• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.55.5-56
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• 2016

Turbulence plays an important role in molecular clouds. However, the properties of turbulence are poorly understood. In order to study the influence of turbulence in molecular clouds, we need to sample the turbulent properties in the full range of scales down to sonic scale. We mapped the $20^{\prime}{\times}60^{\prime}$ area covering the Orion Molecular Cloud (OMC) 1-4 region in HCN 1-0 and HCO+ 1-0 with Taeduk Radio Astronomy Observatory (TRAO) 14-m telescope as part of the TRAO key science program, "Mapping turbulent properties of star-forming molecular clouds down to the sonic scale (PI: Jeong-Eun Lee)". In addition, we combine our TRAO data with other molecular line maps ($^{13}CO$ 1-0, $C^{18}O$ 1-0, CS 1-0, $N_2H^+$ 1-0) obtained with the Nobeyama Radio Observatory (NRO) 45-m telescope. To analyze these data, we apply statistical methods, the principal component analysis (PCA) and spectral correlation function (SCF), which are known to be useful to study underlying turbulent properties and to quantitatively characterize cloud structure. We will present the preliminary results of observations and analyses.

• Journal of Acupuncture Research
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• v.24 no.4
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• pp.81-97
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• 2007

Objective: The purpose of this study was to observe the effects of Cnidii Rhizoma herbal-acupuncture solution(CR-HAS) at Joksamni($ST_{36}$) on arthritis induced by Collagen II in mice. Methods : The author performed several experimental items. The severity of arthritis, changes of mouse weight, size of the spleen and the degree of stenosis, changes of cytokine level, IgG, IgM and anti-collagen II, changes of immunocyte count, histological changes of the CIA mouse joint were analyzed. Results: 1. In the CR-HA, the arthritis index, the incidence of arthritis, the degree of joint edema was significantly decreased. 2. In the CR-HA, weight, spleen size and stenosis rate was low and maintained as the normal group was. 3. In the CR-HA, cytokine level, IgG, IgM and anti-collagen II were significantly decreased. 4. In the CR-HA, on changes of immunocyte count were maintained to the levels of normal group. 5. In histological changes of the CIA mouse joint, the cartilage destruction and synovial cell proliferation were decreased. Conclusions : These results suggest that CR-HA at the $ST_{36}$ has an important role to control the immune reactions and suppress inflammatory response on the collagen induced rheumatoid arthritis. This study can be a significant supporting evidence that CR-HA will be chosen to be the principal therapy for clinical practice of the rheumatoid arthritis in the future.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.79.3-80
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• 2017

Molecular clouds are the sites of stellar birth. Turbulence is a natural phenomenon in molecular clouds, which largely determines the density and velocity fields. Additionally turbulent energy dissipation can affect the gas kinetic temperature via shocks. Turbulence thus controls the mode and tempo of star formation. However, despite its important role in star formation, the properties of turbulence remain poorly understood. As part of the Taeduk Radio Astronomy Observatory (TRAO) Key Science Program (KSP), "Mapping turbulent properties of star-forming molecular clouds down to the sonic scale (PI: Jeong-Eun Lee)", we have been mapping two star-forming clouds, the Orion A and the ${\rho}$ Ophiuchus molecular clouds in 3 sets of lines (13CO 1-0/C18O 1-0, HCN 1-0/HCO+ 1-0, and CS 2-1/N2H+ 1-0) using the TRAO 14-m telescope. We apply a Principal Component Analysis (PCA), which is an useful tool to represent turbulent power spectrum. We will present the preliminary results of our TRAO KSP toward two regions: OMC 1-4 in the Orion A cloud, and L1688 in the ${\rho}$ Ophiuchus cloud.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2636-2646
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• 2002

