection of an object that is placed at seabed in the shallow water. A conventional scheme is to employ a side-scan sonar to obtain images of a detection area and to use image processing schemes to recognize an object. Since this approach relies on high frequency signals to get clear images, its detection range becomes shorter and the processing time is getting longer. In this paper, we consider an active sonar system that is repeatedly sending a linear frequency modulated signal of 6~20 kHz in the shallow water of 100m depth. The proposed approach is to model consecutively received reflected signals and to measure their modeling error magnitudes which decide the existence of an object placed on seabed depending on relative magnitude with respect to threshold value. The feature of this approach is to only require an assumption that the seabed consists of an homogeneous sediment, and not to require a prior information on the specific properties of the sediment. We verify the proposed approach in terms of detection probability through computer simulation.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.89-100
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• 2021

The National Cyber Capability Assessment(NCCA) could be used as meaningful information for improving national cyber security policy because it provides information on the elements necessary for strengthening national cyber capabilities and the level of each country. However, there were few studies on improving cyber capabilities using the NCCA result in Korea. Therefore, we analyzed the result of National Cyber Power Index(NCPI) conducted by Belfer Center of Harvard Univ. by applying modified-IPA method to derive cybersecurity policy agendas for Korea. As a result, the need to set agendas on surveillance and offensive cyber capability and improve the effectiveness of policy implementation for intelligence and defense was drawn. Moreover, we suggested need for in-depth study of each policy agenda deduced from preceding research data as a future tasks. And it is expected to increase practical use of NCCA for domestic policy analysis by developing and using our own NCCA model which considered analysis framework proposed in this study.

• Industry Promotion Research
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• v.7 no.4
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• pp.53-61
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• 2022

This study is a phenomenological study on the dream insight process of intern counselors. The purpose of this study is to promote growth as a professional counselor based on the process of giving meaning to and recognizing their experiences through insight into the unconscious. Therefore, we used dream-integrated art therapy to have a process of recognizing unconscious dreams that clearly express expectations for oneself, others, and the world, and to explore this process more flexibly. The research participants selected three students enrolled in the master's and doctor's courses from among the applicants who applied through public relations and adopted the phenomenological Giorgi research method for data collection and analysis through in-depth interviews with the research participants. The main research results are as First, the intern counselors had a motive for wanting their own unconscious insight through dream-integrated art therapy and were able to gain insight into the problems revealed in their unconscious through dreams, music, and art media. Second, it was found that the intern counselors felt a deepening of concentration and comfort through recent dreams, music, and art media in common. Third, as a defense mechanism that was revealed without the combination of dream integrated art therapy, the avoidance tendency of not wanting to reveal oneself was common, but this showed a gradual decrease. Fourth, it was reported that intern counselors gained flexibility for themselves about the future growth direction had an opportunity to accept themselves, and had a plan for the future direction to become professional counselors. Therefore, it is suggested that follow-up studies using various media, studies to verify the effectiveness of the dream integration program, and various case studies are necessary.

• Fire Science and Engineering
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• v.20 no.3 s.63
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• pp.65-70
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• 2006

From the beginning of the construction stage, the fire protection regulation for the nuclear power plants conforms to the design requirements for the acquisition of the license permit. This regulation is based on the plant status of the normal operation, but it is not enough to be used as an application standard for fire protection at the transient mode of the plant and the outage time for refueling as well as for the plant decommissioning. While the advanced fire protection requirement that has been developed in America recently suggests the performance-based requirement and management rule applicable to the overall life time of the plant, it simply represents the conceptual application. It means that it can not be treated as appropriate standards because it does not deal with the qualitative and quantitative approach in specific ways. By the way, with the use of the performance-based fire risk analysis, the dynamic behavior of the heat and smoke at the fire compartment of the nuclear power plants can be analyzed and the thermal effect to the safety-related equipment and cables can be evaluated as well. At this paper, it suggests the ways to change the applicable fire protection regulations and the required evaluation items for the fire risk resulted from the plant configuration change with an intent to introduce the state-of-the-art quantitative fire risk analysis technology at the domestic nuclear power plants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.566-572
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• 2021

A methodology for the identification and coordinates estimation of air cavities under urban ground or sandy soil using its natural poles and natural resonant frequencies is presented. The potential of this methodology was analyzed. Simulation models of PEC (Perfect Electric Conductor)s with various shapes and dimensions were developed using an EM (Electromagnetic) simulator. The Cauchy method was applied to the obtained EM scattering response of various objects from EM simulation models. The natural poles of objects corresponding to its instinct characterization were then extracted. Thus, a library of poles can be generated using their natural poles. The generated library of poles provided the possibility of identifying a target by comparing them with the computed natural poles from a target. The simulation models were made assuming that there is an air cavity under urban ground or sandy soil. The response of the desired target was extracted from the electromagnetic wave scattering data from its simulation model. The coordinates of the target were estimated using the time delay of the impulse response (peak of the impulse response) in the time domain. The MP (Matrix Pencil) method was applied to extract the natural poles of a target. Finally, a 0.2-m-diameter spherical air cavity underground could be estimated by comparing both the pole library of the objects and the calculated natural poles and the natural resonant frequency of the target. The computed location (depth) of a target showed an accuracy of approximately 84 to 93%.