• The Journal of the Korea Contents Association
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• v.6 no.6
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• pp.26-32
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• 2006

Predictions on stock prices have been a hot issue in stock market as people get more interested in stock investments. Assuming that the stock price is moving by a trend in a specific pattern, we believe that a model can be derived from past data to describe the change of the price. The best model can help predict the future stock price. In this paper, our model derivation is based on automata over temporal data to which the model is explicable. We use Bayesian Information Criterion(BIC) to determine the best number of states of the model. We confirm the validity of Bayesian Information Criterion and apply it to building models over stock price indices. The model derived for predicting daily stock price are compared with real price. The comparisons show the predictions have been found to be successful over the data sets we chose.

• Environmental and Resource Economics Review
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• v.13 no.1
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• pp.119-131
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• 2004

A green market refers to a market that consists of environmentally aware consumers. A few researches have been carried out on the effects of environmental policy measures in a green market. These existing researches were based on a vertical differentiation model with firms' price-setting behavior, and derived that unit emission standard and environmental product taxes could not reduce the amount of pollution emission. This note considers a vertical differentiation model with firms' quantity-setting behavior, and shows that, contrary to the previous result, the amount of pollution emission is reduced by the introduction of unit emission standard. This implies the importance of the nature of firms' interaction in figuring out the pollution abatement effect of environmental policy measures in a green market.

• Journal of Korean Society of Steel Construction
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• v.12 no.6
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• pp.681-690
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• 2000

Recently, a long span is often required for the spacious building. Therefore the increase of stiffness is necessary to prevent floor vibration and control deformation of the building under earthquake and wind loads. For this purpose, steel beams with stiffened ends by reinforced concrete are effective. To realize such an effective reinforcement method, the smoothening of bending and shear stress transmission at the boundaries between middle-part of the steel beam and both end-parts of the steel beam with stiffened ends by reinforced concrete is required. Therefore, the fixed plate was installed at the boundary with the view of transferring the stress smoothly. This paper evaluates the method of effective transmission of bending and shear stress through the numerical analysis that is based on advanced experimental tests.

• Journal of the Korea Society of Computer and Information
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• v.18 no.7
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• pp.101-109
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• 2013

In this paper, a method to decide the number of additional edges to integrate two communities in social network by using modularity is studied. The modularity is a measure to be used to describe the quality of the community. By adding additional edges to the communities, the quality of the communities is enhanced, To integrate two communities, we propose methods to decide the number of additional edges by calculating the modularity. Also, the conditions that the proposed method is valid is investigated in a simple test graph and the efficiency of the proposed method is approved by integrating two communities in Zachary Karate Club network.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.639-648
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• 2006

A shear experiment of one-way monotonic loading was carried out with the shear span ratio as the main experimental variable for reinforced concrete beam. Using the finite element analysis as the experimental analysis tool and the analysis method to compute the shear resistance of small shear span ratio, a new macro-model composed of crooked main strut and sub strut is proposed in consideration of the effect of bond action between re-bar and concrete based on the experimental result. The experimental finding affirmed the validity of the proposed macro-model when the shear span ratio was at or below 0.75 and confirmed that the experimental result was the most consistent with the computed analysis result when the effective factor of concrete compressive strength was set at 0.75.

• The Journal of the Acoustical Society of Korea
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• v.43 no.4
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• pp.406-413
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• 2024

The proposed method uses Generalized Cross Correlation - Phase Transform (GCC-PHAT) method with nonlinear preprocessing and a frequency domain low-pass filter. In this paper, by reinterpreting the calculation process of GCC-PHAT as DFT, we derive that there is an effective frequency band used for time delay estimation in GCC-PHAT, and by using only the effective band using a low-pass filter, the noise component is reduced and it improvesthe time delay performance in impulsive noise environments. By comparing the proposed method with the traditional GCC-PHAT in an impulsive noise environment, we show that the GCC-PHAT becomes more robust to the impulsive noise.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.6
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• pp.589-601
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• 2008

