• Title/Summary/Keyword: 전변(傳變)

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중부전력 북풍전변전소납입 275KV 450MVA 부하시 TAP 절환변압기

  • 등본광소;고추륭사;정천도부
    • 전기의세계
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    • v.28 no.2
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    • pp.14-22
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    • 1979
  • 전력계통의 증대에 따라 변전소용 변압기도 대용량화되어 가고 있다. 변전소용 대용량 변압기의 경우 최대문제가 되는 것은 철도운송의 경우 운송한계에 있다. 일본의 철도는 협궤이기 때문에 운송능력이 작고 275KV 변압기의 경우 조립운송할 수 있는 한계용량은 종래 300MVA라고 되어 왔지만, 최근 기술의 진보와 신뢰성 향상 시책에 따라 450MVA까지도 철도운송을 하는 것이 가능케 되었다. 이와같은 사정때문에 당사는 이번에 중부 전력.북풍전변전소에 3상 60Hz, 275/15 4/31.5KV, 450/450/135MVA 변압기를 납품하였다. 본기는 초고압 변전소용으로는 일본에서 최대급의 것으로 여러가지의 특징을 가지고 있다. 그 주요점을 들면, (1) 철도에 의한 조립운송을 가능케 했다. 더우기 부하시 TAP 절환기를 본체 TANK에 조립해서 운통한다. (2) 일차 초고압 권선에는 선로단을 중앙에 배치한 HISERCAP 권선을 채용한다. (3) 당초 65Phon, 장래 55Phon의 저소음사양을 만족시키기 위해서 고효율의 송유풍냉식 저소음방열관을 사용했다. (4) 기기의 신뢰성을 높이기 위해 설계, 제조, 시험 검사 각면에 만전을 기했다. 그러나 그외에도 여러가지 연구가 추진되고 있으며 다음에 개요를 설명하고져 한다.

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A study on the transmitting and changing aspects of Oksosun stories (<옥소선 이야기>의 전변양상(轉變樣相)과 그 서사적 의미)

  • Jang, Jin-sook
    • Journal of Korean Classical Literature and Education
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    • no.16
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    • pp.297-326
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    • 2008
  • I started this study to solve the doubt about actual condition of Oksosun stories. which was recorded in Cheonyerok(天倪錄) is the first form of Oksosun stories. But this story seems a very outstanding work. had a structure of romance. The hero's character was a romantic figure but Oksosun's character was a figure of Yadam. Afterward recorded in Gyeseoyadam(溪西野譚) and recorded in Cheongguyadam(靑邱野談) took place changes in the structure of the story. A lot of narrative paragraphs were removed in these stories. So and achieved the typical structure of Yadam. In recorded in Dongyahwijip(東野彙輯), the change of style was caused once more. So we can see the transmitting and changing flow of Yadam by this study; Romantic Yadam ${\rightarrow}$Typical Yadam , ${\rightarrow}$Noverized Yadam .

Structural Study of Automotive Seat Frame with High Tension Steel Plate Using Analysis and Experiment (해석과 실험을 이용한 고장력 강판으로 된 자동차 시트 프레임의 구조적 연구)

  • Kim, Key-Sun;Cho, Ho-Sun;Kim, Young-Chun;Cho, Jae-Ung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.27-31
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    • 2014
  • As research development of seat frame is being studied actively, the total deformation of seat frame made of high tension steel plate(HTSP) is examined in this study. The seat frame made of SPFC 980 t=2mm with HTSP is tested to obtain total deformation through repeated fatigue durability tester and total deformation is analyzed by simulation under the same condition as experiment. After analyzing by comparing the results of experiment and analysis, structural stabilities of seat frame models with SPFC 780 t=2mm and SPFC 780 t=1.5mm are investigated by FEM analysis on the basis of these results. And it is considered that which model is more suitable at commercial use can be found through this study result.

Low Cycle Fatigue Life Prediction of HSLA Steel Using Total Strain Energy Density (전변형률 에너지밀도를 이용한 고강도 저 합금강의 저주기 피로수명 예측)

  • Kim, Jae-Hoon;Kim, Duck-Hoi
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.6
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    • pp.166-175
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    • 2002
  • Low cycle fatigue tests are performed on the HSLA steel that be developed for a submarine material. The relation between strain energy density and numbers of cycles to failure is examined in order to predict the low cycle fatigue life of HSLA steel. The cyclic properties are determined by a least square fit techniques. The life predicted by the strain energy method is found to coincide with experimental data and results obtained from the Coffin-Manson method. Also the cyclic behavior of HSLA steel is characterized by cyclic softening with increasing number of cycle at room temperature. Especially, low cycle fatigue characteristics and microstructural changes of HSLA steel are investigated according to changing tempering temperatures. In the case of HSLA steel, the $\varepsilon$-Cu is farmed in $550^{\circ}C$ of tempering temperature and enhances the low cycle fatigue properties.

