• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.111-112
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• 2020

As buildings in South Korea become more skyscrapers, the risk of fire is also emerging. Thus, regulations, regulations, and guidelines are being improved to prevent the spread of smoke in the event of a fire in high-rise buildings, but research on smoke flow and pressure distribution in vertical spaces is insufficient. Therefore, in this study, the temperature of each floor in the vertical space according to the size of the fire is measured through the miniature model experiment, and the pressure difference is calculated to establish the basic data for the improvement of the performance of domestic air supply facilities in the future. Thus, a scale model of one-sixth the size of the actual building was produced to measure the temperature, and the pressure difference was derived by substituting the value for the expression. The pressure difference varies depending on the size of the cause of the fire, and it is believed that the differential pressure and conditions of the building should be taken into account before calculating the supply volume for the analysis of the pressure difference according to the size of the cause of the fire in the event of fire.

• 대한안전경영과학회지
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• 제23권4호
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• pp.43-48
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• 2021

In this study, the experiment was conducted on a fire door(W × H = 0.98 m × 2.19 m) installed on the vestibule. The effective leakage area for each opening angles and closing forces derived from the impulse-momentum equation was compared and analyzed with the experimental results. As a result of the experiment, the major factors affecting the door closing forces were the pressure difference and the area of the door. The difference of door closing forces between measured and calculated values by the impulse-momentum equation showed a deviation of less than ±15% at the opening angles of 5°to 10°. At the door opening angle of 2.5°, the dynamic pressure was much higher than the measured static pressure, and this pressure difference is estimated to be air resistance acting to prevent the door from being completely closed.

• International Journal of Internet, Broadcasting and Communication
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• 제10권1호
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• pp.48-60
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• 2018

The experiments were carried out during a total of nine sessions, that is, 3 sessions over 3 days. The CK levels decreased depending on the experiment session ($P{\leq}0.05$), but there was no significant difference ($P{\leq}0.05$) between the experimental group and the control group. Pressure threshold levels significantly decreased depending on the experiment session and the treatments had higher effects in the experimental group. VAS figures significantly decreased depending on the experiment session ($P{\leq}0.005$) and the treatments had higher effects in the experimental group. The results of this study verified the contention that applying vibration treatment immediately after inducing DOMS is more effective in terms of pressure pain threshold (PPT) and VAS, but not CK levels, than applying the treatment 24 hours after inducing DOMS. In addition, the experimental group showed a statistically significant difference compared to the control group. Therefore, it was concluded that applying vibration treatment immediately after inducing DOMS can be used as a DOMS treatment method.

• 한국초전도ㆍ저온공학회논문지
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• 제2권1호
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• pp.45-50
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• 2000

The present study has been conducted to observe the heat transfer under pulsating pressure and oscillating flow. The experimental apparatus was fabricated to measure the gas temperature, the wall temperature. the pressure and the instantaneous heat flux inside the pulse tube. The measured gas temperature and heat flux must be calibarated to compensate their finite time constant in the oscillating flow conditious. The experiment was performed from 1 Hz to 5 Hz. The phase difference between the instantaneous heat flux and the gas-wall temperature difference was clearly observed. The experimental heat fluxes were compared to the theroretical correlations such as Complex Nusselt Number Model(CNNM) and Variable Coefficient Model(CVM). The heat flux predisted by CNNM was always greater than that of VCM. The experiment confirmed the valisity of the VCM for the instantaneous heat flux under the pulsating pressure and oscillating flow in the warm end of the pulse tube.

• 수산해양교육연구
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• 제28권4호
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• pp.893-902
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• 2016

The purpose of this study is to investigate the effect of wearing a weightlifting belt, which is an auxiliary equipment used during squat, by measuring and analyzing biomechanical difference in lower limb and proposing safer and to suggest a more effective exercise method for general population. Selected 8 male participants in their 20s who have not performed regular resistance exercise for at least a year, but have experience of performing squat. The comprehensive method of study is as follows: subjects were notified of the purpose of the study and were told to practice warm-up and the squat motion for the experiment for 20 minutes. When the participant believed they were ready to begin, the experiment was started. At controlled points, foot pressure distribution sensor has been installed. Then left and right feet have been placed on the pressure distribution sensor, from which data for successful squat position that does not satisfy the criteria for failure have been collected and computed with Kwon3D XP program and TPScan program. For data processing of this study, SPSS 21.0 was used to calculated mean (M) and standard deviation (SD) of the analyzed values, and paired t-test has been conducted to investigate the difference before and after wearing the weightlifting belt, with p-value of ${\alpha}<.05$. As for time consumed depending on usage of weightlifting belt in squat, statistically significant difference has been found in P2, which is recovery movement. Lower limb angle depending on usage of weightlifting belt in squat has shown statistically significant difference in E1 foot joint(p<. 001). There has been statistically significant difference in E2 knee joint. Foot pressure percentage depending on usage of weightlifting belt in squat were found to be statistically significant (p<. 01) in both regions of anterior and posterior foot.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.195.1-195.1
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• 2016

