• 대한인간공학회지
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• 제17권2호
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• pp.65-82
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• 1998

To investigate the difference of sweating reaction by the somato types, we measured total sweat rate, local sweat rate, skin temperature, physiological reaction and psychological reaction at $25{\pm}1^{\circ}C$ and $29{\pm}1^{\circ}C$ under laboratory conditons. Nine healthy adult females were divided into three somato types : slender (3), normal (3) and obese (3). The results were as follows ; Total sweat rate was highest in the obese type, followed by the normal and slender types in order. Local sweat rate was highest in the infrascapular area, and then came breast, the back of the hand, upper ann, anterior leg, and anterior thigh in all somato types. Mean skin temperature was highest in the slender type, and followed the normal and obese types. Rectal temperature, blood pressure and pulse rate were highest in the obese type. Psychological reaction appeared 'hot', 'humid', 'sweaty' as ambient temperature went up. Somato types made little difference in psychological reaction.

• 패션비즈니스
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• 제3권1호
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• pp.125-137
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• 1999

The present study aims to reveal the sweating reaction of male adults, focused on athletes. With six subjects (3 athletes and 3 non-athletes) in two different conditions of ambient temperature (I : $25\pm1.0^{\circ}C$, II : $29.5\pm1.0^{\circ}C$), their total sweat rate, local sweat rate, skin temperature, physiological reaction (rectal temperature, blood pressure, and pulse rate), and psychological reaction (thermal, moisture, comfort, and perceptive sweat sensations) were measured. The comparison gave the following results: Total sweating rate was greater in non-athletes, while the two groups had more perspiration in ambience II. Local sweating rate in both ambiences was the greatest in the central breast area (athletes) and the infrascapular area (non-athletes). The mean skin temperature had more changes of increase and decrease in athletes. As to physiological reaction, non-athletes had lower rectal temperature and blood pressure as well as higher pulse rate. As for psychological reaction in Ambience II, the 4 sensations were mostly 'hot', 'humid', 'uncomfortable', and 'sweaty'.

• Journal of Mechanical Science and Technology
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• 제18권8호
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• pp.1470-1478
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• 2004

In this paper, a new 'presumed' Probability Density Function (PDF) approach coupled with a Lagrangian tracking method is proposed for turbulent combustion modeling. The test and the investigation of the model are conducted by comparing the model results with DNS data for a premixed flame subjected in a decaying turbulent field. The newly constructed PDF, which incorporates the instantaneous chemical reaction term, demonstrates consistent improvement over conventional assumed PDF models. It has been found that the time evolution of the mean scalar, the variance and the mean reaction rate are strongly influenced by a parameter deduced by a Lagrangian equation which takes into account explicitly the local reaction rate. Tests have been performed for a moderate Damkohler number, and it is expected the model may cover a broader range of Damkohler number. The comparison with the DNS data demonstrates that the proposed model may be promising and affordable for implementation in a moment-equation solver.

• 혜화의학회지
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• 제15권2호
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• pp.263-272
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• 2006

Purpose Brain vessles have autoregulation function, so even when perfusion pressure drops, cerebral blood flow remain stable by vasodilation. Latest research on this reserve of cerebral vessels is being done using TCD, which measures the reserve of the vessels. We did a research comparing cerebral vessel and peripheral vessel reserve between Taeumin, who are more likely to suffer CVA, and the normal. We observed blood flow of Internal carotid artery siphon and radial indicis artery of the two group with TCD. Method We picked 20 people out of patients diagnosed as cerebral infarction at Cheon-An Oriental hospital of Daejeon University. They were diagnosed as Taeumin with QSCCII questionnaire and constitutional differentiation. Using TCD, we measured highest blood flow rate, mean blood flow and asymmetric counting blood flow of Internal carotid artery siphon and radial indicis artery at rest. And then we measured again after stimulating cerebral vessels, by triggering hypercapnia by self apnea and peripheral vessels by palm heating. Result At rest, mean blood flow rate of Internal carotid artery siphon showed significant decrease compared to control group. Blood flow rate of Internal carotid artery siphon after hypercapnia showed significant decline in highest blood flow rate and mean blood flow compared to control group. Cerebral vessel reaction after the hypercapnia induction showed great change in experiment group than the control group. Peripheral vessel reaction after palm heating showed significant decline in experiment group compared to control group. Conclusion In conclusion, measuring the alteration of blood flow used in diagnosing cerebral infarction, is more sensitive when vessel stimulation is done. Non-invasive TCD is effective especially in case of Taeumin who are more likely to suffer vascular disorder than others.

• 한국운동역학회지
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• 제26권2호
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• pp.143-151
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• 2016

