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Analysis of Deterioration Characteristics by Filtering Processes at 6.6kV Power Cable Systems in Operation (운전 중인 6.6kV 전력 케이블 시스템의 필터링 과정에 의한 열화 특성 해석)

  • Um, Kee-Hong;Lee, Kwan-Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.205-211
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    • 2014
  • With a development of modern industry, demand for electric power is rapidly increasing and the capacity of power transfer is required to become bigger and bigger. At power station, the high-voltage power cable is used as the only method in order to transfer electric power. In this paper, we have analyzed the deterioration characteristics of 6.6kV power cable systems in operation. For the time duration of 2000 days, we have measured the cable in operation in order to extract the data for the deterioration characteristics. By analyzing the data by means of several steps of filtering processes, we could obtain the linear relations of insulation resistances as a function of time. Furthermore, we can verify that the progress characteristics in deterioration process of 6.6kV power cable systems follows the process of heat deterioration.

Developing Equipment to Detect the Deterioration Status of 6.6kV Power Cables in Operation at Power Station (발전소에서 운전 중인 활성 6.6kV 전력 케이블의 고장상태를 파악하는 장치의 개발)

  • Um, Kee-Hong;Lee, Kwan-Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.197-203
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    • 2014
  • The technology to predict and prevent an accident of the cable system in power station is required. The techniques of inactivated diagnosis, partial discharge and $tan{\delta}$, have been adopted to diagnoze the operating characteristics of cables, but it is not so easy to find out problems in cables in an inactive state before the cable accident happens. In this paper, we did a research on the 6.6kV high-power cables, installed at Korean Western Power Station Co., Ltd. in order to diagonize the cables, playing a major role at the station. We have developed an equipment to measure an insulation resistance based on the temperature and current of the cable. By installing the system in a power station, we could find abnormal status for evaluation of the lifetime. In the short term, by analyzing the data, we apply the research result to the diagnosis and evaluation of the 6.6kV power cables. In the long run, however, we plan to reduce the cost of the installation and operation of cable systems at power stations.

A Comparative Study of Insert Earphones and Circumaural Earphones in the Brainstem Auditory-Evoked Response Test of Dogs

  • Kim, Sang-Woo;Song, Joong-Hyun;An, Su-Jin;Yu, Do-Hyeon;Kim, Young Joo;Han, Donghyun;Jung, Dong-In
    • Journal of Veterinary Clinics
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    • v.37 no.3
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    • pp.123-129
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    • 2020
  • We aimed to investigate the differences in the efficacy of insert and circumaural earphones when performing the brainstem auditory evoked response (BAER) test with dogs. Hearing loss may occur congenitally or secondarily in dogs. The BAER test, unlike the classical ethological method, is the most reliable diagnostic tool to assess canine auditory function. Furthermore, there are certain advantages of using insert earphones rather than the standard, circumaural earphones. We subjected eight dogs to the BAER test with insert earphones and circumaural earphones. The result revealed that the latency of waves was delayed with an insert earphone. The inter-peak latency did not show any significant differences between the two transducers, and the threshold was higher when using an insert earphone. Moreover, the circumaural headphones produced a greater degree of crossover effect than the insert earphones, and this cross-over effect could affect the outcomes of the BAER test. Considering these results, we concluded that insert earphones may be more appropriate when performing the canine BAER test.

A Study of the Anti-Stress Effects of Chijasitang in Mice (생쥐에서 치자시탕(梔子豉湯)의 항스트레스 효과에 대한 연구)

  • Jung, Se-In;Kim, Jae-Hyo;Lee, Go-Eun;Lyu, Yeoung-Su;Kang, Hyung Won
    • Journal of Oriental Neuropsychiatry
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    • v.28 no.3
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    • pp.183-194
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    • 2017
  • Objectives: Chijasitang (CJST) has been prescribed for patients with anxiety disorder, and is believed to treat insomnia. The present study was carried out to investigate whether Fructus Gardeniae, Fermented Semen Sojae Preparatum and CJST have beneficial effects on treating anti-stress. Methods: The mice were divided into the following groups: normal, control, positive control, and experimental. Then, the experimental groups were further divided into the Fructus Gardeniae group (FG), the Fermented Semen Sojae Preparatum group (FS), the Chijasitang water extract group (CJSTW), and the Chijasitang 30% ethanol extract group (CJSTE). In the positive control group, a single dose of imipramine ($500{\mu}g/g$) was applied to the mice. In the experimental groups, each single dose of FG, FS, CJSTW and CJSTE ($50{\mu}g/g$) was applied to the mice. After one hour, the mice in all groups except the normal group were exposed to immobilization stress. Their body weights, phagocytosis, nitric oxide in macrophage, corticosterone, and adrenocorticotropic hormone (ACTH) were observed. Results: Fructus Gardeniae, Fermented Semen Sojae Preparatum and Chijasitang prevented weight loss and suppressed the decrease of phagocytosis in the mice after their exposure to immobilization-stress. Although they did not influence the amount of NO, they suppressed the increment of ACTH and corticosterone in the immobilization-stressed mice. Conclusions: According to the results of this study, they suggest that Fructus Gardeniae, Fermented Semen Sojae Preparatum and Chi-Ja-Si-Tang all have some anti-stress effects.

