• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.3 s.96
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• pp.259-265
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• 2005

A two-degree-of-freedom out-of-plane model with contact stiffness is presented to describe dynamical interaction between the pad and disc of a disc brake system. It is assumed that the out-of-plane motion of the system depends on the friction force acting along the in-plane direction. Dynamic friction coefficient is modelled as a function of both in-plane relative velocity and out-of-plane normal force. When the friction coefficient depends only on the relative velocity, the contact stiffness has the role of negative stiffness. The results of stability analysis show that the stiffness of both pad and disc is equally important. Complex eigen value analysis is conducted for the case that the friction coefficient is also dependent on the normal force. The results further verify the importance of the stiffness. It has also been found that increasing the gradient of friction coefficient with respect to the normal force makes the system more unstable.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.3
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• pp.251-260
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• 2006

To study the correlation between body composition values and practice of the Standard Guideline for Korean Dietary Life, a nationwide cross-sectional survey was conducted with 378 female college students living in four Korean cities in December 2005. Among the student subjects, 98 were analyzed for body fat mass, percent body fat, waist-hip ratio(WHR), body mass index(BMI) and obesity degree using Inbody 3.0(Biospace Co, Seoul, Korea). Percent body fat was at a high level of 54.1 %, WHR was at a high level of 58.2% and BMI was at a high level of 41.8%. However, both weight and body fat were below normal at 79.5% and 77.6%, respectively. Percent body fat, WHR, and BMI were slightly negatively correlated with vegetable consumption, but slightly positively correlated with beer intake. WHR > 0.8 was significantly negatively correlated with exercise. Standard Guideline for Korean Dietary Life was practiced to and above normal level by 64.6% of the female college students. However, female college students who are within the normal range of body composition value should notice that obesity will relate to abdominal or visceral fat on their body.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.42-44
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• 2006

Up to the present, finger replantation patients have complained about various symptoms because of blood circulatory failure. Objective evaluation methods for the level of the blood circulatory failures in fingers were needed other than patient's subjective symptoms and complaints. Photoplethysmogram(PPG) measured from fingers is very useful for evaluation of vascular aging and sclerosis level since the PPG signal represents characteristics of peripheral vascular. Several researchers have reported that second derivative of the finger PPG waveform was useful to evaluate vascular compliance and developed various analysis methods for vascular compliance. However, vascular compliance study for finger replantation patient was never evaluated by using second derivative of PPG. Therefore, we aimed to objectively compare and to assess normal and replanted finger vascular compliance using the second derivative of PPG waveform in this study. The evaluated factors of second derivative of PPG are 'a', 'b', 'c', 'd', 'e' and b/a represents vascular compliance. Study found out that when vascular compliance is decreased, b/a is increased, the absolute value of b/a is decreased. For 43 finger replantation patients, the average vascular compliance of replanted finger is lower than the normal finger statistically(p=0.001). we suggested an objective evaluation of finger vascular compliance for finger replantation patients and effect of surgical operation.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.67-69
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• 2007

Recently, the prevalence rate of diabetes in Korea has been increasing rapidly due to high growth of economy and changes in dietary lifestyle. Vascular complication is one of diabetic complications which have frequently occurred by obesity, hyperglycemia and impaired glucose metabolism. Photoplethysmogram(PPG) measured from finger and toe is very useful for evaluation of vascular aging and sclerosis level since the PPG signal represents characteristics of peripheral vascular. Several researchers have reported that second derivative of the finger PPG waveform was useful to evaluate vascular compliance and developed various analysis methods for vascular compliance. However, peripheral vascular compliance study for diabetic patient was never evaluated by using second derivative of PPG. Therefore, we aimed to objectively compare and to assess normal and diabetic group vascular compliance using the second derivative of PPG waveform in this study. The evaluated factors of second derivative of PPG are 'a', 'b', 'c', 'd', 'e' and b/a represents vascular compliance. Study found out that when vascular compliance is decreased, b/a is increased, the absolute value of b/a is decreased. The average vascular compliance of 50 diabetic patients with neuropathy is statistically lower than the normal group(p<0.05). We suggest an objective evaluation of peripheral vascular compliance for diabetic patients and prevention of vascular complication.

• Journal of Korean Neurosurgical Society
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• v.54 no.5
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• pp.437-440
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• 2013

The cerebrospinal fluid tap test (CSFTT) is recommended as a key step in the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). While there is no generally accepted evaluation period for ascertaining a CSFTT responder, a substantial number of patients are evaluated only once within 24 hours of the test for improvement in gait. We report an iNPH patient with a favorable response to shunt surgery, who was first judged a non-responder by this standard, though subsequently was judged a responder in virtue of repetitively testing gait over 7 days. A 68-year-old man presented with progressive impairment of gait, balance, and memory. He was diagnosed as iNPH with an Evans' ratio of 0.35. At first hospitalization, change in gait was evaluated 24 hours after the CSFTT. He didn't show any significant improvement and was judged as a non-responder. However, at the second CSFTT, we repetitively tested his change in gait over seven days. Forty-eight hours after the tap, he showed significant improvement in his gait. He was then confirmed as a responder. After the operation, the gait difficulties were almost fully resolved. Further studies developing the standard procedure of the CSFTT should be considered.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.9 no.1
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• pp.53-58
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• 1998

