• Title/Summary/Keyword: representativeness

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Discontinuity of Representativeness Heuristic

  • 이호창
    • Korean Management Science Review
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    • v.16 no.1
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    • pp.101-113
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    • 1999
  • The individual behavior on considering prior information when one assesses the probability of uncertain event by representativeness heuristic has been investigated. While prior researches proposed two contrasting behaviors on the employment, we tested the mixed hypothesis that individual ignores the prior information to some extents and begins to consider it above certain threshold when the evidence of representativeness is not salient. The threshold effect of prior probability is positively experimented and the results strongly support the discontinuity hypothesis of representativeness heuristic.

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A study on sensitivity of representativeness indicator in survey sampling (표본 추출법에서 R-지수의 민감도에 관한 연구)

  • Lee, Yujin;Shin, Key-Il
    • The Korean Journal of Applied Statistics
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    • v.30 no.1
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    • pp.69-82
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    • 2017
  • R-indicator (representativeness indicator) is used to check the representativeness of samples when non-responses occur. The representativeness is related with the accuracy of parameter estimator and the accuracy is related with bias of the estimator. Hence, unbiased estimator generates high accuracy. Therefore, high value of R-indicator guarantees the accuracy of parameter estimation with a small bias. R-indicator is calculated through propensity scores obtained by logit or probit modeling. In this paper we investigate the degree of relation between R-indicator and different non-response rates in strata using simulation studies. We also analyze a modified Korea Economic Census data for real data analysis.

Usage and Estimation of R-indicator for Representative (대표성을 위한 R-indicator의 사용과 추정법 연구)

  • Park, Hyeonah;Lee, Kee-Jae
    • The Korean Journal of Applied Statistics
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    • v.28 no.3
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    • pp.417-427
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    • 2015
  • Measures in response rate used to measure the representativeness of the sample (the more high response rate) better explain the representativeness of the sample. However, we cannot often explain the representativeness of the sample because there is nonresponse even in the high response rate. Therefore, Schouten et al. (2009) presented a new R-indicator measure that can be described as a representative of the sample. We research the new estimator of the R-indicator in this paper because there are parameters that require estimations. We describe the meanings as representative of the R-indicator; consequently, the bias and efficiency of the proposed estimator for R-indicator are compared to the existing estimator under various simulations. The representativeness of the sample is also explained by applying the proposed estimators in the actual data.

Active Learning on Sparse Graph for Image Annotation

  • Li, Minxian;Tang, Jinhui;Zhao, Chunxia
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.10
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    • pp.2650-2662
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    • 2012
  • Due to the semantic gap issue, the performance of automatic image annotation is still far from satisfactory. Active learning approaches provide a possible solution to cope with this problem by selecting most effective samples to ask users to label for training. One of the key research points in active learning is how to select the most effective samples. In this paper, we propose a novel active learning approach based on sparse graph. Comparing with the existing active learning approaches, the proposed method selects the samples based on two criteria: uncertainty and representativeness. The representativeness indicates the contribution of a sample's label propagating to the other samples, while the existing approaches did not take the representativeness into consideration. Extensive experiments show that bringing the representativeness criterion into the sample selection process can significantly improve the active learning effectiveness.

The Weather Representativeness in Changma Period Established by the Weather Entropy and Information Ratio - Focused on Seoul, Taegu, Gwangju, Chungju, Puyo - (일기엔트로피 및 정보비에 의한 장마기의 일기대표성 설정 - 서울, 대구, 광주, 충주, 부여를 중심으로 -)

  • 박현욱;문병채
    • Journal of Environmental Science International
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    • v.12 no.4
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    • pp.399-417
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    • 2003
  • The seasonal variation and frequency of rainfalls of Korea peninsula in Changma period show strong local weather phenomenon because of it's topographical and geographical factors in Northeast side of Asia. Based on weather entropy(statistical parameter)-the amount of average weather information-and information ratio, we can define each area's weather representativeness, which can show us more constant form included topographical and geographical factors and seasonal variation. The data used for this study are the daily precipitation and cloudiness during the recent ten years(1990-1999) at the 73 stations in Korea. To synthesize weather Entropy, information ratio of decaying tendency and half$.$decay distance, Seoul's weather representativeness has the smallest in Summer Changma period. And Puyo has the largest value in September.

Evaluation of the Representativeness of Air Quality Monitoring Network in Seoul through Actual Measurement (대기오염도 실측에 의한 대기오염 자동측정망의 대표성 평가)

  • Jeon, Eui-Chan
    • Journal of Environmental Impact Assessment
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    • v.5 no.1
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    • pp.79-85
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    • 1996
  • Simultaneous monitoring in many locations is necessary to evaluate the air quality and analyze future trend of a city, For this purpose, it is essential to install air pollution monitoring network. The first automatic air pollution monitoring network was introduced Seoul in 1973. As of 1995, 20 monitoring stations are now in operation. Concerning the management of the air pollution monitoring network, there was some argument among the relavant scholars, non-governmental organization(NGO) and the government organization. So far, there was no extensive evaluation and analysis about the network. The purpose of this study was to evaluate the representativeness of air quality monitoring network through actual measurement of the concentration of the air pollutant. The concentration of NOx was extensively measured widely in Seoul area three times using the TEA simple measuring technique. Even the judgement level for the area representativeness was lowered to 80%, Ssangmun-dong monitoring station tend to overestimate the pollutant concentration of the covered area. While, Sinlimdong monitoring station tend to underestimate the pollutant concentration of the covered area.

