• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.208-217
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• 2010

This paper presents a novel 10 GHz bio-radar system based on a frequency multiplier and phase-locked loop(PLL) for non-contact measurement of heartbeat and respiration rates. In this paper, a 2.5 GHz voltage controlled oscillator (VCO) with PLL is employed to as a frequency synthesizer, and 10 GHz continuous wave(CW) signal is generated by using frequency multiplier from 2.5 GHz signal. This paper also presents the noise characteristic of the proposed system. As a result, a better performance and economical frequency synthesizer can be achieved with the proposed bio-radar system. The experimental results shows excellent bio-signal measurement up to 100 cm without any additional digital signal processing(DSP), and the proposed system is validated.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.207-214
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• 2003

This study was carried out to establish a novel bioassay system for screening of compounds affecting aromatic amino acid or anthocyanin biosynthesis through investigating a degree of sucrose-induced anthocyanin formation such as size of plant material, buffer conditions, light intensity and irradiated duration, incubation temp., etc were determined and standard procedure (suitable experimental condition) was set up as follows. The second leaf blade of white corn seeding induced by fluridone treatment were segmented into a size of 5${\times}$5 min. The segments were floated on the solution of 1% sucrose in 1.0mM MES buffer (pH6.0∼6.5) and incubated at 26$^{\circ}C$ for 2days under the continuous light condition(70∼100$\mu$mol m$^{-2}$ s$^{-1}$ ). Anthocyanin in the purpled tissues was extracted with methanol containing 1% HCl and the optical density of the clear supematants was determined at 528mm. Influences of some chemicals were tested using this system. Glyphosate, 5-enolpyruvylshikimate 3-phosphate synthase inhibitor, showed most sensitive response with I$_{50}$ value at 3.3$\mu$M. Dicyclohexylcarbodiimide(DCCD) and parachloromercuribenzenesulfonic acid(PCMBS) had a relatively strong ingibition with I50 value at 7.1$\mu$M and 10.2$\mu$M, respectively. These results show that sucrose-induced anthocyanin formation in white com leaf segment provide a very simple and rapid system for searching new compounds affecting aromatic amino acid or anteocyanin biosynthesis by screening at less than 10$\mu$M.

• Progress in Superconductivity and Cryogenics
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• v.5 no.3
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• pp.57-61
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• 2003

In this investigation, the 6.6kV/200A Inductive Superconducting Fault Current Limiter (SFCL) was designed and fabricated. The type of DC reactor for Inductive SFCL was determined as solenoid type during the period of $1${st}$ year research. The 5 bobbins for DC reactor were fabricated and each bobbin was wound with 4 stacked High-Tc superconducting (HTS) tapes and the 5 bobbins were connected in series. The critical current and inductance of DC reactor were simulated by Finite Element method (FEM) and compared with the measured results. The characteristics of DC reactor were enhanced in sub-cooled nitrogen system rather than in liquid nitrogen system. The procedures to accomplish the sub-cooled nitrogen system and the experimental results were introduced in detail. Moreover, the design of sub-cooled nitrogen cryogenic system for next year research was introduced in brief.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.651-663
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• 2011

The purpose of this study was to provide basic data and information for the improvement of school foodservice and efficient management of cooks by surveying the working conditions and the job satisfaction of cooks at schools located in Chungbuk province. The questionnaires of 311 cooks were available for this study. 26.3% of respondents worked at elementary schools, 34.2% of respondents worked at middle schools, and 39.5% of respondents worked at high schools. 72.3% of them were in their forties, 24.4% worked during five to seven years, and 63.0% had qualification certificates. Their job satisfaction was examined from ten dimensions. Respondents were not satisfied with the wage system and working environment which scored 2 points out of 5 points(not satisfied). They gave 1 point out of 5 points to the promotion dimension(not satisfied at all) while organizational committment area received relatively high points. The overall job satisfaction level was 3.06 points. The evaluation of the factors that made their job unsatisfactory were evaluated and the bonus system, treatment system and the wage system were 3.80 points, 3.69 points, and 3.62 points, respectively. In order to improve the job satisfaction of school foodservice employees, a change of the wage system and welfare system are needed.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.574-581
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• 2014

