• 한국환경보건학회지
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• 제28권1호
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• pp.31-39
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• 2002

Generally, inaccurate reports on environmental issues occur due to various factors. The purpose of this study was to find out a way to enhance accuracy of environmental reporting. So the reporters' career and college major had been compared to the accuracy of their articles. The by-lined environmental articles in nine dailies published in 1991 were checked. Results of this study were as follows. (I) Inaccuracy rate in environmental articles was 54.2%. Inaccuracies appeared 1.7 times per an article, while the average frequency of inaccuracies in overall articles was 0.9 time. (2) Errors in the articles consist of 65.8% of subjective inaccuracies and 34.2% of subjective inaccuracies. They derive from the false usage of terminology(15.8% ),misquotation(14.5%), incorrect statistics(13%), exaggeration(13%), inaccurate title(7.9%), and false comparison(5%). (3) Inaccuracy rate by the type of articles was 66.7% in columns, 60% in feature stories, 54.5% in-depth stories, 40.9% in straight news, respectively. (4) Inaccuracy rate by the specific field was shown 71.4% in environmental impacts assessment, 52.5% in water pollution, 37.5% in waste management, and 35.7% in air pollution. (5) According to the result of chi-square test analysis, there were no statistically significant differences of inaccuracy rate and of subjective, and objective inaccuracies relevant to the period of reporters' career covering environmental reporting and the nature of articles, and college major.

• 한국도로학회논문집
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• 제12권4호
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• pp.61-70
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• 2010

본 연구의 목적은 일반국도에서 계획 시에 예측한 교통량과 실제 개통 이후의 교통량을 비교하여 수요예측의 정확도를 파악하는 것이다. 이를 위해 1980년대와 1990년대에 계획된 총 10개 일반국도 구간을 선정하였다. 예측교통량과 실측교통량의 비교를 위해 계획 시의 보고서를 수집하였으며, 상시교통량 조사지점이 있는 구간을 중심으로 선정하였다. 비교를 위한 지표는 오차율을 이용하였으며, 고속국도 등 네트워크 연계성이 있는 구간과 사회경제지표에 의한 구간으로 구분하여 비교 분석하였다. 분석결과, 네트워크 연계성이 있는 구간은 고속국도의 개통에 의한 영향정도에 대한 정확성이 높을수록 오차율이 낮은 것으로 나타났다. 개통시기에 따른 정확도는 개통 이후에 점차적으로 오차율이 낮아지는 것으로 나타나 긍정적인 것으로 판단되었다. 구간별 단위길이에 따른 정확도는 단위길이가 길수록 오차율이 높아지는 것으로 나타났다. 개통 후 3년 시점을 기준으로 오차율을 고속국도와 비교한 결과 일반국도가 다소 안정적인 패턴을 보이고 있으나 개통연도에 따른 오차율의 변화는 큰 차이가 없는 것으로 나타났다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 춘계학술대회 논문집
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• pp.205-209
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• 2000

This paper is concerned with development of the production-oriented structural design information system to predict the inaccuracy level of panel blocks and to consider the result at the structural design stage. Emphasis is placed on that the inaccuracy during production should likely be considered at the structural design stage to reduce the undesirable adjusting work and therefore to enhance the productivity. The primary goal of the present study is to consider the productivity and the efficient design at the same time for a high quality product of panel block. Usefulness of the developed information are illustrated through some application examples.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.52-54
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• 2002

Generally, inaccurate reports on environmental issues occur due to various factors. The purpose of this study was to find out a way to enhance accuracy of environmental reporting. So the reporters' career and college major had been compared to the accuracy of their articles. The by-lined environmental articles in nine dailies published in 1991 were checked. Results of this study were as follows. (1) Inaccuracy rate in environmental articles was 54.2％. Inaccuracies appeared 1.7 times per an article, while the average frequency of inaccuracies in overall articles was 0.9 time. (2) Errors in the articles consist of 65.8％ of subjective inaccuracies and 34.2％ of subjective inaccuracies. They derive from the false usage of terminology(15.8％), misquotation(14.5％), incorrect statistics(13％), exaggeration(13％), inaccurate title(7.9％), and false comparison(5％), (3) Inaccuracy rate by the type of articles was 66.7％ in columns, 60％ in feature stories, 54.5％ in-depth stories, 40.9％ in straight news, respectively. (4) Inaccuracy rate by the specific field was shown 71.4％ in environmental impacts (5) According to the result of chi-square test analysis, there were no statistically significant differences of inaccuracy rate and of subjective, and objective, and objective inaccuracies relevant to the period of reporters' career covering environmental reporting and the nature of articles, and college major.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.289-297
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• 2014

This paper proposed a novel high performance sensorless control scheme for IPMSM based on an extended nonlinear state observer. The gain-matrix of the observer has been derived by using state linearization method. Steady state errors in estimated rotor position and speed due to parameter inaccuracy have been analyzed, and an equivalent flux error is defined to represent the overall effect of parameter errors contributing to the wrong convergence of the estimated rotor speed as well as rotor position. Then, an online compensation strategy was proposed to limit the estimation errors in rotor position and speed. The effectiveness of the extended nonlinear state observer is validated through simulation and experimental test.

