• Journal of the Korean Society for Railway
• /
• v.14 no.6
• /
• pp.545-554
• /
• 2011

In order to get dynamic serviceability of a train travelling on a railway bridge, comfort limits with the deflection of bridge and vertical acceleration on car body are proposed in Eurocode, Shinkansen design criteria, The design guideline of the Honam High-speed railway. The design guideline of the Honam High-speed railway has quoted Eurocode. Therefore it is expected that supplementation of comfort limit of railway bridge according to expansion of span length and the improvement traveling speed of trains in the future would relatively fall behind developed countries in railway. Therefore, in order to secure technological competitiveness in world market, the study was conducted to propose the deflection limit based on vibration serviceability of railway bridges that can consider bridge-train interaction and travelling speed increase. The parameter study and bridge-train dynamic interaction analysis was conducted to figure out the correlation of vertical acceleration on car body and bridge displacement according to the increase in travelling speed. Also, the trend of increasing vertical acceleration on car body according to the increase in travelling speed was confirmed, and the amplification coefficient of vertical acceleration on car body was suggested. And the deflection form and vibration of the bridge were assumed to be in harmonic motion, and transfer function and the amplification coefficient were used to develop the dynamic serviceability deflection limit of the high-speed railway bridge as a formula.

• The Journal of the Petrological Society of Korea
• /
• v.26 no.4
• /
• pp.385-398
• /
• 2017

Jiri Mountain lies in the southwestern portion of the Yeongnam massif, which is one of the Precambrian basement massifs of the Korean Peninsular, consisting essentially of high-grade metamorphic rocks. The geology of the area mainly consists of Paleoproterozoic metasedimentary migmatitic gneisses, granitic gneisses which are classified into granitic gneiss, (K-feldspar porphyroblastic) granitic gneiss and quartzo-feldspathic gneiss, charnockite and anorthosite based on their occurrence and petrographic characteristics. The ages obtained from these rocks mainly span a narrow range between ca. 1,876 and 1,856 Ma although inherited cores of zircons from massive granite gneiss yielded much older age spectrum (>2,029 Ma). The age of major metamorphism is ca. 1850-1840 Ma and the metamorphic condition obtained from mineral assemblages and geothermobarometers is about 4-6 kb and up to $700-750^{\circ}C$. These results indicate that in the area intense granitic magmatism and metamorphism occurred in the deep crust during Paleoproterozoic orogeny. Some younger age of charnockite (1,856-1,865 Ma) and anorthosite (1,861-1,862 Ma) might indicate the beginning of intraplate rifting leading to felsic and mafic magmatism just after the orogeny. In conclusion, the rocks in the Jiri Mountain area which formed at a mid to deep crustal zone provide us windows into the deep crust.

• Archives of Pharmacal Research
• /
• v.21 no.5
• /
• pp.581-590
• /
• 1998

We developed a novel water-soluble camptothecin analobue, CKD602, and evaluated the inhibition of topoisomerase I and the antitumor activities against mammalian tumor cells and human tumor xenografts. CKD602 was a nanomolar inhibitor of the topoisomerase I enzyme in the cleavable complex assay. CKD602 was found to be 3 times and slightly more potent than topotecan and camptothecin as inhibitors of topoisomerase, respecitively. In tumor cell cytotoxicity, CKD602 was more potent than topotecan in 14 out of 26 human cancer cell lines tested, while it was comparable to camptothecin. CKD602 was tested for the in vivo antitumor activity against the human tumor xenograft models. CKD602 was able to imduce regression of established HT-29, WIDR and CX-1 colon tumors, LX-1 lung tumor, MX-1 breast tumor and SKOV-3 ovarian tumor as much as 80, 94, 76, 67, 87% and 88%, respectively, with comparable body weight changes to those of topotecan. Also the therapeutic margin (R/Emax: maximum tolerance dose/$ED-{58}$) of CKD602 was significantly higher than that of topotecan by 4 times. Efficacy was determined at the maximal tolerated dose levels using schedule dependent i.p. administration in mice bearing L1210 leukemia. On a Q4dx4 (every 4 day for 4 doses) schedule, the maximum tolerated dose (MTD) was 25 mg/kg per administration, which caused great weight loss and lethality in <5% tumor bearing mouse. this schedule brought significant increase in life span (ILS), 212%, with 33% of long-term survivals. The ex vivo antitumor activity of CKD602 was compared with that of topotecan and the mean antitumor index (ATI) values recorded for CKD602 were significantly higher than that noted for topotecan. From these results, CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I.

