• Title/Summary/Keyword: 선형 추세

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Visualization Tool of Distortion-Free Time-Series Matching (왜곡 제거 시계열 매칭의 시각화 도구)

  • Moon, Seongwoo;Lee, Sanghun;Kim, Bum-Soo;Moon, Yang-Sae
    • KIPS Transactions on Software and Data Engineering
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    • v.4 no.9
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    • pp.377-384
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    • 2015
  • In this paper we propose a visualization tool for distortion-free time-series matching. Supporting distortion-free is a very important factor in time-series matching to get more accurate matching results. In this paper, we visualize the result of time-series matching, which removes various time-series distortions such as noise, offset translation, amplitude scaling, and linear trend by using moving average, normalization, linear detrending transformations, respectively. The proposed visualization tool works as a client-server model. The client sends a user-selected time-series, of which distortions are removed, to the server and visualizes the matching results. The server efficiently performs the distortion-free time-series matching on the multi-dimensional R*-tree index. By visualizing the matching result as five different charts, we can more easily and more intuitively understand the matching result.

Regional Characteristics of Global Warming: Linear Projection for the Timing of Unprecedented Climate (지구온난화의 지역적 특성: 전례 없는 기후 시기에 대한 선형 전망)

  • SHIN, HO-JEONG;JANG, CHAN JOO
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.21 no.2
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    • pp.49-57
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    • 2016
  • Even if an external forcing that will drive a climate change is given uniformly over the globe, the corresponding climate change and the feedbacks by the climate system differ by region. Thus the detection of global warming signal has been made on a regional scale as well as on a global average against the internal variabilities and other noises involved in the climate change. The purpose of this study is to estimate a timing of unprecedented climate due to global warming and to analyze the regional differences in the estimated results. For this purpose, unlike previous studies that used climate simulation data, we used an observational dataset to estimate a magnitude of internal variability and a future temperature change. We calculated a linear trend in surface temperature using a historical temperature record from 1880 to 2014 and a magnitude of internal variability as the largest temperature displacement from the linear trend. A timing of unprecedented climate was defined as the first year when a predicted minimum temperature exceeds the maximum temperature record in a historical data and remains as such since then. Presumed that the linear trend and the maximum displacement will be maintained in the future, an unprecedented climate over the land would come within 200 years from now in the western area of Africa, the low latitudes including India and the southern part of Arabian Peninsula in Eurasia, the high latitudes including Greenland and the mid-western part of Canada in North America, the low latitudes including Amazon in South America, the areas surrounding the Ross Sea in Antarctica, and parts of East Asia including Korean Peninsula. On the other hand, an unprecedented climate would come later after 400 years in the high latitudes of Eurasia including the northern Europe, the middle and southern parts of North America including the U.S.A. and Mexico. For the ocean, an unprecedented climate would come within 200 years over the Indian Ocean, the middle latitudes of the North Atlantic and the South Atlantic, parts of the Southern Ocean, the Antarctic Ross Sea, and parts of the Arctic Sea. In the meantime, an unprecedented climate would come even after thousands of years over some other regions of ocean including the eastern tropical Pacific and the North Pacific middle latitudes where an internal variability is large. In summary, spatial pattern in timing of unprecedented climate are different for each continent. For the ocean, it is highly affected by large internal variability except for the high-latitude regions with a significant warming trend. As such, a timing of an unprecedented climate would not be uniform over the globe but considerably different by region. Our results suggest that it is necessary to consider an internal variability as well as a regional warming rate when planning a climate change mitigation and adaption policy.

Prospecting the Market of the Modular Housing Using the Nonlinear Forecasting Models (비선형 예측모형을 활용한 모듈러주택 시장전망)

  • Park, Nam-Cheon;Kim, Kyoon-Tai;Kim, In-Moo;Kim, Seok-Jong
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.6
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    • pp.631-637
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    • 2014
  • Recently, following the application of modular housing techniques to not only residential sector, but also to business sector, the scope of modular housing market b expanding. In the case of other developed countries, such markets are entering into the maturity stage, though the market in Korea is not fully formed yet. Thus, it is difficult to check its trend to estimated mid- to long-term prospects of the market. In this context, the study predicted demand of the modular housing market by using a non-linear prediction model based on time series analysis. To get the prospects for the modular housing market, the quantity of housing supply was estimated based on the estimated quantity of newly built housings, and assumed that a portion of the supplied quantity would be the demand for modular housings. Based on the assumption of demand for modular housings, several scenarios were analyzed and the prospects of the modular housing market was obtained by utilizing the non-linear prediction model.

