• Title/Summary/Keyword: time-trend

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A Study of Discriminant Analysis about Korean Quick Response System Adoption (국내(國內) 신속대응(迅速對應)시스템 도입업체(導入業體)의 판별분석(判別分析) 연구(硏究))

  • Ko, Eun-Ju
    • Journal of Fashion Business
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    • v.4 no.3
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    • pp.103-114
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    • 2000
  • The purpose of this study was to test the discriminant analysis model of Quick Response system and to examine the detailed relationship between each discriminant factor and Quick Response adoption. In this discriminant analysis model of Quick Response system, firm size, strategic type, product category, fashion trend, selling time and the Quick Response benefits were included as discriminant factors. Onehundred and two subjects were randomly selected for the survey study and discriminant analysis, descriptive analysis, t-test, and x square test were used for the data analysis. The results of this study were: 1. Wilks Lambda and F value support the discriminant analysis model that, taken together firm size, strategic type, product category, fashion trend, selling time and the Quick Response benefits significantly help to explain Quick Response adoption. 2. The importance of discriminant ability was, in order, firm size, the Quick Response benefits, women's wear, fashion trend, analyzer, selling time, reactor, defender and men's wear. 3. The discriminant function had the high hit ratio, so this can be well used for the classification of Quick Response adoption/nonadoption.

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Analysis of the Effect of Cigarette Price Hike (담배가격인상 효과분석)

  • Kim Do-Hoon;Han Kwang-Hwan
    • Journal of the Korean Society of Tobacco Science
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    • v.27 no.2
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    • pp.235-243
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    • 2005
  • The government continuously increases cigarette price to reduce the smoking rates. Opinions of cigarette makers and Ministry of Health and Welfare on the effect of cigarette price hike are sharply opposed. This dispute is important because there is possibility of additional increase of cigarette price by 500 won. Therefore, as an inquiry into existing studies for the effect of cigarette price hike on tobacco product, namely analysis of the effect of cigarette price hike consumption, we empirically analyzed the effect of cigarette excise tax hike through establishing improved analytic models considering time trend. As a result, it is substantiated that time trend in the effect of cigarette excise tax hike is certainly exist and early impact is heavy. However, the amount of cigarette consumption is recovered to the level of the average in 5 months. Since it is proved that the long term effect of cigarette price hike is immaterial, health authority should reconsider the plan of additional raising cigarette price by 500 won.

Rule discovery for sequential patterns of trend from Time-Series (시계열 데이터로부터 경향성을 이용한 순차패턴의 탐색)

  • 오용생;남도원;장지숙;이동하;이전영
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2000.11a
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    • pp.325-332
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    • 2000
  • 데이터마이닝 분야에서 시계얼 데이터(time-series data)내에서 숨어 있는 순차패턴의 발견은 상품(Items)이나 어떤 사건(Event)과 같이 데이터의 특징이 명확한 대상에 대한 연구는 많이 되어왔으나 수치 값을 가지는 시계열 데이터에서 이들 내부에 숨어 있는 패턴을 발견하는 것은 최근에 관심을 가지게 되었다. 우리는 시계열 데이터를 시간적 변화에 따라 값의 변화 경향(Trend)이 같은 데이터 그룹을 패턴 요소인 벡터 (Vestor)로 표현하여 이들을 이용해서 흥미로운 패턴들을 발견한다. 이와 같은 벡터적인 표현으로 우리는 벡터들 간의 포함관계를 적용해 모든 가능한 형태의 패턴 발견을 목적으로 한다. 또한 경향성을 가진 패턴 요소를 사건(Event)과 같이 취급함으로써 다양한 종류의 시계열 데이터가 동시에 발생될 때 이들 상호간에 연관된 시간적 패턴을 찾을 수 있다. 따라서 이 연구에서 제안하는 경향성을 기초로 한 순차패턴의 탐식은 기업내부의 판매실적의 변화 패턴이나, 고객의 구매 행동분석에 적용이 가능하리라 여겨진다

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The Serial Change Analysis of Heart Rate According to Expiration-to-inspiration Time Ratio in Adults (호흡패턴에 따른 성인의 심박수 동태 해석)

