• Journal of Korea Foundry Society
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• v.38 no.5
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• pp.95-102
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• 2018

The dependence of the tensile properties on variations in the porosity of A356 aluminium alloys was investigated in terms of the quality index of the tensile properties based upon the ultimate tensile strength and elongation as well as the variation of the strength coefficient and strain-hardening exponent with regard to a T6 treatment. The test specimens were prepared by low-pressure die-casting and a subsequent T6 treatment, and the experimental results of a tensile test carried out at room temperature were compared to the theoretical description using a modified constitutive model. The nominal value of the quality index of A356 alloys increases gradually with a lapse of the ageing time upon a T6 treatment, despite the fact that this value is temporarily decreased during the initial stage of ageing from a solutionised condition. Additionally, the quality index depends practically upon the porosity variation with a power law relationship without regard to whether in solutionised or artificial aged conditions. The theoretical description indicates that the strength coefficient directly determines the nominal level of the quality index. Moreover, the overall dependence of the quality index on the porosity variation is remarkably weakened with an increase in the tensile strain, whereas the quality index depends sensitively upon the porosity variation with a low value of the strain-hardening exponent.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.2
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• pp.17-33
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• 2016

Clustering is one of the leading methods to analyze big data and is used in many different fields. This study deals with Clustering Validity Index (CVI) to verify the effectiveness of clustering results. We compare the performance of CVIs with business applications of various field. In this study, the used CVIs for comparing performance are DU, CH, DB, SVDU, SVCH, and SVDB. The first three CVIs are well-known ones in the existing research and the last three CVIs are based on support vector data description. It has been verified with outstanding performance and qualified as the application ability of CVIs based on support vector data description.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.281-284
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• 2002

Error resilience for image coding is an important component of multimedia communication system. Error resilience schemes address loss recovery from the compression perspective. Multiple description coding (MDC) is one of the error resilience techniques promising for robust video transmission. It is the way to achieve tradeoff description such as scalar quantization, correlating transform and the quantized frame expansion. In this paper, we consider Multiple Description Scalar Quantization (MDSQ) to wavelet domain. Conventional MDSQ schemes considered description with equal weights in each sub-bands. But, we can see that the each sub-bands is unequal contribution to whole image quality. Therefore, we experiment the multiple design MDSQ table to make probability of zero index high, which gives high efficiency in arithmetic symbol coder. We also compare our proposed method with the conventional methods and show improved performance in terms of redundancy-rate-distortion.

• Journal of the Korean Dietetic Association
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• v.22 no.3
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• pp.193-213
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• 2016

The purpose of this study is to provide a standard job description for a nutrition teacher placed in primary and secondary schools by analyzing their duties. DACUM is an acronym for 'Developing A CUrriculuM'. It was used by experts to determine the job duties, tasks and task elements to establish the job descriptions of a nutrition teachers through the development of a DACUM chart. An expert panel consisting of 10 nutrition teachers participated in a DACUM workshop and derived nutrition teacher's DACUM chart. A total of 1,550 nutrition teachers across the country were targeted as the survey subjects for validation of the DACUM chart through their perception of the frequency, importance, and difficulty of each item in the job description. A tree structure, criticality analysis, and contents validity index were added for verification. The definition of the nutrition teacher's job and DACUM chart with 5 duties, 28 tasks, and 107 task elements were derived by the DACUM method. The definition of a nutrition teacher was 'A teacher who is responsible for food service management and nutrition education and counseling for health promotion and disease prevention for students in primary and secondary schools'. The validation results of the tree structure were the priorities of the 28 tasks with ranks 1 and 2. Because there was no third priority, it was considered to be a good representation of the tasks of nutrition teachers. The DACUM chart was found to be evenly distributed with relative importances of more than 17 or less than 11 through the criticality analysis. Since the C5-4 (Conduct simulation exercise against food poisoning)'s content validity index was significantly less than the reference value of 0.78, it was not included in the final job description. 5 duties, 28 tasks, 102 task elements were included in the final job description of a nutrition teacher.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.944-958
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• 2011

Soil hydraulic properties such as hydraulic conductivity or water retention which are costly to measure can be indirectly generated by soil pedotransfer function (PTF) using easily obtainable soil data. The field soil structure description which is routinely recorded could also be used in PTF as an input to reduce the uncertainty. The purposes of this study were to use qualitative morphological soil structure descriptions and soil structural index into PTF and to evaluate their contribution in the prediction of soil hydraulic properties. We transformed categorical morphological descriptions of soil structure into quantitative values using categorical principal component analysis (CATPCA). This approach was tested with a large data set from the US National Pedon Characterization database with the aid of a categorical regression tree analysis. Six different PTFs were used to predict the saturated hydraulic conductivity and those results were averaged to quantify the uncertainty. Quantified morphological description was successively used in multiple linear regression approach to predict the averaged ensemble saturated conductivity. The selected stepwise regression model with only the transformed morphological variables and structural index as predictors predicted the $K_{sat}$ with $r^2$ = 0.48 (p = 0.018), indicating the feasibility of CATPCA approach. In a regression tree analysis, soil structure index and soil texture turned out to be important factors in the prediction of the hydraulic properties. Among structural descriptions size class turned out to be an important grouping parameter in the regression tree. Bulk density, clay content, W33 and structural index explained clusters selected by a two step clustering technique, implying the morphologically described soil structural features are closely related to soil physical as well as hydraulic properties. Although this study provided relatively new method which related soil structure description to soil structure index, the same approach should be tested using a datasets containing the actual measurement of hydraulic properties. More insight on the predictive power of soil structure index to estimate hydraulic properties would be achieved by considering measured the saturated hydraulic conductivity and the soil water retention.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.433-438
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• 1997

