• Journal of Advanced Marine Engineering and Technology
• /
• v.38 no.4
• /
• pp.451-455
• /
• 2014

In LTE (Long Term Evolution)/LTE-A (Long Term Evolution-Advanced) networks, hierarchical macro/femto-cell structure is adopted to enhance system capacity. Such a femto-cell is deployed as a Closed Subscriber Group (CSG) eNB. However, the inbound handover to CSG cell experiences longer delay than normal handover because it spends more time detecting the associated CSG cells due to its sparse deployment. Most of all the legacy UEs (User Equipments) have been implemented without considering the inbound CSG handover. Accordingly, they may not meet the performance requirements on the cell discovery described in the LTE/LTE-A standards. Therefore, in this paper, the performance of the CSG femto-cell detection is evaluated using computer simulation. The evaluation results will provide a basis to tackle the latency problem of inbound CSG handover.

• Journal of the Korean Society for Railway
• /
• v.18 no.1
• /
• pp.71-80
• /
• 2015

During normal subway rush hours, a train-driver is in charge of more than 3,000 people on a daily basis. When an emergency event occurs, millions of people and their property come to depend only on the train-driver's ability. After the Daegu subway fire disaster in February 2003, the Railway Safety Act was enacted in October 2004 and the 'Train Drivers' Licensing System' was introduced by the National Railroad Administration in July 2006 to secure and improve protection. This study was conducted to investigate and evaluate the effects of the Train Drivers' Licensing System since the Licensing System was first introduced eight years ago. In addition, the analysis will suggest better policies for the effectiveness of the 'Train Drivers' Licensing System'.

• Journal of The Korean Association of Information Education
• /
• v.8 no.3
• /
• pp.397-402
• /
• 2004

In this paper, via analysis a education method of chapter for computer basic knowledge, whether educational computer game one of various education methods is able to extend computer basic knowledge, we taught and analyzed applied result, then we wanted to find possibility that educational computer games is possible to be contributed in computer education of elementary school. For extending of computer literacy of student, we did computer class with educational game. As a result, we could got a more effective outcome that student felt a fun and participated in class more active than normal class. Therefore, If we will use educational computer games to aim to raise abilities of computer literacy and problem solving that will be contributed in education which is coincided with knowledge basis society of informational period.

• Water for future
• /
• v.6 no.2
• /
• pp.12-18
• /
• 1973

This paper describes the study and test for sand and gravel embankment in winter season and also contribute to the development of construction method for the practical purposes. In order to make possible sand and gravel embankment in winter season, at first, the following eriteria on work are given under the normal weather condition: 1) The maximum diameter of material shall not exceed 30cm and sand content which is the ratio of the weight of sand to gravel shall not exceed 60% 2) Spreading depth shall not exceed 60cm each layer of material shall be compacted by over 6 times passing by thell ton smooth drum type of uibratory roller and the relative density shall exceed 60% In addition to the above conditions, the following criteria are given as winter season condition. 3) Sand contsnt shall not exceed 25%, and water content shall not exceed 4% 4) Dwing construction, the air temperature should be $70^{\circ}C$ below zero at minimum and $3^{\circ}C$ below zero onthe average and all the construction work should he continued without intersuptions. With above criteria, it is come to a conclusion that the conclusion that the construction of sand and gravel embankment in winter season will be done satisfactorily without any difficulty. On the basis of these criteria an actual construction was practiced and it was proved that those criteria are applicable to actual embankment of materials.

• Physical Therapy Rehabilitation Science
• /
• v.9 no.1
• /
• pp.18-24
• /
• 2020

