• Title/Summary/Keyword: positive real function

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RADII PROBLEMS OF CERTAIN SUBCLASSES OF ANALYTIC FUNCTIONS WITH FIXED SECOND COEFFICIENTS

  • PORWAL, SAURABH;BULUT, SERAP
    • Honam Mathematical Journal
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    • v.37 no.3
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    • pp.317-323
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    • 2015
  • The purpose of the present paper is to study certain radii problems for the function $$f(z)=\[{\frac{z^{1-{\gamma}}}{{\gamma}+{\beta}}}\(z^{\gamma}[D^nF(z)]^{\beta}\)^{\prime}\]^{1/{\beta}}$$, where ${\beta}$ is a positive real number, ${\gamma}$ is a complex number such that ${\gamma}+{\beta}{\neq}0$ and the function F(z) varies various subclasses of analytic functions with fixed second coefficients. Relevant connections of the results presented herewith various well-known results are briefly indicated.

ON APPROXIMATION OF CONTROLS BY FUZZY SYSTEMS

  • Nguyen, Hung T.;Kreinovich, Vladik
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1414-1417
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    • 1993
  • Wang and Medel proved (1991) that fuzzy systems with product inference, centroid defuzzification, and everywhere positive membership functions (in particular, Gaussians, Wang, 1992) are capable of approximating any real continuous control function on a compact set to arbitrary accuracy. Kosko (1992) proved that fuzzy systems, in which membership functions have compact support, and combination operation (V-operation) for rules is the sum, are also universal approximators. In this paper, we generalize this result of Kosko and prove that for any &- and V-operations, any defuzzification procedure, and any basic membership function with a compact support, the resulting fuzzy controls are universal approximators. Also, Wang's result is transfered to min-inference.

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Pole Placement Method to Move a Equal Poles with Jordan Block to Two Real Poles Using LQ Control and Pole's Moving-Range (LQ 제어와 근의 이동범위를 이용한 조단 블록을 갖는 중근을 두 실근으로 이동시키는 극배치 방법)

  • Park, Minho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.608-616
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    • 2018
  • If a general nonlinear system is linearized by the successive multiplication of the 1st and 2nd order systems, then there are four types of poles in this linearized system: the pole of the 1st order system and the equal poles, two distinct real poles, and complex conjugate pair of poles of the 2nd order system. Linear Quadratic (LQ) control is a method of designing a control law that minimizes the quadratic performance index. It has the advantage of ensuring the stability of the system and the pole placement of the root of the system by weighted matrix adjustment. LQ control by the weighted matrix can move the position of the pole of the system arbitrarily, but it is difficult to set the weighting matrix by the trial and error method. This problem can be solved using the characteristic equations of the Hamiltonian system, and if the control weighting matrix is a symmetric matrix of constants, it is possible to move several poles of the system to the desired closed loop poles by applying the control law repeatedly. The paper presents a method of calculating the state weighting matrix and the control law for moving the equal poles with Jordan blocks to two real poles using the characteristic equation of the Hamiltonian system. We express this characteristic equation with a state weighting matrix by means of a trigonometric function, and we derive the relation function (${\rho},\;{\theta}$) between the equal poles and the state weighting matrix under the condition that the two real poles are the roots of the characteristic equation. Then, we obtain the moving-range of the two real poles under the condition that the state weighting matrix becomes a positive semi-finite matrix. We calculate the state weighting matrix and the control law by substituting the two real roots selected in the moving-range into the relational function. As an example, we apply the proposed method to a simple example 3rd order system.

Web Contents Mining System for Real-Time Monitoring of Opinion Information based on Web 2.0 (웹2.0에서 의견정보의 실시간 모니터링을 위한 웹 콘텐츠 마이닝 시스템)

  • Kim, Young-Choon;Joo, Hae-Jong;Choi, Hae-Gill;Cho, Moon-Taek;Kim, Young-Baek;Rhee, Sang-Yong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.1
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    • pp.68-79
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    • 2011
  • This paper focuses on the opinion information extraction and analysis system through Web mining that is based on statistics collected from Web contents. That is, users' opinion information which is scattered across several websites can be automatically analyzed and extracted. The system provides the opinion information search service that enables users to search for real-time positive and negative opinions and check their statistics. Also, users can do real-time search and monitoring about other opinion information by putting keywords in the system. Proposing technique proved that the actual performance is excellent by comparison experiment with other techniques. Performance evaluation of function extracting positive/negative opinion information, the performance evaluation applying dynamic window technique and tokenizer technique for multilingual information retrieval, and the performance evaluation of technique extracting exact multilingual phonetic translation are carried out. The experiment with typical movie review sentence and Wikipedia experiment data as object as that applying example is carried out and the result is analyzed.

