• Journal of Digital Convergence
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• v.18 no.4
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• pp.341-346
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• 2020

Polymethyl methacrylate (PMMA), a self-curing resin mainly used in removable orthodontic appliances, is an acrylic resin mainly used in the field of modern dentistry. As an advantage, it has been used for a long time as a material for orthodontic devices in dentistry due to its color and volume, tissue affinity, and stability. The production of PMMA can be divided into self-polymerization method and thermal polymerization method according to activation method. Self-curing resins have long been used as orthodontic devices. The resin injection method is largely divided into a sprinkle-on method and a mixing method. In this study, we intend to test the mechanical properties according to the resin injection method of the orthodontic device, such as strength, modulus of elasticity, and surface roughness. There was no significant difference in strength as a result of three-point bending strength test on rectangular specimens (1.4 × 3.0 × 19.0 mm) of orthodontic PMMA. There was also no significant difference in hardness. There was no significant difference in surface roughness. It was confirmed that the orthodontic PMMA had no significant difference in mechanical properties according to the resin injection method of the orthodontic device.

• Korean Journal of Childcare and Education
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• v.5 no.2
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• pp.43-71
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• 2009

This study is aimed at performing art therapy and looking into the effect on declining depression and anxiety and improving self-esteem, targeting at maladaptive behavior child in home and school living. So, this study made an application of fine art programs 2 session a week, for 50minutes each, total 24 sessions, targeting at elementary 1st girl graders(7 years old in full) in J city. In the end-term, this study performed a fine art therapy for 6 sessions together with mother-children. This study used a Korean-style Children Depression Inventory(CDI) developed by Kovacs and Beak(1977) and adapted by Jo Su Cheol and Lee Young Sik(1990) to look into children's decline in depression and anxiety and Revised Child Manifest Anxiety Scale(RCMAS) produced by Reynolds and Richmond(1978) and adapted by Jo Su Cheol and Choi Jin Suk(1990) to look into improvement of self-esteem. This study performed and analyzed KHTP, KFD painting examination, prior as well as post, to perform children's emotional appraisal and analyzed, classified with sessions, children's change in the progress of programs. The results of this study were as follows: First, fine art therapy was effective in declining children's depression and anxiety. Second, fine art therapy was effective in improving children's self-esteem. Third, children changed their emotional stability affirmatively in KHTP, KFD painting tests. Family affinity and cohesion were strengthened and changed into friendly family. Fourth, in the progress of programs, classified with sessions, children inclined their depression and anxiety and improved their self-esteem. This study leads to the result that art therapy inclines depression and anxiety in maladaptive behavior child and has an affirmative effect on improving self-esteem.

• Korean Journal of Social Welfare
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• v.59 no.4
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• pp.137-162
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• 2007

In democracy basic rights such as political equality and participation through elections have been respected, opportunities of corporation and opposition have been guaranteed, and ability of self-learning and self-correction have been developed. These positive factors give preconditions for the welfare development in the democratic state. Because in this state adults get the suffrage and the open competition for official positions induces political parties use social policies as means to win the election. That is to say, political parties have an incentive to use various social policies to win the election. Democracy, therefore, has affinity with social policy. The affinity between democracy and social policy can be found also in Korea which was democratized in 1987. But, in Korea, the positive relationship between democracy and social policy is very weak due to the problem of constitutional structures. Korean Parliament usually enacts abstract social act and delegates the right to fill concrete contents of the social acts to the executive. Delegation itself has no problem, but excessive delegation is a problem since the executive can overuse its discretion as sacrificing the social rights of the citizen. In addition social consensus could not be achieved in this constitutional structures, which are a obstacle to establishing a political process in the Parliament to promote the welfare development through party competition. Excessive delegation should be reduced, and the Parliament should fill concrete contents of the social acts as exercising its legislative power more. Then a mechanism of welfare development can be launched in Korea.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.213-223
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• 2007

In this paper, we carry out a cyber group consultation by means of the video-based education system, and verify the effects. For the verification of this study, two assumptions were set up. These assumptions were inspected by selecting 45 students of D elementary school located in a big city, and coming up with a test utilizing one of video-based education systems. Following up, a self-respect test form and a questionnaire were made to verify of the group consultation to the video-based education system, and by analyzing the test form and the questionnaire, the conclusion of this study was finally drawn. The conclusion gained through the process adove is as follows: It turned out that real-time video-based cyber group consultation promoted self-respect and enthusiastic participation of consulters as well as formed emotinal stability and a close affinity between the consultant and the consulter through active interaction. The results of this video-based education system operation will be helpful to broaden the area of elementary school cyber group consultation. Further, it is thought that it will contribute to the basic investigation to verify the educational effects of Multi-point imaging system in the run-up to the operation of full-scale real-time video-based education systems.

