• Title/Summary/Keyword: Chang

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Charteristic Analysis Consdering End-ring of 3Phase Squirrel-cage Induction Motor (3상농형 유도전동기의 엔드링을 고려한 전동기 특성해석)

  • Ha, Kyung-Ho;Kim, Young-Kyoun;Sin, Sang-Yun;Hong, Jung-Pyo;Kim, Gyu-Tak;Im, Tae-Bin
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.158-160
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    • 1998
  • This paper proposed the 2-D Finite Element analysis method taking into end-ring of squirrel cage induction motor. Secondary conductor resistance can be simply replaced new one considering end-ring resistance. In the case of 2-D FEM, the end-ring resistance is hard to condsider. And the results without considering end-ring resistance have an error. To verify the proposed method we compared the analysis results and test ones.

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Characteristics analysis of V-skew model for minimization of lateral force in PMLSM (PMLSM의 lateral force 최소화를 위한 V-skew 모델의 특성 해석)

  • Hwang, In-Cheol;Lee, Seong-Hoon;Yun, Byung-Chae;Jang, Ki-Bong;Kim, Gyu-Tak
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1021-1022
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    • 2007
  • By enforcing skew of permanent magnet, detent force decreases, but lateral force that acts for vertical direction of moving direction occurs. This force deteriorates various performance of PMLSM as that acts to friction force between mover and LM guide. Therefore, in this paper, V skew model is proposed for lateral force's reduction and simulation results are compared to experimental value.

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Seismic performance evaluation of steel moment frames with self-centering energy-dissipating coupled wall panels

  • Lu Sui;Hanheng Wu;Menglong Tao;Zhichao Jia;Tianhua Zhou
    • Steel and Composite Structures
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    • v.47 no.5
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    • pp.663-677
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    • 2023
  • The self-centering energy-dissipating coupled wall panels (SECWs) possess a dual capacity of resiliency and energy dissipation. Used in steel frames, the SECWs can localize the damage of structures and reduce residual drifts. Based on OpenSEES, the nonlinear models were established and validated by experimental results. The seismic design procedure of steel frame with SECW structures (SF-SECW) was proposed in accordance with four-level seismic fortification objectives. Nonlinear time-history response analyses were carried out to validate the reasonability of seismic design procedure for 6-story and 12-story structures. Results show that the inter-story drifts of designed structures are less than drift limits. According to incremental dynamic analyses (IDA), the fragility curves of mentioned-above structure models under different limit states were obtained. The results indicate that designed structures have good seismic performance and meet the seismic fortification objectives.

Alignment of Schwarzchild-Chang Off-axis Telescope with a Shack-Hartmann Wavefront Sensor and Sensitivity Table Method

  • Lee, Sunwoo;Park, Woojin;Kim, Yunjong;Kim, Sanghyuk;Chang, Seunghyuk;Jeong, Byeongjoon;Kim, Geon Hee;Pak, Soojong
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.79.1-79.1
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    • 2019
  • The Schwarzchild-Chang telescope is a confocal off-axis two mirror telescope with D = 50 mm, F = 100 mm and FOV = 8 ° × 8 °. Unlike common off-axis telescopes, the mirrors of the Schwarzchild-Chang telescope share their focal points to remove the linear astigmatism. In this poster, we show the alignment process of the Schwarzchild-Chang telescope with wavefront measurement and the sensitivity table method. Wavefront is measured using the Shack-Hartmann sensor, and Zernike polynomials are obtained from measured wavefront. Sensitivity table method is to calculate alignment errors from the Zernike coefficients. As a result, we evaluate tilt, decenter, and despace of each mirror of linear astigmatism-free con-focal off-axis system.

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Design of Robust PI Controller for DC-DC Converter (DC-DC 컨버터에 대한 강인한 PI 제어기 설계)

  • Lee, Hyun-Seok;Ko, Chang-Min;Park, Seong-Hun;Park, Seung-Kyu;Ahn, Ho-Kyun
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.997_998
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    • 2009
  • Nowadays DC-DC converter has been used widely in electronic production. It has a high requirement in wide input voltage, load variations, stability, providing a fast transient response and the most important thing is that it can be applied easily and efficiently. However, it is not easy to be controlled because of nonlinear system. This study introduces a fuzzy linear control design method for nonlinear systems with optimal $H^{\infty}$ robustness performance. First, the Takagi and Sugeno fuzzy linear model is employed to approximate a nonlinear system. Next, based on the fuzzy linear model, a fuzzy controller is developed to stabilize the nonlinear system, and at the same time the effect of external disturbance on control performance is attenuated to a minimum level. Thus based on the fuzzy linear model, ��$H^{\infty}$ performance design can be achieved in nonlinear control systems. Linear matrix inequality (LMI) techniques are employed to solve this robust fuzzy control problem. PI control structure is used and the control gains are determined based on $H^{\infty}$ control.

