• Title/Summary/Keyword: power space

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An In-depth Study on Applying Metric Weighting to Space Syntax (공간구문론에의 거리가중개념 적용에 관한 심층 연구)

  • Kim, Minseok;Piao, Gensong
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.12
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    • pp.49-54
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    • 2018
  • Applying metric(distance) factor as weighting to spatial syntax is known to not contribute to the explanatory power for the human movement behavior as compared to the geometric(angle) factor according to the negative results of several related studies. However, Kim & Piao (2017) assumed that there is not a problem of the metric factor itself but a problem of the way of applying the metric factor as weighting, and presented a new possibility of the metric factor as weighting by proposing and verifying the methods of applying the metric weighting, which are different from the existing ones. The purpose of this study is to propose advanced methods of applying the metric weighting to space syntax, and to verify whether they contribute to the improvement of explanatory power of space syntax analysis. In this paper, we propose functions for combined depth of distance-step that combine the distance-weighted depth function with the step depth function and apply them to axial segment analysis to check the improvement of explanatory power of them.

Analog Implementation of Space Vector PWM (공간벡터 변조법의 아날로그 구현)

  • 이지명;홍명보;이동춘
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.299-302
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    • 1999
  • An analog implementation of space vector PWM is proposed in this paper. It is shown that a space vector PWM can be implemented by adding a zero sequency voltage to reference voltage of triangle comparison PWM. The proposed scheme is implemented by six diodes and, an operational amplifier circuit and, a few resistors.

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Linearization and harmonic analysis of output voltages in overmodulation range of space vector PWM (공간벡터 PWM에서 과변조시 출력전압의 선형화 및 고조파 분석)

  • 이지명;이동춘
    • The Transactions of the Korean Institute of Power Electronics
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    • v.3 no.2
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    • pp.118-124
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    • 1998
  • This paper describes a relationship of a space vector PWM and a sinusoidal PWM and presents that the space vector PWM can produce linearly the output voltage to the unity MI(modulation index). At first, reference angles and holding angles are derived from expanding a Fourier series of the reference voltage waveform and then the angles are used for the inverter switching to linearize transfer characteristics of the inverter. In addition, the harmonic components of the output voltage are analyzed and on-line control is shown to be feasible by approximating in piecewise-linearization the reference and holding angles versus the MI. In V/f control of the induction motor, it is verified by the experiment that the motor current is changed smoothly for the variation of the inverter input voltage and the change of the reference voltage.

An Equivalent Carrier-based Implementation of a Modified 24-Sector SVPWM Strategy for Asymmetrical Dual Stator Induction Machines

  • Wang, Kun;You, Xiaojie;Wang, Chenchen
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1336-1345
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    • 2016
  • A modified space vector pulse width modulation (SVPWM) strategy based on vector space decomposition and its equivalent carrier-based PWM realization are proposed in this paper, which is suitable for six-phase asymmetrical dual stator induction machines (DSIMs). A DSIM is composed of two sets of symmetrical three-phase stator windings spatially shifted by 30 electrical degrees and a squirrel-cage type rotor. The proposed SVPWM technique can reduce torque ripples and suppress the harmonic currents flowing in the stator windings. Above all, the equivalent relationship between the proposed SVPWM technique and the carrier-based PWM technique has been demonstrated, which allows for easy implementation by a digital signal processor (DSP). Simulation and experimental results, carried out separately on a simulation system and a 3.0 kW DSIM prototype test bench, are presented and discussed.

Improved Space Vector Modulation Strategy for AC-DC Matrix Converters

  • Liu, Xiao;Zhang, Qingfan;Hou, Dianli;Wang, Siyao
    • Journal of Power Electronics
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    • v.13 no.4
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    • pp.647-655
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    • 2013
  • In this paper, an approach to reduce the common-mode voltage and to eliminate narrow pulse for implemented AC-DC matrix converters is presented. An improved space vector modulation (SVM) strategy is developed by replacing the zero space vectors with suitable pairs of active ones. Further, while considering the commutation time, the probability of narrow pulse in the conventional and proposed SVM methods are derived and compared. The advantages of the proposed scheme include: a 50% reduction in the peak value of the common-mode voltage; improved input and output performances; a reduction in the switching loss by a reduced number of switching commutations and a simplified implementation via software. Experimental results are presented to demonstrate the correctness of the theoretical analysis, as well as the feasibility of the proposed strategy.

A Study on The Brand Image Elements of Housing Cultural Center (주택문화관의 브랜드 이미지 요소에 관한 연구)

  • Kim, Jung-Yoon;Lee, Hyun-Soo
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.11a
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    • pp.26-29
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    • 2007
  • By changing housing market, housing cultural center furnishes information, value added, image of housing. For publicity their unique house, construction companies provide not only concrete and substantial material but also sensible and capacity service through the community space of housing cultural center. The consumer's experience of housing cultural center have an effect on purchase power apartment. The image of enterprise is important to select commodities to consumers. Though main clients are women, housing cultural center has not space concept and aim to concern for them. According to begin women a group of consumers, they have purchasing power in family. Apartment is no exception. Housing cultural center is used as continuous culture space that provide various experiential chance for consumer, especially women by systematize and distinct design detail and feature component. Accordingly, the purpose of this study is an analysis about community space of housing cultural center with the woman marketing based on experience.

