• 경영과학
• /
• 제20권2호
• /
• pp.1-16
• /
• 2003

Previous research on data extraction and integration for data warehousing has concentrated mainly on the relational DBMS or partly on the object-oriented DBMS. Mostly, it describes issues related with the change data (deltas) capture and the incremental update by using the triggering technique of active database systems. But, little attention has been paid to data extraction approaches from other types of source systems like hierarchical DBMS, etc. and from source systems without triggering capability. This paper argues, from the practical point of view, that we need to consider not only the types of information sources and capabilities of ETT tools but also other factors of source systems such as operational characteristics (i.e., whether they support DBMS log, user log or no log, timestamp), and DBMS characteristics (i.e., whether they have the triggering capability or not, etc), in order to find out appropriate data extraction techniques that could be applied to different source systems. Having applied several different data extraction techniques (e.g., DBMS log, user log, triggering, timestamp-based extraction, file comparison) to S bank's source systems (e.g., IMS, DB2, ORACLE, and SAM file), we discovered that data extraction techniques available in a commercial ETT tool do not completely support data extraction from the DBMS log of IMS system. For such IMS systems, a new date extraction technique is proposed which first creates Index database and then updates the data warehouse using the Index database. We illustrates this technique using an example application.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제46권5호
• /
• pp.328-334
• /
• 2020

Objectives: This study aimed to validate the effectiveness of a recently proposed difficulty index for removal of impacted mandibular third molars based on extraction time and suggest a modified difficulty index including the presence of pathologic conditions associated with third molars. Materials and Methods: This retrospective study enrolled 65 male patients younger than 25 years with third molars. Extraction time was calculated from start of the incision to the last suture. The difficulty scores for third molars were based on spatial relationship (1-5 points), depth (1-4 points), and ramus relationship (1-3 points) using cone-beam computed tomography. The difficulty index was defined as follows: I (3-4 points), II (5-7 points), III (8-10 points), and IV (11-12 points). The modified difficulty score was calculated by adding one point to the difficulty score if the third molar was associated with a pathologic condition. Two modified difficulty indices, based on the presence of pathologic conditions, were as follows: the half-level up difficulty index (HDI) and the one-level up difficulty index (ODI) from the recently proposed difficulty index. Results: The correlations between extraction time and difficulty index and or modified difficulty indices were significant (P<0.001). The correlation coefficient between extraction time and difficulty index was 0.584. The correlation coefficients between extraction time and HDI and ODI were 0.728 and 0.764, respectively. Conclusion: Extraction time of impacted third molars exhibited a moderate correlation with difficulty index and was strongly correlated with the modified indices. Considering the clinical implications, the difficulty index of surgical extraction should take into consideration the pathologic conditions associated with third molars.

• 한국재료학회지
• /
• 제32권6호
• /
• pp.293-300
• /
• 2022

This study investigated a graded-refractive-index (GRIN) coating pattern capable of improving the light extraction efficiency of GaN light-emitting diodes (LEDs). The planar LEDs had total internal reflection thanks to the large difference in refractive index between the LED semiconductor and the surrounding medium (air). The main goal of this paper was to reduce the trapped light inside the LED by controlling the refractive index using various compositions of (TiO₂)_x(SiO₂)_1-x in GRIN LEDs consisting of five dielectric layers. Several types of multilayer LEDs were simulated and it was determined the transmittance value of the LEDs with many layers was greater than the LEDs with less layers. Then, the specific ranges of incident angles of the individual layers which depend on the refractive index were evaluated. According to theoretical calculations, the light extraction efficiency (LEE) of the five-layer GRIN is 25.29 %, 28.54 % and 30.22 %, respectively. Consequently, the five-layer GRIN LEDs patterned enhancement outcome LEE over the reference planar LEDs. The results suggest the increased light extraction efficiency is related to the loss of Fresnel transmission and the release of the light mode trapped inside the LED chip by the graded-refractive-index.