  • Park, Young-Bae;Han, Kyung-Sook;Nam, Tong-Hyun
    • Journal of Society of Preventive Korean Medicine
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    • v.14 no.2
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    • pp.105-120
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    • 2010
  • Objectives : This study aims to evaluate the effects of expiration-to-inspiration time ratio (E/I-ratio) on heart rate, which represents cardiac autonomic function, and cold-heat in the healthy people. Methods : 49 healthy young volunteers(male : female = 32 : 17) were recruited in the study. The participants completed the questionnaire for yin-yang pattern identification and then we measured the chest plethysmogram for respiration signal and the electrocardiogram for NN intervals during different E/I-ratio from 1 to 2. We compared heart rate variability including RMS-SD, VLF, LF and HF, and the trend-cycle factors decomposed from NN interval data by time series analysis among the respective E/I-ratio. We also confirmed the difference on the trend-cycle factors according to the score of the questionnaire for cold and heat pattern identification. Results : There were differences on the trend-cycle factors from NN interval data, but no significant difference on heart rate variability, among the respective E/I-ratio. We also found significant relationship between the trend-cycle factors and the heat pattern identification scores. Conclusions : The results indicate that cardiac autonomic function can be modulated by the E/I-ratio and the modulation will be slower and more tendencious than respiratory sinus arrhythmia.

Characteristic Trend Analysis of Cancer Patients Hospitalized in Shanxi Tumor Hospital for the First Time during 2001 and 2010

  • Zhang, Wen-Li;Wang, Yan;Han, Cun-Zhi
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3673-3676
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    • 2015
  • To observe and analyze the characteristic trend of cancer patients hospitalized for the first time in Shanxi Tumor Hospital from 2001 to 2010, clinical data including case number, age, gender, and frequency of different tumor occurrences were collected and statistically analyzed. Results: (i) From 2001 to 2010, the number of cancer patients hospitalized for the first time increased by 1.3-fold; (ii) The patient overall average age also increased from 51.8 to 54.4, for males from 55.5 to 58.7 and females from 48.4 to 51.1, respectively. (iii) Male patients accounted for 43-48% and females accounted for 52-57% of the total. The percentage of female patients was higher than that of male patients in every year and showed an upward trend over the years, while that of the males showed a downward trend (${\chi}^2=7.031$, p=0.008); (iv) Among the top 6 most common cancers, lung, cervical, esophageal, colorectal and breast cancers tended to increase over the years (p<0.05), but not gastric cancer (p=0.423). Conclusions: (i) The number of cancer patients hospitalized for the first time during the past 10 years increased year by year, and was higher for female than male; (ii) the average age of patients increased year after year and was greater for male than female; (iii) the number of patients with lung cancer, cervical cancer, esophageal cancer, colorectal cancer and breast cancer increased over years.

Comparison Studies of Hybrid and Non-hybrid Forecasting Models for Seasonal and Trend Time Series Data (트렌드와 계절성을 가진 시계열에 대한 순수 모형과 하이브리드 모형의 비교 연구)

  • Jeong, Chulwoo;Kim, Myung Suk
    • Journal of Intelligence and Information Systems
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    • v.19 no.1
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    • pp.1-17
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    • 2013
  • In this article, several types of hybrid forecasting models are suggested. In particular, hybrid models using the generalized additive model (GAM) are newly suggested as an alternative to those using neural networks (NN). The prediction performances of various hybrid and non-hybrid models are evaluated using simulated time series data. Five different types of seasonal time series data related to an additive or multiplicative trend are generated over different levels of noise, and applied to the forecasting evaluation. For the simulated data with only seasonality, the autoregressive (AR) model and the hybrid AR-AR model performed equivalently very well. On the other hand, if the time series data employed a trend, the SARIMA model and some hybrid SARIMA models equivalently outperformed the others. In the comparison of GAMs and NNs, regarding the seasonal additive trend data, the SARIMA-GAM evenly performed well across the full range of noise variation, whereas the SARIMA-NN showed good performance only when the noise level was trivial.

