• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2287-2293
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• 2009

Gas Chromatography-Mass Spectrometry (GC-MS) fingerprint analysis, Principle Components Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were introduced for quality assessment of Curcuma longa L. (C. longa). The GC-MS fingerprint method was developed and validated by analyzing 33 batches of samples of C. longa from different geographic locations. 18 chromatographic peaks were selected as characteristic peaks and their relative peak areas (RPA) were calculated for quantitative expression. Two principal components (PCs) were extracted by PCA. C. longa collected from Guizhou and Fujian were separated from other samples by PC1, capturing 71.83% of variance. While, PC2 contributed for their further separation, capturing 11.13% of variance. HCA confirmed the result of PCA analysis. Therefore, GC-MS fingerprint study with chemometric techniques provides a very flexible and reliable method for quality assessment of C. longa.

• 컴퓨터교육학회논문지
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• 제23권1호
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• pp.77-90
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• 2020

본 연구는 온라인 문제기반학습에서 학습자의 학습행태에 따른 학습유형을 파악하고 각 학습유형의 특징을 조사하여 효과적인 온라인 문제기반학습 설계를 위한 시사점을 도출하기 위해 수행되었다. 본 연구를 위해 6주 동안 K대학에서 운영된 문제기반학습 프로그램에 참여한 1,341명의 초·중학생의 온라인 활동 데이터가 수집되었고, 이를 통하여 학습자들의 학습행태를 나타내는 48개의 변인이 추출되었다. 추출된 변인은 학습자들의 학습유형을 구분하기 위한 계층적 군집분석 기법에 활용되었으며, 구분된 학습유형에 따라 학습행태와 학업성취도 측면에서 어떠한 차이가 있는지 비교·분석하였다. 그 결과, 학습자의 온라인 학습유형은 학습참여 수준에 따라 '고수준 학습참여형(군집 1)', '중수준 학습참여형(군집 2)', '저수준 학습참여형(군집 3)'으로 구분되었다. 또한, 학습참여 수준이 높은 군집이 높은 학업성취도를 얻은 것으로 확인되었다. 이러한 결과를 바탕으로 온라인 문제기반학습을 효과적으로 설계·운영하기 위한 시사점을 제시하였다.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1547-1553
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• 2011

An effective analytical method of gas chromatography/mass spectrometry (GC/MS) was developed for the rapid determination of essential oils in the crude extract of Acorus species (Acorus gramineus, Acorus tatarinowii, and Acorus calamus). Major phenypropanoids (${\beta}$,${\alpha}$-asarone isomers, euasarone, and methyleugenol) and ${\beta}$-caryophyllene in Acorus species were used as marker compounds and determined for the quality control of herbal medicines. To extract marker compounds, various extraction techniques such as solvent immersion, mechanical shaking, and sonication were compared, and the greatest efficiency was observed with sonication extraction using petroleum ether. The dynamic range of the GC/MS method depended on the specific analyte; acceptable quantification was obtained between 10 and 2000 ${\mu}g/mL$ for ${\beta}$-asarone, 10 and 500 ${\mu}g/mL$ for ${\alpha}$-asarone, 10 and 200 ${\mu}g/mL$ for methyleugenol, and between 5 and 100 ${\mu}g/mL$ for ${\beta}$-caryophyllene. The method was deemed satisfactory by inter- and intra-day validation and exhibited both high accuracy and precision, with a relative standard deviation < 10%. Overall limits of detection were approximately 0.34-0.83 ${\mu}g/mL$, with a standard deviation (${\sigma}$)-to-calibration slope (s) ratio (${\sigma}$/s) of 3. The limit of quantitation in our experiments was approximately 1.13-3.20 ${\mu}g/mL$ at a ${\sigma}$/s of 10. On the basement of method validation, 20 samples of Acorus species collected from markets in Korea were monitored for the quality control. In addition, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed on the analytical data of 20 different Acorus species samples in order to classify samples that were collected from different regions.

