• Title/Summary/Keyword: Local linear fitting

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A Baseline Correction for Effective Analysis of Alzheimer’s Disease based on Raman Spectra from Platelet (혈소판 라만 스펙트럼의 효율적인 분석을 위한 기준선 보정 방법)

  • Park, Aa-Ron;Baek, Sung-June
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.49 no.1
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    • pp.16-22
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    • 2012
  • In this paper, we proposed a method of baseline correction for analysis of Raman spectra of platelets from Alzheimer's disease (AD) transgenic mice. Measured Raman spectra include the meaningful information and unnecessary noise which is composed of baseline and additive noise. The Raman spectrum is divided into the local region including several peaks and the spectrum of the region is modeled by curve fitting using Gaussian model. The additive noise is clearly removed from the process of replacing the original spectrum with the fitted model. The baseline correction after interpolating the local minima of the fitted model with linear, piecewise cubic Hermite and cubic spline algorithm. The baseline corrected models extract the feature with principal component analysis (PCA). The classification result of support vector machine (SVM) and maximum $a$ posteriori probability (MAP) using linear interpolation method showed the good performance about overall number of principal components, especially SVM gave the best performance which is about 97.3% true classification average rate in case of piecewise cubic Hermite algorithm and 5 principal components. In addition, it confirmed that the proposed baseline correction method compared with the previous research result could be effectively applied in the analysis of the Raman spectra of platelet.

Political Regionalism in Korean Congressional Elections 1988$\sim$2004: A case study with provincial border regions Yeongdong, Muju and Kimcheon (총선으로 본 지역주의 -영동.무주.김천 지역을 중심으로-)

  • Kim, Jai-Han
    • Journal of the Korean association of regional geographers
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    • v.13 no.4
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    • pp.381-395
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    • 2007
  • After the democratization process since 1988, the national scale voting behavior in congressional elections has changed from a rural-government party and urban-opposite party connection to a political regionalism oriented pattern. In this context, the case study with provincial border regions aims to investigate possible party identification change of the region, and to find a relationship between polling score ratio and socio-political characteristics of the candidates. As a result, Yeongdong shows a strong negation to the presumed Chungcheong local party and shows a continuous party identification with the Kyungsang local party. Muju reveals a more or less weakened identification with the Jeolla local party, on the contrary, Kimcheon shows a unchanged strong identification with the Kyungsang local party. The regional neighborhood effect was verified quite partly between the subdivision districts of the border regions. With a application of linear fitting method, it is certified that voters have attached great importance to the belonging party, native place, as well as political career of the candidates as a voting criterion.

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Correction of Antenna Position for Projection Center Coordinates by Kinematic DGPS-Positioning (동적 DGPS 측위에 의한 투영중심좌표 결정을 위한 수신기 위치의 보간)

  • 이종출;문두열;신상철
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.15 no.2
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    • pp.165-173
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    • 1997
  • The combined bundle block adjustment with projection center coordinates determined by kinematic DGPS-positioning has reached a high level of accuracy. Standard deviations of the ground coordinates of $\pm{10cm}$ or even better can be reached. On this accuracy level also smaller error components are becoming more important. One major point of this is the interpolation of the projection centers as a function of time between the GPS-antenna locations. A just linear interpolation is not respecting the not linear movement of the aircraft. Based on a least squares polynomial fitting the aircraft maneuver can be estimated more accurate and blunders of the GPS-positions caused by loss of satellite and cycle slips are determinable. The interpolation with a time interval of 3sec in the study area RHEINKAMP is quite different to the interpolation with a time interval of 6-7sec in the study area MAAS. The GPS-positions of the study area are identified as blunders based on a local polynomial regression. This cannot be neglected for precise block adjustment.

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Possible Causes of Paleosecular Variation and Deflection of Geomagnetic Directions Recorded by Lava Flows on the Island of Hawaii

