• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.137-142
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• 2016

When injecting intravenously of CT inspection, the effusion of the contrast meium can induce the tissue damage with the blood vessel outside. We detect extravasation which is generated in the course where we inject the contrast medium into the blood vessel. And we use the bolus tracking system for the detection of that. By using MPR and VR images, moreover we detected the extravasation in order to prevent the tissue damage. In order to detect the effusion of the contrast medium, we used 16-MDCT and 64-MDCT. Three dimensional images about the outflow of the blood vessel can provide the treatment information which is important in the patient treatment. Moreover we applied the image processing technique in order to improve sharpness between contrast media and organization. And sharpness and contrast was improved.

• Atmosphere
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• v.21 no.3
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• pp.229-241
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• 2011

The continuous urbanizations by a rapid economic growth and a steady increase in population are expected to have a possible impact on meteorology in the downwind region. Long-term (1972~2007) trends of precipitation have been examined in the mid-Korean peninsula for the westerly condition only, along with the sensitivity simulations for a golden day (11 February 2009). During the long-term period, both precipitation amount (PA) and frequency (PF) in the downwind region (Chuncheon, Wonju, Hongcheon) of urban area significantly increased for the westerly and light precipitation ($PA{\leq}1mm\;d^{-1}$) cases, whereas PA and PF in the mountainous region (Daegwallyeong) decreased. The enhancement ratio of PA and PF for the downwind region vs. urban region remarkably increased, which implies a possible urbanization effect on downwind precipitation. In addition, the WRF simulation applied for one golden day demonstrates enhanced updraft and its associated convergence in the downwind area (about 60 km), leading to an increase in the cloud mixing ratio. The sensitivity experiments with the change in surface roughness demonstrates a slight increase in cloud water mixing ratio but a negligible effect on precipitation in the upwind region, whereas those with the change in heat source represents the distinctive convergence and its associated updraft in the downwind region but a decrease in liquid water, which may be attributable to the evaporation of cloud droplet by atmospheric heating induced by an increase in an anthropogenic heat. In spite of limitations in the observation-based analysis and one-day simulation, the current result could provide an evidence of the effect of urbanization on the light precipitation in the downwind region.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.3
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• pp.157-164
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• 2016

The performance of convective heat transfer in rod bundle flow was experimentally evaluated using a twist-vane spacer grid. A $4{\times}4$ square-arrayed rod bundle was prepared as the test section, with a pitch-to-diameter ratio(P/D) of ~1.35. To check the convective heat transfer performance, the circumferential and longitudinal variations in rod-wall temperatures were measured downstream of the twist-vane spacer grid. In the circumferential measurements, the rod-wall temperature toward the twist-vane tip showed the lowest value, which might be due to the deflected water flow caused by the twist-vane. On the other hand, the wall temperature of the longitudinal measurements near the twist-vane spacer grid decreased dramatically, which implies that the convective heat transfer performance was enhanced. A heat transfer enhancement of ~35 % was achieved near downstream of the twist-vane spacer grid, as compared with the upstream value. Based on the present experimental data, a correlation for predicting the heat transfer performance of a twist-vane spacer grid was proposed.

• Journal of Electrical Engineering and Technology
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• v.5 no.3
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• pp.389-399
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• 2010

Available transfer capability (ATC) is a measure of the transfer capability remaining in a transmission system. Application of unified power flow controllers (UPFCs) could have positive impacts on the ATC of some paths while it might have a negative impact on the ATC of other paths. This paper presents an approach to evaluate the impacts of UPFCs on the ATC from a cost/worth point of view. The UPFC application worth is considered as the maximum cost saving in enhancing the ATC of the paths due to the UPFC implementation. The cost saving is considered as the cost of optimal application of other system reinforcement alternatives (except for UPFC) to reach the same ATC level obtained by UPFC application. UPFC application costs include the maximum cost of alleviating the probable negative impact on the ATC of some paths caused by implementing UPFCs. Optimal system reinforcement is used for systems with UPFCs to determine the aforementioned cost. The proposed method is applied to the IEEERTS and the results are evaluated through a sensitivity analysis. The cost/worth of UPFC application is also used to develop an index for optimal UPFC location and the results are compared with those of other indices. A comparison is finally made with the results obtained using an existing ATC allocation profit-based approach to determine UPFC application worth.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.3
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• pp.95-103
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• 1998

