• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.703-709
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• 2023

This study was conducted to investigate the association between hyperuricemia and the risk of hypertension in Korean adult women using data from the 2019 Korea National Health and Nutrition Examination Survey (KNHANES) 8th wave. Study subjects were 2,693 and descriptive analysis was used to investigate the general characteristics of the subjects. The effects of hyperuricemia on the risk of hypertension were evaluated using binomial logistic regression and it was shown that the risk of hypertension in the hyperuricemia group was higher than in the normal group (OR:1.94, p<.001), after adjusting socioeconomic factors (OR:1.81, p=.001) and even after additional adjustment for health behavioral factors, the risk of hypertension was high (OR:1.54, p=.019). Therefore, in order to prevent hypertension in adult women, it is necessary to develop programs and policies to effectively manage their uric acid levels.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.6
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• pp.145-155
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• 2023

A radial combiner with high efficiency characteristics in the X-band was designed and manufactured using a waveguide and matching structure. In particular, in order to manufacture it in a small size, a dual waveguide to coaxial transition structure was applied that allows two ports to be matched to one waveguide. Applying this structure makes it possible to manufacture smaller than typical coaxial to waveguide radial combiner. As a result of measurement in the X-band band of 9.2~10GHz, the return loss was less than -18.408dB and the output insertion loss was less than 0.206dB, and the output combining efficiency was obtained as high as 95.37% or more. It is expected that it can be used in the combining part for high output transmitters in the millimeter wave band in the future. In particular, the range of use is expected to increase by reducing the size and weight.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1049-1056
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• 2023

The height of the atmospheric boundary layer indicates the peak developed when turbulence is generated by mixing heat and water vapor, and is generally determined through thermodynamic methods. Wind profilers produce atmospheric information from the scattering of signals sent into the atmosphere. A method for making the spectrum of turbulent components, turbulent kinetic energy dissipation rate, and refractive index structure coefficient was presented to determine the atmospheric boundary layer depth. Compared with the vertical distribution characteristics of potential temperature and specific humidity based on radiosonde data, the determination method of the atmospheric boundary layer height from wind profiler output was evaluated as very useful.

• Economic and Environmental Geology
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• v.57 no.1
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• pp.17-23
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• 2024

Ground penetrating radar (GPR) survey is a geophysical method that utilizes electromagnetic waves reflecting from a boundary where the electromagnetic property changes. As the frequency of the antenna is about 25 MHz ~ 1 GHz, it is effective to acquire high resolution images of underground pipe, artificial structure, underground cavity, and underground structure. In this study, we analyzed the change of signals reflected from the same underground objects according to the arrangement of transceiver antennas used in ground penetrating radar survey. The antenna used in the experiment was 200 MHz, and the survey was performed in the vertical direction across the sewer and the parallel direction along the sewer to the sewer buried under the road, respectively. A total of five antenna array methods were applied to the survey. The most used arrangement is when the transmitting and receiving antennas are all perpendicular to the survey line (PR-BD). The PR-BD arrangement is effective when the object underground is a horizontal reflector with an angle of less than 30°, such as the sewer under investigation. In this case study, it was confirmed that the transmitter and receiver antennas perpendicular to the survey line (PR-BD) are the most effective way to show the underground structure. In addition, in the case where the transmitting and receiving antennas are orthogonal to each other (XPOL), no specific reflected wave was observed in both experiments measured across or parallel to the sewer. Therefore, in the case of detecting undiscovered objects in the underground, the PR-BD array method in which the transmitting and receiving antennas are aligned in the direction perpendicular to the survey line taken as a reference and the XPOL method in which the transmitting and receiving antennas are orthogonal to each other are all used, it can be effective to apply both of the above arrangements after setting the direction to 45° and 135°.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.374-381
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• 2024

This paper delves into the application of the short-wave infrared (SWIR) region, with a focus on the synthesis and optical characteristics of silver sulfide (Ag₂S) nanostructures. SWIR offers advantages such as reduced damage to biological tissues and enhanced optical transparency, making it valuable across various domains. The study introduces three distinct synthesis methods, each showcasing the ability to obtain nanostructures with improved optical properties. These research findings open up the possibility of providing tailored solutions in detection, imaging, and other applications by controlling the size and ligands of Ag₂S nanoparticles. This paper provides new insights into the utilization of Ag₂S in the SWIR region, which is expected to foster advancements in future technologies.

