• Journal of the Korean earth science society
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• v.21 no.6
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• pp.675-682
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• 2000

25 seismic shot gathers were obtained to study the two dimensional subsurface shear wave velocities in a landfilled area near the Keum river estuary. Borehole(BH#1 and BH#2) tests at two sites were made in the same area. Standard Penetration Tests were also performed at the same time. The 2-D shear wave velocity structure resulted from the inversion of the seismic data shows that the subsurface of the studied area consists of the upper 1${\sim}$3 meter thick layer(200 m/sec${\sim}$700 m/sec), the middle 5${\sim}$8 m thick low velocity layer(100 m/sec${\sim}$400 m/sec), and the lower layer of 1000m/sec or higher shear wave velocities. The thickness of the low velocity layer decreases from the BH #1 site to the BH #2 site. The depth to the basement also decreases toward the BH #2 site. The examination of the S wave velocity structure, the description of the geologic contents, and the Standard Penetration Test values indicate that the middle layer of low shear wave velocity may be related to the clay content of the layer. On the other hand, the Standard Penetration test values increase with depth, showing no significant relationship with the geologic contents of the subsurface. This study shows that the inversion of surface waves can be effective in the study of the shear wave velocity, especially in the area where low velocity layers can be found. The method of inversion of surface waves also can be used as a viable technique to overcome the limit of the seismic refraction method.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.67-88
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• 1992

The purpose of this study was to investigate the changes of mandibular movement and muscle activity following orthognathic surgery in patients with mandibular prognathism. Lateral cephalogram, M.K.G., E.M.G. recordings were obtained immediately before surgery, and 2 months and 8 months after surgery. Among the patients who received orthognathic surgery, 19(13 men, 6 women) were selected for this study. Statistical analysis for each time interval differences were performed with the SPSS package. The results were as follows: 1. Compared with the pre-operative group (opening 349.7mm/sec, closing 313.1mm/sec), the mean values of the maximum opening and closing velocity in the skeletal Class III surgery group were significantly decreased in the 2 months post-operative (opening 232.9mm/sec, closing 206.9mm/sec), but the values tended to increase in the 8 months post-operative group (opening 280.9 mm/sec, closing 319.1mm/sec). 2. Compared with the pre-operative group (61.7 mm/sec), the maximum velocity of the terminal tooth contact increased in the 2 months (72mm/sec) and 8 months (105.7mm/sec) postoperative groups. 3. In the mean value of vertical freeway space, there was significant difference between the normal group and the pre-operative group, but not between the normal group and the 8 months post-operative group. 4. In the mean values of the maximum opening, the maximum anterio-posterior movement from centric-occlusion, and the lateral deviation from centric occlusion, there was no significant difference between the normal group and the surgery group (the pre-operative and the 8 months post-operative groups). 5. The mature swallowing pattern was 58% in the pre-operative group, but 90% in the 2 months post-operative group, and 63% in the 8 months post-operative group. 6. In the comparison of muscle activity, there was no significant difference between the normal group and the surgery group during the rest position. However, during cotton roll clenching, there was significant difference between the normal group and the pre-operative group, but not between the normal group and the 8 months post-operative group.

• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.16-23
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• 2002

Physical properties of composite resins such as strength, resistance to wear, discoloration, etc depend on the degree of conversion of the resin components. The purpose of this study was to evaluate the degree of conversion of the composite resins according to the thickness of tooth structure penetrated by light and applied light curing time. The coronal portions of extracted human teeth (one anterior tooth, three posterior tooth) was embedded by pink denture material. the mounted teeth were cut into three illumination sections (1mm thickness enamel section, 1mm thickness dentin section, 2mm thicknes dentin section) and one backing section with cutting wheel. Thin resin films were made by using 6kg pressure between slide glass during 5 minutes Thin resin film was light cured on coupled illumination section during 40sec, 80sec and 120sec. each illumination section was coupled as follows; no tooth structure(X), ename section(E), enamel section + 1mm dentin section(ED1), enamel section + 2mm dentin section(ED2), enamel section + 1mm dentin section + 2mm dentin section(EDD). To simulate the clinical situation more closely, thin resin films was cured against a backing section of tooth structure. The degree of conversion of carbon double bonds to single bonds in the resin films were examined by means of Fourier Transform Infrared Spectrometer. The results were obtained as follows ; 1 As curing time was increased, conversion rate was increased and as tooth thickness which was penetrated by curing light was increased, conversion rate was decreased. 2. At all tooth thickness groups, conversion rate between 80sec and 120sec was not significantly increased(P＞0.05). 3. At 40sec group and 80sec, conversion rate between no tooth structure(X) group and 1mm enamel section(E) group was not significantly decreased(P＞0.05). 4. At 80sec group and 120sec, conversion rate between 1mm enamel section(E) group and 1mm enamel section + 1mm dentin section(ED1) group was not significantly decreased(P＞0.05).

