• 한국항해항만학회지
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• 제33권2호
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• pp.99-104
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• 2009

The Kinematic GPS is well known to provide a quite good accuracy of positioning within an level. Although kinematic GPS assures high precision measurement on the basis of an appreciable distance between a reference station and an observational point, it has measurable distance restriction within 20 km from a reference station on land. Therefore, it is necessary to make out a simple and low-cost method to obtain accurate positioning information without distance restriction In this paper, the velocity integration method to get the precise velocity information of a ship is explained. The experimental results of Zig-zag maneuver and Williamson turn as the ship's maneuvering test, and other experimental results of ship's movement during leaving and entering the port with low speed were shown. From the experimental results, ship's course, speed and position are compared with those obtained by kinematic-GPS, velocity integration method and dead reckoning position using Gyro-compass and Doppler-log.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 Asia Navigation Conference
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• pp.49-55
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• 2006

Kinematic GPS provides quite good accuracy of position in cm level. Though K-GPS assures high precision measurement in cm level on the basis of an appreciable distance between a station and an observational point, but it has measurable distance restriction within 20 km from a reference station on land. So it is necessary to make out a simple and low-cost method to obtain accurate positioning information without distance restriction. In this paper, the velocity integration method to get the precise velocity information of ship is explained. Next two experimental results (Zig-zag maneuvering test and Williamson turn) as the ship's maneuvering test and also the experimental results of leaving and entering port as slow speed ship's movement were shown. In these experimental results, ship's course, speed and position are compared with those obtained by kinematic-GPS, velocity integration method and dead reckoning position using Gyro-compass and Doppler-log.

• International Journal of Aeronautical and Space Sciences
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• 제18권3호
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• pp.414-424
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• 2017

This paper introduces an experimental device which can measure accurate aerodynamic forces without support interference in wide experimental region for wind tunnel test of micro aerial vehicles (MAVs). A stereo pattern recognition (SPR) method was introduced to a magnetic suspension and balance system (MSBS), which can eliminate support interference by levitating the experimental model, to establish wider experimental region; thereby MSBS-SPR integrated system was developed. The SPR method is non-contact, highly accurate three-dimensional position measurement method providing wide measurement range. To evaluate the system performance, a series of performance evaluations including SPR system measurement accuracy and 6 degrees of freedom (DOFs) position/attitude control of the MAV model were conducted. This newly developed system could control the MAV model rapidly and accurately within almost 60mm for translational DOFs and 40deg for rotational DOFs inside of $300{\times}300mm$ test section. In addition, a static wind tunnel test was conducted to verify the aerodynamic force measurement capability. It turned out that this system could accurately measure the aerodynamic forces in low Reynolds number, even for the weak forces which were hard to measure using typical balance system, without making any mechanical contact with the MAV model.

• 대한기계학회논문집A
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• 제28권11호
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• pp.1799-1806
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• 2004

The static photoelastic experiment was applied to orthotropic materials. And then the specimens used in photoelastic experiment were fractured under static load. The static photoelastic experimental hybrid method for orthotropic material was introduced and its validity had been assured. Crack propagation criterion used the stress components, which are considered the higher order terms, obtained from the static photoelastic experimental hybrid method was introduced and it was applied to the minimum strain energy density criterion, the maximum tangential stress criterion and mode mixity. Comparing the actual initial angle of crack propagation with the theoretical initial angle of crack propagation obtained from the above failure criterions, the validities of the above two criterions are assured and the optimal distance (${\gamma}$) from the crack-tip is 0.01mm in order to get the initial angle of crack propagation of orthotropic material(C.F.E.C.).

• International Journal of Oral Biology
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• 제46권2호
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• pp.94-97
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• 2021

The purpose of this study was to introduce a new in vitro method for evaluating the antimicrobial activity of toothpaste, reflecting the actual toothbrushing time and the dilution of toothpaste by salivation. We designed three experimental groups and one negative control group. The experimental groups were (1) 90 μL of toothpaste + 10 μL 1X phosphate-buffered saline (PBS, 9/10 dilution group), (2) 50 μL of toothpaste + 40 μL 1X PBS (1/2 dilution group), and (3) 25 μL of toothpaste + 65 μL 1X PBS (1/4 dilution group). During toothbrushing, saliva is continuously secreted into the oral cavity and the toothpaste concentration is diluted over time during toothbrushing. Therefore, the 1/2 and 1/4 dilution experimental groups were added. The negative control group was toothpaste diluted 20,000-fold with 1X PBS. Miracle Fresh Doctor toothpaste and Streptococcus mitis KCOM 1350, Prevotella intermedia KCOM 1107, Fusobacterium nucleatum subsp. polymorphum KCOM 1322, and Aggregatibacter actinomycetemcomitans KCOM 1306 were used as the toothpaste and target bacterial strains, respectively. The number of bacterial cells plated on agar plates in the negative control group was 1,000 CFU. If the number of colonies on the experimental group plate was less than one, the treatment was considered to have > 99.9% bactericidal activity. These results suggest that this new in vitro method for antimicrobial evaluation could be used as the standard method for testing the antimicrobial activity of toothpaste.

• 유통과학연구
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• 제19권4호
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• pp.53-60
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• 2021

Purpose: This study focuses on exploring ways to improve the distribution method of shrimp farming so that it is eco-friendly and increases the distribution of shrimp. Research design, data and methodology: The experimental device installed in a biofloc shrimp culture in one area tested 10 times. Complex odor, concentration of H2S, water quality improvement effected by decomposition of organic substances, and degree of microbial activation measured. The data of the experimental results verified using the T-test technique, and the p value was determined based on the significance probability of 0.05. Results: This experimental device was effective in reducing odor and hydrogen sulfide in shrimp farms. With the improvement of water quality, dissolved oxygen increased due to the microbubble and cavitation action of air ejector and ultrasonic waves. In addition, the cultured microorganisms in the cultured water treated by the experimental device were remarkably proliferated compared to the raw water. Conclusions: The biofloc distribution method has a significant effect on improving water quality and reducing odor substances and will become a new eco-friendly and efficient distribution method for shrimp farming in the future.

