• Title/Summary/Keyword: accuracy of survey

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Factors Affecting the Accuracy of Internet Survey (인터넷 여론조사의 정확도 관련요인)

  • Cho, Sung-Kyum;Joo, Young-Soo;Cho, Eun-Hee
    • Survey Research
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    • v.6 no.2
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    • pp.51-74
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    • 2005
  • The internet survey methods have been more and more widely used as the coverage of the fixed-line telephone is being reduced due to the diffusion of mobile phone. So, there is a need to know the accuracy of this new survey method. This study aims to estimate the accuracy of the internet survey method and identify the factors affecting the accuracy of this method, For this purpose, we analyzed the election poll data during the 17th general election period. These data include fixed-line telephone survey data, internet survey data, mobile phone survey data and the election voting data. The analysis shows that the prediction errors of the internet survey were a little more than those of the telephone or mobile phone survey. But the differences are not significant. It follows from this result that we can use the internet survey method in social survey context. This study also found that the respondent's willingness to participate in the survey, the probability of being at home during survey and the respondent's educational level were affecting the accuracy of the internet survey. Further studies to develop weighting method with these factors are needed.

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Comparative Analysis of Classification Accuracy for Calculating Cropland Areas by using Satellite Images (위성영상별 경지면적 분류 정확도 비교 분석)

  • Jo, Myung-Hee;Kim, Sung-Jae;Kim, Dong-Young;Choi, Kyung-Sook
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.2
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    • pp.47-53
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    • 2012
  • Recently many developed countries have used satellite images for classifying cropland areas to reduce time and efforts put into field survey. Korea also has used satellite images for the same purpose since KOMPSAT-2 was successfully launched and operated in 2006, but still far way to go in order to achieve the required accuracy from the products. This study evaluated the accuracy of the calculated croplands by using the objected classification method with various satellite images including ASTER, Spot-5, Rapid eye, Quickbird-2, Geo eye-1. Also, their usability and effectiveness for the cropland survey were verified by comparing with field survey data. As results. Geo eye-1 and Rapid eye showed higher accuracy to calculate the paddy field areas while Geo eye-1 and Quickbird-2 showed higher accuracy to calculate the upland field areas.

Evaluationn of the Accuracy for Regional Input Coefficients Estimated by Non-survey Methods (지역투입계수의 정확성 평가에 관한 연구)

  • 고석남;곽철홍
    • Journal of the Korean Regional Science Association
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    • v.12 no.2
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    • pp.1-19
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    • 1996
  • The purpose of this paper is to evaluate the accuracy of input coefficients which are usually estimated by various non-survey methods. The resulting analysis showed that there were considerable differences employed. One of the interesting findings was that the simple LQ method was shown to be better then the other non-survey methods with respect to the degree of accuracy. And from a sensitivity analysis which was to show the effect of changes in input coefficients on the level of production by industry, an increase of 10% in the value of input coefficient (machinary and equipment setor) resulted up to 500billion Won in GRP for the case region. Therfore one of the implications which we can derive from the resulting analysis is that it necessary to pay attention to the key coefficients first to save out time and money, while retaining a certain level of accuracy. One thing to be noted, however, is that the key coefficients but the total effects which are calculated through the Leontief inverse matrices. Therfore to enhance the accuracty of input coefficients estimated by nonsurvey methods it is required to handle the relevant setoral data more carefully or to employ semi-survey method in part.

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The Effective Means to Promote GPS-Based Survey for Cadastral Surveying of GPS Performance Standards and Measures (GPS기반의 효율적인 지적측량성과를 위한 측량기준 및 방안에 대한 연구)

  • Ahn, Jong Soon;Kang, Joon Mook;Yun, Hee Cheon
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.1
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    • pp.65-75
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    • 2013
  • In this study, one of the main aims is to build up a technical foundation for promoting the cadastral resurvey effectively and to improve the accuracy of cadastral surveying is to make use of precise surveying techniques in allowance of position errors as reference accuracy in cadastral resurvey, which is proper to obtain the sufficient accuracy of the cadastral control points, and parcel boundary points by introducing the GNSS-based surveying techniques on cadastral survey. In detail, the existing procedures and outcomes of cadastral survey were compared and analyzed for suggesting a better survey technique than that of the other techniques in a variety of aspects of capability of cadastral survey. The new skills and supports could be upmost importance when doing cadastral survey. What's more, essentially, 'The Measurement Department' makes all the efforts to establish 'The Surveying Regulations'. This could possibly apply GNSS-based surveying technique to the cadastral resurvey for the foreseeable future and this research paper suggested that how to improve absolute accuracy of cadastral reference points by means of putting to use the appropriate models of measurement further.

Validation of Unmanned Aerial Photogrammetry by Research Case Study and Accuracy Analysis (연구사례 조사 및 정확도 분석에 의한 무인항공사진측량의 유효성 평가)

  • Lee, Keunwang;Park, Joonkyu
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.14 no.4
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    • pp.155-161
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    • 2018
  • Recently, the development of sensor technology has led to an increase in research on unmanned aerial photogrammetry in various fields such as digital mapping, monitoring, cadastral survey, coastal survey, and topographic survey. However, existing studies are mainly limited experiments and analysis of specific application field, which is insufficient to demonstrate the validity of unmanned aerial photogrammetry for geospatial information construction. In this study, the studies related to the accuracy of unmanned aerial photogrammetry were investigated. The flight altitude and accuracy of horizontal direction is proportional to the GSD by analyzing the results of the individual studies conducted on the unmanned aerial photogrammetry within the last 5 years. In addition, the accuracy of the evaluation results varied widely according to the experimental conditions, and the problems of the previous studies that lacked the number of samples to evaluate the results were identified. A total accuracy analysis of 322 checkpoints yielded an accuracy of 0.028m in the horizontal direction and 0.044m in the vertical direction. In the future, the results of this study can be used as a basis for the validity of spatial information construction using unmanned aerial photogrammetry.

