• Title/Summary/Keyword: 최소분산법

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Nonlinear Inference Using Fuzzy Cluster (퍼지 클러스터를 이용한 비선형 추론)

  • Park, Keon-Jung;Lee, Dong-Yoon
    • Journal of Digital Convergence
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    • v.14 no.1
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    • pp.203-209
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    • 2016
  • In this paper, we introduce a fuzzy inference systems for nonlinear inference using fuzzy cluster. Typically, the generation of fuzzy rules for nonlinear inference causes the problem that the number of fuzzy rules increases exponentially if the input vectors increase. To handle this problem, the fuzzy rules of fuzzy model are designed by dividing the input vector space in the scatter form using fuzzy clustering algorithm which expresses fuzzy cluster. From this method, complex nonlinear process can be modeled. The premise part of the fuzzy rules is determined by means of FCM clustering algorithm with fuzzy clusters. The consequence part of the fuzzy rules have four kinds of polynomial functions and the coefficient parameters of each rule are estimated by using the standard least-squares method. And we use the data widely used in nonlinear process for the performance and the nonlinear characteristics of the nonlinear process. Experimental results show that the non-linear inference is possible.

Fuzzy Inference Systems Based on FCM Clustering Algorithm for Nonlinear Process (비선형 공정을 위한 FCM 클러스터링 알고리즘 기반 퍼지 추론 시스템)

  • Park, Keon-Jun;Kang, Hyung-Kil;Kim, Yong-Kab
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.5 no.4
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    • pp.224-231
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    • 2012
  • In this paper, we introduce a fuzzy inference systems based on fuzzy c-means clustering algorithm for fuzzy modeling of nonlinear process. Typically, the generation of fuzzy rules for nonlinear processes have the problem that the number of fuzzy rules exponentially increases. To solve this problem, the fuzzy rules of fuzzy model are generated by partitioning the input space in the scatter form using FCM clustering algorithm. The premise parameters of the fuzzy rules are determined by membership matrix by means of FCM clustering algorithm. The consequence part of the rules is expressed in the form of polynomial functions and the coefficient parameters of each rule are determined by the standard least-squares method. And lastly, we evaluate the performance and the nonlinear characteristics using the data widely used in nonlinear process.

Correlation between Urban Green Areas and Outdoor Crime Rates - A Case Study of Austin, Texas - (도시녹지와 옥외범죄율 간의 상관관계 연구 - 텍사스 오스틴 지역을 중심으로 -)

  • Kim, Young-Jae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.1
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    • pp.49-56
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    • 2019
  • Urban green spaces have been contributing to the improvement of environmental, mental, and physical health for humans. In addition, recent studies showed the potential role of vegetation in reducing the amount of crime in inner-city neighborhoods at the micro-scale level. However, little is known about the positive role of urban green areas in improving urban safety at the regional level. The purpose of this study is to examine the relationship between urban green areas and actual outdoor crime rates, while also considering socio-demographic factors. The study area is the city of Austin, Texas, USA, which consists of 506 block groups. This study utilized socio-demographic factors based on U.S. Census data and vegetation-related factors utilizing GIS and ENVI software. For analyses, the analysis of variance (ANOVA) and an ordinary least square (OLS) regression were utilized. The results from ANOVA showed that yearly crime rates per acre for areas having 0%~25% trees in their neighborhoods were 0.46% and 1.05% higher than those of having 25%~50% and >50% trees in the neighborhoods, respectively. The results from the OLS regression represented that income, NDVI and park rates in neighborhoods were negatively associated with the crime rate per acre, whereas the percentage of minorities and the percentage of teenage school dropouts were positively associated with the crime rate per acre. This study implies that urban green areas may help to improve the safety of urban areas.

Earthquake Monitoring : Future Strategy (지진관측 : 미래 발전 전략)

  • Chi, Heon-Cheol;Park, Jung-Ho;Kim, Geun-Young;Shin, Jin-Soo;Shin, In-Cheul;Lim, In-Seub;Jeong, Byung-Sun;Sheen, Dong-Hoon
    • Geophysics and Geophysical Exploration
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    • v.13 no.3
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    • pp.268-276
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    • 2010
  • Earthquake Hazard Mitigation Law was activated into force on March 2009. By the law, the obligation to monitor the effect of earthquake on the facilities was extended to many organizations such as gas company and local governments. Based on the estimation of National Emergency Management Agency (NEMA), the number of free-surface acceleration stations would be expanded to more than 400. The advent of internet protocol and the more simplified operation have allowed the quick and easy installation of seismic stations. In addition, the dynamic range of seismic instruments has been continuously improved enough to evaluate damage intensity and to alert alarm directly for earthquake hazard mitigation. For direct visualization of damage intensity and area, Real Time Intensity COlor Mapping (RTICOM) is explained in detail. RTICOM would be used to retrieve the essential information for damage evaluation, Peak Ground Acceleration (PGA). Destructive earthquake damage is usually due to surface waves which just follow S wave. The peak amplitude of surface wave would be pre-estimated from the amplitude and frequency content of first arrival P wave. Earthquake Early Warning (EEW) system is conventionally defined to estimate local magnitude from P wave. The status of EEW is reviewed and the application of EEW to Odesan earthquake is exampled with ShakeMap in order to make clear its appearance. In the sense of rapidity, the earthquake announcement of Korea Meteorological Agency (KMA) might be dramatically improved by the adaption of EEW. In order to realize hazard mitigation, EEW should be applied to the local crucial facilities such as nuclear power plants and fragile semi-conduct plant. The distributed EEW is introduced with the application example of Uljin earthquake. Not only Nation-wide but also locally distributed EEW applications, all relevant information is needed to be shared in real time. The plan of extension of Korea Integrated Seismic System (KISS) is briefly explained in order to future cooperation of data sharing and utilization.

