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Development of a simple model for batch and boundary information updation for a similar ship's block model

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Science China(Information Sciences) 2012年第5期55卷 1019-1031页

作者： lee Hyeon-deok SON Myeong-jo OH Min-jae lee hyung-woo KIM Tae-wan Daewoo Shipbuilding & Marine Engineering Co. LTD.Geoje 656-714South Korea Department of Naval Architecture and Ocean Engineering Seoul National UniversitySeoul 151-744South Korea Research Institute of Marine Systems Engineering Seoul National UniversitySeoul 151-744South Korea

In early 2000,large domestic shipyards introduced shipbuilding 3D computer-aided design (CAD) to the hull production design process to define manufacturing and assembly *** production design process accounts for most of the man-hours (M/H) of the entire design process and is closely connected to yard production because designs must take into account the production schedule of the shipyard,the current state of the dock needed to mount the ship’s block,and supply ***,many shipyards are investigating the complete automation of the production design process to reduce the M/H for ***,these problems are still currently unresolved,and a clear direction is needed for research on the automatic design base of manufacturing rules,batches reflecting changed building specifications,batch updates of boundary information for hull members,and management of the hull model change history to automate the production design *** this study,a process was developed to aid production design engineers in designing a new ship’s hull block model from that of a similar ship previously built,based on AVEVA *** automation system that uses the similar ship’s hull block model is proposed to reduce M/H and human errors by the production design ***,scheme files holding important information were constructed in a database to automatically update hull block model ***,for batch updates,the database’s table,including building specifications and the referential integrity of a relational database were *** particular,this study focused on reflecting the frequent modification of building specifications and regeneration of boundary information of the adjacent panel due to changes in a specific ***,the rollback function is proposed in which the database (DB) is used to return to the previously designed panels.

关键词： ship design production design model reuse model history management referential integrity scheme file

Improved corrosion resistance of Mg alloy AZ31B induced by selective evaporation of Mg using large pulsed electron beam irradiation

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Journal of Materials Science & Technology 2019年第5期35卷 891-901页

作者： woo Jin lee Jisoo Kim hyung wook Park Department of Mechanical Aerospace and Nuclear Engineering Ulsan National Institute of Science and Technology

Large pulsed electron beam(LPEB) irradiation was employed as a surface treatment of magnesium(Mg)alloy AZ31B to enhance its corrosion and wear resistance. Selective evaporation of Mg induced by LPEB irradiation at an energy density of 5J/cm^2 for 40 cycles has led to the formation of an Al-enriched resolidified layer with nano-grained structure consisting of Mg3.1 Al0.9 metastable phase. The formation of such a re-solidified layer after LPEB irradiation has enabled a decrease in corrosion rate of Mg alloy AZ31B in 3.5% NaCl solution. Different equivalent electrical circuit models were proposed to account for the corrosion behavior of untreated Mg alloy AZ31B and those subjected to LPEB irradiation. A decrease in wear depth when compared to that of the untreated alloy suggests an increase in wear resistance of LPEB-irradiated Mg alloy AZ31B. Adhesive wear is the predominant mechanism of untreated Mg alloy AZ31B while abrasive wear mechanism dominates for LPEB-irradiated Mg alloy AZ31B.

关键词： Magnesium alloys Electron beam treatment Corrosion resistance Microstructure Rapid re-solidification Wear resistance

Optimal design considering structural efficiency of compressed natural gas fuel storage vessels for automobiles

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 199-204页

作者： Myung-Chang KANG hyung woo lee Chul KIM National Core Research Center for Hybrid Materials Solution Pusan National University Research Institute of Mechanical Technology Pusan National University

The shape and thickness of the dome were investigated with the aim of optimizing the type II CNG storage vessels by using a finite element analysis technique. The thickness of the liners and reinforcing materials was optimized based on the requirement of the cylinder and dome parts. In addition, the shape of the dome, which is most suitable for type lI CNG storage vessels, was proposed by a process of review and analysis of various existing shapes, and the minimum thickness was established in this sequence： metal liners, composite materials and dome parts. Therefore, the new proposed shape products give a mass reduction of 4.8 kg（5.1%）

关键词： CNG fuel storage vessel mechanical property dome part bursting structural analysis

Effects of structure and electronic properties of D-π-A organic dyes on photovoltaic performance of dye-sensitized solar cells

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Journal of Energy Chemistry 2021年第3期30卷 208-216页

作者： Min-woo lee Jae-Yup Kim hyung-Geun lee Hyun Gil Cha Duck-hyung lee Min Jae Ko Bio-Based Chemistry Research Center Advanced Convergent Chemistry DivisionKorea Research Institute of Chemical Technology(KRICT)Ulsan 44429Republic of Korea Department of Chemical Engineering Dankook UniversityYongin 16890Republic of Korea Department of Chemistry Sogang UniversitySeoul 04107Republic of Korea Department of Chemical Engineering Hanyang UniversitySeoul 04763Republic of Korea Institute of Nano Science and Technology Hanyang UniversitySeoul 04763Republic of Korea