Objective: The purpose of this study was to investigate the effect of fatigue induction on ground reaction force (GRF) components, postural stability, and vertical jump performance in Taekwondo athletes. Method: Ten Taekwondo athletes (5 men, 5 women; mean age, $22.30{\pm}2.62years$; mean height, $174.21{\pm}9.20cm$; mean body weight, $67.28{\pm}12.56kg$) participated in this study. Fatigue was induced by a short period of strenuous exercise performed on a motorized treadmill. The analyzed variables included vertical jump performance, static stability (mediolateral [ML], center of pressure [COP], anteroposterior [AP] COP, ${\Delta}COPx$, ${\Delta}COPy$, and COP area), postural stability index values (ML stability index [MLSI], AP stability index [APSI], vertical stability index [VSI], dynamic postural stability index [DPSI]), and GRF components (ML force, AP force, peak vertical force [PVF], and loading rate). To analyze the variables measured in this study, PASW version 22.0 was used to calculate the mean and standard deviation, while a paired t-test was used to evaluate the pre- versus post-fatigue results. Pearson's correlation coefficients among variables were also analyzed. The statistical significance level was set at ${\alpha}$ = .05. Results: Vertical jump performance decreased significantly after the induction of fatigue, while AP COP, ${\Delta}COPx$, COP area, APSI, VSI, and DPSI increased significantly. PVF and loading rate increased significantly after the induction of fatigue, while the postural stability variables (AP COP, ${\Delta}COPy$, COP area, APSI, VSI, DPSI) were similarly correlated with GRF components (PVF, loading rate) after fatigue was achieved (r = .600, $R^2$ = 37%). Conclusion: These results suggest that the induction of fatigue can decrease postural stability and exercise performance of Taekwondo athletes during training and competition sessions.

• 공업화학
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• 제9권7호
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• pp.1004-1010
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• 1998

Single-jet 반회분식 결정화 반응기에서 동력투입량, 반응물의 주입시간 및 주입방법등 반응조건의 변화가 란타늄 옥살레이트 결정입자의 반응성 결정화에 미치는 영향에 대해 실험적으로 조사하였다. 란타늄 옥살레이트 결정입자의 크기분포는 반응조건에 관계없이 monomodal 형태의 크기분포를 나타내었으나 평균결정크기는 반응조건에 크게 영향을 받았다. 동력투입량이 증가할수록, 반응물의 주입속도가 빠를수록, 란타늄 옥살레이트의 결정입자크기는 감소하였으나 상대적 유도시간은 증가하였다. 반응물의 주입방법에 있어서 옥살산 용액이 주입되는 경우보다 염화란타늄 용액이 주입되는 경우에 결정입자는 크게 나타났으며 상대적 유도시간은 감소하였다. 그리고 결정입자의 형태는 모두 침상형으로 반응조건의 변화에 크게 영향을 받지 않았다.

• 한국결정성장학회지
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• 제9권2호
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• pp.191-196
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• 1999

수열합성법을 이용한 $\alpha$-$SiO_2$ 단결정 분말 제조시 교반의 추가와 승온속도의 변화가 입자의 결정성, 입도분포 및 평균입경에 미치는 영향을 조사하였다. KOH를 광화제로 사용하였으며, $350^{\circ}C$에서 3시간 동안 반응을 시켜 평균입자 크기가 1~3.2$\mu\textrm{m}$인 결정 분말을 제조하였다. 실험결과 반응초기부터 교반을 한 경우에는 교반속도가 증가함에 따라 평균입경이 감소했으나, 결정성은 나빠지다가 150r/min 이상에서는 다시 좋아졌다. 또한 반응 도중에 교반을 추가하면 반응초기부터 교반을 한 경우보다 입자의 크기가 커졌다. 그러나 교반속도를 일정하게 한 후 승온속도를 느리게 하면 입자의 크기가 작아졌다.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.115-123
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• 2003

Simultaneous measurements of velocity and OH distribution were made using particle image velocimetry(PIV) and planar laser-induced fluorescence(PLIF) of OH radical in turbulent hydrogen nonpremixed flames with coaxial air. The OH radical was used as an approximate indicator of chemical reaction zone. The OH layer was correlated well with the stoichiometric velocity, $U_s$, instantaneously and on average. In addition, high strain-rate regions almost coincide with the OH distribution. The residence time in flame surface, calculated from the root-mean-square value of the radial velocity, is proportional to $(x/d_F)^{0.7}$. It is found that the mean value of principal strain rate on the OH layer can be scaled with $(x/d_F)^{-0.7}$ and therefore, the product of the residence time and the mean strain rate remains constant over all axial positions.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.72-96
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• 1997

To investigate the difference of sweating reaction on somato types. We measured total sweat rate, locl sweat rate, skin temperature, physiological reactions and psyschological reactions at $25{\pm}1^{\circ}C$ and $25{\pm}1^{\circ}C$ under laboratory conditions. Nine healthy adult females were divided into three somato types (slender(3), normal(3) and obese type(3)). The results were as follows; Total sweat rate was highest in obese type, and then comes normal type and slender type in order. Local sweat rate was highest in infrascapular area, and then breast, the back of the hand, upperarm, ant. leg, and ant. thigh in order in all somato types. Mean skin temperature was highest in slender type, and then normal type and obese type in order. Rectal temperature, blood pressure and pulse rate were highest in boese type. Psychological reactions were appeared 'hot' 'humid' 'sweat' as ambient temperature go up. And somato types make little difference in psychological reactions.

• 항공우주시스템공학회지
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• 제1권2호
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• pp.37-42
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• 2007

This paper proposes a numerical modeling approach to simulate the hybrid combustion phenomena. From the physical understandings of hybrid combustion, the computational domain was separated into three regions: the solid fuel, gas phase reactive flow, and the interface between solid and fluid. Moreover, for the accurate calculation, computational grids for these regions was generated at every time step considering the instantaneous moving interface which are governed by the balance equations using thermal pyrolysis. In the domain of reactive flow, by virtue of diffusion flame structure, turbulent combustion modeling was introduced using either mixture fraction approach or mean reaction rate approach.