This paper deals with a problem occuring in recognition of tactile images due to the effects of imposed force at a me urement moment. Tactile image of a contact surface, used for recognition of the surface type, varies depending on the forces imposed so that a false recognition may result in. This paper fuzzifies two parameters of the contour of a tactile image with the membership function formed by considering the imposed force. Two fuzzifed paramenters are fused by the average Minkowski's dist; lnce. The proposed algorithm was implemented on the multisensor system cnmposed of an optical tact le sensor and a 6 axes forceltorque sensor. By the experiments, the proposed algorithm has shown average recognition ratio greater than 869% over all imposed force ranges and object models which is about 14% enhancement comparing to the case where only the contour information is used. The pro- ~oseda lgorithm can be used for end-effectors manipulating a deformable or fragile objects or for recognition of 3D objects by implementing on multi-fingered robot hand.

• Hwankyungkyoyuk
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• v.22 no.3
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• pp.15-30
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• 2009

This study focuses on the comparison of PBL and GBS. PBL is a famous model that emphasizes diversity of students and self directed learning within the theory of constructivism. GBS has not been studied that extensively. GBS is most similar to PBL but this model has not been actively applied to school education. This study focuses on how to enhance students' interest in an educational environment that is encompassing a new and changing teach-learn paradigm and the development of new technology. Furthermore, PBL and GBS methods were compare actively applied to "Environmental Education" to make the students learn self-directed education through the transformation of one's environmental awareness. Specifically, the models were applied to the "Ecology and Environment" subject taught in general high schools and the degree of 'environmental literacy' were measured, From March to May of 2007, the PBL and GBS models were applied to 3rd grade students at D high school and the subject was 'Ecology and Environment'. The students were divided according to age into groups of $5{\sim}7$. The PBL group attempted to solve the given problems and the GBS group carried out their missions. In conclusion, after analyzing the 'environmental literacy' survey results by SPSS 12.0, just 'Knowledge of Ecology (KEOC)' and 'Locus of Control (LOC)' were slightly significant in PBL. This shows that PBL enhances the students' problem solving ability and thinking power. This is a result of the enhancement of students' problem-solving and thinking abilities through PBL. Students can learn many things because they completed their projects based on their experience and knowledge, both individually and interpersonally. We have to study how to apply PBL and GBS to the education field in spite of the many limited conditions. Therefore, this study looks at the application of PBL and GBS in environmental education and suggests specific strategies for educators who want to apply GBS and PBL and adapt them into their education curricula.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.3
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• pp.301-306
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• 2010

In this paper, a SIT(Source Independent Tree) method for ray tracing is proposed to enhance the efficiency of tree construction with reuse of sub tree in urban environment, As the SIT method is applied, the decrease of the number of nodes for picocell and microcell simulations is 100 times. And 88~98 % of the total nodes are reused with change of location of signal source from an analysis of node reuse efficiency. Therefore the proposed SIT method is useful in performance enhancement of ray tracing, especially, for multiple antenna simulation like as MIMO system and cell planning.

• Progress in Superconductivity
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• v.14 no.1
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• pp.30-33
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• 2012

