• Smart Structures and Systems
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• v.15 no.2
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• pp.489-503
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• 2015

Response estimation at unmeasured locations using the limited number of measurements is an attractive topic in the field of structural health monitoring (SHM). Because of increasing complexity and size of civil engineering structures, measuring all structural responses from the entire body is intractable for the SHM purpose; the response estimation can be an effective and practical alternative. This paper investigates a response estimation technique based on the Kalman state estimator to combine multi-sensor data under non-zero mean input excitations. The Kalman state estimator, constructed based on the finite element (FE) model of a structure, can efficiently fuse different types of data of acceleration, strain, and tilt responses, minimizing the intrinsic measurement noise. This study focuses on the effects of (a) FE model error and (b) combinations of multi-sensor data on the estimation accuracy in the case of non-zero mean input excitations. The FE model error is purposefully introduced for more realistic performance evaluation of the response estimation using the Kalman state estimator. In addition, four types of measurement combinations are explored in the response estimation: strain only, acceleration only, acceleration and strain, and acceleration and tilt. The performance of the response estimation approach is verified by numerical and experimental tests on a simply-supported beam, showing that it can successfully estimate strain responses at unmeasured locations with the highest performance in the combination of acceleration and tilt.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.97-105
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• 2016

As information system is getting higher and amount of information assets is increasing, skills of threatening subjects are more advanced, so that it threatens precious information assets of ours. The purpose of this study is to present a strategic direction for the types of companies seeking access to information security. The framework classifies companies into eight types so company can receive help in making decisions for the development of information security strategy depending on the type of company it belongs to. Paired comparison method survey conducted by a group of information security experts to determine the priority and the relative importance of information security management elements. The factors used in the security response strategy are the combination of the information security international certification standard ISO 27001, domestic information protection management system certification K-ISMS, and personal information security management system certification PIMS. Paired comparison method was then used to determine strategy alternative priorities for each type. Paired comparisons were conducted to select the most applicable factors among the 12 strategic factors. Paired comparison method questionnaire was conducted through e-mail and direct questionnaire survey of 18 experts who were engaged in security related tasks such as security control, architect, security consulting. This study is based on the idea that it is important not to use a consistent approach for effective implementation of information security but to change security strategy alternatives according to the type of company. The results of this study are expected to help the decision makers to produce results that will serve as the basis for companies seeking access to information security first or companies seeking to establish new information security strategies.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.1-7
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• 2016

Structural MRI(sMRI) imaging is used to extract morphometric features after Grey Matter (GM), White Matter (WM) for several univariate and multivariate method, and Cerebro-spinal Fluid (CSF) segmentation. A new approach is applied for the diagnosis of very mild to mild AD. We propose the classification method of Alzheimer disease patients from normal controls by combining morphometric features and Gaussian Mixture Models parameters along with MMSE (Mini Mental State Examination) score. The combined features are fed into Multi-kernel SVM classifier after getting rid of curse of dimensionality using principal component analysis. The experimenral results of the proposed diagnosis method yield up to 96% stratification accuracy with Multi-kernel SVM along with high sensitivity and specificity above 90%.

• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.171-177
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• 2018

In 3D printing technologies, many parameters should be optimized for obtaining a part with higher quality. FDM (fused deposition modeling) printer has also diverse parameters to be optimized. Among them, it can be said that nozzle temperature and moving speed of nozzle are fundamental parameters. Thus, it should be preceded to know the optimal combination of the two parameters in the use of FDM 3D printer. In this paper, a new method is proposed to estimate the range of the stable combinations of the two parameters, based on the single line quality. The proposed method was verified by comparing the results between single line printing and multi-layered single line printing. Based on the comparison, it can be said that the proposed method is very meaningful in that it has a simple test approach and can be easily implemented. In addition, it is very helpful to provide the basic data for the optimization of process parameters.

• The korean journal of orthodontics
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• v.50 no.6
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• pp.383-390
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• 2020

Objective: To investigate the distribution, side involvement, phenotype, and associated anomalies of Korean patients with craniofacial clefts (CFC). Methods: The samples consisted of 38 CFC patients, who were treated at Seoul National University Dental Hospital during 1998-2018. The Tessier cleft type, sex, side involvement, phenotype, and associated anomalies were investigated using non-parametric statistical analysis. Results: The three most common types were #7 cleft, followed by #0 cleft and #14 cleft. There was no difference between the frequency of male and female. Patients with #0 cleft exhibited nasal deformity, bony defect, and missing teeth in the premaxilla, midline cleft lip, and eye problems. A patient with #3 cleft (unilateral type) exhibited bilateral cleft lip and alveolus. All patients with #4 cleft were the bilateral type, including a combination of #3 and #4 clefts, and had multiple missing teeth. A patient with #5 cleft (unilateral type) had a posterior openbite. In patients with #7 cleft, the unilateral type was more prevalent than the bilateral type (87.0% vs. 13.0%, p < 0.001). Sixteen patients showed hemifacial microsomia (HFM), Goldenhar syndrome, and unilateral cleft lip and palate (UCLP). There was a significant match in the side involvement of #7 cleft and HFM (87.5%, p < 0.01). Patients with #14 cleft had plagiocephaly, UCLP, or hyperterorbitism. A patient with #30 cleft exhibited tongue tie and missing tooth. Conclusions: Due to the diverse associated craniofacial anomalies in patients with CFC, a multidisciplinary approach involving a well-experienced cooperative team is mandatory for these patients.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.6
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• pp.323-341
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• 2019