Objective: The purpose of this study was to compare the activities of the abdominal muscles according to trunk stabilization exercises using Swiss ball in normal individuals. Design: Cross-sectional study. Methods: Ten healthy university students participated in this study. The subjects were required to complete the following three exercise positions: Exercise position 1, sitting on a Swiss ball and lifting the legs; Exercise position 2, pushing to a plank position from an ending position; and Exercise position 3, push-up posture with the legs on a Swiss ball. Changes in the trunk muscle activities were estimated using Biometric electromyography (EMG). Activities of the dominant side internal oblique muscle (IOM) and external oblique muscle (EOM) were estimated in all participants. The maximal voluntary isometric contraction (MVIC %) was measured to standardize the EMG signals for the IOM and EOM during maximum resistance when sitting up with each shoulder pointing towards the contralateral pelvis with knees bent and both arms crossed on the chest for 5 seconds. Results: There was a significant difference in the activity of the internal and external oblique muscles between Exercises 1 and 2 and Exercises 1 and 3 (p<0.05). Furthermore, the IOM/EOM activity ratio was the greatest during Exercise 3 and the smallest during Exercise 1. IOM and EOM activities were the greatest during Exercise 2 with greater EOM activity. Conclusions: In future studies, it will be necessary to investigate muscle activities by supplementing the above-mentioned limitations during the stabilization exercise. The results of this study may be used as a basis for controlling the intensity and frequency of exercise while prescribing trunk stabilization exercises.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.23 no.6
• /
• pp.1349-1357
• /
• 2009

This study was performed to investigate the effects of Shigyungbanha-tang(SGT) on the lipopolysaccharide(LPS) induced acute lung injury(ALI) in mice. 1 and 24 h before LPS intratracheal instillation, control group was taken distilled water orally. Treated groups was taken each concentrate SGT(2.5 g/kg, 6.7 g/kg) by orally as same times. Normal group was not instilled with LPS and was taken distilled water. 24 h after LPS intratracheal instillation, lung histology was performed in inflated-fixed lungs in 3 mice of each groups. The other mice of each groups, bronchoalveolar lavege fluids(BALF) was obtained to measure proinflammatory cytokines(TNF-$\alpha$, IL-$1{\beta}$, IL-6) and blood sample was obtained to measure white blood cell(WBC). In vitro, the effect of SGT($100\;ug/m{\ell}$, $500\;ug/m{\ell}$, $1000\;ug/m{\ell}$) on the release of RANTES, TARC induced by TNF-$\alpha$ and IL-4 in human alveolar epithelial cell(A549) was examined. Histopathologically, SGT prevented LPS-induced lung injury. SGT decreased protein, TNF-$\alpha$, IL-$1{\beta}$ and IL-6 according to concentrations. In vitro, $500\;ug/m{\ell}$, $1000\;ug/m{\ell}$ concentrate SGT suppressed the expression of RANTES and TARC on A549 cells. On the basis of these results, SGT had a markedly anti-inflammatory effect in a clinically relevant model of ALI. Nevertheless, further investigations are required to determine the potential clinical usefulness of SGT in the adjunctive therapy of ALI.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.52 no.12
• /
• pp.562-567
• /
• 2003

Lightning arresters are deteriorated by repetition of protective operation against overvoltages or impulse currents in environments of its use. If a deteriorated arrester is left in power lines, it can lead to an accident such as a line to ground fault even in a normal system. Therefore, it is necessary to eliminate the deteriorated arrester in advance by checking the soundness of arresters on a regular basis, and to ensure the reliability of power systems by preventing accidents. Various deterioration diagnostic techniques and devices are suggested, and most of which measure leakage current components as an indicator of arrester ageing. However, the techniques based on the magnitude of leakage current measure simply RMS or peak value of leakage current components and do not provide detailed information needed in the diagnosis. In this study, we found that the wave height distributions of the total leakage currents are remarkably changed or a new wave height are produced with the progress of arrester deterioration. To propose a new technique for the diagnosis, we designed a leakage current detection unit and an analysis program which can measure leakage current magnitudes and analyze wave height distributions. From the experimental results, we confirmed that the proposed technique by analyzing the wave height distribution can simply diagnose the mode of defects such as a partial damage and an existence of punctures in arresters as well as deterioration of arresters.

