• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.447-451
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• 2007

A triplexer based on a silica planar lightwave circuit Mach-Zehnder nterferometer(MZI) is proposed and its characteristics are analyzed through simulations. To separate 1310 nm band and $1480{\sim}1560nm$ band properly, the path length difference of an MZI is set to be the multiple and half of the wavelength 1310 nm and the balance of the directional coupler is optimized in the $1480{\sim}1560nm$ band. The same MZI is additionally cascaded to provide good crosstalk characteristics. The 1490 nm band and 1550 nm band are further separated using additional two stage MZI's. A three-dimensional BPM and transfer matrix method analysis predicts the low crosstalk characteristics and the fabrication-error-tolerance of the proposed triplexer.

• Journal of KIISE
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• v.43 no.9
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• pp.1008-1014
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• 2016

Data such as Twitter, Facebook, and customer reviews belong to the informal document group, whereas, newspapers that have grammar correction step belong to the formal document group. Finding consistent rules or patterns in informal documents is difficult, as compared to formal documents. Hence, there is a need for additional approaches to improve informal document analysis. In this study, we classified Twitter data, a representative informal document, into ten categories. To improve performance, we revised and expanded features based on LDA(Latent Dirichlet allocation) word distribution. Using LDA top-ranked words, the other words were separated or bundled, and the feature set was thus expanded repeatedly. Finally, we conducted document classification with the expanded features. Experimental results indicated that the proposed method improved the micro-averaged F1-score of 7.11%p, as compared to the results before the feature expansion step.

• Molecules and Cells
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• v.24 no.2
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• pp.255-260
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• 2007

Bone marrow (BM) derived mesenchymal stem cells (MSC) are pluripotent cells which can differentiate into osteogenic, adipogenic and other lineages. In spite of the broad interest, the information about the changes in BM cell composition, in particularly about the variation of MSC number and their properties in relation to the age of the donor is still controversial. The aim of this study was to investigate the age associated changes in variations of BM cell composition, phenotype and differentiation capacities of MSC using a rat model. Cell populations were characterized by flow cytometry using light scattering parameters, DNA content and a set of monoclonal antibodies. Single cell analysis was performed by conventional fluorescent microscopy. In vitro culture of MSC was established and their phenotype and capability for in vitro differentiation into osteogenic and adipogenic cells was shown. Age related changes in tibiae and femurs, amount of BM tissue, BM cell composition, proportions of separated MSC and yield of MSC in 2 weeks of in vitro culture were found. At the same time, neither change in phenotype no in differentiation capacities of MSC was registered. Age-related changes of the number of MSC should be taken into account whenever MSC are intended to be used for investigations.

• Herbal Formula Science
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• v.22 no.2
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• pp.1-13
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• 2014

Objectives : ShangHanLun is a clinical guideline, and its core is in the part of Six-meridian Diseases. In recent philological sutdies, independent textual analysis of Shanghanlun is essential to define the scope of research. Methods : By the textual study, I defined the Shanghanlun clinic model. And I researched about medical range of Shanghanlun, and relations between Shanghanlun and JinGuiYaoLue, and between Shanghanlun and Huangdineijing. Results : In six topic sentences, the word '-之爲' means 'a process'. In provisions following topic sentences, the word '者' means 'a person'. So Shanghanlun is describing processing factors of Six-meridian Diseases and related human changes with clinical therapy. In the philological studies, meaning of '傷寒' was possibly just the 3rd provision of the greater yang disease part. Practically Shanghanlun's study range is over the concept of Cold damage today. Additionally Jinguiyaolue deals diseases, but Shanghanlun deals human. Gangpyeong-Shanghanlun's phrases can be separated into five part, and oldest part is independent of Huangdineijing. Conclusions : So we need to set a new and independent clinic model of Shanghanlun to verify it. The Shanghanlun's clinic model has a 3 steps. 1st step is to find 6 type defined symptoms, which act as processing factors of Six-meridian Diseases. 2nd step is to confirm a human changes after a Disease appeared. 3rd step is to treat a patient as a provision suggests. Philologically Shanghanlun's clinic range is not limited by the word '傷寒'. And many concepts in Shanghanlun should be independent of Huangdineijing.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.230-236
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• 2011

