• Journal of the Optical Society of Korea
• /
• v.3 no.1
• /
• pp.1-9
• /
• 1999

We have studied the sensitivity of four different phase shift measurement schemes with a Mach-Zehnder interferometer. The input light is considered to be in a coherent state and the detectors are assumed to be ideal with the quantum efficiency of unity. It is shown by direct calculation of the operators corresponding to the measurement schemes that the uncertainty of the phase-shift measurement is limited to the classical one $\frac{1}{\sqrt{m}}$(m is the average number of the photons in the input state) regardless of the phase-shift measurement schemes.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.16 no.2
• /
• pp.117-128
• /
• 2020

The aim of this study was to examine price sensitivity of industrial products purchased via a group buying system and how industrial products for a group buying system differ from general industrial products, and then identify the major factors in selecting products and the important determinants in purchasing industrial products for school foodservices. The survey was conducted with 250 dietitians (teachers) in Gyeonggi-do Province, who were using industrial products for a group buying system and general industrial products. A paired t-test showed a difference in satisfaction between industrial products for a group buying system and general industrial products by factors, while statistically significant differences were found for red pepper paste, fermented soybean paste and soy sauce in all nine satisfaction factors, including product quality, packaging state, labeling, hygiene, item diversity, specification diversity, price appropriateness and supply. Moreover, analyzing price sensitivity for industrial products for a group buying system, using the PSM method with respect to the issue of high price, showed that the respondents considered that the current unit purchase prices were high for all items investigated. This study suggests that schools would purchase more industrial products for a group buying system, when the pricing of the products are considered with the purchase intention of dietitians (teachers).

• Fire Science and Engineering
• /
• v.24 no.5
• /
• pp.102-106
• /
• 2010

This paper studied the measurement about the gunpowder residue quantity by using a handgun and we carried out an experiment ignition characteristics of the gunpowder residue for the investigation fire cause into the indoor shooting range in Busan. The measurement of the gunpowder residue quantity is spouted by using a 0.38 inch gun and 9 mm gun. We were carried out evaluation experiments such as impact sensitivity test, static electricity sensitivity test, friction sensitivity test and measuring a flash point for the ignition characteristics about the gunpowder residue. From experiment results, the impact sensitivity and friction sensitivity of the gunpowder residue in comparison with ball powder are highly sensitive and the gunpowder residue ignites at a relatively low temperature.

• Journal of the East Asian Society of Dietary Life
• /
• v.26 no.2
• /
• pp.117-124
• /
• 2016

As the number of cafeterias at universities has increased, studies on student perception of price sensitivity at cafeterias have gained increased attention. Therefore, the study investigated the relationship between students and university cafeterias according to price sensitivity measurement (PSM). According to the analysis, the indifference price (IDP) was 3,444.06 Korean Won while the subsequent cumulative distribution percentage was approximately 17.68%. The optimal pricing point (OPP) was 3,233.73 Korean Won and the stress price (IDP-OPP) was 210.33 Korean Won. The point of marginal expensiveness (PME) was 4,602.24 Koean Won and the point of marginal cheapness (PMC) was 2,036.29 Korean Won. Therefore, the range of acceptable prices (RAP) was established as 2,565.95 Korean Won. In addition, the study examined differences between price sensitivity measurement (PSM) for the respondent subgroups. Hence, the results will provide a practical background for development of business plans for university cafeterias.

• Journal of radiological science and technology
• /
• v.46 no.3
• /
• pp.219-229
• /
• 2023

In this study, basic characteristics such as reproducibility, linearity, and directionality of RPL glass dosimeters were evaluated to improve the reliability of dose evaluation through RPL glass dosimeters, and uncertainty elements such as sensitivity by glass element and magazine slot sensitivity were evaluated. Using a mathematical model to calibrate the measured values of the RPL glass dosimeter, the measurement uncertainty was calculated assuming an example. As a result of the characteristic evaluation, the RPL glass dosimeter showed excellent performance with a standard deviation of ±1% (1 SD) for the reproducibility of the reading process, a coefficient of determination for linearity of 0.99997. And the read-out of the RPL glass dosimeter are affected by the circular rotation direction of the glass dosimeter during irradiation, fading according to the period after irradiation, the number of laser pulses of the reader, and response degradation due to repeated reading, it is judged that measurement uncertainty can be reduced by irradiation and reading in consideration of these factors. In addition, it was confirmed that the dose should be determined by calculating the correction factors for the sensitivity of each element and, the sensitivity of each reading magazine slot. It is believed that the reliability of dosimetry using glass dosimeters can be improved by using a mathematical model for correction of glass dosimeter readings and calculating measurement uncertainty.

