• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.50-50
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• 2000

In this paper, a new measuring system is :proposed which can measure the fine 6-DOF displacement of rigid bodies. Its measurement principle is based on detection of laser beam reflected from a specially fabricated mirror that looks like a triangular pyramid having an equilateral cross-sectional shape. The mirror has three lateral reflective surfaces inclined 45$^{\circ}$ to its bottom surface. We call this mirror 3-facet mirror. The 3-facet mirror is mounted on the object whose 6-DOF displacement is to be measured. The measurement is operated by a laser-based optical system composed of a 3-facet mirror, a laser source, three position-sensitive detectors(PSD). In the sensor system, three PSDs are located at three corner points of a triangular formation, which is an equilateral triangular formation tying parallel to the reference plane. The sensitive areas of three PSDs are oriented toward the center point of the triangular formation. The object whose 6-DOF displacement is to be measured is situated at the center with the 3-facet mirror on its top surface. A laser beam is emitted from the laser source located at the upright position and vertically incident on the top of the 3-fatcet mirror. Since each reflective facet faces toward each PSD, the laser beam is reflected at the 3-facet mirror and splits into three sub-beams, each of which is reflected from the three facets and finally arrives at three PSDs, respectively. Since each PSD is a 2-dimensional sensor, we can acquire the information on the 6-DOF displacement of the 3-facet mirror. From this principle, we can get 6-DOF displacement of any object simply by mounting the 3-facet mirror on the object. In this paper, we model the relationship between the 6-DOF displacement of the object and the outputs of three PSDs. And, a series of simulations are performed to demonstrate the effectiveness of the proposed method. The simulation results show that the proposed sensing system can be an effective means of obtaining 3-dimensional position and orientation of arbitrary objects.

• Journal of Korean Library and Information Science Society
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• v.32 no.4
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• pp.147-170
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• 2001

This study intends to 1)conform the possibility to transform the enumerated scheme into the faceted scheme, 2)review general theories on facet structure employed in DDC 780, and 3) analyze the facet structure of music. Findings are 1) The facet structure of DDC synthesize the standard subdivisions or specific facet indicators with basic facet. 2) facet indicator 0 is in use to indicate standard subdivision or general principle of music. and facet indicator 1 to general principles and musical forms. DDC has transformed the entire system into the facet structure through its revisions. Especially the music transformed into the facet structure employes the facet indicators and applies them to all the systems in music. But the notation have sometimes twofold meanings, and no ability to differentiate the meanings in the same notation.

• Journal of KIISE:Software and Applications
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• v.27 no.2
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• pp.168-179
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• 2000

In reusable component retrieval systems with facet-based schemes, facet queries are generally used for representing the characteristics of components relevant to users. This paper proposes an expanded facet query equipped with an object-based thesaurus to precisely formulate user's intents. To evaluate the query, a component retrieval system is also designed and implemented. For exactly retrieving the components, user's query should include relevant facet values capable of fully specifying their characteristics. However, simply listing a series of facet values directly inputted by users, conventional queries fails to precisely represent user's intents. Our query, called expanded facet query, employs fuzzy boolean operators and object-based thesaurus; the former logically expresses the fuzzy connectives between facet queries and required components, whereas the latter helps users appropriately select the specific facet values into the query. A thesaurus query is provided to recommend the relevant facet values with their fuzzy degrees from the thesaurus as well. Furthermore, our retrieval system can automatically formulate queries with the recommended facet values, if necessary.

• Journal of Korean Library and Information Science Society
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• v.30 no.3
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• pp.53-96
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• 1999

This study intends to : 1) confirm the possibility to transform the enumerated scheme into the faceted scheme, 2) review general theories on facet structure employed in DDC of the enumerated scheme, 3) analyze the facet structure of life science and literature in DDC, and 4) comparison of the facet structure of life science and literature in DDC and CC. This study suggests following conclusions. 1) CC follows throughly the classification principles by Ranganathan, but all classification theories are not property applied to DDC yet. 2) Because DDC does not have any formula to classify the compound subject, but has to follow the compounding methods presented in each subject, its facet structure is too complicated. 3) DDC has transformed the entire system into the facet structure through its revision. Expecially the life science transformed into the facet structure employed the facet indicators and applies them to all the systems in life science. But the notations have sometimes twofold meanings, and no ability to differentiate the meanings in the same notation,. When DDC follows the classification method by facet, the number of items for classification so limited that it is difficult to array the subdivision and that length of notation becomes longer and longer.

• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.18-25
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• 2018

Purpose: To investigate the various imaging factors associated with aggravation of lumbar disc herniation (LDH) and develop a scoring system for prediction of LDH aggravation. Materials and Methods: From 2015 to 2017, we retrospectively reviewed the magnetic resonance imaging (MRI) findings of 60 patients (30 patients with aggravated LDH and 30 patients without any altered LDH). Imaging factors for MRI evaluation included the level of LDH, disc degeneration, back muscle atrophy, facet joint degeneration, ligamentum flavum thickness and interspinous ligament degeneration. Flexion-extension difference was measured with simple radiography. The scoring system was analyzed using receiver operating characteristic (ROC) analysis. Results: The aggravated group manifested a higher grade of disc degeneration, back muscle atrophy and facet degeneration than the control group. The ligamentum flavum thickness in the aggravated group was thicker than in the group with unaltered LDH. The summation score was defined as the sum of the grade of disc degeneration, back muscle atrophy and facet joint degeneration. The area under the ROC curve showing the threshold value of the summation score for prediction of aggravation of LDH was 0.832 and the threshold value corresponded to 6.5. Conclusion: Disc degeneration, facet degeneration, back muscle atrophy and ligamentum flavum thickness are important factors in predicting aggravation of LDH and may facilitate the determination of treatment strategy in patients with LDH. The summation score is available as supplemental data.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.15 no.1
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• pp.23-41
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• 2004

In indexing and organizing Web resources, there have been two basic methods: automatic indexing by extracting key words and library classification schemes or subject directories of search engines. But, both methods have failed to satisfy the user's information needs, due to the lack of standard criteria and the irrationality of its structural system. In this paper I have examined the limits of library classification scheme's structures and the problems related to the nature of Web resources such as specificity and exhaustivity. I have also attempted to explain the logicality of Web resources organization by facet analysis and its strengths and limitations. In so doing, I have proposed three specific methods in using facet analysis: firstly, indexing system by facet analysis; secondly, the alternative transformation of the enumerative classification scheme into facet classification scheme; and finally, the facet model of subject directory of domestic search engine. After examining the three methods, my study concludes that a controlled vocabulary by facet analysis can be employed as a useful method in organizing Web resources.

• Journal of Information Management
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• v.37 no.3
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• pp.61-84
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• 2006

In this paper, we proposed one of the methods for building thesaurus in Science & Technology domain and investigated its applicability as an inference service based on ontology. There exist as many building methods for thesaurus as its role and function, and actually many thesauri capable of ensuring the accuracy and efficiency in information search are being built by many experts. After examining the previous studies related to the principles of building thesaurus and relevant concept "facet", we focused on its characteristics and applied it to building thesaurus. The facet is classified into 2 categories, conceptual facet and relational facet. The latter contains 3 subcategories: category relational facet, attribute relational facet and thematic relational facet. The thesaurus for Science & Technology domain using facets can be applied as a web-based inference service. As a result, the three types of inference service, COP(Communities of Practice), Researcher Tracing and Research Map are provided by means of ontology, and can be applied for the Query Expansion.

• Journal of Korean Library and Information Science Society
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• v.48 no.1
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• pp.345-371
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• 2017

Traditionally, the construction industry field is one of the typical fields using facet analysis method. Internationally the facet analysis method is applied to the classification scheme "Uniclass" or thesaurus "Construction Industry Thesaurus(CIT)". In the case of Korea, the facet analysis method is being used in classification scheme "Construction Industry Classification System" but it is difficult to find studies on facet analysis method in thesaurus or building case study. This study aims to establish facet types by introducing building of thesaurus for information retrieval in construction field using facet analysis method and to suggest building plan of thesaurus in construction field using facet analysis method. In this paper, We establish the 11 top facets(agent/patient, artifacts, abstract, material, parts/component, works, attribute, media, process, space, time) and the 13 subfacet as rudimental facets and suggest building plan according to thesaurus building procedure which is suggested by International Standard(ISO 25964-1). The result of this study is expected to apply to facet based thesaurus. And it is also expected to reuse in Taxonomy or Ontology etc. and to use in interoperability with the classification scheme of Construction filed.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.51-58
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• 2008

A version control system is used in a rapidly changed environment or a program which developed in a complicated environment. it is a problem of configuration thread in supporting information that we, in this method, can't know a exactly well-defined configuration rule information and a predefined information. In this paper. Library system is suggested, modelled, and implemented so as to configuration thread control the components required by the user in many ways. As for the library used in the configuration thread control suggested in this paper, the components can be retrieved from the library regardless of the infrastructure, applying the extended facet classification. This retrieval framework is managed using TreeSearch class and the configuration thread control function. The library system of this paper can be used by the interface with other languages, and this system is to have a advantage to extend a facet by user.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.5
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• pp.566-571
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• 1988

Laser scanning system using a hologram is simpler in optical system, lower in cost than using a polygon. In this paper, a thick hologram is fabricated for the underfilled transmission disk type with a merit of wabble insensitivity to vibration. High diffraction efficiency over 50% is obtained using silver halide recording material. The two-dimensional scan pattern with 13 scan-line is made by 7-facet hologon and mirror system. This system can be practically applied to POS(Point of Sale) bar-code symbol reader.