• Title/Summary/Keyword: Acute disturbance

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A study of the spatial amplification of the $K{\acute{a}}rm{\acute{a}}n$ boundary-layer ($K{\acute{a}}rm{\acute{a}}n$ 경계층 유동의 공간증폭에 관한 이론적 연구)

  • Hwang, Young-Kyu;Lee, Yun-Yong
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.585-590
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    • 2000
  • The hydrodynamic instability of the three-dimensional boundary layer on a rotating disk introduces a periodic modulation of the mean flow in the form of stationary cross flow vortices. Detailed numerical values of the growth rates, neutral curves and other characteristics of the two instabilities have been calculated over a wide range of parameters. Presented are the neutral stability results concerning the two instability modes by solving new linear stability equations reformulated not only by considering whole convective terms but by correcting some errors in the previous stability equations. The present stability results are agree with the previously known ones within reasonable limit. The flow is found to be always stable for a disturbance whose dimensionless wave number at Re=1200 is greater than 0.75. Also, the spatial amplification contours have been calculated for the moving disturbance wave, whose azimuth angle is between ${\varepsilon}=15^{\circ}$ and $12.5^{\circ}$.

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Robust Trajectory Tracking Control of a Mobile Robot Based on Weighted Integral PDC and T-S Fuzzy Disturbance Observer (하중 적분 PDC와 T-S 퍼지 외란 관측기를 이용한 이동 로봇의 강인 궤도 추적 제어)

  • Baek, Du-san;Yoon, Tae-sung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.2
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    • pp.265-276
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    • 2017
  • In this paper, a robust and more accurate trajectory tracking control method for a mobile robot is proposed using WIPDC(Weighted Integral Parallel Distributed Compensation) and T-S Fuzzy disturbance observer. WIPDC reduces the steady state error by adding weighted integral term to PDC. And, T-S Fuzzy disturbance observer makes it possible to estimate and cancel disturbances for a T-S fuzzy model system. As a result, the trajectory tracking controller based on T-S Fuzzy disturbance observer shows robust tracking performance. When the initial postures of a mobile robot and the reference trajectory are different, the initial control inputs to the mobile robot become too large to apply them practically. In this study, also, the problem is solved by designing an initial approach path using a path planning method which employs $B\acute{e}zier$ curve with acceleration limits. Performances of the proposed method are proved from the simulation results.

A Study on the Small Disturbance Measurement of Liquid Film Thickness by $Moir\acute{e}$ Fringe ($Moir\acute{e}$ Fringe에 의한 액막 두께 미소 변위 측정 연구)

  • Jeon, H.S.;Kim, K.H.
    • Journal of ILASS-Korea
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    • v.2 no.4
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    • pp.29-35
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    • 1997
  • Liquid film thickness is measured by $moir\acute{e}$ topography which monitored liquid surface. $Moir\acute{e}$ fringe measurement techniques share the inherent simplicity found in optical interferometric techniques have the advantage of use over a greater range of displacement. $Moir\acute{e}$ fringe are the geometric interference patterns observed when two dense line grating are superposed. Light transmitted through a fixed line grating is deviated by the liquid film surface, producing a distored image of the grating. The $moir\acute{e}$ fringe produced by projection of this optically distored grating onto a second stationary grating permit visualization of the liquid surface and measurement of the liquid film thickness. This study measured the small amplitude of liquid film thickness to the $moir\acute{e}$ fringe pattern produced when spherical metal was dropped glycerin put)1 And the measurement of liquid film thickness flowing down an inclined plate are required to calculate the liquid slope in a position.

