• Journal of Surface Science and Engineering
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• 제41권4호
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• pp.156-162
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• 2008

Small FRP(fiber-reinforced polymer) fishing ships have numerous problems with the point of the environmental and recycling perspectives. In light of these aspects, aluminum can be used as a material for ship building. It is environmental friendly, easy to recycle, and provides a high added value to fishing boats. In this paper, we report on mechanical and electrochemical characteristics of welding parts for friction stir welded 5456-H116 Al alloy. In friction stir welded at various traveling speeds under the rotation speed of 500 RPM, the best characteristics presented in traveling speed of 15mm/min. The anodic polarizations of base metal and welding metal were observed tendency which current density from the open circuit potential suddenly increase. The cathodic polarization presented concentrated polarization caused by the dissolved oxygen reduction reaction and activation polarization caused by hydrogen generation. From result of Tafel analysis, the corrosion potential of 5456 alloy(Base metal) was lower than that of friction stir welded part, as were its corrosion current densities.

• Journal of The Korean Digital Architecture Interior Association
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• 제3권1호
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• pp.39-49
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• 2003

The height provisions, by the urban planning, describe the hightest height per width division, also define oblique line limitation by road without mentioning the highest per width division. Therefore this study will be a basic model for the standard of measuring the highest height per width division analysizing the propriety of current standard of oblique limitation. This technique is prepared to prevent the confusion and to complements the existing planning method. Therefore, it takes more time to establish this new method and to apply it to the existing condition. This study reviewed density control in District Units Plan, based on the guidelines of density, which included height, ratio of total floor to ground area, and land distribution. This study aims to provide efficient analysis by using current oblique limitation provisions Thus, proving the area rations of general residential areas are decreasing. Since the purpose of the District Units Plan is to avoid confusion and help ease the existing problematic conditions which have risen from the two above-mentioned conventional systems, further observation and research on these areas are necessary.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권3호
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• pp.241-255
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• 2012

Three types of 100 kW-class tidal stream turbines are proposed and their performance is studied both numerically and experimentally. Following a wind turbine design procedure, a base blade is derived and two additional blades are newly designed focusing more on efficiency and cavitation. For the three designed turbines, a CFD is performed by using FLUENT. The calculations predict that the newly designed turbines perform better than the base turbine and the tip vortex can be reduced with additional efficiency increase by adopting a tip rake. The performance of the turbines is tested in a towing tank with 700 mm models. The scale problem is carefully investigated and the measurements are compared with the CFD results. All the prediction from the CFD is supported by the model experiment with some quantitative discrepancy. The maximum efficiencies are 0.49 (CFD) and 0.45 (experiment) at TSR 5.17 for the turbine with a tip rake.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제28권6호
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• pp.40-44
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• 2014

In this paper, maximum power is the lowering device using the facility's energy use and peak load electricity through analyzing attitude should like to make it reduce its power base rate. Simulator to manage the demand for power, a maximum electric power base power from electronic watt-hour meters by a device's signal, predictive power, the current power by computing the goal of power for less than Maximum peak power and peak shift, so that you can manage, and peak York, which role you want a cut Metal heat treatment result which analyzes the data, demand for electricity company over the years of analyzing the characteristics of each load, and effects and Reducing power consumption device every month identified seven Sequence control to the load system and successful power control is about showing that the defined goals.

• Journal of architectural history
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• 제31권4호
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• pp.45-56
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• 2022

Gachiljang(假漆匠), along with Jinchiljang(眞漆匠), is an important craftsman who cannot be left out during the finishing process of wooden furniture and wooden buildings during the Joseon Dynasty. The current definition of Gachiljang does not properly explain the nature and role of Gachiljang. In many related terminology dictionaries, Gachiljang is defined as "artisan who dose the base paintwork of Dancheong." But an analysis of the Joseon Dynasty's Uigwe(儀軌) shows that Gachiljang appears frequently in works that are not related to Dancheong at all. Therefore the current definition seems to be inaccurate and need to be revised. Gachiljang is a name that contrasts with Jinchiljang, and he makes and paints Myongyu(明油). Just as Jinchiljang uses not only lacquer but also various pigments to paint colorful lacquer, Gachiljang also uses various pigments to decorate buildings or furniture in a fancy way and then finishs with a transparent paint. Even in the Dancheong(丹靑) work of the building, all the base painting and finish coating work will be in charge of Gachiljang, except for the paintings performed by the Whawon(畫員) or the Whasa(畫師).

