• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.136-143
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• 2002

Emission of methane and nitrous oxide affected by nitrogen fertilizer materials were measured simultaneously in rice paddy fields under flooding and intermittent irrigation in 2000. Studies focused on mitigating $CH_4$ emission from rice paddy fields are summarized and the possibilities and limits applied to world's rice cultivation are discussed. The mitigation options are water management, soil amendments, organic matter management, different tillage, rotation, and cultivar selection. Altering water management, in particular promoting midseason aeration by short-term drainage, is one of the most promising strategies, although these practices may be limited to the rice paddy fields where the irrigation system is well prepared. The test site was divided into two water managements: a continuously flooded plot which was maintained flooded by constant irrigation from May to September, and an intermittently drained plot in which short-term (20days) draining practices were performed one times during the flooding period. By total emission of GHGs converted by global warming potential (GWP), flooding plots were higher 170$\sim$208% than interimittent irrigation plots. For emission of GHGs in fertilizer materials, it was high in the order of Swine slurry>Urea+Rice straw>Urea>LCU. Basing on GHGs emission of urea fertilization under flooding as baseline GWP of urea fertilization and Latex-coated urea under intermittent irrigation showed lower GHGs emission by 41.4% and 55.8 respectively. In this case fertilizer use efficiency (kg unhulled rice/ of applied N) were 18.2$\sim$20.2 and 18.7$\sim$19.0 and 9.3 and 5.8$\sim$6.6 for Swine slurry and LCU and Urea+Rice straw and Urea in the continuously flooded and intermittently drained plot.

• Economic and Environmental Geology
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• v.34 no.6
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• pp.555-571
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• 2001

The dynamic evolution of the Chugaryeong fault valley is studied by paleomagnetic works on 163 samples at 16 sites from Late Cretaceous and Quaternary volcanic rocks in the valley. Conglomerate test and stepwised thermal/alternating field demagnetization indicate that all the characteristic directions are of primary origin. Paleomagnetic pole ponsition(216.8$^{\circ}$E/7l .6$^{\circ}$N; dp=7.1$^{\circ}$, dm=10.0$^{\circ}$) for the upper par of the Jijangbong Volcanic Complex Is indistinguishable from the coeval retference pole position from the Gyeongsang Basin, which further substanciates the reliability of the Paleomagnetic data. This indicates the study area has not undergone any tectonic rotation since Late Cretaceous by uy significant reactivation of the Chugaryeong fault valley. The Quaternary pole position (134.2$^{\circ}$E/86.5$^{\circ}$N; $A_{95}$=7.1 $^{\circ}$) from the Jeongog Basalt reflects the present geocentric axial dipole field for the area, supporting the above conclusion. Unlike the upper part, paleomasnelic directions of the lower part of the Jijangbong Volcanic Complex show random distrinution between sites. We interpret that the early stage of the volcanic activity was created by sinistral strike slip motion of the Chugaryeong fault during early Late Cretaceous. The creation and evolution of the Chugaryeong fault valley emphasize the significance of the kinematic FR (folding ruler) model in east Asia.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.10-21
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• 2014

The joint of prefabricated steel grid composite deck is composed of concrete shear key and high-tension bolts. The flexural and shear strength of the joint were experimentally evaluated only by the bending and push-out test of the joint element. In this study the lateral load transfer behavior of the joint in deck structure system is experimentally evaluated. Several decks connected by the joint are prefabricated and loaded centrically and eccentrically. In the case of centrically loaded specimens, the analysis results show that for the same loading step the rotation angle of the joint with 4 high-tension bolts is larger than the case of the joint with 9 high-tension bolts. Consequently, flexural stiffness of deck and lateral load transfer decrease in the case of specimen with 4 high-tension bolts. But, in the case of eccentrically loaded specimens, it is found that there are no significant differences in the load transfer behavior. The further analysis results about the structural behavior of the joint show that lateral load transfer can be restricted by the load bearing capacity of the joint as well as punching shear strength of the slab. Furthermore, considering that high-tension bolts in the joint didn't reach to the yielding condition until the punching shear failure, increase in the number of high-tension bolts from 4 to 9 has a greater effect on the flexural stiffness of the joint and deck system than the strength of them.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.57-66
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• 2012

