• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.183-183
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• 2020

Accurate quantitative precipitation estimation plays an important role in hydrological modelling and prediction. Instantaneous quantitative precipitation estimation (QPE) by utilizing the weather radar data is a great applicability for operational hydrology in a catchment. Previously, regression technique performed between reflectivity (Z) and rain intensity (R) is used commonly to obtain radar QPEs. A novel, recent approaching method which might be applied in hydrological area for QPE is Long Short-Term Memory (LSTM) Networks. LSTM networks is a development and evolution of Recurrent Neuron Networks (RNNs) method that overcomes the limited memory capacity of RNNs and allows learning of long-term input-output dependencies. The advantages of LSTM compare to RNN technique is proven by previous works. In this study, LSTM networks is used to estimate the quantitative precipitation from weather radar for an urban catchment in South Korea. Radar information and rain-gauge data are used to evaluate and verify the estimation. The estimation results figure out that LSTM approaching method shows the accuracy and outperformance compared to Z-R relationship method. This study gives us the high potential of LSTM and its applications in urban hydrology.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.269-274
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• 2004

Recent adoption of the generalized sensor model to IKONOS and Quickbird satellite imagery have promoted various research activities concerning alternative sensor models which can replace conventional physical sensor models. For example, there are the Rational Function Model(RFM), the Direct Linear Transform(DLT) and the polynomial transform. In this paper, the DLT model which uses just a few number of GCPs was suggested. To evaluate the accuracy of the proposed DLT model, the RFM using 35 GCPs and the bias compensation method(Fraser et al., 2003) were compared with it. Quantitative evaluation of 3B positioning results were performed with independent check points and the digital elevation models(DEMs). In result, a 1.9- to 2.2-m positioning accuracy was achieved for modeling and DEM accuracy is similar to the accuracy of the other model methods.

• The Journal of Advanced Prosthodontics
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• 제11권2호
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• pp.138-146
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• 2019

PURPOSE. Comparing the accuracy of casts produced from digital workflow to that of casts produced from conventional techniques. MATERIALS AND METHODS. Whole arch alginate (ALG) and polyvinyl siloxane (PVS) impressions were taken with stock trays and custom trays, respectively. The ALG impressions were poured with type III dental stone, while the PVS impressions were poured with type IV dental stone. For the digital workflow, IOS impressions were taken and physical casts were produced by 3D printing. In addition, 3D printed casts were produced from images obtained from a laboratory scanner (LS). For each technique, a total of 10 casts were produced. The accuracies of the whole arch and separated teeth were virtually quantified. RESULTS. Whole arch cast accuracy was more superior for PVS followed by LS, ALG, and IOS. The PVS and ALG groups were inferior in the areas more susceptible to impression material distortion, such as fossae and undercut regions. The LS casts appeared to have generalized errors of minor magnitude influencing primarily the posterior teeth. The IOS casts were considerably more affected at the posterior region. On the contrary, the IOS and LS casts were more superior for single tooth accuracy followed by PVS and ALG. CONCLUSION. For whole arch accuracy, casts produced from IOS were inferior to those produced from PVS and ALG. The inferior outcome of IOS appears to be related to the span of scanning. For single tooth accuracy, IOS showed superior accuracy compared to conventional impressions.

• 분석과학
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• 제29권6호
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• pp.261-268
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• 2016

TXRF는 시료전처리 없이 분말상 시료의 정량분석이 가능하여 토양시료를 효율적으로 분석할 수 있다. 기존의 내부표준법을 이용한 분석법은 매질 효과 및 형광신호의 겹침으로 인한 간섭 효과로 인해 정확도가 떨어진다. 이를 개선하기 위해 외부표준법을 적용하여 용액화한 토양시료와 분말상 토양시료를 분석하였다. 용액화한 토양시료의 경우 개별표준물질로 만든 표준용액으로 작성한 검량선으로 분석하였는데, 내부 및 외부표준법 간 유의미한 차이가 없었다. 반면 분말상 토양시료로 부유용액을 만들어 검량선을 작성한 후 이를 이용하여 분말상 토양시료를 분석한 결과, 전반적으로 외부표준법을 적용한 결과가 내부표준법의 그것에 비해 정확도가 높았다. 두 가지 표준토양시료로 교차검증한 결과, Al, Fe, K, Ca, Ti, Ba, Mn, Sr, Rb, Cu 등 10개의 원소들에 대해 ${\pm}20%$ 내외의 상대오차가 측정되었다.

• 대한의용생체공학회:의공학회지
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• 제31권1호
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• pp.27-32
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• 2010

Noninvasive detection of patients with probable Alzheimer's disease (AD) is of great importance for assisting a medical doctor's decision for early treatment of AD patients. In the present study, we have extracted quantitative electroencephalogram (qEEG) variables, which can be potentially used to diagnose AD, from resting eyes-closed continuous EEGs of 22 AD patients and 27 age-matched normal control (NC) subjects. We have extracted qEEG variables from mean phase coherence (MPC) and EEG coherence, evaluated for all possible combinations of electrode pairs. Preliminary trials to discriminate the two groups with the extracted qEEG variables demonstrated that the use of MPC as a supplementary or alternative measure for the EEG coherence may enhance the accuracy of noninvasive diagnosis of AD.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 2010년도 춘계학술대회
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• pp.402-408
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• 2010

Forecasting have qualitative and quantitative methods. Quantitative one analyze macro-economic factors such as the rate of exchange, oil price, interest rate and also predict the micro-economic factors such as sales and demands. Applying various statistical methods depends on the type of data. when data has seasonality and trend, Time Series analysis is proper but when it has casual relation, Regression analysis is good for this. Time Series and Regression can be used together. This study investigate artificial neural networks which is predictive technique for casual relation and try to compare the accuracy of forecasting between regression analysis and artificial neural network.

