• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.104-111
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• 2018

The sensorless control of high efficiency air compressors using a permanent magnet type synchronous motor as an oil-free air compressor is quite common. However, due to the nature of the air compressor, it is difficult to install a position sensor. In order to control the permanent magnet type synchronous motor at variable speed, the inclusion of a position sensor to grasp the position of the rotor is essential. Therefore, in order to achieve sensorless control, it is essential to use a permanent magnet type synchronous motor in the compressor. The position estimation method based on the back electromotive force, which is widely used as the sensorless control method, has a limitation in that position errors occur due either to the phase delay caused by the use of a stationary coordinate system or to the estimated back electromotive force in the transient state caused by the use of a synchronous coordinate system. Therefore, in this paper, we propose a method of estimating the position and velocity using a rotation angle tracking observer and reducing the speed ripple through a disturbance observer. An experimental apparatus was constructed using Freescale's MPU and the feasibility of the proposed algorithm was examined. It was confirmed that even if a position error occurs at a certain point in time, the position correction value converges to the actual vector position when the position error value is found.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.34-40
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• 2004

In this paper, we have studied the OCT(Optical Coherence Tomography) system which has been advantages of high resolution, 2-D cross-sectional images, low cost and small size configuration. The characteristics of light source determine the resolution and coherence length. The light source has a commercial SLD with a central wavelength of 1,285 ill11, 35.3 nm(FWHM). The optical delay line is necessary to make equal with the optical path length to scattered light or reflected light from a sample. In order to make equal the optical path length, the stage that is attached to a reference mirror is controled by a step motor. And the interferometer is configured with the Michelson interferometer by using a single mode fiber, and the scanner can be focused on the sample by using a reference ann Also, the 2-dimension cross-sectional images were measured with scanning the transverse direction of the sample by using a step motor. After detecting the internal signal of lateral direction, a scanner is moved to obtain the cross-sectional image of 2-dimension by using step motor. A photodiode, which has high detection sensitivity and excellent noise characteristics has been used. The detected small signal has a noise and interference. After filtering and amplifying the signal, the output signal is demodulated the waveform And then, a cross-sectional image is seen through converting this signal into a digitalized signal by using an AID converter. The resolution of the sample is about 30${\mu}{\textrm}{m}$, which corresponds to the theoretical resolution. Also, the cross-sectional images of onion cells were measured in real time scheme.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.5-9
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• 2004

In this paper, we studied the OCT(Optical Coherence Tomography) system which it has been extensively studied because of having some advantages such as high resolution cross-sectional images, low cost, and small size configuration. A basic principle of OCT system is Michelson interferometer. The characteristics of light source determine the resolution and the transmission depth. As a results, the light source have a commercial SLD with a central wavelength of 1,285 nm and FWHM(Full Width at Half Maximum) of 35.3 nm. The optical delay line part is necessary to equal of the optical path length with scattered light or reflected light from sample. In order to equal the optical path length, the stage which is attached to reference mirror is moved linearly by step motor And the interferometer is configured with the Michelson interferometer using single mod fiber, the scanner can be focused of the sample by using the reference arm. Also, the 2-dimensional cross-sectional images were measured with scanning the transverse direction of the sample by using step motor. After detecting the internal signal of lateral direction at a paint of sample, scanner is moved to obtain the cross-sectional image of 2-demensional by using step motor. Photodiode has been used which has high detection sensitivity, excellent noise characteristic, and dynamic range from 800 nm to 1,700 nm. It is detected mixed small signal between noise and interference signal with high frequency After filtering and amplifying this signal, only envelope curve of interference signal is detected. And then, cross-sectional image is shown through converting this signal into digitalized signal using A／D converter. The resolution of the OCT system is about 30$\mu\textrm{m}$ which corresponds to the theoretical resolution. Also, the cross-sectional image of ping-pong ball is measured. The OCT system is configured with Michelson interferometer which has a low contrast because of reducing the power of feedback interference light. Such a problem is overcomed by using the improved inteferometer. Also, in order to obtain the cross-sectional image within a short time, it is necessary to reduce the measurement time for improving the optical delay line.

