• PNF and Movement
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• 제20권1호
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• pp.59-66
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• 2022

Purpose: The aim of this research was to verify the relationship between three-dimensional (3D) ground reaction force (GRF) and severity of leg length discrepancy (LLD) while walking at a normal speed. It used a 3D motion analysis system with force platforms in standing workers with LLD. Methods: Subjects comprising 45 standing workers with LLD were selected. Two force platforms were used to acquire 3D GRF data based on a motion analysis system during gait. Vicon Nexus and Visual3D v6 Professional software were used to analyze kinetic GRF data. The subjects were asked to walk on a walkway with 40 infrared reflective markers attached to their lower extremities to collect 3D GRF data. Results: The results indicated the maximal force in the posterior and lateral direction of the long limb occurring in the early stance phase during gait had significant positive correlation with LLD severity (r = 0.664~0.738, p <0.01). In addition, the maximal force medial direction of the long limb occurring in the late stance phase showed a highly positive correlation with the LLD measurement (r = 0.527, p <0.01). Conclusion: Our results indicate that greater measured LLD severity results in more plantar pressure occurring in the foot area during heel contact to loading response of the stance phase and the stance push-off period during gait.

• 오토저널
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• 제10권2호
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• pp.46-53
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• 1988

Effect of Notch Shape and Hardness Ratio on Characteristics of Impact Fracture in Dual Phase Steels. In this study, it is investigated the effect of notch shape and hardness ratio on the characteristics of impact fracture in dual phase steels. The impact test was carried out at the temperature range from -40.deg. C to room temperature with Instrumented Charpy Impact Tester. The main results obtained are as follows; 1, The maximum impact bending strength (.sigma.$_{max}$) increases with the tensile strength. Also, the impact energy depends on .sigma.$_{max}$. 2, In room temperature, the impact energy depends on crack-initiation energy (E$_{i}$) in case of the high hardness ratio (R=3.4), whereas depends on crack-propagation energy (E$_{p}$) in case of the low hardness ratio (R=1.8) and the dependence of crack-initiation energy of the impact characteristics decreases with increasing test temperature. These phenomena are result from the difficulty of cleavage facet formation.ion.ion.

• Archives of Plastic Surgery
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• 제35권3호
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• pp.243-247
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• 2008

Purpose: For a proper wound care, the correct evaluation of wound is very important. Usually the evaluation of wound was subjective, and as a result, wound care was empirical. There were many attempts to objectify the wound evaluation, and one of them was measurement of the wound pH. The purpose of this study is to observe the wound pH changes during wound healing phase. Methods: From 2005 to 2007, we measured the pH values of 6 acute wounds, which were split thickness skin graft donor sites. In addition, we measured the pH values of 18 chronic wounds, which were 17 pressure sores and 1 tuberculosis ulcer. After pH meter ($SkinCheck1^{(R)}$, Hanna Instruments, Italy) was calibrated, wound pH was checked. Wound was cleansed with saline gauze and dressed with polyurethane foam dressing($Medifoam^{(R)}$, Biopol, Korea). Results: In split thickness skin graft donor sites, the pH raised(mean pH value: $7.45{\rightarrow}7.62$) when the wound was on the process of healing(*p=0.027, analysis of Wilcoxon signed-rank test). If wound became re-epithelialised, the pH value dropped to that of normal skin. However, we could not find a relation between time and the pH values in chronic wound. Conclusion: We could observe the consistent wound pH changes during wound healing phase in acute wound.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.481-485
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• 1992

In order to upgrade native sheep, Rambouillet (R) rams were mated to Kaghani (K) ewes to generate F1 ($R{\times}K$) crossbred ewes. Crossbred ewes were backcrossed to Rambouillet rams to produce B1 ($R{\times}F1$), B2 ($R{\times}B1$) and B3 ($R{\times}B2$) genotypes. Weaning weight of 2605 lambs and wool weight of 2378 mature ewe records, representing R, K, F1, B1, B2 and B3 genotypes, were analyzed to compare genetic variation among genotypes produced during upgrading process and identify genotypes of the highest performance. Performance of Rambouillets was also evaluated under semi-temperate climate. Data were adjusted for yearly variation considering Rambouillet as a control. Genotypes influenced lambs weaning weight (p<.01). B1 lambs were heaviest (18.4 kg) followed in order by B2, F1, B3, R and K lambs (18.3, 17.9, 16.9, 16.8 and 13.2 kg, respectively). The highest wool production was 2.5 kg from R ewes followed by B2 (2.3), B3 (2.3), F1 (2.0) and K (1.2) ewes (p < .01). Ewe mating weight, reproduction, growth and wool production of Rambouillets deteriorated significantly after the first decade of their importation. Compared with the first phase (1959-1971), ewe mating weight, litter size, birth weight, lamb weaning weight and wool production declined by 20, 23, 32 and 36%, respectively, in the second phase (1972-1988).

• 대한화장품학회지
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• 제38권4호
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• pp.263-270
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• 2012

아스코르빅산(비타민 C)은 수용액상에서 공기와 빛, 알칼리 등에 의해 쉽게 불안정화되는 성질이 있어 화장품에 적용에 있어서 제한적이다. 아스코르빅산은 수용액상에서 불안정성에 영향을 주는 가장 중요한 인자인 공기, 특히 산소와 열, 빛 등의 외부환경에 민감하게 반응하여 산화에 의해 쉽게 분해되는 문제점이 있다. 본 연구에서는 이러한 아스코르빅산의 안정성을 증가시키고자 폴리올과 유화방법을 변화시켜 안정화하는 연구를 수행하였고 실온과 고온에서 색상과 아스코르빅산의 함량변화를 HPLC로 측정하여 비교하였다. 그 결과 실험한 조건들 중 폴리올은 글리세린을 사용한 경우 아스코르빅산의 안정화 가장 좋았으며 비수유화방법을 사용한 경우에 있어서 가장 안정하였다. 이러한 결과들로부터 아스코르빅산이 본 실험의 비수유화로 안정성이 증가하며 안정한 화장품을 만드는 데 적용이 가능하다.

