• 한국자동차공학회논문집
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• 제3권1호
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• pp.129-135
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• 1995

This study aims to compare the heat release calculated using the ensemble average of pressure data with the heat release calculated using the least squares method for pressure data. This paper propose a heat release computation method that can analyze the most correct, straight and simple method to analyse combustion phenomenon. In conclusion, we found that the least squares method of third-order was the best computational method for heat release calculation.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.93-98
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• 1999

This study is performed to select irrigation design year from 10-year return period 7-month(April to October) precipitation amount and compare reference crop evapotranspiration at 13 regions by REF-ET model. 1. Seven-month growing season average reference crop evapotranspiration values showed low values of 4.1 ∼4.2mm /day by FAO-24 Corrected Penman method, and 3.6 ∼3.7mm/day by FAP-24 Blaney Criddle method in Chinjin and Ulsan, high values of 4.9mm/day by FAO-24 Corrected Penman method , 4.1mm/day by FAO -24 Blaney Criddle method in Mokpo and Pohang. 2. Estimated seven-month growing season average reference crop evapotranspirations are 4.6mm/day by FAO-24 Corrected Penman method, 3.9,mm/day by FAO-24 Balney Criddle method, 4.0mm/day 1985 Hargreaves method, respectively.

• 한국음향학회지
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• 제42권6호
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• pp.565-571
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• 2023

사후확인제 도입으로 현장에서의 바닥충격음 성능 측정이 의무화되고, 평가 방법이 변경되었다. 제도 변화에 따른 바닥충격음 성능 변화를 추적하기 위해서는 변경된 평가방법에 따라 중량충격음 특성이 어떻게 나타나는지에 대한 연구가 필요하다. 본 연구에서는 평면과 바닥구조가 동일한 하나의 아파트 건물에 위치한 59세대를 대상으로 충격원 및 평가지표에 따라 단일수치평가량을 결정하는 주파수 대역의 기여율을 분석하였다. 단일수치평가량에 따른 주파수대역별 기여도 산출방법이 상이하여 단순 비교는 어려우나, 사후확인제 도입 이전 평가방법(뱅머신 측정 및 L'_i,Fmax,AW으로 평가)에서는 63 Hz가 미치는 기여율은 평균 80.8 %로 나타났으며, 125 Hz가 미치는 기여율은 평균 19.2 %으로 나타났다. 현행 평가방법(고무공 측정 및 L'_iA,Fmax으로 평가) 에서는 기여율은 50 Hz ~ 80 Hz에서 평균 33.1 %, 100 Hz ~ 160 Hz에서 평균 58.7 %, 200 Hz ~ 315 Hz에서 평균 6.9 %, 400 Hz ~ 630 Hz에서 평균 1.3 %으로, 63 Hz 대역의 기여도가 낮아진 것으로 나타났다. 이 결과는 대상 공동주택에 대한 사례 분석 내용으로, 더 다양한 공동주택에 대한 측정 데이터를 분석할 필요가 있다.

• 한국환경보건학회지
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• 제22권1호
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• pp.12-20
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• 1996

This study was carried out to investigate the change of average .specific resistance according to suspension concentration for study phenomena occurring during filtration period. As the results of this study, the following conclusions were obtained. The average specific resistance in 1% $CaCO_3$ suspension was showed power function(R=0.99), whereas in TOYO 5C and TOYO 5A paper were made little difference under high pressure. It represented from results that filtration theory in concord with cake filtration was no affected the average specific resistance of filter medium in cake filtration. In case of 0.1% $CaCO_3$ suspension filtration, the TOYO 5C was showed power function, whereas in TOYO 5A paper differently. In the present study, the $P_1$ value was calculated from the average specific resistance by filtration method. Therefore, $P_1$ value were $1.68\times 10^4Pa$, $4.05\times 10^3Pa$, and $3.15\times 10^3Pa$ in $5.3\times 10^4Pa$, $1.3\times 10^4Pa$, and $8.2\times 10^3Pa$, respectively. We concluded that propriety of new filtration theory was also proved.