Background: Local anesthetics alone or in combination with adjuncts, such as oral medications, have routinely been used for pain control during endodontic treatment. The best clinical choice amongst the vast numbers of agents and techniques available for pain control for irreversible pulpitis is unclear. This network meta-analysis combined the available evidence on agents and techniques for pulpal anesthesia in the maxilla and mandible, in order to identify the best amongst these approaches statistically, as a basis for future clinical trials. Methods: Randomized trials in MEDLINE, DARE, and COCHRANE databases were screened based on inclusion criteria and data were extracted. Heterogeneity was assessed and odds ratios were used to estimate effects. Inconsistencies between direct and indirect pooled estimates were evaluated by H-statistics. The Grading of Recommendation, Assessment, Development, and Evaluation working group approach was used to assess evidence quality. Results: Sixty-two studies (nine studies in the maxilla and 53 studies in the mandible) were included in the meta-analysis. Increased mandibular pulpal anesthesia success was observed on premedication with aceclofenac + paracetamol or supplemental 4% articaine buccal infiltration or ibuprofen+paracetamol premedication, all the above mentioned with 2% lignocaine inferior alveolar nerve block (IANB). No significant difference was noted for any of the agents investigated in terms of the success rate of maxillary pulpal anesthesia. Conclusion: Direct and indirect comparisons indicated that some combinations of IANB with premedication and/or supplemental infiltration had a greater chance of producing successful mandibular pulpal anesthesia. No ideal technique for maxillary anesthesia emerged. Randomized clinical trials with increased sample size may be needed to provide more conclusive data. Our findings suggest that further high-quality studies are required in order to provide definitive direction to clinicians regarding the best agents and techniques to use for mandibular and maxillary anesthesia for irreversible pulpitis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.4
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• pp.427-435
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• 2008

In this paper, a stable marching-on in time(MOT) method with a time domain combined field integral equation(CFIE) is presented to obtain the transient scattering response from arbitrarily shaped three-dimensional conducting bodies. This formulation is based on a linear combination of the time domain electric field integral equation(EFIE) with the magnetic field integral equation(MFIE). The time derivatives in the EFIE and MFIE are approximated using a central finite difference scheme and other terms are averaged over time. This time domain CFIE approach produces results that are accurate and stable when solving for transient scattering responses from conducting objects. Numerical results with the proposed MOT scheme are presented and compared with those obtained from the conventional method and the inverse discrete Fourier transform(IDFT) of the frequency domain CFIE solution.

• Korean Journal of Construction Engineering and Management
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• v.4 no.2 s.14
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• pp.99-108
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• 2003

Recently, the construction companies are forced to cut down the investment amount due to increasing financial problems caused by severe recession and restructuring in the financial market as well as the long-term depression of the construction industry. To overcome this type of problems, a great many efforts have been made. An alternative may be adopting the advanced financing methods. However, during the course of enforcing process of the financing methods, many problems are revealed without any proper solutions being proposed. Therefore, the fundamental problems need to be solved through comprehensive and systematic approach under the changing environment of construction financing. In this paper, as a result of reviewing some financing methods such as ABS, REITS, and Project Financing, multiple business strategies for construction companies to cope with the changing construction market are found in the sense of effectiveness in implementing construction projects. Further, this paper presents diversified financing methods for the effective practice of construction projects through combination of above mentioned methods, and also proposes improvement plans to strengthen the financing function for the construction industry.

• Fashion & Textile Research Journal
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• v.14 no.6
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• pp.889-897
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• 2012

This study suggests a direction for stage-costume design by making stage costumes based on amusement, eclecticism, and the masquerade, which are the criteria for approaching stage costume designs according to characteristics of the mask theatre presented by P. G. Bogatyryov. The conclusions of this study are as follows. First, criteria to approach stage costume design for mask theatre can be classified into amusement, eclecticism, and masquerade according to the characteristics of the mask theatre presented by P. G. Bogatyryov. Second, the stage costume of a mongrel dog showed amusement through the expression of the image of therianthropy through the combination of a fur-lined vest and wristlet, Korean traditional trousers with the paw-prints of a dog. Third, eclecticism contains diverse characteristics and escapes from being singularly defined due to the fusion of severally different heterogeneous objects. The stage costume differently used a method of wearing clothing in a different period, of choosing clothing materials, and of expressing color in every character to indicate ambiguity to which the drama points through the integration of various expression elements. Fourth, the masquerade present characters (Taembang, Daejang, and Changseok)who simultaneously play the role of fairies after having changed into a white mask and having worn Korean a traditional overcoat (Durumagi) on the original clothes; the, result is the change of the theatrical structure into another time and space inside the theatrical scene of imagination through a concealment of the original clothing.

• Journal of Korean Society of Disaster and Security
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• v.5 no.1
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• pp.7-12
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• 2012

This study analyzed appropriate equipment combination for emergency recovery after flood disasters and proposed an alternative approach for economic and rapid emergency recovery based on the utilization of human resources who have practical experience in construction business and in equipment operation. The current countermeasures and response to flood disaster including emergency procedures and methodologies are investigated and related legal framework was also analyzed. Currently, some emergency recovery works are over payed and delayed due to unclear and inefficient processes on equipment and human resources mobilization during and after flood disasters, particularly in local governments. Best practices in mobilizing equipment and human resources were compiled, theoretical foundation was investigated and analyzed, and improved emergency recovery schemes were proposed for effective flood disaster countermeasures in local government. Prioritization in equipment and human resources mobilization was also proposed considering equipment transportation distance and accessability to disaster sites. This study also proposed improved ways to utilize experts in local areas in supporting community emergency response volunteers for disaster risk management.