The purpose of this study was to evaluate the relation between intentionally induced internal stress and cyclic fatigue failure of ProTaper Universal. ProTaper Universal (Dentsply Maillefer) S1, S2, F1, F2, F3, F4 and F5 (25 mm length) were used in this study. To give the internal stress, the ProTaper Universal were put into the .02 taper Endo-Training-Bloc (Dentsply Maillefer) until auto-stop by torque controlled motor. The rotation speed was 300 rpm and torque value was 1.0 Ncm. ProTaper Universal were grouped by the induced number of internal stress and randomly distributed among one control group and three experimental groups (n=10). The four groups were Stress 0 (control), Stress 1, Stress 2 and Stress 3. These instruments were rotated until separation. For cyclic fatigue measurement, inclined plane was used and time for separation was recorded. It was statistically analyzed using two-way ANOVA and Duncan post-hoc test at 95% confidential level. In all ProTaper Universal, there was statistically significant decrease on time for separation in Stress 3. In F2 and F3, there were statistically significant difference between control group and all experimental groups. And in F4 and F5, Stress 2 and 3 groups showed significantly lower cyclic fatigue resistance from Stress 0 group. In the limitation of this study, cyclic fatigue failure of ProTaper Universal is influenced by accumulated internal stress.

• The Journal of the Acoustical Society of Korea
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• v.21 no.5
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• pp.471-477
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• 2002

Recently, lip-reading has been studied actively as an auxiliary method of automatic speech recognition(ASR) in noisy environments. However, almost of research results were obtained based on the database constructed in indoor condition. So, we dont know how developed lip-reading algorithms are robust to dynamic variation of image. Currently we have developed a lip-reading system based on image-transform based algorithm. This system recognize 22 words and this word recognizer achieves word recognition of up to 53.54%. In this paper we present how stable the lip-reading system is in environmental variance and what the main variant factors are about dropping off in word-recognition performance. For studying lip-reading robustness we consider spatial valiance (translation, rotation, scaling) and illumination variance. Two kinds of test data are used. One Is the simulated lip image database and the other is real dynamic database captured in car environment. As a result of our experiment, we show that the spatial variance is one of degradations factors of lip reading performance. But the most important factor of degradation is not the spatial variance. The illumination variances make severe reduction of recognition rates as much as 70%. In conclusion, robust lip reading algorithms against illumination variances should be developed for using lip reading as a complementary method of ASR.

• Korean Journal of Environment and Ecology
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• v.6 no.1
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• pp.72-85
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• 1992

The analysis of visitor's behavior in Hallasan National Park was executed for a month in september, 1990. In the characteristics of trip purpose, the nature-oriented motive was 68.9% of the total. And in the characteristics of the accompanied, the ratio of such items as company, friends,2-3 persons and above 12 persons was generally high. The ratio of lunch box was 62.7％ and the item of bring back waste treatment was 69.6% in the characteristic of activity. The degree of landscape satisfaction was 3.98 and comparatively high on considering the maximum degree of 5.0, but in the degree of facility, the degree of dissatisfaction was high. Therefore the degree of total satisfaction was 3.43. In the opinion of users, the entrance by order of arrival, the adoption of reserved system and the limitation of the entrance of a group were gen- orally objected but the adoptation of nature rest-rotation system was comparatively assented Specially, visitor center was rarely used but many visitor who has attended there positively think about it. In factor analysis, 4 factors were extracted. Facilitate, social. user behavior and natural property were the most affecting factor to psychological satisfaction test. Multiple regression results showed that cleanness, land-scape, safety, no. of wastebasket and crowdness items affected the total satisfaction variable in total and local area.

• Journal of Acupuncture Research
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• v.23 no.5
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• pp.23-29
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• 2006