• Journal of applied mathematics & informatics
• /
• 제40권1_2호
• /
• pp.289-303
• /
• 2022

This article examines the multidimensional index extraction method of the disability social security system based on data mining. While creating the data warehouse of the social security system for the disabled, we need to know the elements of the social security indicators for the disabled. In this context, a clustering algorithm was used to extract the indicators of the social security system for the disabled by investigating the historical dimension of social security for the disabled. The simulation results show that the index extraction method has high coverage, sensitivity and reliability. In this paper, a multidimensional extraction method is introduced to extract the indicators of the social security system for the disabled based on data mining. The simulation experiments show that the method presented in this paper is more reliable, and the indicators of social security system for the disabled extracted are more effective in practical application.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제26권2호
• /
• pp.113-118
• /
• 2013

In this study, silk sericin films were prepared using different extraction methods, and the molecular conformation of sericin was examined using Fourier-transform infrared spectroscopy with attenuated total reflection geometry. Additionally, the effect of the film side (air-facing side or plate-facing side) on the molecular conformation of the sericin films was investigated. Interestingly, the molecular conformation of the sericin film depended on the film side. The molecular conformation of air-facing side of the sericin film was significantly influenced by extraction solution and time. The ${\beta}$-sheet crystallization and the crystallinity index of the sericin film markedly increased with an increase in the extraction time in hot water. The order of the crystallinity indices for the sericin films obtained with different extraction solutions was as follows: citric acid solution > urea solution >> hot water. In contrast, no remarkable differences were observed in the molecular conformation of the plate-facing side of the sericin film after extraction in hot water for different time periods. Urea and citric acid solution extractions showed remarkably higher crystallinity indices for sericin than those obtained after hot water extraction. However, no significant differences were observed in the crystallinity index of sericin between urea and citric acid solution extraction in plate-facing side of the film.

• 한국정보처리학회논문지
• /
• 제7권4호
• /
• pp.1122-1131
• /
• 2000

The efficiency of thesytem depends upon an accurate extraction capability of index terms in the system of information search or in that of automatic index. Therefore, extraction of accurate index terms is of utmost importance. This report presents the generation methods of composition noun for efficient index term extraction by using words of high frequency appearance, so that the right documents can be found during information search. For the sake of presentation of this method, index terms of composition noun shall be extracted by applying the rule of composition and disintegration to the nouns with high frequency of appearance in the documents, such as those with upper 30%∼40% of frequency ratio. In addition, for he purpose of effecting an inspection of validity in relation to a composition of high frequency nouns such as those with upper 30∼40% of frequency ratio as presented in this report, it proposes an adequate frquency ratio during noun composition. Based upon the proposed application, in this short documents with less than 300 syllables, low frequency omissions were noticed, when composed with nouns in the upper 30% of frequency ratio; whereas the documents with more than 30 syllables, when composed with nouns in he upper 40% of frequency ration, had a considerable reduction of low frequency omissions. Thus, total number of index terms has decreased to 57.7% of these existing and an accurate extraction of index terms with an 85.6% adequacy ratio became possible.

• 한국환경과학회지
• /
• 제21권10호
• /
• pp.1265-1274
• /
• 2012

This study was conducted to investigate the extraction characteristics including total polyphenol compound content (TPC) and the antioxidative effect of Rumex crispus root extract on commercial corn oil. Extraction yield was increased with extraction temperature but decreased with extraction ratio. No significant differences in aromatics content were found among the extracts prepared with various extraction conditions; extraction ratio, extraction temperature, extraction pH and composition of extractant. Total flavonoid content of the extract was increased with extraction temperature and extraction pH, and highest value of it was found when extractant composition of ethanol in water was 75%. Total polyphenol compound content (TPC) of the extract with 10 fold extraction ratio showed the highest value, but no significant difference in TPC was found with extraction temperature. Reducing power and DPPH (${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging ability (RSA) of the extract in spectrophotometric absorbance were decreased with extraction ratio but increased with extraction temperature and showed 63.1%~98.4% and 67.6%~86.7% of those of ascorbic acid in reducing power and DPPH RSA, respectively. The antioxidative effects of the extract on corn oil were 84.8~93.0% of that of commercial butylated hydroxytoluene, the antioxidant index value was highest when the ethanol composition to water in extractant was equal ratio.