• 사회복지연구
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• 제49권1호
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• pp.163-190
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• 2018

서울시에서 추진하고 있는 복지생태계조성사업, 마을공동체지향복지관 변화지원 사업과 최근 발의된 <마을공동체기본법> 등 주민주도성은 지역복지활동의 방향성으로 중요하게 부상하고 있는 개념이다. 그러나 주민주도성 개념이 무엇인지에 대한 합의 없이 사용되고 있어, 현장에서 활용되는데 한계가 지적되고 있다. 본 연구는 개념도 연구법(Concept mapping)을 적용하여 서울시내 복지관의 실무자 10명을 대상으로 주민주도성에 대한 59개의 진술문을 생성하여 개념지도를 그리고 다차원척도분석과 위계적 군집분석을 실시하여 총 6개의 범주를 도출하였다. 6개의 범주는 "참여유도", "실천", "절차", "인식과 관심 확장", "의견표출", "태도와 정서"로 명명할 수 있었으며, 주민주도성 개념에서 "실천"이 핵심범주로 드러났다. 본 연구는 주민주도성의 개념에 대해 실제 사회복지실천현장의 실무자들은 어떻게 정의하고 있는지, 또 주민주도성을 실현하기 위해 사회복지사의 역할은 어떠해야 하는지에 대한 고민을 논의하고 향후 합의된 정의를 만들어가는 첫 시도로서 그 의의가 있다.

• 디지털산업정보학회논문지
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• 제18권4호
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• pp.97-110
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• 2022

The purpose of this study is to analyze the level of public data convergence capabilities of administrative organizations and to explore important variables in data-based organizational capabilities. The theoretical background was summarized on public data and use activation, joint use, convergence, administrative organization, and convergence constraints. These contents were explained Public Data Act, the Electronic Government Act, and the Data-Based Administrative Act. The research model was set as the data-based organizational capabilities effect by a data-based administrative capability, public data operation capabilities, and public data operation constraints. It was also set whether there is a capabilities difference data-based on an organizational operation by the level of data convergence capabilities. This study analysis was conducted with hierarchical cluster analysis and multiple regression analysis. As the research result, First, hierarchical cluster analysis was classified into three groups. It was classified into a group that uses only public data and structured data, a group that uses public data on both structured and unstructured data, and a group that uses both public and private data. Second, the critical variables of data-based organizational operation capabilities were found in the data-based administrative planning and administrative technology, the supervisory organizations and technical systems by public data convergence, and the data sharing and market transaction constraints. Finally, the essential independent variables on data-based organizational competencies differ by group. This study contributed. As a theoretical implication, this research is updated on management information systems by explaining the Public Data Act, the Electronic Government Act, and the Data-Based Administrative Act. As a practical implication, the activity reinforcement of public data should be promoting the establishment of data standardization and search convenience and elimination of the lukewarm attitudes and Selfishness behavior for data sharing.

• 한국의류학회지
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• 제20권6호
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• pp.1062-1070
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• 1996

Concept of the comfort and fitness has become a major concern in the basic function of the ready-made clothes. Until now, ready-made clothes were not made by on the basis of the bodytype, but by the body size only. This research was performed to classify and characterize the bodytypes of Korean adult males. Sample size was 1290 subjects and their age range was from 19 to 54 years old. 15 variables from the photographic data of 1112 subjects were applied to analyse the bodytype of th\ulcorner lower part of trunk. Data were analyzed by the multivariate method, especially factor and cluster analysis. The groups forming a cluster can be subdivided into 5 sets by crosstabulation extracted by the hierarchical cluster analysis. 5 bodytypes classified by the photographic sources could be combined with the anthropcmetric data and were demonstrated with 5 silhouette. Type 2 and 3 in the lower part of trunk were dominant and were composed of the majority of 56.8% of the subjects. Bodytypes of Korean males were influenced by the degree of posture erectness and of curvature of the front side of the body in waist and abdomen.

• 아동학회지
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• 제32권1호
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• pp.87-101
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• 2011

This study employed a child-centered approach in the examination of patterns of preschooler's learning behaviors. A hierarchical cluster analysis was employed in order to discern a meaningful typology of such behavior. The subjects consisted of 232 children (117 boys, 106 girls) and their mothers from 6 kindergartens and 6 day care centers. The results of this study were as follows. The cluster analysis yielded five types of learning behaviors; the competent type, the average type, the low attention/persistence type, the low motivation -attitude type, and the deficient type. The most consistent level differences among these types appeared to lie in distinctions among the average Attention/Persistence scores. The composition of the cluster types, including both the age and gender of the children, was ascertained. Our results indicated that preschool learning behavior types could be seen to differentially relate to children's self-regulation, cognitive styles, problem behaviors, and the level of maternal involvement. It was revealed that a child's characteristics was more important than maternal involvement and beliefs. As there were more girls and older children in the learning type, this type was seen to be more competent.

