• Title/Summary/Keyword: selection rate

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An Enhanced Mobile Multicast Protocol

  • Nam, Sea-Hyeon
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2005.11a
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    • pp.61-64
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    • 2005
  • The packet loss problem that occurs in the mobile multicast (MoM) protocol due to designated multicast service provider (DMSP) handoff is investigated through simulation experiments for several DMSP selection policies. Then, two enhanced DMSP schemes are proposed to minimize the packet loss of the MoM protocol with single DMSP. The first scheme uses a backup DMSP and greatly reduces the packet loss rate at the expense of the increased network traffic. The second scheme utilizes the extended DMSP operation and shows many desirable features such as the almost-zero packet loss rate and relatively low network traffic.

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Model Grouping in a Mixed-model Assembly Line (조립생산 시스템에서의 혼합 모델 그룹화)

  • Kim, Yearn-Min;Seo, Yoon-Ho
    • IE interfaces
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    • v.9 no.2
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    • pp.39-45
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    • 1996
  • This paper investigates the problems of grouping N products on an assembly line with an objective of maximizing the option grouping rate. Before developing a mixed model grouping algorithm, simulation studies are committed for developing operating rules and evaluating the layout production systems. A mixed model grouping algorithm is suggested and it is applied to the color selection lane in automobile production system, which reveals a high mixed model grouping rate.

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The Right Gastroepiploic Artery Graft for Coronary Artery Bypass Grafting: A 30-Year Experience

  • Suma, Hisayoshi
    • Journal of Chest Surgery
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    • v.49 no.4
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    • pp.225-231
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    • 2016
  • Throughout its 30-year history, the right gastroepiploic artery (GEA) has been useful for in situ grafts in coronary artery bypass grafting (CABG). The early graft patency rate is high, and the late patency rate has improved by using the skeletonized GEA graft and proper target selection, which involves having a target coronary artery with a tight >90% stenosis. Total arterial revascularization with the internal thoracic artery and GEA grafts is an option for achieving better outcomes from CABG procedures.

Analyzing Customer Management Data by Data Mining: Case Study on Chum Prediction Models for Insurance Company in Korea

  • Cho, Mee-Hye;Park, Eun-Sik
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.4
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    • pp.1007-1018
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    • 2008
  • The purpose of this case study is to demonstrate database-marketing management. First, we explore original variables for insurance customer's data, modify them if necessary, and go through variable selection process before analysis. Then, we develop churn prediction models using logistic regression, neural network and SVM analysis. We also compare these three data mining models in terms of misclassification rate.

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Self-optimizing feature selection algorithm for enhancing campaign effectiveness (캠페인 효과 제고를 위한 자기 최적화 변수 선택 알고리즘)

  • Seo, Jeoung-soo;Ahn, Hyunchul
    • Journal of Intelligence and Information Systems
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    • v.26 no.4
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    • pp.173-198
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    • 2020
  • For a long time, many studies have been conducted on predicting the success of campaigns for customers in academia, and prediction models applying various techniques are still being studied. Recently, as campaign channels have been expanded in various ways due to the rapid revitalization of online, various types of campaigns are being carried out by companies at a level that cannot be compared to the past. However, customers tend to perceive it as spam as the fatigue of campaigns due to duplicate exposure increases. Also, from a corporate standpoint, there is a problem that the effectiveness of the campaign itself is decreasing, such as increasing the cost of investing in the campaign, which leads to the low actual campaign success rate. Accordingly, various studies are ongoing to improve the effectiveness of the campaign in practice. This campaign system has the ultimate purpose to increase the success rate of various campaigns by collecting and analyzing various data related to customers and using them for campaigns. In particular, recent attempts to make various predictions related to the response of campaigns using machine learning have been made. It is very important to select appropriate features due to the various features of campaign data. If all of the input data are used in the process of classifying a large amount of data, it takes a lot of learning time as the classification class expands, so the minimum input data set must be extracted and used from the entire data. In addition, when a trained model is generated by using too many features, prediction accuracy may be degraded due to overfitting or correlation between features. Therefore, in order to improve accuracy, a feature selection technique that removes features close to noise should be applied, and feature selection is a necessary process in order to analyze a high-dimensional data set. Among the greedy algorithms, SFS (Sequential Forward Selection), SBS (Sequential Backward Selection), SFFS (Sequential Floating Forward Selection), etc. are widely used as traditional feature selection techniques. It is also true that if there are many risks and many features, there is a limitation in that the performance for classification prediction is poor and it takes a lot of learning time. Therefore, in this study, we propose an improved feature selection algorithm to enhance the effectiveness of the existing campaign. The purpose of this study is to improve the existing SFFS sequential method in the process of searching for feature subsets that are the basis for improving machine learning model performance using statistical characteristics of the data to be processed in the campaign system. Through this, features that have a lot of influence on performance are first derived, features that have a negative effect are removed, and then the sequential method is applied to increase the efficiency for search performance and to apply an improved algorithm to enable generalized prediction. Through this, it was confirmed that the proposed model showed better search and prediction performance than the traditional greed algorithm. Compared with the original data set, greed algorithm, genetic algorithm (GA), and recursive feature elimination (RFE), the campaign success prediction was higher. In addition, when performing campaign success prediction, the improved feature selection algorithm was found to be helpful in analyzing and interpreting the prediction results by providing the importance of the derived features. This is important features such as age, customer rating, and sales, which were previously known statistically. Unlike the previous campaign planners, features such as the combined product name, average 3-month data consumption rate, and the last 3-month wireless data usage were unexpectedly selected as important features for the campaign response, which they rarely used to select campaign targets. It was confirmed that base attributes can also be very important features depending on the type of campaign. Through this, it is possible to analyze and understand the important characteristics of each campaign type.