  • Czango Baag
    • Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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    • 2003.05a
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    • pp.20-20
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    • 2003
  • In the summers of 1997 and 1998 and in February of 2000 we made 570 measurements of the ambient geomagnetic field 120 cm above the pavement surface of State Route 130, south of Pahoa, the island of Hawaii using a three-component fluxgate magnetometer. We measured at every 15.2 m (50 feet) interval covering a distance of 6, 310 m (20, 704 ft) where both historic and pre-historic highly magnetic basalt flows underlie. We also collected 197 core samples from eight road cuts, 489 specimens of which were subject to AF demagnetizations at 5 - 10 mT level up to a maximum field of 60 mT. We observed significant inclination anomalies ranging from a minimum of $31^{\circ}$ to a maximum $40^{\circ}$ where a uniform inclination value of $36.7^{\circ}$ (International Geomagnetic Reference Field, IGRF) was expected. Since the mean of the observed inclinations is approximately $35^{\circ}$ we assume that the study area is slightly affected by the magnetic terrain effect to a systematically shallower inclinations for being located in the regionally sloping surface of the southern side of the island (Baag, et al., 1995). We observed inclination anomalies showing wider (spacial) wavelength (160 - 600 m) and higher amplitudes in the historic lava flows area than in the northern pre-historic flows. Our observations imply that preexisting inclination anomalies such as those that we observed would have been interpreted as paleosecular variation (PSV). These inclination anomalies can best be attributed to concealed underground highly magnetic dikes, channel type lava flows, on-and-off hydrothermal activities through fissure-like openings, etc. Both the within- and between-site dispersions of natural remanent magnetization (NRM) are largest (up to ${\pm}7^{\circ}$) above the flows of 1955, while the area of pre-historic flows in the northern part of the study area exhibit the smallest dispersion. Nevertheless, mean inclinations of each historic flow of 1955 and 1790 are almost identical to that of the corresponding present field, whereas mean of NRM (after AF demagnetization) inclinations for each of the four pre-historic lava flow units is twelve to thirteen degrees lower than the present field inclination. We observed three cases of very large inclination variations from within a single flow, the best fitting curves of which are linear, second and third order polynomials each from within a single flow, whereas no present field variations are observed. This phenomena can be attributed to the notion that local magnetic anomalies on the surface of an active volcano are not permanent, but are transient. Therefore we believe that local magnetic anomalies of an active volcano may be constantly modified due to on going subsurface injections and circulations of hot material and also due to wide spacial and temporal distribution of highly magnetic basaltic flows that will constantly modify the topography which will in turn modify the local ambient geomagnetic field (Baag, et al., 1995). Our observations bring into question the general reliability of PSV data inferred from volcanic rocks, because on-going various geologic and geophysical activities associated with active volcano would continuously deflect and modify the ambient geomagnetic field.

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Forecasting of the COVID-19 pandemic situation of Korea

  • Goo, Taewan;Apio, Catherine;Heo, Gyujin;Lee, Doeun;Lee, Jong Hyeok;Lim, Jisun;Han, Kyulhee;Park, Taesung
    • Genomics & Informatics
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    • v.19 no.1
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    • pp.11.1-11.8
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    • 2021
  • For the novel coronavirus disease 2019 (COVID-19), predictive modeling, in the literature, uses broadly susceptible exposed infected recoverd (SEIR)/SIR, agent-based, curve-fitting models. Governments and legislative bodies rely on insights from prediction models to suggest new policies and to assess the effectiveness of enforced policies. Therefore, access to accurate outbreak prediction models is essential to obtain insights into the likely spread and consequences of infectious diseases. The objective of this study is to predict the future COVID-19 situation of Korea. Here, we employed 5 models for this analysis; SEIR, local linear regression (LLR), negative binomial (NB) regression, segment Poisson, deep-learning based long short-term memory models (LSTM) and tree based gradient boosting machine (GBM). After prediction, model performance comparison was evelauated using relative mean squared errors (RMSE) for two sets of train (January 20, 2020-December 31, 2020 and January 20, 2020-January 31, 2021) and testing data (January 1, 2021-February 28, 2021 and February 1, 2021-February 28, 2021) . Except for segmented Poisson model, the other models predicted a decline in the daily confirmed cases in the country for the coming future. RMSE values' comparison showed that LLR, GBM, SEIR, NB, and LSTM respectively, performed well in the forecasting of the pandemic situation of the country. A good understanding of the epidemic dynamics would greatly enhance the control and prevention of COVID-19 and other infectious diseases. Therefore, with increasing daily confirmed cases since this year, these results could help in the pandemic response by informing decisions about planning, resource allocation, and decision concerning social distancing policies.

Feature Ranking for Detection of Neuro-degeneration and Vascular Dementia in micro-Raman spectra of Platelet (특징 순위 방법을 이용한 혈소판 라만 스펙트럼에서 퇴행성 뇌신경질환과 혈관성 인지증 분류)

  • Park, Aa-Ron;Baek, Sung-June
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.4
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    • pp.21-26
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    • 2011
  • Feature ranking is useful to gain knowledge of data and identify relevant features. In this study, we proposed a use of feature ranking for classification of neuro-degeneration and vascular dementia in micro-Raman spectra of platelet. The entire region of the spectrum is divided into local region including several peaks, followed by Gaussian curve fitting method in the region to be modeled. Local minima select from the subregion and then remove the background based on the position by using interpolation method. After preprocessing steps, significant features were selected by feature ranking method to improve the classification accuracy and the computational complexity of classification system. PCA (principal component analysis) transform the selected features and the overall features that is used classification with the number of principal components. These were classified as MAP (maximum a posteriori) and it compared with classification result using overall features. In all experiments, the computational complexity of the classification system was remarkably reduced and the classification accuracy was partially increased. Particularly, the proposed method increased the classification accuracy in the experiment classifying the Parkinson's disease and normal with the average 1.7 %. From the result, it confirmed that proposed method could be efficiently used in the classification system of the neuro-degenerative disease and vascular dementia of platelet.

