• Title/Summary/Keyword: fixed point theory

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An Analysis of Spactial Practice of Morden People appeared in the early 20th century film (20세기 초 영화에 나타난 근대인의 공간적 실천 분석 연구)

  • Lee, Young-Soo;Roh, Eun-Joo
    • Korean Institute of Interior Design Journal
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    • v.20 no.6
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    • pp.124-134
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    • 2011
  • The space has been interpreted from various perspectives, such as hierarchical, cultural, economic, political factors, etc. So we can see the space as a social existence. Space is now being formed through the dialectical relations of these elements. From this point of view, this study started to research the spatial practice of morden people through the case in the early 20th century film. With the discourse of Henri Lefebvre and David Harvey, and Michel de Certeau's theory, this research tried to find the mechanisms of spatial practice. Also Benjamin is a philosopher who intervenes the relationship between modernity and cultural production and his way of reading cultural phenomena seems to serve as the useful methodology of cultural studies. Modern people were individual unawared of the era, awakened to the ego. They were wandering the room and the street, private and public places. They were city dwellers walking around, collecting goods, and living of everyday life. Spatial practice is a fixed activity and have continuity. spatial practice appeared in the early 20th century film is at the intersection of social practices and the practice of everyday life. Social practices are a fixed practice and continuous practice. The practices of everyday life are nomadic practice and amusable practice. Modern people accommodate and adapt to a given space of the city through fixed practice. They realizes the access and the distance from spaces through continuous practice. They select and approved the spaces through nomadic practice. And they possess exclusively and utilize the spaces through amusable practice. Through These research spatial practices, it could easily found similarities and differences between modern space on the early 20th century and contemporary space of 21st century. True modern is not the past but the present.

Robust Air-to-fuel Ratio Control Algorithm of Passenger Car Diesel Engines Using Quantitative Feedback Theory (QFT 기법을 이용한 승용디젤엔진 공연비 제어 알고리즘 설계 연구)

  • Park, Inseok;Hong, Seungwoo;Shin, Jaewook;Sunwoo, Myoungho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.3
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    • pp.88-97
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    • 2013
  • This paper presents a robust air-to-fuel ratio (AFR) control algorithm for managing exhaust gas recirculation (EGR) systems. In order to handle production tolerance, deterioration and parameter-varying characteristics of the EGR system, quantitative feedback theory (QFT) is applied for designing the robust AFR control algorithm. A plant model of EGR system is approximated by the first order transfer function plus time-delay (FOPTD) model. EGR valve position and AFR of exhaust gas are used as input/output variables of the plant model. Through engine experiments, parameter uncertainty of the plant model is identified in a fixed engine operating point. Requirement specifications of robust stability and reference tracking performance are defined and these are fulfilled by the following steps: during loop shaping process, a PID controller is designed by using a nominal loop transmission function represented on Nichols chart. Then, the frequency response of closed-loop transfer function is used for designing a prefilter. It is validated that the proposed QFT-based AFR control algorithm successfully satisfy the requirements through experiments of various engine operating points.