• 한국조경학회지
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• 제35권3호
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• pp.62-70
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• 2007

The purpose of this research is to suggest an improved method of how to apply and operate an average floor height system to rebuilt or redeveloped apartment buildings in general residential areas of Seoul. This research suggested two research findings by a computer simulation study for analyzing the difference between the average floor height of apartment buildings in experimental sites and the average of floors of buildings near experimental sites. The first finding is that an average floor height system should be applied to apartment buildings with a limitation of maximum height at sites larger than $12,000m^2$ in order to control the difference of the maximum height of buildings between apartment sites and their surroundings. The second finding is that the average floor height system should be operated by an appropriate average floor height ratio at sites greater than $50,000m^2$ in order to harmonize rebuilt or redeveloped apartment buildings with their surroundings.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제15권1호
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• pp.1-17
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• 2011

A new method for option pricing based on the trinomial tree method is introduced. The new method calculates the local average of option prices around a node at each time, instead of computing prices at each node of the trinomial tree. Local averaging has a smoothing effect to reduce oscillations of the tree method and to speed up the convergence. The option price and the hedging parameters are then obtained by the compact scheme and the Richardson extrapolation. Computational results for the valuation of European and American vanilla and barrier options show superiority of the proposed scheme to several existing tree methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.474-479
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• 2004

According to our previous study, it is confirmed that the Petrov-Galerkin natural element method (PGNEM) completely resolves the numerical integration inaccuracy in the conventional Bubnov-Galerkin natural element method (BG-NEM). This paper is an extension of PG-NEM to two-dimensional nonlinear dynamic problem. For the analysis, a constant average acceleration method and a linearized total Lagrangian formulation is introduced with the PG-NEM. At every time step, the grid points are updated and the shape functions are reproduced from the relocated nodal distribution. This process enables the PG-NEM to provide more accurate and robust approximations. The representative numerical experiments performed by the test Fortran program, and the numerical results confirmed that the PG-NEM effectively and accurately approximates the nonlinear dynamic problem.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.621_622
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• 2009

This paper presents an efficient calculation method for torque and torque ripple of a permanent magnet synchronous motor by using superposing method of load angle torque curves from finite element method. The load angle range having minimum torque ripple as well as average torque according to load angle can be induced by proposed method. We selected a permanent magnet assisted synchronous reluctance motor (PMa-SynRM) as a study model because of its high torque ripple. We performed experiment of torque ripple and average torque according to load angle for the verification of proposed method in the paper.

• Journal of electromagnetic engineering and science
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• 제13권3호
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• pp.192-194
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• 2013

This paper proposes a validation model using a reverberation chamber for verification of the effectiveness and accuracy of the statistical power balance (PWB) method. The PWB method treats electromagnetic (EM) field distributions in certain environments as a representative value of an "ensemble" average, so a reverberation chamber is utilized as a testing apparatus to experimentally simulate the sets of measurement field "ensemble" inside a complex environment. Measurements are performed with various test conditions for environmental loss using flat absorbers, and front and side doors of the chamber. Comparison between the PWB analysis and the measurement results shows good agreement, indicating the usefulness of this statistical analysis method for stating the electromagnetic field inside the EM zone as a representative value to general structures.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.470-475
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• 2002

Instantaneous following PWM control technique is pulsed nonlinear dynamic control method. This new control technique using analog integrator is proposed to control the duty ratio D of do-dc converter. In this control method, the duty ratio of a switch is exactly equal In or proportional to the control reference in the steady state or in a transient. Proposed control method compensates power source perturbation in one switching cycle, and the average value of the dynamic reference in one switching cycle. There is no steady state error nor dynamic error between the control reference and the average value of the switched variable. Experiments with buck converter have demonstrated the robustness of the control method and verified theoretical prediction. The control method is very general and applicable to all type PWM