• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.773-782
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• 2002

In this study, a series of fatigue tests are performed in order to estimate quantitatively the characteristics of fatigue crack growth rate according to the base metal, heat affected zone(HAZ) and weld metal, and the welding method and grade of strength of object steels, and the influence on fatigue crack growth rate according to the direction of welded line for high strength steels of SM570, POSTEN60, and POSTEN80 steels. From the fatigue test results, the retardations of fatigue crack growth rate are remarkable in case that the direction of notch is parallel to welded line than in case that the direction of notch is perpendicular to welded line because of compresive residual stress in weld metal & HAZ. And the characteristics of fatigue crack growth rate according to welding method are that the dispersion of fatigue crack growth rate in case of FCAW method is smaller than that of SAW method. Also, it knows that the fatigue crack growth rate converges in high stress intensity factor range. Meanwhile, fatigue safety is guaranteed sufficiently in the object steels because the fatigue crack growth rate in the range of fatigue crack propagation has a similar tendency to the test results & existing results.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.2
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• pp.99-108
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• 2014

One year long time-series current data were obtained at two stations (K1 and K2) located in the Usan Trough in the area north of Ulleungdo in the East Sea from September 2006. The observed data reveal enhanced seafloor flows in both stations with variabilities of about 20 days which is possibly governed by the topographic Rossby wave. After February 2007, strong flow in the upper layer in St. K1 appears throughout the mooring period and this is due to the passage of the warm eddy comparing with satellite sea surface temperature data. During this period, no significant correlation between the current in the upper layer and those in two deep layers is shown indicating the eddy does not affect flows in the deep ocean. It is also observed that the flow direction rotates clockwise with depth in both stations except for the upper of the K1. This implies that the deep flow does not parallel to the isobaths exactly and it has a downwelling velocity component. The possibility of the flow from the Japan Basin to the Ulleung Basin across the Usan Trough is not evidenced from the data.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.95-100
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• 2006

The COMS(Communication, Ocean and Meteorological Satellite) EPS(Electrical Power Subsystem) is derived from an enhanced Eurostar 3000 version. Eurostar 3000 EpS is fully autonomous operation in nominal conditions or in the event of a failure and provides a high level of reconfigure capability. This paper introduces the COMS EPS preliminary design result. COMS EPS consists of a battery, a solar arrat wing, a PSR(Power Supply Regulator), a PRU(Pyrotechnic Unit), a SDAM(Solar Array Drive Mechanism) and relay and fuse brackets. COMS EPS can offer a bus power capability of 3 kW. The solar array is made of a deployable wing with two panels. One type fo solar cells is selected ad GaAs/Ge triple junction cells. Li-ion battery is base lined with ten series cell module of five cells in parallel. PSR associated to battery and solar array wing generates a power bus fully regulated at 50 V. Power bus os centralized protection and distribution by relay and fuse brackets. PRU provides power for firing actuarors devices. The solar array wing is rotated by the SADM under control of the attitude orbit control subsystem. The control and monitoring of the EPS, especially of the battery, is performed by the PSR in combination with the on-board software.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8665-8670
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• 2016

Background and Aims: Hepatitis B virus (HBV) reactivation was reported to be induced by transcatheter arterial chemoembolization (TACE) in HBV-related hepatocellular carcinonma (HCC) patients with a high incidence. The effective strategy to reduce hepatitis flares due to HBV reactivation in this specific group of patients was limited to lamivudine. This retrospective study was aimed to investigate the efficacy of prophylactic entecavir in HCC patients receiving TACE. Methods: A consecutive series of 191 HBV-related HCC patients receiving TACE were analyzed including 44 patients received prophylactic entecavir. Virologic events, defined as an increase in serum HBV DNA level to more than 1 log10 copies/ml higher than nadir the level, and hepatitis flares due to HBV reactivation were the main endpoints. Results: Patients with or without prophylactic were similar in host factors and the majorities of characteristics regarding to tumor factors, HBV status, liver function and LMR. Notably, cycles of TACE were parallel between the groups. Ten (22.7%) patients receiving prophylactic entecavir reached virologic response. The patients receiving prophylactic entecavir presented significantly reduced virologic events (6.8% vs 54.4%, p=0.000) and hepatitis flares due to HBV reactivation (0.0% vs 11.6%, p=0.039) compared with patients without prophylaxis. Kaplan-Meier analysis illustrated that the patients in the entecavir group presented significantly improved virologic events free survival (p=0.000) and hepatitis flare free survival (p=0.017). Female and Eastern Cooperative Oncology Group (ECOG) performance status 2 was the only significant predictors for virological events in patients without prophylactic antiviral. Rescue antiviral therapy did not reduce the incidence of hepatitis flares due to HBV reactivation. Conclusion: Prophylactic entecavir presented promising efficacy in HBV-related cancer patients receiving TACE. Lower performance status and female gender might be the predictors for HBV reactivation in these patients.

