• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2000년도 춘계학술대회논문집
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• pp.135-143
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• 2000

COCOMO II 모델은 비순차적이며, 빠른 개발방법 과정 등의 새로운 소프트웨어 생명주기에 적합한 비용 모델이다. COCOMO II 모델에서 조율 방법으로 널리 사용된 최소자승 회귀분석 방법은 소프트웨어공학 데이터 셀과 가정이 위배되는 점이 있다 즉, 원시자료는 특히 서로 다른 개발조직으로부터 비용인자 등급, 노력, 크기가 수집되며 부정확하고 이상치가 존재한다. 본 논문에서는 이러한 한계를 극복하기 위하여 우리는 COCOMO II 모델을 가지고 상대오차를 최소화하는 모델 조율에 대한 새로운 방법을 제안한다. 제안된 방법의 특징은 이상치를 갖는 원시 데이터에 덜 민감한 특성을 갖고 있다. 실험결과, 제안된 새로운 조율방법 MRE가 조정된 결정계수(adj-$R^2$), 표준편차(^$\sigma$), 예측 정도( PRED(L))에서 기존의 전통적 회귀분석 방법보다 우수하게 나타났다.

• 한국전자파학회논문지
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• 제29권7호
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• pp.491-499
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• 2018

잡음지수분석기의 일반적인 교정방법은 잡음전원을 이용하는 방법이다. 이 방법은 교정 시 잡음전원과 잡음지수분석기의 부정합을 고려하지 않기 때문에 측정결과에서 심각한 불규칙 리플을 동반한다. 본 논문에서는 잡음전원과 잡음지수분석기의 부정합을 모두 고려한 새로운 잡음지수분석기의 교정 및 이를 이용한 새로운 잡음상관행렬 측정방법을 제안한다. 제안하는 방법은 uncorrected 잡음전력을 이용, 교정하지 않은 잡음지수분석기의 이득과 잡음상관행렬을 결정하였다. 그리고 결정된 이득과 잡음상관행렬을 이용, DUT에 대한 잡음상관행렬 측정결과에서 잡음지수분석기의 영향을 교정하였다. 제안된 방법을 통해, 측정된 DUT의 잡음파라미터는 상대적인 잡음비를 이용한 측정 결과와 같은 정도의 불규칙 리플을 보였다.

• 한국농공학회논문집
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• 제47권4호
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• pp.65-74
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• 2005

AnnAGNPS model was applied to a catchment mainly occupied with bushland for modeling non-point source pollution. Since the single event model cannot handle events longer than 24 hours duration, the event-based calibration was carried out using the continuous mode. As event flows affect sediment and nutrient generation and transport, the calibration of the model was performed in three steps: Hydrologic, Sediment and Nutrient calibrations. The results from hydrologic calibration for the catchment indicate a good prediction of the model with average ARE(Absolute Relative Error) of $24.6\%$ fur the runoff volume and $12\%$ for the peak flow. For the sediment calibration, the average ARE was $198.8\%$ indicating acceptable model performance for the sediment prediction. The predicted TN(Total Nitrogen) and TP(Total Phosphorus) were also found to be acceptable as the average ARE for TN and TP were $175.5\%\;and\;126.5\%$, respectively. The AnnAGNPS model was therefore approved to be appropriate to model non-point source pollution in bushland catchments. In general, the model was likely to result in underestimation for the larger events and overestimation fur the smaller events for the water quality predictions. It was also observed that the large errors in the hydrologic prediction also produced high errors in sediment and nutrient prediction. This was probably due to error propagation in which the error in the hydrologic prediction influenced the generation of error in the water quality prediction. Accurate hydrologic calibration should be hence obtained for a reliable water quality prediction.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제4권4호
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• pp.177-186
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• 2015

레이저 거리센서와 비전 카메라의 정보를 융합하기 위해서는 두 센서 사이의 상대적인 위치관계를 설명하는 외부 파라미터를 정확하게 보정하는 것이 필수적이다. 본 논문에서는 레이저 거리센서와 카메라 좌표계 간의 외부 파라미터를 기존에 알려진 방법보다 쉬우면서도 정확하게 획득할 수 있는 새로운 보정 방법을 제안하고자 한다. 본 논문에서 제안한 방법의 접근법은 레이저 거리센서로 획득한 3차원 구조물의 모서리 정보를 영상으로 투영하였을 때 반드시 하나의 직선상에 존재해야 한다는 것을 제약조건으로 한다. 이러한 제약조건을 만족하는 3차원 기하모델을 제시하고 이 모델의 에너지 함수를 최소화하기 위한 수치적 해법을 소개한다. 또한 높은 정밀도의 보정을 위하여 레이저 거리정보 및 카메라 영상의 획득 과정에 대해서도 상세히 설명한다. 실험을 통해 제안된 방법의 성능이 기존의 방법에 비하여 보다 높은 정밀도를 보임을 확인할 수 있었다.