• Journal of the Korea Institute of Building Construction
• /
• v.4 no.1
• /
• pp.97-103
• /
• 2004

In case of a fire in road or railway tunnel it is always necessary to keep the escape condition as good as possible. Most of the victims of major fires in tunnels are because they couldn't leave the tunnel in time and were trapped by smoke, or rescue teams couldn't reach the place of the accident due to low visibility and high temperature. In spring 2003 a comprehensive field experiment was undertaken in a large scaled tunnel in Youngin City to test the effectiveness of a new water spray curtain system, designed to the air qualify inside of a tunnel in case of fire during passenger's escape to safe routes, In order to control the smoke propagation, fixed water sprayed nozzles were used to make water curtain system, which can be installed or hanging water piping line below ceiling. The experiment was accompanied by an extensive measurement campaign in order to measure temperature dropping effect and flow conditions as well as CO concentration for various water sprayed curtains produced by sprinkler heads or water spray nozzle. Eventually comparison analysis were undertaken to investigate the performance of water curtains under fixed water pressure. Therefore most effective water curtain system was presented on the basis of water droplet size in long tunnel.

• The Korean Journal of Physiology
• /
• v.2 no.2
• /
• pp.53-61
• /
• 1968

Maximal oxygen debt, lactate and excess lactate were measured in 13 men with low hematocrit ratio before and after maximal exercise. Maximal exercise run was performed on a treadmill and the duration of run was 2 minutes 45 seconds in each subject. Hematocrit ratio ranged between 35 and 47%, the mean being 39.8%. The following results were obtained. 1. Maximal oxygen debt expressed on basis of body weight increased as the hematocrit ratio decreased. The correlation coefficient between the two was r= -0.770. 2. The time necessary for decreasing to 50% of total maximal $O_2$ debt(half time) became longer as the hematocrit ratio decreased. In normal men the half time was about 4 minutes and at the longest it was 12 minutes in men with the lowest hematocrit ratio. 3. The lactate concentration reached its peak value after 3 minutes of recovery. Thereafter, the time course of decrease in lactate concentration coincided roughly with that of respiratory oxygen debt curve. To reach to the resting level, however, it took longer time than that of respiratory oxygen debt. 4. Resting concentrations of lactate was 1.28 mM/l, pyruvate 0.13 mM/l and L/P ratio was 9.8. Peak value of ${\Delta}L$ after exercise reached to the value of 10.4 mM/l and ${\Delta}L/P$ reached 26.0. Peak excess lactate after exercise was 6.34 mM/l. 5. The part of oxygen debt accounted for by the oxygen equivalent of excess lactate was only 38.4%. A better relationship between lactate and oxygen debt was observed and the part of oxygen debt accounted for by the oxygen equivalent of lactate was 63.3%. 6. Peak value of lactate after maximal exercise increased as the hematocrit ratio decreased. 7. Respiratory oxygen debt of 100 ml/kg was accounted for by lactate more than 60% and only 30% was by excess lactate. 8. Excess lactate was not a good index of respiratory oxygen debt.

• The Korean Journal of Physiology and Pharmacology
• /
• v.10 no.5
• /
• pp.263-271
• /
• 2006

Since astrocytes were shown to play a central role in maintaining neuronal viability both under normal conditions and during stress such as ischemia, studies of the astrocytic response to stress are essential to understand many types of brain pathology. The micro array system permitted screening of large numbers of genes in biological or pathological processes. Therefore, the gene expression patterns in the in vitro model of astrocytes following exposure to oxygen-glucose deprivation (OGD) were evaluated by using the micro array analysis. Primary astrocytic cultures were prepared from postnatal Swiss Webster mice. The cells were exposed to OGD for 4 hrs at $37^{\circ}C$ prior to cell harvesting. From the cultured cells, we isolated mRNA, synthesized cDNA, converted to biotinylated cRNA and then reacted with GeneChips. The data were normalized and analyzed using dChip and GenMAPP tools. After 4 hrs exposure to OGD, 4 genes were increased more than 2 folds and 51 genes were decreased more than 2 folds compared with the control condition. The data suggest that the OGD has general suppressive effect on the gene expression with the exception of some genes which are related with ischemic cell death directly or indirectly. These genes are mainly involved in apoptotic and protein translation pathways and gap junction component. These results suggest that microarray analysis of gene expression may be useful for screening novel molecular mediators of astrocyte response to ischemic injury and making profound understanding of the cellular mechanisms as a whole. Such a screening technique should provide insights into the molecular basis of brain disorders and help to identify potential targets for therapy.