• Journal of Korea Water Resources Association
• /
• v.45 no.9
• /
• pp.875-885
• /
• 2012

In this study, the total precipitation amount in Jeju Island was estimated with the simulated precipitation for ungauged stations missing precipitation data using the spatial precipitation analysis. The missing data were generated through the modified multiple linear regression in this study, and the analysis of spatial precipitation was conducted with the PRISM(Parameter-elevation Regression on Independent Slope Model). The generated data with modified multiple linear regression model have similar pattern with original data. Thus, the model in this study shows good applicability to estimate the missing data. The difference of annual average precipitation between Case 1 (original data) and Case 2 (modified data) appears very small ratio which is about 1.5%. However, the difference of annual average precipitation according to elevation shows the large ratio up to 37.4%. As the results, the method of estimating missing data in this study would be useful to calculate the total precipitation amount at the low station density area and the places with the high spatial variation of precipitation.

• Journal of Korean Society of Transportation
• /
• v.26 no.2
• /
• pp.109-119
• /
• 2008

The number of card users has grown steadily after the adaption of smart card. Considering the diverse information from smart card data, the increase of card usage rate leads to various useful implications meaning in travel pattern analysis and transportation policy. One of the most important implications is the possibility that the data enables us to generate transit O/D tables easily. In the case of generating transit O/D tables from smart card data, it is necessary to filter data error and/or data missing. Also, the correction of data missing is an important procedure. In this study, it is examined to compute the level of data error and data missing, and to correct data missing for transit O/D generation.

• The korean journal of orthodontics
• /
• v.51 no.5
• /
• pp.337-345
• /
• 2021

Objective: To investigate the phenotypes and predominant skeletodental pattern in pre-adolescent patients with Pierre-Robin sequence (PRS). Methods: The samples consisted of 26 Korean pre-adolescent PRS patients (11 boys and 15 girls; mean age at the investigation, 9.20 years) treated at the Department of Orthodontics, Seoul National University Dental Hospital between 1998 and 2019. Dental phenotypes, oral manifestation, cephalometric variables, and associated anomalies were investigated and statistically analyzed. Results: Congenitally missing teeth (CMT) were found in 34.6% of the patients (n = 9/26, 20 teeth, 2.22 teeth per patient) with 55.5% (n = 5/9) exhibiting bilaterally symmetric missing pattern. The mandibular incisors were the most common CMT (n = 11/20). Predominant skeletodental patterns included Class II relationship (57.7%), posteriorly positioned maxilla (76.9%) and mandible (92.3%), hyper-divergent pattern (92.3%), high gonial angle (65.4%), small mandibular body length to anterior cranial base ratio (65.4%), linguoversion of the maxillary incisors (76.9%), and linguoversion of the mandibular incisors (80.8%). Incomplete cleft palate (CP) of hard palate with complete CP of soft palate (61.5%) was the most frequently observed, followed by complete CP of hard and soft palate (19.2%) and CP of soft palate (19.2%) (p < 0.05). However, CP severity did not show a significant correlation with any cephalometric variables except incisor mandibular plane angle (p < 0.05). Five craniofacial and 15 extra-craniofacial anomalies were observed (53.8% patients); this implicated the need of routine screening. Conclusions: The results might provide primary data for individualized diagnosis and treatment planning for pre-adolescent PRS patients despite a single institution-based data.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.7
• /
• pp.405-413
• /
• 2004

Traditionally, electrical power systems had the vertically-integrated industry structures based on the economics of scale. However power systems have been recently reformed to increase the energy efficiency of the power system. According to these trends, Korean power industry has been partially restructured, and the competitive generation market was opened in 2001. In competitive electric markets, correct demand data are one of the most important issue to maintain the flexible electric markets as well as the reliable power systems. However, the measuring load data can have the uncertainty because of mechanical trouble, communication jamming, and other things. To obtain the reliable load data, an efficient evaluation technique to adust the missing load data is needed. This paper analyzes the load pattern of historical real data and then the turned ARIMA (Autoregressive Integrated Moving Average) model, PCHIP(Piecewise Cubic Interporation) and Branch & Bound method are applied to seek the missing parameters. The proposed method is tested under a variety of conditions and tested with historical measured data from the Korea Energy Management Corporation (KEMCO).

• KIEE International Transactions on Power Engineering
• /
• v.4A no.4
• /
• pp.254-261
• /
• 2004

Traditionally, electrical power systems had formed the vertically integrated industry structures based on the economics of scale. However, power systems have been recently reformed to increase their energy efficiency. According to these trends, the Korean power industry underwent partial reorganization and competition in the generation market was initiated in 2001. In competitive electric markets, accurate load data is one of the most important issues to maintaining flexibility in the electric markets as well as reliability in the power systems. In practice, the measuring load data can be uncertain because of mechanical trouble, communication jamming, and other issues. To obtain reliable load data, an efficient evaluation technique to adjust the missing load data is required. This paper analyzes the load pattern of historical real data and then the tuned ARIMA (Autoregressive Integrated Moving Average), PCHIP (Piecewise Cubic Interpolation) and Branch & Bound method are applied to seek the missing parameters. The proposed method is tested under a variety of conditions and also tested against historical measured data from the Korea Energy Management Corporation (KEMCO).

