• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.46-56
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• 1999

A semi-actively controlled impact system which adjusts an impulse exerted by the external impact is studies. The main control variables are internal pressure difference inside the cylinder and the shock absorber displacement while it travels. Compared to a conventional one so called a passive system with a variable orifice inside the cylinder, a semi-actively controlled system utilizes an external orifice controlled by a highly fast responding electrical proportional valve. This device overcomes the temperature and viscosity change due to continuous operating and keeps the desired pressure difference and displacement in every operation. In this article a new prototype impact system is designed and manufactured based on a semi-actively control system. Through computer simulations and experiments, we verify the possibility of controlling the shock absorber pressure and displacement. After investigating the control performance a modified semi-actively controlled system with better control performance is also proposed.

• Transactions of The Korea Fluid Power Systems Society
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• v.6 no.3
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• pp.16-22
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• 2009

This paper deals with the issue of robust position tracking control and energy-saving control for a valve-controlled cylinder system using speed-controlled fixed displacement pump. The whole feedback control system is composed of a pair of interconnected subsystems, that is, valve-controlled cylinder system and load-sensing control system. From experiments it is shown that position tracking control in the load sensing control system can accomplish significant reduction in input energy to pump comparing to a conventional valve-controlled cylinder system, while exhibiting the same position tracking control accuracy.

• Journal of The Korean Dental Society of Anesthesiology
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• v.13 no.4
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• pp.179-188
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• 2013

Background: Today, there are computer controlled local anesthesia devices used clinically. The main principle is to control injection speed by computer aided system, and it relieves pain. However, there are few objective data considering this subject. In this literature review, we researched studies about computer controlled anesthetic delivery. We compared pain control effect of computer controlled to conventional local anesthetic syringe system. Methods: A bibliographic search in PubMed was performed and we reviewed original articles. Results: There were 18 publications that compared pain control effect of computer controlled to conventional system. There were 8 articles reported of children, similar pain control effect was found in 7 of them. One study showed superior pain control effect of computer controlled anesthetic delivery. For adults, 10 studies showed superior pain control effect in computer aided system. Conclusions: Computer controlled anesthetic delivery has similar or superior pain control effect compared to conventional local anesthetic syringe system. For both children and adults, computer controlled anesthetic delivery could be clinically useful, still it may be more effective for adults.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.14 no.3
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• pp.315-322
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• 2007

Purpose: The purpose of this study was to examine the effect of three kinds of modes using bolus button of PCA on level of pain and side effects of analgesic and amount of drug consumption in post-operative patients according to whether the medication is controlled by the patient, the caregiver or the nurse. Method: The participants were 684 patients using PCA after an operation. The data collection period was from March 19 to April 6, 2007. Results: It was found that there were statistical differences in gender, age, type of surgery, pain on first post-operative day, amount of drug consumption, nausea, and vomiting. The ratio for patient controlled medication was 55.7% for women, and 70.5% for men, and for care-giver controlled medication, 35.1% for women, and 20.0% for men. Average pain scores for the first post-operative day were $3.9{\pm}2.2$ for patient controlled medication and $4.5{\pm}2.3$ for care-giver controlled medication. There were statistical differences according to mode used for PCA for amount of drug consumptions, nausea and vomiting but not for pain, operation day or pruritus. Conclusion: This study was carried out to examine risks according to who controls the PCA for post-operative patients. The results can help to develop education program for everyone who is involved in PCA, patients, caregivers, nurses and doctors.

• IE interfaces
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• v.17 no.1
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• pp.113-120
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• 2004

The increased use of computers has introduced a variety kind of human-computer interfaces. Mouse is one of the useful interface tools to place the cursor on the desired position on the monitor. This paper suggested a foot controlled isotonic mouse which was similar to the ordinary hand-controlled mouse except that positioning was controlled by the right foot and the clicking was performed by the left foot. Experimental results showed that both the index of difficulty(IOD) and the display-control gain(DC gain) varied the total movement time in a target acquisition task on the monitor. The present authors also drew the optimal display-control gain of the foot-controlled isotonic mouse over the index of difficulty of 1.0 to 3.0. The optimal display-control gain, i. e., 0.256, could be used when designing a foot-controlled isotonic mouse.

