• Title/Summary/Keyword: frequency-response

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Development of an Interactive Graphic Software for the Education and Training of Power System Operation and Control (전력계통 운용 및 제어에 대한 교육 및 훈련용 대화식 그래픽 소프트웨어 개발)

  • Shin, Joong-Rin;Lee, Wook-Hwa
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.8
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    • pp.932-940
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    • 1999
  • This paper discusses the development of an interactive and graphic software for the education and training of power system operation and control, especially for students and beginners. This software has a lot of functions for users to simulate the power system operation and control with ease. These functions included in this software are followings. First, this software includes a Graphic User Interface (GUI) - which contains interactive simulation scheme, Windows dialog box, graphic representations, and graphic icons - so that users can handle the software in user-friendly environments. Second, it uses a graphic editor so that users can easily edit the one-line diagram of the power system. Third, it prepares a database system so that users can manage the power system data for simulation easily. Fourth, the application modules included in the software are the Economic Dispatch (ED) and the Automatic Load-Frequency Control (ALFC). These application modules are designed as independent modules. Using the ED module, users can understand the basic concepts of the ED with ease. And using the ALFC module, they can easily acquire the basic understanding of the response of the ALFC between the two-area systems. The proposed software is tested on both the 16 bus and the two-area sample system. The test has confirmed the functions of the developed software. It is anticipated that the software will be useful for the education and training of power system operation and control for the power engineering study at university or for the training of the beginner at power industry.

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Genetic Variations of ABCC2 Gene Associated with Adverse Drug Reactions to Valproic Acid in Korean Epileptic Patients

  • Yi, Ji Hyun;Cho, Yang-Je;Kim, Won-Joo;Lee, Min Goo;Lee, Ji Hyun
    • Genomics & Informatics
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    • v.11 no.4
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    • pp.254-262
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    • 2013
  • The multidrug resistance protein 2 (MRP2, ABCC2) gene may determine individual susceptibility to adverse drug reactions (ADRs) in the central nervous system (CNS) by limiting brain access of antiepileptic drugs, especially valproic acid (VPA). Our objective was to investigate the effect of ABCC2 polymorphisms on ADRs caused by VPA in Korean epileptic patients. We examined the association of ABCC2 single-nucleotide polymorphisms and haplotype frequencies with VPA related to adverse reactions. In addition, the association of the polymorphisms with the risk of VPA related to adverse reactions was estimated by logistic regression analysis. A total of 41 (24.4%) patients had shown VPA-related adverse reactions in CNS, and the most frequent symptom was tremor (78.0%). The patients with CNS ADRs were more likely to have the G allele (79.3% vs. 62.7%, p=0.0057) and the GG genotype (61.0% vs. 39.7%, p=0.019) at the g.-1774delG locus. The frequency of the haplotype containing g.-1774Gdel was significantly lower in the patients with CNS ADRs than without CNS ADRs (15.8% vs. 32.3%, p=0.0039). Lastly, in the multivariate logistic regression analysis, the presence of the GG genotype at the g.-1774delG locus was identified as a stronger risk factor for VPA related to ADRs (odds ratio, 8.53; 95% confidence interval, 1.04 to 70.17). We demonstrated that ABCC2 polymorphisms may influence VPA-related ADRs. The results above suggest the possible usefulness of ABCC2 gene polymorphisms as a marker for predicting response to VPA-related ADRs.

Reflex Eye Movements Induced by Stimulation of the Semicircular Canal Nerve in Rabbits (가토반규관신경자극(家兎半規管神經刺戟)에 의(依)한 반사성안구운동기전(反射性眼球運動機轉)에 관(關)하여)