The aim of this study was to investigate the alteration of lumbar spine and trunk postures on different load-carrying types and amounts under static loading. Two load-carrying types(unilateral carrying: UC vs. bilateral carrying: BC) and four different loads(0, 5, 10, and 15 kg) were randomly tested in this study. Carrying a heavy bag would affect human body posture, specifically lumbar spine curvature, which is considered as one of sources of back problems. Previous studies have not paid attention to the approach of the multisegment model of the lumbar spine and trunk. This study separated two compartments of trunk segment(the lumbar and thorax) in the analysis. The multisegment model of the lumbar spine in addition to Helen-Hayes marker set was used. Eight motion analysis cameras and a force plate were utilized. Ten male subjects(mean mass, $70.6{\pm}3.97$ kg; mean height, $178{\pm}4.18$ m) having no musculoskeletal disease participated in this study. We analyzed trunk angles in three anatomical planes and the spinal curvature in sagittal and frontal planes. Increased loading in both UC and BC significantly resulted in increases in trunk forward lean but only UC induced increases in trunk lateral lean. In addition, increased loading in BC produced flatten lumbar curvature in sagittal plane. As far as coupling motion, subjects tended to use axial rotation of the lumbar spine in transverse plane in response to increased UC loading. Finally, it is concluded that the increased static loading in UC rather than in BC tends to causes combined alterations of the spinal postures(sagittal and transverse planes together), which would be vulnerable to improper mechanical stresses on the spine.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.2
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• pp.11-22
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• 2004

Conventional algorithms of separating overlapped objects are mostly based on template matching methods and thus their application domain is restricted to 2D objects and the processing time increases when the number of templates (object models) does. To solve these problems, this paper proposes a new approach of separating the occluding object from the stack of 3D objects using the relationship between surfaces without any information on the objects. The proposed algorithm considers an object as a combination of surfaces which are consisted with a set of boundary edges. Overlap of 3D objects appears as overlap of surfaces and thus as crossings of edges in 2D image. Based on this observation, the types of edge crossings are classified from which the types of overlap of 3D objects can be identified. The relationships between surfaces are represented by an attributed graph where the types of overlaps are represented by relation values. Using the relation values, the surfaces pertained to the same object are discerned and the overlapping object on the top of the stack can be separated. The performance of the proposed algorithm has been proved by the experiments using the overlapped images of 3D objects selected among the standard industrial parts.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1284-1290
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• 2004

In market-basket analysis, weighted association rule(WAR) discovery can mine the rules which include more beneficial information by reflecting item importance for special products. However, when items are divided into more than one group and item importance for each group must be measured by different measurement or separately, we cannot directly apply traditional weighted association rule discovery. To solve this problem, we propose a novel methodology to discovery the weighted association rule in this paper In this methodology, the items should be first divided into sub-groups according to the properties of the items, and the item importance is defined or calculated only with the items enclosed to the sub-group. Our algorithm makes qualitative evaluation for network risk assessment possible by generating risk rule set for risk factor using network sorority data, and quantitative evaluation possible by calculating risk value using statistical factors such as weight applied in rule generation. And, It can be widely used for new model of more delicate analysis in market-basket database in which the data items are distinctly separated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.125-130
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• 2018

Linear discriminant analysis is a statistical analysis method that is generally used for dimensionality reduction of the feature vectors or for class classification. However, in the case of a data set that cannot be linearly separated, it is possible to make a linear separation by mapping a feature vector into a higher dimensional space using a nonlinear function. This method is called generalized discriminant analysis or kernel discriminant analysis. In this paper, we carried out target classification experiments with active sonar target signals available on the Internet using both liner discriminant and generalized discriminant analysis methods. Experimental results are analyzed and compared with discussions. For 104 test data, LDA method has shown correct recognition rate of 73.08%, however, GDA method achieved 95.19% that is also better than the conventional MLP or kernel-based SVM.

• Convergence Security Journal
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• v.11 no.3
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• pp.91-98
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• 2011

Medical information system based on ad hoc network designed for general information systems and information networks have different security requirements. Malicious code infiltration and security features are performed on same medical information network architecture along the route. Security domain of medical information systems is the ground of penetration and defense performed over the network architecture and it is also the traffic handling areas separated by a concept of differentiated group. Ad hoc-based medical information systems in the network security domain, set some standards about what should be the methodology of this study. In this paper, medical information system network configuration, the determining factor based on the security domain, the structure selection criteria and blocking positionings are presented according to the traffic route configuration. If you apply this methodology designed to increase security, efficiency can be possible. Health information systems in accordance with the security domain areas requires differentiated protection needs of the security mechanism that is proposed by this study.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.2
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• pp.75-85
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• 2016

A pyrotechnic system consisting of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor charges. Despite of its common use, numerical study of such pyrotechnic train configuration is seldom reported because proper modeling of the full process requires precise capturing of the shock wave attenuation in the gap prior to triggering a full detonation of high explosive and accurate description of the high strain rate dynamics of the explosively loaded inert confinements. We apply a Eulerian level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized RDX as acceptor charge. The complex shock interaction, critical gap thickness, acoustic impedance, and go/no-go characteristics of the gap test are quantitatively investigated.