A Satisfaction Survey on the Human Translation Outcomes and Machine Translation Post-Editing Outcomes

  • Hong, Junghee;Lee, Il Jae
    • International journal of advanced smart convergence
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    • v.10 no.2
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    • pp.86-96
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    • 2021
  • This cross-sectional survey research carried out with the inquisitive agenda on satisfaction of the translation outcomes as performed by human translation and (machine translation) post-editing. The survey group consisted of 166 Korean translators primarily working with the English, Chinese, and Japanese languages. They were asked to rate the satisfactory level with accuracy, fluency, idiomatic expression, and terminology in the Richter's scale of four. The result reveals that human translation is more satisfactory than post-editing with respect to accuracy, but it is uneasy to assert that accuracy is unsatisfactory in post-editing. On the other hand, the Korean translators are less satisfied with fluency, idiomatic expression, and terminology than accuracy. It can be assumed that although human translation is more satisfactory than post-editing, the accuracy of post-editing seems to be more acknowledged than fluency, idiomatic expression, and terminology, which lead the translators to take the accuracy of raw machine-translation products and to go on to improve the fluency, idiomatic expression, and terminology. Nevertheless, Korean translators believe Korean idiomatic expressions cannot be satisfactorily produced in post-editing, while fluency and terminology can be improved in post-editing.

Availability Analysis of Network RTK-GPS/GLONASS (Network RTK-GPS/GLONASS에 의한 지적측량 활용성 평가)

  • Lee, Jong-Min;Lee, In-Su;Tcha, Dek-Kie
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.177-180
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    • 2010
  • In cadastral field GPS mainly applies to fundamental survey, while there are numerous research about cadastral detail survey using GPS application in order to increase surveying efficiency as survey technology improve. The purpose of this experiment is to analyze the accuracy of position and estimate the efficiency of GPS/GLONASS combination surveying with control points. As the result of this experiment, Network RTK-GPS/GLONASS combination survey is superior to Newtork RTK-GPS with respect to position accuracy and work efficiency.

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Land Cover Classification and Accuracy Assessment Using Aerial Videography and Landsat-TM Satellite Image -A Case Study of Taean Seashore National Park- (항공비디오와 Landsat-TM 자료를 이용한 지피의 분류와 평가 - 태안 해안국립공원을 사례로 -)

  • 서동조;박종화;조용현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.4
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    • pp.131-136
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    • 1999
  • Aerial videography techniques have been used to inventory conditions associated with grassland, forests, and agricultural crop production. Most recently, aerial videography has been used to verity satellite image classifications as part of the natural ecosystem survey. The objectives of this study were: (1) to use aerial video images of the study area, one part of Taean Seashore National Park, for the accuracy assessment, and (2) to determine the suitability of aerial videography as an accuracy assessment, of the land cover classification with Landsat-TM data. Video images were collected twice, summer and winter seasons, and divided into two kinds of images, wide angle and narrow angle images. Accuracy assessment methods include the calculation of the error matrix, the overall accuracy and kappa coefficient of agreement. This study indicates that aerial videography is an effective tool for accuracy assessment of the satellite image classifications of which features are relatively large and continuous. And it would be possible to overcome the limits of the present natural ecosystem survey method.

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The Improvement Method of Position Accuracy of Digital-Map in Small Area (소규모 지역에서 수치지도의 위치정확도 향상 방안에 관한 연구)

  • 이근상;장영률
    • Spatial Information Research
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    • v.9 no.2
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    • pp.263-275
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    • 2001
  • With increasing of utilization of 1/1,000 Digital-Map being constructed with NGIS project, it is entering upon the stage that problem as the inspection of position accuracy of Digital-Map before its use. This paper evaluated position accuracy of Digital-Map being based on the construction of college facility management system into small area and presented modification/renovation of Digital-Map on area being occurred position error. With a view to evaluation of position error to building using RTK survey, position error was shown more than 0.5mm that is prescribed in survey-law. In order to acquire good position accuracy, first we carried out Static survey to college and selected control point. And, we evaluated coordinate value to important building from control point and compared these results with RTK survey results. Second, we carried out Affine transform based on the control point of building being surveyed with RTK, transformed pre-constructed Digital-Map and compared these results with RTK Survey results. We analyzed first and second method and presented improvement method of position accuracy of Digital-Map suited on small area.

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A Study on Comparison of Accuracy Degree in Boundary Survey (경계측량의 정확도비교에 관한 연구)

  • 오창수
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.15 no.1
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    • pp.107-116
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    • 1997
  • This study is concerned about the comparison of accuracy between the plane table survey and the transit survey in the boundary survey. Up to the present, the plane table survey is used for the boundary survey in Korea the plane table survey usually causes both human and mechanical observational errors large enough. In this study, both the plane table survey and the transit survey using total station were used and the same points were measured from the same station. As the results, the positional error has 2~20 cm in plan table survey and 0~2 cm in the transit survey. Thus the transit survey is considerably accurate compared to the plane table survey in the boundary survey.

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