• Korean Journal of Clinical Laboratory Science
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• v.42 no.3
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• pp.155-160
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• 2010

Transcranial Doppler ultrasonography (TCD) allows measurement of blood flow velocity to be made from the basal intracerebral vessels. Blood flow velocity in TCD is highly affected not only by blood vessel diameter, blood flow volume, blood viscosity, but also age and sex. Therefore, the study is focused on the correlation between TCD measurement index and sex/age. Subjects were 214 (male 147, famale 67) who had TCD for headache and stroke evaluations at Dongguk University Ilsan Hospital neurology department from December 2009 to April 2010. Sex did not show significant differences with mean flow velocity (MFV), peak systolic flow velocity (PSFV), end diastolic flow velocity (EDFV), pulsatility index (PI) and resistance index (RI) in middle cerebral artery (MCA). Although age also did not show significant differences with MFV and PSFV, EDFV has statistically decreased with age, and PI and RI has statistically increased with age. In addition, age showed significant correlation with MFV, EDFV, PI and RI, but not with PSFV. Therefore, TCD is definitely correlated with age and sex, so that those influencial factors must be considered when being tested.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.3
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• pp.135-139
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• 2009

Pulmonary function test has been know to be greatly affected by body indices, such as sex, age, height, body weight, body surface area (BSA) and body mass index (BMI), so hat this study was focused to see the relationship between body index and flow-volume curves. Subjects were 156 (male 90, female 66) and they were examined for pulmonary function test in terms of body index and correlation/multiple regression analysis of flow-volume curves at Presbyterian Medical Center from March to August, 2009. The followings results after analyzing the correlation between body index and flow-volume curves. Although flow-volume curve FEF25-75% showed close correlation with age, body weight, and body surface area, but not with body mass index. In addition, multiple regression analysis was performed to see how each body index affects flow-volume curve FEF25-75%, and FEF25-75% dispersion was explained as 74.5% with age only, 94.2% with age and height, and 96% with age, height, and sex. Therefore, sex, age and height that are mainly used for predictive formular of pulmonary function test and nomogram were important factors for pulmonary function test itself, and further study must be done for other body index.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.12 no.4
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• pp.40-46
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• 2016

In order to improve air quality of indoor environment, studies of the underfloor air distribution (UFAD) system for application in buildings are actively in progress based on temperature and air flow distribution. However, although the age of air is the major evaluation parameter, there has been very little study on this parameter for the UFAD system. In this study, we investigated the age of air to reach the air diffuser, which is installed at the bottom of the interior by the UFAD system. Computational fluid dynamics simulations showed no regular pattern to the maximum value of the age of air in accordance with air flow rate and the velocity at air diffuser. These factors can be deduced from air movement by considering that air emitted from air conditioners was rotated according to the bottom shape of the floor, and then, the age of air in the rotation center was increased. The average age of air of internal interior was reduced considerably as the flow velocity at the underfloor air diffuser was increased from 0.5 m/s to 1.0 m/s However, the age of air was not substantially affected with change in the air volume. Moreover, when the flow velocity at the underfloor air diffuser was higher than 1.0 m/s, the age of air showed no significant difference with change in air volume or height of measurement. These results imply that indoor air quality is more substantially influenced by flow velocity than air volume, and the appropriate flow velocity is 1 m/s or more.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.175-180
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• 2006

Background: A transforaminal epidural steroid injection has been used for the treatment of radicular arm or leg pain, which has the advantage of ventral epidural spreading compared to either an interlaminar or caudal approach. However, several factors are known to affect the epidural spread pattern of contrast dye; therefore, the injected medication can not be delivered to the target site. The objective of our study was to observe any differences in the contrast flow patterns according to several factors. Methods: A total of 34 epidurographies in 29 patients, who underwent fluoroscopically guided transforaminal epidural steroid injections, were evaluated. After confirming the location of the needle tip within the anterior superior aspect of the neural foramen in the lateral view, and at the 6 o'clock position to the pedicle in the anteroposterior view, 2 ml of contrast dye was injected. The contrast flow patterns of ventral, ventral and dorsal, and dorsal epidural filling were analyzed, according to age, gender, magnetic resonance imaging finding and history of previous back surgery. Results: Ventral contrast flow occurred in 30 out of the 34 epidurographies (88%). Both ventral and dorsal contrast flow patterns were observed 13 out of 16 (81%) patients in the older age group. Also, both ventral and dorsal contrast flow patterns were observed in 16 out of 18 (88%) patients with spinal stenosis. Conclusions: Transforaminal epidural steroid injections, performed uner fluoroscopy, provide excellent nerve root filling and ventral epidural spreading. Patients with spinal stenosis or an old age have both ventral and dorsal epidural spreading patterns.

• Clinical and Experimental Pediatrics
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• v.45 no.2
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• pp.192-198
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• 2002

Purpose : It is important to select and use kinds of Inhaler appropriate to the age of the patient and severity of symptoms. Several kinds of Inhaler have been developed and recommended according to each inhaler's resistance and usage method. We evaluated the usable age of 4 inhalers (turbulent flow inhalers, multi unit dose inhalers, breath actuated MDI, and autohalers) by measuring peak inspiratory flow(PIF) using $In-Check^{(TM)}$ Inspiratory Flow Meter. Methods : Ninety three patients aged from 3 to 7 years(mean $57{\pm}12.9$ mo.) who had admitted to CHA hospital from July 2000 to April 2001 were enrolled. Study patients were divided into 4 groups according to age : 3-4 years of age(group A, n=31), 4-5 years of age(group B, n=32), 5-6 years of age(group C, n=18), and 6-7 years of age(group D, n=12). Results : Out of total 93 patients, 23(71%), 27(84%), 17(94%) patients of each group A, B, C and all 12 patients of group D could use the 4 types of inhaler through adequated education. In all four groups, height, body weight and age were significantly correlated(P<0.05). Usable age, height and weight of children who can use turbulent flow inhaler(TFI) were each 8 year 7 month old, 144 cm, 32.0 kg, and those of multi unit dose inhaler(MUD) were 2 year 10 month old, 92 cm, 12.0 kg. Also that of breath-actuated MDI were 1 yr 8 months, 83 cm, 8.5 kg and that of autohaler were 2 yr 8 months, 91 cm, 11.0 kg Conclusion : We concluded that the ability to use inhalers correlated with height, weight and age of the patients. Multi unit dose inhalers, Breath actuated MDI and Autohaler are useful after 3 years of age through adequate education.