Herein,we examine the performance of dye-sensitized solar cells containing five D-π-A organic dyes designed by systematic modification of π-bridge size and geometric *** dye has a simple push-pull structure with a triarylamino group as an electron donor,bithiophene-4,4-dimethyl-4 H-cyclopenta 1,2-b:5,4-b’]dithiophene(M11),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophenethiophene(M12),thiophene-4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M13),4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene-benzene(M14),and 4,4-dimethyl-4 H-cyclopenta[1,2-b:5,4-b’]dithiophene(M15)units asπ-bridges,and cyanoacrylic acid as an electron acceptor/*** extension of theπ-bridge linkage favors wide-range absorption but,because of the concomitant molecular volume increase,hinders the efficient adsorption of dyes on the TiO_(2) film ***,higher loadings are achieved for smaller dye molecules,resulting in(i)a shift of the TiO_(2) conduction band edge to more negative values,(ii)a greater photocurrent,and(iii)suppressed charge recombination between the photoanode and the redox couple in the ***,under one-sun equivalent illumination(AM 1.5 G,100 mW/cm^(2)),the highest photovoltage,photocurrent,and conversion efficiency(η=7.19%)are observed for M15,which has the smallest molecular volume among M series dyes.

关键词： Dye-sensitized solar cells Donor-acceptor dyes Electron-rich unit Wide-range absorption Impedance spectroscopy

Effect of ammonia gas etching on growth of vertically aligned carbon nanotubes/nanofibers

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 130-134页

作者： Sang-Gook KIM Sooh-Yung KIM hyung-woo lee Department of Mechanical Engineering Massachusetts Institute of Technology 77 Massachusetts Ave Cambridge MA 02139 USA National Core Research Center for Hybrid Materials Solution Pusan National University

The etching effect of ammonia （NH3） on the growth of vertically aligned nanotubes/nanofibers （CNTs） was investigated by direct-current plasma enhanced chemical vapor deposition （DC-PECVD）. NH3 gas etches Ni catalyst layer to form nanoscale islands while NH3 plasma etches the deposited amorphous carbon. Based on the etching effect of NH3 gas on Ni catalyst, the differences of growing bundles of CNTs and single strand CNTs were discussed; specifically, the amount of optimal NH3 gas etching is different between bundles of CNTs and single strand CNTs. In contrast to the CNT carpet growth, the single strand CNT growth requires shorter etching time （5 min） than large catalytic patterns （10 rain） since nano dots already form catalyst islands for CNT growth. Through removing the plasma pretreatment process, the damage from being exposed at high temperature substrate occurring during the plasma generation time is minimized. High resolution transmission electron microscopy （HTEM） shows fishbone structure of CNTs grown by PECVD.

关键词： carbon nanotube ammonia etching nickel catalyst plasma enhanced chemical vapor deposition (PECVD)

Effective parameters on diameter of carbon nanotubes by plasma enhanced chemical vapor deposition

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中国有色金属学会会刊：英文版 2012年第S3期22卷 712-716页

作者： Kang Young JEONG Hyun Kyung JUNG hyung woo lee National Core Research Center for Hybrid Materials Solution Hybrid Graduate SchoolPusan National University Department of Diagnostic Radiology Inje University College of MedicineHaeundae Paik Hospital

The effective parameters on the diameter of carbon nanotubes (CNTs) by plasma enhanced chemical vapor deposition (PECVD) were *** lots of influential parameters,the effects of the catalytic film thickness and the pretreatment plasma power on the growth of CNTs were *** results show that the size of catalytic islands increases by increasing the thickness of catalytic layer,but the density of CNTs *** pretreatment duration time of 30 s is the optimal condition for growing CNTs with about 50 nm in *** increasing the pretreatment plasma power,the diameter of CNTs decreases ***,the diameter of CNTs does not change drastically from 80 to 120 *** uniformly grown CNTs with the diameter of 50 nm are obtained at the pretreatment plasma power of 100 W.

关键词： carbon nanotubes catalytic film thickness pretreatment plasma power plasma enhanced chemical vapor deposition

Observation and Numerical Simulations with Radar and Surface Data Assimilation for Heavy Rainfall over Central Korea

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Advances in Atmospheric Sciences 2011年第3期28卷 573-590页

作者： Ji-Hyun HA hyung-woo KIM Dong-Kyou lee Atmospheric Sciences Program School of Earth and Environmental SciencesSeoul National UniversitySeoul 151-747Korea