• Journal of the korean academy of Pediatric Dentistry
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• v.4 no.1
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• pp.28-34
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• 1977

The present study was undertaken to evaluate gingivitis and oral hygiene status of the crowned teeth comparing to controlled teeth by use of P. M. A. Index and Oral Hygiene. Index in children from $3\frac{1}{2}$ to $7\frac{1}{2}$ years old. The results were as followings. 1. In P. M. A. Index, satisfactory crowned teeth (1.53) showed statistically significant increment compare to the controlled teeth (0.68) (P<0.01). 2. In P. M. A. Index, unsatisfactory crowned teeth (2.22) showed statistically significant increment compare to the controlled teeth (0.70) (P<0 01). 3. In Oral Hygiene Index, satisfactory crowned teeth (1.49) showed statistically nonsignificant increment compare to the controlled teeth (1.27). 4. In Oral Hygiene Index, unsatisfactory crowned teeth (1.62) showed statistically nonsignicant increment compare to the controlled (1.39) 5. The severity of gingivitis following Oral Hygiene Index showed higher in crowed teeth than the controlled teeth. 6. The severity of giginvitis showed the highest in the unsatisfactory crowned teeth, the next was the satisfactory crowned teeth, and the controlled teeth showed the lowest.

• Journal of The Korean Dental Society of Anesthesiology
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• v.10 no.2
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• pp.166-171
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• 2010

Background: Controlled hypotension is used to reduce bleeding and improve surgical conditions during surgery. Nicardipine and remifentanil have been used to induce controlled hypotension in healthy patients. This study compared controllability of nicardipine and remifentanil on hemodynamic stability during controlled hypotension. Methods: Forty healthy patients scheduled for orthognathic two jaw surgery were randomly allocated to nicardipine (group N) and remifentanil (group R) group. After induction of anesthesia, group N (n = 20) was infused with nicardipine to induce hypotension and group R (n = 20) was infused with remifentanil. Mean arterial pressure (MAP) and heart rate (HR) were measured over 5 minute interval. Surgical field rating and blood loss were measured after surgery. Results: HR was lower in group R than group N. MAP was maintained at 50-60 mmHg during controlled hypotension but the fluctuation of blood pressure and HR were more frequent in group N than group R. There were no significant differences in the surgical field rating and blood loss between the groups. Conclusions: Nicardipine and remifentanil enabled controlled hypotension and provided good surgical conditions, but the fluctuation of hemodynamic parameters was more frequent in nicardipine group.

• Physical Therapy Korea
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• v.12 no.1
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• pp.36-44
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• 2005

The purpose of this study was to examine the effects of self-controlled learning using the (KR) feedback schedule versus the yoked KR on the acquisition and retention of balance training for individuals with hemiplegics. Sixteen hemiplegics were randomly assigned to either a self-controlled or yoked KR group. All subjects were ambulatory with or without an assistive device. The self-controlled group was provided with feedback whenever they requested it, whereas the yoked group had no influence on the feedback schedule. All subjects performed 10 acquisition trials and 10 retention trials the day after acquisition. The data were analyzed using an independent t-test and a Mann-Whitney U test. Participants in the self-controlled group achieved significantly more effective learning than the yoked group during the acquisition and retention test except anterior/posterior (AP) body sway. These results suggest that a feedback schedule which is controlled by the individuals with hemiplegics may be more effective in balancing training than a yoked KR which is not controlled by the subject.

• Communications for Statistical Applications and Methods
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• v.4 no.1
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• pp.151-159
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• 1997

In sample surveys, we expect preferred samples that reduce the survey cost and increase the precision of estimators will be selected. Goodman and Kish (1950) introduced controlled selection as a method of sample selection that increases the probability of drawing preferred samples, while decreases the probability of drawing nonpreferred samples. In this paper, we obtain the controlled plans using the maximum entropy principle, and when the order of nonpreferred samples is considered, we propose the algorithm to obtain a controlled plan.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.114-115
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• 2013

This paper proposes an estimation method of back emf for the sensorless controlled high speed PMSM drive in turbo compressors with air bearings. The back emf of PMSM motor varies due to the temperature variation, which deteriorates the control performance of sensorless controlled PMSM drives. The proposed method is based on the current model of the PMSM motor. The simulation results show that the proposed method estimates the back emf of sensorless controlled PMSM drives with reasonable accuracy for parameter adaptation.