On the "Virtual and Real" and Blankness in Chinese Landscape Painting

  • Dongqi, Liu
    • International Journal of Advanced Culture Technology
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    • v.10 no.3
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    • pp.174-183
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    • 2022
  • The abstract should summarize the contents of the paper and written below the author information. Use the word "Abstract" as the title, in 12-point Times New Roman, boldface type, italicized, centered relative to the column, initially capitalized, fixed-spacing at 13 pt., 12 pt. spacing before the text and 6 pt. after. The abstract content is to be in 11-point, italicized, single spaced type. Leave one blank line after the abstract, and then begin the keywords. All manuscripts must be in English. When it comes to the issue of "virtual and real" in traditional Chinese painting, the first impression is to describe the problems of painting strokes and ink, layout of pictures, etc., but it runs through the initial conception of the work, creation in the middle and aesthetic appreciation of the work. It exists in the whole process of artistic creation and appreciation. In essence, it is a problem of aesthetic thinking and philosophical thinking. Because the traditional Chinese painting theory is influenced by Taoism, when the concept of "virtual and real" is implemented in the specific picture of Chinese painting, it is contained in the specific shape of "physics", that is, the painting theory research of "blank space" in the picture. Based on the traditional Taoist philosophy of China, this paper takes the "virtual and real" view in Lao Zhuang's thought as the research object, deeply analyzes and compares its relationship with the "virtual and real" in Chinese landscape painting, and finds out their artistic spirit, essential characteristics and how to present them. This paper mainly discusses the internal relationship between Taoist philosophy and "virtual and real" in Chinese landscape painting from the following aspects. The introduction expounds the origin, purpose, significance, innovation and research methods of the topic. This paper analyzes the philosophical thoughts about landscape in the philosophical thoughts represented by Lao Tzu and Zhuangzi. The development of Chinese traditional aesthetics theory is closely related to Taoist philosophy, which has laid the foundation and pointed out the direction for the development of Chinese painting theory since ancient times. It also discusses the influence of the Taoist philosophy of "the combination of the virtual and real" on the emergence and development of the artistic conception of landscape painting. Firstly, through the analysis of the artistic conception of landscape painting and its constituent factors, it is pointed out that the artistic conception is affected by the personality and the painting artistic conception. Secondly, through the Taoist thought of "the combination of the virtual and real" in landscape painting, so as to reflect that it is the source of the artistic conception of Chinese landscape painting. It is the unique spiritual concept of "Yin and Yang" and "virtual and real" that creates the unique "blank space" aesthetic realm of Chinese painting in the composition of the picture. Finally, it focuses on the "nothingness" in Taoist philosophy and the "blank space" in Chinese landscape painting. The connotation of the "blank space" in Chinese painting exceeds its own expressive significance, which makes the picture form the aesthetic principle of emotional blending, virtual and real combination and dynamic and static integration. Through the "blank space", it deepens the artistic characteristics of the picture and sublimates the expression of "form" in Chinese painting.

A Study of Temporal Characteristics From Multi-Dimensional Precipitation Model (다차원 강우모형의 시간적인 특성 연구)

  • Kim, Sangdan;Yoo, Chulsang;Kim, Joong-Hoon;Yoon, Yong Nam
    • Journal of Korea Water Resources Association
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    • v.33 no.6
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    • pp.783-791
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    • 2000
  • A multidimensional representation for precipitation, given In the theory proposed by E. Waymire et al. (1984), is used for simulating rainfall in space and time. The model produces moving storms with realistic meso-scale meteorological features in time and space. The first- and second-order statistics derived from observed JX)int gauge data were used to estimate the model parameters based on the Nelder-Mead algorithm of optimization. Then twelve-year traces of rainfall intensities at fixed gage stations were generated at intervals of 1 hours. First- and second-order statistics are evaluated from the above series, which are used for estimating the parameters of one dimensional model of temporal rainfall at a point. As a result from the comparisons of one dimensional model parameters used observed and generated data from multidimensional model, we found that the multidimensional rainfall model generated visually realistic spatial patterns of rainfall as well as realistic temporal hyetographs of rainfall at a point. point.

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Option-type Default Forecasting Model of a Firm Incorporating Debt Structure, and Credit Risk (기업의 부채구조를 고려한 옵션형 기업부도예측모형과 신용리스크)

  • Won, Chae-Hwan;Choi, Jae-Gon
    • The Korean Journal of Financial Management
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    • v.23 no.2
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    • pp.209-237
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    • 2006
  • Since previous default forecasting models for the firms evaluate the probability of default based upon the accounting data from book values, they cannot reflect the changes in markets sensitively and they seem to lack theoretical background. The market-information based models, however, not only make use of market data for the default prediction, but also have strong theoretical background like Black-Scholes (1973) option theory. So, many firms recently use such market based model as KMV to forecast their default probabilities and to manage their credit risks. Korean firms also widely use the KMV model in which default point is defined by liquid debt plus 50% of fixed debt. Since the debt structures between Korean and American firms are significantly different, Korean firms should carefully use KMV model. In this study, we empirically investigate the importance of debt structure. In particular, we find the following facts: First, in Korea, fixed debts are more important than liquid debts in accurate prediction of default. Second, the percentage of fixed debt must be less than 20% when default point is calculated for Korean firms, which is different from the KMV. These facts give Korean firms some valuable implication about default forecasting and management of credit risk.

