• 제목/요약/키워드: operator ideal

검색결과 39건 처리시간 0.04초

NEW FORM OF NJÅSTAD'S α-SET AND LEVINE'S SEMI-OPEN SET

  • Modak, Shyamapada;Islam, Md. Monirul
    • Journal of the Chungcheong Mathematical Society
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    • 제30권2호
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    • pp.165-175
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    • 2017
  • This paper gives an extensive study of ideal topological space and introduce two new types of set with the help of local function. Several characterizations of these sets will also be discussed through this paper and finally gives new representation of ${\alpha}$-sets and semi-open sets.

THE HYPERINVARIANT SUBSPACE PROBLEM FOR QUASI-n-HYPONORMAL OPERATORS

  • Kim, An-Hyun;Kwon, Eun-Young
    • Communications of the Korean Mathematical Society
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    • 제22권3호
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    • pp.383-389
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    • 2007
  • In this paper we examine the hyperinvariant subspace problem for quasi-n-hyponormal operators. The main result on this problem is as follows. If T = N + K is such that N is a quasi-n-hyponormal operator whose spectrum contains an exposed arc and K belongs to the Schatten p-ideal then T has a non-trivial hyperinvariant subspace.

Edge Detection Using Informations of Edge Structures (에지의 구조적정보을 이용한 에지추출)

  • Kim, Su-Gyeom;Jang, Yu-Jeong
    • The Transactions of the Korea Information Processing Society
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    • 제3권5호
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    • pp.1337-1345
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    • 1996
  • Edge detection is the first step and very important step in image nalyisi. In this paper, proposed edge detection algorithm based on informations of edge structures and it is different from other classical edge detection operators such asgradient and surface fitting algorithm. The firs, we defined characteristics of edge structures such as continuity, thinness, localization, length. The second, we defined valid edge structures and ideal edge pixel positions in $3\times3$ window based on edge characteristics of edge structures. And we proposed twelve windows for enhance dissimilarity regions based on valid edge structures and ideal edge pixel positions. In specially, proposed algorithm was shown better performance of edge detection than other operators such as gradient operator and the LoG(Laplacian of gradient) operator of zero crossings in noisy test image with $\sigma=30$.

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A Statistical Analysis of Edge Enhancing Filters and Their Effects on Edge Detection (에지개선 필터들의 통계적 분석과 에지검출에 대한 영향)

  • 박순영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제18권11호
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    • pp.1635-1644
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    • 1993
  • In this paper, we examine the statistical characteristics of edge enhancing filters and their efficacy as preprocessing operator before edge detection. In particular, edge enhancing filters called the Comparison and Selection(CS), Hachimura-kuwahara(HK), and Selective Average(SA) filters are considered. These filters can reduce noise while producing step-type edges, thus seem to be effective for preprocessing noisy images prior to applying edge detecors. The ability of edge enhancing filters to suppress white Gaussian noise and the error probabilities occured during the edge detection following SA prefiltering are evaluated statistically through numerical analysis. The effect of prefiltering on edge detection is assessed by applying the edge enhancing fitters to a noise image degraded by additive white noise prior to applying the Sobel operator and the Laplacian of Gaussian( LoG ) operator, respectively. It is shown that the edge enhancing filters tend to produce ideal step-type edges while reducing the noise reasonably well, and the use of edge enhancing filters prior to edge detection can improve the performance of subsequent edge detector.

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Error Analysis of the Image Measurement System (영상 측정 시스템의 오차 분석)

  • 김준희;유은이;사승윤;김광래;유봉환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.490-495
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    • 1996
  • Though the increment of using computer vision system in modern industry, there are lots of difficulties to measure precisely because of measurement error distortion phenomenon. Among these reasons, the distortion of edge is dominant reason which is occurred by the blurred image. The blurred image is happened when camera can not discriminate its precise focus. To calibrate and generalize distortion phenomenon is important. Thus, we must fix the discrimination criteria which is collected by image recognition of precise focus. Also, radial distortion causes an inward or outward displacement of a given image point from its ideal location. This type of distortion is mainly caused by flawed radial curvature curve of the elements. Thus, we were analyzed the distortion in terms of the changed with lens magnification.

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HUMAN-MACHINE INTERACTION IN NUCLEAR POWER PLANTS

  • YOSHIKAWA HIDEKAZU
    • Nuclear Engineering and Technology
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    • 제37권2호
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    • pp.151-158
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    • 2005
  • Advanced nuclear power plants are generally large complex systems automated by computers. Whenever a rare plant emergency occurs the plant operators must cope with the emergency under severe mental stress without committing any fatal errors. Furthermore, The operators must train to improve and maintain their ability to cope with every conceivable situation, though it is almost impossible to be fully prepared for an infinite variety of situations. In view of the limited capability of operators in emergency situations, there has been a new approach to preventing the human error caused by improper human-machine interaction. The new approach has been triggered by the introduction of advanced information systems that help operators recognize and counteract plant emergencies. In this paper, the adverse effect of automation in human-machine systems is explained. The discussion then focuses on how to configure a joint human-machine system for ideal human-machine interaction. Finally, there is a new proposal on how to organize technologies that recognize the different states of such a joint human-machine system.