• Journal of Families and Better Life
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• v.22 no.5
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• pp.47-58
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• 2004

In this article the relations between demographics, variables related to credit card, flow and compulsive buying tendency were explored. The survey data collected from 318 university students. The results of regression analysis showed that older students were related to the greater number of card. The greater allowance and number of card were related to the greater average card expenditure per month. Female, younger and the greater average card expenditure per month were related to greater flow. And younger students tended to be more compulsive buying tendency than older students. The greater allowance and flow were related to greater compulsive buying tendency. The results of path analysis showed that the age, allowance and flow influenced on compulsive buying tendency direct. Also age and allowance influenced on compulsive buying tendency direct and indirect.

• The Korean Journal of Emergency Medical Services
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• v.27 no.1
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• pp.59-70
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• 2023

Purpose: This study was designed to identify the effects of social support, learning flow, and learning satisfaction on academic achievement in university students. Methods: This study involved university students who agreed to participate the investigation in D City using a structured online questionnaire from December 1, 2022 to December 31, 2022. Results: Social support, learning flow, learning satisfaction, and academic achievement had significant correlations. The influencing factors of academic achievement were age and learning flow, with an explanatory power of 20%. Conclusion: Further active management and attention are imperative for vulnerable students in high-age groups to search for the ways to improve learning flow.

• Journal of Information Technology Services
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• v.6 no.1
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• pp.83-99
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• 2007

The purpose of this research is to identify the determinants of loyalty in online games. This study developed a research model to analyze the factors explaining the loyalty level from gamers, employing social identification, flow, and positive anticipated emotion as major research variables, and collected 1308 survey responses from gamers. Within the context of arguing that the exploration of age range issues with respect to online games is important, this research also examines the age differences in path coefficients. To this end, the structural model was tested with the data from entire data sample (i.e., the age of 10s, 20s, and 30s pooled together) and each of the subsamples (i.e., teens taken separately, twenties taken separately, and thirties taken separately). Properties of the causal paths, including standardized path coefficients, the significance of difference, in the hypothesized model, are also presented, so that we can investigate the relative influences of different dominants, demonstrating how teens, twenties, and thirties differ in their decision-making processes regarding the flow, social identification and loyalty from online games.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.923-928
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• 2000

Objective : The reliability of transcranial doppler sonography(TCD) for predicting delayed ischemic neurologic deficit( DIND) was investigated in patients with aneurysmal subarachnoid hemorrhage(SAH). Methods : The velocity of blood flow through the middle cerebral artery was measured by TCD in 70 patients treated surgically within 72 hours due to ruptured cerebral aneurysm. A correlation between measured maximal mean blood flow velocities and clinical factors including age, hypertension, Hunt-Hess grade, Fisher grade, DIND, and outcome was made. Results : An age-dependent reduction of the measured maximal mean velocities was found(r＝-0.4043, p<0.001). Flow velocities in hypertensive patients were significantly lower than in the normotensive individuals(two-tailed T test, p<0.05). There was no significant difference between the flow velocities and evaluated other clinical factors. When the flow velocities of 14 patients who developed DIND were compared with those of patients without deficits, no significant difference was seen. A significant increase in flow velocities in the days before the onset of DIND was found only in 4 of 14 cases. High flow velocities did not necessarily mean impending neurological deficits : 6 of 70 patients tolerated flow velocities over 160cm/s. Conclusion : We suggest that TCD readings have limited utility for predicting DIND following SAH, especially in older or hypertensive patients. More direct measurements of blood flow are necessary to adequately predict which patients are at high risk of DIND.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.1
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• pp.43-48
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• 2004

Cerebral vasoreactivity is an index of autoregulation of cerebral perfusion, and can be measured using functional images such as Xe CT, SPECT and PET in reponse to hypercapneic stimulus. In order to measure cerebral $CO_2$ vasoreactivity in routine TCD study conveniently and reliably, we devised a method of rebreathing into closed volume of reservoir bag as a hypercapneic stimulus, and applied it to 44 healthy volunteers. As a hypercapneic stimulus, we applied fitting mask connected with closed reservoir bag for about 90 seconds, and mean blood flow velocity(MBFV) and pulsatility index(PI) were evaluated at proximal middle cerebral arteries(MCA) of 50-55 mm depth, before and after the hypercapneic stimulus. Age affected the MFV and PI value showed significant and the MFV was 56.45(SD=9.75)cm/sec, while PI was 0.406(SD=0.089). As age increases the flow velocity decreased significantly whereas PI value increased(P<0.05). The vasoreactvity significantly decreased with age(P<0.05). The decrease of cerebral blood flow quantity and cerebral blood flow velocity is not only because of increase of diameter of cerebrovascular resulting from aging, but the resistance increase of small blood vessel resulting from the increase of PI & RI value is regarded. We suppose that the rebreathing method is a reliable and convenient technique as a hypercapneic stimulus in determining cerebral $CO_2$ vasoreactivity. The rebreathing method could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied to the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.