• 대한인간공학회지
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• 제32권6호
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• pp.489-494
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• 2013

Objective: This study compared the effects of streamlined shoes on dynamic gait and foot plantar pressure in healthy young adults. Background: With the importance of ankle and lower extremity mechanism, streamlined shoes are contributing to a static gait factors. However, the study of dynamic gait factor is still insufficient. Method: Sixty subjects were randomly allocated to two groups: experimental group(n=30) and control(n=30), respectively. The experimental group performed streamlined shoes, whereas the control group applied usual shoes. Main outcome measurements were assessed contact time, step length and foot plantar pressure using gait analysis with the treadmill. Independent t-test was used to compare the both groups. Results: Compared with control group, contact time of forefoot, midfoot and hindfoot decreased significantly in experimental group(p<.05), Step length increased significantly in experimental group(p<.05). Foot plantar pressure of midfoot and hindfoot increased significantly in experimental group(p<.05), whereas that of forefoot did not show significantly in experimental group(p>.05). Conclusion: Our findings suggest that streamlined shoes was more effective than usual shoes in dynamic gait change including contact time and step length and foot plantar pressure in healthy young adults. Application: The results of streamlined shoes might help to control for the gait of industrial workers.

• 패션비즈니스
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• 제15권6호
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• pp.40-55
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• 2011

The purpose of this research is to review testing principle, testing design and experimental results of the four dynamic moisture movement testers. The research analyzes Moisture Manager Tester (MMT), Alambeta Instrument, Dynamic Surface Moisture Movement Tester, and Gravimetric Absorbent Testing Method based on American Society for Testing and Material (ASTM) E 96 which is an international standard testing method. Although many of researches use ASTM E 96 to measure moisture movement on a fabric, it has several weaknesses, such as long experimental time and a physical change of sample by a holder of the frame. Hence, lots of researchers have studied and developed the new measurement systems measuring moisture management on a fabric or garment and ultimately mimic heat energy and perspiration created by the human body. These moisture management systems use a variety of parameters, such as electricity, color, and sensor to measure their movement in the fabric. Through comparison with the existing tester (ASTM E 96), the research recognizes the strength and weakness in the dynamic moisture movement testers.

• 한국정보통신학회논문지
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• 제9권8호
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• pp.1683-1690
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• 2005

본 논문에서는 UDP에서의 동적 흐름 제어기법을 제안하며, 기존의 동적 흐름제어에서 많이 사용되는 측정 요소인 패킷 손실과 왕복시간의 특성에 대해 분석한 후 새로운 측정요소인 RSTT를 제안한다. 제안된 RSTT를 사용한 알고리즘은 전송률을 조절하는데 있어서 현재 측정된 네트워크 상태와 과거의 상태를 고려함으로써 보다 정확한 네트워크 상태측정을 할 수 있었다. 비교실험을 위하여 전송량과 네트워크의 상태를 출력하고 네트워크의 흐름패턴에 대한 상세 정보를 보여주는 네트워크 상태측정 프로그램을 구현하였다. 이를 이용한 성능실험을 통해 제안된 알고리듬이 기존 알고리듬에 비해 낮은 패킷 손실률로 네트워크 상태에 더욱 빠르게 적응함을 보여준다.

• 한국안광학회지
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• 제21권3호
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• pp.227-233
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• 2016

목적: 본 연구는 우세안의 방향과 우세성의 강도, 우세안과 우세손 방향의 일치와 불일치 시의 동적 입체시를 비교해보았다. 방법: 평균연령 $21.06{\pm}2.21$세인 성인 130명(남자 70명, 여자60명)을 대상으로 $3.8cm{\times}3.8cm$ 직경의 가는 링을 이용한 타각적인 방법으로 우세안(dominant eye)의 방향과 강도를 측정하였고, 삼간계(three-rods test, iNT, Korea)를 이용하여 동적 입체시(dynamic stereoacuity)를 측정하였다. 결과: 우세안의 방향에 따른 동적 입체시는 우세성이 없는 중심우세안일 때 $14.97{\pm}13.80$초, 우안 $22.10{\pm}20.01$초, 좌안 $22.31{\pm}20.39$초로 눈의 우세성이 없을 때 더 좋았으나 우세안의 방향과 동적 입체시의 상관성은 매우 낮았다. 우세안의 강도를 Center, Mild, Strong로 구분하였을 때 동적 입체시는 각각 $14.97{\pm}13.80$초, $20.76{\pm}15.73$초, $24.45{\pm}25.60$초로 우세성이 강할수록 나빠지는 결과를 보였으나 우세안 좌안에서 우세성이 Strong으로 강할 때 오히려 동적 입체시가 중심우세보다도 더 좋게 나타났다. 우세안과 우세손 방향에 따른 동적 입체시는 우안과 오른손일 때 $22.63{\pm}20.54$초, 좌안과 왼손일 때 $17.36{\pm}10.13$초, 우안과 왼손일 때 $14.79{\pm}7.05$초, 좌안과 오른손일 때 $22.97{\pm}21.42$초로 나타나 상대적으로 우세손이 오른손보다 왼손인 경우가 빈도수는 낮았으나 동적 입체시는 우세손이 왼손일 때 비교적 좋게 나타났다. 결론: 우세안의 방향과 강도에 따른 동적 입체시의 상관성은 낮았으나 눈의 우세성이 없을때 14.97초, Strong 일 때 24.45초로 우세안 강도가 강할 때 동적 입체시가 나빠지는 경향을 보였다. 따라서 우세안 방향과 강도는 입체시와 같은 양안시기능과 sport vision training, 노안교정과 mono vision과 같은 시력교정 시에 양안균형 면에서 착용자에게 좀 더 편안한 처방을 하는데 고려되어야 요소로 사료된다.

