• 경영과학
• /
• 제16권1호
• /
• pp.101-113
• /
• 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.

• 응용통계연구
• /
• 제30권1호
• /
• pp.69-82
• /
• 2017

R-지수(representativeness indicator)는 무응답이 발생했을 때 표본의 대표성을 나타내주는 지표이다. 표본의 대표성은 모수 추정의 정확성(accuracy)과 관계가 있으며 정확성은 편향(bias)와 관계가 있다. 따라서 표본의 대표성을 나타내는 R-지수가 높으면 대표성이 높아 편향이 없고 정확성이 높은 결과를 얻을 수 있다. R-지수는 일반화선형모형의 로짓 또는 프로빗 모형을 적합한 후 얻어진 경향 점수(propensity score)에 의해 계산된다. 본 논문에서는 R-지수와 이질적인 층별 응답률과의 관련성을 연구하였으며 편향, 제곱근 RMSE 등과 같은 비교통계량이 무응답에 얼마나 민감한지 등을 모의실험을 통하여 살펴보았다. 또한 변형된 2010년 경제총조사 자료를 이용하여 실제 자료분석도 실시하였다.

• 응용통계연구
• /
• 제28권3호
• /
• pp.417-427
• /
• 2015

표본의 대표성을 측정하기 위한 척도로 응답률이 사용된다. 즉 높은 응답률일수록 표본의 대표성을 더 잘 나타낸다고 할 수 있다. 그러나 높은 응답률이라 할지라도 무응답이 존재하는 것이므로 표본의 대표성을 설명하기에는 한계가 있는 경우가 발생한다. 그래서 Schouten 등 (2009)에서는 R-indicator라는 새로운 척도를 제시하여 표본의 대표성을 더 설명할 수 있게 하였다. 본 논문에서는 R-indicator도 표본에 의해 추정되어야 한다는 것에 착안하여 그것에 관한 새로운 추정량을 제시한다. 또한 여러 모의실험하에 R-indicator의 대표성으로써의 설명력과 제안된 추정량의 편향과 효율을 기존의 추정량과 비교분석하며 실제자료에도 제안한 추정량을 적용하여 표본의 대표성을 설명한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권10호
• /
• pp.2650-2662
• /
• 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.

• 한국환경과학회지
• /
• 제12권4호
• /
• pp.399-417
• /
• 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.

• 환경영향평가
• /
• 제5권1호
• /
• pp.79-85
• /
• 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.

• 대한수학교육학회지:수학교육학연구
• /
• 제25권2호
• /
• pp.225-240
• /
• 2015

본 연구에서는 중점연결정리의 사각형으로의 확장을 소재로 학교수학에서 다루어지는 증명의 대표성에 대해 고찰하였다. 다양한 사각형을 생각하고, 그에 맞는 중점연결정리의 확장을 증명하였으며, 이들 증명 간의 관계를 파악하여 학교수학에서의 증명이 대표성을 가짐을 보였다. 한편, 이러한 내용에 기초한 실태조사에서 학생들은 사각형 종류의 일부만을 찾았으며, 찾은 사각형 각각에 대한 증명은 쉽게 완성하였으나, 같은 수학적 사실을 증명하고 있음에도 대상 도형이 바뀌면 다른 증명 방법이나 수학적 개념을 사용하는 경향을 보였다. 따라서 증명들 간의 관계를 파악하는 것을 어려워하였다. 이러한 사실들은 구체적 도형에 대한 증명은 할 수 있으나, 증명들 간의 관계를 이해하여 일반화하는 증명의 대표성에 대한 이해는 부족함을 보여준다. 따라서 증명활동이 유기적이고 의미론적으로 이루어질 필요가 있음을 알 수 있다.

• 한국대기환경학회지
• /
• 제13권6호
• /
• pp.415-426
• /
• 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.

• 한국대기환경학회지
• /
• 제29권6호
• /
• pp.745-756
• /
• 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.

• 마케팅과학연구
• /
• 제13권
• /
• pp.49-70
• /
• 2004

소비자들은 상표에 대하여 과거에 자신이 경험한 주관적인 감정반응을 기억하여 상표를 평가한다는 연구가 최근 제시되고 있는데, 기억감정이 상표평가에 사용되기 위한 조건에 관한 연구는 미흡하다. 따라서, 본 연구에서는 소비자가 상표를 평가하는 데에 기억감정이 작용하기 위한 조건으로 접근속도, 상표에 대한 기억감정의 표상성, 소비목적관련성을 탐색해 보았다. 또한 상표평가에서 기억감정의 반응수준(접근속도, 표상성)에 영향을 미치는 요인들로 부호화 유사성과 조직화 수준을 탐색하였다. 실증연구 결과 기억 속에 감정의 조직화 수준은 기억감정의 접근속도, 표상성에 긍정적인 영향을 미치게 되며, 기억감정의 접근속도, 상표에 대한 기억강정의 표상성이 상표평가에서 기억감정의 이용 정도에 영향을 미치는 것으로 나타났다.