Preparation of Polystyrene Beads by Suspension Polymerization with Hydrophobic Silica as a Stabilizer in Aqueous Solution (소수성 실리카를 안정제로 이용하는 수용액 상에서의 현탁중합법에 의한 폴리스티렌 입자 합성)

  • Park, Moon-Soo
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.498-504
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    • 2006
  • A suspension polymerization of styrene In aqueous phase was employed to study if polystyrene particles ranging from 1 to $20{\mu}m$ can be produced. Hydrophobic silica was selected as a stabilizer and azo-bisisobutyronitrile (AIBN) as an initiator. Polymerization reaction was carried out at a selected temperature in the range of $65{\sim}95^{\circ}C$. Stabilizer concentration was varied from 0.17 to 3.33 wt% compared to the water while the concentration of the initiator was raised from 0.13 to 6.0 wt% compared to the monomer. Dispersion of hydrophobic silica into the water phase was achieved by precise control of pH. Optimum dispersion of silica was obtained at pH 10. Average particle diameter decreased with increasing amounts of stabilizer concentration initially, exhibiting the minimum average diameter at 1.67 wt% of stabilizer concentration, after which it started to Increase. It is speculated that an excessive presence of stabilizer encouraged a secondary reaction in the reaction medium, which led to particle agglomeration, and as a result an increase in average particle diameter. Molecular weight was found to be independent of stabilizer concentration between 0.13 and 1.00 wt% whereas, it increased when stabilizer concentration exceeded 1.67 wt%. Variation of molecular weight was probably caused by the reduced activity and efficiency of initiator due to the high concentration of silica, and the secondary reaction in the reaction medium, as well. An increase in the Initiator concentration and/or reaction temperature resulted in an increase in both reaction rate and particle diameter. Consequently, we have confirmed that spherical polystyrene particles with $1{\sim}20{\mu}m$ in diameter can be prepared by careful selection of the concentration of stabilizer, initiator, pH and reaction temperature.

A Study on the Numerical Modeling of the Fish Behabior to the Model Net - Parameter Estimation in Numerical Model of Fish Behavior - (모형그물에 대한 어군행동의 수직 모델링에 관한 연구 - 어군행동을 나타내는 수치 모델의 파라메터 추정 -)

  • Lee, Byoung-Gee;Lee, Dae-Jae;Chang, Ho-Young
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.4
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    • pp.307-325
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    • 1995
  • IN order to gain a fundamental data for forecast or control of fish behavior and evaluated the feasibility of an application of the modeling technique to a field, in this paper a numerical model for describing the behavior of fishes in a water tank was presented. The parameters of the model were estimated by using the time-series data on the three-dimensional position of fishes and by applying the least squares algorithm. The estimated parameters were standardized to examine the variation of parameters according to the number of individuals and flow speed that the mean values of parameters were to be zero and their variances were to be one. The results obtained can be summarized as follows: (1) The standardized parameter $a^*$of propulsive force decreased according to increased the number of individuals and the flow speed. (2) The standardized parameter ${k_b}^*$ of interactive force increased according to increased the number of individuals, but decreased according to the flow speed. (3) The standardized parameter ${k_c}^*$ of schooling force increased according to │increased the number of individuals and the flow speed. (4) The standardized parameter │${k_w}^{+*}$│ of repulsive force against wall or bottom increased according to increased the number of individuals, but decreased according to the flow speed. (5) The standardized parameter │${k_w}^{-*}$│ of attractive force against wall or bottom was generally constant according to increased the number of individuals, but increased according to the flow speed. (6) The standardized parameter $\upsilon$ super(*) of damping force increased according to increased the number of individuals, but decreased according to the flow speed.