Moving obstacle avoidance of a robot using avoidability measure (충돌 회피 가능도를 이용한 로봇의 이동 장애물 회피)

  • Ko, Nak-Yong;Lee, Beom-Hee
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.2
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    • pp.169-178
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    • 1997
  • This paper presents a new solution approach to moving obstacle avoidance problem of a robot. A new concept, avoidability measure(AVM) is defined to describe the state of a pair of a robot and an obstacle regarding the collision between them. As an AVM, virtual distance function(VDF) is derived as a function of three state variables: the distance from the obstacle to the robot, outward speed of the obstacle relative to the robot, and outward speed of the robot relative to the obstacle. By keeping the virtual distance above some positive limit value, the robot avoids the obstacle. In terms of the VDF, an artificial potential is constructed to repel the robot away from the obstacle and to attract the robot toward a goal location. At every sampling time, the artificial potential field is updated and the force driving the robot is derived from the gradient of the artificial potential field. The suggested algorithm drives the robot to avoid a moving obstacle in real time. Since the algorithm considers the mobility of the obstacle and robot as well as the distance, it is effective for moving obstacle avoidance. Some simulation studies show the effectiveness of the proposed approach.

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Comparison of Usability and Prefrontal Cortex Activity of Cognitive-Motor Training Programs using Sensor-Based Interactive Systems

  • Jihye Jung;Seungwon Lee
    • Physical Therapy Rehabilitation Science
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    • v.11 no.4
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    • pp.571-578
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    • 2022
  • Objective: Cognitive-motor trainings had a positive impact on cognitive function and dual-task trainings led to improvements of global cognitive function. The brain activity of the prefrontal cortex (PFC) is another indicator that can infer cognitive function. This study aims to confirm the usability of the interactive system cognitive-motor training program and the changes in the prefrontal cortex through training. Design: Cross-sectional study Methods: In this study, two cognitive tasks were randomly applied to 20 adults as cognitive-motor training using an interactive system, and the same task was performed using the original method. During all tasks, the brain activity of the prefrontal cortex was measured by the change in oxyhemoglobin (HbO) in real-time using Functional Near-Infrastructure. After performing the tasks, the usability of the developed interactive system was evaluated by a usability questionnaire which consists of five items, and each item consists of a 7-point Likert scale that responds from 1 point to 7 points. Results: The HbO levels were increased during cognitive task performance than at the resting phase. And evaluating the usefulness of the interactive system, a questionnaire result showed that it would be useful for cognitive-motor programs. Conclusions: The cognitive-motor training using the interactive system increased the activity of the prefrontal cortex, and the developed wearable sensor-based interactive system confirmed its usefulness.

A study of the relationship between corporate governance and real earnings management: Based on foreign investors and growth (기업지배구조와 실제이익조정의 관계 연구: 외국인투자자와 성장성을 중심으로)

  • Kang, Shin-Ae;Kim, Tae-Joong
    • Journal of Distribution Science
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    • v.12 no.4
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    • pp.85-92
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    • 2014
  • Purpose - This study conducted empirical research on non-financial corporations listed on the stock exchange from 2001 to 2010, focusing on the effects of corporate governance on real earnings management of corporations. In particular, this study examined primarily the impact of the largest shareholder who could use earnings management to pursue his own self-interest, and foreign investors who played a checking role against the largest shareholders. The study also reviewed the relationship between corporate governance and earnings management while also considering corporate growth. Research design, data, and methodology - As for the measurements of real earnings management, abnormal operating cash flow and abnormal production cost were utilized. As for the independent variables, share ratio of the largest shareholder and affiliate person (M) and share ratio of foreign investors (FT) were leveraged. This study excluded those organizations that had changed their fiscal years, those that had not submitted an audit report, corporations under supervision, delisted corporations, corporations that had changed their business type, and so on, from the non-financial corporations out of the publicly traded corporations whose fiscal year ended in December from 2001 to 2010 in addition, KIS values were utilized for the corporate financial data in the study. To verify whether management structure and growth had an impact on real earnings management of a corporation through empirical analysis, a multiple regression analysis model was applied. Result - First, as a result of the analysis, the share ratio (M) of the largest shareholder and affiliate person was found to have a significant positive correlation with abnormal cash flow from operations(ACF) and abnormal production cost (APD). When controlling the growth, the share ratio (M) of the largest shareholder and affiliate person was found to have an insignificant correlation with abnormal cash flow from operations(ACF) but a significant correlation with abnormal production cost (APD). Second, foreign ownership (FT) was found to have a significant positive correlation with abnormal cash flow from operations(ACF) and abnormal production cost (APD) at the confidence level of 1 percent when not including the growth dummy. When controlling the growth, foreign ownership (FT) was found to have a significant negative correlation with abnormal cash flow from operations (ACF) and with abnormal production cost (APD). Conclusion - The results imply that the largest shareholder is closely related to earnings management through real activities regardless of corporate growth. It is also possible to determine from these results that foreign investors are related to earnings management through real activities when not considering corporate growth, but that they would reduce earnings management in the case of considering the growth. Thus, this study verified along with the existing studies that foreign investors were conducting the control function on controlling shareholders.

