• International Journal of Control, Automation, and Systems
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• v.6 no.3
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• pp.386-393
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• 2008

A position control method for interpolating aspherical grinding and polishing tool path was reviewed and experimented in a nano precision machine. The position-base algorithm was reformed from the time-base algorithm, proposed in the previous study. The characteristics of the algorithm were in the velocity control loop with position feedback. The aspherical surface was divided by an interval at which each velocity and acceleration were calculated. The theoretical velocity was corrected by position error during processing. In the experiment, a machine was constructed and nano-scale linear encoders were installed at each axis. Relation between process parameters and the variation of position error was monitored and discussed. The best result from optimized parameters showed that the accuracy was 150nm and improved from the previous report.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.5
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• pp.422-428
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• 1988

An iterative learning control system is a control system which makes system outputs follow desired outputs by iterating its trials over a finite time interval. In a discrete time system, we proposed one method in which present control inputs can be obtained by a linear combination of the input sequence and time-shifted error sequence at previous trial. In contrast with a continous time learning control system which needs differential opreration of an error signal, the time shift operation of the error sequence is simpler in a computer control system and its effectiveness is shown by a simulation.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.500-510
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• 1996

A Direct injection -mixing total -flow -control sprayer was developed and evaluated . The system provided precise application rates and minimized operator exposure to chemicals as well as providing a possibility for recycling container so f unused chemicals that can causes environmental contamination. Chemicals were metered and injected proportionally to the diluent flow rate to provide constant concentrations. The main diluent flow was varied in response to changes in travel speed. Experimental variables of the sprayer were the control interval, the sensitivity of flow regulating valve, the tolerance of control object and the sensitivity of the injection pump system. The optimal performance of the flow control system was with an average response time of 8.5 sec at an absolute steady state of error of 0.067 L/min (0.8% of flow rate). The average response time of the injection rate was -0.53 sec and the coefficient of variation (CV) of concentration was 3.2%.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.4
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• pp.51-56
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• 2006

This paper proposes a control algorithm, which is verified experimentally, for aspherical surface grinding and polishing. The algorithm provides simultaneous control of the position and interpolation of an aspheric curve. The nonlinear formula for the tool position was derived from the aspheric equation and the shape of the tool. The function was partitioned at specific intervals and the control parameters were calculated at each control section. The position, acceleration, and velocity at each interval were updated during the process. A position error feedback was introduced using a rotary encoder. The feedback algorithm corrected the position error by increasing or decreasing the feed speed. In the experimental verification, a two-axis machine was controlled to track an aspherical surface using the proposed algorithm. The effects of the control and process parameters were monitored. The results demonstrated that the maximum tracking error with tuned parameters was at the submicron level for concave and convex surfaces.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.127-127
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• 1995

The present study was conducted to examine the effect of recombinant bovine somatotropin(${\gamma}$ bST), which was administered to cow to promote milk production, on bST levels in milk. Fourteen cows were divided into two groups: 1) control cows received neither y bST nor vehicle, 2) treated cows were administered twice at two-week interval with 500mg ${\gamma}$ bST each cow by subcutaneous injection. Milk samples were taken on day 0 (prior to injection), day 7 (7 days after 1st injection), day 21 (7 days after 2nd injection) and day 35 (21 days after 2nd injection).

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.453-460
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• 2010

For high quality image acquisition, compensating air-vehicle motion is essential for airborne SAR system. This paper describes a timing control based motion compensation method for airborne SAR system. Efficient timing control is critical for SAR system since it maintains many timing signals and timing setting for the signals should be updated frequently. This paper proposes Timing Cluster method as an efficient means for timing control of SAR system. Moreover, this paper suggests a simple and efficient method to compensate air-vehicle motion based on the Timing Cluster method. Timing Cluster method enables SAR system to control the timing in a timing noncritical way just maintaining little amount of information.

• Korean Journal of Poultry Science
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• v.20 no.3
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• pp.133-140
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• 1993