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A study of the spatial amplification of the Type II instability for the Rotating-disk flow (회전원판 유동의 제2형 불안정성 공간증폭에 관한 이론적 연구)

  • Lee, Yun-Yong;Lee, Kwang-Won;Hwang, Young-Kyu
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.481-486
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    • 2001
  • The hydrodynamic instability of the three-dimensional boundary layer on a rotating disk introduces a periodic modulation of the mean flow in the form of stationary cross flow vortices. Detailed numerical values of the growth rates, neutral curves and other characteristics have been calculated for the Type II-instabilities. Presented are the neutral stability results concerning the two instability modes by solving new linear stability equations reformulated not only by considering whole convective terms but by correcting some errors in the previous stability equations. The present stability results are agree with the previously known ones within reasonable limit. The spatial amplification contours have been calculated for the moving disturbance wave, whose azimuth angle is between $\varepsilon=-10^{\circ}$ and $-20^{\circ}$. The transition flow of the moving disturbance wave will be developed at $\varepsilon=-15^{\circ}$ and Re=352 corresponding at the growth rates n = 5.8 from the spatial amplification contours.

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Bibliographic Study on the Moschus used to Acute Stage of Stroke (중풍급성기(中風急性期)에 활용(活用)되는 사향(麝香)에 관(關)한 문헌적(文獻的) 고찰(考察))

  • Huh, Jae-Hyeok;Kim, Sae-Gil;An, Ill-Hoe;Shin, Sun-Ho;Moon, Byung-Soon;Sung, Gang-Kyung
    • The Journal of Korean Medicine
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    • v.16 no.2 s.30
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    • pp.100-114
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    • 1995
  • This bibliographic study was designed to research indications of the Moschus which was representatively used for resuscitation in acute stage of stroke throughout successive books of oriental medicine. Especially, in this study, severe cases with disturbance of consciousness and acute stage of stroke were investigated. The results were summarized as the followings: 1. The Moschus was dried material which secreted from aromatic vescicle of Moschus moschiferus L.. which was pungent in flavor, warm in nature, nontoxic and strongly aromatic. The Moschus removed the obstruction in the channels and used to early stage of stroke. 2. The Moschus was aromatic resuscitatable medicine, which recovered disturbance of consciousness due to stroke. 3. The Moschus had excitatory actions of respirtory center and vascular motor center, heart stimulating action, inhibitatory action of the platelet aggregation and anti thrombin action and recovered cerebral ischemic change. According to these actions, the Moschus could be used cerebral infarction. 4. Prescriptions included the Moschus was used to symptoms of unconsciousness, secretion, stuporous mental state, dysarthria, facial palsy and hemiplegia. That was Angungwoohwangh wan(安宮牛黃丸), Woohwangchungshimwon(牛黃淸心元), Sahyangsohaphangwon(麝香蘇合香元), etc. According to the above mentioned results, the Moschus was aromatic resuscitatable medicine which was used for symptoms of conscius disturbance, convulsion, sudden fainting etc., promoted cerebral blood flow and had good effect on acute stage of stroke and severe cases with conscious disturbance. Therefore, it is considered that the Moschus must be studied for effect of cerebral infarction and hemorrhage in clinic with animal's and pharmacological experimental results.

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Relationship between Warning Signs and Sasang Constitution(SC) in Early Stroke Patients (급성기 중풍환자의 사상체질과 중풍 경고증상, 전조증상과의 상관성 연구)

  • Choi, In-Young;Kim, Yong-Hyung;Choi, Dong-Jun;Han, Chang-Ho;Lee, Won-Chul;Jun, Chan-Yong;Cho, Ki-Ho;Choi, Sun-Mi
    • The Journal of Internal Korean Medicine
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    • v.28 no.4
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    • pp.733-740
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    • 2007
  • Objective : This study investigated the relationship between warning signs and Sasang constitution (SC) in acute stroke patients. Methods : From October in 2005 to March in 2007, 629 acute stroke patients were studied. Patients were hospitalized within 14 days after the onset ofstroke at one of 3 oriental medical hospitals in Seoul and Kyong-gi province. We assessed the type of SC of acute stroke patients by Questionnaire for Sasang Constitution Classification II (QSCC II). We investigated warning signs (motor weakness, blindness, dysarthria, sensory disturbance, finger dullness, facial & eyelid spasm, neck stiffness), general characteristics, etc. Results : This study showed a higher proportion of Tae-eum & So-eum experience upper extremity sensory disturbance but So-yangexperience lower extremity sensory disturbance. Smoker So-eumexperience 1st & 2nd finger dullness more than non-smoker So-eum. So-eum women experience motor weakness more than So-eum men. Conclusion : Besides these results, we could observe almost no relationship between warning signs and Sasang constitution (SC) in acute stroke patients. More data from prospective cohort studies will help people better understand the relationship between warning signs and Sasang constitution (SC) in acute stroke patients.