• The Journal of Korean Academy of Sensory Integration
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• v.15 no.2
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• pp.66-79
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• 2017

Objective : The purpose of this study is investigate the effects of sensory integration combined with auditory treatment on the sensory processing, visual perception and attention ability of children with developmental delay. Methods : A combined treatment of auditory training and sensory integration therapy was implemented to 3 children aged 4 to 7 and diagnosed with developmental delay during 9 weeks period from December 2016 to January 2017. ABA' design which is one of single subject research designs was used in this study. Baseline A had 4 sessions, intervention B had 15 sessions, and baseline A' had 4 sessions, so 23 sessions were applied in total. During the baseline A and A 'periods, visual perception ability was measured by K-DTVP-2 (Korea Developmental Test Visual Perception-2) and sensory processing ability was evaluated by sensory profile. The maintenance time of attention was measured with the absence of intervention for the baseline period, and for the intervention period, it was measured at 10 minutes break time which was provided after the intervention. The children's attention time during a fine motor task provided were measured using video recorder with the interval recording method, and the interval for the evaluation was 30 seconds. Results : No statistically significant difference were found in the visual perception function and sensory processing scores before and after treatment. Attention of participant A enhanced significantly while that of participant B and C did not improve significantly. Conclusion : It is hard to conclude that sensory integration therapy combined with auditory perception training has positive effects on visual perception function and attention of children with developmental delays. However, there were significant increase in attention and improvements in behavior related to sensory processing for some cases in this study. In further study, longer intervention periods and valid measurement need to be applied in order to get better results. And it is proposed that more studies need to be done to enhance evidence of auditory perception training as a mean to facilitate attention and to prepare learning.

• Korean journal of psychology:General
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• v.36 no.1
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• pp.81-107
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• 2017

The study aims to investigate the clinical utility of Bayley-III using US norm in Korea. A total of 98 preterm infants and 93 term infants were assessed with the K-Bayley-III. The performance pattern of preterm infants was analyzed with mixed design ANOVA which examined the differences of scaled scores and composite scores of Bayley-III between full term- and preterm- infant group and within preterm infants group. Then, We have investigated agreement between classifications of delay made using the BSID-II and Bayley-III. In addition, ROC plots were constructed to identify a Bayley-III cut-off score with optimum diagnostic utility in this sample. The results were as follows. (1) Preterm infants have significantly lower function levels in areas of 5 scaled scores and 3 developmental indexes compared with infants born at term. Significant differences among scores within preterm infant group were also found. (2) Bayley-III had the higher scores of the Mental Development Index and Psychomotor Developmental Index comparing to the scores of K-BSID-II, and had the lower rates of developmental delay. (3) All scales of Bayley-III, Cognitive, Language and Motor scale had the appropriate level of discrimination, but the cut-off composite scores of Bayley-III were adjusted 13~28 points higher than 69 for prediction of delay, as defined by the K-BSID-II. It explains the lower rates of developmental delay using the standard of two standard deviation. This study has provided empirical data to inform that we must careful when interpreting the score for clinical applications, identified the discriminating power, and proposed more appropriate cut-off scores. In addition, discussion about the sampling for making the Korean norm of Bayley-III was provided. It is preferable that infants in Korea should use our own validated norms. The standardization process to get Korean normative data must be performed carefully.