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Predict ion-based Concurrency Control for A Large Scale Networked Virtual Environment Supporting Various Navigation Speed (다양한 이동속도를 지원하는 대규모 네트웍 가상 환경을 위한 예측 기반 동시성 제어)

  • 이은희;이동만;한승현;현순주
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.10c
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    • pp.202-204
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    • 2001
  • 가상 세계의 공유 개념은, 특히 사용자들이 인터넷 같이 대규모 네트웍을 통해 지역적으로 분산된 경우는 복제가 수용할 수 있는 상호작용 성능을 제공하기 때문에 각 사용자의 사이트에 정보를 복제함으로써 확장된다. 그러나, 다수의 동시 갱신은 replicas간의 일관되지 않은 뷰를 일으키게 될 것이다. 따라서, 동시성 제어가 복제자들간에 일관된 상태를 유지하도록 하기 위한 중요한 요소가 된다. 우리는 단지 대상 객체의 주변에 있는 사용자들만이 소유권 요청을 다중 전송하게 하는 확장성 있는 예측기반 동시성 제어 스킴을 제안했었다. 이 작업에서, 우리는 모든 사용자들이 동일한 속도론 가지고 가상 세계를 이동한다고 가정했다. 이것은, 그러나, 좀더 사실성을 더하기 위해 사용자가 가상 세계와 상호작용을 할 매 그들의 이동속도를 변경하도록 하는 네트웍 게임같은 네트웍 가상 환경에서는 너무 common 하다. 본 논문은 다양한 속도를 가진 사자를 지원하기 위한 확장을 제안한다. 확장된 스킴은 다른 속도의 수만큼의 다중 Entity Radii를 가지며 각 속도를 가진 사용자에게 분리된 큐를 할당한다. 각 큐는 다음 소유자 후보를 예측하기 위해 동시에 예측을 수행하고 선택된 후보들간에서 최소의 Predicted Collision Time을 가지는 최종 후보자가 선택된다. 이는 사용자의 속도에 기반을 둔 적절한 Entity Radius를 사용함으로써 소유권의 timely advanced transfer과, 다른 이돔 속도와 latency를 가지는 사용자들 간의 간섭을 줄임으로써 공정(공평)한 소유권 양도, 그리고 불필요한 소유권 전송을 줄임으로써 놓은 예측 정확도를 제공한다.성을 지닌 AMMQL 학습법은 로봇축구와 같이 끊임없이 실시간적으로 변화가 일어나는 다중 에이전트 환경에서 특히 높은 효과를 볼 수 있다. 본 논문에서는 AMMQL 학습방법의 개념을 소개하고, 로봇축구 에이전트의 동적 위치 결정을 위한 학습에 어떻게 이 학습방법을 적용할 수 있는지 세부 설계를 제시한다.다.으로서 hemicellulose구조가 polyuronic acid의 형태인 것으로 사료된다. 추출획분의 구성단당은 여러 곡물연구의 보고와 유사하게 glucose, arabinose, xylose 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아

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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.

Recommendation of Nitrogen Fertilization for Cucumber from Relationship between Soil Nitrate Nitrogen and Yield (토양의 질산태 질소와 수량과의 관계를 통한 오이의 질소 시비량 설정)

  • Lim, Tae-Jun;Hong, Soon-Dal;Kim, Seung-Heui;Park, Jin-Myeon
    • Korean Journal of Environmental Agriculture
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    • v.26 no.3
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    • pp.223-227
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    • 2007
  • This study was carried out to establish the reasonable level of nitrogen (N) fertilization based on soil nitrate nitrogen $(NO_3-N)$ content for cucumber (Cucumis sativus L.) under plastic film house. Cucumber plants were cultivated with standard and free N fertilization in eight soils which had various amount of $NO_3-N$ ranging from 67 to 343 mg/kg. The yield of cucumber was in the range of 1006 to 2369 g/plant depending on the nitrogen supplying capability of soils. The amount of $NO_3-N$ in the soil was negatively correlated with agronomic efficiency (AE) and N use efficiency (NUE). The critical level of soil $NO_3-N$ content for cucumber in N free fertilization was found to be about 260 mg/kg in Cate-Nelson analysis of variance between soil $NO_3-N$ and AE or NUE. Also the same critical soil $NO_3-N$ content was found in the yield and amount of N uptake of cucumber under N free fertilization. A standard N fertilization was required when soil $NO_3-N$ content was below 70 mg/kg. The optimal application rate of N fertilizer for cucumber in the soils containing $NO_3-N$ between 260-70 mg/kg could be recommended by the equation Y=-1.032X+269.2 (Y: N fertilization rate, kg/ha; X : soil $NO_3-N$ content mg/kg).

A Study on the Establishment of Disc Braking Force Pattern to reduce the Wear Mass of Pad (패드 마모량 감소를 위한 디스크 제동력 패턴 설정에 관한 연구)

  • Kim, Seog-Won;Kim, Young-Guk;Kim, Ki-Hwan
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.786-791
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    • 2007
  • Korean high speed train(HSR-350x) has adopted a combined electrical and mechanical(friction) braking system. Brake blending control unit(BBCU) controls each brake system to fulfill the required brake performances such as braking distance, deceleration and jerk. Also the braking system should be designed considering the economical management, such as effective use of generated braking energy and the minimum wear of friction materials(a pad and a brake shoe). In this paper, we establish the disc braking force pattern that reduces the wear of pad in the disc braking system by minimizing the variance of the instantaneous disk baking energy during braking time, and compare the wear mass of pad between the conventional disc braking force pattern and the established results.

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