• 대한수학회보
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• 제42권1호
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• pp.203-211
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• 2005

If a meromorphic solution of second order homogeneous linear differential equation is factorizable, then the right factor of the factorization of the solution has order not more than the coefficient's. And some asympotic properties of solutions are studied.

• 대한교통학회지
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• 제1권1호
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• pp.56-63
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• 1983

Intersection control has dual-purposes; increasing capacity and reducing delay. The primary concern of efficient intersection control under oversaturated condition as in Korea is to increase capacity. Prevailing intersection operation technique permits thru traffic to utilize left turn lane, because the intersection without left turn pocket has left turn signal interval. In this situation, it seems not to be valid to calculate capacity, delay, and signal timings by conventional methods. By critical lane technique, capacity increases as cycle length increases. However, when thru traffic utilize LT lane, the capacity varies according to LT volume, LT interval as well as cycle length, which implies that specific cycle length and LT interval exist to maximize capacity for given LT volume. The study is designed is designed to calculate utilization factors of LT lane for thru traffic and capacities, and identify signal timings to yield maximum capacity. The experimental design involved has 3 variables; 1)LT volumes at each approach(20-300 vph), 2)cycle lengths (60-220 sec), and 3)LT intervals(2.6-42 sec) for one scenario of isolated intersection crossing two 6-lanes streets. For LT volume of 50-150 vph, capacity calculated by using the utilization factor is about 25% higher than that by critical lane method. The range of optimum cycle length to yield maximum capapcity for LT volume less than 120 vph is 140-180 sec, and increases as LT volume increases. The optimum LT interval to yield maximum capacity is longer than the intrval necessary to accommodate LT volume at saturation flow rate.

• 한국운동역학회지
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• 제25권2호
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• pp.149-155
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• 2015

Purpose : Recently, many researchers and golf coachers demonstrated that X-factor and X-factor stretch had a co-relationship with driving distance. However, its relationship is still controversial and ambiguous. Thus, the aim of this study was to examine the relationship among X-factor, X-factor stretch and swing-related factors, including driving distance in elite golfers. Method : Seventeen male elite golfers (handicap: ${\leq}4$) with no history of musculo-skeletal injuries participated in the study. Thirty spherical retro-reflective markers were placed on including the middle point of PSIS, the right/left ASIS, the right/left lateral acromion of the scapula, driver head and shaft grip. All motion capture data was collected at 100Hz using 6 infrared cameras. Carry distance, club speed, ball speed, smash factor, launch angle, and spin rate were collected from radar-based device, TrackMan. Results : Pearson's correlation coefficient method was used to find the correlations among X-factor, X-factor stretch and swing-related factors. Positive correlations between driving distance and other swing-related factors which include club speed(r=.798, p<.001), and ball speed(r=.948, p<.001) were observed. In contrast to the swing-related factors, X-factor and X-factor stretch had no relationship to driving distance. Conclusion : These results indicate that X-factor and X-factor stretch are not key regulators in driving distance.

• Journal of Chest Surgery
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• 제18권1호
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• pp.19-23
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• 1985

There are several factors influencing post-operative mortality in Tetralogy of Fallot, such as degree of RV outflow tract obstruction, combined anomaly, and age of the patient. Another factor is preoperative left ventricular volume reported by Kirklin and Graham in 1978. From March to September, 1984, 10 patient with Tetralogy of Fallot have been taken biplane cinecardioangiography [LAO and RAO projection] for measuring left ventricular volume by area-length method. The mean age of the patients was 84.9 [S.D.] and 3 males and 7 females were there. Mean value of left ventricle was 62.9ml/m2, which was no statistically difference from normal value. [p value=0.08]. In conclusion, though this study suggests that there is some decrease of left ventricular end-diastolic volume in Tetralogy of Fallot preoperatively as compared with normal individuals, further evaluation is needed to make it confirmatory with more number of patients and lesser range of age of the patients submitted to the study.