• Elastomers and Composites
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• 제52권4호
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• pp.309-316
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• 2017

In injection molding, the quality of an injection molded product varies greatly depending on the molding conditions. Many researche studies have been conducted on the quality analysis of molded parts according to the molding conditions such as injection pressure, injection temperature, and packing pressure. However, there have not been many studies on the V/P switchover timing. It is known that when a large pressure is applied to a cavity in the packing phase, the cavity pressure is most affected by the packing pressure. In addition, depending on the position (timing) of the packing pressure, it can have a direct influence on quality based on the shrinkage and dimensions of the molded parts. In this study, the change in pressure profile in the cavity according to the V/P switchover position is confirmed. A CAE analysis program (Moldflow) was used to simulate and analyze two models using the PC and PBT materials. In order to compare these results with the actual injection molding results, injection molding was performed for each V/P switchover position, and the correlation between simulation and experiment, especially for the shrinkage of molded parts, was evaluated.

• 한국소프트웨어감정평가학회 논문지
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• 제16권1호
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• pp.55-63
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• 2020

광대역 광통신 시스템에 사용되는 레이저는 우수한 주파수 선택성과 모드 안정성을 가져야한다. DFB(Distributed Feedback) 레이저는 고주파로 전류 변조를 하더라도 발진 주파수의 변화가 적다. 본 연구에서는 1.55um의 파장을 갖는 DFB 레이저에서 굴절률 격자와 이득 격자가 동시에 존재할 때, 오른쪽 거울 면에 반사가 일어나지 않도록 유전막 코팅을 하여 ρ_r=0 이 되도록 하였다. 문턱에서 최소 이득을 필요로 하는 제 1모드에 대하여, 종 방향으로의 발진 모드의 빔 분포와 방사전력비 P_l/P_r를 ρ_l의 위상=π인 경우와 ρ_l의 위상=π/2인 경우에 대하여 비교 검증했다. ρ_l의 위상=π인 경우, 낮은 문턱 전류와 높은 주파수 안정성을 얻기 위해서는, κL이 8보다 커야 한다. ρ_l의 위상=π/2인 경우, 낮은 문턱 전류를 위해서는 κL=1.0이 되도록 해야 하고, 이때 발진 주파수는 격자 주파수와 일치한다. 반사 방지 코팅을 하지 않은, 두 개의 거울 면을 가진 1.55um의 파장을 갖는 DFB 레이저보다, 한쪽 거울 면에 무반사 코팅을 한 경우에 모드 선별성이 훨씬 크다.

• Elastomers and Composites
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• 제44권4호
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• pp.436-441
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• 2009

주사슬에 방향족 고리와 펜타메틸렌 그룹을 포함하고 있는 반유연성 폴리에스터가 direct polycondensation 에 의하여 합성되었다. 합성된 중합체의 구조는 $^1H$-NMR과 FT-IR에 의해, 상전이거동에 대해서는 DSC, TGA 및 직교된 편광현미경에 의하여 관찰되었다. 합성된 중합체의 고유점성도 ($\eta_{inh}$)는 0.46에서 1.30 dL/g 사이의 값으로 측정되었고, 분자사슬 중 강직사슬그룹의 선형성이 클수록 용융전이온도 ($T_m$)는 높았으며, 용해도 조사에 사용된 유기용매에 대한 용해도는 감소되었다. 그리고, 중합체들 중 P-H, P-mH, P-4H는 넓은 비등방성 영역에서 열방성 네마틱 액정상을 나타내었으나 P-R, P-C, P-2B는 액정상을 나타내지 않았다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.351-352
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• 2009

이중의 망간 페로브스카이트 블록을 가진 Ruddlesden-Popper 상 (R-P phase) $Sr_3Mn_2O_7$은 공기중에서 불안정하다. 본 연구에서는 Sr이온 자리에 La, Ca이온을 치환함으로써 R-P상을 안정화 시켰으며, 이들의 결정구조는 Neutron Diffraction 데이터를 이용하여 Rietveld 법으로 정밀화하였다 $La_{1.4}Sr_{0.8}Ca_{0.8}Mn_2O_7$, $La_{1.2}Sr_{0.9}Ca_{0.9}Mn_2O_7$은 $T_N$이 80K이며 25K에서 spin-glass 변이가 관찰되었다.

• Mass Spectrometry Letters
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• 제2권4호
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• pp.88-91
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• 2011

The pharmacokinetic properties of S-amlodipine were studied using racemic amlodipine and single S-enantiomer (SK310) administration to rats. Plasma levels of the drug were determined using chiral liquid chromatography coupled with tandem mass spectrometry following solid phase extraction. The stereospecific analysis of amlodipine was performed on an ${\alpha}$-acid glycoprotein (AGP) column using a mobile phase comprising 10 mM ammonium acetate (pH 4.0) and propanol at a flow rate of 0.2 mL/min. This method was used to perform a comparative study of the pharmacokinetics of amlodipine and SK310. The results revealed that the pharmacokinetic profile of S-amlodipine after the administration of SK310 was comparable to that following the administration of the racemic mixture.