• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.499-499
• /
• 2002

The goal of this study is to apply and evaluate the precipitation outflow in river basin using satellite data and GIS for proposing the efficient watershed management method. Not only precipitation outflow data but also various spatial data such as digital map, soil map, geologic map and multi-temporal TM images were used. Using landcover classification result and soil map were applied to estimate the average CN. The CN value of 63.37 by SCS method was produced in AMC-2 condition otherwise the result of direct estimation with observation method was 63 CN value. The relative error of two results was 0.59%. It can be possible to apply the satellite data for precipitation outflow analysis. For more accurate and credible analysis of this, the more multi-temporal satellite and real observation data will be needed.

• 대한통합의학회지
• /
• 제5권1호
• /
• pp.43-53
• /
• 2017

Purpose : To examine the relative absolute reliability and validity of step test (ST) scores in subjects with chronic stroke. Method : A total of 27 stroke patients, participated in the study. A relative reliability index (intraclass correlation coefficient, ICC) was used to examine the level of agreement of inter-rater test-retest reliability for ST score. Absolute reliability indices, including the standard error of measurement(SEM) and the minimal detectable change (MDC), and limits of agreement by Bland and Altman analysis. The validity was demonstrated by spearman correlation of ST score with 10 m Walk Test (10mWT), Fugl-Meyer Assessment-Lower/Extremity (FMA-L/E)-total score, Berg Balance Scale (BBS)-total score. Result : An excellent inter-rater reliability in ST scores was found (paretic, ICC=0.993~0.996; nonparetic, ICC=0.982~0.991). In addition, excellent test-retest reliability was found (paretic, ICC=0.992; nonparetic, ICC=0.967). It all showed acceptable SEM of the ST score as paretic and nonparetic were 0.22 and 0.46 respectively (average score <10 %), and the MDC of the paretic and nonparetic were 0.61 and 1.27 respectively (possible highest score <20 %). indicating that measures had a small and acceptable measurement error. The ST score of paretic and nonparetic were also found to be significantly associated with 10MWT (r=0.77~0.79), FMA-LE scores (r=0.73~0.81) and BBS scores (r=0.72~0.76). Conclusion : The ST showed highly sufficient Inter-rater test-retest agreement and validity and acceptable measurement errors caused by due to chance variation in measurement. It also can be used by clinicians and researchers to assess the balance and mobility performance and monitor functional change in chronic stroke patients.

• 한국정보통신학회논문지
• /
• 제20권1호
• /
• pp.142-152
• /
• 2016

실내 측위 분야에서는 사용할 수 없는 GPS 의 한계를 극복하기 위해 대두되고 있는 기술들은 대부분 사설 무선 통신망(Private Wireless Network)를 이용한 방법이다. 그러나 이러한 방법들은 설치 및 유지 보수비용이 많이 들고 측위 오차가 수 미터로 실내 주차장 등 정밀한 측위가 필요한 장소에서 사용하기에 부적합하다. 본 논문에서는 QR 코드 인식 기반 차량용 실내 측위 방법을 제안하였다. QR 코드 스캔을 통해 절대 좌표를 얻고 아핀 변환(affine transform)을 통한 기울기(Tilt) 및 회전(Roll) 보정과 스케일 변환 및 삼각함수를 이용한 카메라의 위치 정보(상대좌표)를 획득하여 정밀한 위치 좌표를 계산한다. 결과적으로 13.79cm 의 평균 오차를 달성해 기존 무선 네트워크 기반 기술의 오차 50cm 대비 단지 27.6% 정도 오차율에 해당함을 확인하였다.

• 한국안광학회지
• /
• 제3권1호
• /
• pp.75-86
• /
• 1998

18세에서 27세 사이의 남자 82명 여자 70명 총 152명을 대상으로 2시간 동안 쉬지 않고 VDT작업을 하도록 한 후, 안구 및 전신증상 등을 조사하고 시력, 타각적 굴절이상, 조절력 상위량 등을 측정한 결과, 안구증상으로는 눈의 피로를 느끼는 사항이 45.71%로 가장 많았고, 시기능 이상으로는 물체가 흐려 보이는 경우가 80.39%, 전신증상으로는 어깨가 아픈 사람이 33.33%로 가장 높게 나타났다. 시력변화는 평균나안시력 0.47에서 0.42로 약 10%가 저하했으며 타각적 굴절이상은 0.10D정도 근시도가 증가했다. 조절력은 7.46D에서 6.74D로 약 0.72D 정도 줄었고, 조절용이성은 2.27초에서 2.50초로 0.23초만큼 지연되었다. 실성상대조절량은 4.76D에서 4.16D로 0.50D만큼 감소했고 허성상대조절량은 2.46D에서 2.33D로 0.13D 만큼 줄었다. 사위량은 평균 $1.82{\Delta}$ B.O.에서 $3.24{\Delta}$ B.O.으로 내 사위량이 증가했다.

• Journal of Information Technology Applications and Management
• /
• 제27권3호
• /
• pp.69-75
• /
• 2020

In this paper, we applied the shape parameters of the exponentialized exponential life distribution widely used in the field of software reliability, and compared the reliability properties of the software using the non-homogeneous Poisson process in finite failure. In addition, the average value function is also a non-decreasing form. In the case of the larger the shape parameter, the smaller the estimated error in predicting the predicted value in comparison with the true value, so it can be regarded as an efficient model in terms of relative accuracy. Also, in the larger the shape parameter, the larger the estimated value of the coefficient of determination, which can be regarded as an efficient model in terms of suitability. So. the larger the shape parameter model can be regarded as an efficient model in terms of goodness-of-fit. In the form of the reliability function, it gradually appears as a non-increasing pattern and the higher the shape parameter, the lower it is as the mission time elapses. Through this study, software operators can use the pattern of mean square error, mean value, and hazard function as a basic guideline for exploring software failures.

