• Korean Journal of Social Welfare
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• v.59 no.2
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• pp.327-354
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• 2007

The purpose of this paper is to compare the family policies of Nordic countries(Denmark, Finland, Norway, and Sweden) from 1980 to 2002. Three meaningful findings were found. First, there are several different characteristics in the family policies of Nordic countries in which the ideal understanding of similarity has departed from the reality. Especially, the differences of family policies have extensively expanded since 2000s. Second, for the last 20 years, all four countries have focused their efforts on expanding parents' (re)commodification rather than (re)familialization. Third, the countries have changed their direction in family policies. For example, Finland has changed from familialization to commodification during the mid-1990s.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.731-738
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• 2013

This paper describes a fault-tolerant driving control strategy for an independent steer-by-wire system in sixwheel-drive/six-wheel-steering vehicles. An algorithm has been designed to realize vehicle maneuverability that is as close as possible to that of non-faulty vehicles by inducing high slip ratio of the wheel through a faulty steer-by-wire system in order to reduce the lateral tire force, which is resistant to the yaw motion. Considering the transition of the longitudinal tire force of a wheel with a faulty steer-by-wire component, the longitudinal tire forces are optimally distributed to the other wheels. Fault-tolerant driving performance has been investigated via computer simulations. Simulation studies show that the proposed algorithm can significantly improve the maneuverability of a vehicle with a faulty steer-by-wire system as compared to the optimal traction distribution method.

• Journal of Korea Multimedia Society
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• v.13 no.5
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• pp.771-779
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• 2010

Sketch-based interface is used more and more in developing animation contents. Particularly, there has been a system where the user's sketch inputs are interpreted and presented as live motions. In this study¸ it is to design an animated flight learning system using sketch-based interface. Most of the flights include movements in three-dimensional space and have unique and complex flight patterns. In other words, the actual flight movements not only include acceleration and deceleration, rising and falling, straight or circular flying, but also may include combinations of two or more movements as they simultaneously occur such as accelerating while falling, or slowing down while rising, and so forth. And, currently existing flight learning animation system cannot present such complex flight patterns to the pilots of aircrafts or to those personnel for air-traffic controllers. Hence, it is to be shown in this study that unit-path sketch animation method can support quicker ways to create animations to present those complex flight movements, and requires lesser inputs compared to the existing frame-based animation method. Also, the flight learning system suggested uses the flight-route realization tasks to reflect complex flight patterns, and therefore creates animations close to real as possible.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1311-1316
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• 2010

In this study, straight slot welding was carried out using a 316L stainless steel test block, and numerical simulation of the slot weld process was performed using finite element analysis. Data on the residual stress were obtained at equally spaced points on the top surface of the test block along directions parallel and perpendicular to the welding direction. After electrolytic polishing of the top surface of the block, the residual stress was measured by the X-ray diffraction method. The calculated weld residual stresses were compared with the measured data, and they were in good agreement with the data. The weld residual stress distribution inside the plate was determined from the results of finite element analysis, and the characteristics of the distribution were discussed in detail in this paper.

• Journal of the Mineralogical Society of Korea
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• v.31 no.2
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• pp.103-111
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• 2018

Mineralogical properties of two Asian dust (Hwangsa) samples collected during dust events in April 6 and 15, 2018 were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analyses showed that Asian dusts were dominated by phyllosilicates (62 wt%) comprising illite-smectite series clay minerals (ISCMs) (55%), chlorite (3%) and kaolinite (4%). Nonphyllosilicate minerals were quartz (18%), plagioclase (9%), K-feldspar (3%), calcite (3%), and gypsum (2-4%). Mineral compositions determined by SEM chemical analyses were consistent with XRD data. ISCMs occur as submicron grains forming aggregate particles or coating coarse mineral grains such as quartz, plagioclase, K-feldspar, chlorite, and calcite. The ISCMs are often associated with calcite nanofibers and gypsum blades. Mineralogical properties of 2018 dusts were similar to those of previous dusts although clay contents were higher than that of coarse 2012 dust.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.9
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• pp.731-737
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• 2014