• 한국농공학회지
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• 제33권2호
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• pp.51-60
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• 1991

The main objective of this study is to examine the adaptability for the large watershed of the storage tank model which can be applied for the analysis of both long and short terms runoff developed on the basis of hydrologic data for a smaH mountaineous watershed. The results obtained in this study are summarized as follows ; 1. Areal rainfalls of the Dae Chong watershed were calculated by Thiessen method composed of 9 Thiessen networks. 2. Optimal parameters for two types, Model A and Model B of tank models were derived through calibration procedure by standardized Powell method. 3. Monthly simulated flows of Model B are seemed to be closer to the monthly observed than those of Model A during calibration period in the long terms runoff. 4. Relative errors for the simulated flood flows of Model B were apperaed as lower percentage to the observed than those of Model A during calibration period in the short terms runoff. 5. Daily simulated hydrographs of Model B are seemed to be closer to the daily observed than those of Model A during verification period in the long terms runoff. Significance of Model B was highly acknowledged in comparison with Model A in the correlation analysis between annual observed and annual simulated runoff. 6. Reproducibility of simulated flows for Model B is generally seemed to be better than that of Model A during calibration period in the short terms runoff. 7. It can be concluded that reproducibility of Model B is superior to that of Model A in the long and short terms runoff even a large watershed like the result of the small one. 8. It was verified that adaptability for the large watershed of Model B is superior to that of Model A between the two models which were developed by a small watershed characteristics for both long and short terms runoff. 9. Further study for getting a suitable tank model is desirable to be established by the decision, calibration method of initial parameters of tank model and by additional application of another watershed with different watersheds and meterological characteristics.

• 한국산업정보학회논문지
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• 제5권2호
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• pp.47-55
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• 2000

개발하는 소프트웨어의 비용, 스케줄 및 노력을 예측하기 위하여 오늘날 많은 소프트웨어 비용 모델이 개발되었다. COCOMO II은 비순차적이며, 빠른 개발방법 과정 등의 새로운 소프트웨어 생명주기에 적합한 비용 모델이다. COCOMO II모델에서 최소자승 회귀분석 방법은 조율 방법으로 널리 사용되었다. 전통적인 회귀분석 조율 방법은 데이터 ？에 대한 가정이 위배된다. 즉, 원시자료는 특히 서로 다른 개발조직으로부터 비용인자 등급, 노력, 크기가 수집되며 부정확하고 이상치가 존재한다. 본 논문에서는 이러한 한계를 극복하기 위하여 우리는 COCOMO II모델을 가지고 상대오차를 최소화하는 모델 조율에 대한 새로운 방법을 제안한다. 제안된 방법의 특징은 이상치를 갖는 원시 데이터에 덜 민감한 특성을 갖고 있다. 실험결과, 제안된 새로운 조율방법 MRE가 조정된 결정계수(adj-$R^2$), 표준편차(^$\sigma$), 예측 정도(PRED(L))에서 기존의 전통적 회귀분석 방법보다 우수하게 나타났다.

• 대한방사선치료학회지
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• 제10권1호
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• pp.11-22
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• 1998

The absolute absorbed dose can be determined according to the measurement conditions ; measurement material, detector, energy and calibration protocols. The purpose of this study is to compare the absolute absorbed dose due to the differences of measurement condition and calibration protocols for photon beams. Dosimetric measurements were performed with a farmer type PTW and NEL ionization chambers in water, solid water, and polystyrene phantoms using 6MV photon beams from Siemens linear accelerator. Measurements were made along the central axis of $10{\times}10cm$ field size for constant target to surface distance of 100cm for water, solid water and polystyrene phantom. Theoretical absorbed dose intercomparisons between TG21 and IAEA protocol were performed for various measurement combinations on phantom, ion chamber, and electrometer. There were no significant differences of absorbed dose value between TG2l and IAEA protocol. The differences between two protocols are within $1\%\;while\;the\;average\;value\;of\;IAEA\;protocol\;was\;0.5\%$ smaller than TG2l protocol. For the purpose of comparison, all the relative absorbed dose were nomalized to NEL ion chamber with Keithley electrometer and water phantom, The average differences are within $1\%,\;but\;individual\;discrepancies\;are\;in\;the\;range\;of\;-2.5\%\;to\;1.2\%$ depending upon the choice of measurement combination. The largest discrepancy of $-25\%$ was observed when NEL ion chamber with Keithley electrometer is used in solid water phantom. The main cause for this discrepancy is due to the use of same parameters of stopping power, absorption coefficient, etc. as used in water phantom. It should be mentioned that the solid water phantom is not recommended for absolute dose calibration as the alternative of water, since absorbed dose show some dependency on phantom material other than water. In conclusion, the trend of variation was not much dependent on calibration protocol. However, It shows that absorbed dose could be affected by phantom material other than water.