A Study on the Strategy to Maintain Optimal Flow-rate and Pressure of the Piping System for Individual Heating (개별 난방방식에서의 배관 내 절정 유량 및 압력유지에 관한 연구)

  • Hong Seok-Jin;Ryu Seong-Ryong;Seok Ho-Tae;Yeo Myoung-Souk;Kim Kwang-Woo
    • Journal of the Korean housing association
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    • v.17 no.2
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    • pp.11-18
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    • 2006
  • For the more comfortable thermal environment in residential buildings, it was necessary for variable components like as automatic flow limiting valves and/or balancing valves in hydronic system. And, these components had an effect on flow-rate and pressure inside pipe. In this case, the incompatibility between the design for the heating system and the selection of equipment was the causes of several problems in heating pipe network. In this study, we peformed measurements and analyses of flow rate and pressure inside pipe for radiant floor heating in residential buildings through field surveys and experiments in order to find out the actual conditions and problems. On the basis of this, we suggested the approach for the optimal flow-rate and pressure maintaining inside pipe in individual heating system.

Efficient Rate Control by Fast Adaptive Mode Selection

  • Ryu, Chul
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.4E
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    • pp.43-50
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    • 1999
  • A fast converging coding algorithm that adaptively selects the modes of macroblocks is introduced. For a given frame, the optimal modes are selected based on the decision curves that minimize the overall distortion at a given bit rate. The method proposed in this paper is different from the conventional ones in that it does not manipulate the quantizer to meet the target bit rate but it satisfies the target bit rate by finding optimal modes of macroblocks which result consistent visual quality. Lagrange multiplier of the unconstrained cost function is controlled to trigger decision curves to generate appropriate modes to meet bit rate and the curve is obtained by utilizing simulated annealing optimization technique. The algorithm is implemented within H.261 video codec and simulation results demonstrate superior visual quality.

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The Comparative Experiment of Duct Design Method with Equal Friction Loss Method and T-Method on a House Ventilation System (등압법과 T-Method법을 이용한 주택환기시스템 덕트설계법의 비교실험)

  • Joo, Sung-Yong;Kim, Kwang-Hyun;Choi, Seok-Yong;Yee, Jurng-Jae
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.99-104
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    • 2006
  • Accurate flow rate distribution has been become a very important part for controling of air change rate since the introduction of house ventilation system. An inappropriate selection of fan due to Incorrect prediction of friction loss makes waste energy. The purpose of this study is to recognize applicability of T-Method at house ventilation system by comparing experiment with T-method, The result of this study is as follows Flow rate is small amount in a house, so duct size must be accurate. And duct design with Equal Friction Loss Method presented large error range. Equal friction loss method is not fit to applicate small amount air flow rate. T-Method predicts accurate flow rate comparatively in a house ventilation system. Error range was 3.5%.

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Use of big data for estimation of impacts of meteorological variables on environmental radiation dose on Ulleung Island, Republic of Korea

  • Joo, Han Young;Kim, Jae Wook;Jeong, So Yun;Kim, Young Seo;Moon, Joo Hyun
    • Nuclear Engineering and Technology
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    • v.53 no.12
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    • pp.4189-4200
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    • 2021
  • In this study, the relationship between the environmental radiation dose rate and meteorological variables was investigated with multiple regression analysis and big data of those variables. The environmental radiation dose rate and 36 different meteorological variables were measured on Ulleung Island, Republic of Korea, from 2011 to 2015. Not all meteorological variables were used in the regression analysis because the different meteorological variables significantly affect the environmental radiation dose rate during different periods, and the degree of influence changes with time. By applying the Pearson correlation analysis and stepwise selection methods to the big dataset, the major meteorological variables influencing the environmental radiation dose rate were identified, which were then used as the independent variables for the regression model. Subsequently, multiple regression models for the monthly datasets and dataset of the entire period were developed.

An Optimal Selection of Frame Skip and Spatial Quantization for Low Bit Rate Video Coding (저속 영상부호화를 위한 최적 프레임 율과 공간 양자화 결정)

  • Bu, So-Young;Lee, Byung-Uk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.6C
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    • pp.842-847
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    • 2004
  • We present a new video coding technique to tradeoff frame rate and picture quality for low bit rate video coding. We show a model equation for selecting the optimal frame rate from the motion content of the source video. We can determine DCT quantization parameter (QP) using the frame rate and bit rate. For objective video quality measurement we propose a simple and effective error measure for skipped frames. The proposed method enhances the video quality up to 2 ㏈ over the H.263 TMN5 encoder.