• Journal of the Optical Society of Korea
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• v.18 no.3
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• pp.274-282
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• 2014

In this study, closely spaced Au nanoparticles which are arranged in nanocluster (heptamer) configurations have been employed to design efficient plasmonic subwavelength devices to function at the telecommunication spectrum (${\lambda}$~1550 nm). Utilizing two kinds of nanoparticles, the optical properties of heptamer clusters composed of Au rod and shell particles that are oriented in triphenylene molecular fashion have been investigated numerically, and the cross-sectional profiles of the scattering and absorption of the optical power have been calculated based on a finite-difference time-domain (FDTD) method. Plasmon hybridization theory has been utilized as a theoretical approach to characterize the features and properties of the adjacent and mutual heptamer clusters. Using these given nanostructures, we designed a complex four-branch ($1{\times}4$) Y-shape splitter that is able to work at the near infrared region (NIR). This splitter divides and transmits the magnetic plasmon mode along the mutual heptamers arrays. Besides, as an important and crucial parameter, we studied the impact of arm spacing (offset distance) on the guiding and dividing of the magnetic plasmon resonance propagation and by calculating the ratio of transported power in both nanorod and nanoshell-based structures. Finally, we have presented the optimal structure, that is the four-branch Y-splitter based on shell heptamers which yields the power ratio of 23.9% at each branch, 4.4 ${\mu}m$ decaying length, and 1450 nm offset distance. These results pave the way toward the use of nanoparticles clusters in molecular fashions in designing various efficient devices that are able to be efficient at NIR.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.338-343
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• 2009

Tomography is the imaging method of cross sectional area using multi beam signals and is mainly applied to the medical diagnosis to acquire the image of the inside human body. This method is pretty meaningful in nondestructive evaluation field since the imaging of the inspection region can enhance the comprehension of the inspector. Recently, much attention has been paid to the guided wave for the diagnosis of platelike structures. So, in this work, a study on the imaging of the damage location in a plate was carried out on the basis of computer aided analysis of guided waves and tomographic imaging. To this end, boundary element method was employed to analyze the effect of the damage in plate on the propagation of the guided waves and the analytic results were applied to the tomographic imaging method to identify the damage location. Consequently, it was shown that the number of sensors heavily affect the inspection performance of the damage location.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.156-162
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• 2008

The static aeroelastic analysis of composite hingeless rotor blades in hover was performed using free-wake method. Large deflection beam theory was applied to analyze blade motions as a one-dimension beam. Anisotropic beam theory was applied to perform a cross-sectional analysis for composite rotor blades. Aerodynamic loads were calculated through a three-dimensional aerodynamic model which is based on the unsteady vortex lattice method. The wake geometry in hover was described using a time-marching free-wake method. Numerical results of the steady-state deflections for the composite hingeless rotor blades were presented and compared with those results based on two-dimensional quasi-steady strip theory and prescribed wake method. It was shown that wakes affect the steady-state deflections.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.141-144
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• 1997

Femoral neck anteversion is the angle between the neck and the knee axis projected on a plane perpendicular to the longitudinal axis. Conventional methods that use cross-sectional Computed Tomography(CT) images to estimate femoral anteversion have several problems because of the complex 3D structure of the femur. These are the ambiguity of defining the longitudinal axis, the femoral neck axis and condylar line, and the dependence on patient positioning. Especially the femoral neck axis that is known as a major source of error is hard to determine from a single or multiple 2D transverse images. So we developed a new method for measuring femoral anteversion by 3D modeling method. In this method, femoral head is modeled as a sphere. The center of femoral neck is the mid-point of the 2D reconstructed oblique image in the femoral neck part. Then neck axis is a line connecting foregoing two centers. We model the longitude of femur as a cylinder, and the long axis is defined from the fitted cylinder. The knee axis which is tangent to the back of the femoral condyles is easily determined by table-top method. By the definition of femoral anteversion, the femoral anteversion is easily calculated from this model.

• Computational Structural Engineering
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• v.8 no.4
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• pp.75-85
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• 1995

The purpose of the present study is to develop a computer program which can be used to analyze prestressed concrete structures containing either bonded or unbonded tendons. To accomplish this, first, the concrete, nonprestressed, and prestressed steels are modeled with cyclic constitutive laws to take into account the various loading effects. Then, the hybrid-type element method is derived to improve the computations capability of stresses and strains, especially for the unbonded tendon. Since it allows one to determine the cross-sectional deformations in an element without any assumptions for its deformed shape, the element length can be much longer than that of the conventional finite element method. In order to achieve such a long element, various integral schemes are examined to implement them into the program. Then, the computational method for prestressing effects is developed consistently with the analytical method for the structure. Finally, analytical studies for actual tests were carried out to verify the program developed in this study.