• Journal of Korean Elementary Science Education
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• v.23 no.4
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• pp.344-356
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• 2004

In this study, we developed the program for 'Discretionary Activity' focusing on the multiple activities with everyday-life materials to enhance scientific creativity (MAEM-SC), which was specifically for students in the 6-7th grade according to the 7th curriculum in Korea. As important factors for scientific creativity, we selected the ability to find out the context relevant to scientific problems, the ability to connect the problem context to scientific knowledge, the ability to invent the ways to solve the problem scientifically, and ability to concentrate on the scientific problem solving activity. The topics of the program were drawn from common and familiar things in our everyday contexts, such as human body, everyday tools, food, play and toys, and everyday episodes. The multiple activities here mean the activities which are systematically constructed with the various types of activities with a specific intention. The multiple activities were designed in three types, that is, series type, parallel type, and combination type. Each of them consists of the several activities as follows: estimating and measuring, carrying out an experiment using body, inventing implement (tools), thinking statistically, writing creatively with scientific themes, and connecting one concept to another concept etc. Through a trial of the program, we found that this program has some positive influence on the enhancement both of the ability to find out the context relevant to scientific problems and the ability to connect it to the students' existing scientific knowledge.

• Journal of Acupuncture Research
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• v.23 no.6
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• pp.239-254
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• 2006

The 3rd Japan-Korea Workshop on Acupuncture and EBM was held at Kanazawa on June $16^{th}$. From Korea team, 4 papers were presented. Dr. Hahn introduced a new approach of data analysis on series of n-of-1 trials using the Bayesian statistics. It offered important information for the future n-of-1 trials. Dr. Park clearly demonstrated the significance of various sham devices proposed and stressed the importance of research questions when we choose the control intervention in RCT. Dr. Lee reported the results of survey in Korean Medical Doctors (KMD) for their point selection and techniques to the distal and local points. Dr. Kim presented the results of face to face survey on the KMD with 28 items for acupuncture treatment on the knee OA. Finally, a draft of protocol was introduced by Dr. Kim. The title was "multi-center, a randomized, single blinded, two arms, parallel-group study to compare the effectiveness and safety of 'individualized acupuncture' and 'standardized minimal acupuncture' in Korean and Japanese patients with knee osteoarthritis (Phase IV)". From Japan team, 7 speakers presented their comments and proposals on the protocol. Dr. Takahashi introduced several issues regarding n-of-1 trials and pointed out the importance of obtaining generalizability from n-of-1 trials. Dr. Shichidou pointed the importance of research design, selection of outcome measures and reduction of biases. Dr. Itoh presented the results of point selection for the knee OA based on the literature survey. Dr. Sumiya introduced several differences between KMD and Japanese acupuncturists based on the questionnaire used in KMD survey. Dr. Furuya demonstrated a result of press tack needle and its sham device on shoulder stiffness. Dr. Yamashita introduced the results of literature survey regarding adverse events occurred by acupuncture on knee OA. Dr.Tsukayama stressed the importance of responsibility of Institutional Review Board (IRB) for the conduction of clinical trials. After several issues were discussed, the need of continued meeting for final protocol development was agreed, then the workshop was closed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.51-59
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• 1993