• Korean journal of applied entomology
• /
• v.50 no.4
• /
• pp.257-265
• /
• 2011

To investigate host preferencse of Myzus persicae on 15 sweet pepper cultivars grown in Jeonnam Province, EPG (electrical penetration graph) and life table experiments were carried out in the laboratory. Phloem phase times were significantly longer on Ferrari, Jinju, Debla, and Rapido than Orobell and Thialf. Non-penetration times were conversely observed. Life span, reproduction period, total fecundity, and intrinsic rate of increase ($r_m$) of M. persicae, were higher on Ferrari, Debla, Orange glory, and Jinju than on Purple, GreenAce, Orobell, and Thialf. On the bases of these results, we conclude that M. persicae preferred Ferrari, Jinju, Orange glory, and Debla among the 15 tested sweet pepper varieties. However, we could not show the preference of the aphid for Purple, Orobell, and Thialf.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.22 no.4
• /
• pp.253-261
• /
• 2011

Objectives : This study aimed to investigate the efficacy and safety of Metadate CD (MCD) when given to Korean children and adolescents with attention-deficit hyperactivity disorder (ADHD). We also explored the effects of the drug on diverse neuro-cognitive functions. Methods : Ninety-one subjects with ADHD (mean age 8.6${\pm}$2.2 years) were recruited at 6 outpatient clinics in Seoul, Korea. We used the ADHD Rating Scale (ARS), Clinical Global Impression (CGI), and comprehensive attention test (CAT) to measure the drug's effects. Results : After 0.92${\pm}$0.32mg/kg/day of MCD were administered for 57.4${\pm}$7.6 days, there was a 48.5% reduction in the mean total ARS scores (p<.001). Fifty-seven subjects (64.8%) showed either much improved or very much improved outcomes on the CGI-Improvement scale. The CGI-Severity scale also decreased from an average of 4.7 to an average of 2.9 (p<.001). Errors and response time standard deviations of the CAT, sustained attention test-to-response tasks, the flanker test, and divided attention test scores decreased after treatment (p<.05). The forward memory span of the spatial working memory test scores increased (p<.05). Thirty-five patients (39.8%) experienced side effects, of which the most common were headache (14.8%), nausea (12.5%), and anorexia (9.1%). Conclusion : This open-label study suggests that MCD is effective and safe in improving the symptoms and neurocognitive functions of Korean children and adolescents with ADHD.

• Sleep Medicine and Psychophysiology
• /
• v.6 no.2
• /
• pp.143-148
• /
• 1999

Objectives: We studied correlations between neuropsychological tests and perceptual disorder in patients with head trauma and psychiatric patients in order to explore the functional localization of brain in perceptual disorders. Methods: Halstead Reitan Neuropsychological Test Battery, Korean Wechsler Intelligent Scale, and Minnesota Multiphasic Peronality Inventory(MMPI) were administered to one hundred ninteen patients consisting of sixty nine psychiatric patients and fifty patients with brain damage. We tested the correlation between results of neuropsychological tests and peceptual disorder scale PDS) made from nine items related with perceptual disorder in MMPI. T-tests between twenty one higher scorers and seventeen lower scorers of PDS were also performed in the psychiatric group. Results: In brain damage group, significant correlations were found in tests related with function of frontal lobe such as category tests, trail making tests, tactual performance test, and fingertip number writing test, and significant correlations were also noted in the tests related with function of right hemisphere such as tactual performance test, performance, picture completion, picture arrangement and block design. Tests related with subcortical function such as digit symbol test, arithmetic and digit span were signigicantly correlated, too. In psychiatric group, there were significant differences of PDS in the tests related with function of right hemisphere such as picture completion, block design, and right laterality index, and in the tests related with function of left hemisphere such as comprehension, vocabulary, and similarities. Conclusion: Perceptual disorder seems to be related with functions of frontal lobe, right hemisphere, and subcortex in both groups. In a psychiatric group, left hemisphere may be also partially related with perceptual disorder.

• Journal of Korean Association for Spatial Structures
• /
• v.7 no.5
• /
• pp.75-82
• /
• 2007

The present work measured and analyzed changes in the acoustics of a sound field which has a retractable ceiling. An 1/20 scale model of an openable space was built and measurement was carried out by varying the opened area of a ceiling. The most widely used room acoustic and design parameters, RT, EDT, and D50 were investigated. The results suggest that the use of RT as an acoustic design parameter may not be proper in an openable space and further it is likely to mislead the initial acoustic design of such spaces. It is mainly due to the characteristics of RT in which non-exponential decay processes are linearly fitted. Early decay times were found to be decreased in proportion to increaing the ratio of opened area. D50, an index of speech intelligibility, was effectively shows the influence of openings on the acoustics. It is also found that EDT and D50 at the seats, not directly exposed to the opened part of a ceiling, were almost linearly decreased in proportion to the ratio of opened area, while little influence was found for the opening ratio larger than 40% at the directly exposed seats to the opened part of a ceiling.