Development of Reliability Analysis Procedures for Repairable Systems with Interval Failure Time Data and a Related Case Study (구간 고장 데이터가 주어진 수리가능 시스템의 신뢰도 분석절차 개발 및 사례연구)

  • Cho, Cha-Hyun;Yum, Bong-Jin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.5
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    • pp.859-870
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    • 2011
  • The purpose of this paper is to develop reliability analysis procedures for repairable systems with interval failure time data and apply the procedures for assessing the storage reliability of a subsystem of a certain type of guided missile. In the procedures, the interval failure time data are converted to pseudo failure times using the uniform random generation method, mid-point method or equispaced intervals method. Then, such analytic trend tests as Laplace, Lewis-Robinson, Pair-wise Comparison Nonparametric tests are used to determine whether the failure process follows a renewal or non-renewal process. Monte Carlo simulation experiments are conducted to compare the three conversion methods in terms of the statistical performance for each trend test when the underlying process is homogeneous Poisson, renewal, or non-homogeneous Poisson. The simulation results show that the uniform random generation method is best among the three. These results are applied to actual field data collected for a subsystem of a certain type of guided missile to identify its failure process and to estimate its mean time to failure and annual mean repair cost.

A Study of Non-parametric Statistical Tests to Analyze Trend in Water Quality Data (수질자료의 추세분석을 위한 비모수적 통계검정에 관한 연구)

  • Lee, Sang-Hoon
    • Journal of Environmental Impact Assessment
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    • v.4 no.2
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    • pp.93-103
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    • 1995
  • This study was carried out to suggest the best statistical test to analyze the trend in monthly water quality data. Traditional parametric tests such as t-test and regression analysis are based on the assumption that the underlying population has a normal distribution and regression analysis additionally assumes that residual errors are independent. Analyzing 9-years monthly COD data collected at Paldang in Han River, the underlying population was found to be neither normal nor independent. Therefore parametric tests are invalid for trend detection. Four Kinds of nonparametric statistical tests, such as Run Test, Daniel test, Mann-Kendall test, and Time Series Residual Analysis were applied to analyze the trend in the COD data, Daniel test and Mann-Kendall test indicated upward trend in COD data. The best nonparametric test was suggested to be Daniel test, which is simple in computation and easy to understand the intuitive meaning.

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Research for Modeling the Failure Data for a Repairable System with Non-monotonic Trend (복합 추세를 가지는 수리가능 시스템의 고장 데이터 모형화에 관한 연구)

  • Mun, Byeong-Min;Bae, Suk-Joo
    • Journal of Applied Reliability
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    • v.9 no.2
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    • pp.121-130
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    • 2009
  • The power law process model the Rate of occurrence of failures(ROCOF) with monotonic trend during the operating time. However, the power law process is inappropriate when a non-monotonic trend in the failure data is observed. In this paper we deals with the reliability modeling of the failure process of large and complex repairable system whose rate of occurrence of failures shows the non-monotonic trend. We suggest a sectional model and a change-point test based on the Schwarz information criterion(SIC) to describe the non-monotonic trend. Maximum likelihood is also suggested to estimate parameters of sectional model. The suggested methods are applied to field data from an repairable system.

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An Analysis of New Textile Material Developmental Trend (섬유 신소재 개발 Trend에 대한 고찰)

  • 이유경;김순심
    • Korean Journal of Rural Living Science
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    • v.6 no.1
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    • pp.11-24
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    • 1995
  • The new textile materials may be defined as textile materials different from already existing ones in the physical and chemical structure, manufacturing process, or end-use property. The present time what is called the post-industrial society is characterized by rapid change and new technology. Also, textile materials have been changed rapidly and diversely in the post-industrial society than in any other periods. The study aimed to analyze the trend of new tektite materials development in Korea and to forecast the development trend in the future. To investigate the trend of new textile materials, various written materials and informations were collected from the manufacturers, textile related periodicals, and research journals, and they were analyzed. The period of analysis was from January 1992 to May 1995. The results of this research are as followings : (1) Mixed textile materiasl such as bicomponent fiber, blended yam and blended fabric were increased. (2) High technology has an important effect upon new textile material development. (3) functional textile materials were increased (4) The high value-added products were increased. (5) The naturalized textile materials were increased.

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