A vortex chamber is a simple device that separates compressed gas into a high-temperature stream and a low-temperature stream. It is increasing in popularity as a next-generation heat exchanger, but the flow physics associated with it is not yet well understood. In the present study, both experimental and numerical analyses were performed to investigate the temperature separation phenomenon inside the vortex chamber. Static pressures and temperatures were measured using high-sensitivity pressure transducers and thermocouples, respectively. Computational fluid dynamics was applied to simulate 3D unsteady compressible flows. The simulation results showed that the temperature separation is strongly dependent on the diameter of the vortex chamber and the supply pressure at the inlet ports, where the latter is closely related to the viscous work. The previous concept of a pressure gradient wave may not be a reasoning for temperature separation phenomenon inside the vortex chamber.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1119-1124
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• 2017

The stabilizer bar mounted on the vehicle underbody makes for a more comfortable ride by holding the vehicle itself when the vehicle is cornering. Stabilizer bars are available in two types: solid and tube. To lighten the weight of the vehicle, and owing to weight reduction requirements, tubular stabilizer bars are increasingly being used. Tubular stabilizer bars can be fabricated to be over 34％ lighter than solid bars, but the lifetime of the product tends to decrease rapidly as the weight ratio increases. However, the durability can be improved by utilizing high-strength and high-hardness materials for the stabilizer bar or by improving the shot peening method.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.1
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• pp.75-84
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• 2007

The effects of hydrogen enrichment to methane on NOx formation have been investigated with swirl stabilized pre-mixed hydrogen enriched methane flame in a laboratory-scale pre-mixed combustor(nominally of 5,000 kcal/hr). The hydrogen enriched methane fuel and air were mixed in a pre-mixer and introduced to the combustor through different degrees of swirl vanes. The flame stability was examined for different amount of hydrogen addition to the methane fuel, different combustion air flow rates and swirl strengths by comparing equivalence ratio at the lean flame limit. The hydrogen addition effects and swirl intensity on the combustion characteristics of pre-mixed methane flames were examined using gas analyzers, and OH chemiluminescence techniques to provide information about species concentration of emission gases and flowfield. The results of NOx and CO emissions were compared with a diffusion flame type combustor. The results show that the lean stability limit depends on the amount of hydrogen addition and the swirl intensity. The lean stability limit is extended by hydrogen addition, and is reduced for higher swirl intensity at lower equivalence ratio. The addition of hydrogen increases the NOx emission, however, this effect can be reduced by increasing either the excess air or swirl intensity. The NOx emission of hydrogen enriched methane premixed flame was lower than the corresponding diffusion flame under the fuel lean condition.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.47-52
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• 2006

Recently, ship collision accidents account for $20%{\sim}34%$ of domestic marine accidents, also have increased continually. In this paper, therefore we propose the development of Ship Collision A voidance Support program for decreasing ship collision accidents. This program has been developed on the basis of CCAS-Model. A CCAS-Model has ship's maneuvering performance and has been studied for the propose of supporting to avoid ship collision in close quarters. Besides. the program will effectively support maneuvering for collision avoidance through display of the feasible area and the method of collision avoidance using own ship's turning characteristic about action of target ship's keeping course and velocity in various encounter.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.307-312
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• 2009

Motukoreaite and quintinite-3T, Mg-Al layered double hydroxides, were found in the Sinyangri Formation of Jeju Island. They fill the pores of basaltic volcaniclastic sediments in globular and botryoidal aggregates of fine platy particles. Globular aggregates of quintinite-3T were crusted with the parallel overgrowth of motukoreaite plates. X-ray diffraction data and chemical composition are consistent with those reported in literature, while the Mg/Al ratio of motukoreaite is higher. Structural formula of motukoreaite and quintinite-3T derived from electron microprobe analysis are $Na_{1.6}Ca_{0.1}Mg_{40.7}Al_{20.7}Si_{0.9}(CO_3)_{13.6}(SO_4)_{7.4}(OH)_{108}56H_2O$, and $Mg_{3.7}Al_{1.9}Si_{0.2}(OH)_{12}(CO_3)_{0.8}(SO_4)_{0.2}3H_2O$, respectively. Motukoreaite and quintinite-3T were formed by reaction between seawater and basaltic glass, and contributed to the cementation and lithification of the volcaniclastic sediments.