Statistical review and explanation for Lanchester model (란체스터 모형에 대한 통계적 고찰과 해석)

  • Yoo, Byung Joo
    • The Korean Journal of Applied Statistics
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    • v.33 no.3
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    • pp.335-345
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    • 2020
  • This paper deals with the problem of estimating the log-transformed linear regression model to fit actual battle data from the Ardennes Campaign of World War II into the Lanchester model. The problem of determining a global solution for parameters and multicollinearity problems are identified and modified by examining the results of previous studies on data. The least squares method requires attention because a local solution can be found rather than a global solution if considering a specific constraint or a limited candidate group. The method of exploring this multicollinearity problem can be confirmed by a statistic known as a variance inflation factor. Therefore, the Lanchester model is simplified to avoid these problems, and the combat power attrition rate model was proposed which is statistically significant and easy to explain. When fitting the model, the dependence problem between the data has occurred due to autocorrelation. Matters that might be underestimated or overestimated were resolved by the Cochrane-Orcutt method as well as guaranteeing independence and normality.

Rethinking OTT regulation based on the global OTT market trends and regulation cases (OTT 서비스의 유형과 주요국의 규제 정책에 대한 고찰)

  • Kim, Suwon;Kim, Daewon
    • Journal of Internet Computing and Services
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    • v.20 no.6
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    • pp.143-156
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    • 2019
  • Discussion on OTT regulation has become fiercer, as OTT services' impacts on the global and domestic media market have been exponentially growing. In South Korea, it is argued that, on the basis of the similarity between television program and OTT's video content, OTT needs to be regulated in order to protect fair competition and to control sociocultural effects. In many of the discussions, developed countries' cases have been used for supporting OTT regulation. In this paper, we first analyzed the global OTT market trends based on our own categorization of OTT services. then we assessed the validity of the application of the foreign cases in the current OTT regulation debates in Korea. We proposed six OTT types (aggregation, mediation, mediation-aggregation, multi-screen, outlet, and outlet-linear) simultaneously considering service operator' origin, business model, content format, and content delivery. These services have been consistently evolving, and the OTT market has been increasingly competitive especially around content differentiation. Regulators must be wary of hastily introducing competition regulation to the dynamically innovating OTT market. The foreign cases, including the US, EU, the UK, and Japan, hardly seem to be appropriate bases for strengthening OTT regulation. Rather, they were focused more on promoting competition in the domestic media market and enriching the content ecosystem. Therefore, we need to consider revision of the outdated media regulation frameworks instead of fitting OTT under them, and to recognize the priority of securing practical jurisdiction on global service providers before capturing local players into the conventional regulation systems.

VARIABLE STARS IN THE REGION OF CYG OB3 ASSOCIATION CENTERED ON THE OPEN CLUSTER NGC 6871 I: δ SCUTI TYPE STARS (산개성단 NGC 6871을 중심으로 한 Cyg OB3 성협 영역의 변광성 I: δ Scuti 형 변광성)

  • Jeon, Young-Beom;Lee, Uiryeol;Park, Yoon-Ho;Kim, Donghyeon;Jang, Hyeeun;Cho, Sungyoon
    • Publications of The Korean Astronomical Society
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    • v.27 no.5
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    • pp.399-409
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    • 2012
  • As a part of the short-period variability survey (SPVS) at Bohyunsan Optical Astronomy Observatory, we obtained time-series BV CCD images in the region of Cyg OB3 association centered on the open cluster NGC 6871. The observations were performed for 18 nights from September 5, 2008 to September 1, 2009. We found 15 short-period variable stars in the region. They are ${\delta}$ Scuti type stars belonging to the local spiral arm, Orion spur. Among them, only two stars were previously known, and the rest are newly discovered ones. In this paper, we have performed a multiple-frequency analysis to determine frequencies of the 15 ${\delta}$ Scuti type stars, using the discrete Fourier transform and linear least-square fitting methods. One of the newly discovered variable stars is a double-mode ${\delta}$ Scuti type star with the fundamental and the first overtone modes, and two are high amplitude ${\delta}$ Scuti stars.