A Study on a High Speed Computational Scheme for the Reflected IR Signal Component by Considering the BRDF (BRDF를 고려한 적외선 신호의 반사 성분 고속 연산기법에 관한 연구)

  • Kim, Dong-Geon;Han, Kuk-Il;Choi, Jun-Hyuk;Choi, Soon-Ho;Kim, Tae-Kuk
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.1
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    • pp.18-24
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    • 2017
  • This paper is a part of developing a computer code that can be used to generate synthetic IR images by calculating the outgoing infrared signal from objects. To predict the reflected component that is a part of the outgoing IR signal, such as those components reflected from the target surface by the solar and sky irradiations, it is necessary to calculate the complicated BRDF values for considering the directional surface reflection characteristics. Since the calculation of reflectance using the BRDF requires a large amount of computation time due to the hemispherical integral term, it is frequently restricted in applying for a real-time prediction of IR signal. In this research, the simplified method for calculating IR reflected component has been proposed by replacing the integral terms into two parts, a directionally uniform component and a step function representing the specular component, to reduce computation time. The proposed method is proved to result in very fast calculation of the BRDF (up to 600 times faster calculations) for most of the surfaces with minimal loss of the accuracy.

Study Review of Horticultural Therapy As a Nursing Intervention (간호중재로서의 원예요법에 관한 고찰)

  • Kim, Boo-Young;Kim, Jeong-Sun
    • Korean Journal of Adult Nursing
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    • v.13 no.3
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    • pp.409-419
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    • 2001
  • The reference study was performed to investigate the nursing importance which was based a theoretical background related to horticultural therapy and to examine the possibility which horticultural therapy was applicable as a nursing intervention through analysis on a preceding study. The research subjects related to the areas of horticultural therapy which related as a nursing intervention, were psychological, physical, environmental, and psycho-social aspects. It is judged that the horticultural therapy is effective in treating depression, emotional disruption or anxiety. It seems to be also effective in increasing the muscular tension and, thereby, expanding the scope of joint movements. Such theories show that horticultural therapy may be a good alternative nursing means. Plants act to create a pleasant interior atmosphere by generating anion, controlling the temperature and humidity and purifying the air, and therefore, the horticultural therapy may be applied to clinic or environmental therapy. When horticultural therapy is used as a nursing intervention, patients' sociopsychological needs may be fulfilled. It has been found that horticultural therapy is instrumental in treating perceptive or emotional disruption, depression, loss of self-respect, disrupted everyday activities and social behaviors. In particular, horticultural therapy seems to be effective in managing chronic patients' crisis or improving life quality. Intervention method applied on a preceding study was activity therapy and scene therapy in the horticultural therapy The above findings suggest that the pro-environmental horticultural therapy is useful as a new paradigm of nursing or holistic nursing conducive to improvement of health. So, it is desirable to prove its effects by applying it in the clinic. In order to apply horticultural therapy as a nursing intervention, it will be necessary to educate nurses on principles and methods of horticultural therapy and encourage them to apply it in nursing and clinics. Moreover, it may well be necessary to develop landscape therapy as nursing intervention as well as a variety of horticultural therapy programs befitting the clinic conditions. On the other hand, we need to provide for some scientific ground for horticultural therapy through continued studies. In this regard, this study which focuses on patients' health improvement through change of environment. may well provide for a framework for such studies.

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Sand particle-Induced deterioration of thermal barrier coatings on gas turbine blades

  • Murugan, Muthuvel;Ghoshal, Anindya;Walock, Michael J.;Barnett, Blake B.;Pepi, Marc S.;Kerner, Kevin A.
    • Advances in aircraft and spacecraft science
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    • v.4 no.1
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    • pp.37-52
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    • 2017
  • Gas turbines operating in dusty or sandy environment polluted with micron-sized solid particles are highly prone to blade surface erosion damage in compressor stages and molten sand attack in the hot-sections of turbine stages. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains in the middle eastern countries or in volcanic zones; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on the durability of these engines as well as performance. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The focus of this research work is to simulate particle-surface kinetic interaction on typical turbomachinery material targets using non-linear dynamic impact analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and to develop sand-phobic thermal barrier coatings for turbine blades. This paper outlines the research efforts at the U.S Army Research Laboratory to come up with novel turbine blade multifunctional protective coatings that are sand-phobic, sand impact wear resistant, as well as have very low thermal conductivity for improved performance of future gas turbine engines. The research scope includes development of protective coatings for both nickel-based super alloys and ceramic matrix composites.