• Geomechanics and Engineering
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• v.36 no.5
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• pp.465-474
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• 2024

Uniaxial compressive strength (UCS) is a critical geomechanical parameter that plays a significant role in the evaluation of rocks. The practice of indirectly estimating said characteristics is widespread due to the challenges associated with obtaining high-quality core samples. The primary aim of this study is to investigate the feasibility of utilizing the gene expression programming (GEP) technique for the purpose of forecasting the UCS for various rock categories, including Schist, Granite, Claystone, Travertine, Sandstone, Slate, Limestone, Marl, and Dolomite, which were sourced from a wide range of quarry sites. The present study utilized a total of 170 datasets, comprising Schmidt hammer (SH), porosity (n), point load index (Is(50)), and P-wave velocity (Vp), as the effective parameters in the model to determine their impact on the UCS. The UCS parameter was computed through the utilization of the GEP model, resulting in the generation of an equation. Subsequently, the efficacy of the GEP model and the resultant equation were assessed using various statistical evaluation metrics to determine their predictive capabilities. The outcomes indicate the prospective capacity of the GEP model and the resultant equation in forecasting the unconfined compressive strength (UCS). The significance of this study lies in its ability to enable geotechnical engineers to make estimations of the UCS of rocks, without the requirement of conducting expensive and time-consuming experimental tests. In particular, a user-friendly program was developed based on the GEP model to enable rapid and very accurate calculation of rock's UCS, doing away with the necessity for costly and time-consuming laboratory experiments.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.3
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• pp.311-318
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• 2024

In this paper, a design for a radio frequency(RF) and infrared(IR) absorber with metasurfaces is discussed in microwave frequency bands. The RF absorber includes double layers of metasurfaces to operate in S- and X-bands. Effects of sheet resistance of the metasurfaces and thicknesses of dielectric supporting layers on reflection responses are investigated. An IR stealth layer incorporates an array of conductive grids with slits to reflect IR signals but to transmit RF signals and visible rays. Periodicity of the grids and slits is studied for transmission responses in the X-band and a surface area ratio. Reflection responses of the RF/IR multispectral absorber are found to be lower than -10 dB and -16 dB in the S- and X-bands, respectively, from full-wave simulation. Finally, the RF/IR multispectral absorber is fabricated and its reflection responses are measured to verify designed performance.

• Journal of the Korean Regional Science Association
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• v.35 no.3
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• pp.45-58
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• 2019

The government is recently pushing for five large-scale public housing sites near Seoul, the so-called third wave of new towns. In this regard, this study sought to analyze the key considerations in planning new towns from the perspective of the residents who are the consumers, using survey data. For this purpose, frequency analysis and variance analysis(ANOVA) were conducted on existing first and second era of new towns and the third era of new towns scheduled for construction. Eight indicators, such as environmental comfort, self-sufficiency such as jobs, transportation access and convenience, were set as subordinate variables, and characteristics of residents, including gender, age, number of households, household income, occupation, and residential areas, were set as explanatory variables. According to the analysis, the respondents rated the first era of new towns more positively than the second era of new towns. For self-sufficiency items such as jobs, both the first and second era of new towns showed low levels. In addition, for the eight indicators, the first era of new towns were no significant differences depending on gender, number of households, or household income, and the second era of new towns were no significant differences by the number of households, household income, occupations or place of residence. However, for new towns in the third period, the assessment of the importance of each indicator by age, number of households, household income and occupation showed significant differences. The results of the multi-comparison analysis of the third era of new towns showed that the importance of environmental comfort was highly valued by the youth, the managerial/professional/clerical position, single or five more persons of household, and the youth, high income household, the managerial/professional/clerical position when it comes to accessibility and convenience of transportation. It suggests that various personal characteristics and demands for each of the planning indicators need to be considered in planning for the third era of new towns.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.58-63
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• 2005