• Journal of Navigation and Port Research
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• v.38 no.4
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• pp.421-427
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• 2014

In order to protect coastal facilities mainly from wave and current actions, the self-locking eco blocks constituting elements of protecting shore structures against scouring were designed. These blocks are adapted to the sloping bottom, coastal dunes, and submerged coastal pipelines, counteracting the destructive and erosive impulse action. A series of laboratory experiments has been conducted to investigate the reflection of water waves over and against a train of protruded or submerged shore structures and compare the reflecting capabilities of incident waves including wave forces. In this study the hydraulic model experiment was conducted to identify the performance of newly designed water affinity eco blocks to keep the coast slope and bottom mound from scouring by reduction of the wave reflection and to convince stability of the block placement. Revised design of each block element was also tested for field conditions. From the result of experiments, the field applicability of the developed blocks and placement was discussed afterward.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2511-2520
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• 2018

In this study, Multi-Radial Basis Function Support Vector Machine (Multi-RBF SVM) classifier is introduced based on a composite kernel function. In the proposed multi-RBF support vector machine classifier, the input space is divided into several local subsets considered for extremely nonlinear classification tasks. Each local subset is expressed as nonlinear classification subspace and mapped into feature space by using kernel function. The composite kernel function employs the dual RBF structure. By capturing the nonlinear distribution knowledge of local subsets, the training data is mapped into higher feature space, then Multi-SVM classifier is realized by using the composite kernel function through optimization procedure similar to conventional SVM classifier. The original training data set is partitioned by using some unsupervised learning methods such as clustering methods. In this study, three types of clustering method are considered such as Affinity propagation (AP), Hard C-Mean (HCM) and Iterative Self-Organizing Data Analysis Technique Algorithm (ISODATA). Experimental results on benchmark machine learning datasets show that the proposed method improves the classification performance efficiently.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.477-482
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• 2011

The structural analysis of polytrimethylene terephthalate (PTT) and characterization of the hydrolytic degradation products after acid hydrolysis were performed using MALDI-TOF mass spectrometry. Mass spectra of the PTT samples were analyzed using a self-calibration method as well as an internal calibration method with standard materials of known masses. PTT structures constituting the samples were determined from the analyses of the spectra, and their relative compositions were estimated. The MALDI-TOF mass spectra of the acid-hydrolyzed PTT sample showed three main series of oligomer products with different end groups in accordance with the hydrolysis schemes. From the spectra of both $Na^+$ and $K^+$ adducts, it was concluded that the PTT samples have higher affinity for $Na^+$ compared with $K^+$ and therefore show higher ionization efficiency with sodium ions when dithranol is used as a matrix. Two different wavelength laser beams ($\lambda$ = 337 nm and 355 nm) were tested and it was observed that the 355 nm beam was more efficient in obtaining the MALDI spectra of PTT using dithranol as a matrix under our experimental conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.6
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• pp.1273-1293
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• 2010

Immune-inspired intrusion detection is a promising technology for network security, and well known for its diversity, adaptation, self-tolerance, etc. However, scalability and coverage are two major drawbacks of the immune-inspired intrusion detection systems (IIDSes). In this paper, we propose an IIDS framework, named GEP-IIDS, with improved basic system elements to address these two problems. First, an additional bio-inspired technique, gene expression programming (GEP), is introduced in detector (corresponding to detection rules) representation. In addition, inspired by the avidity model of immunology, new avidity/affinity functions taking the priority of attributes into account are given. Based on the above two improved elements, we also propose a novel immune algorithm that is capable of integrating two bio-inspired mechanisms (i.e., negative selection and positive selection) by using a balance factor. Finally, a pruning algorithm is given to reduce redundant detectors that consume footprint and detection time but do not contribute to improving performance. Our experimental results show the feasibility and effectiveness of our solution to handle the scalability and coverage problems of IIDS.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.279-279
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• 2010

Smart gels have recently associated with photonic crystals to form photonic gels. Since these photonic gels are capable of reversibly converting the volume change of gels induced in response to external chemical or electric stimuli into characteristic optical signals, they have been considered not only as a good platform for label-free chemical or biological detection, actuators or optical switches but also as a good model system to investigate gel swelling behaviour. Recently, we reported block copolymer photonic gels self-assembled from polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) block copolymers, and demonstrated that selective swelling of lamellar structure allows extremely large tunability of the photonic stop band from UV region to IR region ($\lambda$ peak=350~1,600 nm). Herein we report block copolymer photonic gels which exhibit strong tunable optical hysteresis and their applications. As nonlinear responses in swelling of hydrogels were often observed, photonic gels exhibit optical hysteresis with change of external pH. We demonstrate such optical hysteresis can be precisely programmed by controlling ion-pairing affinity. We anticipate that photonic gels with carefully tunned optical hysteresis are applicable to optical memory devices.

• Journal of Korean Society for Quality Management
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• v.47 no.2
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• pp.217-236
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• 2019

Purpose: This article aims 1) to identify key elements for building quality culture, 2) to design and analyze survey data from defense industry companies, and 3) to suggest directions for enhancing quality culture levels. Methods: Key elements and items for a quality culture are derived by investigating related references and using affinity diagram. Questionnaire items to investigate the quality culture level of the organizations are prepared and the survey data on the level of quality culture of military defense companies are analyzed. Results: 1) Descriptive statistical analyses are presented to compare the levels of the six key elements. 2) In each element items with low scores are identified, which should be improved. 3) Among six key elements, 'support 'element shows lowest level. 4) The quality culture level of the small-sized companies are relatively low. Conclusion: 1) To improve the quality culture level of the defense industry companies, it is necessary to provide quality education, to enhance recognition and rewards, and to invest resources for employees' self-development. 2) Small-sized companies can easily be adapted to quality-oriented cultural change if the CEO leadership focuses on quality culture.