Design of A Narrow Bandpass Filter with Wideband Harmonic Suppression Using Hairpin Step Impedance Resonators (광대역의 고조파 억제가 가능한 헤어핀 SIR을 사용한 협대역 통과 여파기 설계)

  • Park, Ju-Seong;Mohyuddin, Wahab;Choi, Hyun-Chul;Kim, Kang-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.3
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    • pp.151-158
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    • 2018
  • This paper proposes a new design method for narrow bandpass filters using two cascaded hairpin step impedance resonators (SIRs) with wideband harmonic suppression. The proposed bandpass filter utilizes a suspended strip line (SSL) to maximize the characteristic impedance ratio, thereby maximizing the harmonic suppression bandwidth. As an example of the proposed design method, the SSL bandpass filter with a center frequency of $f_0=1.4GHz$ and fractional bandwidth of 5 % was implemented, and proved to suppress harmonics up to $7.5f_0$ with a passband insertion loss of approximately -0.9 dB. This result implies that the proposed SSL narrow bandpass filter (NBPF) can suppress the harmonic bandwidth more than two times as compared with the filter design on a microstrip line (MSL).

Physicochemical and Storage Characteristics of Hanwoo Tteokgalbi Treated with Onion Skin Powder and Blackcurrant Powder

  • Chung, Yoon-Kyung;Choi, Jung-Seok;Yu, Sung-Beom;Choi, Yang-Il
    • Food Science of Animal Resources
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    • v.38 no.4
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    • pp.737-748
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    • 2018
  • We evaluated the physicochemical and storage characteristics of Hanwoo Tteokgalbi treated with onion skin powder (OSP) and blackcurrant fruit powder (BFP). The experimental design included seven treatments: a control (ascorbic acid 0.1%), T1: OSP 0.3%, T2: OSP 0.6%, T3: BFP 0.3%, T4: BFP 0.6%, T5: OSP 0.15%+BFP 0.15%, and T6: OSP 0.3%+BFP 0.3%. The OSP was higher in both polyphenol and flavonoid contents compared to BFP (p<0.05). The moisture and ash contents of all Tteokgalbi samples with a large amount of added natural antioxidant powder (0.6%) were higher than those with small amounts of added antioxidant (0.3%). The cooking loss and water holding capacity were outstanding in the T2 treatment compared to the others (p<0.05). The lightness, redness, and yellowness values were reduced on the addition of 0.6% antioxidant powder (p<0.05). The springiness and cohesiveness values of the Tteokgalbi samples were higher for the 0.3% addition than the control and 0.6% addition (p<0.05). The Tteokgalbi samples with natural antioxidants showed similar sensory attribute scores compared to the control. The pH values reduced as the BFP increased (p<0.05), and the total microbial count increased after OSP addition. The 2-thiobarbituric acid reactive substance values of the samples treated with OSP were significantly lower than the control after day 10 (p<0.05). As a result, the addition of OSP or BFP did not have a significant negative influence on the quality characteristics of Hanwoo Tteokgalbi. In particular, the addition of 0.6% OSP was effective in increasing water retentivity and inhibiting lipid oxidation.

Myocardial degeneration in Russian rat snake (Elaphe schrenckii)

  • Tiwari, Shraddha;Aufa, Sulhi;Park, Hyung-Hun;Cho, Ho-Seong;Park, Byung-Yong;Oh, Yeonsu
    • Korean Journal of Veterinary Service
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    • v.41 no.3
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    • pp.217-220
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    • 2018
  • A female Russian rat snake, Elaphe schrenckii, was presented for loss of movement. Physical examination showed the swelling in the area of heart. Radiographic examination revealed cardiomegaly, pericardial effusion, and a soft opacity in the area of swelling. Although pericardiocentesis to remove fluid out from the heart as well as vigorous treatments were given to the Russian rat snake, it died during treatments. Postmortem examination confirmed pericardial effusion of pale yellow, translucent fluid with mild dilation of the right atrium and ventricle. Formalin -fixed paraffin embedded tissue sections were stained with routine H&E and the classical von Kossa's method for histopathological demonstration. Histopathological examination revealed multifocal calcification in myocardium and consists of the displacement of muscular fiber by limy deposits. Congestive heart failure was suspicious for the snake when it was alive. In wild reptiles, muscle degeneration has been reported with nutrition disorders but the present case is the first report of myocardial degeneration in a Russian rat snake and contributes to the rare reports of cardiac disease in snakes.