• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.8-16
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• 2008

The aim of this study was to evaluate the motor recovery in 4 chronic hemiparetic patients with Fugl-Meyer (FM) and EMG characteristics before and after the training program. The training was performed at 1hr/day, 5days/week during 6 weeks in 4 chronic stroke patients. Electromyographic activities of the affected hand were recorded during isometric wrist flexion/ extension movements. In all patients, FM was significantly improved after the 6-week training. Onset/offset delay of muscle contraction significantly decreased in the affected wrist after the training. The co-contraction ratio of flexor/extensor muscles decreased significantly. Also, onset/offset delay of muscle contraction and co-contraction ratio correlates significantly with upper limb motor impairment and motor recovery. This EMG technique allows an objective evaluation of changes in muscle activity in post-stroke patients, providing easily measurable, quantitative indices of muscle characteristics.

• 한국초전도ㆍ저온공학회논문지
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• 제23권1호
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• pp.1-6
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• 2021

Thermoacoustic oscillations (TAOs) could be often observed in liquid helium cryogenic system especially in half-open tubes. These tubes have closed warm end (300K) and open cold end (usually 4.4K). This phenomenon significantly induces additional heat load to cryogenic system and other undesirable effects. This work focuses on using computational fluid dynamics (CFD) method to study TAOs in liquid helium. The calculated physical model, numerical scheme and algorithm, and wall boundary conditions were introduced. The simulation results of onset process of thermoacoustic oscillations were presented and analyzed. In addition, other important characteristics including phase relation and frequency were studied. Moreover, comparisons between experiments and the CFD simulations were made, which demonstrated thevalidity of CFD simulation. CFD simulation can give us a better understanding of onset mechanism of TAOs and nonlinear characteristics in liquid helium cryogenic system.

• Journal of Genetic Medicine
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• 제18권2호
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• pp.132-136
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• 2021

Maturity-onset diabetes of the young (MODY) is caused by autosomal dominant pathogenic variants in one of 14 currently known monogenic genes. Characteristics of patients with MODY include early-onset clinical disease with a family history of diabetes and negative autoantibodies and may present with heterogeneous phenotypes according to the different subtypes. Here, we report a patient with early-onset diabetes who presented asymptomatic mild fasting hyperglycemia with the absence of autoantibodies. She was diagnosed with glucokinase (GCK)-MODY caused by a GCK variant, c.1289T>C (p.L430P), identified by targeted gene-panel testing, and the affected father had the same variant. We interpreted this rare missense variant as a likely pathogenic variant and then she stopped taking oral medication. This case highlights the usefulness of gene-panel testing for accurate diagnosis and appropriate management of MODY. We also note the importance of familial genetic testing and genetic counseling for the proper interpretation of MODY variants.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.372-375
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• 2009

We have studied on plasma diagnosis, characteristics of the glow discharge at the several different conditions of pressure, discharge current and such. The discharge onset voltage and onset current decreased as pressure increase, the general trend was nearly in agreement with the left regions of Paschen's curve. As normal glow discharge, discharge voltage was constant according to discharge current.

• Annals of Clinical Neurophysiology
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• 제7권1호
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• pp.7-12
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• 2005

Background: Essential tremor (ET) is a common movement disorder that often causes functional disability. There have been very few investigations about the clinical characteristics of ET in Korea. Therefore, we performed a study showing the clinical features and electrophysiological findings of ET. Methods: We analyzed medical records and accelerometry data of 152 patients (male vs female; 79 vs 73) with ET, who visited the Neurology Clinic of Hospital from 2000 to 2003. Clinical characteristics of ET were summarized including the age of onset, family history, tremor type, body part involved, and associated symptoms. The frequency of tremor was recorded and the spectral analysis of tremor was performed. Results: The age of tremor onset showed bimodal distribution with peaks in the 2nd and 5th decades. Family history was found in 46 patients (30.3%). The patients with the family history presented earlier onset of tremor than patients without the history (mean age of onset, y: 35.2 vs. 49.9, P < 0.001). Tremor appeared most frequently in hands (94%), and followed by head (25%). In head tremor, "no-no" pattern was mainly observed and the head tremor was more frequently observed in female. The frequency of tremor was negatively correlated with age (r=-0.49, P<0.001). Conclusions: The present study indicated some important findings about ET: (1) bimodal distribution for an age of onset, (2) younger age of onset in patients with a family history, (3) decreasing frequency of the tremor according to age, and (4) higher prevalence of head tremor in female patients.

