• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.589-601
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• 2016

Sea surface currents were estimated by applying the Maximum Cross Correlation (MCC), Zero-mean Sum of Absolute Distances (ZSAD), and Zero-mean Sum of Squared Distances (ZSSD) algorithms to Himawari-8/Advanced Himawari Imager (AHI) thermal infrared channel data, and the comparative analysis was performed between the results of these algorithms. The sea surface currents of the Kuroshio Current region that were retrieved using each algorithm showed similar results. The ratio of errors to the total number of estimated surface current vectors had little difference according to the algorithms, and the time required for sea surface current calculation was reduced by 24% and 18%, relative to the MCC algorithm, for the ZSAD and ZSSD algorithms, respectively. The estimated surface currents were validated against those from satellite-tracked surface drifter and altimeter data, and the accuracy evaluation of these algorithms showed results within similar ranges. In addition, the accuracy was affected by the magnitude of brightness temperature gradients and the time interval between satellite image data.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.5
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• pp.98-107
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• 1995

The in-process detection of drill wear and breakage is one of the most importnat technical problems in unmaned machining system. In this paper, the monitoring system is developed to monitor abnormal drilling states such as drill breakage, drill wear and unstable cutting using motor current. Drill breakage is detected by level monitoring. Tool wear is classified by fuzzy pattern recognition. The key feature for classification of tool wear is the estimated flank wear which is calculated by the proposed flank wear model. The characteristic of the model is not sensitive to the variation of cutting conditions but is sensitive to drill wear state. Unstable cutting states due to the unsmooth chip disposal and the overload are monitored by the variance/mean ratio of spindle motor current. Variance/mean ratio also includes the information about the prediction of drill wear and drill breakage. The evaluation experiments have shown that the developed system works very well.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.2
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• pp.1-6
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• 1986

Even though it is well known that the tidal current in the East China Sea rotates clockwise, few report can be found about the precise pattern of it. To furnish some information available for the stow net fishermen, the author carried out the observation over 235 semidiurnal tidal cycle to investigate the pattern of the set and the rate of tidal current in the Korean fishing section 250 and 494, by reading the current meter and by tracing the corner reflectors with radar onboard the anchored obsen'ation vessel, from May 12, 1984 through February 27, 1986. The results obtained are as follows: 1. The mean semidiurnal tidal cycle was 12 h 20 m during spring tide, and 12 h 30 m during neap tide. 2. The mean interval from the calculated time of high water until the current began to set north was 2 h 30 m and 2 h 15 m in the fishing section 250 and 494 respectively, and the mean interval from the time of low water current began to set south was about 2 h 0 m in both sections. 3. In comparison of the occupied times to vary the set from one of 8 principal bearing points to the neighboring one, the shortest was while the set varied from N to NE and S to SW in the section 250 and 494 respectively. Contrary the longest was while the set varied from SE to S and from W to NW in the section 250 and 494 respectively. 4. In comparison of the rate while the set varied from one of 8 principal bearing points to the neighboring one, the fastest was while the set varied from SE to Sand NW to N in the section 250, and E to SE and W to NW in the section 494. Contrary the slowest was while the current set to NE and S W in the section 250, and N, NE and S W in the section 494.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.947-951
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• 1997

Recently, the necessity of the detection of abnormal machining process is being emphasized in order to improve the machining accuracy and reduce the cost in unmanned operating system. The vibration by chatter generated in cutting processes within machine tools is a relative motion between tools and workpieces. So, if the chatter occurs, the surface roughness and accuracy of workpieces will be deteriorate and it leads to the rapid wear of tools. The author intended to use the I /sab/RMS (current of root mean square) of current sigals and the movimg C.V. (coefficient of variation) of each phase for the detection method of chatter.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.4 no.1
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• pp.1-12
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• 2006

This study conducted RIII reflex measurement to examine degree of pain depending on polarity of high voltage pulsed current of primary and secondary hyperalgesia site in hyperalgesia rat by local thermal injury. Hind paw which was injury site was taken as primary hyperalgeisa site, sole which was injury adjacent site was taken as secondary hyperalgesia site, and mechanical pain threshold, thermal pain threshold and root mean square of RIII reflex were measured. This study was conducted with control group I of hyperalgesia rat at hind paw by thermal injury and experimental groups divided into cathodal high voltage treatment group II, anodal high voltage treatment group III and alternate high voltage treatment group IV, applied active electrode of high voltage pulsed current to hind paw directly, placed reference electrode on the sole of injury adjacent site and applied pulse frequency. It measured RIII reflex and obtained the following results: Root mean square of RIII reflex at primary hyperalgeisa site was significantly reduced in group II after 2 days of hyperalgesia. Group II showed significant decrease after 5 and 6 days of hyperalgesia. Root mean square of RIII reflex at secondary hyperalgesia site showed significant reduction in group II after 6 days of hyperalgesia. Consequently it was found that application of high voltage pulsed current of hyperalgesia site reduced RIII reflex at primary hyperalgeisa site and secondary hyperalgesia site by electrical stimuli. Effects by polarity of high voltage pulsed current showed the greatest reduction of pain threshold when cathodal active electrode was used.

