• International Journal of Highway Engineering
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• v.11 no.2
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• pp.27-35
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• 2009

This study was conducted to suggest resonable quality measurement methods of asphalt pavements to be used in the Pay adjustment. The Pay adjustment is a method to adjust the construction cost according to the pavement quality based on the statistic theories. Many U.S states use Pay adjustment and the PWL(Percent with in Limit) is calculated using their quality index tables. In this study, the application of PWL in Korea was evaluated by comparing the PWL South Carolina with the probability theories. The probability values and the PWL obtained using the data collected from the test roads were used to determine the pay factors suggested by AASHTO and the pay factors between them were closed to each other. In addition, the PWL was very similar to the probability obtained using the predicted average of the population when calculating the Z-values. The pay factors were obtained using artificial data whose average satisfied the codes and whose standard deviation was large. The pay factors were less than 100% in the quality measurements can be performed using the PWL methods, and with the development of the korea quality index table, the PWL methods can be applied in korea.

• School Mathematics
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• v.15 no.2
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• pp.289-314
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• 2013

Achievement profile by attribute in Korean students' mathematics was analyzed by applying cognitive diagnostic model, which is the newest measurement theory, to 2011 NAEA(National Assessment of Educational Assessment) results. The results are as follows. As the level of school is higher from 6th grade, 9th grade to 11th grade, the percentage of students mastering cognitive attribute 9(expressions using picture, table, graph, formula, symbol, writing, etc) drastically declined from 78%, 35% to 26%. It is necessary to have learning strategies to reinforce their abilities of expressing table, graph, etc. that higher graders in mathematics are more vulnerable to. Next, the property of mastering cognitive attributes according to gender, multi-cultural family was analyzed. In terms of mathematics, the percentage of girls mastering most of the attribute generally is higher than that of boys from 6th grade to 9th grade, however, boys show higher mastery in almost attributes than girls in the 11th grade. Compared to boys, the part where girls have the most trouble is attribute 9 in mathematics(expressions using picture, table, graph, formula, symbol, writing, etc). As international marriage, influx of foreign workers, etc. increase, the number of students from Korea's multi-cultural families is expected to be higher, therefore, identifying the characteristics of their educational achievement is significant in reinforcing Korea's basic achievement. In mathematics, gap of mastery level of attributes between multi-cultural group and ordinary group is more severe in higher grade and the type of multi-cultural group that needs supports for improving achievement most urgently changed in 6th grade, 9th grade and 11th grade respectively. In the 6th and 11th grade, migrant students from North Korea show the lowest level of mastering attributes, however, in the 9th grade, the mastery rate of immigrant students is lowest. Therefore, there is an implication that supporting plans for improving achievement of students from multi-cultural family should establish other strategies based on the characteristics of school level.

• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.44-49
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• 2020

In this paper, a measuring circuit is designed through analyzing manufacture specification of the sensor based on MOS. And the best input-output polynomial are induced that really gas sensors are used in gas safety management industrial fields. Response characteristics of a MOS gas sensor is analysed by through sensor's output voltages are measured after standard gases with six kinds of concentrations are manufactured and are injected to the sensor. A lookup table is created by relations of sensor's output voltages by injecting gases with other concentrations. Because data of the formed lookup table are equal interval, a polynomial can be induced of method of approximation function. So the 5th polynomial of input-output for a sensor is defined, coefficients are calculated by using least squares method, and the 5th polynomial is completed for representing characteristics of the sensor. If the proposed polynomial is applied to gas leak detectors, an inverse transformation of polynomial and programing of array codes are recreated. In this research, polynomial is implemented with array types that intervals of values of a lookup table are one-fifth sampled and interpolated. The performance of proposed 5th calibration equation is verified that errors are reduced than a linear expression when tests are performed by measurement of concentrations against injection of standard gases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.499-504
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• 2017

A Mobile Radio Wave Measurement System (MRWMS)is a vehicle-mounted system designed to be operating in a single mission. The mission characteristic for mobile measurement requires mobility. For this, we must consider the arrangement and embedded method of MRWMS's antennas. In this paper, we described the measurement method design of direction detecting accuracy for MRWMS and designed the direction finding antenna mast capable of rotating itself by using a slip ring without turntable for Direction Finding (DF) accuracy test. As we removed the dependency of a limited local area by designing a measurement method of direction detecting accuracy, Equipment Under Test (EUT) zero-Adjustment and mounted process shortened. So, we the reduced production costs. We expect an improved cable loss value by shortening the RF cable length in accordance with our design. In addition, due to the same phenomenon, the entire system is lighter and the mobility is improved.