Objectives: REM sleep behavior disorder (RBD), characterized by excessive motor activity during REM sleep, is associated with loss of muscle atonia. In recent years, it has been reported that RBD has high co-morbidity with CNS disorders (especially, Parkinson's disease, dementia, multiple system atrophy, etc.). We aimed to assess differences in clinical and polysomnographic findings among RBD patients, depending on the presence or absence of central nervous system (CNS) disorders. Methods: The medical records and polysomnographic data of 81 patients who had been diagnosed as having RBD were reviewed. The patients were classified into two groups: associated RBD (aRBD, i.e., with a clinical history and/or brain MRI evidence of CNS disorder) and idiopathic RBD (iRBD, i.e., without a clinical history and/or brain MRI evidence of CNS disorder) groups. Twenty-one patients (25.9%) belonged to the aRBD group and 60 patients (74.1%) belonged to the iRBD group. The clinical characteristics and polysomnographic findings of the two groups were compared. Results: Periodic limb movement disorder (PLMD), i.e., PLMI (periodic limb movement index)>5, was observed more frequently in the aRBD group than in the iRBD group (p<0.001, Fisher's exact test). Also, obstructive sleep apnea syndrome (OSAS), i.e., RDI (respiratory disturbance index)>5, was found more frequently in the aRBD group (p=0.0042, Fisher's exact test). The percentages for slow wave sleep and sleep efficiency were significantly lower in the aRBD group than in the iRBD group. Conclusion: We found that 1 out of 4 RBD patients had associated CNS disorders, warranting more careful neurological evaluation and follow-up in this category of RBD. In this category of RBD patients, we also found more frequent PLMD and OSAS. These patients were also found to have lower slow wave sleep and sleep efficiency. In summary, RBD patients with associated CNS disorders suffer from more disturbed sleep than those without them.

• Journal of the Korean Society of Costume
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• v.58 no.3
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• pp.63-78
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• 2008

Since 1960, minimalism has been one of the fashion phenomenon and turned out in many different ways. After postmodernism which contains negotiation and pluralism, appeared in 1980, there was a new wave of post minimalism that inherited 1960's minimalism. Minimal style which come out of 60's fashion, is marked by simplicity, minimal expression, and monochrome color, and it shows up simple style with no decoration. It opened up a young fashion period, and we saw minimal style in sports wear which utilized simplicity and function with spread of sports in the 70's. And also since 1980, Post-Modern widely influenced the idea about modern culture as well as complicated clothes getting rid of fixed concept, seeking to break the boundary between culture and life which were seek in fashion and personality as well as various characteristic, Accordingly in different ages, The style and image were borrowed from different culture and natural environment mixing the image, cultural phenomena like these appearing in complexity and expression, variety and possibility of new vision was expanded. Since 1980, Fashion has become more gradually diversity, high classed, required of each individuality. The phenomenon of fashion reappearance which was influenced by minimalism is continued to 2000. The Oriental style fashion is still attracted, so The new term "Ethic Minimalism" has appeared along with the trends which is put together. Therefore the purpose of this study is to search the concept and the characteristics of ethnic minimalism, to consider the relationship between minimalism and ethnic minimalism, and reveal the characteristic of ethnic minimalism happened to modern fashion. The study method went through literature research and practice research. The range of this study is oriental fashion spanning of from 1960 to current day. Photo records from this period show well the spirit of the oriental and the personality of minimalism. The oriental representative designer and western representative designer are centered Consequently, The formative characteristics of ethnic minimalism are simple, pure, unbalanced free style and representing the phenomena of compromise, blending oriental and western fashion. Structually, Elements of space and plane are emphasized, colors are restricted, and materials are composed mainly of natural fiber. So, minimalism based on simplicity combined with a structure of oriental spiritual depth and space, It could be called ethnic minimalism as a rational fashion.