• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.99-107
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• 2021

We live in a myriad of data. Various data are created in all situations in which we work, and we discover the meaning of data through big data technology. Many efforts are underway to find meaningful data. This paper introduces an analysis technique that enables humans to make better choices through the trend and prediction of time series data as a principal component analysis technique. Principal component analysis constructs covariance through the input data and presents eigenvectors and eigenvalues that can infer the direction of the data. The proposed method computes a reference axis in a time series data set having a similar directionality. It predicts the directionality of data in the next section through the angle between the directionality of each time series data constituting the data set and the reference axis. In this paper, we compare and verify the accuracy of the proposed algorithm with LSTM (Long Short-Term Memory) through cryptocurrency trends. As a result of comparative verification, the proposed method recorded relatively few transactions and high returns(112%) compared to LSTM in data with high volatility. It can mean that the signal was analyzed and predicted relatively accurately, and it is expected that better results can be derived through a more accurate threshold setting.

• Journal of the Korean Geographical Society
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• v.38 no.2
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• pp.145-155
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• 2003

In this research, the primary factors affected to the formation of lake current of surface layer and thermal stratification of temperate lake have been analyzed, the daily change of water temperature, relationship with lake current and the research about the elements of meteorological phenomenon have been implemented. As a result, the lake current of surface layer occurring while the period of thermal stratification is showing the proportional difference of water temperature, thermal exchange caused by this has been known as the main energy source, and this is, secondly, considering as the interaction of the wind driven current by the prevailing wind. On the other hand, during the night time when the water surface is cooled, and it is considering as the vertical convection is occurring than horizontal circumfluence. Also, there exists the water mass, which is circumfluent counterclockwise and clockwise direction separately. The prevailing md is rather affected to the moving direction and moving speed of water mass, but it doesn't affect to the whole flowing direction.

• The KIPS Transactions:PartB
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• v.16B no.4
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• pp.257-262
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• 2009

A method of the region extraction and recognition of a speed sign in the real road environment is proposed. The region of speed sign is extracted by using color information and then numbers are segmented in the region. We improve the recognition rate by performing an incline compensation of the speed sign for directions clockwise and counterclockwise. In image sequences of the real road environment, a robust recognition results are achieved with speed signs at normal condition as well as inclined.

• Korean Journal of Optics and Photonics
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• v.8 no.2
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• pp.99-106
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• 1997

In this paper, we demonstrated, through experiment and numerical reconstruction, that the bias and the conjugate image, which are main drawbacks in incoherent holography, can be removed. By using wave plates of the modified triangular interferometer, which was made by adding simple passive devices to the conventional triangular interferometer, we adjusted the relative phase differences of two optical waves traveling in clockwise and counterclockwise. In this way, we obtained four intensity patterns, and then by manipulating the four intensity patterns electronically we obtained the complex hologram without bias and the conjugate image. Comparing numerical reconstruction results of the complex hologram with numerical reconstruction results of the hologram obtained from the conventional triangular interferometer, we demonstrated that bias and the conjugate image can be removed using the modified triangular interferometer.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.245-251
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• 1994

The charateristics of switching between two modes in a ring dye laser has been analyzed by the Monte-Carlo computer simulation. The effect of including pump fluctuations in the first-passage-time (FPT) distributions was compared with the distribution with the quantum fluctuation. The results show the same tendency in both cases, such as steep increases from 0 to peak an exponential decrease in long time range. However the introduction of pumping fluctuation is turned out to shorten the mean FPT. The variation of the mean FPT is examined for the various fluctuationrelated parameters. The mean FPT is lengthened when pump parameter a is increased while it is shorted when Q. $\GAMMA$ are decreased. eased.

• The KIPS Transactions:PartB
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• v.17B no.3
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• pp.207-214
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• 2010

A method of the region extraction and recognition of a traffic light and speed sign board in the real road environment is proposed. Traffic light was recognized by using brightness and color information based on HSI color model. Speed sign board was extracted by measuring red intensity from the HSI color information We improve the recognition rate by performing an incline compensation of the speed sign for directions clockwise and counterclockwise. The proposed algorithm shows a robust recognition rate in the image sequence which includes traffic light and speed sign board.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.2
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• pp.47-59
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• 2007