• 한국도서관정보학회지
• /
• 제36권2호
• /
• pp.327-348
• /
• 2005

본 연구의 목적은 서지정보검색시스템의 색인 정의의 중요성을 강조하고 최적 색인의 기초 자료를 마련하기 위함이다. 이를 위해 서지마크 데이터베이스로부터 색인 태그 정의 및 정규화를 통한 색인어추출이론에 대해 고찰하고, 이론에 따라 생성된 색인어의 검색 활용도를 분석하였다. 실험은 서지 2,200,488건에서 생성된 색인어 29,219,853건을 텍스트형 색인과 코드형 색인으로 나누어 이용자 왱 검색 로그에 나타난 색인 항목과 비교하여 어떤 색인 정의가 얼마나 활용되는가를 분석하였다. 결과에 따르면 서명, 저자, 출판사, 주제와 같은 텍스트형 색인어는 높은 검색 활용도를 보인 반면에 코드형 색인어는 검색 활용도가 낮아 검색에 활용되지 않는 불필요한 색인 정의들은 과감하게 제거하여 색인 정의를 최적화해야 함을 제안하였다.

• 구강회복응용과학지
• /
• 제30권3호
• /
• pp.223-230
• /
• 2014

목적: 하악 절치 발치 치료를 받은 환자들의 치료로 인한 향상과 유지기간 후의 안정성을 평가하는 것이다. 연구 재료 및 방법: 하악 절치를 발치한 환자 총 20명을 대상으로 치료 전, 치료 직후, 2년의 유지기간 후의 모형 및 파노라마 방사선 사진을 분석하였다. Irregularity index, overjet, overbite, 치아 크기와 악궁 길이의 차이, 견치간 폭경, 제1 대구치간 폭경 및 미국교정학회에서 제시한 방법(ABO-CRE)을 평가하였다. 통계분석은 Wilcoxon signed-rank test를 이용하였다. 결과: 치료 전후 irregularity index가 유의하게 감소되었고(P = 0.000), 치아 크기와 악궁 길이의 차이는 유의하게 증가 하였다(P = 0.028). 유지기간 동안에 irregularity index는 유의하게 악화 되었다(P = 0.001). ABO-CRE 전체값의 변화는 치료 전후에 유의한 감소를 보이고(P = 0.000), 유지 전후에는 유의한 차이를 보이지 않았다(P = 0.053). 결론: 모형과 파노라마 방사선 사진을 이용하여 치료의 안정성 평가 결과, 하악 절치 발치 치료는 2년간의 유지기간 동안 치료 결과가 안정적으로 유지되었다고 할 수 있다.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제29권8호
• /
• pp.584-594
• /
• 2002

정보 검색(Information Retrieval)이나 디지털 도서관(Digital Library)과 같은 분야에서 가장 중요한 요소는 사용자가 필요로 하는 정보를 찾아주는 것이다. 이를 위해서 사용자가 사용하는 장치는 사용자의 의도뿐만 아니라 문서의 내용 또한 잘 파악하여야 한다. 본 논문은 문서의 의미적인 내용을 파악하는데 도움을 주는 효과적인 키워드 추출 시스템을 제안한다. 제안된 시스템은 문서에서 추출된 명사들의 의미(sense)를 결정(disambiguation)하고, 의미가 결정된 명사로 어휘체인을 생성한다. 특정 척도를 이용하여 강한 체인을 선별하고, 몇 개의 강한 체인에서 키워드들을 추출한다. 문서에서 사용된 명사들의 실제 센스를 결정하는 단계에서 semantic window라는 개념을 제안한다. 이것은 주변 명사들과의 의미관계를 미리 살펴보고, 문서내의 명사들의 센스를 결정하는 것이다. 본 시스템의 성능을 검증하기 위하여, 주요 구(key phrase) 추출 시스템인 KEA의 성능과 비교 분석하였다. 본 시스템은 정보 검색과 디지털 도서관을 포함한 범용적인 도메인에서 유용하게 사용될 수 있을 것으로 판단된다.