• Preventive Nutrition and Food Science
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• 제14권3호
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• pp.233-239
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• 2009

The effects of guar gum (GG) and xanthan gum (XG) at different concentrations (0, 0.2, 0.4, and 0.6% w/w) on the rheological properties of Korean waxy rice starch (WRS) pastes were evaluated under both steady and dynamic shear conditions. The flow properties of WRS-gum mixtures were determined from the rheological parameters of the power law model. The addition of GG and XG to WRS resulted in an increase in the apparent viscosity ($\eta_{a,100}$) and consistency index (K) values obtained from power law model. The flow behavior index (n) values of the WRS-XG mixtures decreased with an increase in gum concentration while there was only a marginal difference between n values for the WRS-GG mixtures. Dynamic moduli (G', G", and $\eta^*$) values in the WRS-gum mixture systems also increased with an increase in gum concentration. WRS-XG mixtures had higher dynamic moduli and lower tan $\delta$ (ratio of G"/G') values than WRS-GG mixtures, indicating that the higher dynamic rheological properties of WRS-XG can be attributed to an increase in the viscoelasticity of the continuous phase in the starch-gum mixture systems, which was due to the higher viscoleastic properties of XG compared to GG. The dynamic ($\eta^*$) and steady shear ($\eta_a$) viscosities of the WRS-XG paste at a 0.2% gum concentration followed the Cox-Merz superposition rule.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.61-67
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• 2010

Thick soft clay deposits which are generally located at the west and south coast of the Korean peninsula have complicated characteristics according to their orientation and formation history. Thus, several geotechnical problems could possibly occur when those soft clay deposits are used as foundations for marine structures. Deep cement mixing (DCM) method is one of the most widely used soft soil improvement method for various marine structures, nowadays. DCM method injects binders such as cement into the soft ground directly and mixes with the in-situ soil to improve the strength and other geotechnical properties sufficiently. However, the natural impacts induced by dynamic motions such as ocean waves, wind, typhoon, and tusnami give significant influences on the stability of marine structures and their underlaying foundations. Thus, the dynamic properties become important design criteria to insure the seismic stability of marine structures. In this study, the dynamic behavior of cemented Busan clay is evaluated. Laboratory unconfined compression test and resonant column test are performed on natural in-situ soil and cement mixed specimens to confirm the strength and strain-dependent dynamic behavior variation induced by cement mixing treatment. Results show that the unconfined compressive strength and shear modulus increase with curing time and cement content increment. Finally, the optimized cement mixing ratio for sufficient dynamic stability is obtained through this study. The results of this study are expected to be widely used to improve the reliability of seismic design for marine structures.

• Investigative Magnetic Resonance Imaging
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• 제23권1호
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• pp.38-45
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• 2019

Purpose: To demonstrate the high-resolution numerical simulation of the respiration-induced dynamic $B_0$ shift in the head using generalized susceptibility voxel convolution (gSVC). Materials and Methods: Previous dynamic $B_0$ simulation research has been limited to low-resolution numerical models due to the large computational demands of conventional Fourier-based $B_0$ calculation methods. Here, we show that a recently-proposed gSVC method can simulate dynamic $B_0$ maps from a realistic breathing human body model with high spatiotemporal resolution in a time-efficient manner. For a human body model, we used the Extended Cardiac And Torso (XCAT) phantom originally developed for computed tomography. The spatial resolution (voxel size) was kept isotropic and varied from 1 to 10 mm. We calculated $B_0$ maps in the brain of the model at 10 equally spaced points in a respiration cycle and analyzed the spatial gradients of each of them. The results were compared with experimental measurements in the literature. Results: The simulation predicted a maximum temporal variation of the $B_0$ shift in the brain of about 7 Hz at 7T. The magnitudes of the respiration-induced $B_0$ gradient in the x (right/left), y (anterior/posterior), and z (head/feet) directions determined by volumetric linear fitting, were < 0.01 Hz/cm, 0.18 Hz/cm, and 0.26 Hz/cm, respectively. These compared favorably with previous reports. We found that simulation voxel sizes greater than 5 mm can produce unreliable results. Conclusion: We have presented an efficient simulation framework for respiration-induced $B_0$ variation in the head. The method can be used to predict $B_0$ shifts with high spatiotemporal resolution under different breathing conditions and aid in the design of dynamic $B_0$ compensation strategies.

• Communications for Statistical Applications and Methods
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• 제4권1호
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• pp.193-205
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• 1997

The multiprocess dynamic model provides a good framework for the modeling and analysis of the time series that contains outliers and is subject to abrupt changes in pattern. In this paper we consider the multiprocess discount generalized model with parameters having a dependent non-linear structure. This model has nice properties such as insensitivity to outliers and quick reaction to abrupt change of pattern in parameters.

• Journal of Photoscience
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• 제8권2호
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• pp.70-73
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• 2001

The chlorin-bromine building block was constructed and applied to synthesize $\delta$-bromo compounds of methyl pyropheophorbide-a. The visible spectra of the title compounds were discussed.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2001년도 한국해안해양공학발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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• pp.79-83
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• 2001