• 대한수학회지
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• 제42권3호
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• pp.457-470
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• 2005

Yu showed that every right (left) primitive factor ring of weakly right (left) duo rings is a division ring. It is not difficult to show that each weakly right (left) duo ring is abelian and has the classical right (left) quotient ring. In this note we first provide a left duo ring (but not weakly right duo) in spite of it being left Noetherian and local. Thus we observe conditions under which weakly one-sided duo rings may be two-sided. We prove that a weakly one-sided duo ring R is weakly duo under each of the following conditions: (1) R is semilocal with nil Jacobson radical; (2) R is locally finite. Based on the preceding case (1) we study a kind of composition length of a right or left Artinian weakly duo ring R, obtaining that i(R) is finite and $\alpha^{i(R)}R\;=\;R\alpha^{i(R)\;=\;R\alpha^{i(R)}R\;for\;all\;\alpha\;{\in}\;R$, where i(R) is the index (of nilpotency) of R. Note that one-sided Artinian rings and locally finite rings are strongly $\pi-regular$. Thus we also observe connections between strongly $\pi-regular$ weakly right duo rings and related rings, constructing available examples.

• The Journal of Advanced Prosthodontics
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• 제8권2호
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• pp.110-115
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• 2016

PURPOSE. The purpose of this study was to compare the removal torques of a chemically modified SLActive implant and a blasted, laser-treated (BLT) implant, which were soaked in saline for 2 weeks after their surface modifications. The removal torques of the two implants were measured 4 weeks after their implantation into the bone defect area in rabbit tibias with concentrated growth factor (CGF) application. MATERIALS AND METHODS. To make artificial bone defects in the cortical layers of both tibias, an 8-mm diameter trephine bur was used. Then, prepared CGF was applied to the bony defect of the left tibia, and the bony defect of the right tibia was left unfilled. Four weeks later, the surgical sites of 16 rabbits were re-exposed. For 8 rabbits, the SLActive implants (Straumann, Switzerland) were inserted in the left tibia, and the BLT implants (CSM implant, Daegu, Korea) were inserted in the right tibia. For other rabbits, the BLT implants were inserted in the left tibia, and the SLActive implants were inserted in the right. Four weeks afger the insertion, torque removal was measured from 4 rabbits exterminated via $CO_2$ inhalation. RESULTS. No significant difference was observed between removal torques of the BLT implant and the SLActive implant (P>.05). CONCLUSION. It was found that BLT surface modification exhibited excellent osseointegration. In addition, CGF application did not affect the insertion and removal torque of the implants.

• 대한방사선기술학회지:방사선기술과학
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• 제43권3호
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• pp.177-185
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• 2020

This study investigated the relationship between metabolic syndrom risk factors to patients with left atrial enlargement according to the results of echocardiography. Male were 269(8.9%) and female were 46(1.5%) that of the total 315 patients (10.5%) with left atrial enlargement. In the obesity factors analysis, BMI, WC, and WHtR were associated with left atrial enlargement. Among them, WHtR included the many obese people with left atrial enlargement. In the analysis of blood pressure, The systolic blood pressure was the highest in the borderline hypertension group in the left atrial enlargement and the diastolic blood pressure was the highest in the normal range group in the left atrial enlargement. In the blood result analysis, there was no correlation with left atrial enlargement that total cholesterol, HDL, LDL cholesterol, triglyceride, and fasting blood glucose level were within the normal range. Therefore, obesity and systolic blood pressure were associated with the left atrial enlargement group. However, the systolic blood pressure did not show pathological condition due to borderline hypertension, and the distribution of the left atrial enlargement group was smaller than that of obesity. Obesity, which includes the largest number of left atrial enlargement group, has been identified to be the highest risk factor for left atrial enlargement.

