• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.6
• /
• pp.95-99
• /
• 2013

Furnace is currently the most important doping process using POCl3 in solar cell. However furnace need an expensive equipment cost and it has to purge a poisonous gas. Moreover, furnace typically difficult appling for selective emitters. In this study, we developed a new atmospheric pressure plasma source, in this procedure, we research the atmospheric pressure plasma doping that dopant is phosphoric acid($H_3PO_4$). Metal tube injected Ar gas was inputted 5 kV of a low frequency(scores of kHz) induced inverter, so plasma discharged at metal tube. We used the P type silicon wafer of solar cell. We regulated phosphoric acid($H_3PO_4$) concentration on 10% and plasma treatment time is 90 s, 150 s, we experiment that plasma current is 70 mA. We check the doping depth that 287 nm at 90 s and 621 nm at 150 s. We analysis and measurement the doping profile by using SIMS(Secondary Ion Mass Spectroscopy). We calculate and grasp the sheet resistance using conventional sheet resistance formula, so there are 240 Ohm/sq at 90 s and 212 Ohm/sq at 150 s. We analysis oxygen and nitrogen profile of concentration compared with furnace to check the doped defect of atmosphere.

• Proceedings of the KWS Conference
• /
• 2002.10a
• /
• pp.156-161
• /
• 2002

It depends on the joint configuration, dimensions and constraints on the joint whether the residual stress at the root of single-sided butt weld is tensile or not. Therefore, recommendation is generally made that high R ratio should be used in the fatigue test of this type of joint in order to prevent excessively long life caused by compressive residual stress. in this research, the residual stress profile in butt weld joint was obtained through compliance method, using successive extension of a slot and measurement of the variation of strain during the slot extension. The residual stress profile was firstly assumed to be the linear summation of Legendre polynomials up to 9th order excluding 0th and 1st order. Strain variation on the surface was measured while the slot was being extended by cutting to find out the 8 unknown coefficients of each polynomial tenn. The cut was made by the electric discharge machine. It was concluded that the residual stress near the surface stayed positive, however, it turned into the negative value as soon as it passed through 2 or 3 mm depth. Several fatigue tests were also carried out under zero stress ratio. Test results showed that fatigue life coincides well with the design cuive of butt joint in British Standards, which supports that it is tensile residual stress that exists near the weld root.

• Journal of Korean society of Dental Hygiene
• /
• v.12 no.3
• /
• pp.471-483
• /
• 2012

Objectives : This study looked at the relationship between occupational stress and the Oral Health Impact Profile (OHIP), to evaluate the effect of occupational stress-related factors. Methods : Data was obtained from a cross-sectional survey of 260 local officials in Gangwondo. The research comprised three questions relating to subjective oral symptoms, an occupational stress measurement tool and an oral health impact factor which was composed of questions. The data was analysed using t-test, one-way ANOVA, Pearson correlation and path analysis in Amos. Results : Occupational stress had a positive correlation to drinking frequency, Oral symptoms had a negative correlation. And drinking frequency, smoking amount and occupational stress had a positive correlation to oral symptoms. It denoted that drinking frequency, occupational stress and oral symptoms had a negative correlation to OHIP. The path model had an excellent goodness of fit (p=0.07, namely p>0.05). Five 'goodness-of-fit indices' of the model were all above 0.9: GFI=0.987, AGFI=0.952, NFI=0.902, IFI=0.939, CFI=0.934), and its RMSEA was 0.045. Occupational stress and oral symptoms had a firsthand impact on OHIP. In addition, it affected OHIP through the parameters of oral symptoms. Occupational stress exercised a firsthand influence on drinking frequency, drinking frequency exercised a firsthand influence on smoking amount. Smoking amount had a firsthand impact on oral symptoms. Conclusions: Oral health education programs for the development of an improved oral hygiene environment through reduction in drinking and smoking also need to focus on relieving stress by improving workplace culture. In addition, due to good communication is required to reduce occupational stress caused by interpersonal conflict.

• Fashion & Textile Research Journal
• /
• v.11 no.3
• /
• pp.453-459
• /
• 2009

The purpose of this study was to provide the basic knowledge to determine the proper seam finish according to the design of sewing products. Four seam finishes(no seam finishes, over-edged seam finishes, turned-and-stitched seam finishes, and bias-bound seam finishes) were constructed with seams in warp, weft and bias directions of the fabric. Using a drape measurement system involving two 18cm diameter supporting disks and a digital camera, the images of draped specimens were captured and processed. Drape behavior was evaluated in terms of drape coefficient, node number, and drape profile. Drape coefficients of the fabrics increased with seam formation and varied by the seam finishes, however no significant differences in drape coefficients by the seam finishes were observed on the heavier fabric. Node numbers of heavier fabric were more deeply affected by the seam finishes than those of lighter fabric. The specimens with turned-and-stitched seam finishes and bias-bound seam finishes showed significantly smaller node numbers compared to the specimens with no seam finishes and over-edged seam finishes on heavier fabric. The length of the seamed part showed positive correlation with the weight of the specimens and negative correlation with the number of nodes in each seam direction. The maximum length of all draped specimens was found in the same direction as the seam direction. In the case of the lighter fabric, the seam and the seam finish had a great influence on the shape of the draped profile.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.18 no.6
• /
• pp.737-745
• /
• 2008

Recent developments of process and measurement technology bring much interest to the online monitoring of process operations such as milling, grinding, broaching, etc. The objective of online monitoring systems is to detect process changes as early as possible. This is helpful in protecting facilities against unexpected failures and then preventing unnecessary loss. This paper investigates, when the process monitoring data are obtained as a profile, the monitoring performances of a statistical $T^2$-statistic and a feedforward neural network by using a wavelet transform. Numerical experiments using cutting force data presented by Axinte show that the proposed wavelet based $T^2$-test has an acceptable power in detecting profile changes. However, its operating characteristic is very sensitive to autocorrelation. On the contrary, compared with $T^2$-test, the neural network has more stable performance in the presence of autocorrelation. This indicates that an adaptive feature to analyze noises should be incorporated into the wavelet based $T^2$-test.