• Clinical and Experimental Pediatrics
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• v.51 no.12
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• pp.1342-1345
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• 2008

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare white matter disorder, first described in the early 1990s. The brain in patients with MLC appears swollen on MRI, with diffuse white matter abnormalities; in addition, there is an invariable presence of subcortical cysts, primarily in the anterior temporal region sparing the deep white matter, basal ganglia, thalami, and cerebellum. Patients with MLC present with macrocephaly and neurological abnormalities such as motor deterioration, ataxia, spasticity, and cognitive deficits. We report a twenty-month-old boy who presented with seizures and macrocephaly, delay in development, and abnormal brain MRI findings compatible with the diagnosis of MLC. The brain MRI revealed bilateral hypersignal intense subcortical white matter regions in the frontal, temporal, and parietal lobes on T2-weighted images, which were not yet associated with cystic changes. During follow-up, the frequency of seizures decreased after anticonvulsant medication was started, but the head circumference remained above the 97th percentile, and the patient continued to have developmental delay.

• Research in Community and Public Health Nursing
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• v.13 no.1
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• pp.89-97
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• 2002

Purpose: The purpose of this study is to explore the validity of the application of the Denver II developmental screening test to Korean children. This screening test. which was developed and standardized in United States. was designed to screen for developmental delay in Korea. and to compare the levels of development of Korean children with the development of children from the U.S. Method: Quota sampling. NP To facilitate field sampling. the age range used from 0 to 6 years old. was split into 10 different age groups. Sample size was estimated according to residence. 1.054 children were recruited from Seoul's metropolitan. urban and rural areas. NP To fill the quota established. the Recruitment and testing of children was done at public health centers, pediatric outpatient clinics of general hospitals and a child care center. The 25, 50, 75 and 90 percentiles were identified by using logistic regression analysis and were calculated as norms. The items in which the ages of both 50 and 90 percent passing differed more than 20 percent by the calculation was identified for comparison. NP Result: There were significant differences found in 45 items between Korean children and the children from the City of Denver as it relates to age differences. 90% of the sample passed items among 125 items from 4 sectors, e.g., personal- social. fine motor adaptive, language, and gross motor sectors. Korean children were found to be advanced in 9 items, whereas there were significant differences found in 38 items in our comparison of the two countries for age differences when 50% of sample pass items. Korean children were found to be advanced in 16 items. NP Conclusion: The result showed that there was a discrepancy in the developmental norms. It could be explained by the differences in the developmental environment. including child rearing patterns and ethnicity. Therefore, a restandardization of the Denver Screening Test is necessary as it relates to its application on Korean children. This restandardization is necessary in order to avoid both under and over-referrals of children with developmental abnormality. The modification of items in the language sector is especially suggested.

• Journal of Chest Surgery
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• v.29 no.1
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• pp.14-23
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• 1996

Circulatory arrest under deep hypothermia is an important auxiliary means for cardiac surgery, especially useful in pediatric patients. However, its clinical safety, particularly with regard to the neurologic outcome after long duration of circulatory arrest, is still not established. This study is a review of the eight years'clinical experience of hypothermic circulatory arrest at the Seoul national University Children's Hospital. During an eight-year period from January 1986 through December 1993, a total of 589 consecutive cardiac operations were done using circulatory arrest under deep hypothermia. Among them, 434 consecutive patients, in whom the duration of arrest was 20 minutes or more, are the subject of this study. The duration of arrest ranged from 20 minutes to 82 minutes (mean = 38.7 minutes) under rectal temperature in the range from 12.5$^{\circ}C$ to 25.8$^{\circ}C$. Early neurologic abnormalities occurred in 47 patients : seizure attacks in 28 patients, motor paralyses with or w thout seizure in 12, blindness in 2, and no recovery of consciousness in 5 patients. The rate of incidence of early neurologic abnormalities was calculated at 15.7%. 25 patients showed late neuropsychologic sequelae, such as motor paralysis (9 patients), recurrent seizures (6), developmental delay (8), and definitely low intelligence (2). The rate of incidence of late neurologic sequelae was 8.5%, By statistical analysis, the following factors were identified as the risk factors for post-arrest neurologic abnormalities ; 1) long duration of circulatory arrest, 2) lower-than-ideal body weight, 3) preexisting neurological abnormalities, 4) associated non-cardiovascular congenital anouialies, and 5) low blood pressure during the early post-arrest period. It is concluded that circulatory arrest under deep hypothermia is a relatively safe means for pediatric cardiac surgery with acceptable risk. However, to warrant maximal safety, it is desirable to limit the duration of arrest to less th n 40 minutes. In addition, it is our contention that the early post-arrest period is a very critical period during which maintenance of adequate perfusion pressure in important for the neurologic outcome.

