• Korean Journal of Exercise Nutrition
• /
• v.24 no.4
• /
• pp.15-23
• /
• 2020

[Purpose] Lactate is a principal energy substrate for the brain during exercise. A single bout of high-intensity interval exercise (HIIE) can increase the blood lactate level, brain lactate uptake, and executive function (EF). However, repeated HIIE can attenuate exercise-induced increases in lactate level and EF. The lactate levels in the brain and blood are reported to be correlated with exercise-enhanced EF. However, research is yet to explain the cause-and-effect relationship between lactate and EF. This study examined whether lactate consumption improves the attenuated exercise-enhanced EF caused by repeated HIIE. [Methods] Eleven healthy men performed two sets of HIIE, and after each set, 30 min were given for rest and examination. In the 2^nd set, the subjects consumed experimental beverages containing (n = 6) and not containing (n = 5) lactate. Blood, cardiovascular, and psychological variables were measured, and EF was evaluated by the computerized color-word Stroop test. [Results] The lactate group had a higher EF (P < 0.05) and tended to have a higher blood lactate level (P = 0.082) than the control group in the 2^nd set of HIIE. Moreover, blood lactate concentration was correlated with the interference score (i.e., reverse score of EF) (r = -0.394; P < 0.05). [Conclusion] Our results suggest that the attenuated exercise-enhanced EF after repeated HIIE can be improved through lactate consumption. However, the role of lactate needs to be elucidated in future studies, as it can be used for improving athletes' performance and also in cognitive decline-related clinical studies.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.4106-4106
• /
• 2001

A method to discriminate human gallstones by nea. infrared(NIR) spectrometry using a soft independent modeling of class analogy (SIMCA) has been studied. The fifty NIR spectra of gallstones in the wavenumber range from 4500 to 10,000 cm$\^$-1/ were measured. The forty samples were classified to three classes, cholesterol stone, calcium bilirubinate stone and calcium carbonate stone according to the contents of major components in each gallstone. The training set which contained objects of the different known class was constructed using forty NIR spectra and the test set was made with ten different gallstone spectra. The number of important principal components(PCs) to describe the class was determined by cross validation in order to improve the decision criterion of the SIMCA for the training set. The score plots of the class training set whose objects belong to the other classes were inspected. The critical distance of each class was computed using both the Euclidean distance and the Mahalanobis distance at a proper level of significance(${\alpha}$). Two methods were compared with respect to classification and their robustness towards the number of PCs selected to describe different classes.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.26 no.1
• /
• pp.29-37
• /
• 2020

Purpose: The purpose of the research is to find difficulty levels of LEED credits in each LEED level based on credits achievement in order to find important of LEED-HC credits to gain LEED-HC. Methods: The individual credits of LEED-HC v.2009 scorecards from USGBC website are analyzed. With achieved scores rate of LEED credits per each Level, all credits are reassembled in 4 different ranges (A~D); easy (A), easy-moderate (B), moderate-hard (C) and hard (D) to achieve scores. Results: 1) Achieved point rate in LEED-HC specific credits are low. These credits need to be reviewed carefully. 2) In 88 projects, 37 projects are gained Silver level which is more than projects in certification level. In order to encourage to gain LEED-HC level, Average Achieved rate to earn Certificate level needs to be risen. 3) Credits in range D rarely affect to gain platinum level. EAc1 (24 points) are critical to gain Silver and Gold level. However, EAc1 points are not effective to achieve Certificate level. Implications: This research will provide a fundamental back data to set up Korean Green building rating system for Healthcare.

• Journal of Biosystems Engineering
• /
• v.43 no.4
• /
• pp.263-272
• /
• 2018

Purpose: The load on the planet gear of a planetary gear set is uniformly distributed. However, manufacturing and assembly errors cause uneven load sharing in the planetary gear set. To solve this problem, most studies have suggested applying a floating sun gear to the planetary gear set. However, the effect of the floating ring gear and floating carrier has not been extensively studied. This study aimed to investigate the effect of the floating ring gear. Methods: Two models were developed; one was the fixed ring gear model, and the other was the floating ring gear model. In the fixed ring gear model, the clearance between the ring gear and the housing was $0{\mu}m$, and in the floating ring gear model, the clearance was from $10{\mu}m$ to $100{\mu}m$. The load sharing of the planetary gear set was evaluated by the load sharing factor. Results: Our study showed that with increase in clearance, the load sharing factor of the planetary gear set approached unity. In addition, when the clearance increased above a certain level by which a fully floating ring gear was achieved, the load sharing factor was not affected by the clearance. Conclusions: This indicates that the fully floating ring gear increased the power density of the planetary gearbox by uniformly dividing the load of the planetary gear set. For this reason, the size of the gearbox could be decreased by using a fully floating ring gear.

