• Title/Summary/Keyword: Indirect method

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A Carrier-Based Pulse Width Modulation Method for Indirect Matrix Converters

  • Nguyen, Dinh-Tuyen;Lee, Hong-Hee;Chun, Tae-Won
    • Journal of Power Electronics
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    • v.12 no.3
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    • pp.448-457
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    • 2012
  • This paper proposes a carrier-based pulse width modulation (PWM) method to control an indirect matrix converter (IMC) by analyzing the relationship between the space vector PWM (SVPWM) and the carrier-based PWM. The complexity of the SVPWM method for an IMC can be reduced by using an equivalent carrier-based PWM method. The advantage of the proposed algorithm is its ability use only one symmetrical triangular carrier signal to generate the gate signals for all of the power switches in both the rectifier and inverter stages as compared to the conventional method where the carrier signal used in the rectifier stage is different from that of the inverter stage. In addition, by using a suitable offset voltage component in the modulation signals, the output voltage magnitude reaches 0.866 of the input voltage magnitude. Simulation and experimental results are provided in order to validate the proposed method.

A Study on the Moxa-extract Moxibustion Method (약쑥엑스제 뜸 방식에 관한 연구)

  • Jo, Bong-Kwan;Lee, Yoon-Ho;Yoon, Dong-Eop
    • Journal of Acupuncture Research
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    • v.23 no.4
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    • pp.1-14
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    • 2006
  • Objectives : We implemented the Moxa-Extract Moxibustion Method in order to improve the conventional moxibustion therapy. This method is aimed to eliminate burning wounds and smoke, which are the defects of conventional moxibustion therapy. And we performed to verify the efficiency by comparing the Moxa-Extract Moxibustion Method with the conventional Indirect Moxibustion Method. We measured the body heat and the lasting time of blood circulation improveent using thermography. We implemented the Moxa-Extract Moxibustion Method in order to improve the conventional moxibustion therapy. This method is aimed to eliminate burning wounds and smoke, which are the defects of conventional moxibustion therapy. And we performed to verify the efficiency by comparing the Moxa-Extract Moxibustion Method with the conventional Indirect Moxibustion Method. We measured the body heat and the lasting time of blood circulation improvement using thermography. Methods : The moxibustion therapy has two kinds of effects: The formers are pharmacological effects of the Moxa's vasodilators and antioxidants. The latters are thermal effects which cause improvement of the blood circulation. To remove the demerits without omission of above therapeutic effects, we extracted the vasodilators and antioxidant compounds from the Moxa-CH2Cl2 fraction Moxa-EtOA and composed the moxibustion kit with (Ba0.8 Sr0.2)0.996 Y0.004 TiO2 + 0.5WT SiO2% positive Temperature Coefficients Thermistor. The experimental demonstrations have been made by the stimulating the spot which is CV4(Kwan-Won), CV8(Shin-Guel), CV12(Jung-Wan) acupuncture points of the conception vessel meridian(CV). And stimulating time was one hour. We divided the subjects into 5 groups such as no stimulation group, conventional Indirect Moxibustion group, only Moxa-Extract stimulation group, only heat stimulation group, and Moxa-Extract Moxibustion group. In the different cases, we have measured the body heat in pre-stimulation, just after stimulation, 2 hours after, and 4 hours after. Results : he body heats of the group who were stimulated by the Moxa-Extract Moxibustion method were increased by over the $2^{\circ}C$. And the body heats of the group who were stimulated by the Indirect Moxibustion Method were increased by average the $1^{\circ}C$. We have evaluated that the Moxa-Extract Moxibustion Method is improvement on the Indirect Moxibustion Method by the increasing rate is 200% and increasing time is 150% with the body heat of the abdominal region. Conclusion : We have implemented the Moxa-Extract Moxibustion Method and evaluated the efficiency of the Moxa-Extract Moxibustion Method comparing with the Indirect Moxibustion Method.

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Performance Comparison between Indirect Evaporative Cooler and Regenerative Evaporative Cooler made of Plastic/Paper (플라스틱/종이 재질의 간접 증발 소자와 재생 증발 소자 성능 비교)

  • Kim, Nae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.88-98
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    • 2016
  • The Korean summer is hot and humid, and air-conditioners consume considerable amounts of electricity. In such cases, the simultaneous use of indirect evaporative coolers may help reduce the sensible heat and save electricity. In this study, heat transfer and pressure drop characteristics of indirect or regenerative evaporative coolers made from plastic/paper are investigated. The results showed that heat and mass transfer model based on the ${\epsilon}-NTU$ method predicted the indirect evaporation efficiencies, cooling capacities and pressure drops adequately. Both for indirect or regenerative evaporative cooler, the indirect evaporation efficiency increased with increasing dry channel inlet temperature or relative humidity. The indirect evaporation efficiency of the regenerative evaporative cooler was larger than that of the indirect evaporative cooler.