• Journal of Chest Surgery
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• 제15권2호
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• pp.204-212
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• 1982

The presence of left atrial thrombus in mitral stenosis has been reported to be associated with several factors. These are age, sex, presence of atrial fibrillation, episodes of congestave heart failure, calcification of mitral valve, embolic episode, etc. Since none of these single factor has been always related to the presence of left atrial thrombus, related risk factors to left atrial thrombosis were studied in patients with mitral stenosis using chi square test. We had operated on 191 cases of mitral valvular heart disease from Jan. 1978 to June 1981 at Severance Hospital, Yunsei University College of Medicine. The left atrial thrombi were present in 41 cases among 191 cases of mitral valvular heart disease and it was present in 31 cases among 89 cases of pure mitral stenosis. Only 10 cases among 74 cases of mitral stenoregurgitation had left atrlal thrombi, whereas no left atrlal thrombus was found in patients with pure mitral regurgitation. Related risk factors studied herein were sex, episodes of congestive heart failure, atrial fibrillation, pulmonary capillary wedge pressure, mitral valve area calculated by Gorlin and Gorlin`s formula cardiac output and left atrial dimension by echocardiogram. In this study presence of atrial fibrillation was deemed to be one of the most potential risk factors and other factors of age, duration of symptoms, episode of embolization, calclfication of mitral valve, associated aortic and tricuspid valve disease, ejection fraction of left ventricle by cineangiocardiogram and echocardiogram were not significantly related to the presence of left atrlal thrombi in a statistical viewpoint.

• Korean Journal of Acupuncture
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• 제21권4호
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• pp.21-30
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• 2004

Objectives : Assuming that the characteristic of meridian system has been similar to this of electric potentials in human body and that measurements of electric potential at well(井穴) and sea(合穴) points in branches of the twelve meridians(WSBTM) will be representative of measurements of the twelve meridians, to measure the electric potentials of 13 patients with Arthroncus of Knee(슬안풍<膝眼風>, AK), to find out the characteristic of meridian system in patients with AK. Methods : Electric potentials of well and sea points in the meridians in twenty one patients with the pain in the lion diagnosed as AK were repeatedly measured by physiograph(PowerLab). Measurements of those electric potentials were analyzed by factor analysis. Results : Their electric potentials at the left and right side were factors which are different from each side. In the left side, Factor 1 included Small Intestine, Pericardium, Spleen, Kidney meridian, and Factor 2 included Heart, Tripple Energizer, Bladder, Liver meridian. Factor 3 included Large Intestine, Stomach, Gall bladder meridian, and Factor 4 included Lung meridian. In the right side, Factor 1 included Heart, Pericardium, Tripple Energizer, Spleen, Bladder meridian and Factor 2 included Lung, Liver, Gall bladder meridian. Factor 3 included Small Intestine, Stomach, Kidney meridian and Factor 4 included Large Intestine Meridian. Conclusions : The electric potentials of AK differ from those of normal bodies as well as of bodies with other diseases-shoulder lesions, waist lesions, Lumbago due to Strain and Contusion-. Thus electric potentials of well and sea points might be the representative meridian to show their characteristics.

• Journal of Preventive Medicine and Public Health
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• 제27권2호
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• pp.226-229
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• 1994

In hypertensives, electrocardiographic left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular disease. Animal and human studies suggest an association between left ventricular mass and dietary sodium (Na) intake. This study determined if dietary Na intake in a homogenous ethnic population is associated with electrocardiographic LVH (S in Vl + R in $V5{\geq}5.5 mV$). Blood pressure (BP), body mass index, EKG, and 24 hour urine Na and potassium (K) excretion were determined in 40 otherwise healthy Korean patients with untreated essential hypertension on the standard Korean diet. Among these variables, only Na excretion (mmol/day) was significantly different between those with and without LVH $[LVH+:357{\pm}50,\;LVH-;\;268{\pm}25(p=0.04]$. Thus, dietary sodium intake may be predictive of electrocardiographic LVH.