  • Kim, Ki-Ho
    • The Korean Journal of Physiology
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    • v.2 no.2
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    • pp.75-81
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    • 1968
  • According to recent observations of Cohen et al. the patterns of vestibular eye movements of rabbits are different from those of cats. However, the causes of such difference of the reflex eye movements in these species are not wholly explained. While the accumulated data obtained from cats appear to be established, experimental evidences in rabbits are rather meager. The author had re-examined the reflex eye movements of rabbits and attempted to find a mechanism which causes such difference in the reflex eye movements between two species. In anesthesized rabbit, unilateral individual semicircular canal nerve was stimulated selectively with a fine insulated electrode which was inserted through a hole made on the corresponding osseous canal, under a dissecting microscope. When an individual canal nerve was stimulated, the reflex movements of both eyes were observed, photographed, and recorded kymographically. Extraocular muscles were also studied to find their morphological characteristics and to correlate them with the function of the muscles. 1. At the beginning of the stimulation, both eyes moved to a specific direction depending upon the canal stimulated, and such directional eye movements were sustained during the whole course of stimulation. Amplitude of the eye movement showed graded responses to the increasing frequency of the stimulus, reaching to the maximal response at 200-300 cps. 2. Stimulation of the unilateral horizontal canal nerve caused conjugate eye movements, which was also observed in cats and other species by other investigators. 3. Stimulation of the unilateral vertical canal nerve caused a pattern of non-conjugate eye movements, which are different from those observed in cats. Such different patterns of vestibular eye movements in two different species are ascribable to the functional difference of the inferior and superior oblique muscles.

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Intractable Hemifacial Spasm Treated by Pulsed Radiofrequency Treatment

  • Park, Hae Lang;Lim, Seung Mo;Kim, Tae Hwa;Kang, Kyung Ho;Kang, Hyun;Jung, Yong Hun;Baek, Chong Wha;Woo, Young Cheol;Kim, Jin Yun;Koo, Gill Hoi;Shin, Hwa Yong
    • The Korean Journal of Pain
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    • v.26 no.1
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    • pp.62-64
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    • 2013
  • Hemifacial spasm is defined as unilateral, involuntary, irregular twitching of all or parts of the muscles innervated by facial nerves. Here, we present a case of recurrent hemifacial spasm after microvascular decompression (MVD) treated with pulsed radiofrequency (PRF) treatment with good results. A 35-year-old woman suffered from recurrent hemifacial spasm after MVD that was refractory to medical treatment and botulinum toxin injections. We attempted a left facial nerve block twice. Then, we applied PRF at a maximum temperature of $42^{\circ}C$ for 120 sec. Some response was observed, so we applied PRF two additional times. The frequency of twitch decreased from 3-4 Hz to < 0.5 Hz, and subjective severity on a visual analogue scale also decreased from 10/10 to 2-3/10. PRF treatment might be an effective medical treatment for refractory hemifacial spasm and has fewer complications and is less invasive compared with those of surgery.

Current Status of Parents' Monitoring of and Level of Trust in School Lunch Programs (학부모의 학교급식 모니터링 현황 및 학교급식에 대한 신뢰도)

  • Hur, Boyoung;Choi, Injoo;Kim, Meeyoung;Kwon, Jinwook;Lee, Jiyoung;Yoon, Jihyun
    • Korean Journal of Community Nutrition
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    • v.22 no.5
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    • pp.401-412
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    • 2017
  • Objectives: The purpose of this study was to investigate the current status of parents' monitoring of school lunch programs and to examine the relationship of parents' school lunch monitoring with their level of trust in school lunch programs. Methods: During November 2016, a web survey was conducted with 1,283 parents who had participated in monitoring of school lunch programs. A total of 621 parents completed the questionnaires (48.4% response rate) and the responses from 442 parents were analyzed (34.5% analysis rate) for elementary (n=196) and middle/high school parents (n=246), respectively. Results: Both the elementary and middle/high school parents most wanted to participate in monitoring 1~2 times per month, which was less frequent than their current practice. They showed the highest experience rate in 'food sanitation' area in both the prior training and actual practice of school lunch monitoring. They most responded 'increasing trust in school lunch programs' as a merit and 'lack of parents participating in monitoring' as a problem of school lunch monitoring. The average levels of trust did not differ between elementary and middle/high school parents. Multiple regression analyses showed that elementary school parents' level of satisfaction in the monitored school lunch programs was positively associated with the parents' level of trust in general school lunch programs. Monitoring frequency and parents' age, in addition to level of satisfaction in the monitored school lunch program, were associated with level of trust in general school lunch programs among middle/high school parents. Conclusions: There was room for change in parents' school lunch monitoring programs to meet parents' needs better. Well-managed school lunch monitoring programs contributing to parents' satisfaction with school lunch programs could increase parents' level of trust in school lunch programs.

