• 한국가구학회지
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• 제23권3호
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• pp.261-270
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• 2012

Nowadays, kitchen are not for the housewives who were independent themselves in the past but for the functional spaces. Kitchen spaces are not only the main function in the residence but also changing spaces which provide the mutual understanding communication between the family members. Although the primary function of the kitchen is food preparation, it is commonly a gathering spot for family and friends, especially if it includes an informal eating area. With so much time spent in the kitchen, and can easily become tired do the decorating scheme. But, for fear of high remodeling costs, it is often unchanged for many years. Surprisingly, there are many changes that can de made to the decorating scheme of a kitchen without either the expense or the inconvenience of remodeling. Between materials on the market, materials for kitchen interior were chosen for this study. Following results came from the materials after combustion. Among boards, MDF showed the highest score in these four categories; residual inflame time, residual glow time, carbonization length, carbonization area. Also, among finishing materials (interior materials), MDF + Poly Coating showed the highest score in those categories. Therefore, it seemed that interior materials need flame retardancy.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.555-562
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• 2014

Characteristics of carbonized fiberboard such as chemical materials absorption, electromagnetic shielding, and electrical and mechanical performance were determined in previous studies. The carbonized board therefore confirmed that having excellent abilities of these characteristics. In this study, the effect of density on physical properties and sound absorption properties of carbonized fiberboards at $800^{\circ}C$ were investigated for the potential use of carbonized fiberboards as a replacement of conventional sound absorbing material. The thickness of fiberboards after carbonization was reduced 49.9%, 40.7%, and 43.3% in low density fiberboard (LDF), medium density fiberboard (MDF), and high density fiberboard (HDF), respectively. Based on SEM images, porosity of carbonized fiberboard increased by carbonization due to removing adhesives. Moreover, carbonization did not destroy structure of wood fiber based on SEM results. Carbonization process influenced contraction of fiberboard. The sound absorption coefficient of carbonized low density fiberboard (c-LDF) was higher than those of carbonized medium density fiberboard (c-MDF) and carbonized high density fiberboard (c-HDF). This result was similar with original fiberboards, which indicated sound absorbing ability was not significantly changed by carbonization compared to that of original fiberboards. Therefore, the sound absorbing coefficient may depend on source, texture, and density of fiberboard rather than carbonization.

• 천문학회보
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• 제35권2호
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• pp.31.2-31.2
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• 2010

We have performed a spectroscopic study of globular cluster (GC) system associated with the Virgo cD galaxy M87 using the Subaru/FOCAS MOS mode. We derive ages, metallicities and abundance ratios from the GC spectra using Simple Stellar Population (SSP) models. The metallicity distribution function (MDF) obtained empirically based on Milky Way GCs is consistent with the MDF derived from SSP models. A comparison with a meta-analysis using literature data sample of 15 other GC systems shows good agreement with our results. The properties of GCs acquired from the spectra will be used to test the recent theoretical prediction of a significant inflection along the colour-metallicity relations (Yoon et al. 2006). If confirmed, the non-linearity of the relations would shed new light on the interpretation of the GC colour bimodality. The robustness of our results is being tested against the choice of a SSP model, measurement errors and sample selection towards the goal of better understanding the formation history of GCs and host galaxy.

• The Journal of Korean Physical Therapy
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• 제19권3호
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• pp.11-17
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• 2007

Purpose: The purpose of this study were to analyze fatigue patterns of the rectus femoris muscle by isometric contraction. Methods: Twenty healthy subjects(10 male, 10 female) participated in this study. Maximal voluntary isometric contraction(MVIC) was measured by the dynamometer. Muscle activity was recorded from the rectus femoris muscle. During the experiment, the subject was seated in the chair. The measured items, median frequency(MDF) and root mean square (RMS), were collected from the surface EMG. All data were analyzed using repeated measures ANOVA. Results: There was significant difference of MVIC between male and female. Endurance time was significant difference by the level of MVIC but no significant in the main effect(sex) and interaction effect. The MDF and fatigue index were significant differences in the interaction effect. The RMS was not significant difference in both of main and interaction effect. The muscle fatigue patterns of female was greater than male after 60% MVIC. Conclusion: This study showed that sex differences of muscle fatigue were started from 60% MVIC.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.18-26
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• 1991

This study was carried out to examine not only the effect and the process of activation of aluminum sulfate for the manufacture of PB and MDF, but also application of the activation treatment to PB and MOF made with MDI adhesive. The results were as follows: 1. For the manufacture of PB, activating effect did not take place Because the low moisture content of 30% in the process of activation treatment made probably insufficient activation. It needs to examine higher moisture content for the uniform and enough activation same as that of MOF. 2. In the case of MOF, Activating effect was excellent, it showed not only better results of MOR 48%, MOE 29%, IB 60% than those of the control but also better dimensional stability. 3. Application of alum activation to the PB and MDF made with MDI adhesive yielded no effects. Maybe it was the reson that the curing mechanism of MDI is different. 4. Modifing the wood surface was the oxidation and wettability was not the variable limiting glueline performance. It is necessary to make a more study about activating reaction.