• Korean Journal of Clinical Pharmacy
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• v.22 no.4
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• pp.356-366
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• 2012

Background: Chemotherapy-induced peripheral neuropathy (CIPN) involving sensory and motor nerve damage or dysfunction is a common and serious clinical problem that affects many patients receiving cancer treatment. This condition may pose challenges for the clinician to diagnose and manage, particularly in patients with coexisting conditions or disorders that involve the peripheral nervous system. Many chemotherapeutic agents used today are associated with the development of serious and dose-limiting CIPN that can adversely affect the administration of planned therapy and can impair quality of life by interference with the patients' activities of daily living. The most important clinical objective in the evaluation of patients with CIPN is to determine their level of functional impairment involving activities of daily living. These findings are used to make medical decisions to continue, modify, delay, or stop treatment. The most commonly reported drugs to cause CIPN include taxanes, platinum agents, vinca alkaloids, thalidomide, and bortezomib. We aimed to determine PN incidence during cisplatin, carboplatin and oxaliplatin administration. Methods: We collected data from 125 patients who received at least one cycle of cisplatin, carboplatin or oxaliplatin. They completed a self-reported questionnaire and items related to their disease and peripheral neuropathy. The investigators filled in part of items about disease and treatment. Patient Neurotoxicity Qeustionnaire developed by Bionumerik company were applied for PN assessment. Results: The incidences of sensory neurotoxicities of cisplatin, carboplatin and oxaliplatin were respectively 23%, 56% and 50%. The incidences of motor neurotoxicities of cisplatin, carboplatin and oxaliplatin were respectively 18%, 42% and 19%. The incidences of severe neurotoxicities of cisplatin, carboplatin and oxaliplatin were respectively 13%, 28% and 14%. The incidences of PN were associated with cumulative dose but not age, gender and concurrent illness. 19.2% of the patients (24/125) were prescribed with gabapentin, nortriptyline or gabapentin plus nortriptyline to reduce these peripheral symptoms and 75% of the patients answered the drug were effective. Conclusion: Incidence of PN after cisplatin or oxaliplatin administration is cumulative dose-related. Physician-based assessments under-reported the incidence and severity of CIPN. To overcome this limitation, diagnostic tools specifically designed to assess peripheral neuropathy severity associated with chemotherapy must be developed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.1
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• pp.12-20
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• 1994

Generally, the totally paralyzed face can never be made normal by any of the current methods of reconstruction. Careful selection of patients based on sound judgment of what can and cannot be achieved by the proposed surgical technique is paramount to a successful operation and a satisfied patient. The results are related to time of delayed between injury and repair ; the shorter the delay the better are the results. The objectives in correcting facial paralysis are to achieve normal appearance at rest ; symmetry with voluntary motion ; control of the ocular, oral, and nasal sphincter ; symmetry with involuntary emotion and controlled balance when expressing when expressing emotion ; and no significant functional deficit secondary to the reconstructive surgery. It must be employed a number of concepts, for treatment of the paralyzed face by surgeon, depending on the cause, time interval, and wound characteristics, as well as the availability of and necessity for neuromuscular substitution. Nerve grafts, crossovers, muscle transfers, free muscle and nerve-muscle grafts, micronuerovascular muscle transfers, and regional muscle transposition are the principal methods being developed. We applied the temporal musle transposition for reanimation of unilatrally paralyzed faces for long times on two patients. The results of muscle transposition can be enhanced by the patient's learning to activate the transposed muscle by voluntary effort, and are best in patients who are motivated to learn the necessary motor-sensory coordination techniques.