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A study on Chang-Won Lee's theory of sasang and acupuncture of constitution (용성산인(龍城山人) 이창원(李昌遠)의 사상학설(四象學說)과 체질침(體質鍼)에 대한 고찰(考察))

  • Ahn, Chang-beohm;Youn, Byuon-Min;Hea, Jae-young;Kwon, Hae-Yon
    • Journal of Acupuncture Research
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    • v.19 no.1
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    • pp.225-235
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    • 2002
  • Objective : This study was carried out to review Chang-Won Lee's theory of Sasangand acupuncture of constitution. Methods : We have investigated Chang-Won Lee's unknown literature "Medicine of sassang "(四象醫學). Results : Constitutional acupuncture is based on the diversity of human being and medically developed the response variation to disease and acupuncture. The diversity is due to the Organ's Congenital Formation Variation based on human nature and it is categorized as four from physiology, pathology, symptoms, to therapy. Chang-Won Lee's constitutional acupuncture discriminated constitution of comparison palpations of right and left both sides. He insisted that constitution only four type(Sasang), not exist man of To-Hyoung (土形人) in "young -chu"(靈樞) and his constitutional acupuncture all used Jung-kyuck (reinforcement acupuncture method) and Seong-kyuck(reducing acupuncture method) of Sa-am(舍岩)

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Comparison of Attenuation Correction Methods for Brain SPECT Ima (Brain SPECT 영상의 Attenuation Correction 방법들에 대한 비교)

  • Jo, Jin U;Kim, Chang Ho;Na, Soo Kyung;Lee, Gui Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.120-125
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    • 2012
  • Purpose : The purpose of this study was to compare count between Chang's method and CT-based attenuation correction (AC-CT) among the attenuation correction (AC) methods for non-attenuation correction (AC-non) images of Brain SPECT (Single Photon Emission Computed Tomography). Materials and Methods : We injected $^{99m}Tc$ 37Mbq in a Hoffman 3D phantom filled with distilled water in the phantom study, and injected intravenously $^{99m}Tc$-HMPAO 740Mbq in a normal volunteer in the patient study, and then obtained Brain SPECT images with Symbia T6 of Siemens and conducted quantitative brain analysis. Transverse images to which each method was applied were rebuilt at the same position, and 6 regions of interest (ROI) were drawn on each of Slice No. 10, 20 and 30 and then the counts of AC-non, AC-CT and Chang's method were compared. Results : The mean counts of AC-non, AC-CT and Chang's method were $4606.8{\pm}511.3$, $16794.6{\pm}2429.4$, and $8752.6{\pm}896.5$, respectively, in the phantom study and $5460.8{\pm}519.6$, $15320{\pm}1171.6$ and $12795{\pm}1422.1$, respectively, in the patient study. In the phantom study, the ratio of AC-CT to AC-non was 3.70 and the ratio of Chang's method to AC-non was 1.92, and in the patient study, they were 2.85 and 2.38, respectively. Conclusion : From this study, we found that AC-CT makes higher AC than Chang's method. In addition, when Chang's method was used, AC in the patient study was higher than that in the phantom study. These results need to be considered also in other examinations.

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A Study on the Reality and Improvement Plan of Scenic Landscape Agriculture in Korea - Case Study of the Go-Chang County in Jeon-Buk Province - (한국의 경관농업의 실태와 개선방안에 관한 연구 -전라북도 고창군 공음면 사례를 중심으로-)

  • Chung, Cheol-Mo;Park, Mi-Ho
    • Journal of Korean Society of Rural Planning
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    • v.13 no.3
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    • pp.13-21
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    • 2007
  • This study focus on the pilot case of a scenic landscape agriculture in Go-Chang county for the innovative rural development strategy related the green tourism in Korea. The Go-Chang county in Jeon-Buk province has been progressed the diversified agricultural crops production region. The Go-Chang county is known as the famous cultural tour place that has the many historical and cultural resources (provincial natural park, traditional music, great stone cluster area, military castle walls, good tasted eel food and wine). But, today, the circumstances of global agricultural free trading situations is rapidly proliferated, it invited the depression of the agricultural incomes in rural regions in Korea. So, the Go-Chang county seeks trying to alternative development methods. The new frontier like scenic landscape agriculture is the one of the innovative strategies in this processes. The Go-Chang county selects and supports the scenic landscape agriculture for the new income production policy in connection with the green tourism. This study finds out the important components of the success of a scenic landscape agriculture for the introduction to the new frontier of peen tourism in Go-Chang county. First the scenic landscape agriculture development must be related the 4 season-ecological cultivation methods connected well-being trends. Second, it will be increased the income level of rural people by the competitive the rural green products and diversified green tourism programs which produced by the efforts of the rural people. Third, the success of scenic landscape agriculture and place marketing of rural green tourism depend on the creative community leaders.