This paper develops practical and realistic reliability models and methods for the evaluation of system-reliability and system reliability-based rating of various types of box-girder bridge superstructures. The strength limit state model for box-girder bridges suggested in the paper are based on not only the basic flexural strength but also the strength interaction equations which simultaneously take into account flexure, shear and torsion. And the system reliability problem of box-girder superstructure is formulated as parallel-series models obtained from the FMA(Failure Mode Approach) based on major failure mechanisms or critical failure states of each girder. In the paper, an improved IST(Importance Sampling Technique) simulation algorithm is used for the system reliability analysis of the proposed models. This paper proposes a practical but rational approach for the evaluation of capacity rating in terms of the equivalent system-capacity rating corresponding to the estimated system-reliability index which is derived based on the concept of the equivalent FOSM(First Order Second Moment) form of system reliability index. The results of the reliability evaluation and rating of existing bridges indicate that the reserved reliability and capacity rating at system level are significantly different from those of element reliability or conventional methods especially in the case of highly redundant box-girder bridges.

• Korean Journal of Plant Taxonomy
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• v.43 no.4
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• pp.312-318
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• 2013

Morphological characters of aggregated achenes, and achene and its epidermal microstructures were observed for 7 taxa belonging to the section Adonanthe of subgenus Adonanthe [A. amurensis Regel et Radde, A. bobroviana Sim., A. davidii Franch., A. multiflora Nishikawa et Ko. Ito, A. pseudoamurensis W. T. Wang, A. ramosa Franch. and A. tianschanica (Adolf) Lipsch. ex Bobrov] and for 1 taxon belonging to the section Lophocarpa of subgenus Adonis (A. aestivalis var. parviflora M. Bieb.). The morphological characters such as shape of aggregated achenes, length of aggregated achenes, shape of achene, and recurved type of persistent style were useful in the classification of the subgenera Adonanthe and Adonis, and each species of the series under section Adonanthe. Epidermal microstructures of achene were grouped into three types according to the presence of microwrinkles and their arranged patterns. These microwrinkles were absent in A. amurensis, were of parallel type in A. bobroviana, A. pseudoamurensis, A. ramosa, and A. aestivalis var. parviflora, and were of parallelperpendicular mixed type in A. davidii, A. multiflora, and A. tianschanica. Also, a new key to them was made using morphological characters of their aggregated achenes and achene.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1375-1382
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• 2008

Frequency adjustable D-CRLH(dual-composite right/left handed) transmission lines, which solve the problem of design complexity and uncontrolled frequency of the existing structures, are proposed in this paper. The first design(type I), consisting of defected ground structure(DGS), island pattern in DGS, fixed stub and varactor diodes, controls $C_L$ in the parallel resonant circuit, while the second structure(type 2) composed of fixed DGS, shunt stub and diode adjusts $C_R$ in the series resonant circuit. The dual band frequency points which correspond to the meaningful electrical length of +/-90 degree in the RH/LH region are adjustable according to the bias voltage. The measurement shows that the LH frequency point which has -90 degree of electrical length are adjusted over $4.22{\sim}5.39\;GHz$ and $4.21{\sim}5.05\;GHz$ for type 1 and type 2, respectively, under $1{\sim}12\;V$ of bias voltage. In addition, the frequency Woo where RH turns over LH is controled over $3.26{\sim}4.22\;GHz$ for type 2 with the same bias condition.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.683-693
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• 2011

In this paper, a design of high current and broad-band microwave bias-tee was presented for a stable bias of a high power amplifier. An input impedance of bias-tee should be shown to 50 ohm with the wideband in order to be stably-biased the amplifier. For this design of the bias-tee, a capacitor of bias-tee for a DC block was designed with a high wide-band admittance by a parallel sum of capacitors, and a inductor for a RF choke and a DC feeding was designed with a high wide-band impedance by a series sum of inductors. As this inductor and capacitor for the sum has each SRF, band-limitation of lumped element was driven from SRF. This limitation was overcome by control of a resonance's quality factor with adding a resistor. 1608 SMD chips for design's element was mounted on the this pattern for the designed bias-tee. The fabricated bias-tee presented 10 dB of return loss and wide-band about 50 ohm input impedance at 10 MHz~10 GHz.