We have grown $MgB_2$ superconducting thin films on the SiC buffer layers by means of hybrid physical-chemical vapor deposition (HPCVD) technique. Prior to that, SiC was first deposited on $Al_2O_3$ substrates at various temperatures from room temperature to $600^{\circ}C$ by using the pulsed laser deposition (PLD) method in a vacuum atmosphere of ${\sim}10^{-6}$ Torr pressure. All samples showed a high transition temperature of ~40 K. The grain boundaries of $MgB_2$ samples with SiC layer are greater in amount, compare to that of the pure $MgB_2$ samples. $MgB_2$ with SiC buffer layer samples show interesting change in the critical current density ($J_c$) values. Generally, at both 5 K and 20 K measurements, at lower magnetic field, all $MgB_2$ films deposited on SiC buffer layers have low $J_c$ values, but when they reach higher magnetic fields of nearly 3.5 Tesla, $J_c$ values are enhanced. $MgB_2$ film with SiC grown at $600^{\circ}C$ has the highest $J_c$ enhancement at higher magnetic fields, while all SiC buffer layer samples exhibit higher $J_c$ values than that of the pure $MgB_2$ films. A change in the grain boundary morphologies of $MgB_2$ films due to SiC buffer layer seems to be responsible for $J_c$ enhancements at high magnetic fields.

• Archives of Pharmacal Research
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• v.22 no.3
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• pp.249-254
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• 1999

Enzymatic conversion of brain glycosylphosphatidylinositol-linked alkaline phosphatase (GPI-AP), amphiphilic, was examined. When GPI-AP was incubated with glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD), a negligible conversion of GPI-AP to hydrophilic form was observed. The inclusion of monoacylglycerols enhanced the enzymatic conversion, although the action of monoacylglycerols differed greatly according to the size of acyl group; the enzymatic conversion was enhanced considerably in the presence of monoacylglycerols possessing acyl group of longer chain length ($C_{10-}C_{18}$), which monoacylglycerols with acyl moiety of shorter length ($C_{4-}C_{8}$) did fail to augment the enzymatic conversion. Noteworthy, monooleoylglycerol was much more effective than the other monoacylglycerols in promoting the enzymatic conversion, indicating a beneficial role of the unsaturation in acyl chain. Meanwhile, ionic amphiphiles such as monohexadecyllysophosphatidylcholoine and palmitoyl-carnitine decreased the enzymatic conversion of GPI-AP in a concentration-dependent manner, with monohexadecyllysophosphatidylcholine and palmitoyl-carnitine deceased the enzymatic conversion of GPI-AP in a concentration-dependent manner, with monohexadecyllysophosphatidylcholoine being more inhibitory than palmitoylcarnitine. Separately when GPI-AP was exposed to various oxidants prior to the incubation with GPI-PLD, a remarkable decrease of the enzymatic conversion was observed with hypochlorite and peroynitrite generators, but not $H_{2}O_{2}$. In further study, hypochlorite was found to inactivate GPI-PLD at low concentrations ($3~100{\mu}M$). From these results, it is suggested that the enzymatic conversion of GPI-AP by GPI-PLD may be regulated in vivo system.

• Journal of Ocean Engineering and Technology
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• v.35 no.3
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• pp.173-182
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• 2021

The maneuvering performance of a ship on the actual sea is very different from that in calm water due to wave-induced motion. Enhancement of a ship's maneuverability in waves at the design stage is an important way to ensure that the ship navigates safely. This paper focuses on the maneuvering prediction of a Russian trawler in wind and irregular waves. First, a unified seakeeping and maneuvering analysis of a Russian trawler is proposed. The hydrodynamic forces acting on the hull in calm water were estimated using empirical formulas based on a database containing information on several fishing vessels. A simulation of the standard maneuvering of the Russian trawler was conducted in calm water, which was checked using the International Maritime Organization (IMO) standards for ship maneuvering. Second, a unified model of seakeeping and maneuvering that considers the effect of wind and waves is proposed. The wave forces were estimated by a three-dimensional (3D) panel program (ANSYS-AQWA) and used as a database when simulating the ship maneuvering in wind and irregular waves. The wind forces and moments acting on the Russian trawler are estimated using empirical formulas based on a database of wind-tunnel test results. Third, standard maneuvering of a Russian trawler was conducted in various directions under wind and irregular wave conditions. Finally, the influence of wind and wave directions on the drifting distance and drifting angle of the ship as it turns in a circle was found. North wind has a dominant influence on the turning trajectory of the trawler.