This research presents an analytical model to investigate vibration due to ball bearing waviness in a rotating system supported by two or more ball bearings, taking account of the centrifugal force and gyroscopic moment of the ball. The waviness of rolling elements is modeled by the sinusoidal function, and it is incorporated into the position vectors of the race curvature center. The Hertzian con tact theory is applied to calculate the elastic deflection and nonlinear contact force while the rotor has translational and angular motions. Both the centrifugal force and gyroscopic moment of the ball and the waviness of the rolling elements are included in the kinematic constraints and force equilibrium equations of a ball to derive the nonlinear governing equations of the rotor, which are solved by using the Runge-Kutta-Fehlberg algorithm to determine the new position of the rotor. The proposed model is validated by the comparison of the results of the prior researchers. This research shows that the centrifugal force and gyroscopic moment of the ball plays the important role in determining the bearing frequencies, i.e. the principal frequencies, their harmonics and the sideband frequencies resulting from the waviness of the rolling elements of ball bearing. It also shows that the bearing vibration frequencies are generated by the waviness interaction not only between the rolling elements of one ball bearing but also between those of two or more ball bearings constrained by the rotor.

• Journal for History of Mathematics
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• v.21 no.3
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• pp.31-52
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• 2008

The concept of infinity, as with other scientific concepts, has a history of evolution. In the present work we intend to discuss the subject matter with regard to Bolzano since he is considered to be the first to accept the idea of actual infinity not just from a metaphysical perspective but from a mathematical one. Like modem platonists, Bolzano defended the infinite set itself regardless of the construction process; this is based on the principal of comprehension and unicity of denotation regarding all concepts. In addition, instead of considering as paradoxical the fact that a one-to-one correspondence existed between an infinite set and its parts, he regarded it in a positive way as a special characteristic. While the Greek era recognized the existence of only one infinity, Balzano acknowledged the existence of various types of infinity and formulated a logical definition for it. The question of infinity is a touchstone of constructive method which holds an increasingly important role in mathematics. The present study stops with just a brief reference to the subject matter and we will leave further in-depth investigation for later.

• Journal of Microbiology
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• v.44 no.4
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• pp.409-416
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• 2006

Clarithromycin resistance in Helicobacter pylori is a principal cause of failure of eradication therapies, and its prevalence varies geographically. The IceA gene is a virulence factor associated with clinical outcomes. The objective of this study was to determine the current state of clarithromycin resistance prevalence, and to investigate the role of iceA genotypes in 87 Turkish adult patients (65 with functional dyspepsia and 22 with duodenal ulcer). A2143G and A2144G point mutations were tested by PCR-RFLP for clarithromycin resistance. Among the patients in the study, 28 patients were tested by agar dilution as well. Allelic variants of the iceA gene were identified by PCR. A total of 24 (27.6%) strains evidenced one of the mutations, either A2143G or A2144G. IceA1 was found to be positive in 28 of the strains (32.2 %), iceA2 was positive in 12 (13.8 %) and, both iceA1 and iceA2 were positive in 22 (25.3 %) strains. In conclusion, we discovered no relationships between iceA genotypes and functional dyspepsia or duodenal ulcer, nor between clarithromycin resistance and iceA genotypes. clarithromycin resistance appears to be more prevalent in Turkish patients.

• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.246-262
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• 2007

The performance of projects has always been an area of interest in the construction industry. Roles of all construction supply chain partners are necessary; however the role of a contractor firm in the construction project is pivotal. So, this research intended to explore a Construction Firm's performance criteria which could measure the level of performance of that firm in an ongoing project. Data was collected from construction professionals working in three principal project participant organizations, namely Owner, Consultant and Contractor. A total of 113 nos. of performance measuring items were sorted from literature review and used to collect data. Statistical tools processed by SPSS program was employed to analyze the data. Out of total 113 items, only 65 nos. of variables were found to be acceptable to every population group of this study. Factor analysis revealed 12 key performance predicting factors (KPPF) with 53 predictive indicators. 12 KPPFS with index weight are: work progress and smoothening (9.3%), change order management and work accuracy (9.1%), business relationship building (8.1%), adequacy of construction work procedure (8.6%), quality performance (8.0%), health and site safety adequacy (8.8%), Innovative contractor (8.0%), adequacy of construction site information (6.8%), compliance with contract plan/specification requirements (8.9%), creditworthiness and financial capability (8.3%), intra-agency relationship and responsiveness (7.0%) and resource management (9.2%). These results could be useful to project management body to evaluate performance of its contractor firm on site as well as the contractor itself to assess own performance and its subcontractors on-site.