This paper presents the design and evaluation of the optical zoom system for an LWIR camera. The 12.8operating wavelength range of this system is from $7.7{\mu}m$ to $12.8{\mu}m$. Through a paraxial design and optimization process, we have obtained the extended four-group inner-focus zoom system with focal lengths of 10 to 100 mm, which consists of the six lenses including four aspheric surfaces and two diffractive surfaces. The diffractive lenses were used to balance the higher-order aberrations, and its diffraction properties were evaluated by scalar diffraction theory. We have calculated the polychromatic integrated diffraction efficiency and the MTF drop generated by background noise. The f-number of the zoom system is F/1.4 at all positions. Fields of view are given by $51.28^{\circ}{\times}38.46^{\circ}$ at wide field and $5.50^{\circ}{\times}4.12^{\circ}$ at narrow field positions. In conclusion, this design procedure results in a $10{\times}$ compact zoom lens system useful for an LWIR camera.

• Journal of Korean Elementary Science Education
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• v.22 no.2
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• pp.156-162
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• 2003

The purpose of this study was to explore effects of 4MAT system program on the creativity, science achievement and science-related attitudesof elementary school students. 4MAT learning program is a model based on the whole brain learning including the learning styles and the cognitive specialization of left and right hemispheres. The study was conducted for 10 weeks during the 1998 second semester in H elementary school which is located in Incheon. 4MAT learning program was applied to the 5th and 6th grade students. One hundred 5th grade students and eighty three 6th grade students are selected for this study. The experimental group was taught in applying the 4MAT system, and the control group was taught by the traditional manner. The results of this study were as follows: There was a significant difference on creativity between the instruction by applying 4MAT system and the traditional instruction. In the 6th grade, there was a statistically significant difference on science achievement and science-related attitude. In the 5th grade, there was slightly increased, but statistically onsignificant. In conclusion, the instruction by applying 4MAT system was more effective in developing student's creativity than the traditional instruction in both grades.

• Smart Structures and Systems
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• v.11 no.5
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• pp.533-553
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• 2013

In this paper, system identification of a cable-stayed bridge in Korea, the Hwamyung Bridge, is performed using vibration responses measured by a wireless sensor system. First, an acceleration based-wireless sensor system is employed for the structural health monitoring of the bridge, and wireless sensor nodes are deployed on a deck, a pylon and several selected cables. Second, modal parameters of the bridge are obtained both from measured vibration responses and finite element (FE) analysis. Frequency domain decomposition and stochastic subspace identification methods are used to obtain the modal parameters from the measured vibration responses. The FE model of the bridge is established using commercial FE software package. Third, structural properties of the bridge are updated using a modal sensitivity-based method. The updating work improves the accuracy of the FE model so that structural behaviors of the bridge can be represented better using the updated FE model. Finally, cable forces of the selected cables are also identified and compared with both design and lift-off test values.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.5
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• pp.717-725
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• 2017

Traditionally, a design has been applied on a various defense area for the improvement of the mobility, reducing the radar detection area and other reasons. In case of Korean Wheeled Armored Vehicle(WAV), a design has been also applied for retaining the agility and threatening feature in the battlefield. However some figures has been changed because of constraints such as assembling and manufacturing in the development stage. Today, the government has planned to develop the Wheeled Armored Command Post Vehicle(CPV), a variant of WAV, and it is necessary to apply the latest design trend, which is suitable for the concept of the CPV, on it.

• Journal of the Korean Solar Energy Society
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• v.35 no.5
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• pp.1-10
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• 2015

Whereas recent domestic buildings and industrial facilities are being constructed as large as possible, the daylighting systems for the large space have rarely been developed. Domestic situation has been reported as only several small or medium sized daylighting systems have been developed, and the large scaled systems have entirely being imported from abroad. We have developed a large scaled daylighting system for the big space. The developed system have been evaluated in terms of the average system efficiency and daylighting factor. Each results are shown with tabulated experimental data.

• Journal of Electrical Engineering and Technology
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• v.5 no.2
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• pp.220-227
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• 2010

This paper presents a novel fault location scheme on Korean AC electric railway systems. On AC railway system, because of long distance, 40[km] or above, between two railway substations, a fault location technique is very important. Since the fault current flows through the catenary system, it must be modeled exactly to analyze the fault current magnitude and fault location. In this paper, suggesting the novel scheme of fault location, a 9-conductor modeling technique including boost wires and impedance bonds is introduced based on the characteristics of Korean AC electric railway. After obtaining a 9-conductor modeling, the railway system is constructed for computer simulation by using PSCAD/EMTDC. By case studies, we can verify superiority of a new fault location scheme and propose a powerful model for fault analysis on electric railway systems.