• 대한기계학회논문집B
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• 제20권1호
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• pp.266-274
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• 1996

An experimental work was conducted to investigate the characteristics of the onset of flooding in vertical annuli with a direct injection mode using air and water. The onset of flooding was determined by means of pressure drop measurement while the air velocity was increased gradually under fixed liquid flow rates. Data of the onset of flooding were collected for various combinations of the tube size and the nozzle number. A theoretical analysis of the onset of flooding was also performed based on an envelope theory. The result shows that the onset of flooding in small-scale annuli can be predicted relatively well by the theory. A modified Wallis parameter was used to investigate the scaling effect of flooding phenomena in the annuli, indicating a relatively reasonable result. The number of nozzle has no effect on the flooding velocity when liquid was injected through 2, 3, 4 and 6 nozzles but the initiation of flooding was significantly expedited when 12 nozzles were employed for liquid injection.

• Journal of Preventive Medicine and Public Health
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• 제40권2호
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• pp.130-136
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• 2007

Objectives : Recent educational efforts have concentrated on patient's early hospital arrival after symptom onset. The purpose of this study was to evaluate the time interval between symptom onset and hospital arrival and to investigate its relation with clinical outcomes for patients with acute ischemic stroke. Methods : A prospective registry of patients with signs or symptoms of acute ischemic stroke, admitted to the OO Medical Center through emergency room, was established from September 2003 to December 2004. The interval between symptom onset and hospital arrival was recorded for each eligible patient and analyzed together with clinical characteristics, medication type, severity of neurologic deficits, and functional outcomes. Results : Based on the data of 256 patients, the median interval between symptom onset and hospital arrival was 13 hours, and 22% of patients were admitted to the hospital within 3 hours after symptom onset. Patients of not-mild initial severity and functional status showed significant differences between arrival hours of 0-3 and later than 3 in terms of their functional outcomes on discharge. Logistic regression models also showed that arrival within 3 hours was a significant factor influencing functional outcome (OR=5.6; 95% CI=2.1, 15.0), in addition to patient's initial severity, old age, cardioembolism subtype, and referral to another hospital. Conclusions : The time interval between symptom onset and hospital arrival significantly influenced treatment outcome for patients with acute ischemic stroke, even after controlling for other significant clinical characteristics. The findings provided initiatives for early hospital arrival of patients and improvement of emergency medical system.

• 대기
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• 제24권2호
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• pp.189-196
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• 2014

The definition of onset date of Changma is revisited in this study using a quality controlled Ieodo ocean research station data. The Ieodo station has great importance in terms of its southwest location from Korean Peninsula and, hence, makes it possible to predict Changma period in advance with less impact of continents. The onset date of Changma using the Ieodo station data is defined by the time that meridional wind direction changes and maintains from northerly to southerly, and then the zonal wind changes from easterly to westerly after first June. This definition comes from a recognition that the establishment and movement of the western North Pacific subtropical high (WNPSH) cause Changma through southwesterly flow. The onset data of Changma has been determined by large-scale dynamic-thermodynamic characteristics or various meteorological station data. However, even the definition based on circulation data at the Ieodo station has a potential for the improved prediction skill of the onset date of Changma. The differences between before and after Changma, defined as Ieodo station data, are also found in synoptic chart. The convective instability and conspicuous circulations, corresponding low-level southwesterly flow related to WNPSH and strong upper-level zonal wind, are represented during Changma.

• 한국자동차공학회논문집
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• 제6권5호
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• pp.153-161
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• 1998

The knock in a spark ignition engine has been investigated to avoid the damage to the engine and unpleasant feeling caused by the pressure waves propagating across the combustion chamber. Knock intensity and knock onset angle were used as physical parameters to quantify the knock characteristics. The knock intensity is defined as a peak to peak value of the bank pass filtered combustion pressure signal and the knock onset angle is determined as the crank angle at which this signal exceeded the threshold level on each cycle. The cyclic variation of knock in four valve single cylinder engine was investigated with these two parameters. The location of autoignition was also examined by ion probes in the cylinder head gasket and squish region in the combustion chamber. For this measurement, a single cylinder engine was modified to accept the pressure transducer, 18 ion probes in the squish region and 8 ion probes in the specially designed PCB (Printed \ulcornerCircuit Board) cylinder head gasket.

• 대한기계학회논문집B
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• 제30권2호
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• pp.95-100
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• 2006

Electrostatic precipitators(EPs) have low pressure drop and high dust collection efficiency and are widely used for industrial dust collectors. The current-voltage characteristics, which are important to maintain high dust collection efficiency, depend on several factor: discharge electrode shape, gas flow property, dust loading etc. In this study, experiments are performed to investigate the current-voltage characteristics of the corona discharge of various electrode geometries and an empirical model is proposed to predict current-voltage characteristics of the corona discharge. The corona onset voltage correction coefficient$(\alpha)$ and the geometry correction coefficient$(k_g)$ are used to the conventional equation for wire-plate type discharge electrode. The corona onset voltages are -6.3kV and almost constant when the numbers of discharge pins are varied from 3 to 9. The length of discharge pins has very sensitive effects on the corona onset voltage. They are increased from -6.3 to -7.8kV when the discharge pin length are 8.5 and 4.5mm, respectively. The empirical model shows good agreement with experimental results and can predict the effects of discharge pin length and number.