• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
• /
• pp.223-238
• /
• 1998

In this study, to investigate the effect of process variables such as reduction in area, semi-die angle and the rectangular ratio to the corner filling which influences the dimensional accuracy of the final product in the drawing of the cluadrangle rod from a round bar, it has been simulated by three dimensional rigid-plastic finite element method. In order to reduce the number of simulation artificial neural network has been introduced. Also, through the experimental investigation, the present results have been implemented on the industrial product. In results, the main process variable is the combination of the semi-die angle in case of the irregular shaped drawing process and reduction in area in the event of regular shaped drawing process, respectively.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2004년도 추계학술대회논문집
• /
• pp.89-92
• /
• 2004

This paper is concerned with the drawing process of Al-Si wire. In this study, the finite-element model established in previous work was used to analyze the effects of various forming parameters, which included the reduction in area, the semi-die angle, the aspect ratio and the inter-particle spacing of the Si in drawing processes. The finite-element results gave the consolidation condition. From the results of analysis, the effects of each forming parameter were determined. It is possible to obtain the important basic data which can be guaranteed in the fracture prevention of Al-Si wire by using FEM simulation.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 2부
• /
• pp.53-56
• /
• 2010

In this study, three kinds of cellulose fibers to crack reduction performance were evaluated and the results are as follows. Plastic shrinkage cracking is evaluated by the relative crack area, at all levels between $0.9kg/m^3$ and $1.2kg/m^3$, except for UF0.9% of upto50% showed are duction compared with Plain. In according to recommended amount of fiber in each area of the crack HF0.9>CEL1.2>UF0.6 effect of the order was more effective. While the impact strength of UF and CEL fibers until the final destruction are about five times the number of falls, HF fiber count drop was 10-18 time.

• Korean Journal of Hydrosciences
• /
• 제4권
• /
• pp.105-116
• /
• 1993

Areal Reduction Factor(ARF) has been developed and used to convert point Rainfall intensity-Duration-Frequency(I-D-F) to areal I-D-F in many countries. In Korea, though ARF was estimated in Han river basin by several researchers, it has some limitations to apply to other regions due to low denisity of rainfall gauging station and shortage of data. In this study ARF has been developed in area of relatively high density of rainfall gauging station, i.e., Pyungchang river(Han river), Wi stream(Nakdong river), and Bochung stream(Guem river) basin by geographically fixed-area method. And coefficient of variation of mean annual precipitation was presented to use ARE in other areas and its applicability was analyzed.

• 교육녹색환경연구
• /
• 제9권2호
• /
• pp.30-37
• /
• 2010

This study purposed realization and a phase reduction of school building $CO_2$ emissions. Accordingly selected standard school buildings and evaluated life cycle environmental load($CO_2$). This study proposed Green building technology which separated design sector, energy sector, afforestation sector for carbon-neutral city school buildings realization of M-city. As a result, elementary, middle and high schools of M-city built in the year 2013 were required that design sector was Energy Performance Index(EPI) 75 point and energy sector was solar installations more than 25% of the power usage, Solar systems installed more than 10% of total gas consumption and the area of afforesting more than 35% of the ecological area to achieve 30% $CO_2$ reduction compared to the Respectively standard school buildings.

• 한국정밀공학회지
• /
• 제15권10호
• /
• pp.113-119
• /
• 1998

Ship structures and aircraft structures are consisted of thin sheet alloy, so it is very important to understand the characteristics of fatigue crack propagation of that material and to establish the data base. The data for fatigue crack propagation behavior scatter very much even under identical experimental conditions with constant loading. The behavior of fatigue crack propagation under regular and irregular cyclic loadings is known to be highly affected by complicated factors such as plastic zone developed at the vicinity of crack tip and reduction of cross sectional area. In this paper, the controlled stress amplitude and overload fatigue crack propagation tests have been conducted to investigate the effect of varying factors such as plastic zone size near the crack tip and area reduction factor (AF) on the fatigue crack propagation behavior A better simulation of fatigue crack propagation behavior is found to be obtainable by using Wheeler and Willenborg models with AF effect.

• 한국항해항만학회지
• /
• 제35권9호
• /
• pp.777-783
• /
• 2011

Interest about Modal Shift is not being decreased, and it is drawing limelight as green logistics which meets low carbon green growth of National development vision. As an effect of Modal Shift, not only reduction in CO2 emission but also reduction in social cost, logistics cost etc. are being discussed. However, until now research about its practical transformation effect has been scanty. In this study, the actual expenses via CO2 emission, social cost, and logistics cost etc. by road transportation and rail transportation of container cargo with Origin/Destination between Busan-Kyeonggi Area were calculated and we propose beneficial effects when transportation mode is transformed from road to rail with Scenario Planning.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2017년도 특별논문집
• /
• pp.54-58
• /
• 2017

The vessels which are operated in ECA (Emission Control Area) after $1^{st}$ January 2016 shall be complied with revised NOx emission requirement (Tier III). Effective solutions for NOx emission requirement are SCR (Selective Catalytic Reduction), EGR (Exhaust Gas Recirculation) and Installation of LNG Dual Fuel Engine. This study is considered the design modification as per application of LNG Ready notation. In case of LNG Ready - S notation, the vessel shall be retrofitted the Main engine with Dual fuel engine and LNG Fuel system after delivery. On this paper, the entire process for design modification was explained to meet the requirement for LNG Ready notation.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.13-14
• /
• 2006

In this paper, an efficient butterfly structure for Radix-4 FFT algorithm using DA(Distributed Arithmetic) is proposed. It is shown that DA can be efficiently used in twiddle factor calculation of the Radix-4 FFT algorithm. The Verilog-HDL coding results for the proposed DA butterfly structure show 61.02% cell area reduction comparison with those of the conventional multiplier butterfly structure. Furthermore, the 64-point Radix-4 pipeline structure using the proposed butterfly and delay commutators is compared with other conventional structures. Implementation coding results show 46.1% cell area reduction.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.1073-1074
• /
• 2011

The loss is most important problems for the practical applications of permanent magnet synchronous motor(PMSM). In this paper, rotor sleeve and stator shape design of high speed permanent magnet motor for loss reduction. First, this paper found optimum sleeve thickness for calculation eddy current loss on the basis of analytical method, because eddy current is influenced by conductivity of material and area. Then, stator shape design is changed as maintain same slot area for reducing stator core loss. Finally, this paper compared analytical result with optimum sleeve thickness obtained from finite element(FE) method, and stator core loss is calculated from FE method.