The variation of groundwater level near the Shingok weir has been analyzed. To consider the soil inhomogeneity, coefficient of effective permeability was computed to be 0.313 m/day in the horizontal direction, and 0.0423 m/day in vertical direction. Anisotropic ratio is 7.19. The river water level drawdown (caused by the removing of the weir) causes the groundwater level drawdown, and 3 months are required for the new steady condition. and groundwater flows from Han river toward Gulpo stream before the removing of the weir, but when the weir removed, the flow direction changes. The groundwater level falls maximum 30 cm in the areas under the influence of Han river, but, in the areas near Kulpo stream, groundwater level falls about 10 cm. The amount of groundwater use in the study area was investigated to be $52m^3/day$ and in this condition, groundwater level falls maximum 1m (before or after the removing of Shingok weir). therefore, the variation of groundwater level caused by the removing of Shingok weir is less than that caused by the usual use of groundwater.

• Magazine of the Korea Concrete Institute
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• v.5 no.2
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• pp.151-161
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• 1993

본 논문은 전단철근을 갖지 않는 비교적 짧은 지간의 철근콘크리트 보에서 전단특성을 규명하고 균열전단강도와 극한전단강도를 예측하기 위한 것으로 총30개의 보를 4 series로 나누어 실험을 수행하였다. 실험의 변수는 콘크리트의 강도, 전단지간-유효높이의 비, 인장철근량등이며, 실험과정을 통해 파괴형상, 처짐, 전단강도등을 측정하였다. 실험결과로부터 콘크리트의 강도가 커지고 철근량이 많아질수록, 그리고 전단지간이 짧아질수록 철근콘크리트 보의 균열 및 극한전단강도가 증가됨을 밝혔다. 또한, 실험성과를 회귀분석하여 균열전단강도와 극한전단강도 추정식을 제안하였다. 제안된 추정식에 의한 계산값과 실험성과를 비교 검토하여 그 상관성을 확인하였다.

• Korean Journal of Logic
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• v.10 no.2
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• pp.47-107
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• 2007

나는 이 글에서 프레게 제한에 대한 라이트의 해석이 옳지 않다는 것을 보인다. 우선 나는 그가 산수 개념의 적용에 대한 반성을 통해 그 개념에 대한 선천적 지식을 얻을 수 있다고 여긴 사례를 검토한다. 이 검토를 기초로 나는 산수 개념의 적용을 지배하는 원리가 있고, 프레게 제한은 바로 그런 원리가 성립하도록 해당 개념을 정의하라는 요구임을 보인다. 둘째로 나는 라이트의 해석은 수학의 적용에 대한 아주 좁은 견해에 의존한다는 것을 보인다. 나는 산수의 적용에 대한 프레게의 견해를 살펴본 후에 실수가 적용될 수 있는 양을 산수량, 순수 공간량 및 물리량 세 부류로 나눈다. 나는 실수 적용 원리는 순수 공간량만 아니라 물리량에 대해서도 성립한다는 것을 보인다. 이에 근거해서 나는 실수 이론을 확립하는 데에도 여전히 프레게 제한은 유효하다고 결론짓는다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.432-438
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• 2017

The primary objective of the current work was to develop a standardized retrofit hull form capable of saving energy based on existing vessels. The bow shape of existing vessels was investigated, giving consideration to design draft and speed. Resistance performances were assessed for existing vessels according to operating conditions. Commercial CFD codes and model test materials were used for assessment of effective power. Three retrofit hull forms with minimum resistance were selected given real operating conditions. These vessels were named after customized ready-made hull forms to enable ship owners to make easier choices. The effective power of each vessel was estimated under real operating conditions. Subjects were operated with the lowest draft, and performance for retrofit No. 3 showed an 11-16% improvement in effective power at low speed ranges of 16-18 knots compared to existing vessels. When operated with a middle draft, performance for retrofit No. 3 showed a 6-11% improvement in effective power at low speed ranges compared to existing vessels. When operated with the highest draft, performance for all vessels showed little difference in effective power.