A study was conducted to investigate the concentrations of Ca, P and ash in metatarsal bone of broiler chicks exposed to UV light in different Interval. Day-old Hubbard broiler chicks (199＝10 control＋3 irradiation interval $\times$ 9 elapsed time $\times$ 7 replicate) were fed vitamin D3 deficient diet for 3 wk in a windowless subdued-light room and exposed to 297 nm UVB light by 0.068 mJ/$\textrm{cm}^2$ three times In 0, 12 or 24 h interval. The metatarsal bones were taken at 0, 6, 12, 18, 24, 48, 96, 144 or 240 h after last irradiation, separated from adhering tissue, ether extracted, dried and ashed. The Ca concentration was measured by atomic absorption spectrophotometry and P by ammonium metavanadate colorimetry. When the birds were continuously exposed to UVB light for 30 min without interval, the Ca content in metatarsus increased gradually according to the time after irradiation and reached the highest value 16.75% at 240 h after exposure. The P content also increased gradually until 144 h, where it was 9.75%. The ash content in metatarsus increased continuously until 240 h, the final time in this research, where 42.75% was shown. As 10 min three times irradiation in 12 h interval was applied to the chicks, the metatarsal Ca presented a small peak(13.31%) at 12 h after irradiation and a large peak(16.91%) at 144 h. P content showed a small peak(7.18%) at 12 h and a large level(8.34%) at 240 h. Ash content increased continuously until 240 h, where it was 46.53%. The small peaks in Ca and P concentration were thought to be derived from preirradiation at 12 and 24 h before final irradiation for 10 min. When 24 h interval system was treated, the peak value of Ca content(24.18%) occurred earlier(96 h) than those in 0 and 12 h interval systems. P content also showed the maximum value at 96 h(7.29%). Ash content presented an increasing trend until 240 h, where 45.75% was appeared. In respecting the method of UVB irradiation, the peak value of Ca content in metatarsus appeared earlier in 24 h interval system than in other systems. Meanwhile the ash contents in metatarsus of birds exposed to UVB light in 12 and 24 h interval procedures were higher than those in 0 h interval one. Therefore, it was concluded that a daily 10 min irradiation of UVB light would be desirable for increasing the Ca and ash content in metatarsus of brolier chicks.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.97-105
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• 2010

An All-red clearance interval(AR) has been operating with amber signal in order to avoid collision between vehicles which cannot come out of the intersections, vehicles coming in from the opposite direction, and pedestrians(bicycles) on the crosswalk during the signal conversion time at the intersections. Foreign nations have been analyzing AR's influences of traffic accidents. On the other hand, the similar research has not been conducted in the country. The objective of this paper, therefore, is to analyze the safety at the intersections with respect to the installation of AR through the hypothesis test. A before-and-after analysis has been performed for 10 intersections where applied AR. From the 95% of significance level, the results of Non-parametric Test show that the installation of AR improves a safety at the intersections. The results indicates that AR discharges vehicles passing through the intersections and control entering vehicles at the intersections.

• Journal of Pharmacopuncture
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• v.23 no.1
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• pp.25-29
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• 2020

Objectives: Heavy menstrual bleeding has a significant effect on women's daily life and health consequences for theirs. Attention to women's and girls' menstrual health is critical for their health. This study presents the results of a novel research on the effect of chamomile capsule on the amount of bleeding, and the duration and interval of menstrual cycles. Methods: The current study was a randomized, double-blind, clinical trial, which was carried out on 118 female students living in dorms of Guilan University of Medical Sciences. The participants were divided into two groups of 59, each receiving either chamomile capsule 250 mg or placebo three times a day, for an interval beginning from 7 days before the starting menstruation till the next onset. Higham chart is the pictorial blood loss assessment to determine the amount and duration of menstrual bleeding. Data were analyzed using SPSS version 20. Alpha was set at 0.05 for all analyses. Results: The average amount of bleeding in the chamomile group decreased after taking the capsule (p = 0.001). However, statistical tests did not show any significant difference in terms of duration and interval between two bleeding in both the experimental and control groups (p > 0.05). Conclusion: The present study showed that the chamomile capsule decreases the amount of menstrual bleeding and can be used as a therapeutic method. Conclusion:The present study showed that the chamomile capsule decreases the amount of menstrual bleeding and can be used as a therapeutic method.

• Animal cells and systems
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• v.6 no.3
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• pp.221-225
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• 2002

This study was conducted to find out how young black-tailed gulls (Larus crassirostris) recognize adult voice signals after hatching. For the experiment, adult voice recorded in the natural environment was played back at controlled intervals and intensity (dB) to 15 young gulls that were artificially hatched in the laboratory. The chirirah call frequency of young gulls increased as the intensity of the mew call increased. The chirirah response of the control group was highest to the mew call at intervals of 1.8s. The adult long ca11 and alarm call also showed similar results to the mew call when the interval and intensity were manipulated similar to the mew call. Based on the results of this experiment, it is assumed that the young black-tailed gulls recognize adult voice signals based on the simple structure of adult voice signals, that is, the interval and intensity of the voice.