When the fixation point moved far distance to near distance, the change of astigmatism type in total astigmatism showed no-changed eyes: 1,020 eyes (63.8%), changed eyes: 578 eyes(36.1 %). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into with-the-rule, against-the-rule into oblique-astigmatism of change was plenty the most respectively. In corneal astigmatism was no-changed eyes: 1,164 eyes (72.8%), changed eyes: 434 eyes(27.1%). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into with-the-rule, against-the-rule into with-the-rule astigmatism was plenty the most respectively. In residual astigmatism is no-changed eyes: 935 eyes(58.5%), changed eyes: 663 eyes(41.4%). The change of with-the-rule into oblique-astigmatism, oblique-astigmatism into against-the-rule, against-the-rule into oblique-astigmatism was plenty the most respectively. When the fixation point moved far distance to near distance, the change of astigmatism axis in total astigmatism was no-changed eyes: 761 eyes(48.5%), cyclotorsioned eyes the above 10 degrees: 837 eyes(52.3%). In corneal astigmatism was no-changed eyes: 846 eyes(52.9%), cyclotorsioned eyes the above 10 degrees : 752 eyes(47%). In residual astigmatism was no-changed eyes: 614 eyes(38.4%), cyclotorsioned eyes the above 10 degrees : 984 eyes(62.5%). The magnitude of cyclotorsion of astigmatism axis in total astigmatism was Counter clockwise rotation: 31 degrees, clockwise rotation: 20 degrees. In coneal astigmatism was Counter clockwise rotation: 25 degrees, clockwise rotation: 27 degrees. In residual astigmatism was Counter clockwise rotation: 33 degrees, clockwise rotation: 35 degrees.

• The Korean Journal of Financial Studies
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• v.7 no.1
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• pp.1-47
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• 2001

증권가격의 시계열을 그래프로 표시하면 이 시계열의 운동양태가 파악될 수도 있다. 그래프를 통하여 추세가 존재하고 있는지 아니면 존재하지 않는지를 파악할 수 있을 것이다. 그리고 이 그래프를 통하여 증권가격 시계열이 정상적과정에 의하여 생성되는지의 여부가 인식될 수도 있을 것이며, (조건부) 이분산이 존재하고 있는지 또는 (조건부) 동분산이 존재하고 있는지도 인식될 수 있을 것이다. 간단한 기술통계량을 통하여 증권시계열의 성질을 파악할수도 있다. 이 시계열이 선형과정에 의하여 생성되는지 아니면 비선형과정에 의하여 생성되는지도 인식할 수 있을 것이다. 뿐만아니라 비선형과정중 하나인 카오스 과정에 의하여 증권가격이 생성되는지의 여부도 파악할 수 있을 것이다. 증권가격의 실현된 표본경로와 시뮬레이션을 통하여 얻은 표본경로가 일치하는지 또는 불일치하는지에 대한 판별을 통하여 모형정립에서 특히 많이 사용되고 있는 확률과정들이 생성시키는 증권가격 시계열이 실제로 관찰된 가격 시계열과 일치하여 현실적합성을 가지고 있는지의 여부도 판단할 수 있을 것이다. 주가시계열 그 자체를 출발점으로 하여 이 시계열의 움직임과 행동양식을 파악해가면 수많은 연구를 통하여 축적된 이론들과 주가를 형성시키는 성질들이 현실적으로 성립하고 있는지도 밝힐 수 있고 개발된 이론들의 장점과 단점을 강도높게 밝힐 수 있는 계기도 갖게 될 것이다. 데이터를 있는 그대로 면밀하게 검토하면 이미 공개된 문제점(open question)도 확인할 수 있을 것이고 아직 알려지지 않은 문제점들과 질문들을 찾게 될 수도 있을 것이다. 이것들은 앞으로의 연구를 위한 중요한 발견이 될 수 있을 것이다. 이 논문에서는 문제와 질문의 발견에 초점을 둔다. 이 논문에서는 한국의 주식시장과 미국의 주식시장을 대비하여 다룬다. 우리가 그동안의 연구를 통하여 미국의 문헌과 미국의 시장에 대한 지식을 상당히 축적하고 있는 만큼 이 대비를 통하여 두 시장이 동일하게 가지고 있는 행동양태와 서로 상이하게 가지고 있는 점들을 파악하면 두 시장에 대한 이해의 폭도 넓어질 것이며 동시에 미국의 연구결과를 수용하는 큰 방향을 결정하는데에도 일조가 되리라고 생각된다.

• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.19-28
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• 2009

Prediction problem of the time-series data has been a research issue for a long time among many researchers and a number of methods have been proposed in the literatures. In this paper, a method is proposed that similarities among time-series data are examined by use of Hidden Markov Model and Likelihood and future direction of the data movement is determined. Query sequence is modeled by Hidden Markov Modeling and then the model is examined over the pre-recorded time-series to find the subsequence which has the greatest similarity between the model and the extracted subsequence. The similarity is evaluated by likelihood. When the best subsequence is chosen, the next portion of the subsequence is used to predict the next phase of the data movement. A number of experiments with different parameters have been conducted to confirm the validity of the method. We used KOSPI to verify suggested method.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.371-374
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• 2003

서브시퀀스 매칭은 주어진 질의 시퀀스와 변화의 추세가 유사한 서브시퀀스들을 시계열 데이터베이스로부터 검색하는 연산이다. 본 논문에서는 기존에 제안된 서브시퀀스 매칭 기법인 FRM과 Dual-Match를 대상으로 다양한 실험을 통하여 윈도우 크기 효과를 정량적으로 분석한다. 또한, 이러한 분석 결과를 기반으로 서브시퀀스 매칭 처리의 성능 개선을 위한 향후의 연구 방향을 제시한다.