• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.4
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• pp.357-365
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• 2009

A general analysis of a microstrip-to-vertically mounted slotline(VMS) coupler is presented with a view to developing an equivalent circuit, and the efficient evaluation of the related circuit element values. Based on this theory, the effects of frequency and structure parameters such as aperture length and VMS width on the characteristics of the coupler are studied. In order to check the validity of the proposed analysis and design theory, a C-band linearly tapered slot antenna fed by an aperture-coupled back-to-back microstripline-to- VMS coupling structure is optimally designed using a hybrid genetic algorithm. Moreover, the computed characteristics from the network analysis is compared to the measurement and simulation results. The obtained results fully validate the efficiency and accuracy of the proposed network model.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.261-267
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• 2011

The test fit has commonly used for the evaluation of the railbed condition, and indirect methods by using the compressional wave are also studied. the direct evaluation method by penetration test has not been studied. For the measurement of in-situ cone tip resistance of the railbed with minimizing the disturbance of the upper railbed. the cone penetrometer with the helical type outer rod(CPH) was developed. The outer rod, which has helical screw, is penetrated through the gravel layer and provides the reaction force for cone penetration testing. the cone tip resistances are measured by the mini cone penetrometer, where diameter is 15mm. For the developing the mini cone, strain gauge installation, circuit configuration, penetration rates and calibration process are considered. For the easy penetration of the screw rod in the field, the reaction force stepping plate and guide column are arranged. The screw rod are penetrated through the gravel layer. And the mini cone was pushed into the subgrade railbed at the penetration rate of 1mm/sec. The penetration test shows that the cone tip resistance increases along the depth. In addition, the subgrade condition is evaluated. This study demonstrates that the CPH may be effectively used for the evaluation of subgrade method any damage of the gravel layer.

• Smart Structures and Systems
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• v.8 no.3
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• pp.303-320
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• 2011

Comparing to active damage monitoring, impact localization on composite by using time reversal focusing method has several difficulties. First, the transfer function of the actuator-sensor path is difficult to be obtained because of the limitation that no impact experiment is permitted to perform on the real structure and the difficulty to model it because the performance of real aircraft composite is much more complicated comparing to metal structure. Second, the position of impact is unknown and can not be controlled as the excitation signal used in the active monitoring. This makes it not applicable to compare the difference between the excitation and the focused signal. Another difficulty is that impact signal is frequency broadband, giving rise to the difficulty to process virtual synthesis because of the highly dispersion nature of frequency broadband Lamb wave in plate-like structure. Aiming at developing a practical method for on-line localization of impact on aircraft composite structure which can take advantage of time reversal focusing and does not rely on the transfer function, a PZT sensor array based phase synthesis time reversal impact imaging method is proposed. The complex Shannon wavelet transform is presented to extract the frequency narrow-band signals from the impact responded signals of PZT sensors. A phase synthesis process of the frequency narrow-band signals is implemented to search the time reversal focusing position on the structure which represents the impact position. Evaluation experiments on a carbon fiber composite structure show that the proposed method realizes the impact imaging and localization with an error less than 1.5 cm. Discussion of the influence of velocity errors and measurement noise is also given in detail.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.1029-1033
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• 2013

Elliptical gear is used as a rotor of oval flowmeter. The elliptical gear can assist water flow-rate measurement by the space of the elliptical shape. Presently, elliptical gears have been processed using hob tool imported from Japan. But if it were not for the technical cooperation with Japan company, the Elliptical gears can't be processed. The purpose of this study is developing a domestic technology for elliptical gears and overcoming the dependence of foreign technical skills. It will bring the import substitution effect. In case of pressure angle $20^{\circ}$, the elliptical gears have an interference of tooth. The increase of pressure angle makes the root of a tooth thick and the top of tooth thin. By results of this study, tooth of elliptical gear was designed and verified through the 2D and 3D simulation.

• Journal of Preventive Medicine and Public Health
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• v.47 no.1
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• pp.7-17
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• 2014

Risk assessment considers the situations and characteristics of the exposure environment and host. Various physiological variables of the human body reflects the characteristics of the population that can directly influence risk exposure. Therefore, identification of exposure factors based on the Korean population is required for appropriate risk assessment. It is expected that a handbook about general exposure factors will be used by professionals in many fields as well as the risk assessors of the health department. The process of developing the exposure factors handbook for the Korean population will be introduced in this article, with a specific focus on the general exposure factors including life expectancy, body weight, surface area, inhalation rates, amount of water intake, and soil ingestion targeting the Korean population. The researchers used national databases including the Life Table and the 2005 Time Use Survey from the National Statistical Office. The anthropometric study of size in Korea used the resources provided by the Korean Agency for Technology and Standards. In addition, direct measurement and questionnaire surveys of representative samples were performed to calculate the inhalation rate, drinking water intake, and soil ingestion.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.31-43
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• 2012

Domestic road type-and period-specific driving pattern measurement was required as Korea's participation in developing "Worldwide harmonized light-duty vehicle emission test procedure (WLTP/DHC)" studied by UN WP29. This study measured road driving data reflecting road and traffic conditions of Korea, and analyzed seven types of representative road type-and period-specific driving patterns with driving pattern standardization methodology proposed by WP29. PAMS (Portable Activity Monitoring Systems) equipment was used to collect enormous (35,410km) road driving data. There are significant difference among seven derived driving patterns.

