• 제목/요약/키워드: hidden population

검색결과 41건 처리시간 0.022초

Probability Sampling Method for a Hidden Population Using Respondent-Driven Sampling: Simulation for Cancer Survivors

  • Jung, Minsoo
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권11호
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    • pp.4677-4683
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    • 2015
  • When there is no sampling frame within a certain group or the group is concerned that making its population public would bring social stigma, we say the population is hidden. It is difficult to approach this kind of population survey-methodologically because the response rate is low and its members are not quite honest with their responses when probability sampling is used. The only alternative known to address the problems caused by previous methods such as snowball sampling is respondent-driven sampling (RDS), which was developed by Heckathorn and his colleagues. RDS is based on a Markov chain, and uses the social network information of the respondent. This characteristic allows for probability sampling when we survey a hidden population. We verified through computer simulation whether RDS can be used on a hidden population of cancer survivors. According to the simulation results of this thesis, the chain-referral sampling of RDS tends to minimize as the sample gets bigger, and it becomes stabilized as the wave progresses. Therefore, it shows that the final sample information can be completely independent from the initial seeds if a certain level of sample size is secured even if the initial seeds were selected through convenient sampling. Thus, RDS can be considered as an alternative which can improve upon both key informant sampling and ethnographic surveys, and it needs to be utilized for various cases domestically as well.

대화형 진화 연산을 이용한 아바타 생성 (An Interactive Approach based on Genetic Algorithm Using Hidden Population and Simplified Genotype for Avatar Synthesis)

  • 이자용;백일현;강훈
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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    • pp.482-487
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    • 2002
  • 본 논문에서는 사용자 개개인에 최적화된 아바타를 생성하기 위해 대화형 진화 연산(Interactive Genetic Algorithm, IGA)을 적용하는 방법을 제안하고 있다. IGA는 사용자의 선택을 적합도 평가에 사용하는 방법이기 때문에, 사용자의 개인적인 취향을 아바타 생성 과정에 반영할 수 있다. 본 연구에서는 기존의 IGA가 가지고 있는 단점을 극복하기 위해 'hidden population' , 'primitive avatar' , 'simplified genotype' 기법을 제안한다. 이러한 방법들은 단시간 내에 최적화된 결과물을 생성하도록 유도함으로써 IGA 시스템의 최대 문제점인 사용자의 피로도를 최소화한다. 마지막으로, 제안하고 있는 알고리즘의 우수성을 증명하기 위해 사용자의 만족도나 신뢰도를 측정할 수 있는 독자적인 평가 방법을 소개하고 있다.

Limiting Processes of Stopping Time in Estimating a Population Size

  • Choi, Ki-Heon
    • Journal of the Korean Data and Information Science Society
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    • 제11권2호
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    • pp.327-334
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    • 2000
  • Suppose that there is a population of hidden objects of which the total number N is unknown. From such data, we derive some properties of the limiting processes of stopping time in estimating a population size.

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Asymptotic Distribution in Estimating a Population Size

  • Choi, Ki-Heon
    • Journal of the Korean Data and Information Science Society
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    • 제10권2호
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    • pp.313-318
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    • 1999
  • Suppose that there is a population of hidden objects of which the total number N is unknown. From such data, we derive an asymptotic distribution.

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An Interactive Approach based on Genetic Algorithm Using Hidden Population and Simplified Genotypes for Avatar Synthesis

  • Lee, Jayong;Lee, Janghee;Kang Hoon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.120.1-120
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    • 2002
  • In this paper, we propose an interactive genetic algorithm (IGA) to implement an automated 2D avatar synthesis. The IGA technique is capable of expressing user's personality in the avatar synthesis by using the user's response as a candidate for the fitness value. Our suggested IGA method isapplied to creating avatars automatically. Unlike the previous works, we introduce the concepts of 'hidden population', as well as 'primitive avatar' and 'simplified genotype', which are used to overcome the shortcomings of IGA such as human fatigue or reliability, and reasonable rates of convergence with a less number of iterations. The procedure of designing avatar models consists of two steps. The firl...

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군용 무전기를 이용한 근거리 무선 데이터 전송에서의 분산 매체 접근 제어 방식의 성능 분석 (A Performance Analysis of DFWMAC Protocols in Short-Distance Wireless Data Transmission Using Military Radio)

  • 이성규;최영윤
    • 한국군사과학기술학회지
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    • 제2권2호
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    • pp.117-130
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    • 1999
  • In this paper, the performance of data communication function of military radio equipment P-999K is analyzed based on the standard CSMA/CA protocol which is DFWMAC standard protocol done by IEEE802.11 work group. Basic three standard protocols, i.e. Basic CSMA/CA, Stop & Wait ARQ and 4-Way Handshake CSMA/CA protocols are analyzed and compared with each other under the hidden terminal environment. The computer simulation is also done by using SIMSCRIPT II.5 which is popular software tool for an independent processing. The results show that p-persistent(with p=0.3) CSMA scheme is superior to non-persistent CSMA scheme with non-hidden terminal condition, but the performances of both schemes are almost same with hidden terminal situation. And the results of computer simulations are also showed that Basic CSMA/CA protocol is superior to the other protocols when the ratio of hidden terminals is below 10 % of total user population, however, with the above 20% hidden terminals environment and the higher offered traffic conditions the 4-Way Handshake CSMA/CA protocol shows the most superior performance.

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An Interactive Approach Based on Genetic Algorithm Using Ridden Population and Simplified Genotype for Avatar Synthesis

  • Lee, Ja-Yong;Lee, Jang-Hee;Kang, Hoon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제2권3호
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    • pp.167-173
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    • 2002
  • In this paper, we propose an interactive genetic algorithm (IGA) to implement an automated 2D avatar synthesis. The IGA technique is capable of expressing user's personality in the avatar synthesis by using the user's response as a candidate for the fitness value. Our suggested IGA method is applied to creating avatars automatically. Unlike the previous works, we introduce the concepts of 'hidden population', as well as 'primitive avatar' and 'simplified genotype', which are used to overcome the shortcomings of IGA such as human fatigue or reliability, and reasonable rates of convergence with a less number of iterations. The procedure of designing avatar models consists of two steps. The first step is to detect the facial feature points and the second step is to create the subjectively optimal avatars with diversity by embedding user's preference, intuition, emotion, psychological aspects, or a more general term, KANSEI. Finally, the combined processes result in human-friendly avatars in terms of both genetic optimality and interactive GUI with reliability.

Discussion: A Study on the Population Structure of Democratic People's Republic of Korea

  • Kim, Keewhan
    • Communications for Statistical Applications and Methods
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    • 제22권1호
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    • pp.15-18
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    • 2015
  • Reunification, (considered a 'bonanza'), is often expected to bring economic and social benefits as well as solutions to the population aging problem; consequently, the study on the population structure of North Korea is salient. This paper reviews and talks on the North Korean population and implications. In view of reliability and consistency, the North Korean population appears at an explicit change compared to the past, and shows significant differences from the South, implying that it needs significant resources to integrate during reunification. Therefore, it is opportune to discuss the North Korean population prior to the clamor for the reunification.