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.145-152
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• 2000

Pcak torque. angle of peak torque occurrence. total work, average power. endurance of the ankle plantar flexors were studied with the knee positioned $0^{\circ}\;and\;90^{\circ}$ flexion. Plantar flexors of 20 students were tested on Cybex 6000 dynamometer. The results were as fallows ; 1. The peak torque values were significantly higher with knee extension than knee $90^{\circ}$ flexion. 2. The angle of peak torque occurrence were earlier with knee extension than knee $90^{\circ}$ flexion, but no significant. 3. The total work were significantly higher with knee extension than knee $90^{\circ}$ flexion. at$30^{\circ}/sec$, but no significant at $90^{\circ}/sec$ 4. The endurance ratio were higher significantly with knee $90^{\circ}$ flex ion than knee extension 5. The mean average power were significantly higher with knee extension than knee $90^{\circ}$ flextion

• The Journal of Korean Medicine
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• v.17 no.1 s.31
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• pp.345-360
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• 1996

Background and Purpose: To evaluate the blood flow velocity using doppler ultrasound of the carotid artery, vertebral artery, and basilar artery in stroke patients Material and Methods: To evaluate the blood flow, I measured the peak systolic velocity and mean velocity of the common carotid artery(CCA), internal carotid artery(ICA), external carotid artery (ECA). vertebral artery(VA), and basilar artery(BA) in 44 stroke patients and 15 healthy adults. To investigate the difference between ischemic stroke patients and normal healthy adults, I selected 44 ischemic stroke patients diagnosed by brain CT and brain MRI, and 15 healthy adults who did not have any symptoms of stroke, hypertension, heart disease, and diabetes melitus. Results: Peak velocity in normal adults was 50.6${\pm}$1.6cm/sec in the CCA, 67.2${\pm}$1.7cm/sec in the ICA, 62.5${\pm}$2.4cm/see in the ECA, 45.5${\pm}$1.9cm/sec VA. and 50.5${\pm}$3.5cm/sec in the BA. Mean velocity in normal adults was 26.9${\pm}$1.1cm/sec in the CCA, 43.7${\pm}$1.4cm/sec in the ICA, 26.7${\pm}$1.3cm/sec in the ECA. 31.6${\pm}$1.9cm/sec in the VA and 33.0${\pm}$2.6cm/sec in the BA. In this study, there was a significant increase in the velocity of ICA, ECA, and VA of ischemic stroke patients in comparison with normal healthy adults. And the blood flow velocity of this study in the CCA and ECA was different from other reported foreign values and the other known values in my country. Conclusion: There was a significant difference in the blood flow velocity between ischemic stroke patients and normal healthy adults. And the blood flow velocity of this study was different from other reported foreign values and the other known values in my country. Therefore, it needs more detailed studies about old aged Korean and ischemic stroke patients than previous studies.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.271-280
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• 2014

Some bacterial metabolites of Xenorhabdus nematophila (Xn) inhibit phospholipase $A_2$ ($PLA_2$) activity to shutdown eicosanoid biosynthesis in target insects. However, little has been known about the target insect $PLA_2$ of these bacterial metabolites. Eight bacterial metabolites identified in Xn culture broth exhibited significant insecticidal activities against larvae of both lepidopteran species of Plutella xylostella and Spodoptera exigua. Moreover, these bacterial metabolites significantly enhanced insecticidal activities of Bacillus thuringiensis (Bt). To determine target $PLA_2$, we cloned and over-expressed cellular $PLA_2$ ($SecPLA_2$) of S. exigua. Purified $SecPLA_2$ catalyzed phospholipids derived from the fat body and released several polyunsaturated fatty acids. Most Xn metabolites significantly inhibited $SecPLA_2$ activity, but were different in their inhibitory activities. There was a positive correlation between the inhibition of $SecPLA_2$ and the enhancement of Bt insecticidal activity. These results indicate that $SecPLA_2$ is a molecular target inhibited by Xn metabolite.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.624-634
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• 1995