Objectives : To compare the voice quality and voice problems of untrained professional voice user groups with that of normal control group without voice problem. Materials and Methods : The sustained vowel sounds of 13 male and 36 female teachers, 46 clergies and 15 telephone operators, and 40 normal male and 20 normal female persons were analyzed, using a videostroboscopy and acoustic analyzer. Together with these analyses, a questionnaire associated with risk factors for current and past voice problems was handed over to the patients. Results : The most common symptom in subjective groups was the voice fatigue. In stroboscopic examination, the professional voice user groups shelved functional voice disorder findings regardless of the Intensity of voice use. In the clergy and teacher using loud voice, vocal polyp, vocal nodule and hyperfunction of laryngeal muscle were frequently observed. In the clergy and telephone operator, jitter and shimmer were significantly increased. In the female teacher, the value of jitter, fundamental frequency variation and fundamental frequency were statiscally significant. However, the voice of male teacher showed no significant findings in the acoustic and aerodynamic studies. Conclusion : In the management of voice problems for untrained professional voice user groups, it is important to find the exact causes and patterns of voice problems, and to be individualized the management according to the causes.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.139-143
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• 1998

The occurrence and physico-chemical properties of flat leaves found in 1997 curing trial related to the prevention of occurrence of flat leaves at bulk curing of flue-cured tobacco were investigated and compared with those of normal leaves. Cured leaves of NC82 were separated into 4 classes of none, slight, fair and severe symptoms of flat leaf by the percentage of flattened parts to whole leaf area. The flat leaves were mostly found among the leaves of lower stalk position, and it was estimated that growth rate of lower leaves also influenced on the occurrence of flat leaves. In chromatic aberration of cured leaf, flat leaves showed remarkably lower b and L values than in those of normals but there was no difference in a value. On the other hand, in chemical analyses of flat leaf samples, nicotine, total sugar, ether extract and total nitrogen contents were decreased with the degree of flat symptoms. In physical properties, filling capacity of cured leaves was decreased with the degree of flat symptoms comparing with those of normal leaves, while shatter index was showed a reverse tendency, and then within the same leaf, flat parts were decreased in total sugar, ether extract and filling capacity compared with those of normal ones, but remarkably increased in shatter index, and there was no difference in nicotine and total nitrogen contents.

• Korean Journal of Veterinary Research
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• v.2 no.2
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• pp.5-13
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• 1962

The blood samples of 280 suckling pigs and of 300 adult pigs were studied in a hope to establish normal hemograms of swine as reared in Korean local conditions. The examination included total counts of erythrocytes, leukocytes differential count, hemoglobinometry, and reticulocyte count. The results of this study are summarized as following. 1. Higher erythrocyte count was observed in adult pigs as compared with the values reported by other workers. The normal erythrocyte value for malewas $8.4{\pm}0.9$ millions with approximately 0.6 million less for female. 2. Relatively higher hemoglobin concentration was measured in the piglets at birth, which slightly decreased in piglets of 2nd and 3rd weeks. The Hb concentration was highest in piglets of 5th week amounting to 15.8gm/100ml of blood, and it gradually decreased to the adult-level thereafter. 3. The average diameter of erythrocyte was $6.6{\pm}0.72{\mu}$ in suckling pigs and $6.3{\pm}0.11{\mu}$ in adult pigs. This shows that erythrocytes of piglets are larger than those of adult pigs and the mean diameter is also arger than reported by other investigators. 4. The lower mean percentages of eosinopils, basophils, monocytes were found both in the blood of suckling and adult pigs. 5. The other blood values were in general agreements with the values reported by other workers.

• Journal of Sasang Constitutional Medicine
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• v.20 no.2
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• pp.53-57
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• 2008

1. Objectives When we give Jowiseungcheong-tang to Taeumin patients, analyzing a change of their autonomic nervous system. It is measured by the heart rate variability(HRV) analyzer. 2. Methods We give Jowiseungcheong-tang to ten Taeumin patients for three days and examine the HRV at first time and three days later. 3. Results and Conclusions We compared two HRV results. The value of RRNN(average of normal RR intervals), SDNN(the standard deviation of all normal RR intervals), RMSSD(the root mean square of successive differences between the normal heart beats) have a downward tendency. Norm HF(normalized high frequency power) have a upward tendency. norm LF (normalized low frequency power) and LHR(LF/HF ratio) have a downward tendency. It means hypofunction of autonomic nervous system. But all results are not significant. We think that restudy is needed with more patients and longer periods afterward.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.286-293
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• 2010

Peak bone mass is established predominately during childhood and adolescence. It is an important determinant of future resistance to osteoporosis and fractures to gain bone mass during growth. The issue of low bone density in children and adolescents has recently attracted much attention and the use of pediatric dual-energy X-ray absorptiometry (DXA) is increasing. The process of interpretation of pediatric DXA results is different from that of adults because normal bone mineral density (BMD) of children varies by age, body size, pubertal stage, skeletal maturation, sex, and ethnicity. Thus, an appropriate normal BMD Z-score reference value with Z-score should be used to detect and manage low BMD. Z-scores below -2.0 are generally considered a low BMD to pediatrician even though diagnoses of osteoporosis in children and adolescents are usually only made in the presence of at least one fragility fracture. This article will review the basic knowledge and practical guidelines on pediatric DXA based on the International Society for Clinical Densitometry (ISCD) Pediatric Official Positions. Also discussed are the characteristics of normal Korean children and adolescents with respect to BMD development. The objective of this review is to help pediatricians to understand when DXA will be useful and how to interpret pediatric DXA reports in the clinical practice for management of children with the potential to develop osteoporosis in adulthood.