• Title/Summary/Keyword: ILL

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IMPROVING THE SOLVABILITY OF ILL-CONDITIONED SYSTEMS OF LINEAR EQUATIONS BY REDUCING THE CONDITION NUMBER OF THEIR MATRICES

  • Farooq, Muhammad;Salhi, Abdellah
    • 대한수학회지
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    • 제48권5호
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    • pp.939-952
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    • 2011
  • This paper is concerned with the solution of ill-conditioned Systems of Linear Equations (SLE's) via the solution of equivalent SLE's which are well-conditioned. A matrix is rst constructed from that of the given ill-conditioned system. Then, an adequate right-hand side is computed to make up the instance of an equivalent system. Formulae and algorithms for computing an instance of this equivalent SLE and solving it will be given and illustrated.

비최소 위상을 갖는 외팔보에서 SVD를 이용한 역변환 문제에 관한 연구 (A Study on the Application of SVD to an Inverse Problem in a Cantilever Beam with a Non-minimum Phase)

  • 이상권;노경래;박진호
    • 한국소음진동공학회논문집
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    • 제11권9호
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    • pp.431-438
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    • 2001
  • This paper present experimental results of source identification for non-minimum phase system. Generally, a causal linear system may be described by matrix form. The inverse problem is considered as a matrix inversion. Direct inverse method can\`t be applied for a non-minimum phase system, the reason is that the system has ill-conditioning. Therefore, in this study to execute an effective inversion, SVD inverse technique is introduced. In a Non-minimum phase system, its system matrix may be singular or near-singular and has one more very small singular values. These very small singular values have information about a phase of the system and ill-conditioning. Using this property we could solve the ill-conditioned problem of the system and then verified it for the practical system(cantilever beam). The experimental results show that SVD inverse technique works well for non-minimum phase system.

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물이 인체 건강에 미치는 영향 (Human Health Effects due to Consumption of Low TDS Water)

  • Rozelle, Lee T.
    • 멤브레인
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    • 제6권4호
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    • pp.189-195
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    • 1996
  • It is concluded from this study that human consumption of very low TDS water does not leach minerals from the body that cause ill health effects because; -The human body's own control mechanism of homeostasis and internal body secretions keep tight controls on body fluid composition regardless of drinking water TDS for a normal person under normal csonditions. -The unofficial WHO document's proposed guideline of a 100m/l lower limit for drinking water due to mineral leaching and subsequent ill health was not found to be scientifically or physiologically credible. Leaching of minerals from the body is not officially recognized by WHO. -The experience of the U.S. Navy, Army, NASA and dommunity demonstrations do not support ill health symptoms caused by consumption of low TDS drinking water. -Millions of people regularly consume maturally occurring low TDS water without symptoms of ill health.

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스펙트럼 적응 사상을 이용한 선형시스템의 불량조건 완화기법 (An alleviant technique for solving III-Conditioned Linear Systems Using Spectral Adaptive Mapping)

  • 전재웅;조기선;박종배;신중린
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 A
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    • pp.110-112
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    • 2003
  • This paper presents an alleviant technique for solving ill-conditioned linear systems using spectral adaptive mapping, which is based on spectral mapping theorem. The conventional approaches to solve the ill-conditioned linear systems are divided into reformulation and alleviant technique. So far, the alleviant technique is evaluated the most effective one. In this paper, an adaptive mapping of spectrum is adopted to alleviate the condition number of ill-conditioned linear systems. A shift constant, which is a dominant factor of the spectral adaptive mapping that are proposed, is assessed by the system spectrum. The proposed spectral adaptive mapping technique is tested to demonstrated the validation on several size Hilbert matrices and small scale power systems, which are provide the promising results.

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악조건하의 비동일평면 카메라 교정을 위한 알고리즘

  • 안택진;이문규
    • 제어로봇시스템학회논문지
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    • 제7권12호
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    • pp.1001-1008
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    • 2001
  • This paper presents a new camera calibration algorithm for ill-conditioned cases in which the camera plane is nearly parallel to a set of non-coplanar calibration boards. for the ill-conditioned case, most of existing calibration approaches such as Tsais radial-alignment-constraint method cannot be applied. Recently, for the ill-conditioned coplanar calibration Lee&Lee[16] proposed an iterative algorithm based on the least square method. The non-coplanar calibration algorithm presented in this paper is an iterative two-stage procedure with extends the previous coplanar calibration algorithm. Through the first stage, camera, position and orientation parameters as well as one radial distortion factor are determined optimally for a given data of the scale factor and the focal length. In the second stage, the scale factor and the focal length are locally optimized. This process is repeated until any improvement cannot be expected any more Computational results are provided to show the performance of the algorithm developed.

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입력관측기의 정량적 성능지표 (I) -과도상태 해석- (A Quantitative Performance Input for an Input Observer ( I ) - Analysis in Transient State -)

  • 정종철;이범석;허건수
    • 대한기계학회논문집A
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    • 제26권10호
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    • pp.2060-2066
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    • 2002
  • The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor transient performance with respect to ill-conditioning factors such as unknown initial estimates, round-off error, etc. For the robust transient performance, the effects of these ill-conditioning factors must be minimized in designing observers. In this paper, the transient performance of the closed-loop state and input observer is investigated quantitatively by considering the error bounds due to ill-conditioning factors. The performance indices are selected from these error bounds and are related to the observer robustness with respect to the ill -conditioning factors. The closed-loop state and input observer with small performance indices is considered as a well-conditioned observer from the transient perspective.