• 한국화재소방학회논문지
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• 제23권5호
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• pp.78-83
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• 2009

방염도료의 주성분 및 특성에 따른 방염성능과 발연특성에 대하여 알아보기 위하여 국내에 유통되어지는 17종의 방염도료를 MDF에 방염처리하여 45도 연소실험과 연기밀도실험을 실시하였다. 45도 연소실험 결과 주성분별로는 아크릴 수지를 주성분으로 한 방염도료의 방염성능이 가장 우수한 것으로 평가되어지며 유성방염도료 보다는 수성방염도료의 방염성능이 우수한 것으로 나타났고 또한 무광방염도료보다 유광방염도료의 방염성능이 더 우수한 것으로 평가되었다. 연기밀도실험을 통한 발연특성은 아크릴 수지를 주성분으로 한 시료에서 연기밀도가 상대적으로 낮게 측정되었으며 특성별로는 수성방염도료를 처리한 시료들에서 유성방염도료를 칠한 시료보다 연기밀도가 낮게 측정되었다.

• 한국대기환경학회지
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• 제27권4호
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• pp.436-442
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• 2011

In this study, the Total Volatile Organic Compounds (TVOC) emitted from wood-based panels were compared by two analytical methods using the GC/FID and the GC/MS. Japanese Larch, Yellow Poplar, Particle Board (PB) and Medium Density Fiberboard (MDF) were selected as target materials. Major compounds emitted from the panels were Toluene, ${\alpha}$-pinene, ${\beta}$-pinene and limonene. In case of TVOC using GC/FID method, MDF E2 (1,497 ${\mu}g/m^3$) revealed the highest concentration among all wood-based panels, while Japanese Larch (1,772 ${\mu}g/m^3$) showed the highest value with respect to GC/MS method. Furthermore, it was found that the amount of VOC emitted from panels was different depending upon analytical methods. This significant difference was attributed to analytical sensitivities of GC/FID and GC/MS for various VOC. Besides, it was found that the composition ratios of main VOC compounds were not significantly different.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.220-223
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• 2008

Large curved plate blocks are widely used to construct hull structure in shipbuilding industry. Most curved plates are manufactured by using manual method called as line heating that use deformation caused by residual stress after local heating along a line which is perpendicular to the curvature direction. However, its working environment is poor and its formability is totally dependent on an experienced technician. In view of that, multi-point dieless forming (MDF) technology that use reconfigurable punch arrays instead of one piece die is proposed in this study. The MDF process is based on a concept of equivalent die surface made by numbers of punches which has round tip at the end of it. In this study, numerical simulation for common curvature type such as saddle shape was carried out. In addition, experiments in the plate forming process were also conducted to compare with the numerical results in view of final configuration. Consequently, it was noted that the proposed dieless forming method has considerable feasibility to substitute the new process for conventional manual method.

• Journal of the Korean Wood Science and Technology
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• 제30권1호
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• pp.34-39
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• 2002

국내 주요 간벌재와 목질재료 탄화물중 성능면과 자원면을 고려하여 선정한 후 오수정화 실험을 실시하였다. 덩어리상태(약 3×3×3 cm)의 탄화물의 주방오수 및 정화조오수 정화실험에서 간벌재 탄화물보다 목질재료 탄화물의 정화능력이 뛰어났다. 덩어리상태에서는 미세세공보다는 파티클보드의 파티클 및 MDF의 섬유간의 간극이 정화에 더 유효하게 작용했기 때문이라고 판단된다. 처리오수의 색은 처리 후 옅어졌으며 목질재료탄이 간벌재탄보다 더 옅은 색을 보였다. 냄새는 모두 감소하는 경향을 보였다.

• 대한의용생체공학회:의공학회지
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• 제44권3호
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• pp.218-224
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• 2023

This study aimed to analyze the coordination of muscle and muscle fatigue between biceps, lateral deltoid, and anterior deltoid during dumbbell side lateral raise using bio-signal. One male subject performed dumbbell side lateral raise with 3% of 1RM dumbbell at the rate of 30bpm until failure (8 minutes). While performing, ECG were recorded to observe the participant's performance. EMG were recorded from biceps, lateral deltoid, and anterior deltoid for observing coordination and fatigue. ECG were analyzed in time and frequency domain to observe Heart rate, normLF, normHF. Changes in heart rate, normLF, and normHF indicate that the sympathetic nervous system is activated, while changes in median frequency (MDF) indicate the occurrence of muscle fatigue. Moreover, the coordination relationship of muscle changed. The correlation of MDF between each muscles indicated that lateral deltoid is associated with biceps and anterior deltoid. These results showed that our study can contribute to improving understanding of muscle fatigue and muscle coordination relationships.