• Polymer(Korea)
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• v.36 no.6
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• pp.756-760
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• 2012

In this work, the coal tar pitch-based activated carbons (ACs) were prepared by KOH activation for electrode materials of supercapacitor. The effects of activation temperature on electrochemical performance of the ACs were investigated with cyclic voltammogram (CV) measurement. The textural and morphological properties of the ACs were measured by adsorption isotherms and field emission scanning electron microscope (FE-SEM) analyses, respectively. The experimental results indicated that the specific capacitance of the ACs increased with developing the micropore volume by activation temperature. As a result the specific capacitance of the ACs increased, owing to the development of micro pore volume of the ACs.

• Fashion & Textile Research Journal
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• v.14 no.5
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• pp.834-845
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• 2012

This study was conducted to provide basic information on developing highschool-uniform pants with more suitable fit and to suggest a sizing system for highschool girls' uniform pants that adequately reflects their body figures. To understand the features of high school girls' lower body type, the body measurement values of 833 girls from 16~18 years of age based on Size Korea(2010) were analyzed statistically. For the classification of lower body type for high school girls, a factor analysis and cluster analysis were conducted. The collected data were processed with the programs SPSS 18.0 for windows. The results in this study are follows: The lower body types for high school girls were divided into 3 groups. Body Type A is average stature but the biggest circumference, Type B is the biggest stature and the medium body type, Type C is the smallest stature and skeleton structure. KS size intervals were used for frequency distribution of height and waist for the lower body. Sizing system of the uniform company and frequency distribution of sizes were compared. Using the two-way distribution of highschool girls' waist circumference and hip circumference, sizing system considering body type distribution and high frequency distribution section of sizes was suggested. This study established new sizing system depending on lower body fixed as 26 number of sizes. The most suitable standard is fixed as 12 number of sizes ; 64-88, 64-91, 67-88, 67-91, 67-94, 70-91, 70-94, 70-97, 73-94, 73-97, 76-97, 76-100. The coverage is also calculated. And the coverage of new standard was 63.5%. The continuous study on the uniform pants sizing system of the obesity types is required.

• Journal of Korean Academy of Nursing
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• v.36 no.4
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• pp.637-644
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• 2006

Purpose. The purpose of this study was to construct a measurement instrument for climacteric symptoms among Korean and Japanese women. Methods. From Dec. $1^{st}$ of 2003 to March $30^{th}$ of 2004, in-depth interviews were made with 26 women (15 in Jinju, Korea and 11 in Nagasaki, Japan) aged from 45 to 59 years who had not taken hormone replacement therapy to relieve the climacteric symptoms. A draft questionnaire with 45 items was constructed on the basis of the interview data and literature review. Three obstetricians, three PhDs in nursing science, and a chief nurse who was exclusively in charge of the climacteric management, examined the draft questionnaire to evaluate content validity. After deletions 39 items remained for a preliminary questionnaire. A survey was conducted by using a convenient sampling method in Jinju of Korea and Nagasaki of Japan during the period from April $1^{st}$, 2004 to July $10^{th}$, 2005. Results. Factor analysis identified 4 factors, which were 'mental and psychological symptoms', 'physical symptoms', 'loss of autonomic nervous system symptoms', 'sexual symptoms'. These four factors explained 46.9% of total variance. Conclusions. The results demonstrated that climacteric symptom scale was multidimensional, and the reliability and validity of the scale was supported.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.2
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• pp.107-119
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• 2018

The slope monitoring systems which have been operating at home and abroad were investigated and then the real-time monitoring management system for evacuating inhabitants based on Web-EOC(Emergency Operating Center) was constructed. We tried to analyze realistically and precisely the situation by changing from the existing field-centered management to sensor-centered management that measures coordinates and provides in real-time data of measuring/monitoring sensors installed at a field site and developing related viewer programs. In addition, the 3D based monitoring management system, which has alarm functions in case of emergency and provides information about the evacuation place, was constructed on the base that is able to expand to nationwide fields by using Vworld 3D map. Ten steep slope monitoring sites were registered on Web-EOC slope monitoring management system constructed in the research and then application instances were suggested.