• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2049-2056
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• 2011

The reinforced-roadbed materials composed of crushed stones are used for preventing vertical deformation and reducing impact load caused by highspeed train. Repeated load application can induce deformation in the reinforced-roadbed layer so that it causes irregularity of track. Thus it is important to understand characteristics of permanent deformation in the reinforced-subbase materials. The characteristics of permanent deformation can be simulated by prediction model that can be obtained by performing repetitive triaxial test. The prediction model of permanent deformation is a key-role in construction of design method of track. The prediction model of permanent deformation is represented in usual as the hyperbolic function with increase of number of load repetition. The prediction model is sensitive to many factors including stress level etc. so that it is important to define parameters of the model as clearly as possible. Various data obtained from repetitive triaxial test and resonant column test using the reinforced-roadbed of crushed stone are utilized to develop a new prediction model based on concept of shear-stress ratio and elastic modulus. The new prediction model of permanent deformation can be adapted for developing design method of track in the future.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.2
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• pp.27-34
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• 2011

Creative application of exaggerated measurements and origami principles can make clothing design unique and formative clothing design possible. There have been many techniques applied to formative clothing design, but, in particular, origami principles, in company with exaggerated measurements, play a significant role in enlightening clothing uniqueness and formativeness in contemporary fashion design. The primary purpose of this study was to make a new suggestion for the production of high value-added fashion by reviewing and synthesizing exaggerated measurements and origami principles. Diverse relevant designs were retrieved through a comprehensive literature review on topic-related theses, books, and fashion media from 2000 and significant cases were retrieved from Rick Owens, Damir Doma & Haider Ackermann out of 2008 & 2009 F/W collections. From a comprehensive review, the following formative characteristics of exaggerated measurements and origami principles applied to clothing design were identified: (1) expandability, (2) fluidity, (3) deconstruction, and (4) irregularity. In addition, the following value of exaggerated measurements and origami principles applied to clothing design were identified: (1) alterability, (2) form potentiality, and (3) contradistinctive formativeness.

• Journal of Navigation and Port Research
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• v.35 no.9
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• pp.701-706
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• 2011

Radio waves including GPS signals, various TV communications, and radio broadcasting can be disturbed by a strong solar storm, which may occur due to solar flares and produce an ionospheric delay anomaly in the ionosphere according to the change of total electron content. Electron density irregularities can cause deep signal fading, frequently known as ionospheric scintillation, which can result in the positioning error using GPS signal. This paper proposes a detection algorithm for the ionosphere delay anomaly during a solar storm by using multi-reference stations. Different TEC grid which has irregular electron density was applied above one reference station. Then the ionospheric delay in zenith direction applied different TEC will show comparatively large ionospheric zenith delay due to the electron irregularity. The ionospheric slant delay applied an elevation angle at reference station was analyzed to detect the ionospheric delay anomaly that can result in positioning error. A simulation test was implemented and a proposed detection algorithm using data logged by four reference stations was applied to detect the ionospheric delay anomaly compared to a criterion.

• Journal of Korean Academy of Nursing
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• v.32 no.2
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• pp.196-205
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• 2002

The purposes of this study was to evaluate an occupational health promotion program for the prevention of cardiovascular disease. Method: This study employed a quasi-experimental non-equivalent pre and post test to evaluate the program. The subjects of this study were 48 employees selected by convenience sampling who were suspected of having hypertension and hyperlipidemia in routine physical examinations and who were working in A University Hospital in Suwon. 25 subjects were assigned to the experimental group and 23 to the control group. Data collection was done using questionnaries before and after the subjects used the program. Results: The results of this study showed that systolic blood pressure, ALT, γ-GTP in the experimental group was lower than that of the control group. There were significant differences between two groups in the percentage of 'irregularity of diet' and in health behavior compliance. There were significant differences between the two groups in the number of complaints of symptoms after using the program. Conclusion: This study shows that there were no obvious differences between the two groups in all areas, but this program had a positive effect on health behavior changes. It is expected that employees' lifestyles can be changed through continuous health promotion programs.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.183-195
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• 1990

The purposes of present study were to identify possible relationships between post-treatment changes and post-retention changes. The patient's models were composed of 58 samples, and were classified non-extraction group (30 samples) and extraction group (28 samples). For each sample the first models were taken prior to the start of treatment, the second models just after the end of treatment, and the third models two years after. The results were as follows: 1. In the cases of non-extraction group, increases were in intermolar width of maxilla, interbicuspid width of maxilla and arch perimeter of mandible during treatment period, but decreases were in the same measurements during post-retention period. 2. In the cases of extraction group, decreases were in intermolar width of mandible, interbicuspid widths of maxilla and mandible, arch length of mandible, arch perimeters of maxilla and mandible during treatment period. 3. Significant decreases were in the irregularity index of both extraction and non-extraction group during treatment period. 4. There were significant differences of arch dimensional changes in intermolar widths of maxilla and mandible, interbicuspid widths of maxilla and mandible, arch lengths of maxilla and mandible, arch perimeters of maxilla and mandible between non-extraction and extraction group.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1534-1538
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• 2011