Adaptive backstepping control with grey theory for offshore platforms

  • Hung, C.C.;Nguyen, T.
    • Ocean Systems Engineering
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    • 제12권2호
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    • pp.159-172
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    • 2022
  • To ensure stable performance, adaptive regulators with new theories are designed for steel-covered offshore platforms to withstand anomalous wave loads. This model shows how to control the vibration of the ocean panel as a solution using new results from Lyapunov's stability criteria, an evolutionary bat algorithm that simplifies computational complexity and utilities. Used to reduce the storage space required for the method. The results show that the proposed operator can effectively compensate for random delays. The results show that the proposed controller can effectively compensate for delays and random anomalies. The improved prediction method means that the vibration of the offshore structure can be significantly reduced. While maintaining the required controllability within the ideal narrow range.

One-sided Readings of Numbers in Modal Sentences

  • Kwak, Eun-Joo
    • Journal of English Language & Literature
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    • 제57권3호
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    • pp.429-455
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    • 2011
  • Numbers have been regarded as one-sided, and their exactly readings have been understood as the results of scalar implicature. This Neo-Gricean view on numbers becomes less persuasive due to theoretical and experimental counterarguments. In spite of growing evidence for theirtwo-sided readings, numbers are still one-sided in modal sentences. Moreover, the occurrence of a negative operator may worsen the acceptability of modal sentences with numbers. In the framework of Vector Space Semantics, I have derived two-sided readings of numbers with the simple notions of monotonicity of modals and scopal relations between modals and numbers. I have also argued that the awkwardness incurred by negation is the result of a split set of vectors for a number. The incoherent set of vectors is understood as the lack of an ideal behavior, which is against the deontic modality of the sentence.

3-D vision sensor for arc welding industrial robot system with coordinated motion

  • Shigehiru, Yoshimitsu;Kasagami, Fumio;Ishimatsu, Takakazu
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.382-387
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    • 1992
  • In order to obtain desired arc welding performance, we already developed an arc welding robot system that enabled coordinated motions of dual arm robots. In this system one robot arm holds a welding target as a positioning device, and the other robot moves the welding torch. Concerning to such a dual arm robot system, the positioning accuracy of robots is one important problem, since nowadays conventional industrial robots unfortunately don't have enough absolute accuracy in position. In order to cope with this problem, our robot system employed teaching playback method, where absolute error are compensated by the operator's visual feedback. Due to this system, an ideal arc welding considering the posture of the welding target and the directions of the gravity has become possible. Another problem still remains, while we developed an original teaching method of the dual arm robots with coordinated motions. The problem is that manual teaching tasks are still tedious since they need fine movements with intensive attentions. Therefore, we developed a 3-dimensional vision guided robot control method for our welding robot system with coordinated motions. In this paper we show our 3-dimensional vision sensor to guide our arc welding robot system with coordinated motions. A sensing device is compactly designed and is mounted on the tip of the arc welding robot. The sensor detects the 3-dimensional shape of groove on the target work which needs to be weld. And the welding robot is controlled to trace the grooves with accuracy. The principle of the 3-dimensional measurement is depend on the slit-ray projection method. In order to realize a slit-ray projection method, two laser slit-ray projectors and one CCD TV camera are compactly mounted. Tactful image processing enabled 3-dimensional data processing without suffering from disturbance lights. The 3-dimensional information of the target groove is combined with the rough teaching data they are given by the operator in advance. Therefore, the teaching tasks are simplified

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Safe Sedation and Hypnosis using Dexmedetomidine for Minimally Invasive Spine Surgery in a Prone Position

  • Kim, Kyung Hoon
    • The Korean Journal of Pain
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    • 제27권4호
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    • pp.313-320
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    • 2014
  • Dexmedetomidine, an imidazoline compound, is a highly selective ${\alpha}_2$-adrenoceptor agonist with sympatholytic, sedative, amnestic, and analgesic properties. In order to minimize the patients' pain and anxiety during minimally invasive spine surgery (MISS) when compared to conventional surgery under general anesthesia, an adequate conscious sedation (CS) or monitored anesthetic care (MAC) should be provided. Commonly used intravenous sedatives and hypnotics, such as midazolam and propofol, are not suitable for operations in a prone position due to undesired respiratory depression. Dexmedetomidine converges on an endogenous non-rapid eye movement (NREM) sleep-promoting pathway to exert its sedative effects. The great merit of dexmedetomidine for CS or MAC is the ability of the operator to recognize nerve damage during percutaneous endoscopic lumbar discectomy, a representative MISS. However, there are 2 shortcomings for dexmedetomidine in MISS: hypotension/bradycardia and delayed emergence. Its hypotension/bradycardiac effects can be prevented by ketamine intraoperatively. Using atipamezole (an ${\alpha}_2$-adrenoceptor antagonist) might allow doctors to control the rate of recovery from procedural sedation in the future. MAC, with other analgesics such as ketorolac and opioids, creates ideal conditions for MISS. In conclusion, dexmedetomidine provides a favorable surgical condition in patients receiving MISS in a prone position due to its unique properties of conscious sedation followed by unconscious hypnosis with analgesia. However, no respiratory depression occurs based on the dexmedetomidine-related endogenous sleep pathways involves the inhibition of the locus coeruleus in the pons, which facilitates VLPO firing in the anterior hypothalamus.