• 로봇학회논문지
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• 제17권1호
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• pp.58-67
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• 2022

In this paper, we propose an approach resolving inaccuracy of the low-cost redundant manipulator workspace with low encoder and low stiffness. When the manipulators are manufactured with low-cost encoders and low-cost links, the robots can run into workspace inaccuracy issues. Furthermore, trajectory generation based on conventional forward/inverse kinematics without taking into account inaccuracy issues will introduce the risk of end-effector fluctuations. Hence, we propose an optimization for the trajectory generation method based on the DDPG (Deep Deterministic Policy Gradient) algorithm for the low-cost redundant manipulators reaching the target position in Euclidean space. We designed the DDPG algorithm minimizing the distance along with the jacobian condition number. The training environment is selected with an error rate of randomly generated joint spaces in a simulator that implemented real-world physics, the test environment is a real robotic experiment and demonstrated our approach.

• 한국환경농학회지
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• 제34권3호
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• pp.230-237
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• 2015

BACKGROUND: To identify the sources of inaccuracy in LC/MS/MS methods used in the routine quantitation of small molecules are described and discussed. METHODS AND RESULTS: Various UPLC coupled to triple quadrupole mass spectrometer and time of flight (TOF) were used to identify the potential sources of inaccuracy and inducing the pitfalls of qualification and quntitation during the veterinary drug residue analysis. Some of stable isotope labelled veterinary drugs, which were used as internal standards, presented "cross-talk", regardless of manufactures of mass spectrometer and types of spectrometer. Group of sulfonamides also presented inaccuracy qualification and quantitation due to the multi-residue analytical method with the same fragment ions at the close retention times. CONCLUSION: The phenomena of "cross-talk" occurring between subsequently monitored transition from stable isotope labelled and isotope non-labelled authentic chemical were identified. To prevent errors and achieve more accurate data during the analysis of small molecules by LC/MS/MS SRM method, Followings should be taken care of and kept checking; purity and concentration of stable isotope as an internal standard, prevention of carry-over during the separation in column, minimizing the ion suppression by matrix effect, identification of retention time, precursor ion and product ion, and full knowledge of data processing including smoothing and peak integration.

• 대한공간정보학회지
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• 제10권5호
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• pp.75-80
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• 2002

Depending upon geographical features and surrounding errors in the survey field, inaccurate positioning is inevitable in a kinematic DGPs survey. Therefore, a data inaccuracy detection algorithm and an interpolation algorithm are essential to meet the requirement of a digital map. In this study, GPS characteristics are taken into account to develop the data inaccuracy detection algorithm. Then, the data interpolation algothim is obtained, based on the feature type of the survey. A digital map for 20km of a rural highway is produced by the kinematic DGPS survey and the features of interests are lines associated with the road. Since the vertical variation of GPS data is relatively higher, the trimmed mean of vertical variation is used as criteria of the inaccuracy detection. Four cases of 0.5%, 1%, 2.5% and 5% trimmings have been experimented. Criteria of four cases are 69cm, 65cm, 61cm and 42cm, respectively. For the feature of a curved line, cublic spine interpolation is used to correct the inaccurate data. When the feature is more or less a straight line, the interpolation has been done by a linear polynomial. Difference between the actual distance and the interpolated distance are few centimeters in RMS.

• 대한교통학회지
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• 제32권6호
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• pp.589-599
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• 2014

본 논문에서는 개통연도 예측 교통량과 개통 후의 실제 교통량의 비교를 통해 교통량 예측 오차를 분석하였다. 분석 결과, 역별 개통연도 교통량(승 하차 인원)의 평균오차(I)는 7.27수준인 것으로 분석되었다. 또한 지역별로 오차가 상이하고 공사기간이 장기간이거나 역간거리가 짧아지면 교통량 과다 추정 오차가 증가하는 것으로 분석되었다. 따라서 도시철도사업이 정해진 계획대로 정해진 기간 안에서 진행될수록 교통예측 오차를 줄일 수 있을 것으로 판단된다. 이외에도 수요예측연도가 최근일수록 오차가 줄어드는 것으로 나타났다. 향후 추진될 도시철도 신규 노선에 대해서는 지금까지의 도시철도 이용객 추정의 오차와 경향을 바탕으로 보다 정확하고 현실적인 이용객 추정이 필요하다. 본 논문의 한계점은 초기연도의 오차에 대해서만 분석하였고 오차발생 변수도 외생변수에 국한하여 분석한 점이다. 향후에는 오차발생에 대해서 다양한 변수를 대상으로 검토되어야 할 것이다.

• 한국해양공학회지
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• 제23권2호
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• pp.87-91
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• 2009

The welding distortion of a hull structure in the shipbuilding industry is inevitable at each assembly stage. The geometric inaccuracy caused by welding distortion tends to preclude the introduction of automation and mechanization and requires additional man-hours for adjustment work during the following assembly stage. To overcome this problem, a distortion control method should be applied. For this purpose, it is necessary to develop an accurate prediction method that can explicitly account for the influence of various factors on the welding distortion. The validity of this prediction method must also be clarified through experiments. For the purpose of reducing the weld-induced bending deflection, this paper proposes the plastic counter-deforming method (PCDM), which uses line heating as the optimum distortion control method. The validity of this method was substantiated by a number of numerical simulations and actual measurements.