• Journal of the Korean Society for Precision Engineering
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• v.3 no.2
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• pp.28-38
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• 1986

An analytical and experimental investigation is made to the dynamic responese of a cantilever with a tip mass that models some of the basic phenomena involved in the response of a flexible manipulator with a tip mass on its free end under the given rotating motion. The system equation is derived from the Hamilton's principle on the basis of the Euler-Bernoulli hypothesis and an approximate solution is obtained from model analysis using Galerkin's method for the vibation response of the system subjected to a sudden stop after an impulsive rotation. Experiment was performed to verify the validity of the theoretical analysis. Results are given for the vibration amplitude of the free end with respect to tip mass ratio, non-dimensionalized rotating velocity, rotating angle and non- dimensionalized hub length. The rotating condition to minimize the vibration amplitude of the free end can be determined for the given basic paramenters.

• Journal of Korean Medical Science
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• v.33 no.47
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• pp.300.1-300.17
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• 2018

Parkinson's disease (PD) is the second most common neurodegenerative disorder. Although its major manifestation is motor symptoms, resulting from the loss of dopaminergic neurons in the substantia nigra, psychiatric symptoms, such as depression, anxiety, hallucination, delusion, apathy and anhedonia, impulsive and compulsive behaviors, and cognitive dysfunction, may also manifest in most patients with PD. Given that the quality of life - and the need for institutionalization - is so highly dependent on the psychiatric well-being of patients with PD, psychiatric symptoms are of high clinical significance. We reviewed the prevalence, risk factors, pathophysiology, and treatment of psychiatric symptoms to get a better understanding of PD for improved management.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.332-336
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• 2023

In this paper, we design and implement an ADHD diagnostic rating scale algorithm and virtual reality- based digital treatment by combining virtual reality technology that enables multiple access based on specialized medical data. The VR ADHD digital treatment to be implemented is intended to be applied directly to diagnosis and treatment of child/adolescent ADHD by applying various psychiatric treatment technologies. In order to evaluate the usability of the digital therapeutic agent developed in this paper, an expert group consisting of 2 males and 12 females "targeted counseling psychology majors at the Asian Dementia Center once a day for 3 weeks, ADHD VR-based digital therapeutics for children Experienced and usability evaluation conducted. As a final result of this thesis, it was possible to develop attentional concentration ability, working memory improvement ability, and impulsive control ability in four games of digital therapy, and it was possible to confirm significant results that can be expected to have ADHD therapeutic effects.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.10
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• pp.51-59
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• 2005

In this paper, results of a multiple spacecraft formation-keeping control using the orbital relative motion and optimization technique are presented. To analyze and predict the relative motion between the formation-flying satellites, a closed-form orbit propagator obtained using the method of ephemeris compression is used. This closed-form orbit propagator is combined with optimization technique to plan a series of impulsive maneuvers, which maintain the formation configuration within the specified limit. As an example, this method is applied to the problem of maintaining the projected circular formation geometry and results from nonlinear simulation are presented.

• The Journal of the Acoustical Society of Korea
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• v.32 no.5
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• pp.408-414
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• 2013

The famous filtered-x least mean square (FxLMS) algorithm for active noise control (ANC) systems may become unstable in non-stationary noise environment. To solve this problem, Sun's algorithm and Akhtar's algorithm are developed based on modifying the reference signal in update of FxLMS algorithm, but these two algorithms have dissatisfactory stability in dealing with sustaining impulsive noise. In proposed algorithm, probability estimation and zero-crossing rate (ZCR) control are used to improve the stability and performance, at the same time, an optimal parameter selection based on fuzzy system is utilized. Computer simulation results prove the proposed algorithm has faster convergence and better stability in non-stationary noise environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.9
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• pp.983-989
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• 2014