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A Study on the Representativeness of Proofs in the Geometry (기하 증명에서의 대표성에 관한 연구)

  • Chung, Young Woo;Kim, Boo Yoon
    • Journal of Educational Research in Mathematics
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    • v.25 no.2
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    • pp.225-240
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    • 2015
  • In this study, we investigated the representativeness of proofs in school mathematics, based on the extension of the midpoint connector theorem for the quadrilateral. To this end, we considered a variety of quadrilateral and proved their extensions of the midpoint connector theorem, and identified the relationships between them, therefore seemed that the proof in school mathematics has a representativeness. On the other hand, in the survey based on this information, students were found only some types of quadrilateral and completed easily the proofs for each quadrilateral they found, but students tended to use other proof or mathematical concepts, if the target figures changes in despite of proving the same mathematical fact. Thus, students were more difficult to figure out the relationship between the proofs. From these facts, we know that students are poorly understood the representativeness of proofs to understand the relationship between concrete proofs and to generalize it, though they are able to proof to the specific figures. Therefore it can be seen that the proof activity needs to be done with organic and semantic.

Evaluation and Complement of the Representativeness of Air Quality Monitoring Stations Using Passive Air Samplers (수동측정기에 의한 대기오염 자동측정망의 지역대표성 조사 및 보완방완에 대한 기초연구)

  • 우정현;김선태;김정욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.13 no.6
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    • pp.415-426
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    • 1997
  • Some arguments have been about over the representativeness of government-run air quality monitoring stations among scholars and non-governmental organizations (NGOs). However, it is not a simple problem to move monitoring stations because of continuity of data and high cost. So it is necessary to complement the monitoring data if it do not represent the ambient air quality properly. The purpose of this study was to evaluate the representativeness of some monitoring stations using passive $NO_2$ samplers and to find a complementary method from linear regression. Two stations were chosen for the evaluation: Shinlim Station was one of the most controversial stations in Seoul and Banpo Station had the best reputation. Air qualities were surveyed at seven points around each monitoring station with consideration of land use and distance. The ratios of the average $NO_2$ levels of the areas to these at the monitoring stations were 1.59 for Shinlim Station and 1.03 for Banpo Station. The differences between the average $NO_2$ levels and those at the monitoring stations were 10.75 ppb for Shilim Station and 0.34 ppb for Banpo Station. The correlation coefficients between the two levels were 0.7668 for Shinlim and 0.7662 for Banpo. The average coefficients of determination $(R^2)$ were 0.61 for Shinlim and 0.61 for Banpo. The Shinlim Station could not represent the air quality of Shinlim-Dong good because it is located in a green area at an outskirt of Shinlim-Dong. But the Banpo Station located in a central residential area of Banpo-Dong showed a fair representativeness. However, air quality turned out to be different with land use such as residential area, green area or road: the air quality data from a monitoring station located at a certain land use should not be interpreted as representing the air quality at any sites around the station. Equations to predict the average $NO_2$ levels of each area from the data from the monitoring stations were presented based on linear regression.

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Evaluations for Representativeness of Light-Duty Diesel Vehicles' Fuel-based Emission Factors on Vehicle Operating Conditions (연료 소비량에 기반한 소형 경유차 대기오염물질 배출계수의 운전조건별 대표성 평가)

  • Lee, Taewoo;Kwon, Sangil;Son, Jihwan;Kim, Jiyoung;Jeon, Sangzin;Kim, Jeongsoo;Choi, Kwangho
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.6
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    • pp.745-756
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    • 2013
  • The purpose of this study is to evaluate representativeness of fuel-based emission factors. Twelve light-duty diesel vehicles which meet Euro-3 to 5 legislative emission limits were selected for emission tests. Second-by-second modal emission rates of vehicles were measured on a standard laboratory chassis dynamometer system. An off-cycle driving cycle was developed as a representative Korean real-world on-road driving cycle. Fuel-based emission factors were developed for short trip segments that involved in the selected driving cycle. Each segment was defined to have unit travel distance, which is 1 km, and characterized by its average speed and Relative Positive Acceleration (RPA). Fuel-based $NO_x$ emission factors demonstrate relatively good representativeness in terms of vehicle operation conditions. $NO_x$ emission factors are estimated to be within ${\pm}20%$ of area-wide emission factor under more than 40% of total driving situations. This result implies that the fuel-based $NO_x$ emission factor could be practically implemented into the on-road emission management strategies, such as a remote sensing device (RSD). High emitting vehicles as well as high emitting operating conditions heavily affect on the mean values and distributions of CO and THC emission factors. Few high emitting conditions are pulling up the mean value and biasing the distributions, which weaken representativeness of fuel-based CO and THC emission factors.

A Study on the Factors Promoting the Use of Memory-based Emotion in Evaluating the Brand (상표평가에서 기억감정의 이용을 촉진하는 요인에 관한 연구)

  • Choi, Nak-Hwan;Na, Ji-Eun
    • Journal of Global Scholars of Marketing Science
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    • v.13
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    • pp.49-70
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    • 2004
  • Recently, consumer researchers have suggested that consumers evaluate brand by subjective memory-based-emotion which was formed by their experience. However, relatively little consumer research has been done to explore conditions under which memory-based-emotion is used in brand evaluation. Therefore, this study explored the conditions to facilitate usage of memory-based- emotion such as accessibility, representativeness, relevance of consumption goal, when consumers evaluate brand. In addition, we investigated the factors that influence responses of memory-based- emotion, such as similarity of encoding and retrieving condition and level of organization. The results of this study suggest that level of organization was positively related to accessibility and representativeness. But similarity of encoding and retrieving condition was not related to them. And accessibility, representativeness influence on use of memory-based-emotion in consumer brand evaluation. But relevance of consumption goal did not influence on use of memory-based-emotion in consumer brand evaluation.

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