• 대기
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• 제33권5호
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• pp.549-560
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• 2023

This study evaluates three distinct observation methods, CRDS, OA-ICOS, and OF-CEAS, in greenhouse gas monitoring equipment for atmospheric CO₂ and CH₄ concentrations. The assessment encompasses fundamental performance, high-concentration measurement accuracy, calibration methods, and the impact of atmospheric humidity on measurement accuracy. Results indicate that within a range of approximately 500 ppm, all three devices demonstrate high accuracy and linearity. However, beyond 1000 ppm, CO₂ accuracy sharply declines (84%), emphasizing the need for caution when interpreting high-concentration CO₂ data. An analysis of calibration methods reveals that both CO₂ and CH₄ measurements achieve high accuracy and linearity through 1-point calibration, suggesting that multi-point calibration is not imperative for precision. In dynamic atmospheric conditions with significant CO₂ and CH₄ concentration variations, a 1-point calibration suffices for reliable data (99% accuracy). The evaluation of humidity impact demonstrates that humidity removal devices significantly reduce air moisture levels, yet this has a negligible effect on dry CO₂ concentrations (less than 0.5% relative error). All three observation method instruments, which have integrated humidity correction to calculate dry CO₂ concentrations, exhibit minor sensitivity to humidity removal devices, implying that additional removal devices may not be essential. Consequently, this study offers valuable insights for comparing data from different measurement devices and provides crucial information to consider in the operation of monitoring sites.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1141-1141
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• 2001

The aim of the study was to evaluate the performance of 3 calibration methods, modified partial least squares (MPLS), local PLS (LOCAL) and artificial neural network (ANN) on the prediction of chemical composition of forages, using a large NIR database. The study used forage samples (n=25,977) from Australia, Europe (Belgium, Germany, Italy and Sweden) and North America (Canada and U.S.A) with information relative to moisture, crude protein and neutral detergent fibre content. The spectra of the samples were collected with 10 different Foss NIR Systems instruments, which were either standardized or not standardized to one master instrument. The spectra were trimmed to a wavelength range between 1100 and 2498 nm. Two data sets, one standardized (IVAL) and the other not standardized (SVAL) were used as independent validation sets, but 10% of both sets were omitted and kept for later expansion of the calibration database. The remaining samples were combined into one database (n=21,696), which was split into 75% calibration (CALBASE) and 25% validation (VALBASE). The chemical components in the 3 validation data sets were predicted with each model derived from CALBASE using the calibration database before and after it was expanded with 10% of the samples from IVAL and SVAL data sets. Calibration performance was evaluated using standard error of prediction corrected for bias (SEP(C)), bias, slope and R2. None of the models appeared to be consistently better across all validation sets. VALBASE was predicted well by all models, with smaller SEP(C) and bias values than for IVAL and SVAL. This was not surprising as VALBASE was selected from the calibration database and it had a sample population similar to CALBASE, whereas IVAL and SVAL were completely independent validation sets. In most cases, Local and ANN models, but not modified PLS, showed considerable improvement in the prediction of IVAL and SVAL after the calibration database had been expanded with the 10% samples of IVAL and SVAL reserved for calibration expansion. The effects of sample processing, instrument standardization and differences in reference procedure were partially confounded in the validation sets, so it was not possible to determine which factors were most important. Further work on the development of large databases must address the problems of standardization of instruments, harmonization and standardization of laboratory procedures and even more importantly, the definition of the database population.

• International Journal of Railway
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• 제9권1호
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• pp.1-9
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• 2016

In order to achieve a comprehensive utilization of railway networks, it is necessary to accurately assess the timetable indicators that effect the train operation. This paper describes the parameter calibration for two timetable indicators: scheduled running time and scheduled dwell time. For the scheduled running time, an existing model is employed and the single timetable parameter (percentage of minimum running time) in that model is optimized. For the scheduled dwell time, two intrinsic characteristics: the significance of stations and the average headway at each station are proposed firstly to form a new model, and the corresponding timetable parameters (the weight of the significance and the weight of the average headway) are calibrated subsequently. The Floyd Algorithm is used to obtain the connectivity among stations, which represents the significance of the stations. A case study is conducted in a light rail transportation system with 17 underground stations. The results of this research show that the optimal value of the scheduled running time parameter can be automatically determined, and the proposed model for the scheduled dwell time works well with a high coefficient of determination and low relative root mean square error through the leave-one-out validation.