• Journal of the Korean Home Economics Association
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• v.43 no.11 s.213
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• pp.73-95
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• 2005

The purpose of this research was to reduce the burden of household management and the difficulty of rearing children, which are two most important obstacles for a dual-income family. For this, we suggested a cohousing project, as an alternative concept to conventional housing, where people can socially interact with each other and share mutual cooperation for a better quality of life. We surveyed the lifestyle of dual-income families in Korea, how they understood the cohousing project and their opinions on it. We carried out a survey with the wives from dual income families who were living in the metropolitan areas including Seoul. We contacted 30 wives for the survey to determine the reality of the double income couple family and interviewed them to make a detailed plan for cohousing based on their understanding and needs. In the results, many women who responded to the interview agreed that cohousing was an ideal housing arrangement for the dual-income family. However, they were anxious that it would take too much time and effort to develop their own housing estate by themselves. Therefore, we looked for a way to save time, efforts and cost in developing a cohousing project and came up with the remodeling as a solution.

• Journal of Auto-vehicle Safety Association
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• v.14 no.2
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• pp.57-69
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• 2022

Recently, as interest in self-driving cars has increased worldwide, research and development on the Advanced Driver Assist System is actively underway. Among them, the purpose of Adaptive Cruise Control (ACC) is to minimize the driver's driving fatigue through the control of the vehicle's longitudinal speed and relative distance. In this study, for the research of the ACC test in the real environment, the real-road test was conducted based on domestic-road test scenario proposed in preceding study, considering ISO 15622 test method. In this case, the distance measurement method using the dual camera was verified by comparing and analyzing the result of using the dual camera and the result of using the measurement equipment. As a result of the comparison, two results could be derived. First, the relative distance after stabilizing the ACC was compared. As a result of the comparison, it was found that the minimum error rate was 0.251% in the first test of scenario 8 and the maximum error rate was 4.202% in the third test of scenario 9. Second, the result of the same time was compared. As a result of the comparison, it was found that the minimum error rate was 0.000% in the second test of scenario 10 and the maximum error rate was 9.945% in the second test of scenario 1. However, the average error rate for all scenarios was within 3%. It was determined that the representative cause of the maximum error occurred in the dual camera installed in the test vehicle. There were problems such as shaking caused by road surface vibration and air resistance during driving, changes in ambient brightness, and the process of focusing the video. Accordingly, it was determined that the result of calculating the distance to the preceding vehicle in the image where the problem occurred was incorrect. In the development stage of ADAS such as ACC, it is judged that only dual cameras can reduce the cost burden according to the above derivation of test results.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.1
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• pp.38-44
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• 2015

This paper presents the sensorless drive method for mono inverter dual parallel (MIDP) surface mounted permanent magnet synchronous motor (SPMSM) drive system. MIDP motor drive system is a technique that can reduce the cost of the multi motor driving system. To maximize this merit of the MIDP motor drive system, the sensorless technique is essential to eliminate the position sensors. This paper adopts an appropriate sensorless method for MIDP SPMSM drive system, which uses the reduced order observer and phase locked loop (PLL) to reduce the calculation burden. The I-F control method is implemented for start-up and low speed operation. The validity and performance of the proposed algorithm are shown via experiments with 600-W SPMSMs.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.113-114
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• 2006

In this paper, dual-gate mixer has been designed and optimized to have variable conversion gain for WiBro and WLAN applications and to save power. With the LO power of 0dBm and RF power of -50dBm, the mixer shows 15dB conversion gain. When RF power increases from -50dBm to -20dBm, the conversion gain decreases to -2dB with bias change. The variable conversion gain can reduce the high dynamic range requirement of AGC burden at IF stage. Also, it can save the dc power dissipation of mixer up to 90%.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.34-39
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• 2008

An RF front-end dual-conversion receiver for $3{\sim}5\;GHz$ MB-OFDM UWB systems is implemented in $0.18\;{\mu}m$ CMOS technology. The receiver includes a two-stage UWB LNA, an RF mixer, an IF I/Q mixer, and a frequency synthesizer. The proposed receiver adopts the dual-conversion architecture to mitigate the burden of design of the frequency synthesizer. Accordingly, the proposed frequency synthesizer generates four LO tones from only one VCO. The receiver front-end achieves power gain of 16.3 to 21 dB, NF of 7 to 7.6 dB over $3{\sim}5\;GHz$, and IIP3 of -21 dBm, while consuming 190 mW from a 1.8 V supply.

