Young-Ki Kim - Academia.edu (original) (raw)
Papers by Young-Ki Kim
Bulletin of The Korean Chemical Society, 2009
Graphene sheets formed by the reaction of carbon monoxide (CO) with aluminum sulfide (Al2S3) at r... more Graphene sheets formed by the reaction of carbon monoxide (CO) with aluminum sulfide (Al2S3) at reaction temperatures ≥ 800 o C were characterized by X-ray diffraction (XRD), Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM). The graphene sheets, formed as CO was reduced to gaseous carbon by the reaction with Al2S3, in the temperature range 800 -1100 o C, did not exhibit their characteristic XRD peaks because of the small number of graphene layers and/or low crystallinity of graphene sheets. Raman spectra of graphene sheets showed that the intensity ratio of the D band to the G band decreased and the 2D band was shifted to higher frequencies with increasing reaction temperature, indicating that the number of graphene layers increased with increasing reaction temperature.
Fusion Engineering and Design, 2011
The ITER vacuum vessel (VV) consists of three main sub-components; main vessel, port structures a... more The ITER vacuum vessel (VV) consists of three main sub-components; main vessel, port structures and the VV supporting system. In this study, the modified designs for the main vessel and the supporting system have been proposed, and the stress analyses have been conducted to investigate their structural integrities. In the original design of the main vessel, the assembling works of the flexible support housing into the outer shell is so difficult that the modified design concept is suggested for easier fabrication. To simplify the VV supporting system for better maintainability and to reduce its fabricating cost, the multiflexible plates with rigid restraint for the VV support have been proposed. The flexible plate support is surrounded by a rigid restraint with a rectangular cask. As a result of this study, the availability to adopt the modified design concept of the supporting system as well as the main vessel in the ITER VV design has been reviewed.
Fusion Engineering and Design, 2011
The ITER vacuum vessel has upper, equatorial and lower port structures used for equipment install... more The ITER vacuum vessel has upper, equatorial and lower port structures used for equipment installation, utility feedthroughs, vacuum pumping and access inside the vessel for maintenance. A neutral beam (NB) port of equatorial ports provides a path of neutral beam for plasma heating and current drive. An internal duct liner is built in the NB ports, and copper alloy panels are placed in the top and bottom of the liner to protect duct surface from high-power heat loads. Global NB liner models for the upper panel and the lower panel have been developed, and flow field and conjugate heat transfer analyses have been performed to find out pressure drop and heat transfer characteristics of the liner. Heat loads such as NB power, volumetric heating and surface heat flux are applied in the analyses for beam steering and misalignment conditions. For the upper panel, it is found that unbalanced flow distribution occurs in each flow path, and this causes poor heat transfer performance as well. In order to improve flow distribution and to reduce pressure losses, hydraulic analyses for modified cooling path schemes have been carried out, and design recommendations are made based on the analysis results. For the lower panel, local flow distributions and pressure drop values at each header and branch of the tube are obtained by applying design coolant flow rate. Together with the coolant flow field, temperature and heat transfer coefficient distributions are also acquired from the analyses. Based on the analysis results, it is concluded that the lower panel for the NB liner is relatively well designed even though the given heat loads are very severe.
Software organizations increasingly see themselves confronted with software solutions evolved and... more Software organizations increasingly see themselves confronted with software solutions evolved and maintained with more than a single development project. The delta specifications and artifacts that result from each project make reuse difficult and challenge a company's ability to innovate. Software product management is a growing discipline for understanding how to productize and align software with company strategy, how to evolve software, and how to coordinate product stakeholders. With product focus, in addition to project focus, planning accuracy can be improved, time-to-market reduced, product quality enhanced, and economic success sustained. This chapter provides an overview on software product management and discusses what today is known about this discipline.
Bulletin of The Korean Chemical Society, 2009
Graphene sheets formed by the reaction of carbon monoxide (CO) with aluminum sulfide (Al2S3) at r... more Graphene sheets formed by the reaction of carbon monoxide (CO) with aluminum sulfide (Al2S3) at reaction temperatures ≥ 800 o C were characterized by X-ray diffraction (XRD), Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM). The graphene sheets, formed as CO was reduced to gaseous carbon by the reaction with Al2S3, in the temperature range 800 -1100 o C, did not exhibit their characteristic XRD peaks because of the small number of graphene layers and/or low crystallinity of graphene sheets. Raman spectra of graphene sheets showed that the intensity ratio of the D band to the G band decreased and the 2D band was shifted to higher frequencies with increasing reaction temperature, indicating that the number of graphene layers increased with increasing reaction temperature.
Fusion Engineering and Design, 2011
The ITER vacuum vessel (VV) consists of three main sub-components; main vessel, port structures a... more The ITER vacuum vessel (VV) consists of three main sub-components; main vessel, port structures and the VV supporting system. In this study, the modified designs for the main vessel and the supporting system have been proposed, and the stress analyses have been conducted to investigate their structural integrities. In the original design of the main vessel, the assembling works of the flexible support housing into the outer shell is so difficult that the modified design concept is suggested for easier fabrication. To simplify the VV supporting system for better maintainability and to reduce its fabricating cost, the multiflexible plates with rigid restraint for the VV support have been proposed. The flexible plate support is surrounded by a rigid restraint with a rectangular cask. As a result of this study, the availability to adopt the modified design concept of the supporting system as well as the main vessel in the ITER VV design has been reviewed.
Fusion Engineering and Design, 2011
The ITER vacuum vessel has upper, equatorial and lower port structures used for equipment install... more The ITER vacuum vessel has upper, equatorial and lower port structures used for equipment installation, utility feedthroughs, vacuum pumping and access inside the vessel for maintenance. A neutral beam (NB) port of equatorial ports provides a path of neutral beam for plasma heating and current drive. An internal duct liner is built in the NB ports, and copper alloy panels are placed in the top and bottom of the liner to protect duct surface from high-power heat loads. Global NB liner models for the upper panel and the lower panel have been developed, and flow field and conjugate heat transfer analyses have been performed to find out pressure drop and heat transfer characteristics of the liner. Heat loads such as NB power, volumetric heating and surface heat flux are applied in the analyses for beam steering and misalignment conditions. For the upper panel, it is found that unbalanced flow distribution occurs in each flow path, and this causes poor heat transfer performance as well. In order to improve flow distribution and to reduce pressure losses, hydraulic analyses for modified cooling path schemes have been carried out, and design recommendations are made based on the analysis results. For the lower panel, local flow distributions and pressure drop values at each header and branch of the tube are obtained by applying design coolant flow rate. Together with the coolant flow field, temperature and heat transfer coefficient distributions are also acquired from the analyses. Based on the analysis results, it is concluded that the lower panel for the NB liner is relatively well designed even though the given heat loads are very severe.
Software organizations increasingly see themselves confronted with software solutions evolved and... more Software organizations increasingly see themselves confronted with software solutions evolved and maintained with more than a single development project. The delta specifications and artifacts that result from each project make reuse difficult and challenge a company's ability to innovate. Software product management is a growing discipline for understanding how to productize and align software with company strategy, how to evolve software, and how to coordinate product stakeholders. With product focus, in addition to project focus, planning accuracy can be improved, time-to-market reduced, product quality enhanced, and economic success sustained. This chapter provides an overview on software product management and discusses what today is known about this discipline.