• The Journal of Korean Academy of Prosthodontics
• /
• v.41 no.3
• /
• pp.288-299
• /
• 2003

Statement of problem: Many kinds of post and core systems are in the market, but there are no clear selection criteria for them. Purpose: The purpose of this study was to compare the flexural strength and modulus of elasticity of core materials, and measure the bending strength of post systems made of a variety of materials. Material and Methods: The flexural strength and elastic modulus of thirteen kinds core buildup materials were measured on beams of specimens of $2.0{\times}2.0{\times}24{\pm}0.1mm$. Ten specimens per group were fabricated and loaded on an lnstron testing machine at a crosshead speed of 0.25mm/min. A test span of 20 mm was used. The failure loads were recorded and flexural strength calculated with the measured dimensions. The elastic modulus was calculated from the slopes of the linear portions of the stress-stram graphs. Also nine kinds commercially available prefabricated posts made of various materials with similar nominal diameters, approximately 1.25mm, were loaded in a three-point bend test until plastic deformation or failure occurred. Ten posts per group were tested and the obtained data were anaylzed with analysis of variance and compared with the Tukey multiple comparison tests. Results: Clearfil Photo Core and Luxacore had flexural strengths approaching amalgam, but its modulus of elasticity was only about 15% of that of amalgam. The strengths of the glass ionomer and resin modified glass ionomer were very low. The heat pressed glass ceramic core had a high elastic modulus but a relatively low flexural strength approximating that of the lower strength composite resin core materials. The stainless steel, zirconia and carbon fiber post exhibited high bending strengths. The glass fiber posts displayed strengths that were approximately half of the higher strength posts. Conclusion: When moderate amounts of coronal tooth structure are to be replaced by a post and core on an anterior tooth, a prefabricated post and high strength, high elastic modulus core may be suitable. CLINICAL IMPLICATIONS In this study several newly introduced post and core systems demonstrated satisfactory physical properties. However when the higher stress situation exists with only a minimal ferrule extension remaining a cast post and core or zirconia post and pressed core are desirable.

• The Journal of Advanced Prosthodontics
• /
• v.5 no.1
• /
• pp.29-35
• /
• 2013

PURPOSE. To longitudinally assess the quality of life in maxillectomy patients rehabilitated with obturator prosthesis. MATERIALS AND METHODS. Thirty-six subjects were enrolled in the span of 16 months, out of which six were dropouts. Subjects (age group 20-60 years) with maxillary defects, irrespective of the cause, planned for definite obturator prosthesis, were recruited. The Hindi version of European Organization for Research and Treatment of Cancer, Head and Neck version 1 of Quality of Life Questionnaire was used before surgical intervention and one month after definitive obturator. Questionnaire includes 35 questions related to the patient's physical health, well being, psychological status, social relation and environmental conditions. The data were processed with statistical package for social science (SPSS). Probability level of P<.05 was considered statistically significant. RESULTS. The quality of life after rehabilitation with obturator prosthesis was 81.48% (${\pm}13.64$) on average. On item-level, maximum mean scores were obtained for items problem with teeth ($1.87{\pm}0.94$), pain in mouth ($1.80{\pm}0.92$), trouble in eating ($1.70{\pm}0.88$), trouble in talking to other people ($1.60{\pm}1.22$), problems in swallowing solid food ($1.57{\pm}1.22$) and bothering appearance ($1.53{\pm}1.04$); while minimum scores were obtained for the items coughing ($1.17{\pm}0.38$), hoarseness of voice ($1.17{\pm}0.53$), painful throat ($1.13{\pm}0.43$), trouble in having social contacts with friends ($1.10{\pm}0.40$) and trouble having physical contacts with family or friends ($1.10{\pm}0.31$). CONCLUSION. Obturator prosthesis is a highly positive and non-invasive approach to improve the quality of life of patients with maxillectomy defects.

• The Journal of the Acoustical Society of Korea
• /
• v.37 no.2
• /
• pp.99-109
• /
• 2018

The precision of the vibration-sensors, contact or non-contact types, is usually satisfactory for the practical measurement applications, but a sensor is confined to the measurement of a point or a direction. Although the precision and frequency span of the low-cost camera are inferior to these sensors, it has the merits in the cost and in the capability of simultaneous measurement of a large vibrating area. Furthermore, a camera can measure multi-degrees-of-freedom of a vibrating object simultaneously. In this study, the calibration method and the dynamic characteristics of the low-cost machine vision camera as a sensor are studied with a demonstrating example of the two-dimensional vibration of a cantilever beam. The planar image of the camera shot reveals two rectilinear and one rotational motion. The rectilinear vibration motion of a single point is first measured using a camera and the camera is experimentally calibrated by calculating error referencing the LDV (Laser Doppler Vibrometer) measurement. Then, by measuring the motion of multiple points at once, the rotational vibration motion and the whole vibration motion of the cantilever beam are measured. The whole vibration motion of the cantilever beam is analyzed both in time and frequency domain.