• Steel and Composite Structures
• /
• 제21권4호
• /
• pp.921-947
• /
• 2016

Concrete Filled Fibre Reinforced Polymer Tube (CFFT) for new columns construction has attracted significant research attention in recent years. The CFFT acts as a formwork for new columns and a barrier to corrosion accelerating agents. It significantly increases both the strength capacity (Strength enhancement ratio) and the ductility (Strain enhancement ratio) of reinforced concrete columns. In this study, based on predefined selection criteria, experimental investigation results of 134 circular CFFT columns under axial compression have been compiled and analysed from 599 CFFT specimens available in the literature. It has been observed that actual confinement ratio (expressed as a function of material properties of fibres, diameter of CFFT and compressive strength of concrete) has significant influence on the strength and ductility of circular CFFT columns. Design oriented models have been proposed to compute the strength and strain enhancement ratios of circular CFFT columns. The proposed strength and strain enhancement ratio models have significantly reduced Average Absolute Error (AAE), Mean Square Error (MSE), Relative Standard Error of Estimate (RSEE) and Standard Deviation (SD) as compared to other available strength and strain enhancement ratios of circular CFFT column models. The predictions of the proposed strength and strain enhancement ratio models match well with the experimental strength and strain enhancement ratios investigation results in the compiled database.

• 한국농공학회지
• /
• 제40권1호
• /
• pp.68-77
• /
• 1998

The purpose of this paper is to establish a method estimating the daily urban water demand using statistical analysis that is used for developing the efficient management and operation of the water supply facilities, and accurary of the model is verified by error rate and F-value. The data used in this study were the daily urban water use, the weather conditions such as temperature, precipitation, relative humidity, etc, and the day of The week. The case study was taken placed for the city of Namwon in Korea. The raw data used in this study were rearranged either by month or by season for analysis purpose, and the statistical analysis was applied to the data to obtain the regression model As a result of this study, the linear regression model was developed to estimate the daily urban water use with weather condition. The regression constant and coefficients of the model were determined for each month of a year. The accuracy of the model was within 3% of average error and within 11% of maximum error. The resulting model was found to he useful to the practical operation and management of the water supply facilities.

• KIEAE Journal
• /
• 제10권6호
• /
• pp.97-103
• /
• 2010

Sky simulator is a effective daylighting design tool that can evaluate three dimensional performance of lighting. Especially, the dome type sky simulator offer reliable and reproducible daylighting performance with different standard sky models. Recently, K university has developed the dome type sky simulator(sky dome) with the diameter of 6.5m and the height of 3.7m. The sky dome consists of a group of 145 large steel panels with 72 halogen lamps which are arranged in a circular array. The luminance distribution of the sky dome can be calibrated by changing the angle and the brightness of the lamps respectively. To allow more reliable prediction and evaluation of daylighting through the sky dome, It is essential to validate the sky luminance distribution of the sky dome. This study consider the validation of the comparisons between the measured and the calculated luminance values for the CIE standard overcast sky. Also, the error rate between the measured and the calculated luminance values were compared to the previous studies. The results indicated that the K university sky dome can reproduce reliable CIE standard overcast sky with the average relative error rate of 4.4% and root-mean-square error(RMSE) of 5.4%.

• 한국정보통신학회논문지
• /
• 제21권12호
• /
• pp.2365-2370
• /
• 2017

본 논문에서는 체험형 VR 환경을 고려한 동작 및 위치 인식 기법을 제안한다. 동작 인식은 신체부위에 복수개의 AHRS 디바이스를 부착하고 이를 기준으로 좌표계를 정의한다. 각각의 AHRS 디바이스로부터 측정되는 9축 움직임 정보를 기반으로 사용자의 동작을 인식하고 신체 분절 간의 관절각을 추출하여 동작을 보정한다. 위치인식은 AHRS 디바이스의 관성센서를 통해 보행 정보를 추출하여 상대위치를 인식하고 BLE Fingerprint를 이용하여 누적오차를 보정한다. 제안하는 동작 및 위치인식 기법의 구현을 위해 AHRS기반의 위치인식과 관절각 추출 실험을 진행하였다. 위치 인식 실험의 평균 오차는 0.25m, 관절 각 추출 실험에서 관절 각 평균 오차는 $3.2^{\circ}$로 나타났다.

• 대한조선학회논문집
• /
• 제58권5호
• /
• pp.281-293
• /
• 2021

Oil and steel prices, which are major pricescosts in the shipbuilding industry, were predicted. Firstly, the error of the moving average line (N=3-5) was examined, and in all three error analyses, the moving average line (N=3) was small. Secondly, in the linear prediction of data through existing theory, oil prices rise slightly, and steel prices rise sharply, but in reality, linear prediction using existing data was not satisfactory. Thirdly, we identified the limitations of linear prediction methods and confirmed that oil and steel price prediction was somewhat similar to actual moving average line prediction methods. Due to the high volatility of major price flows, large errors were inevitable in the forecast section. Through the time series analysis method at the end of this paper, we were able to achieve not bad results in all analysis items relative to artificial intelligence (Prophet). Predictive data through predictive analysis using eight predictive models are expected to serve as a good research foundation for developing unique tools or establishing evaluation systems in the future. This study compares the basic settings of artificial intelligence programs with the results of core price prediction in the shipbuilding industry through time series prediction theory, and further studies the various hyper-parameters and event effects of Prophet in the future, leaving room for improvement of predictability.