Experience of Treating Critically Ill COVID-19 Patients in Daegu, South Korea

  • Shin, Kyeong-Cheol
    • Tuberculosis and Respiratory Diseases
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    • 제84권3호
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    • pp.176-181
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    • 2021
  • At the beginning of February 2020, Daegu faced a serious situation due to the rapid outbreak of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus-2. The healthcare system in Daegu Metropolitan City was ill-prepared for this sudden disaster situation. The COVID-19 pandemic is still ongoing in South Korea. Daegu has limited medical resources compared to the Seoul Metropolitan Area, and it is hypothesized that a review of the outbreak therein could provide information that will be valuable for dealing with future outbreaks. The likelihood of death due to COVID-19 depends on the capacity of the area for the treatment of critically ill patients. This report reviews the overall treatment process followed for critically ill patients in Daegu.

Analysis of Survival in 273 Terminally Ill Cancer Patients Treated with Traditional Oriental Therapies

  • Cho Jung-Hyo;Kang Wee-Chang;Son Chang-Gue;Lee Yeon-Weol;Yoo Hwa-Seung;Lee Nam-Heon;Yun Dam-Hee;Cho Chong-Kwan
    • 대한한의학회지
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    • 제25권4호
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    • pp.152-160
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    • 2004
  • Objective : Recently, an increasing portion of cancer patients use various therapies of complementary and alternative medicine (CAM) including traditional oriental medicine, which is believed to improve the consequence of cancer according to clinical experience and laboratory data. But the clinical-based systemic statistic validity of these therapies is lacking, so this study was aimed to validate the traditional oriental therapies (TOT) for terminally ill cancer patients. Patients and methods : This retrospective study was performed on 273 patients who were diagnosed with terminally ill cancer in Korea and treated with TOT in the oriental hospital of Daejeon University, from March 1997 to June 2003. We examined the median duration of the terminal period and the correlations between 9 factors and survival of terminally ill cancer patients. Results : During the study period, we could confirm 142 patients' death (52.01%) in 273 subjects. The median length of survival in terminally ill cancer patients was 16 weeks (95%CI 14.0∼20.0) and 40.15% (95%CI 40.07∼40.22) of patients had survived more than 24 weeks. According to Cox's proportional hazard model including gender, age, conventional therapies (chemotherapy, radiotherapy and surgery), performance status and clinical symptoms as independent variables, history of conventional therapies (RR 0.581, 95%CI 0.381∼0.885), higher performance status (RR 1,855, 95%CI 1.454∼2.366) and absence of ascites and pleural effusion (RR 1.631, 95%CI 1.047∼2.538) showed independent prognostic value of survival. Conclusion : Our findings suggest that TOT offer potential benefits for cancer patients at the terminal stage.

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보건소에서 접근할 수 없는 재가 정신질환자에 대한 조사연구: B시 일 보건소를 중심으로 (A Survey on Community dwelling Mentally Ill Patients Who could not be Accessed by a Community Health Center)

  • 류정숙;김명희;정추영
    • 재활간호학회지
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    • 제15권2호
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    • pp.91-99
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    • 2012
  • Purpose: The purpose of this study was to identify the frequency and status of mentally ill patients who registered in a community health center (CHC) but they could not be accessed. Methods: A total of 233 mentally ill individuals who were registered to a CHC in B Metropolitan City participated in this survey. Data were collected from December 1 to 31, 2010 and analyzed. Results: There were 140 (60.1%) community dwelling mentally ill patients who had been registered to that CHC but were not accessible. The major reasons of this inaccessibility were patients' rejection to be accessed (27.1%) and the wrong or missing address in hospital's discharge note (22.9%). The nursing problems of the subjects were rejection of medication (93.4%); poor personal hygiene (85.8%); violence including harassment of family member(s), assault, property destruction, threat with weapon (38.7%); and so on. Among 159 cases of referrals and requests for help immediate action with patient's compliance were only 8.8%. Conclusion: The findings show that mentally ill patients who had registered to the CHC but were not able to be accessed failed to be managed properly. This would become risk factors of social problems which threat to the community as well as individuals. Thus, we need to prepare programs for this population to make them take medicine at a minimum.

지역사회 정신보건서비스 제공 전$\cdot$후 정신장애인의 의료비용, 삶의 질, 가족 부담감 비교연구 (Comparative Research of the Medical Cost, The Quality of Life, The Family burden of the Mentally III before and after the Community Mental Health Service)

  • 노인영
    • 한국보건간호학회지
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    • 제15권1호
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    • pp.56-72
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    • 2001
  • Community mental health management system emphasizing on the rehabilitation and the return to the community has been established and carried out for many years. The study has been demanded to prove that the decreasing rate of the recurrence of the mentally ill resulted to lower their medical costs, to enrich the quality of life, and to reduce the psychological burden of their family. This study tried to prove that the mental health services to the mentally ill which were registered in community mental health center of A city have an influence on the medical cost, the quality of their lives. the family burden. The subject group of this study were 39 home-based mentally ill patients and their 37 family members, totally 76 people registered in mental health center of A city and participated in its program. This research had been measured twice, the first before the intervention and the second after at least a year. The measuring tools in the research were the medical cost measurment tools developed by the researcher, the quality of life index by Yoo ja, Noh(1988) and the family burden by Montgonery(1985). The methods were modified and supplemented in this study. This research made use of SPSS Win 10.0. The results of this study are the same as followings. 1) There were the significant difference in the medical cost before and after the mental health service delivery. 2) The quality of lives of the mentally ill, after the mental health services delivered were significantly higher than before. 3) The family burden were significantly reduced after the delivery of community mental health services. Community mental health services brought out efficient results to the social return and rehabilitation. And these results means that the mentally ill changed highly the quality of life and their burden of family and medical cost were reduced. So the public organization and the private society should help positively the mentally ill and their family through mental health policy and social service agency to live healthy lives and to be valuable member of society.

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