This study investigated the impact of multiple-Doppler radar data and surface data assimilation on forecasts of heavy rainfall over the central Korean Peninsula;the Weather Research and Forecasting(WRF) model and its three-dimensional variational data assimilation system(3DVAR) were used for this purpose. During data assimilation,the WRF 3DVAR cycling mode with incremental analysis updates(IAU) was used. A maximum rainfall of 335.0 mm occurred during a 12-h period from 2100 UTC 11 July 2006 to 0900 UTC 12 July *** radar data showed that the heavy rainfall was due to the back-building formation of mesoscale convective systems(MCSs).New convective cells were continuously formed in the upstream region,which was characterized by a strong southwesterly low-level jet(LLJ).The LLJ also facilitated strong convergence due to horizontal wind shear,which resulted in maintenance of the *** assimilation of both multiple-Doppler radar and surface data improved the accuracy of precipitation forecasts and had a more positive impact on quantitative forecasting(QPF) than the assimilation of either radar data or surface data *** back-building characteristic was successfully forecasted when the multiple-Doppler radar data and surface data were *** data assimilation experiments,the radar data helped forecast the development of convective storms responsible for heavy rainfall,and the surface data contributed to the occurrence of intensified low-level *** surface data played a significant role in enhancing the thermal gradient and modulating the planetary boundary layer of the model,which resulted in favorable conditions for convection.

关键词： radar and surface data data assimilation mesoscale convective system heavy rainfall

Radar Data Assimilation for the Simulation of Mesoscale Convective Systems

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Advances in Atmospheric Sciences 2010年第5期27卷 1025-1042页

作者： Jo-Han lee Hyun-Ha lee Yonghan CHOI hyung-woo KIM Dong-Kyou lee School of Earth and Environmental Sciences Seoul National University

A heavy rainfall case related to Mesoscale Convective Systems （MCSs） over the Korean Peninsula was selected to investigate the impact of radar data assimilation on a heavy rainfall forecast. The Weather Research and Forecasting （WRF） three-dimensional variational （3DVAR） data assimilation system with tuning of the length scale of the background error covariance and observation error parameters was used to assimilate radar radial velocity and reffectivity data. The radar data used in the assimilation experiments were preprocessed using quality-control procedures and interpolated/thinned into Cartesian coordinates by the SPRINT/CEDRIC packages. Sensitivity experiments were carried out in order to determine the optimal values of the assimilation window length and the update frequency used for the rapid update cycle and incremental analysis update experiments. The assimilation of radar data has a positive influence on the heavy rainfall forecast. Quantitative features of the heavy rainfall case, such as the maximum rainfall amount and Root Mean Squared Differences （RMSDs） of zonal/meridional wind components, were improved by tuning of the length scale and observation error parameters. Qualitative features of the case, such as the maximum rainfall position and time series of hourly rainfall, were enhanced by an incremental analysis update technique. The positive effects of the radar data assimilation and the tuning of the length scale and observation error parameters were clearly shown by the 3DVAR increment.

关键词： WRF 3DVAR 3DVAR cycling initialization tuning heavy rainfall radar data

Highly efficient and stable solid-state fiber dye-sensitized solar cells with Ag-decorated SiO_(2) nanoparticles

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Nano Research 2021年第8期14卷 2728-2734页

作者： Jae Ho Kim Seok-Ju Yoo Daseul lee Jin woo Choi Sang-Cheol Han Tae In Ryu hyung woo lee Myunghun Shin Myungkwan Song Materials Center for Energy Convergence Korea Institute of Materials Science(KIMS)797Changwon-daeroSungsan-guChangwonGyeongsangnam-do51508Republic of Korea CEN Nano.Co.Ltd. Nano Convergence CenterMuan-roBuduk-myeonMiryang-siGyeongsangnam-do50404Republic of Korea Accident Coordination and Training Division National Institute of Chemical Safety(NICS)90Gajeongbuk-roYuseong-guDaejeon34114Republic of Korea Department of Nanoenergy Engineering and Research Center of Energy Convergence Technology Pusan National UniversityBusandaehak-ro 63-2Geumjeong-guBusan 46241Republic of Korea School of Electronics and Information Engineering Korea Aerospace University Goyang-cityGyeonggi-do10540Republic of Korea

Fiber-shaped dye-sensitized solar cells(FDSSCs)represent promising futuristic flexible or wearable power sources,owing to their simple fabrication process,light weight,weavability,and *** with strategies on changing the properties of semiconductor materials,the effects of incorporating silver-embedded SiO_(2) nanoparticles(Ag@SiO_(2)NPs)on the photoanodes of solid-state FDSSCs(SS-FDSSCs)are *** power conversion efficiency(PCE)of SS-FDSSCs with Ag@SiO_(2) NPs reaches 5.38%,which is comparable to the reference(3.98%).The PCEs remain at 95%between-16.9 and 91.7℃,indicating the operational stability of SS-FDSSCs within this temperature *** fabricated SS-FDSSCs,whose radii were 2 mm,maintains more than 90%of their efficiency over 500 bending cycles and 10 washing cycles.

关键词： dye-sensitized solar cells fiber-shaped solar cells SiO_(2)nanoparticles plasmonic effect solid-state electrolyte