• 지능정보연구
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• 제25권1호
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• pp.219-239
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• 2019

개인에게 맞춤형 서비스를 제공하는 것이 중요해지면서 개인화 추천 시스템 관련 연구들이 끊임없이 이루어지고 있다. 추천 시스템 중 협업 필터링은 학계 및 산업계에서 가장 많이 사용되고 있다. 다만 사용자들의 평점 혹은 사용 여부와 같은 정량적인 정보에 국한하여 추천이 이루어져 정확도가 떨어진다는 문제가 제기되고 있다. 이와 같은 문제를 해결하기 위해 현재까지 많은 연구에서 정량적 정보 외에 다른 정보들을 활용하여 추천 시스템의 성능을 개선하려는 시도가 활발하게 이루어지고 있다. 리뷰를 이용한 감성 분석이 대표적이지만, 기존의 연구에서는 감성 분석의 결과를 추천 시스템에 직접적으로 반영하지 못한다는 한계가 있다. 이에 본 연구는 리뷰에 나타난 감성을 수치화하여 평점에 반영하는 것을 목표로 한다. 즉, 사용자가 직접 작성한 리뷰를 감성 수치화하여 정량적인 정보로 변환해 추천 시스템에 직접 반영할 수 있는 새로운 알고리즘을 제안한다. 이를 위해서는 정성적인 정보인 사용자들의 리뷰를 정량화 시켜야 하므로, 본 연구에서는 텍스트 마이닝의 감성 분석 기법을 통해 감성 수치를 산출하였다. 데이터는 영화 리뷰를 대상으로 하여 도메인 맞춤형 감성 사전을 구축하고, 이를 기반으로 리뷰의 감성점수를 산출한다. 본 논문에서 사용자 리뷰의 감성 수치를 반영한 협업 필터링이 평점만을 고려하는 전통적인 방식의 협업 필터링과 비교하여 우수한 정확도를 나타내는 것을 확인하였다. 이후 제안된 모델이 더 개선된 방식이라고 할 근거를 확보하기 위해 paired t-test 검증을 시도했고, 제안된 모델이 더 우수하다는 결론을 도출하였다. 본 연구에서는 평점만으로 사용자의 감성을 판단한 기존의 선행연구들이 가지는 한계를 극복하고자 리뷰를 수치화하여 기존의 평점 시스템보다 사용자의 의견을 더 정교하게 추천 시스템에 반영시켜 정확도를 향상시켰다. 이를 기반으로 추가적으로 다양한 분석을 시행한다면 추천의 정확도가 더 높아질 것으로 기대된다.

• 대한방사선기술학회지:방사선기술과학
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• 제41권4호
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• pp.329-337
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• 2018

This study was investigated quantitative ultrasound (QUS) usage in Korea for the QUS quality control guidelines. A total of 344 questionnaires collected from July 24th to August 25th 2017 were analyzed. Questionnaires were created through user interviews, expert group advice, literature review and field observation. As a result of the general characteristics of quantitative ultrasound holding amounted to 81.98% of clinic and 6.69% of hospitals. The main user was radio-logical technologists as 31.39%. The contact methods of the gel pad (balloon) were the most used at 56.68% and the scan region was 91.9% of calcaneus. The quantitative ultrasound quality control cycle was 67.37% when the abnormality was found in the equipment, and 63.66% when the accuracy control was implemented according to the manual. The phantoms of QUS were 34.30% of the manufacturer's own phantoms. User of QUS had never received education for quality control of quantitative ultrasound as 62.20%. This study was expected to be useful when creating detailed quality control guidelines in the future, as well as guidelines for the quality control of Korea's standard quantitative ultrasound.

• Natural Product Sciences
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• 제16권4호
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• pp.251-258
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• 2010

In this study, quantitative analysis for the quality evaluation of Salviae Miltiorrhizae Radix using HPLC/UV was developed. For quantitative analysis, six major bioactive compounds were determined. The separation conditions employed for HPLC/UV were optimized using ODS $C_{18}$ column ($250{\times}4.6\;mm$, $5\;{\mu}m$) with gradient condition of A (1% formic acid in $H_2O$) and B (acetonitrile : methanol : formic acid = 100 : 75 : 1) as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 280 nm. These methods were fully validated with respect to the linearity, accuracy, precision and recovery. The HPLC/UV method was applied successfully to the quantification of six major compounds in the Salviae Miltiorrhizae Radix. The results indicate that the established HPLC/UV method is suitable for the quantitative analysis.

• 한국IT서비스학회지
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• 제3권1호
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• pp.21-41
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• 2004

The technical proposal suggested and published by MIC(Ministry of Information and Communication, henceforth MIC) contains too general assessment elements, which causes qualitative and subjective assessment of technical proposals. Thus, in terms of the technical proposal assessment. It lacks In fairness, validity and accuracy. Furthermore, it has a great deal of difficulty in assessment caused by the inconsistency between proposal planning and assessment methods. Also, each company has different writing format, so it is impossible to make use of its maneuvering data for the assessment. To overcome these weaknesses, our research focused on a quantitative evaluation on development organization, which is a part of organizational and administrative part of the technical proposal suggested and published by MIC. In this research, we divided development organization for the technical proposal into organization, teams, and team members, and then studied addition, deletion and merging for the assessment criteria. For the related study, we chose especially CMM(Capability Maturity Model) from a lot of international and national references, which is a model measuring the maturity of organization, and then we focused on Small-CMM which is available in the small-sized organization. We also suggested input form, description method, assessment elements for the quantitative assessment in the chosen developmental organization, and finally we proposed standard referencing criteria for the assessment. Our study concludes that our assessment method are valid and available in comparison with the previous Delphi method through a validity evaluation test.