• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.237-240
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• 2002

In this paper, we designed and implemented the dual band antenna for IMT-2000 and 5.7㎓ WLAN(Wireless Local Area Network). The antenna was designed by using 3D simulations program, HFSS(High Frequency Structure Simulator). The electrical characteristics were measured by using HP 8720C network analyzer and measured maximum S$\sub$11/ was -25㏈, and maximum VSWR(Voltage Standing Wavc Ratio) was 1.26 for all frequency bands of interests in IMT-2000 and 5.7㎓ WLAN. Simulation results for antenna gain at 2㎓ and 5.7㎓ were 1.31㏈i and 4.1㏈i with omni directional radiation pattern. Implemented antenna is compact sized and can be produced in low cost enough for commercialization.

• Journal of the Korean Home Economics Association
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• v.44 no.6 s.220
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• pp.129-140
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• 2006

In this study, the various financial management systems practiced by modem dual-income families were assessed by in-depth interviews with 6 people, 3 practicing integrated financial management and 3 practicing individual financial management. The results indicated significant differences between the two financial management methods regarding family structure, individual values, and family finances. Families that practiced individual financial management consisted of weekend couples without children who showed an individual-centered value tendency and seemed to take a positive attitude towards their future economic situation due to possession of their on stabilized financial assets. Based on these results, we can expect more families to adopt methods of individual financial management and show a wider variety in their financial planning tools which will require adequate and efficient countermeasures and strategies suitable for each financial management practice.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.9
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• pp.2981-2990
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• 1996

Dual solutions for steady natural convection of air between two horizontal concentric cylinders are numerically investigated in the range of $D_i$/TEX>/L(=diameter of inner cylinder/gap width)$\leq$10. It is found that, when the Rayleigh number based on the gap width exceeds a certain critical value, a new flow pattern forming two counter-rotating eddies in the half of the annulus can be realized, which is different from the crescent-shaped flow commonly observed. In the new flow pattern, the fluid near the top of the hot inner cylinder moves downward. This solution is found for D$_{i}$/L.geq.0.3, but not for$D_i$/TEX>/L$\leq$0.2. As $D_i$/TEX>/L increase, the critical Rayleigh number is decreased, and tends to a finite limit.t.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.244-249
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• 2001

Collision free task planning for dual-arm robot which perform many subtasks in a common work space can be achieved in two steps : path planning and trajectory planning. Path planning finds the order of tasks for each robot to minimize path lengths as well as to avoid collision with static obstacles. A trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position or reduce speed at the middle of its path to avoid collision with the other robot.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1327-1331
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• 1990

A new dual loop controller using color LCD bar graphs with LED back lights has been developed. An optional memory card is used to load or save the controller configuration, which may be a preprogrammed standard package or a user-programmed configuration, in addition to the built-in functions ready for user selection. The bar-graph display is selectable for single-loop or dual-loop use. A high grade of self-tuning functions using a modeling technique is built-in as standard. The controller can accommodate optional plug-in modules for thermocouples, communication, etc. All the options are fully field upgradable.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.173-177
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• 2009

Digital holographic microscopy allows optical path difference measurement. Optical path difference depends on the both refractive index and morphology of sample. We developed a dual-wavelength in-line digital holographic microscope that can measure simultaneously the refractive index and morphology of a sample, providing highly precise three-dimensional information. Here we propose theoretical and experimental methods for dual-wavelength in-line digital holographic microscopy. The measured data were reasonable, although there was data error. By improving the experimental method, we could measure the refractive index more precisely and obtain more accurate three-dimensional information on samples.

• Journal of computational fluids engineering
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• v.4 no.2
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• pp.1-8
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• 1999

Natural convection in a horizontal annulus with the inner cylinder heated by the application of a constant heat flux and the isothermally cooled outer cylinder is considered, and the transition of flows and the bifurcation phenomenon are numerically investigated for air with Pr=0.7. The zero initial condition always induces a crescent-sheped eddy flow. A bicellular flow in which the fluid descends along the vertical central plane of the annulus can be obtained at high Rayleigh number by introducing artificial numerical disturbances. Dual solutions are found above a certain critical Rayleigh number. Hysteresis phenomena have not been observed.

• Journal of mucopolysaccharidosis and rare diseases
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• v.1 no.1
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• pp.28-30
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• 2015

Biologics present a challenge to both the manufacturer and end user. They must usually be formulated as parenterals. However, they are often unstable in liquid form, due to their complex structure and composition. In that case, they must be manufactured using highly specialized processes, such as lyophilization (freeze-drying). Lyophilization nearly eliminates stability issues. Reducing a compound's sensitivity to temperature prolongs its shelf life. However, reconstitution can be cumbersome, involving multiple steps that increase the potential for error. Dual-chamber technology provides an effective alternative, combining a lyophilized drug and diluent in a closed system and enabling reconstitution in a few simple steps.

• The Journal of the Acoustical Society of Korea
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• v.28 no.1E
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• pp.29-34
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• 2009

MPEG4 High Efficiency Advanced Audio Coding (HE-AAC) and MPEG Surround are one of the most efficient combinations for low bit rate multi-channel audio coding. Based on the fact that these two codecs have identical quadrature mirror filter (QMF) analysis and synthesis structures, we propose a dual-domain connection scheme for the codecs. Specifically two time-domain connection methods are analyzed and compared to the QMF subband-domain connection method. Experimental results show that both the time-domain connection methods cause no subjective sound quality degradation compared to the QMF subband-domain connection method, which verifies that one can select either of them depending on application scenarios.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1127-1136
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• 2017

This paper proposes a new soft switching dual input converter for renewable energy systems. Multi-input converters are produced by combining discrete converters. These converters reduce the number of circuit elements, cost, volume and weight of the converter and provide a constant output power in different weather conditions. Furthermore, soft switching techniques can be applied to increase efficiency. In this paper, a Zero Voltage Transition (ZVT) dual input boost converter is presented. Only one auxiliary circuit is used to provide the soft switching condition for all of the semiconductor elements. The proposed converter, which is simulated by ORCAD software, is theoretically analyzed. To confirm the validity of the theoretical analysis, a prototype of proposed converter was constructed. Simulation and experimental results confirm the theoretical analysis. An efficiency comparison shows a one percent improvement at nominal loads.