Acoustic Characteristics of Watermelon According to Impact Conditions (타격조건에 따른 수박의 음파특성)

  • 최동수;최규홍;이영희;이강진;김만수
    • Journal of Biosystems Engineering
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    • v.27 no.1
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    • pp.67-76
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    • 2002
  • This study was conducted to investigate the effects of impact conditions on the acoustic characteristics of a watermelon. The study was crucial to develop a device for nondestructive internal quality evaluation of a watermelon by an acoustic impulse response method. An impact device was constructed with a pendulum to hit the watermelon, a microphone to detect the acoustic impulse responses, and a digital oscilloscope and computer to store and analyze the data. The selected samples were Guemcheon cultivar watermelons(Citrulus Vulgaris Schrad) harvested on Oct. 20,1998. Sixty watermelons were tested on flour different types of sample holders, with four kinds of ball made of different materials, at four bevels of the angular position of the pendulum and distance from the watermelon to the microphone. Since the magnitudes of frequencies obtained by hitting with the steel and rubber ball were relatively small at the bandwidths of above 500 Hz, it was shown that the steel and rubber ball were not suitable far a hitting ball in the pendulum to get informations on internal quality of the watermelon. In case of using broth of the wood and acryl ball, almost the same and good acoustic responses were shown on the wide range of frequency bandwidth. Therefore, it seemed that the acryl ball was more suitable to the test than the wood ball in considering its mechanical properties. The acoustic characteristics of the watermelon were not shown a significant difference between the types of sample holder. The amplitudes of the acoustic signals and the magnitudes of frequencies from the whole samples increased with increase of the angular position of pendulum and with decrease of the distance from the watermelon to the microphone. However, the resonance resonance of the sample were almost the same regardless of the angular positions and the distances.

Free Vibration Characteristics of Rectangular Plates under Uniform Thermal Loading Part II. Experimental Modal Test (균일 열부가 하중을 받는 사각판의 자유 진동특성 연구 Part II. 고유진동 실험)

  • Jeon, Byoung-Hee;Kang, Hui-Won;Lee, Young-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.2
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    • pp.106-113
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    • 2011
  • This paper was conducted on experimental analysis in the free vibration analysis of rectangular plates under uniform thermal loading. Materials of three rectangular plates were aluminum, steel and stainless-steel respectively. The dimension of rectangular plates was 0.1 $\times$ 0.1 $\times$ 0.002 m. Infrared quartz lamps were used for thermal loading. The PCS(Power Control System) electric control system was applied for control and scanning vibrometer (Poly Tech) was used for acquisition of frequency response function. Applied temperature was increased from room temperature to $300^{\circ}C$ by $50^{\circ}C$. Boundary condition was free-free condition using bungee cord. Front face of rectangular plate was heated uniformly.

Changes of Afferent Transmission to the SI Cortex by Transient Co-Stimulation of Receptive Field Center and Outside in Anesthetized Rats

  • Yang, Yu-Mi;Lim, Sa-Bina;Won, Chung-Kil;Shin, Hyung-Cheul
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.1
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    • pp.27-32
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    • 2001
  • We have characterized the aftereffects of impulse activities on the transmission of afferent sensory to the primary somatosensory (SI) cortex of the anesthetized rats (n=22). Following conditioning stimulation (CS, 10 sec, either 5 Hz or 200 Hz) to the receptive field (RF), quantitative determination of the changes of afferent sensory transmission was done by generating post-stimulus time histogram of unit response to the testing stimulation (TS, at 0.5 Hz) to the RF center (RFC) for 60 min. In one group of experiments, CS was delivered to the RF center (RFC). In another group of experiments, CSs were simultaneously given to both RFC and RF outside (RFO, either forepaw or hindpaw). CS of 5 Hz to RFC exerted irreversible facilitation of sensory transmissions evoked by TS. Simultaneous CSs of 5 Hz to RFC and hindpaw RFO exerted reversible suppression of afferent transmission. However, CSs of 5 Hz to RFC and forepaw RFO did not significantly altered afferent sensory transmission to SI cortex neurons. CS of 200 Hz to RFC exerted irreversible suppression of sensory transmissions up to 60 min of experimental period. Simultaneous CSs of 200 Hz to RFC and RFO did not significantly altered afferent sensory transmission to SI cortex neurons. The profiles of CS-induced modulation of afferent sensory transmission were significantly different between two CS conditions. Thus, this study suggests that activity-dependent modulation of afferent transmission from a RF center to the SI cortex may be significantly altered when remote body part was simultaneously activated.