A Study on Dose and Image Quality according to X-ray Photon Detection Method in Digital Radiography System (Digital Radiography System에서 X선 광자 검출 방식에 따른 선량 및 화질 특성에 관한 연구)

  • Hong, Sun Suk;Kim, Ho Chul
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.12
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    • pp.247-253
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    • 2013
  • The purpose is a comparative evaluation in the DR System according to the dosimetry and image quality of the quantitative and objective via Direct digital radiography, Indirect digital radiography, Image intensifier (Charge Coupled Device type) digital radiography. The experimental method used rando phantom and measured the entrance surface dose. And through using the measured entrance surface dose and then using the PCXMC program were evaluated risk due to irradiation and the effective dose. SNR and NPS and CNR were measured and analyzed by using 21cm acryl phantom. Significance of measured value was evaluated by statistics method. Entrance surface dose, major organ dose, effective dose all of them were measured the lowest rated in direct DR when it is on the basis of direct DR dose, high-dose ratio were measured in I.I DR approximately 1.3 times, indirect DR approximately 2.4 times. Risk in accordance with radiation also was measured same as dose ratio. On the conclusion that SNR measurement result based on direct DR SNR measurements, low-SNR ratio were measured in I.I DR approximately 7.25 times, indirect DR approximately 1.48 times. On the conclusion that CNR measurement result based on direct DR CNR measurements, high-dose ratio were measured in I.I type DR approximately 1.16 tims and low-dose ratio were measured in indirect DR approximately 0.87 times. Therefore Direct DR system using a-selenium sensing element to detect x-ray photon is thought effectively at the examination such as infant to sensitive irradiation and the genital gland. Because quality image is built by low dose. Also when it is necessary that image test requiring many diagnosis information, indirect DR system is thought effectively.

Analysis of microstructure and texture evolution in AZ31Mg alloy fabricated by direct/indirect extrusion process (직/간접 압출공정에 의해 제조된 AZ31Mg 합금의 미세조직 및 집합조직 변화 분석)

  • Kim, D.H.;You, B.S.;Park, S.S.;Yoon, D.J.;Choi, S.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.10a
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    • pp.38-41
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    • 2008
  • To investigate the evolution of microstructure and texture in AZ31 Mg alloy, direct/indirect extrusion process was carried out at $300^{\circ}C$ with various extrusion speeds. The distribution of grain size depends on extrusion method and extrusion speed. More homogeneous grain site can be obtained at higher extrusion speed of indirect extrusion process. Extrusion speed does not affect significantly texture evolution during extrusion process regardless of extrusion method. ODF section is more useful to understand texture evolution during extrusion process compared with pole figure.

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Immunohistochemical identification of newcastle disease virus with indirect immunoperoxidase technique (Indirect Immunoperoxidase 법을 이용한 조직내 뉴켓슬병 바이러스 항원동정)

  • Nho, Whan-goog;Sur, Jung-hyang;Kim, Soon-bok
    • Korean Journal of Veterinary Research
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    • v.30 no.3
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    • pp.309-315
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    • 1990
  • The present experiment was done to identify newcastle disease virus(NDV) antigens in frozen sections of various oragns from experimentally NDV-infected with indirect immunoperoxidase method. Section were incubated with rabbit anti-NDV polyclonal as first antibody, followed by incubation with goat anti-rabbit or protein A peroxidase conjugate. Positive reactions were often detected in the epithelium of trachea and in the lymphocyte of spleen at 24 hours after virus inoculation. the viral antigen was localized mainly in the cytoplasm of infected cells. The method approved to be highly specific for the identification of NDV and allowed a precise localization of the viral antigens in infected cells.

