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The Community Structure-Activity Resource (CSAR) benchmark exercise provides a unique opportunity for researchers to objectively evaluate the performance of protein-ligand docking methods. Patch-Surfer and PL-PatchSurfer, molecular surface-based methods for predicting binding ligands of proteins developed in our group, were tested on both CSAR 2013 and 2014 benchmark exercises in combination with an empirical scoring function-based method, AutoDock, while we only participated in CSAR 2013 using Patch-Surfer. The prediction results for Phase 1 task in CSAR 2013 showed that Patch-Surfer was able to rank all the four designed binding proteins within top ranks, outperforming AutoDock Vina. In Phase 2 of 2013, PL-PatchSurfer correctly selected the correct ligand pose for two target proteins. PL-PatchSurfer performed reasonably well in ranking ligands according to their binding affinity and in selecting near-native ligand poses in 2013 Phase 3 and 2014 Phase 1, respectively, although AutoDock Vina showed better performance. Lastly, in the 2014 Phase 2 exercise, the PL-PatchSurfer scores computed for ligands to target protein pairs correlated well with their pIC50 values, which was better or comparable to results by other participants. Overall, our methods showed fairly good performance in CSAR 2013 and 2014. Unique characteristics of the methods are discussed in comparison with AutoDock.

The CUPID code has been developed at KAERI for a transient, three-dimensional analysis of a two-phase flow in light water nuclear reactor components. It can provide both a component-scale and a CFD-scale simulation by using a porous media or an open media model for a two-phase flow. In this paper, recent advances in the CUPID code are presented in three sections. First, the domain decomposition parallel method implemented in the CUPID code is described with the parallel efficiency test for multiple processors. Then, the coupling of CUPID-MARS via heat structure is introduced, where CUPID has been coupled with a system-scale thermal-hydraulics code, MARS, through the heat structure. The coupled code has been applied to a multi-scale thermal-hydraulic analysis of a pool mixing test. Finally, CUPID-SG is developed for analyzing two-phase flows in PWR steam generators. Physical models and validation results of CUPID-SG are discussed.

Clinical risk factors (CRFs), either alone or in combination with bone mineral density, are used to determine the fracture risk for clinical assessment and to determine intervention thresholds. Because fracture risk is strongly affected by ethnicity and population-specific differences, we sought to identify Korean-specific CRFs for fracture, in combination with quantitative ultrasound (qUS) measurements of the radius and tibia. A total of 9351 subjects (4732 men and 4619 women) aged 40 to 69 years were followed for a mean of 46.3 ± 2.2 months. We obtained CRF information using a standardized questionnaire and measured anthropometric variables. Speed of sound at the radius (SoSR) and tibia (SoST) were measured by qUS. Fracture events were recorded using a questionnaire, and a height-loss threshold was used as an indicator of vertebral fracture. Relative risks were calculated by Cox regression analysis. A total of 195 subjects (61 men and 134 women) suffered low-trauma fractures. Older age, lower body mass index (BMI), and previous fracture history were positively associated with fracture risk in both sexes. Decreased hip circumference, lack of regular exercise, higher alcohol intake, menopause, and osteoarthritis history were further independent CRFs for fracture in women. However, neither SoSR nor SoST was independently associated with fracture risk. In this study, we identified the major Korean-specific CRFs for fracture and found that smaller hip circumference was a novel risk factor. This information will allow optimal risk-assessment targeting Koreans for whom treatment would provide the greatest benefit. © 2010 American Society for Bone and Mineral Research

The determination of the hydrogen concentrations in coal and metal samples were investigated by using the PGAA system at the HANARO Research Reactor, KAERI. The calibration curve of the hydrogen concentration was obtained from a standard sample and the effects of the interference peaks near the gamma-energy region of hydrogen were investigated. The background in the hydrogen peak of a prompt gamma-ray spectrum was measured for the sample chamber and shielding materials of an atmospheric state. The combined uncertainties estimated for the analysis procedure were in the range of 4–5%. Two kinds of certified reference materials, NIST SRM 1632c (Coal), NIST SRM 173c (Titaniumbase Alloy) and NIST SRM 2453 (Titanium Alloy) were used to verify the accuracy and precision of the measurement. The relative error was in the range of 3–6% and the relative standard deviation were less than 4%.

This paper presents a set of numerical procedure to innovate CFD code into a PWR component analysis code. A porous media approach is adapted to two-fluid model and conductor model, and a pack of constitutive relations close the numerical model into a PWR component analysis code. The separate verification calculations on conductor model and porous media approach, and the validation calculation for the integrated component-scale code are introduced.Copyright © 2014 by ASME

CUPID-SG is a component scale thermal-hydraulic analysis tool based on CUPID, which is intended to be a computer code for analyzing two-phase flows in porous media with tube bundles such as PWR steam generators. CUPID-SG adopts two-fluid, three-field conservation equations, and uses an in-house semi-implicit solver to obtain numerical efficiency. CUPID-SG can handle unstructured meshes that enable its application in complex geometries. CUPID-SG also has constitutive models for a two-phase flow map, interfacial heat and mass transfer, interfacial drag, wall friction, wall heating, and heat partitioning. CUPID-SG is benchmarked against a few cases of FRIGG tests to confirm that the transport models are correctly implemented and the code is applicable to a two-phase flow over tube bundles. The comparison showed that the constitutive models are properly implemented and CUPID-SG is capable of analyzing a two-phase boiling flow over tube bundles.Copyright © 2013 by ASME

The technique of simultaneous localization and mapping is the most important research topic in mobile robotics. In the process of building a map in its available memory, the robot memorizes environmental information on the plane of grid or topology. Several approaches about this technique have been presented so far, but most of them use mapping technique as either grid-based map or topology-based map. In this paper we propose a frame of solving the SLAM problem of linking map covering, map building, localizing, path finding and obstacle avoiding in an automated way. Some algorithms integrating grid and topology map are considered and they make the SLAM performance faster and more stable. The proposed scheme uses an occupancy grid map in representing the environment and then formulates topological information in path finding by Dijikstra algorithm. The mapping process is shown and the shortest path is decided on grid based map. Then topological information such as direction, distance are calculated on a simulator program then transmitted to robot hardware devices. The localization process and the dynamic obstacle avoidance can be accomplished by topological information on the grid map. While mapping and moving, pose of the robot is adjusted for correct localization by implementing additional pixel based image layer and tracking features. A laser range finder and electronic compass systems are implemented on the mobile robot and DC geared motor wheels are individually controlled by PD based adaptive way. Simulations and experimental results show performance and efficiency of the proposed scheme.

The technique of simultaneous localization and mapping has received much attention recently in mobile robotics. When map is being built, robot memorizes environmental information on the plane of grid or topology. Several approaches about this research have been presented so far, but most of them use mapping technique as either grid-based map or topology-based map. This paper proposes some algorithms integrating grid and topology map and its performance is faster and more stable. The proposed scheme uses an occupancy grid map in representing the environment and then formulate topological information in path finding by A* algorithm. The localization process and the dynamic obstacle avoidance can be accomplished by topological information on grid map. On simulator mapping process is shown and the shortest path is decided on grid based map. Then topological information such as direction, distance is calculated on simulator program then transmitted to robot hardware devices. Three ultrasonic sensors and electronic compass are implemented on our mobile robot and two DC geared motor wheels are individually controlled by PD control method. Simulations and experimental results show the performance and efficiency of the proposed scheme.