• International Journal of Internet, Broadcasting and Communication
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• 제14권3호
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• pp.243-248
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• 2022

Considering the current situation where cash transactions account for 51.5% of private consumption expenditure, it is very important to secure a tax base by exposing business operators' cash transactions. In the September 2011 national audit, it was pointed out that although a significant part of the investment amount of businesses (VAN operators, etc.) related to the issuance of cash receipts has been recovered, they are still supported through the state tax. At this point in time when a significant amount of the initial investment has been recovered, it is necessary to study a new way to support business operators through methods other than the tax credit method. This study proposes various methods to improve the current cash receipt system and describes the advantages and disadvantages of each method. The most important thing for the improvement of the cash receipt system is that the issuance of cash receipts should be beneficial to business operators. As a result of this study, the most desirable improvement method is to provide differential compensation for the discriminatory cost because the cost is different for each cash receipt operator. For this purpose, we analyze the best way to improve the cash receipt system is a tax credit method and a tax credit for maintenance costs.

• Analytical Science and Technology
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• 제11권6호
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• pp.460-468
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• 1998

Schiff base ligands such as $SOPDH_2$, $SNDH_2$, $EBNH_2$, and $PBNH_2$ and their Co(II) complexes such as [$Co(II)(SND)(H_2O)_2$], [$Co(II)(SOPD)(H_2O)_2$], [$Co(II)(EBN)(H_2O)$], and [$Co(II)(PBN)(H_2O)$] have been synthesized. The mole ratio of Shiff base ligand to cobalt(II) for the Co(II) complexes was found to be 1:1. Also these complexes have been configurated with hexa-coordination. Reduction of dioxygen was investigated by cyclic voltammetry at glassy carbon electrodes modified with Schiff base Co(II) complexes in 1 M KOH aqueous solution. At modified glassy carbon electrode with Schiff base Co(II) complexes, reduction peak current of oxygen was increased and peak potential was shifted to more positive direction compared to bare glassy carbon electrode. The electrokinetic parameters such as number of electron and exchange rate constant were calculated from the results of cyclic voltammogrms. The reduction of dioxygen at glassy carbon electrode has been $2e^-$ reaction pathway. Exchange rate constant at glassy carbon electrode modified with Co(II) complexes was increased 2~10 times compared to bare electrode.

• Journal of the Korean Data and Information Science Society
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• 제27권3호
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• pp.639-651
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• 2016

"Law on price announcement for real estate" which was revised as of Jan. 19, 2016 (will be enforced as of Sep. 1, 2016) decided the introduction of 'Price announcement system for non-residential property' for the first time. However, its introduction seems to be delayed based on two reasons. Firstly the methodology for introduction of non-property system is not definitized, despite many problems were brought up for current tax base of non-residential property. In addition, changes in tax base will place a burden on the government. In this regard, this study analyzed actual transaction price data throughout one year to analyze equity of taxation for non-residential property and to find major factor which affects on the tax base, in relation with the change of current public announcement system to actual transaction based system. And this is the first study that applied actual transaction price to non-residential property.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.35-36
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• 2009

In this work, we demonstrate 800V 4H-SiC power DMOSFETs with several structural alterations to obtain a low threshold voltage ($V_{TH}$) and a high figure of merit ($V_B^2/R_{SP,ON}$). To optimize the device performance, we consider four design parameters; (a) the doping concentration ($N_{CSL}$) of current spreading layer (CSL) beneath the p-base region, (b) the thickness of p-base ($t_{BASE}$), (c) the doping concentration ($N_J$) and width ($W_J$) of a JFET region, (d) the doping concentration ($N_{EPI}$) and thickness ($t_{EPI}$) of epi-layer. These parameters are optimized using 2D numerical simulation and the 4H-SiC DMOSFET structure results in a threshold voltage ($V_{TH}$) below ~3.8V, and high figure of merit ($V_B^2/R_{SP,ON}$>${\sim}200MW/cm^2$) for a power MOSFET in $V_B$-800V range.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• 제37권2호
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• pp.147-152
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• 2001

Corrosion damage of boiler, factory equipment and so forth occur quickly due to using of the polluted water, resulting in increasing leak accident. Especially, working life of hot water boiler using the polluted water becomes more short, and energy loss increases. The cathodic protection method is the most economical and reliable one to prevent corrosion damage of steel structures. Mg-base alloys galvanic anode protection of cathodic protection methode is suitable for the application of hot water boiler using water with high specific resistance such as tap water. This paper is studied on the cathodic protection characteristics of hot water boiler. In tap water solution, the measurement of cathodic protection potential according to the time elapsed is carried out, and behavior of cathodic polarization with current change is investigated. The main results obtained are as follows. In hot water boiler shell, the open circuit potential of base metal become less noble than that of weld Bone, and the current density of base metal becomes low than that of weld zone. The further distance from Mg-alloy galvanic anode, the higher cathodic protection potential of hot water boiler appears. And protective potential becomes high according to pass cathodic protection time and after 6∼10 days become stable.