• The Korea Journal of Herbology
• /
• v.30 no.3
• /
• pp.25-34
• /
• 2015

Objectives : This study was performed to investigate the efficacy and safety of the Mulberry Extract Complex in a placebo-controlled randomized clinical trial and animal study on degenerative arthritis. Methods : Animal study: Mulberry Extract Complex is composed of extracts of mulberry (Morus alba L.) fruit, mulberry leaves and black beans (Glycine max (L.) Merr.). To evaluate the serum level of interleukin-2, interferon-$\gamma$, and prostaglandin E2, an animal model of degenerative arthritis induced by monosodium iodoacetate was employed. Clinical study: The efficacy index (VAS, K-WOMAC) was compared among patients with symptoms of degenerative arthritis before and after Mulberry Extract Complex ingestion as well as the one in groups. Evaluations of the improvement by the subjects and by doctor assessment were also performed. Results : Animal study: Mulberry Extract Complex reduced the serum level of interferon-$\gamma$ and prostaglandin E2 in an animal model with degenerative arthritis. Clinical study: The VAS change showed statistical significance in the experimental groups after 4 weeks (PP set) and 8 weeks (ITT set) of ingestion. When the K-WOMAC was analyzed using a modified ITT set to determine the effectiveness, statistically significant results were obtained in the fields of pain & symptom within the Mulberry Extract Complex group as well as between the Mulberry Extract Complex and placebo groups after 8 weeks of ingestion. Results from the improvement evaluation by subjects and the assessment of improvement by doctors showed statistical significance in the experimental groups (PP set) after 8 weeks. Conclusions : Mulberry Extract Complex could be useful for the improvement of various symptoms of degenerative arthritis based on its anti-inflammatory activity and its reduction of VAS and K-WOMAC pain scores.

• Proceedings of the Safety Management and Science Conference
• /
• 2010.04a
• /
• pp.141-147
• /
• 2010

Risk level for each construction work can be very important factors to establish advanced preventionmeasures. But it is important how to produce it. There are three different methods to set it up for consturuction situation. They are as follows; 1) occurrence frequency = the number of accident workers of each work kind / yearly accident workers 2) occurrence frequency = the number of accident workers of each work kind / yearly workers 3) occurrence frequency = the number of accident workers of each work kind / the total workers All these three concepts(=averaged concept)are analyzed. Additionally frequency based on discrete curve, and severity based on continuous curve are also combined for producing risk level with more scientific approach. This risk level can be very useful to make prevention plan or take measures at construction sites. This is study result can change existing risk level concept to new concept of it, namely rail way work and in-water work showed be high risk level and RC work be low risk level, different from the situation which we have thought commonly, so far.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.3
• /
• pp.13-19
• /
• 2010

Risk level for each construction work can be very important factors to establish advanced prevention measures. But it is important how to produce it. There are three different methods to set it up for construction situation. They are as follows; 1) occurrence frequency = the number of accident workers of each work kind / yearly accident workers 2) occurrence frequency = the number of accident workers of each work kind / yearly workers 3) occurrence frequency = the number of accident workers of each work kind / the total workers All these three concepts(=averaged concept)are analyzed. Additionally frequency based on discrete curve, and severity based on continuous curve are also combined for producing risk level with more scientific approach. This risk level can be very useful to make prevention plan or take measures at construction sites. This is study result can change existing risk level concept to new concept of it, namely rail way work and in-water work showed be high risk level and RC work be low risk level, different from the situation which we have thought commonly, so far.

• Journal of the Korean Statistical Society
• /
• v.30 no.1
• /
• pp.1-20
• /
• 2001

We present how bootstrap methods can be used to conduct inference on the rates of Poisson distributions when only the grouped data are available. A theoretical justification for the validity of bootstrap is given with an illustration of proposed method using a data set obtained fro ma pathology laboratory test. Traditional asymptotic methods are compared with bootstrap methods in computing the estimated standard errors and achieved significance levels for one sample and two sample tests. Bootstrap methods are shown to possess a nice property that he small sample distribution of the relevant statistics can be readily obtained from the bootstrap copies.

• Journal of Power Electronics
• /
• v.11 no.6
• /
• pp.811-818
• /
• 2011

Modulation strategies for multilevel inverters have typically focused on synthesizing a desired set of sinusoidal voltage waveforms using a fixed number of dc voltage sources. This makes the average power drawn from different dc voltage sources unequal and time varying. Therefore, the dc voltage sources are unregulated and require that corrective control action be incorporated. In this paper, first two new selections are proposed for determining the dc voltage sources values for asymmetric cascaded multilevel inverters. Then two modulation strategies are proposed for the dc power balancing of these types of multilevel inverters. Using the charge balance control methods, the power drawn from all of the dc sources are balanced except for the dc source used in the first H-bridge. The proposed control methods are validated by simulation and experimental results on a single-phase 21-level inverter.

• Communications for Statistical Applications and Methods
• /
• v.11 no.2
• /
• pp.369-380
• /
• 2004

Clustering algorithms with different similarity measures are commonly used to find an optimal clustering or close to original clustering. The recovery level of using Euclidean distance and distances transformed from correlation coefficients is evaluated and compared using Rand's (1971) C statistic. The C values present how the resultant clustering is close to the original clustering. In simulation study, the recovery level is improved by applying the correlation coefficients between objects. Using the data set from Spellman et al. (1998), the recovery levels with different similarity measures are also presented. In general, the recovery level of true clusters was increased by using the correlation coefficients.