Fast drying after squeezing has known as important for fabrics such as household towels and dishcloths due to the nature of their use. In this study, drying experiments with time were conducted on various fabrics made of materials widely used in homes using a simple experimental device. Similar to the results of previous experimental studies, it was found that in the case of fabrics of the same material with different weight (or thickness), the drying rate over time was similar. In the case of dimensionless weight and time, which are non-dimensionalized by initial weight and complete drying time, the drying characteristics of the fabrics tested in this study were found to have similar drying rates for each mode at both high and low speeds.

The built-in motor with an integrated magnetic gear can realize high torque without a separate reduction device. In this paper, the main design parameters of the magnetic gear constituting the magnetic geared motor are derived and the sensitivity analysis results according to these design parameters are discussed. In particular, processing and assembly issues of modulators sandwiched between rotating bodies are discussed, and loss and magnetic force characteristics of various types of modulators are introduced. Since the modulator, which plays a key role in converting the torque of the magnetic gear, is desirable to have a separate form, it is inevitable to add a non-magnetic support to add torsional stiffness according to high-speed rotation, so the effect of this is also analyzed.

Direct air capture (DAC) refers to the process of permanently removing CO₂ from the atmosphere by capturing CO₂ that has been emitted into the atmosphere from the past to the present directly from the atmosphere. DAC is a process that captures CO₂ that exists at 400 ppm in the atmosphere, so it has the problem of requiring a significant amount of air and high energy compared to CO₂ capture from a point source such as exhaust gas from a coal-fired power plant. In this study, we aim to introduce the performance, characteristics, and processes of absorbents that can be applied to DAC, focusing on the DAC process using absorbents developed to date, and present challenges that must be overcome in future DAC technology development.

The rise of electrification and the advancement of autonomous driving technologies are leading to new forms of mobility, such as serving and delivery robots. However, due to factors such as the small-scale production of various products and the high cost of autonomous driving sensors, product prices have risen, limiting accessibility to consumers. To improve this, we developed a multi-purpose mobility platform that is mass-producible, based on inexpensive, reliable sensors and a configurable human tracking system. As a result, the unit price is approximately 50% of the launch prices of other mobility products, and additional cost savings are possible through component optimization in the future. In addition, more added value will be created through the distribution of integrated mobility platforms that can be combined with various usable modules to meet a variety of user needs, such as cargo transportation, wheelchair power kits, and mobile monitors.

Crosslinked spherical polystyrene particles with a particle diameter of 200-500 ㎛ were synthesized by using suspension copolymerization of styrene and divinylbenzene, and the effect of divinylbenzene content, poreforming agent on their spherical formation, thermal stability, specific surface area, and carbonization characteristics were examined. The spherical copolymer beads were collapsed during carbonization up to 45% of divinylbenzene content. Toluene was used as pore-forming agent since it is more soluble in monomer phase rather than dispersion media during suspension polymerization, and the specific surface area and total pore volume increased with content of pore-forming agent.

This paper presents the effects of a virtual mass with a low-pass filter on stability boundaries of a virtual spring in the haptic system with first-order hold. A virtual mass is required to improve the realism of a virtual environment. However the second derivative of a displacement of a haptic device is needed while the inertia forces are computed, which causes the reflective force to change quickly and then makes the haptic system unstable. A low pass filter is added to resolve this problem and the stability region of a haptic system depends on the characteristics of the filter. In this paper the finite impulse response filter (FIR filter) is applied as one of low pass filters and the effect of the FIR filter on the stable region of a haptic system with first order hold is analyzed. When compared to stable region of the system without the FIR filter, the region of available virtual mass is increased by 20% and the maximum of the stable virtual spring is reduced by 32%, irrespective of the sampling time. Besides it is shown that the stable region of a virtual spring is proportional to the inverse square of the sampling period.

편대 비행중인 선행 항공기에서 발생한 후류는 후행 항공기의 공력특성 및 비행 안정성에 영향을 준다. 최근에는 편대 비행 하는 무인기에서 발생하는 후류의 거동에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 푸리에-스펙트럴법을 이용하여 편대 비행 중인 XQ-58A 무인기에서 발생한 후류의 거동에 대한 연구를 수행하였다. 3개의 무인기 사이의 수직/수평 거리를 조절하여 편대 비행 대형을 바꾸어가며 와 거동을 계산하였다. 항공기 날개 간 수직/수평 이격 거리 매우 근접하는 경우 와들이 날개에서 멀리 떨어지지 못하고 주변에서 거동하였으며, 상대적으로 날개 사이 거리가 멀 경우 빠르게 와들이 하강하였다. 추후 연구에서는 와 거동과 항공기의 날개에 공력 특성 사이의 관계에 대한 연구를 수행하고자 한다.