• 대기
• /
• 제17권4호
• /
• pp.327-337
• /
• 2007

In this study, we examined the new ensemble training approach to reduce the systematic error and improve prediction skill of wind by using the Short-range Ensemble prediction system (SENSE), which is the mesoscale multi-model ensemble prediction system. The SENSE has 16 ensemble members based on the MM5, WRF ARW, and WRF NMM. We evaluated the skill of surface wind prediction compared with AWS (Automatic Weather Station) observation during the summer season (June - August, 2006). At first stage, the correction of initial state for each member was performed with respect to the observed values, and the corrected members get the training stage to find out an adaptive weight function, which is formulated by Root Mean Square Vector Error (RMSVE). It was found that the optimal training period was 1-day through the experiments of sensitivity to the training interval. We obtained the weighted ensemble average which reveals smaller errors of the spatial and temporal pattern of wind speed than those of the simple ensemble average.

• Journal of the Korean Data and Information Science Society
• /
• 제16권3호
• /
• pp.639-650
• /
• 2005

Theoretical and numerical comparison have shown that variable sampling interval (VSI) charts are substantially more efficient than fixed sampling interval(FSI) charts in term of ATS(average time to signal). But the frequency of switching between different sampling intervals is a complicating factor in VSI procedures. VSI EWMA charts for monitoring mean vector of related qualify characteristics are investigated. To compare the efficiencies of the proposed charts, the performances are evaluated for matched FSI and VSI charts in terms of average time to signal(ATS) and average number of samples to signal(ANSS). For the switching behavior of the proposed VSI charts, average number of switches(ANSW) are also investigated.

• International Journal of Computer Science & Network Security
• /
• 제21권6호
• /
• pp.213-221
• /
• 2021

The modernization approach to monitoring regional processes of providing social services is proposed. The methodological approach is developed in the context of the modern public policy, which includes the following stages: the formation of a system of indicators that characterize the level of the social services modernization; the determination of the levels of regions development by such components as the modernization level of the economic sphere, the modernization level of the demographic component and the modernization level of employment; the determination of weights for each group of indicators and calculation of integrated indicators, ranking of regions; the allocation of criteria for classification and grouping of regions according to the modernization level of the social services sphere; highlighting the most important problems of each region. The proposed method is tested on the example of the Ukraine's regions. According to the results of calculations of the modernization level of the processes of providing social services, the ranking and grouping of the regions was carried out. The rating allowed to distinguish four groups of regions: regions with a high modernization level of social services, regions with above-average levels, as well as regions with medium and low levels. The author's modernization approach to monitoring the processes of providing social services allows to investigate the real state of the main indicators influencing these processes and to identify problem regions in order to develop mechanisms to stimulate their development.

• Communications for Statistical Applications and Methods
• /
• 제6권2호
• /
• pp.413-422
• /
• 1999

Multivariate EWMA control charts to simultaneously monitor correlation coefficients of correlated quality characteristics under multivariate normal process are proposed. Performances of the proposed charts are measured in terms of average run length(ARL). Numerical results show that smalle values for smoothing constant with accumulate-combine approach are preferred for detecting smalle shifts.

• 대한족부족관절학회지
• /
• 제9권1호
• /
• pp.47-51
• /
• 2005

중등도 이상의 변형을 가진 족근 관절 관절염에 대해 관혈적 관절 고정술은 양호한 결과를 보였으며 경비골 도달법에 의한 관절 고정술이 이상적인 족근 관절의 고정 위치를 얻는데 보다 용이하였다.

• International Journal of Human Ecology
• /
• 제9권2호
• /
• pp.1-11
• /
• 2008

This paper examines the value of unpaid care work using the 2004 time use survey and compared them to economic measures such as GDP, tax revenue, value of paid work, government expenditure on care-related personnel expenditure and remuneration of paid care workers. It employs the mean earnings approach and generalist approach. It finds that the value of unpaid care work (compared to GDP) is between 18% and 29% using different approaches. The value of care of household members and for others in the community (person care) is between 5% and 8%. Furthermore, the value of unpaid care work is greater than that of direct tax regardless of the approach used. In addition, the value of person care is estimated at between 22% and 35% of the total value of the paid economy. The value of unpaid care work far exceeds the value of government expenditure on care-related personnel and the remuneration of paid care workers. This research suggests that unpaid care work (mostly conducted by women) should be recognized as part of production activities. This is because caring and household maintenance activities are necessary for individual well-being but also it contributes to the national economic competitiveness particularly through human resource development.

• The Journal of the Acoustical Society of Korea
• /
• 제18권3E호
• /
• pp.3-8
• /
• 1999

In speech recognition for real-world applications, the performance degradation due to the mismatch introduced between training and testing environments should be overcome. In this paper, to reduce this mismatch, we provide a hybrid method of spectral subtraction and residual noise masking. We also employ multiple model approach to obtain improved robustness over various noise environments. In this approach, multiple model sets are made according to several noise masking levels and then a model set appropriate for the estimated noise level is selected automatically in recognition phase. According to speaker independent isolated word recognition experiments in car noise environments, the proposed method using model sets with only two masking levels reduced average word error rate by 60% in comparison with spectral subtraction method.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.357-358
• /
• 2011

A major element in the evaluation of reliability worth is the customer cost associated with a loss of supply. This paper proposes a new methodology to estimate the IEAR(Interrupted energy assessment rate) based on expectation value of outage time by using micro approach. The case study in this paper was performed on the basis of the survey data which had been conducted in a previous research.

• Communications for Statistical Applications and Methods
• /
• 제24권1호
• /
• pp.67-80
• /
• 2017

Over the last few decades, ensemble forecasts based on global climate models have become an important part of climate forecast due to the ability to reduce uncertainty in prediction. Moreover in ensemble forecast, assessing the prediction uncertainty is as important as estimating the optimal weights, and this is achieved through a probabilistic forecast which is based on the predictive distribution of future climate. The Bayesian model averaging has received much attention as a tool of probabilistic forecasting due to its simplicity and superior prediction. In this paper, we propose a new Bayesian model averaging method for probabilistic ensemble forecasting. The proposed method combines a deterministic ensemble forecast based on a multivariate regression approach with Bayesian model averaging. We demonstrate that the proposed method is better in prediction than the standard Bayesian model averaging approach by analyzing monthly average precipitations and temperatures for ten cities in Korea.

• ETRI Journal
• /
• 제33권4호
• /
• pp.547-557
• /
• 2011

This study presents an approach for extracting boundaries of various buildings, which have concave boundaries, inner yards, non-right-angled corners, and nonlinear edges. The approach comprises four steps: building point segmentation, boundary tracing, boundary grouping, and regularization. In the second and third steps, conventional algorithms are improved for more accurate boundary extraction, and in the final step, a new algorithm is presented to extract nonlinear edges. The unique characteristics of airborne light detection and ranging (LIDAR) data are considered in some steps. The performance and practicality of the presented algorithm were evaluated for buildings of various shapes, and the average omission and commission error of building polygon areas were 0.038 and 0.033, respectively.