• Journal of Advanced Navigation Technology
• /
• v.23 no.1
• /
• pp.69-76
• /
• 2019

In this paper, a design method for an enhanced-sensitivity microwave sensor based on microstrip defected ground structure was studied for the permittivity measurement of planar dielectric substrates. The proposed sensor was designed by modifying the ridge structure of an H-shaped aperture into the shape of a capacitor symbol. The sensitivity of the proposed sensor was compared with that of a conventional sensor based on a double-ring complementary split ring resonator(DR-CSRR). Two sensors were designed and fabricated on a 0.76-mm-thick RF-35 substrate so that the transmission coefficient would resonate at 1.5 GHz in the absence of the substrate under test. Five types of taconic substrates with a relative permittivity ranging from 2.17 to 10.2 were selected asthe substrate under test. Experiment results show that the sensitivity of the proposed sensor, which is measured by the shift in the resonant frequency of the transmission coefficient, is 1.31 to 1.62 times higher than that of the conventional DR-CSRR-based sensor.

• Corrosion Science and Technology
• /
• v.12 no.5
• /
• pp.220-226
• /
• 2013

The uncertainty in statistical noise resistance measurement was evaluated for a type 316 stainless steel in NaCl solutions at room temperature. Sensitivity coefficients were determined for measurands or variables such as NaCl concentration, pH, solution temperature, surface roughness, inert gas flow rate and bias potential amplitude. The coefficients were larger for the variables such as NaCl concentration, pH, inert gas flow rate and solution temperature, and they were the major factors increasing the combined standard uncertainty of noise resistance. However, the contribution to the uncertainty in noise resistance measurement from the above variables was remarkably low compared to that from repeated measurements of noise resistance, and thus, it is difficult to lower the uncertainty in noise resistance measurement significantly by lowering the uncertainties related with NaCl concentration, pH, inert gas flow rate and solution temperature. In addition, the uncertainty in noise resistance measurement was high amounting to 17.3 % of the mean, indicating that the reliability in measurement of noise resistance is low.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.05a
• /
• pp.1150-1155
• /
• 2001

The updating of the FE model to match it with the experimental results needs the modal information. There are two causes where this methodology is ill-equip to deal with; under-determined and ill-conditioning problem. In this research, the feedback exciter which uses the summation of the white noise and the signals from the measurement sensors multiplied with feedback gains is proposed. The new energy path generated by the feedback exciter changes the modal characteristics of the system and this additional modal information can solve the under-determined problem in the model updating. Through the proper selection of the exciter and sensor locations and the feedback gain, the eigenvalue sensitivity of the updating parameters which cause the ill-conditioning of the sensitivity matrix can be modified. This methodology does not require any additional equipments, makes the acquirement of the additional modal information easy and is robust to the measurement noise.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.11
• /
• pp.587-596
• /
• 1999

The use of Switching elements in power systems causes the current or voltage to involve harmonic waves. Harmonics bring about registration errors of the equipment for measuring power. In case the induction watthour meter designed on sinusoidal source is used in the measurement of power with harmonics, the precise measurement of power has many problems because harmonics cause a decrease of power factor and vibration by the unstable driving force on the aluminum disc. In this paper, analysis and test results on the harmonic sensitivity of an induction watthour meter is reported when the input voltage and current with harmonics were supplied to single-phase watthour meter.

• Journal of the Ergonomics Society of Korea
• /
• v.18 no.3
• /
• pp.1-12
• /
• 1999

This study investigated human operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, the effects of three mechanical parameters consisting vibrotactile stimulations, i.e., vibration frequency, pulse-width modulation duty cycle, and number of contactors, on differential thresholds were examined at five different loci of the hand. It was observed that differential threshold varies with vibration frequency and number of active contactors. Differential sensitivity was the greatest at the vibration frequency of 120 Hz. The differential sensitivity was not found to be affected by loci on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. It should be noted that the conclusions from this study generally correspond to those from the previous study on the absolute sensitivity. which means that tactile sensitivity to vibrotactile stimulations can be controlled with a systematic and consistent passion for emulating normal everyday contact on human hands in teleoperation and virtual reality applications.