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A Non-Periodic Synchronization Algorithm using Address Field of Point-to-Point Protocol in CDMA Mobile Network (CDMA이동망에서 점대점 프로토콜의 주소영역을 이용한 비주기적 동기 알고리즘)

  • Hong, Jin-Geun;Yun, Jeong-O;Yun, Jang-Heung;Hwang, Chan-Sik
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.8
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    • pp.918-929
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    • 1999
  • 동기식 스트림 암호통신 방식을 사용하는 암호통신에서는 암/복호화 과정 수행시 암호통신 과정에서 발생하는 사이클슬립으로 인해 키수열의 동기이탈 현상이 발생되고 이로 인해 오복호된 데이타를 얻게된다. 이러한 위험성을 감소하기 위한 방안으로 현재까지 암호문에 동기신호와 세션키를 주기적으로 삽입하여 동기를 이루는 주기적인 동기암호 통신방식을 사용하여 왔다. 본 논문에서는 CDMA(Cellular Division Multiple Access) 이동망에서 데이타서비스를 제공할 때 사용되는 점대점 프로토콜의 주소영역의 특성을 이용하여 단위 측정시간 동안 측정된 주소비트 정보와 플래그 패턴의 수신률을 이용하여 문턱 값보다 작은경우 동기신호와 세션키를 전송하는 비주기적인 동기방식을 사용하므로써 종래의 주기적인 동기방식으로 인한 전송효율성 저하와 주기적인 상이한 세션키 발생 및 다음 주기까지의 동기이탈 상태의 지속으로 인한 오류확산 등의 단점을 해결하였다. 제안된 알고리즘을 링크계층의 점대점 프로토콜(Point to Point Protocol)을 사용하는 CDMA 이동망에서 동기식 스트림 암호 통신방식에 적용시 동기이탈율 10-7의 환경에서 주기가 1sec인 주기적인 동기방식에서 요구되는 6.45x107비트에 비해 3.84x105비트가 소요됨으로써 전송율측면에서의 성능향상과 오복호율과 오복호 데이타 비트측면에서 성능향상을 얻었다. Abstract In the cipher system using the synchronous stream cipher system, encryption / decryption cause the synchronization loss (of key arrangement) by cycle slip, then it makes incorrect decrypted data. To lessen the risk, we have used a periodic synchronous cipher system which achieve synchronization at fixed timesteps by inserting synchronization signal and session key. In this paper, we solved the problem(fault) like the transfer efficiency drops by a periodic synchronous method, the periodic generations of different session key, and the incorrectness increases by continuing synchronization loss in next time step. They are achieved by the transfer of a non-periodic synchronous signal which carries synchronous signal and session key when it is less than the threshold value, analyzing the address field of point-to-point protocol, using the receiving rate of address bits information and flag patterns in the decision duration, in providing data services by CDMA mobile network. When the proposed algorithm is applied to the synchronous stream cipher system using point-to-point protocol, which is used data link level in CDMA mobile network, it has advanced the result in Rerror and Derror and in transmission rate, by the use of 3.84$\times$105bits, not 6.45$\times$107bits required in periodic synchronous method, having lsec time step, in slip rate 10-7.

Design of Quantitative Feedback Control System for the Three Axes Hydraulic Road Simulator (3축 유압 도로 시뮬레이터의 정량적 피드백 제어 시스템 설계)

  • Kim, Jin-Wan;Xuan, Dong-Ji;Kim, Young-Bae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.3
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    • pp.280-289
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    • 2008
  • This paper presents design of the quantitative feedback control system of the three axes hydraulic road simulator with respect to the dummy wheel for uncertain multiple input-output(MIMO) feedback systems. This simulator has the uncertain parameters such as fluid compressibility, fluid leakage, electrical servo components and nonlinear mechanical connections. This works have reproduced the random input signal to implement the real road vibration's data in the lab. The replaced $m^2$ MISO equivalent control systems satisfied the design specifications of the original $m^*m$ MIMO control system and developed the mathematical method using quantitative feedback theory based on schauder's fixed point theorem. This control system illustrates a tracking performance of the closed-loop controller with low order transfer function G(s) and pre-filter F(s) having the minimum bandwidth for parameters of uncertain plant. The efficacy of the designed controller is verified through the dynamic simulation with combined hydraulic model and Adams simulator model. The Matlab simulation results to connect with Adams simulator model show that the proposed control technique works well under uncertain hydraulic plant system. The designed control system has satisfied robust performance with stability bounds, tracking bounds and disturbance. The Hydraulic road simulator consists of the specimen, hydraulic pump, servo valve, hydraulic actuator and its control equipments