• Journal of Korean Society on Water Environment
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• v.39 no.5
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• pp.396-412
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• 2023

Species from the mayfly genus Ephemera (Order Ephemeroptera) was assessed for their physical microhabitat suitability (namely E. strigata, E. separigata, and E. orientalis-sachalinensis). Probability distribution models (Exponential, Normal, Lognormal, Logistic, Weibull, Gamma, Beta, and Gumbel) based on the data collected from 23,957 sampling units of 6,787 sites in Korea from 2010 to 2021 were used. Mode and standard deviation calculated from the best-fitting models to species distribution along a water depth gradient were 265 cm and 159 cm in E. orientalis-sachalinensis; 10 cm and 83 cm in E. strigata; 20 cm and 15 cm in E. separigata, respectively. The current velocity gradient was 22 cm/s and 40 cm/s in E. orientalis-sachalinensis; 60 cm/s and 53 cm/s in E. strigata; 82 cm/s and 25 cm/s in E. separigata, respectively. The mean diameter (phi scale) of substrate grains were -3.6 and 2.2 in E. orientalis-sachalinensis; -7.4 and 1.5 in E. strigata; -5.8 and 0.9 in E. separigata, respectively. Habitat suitability range of E. orientalis-sachalinensis was estimated to be 161~369 cm (water depth), 5~44 cm/s (current velocity), -5.2~-2.0 (mean diameter); 3~34 cm (water depth), 36~94 cm/s (current velocity), -8.1~-6.3 (mean diameter) for E. strigata; 12~32 cm (water depth), 63~96 cm/s (current velocity), -6.3~-5.2 (mean diameter) for E. separigata. In relative comparison, E. orientalis-sachalinensis was estimated to be rheophobic, eurybathophilic, and eurypsephophilic; E. strigata to be euryrheophilic, bathophobic, and lithophilic; E. separigata to be stenomesorheophilic, stenobathophobic, stenolithophilic.

• Journal of the Korean institute of surface engineering
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• v.36 no.2
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• pp.161-167
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• 2003

In order to investigate the effects of pulse plating conditions on the electrodeposition of trivalent chromium, electroplating experiments from bath with low concentration of trivalent chromium were performed. The variation of current efficiency of chromium electroplating with the electroplating conditions was explained. The maximum current efficiency of pulse plating is 6.4 times as high as that of direct plating at the same mean current density The nodular size increased with pulse plating time and the pulse frequency.

• Korean Journal of Veterinary Research
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• v.22 no.2
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• pp.115-119
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• 1982

Total protein levels of 60 bovine bull sera were treasured with refractometer and the strum proteins were fractionated by cellulose acetate membrane electorphoresis and the relative amount of each fraction was measured with automatic scanning densitometer. The sixty bovine bulls consisted of 17 Charolais bulls, 28 Holstein bulls and 15 Korean bulls. Mean total serum protein level of the total bulls was $7.50{\pm}0.50(Mean{\pm}SD)$, with the mean of Charolais $7.04{\pm}0.37g/dl$, the mean of Holstein $7.62{\pm}0.40g/dl$ and the mean of Korean $7.81{\pm}0.43g/dl$. As barbital-calcium buffer was used in fractionating the bovine serum protein with cellulose acetate membrane, electric current of 0.4 mA per centimeter width of the membrane for an hour resulted in more clear separation between ${\alpha}_1$-globulin and ${\alpha}_2$-globulin than electric current of 0.6 or 1.0 mA for an hour. However ${\alpha}_1$-globulin and ${\alpha}_2$-globulin could not be measured separately with automatic scanning densitometer. Mean serum albumin level of total bulls was $3.54{\pm}0.42g/dl$, with the mean of Charolais $3.42{\pm}0.26g/dl$, the mean of Holstein $3.69{\pm}0.38g/dl$ and the mean of Korean $3.39{\pm}0.55g/dl$. Mean serum ${\alpha}$-globulin level of the total bulls was $0.62{\pm}0.14g/dl$, with the mean of Charolais $0.61{\pm}0.07g/dl$, the mean of Holstein $0.60{\pm}0.11g/dl$ and the mean of Korean $0.67{\pm}0.23g/dl$. Mean ${\beta}$-globulin level of the total bulls was $0.85{\pm}0.21g/dl$, with the mean of Charolais $0.74{\pm}0.11g/dl$, the mean of Holstein $0.83{\pm}0.14g/dl$ and the mean of Korean $1.02{\pm}0.30g/dl$. Mean serum ${\gamma}$-globulin level of the total bulls was $2.48{\pm}0.45g/dl$ with the mean of Charolais $2.27{\pm}0.37g/dl$, the mean of Holstein $2.48{\pm}0.44g/dl$ and the mean of Korean $2.72{\pm}0.47g/dl$.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.610-614
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• 2002

Time-mean and absolute geostrophic velocities of the Kuroshio current south of Japan are derived from TOPEX/Poseidon altimeter data using a Gaussian jet model. When compared with simultaneous measurements from a shipboard acoustic Doppler current profiler (ADCP) at two intersection points, the altimetric and ADCP absolute velocities correlate well with the correlation of 0.55 to 0.74. The time-mean velocity is accurate to 1 cm s$^{-1}$ to 5 cm s$^{-1}$. The errors in the absolute and the mean velocities are similar to those reported previously far other currents. The comparable performance suggests the Gaussian jet model is a promising methodology for determining absolute geostrophic velocities, noting that in this region the Kuroshio does not meander sufficiently, which provides unfavorable environment for the performance of the Gaussian jet model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1377-1389
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• 2016

This paper presents a target model update scheme for the mean-shift tracking with background weighted histogram. In the scheme, the target candidate histogram is corrected by considering the back-projection weight of each pixel in the kernel after the best target candidate in the current frame image is chosen. In each frame, the target model is updated by the weighted average of the current target model and the corrected target candidate. We compared our target model update scheme with the previous ones by applying several test sequences. The experimental results showed that the object tracking accuracy was greatly improved by using the proposed scheme.