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A Case Report of Gait Disturbance due to Acute Low Back Pain Syndrome improved with Whidam's Vibrator Pelvic Sugi Therapy (휘담식 진동기 골반수기로 개선된 급성 요통 증후군으로 인한 보행장애 증례)

  • Jeong Jae hun;Gam Mai Pil;Sam Sik Na
    • Journal of Korean Medical Ki-Gong Academy
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    • v.21 no.1
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    • pp.1-12
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    • 2022
  • Objective : The purpose of this study is to report the results of treating patients with acute low back pain syndrome who are difficult to walk with Whidam's Vibrator Pelvic Sugi Therapy. Methods : We used combinations of korean medicine such as herbal medicine, acupuncture, cupping therapy, and thermal therapy. At the same time, the patient was treated with Whidam's Vibrator Pelvic Sugi Therapy. The first period of hospitalization was 14 days and the second period was 54 days. At the second hospitalization, back pain recurred and was unable to walk. At the first hospitalization, L5-S1 HIVD and L4-5 Mild HIVD were diagnosed on lumbar MRI, and there was no abnormality in blood tests. Results : By relieving muscle tension and restoring the weakened muscle elasticity with herbal treatment and Whidam's Vibrator Pelvic Sugi Therapy, back pain decreased and the inability to walk gradually improved, making it possible to walk on its own. Conclusions : The results of standing and walking on one's own were obtained by relieving muscle tension and restoring weakened muscle elasticity in acute back pain syndrome with gait disturbance diagnosed with lumbar herniated intervertebral disc through korean medicine treatment and Whidam's Vibrator Pelvic Sugi Therapy. Whidam's Vibrator Pelvic Sugi Therapy is thought to help acute back pain by restoring muscle elasticity and strengthening muscle strength. In the future, it is expected that additional clinical studies will be conducted on various pain diseases with Whidam's Vibrator Pelvic Sugi Therapy.

Genetic polymorphisms of monoamine oxidase(MAO) B and serotonin transporter receptor(5-HTTR) influence variability in neurobehavioral symptoms by n-hexane exposur (n-Hexane 노출에 의한 신경행동학적 증상에 monoamine oxidase(B)와 serotonin transporter receptor 유전자다양성의 영향)

  • Kim, Ki-Woong
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.21 no.2
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    • pp.116-122
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    • 2011
  • Human occupational exposure to n-hexane has been associated with neurobehavioral symptoms such as depression, irritablity, acute irritation symptom, concentration disturbance and fatigue. Effects of monoamine oxidase (MAO) B and serotonin transporter receptor (5-HTTR) polymorphisms on the neurobehavioral symptoms were investigated in 70 male workers from TV and computer monitor manufacturing plants exposed to n-hexane. Neurobehavioral symptoms were assessed through a self-reported questionnaire and ambient level of n-hexane was measured by NIOSH method. Blood and urine were collected from each workers to determine the MAO(B), 5-HTTR and urinary 2,5-hexanedione(2,5-HD). The mean concentration of volatile n-hexane was $18.8{\pm}28.8ppm$ and that of urinary 2,5-HD was $1.07{\pm}1.47mg/g$ creatinine. Statistically significant associations with sexual disturbance were age and smoking. The frequencies of MAO(B) AA, AG and GG were 18.6%, 45.7% and 35.7%, respectively, and the frequencies of 5-HTTR ll, ls and ss genotype were 82.9%, 15.7% and 1.4%, respectively. MAO (B) gene polymorphisms had susceptibility to the neurobehavioral symptoms such as fatigue, concentration disturbance, irritability and acute irritation symptom and 5-HTTR gene polymorphism had susceptibility to the sleep disturbance and acute irritation symptom. On multiple logistic regression analysis for the neurobehavioral symptoms, memory disturbance was significantly associated with smoking(OR=6.752, 95% CI=37.46) and drinking(OR=4.033, 95% CI=1.252-12.98), emotional lability was MAO(B) genotype(OR=0.412, 95% CI=0.170-0.996), fatigue (OR=1.011, 95% CI=1.000-1.021) and acute irritation(OR=0.990, 95% CI=0.981-1.000) were working duration and sexual disturbance were significantly associated with age(OR=1.208, 95% CI=1.042-1.399), ambient n-hexane(OR=1.077, 95% CI=1.005-1.154) and 2,5-HD(OR=0.186, 95% CI=0.041-0.841). This finding implies that the MAO (B) and 5-HTTR polymorphisms may affect susceptibility for specific neurobehavioral symptoms associated with n-hexane exposure in workers.

