• International Journal of Automotive Technology
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• 제6권5호
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• pp.483-489
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• 2005

Based on a two-degree of freedom vehicle model, this paper investigates ride comfort for a heavy off-road vehicle mounted a nonlinear hydropneumatic spring, which is influenced by nonlinear stiffness and damping characteristics of the hydropneumatic spring. Especially, the damping force is derived by applying H. Blasius formula in modeling process according to the real physical structure of the hydropneumatic spring, and the established model of nonlinear stiffness characteristics have been validated by experiments. Furthermore, the effects of parameter variations of the hydropneumatic spring, such as initial charge pressure and damping coefficient, on body acceleration, suspension deflection and dynamic tire deflection are also investigated.

• Journal of Yeungnam Medical Science
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• 제40권2호
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• pp.123-135
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• 2023

Advances in perinatal and pediatric intensive care and recent advances in mechanical ventilation during the last two decades have resulted in an exponential increase in the number of children undergoing home mechanical ventilation (HMV) treatment. Although its efficacy in chronic respiratory failure is well established, HMV in children is more complex than that in adults, and there are more considerations. This review outlines clinical considerations for HMV in children. The goal of HMV in children is not only to correct alveolar hypoventilation but also to maximize development as much as possible. The modes of ventilation and ventilator settings, including ventilation masks, tubing, circuits, humidification, and ventilator parameters, should be tailored to the patient's individual characteristics. To ensure effective HMV, education for the parent and caregiver is important. HMV continues to change the scope of treatment for chronic respiratory failure in children in that it decreases respiratory morbidity and prolongs life spans. Further studies on this topic with larger scale and systemic approach are required to ensure the better outcomes in this population.

• 대한기계학회논문집B
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• 제22권5호
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• pp.627-639
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• 1998

A combustion model for the incineration of municipal solid waste(MSW) in the stoker type incinerator was developed by considering the variation of physical composition of MSW. Theoretical analysis and numerical simulation for the combustion characteristics in incinerator were conducted by using the present model and the effects of compositional variation on the incineration characteristics of MSW was examined theoretically. It is found that large excess air enhances drying, but depresses volatilization. For the large value of moisture content, pyrolysis is fast but drying is slow. As the value of plastic content increases, devolatilization becomes slower. Larger amount of primary air supply to the rear side of stoker leads to increase the possibility of delaying the combustion.

• KSTLE International Journal
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• 제7권1호
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• pp.22-26
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• 2006

A simple finite element analysis is performed to simulate the thermal characteristics of a micro sensor package with thin film heater embedded in the glass wall of a micro-channel. In this paper, Electric characteristics of ITO sputtered heater were presented in this study, which can be used as a map of heater design in the range of available system temperature. The effects of thermo-physical properties of materials, geometrical structure and boundary condition on the thermal performance are also investigated. Finally, the design of micro-flow induced thermal sensor that is capable of measuring fluid flow with a lower flow detection limit of approximately 24pL/s is presented.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.196-200
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• 2011

In this work, poly(methyl methacrylate) (PMMA) was grafted onto amine treated graphite nanosheets ($NH_2$-GNs) and the surface characteristics and physical properties of the $NH_2$-GNs-g-PMMA films were investigated. The graft reaction of $NH_2$-GNs and PMMA was confirmed from the shift of the $N_{1S}$ peak, including amine oxygen and amide oxygen, by X-ray photoelectron spectroscopy (XPS). The surface characteristics of the $NH_2$-GNs-g-PMMA films were measured as a function of the $NH_2$-GN content using the contact angle method. It was revealed that the specific component of the surface free energy (${\gamma}s$) of the films was slightly increased as the $NH_2$-GN content increased. Also, the thermal and mechanical properties of the $NH_2$-GNs-g-PMMA films were enhanced with the addition of $NH_2$-GNs. This can be attributed to the chemical bonding caused by the graft reaction between the $NH_2$-GNs and the PMMA matrix.

• The Journal of Korean Physical Therapy
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• 제15권2호
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• pp.52-66
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• 2003

The intervertebral disc is a cartilaginous structure that resembles articular cartilage in its biochemistry, but morphologically it is clearly different. It shows degenerative and ageing changes earlier than does any other connective tissue in the body, It is believed to be important clinically because there is an association of disc degeneration with back pain. Degenerative changes in the intervertebral disc are thought to develop as aging, mechanical stress and metabolic factors. Genetic factors may also play a part in the onset or progress of the degenerative process. They, together with environmental factors, may act as determinants of the structural characteristics of the intervertebral disc and produce a tendency to generation, In this short review we outline the morphplogy and biochemistry of normal intervertebral disc and the changes that arise during degeneration. Therefore this study will review degeneration of intervertebral disc, so we will have knowledge about low back pain associated with degenerative change in the intervertebral disc.

• 한국정밀공학회지
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• 제31권6호
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• pp.527-534
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• 2014

The control system of human torso model and driving system of stethoscope for physical assessment trainer are developed. The detecting characteristics of circular pickup coil which is driven by square wave voltage signal with resonance frequency of LC circuits are investigated and it is confirmed that the pickup coil can detect the existence of chestpiece near the coil region. The control system of human torso model is composed of 8 channel pickup coils, Mp3 and Bluetooth module. The driving system of stethoscope is composed of chestpiece with contact switch and Bluetooth headset. The chestpiece detecting algorithm check the contact of chestpiece with human body model first and excite the pickup coil sequentially to find the location. The proposed system can be applied the physical assessment trainer.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 추계학술발표강연 및 논문개요집
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• pp.55-55
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• 2002

• 한국가구학회지
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• 제18권2호
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• pp.106-110
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• 2007

This study was performed to find potentialities of the leaves of gingko tree (Gingko biloba L.) as a raw material for particleboard (PB) manufacturing. Various amounts of the leaves were mixed with wasted wood particles to manufacture PB. Physical and mechanical properties, such as density, internal bond (IB) strength, and modulus of rupture (MOR) of manufactured PB were not much different from those of the control board. Formaldehyde emission values decreased with increasing the amount of leaves. Especially, the formaldehyde emission of PB made with 5 percent of leaves was decreased to 1.31 mg/l, which is about 36% lower emission than that of the control. From these results, the leaves of gingko tree may be considered as an additive of lowering formaldehyde emission in a functional PB manufacturing process.

• 대한기계학회논문집B
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• 제29권2호
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• pp.247-254
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• 2005

A parametric study on the interactions of two spheres aligned in the streamwise direction is carried out using an immersed boundary method. The numerical results for the case of single sphere for the range of $Rs{\le}300$ are in good agreement with other authors' experimental and numerical results currently available. Then, our main investigation is focused on identifying the change of the vortical structures in the presence of a nearby sphere aligned in the streamwise direction for the range $Re{\le}300$. It turns out that significant changes in physical characteristics are noticed depending on how close the two spheres are. In this paper, not only quantitative changes in the key physical parameters such as the force coefficients, but also qualitative changes in vortex structures are reported and analyzed.