Currently, as Plasma application is expanded to the industrial and medical industrial, low temperature plasma applications became important. Especially in medical and biology, many researchers have studied about generated radical species in atmospheric pressure low temperature plasma directly adapted to human body. Therefore, so measurement their plasma parameter is very important work and is widely studied all around world. One of the plasma parameters is electron density and it is closely relative to radical production through the plasma source. some kinds of method to measuring the electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods have very expensive cost and complex configuration to composed of experiment system. We selected Michelson interferometer system which is very cheap and simple to setting up, so we tried to measuring electron density by laser interferometer with laser beam chopping module for measurement of temporal phase difference in plasma jet. To measuring electron density at atmospheric pressure Ar plasma jet, we obtained the temporal phase shift signal of interferometer. Phase difference of interferometer can occur because of change by refractive index of electron density in plasma jet. The electron density was able to estimate with this phase difference values by using physical formula about refractive index change of external electromagnetic wave in plasma. Our guiding laser used Helium-Neon laser of the centered wavelength of 632 nm. We installed chopper module which can make a 4kHz pulse laser signal at the laser front side. In this experiment, we obtained more exact synchronized phase difference between with and without plasma jet than reported data at last year. Especially, we found the phase difference between time range of discharge current. Electron density is changed from Townsend discharge's electron bombardment, so we observed the phase difference phenomenon and calculated the temporal electron density by using phase shift. In our result, we suggest that the electron density have approximately range between 1014~ 1015 cm-3 in atmospheric pressure Ar plasma jet.

• 대한약리학회지
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• 제8권2호
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• pp.21-26
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• 1972

Zea mays Linne, which belongs to Graminae family, has been ordinarily used as edibles and fodder. Its stigma, Maydis Stigma, has been discarded without any special application with the exception of being used as diuretic in the sphere of Chinese medicine. Moreover, the pharmacological research toward Maydis Stigma as a medicinal herb has not been regretfully undertaken at all. The authors hereby paid attention to this point of view and made experiment to find out whether the water extract of Maydis Stigma might possess some pharmacological effect on the blood pressure of the rats or not. $LD_{50}$ to the mice was determined and the experiment was performed making the use of several agents related to the blood pressure such as atropine, Avil, dichloroisoproterenol and hexamethonium. The blood pressure of the rats and rabbits was recorded with the equipment of polygraph (Grass model 7 DAB) and its accessory, Statham pressure transducer. The results of the experiment are as follows. 1. $LD_{50}$ to the mice weighing 20g is determined 1,125 mg/kg. 2. The blood pressure manifests the gradual decrease by the rate of $-15.50{\pm}3.32,\;-22.14{\pm}8.73$ and $-46.25{\pm}5.17\;mmHg$ in proportion to ZW 25, 50 and 150mg/kg administered to the rats. 3. The blood pressure also manifests the same gradual decrease in proportion to ZW administered to the rabbits. 4. It is of significant difference to manifest the increase of $+5.14{\pm}4.65\;mmHg$ in the rats pretreated with atropine as compared with $-22.14{\pm}8.73\;mmHg$ of control group when administered each ZW 50mg/kg. 5. The administration of ZW 50 mg/kg to the rats pretreated with Avil, dichloroisoproterenol and hexamethonium does not manifest the significant difference in comparison with the control group.