Development of a Nonlinear Concrete Model for Internally Confined Hollow Members Considering Confining Effects (구속효과를 고려한 내부 구속 중공 CFT 부재의 비선형 콘크리트 모델 개발)

  • Han, Taek Hee;Youm, Eung Jun;Han, Sang Yun;Kang, Young Jong
    • Journal of Korean Society of Steel Construction
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    • v.19 no.1
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    • pp.43-52
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    • 2007
  • There is a growing range of applications for concrete-filled steel tube (CFT) member because of its superior performance. But a CFT member may be uneconomical or has weight problems because it is fully filled with concrete. In this study, a new type of member, called internally confined hollow (ICH) CFT member, was developed to solve the high cost and weight problems of the CFT member. To determine stress-strain model of the concrete in an ICH CFT column, possible failure modes of an ICH CFT column were suggested and confining pressure was derived from equilibriums for each failure mode. From the derived equations, a computer program was coded and parametric studies were performed for some examples. Analytical results showed that internally confined concrete has enhanced strength and ductility compared with those of unconfined or biaxially confined concrete.

Continuity Simulation and Trend Analysis of Water Qualities in Incoming Flows to Lake Paldang by Log Linear Models (로그선형모델을 이용한 팔당호 유입지류 수질의 연속성 시뮬레이션과 경향 분석)

  • Na, Eun-Hye;Park, Seok-Soon
    • Korean Journal of Ecology and Environment
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    • v.36 no.3 s.104
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    • pp.336-343
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    • 2003
  • Two types of statistical models, simple and multivariate log linear models, were studied for continuity simulation and trend analysis of water qualities in incoming flows to Lake Paldang. Water quality is a function of one independent variable (flow) in the simple log linear model, and of three different variables (flow, time, and seasonal cycle) in multivariate model. The independent variables act as surrogate variables of water quality in both models. The model coefficients were determined by the monthly data. The water qualities included 5-day Biochemical Oxygen Demand ($BOD_5$), Total Nitrogen (TN), and Total Phosphorus (TP) measured from 1995 to 2000 in the South and the North branches of Han River and the Kyoungan Stream. The results indicated that the multivariate model provided better agreements with field measurements than the simple one in a31 attempted cases. Flow dependency, seasonality, and temporal trends of water quality were tested on the determined coefficients of the multivariate model. The test of flow dependency indicated that BOD concentrations decreased as the water flow increased. In TN and TP concentrations, however, there were no discernible flow effects. From the temporal trend analyses, the following results were obtained: 1) no trends on BOD at all three upstreams, 2) increase on TN at the South Branch and the Kyoungan Stream, 3)decrease on TN at the North Branch,4) no trends on TP at the North and the South Branches and 5) increase on TP at the Kyoungan Stream by 3 to 8% per years. The seasonality test showed that there were significant seasonal variations in all three water qualities at three incoming flows.

Non-stationary Rainfall Frequency Analysis Based on Residual Analysis (잔차시계열 분석을 통한 비정상성 강우빈도해석)

  • Jang, Sun-Woo;Seo, Lynn;Kim, Tae-Woong;Ahn, Jae-Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5B
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    • pp.449-457
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    • 2011
  • Recently, increasing heavy rainfalls due to climate change and/or variability result in hydro-climatic disasters being accelerated. To cope with the extreme rainfall events in the future, hydrologic frequency analysis is usually used to estimate design rainfalls in a design target year. The rainfall data series applied to the hydrologic frequency analysis is assumed to be stationary. However, recent observations indicate that the data series might not preserve the statistical properties of rainfall in the future. This study incorporated the residual analysis and the hydrologic frequency analysis to estimate design rainfalls in a design target year considering the non-stationarity of rainfall. The residual time series were generated using a linear regression line constructed from the observations. After finding the proper probability density function for the residuals, considering the increasing or decreasing trend, rainfalls quantiles were estimated corresponding to specific design return periods in a design target year. The results from applying the method to 14 gauging stations indicate that the proposed method provides appropriate design rainfalls and reduces the prediction errors compared with the conventional rainfall frequency analysis which assumes that the rainfall data are stationary.