The Structure and Performance of Turbo decoder using Sliding-window method (슬라이딩 윈도우 방식의 터보 복호화기의 구조 및 성능)

  • 심병효;구창설;이봉운
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.1
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    • pp.116-126
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    • 2000
  • Turbo codes are the most exciting and potentially important development in coding theory in recent years. They were introduced in 1993 by Berrou, Glavieux and $Thitimajshima,({(1)}$ and claimed to achieve near Shannon-limit error correction performance with relatively simple component codes and large interleavers. A required Eb/N0 of 0.7㏈ was reported for BER of $10^{-5}$ and code rate of $l/2.^{(1)}$ However, to implement the turbo code system, there are various important details that are necessary to reproduce these results such as AGC gain control, optimal wordlength determination, and metric rescaling. Further, the memory required to implement MAP-based turbo decoder is relatively considerable. In this paper, we confirmed the accuracy of these claims by computer simulation considering these points, and presented a optimal wordlength for Turbo code design. First, based on the analysis and simulation of the turbo decoder, we determined an optimal wordlength of Turbo decoder. Second, we suggested the MAP decoding algorithm based on sliding-window method which reduces the system memory significantly. By computer simulation, we could demonstrate that the suggested fixed-point Turbo decoder operates well with negligible performance loss.

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A Study on Nonlinear Water-Wave Profile (비선형 해양파의 파형 연구에 관하여)

  • JANG TAEK-SOO;WANG SUNG-HYUNH;KWON SUN-HONG
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.11a
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    • pp.179-182
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    • 2004
  • This paper deals with a new mathematical formulation of nonlinear wave profile based on Banach fixed point theorem. As application of the formulation and its solution procedure, some numerical solutions was presented in this paper and nonlinear equation was derived. Also we introduce a new operator for iteration and getting solution. A numerical study was accomplished with Stokes' first-order solution and iteration scheme, and then we can know the nonlinear characteristic of Stokes' high-order solution. That is, using only Stokes' first-oder(linear) velocity potential and an initial guess of wave profile, it is possible to realize the corresponding high-oder Stokian wave profile with tile new numerical scheme which is the method of iteration. We proved the mathematical convergence of tile proposed scheme. The nonlinear strategy of iterations has very fast convergence rate, that is, only about 6-10 iterations arc required to obtain a numerically converged solution.

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A Study of Juhakhae(周學海)'s Three Eum and Three Yang[三陰三陽] Field Theory (주학해(周學海)의 삼음삼양(三陰三陽) 분야설(分野說)에 관한 고찰)

  • Jang, Woo-Chang
    • Journal of Korean Medical classics
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    • v.21 no.1
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    • pp.153-162
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    • 2008
  • Three Eum and Three Yang[三陰三陽] is a way of studying the changing of nature from a Eum(陰) and Yang(陽) point of view, Juhakhae(周學海) divides this into two dimensions. The first is the concept of dividing the exterior part of the body excluding the organ into 6 divisions as Eumyang(陰陽) of front and rear characteristic. The second is the concept of dividing the systematic bio-activity of the central organ into another 6 dimensions. The former concept is illustrated in the body as a certain meridian controlling a certain field of the body, while the latter is presented as a certain organ performing an activity of Gi(氣). Three Eum and Three Yang[三陰三陽] is not based on fixed substances. but it is a thought process model of observing the structural-functional changes of the body in disease state. Therefore, by understanding Three Eum and Three Yang[三陰三陽] of field and activity of Gi(氣) respectively and comprehensively putting these into practice, we will be able to approach the essence of the disease state in a more precise manner.

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