Overlapping Guillain-Barr$\acute{e}$ syndrome and Bickerstaff's brainstem encephalitis associated with Epstein Barr virus

  • Rho, Young Il
    • Clinical and Experimental Pediatrics
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    • v.57 no.10
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    • pp.457-460
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    • 2014
  • A flaccid tetraparesis in Bickerstaff's brainstem encephalitis (BBE) is presumed to be a sign of overlapping Guillain-Barr$\acute{e}$ syndrome (GBS). In addition, BBE and Fisher syndrome, which are clinically similar and are both associated with the presence of the immunoglobulin G anti-GQ1b antibody, represent a specific autoimmune disease with a wide spectrum of symptoms that include ophthalmoplegia and ataxia. A 2-year-old boy presented with rapidly progressive ophthalmoplegia, ataxia, hyporeflexia, weakness of the lower extremities, and, subsequently, disturbance of consciousness. He experienced bronchitis with watery diarrhea and had laboratory evidence of recent infection with Epstein-Barr virus (EBV). He was diagnosed as having overlapping GBS and BBE associated with EBV and received treatment with a combination of immunoglobulin and methylprednisolone, as well as acyclovir, and had recovered completely after 3 months. In addition, he has not experienced any relapse over the past year. We suggest that combinations of symptoms and signs of central lesions (disturbance of consciousness) and peripheral lesions (ophthalmoplegia, facial weakness, limb weakness, and areflexia) are supportive of a diagnosis of overlapping GBS and BBE and can be helpful in achieving an early diagnosis, as well as for the administration of appropriate treatments.

The Effect of Aromatherapy Hand Massage on Cognitive Function, Sleep Disturbance and Problematic Behaviors of Elderly with Dementia (향요법 손마사지가 치매노인의 인지기능, 수면장애 및 문제행동에 미치는 효과)

  • Lee, Sun Young
    • Journal of Korean Clinical Nursing Research
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    • v.14 no.2
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    • pp.115-126
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    • 2008
  • Purpose: This study was aimed to develop an aromatherapy hand massage program, and evaluate the effects of aromatherapy hand massage on cognitive function, sleep disturbance and problematic behaviors of elderly with dementia. Method: The research design was a nonequivalent control group non-synchronized quasiexperimental study. Aromatherapy hand massage was administrated to experimental groupI for 2 weeks, jojoba oil massage were administrated to experimental groupII for 2 weeks, and no treatment for control group for 2 weeks. Data were analyzed using the $x^2-test$, ANOVA, ANCOVA and $Scheff{\acute{e}}$ test in the SPSS 12.0 program. Results: Experimental group I showed significant changes in sleep disturbance and problematic behaviors compared to those in experimental groupII or control group. Conclusion: Aromatherapy hand massage program is found effective on sleep disturbance and problematic behaviors of elderly with dementia.

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