Tides at both of northern and southern entrances of Kamag Bay were compared by deploying tide gauges for 18 days during July-August 1994. To examine the response of the inner bay to the tidal waves through both entrances, a current meter was moored at the eastern pan of the inner bay. Current meter mooring failed at the northern entrance (Yosu) while the current data was collected for only 5 days at the southern site (Songdo). Maximum range was 357 and 352 cm at Yosu and Songdo, respectively. Respective amplitudes for M2, S2 Kl O1 tides of 95.5, 48.8, 20.5, 14.0cm at Yosu and 93.6, 47.2, 21.3, 13.1cm at Songdo yielded the form numbers of 0.23 and 0.24, respectively, both of which belong to the predominantly semidiurnal tide, Contributions from the overtides and compound tides were less than $4\%^ at both sites. Differences in Greenwich phase of major partial tides between two sites were negligible. Maximum speed of tidal current was about 100cm/sec at the southern entrance and about 40cm/sec at the inner bay. Residual current speed was 17cm/sec southwestward at the southern entrance and 0.9cm/sec southeastward at the inner bay. Temporal change in current at the inner bay showed that the wind had a significant influence upon the circulation in Kamag Bay.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.271-284
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• 2004

The purpose of this study was to analyse the EMG activity of selected muscles with balance taping treatment and blood fatigue makers which accumulated during exercise of progressive maximal intensity. Ten male college students who did not experience any cardiovascular and musculo-skeletal disease were participated in this study. Balance taping were applied to rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinous, semimembranous, and around knee joint. Isokinetic knee joint flexion/extension force, EMG activity, lactate and ammonia as blood fatigue makers during progressive maximal intensity exercise were measured for with/without applying balance taping. The results indicated that although flexion force of total work at $60^{\circ}/sec$ with taping was increased applied taping did not affect to the aerobic exercise ability parameters. Lactate level as blood fatigue makers during progressive maximal intensity exercise after taping was decreased but the ammonia level did not change with same treatment. In isokinetic knee joint test at the angular velocity of $60^{\circ}/sec$, $180^{\circ}/sec$, and $240^{\circ}/sec$ the taping treatment did not affect to any selected muscle EMG activities except maximal EMG of vastus lateralis at $240^{\circ}/sec$.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.3
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• pp.157-164
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• 2009

Purpose：The purpose of this study was to investigate the effects of angular velocity on muscle strength of biceps brachii. Methods：Subjects was classified into two groups, which were $60^{\circ}/sec$ angular velocity group(n=15) and $240^{\circ}/sec$ angular velocity group(n=15). Each group was applied to perform the isokinetic exercises on flexion muscle group for each 10 times in 3 set(3 days per a week for 2 weeks). Muscle strength was measured using peak torque of biceps brachii. Results：The results were as follows: The peak torque was significantly increased after $60^{\circ}/sec$ angular velocity isokinetic exercise application(p<.05), however, it was not significantly after $240^{\circ}/sec$ angular velocity isokinetic exercise application(p>.05). Conclusions：This study showed that $60^{\circ}/sec$ angular velocity isokinetic exercise application were effective treatment strategy on increase of muscle strength. Therefore, it could be considered as a treatment method in the athlete and patients with musculoskeletal disease.

• Journal of Korean Physical Therapy Science
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• v.6 no.4
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• pp.167-171
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• 1999

Objective: To investigate muscle strength after short term isotonic and isometric exercise. Method: Twenty two healthy men and women were randomly designed isometric and isotonic exercises. Each participant was asked to perform 10 sessions of isometric and isotonic exercises. The assessment measured pre and post 10 sessions exercises by Cybex 340. Result: Isometric exercise significantly increased by $60^{\circ}$/sec and isotonic exercise significantly increased by $120^{\circ}$/sec, $180^{\circ}$/sec. Isometric exercise and isotonic exercise increased by all speeds. Most increased at $120^{\circ}$/sec, $180^{\circ}$/sec by isometric exercise and $60^{\circ}$/see by isotonic exercise but not significantly. Conclusion: Short term isotonic and isometric exercise increase muscle strength. Even if the exercise session is short term, the sessions increase muscle strength.