In this paper, a new active noise control method was proposed to decrease a weight of car, and to increase a fuel efficiency and to provide passengers' comfort and calmness, instead of a passive noise control method such as sound absorbing and insulating materials. The proposed method is an enhanced active noise controller operating by a bidirectional control algorithm. The algorithm is simple to implement and available to analyze mathematically with nearly equivalent complexity of computation. Through simulations for engine noises of a car, the proposed controller was verified that its performances of time and frequency domain were superior to those of both feedforward and feedback controllers, and it had better capability of controlling the noises when the impulsive disturbance was flow in and the response of secondary path was varied.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.23 no.1
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• pp.14-22
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• 2012

Objectives : The purpose of present study is to identify the differences between temperament and character traits among adolescents classified by ego resilience and ego control level. Methods : A Junior Temperament and Character Inventory (TCI) was performed on participants, and a California Child Q-Test (CCQ) was tested for by the parents of the adolescent participants. Results : The result of the factor analysis and discriminant analysis show that the participants are classified into three different groups based on CCQ score and item response patterns. The three groups are named the ego resilience group, the undercontrolled group, and the overcontrolled group. The ego resilience group indicates that they have a high level of interest and curiosity but yet they are not easily tempered. Moreover, they behave proactively with a reasonable level of responsibility in order to improve themselves. In contrast, among the undercontrolled group, it is observed that, although the group shows even higher level of interest, curiosity and honesty, they are careless, more impulsive, and have a lack of delayed gratification and shame. Conclusions : The overcontrolled group shows that they are the most cautious and reflective group among the three but also show emotional instability such as strong criticism and passive-aggressiveness. In this study, implications and limitations are discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.981-984
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• 2005

Recently, filtering methods for attenuating noise while preserving image details are in progress actively. And SM(standard median) fille. showed a great performance for noise removal in impulse noise environment but, it caused edge cancellation error So, variable methods that modified SM(standard median)filter have been proposed, and CWM(center weighted median) filter is representative. Also, there are several methods to improve the efficiency based on min/max operation in term of preserving detail and filtering speed. In this paper, we managed a pixel corrupted by impulsive noise using min/max value of the surrounding band enclosing a pixel, and compared the efficiency with exiting methods in the simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.1001-1004
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• 2006

Many researches have been processed to reconstruct corrupted an image by noise in fields of signal processing such as image recognition and compute. vision, and AWGN(additive white gaussian noise) and impulse noise are representative. Impulse noise consists of fired-valued(salt & pepper) impulse noise and random-valued impulse noise, and non-linear filters such as SM(standard median) filters are used to remove this noise. But basic SM filters still generate many errors in edge regions of an image, and in order to overcome this problem a variety of methods have been researched. In this paper, we proposed an impulse noise removal algorithm which is superior to the edge preserving capacity. At this tine, after detecting a noise by using the noise detector, we applied a noise removal algorithm based on the min-max operation and compared the capacity with existing methods through simulation.

• Genes and Genomics
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• v.40 no.12
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• pp.1309-1317
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• 2018

It is well known that dopaminergic genes affect the development of attention deficit hyperactivity disorder (ADHD) in various populations. Many studies have shown that variable number tandem repeats (VNTRs) located within the 3′-untranslated region of DAT1 and in exon 3 of DRD4 are associated with ADHD development; however, these results were inconsistent. Therefore, we investigated the genetic association between two VNTRs and ADHD in Korean children. We determined the VNTRs using PCR. We examined genotype and allele frequency differences between the experimental and control groups, along with the odds ratios, using Chi square and exact tests. We observed a significant association between the children with ADHD and the control group in the 10R/10R genotype of DAT1 VNTRs (p=0.025). In addition, the 11R allele of DAT1 VNTRs showed a higher frequency in the control group than in the ADHD group (p=0.023). Also, the short repeat (without 11R) and long repeat alleles (including 11R) were associated with ADHD (p<0.05). The analysis of DRD4 VNTRs revealed that the 2R allele is associated with ADHD (p=0.025). A significant result was also observed in long and short repeats (p<0.05). Additionally, ADHD subtypes showed that the DRD4 VNTRs are associated with combined and hyperactive-impulsive subtype groups (p<0.05). Therefore, our results suggest that DAT1 VNTRs and DRD4 VNTRs play a role in the genetic etiology of ADHD in Korean children.