• Wind and Structures
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• 제39권1호
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• pp.1-14
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• 2024

Widespread damages from extreme winds have attracted lots of attentions of the resilience assessment of power distribution systems. With many related environmental parameters as well as numerous power infrastructure components, such as poles and wires, the increased challenge of power asset management before, during and after extreme events have to be addressed to prevent possible cascading failures in the power distribution system. Many extreme winds from weather events, such as hurricanes, generate widespread damages in multiple areas such as the economy, social security, and infrastructure management. The livelihoods of residents in the impaired areas are devastated largely due to the paucity of vital utilities, such as electricity. To address the challenge of power grid asset management, power system clustering is needed to partition a complex power system into several stable clusters to prevent the cascading failure from happening. Traditionally, system clustering uses the Binary Decision Diagram (BDD) to derive the clustering result, which is time-consuming and inefficient. Meanwhile, the previous studies considering the weather hazards did not include any detailed weather-related meteorologic parameters which is not appropriate as the heterogeneity of the parameters could largely affect the system performance. Therefore, a fragility-based network hierarchical spectral clustering method is proposed. In the present paper, the fragility curve and surfaces for a power distribution subsystem are obtained first. The fragility of the subsystem under typical failure mechanisms is calculated as a function of wind speed and pole characteristic dimension (diameter or span length). Secondly, the proposed fragility-based hierarchical spectral clustering method (F-HSC) integrates the physics-based fragility analysis into Hierarchical Spectral Clustering (HSC) technique from graph theory to achieve the clustering result for the power distribution system under extreme weather events. From the results of vulnerability analysis, it could be seen that the system performance after clustering is better than before clustering. With the F-HSC method, the impact of the extreme weather events could be considered with topology to cluster different power distribution systems to prevent the system from experiencing power blackouts.

• 한국발생생물학회지:발생과생식
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• 제18권4호
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• pp.287-292
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• 2014

In this study, seven oligonucleotides primers were shown to generate the shared loci, specific loci, unique shared loci to each species and shared loci by the three species which could be obviously calculated. Euclidean genetic distances within- and between-species were also calculated by complete linkage method with the sustenance of the hierarchical dendrogram program Systat version 13. The genomic DNA isolated from herring (Clupea pallasii), Korean anchovy (Coilia nasus) and large-eyed herring (Harengula zunashi), respectively, in the Yellow Sea, were amplified several times by PCR reaction. The hierarchical dendrogram shows three chief branches: cluster 1 (PALLASII 01, 02, 03, 04, 06 and 07), cluster 2 (NASUS 08, 09, 10, 11, 12, 13 and 14), and cluster 3 (ZUNASHI 15, 16, 17, 18, 19, 20, 21 and PALLASII 05). In three clupeid species, the shortest genetic distance displaying significant molecular difference was between individual PALLASII no. 03 and PALLASII no. 02 (0.018). Individual no. 06 of PALLASII was most distantly related to NASUS no. 11 (genetic distance = 0.318). Individuals from herring (C. pallasii) species (0.920) exhibited higher bandsharing values than did individuals from Korean anchovy (C. nasus) species (0.872) (P<0.05). As a result, this PCR analysis generated on the genetic data displayed that the herring (C. pallasii) species was widely separated from Korean anchovy (C. nasus) species. Reversely, individuals of Korean anchovy (C. nasus) species were a little closely related to those of large-eyed herring (H. zunashi) species.

• 정보처리학회논문지C
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• 제9C권2호
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• pp.283-292
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• 2002

본 논문에서는 무선/이동 인터넷 환경에서 실시간 트래픽의 QoS 보장을 위한 자원 관리 기법에 대해서 연구한다. 이동단말은 이동성때문에 실시간 응용 서비스에서 요구하는 QoS에 중요한 영향을 갖는다. 현재 제안된 MRSVP는 자원 예약 지역 경계의 불명확성과 또한 세션들을 유지하기 위한 신호 과부하를 발생시킬 수 있다. 이러한 문제를 해결하기 위해, MRSVP[1-5]와 이동 클러스터 개념을 조합한 신규자원 예약 프로토콜-이동클러스 기반의 H-MRSVP(Hierarchical MRSVP)-을 제안한다. 본 논문에서는 실시간 이동 호에 대한 이동 클러스터 기반의 H-MRSVP의 분석적인 모델을 설계하고, 시뮬레이션을 이용하여 보호채널 할당 방식, 분산 호 수락제어 기법과 비교 분석한다. 성능 목표값으로는 신규호 차단율, 핸드오프 호 손실율, 무선 시스템에서이 채널 이용율과 호의 서비스 완료율을 보았다. 결과적으로 제안된 기법이 DCA보다는 채널 이용율 측면에서 좀더 유연하고, 보호채널기법보다는 이동호에 대한 좋은 채널 할당을 한다.