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Numerical Feasibility Study for a Spaceborne Cooler Dual-function Energy Harvesting System

  • Kwon, Seong-Cheol;Oh, Hyun-Ung
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.3
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    • pp.579-587
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    • 2017
  • Spaceborne cryocoolers produce undesirable micro-vibration disturbances during their on-orbit operation, which are a primary source of image-quality degradation for high-resolution observation satellites. Therefore, to comply with the strict mission requirement of high-quality image acquisition, micro-vibration disturbances induced by cooler operation have always been subjected to an isolation objective. However, in this study, we focused on the applicability of energy harvesting technology to generate electrical energy from micro-vibration energy of the cooler and investigated the feasibility of utilizing harvested energy as a power source to operate low-power-consumption devices such as micro-electromechanical system (MEMS) devices. A tuned mass damper (TMD)-type electromagnetic energy harvester combined with a conventional passive vibration isolator was proposed to achieve this objective. The system performs the dual functions of electrical energy generation and micro-vibration isolation. The effectiveness of the strategy was evaluated through numerical simulations.

Development of Regenerative Inverter for Electric Railway Using Space Vector PWM (SVPWM을 이용한 전기철도용 회생 인버터 개발)

  • 백병산;정문구;김태완
    • The Transactions of the Korean Institute of Power Electronics
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    • v.9 no.2
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    • pp.97-104
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    • 2004
  • As a device that returns surplus energy, regenerated from trains to d.c. source, to a.c. system and reuses it, the thyristor Inverter has been widely used. Because the conventional thyristor inverter is a unidirectional phase-controlled device, it Is Impossible to control the power factor of its output. Moreover, harmonics emission is high and it needs to take a additional filter. In this paper, to solve the problems stated above, the inverter, which can control real and reactive power by adopting IGBT modules as switching elements and being controlled by means of space vector PWM, is developed. Considering high economical efficiency and reliability in order to apply to the system for commercial use, the developed inverter is equipped with fully digital control system and low pass filter, and reduces harmonics and has compact size. The detail description about the developed inverter is stated in various respects: design criteria, technical description, power circuits, control techniques, the developed system, test results, etc.

A new surrogate method for the neutron kinetics calculation of nuclear reactor core transients

  • Xiaoqi Li;Youqi Zheng;Xianan Du;Bowen Xiao
    • Nuclear Engineering and Technology
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    • v.56 no.9
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    • pp.3571-3584
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    • 2024
  • Reactor core transient calculation is very important for the reactor safety analysis, in which the kernel is neutron kinetics calculation by simulating the variation of neutron density or thermal power over time. Compared with the point kinetics method, the time-space neutron kinetics calculation can provide accurate variation of neutron density in both space and time domain. But it consumes a lot of resources. It is necessary to develop a surrogate model that can quickly obtain the temporal and spatial variation information of neutron density or power with acceptable calculation accuracy. This paper uses the time-varying characteristics of power to construct a time function, parameterizes the time-varying characteristics which contains the information about the spatial change of power. Thereby, the amount of targets to predict in the space domain is compressed. A surrogate method using the machine learning is proposed in this paper. In the construction of a neural network, the input is processed by a convolutional layer, followed by a fully connected layer or a deconvolution layer. For the problem of time sequence disturbance, a structure combining convolutional neural network and recurrent neural network is used. It is verified in the tests of a series of 1D, 2D and 3D reactor models. The predicted values obtained using the constructed neural network models in these tests are in good agreement with the reference values, showing the powerful potential of the surrogate models.

A Study on the Type Analysis and Comparison of Space Contents in the Culture and Art City (문화예술 도시의 공간 콘텐츠 유형분석 및 비교에 관한 연구)

  • Cho, Yeon;Moon, Jeong-Min
    • Korean Institute of Interior Design Journal
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    • v.20 no.1
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    • pp.109-116
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    • 2011
  • As urbanization has evolved, a number of cities have been engaged in building creative power through branding. Cities contain much creative space and creative space within cities develops them. Cities are connected with space, which have a great influence each other, in particular, in cities of culture and art. Space contents in cities have various forms and types and work as important factors for branding of cities. In this high-touch generation, cities of culture and art have special meaning in that design of emotional generation, and cultural meaning of tangible and intangible assets in cities are their competitive power and sources of high added value. The cities of culture and art are oriented toward creative future globally and nationally. In cities of culture which seek for urban development by excavating artistic meaning and value through artistic and cultural development, their cultural meaning itself can become a brand, which effectively leads to building creative cities and marketing of urban brands. This study aims to analyse cases of cities developed through discovering or reactivating art and cultural meaning and value of urban space based on urban space contents. Then it analyses through what urban image, brands and marketing space contents were developed and suggests necessity of space contents development in small and middle sized cities. Therefore, based on the cases of art and cultural cities developed depending on space contents, it analyses and differentiate their various types and contents, aiming to show that any cities can be based on art and culture and creativity depending on creation, regeneration and development of space contents.