• Journal of the Korean Society for Railway
• /
• v.18 no.1
• /
• pp.1-7
• /
• 2015

Maintenance and repair devices used for the inspection of the main parts of domestic railway vehicles have been imported from abroad. Especially, one of the representative domestic devices, the 'Wheel Profile Inspector System (WPIS)', was made by benchmarking foreign devices; this vehicle has been operated in the field. However, problems such as the reliability and performance of the WPIS in operation have appeared. In this study, in order to improve the precision and reliability of the WPIS for maintenance and inspection of railway vehicle wheels, the researchers improved the railway vehicle's WPIS by applying high-speed vision camera technology and an optimized image algorithm. The test results show that the reliability of the developed WPIS improved by approximately 10.4% compared to that of the conventional system.

• International Journal of Precision Engineering and Manufacturing
• /
• v.8 no.2
• /
• pp.54-58
• /
• 2007

This paper describes an atomic force microscope (AFM)-based instrument for measuring the nanoscale cutting edge profiles of diamond cutting tools. The instrument consists of a combined AFM unit and an optical sensor to align the AFM tip with the top of the diamond cutting tool edge over a submicron range. In the optical sensor, a aser beam is emitted from a laser diode along the Y-axis and focused to a small beam spot with a diameter of approximately $10{\mu}m$ at the beam waist, which is then received by a photodiode. The top of the tool edge is first brought into the center of the beam waist by adjusting it in the X-Z-plane while monitoring the variation in the photodiode output. The cutting tool is then withdrawn and its top edge position at the beam center is recorded. The AFM tip can also be positioned at the beam center in a similar manner to align it with the top of the cutting edge. To reduce electronic noise interference on the photodiode output and thereby enhance the alignment accuracy, a technique is applied that can modulate the photodiode output to an AC signal by driving the laser diode with a sinusoidal current. Alignment experiments and edge profile measurements of a diamond cutting tool were carried out to verify the performance of the proposed system.

• Korean Journal of Remote Sensing
• /
• v.25 no.2
• /
• pp.155-163
• /
• 2009

An abundance of internal waves is observed by SAR in the Yellow Sea during summer. They are small scaled internal waves and are not relatively studied well compared to the ones in the East/South China Sea. These internal waves should be considered in the study of physio-biological properties of the Yellow Sea because the mixing of the stratified surface water caused by internal waves during summer is important for ocean biological environment, and they also affect the sediment transport and acoustic signal transmission in the continental shelf region. To understand the characteristics of internal waves, it is important to get the spatio-temporal information of internal waves simultaneously by executing in-situ measurements as well as the SAR observation. This study tracks the internal waves observed by SAR in the time series of temperature profile data by analyzing simultaneously acquired in-situ measurement data and RADARSAT SAR image on 29 May 2002.

• Atmosphere
• /
• v.32 no.2
• /
• pp.163-178
• /
• 2022

This study aims to evaluate the accuracy of retrieved horizontal winds with different quality control methods from three Doppler lidars deployed over the complex terrain during the PyeongChang 2018 Olympic and Paralympic games. To retrieve the accurate wind profile, this study also proposes two quality control methods to distinguish between meteorological signals and noises in the Doppler velocity field, which can be broadly applied to different Doppler lidars. We evaluated the accuracy of retrieved winds with the wind measurements from the nearby or collocated rawinsondes. The retrieved wind speed and direction show a good agreement with rawinsonde with a correlation coefficient larger than 0.9. This study minimized the sampling error in the wind evaluation and estimation, and found that the accuracy of retrieved winds can reach ~0.6 m s^-1 and 3° in the quasi-homogeneous wind condition. We expect that the retrieved horizontal winds can be used in the high-resolution analysis of the horizontal winds and provide an accurate wind profile for model evaluation or data assimilation purposes.

• Journal of the Korean Applied Science and Technology
• /
• v.40 no.5
• /
• pp.1104-1115
• /
• 2023

The present study aims to verify the usefulness of microcurrent stimulation as an effective intervention for managing body shape. Thirty female college students with a percentage body fat of 30% or more participated as subjects and belonged to the one of three groups; control group, combined exercise group, microcurrent stimulation group. Based on the results of analyzing the measurement data from pre- and post-intervention for four weeks for each group, the following conclusions were obtained. There was no statistically significant difference in all measured variables in the control group. However, waist circumference and TC were significantly reduced in the combined exercise group, and also weight, percentage body fat, waist circumference, and apolipoprotein were significantly reduced in microcurrent stimulation group. Considering the above conclusions, it can be suggested that microcurrent stimulation could be an effective intervention to improve body composition and blood lipid profile to have a healthy body.