• Korean Journal of Optics and Photonics
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• v.21 no.3
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• pp.123-128
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• 2010

Sum frequency generation was utilized to obtain a yellow laser with the wavelength of 578.4 nm for a probe laser of an Yb lattice clock. The output of an Nd:YAG laser with wavelength of 1319 nm and that of an Yb-fiber laser with wavelength of 1030 nm were passed through a waveguided periodically-poled lithium niobate (WG-PPLN) for sum frequency generation. It is required that the probe laser has a linewidth of the order of 1 Hz to fully resolve the Yb lattice clock transition. Thus, the linewidth of the probe laser was reduced by stabilizing the frequency to a super-cavity. This was made of ULE with a low thermal expansion coefficient, and was mounted on an active vibration-isolation table at the optimal point for the reduced sensitivity to vibration. Also, this was installed in a vacuum chamber, and the temperature was stabilized to 1 mK level. This system was installed in an acoustic enclosure to block acoustic noise. The finesse of the super-cavity was measured to be 380 000 from the photon life time of the cavity.

• Progress in Medical Physics
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• v.11 no.1
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• pp.59-71
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• 2000

It is possible to obtain a fast CT scan during breath holding with spiral technique. But the risk of radiation is increased due to detailed and repeated scans. However, the limitation of X-ray doses is not fully specified on CT, yet. Therefore, the purpose of the present study is to define the limitation of X-ray doses on CT The CT unit was somatom plus 4. Alderson Rando phantom, Solenoid water phantom, TLD, and reader were used. For determining adequate position and size of organs, the measurement of distance(${\pm}$2mm) from the midline of vertebral body was performed in 40 women(20~40 years). On the brain scan for 8:8(8mm slice thickness, 8mm/sec movement velocity of the table) and 10:10(10mm slice thickness, 10mm/sec movement velocity of the table) methods, the absorption doses of exposed area of the 10:10 were slightly higher than those of 8:8. The doses of unexposed uterus were negligible on the brain scan for both 8:8 and 10:10. On the chest scan for 8:8, 8:10(8mm slice thickness, 10mm/sec movement velocity of the table), 10:10, 10:12(10mm slice thickness, 12mm/sec movement velocity of the table) and 10:15(10mm slice thickness, 15mm/sec movement velocity of the table) methods, 8:8 method of the absorption doses of exposure area was the most highest and 10:15 method was the most lowest. The absorption doses of 8:10 method was relatively lower than those of the other methods. In conclusion, the 8:10 method is the most suitable to give a low radiation burden to patient without distorting image quality.

• Korean Journal of Adult Nursing
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• v.21 no.6
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• pp.559-569
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• 2009

Purpose: This study was to examine the reliability and validity of Patient-Generated Subjective Global Assessment (PG-SGA) as a nutritional measurement for stroke patients. Methods: This was a methodological study performed from May 6 to June 10, 2009 at a tertiary university hospital in Seoul. For reliability of PG-SGA, inter-rater reliability was used for statistics. For concurrent validity, BMI and biomarkers were compared between PG-SGA 0 ~ 8 and ${\geq}$ 9. In addition, sensitivity, specificity, and predictive value of PG-SGA compared with SGA were calculated using a contingency table. For predictive validity, hospital day, complications, and readmission within 1-month after discharge were compared between PG-SGA 0 ~ 8 and ${\geq}$ 9. Results: Correlation of PG-SGA score between two observers was 0.83, and kappa value for the agreement of severe malnutrition was 0.78(all $p_s$ < .001). The scored PG-SGA showed high sensitivity and specificity (100% and 96.7%, respectively). Severe undernourished patients (PG-SGA ${\geq}$ 9) had significantly low TLC, protein, albumin, and prealbumin (all $p_s$ < .01) compared with non-undernourished patients (PG-SGA 0 ~ 8). Also, in severe undernourished patients, complications and readmission (all $p_s$ = 0.01) were more often represented, and hospital days (p = .013) were significantly delayed. Conclusion: PG-SGA is a reliable and valid measurement to assess nutritional status for stroke patients.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.1
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• pp.32-40
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• 2009

