• International Journal of Air-Conditioning and Refrigeration
• /
• 제9권1호
• /
• pp.20-28
• /
• 2001

In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method is to extract the working mixture and then to measure the oil weight. In this study, oil concentration is measured in si.tu way without any extraction of the working fluid. Based on the measurement, a working equation is presented as follows, C=a +b x t +c x $t^2$ +(d + e x t +f x $t^2$) x SG. C is oil concentration, t is temperature($^{\circ}C). SG Is specific gravity of mixture and a~f is coefficients The oil concentration ranges over 0~l2 wt% and the temperature ranges over 20~50$^{\circ}C. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/P0E oil liquid mixtures.

• 한국초전도학회:학술대회논문집
• /
• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
• /
• pp.27-32
• /
• 1999

We developed a 40-channel superconducting quantum interference device (SQUID) system for neuromagnetic measurements. The main features of the system are use of double relaxation oscillation SQUID (DROS), and planar gradiometer for measuring tangential field components. The DROSS with high flux-to-voltage transfers enabled direct readout of the SQUID output by room-temperature electronics and simple flux-locked loop circuits could be used for SQUID operation. The pickup coil is an integrated first-order planar gradiometer with a baseline of 40 mm. The average noise of the 40 channels is around 1.2 fT/cm/${\sqrt{Hz}}$ at 100 Hz, corresponding to the field noise of 5 fT/${\sqrt{Hz}}$ at 100 Hz, operated inside a magnetically shielded room. The 40-Channel system was applied to measure auditory-evoked neuromagnetic fields.

• 한국간호교육학회지
• /
• 제26권1호
• /
• pp.16-24
• /
• 2020

Purpose: This study examined the effects of guided imagery on stress, state anxiety, test anxiety and core basic nursing skill performance score of undergraduate nursing student. Methods: An equivalent control group pretest-posttest design was utilized. A total of 45 senior nursing students were randomly assigned to either an intervention group to receive guided imagery, or a control group (experimental group=23 students, control group=22 students). The guided imagery was provided via audio files to the intervention group for eight minutes, once a day for five days. The pretest was given before the intervention to measure variables for both groups, and the posttest was performed immediately afterward and three days after the intervention. Results: Significant differences were found between the two groups in stress ((F=4.94, p=.012), state anxiety (F=5.99, p=.005), and basic core nursing skill performance scores (Z=-2.45, p=.015). Conclusion: Guided imagery for nursing students has been identified as effective for stress, state anxiety, and basic core nursing skill performance scores. Guided imagery can be used as an effective intervention before performance tests. These study results can provide useful data for nursing education.

• Child Health Nursing Research
• /
• 제12권1호
• /
• pp.75-83
• /
• 2006

Purpose: This study was done to verify the effect of roller acupuncture stimulation on baesu spots of joktaeyang bangkwang kyeong in the reaction to physiologic pain(heart rate, percutaneous oxygen saturation, respiration rate) in neonates. Method: This study was a nonequivalent control group non-synchronized design. The participants were 40 normal neonates who were born at a hospital in Busan. These neonates were undergoing heel puncture for blood type tests. The neonates were divided into 2 groups: 20 in the experimental group who were stimulated with roller acupuncture before the heel puncture and 20 neonates in the control group who were not stimulated. The heart rate and percutaneous oxygen saturation were measured using a cardiopulmonary monitor and the respiration rate was measured directly. The data were analyzed with SPSS 10.0 program using χ²-test, t-test and Repeated Measure ANOVA. Results: There was a significant difference (F=3.287, p=.043) for heart rate on the interaction between time and group. There was a significant difference (F=5.122, p=.008) for percutaneous oxygen saturation on the interaction between time and group. Conclusion: On the basis of results, it was verified that the roller acupuncture stimulation on baesu spots of joktaeyang bangkwang kyeong had effect of relieving pain in the neonates.

• 대한전자공학회논문지
• /
• 제21권4호
• /
• pp.7-12
• /
• 1984

DFT로 대각선화 할 수 있는 circulant matrix가 대칭이고 실수인 경우에 이를 대각선화 할 수 있는 CDFT(composite DFT)를 유도했다. 일반적인 실수 신호의 대칭 covariance matrix에 대하여 DFT와 CDFT 변환했을 경우의 variance 분포를 분석했고, 이를 토대로 rate distortion 이론에 의하여 이들의 성능을 비교한 결과 CDFT가 DFT보다 bit rate면에서 효과적임을 볼 수 있었다. 그리고 f(q)=(0.95)q인 covariance matrix(64×64)에 대해 CDFT가 DFT에 비해. 계산결과, 평균적으로 0.0095bit가 감소될 수 있었다.