Convergent Study by the Structural Durability Analysis of Landing Gear (랜딩기어의 구조적 내구성 해석에 의한 융합 연구)

  • Oh, Bum-Suk;Cho, Jae-Ung
    • Journal of the Korea Convergence Society
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    • v.11 no.6
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    • pp.191-196
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    • 2020
  • In this study, the durability was analyzed as the models with three shapes depending on the length of the landing gear. Overall, the upper part of the landing gear produced a greater amount of deformation, but the equivalent stress was shown to be high in the upper part just above the lower part. Model 3 shows that the maximum equivalent stress is more than 4 times and the maximum total deformation is more than 24 times compared to model 2. Model 3 showed that the damage could occur beyond the yield stress at the lower end. Model 2 with the upper part longer than the lower part showed the lowest equivalent stress and total deformation among the three models. Therefore, from a structural standpoint, it was shown that model 2 was the most durable at landing and model 3 was the most degraded in terms of durability. The design and analysis results of this study can be effectively applied at grasping the structural durability of landing gear. By applying the structural durability analysis of landing gear, this paper is seen as the convergence study that conforms to aesthetic design.

Assessment and Classification of Korean Local Corn Lines by the Application of Principal Component Analysis (I) (Principal Component Analysis Method에 의(依)한 한국재래종(韓國在來種) 옥수수의 해석(解析) 및 계통분류(系統分類)(I))

  • Lee, In Sup;Choe, Bong Ho
    • Korean Journal of Agricultural Science
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    • v.8 no.2
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    • pp.139-151
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    • 1981
  • To obtain breeding materials 57 Korean local corn lines collected were assessed and classified by the application of principal component analysis. The results obtained were as follows. 1. In the result of principal component analysis for 27 characters, 67.1% and 88.6% of total variation could be appreciated by the first four and fir st ten principal component respectively. 2. According to the value of characters and principal components, contribution of characters to principal components were very variable. 3. Biological meaning of the principal component and plant type corresponded to the each principal component were explained clear by the correlation coefficients between principal components and characters. 4. 57 lines were classified into 4 lineal groups by the taxonomic distances.

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Real-time Denoising Using Wavelet Thresholding and Total Variation Algorithm (웨이블릿 임계치와 전변분 알고리즘을 사용한 실시간 잡음제거)

  • 이진종;박영석;하판봉;정원용
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.1
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    • pp.27-35
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    • 2003
  • Because of the lack of translation invariance of wavelet basis, traditional wavelet thresholding denoising leads to pseudo-Gibbs phenomena in the vicinity of discontinuities of signal. In this paper, in order to reduce the pseudo-Gibbs phenomena, wavelet coefficients are thresholded and reconstruction algorithm is implemented through minimizing the total variation of denoising signal using subgradient descent algorithm. Most of experiments were performed under the non-real-time and real-time environments. In the case of non-real-time experiments, the algorithm that this paper proposes was found more effective than that of wavelet hard thresholding denoising by 2.794㏈(SNR) based on the signal to noise ratio. And lots of pseudo-Gibbs phenomena was removed visually in the vicinity of discontinuities. In the case of real-time experiments, the number of iteration was restricted to 60 times considering the performance time. It took 0.49 seconds and most of the pseudo-Gibbs phenomena were also removed.

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Low Cycle Fatigue Behavior of Alloy617 Weldment at 850℃ (850℃에서의 Alloy 617 용접재의 저사이클 피로 특성)

  • Hwang, Jeong Jun;Kim, Seon Jin;Kim, Woo Gon;Kim, Eung-Seon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.3
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    • pp.193-198
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    • 2017
  • Alloy 617 is one of the primary candidate materials to be used in a very high temperature reactor (VHTR) system as an intermediate heat exchanger (IHX). To investigate the low cycle fatigue behavior of Alloy 617 weldments at a high temperature of $850^{\circ}C$, fully reversed strain-controlled fatigue tests were conducted with the total strain values ranging from 0.6~1.5%. The weldment specimens were machined using the weld pads fabricated with a single V-grove configuration by gas tungsten arc welding (GTAW) process. The fatigue life is reduced as the total strain range increases. For all testing conditions, the cyclic stress response behavior of the Alloy 617 weldments exhibited the initial cyclic strain hardening phenomenon during the initial small number of cycles. Furthermore, the overall fatigue cracking and the propagation or cracks showed a transgranular failure mode.