In this paper, we proposed an reconstruction algorithm of transmitted frames from displayed image on video terminal. For image quality assessment of the video streaming in the wireless network, we need information of the image that is transmitted to the end-user's device. Generally, subjective methods are widely used to evaluate the image quality by human beings because it is difficult to extract the transmitted image from the end-user's device. This paper presents an image reconstruction algerian based on the displayed image in video terminal for the extraction of the transmitted image. In the proposed method, we acquired the displayed image on video terminal using the camera. Camera-acquired images exhibit geometric and color distortions caused by characteristics of cameras and display devices. Therefore we correct the geometric distortion by exploiting the homography and color distortion by pre-computed look-up table. The experimental results show that the proposed measurement system yields promising estimation performance in terms of PSNR of $27{\sim}28dB$. We also carried out performance evaluation of the proposed method in terms of EPSNR and the quality of the estimated images by the proposed algerian was in fairly good range of MOS test scale.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.792-795
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• 2005

The guide-ways of precision machine tools are one of important element of machine tools. It has usually a pair of surfaces for constraint of one direction with bearing. In the case of precision machine tools, non-contact bearing such as hydrostatic bearing and aerostatic bearing is adopted usually. In this case, profiles of rails has effect on straightness and the clearance of bearing has effect on stiffness of guide way, which changes to higher if clearance changes to smaller. The clearance is varied along moving table according to relative distance of pair of rails. The relative distance of pair of rail can be divided by three properties. First and second properties are straightness of each pair of rail and bearing pad. And, third is parallelism about pair of rails and pairs of bearing pad. There are several methods for measuring straightness of each surface such as reversal method, sequential two point method, and way straightness. These straightness measuring methods are always acquiring deviation of profile from eliminating linear fitted inclined line and don't have the information of parallelism. Therefore, to get the small clearance for high stiffness, the straightness of rail and bearing pad and parallelism about pair of rails and pair of bearing pads are measured for correction such as regrinding, reassembling and lapping. In this research, new and easy method for measuring parallelism of pair of rails is suggested. Two displacement probe and sensor stage, which is carry on the displacement sensor, are needed. The simulation and experiment was accomplished about pair of horizontal guide way to confirm the measurement of parallelism. And, the third probe is added to measure the straightness of each rails by sequential two point method. From the estimation of combined these two methods, it is confirmed that the profiles of a pairs of rails can be measured.

• Journal of the Korea Fashion and Costume Design Association
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• v.4 no.3
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• pp.89-95
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• 2002

Object of this study presents marketing of new market segmentation as what I classify a social stratum, and analyze sense of value about each social class clothes and a taste, but is. The study way used a questionnaire as an investigation study way, and I did execution from September to October in 1999, and the investigation object picked up an any table with the woman university student who lived in Seoul and did investigation, and analysis targeted total 550 people. I used a measurement item of economic capital and cultural capital as a classification item of a social stratum and selected a dwelling, a kind of property, an annual salary of parents as an index of economic capital. Presentation held an occupation of parents, scholarship, culture activity as an index of cultural capital. It is social stratum structure an occupation arranges in 12 job categories by, for your reference, I do a social orbit of the P. Bourdieu which is a French sociologist and an index of inheritance cultural capital, and having set up eight phases of evaluation, and to do a Y, Cultural Capital with X with economic capital. Sense of value about clothes and attitude selected social value, aesthetic appreciation enemy value, authority a few value in sense of value of the 6 type that E. Spranger(1922) presented, and a proposal did type in 3 about clothes. The measurement way used a 11 question item and measured I with five phases of Likert-type criteria and executed factors analysis by main ingredient analysis and varimax revolution law. I named a more than inherent 1 with the liver which was social man, aesthetic appreciation enemy man, an authority enemy with a basis. The results are as follows : People of the group which they belong to the same social class, and there is have a similar taste and select a similar product, and scholarship and an occupation of parents please lay a taste of children and sense of value, a hierarchical difference of attitude too and do it.