Airborne Video as a Remote Sensor for Linear Target : Academic Research and Field Practices (선형지상물체에 대한 원격센서로서의 항공비디오 : 연구추세 및 실무에서 사용현황)

  • 엄정섭
    • Korean Journal of Remote Sensing
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    • v.15 no.2
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    • pp.159-174
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    • 1999
  • An important aspect of remote sensing research would be ultimately the production of research output so that operational people can directly use it. However, for the strip target, it is not certain how the research output in remote sensing helps the field user in adopting and utilizing the technology successfully. The relative limitation of traditional remote sensing systems for such a linear application is briefly discussed and the strength of videography are highlighted. Based on the postulated advantages of video as corridor sensor, a careful and extensive investigation has been made of research trends for airborne videography to identify how past research matches to demand of field clients. It is found that while video has been operationally used for strip target in field client communities, much research effort has been directed to area target, and relatively little towards the classification and monitoring of linear target. From this critical review, a very important step has been made concerning the practicality of airborne videography. The value of this paper is warranted in proposing a new concept of video strip monitoring(VSM) as future research direction in recognition of sensor characteristics and limitations. Ultimately, the suggestion in this paper will greatly contribute to opening new possibilities for implementing VSM, proposed as an initial aim of this paper.

A Study on Control of High Power PM Excited TFLM for Long Distance (장거리 이송용 고출력 영구자석 여자 횡자속 선형전동기 제어에 관한 연구)

  • Jeon, Jin-Yong;Hwang, Gye-Ho;Kim, Ji-Won;Kim, Gyu-Sik
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.5
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    • pp.471-479
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    • 2006
  • Automatic transfer equipments of manufacturing and process line trend toward big size as LCD glass is big size, heavy weight. The conventional stocker uses rotational motor and mechanical power converter device as travel axis of stocker crane and then frequent maintenances by complex structure and mechanical friction are required. Also it has problem to minimize the particle generation. To solve these problems, this paper verified the performance of permanent magnet(PM) excited transverse flux linear motor(TFLM) that is big power density per unit volume applied for travel axis of 7 generation stocker that is being big size, high power, long distance by the experiment based on proposed control algorithm, controller and power converter device.

Linear SVM-Based Android Malware Detection and Feature Selection for Performance Improvement (선형 SVM을 사용한 안드로이드 기반의 악성코드 탐지 및 성능 향상을 위한 Feature 선정)

  • Kim, Ki-Hyun;Choi, Mi-Jung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.8
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    • pp.738-745
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    • 2014
  • Recently, mobile users continuously increase, and mobile applications also increase As mobile applications increase, the mobile users used to store sensitive and private information such as Bank information, location information, ID, password on their mobile devices. Therefore, recent malicious application targeted to mobile device instead of PC environment is increasing. In particular, since the Android is an open platform and includes security vulnerabilities, attackers prefer this environment. This paper analyzes the performance of malware detection system applying linear SVM machine learning classifier to detect Android malware application. This paper also performs feature selection in order to improve detection performance.

Factor Analysis of Customer Loyalty in Car Insurance Using Generalized Additive Partial Linear Model (일반화가법부분선형모형을 이용한 자동차보험 충성도 요인분석)

  • Ki, Seung-Do;Kang, Kee-Hoon
    • The Korean Journal of Applied Statistics
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    • v.25 no.1
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    • pp.67-79
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    • 2012
  • The car insurance market in Korea has already entered (or is in the process of entry) a mature market that is characterized by increased competition by market participants. Participants are expected to compete more intensively in order to survive. Together with a slowdown in market growth the goal of non-life insurers' marketing strategies is to enhance existing customer loyalty because it is easier to raise their loyalty via customer satisfaction than to attract new customers in a stagnant market. In this article, we investigate what factors affect customer loyalty, and suggest some specific ways to establish and implement marketing strategies. We use a generalized additive partial linear model in order to find some significant factors.