The freshness of apple was evaluated by characterizing the surface texture of flesh cells. The freshness index which was related to the amount of wrinkles on the cell surface was defined to quantify the freshness. Four parameters relevant to the amount of the cell wrinkles were selected and measured using image analysis including wrinkle extraction procedure and Fast Fourier Transform of a wrinkle-extracted image. Out of 4 parameters, three parameters had highly significant correlations with the time elapsed after harvest. But it was concluded that two parameters out of such 3 parameters could be used for description of freshness index.

• Imaging Science in Dentistry
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• v.41 no.4
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• pp.151-153
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• 2011

Purpose : The purpose of this study was to obtain the description of the mandibular bone quality of male and female patients between 40-60 years old and their differences based on mandibular cortical bone thickness measured using Mental Index (MI). Materials and Methods : Forty digital panoramic radiographs, which consisted of twenty male and twenty female patients, 40-60 years old, were observed. Mandibular cortical bone thickness was measured using MI on both sides of the mandible. The average MI score of two groups were then assessed using t-sample independent test. Results : There were significant differences of mandibular bone quality based on mandibular cortical bone thickness measurement using MI between male and female patients (p<0.05). Conclusion : Mandibular bone quality based on cortical bone thickness measurement using MI of male and female patients indicated a significant difference.

• Journal of the Korean Society for information Management
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• v.16 no.2
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• pp.183-199
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• 1999

The three key parts of citation index are the Citation Index, the Source Index and the Permuterm Subject Index. To identify the core elements for citation index database system, it analyzed the items that have been cited in references and source items of Journal of the Korean Society for Information Management from vol. 1 no. l(1984) to vol. 15 no. 3(1998). Ten core elements were identified and the description format was specified respectively. The core elements are author, organization that the author is affiliated, title of article, title or journal, volume/numberlpage numbers, year of publication, keyword, language, subject category, statistics of references in article. Also, characteristics of errors in reference citations were analyzed and categorized in the viewpoint of the citation index development of academic journals in Korea.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.109-116
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• 2021

Since RDF (Resource Description Framework) triples are modeled as graph, we cannot directly adopt existing solutions in relational databases and XML technology. In order to store, index, and query Linked Data more efficiently, we propose a convergence indexing method combined R*-tree and K-dimensional trees. This method uses a hybrid storage system based on HDD (Hard Disk Drive) and SSD (Solid State Drive) devices, and a separated filter and refinement index structure to filter unnecessary data and further refine the immediate result. We perform performance comparisons based on three standard join retrieval algorithms. The experimental results demonstrate that our method has achieved remarkable performance compared to other existing methods such as Quad and Darq.

• Journal of Korean Society of Archives and Records Management
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• v.4 no.2
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• pp.118-162
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• 2004

Archival description in archives has an important role in document control and reference service. Archives has made an effort to do archival description. But we have some differences and problems about a theory and practical processes comparing with advanced countries. The serious difference in a theory is that a function classification, maintenance of an original order, arrangement of multi-level description are not reflected in practical process. they are arranged in shelves after they are arranged by registration order in a unit of a volume like an arrangement of book. In addition, there are problems in history of agency change or control of index. So these can cause inconvenience for users. For improving, in this study we introduced the meaning and importance of arrangement of description, the situation and problem of arrangement of description in The National Archives, and a description guideline in other foreign countries. The next is an example for ISAD(G). This paper has chapter 8, the chapter 1 is introduction, the chapter 2 is the meaning and importance of arrangement of description, excluding the chapter 8 is conclusion we can say like this from the chapter 3 to the chapter 7. In the chapter 3, we explain GOVT we are using now and description element category in situation and problem of arrangement of description in Archives. In the chapter 4, this is about guideline from Archives in U.S.A, England and Australia. 1. Lifecycle Date Requirement Guide from NARA is introduced and of the description field, the way of the description about just one title element is introduced. 2. This is about the guideline of the description from Public Record Office. That name is National Archives Cataloguing Guidelines Introduction. We are saying "PROCAT" from this guideline and the seven procedure of description. 3. This is about Commomon Record Series from National Archives of Australia. we studied Registration & description procedures for CRS system. In the chapter 5, This is about the example which applied ISAD to. Archives introduce description of documents produced from Appeals Commission in the Ministry of Government Administration. In the chapter 6, 7. These are about the problems we pointed after using ISAD, naming for the document at procedure section in every institution, the lack of description fields category, the sort or classification of the kind or form, the reference or identified number, the absence description rule about the details, function classification, multi-level description, input format, arrangement of book shelf, authority control. The plan for improving are that problems. The best way for arrangement and description in Archives is to examine the standard, guideline, manual from archives in the advanced countries. So we suggested we need many research and study about this in the academic field.