• Journal of the Korea Fashion and Costume Design Association
• /
• v.14 no.3
• /
• pp.1-10
• /
• 2012

This study has purpose to understanding recent trends and image effect of textile in fashion by looking to dyeing technique and aesthetics of diffusing image pattern. Further the study will hope to provide basic data for fashion and textile designer fashion. The methods of this study are academic literatures as well as practical study through case studies about actual works. Dyeing techniques and aesthetics of diffusing image pattern since 2000 fashion collection and their results are as follows. First, Dyeing techniques of diffusing image pattern are wet-dyeing and printing. There are plangi dyeing, salt dyeing, alcohol dyeing and ikat dyeing in the wet-dyeing and spray dyeing, discharge dyeing in the printing. There are tie-dyeing, rumpling-dyeing and plank-dyeing in the plangi. Second, Forming of the diffusing image pattern are due to uneven seeping and the contingency of a chemical reaction by reducing the pressure and intensity. Third, Aesthetics of diffusing image pattern are extracted purity missing childhood, fantasy escaping facts of the situation and abstraction representing informal world from formative characteristics of diffusing image pattern.

• Journal of the Korean earth science society
• /
• v.41 no.4
• /
• pp.415-434
• /
• 2020

The purpose of this study was to explore if, what kinds of, how much computational thinking (CT after this) practices could be included in STEAM programs, and what kinds of CT practices could be improved to make STEAM revitalized. The CT analyzing tool with operational definitions and its examples in science education was modified and employed for 5 science-focused and 5 engineering-focused STEAM programs. There was no discerning pattern of CT practices uses between science and engineering STEAM programs but CT practices were displayed depending on their topics. The patterns of CT practices uses from each STEAM program could be used to describe what CT practices were more explored, weakly exposed, or missing. On the basis of these prescription of CT practices from each STEAM program, the researchers could develop the weakly exposed or missing CT practices to be improved for the rich experience in CT practices during STEAM programs.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.4
• /
• pp.1360-1364
• /
• 2014

In this paper, RCS characteristics on defect pattern of crossed dipole slot FSS having a finite size have been analyzed. To analyze RCS, we applied the electric field integral equation analysis which applies BiCGSTab algorithm with iterative method and uses RWG basis function. To verify the validity of this paper, RCS of PEC sphere has been compared to the theoretical results and FSSs with defect patterns are fabricated and measured. As defect patterns in FSS, missing one column, missing some elements, and discontinuity in surfaces are simulated and compared with the measurement results. Resonant frequency shifts in pass band and changes in bandwidth are observed. From the results, precisely predicting and designing frequency characteristics over defect patterns are essential when applying FSS structures such as FSS radomes.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.3
• /
• pp.241-247
• /
• 2016

The trawl fishery is an important fishery accounting for around 30.0% of adjacent water fishery production in Korea, and the commercial fishing is associated with high rate of fatal and non-fatal occupational injury. The hazard analysis for the fishermen's safety of offshore trawler was conducted to serve as basic data for improving the healthy and safe working environment of fishermen using fishermen's occupational accidents of the national federation of fisheries cooperatives (NFFC) from 2012 to 2014 (n=464). As a result, the occupational accident occurrence rate of large powered trawl fishery was 241.4‰ in east sea trawl fishery, 6.9 times the rate of that. In addition, death and missing rate was found to have very serious level management to 97.7‱ in east sea trawl fishery of death at 6.2 times. The accident occurred in 91.7 to 100.0% was happened at sea. The slipping, others and struck by object and son on occurred more frequently in order in the frequency of accident occurrence pattern. However, the occurrence rate of death and missing did not match the frequency of accident pattern. In other words, slipping occurred more frequently while death and missing risk was not high. The fall in the waters was low while death and missing risk was high. The results are expected to help identify and assess safety hazard occurred in offshore trawlers.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.51 no.2
• /
• pp.188-194
• /
• 2015

The powered purse seine fishery is an important fishery accounting for 19.4% of adjacent water fishery production in Korea, and the commercial fishing is associated with high rate of fatal and non-fatal occupational injury. The hazard analysis for the fishermen's safety of offshore large powered purse seiner was conducted to serve as a basic data for improving the healthy and safe working environment of fishermen using fishermen's occupational accidents of the national federation of fisheries cooperatives (NFFC) in 2013 (n=583). As a result, the occupational accident occurrence rate of this fishery was 182.6‰ in all industries 30.9 times the rate of that. In addition, death and missing rate was found to have a very serious level management to 25.1‰ in all industries of death of 17.5 times. The accident occurred in 72.3 to 85.8% was happened at sea. The others, slipping and struck by object etc occurred more frequently in order in the frequency of accident occurrence pattern. However, the occurrence rate of death and missing did not match the frequency of accident pattern. In other words, slipping occurred frequently higher while death and missing risk was not high. And the contact with fishing gear and fall in the waters was low while death and missing risk was high. The results are expected to contribute for identification and assessment of safety hazard occurred in offshore large powered purse seiners.