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The discrete element method simulation and experimental study of determining the mode I stress-intensity factor

  • Shemirani, Alireza Bagher;Haeri, Hadi;Sarfarazi, Vahab;Akbarpour, Abbas;Babanouri, Nima
    • Structural Engineering and Mechanics
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    • v.66 no.3
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    • pp.379-386
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    • 2018
  • The present study addresses the direct and indirect methods of determining the mode-I fracture toughness of concrete using experimental tests and particle flow code. The direct method used is compaction tensile test and the indirect methods are notched Brazilian disc test, semi-circular bend specimen test, and hollow center cracked disc. The experiments were carried out to determine which indirect method yields the fracture toughness closer to the one obtained by the direct method. In the numerical analysis, the PFC model was first calibrated with respect to the data obtained from the Brazilian laboratory test. The crack paths observed in the simulated tests were in reasonable accordance with experimental results. The discrete element simulations demonstrated that the macro fractures in the models are caused by microscopic tensile breakages on large numbers of bonded particles. The mode-I fracture toughness in the direct tensile test was smaller than the indirect testing results. The fracture toughness obtained from the SCB test was closer to the direct test results. Hence, the semi-circular bend test is recommended as a proper experiment for determination of mode-I fracture toughness of concrete in the absence of direct tests.

A Study on the Ceneration of Simulated High-Resolution Satellite Images (고해상도 모의위성영상 제작에 관한 연구)

  • 윤영보;조우석;박종현;이종훈
    • Korean Journal of Remote Sensing
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    • v.18 no.6
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    • pp.327-336
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    • 2002
  • Ever since high resolution satellites were launched, high-resolution satellite images have been utilized in many areas. This paper proposed methods of generating simulated satellite image using DEM(Digital Elevation Model) and digital image such as aerial photograph. There are two methods proposed in the paper: one is Direct-Indirect method and the other Indirect-Indirect, method. It is assumed that satellite attitude is not changing and perspective center is moving in the direction of flight while image is captured. The proposed methods were implemented with aerial photograph, DEM data, arbitrary orbit parameters and attitude parameters of high resolution satellite image under generation. Furthermore, for the stereo viewing, different orientation parameters and perspective center were tested for generating simulated satellite image. In addition, the quality and accuracy of the simulated satellite image generated by the proposed methods were analyzed.

Using the PNF Approach to Improve Respiratory Function in Patients with Cervical Spinal Cord Injuries (고유수용성촉진법을 이용한 호흡운동이 경수 손상환자의 호흡기능에 미치는 영향 : 증례보고)

  • Song, Gui-Bin;Kim, Jung-Bin
    • PNF and Movement
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    • v.12 no.2
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    • pp.115-121
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    • 2014
  • Purpose: The study aimed to examine the influence of PNF direct and indirect breathing treatments for patients with cervical spinal cord injuries who had breathing problems. Methods: For each cervical spinal cord patient, force vital capacity (FVC), peak expiratory flow, maximum phonation time (MPT), rib cage width, and VAS were measured pre-intervention and four weeks after post-intervention. The indirect method and the direct method were used for interventions. We treated patients with the indirect method using scapular anterior depression pattern, bilateral extensor pattern with rhythmic initiation, and a combination of isotonic. We treated patients with the direct method, applying pressure on the sternum and using rhythmic initiation (hold relax and stretch reflex) for the rib cage. Training occurred for 50 minutes a day and three days per week for four weeks. Results: FVC, MPT, peak expiratory flow, and rib cage width were increased and decreased at the VAS point for rolling after treatment. Conclusion: Patients with cervical spinal cord injuries who had breathing problems felt uncomfortable when they had conversations on a couch. We found that PNF direct and indirect treatments improved rib cage width and breathing functions of patients with cervical spinal cord injuries.

Impact of Direct Tax and Indirect Tax on Economic Growth in Vietnam

  • NGUYEN, Hieu Huu
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.4
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    • pp.129-137
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    • 2019
  • Tax can be categorised into direct tax and indirect tax. This paper uses the ordinary least-squares regression method to study the impact of direct and indirect tax on economic growth in Vietnam in the period 2003-2017. Statistical data is collected from the Ministry of Finance of Vietnam. Theoretically, tax generates the state budget revenue and is a tool to regulate the economy. The results of statistical tests show that tax has a positive impact on Vietnam's economic growth. However, the effects of direct tax and indirect tax are different. The indirect tax has a positive influence and promote Vietnam's economic growth, while the impact of the direct tax is invisible. There has not been sufficient evidence to confirm that the indirect tax has a more positive impact than the direct tax. To promote economic growth, Vietnam needs to restructure its tax system towards: (1) Increasing the proportion of indirect tax, reducing the proportion of direct tax in the state budget revenue; (2) Expanding tax bases; (3) Reducing tax rates of corporate income tax and personal income tax; (4) Increasing tax rates of environmental protection tax, natural resources tax, value added tax and excise tax on some types of goods which harm health and environment.