• Journal of Advanced Navigation Technology
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• v.10 no.2
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• pp.138-144
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• 2006

In this paper, dual mode FET mixer for WiBro and wireless LAN(WLAN) applications has been designed in the form of dual gate FET mixer by using the cascode structure of two single gate pHEMTs. The designed dual gate mixer has been optimized to have variable conversion gain for WiBro and WLAN applications in order to save dc power consumption. The LO to RF isolation of the designed mixer is more than 20dB from 2.3GHz to 2.5GHz band. With the LO power of 0dBm and RF power of -50dBm, the mixer shows 15dB conversion gain. When RF power increases from -50dBm to -20dBm, the conversion gain decreases to -2dB from 15dB with bias change. The variable conversion gain has several advantages. It can reduce the high dynamic range requirement of AGC burden at IF stage. Also, it can save the dc power dissipation of mixer up to 90%.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.85-87
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• 2011

The opportunistic human pathogen Candida albicans has the ability to convert from yeast-form to pseudohyphal or true hyphal form. The morphological transition is considered as an important virulence factor, because the decrease or lack in dimorphism causes the reduction of virulence. Our previous study revealed that the disruption of dual specificity kinase gene caused the reduction of dimorphism in C. albicans. Therefore we tested the effect of dual specificity kinase in virulence using mouse model. The mean survival time for kinase-defective strains was about 15 days in comparison with those of wild-type, 3.9 days. Moreover the fungal burden on kidneys for kinase-defective strains was decreased by ten-fold than that for wild-type. These results suggest possible involvement of dual specificity kinase in a novel signal transduction pathway for morphological transition and virulence of C. albicans.

• Journal of Information Processing Systems
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• v.8 no.1
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• pp.55-66
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• 2012

This paper presents a dual modeling method that simulates the graphic and haptic behavior of a volumetric deformable object and conveys the behavior to a human operator. Although conventional modeling methods (a mass-spring model and a finite element method) are suitable for the real-time computation of an object's deformation, it is not easy to compute the haptic behavior of a volumetric deformable object with the conventional modeling method in real-time (within a 1kHz) due to a computational burden. Previously, we proposed a fast volume haptic rendering method based on the S-chain model that can compute the deformation of a volumetric non-rigid object and its haptic feedback in real-time. When the S-chain model represents the object, the haptic feeling is realistic, whereas the graphical results of the deformed shape look linear. In order to improve the graphic and haptic behavior at the same time, we propose a dual modeling framework in which a volumetric haptic model and a surface graphical model coexist. In order to inspect the graphic and haptic behavior of objects represented by the proposed dual model, experiments are conducted with volumetric objects consisting of about 20,000 nodes at a haptic update rate of 1000Hz and a graphic update rate of 30Hz. We also conduct human factor studies to show that the haptic and graphic behavior from our model is realistic. Our experiments verify that our model provides a realistic haptic and graphic feeling to users in real-time.

• Nutrition Research and Practice
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• v.16 no.5
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• pp.658-672
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• 2022

BACKGROUND/OBJECTIVES: Although children of ethnic minority groups are experiencing a transition from a predominance of undernutrition to overnutrition, there is little evidence of a dual-malnutrition burden. Therefore, this study examined the double burden of malnutrition among school-aged ethnic minority children living in mountainous areas and its association with their diets. SUBJECTS/METHODS: A cross-sectional study was conducted from September 2019 to March 2020 in 3 mountainous areas of Northern Vietnam among 1,556 ethnic minority school-aged children. The prevalence of under-nutrition (stunting and thinness) and over-nutrition (overweight and obesity) were measured using the WHO 2006 child growth standards (height-for-age and BMI-for-age Z-score). Nutritional practices were evaluated by the frequency of food consumption based on a 4-level scale. RESULTS: The percentage of children with stunting and thinness were 14.0% and 5.4%, respectively, while the figure for overweight/obesity was 9.4%. The factors positively associated with stunting were living in a family with more than 2 children or being Muong/other ethnicities compared to the Tay ethnicity. Children who consumed fish/shrimps/crabs or milk weekly/daily were less likely to be undernourished compared to those who never consumed these foods. By contrast, children who never consumed foods rich in vitamin A precursors and vitamin A and fruit or consumed daily snacks/junk food were more likely to be overweight/obese. CONCLUSIONS: Undernutrition remains a common issue among school-aged children and adolescents of ethnic minority groups, while over-nutrition exists simultaneously. Public health nutrition programs promoting adequate diets and positive lifestyle changes related to nutrition are essential to tackle the double burden of malnutrition among ethnic minority children.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.5
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• pp.445-454
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• 2015

In this paper, we propose an optimal design method for a dual reflector antenna(DRA) using the Genetic algorithm. In order to reduce the computational burden during the optimal design, we exploit the iterative physical optics(IPO) to calculate the surface current distribution at each reflector antenna. To improve the accuracy, we consider the shadow effect by the structure and the coupling effect by the multi-reflection based on the iterative MFIE(Magnetic Field Integral Equation). To reduce the number of design variables and generate a smooth surface, we use the Bezier function with the control points, which become the design variables in this paper. We adopt the HPBW(Half Power Beam Width), the FNBW(First Null Beam Width), and the SLL(Side Lobe Level) as the objective or cost functions. To verify the results, we compare them with the those of the commercial tool.