• Structural Engineering and Mechanics
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• v.35 no.6
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• pp.677-697
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• 2010

This paper focuses on geometrically non-linear static analysis of a simply supported beam made of hyperelastic material subjected to a non-follower transversal uniformly distributed load. As it is known, the line of action of follower forces is affected by the deformation of the elastic system on which they act and therefore such forces are non-conservative. The material of the beam is assumed as isotropic and hyperelastic. Two types of simply supported beams are considered which have the following boundary conditions: 1) There is a pin at left end and a roller at right end of the beam (pinned-rolled beam). 2) Both ends of the beam are supported by pins (pinned-pinned beam). In this study, finite element model of the beam is constructed by using total Lagrangian finite element model of two dimensional continuum for a twelve-node quadratic element. The considered highly non-linear problem is solved by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. In order to use the solution procedures of Newton-Raphson type, there is need to linearized equilibrium equations, which can be achieved through the linearization of the principle of virtual work in its continuum form. In the study, the effect of the large deflections and rotations on the displacements and the normal stress and the shear stress distributions through the thickness of the beam is investigated in detail. It is known that in the failure analysis, the most important quantities are the principal normal stresses and the maximum shear stress. Therefore these stresses are investigated in detail. The convergence studies are performed for various numbers of finite elements. The effects of the geometric non-linearity and pinned-pinned and pinned-rolled support conditions on the displacements and on the stresses are investigated. By using a twelve-node quadratic element, the free boundary conditions are satisfied and very good stress diagrams are obtained. Also, some of the results of the total Lagrangian finite element model of two dimensional continuum for a twelve-node quadratic element are compared with the results of SAP2000 packet program. Numerical results show that geometrical nonlinearity plays very important role in the static responses of the beam.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.4
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• pp.3-12
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• 2009

In recent years, the development of ubiquitous computing environment, according to the time, place, regardless of the environment changes dynamically based on providing a service. In particular, ubiquitous computing environment, education support services in the fields of education according to the principal of each member is required to provide personalized information. Therefore, this paper describes the education support system which provide adaptive information to member of education. The structure of the proposed system consists of mobile agents multi-agent system platform, JADE (Java Agent DEvelopment framework) is based. Also, we describes the design of agents for application services and the interaction model. In this paper, the performance of proposed system to verify availability, classroom teachers, students and parents and administrators as a service application based on the user's role to provide appropriate information system was implemented. Finally, we shows the result of user interface GUIs according to adaptive education services.

• Korean Journal of Biological Psychiatry
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• v.26 no.2
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• pp.71-78
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• 2019

Objectives Suicide is a complex phenomenon not only caused by the individual's mental illness and economic situation, but also occurred in sociocultural contexts and relationships around the individual. Therefore, the attitudes, which include collective norms, thoughts and feelings of a population, toward suicide play a fundamental role in the prevention of suicide. Factor structure of Attitudes Toward Suicide (ATTS), developed by Renberg, is also various in different sociocultural contexts. This is the first study to investigate factor structure of ATTS along with nationwide sample of Korean adults. Methods This study analyzed the factor structure and reliability of ATTS in 1500 regionally stratified Korean adults. Exploratory factor analysis was performed by using principal axis factoring and varimax rotation. Results The selection of 33 ATTS items based on internal consistency and communality was conducted. Five factors were analyzed, which were named 'Good reason,' 'Negative gaze,' 'Predictability,' 'Means of escape,' and 'Common secret,' respectively. Explained total variance was 41.94%, and the internal consistency ranged from 0.516 to 0.740. Conclusions Each of the five factors contains different semantic dimensions. Consistent with previous studies, factors containing permissive attitude toward suicide was high in those with history of suicidal thought and of suicide attempt. It is notable that the 'Good reason' showed higher score in elderly. This may be related to socioeconomic or physical adversities which have been considered the major cause of suicide in elderly.