• 재활간호학회지
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• 제5권1호
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• pp.18-26
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• 2002

The purpose of this study was to elucidate the effects of inhalation method using essential oils on the preoperative anxiety of hystrectomy patients, and to provide effective and holistic nursing care to them. The research design was a nonequivalent control group non synchronized design. The data were collected from February 1 to March 31, 2002 at D Medical Center in Busan. The subjects were forty one patients that were operated on under general anesthesia for hystrectomy. They were assigned to two groups, twenty one subjects in the experimental group and twenty subjects in the control group. The tool of the Visual Analogue Scale(VAS) was used to anxiety on all patients the day before surgery and the preoperative period. Then systolic and diastolic blood pressure, pulse rate levels were measured the day before surgery and the preoperative period. The experimental group received two treatments of inhalation method using essential oils of with lavender, ylang ylang, and bergamot oil. The data were analyzed by the $X^2$ test and the independent t-test. The results of this study were summarized as follows: 1. Hypothesis 1: It has been supported that the experimental group received inhalation method using essential oils might cause lower level of the preoperative VAS anxiety than that of the control group(t=-2.93, p=.006). 2. Hypothesis 2: It has been rejected that the experimental group received inhalation method using essential oils might cause lower level in the preoperative systolic blood pressure than the control group(t=-.120, p=.905). It has been rejected that the experimental group received inhalation method using essential oils might cause lower level in the preoperative diastolic blood pressure than the control group.(t=1.766, p=.085). 3. Hypothesis 3: It has been supported that the experimental group received inhalation method using essential oils might cause lower level in preoperative pulse rate than the control group(t=5.853, p=.000). According to these results, inhalation method using essential oils can be considered an effective nursing intervention that relieves the preoperative anxiety of hysterectomy patients and stabilizes vital sign partially.

• 소성∙가공
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• 제12권5호
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• pp.504-512
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• 2003

The plastic strain ratios(R-values) of low carbon steel sheets were determined by the automatic strain measurement method using two extensometers, the indirect photo method for the same tensile specimen during tensile test and the indirect method for the specimen after tensile test. The experimental results showed that the measured plastic strain ratios from the automatic strain measurement method using two extensometers coincided with those from the indirect photo method and the indirect method for all tensile specimens. In addition, the strain dependence of plastic strain ratios could be continuously recorded and the anisotropy of the strength coefficient, K, and strain hardening exponent, n, could be automatically calculated in three directions by computer through the use of two extensometers. The experimental results showed that the strain dependence of R-value was related to the anisotropy of strain hardening exponent in low carbon steel sheets.

• 한국한의학연구원논문집
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• 제16권2호
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• pp.83-90
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• 2010

Objective : The purpose of this study was to provide the information about Bojungikki-tang by domestic papers and theses. Method : Domestic papers related to Bojungikki-tang were reviewed and analyzed. These papers were classified by year, research method, experimental method, and subject. Result : The following results were obtained in this study. 1. The study of Bojungikki-tang started from 1984 and continued steadily. 2. The domestic papers about Bojungikki-tang were 47 volumes. Among them, there were 26 volumes since 2000. 3. Classified by research method from the year 2000, 20 experimental studies, 4 clinical experiments, and 2 documentary researches. 4. Classified by experimental method from the year 2000, 10 studies used mouse in vivo experiment and 4 studies used rat in vivo experiment and 6 studies used each cell in vitro experiment. 5. Classified by subject from the year 2000, papers related to immune enhancing effect, nerve and mental system, radiation protection effect, anti-allergy, anti-inflammatory, anti-cancer, remedy of diabetes, skin protection and so on. Conclusion : Many papers of experimental studies, clinical experiments and documentary researches related Bojungikki-tang are included in domestic journals. Bojungikki-tang is being researched variously in immune enhancing effect, nerve and mental system, radiation protection effect, anti-allergy, anti-inflammatory, anti-cancer, remedy of diabetes, skin protection and so on. However, more clinical studies on Bojungikki-tang are needed.

• Structural Engineering and Mechanics
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• 제76권2호
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• pp.251-267
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• 2020

Transmission tower-line systems have come to represent one of the most important infrastructures in today's society. Recent strong earthquakes revealed that transmission tower-line systems are vulnerable to earthquake excitations, and that ground motions may arrive at such structures from any direction during an earthquake event. Considering these premises, this paper presents experimental and numerical studies on the dynamic responses of a 1000 kV ultrahigh-voltage (UHV) transmission tower-line system under different seismic incidence angles. Specifically, a 1:25 reduced-scale experimental prototype model is designed and manufactured, and a series of shaking table tests are carried out. The influence of the seismic incidence angle on the dynamic structural response is discussed based on the experimental data. Additionally, the incidence angles corresponding to the maximum peak displacement of the top of the tower relative to the ground (referred to herein as the critical seismic incidence angles) are summarized. The experimental results demonstrate that seismic incidence angle has a significant influence on the dynamic responses of transmission tower-line systems. Subsequently, an approximation method is employed to orient the critical seismic incidence angle, and a corresponding finite element (FE) analysis is carried out. The angles obtained from the approximation method are compared with those acquired from the numerical simulation and shaking table tests, and good agreement is observed. The results demonstrate that the approximation method can properly predict the critical seismic incidence angles of transmission tower-line systems. This research enriches the available experimental data and provides a simple and convenient method to assess the seismic performance of UHV transmission systems.