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Multi-Mode Reconstruction of Subsampled Chrominance Information using Inter-Component Correlation in YCbCr Colorspace (YCbCr 컬러공간에서 구성성분간의 상관관계를 이용한 축소된 채도 정보의 다중 모드 재구성)

  • Kim, Young-Ju
    • The Journal of the Korea Contents Association
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    • v.8 no.2
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    • pp.74-82
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    • 2008
  • This paper investigates chrominance reconstruction methods that reconstruct subsampled chrominance information efficiently using the correlation between luminance and chrominance components in the decompression process of compressed images, and analyzes drawbacks involved in the adaptive-weighted 2-dimensional linear interpolation among the methods, which shows higher efficiency in the view of computational complexity than other methods. To improve the drawback that the spatial frequency distribution is not considered for the decompressed image and to support the application on a low-performance system in behalf of 2-dimensional linear interpolation, this paper proposes the multi-mode reconstruction method which uses three reconstruction methods having different computational complexity from each other according to the degree of edge response of luminance component. The performance evaluation on a development platform for embedded systems showed that the proposed reconstruction method supports the similar level of image quality for decompressed images while reducing the overall computation time for chrominance reconstruction in comparison with the 2-dimensional linear interpolation.

A Study On the Brand Image of Korean Herbal Cosmetics (한방화장품의 브랜드 이미지에 관한 연구)

  • Kim, Hye-Rang
    • Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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    • v.1 no.1
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    • pp.98-113
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    • 2005
  • This paper provides comparison and analysis between brand images of Korean herbal cosmetics and general, imported cosmetic brands, focusing on product's symbolic and functional images. The objective is to evaluate brand images of Korean herbal cosmetics to suggest a powerful brand image strategy that will be different and competitive. Data collection was performed on 300 adult women who were over 20 years of age and lived in Seoul or KyongKi area. Analysis was carried out using SPSS version 11.5 and frequency analysis, T-Test and $X^2$ verification was also performed. Analysis results for brand images of Korean herbal cosmetics are as follows. First, satisfaction scale as a purchase feature for users of Korean herbal cosmetics were 'Normal' 51.5%, 'Satisfactory' 35.1%, 'Very Satisfactory' 8.2% and 'Unsatisfactory' 5.2%. Regarding improvements, 'Efficacy, Effect' was the highest with 46%. Second, 'SEOLHWASOO' and 'BAEKOKSENG' among Korean herbal cosmetic brands, 'IOPE' and 'ISA KNOX' among general cosmetic brands and 'LANCOME' and 'CHANEL' among imported cosmetic brands displayed high recognition. Third, the symbolic and functional images of Korean herbal cosmetic brands were seen to be better compared to their general and imported counterparts. Especially, product related features of Korean herbal cosmetic brands received a more positive response compared to imported brands, which suggests that with research and improvement regarding non-product related features, functional images of herbal brands may be appraised ahead of imported brands. Fourth, there is a significant difference in brand preference according to the satisfaction of groups who actually use herbal cosmetics and the purchasing attitudes of groups who do not. Therefore, an active relationship marketing strategy is required to maximize satisfaction and to elicit favorable attitudes. By developing functional native ingredients, constructing data that can prove its efficacy and effects, and appealing its unique, differentiated symbolic value together with Orientalism, herbal medicines will be able to take off to be acknowledged worldwide.

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