Uniform, hollow nanosilica spheres were prepared by the chemical coating of cationic polystyrene (cPS) with tetraethylorthosilicate (TEOS), followed by calcination at 600 $^{\circ}C$ under air. cPS was synthesized by surfactant-free emulsion polymerization using 2,2'-azobis (2-methyl propionamidine) dihydrochloride as the cationic initiator, and poly(vinyl pyrrolidone) as a stabilizer. The resulting cPS spheres were 280 nm in diameter, and showed monodispersion. After coating, the hollow silica product was spherically shaped, and 330 nm in diameter, with a narrow distribution of sizes. Dispersion was uniform. Wall thickness was 25 nm, and surface area was 96.4 $m^2/g$, as determined by BET. The uniformity of the wall thickness was strongly dependent upon the cPS surface charge. The effects of TEOS and ammonia concentrations on shape, size, wall thickness, and surface roughness of hollow $SiO_2$ spheres were investigated. We observed that the wall thicknesses of hollow $SiO_2$ spheres increased and that silica size was simultaneously enhanced with increases in TEOS concentrations. When ammonia concentrations were increased, the irregularity of rough surfaces and aggregation of spherical particles were more severe because higher concentrations of ammonia result in faster hydrolysis and condensation of TEOS. These changes caused the silica to grow faster, resulting in hollow $SiO_2$ spheres with irregular, rough surfaces.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.3
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• pp.294-301
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• 2004

This study was conducted to investigate the quality assessment of performance of the university foodservice. Self administered questionnaires were collected from 305 students living in Incheon. Statistical data analysis was completed using a SPSS v. 10.0 program. The results were summarized as follows: 61.4% of male students and 48.1% of female students responded to have lunch regularly. Only 23.4% of male students and 14.1% of female students used the university foodservice daily. Reasons for the irregularity of lunch were responded as “lecture”, “eating when I want” and “appointment with friends”, etc. The quantity, temperature, nutritional value, appearance, hygiene, taste and freshness of foods and price of menus were evaluated as appropriate but using seasonal foods, number of side-dishes, etc. as unsatisfactory. Service speed, cloth hygiene, neatness and kindness of employee were evaluated as appropriate. For the facilities of foodservice, counter location, menu board and lighting facilities were evaluated as appropriate but heating facilities, disposition of tables and chairs of dining hall were as unsatisfactory. Sanitation of floors and walls of dining hall, restroom and utensils, etc. was evaluated as low.

• Earthquakes and Structures
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• v.12 no.3
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• pp.271-284
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• 2017

This paper presents a multimodal adaptive nonlinear static method of analysis that, differently from the nonlinear static methods suggested in seismic codes, does not require the definition of the equivalent Single-Degree-Of-Freedom (SDOF) system to evaluate the seismic response of structures. First, the proposed method is formulated for the assessment of r.c. plane frames and then it is extended to 3D framed structures. Furthermore, the proposed nonlinear static approach is re-elaborated as a displacement-based design method that does not require the use of the behaviour factor and takes into account explicitly the plastic deformation capacity of the structure. Numerical applications to r.c. plane frames and to a 3D framed structure with inplan irregularity are carried out to illustrate the attractive features as well as the limitations of the proposed method. Furthermore, the numerical applications evidence the uncertainty about the suitability of the displacement demand prediction obtained by the nonlinear static methods commonly adopted.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.359.1-359.1
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• 2016

The electromagnetic (EM) properties of media, such as propagation, focusing and scattering, strongly rely on the electric permittivity and the magnetic permeability of media. Recently, artificially-created metamaterials (MMs) composed of periodically-arranged unit cells with tailored electric permittivity and magnetic permeability have drawn wide interest due to their capability of adjusting the EM response. MM absorbers using the conventional sandwich structures usually have very high absorption at a certain frequency, and the absorption properties of MMs can be adjusted simply by changing the geometrical parameters of unit cell. In this work, we suggested an incident-angle-independent broadband perfect absorber based on resistive layers. We analyze the absorption mechanism based on the impedance matching with the free space and the distribution of surface currents at specific frequencies. From the simulation, the absorption was expected to be higher than 96% in 1.4-6.0 GHz. The corresponding experimental absorption was found to be higher than 96% in 1.4-4.0 GHz, and the absorption turned out to be slightly lower than 96% in 4.0-6.0 GHz owing to the irregularity in the thickness of resistive layers.

• Earthquakes and Structures
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• v.8 no.2
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• pp.379-399
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• 2015

Existing building structures can easily present material mechanical properties which can largely vary even within a single structure. The current European Technical Code, Eurocode 8, does not provide specific instructions to account for high variability in mechanical properties. As a consequence of the high strength variability, at the occurrence of seismic events, the structure may evidence unexpected phenomena, like torsional effects, with larger experienced deformations and, in turn, with reduced seismic performance. This work is focused on the torsional effects related to the irregular stiffness and strength distribution due to the concrete strength variability. The analysis has been performed on a case-study, i.e., a 3D RC framed 4 storey building. A Normal distribution, compatible to a large available database, has been taken to represent the concrete strength domain. Different plan layouts, representative of realistic stiffness distributions, have been considered, and a statistical analysis has been performed on the induced torsional effects. The obtained results have been compared to the standard analysis as provided by Eurocode 8 for existing buildings, showing that the Eurocode 8 provisions, despite not allowing explicitly for material strength variability, are conservative as regards the estimation of structural demand.