Objectives : The present study was conducted to evaluate the effects of automatically controlled rotating acupuncture (ACRA) on thermal allodynia in neuropathic pain rats, and to examine whether the endogenous opioid system mediates the effects of ACRA. Methods : For the neuropathic surgery, the right superior caudal trunk was resected at the level between S1 and S2 spinal nerves innervating the tail. Two weeks after the nerve injury, ACRA stimulation with 4 different stimulation conditions (i.e., angle and frequency of rotation: 90o+1Hz, 90o+1/4Hz, 360o+/1Hz, and 360o+1/4Hz) was delivered to the Zusanli (ST36) acupoint for 15 min. The behavioral signs of thermal allodynia were evaluated by the tail immersion test (i.e., immersing the tail in cold $(4^{\circ}C)$ or warm $(4^{\circ}C)$ water and measuring the latency to an abrupt tail movement) before and after the stimulation. In an additional set of experiments, we examined the effects of naloxone (opioid Results : ACRA stimulations under all of the conditions above significantly relieved thermal antagonist, 2mg/kg, i.p.) on the action of ACRA stimulation. allodynia. There is no difference in the anti-allodynic effects among the 4 stimulation conditions. In addition, the effect of ACRA on thermal allodynia was reversed by naloxone pretreatment. Conclusion : These results indicate that ACRA stimulations have relieving effects on thermal allodynia in neuropathic pain rats, irrespective of stimulation parameters, and that this is mediated by the endogenous opioid system.

• Journal of the Korea Concrete Institute
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• v.13 no.3
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• pp.251-260
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• 2001

It is required to evaluate the axial strain of reinforced concrete beams in order to predict the ductility of reinforced concrete beams subjected to reversed cyclic loading. A model was proposed to determine the axial strains In reinforced concrete beams by analysing the behavior of reinforced concrete sections and comparing with published test results. The proposed axial strain model inclusively reflected four kinds of paths : Path 1-steel bar in an elastic stage or a unloading region; Path 2-after flexural yielding; Path 3-a slip region; and Path 4-a reversing loading region. The equations to predict the axial strains of each path were proposed. The proposed equations took into account the effects of the loading program. Comparison of axial strains between experimental results and the results from proposed equations showed to be in a good agreement with experimental results.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.357-364
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• 2002

The resistance curves (R-curves) for 381 m crack extension of CLWL-DCB specimens had been determined. The average velocities of the crack extension measured with strain gages were 0.70 and 55 ㎜/sec. The measured rotation angle of the notch faces showed the existence of the singularity at least before 171 and 93 mm crack extensions for the 0.70 and 55 ㎜/sec crack velocities, respectively. The maximum slopes of the R-curves occurred between 25 and 89 ㎜ crack extensions for 0.70 ㎜/sec crack velocity and between 51 and 127 ㎜ crack extensions for 55 ㎜/sec crack velocity During the maximum slopes of the R-curves, the micro-crack localization can be expected, and faster crack velocity may form longer micro-cracking and micro-crack localizing zones. The fracture resistance of 0.70 ㎜/sec crack velocity reached a roughly constant maximum value of 143 N/m at 152 ㎜ crack extension, while that of 55 ㎜/sec crack velocity increased continuously to 245 N/m at 254 ㎜ crack extension and then decreased to the value of 0.70 ㎜/sec crack velocity. The R-curve of 55 ㎜/sec crack velocity was similar to that of the small size three-point bend test, and it showed that small size specimen or fast crack velocity could cause more brittle behavior.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.177-189
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• 2004

The backfilled space carl have various shapes such as vertical or lateral symmetric, unsymmetric slope depending on field conditions. Kellogg (1993) suggested the different equations for the backfill earth pressure and the lateral stress ratio considering that the stresses are different between the symmetrically sloped backfilled space and the vertical one. Kellogg (1993) assumed the stress generated on sloped wall surface as the simple internal friction angle of backfilled soil. However, Moon (1997) suggested modified Kellogg equation assuming that stress behavior in the sloped wall will be varied according to the rotation angle of principal stress and the friction of sloped wall surface. This study has compared and investigated the horizontal stresss of unsymmetrical backfilled space numerically and experimentally obtained when Kellogg lateral stress ratio is appled to and when average lateral stress ratio considering unsymmetric backfill slop of left and right are applied to the modified Kellogg equation. It is shown that the horizontal stress on the sloped wall has good match numerically and experimentally in the modified Kellogg equation when Kellogg's lateral stress ratio in symmetric condition is applied to the unsymmetric condition. But the horizontal stress on the vertical wall shows disagreement numerically and experimentally. The horizontal stress results in good agreement numerically and experimentally when the average lateral stress ratio of left and right at unsymmetric slop as applied to the modified Kellogg equation. Therefore, it is estimated that the application of the average lateral stress ratio to the left and right wall should be considered when backfilled space formed unsymmetric conditions.