• Journal of Mechanical Science and Technology
• /
• 제16권3호
• /
• pp.327-337
• /
• 2002

This paper applies a recently developed on-line parameter identification (PID) technique to sets of real flight data and compares the results with those of a state-of-the-art off-line PID technique. The on-line PID technique takes Linear Regression from Fourier Transformed equations and the off-line PID is based on the traditional Maximum Likelihood method. Sets of flight data from the NASA F/A-18 High Alpha research Vehicle (HARV) circraft, which has been recorded from specifically designed maneuvers and used for our line parameter estimation, are used for this study. The emphasis is given on the accuracy and on-line measure of reliability of the estimates. The comparison is performed for both longitudinal and lateral-directional dynamics for maneuvers at angles of attack ranging u=20°through $\alpha$=40°. Results of the two estimation processes are also compared with baseline wind tunnel estimates whenever possible.

• 한국의류학회지
• /
• 제13권4호
• /
• pp.388-399
• /
• 1989

The purpose of this study was to investigate the effects of garment design, fabric type and the presence of lining on the thermal insulation value $(I_{cle}\;and\;I{cl})$ and clothing area factor $(f_{cl})$ of skirts. A standing, electrically heated thermal maninkin was used to measure the insultation value of eighty skirts-five skirt styles with eight different fabrics, with and without lining. The air temperature of the chamber was set at $22.2^{\circ}C{\pm}0.5^{\circ}C$ , air velocity was limited to less than 0.1 m/s, and relative humidity was approximately $50\%$. The results are as follows: 1) The Ic, values of gathered skirt and flared skirt, which had high $f_{cl}$ values, were significantly higher than those of other skirts, though the highest $I_{cle}$ value among five styles wer pegged skirt. 2) Insulation values of various skirts were more relevant with physical properties such as thickness, air permeability, and thermal transmission of the materials rather than fiber content. 3) The addition of lining made significant difference in the insulation values of skirts and the differences of gathered and flared skirt were significantly higher than those of othere types of skirts.

• Progress in Superconductivity
• /
• 제2권1호
• /
• pp.20-26
• /
• 2000

A 40-channel superconducting quantum interference device (SQUID) system was constructed for measuring neuromagnetic fields. Main features of the system are the use of double relaxation oscillation SQUIDs (DROSs), and planar gradiometers measuring magnetic field components tangential to the head surface. The DROSs with high flux-to-voltage transfers enabled direct readout of the SQUID output by room-temperature dc preamplifiers and simple flux-locked loop circuits could be used for SQUID operation. The pickup coil is an integrated first-order planar gradiometer with a baseline of 40 mm. Average noise level of the 40 channels is around 1.2 $fT/cm/{\surd}Hz$ at 100 Hz, corresponding to a field noise of 5 $fT/{\surd}Hz$, operated inside a magnetically shielded room. The SQUID insert was designed to have low thermal load, minimizing the loss of liquid helium. The constructed system was applied to measure auditory-evoked neuromagnetic fields.

• 기본간호학회지
• /
• 제24권1호
• /
• pp.9-17
• /
• 2017

Purpose: This study was done to investigate the effects of acupressure on pruritus and sleep among patients undergoing hemodialysis. Methods: The study design was a nonequivalent control group repeat measures quasiexperimental study. Data were collected from June to September 2015 in the kidney center at a hospital located in B city. Participants were 42 patients; 20 in the experimental group and 22 in the control group. For the experimental group, acupressure on the spots of Sameumgyo (SP6), Zoksamli (ST36), Hyolhae (SP10), and Gokji (LI11) was provided at the time of hemodialysis three times a week for 12 weeks. The numeric rating scale (NRS) was used to measure pruritus, and sleep was measured with the sleep scale developed by Jinju Oh et al. Results: There was a significant decrease in pruritus (F=7.80, p=.008) and increase in sleep (F=80.90, p<.001) in the experimental group compared to the control group. Conclusion: The findings confirmed in the study show that acupressure is an effective nursing intervention to decrease pruritus felt by patients on hemodialysis and to increase the quality of their sleep.

• 여성건강간호학회지
• /
• 제14권1호
• /
• pp.36-43
• /
• 2008

Purpose: This study was conducted to develop a postpartum care program and to evaluate the effects of the program on postpartum activity and postpartum discomfort in primiparous women. Methods: For this control group quasi-experimental study, primiparous women who had a normal delivery at OBGYN clinics in G-city and then went home with assistance from their mothers participated from April 10 to August 2, 2006. The participants were assigned to an intervention group of 25 mothers or a control group of 23 mothers. Data analysis was performed by using SPSS/win10.0 PC+. $X^2$-test and t-test, and repeated measure ANOVA. Results: The results showed that the degree of postpartum activity(F=4.66, p=.036) and the degree of postpartum discomfort(F=7.98, p=.007) were supported statistically with significant differences between the two groups. Conclusions: Therefore, this program needs to be applied as a new nursing intervention because this postpartum care program was proven useful as effective postpartum care.