Correlation of Curved Walking Ability with Straight Walking Ability and Motor Function in Patients with Hemiplegia

  • Lim, Jae-Heon;Park, Jang-Sung;Seo, Sam-Ki
    • The Journal of Korean Physical Therapy
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    • v.23 no.3
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    • pp.13-19
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    • 2011
  • Purpose: In real life there are both straight-paths and curved-paths. To evaluate walking ability of both kinds, a figure-8 walking test (F8WT) was developed. The aim of this study was to validate the measure in hemiplegic patients with walking difficulties and to identify correlations of curved walking ability with straight walking ability, motor function, and walking performance ability. Methods: Twenty subjects participated in this study. Curved walking was measured by a F8WT. Straight walking ability was measured by a 10-meter walking test (10MWT). Dynamic balancea bility was measured by timed up and go (TUG) tests. Walking performance ability was measured using a modified motor assessment scale (MMAS). Motor function was measured by the Fugl-Meyer assessment (FMA) scale. Data were analyzed using Pearson correlation analysis. Linear regression analyses were performed to explore other functional tests in mobility ability by F8WT time, 10MWT (dependent variable). Results: There was a significant positive correlation of F8WT time with 10MWT and TUG. There was a significant negative correlation of F8WT time with MMAS and FMA-coordination. There was a significant positive correlation of 10MWT with TUG. There was a significant negative correlation of 10MWT with MMAS and FMA-coordination. The F8WT time for curved walking ability was attributed to 10MWT for straight walking ability as 94% level of contribution. Conclusion: The results suggest that the F8WT is a good instrument for measuring walking ability because there is a robust correlation of F8WT time with 10MWT, TUG, MMAS, and FMA-coordination in hemiplegic patients who, after stroke, have a mobility deficiency.

A Study on the Characteristic of the Speculation Space of Architecture find on Tadao Ando (안도 타다오 건축에 나타난 사색 공간의 표현 특성에 관한 연구)

  • Kim, Do-Yi;Kim, Joo-Yun
    • Korean Institute of Interior Design Journal
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    • v.17 no.2
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    • pp.102-110
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    • 2008
  • Construction space of Japan suggests the factor of speculation to human and reveals tradition. The speculation can be embodied in the aspect of space and human's mental aspect is expressed as a main factor of tradition space of Japan. The purpose of this study is to research expression characteristic of speculation space, shown in the architecture of modem architect, Tadao Ando, who succeeds the concept. His works surveyed through research contain the emotion of nature and human, which are traditional factors of Japan. Moreover, it is reinterpreted by modem space, delivers its function of space and physical factor to user and grants value to activity and behavior of user residing in the space. Users recognize movement, create new meaning of space and accept physical barrier in the space. In conclusion, it can be said that the space of speculation is not a simple visual thing but a frame of visual structure, which is invented for embodiment. The factors show the Japanese architecture, real and contemplating one, which is positive in real life and allows experience. Through the conditions above, the researcher can find the meaning from the aspect that modem architecture of Japan is planned on the basis of concept of speculation.

Suitability of denervated muscle flaps as recipient sites for pancreatic islet cell transplantation

  • Park, Jong-Lim;Kim, Taewoon;Kim, Baek-Kyu
    • Archives of Plastic Surgery
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    • v.48 no.1
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    • pp.133-143
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    • 2021
  • Background Extensive research has been conducted on islet transplantation as a possible cure for diabetes. Islet transplantation in the liver via the portal vein has shown remarkable results, but numerous other recipient sites are currently being investigated. We aimed to show the effectiveness of using a muscle flap as a recipient site for islet transplantation. Methods Islet cells were harvested from 12 isogenic Lewis rats, and then diabetes was induced in another 12 isogenic Lewis rats by streptozotocin injection. In six rats, 3,000 islets were transplanted into gastrocnemius muscle flaps, and in the other six rats, the same number of islets were transplanted into the gastrocnemius muscle. The transplanted islet cell function between the two groups was compared by means of blood glucose tests, glucose tolerance tests, immunohistochemistry, and real-time reverse transcription polymerase chain reaction. Results In the muscle flap group, blood glucose levels significantly decreased after islet transplantation. Blood glucose levels were significantly different between the two groups at 3 weeks after transplantation. The muscle flap group showed nearly normoglycemic results upon the glucose tolerance test, whereas the muscle group was hyperglycemic. Immunohistochemical evaluation showed positive results against insulin and glucagon in biopsies of both groups, and the islet cell density was higher in the muscle flap group. There were no statistically significant differences between the two groups in real-time reverse transcription polymerase chain reaction results. Conclusions Our results suggest that muscle flaps are promising candidates for islet cell transplantation.