• Journal of Advanced Marine Engineering and Technology
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• 제27권2호
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• pp.272-279
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• 2003

This study aimed to understand the effects of transporting ice slurry Particles through Pipes with branches. The experimental apparatus was constructed as ice slurry mixing tank. vortex pump, manometers for differential pressure measuring. IPF(ice packing factor) measuring instruments and branches as test sections. The experiments were carried out under various conditions. with concentration of water solution ranging between 0∼20wt% and velocity of water solution at the entry ranging between 1.5∼2.5m/s. The differential Pressure and IPF between the pipe entry and exit were measured. and flowing form was checked throughout the experiment. The pressure loss in 3d branches appeared compared with 6d branches so that it was very high. In the pressure loss of the inside and outside of branches. 6d branches was showed the difference. but was agreed in 3d branches The pressure loss according to concentration of water solution, low value appeared at 10wt% in 6d branches, at 20wt% in 3d branches. The pressure loss according to velocity, did not show large difference. The change of IPF at outlet, appeared +15∼-25% in 6d branches and 0∼-20% in 3d branches. The difference of IPF at the inside and outside of branches. appeared 10∼15% in 6d branches and maximum 5% in 3d branches.

• 대한약침학회지
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• 제13권4호
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• pp.63-74
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• 2010

Objectives : The purpose of this study was to investigate effect of Exercise on inhibition Blood pressure by Auricular-plaster Vaccaria seeds Methods : This study picked 40 peoples from 20 May 2009 to 30 June 2009 and experiment them. Attached Vaccaria seeds to auricular acupuncture of the experiment group. Did not attach them to the control group. Them to exercise using a Bike-Ergometer exercise. I measured their blood pressure before the exercise, 15 minutes after the exercise and 30 minutes after the exercise. I compared the difference between the systolic blood pressure and diastolic blood pressure. The method to choose the subjects was Random allocation. Results : 1. Comparing the systolic blood pressure of the experiment group and the control group, the average systolic blood pressure of the experiment group, who did the Bike-Ergometer exercise putting on Auricular-plaster Vaccaria seeds, was 125.45 mmHg before the exercise, 121.20 mmHg 15 minutes after the exercise and 120.30 mmHg 30 minutes after the exercise. Terefore, the group's systolic blood pressure after the exercise was more controlled than the systolic blood pressure before the exercise. The control group's systolic blood pressure increased compared to the beginning. To measure the change before and after the exercise, I carried out paird-t test. The result was statistically significant. 2. Comparing the diastolic blood pressure of the experiment group and the control group, the average diastolic blood pressure of the experiment group, who did the Bike-Ergometer exercise putting on Auricular-plaster Vaccaria seeds, was 81.45 mmHg before the exercise, 79.65 mmHg 15 minutes after the exercise and 79.05 mmHg 30 minutes after the exercise. As a result of carrying out paird-t test to measure the change of the diastolic blood pressure, the change of the dilating blood pressure was statistically significant. However, the difference of the dilating blood pressure between 15 minutes after the exercise and 30 minutes after the exercise was not statistically significant. Comparing the systolic blood pressure and the diastolic blood pressure of the experiment group and the control group, the blood pressure of the experiment group, who did the Bike-Ergometer exercise putting on Auricular-plaster Vaccaria seeds, decreased compared to the beginning and the blood pressure of the control group, who did not put on Auricular-plaster Vaccaria seeds, increased compared to the beginning. Conclusions : The hypothesis was supported that the increase of the systolic and diastolic blood pressure of the experiment group, putting on Auricular-plaster Vaccaria seeds, was more controlled than that of the control group. In future, it can be medically used by verifying the various effects through repeated studies.

• 한국초등과학교육학회지:초등과학교육
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• 제34권4호
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• pp.486-501
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• 2015

In the elementary school science curriculum, wind is one of the most important concept. In particular, land and sea breeze has been a key example to deliver how wind is driven, and thus its model experiments have been used to help students understand causes of wind. Here we compare causes and explanations for wind and land and sea breeze between textbooks in colleges and elementary schools to examine any potential improvement for the contents. In addition, we conducted survey to examine how pre-service teachers understand land and sea breeze, and convection box experiment used in elementary school textbooks is useful to understand land and sea breeze. Based on the comparison, we find that college level textbook explains the cause of wind as atmospheric pressure difference while elementary school textbooks explain them differently according to curriculums. In the textbooks, there are a difference in the way described for land and sea breeze. Analysis of questionnaire indicate that pre-service teachers understood land and sea breeze correctly, and they selected the convection box experiment in 2009 curriculum textbooks as the most suitable one. Explanations and experiments for land and sea breeze in the textbooks have been revised as the modification of elementary school curriculums. We expect this study helps to deliver more solid contents for wind and land and sea breeze in the upcoming new curriculum.