• Journal of Korean Association for Spatial Structures
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• v.10 no.4
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• pp.49-57
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• 2010

This study is the research appling the representative Displacement-Based Design which is the basic concept of Direct Displacement Based Design proposed by Chopra and Goel to original Reinforced Concrete structure and determining the thickness of retrofit Steel Jacket about the Maximum design ground acceleration, and developing the more improved Algorithm as well as program by the Retrofit Design method and Nonlinear analysis by the Performance design method before and after reinforcement appling the determined retrofit thickness. To predict the target displacement of retrofitted columns, a nonlinear analysis model of reinforced concrete columns has been developed to be based on the nonlinear fiber cross-sectional and segmental analysis model, and the seismic displacement level of retrofitted columns is estimated by two procedures, the direct displacement-based design method and the displacement coefficient method. In examples of seismic retrofit design, the current seismic improved design method gives good results in improvements of displacement levels and displacement ductilities of retrofitted columns.

• Journal of Korea Water Resources Association
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• v.38 no.1
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• pp.37-48
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• 2005

The evaluation methods of river naturalness were reviewed, and one of the best methods was applied to three sample rivers-Narinchun, Bokhachun, Anyangchun. As a result, Narinchun with well preserved state, Bokhachun with being to restoration stage from the damaged, Anyangchun with severe damaged state showed 2$^{nd}$ , 3$^{rd}$ and 4$^{th}$ Grade. The application result shows the method is reliable for evaluating the damaged habitat in river. The method was improved on the evaluation items to apply lager river systems. This suggested method have 14 evaluation items with two category-river shape and river environment and five different Grades for evaluation degree according to state of natural closeness. The every 2,000-3,000m along the river system is recommended as the interval of evaluation unit. According to calssification of evaluation items, this method can supply various information related to river environment and ecology such as ecological deformation and diversity, cross sectional structure and continuity of river shapes..

• Physical Therapy Rehabilitation Science
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• v.13 no.1
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• pp.113-123
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• 2024

Objective: The study analyzed the awareness of physical therapists regarding correct breathing methods and the effect of breathing training on patients. Design: A cross-sectional survey study. Methods: Physical therapists who agreed to participate in the study, held a license as a physical therapist, and had training or experience in breathing were included as subjects. A total of 136 questionnaires were collected, out of which 129 were analyzed. The questionnaire consisted of 26 items, divided into several sections covering awareness of breathing methods, breathing and muscles, breathing and mind, breathing and movement, perception of mouth breathing and nose breathing, experience applying respiration as a treatment, perception of breathing and treatment, awareness of breathing and pain, awareness of breathing and chronic diseases and prevention, perceptions related to breathing and sleep, and educational background. Results: The study found that most therapists were aware of diaphragmatic breathing, but not Lamaze breathing. 76.7% claimed to that there is a correct breathing method, and the majority were aware of the reasons for correct breathing. The majority believed in the therapeutic effect of breathing, with core exercise breathing training being the most commonly used in therapy. 81.7% of therapists had taught a specific breathing method to a patient, and diaphragmatic breathing was the most provided treatment. There was no significant difference in perception according to clinical experience, but there was a significant difference in perception according to educational background. Conclusions: The study provided clinical background on Physical Therapists' belief on correct breathing method, and uses of breathing training during treatment. The results suggest there is a need for a coherent education on breathing method and techniques among Physical Therapists.

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.87-96
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• 2002

The physico-chemical properties of fresh milt of marbled sole, Limanda yokohamae, brown sole, Limanda herzensteini, starry flounder, Platichthys stellatus and olive flounder, Paralichthys olivaceus among flatfishes, and the fine structure of their cryopresserved spermatozoa were investigated. The highest concentration of sperm among these four species was $3.60\pm1.35\times10^{10}/mL$ in marbled sole. Osmolality and pH of seminal plasma in four flatfish species were approximately 330 mOsm/kg and 7.6-8.1, respectively. Seminal plasma compositions showed interspecific differences. The sperm heads of marbled sole, brown sole and starry flounder were ellipsoidal and that of olive flounder was round. The numbers of mitochondria of these four species were eight in marbled sole, seven in brown sole and starry flounder, and six in olive flounder. Cross-sectional view of flagellum showed typical 9+ 2 structure in all species. Most of sperms cryopreserved with a proper method had no visible ultrastructural changes after freeze-thawing, compared with the fresh sperm, but in a few cases, swelling of their heads and midpiece regions were observed.

• Women's Health Nursing
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• v.15 no.1
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• pp.64-72
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• 2009

Purpose: The purposes of this study were to identify Korean primary school students' knowledge of menstruation, their emotional reaction to menarche, the attitude toward menstruation and coping behaviors. Method: A cross-sectional survey design was employed in this study. The subjects were 200 female students who were recruited from 5th and 6th grade in five primary schools in J city, Korea. Data was collected by a structured questionnaire. Result: About forty-four percent of the subjects had experiences with menarche. The mean age of menarche was 12.4. The mean score of the students' knowledge of menstruation was 2.26 on a seven point scale. The mean scores of the emotional reaction to menarche and the attitude toward menstruation were 3.20 and 3.74 on a five point scale, respectively. Knowledge of menstruation was significantly related with a positive emotional reaction to menarche and a positive attitude toward menstruation. Also, there were significant differences in the knowledge of menstruation, the emotional reaction to menarche and attitude of menstruation among female students with positive coping behaviors and those without positive coping behaviors. Conclusion: Beyond the simple transference of knowledge, girls need to also be given mental and emotional support in order to minimize emotional and socio-psychological problems caused by early menarche.