The studies on the Chang-Pu and physiological theories of "NanJing hoeju jeonjung" ("난경회주전정(難經滙注箋正)"중(中) 장부생리(臟腑生理)에 대한 연구(硏究))

  • Je, Kang-Woo;Yoon, Chang-Yeu
    • Journal of Haehwa Medicine
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    • v.15 no.2
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    • pp.75-93
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    • 2006
  • Chang San-roe re-explained the contents from the 30th question to the 47th question of "Nan Jing" which refered to the Chang-Pu and physiological theories as follows through the western theory which wss different from the tranditioonal chinese theory 1. "Nan Jing" refered to the circulation and the coming into being of Yeong-Wi. He denied that it was classified Yeong from Wi or Eum from Yang. 2. He denied that Sam-Cho was separated to three parts and the theory of "Sam-Cho is name only, not shape", using western medical theory. 3. He denied the view about "Left side is kidney, right side is Myung-Mun" because it was incorrect that kidney was separated to two parts which were Su and Hwa or Eum and Yang 4. Re-explaining the contents of "Nan Jing"- the portions of heart and lungs, the rising and falling of liver and lungs, the relationships of five viscera and sound color smell taste fluid, the relationships of five viscera and nine hole, the relationships of five viscera and O-Chu, the physiological difference of the old and the young owing to the deflection of Yeong-Wi Chi-Heol- he thought that viewing the human body using theory of Eum and Yang, Five elements(五行) was a far-fetched interpretation, so he denied the tranditional chinese theory which understood human body's organs, physiology, pathology. 5. He explained the contents of "Nan Jing"- the portions of the colon and the small intestines, the funtion of the six bowls, the corespondence of Chang-Pu, physical peculiarity of liver, the anatomical aspects which were the sizes, weights, volumes and shapes of the Chang-Pu and the alimentary canal, Chil-Chung-Mun, Pal-Hoe-Hyeolthrough western anatomy and physiology in detail.

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Bony Stability and Soft Tissue Changes after Orthognathic Surgery on Patients with Cleft (구순구개열 환자의 악교정 수술 후의 골조직 안정도와 연조직 변화율)

  • Shin, Heakyeong;Hsieh, Yuh-Jia;Liao, Yu-Fang;Lo, Lun-Jou;Jo, Myoung-Soo
    • Archives of Craniofacial Surgery
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    • v.13 no.1
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    • pp.4-10
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    • 2012
  • Purpose: The objective of this retrospective study was to assess the skeletal stability after orthognathic surgery for patients with cleft lip and palate. The soft tissue changes in relation to the skeletal movement were also evaluated. Methods: Thirty one patients with cleft received orthognathic surgery by one surgeon at the Craniofacial Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Osseous and soft tissue landmarks were localized on lateral cephalograms taken at preoperative (T0), postoperative (T1), and after completion of orthodontic treatment (T2) stages. Surgical movement (T0.T1) and relapse (T1.T2) were measured and compared. Results: Mean anteroposterior horizontal advancement of maxilla at point A was 5.5 mm, and the mean horizontal relapse was 0.5 mm (9.1%). The degree of horizontal relapse was found to be correlated to the extent of maxillary advancement. Mean vertical lengthening of maxilla at point A was 3.2 mm, and the mean vertical relapse was 0.6 mm (18.8%). All cases had maxillary clockwise rotation with a mean of 4.4 degrees. The ratio for horizontal advancement of nasal tip/anterior nasal spine was 0.54/1, and the ratio of A' point/A point was 0.68/1 and 0.69/1 for the upper vermilion/upper incisor tip. Conclusion: Satisfactory skeletal stability with an acceptable relapse rate was obtained from this study. High soft tissue to skeletal tissue ratios were obtained. Two-jaw surgery, clockwise rotation, rigid fixation, and alar cinch suture appeared to be the contributing factors for favorable results.