• Journal of the Korean Society for Precision Engineering
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• v.25 no.12
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• pp.132-138
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• 2008

Recently, mastering processes for high density optical disc such as Blu-ray disc rely on electron beams, which are operable in only vacuum. In the mastering process, one of the most important tasks is to design precision stages for providing precise positioning of the works with respect to the source in a high vacuum environment. In this paper, we have developed a precision rotation table usable in the electron beam mastering. The rotation table adopted air bearings for a high positioning repeatability and velocity stability. The air leakage from the air bearings has been minimized by employing the differential exhaust scheme using three steps of air drain. The design parameters such as diameters of exhaust lines, seal lengths, and pumping speeds were decided according to the optimization method using genetic algorithm. The performance on the vacuum level of the rotation table was evaluated experimentally and theoretically. The results indicate that a vacuum level of $10^{-4}$ Pa is achieved with operation of air bearings in a vacuum chamber, which is sufficient for the electron beam mastering.

• Journal for History of Mathematics
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• v.27 no.1
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• pp.31-45
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• 2014

The book Su Hak Ip Mun(數學入門, Introduction to Mathematics) is one part of 5 sections of the book Seung Aeh Ill Chan(升厓日簒), which is a hand written manuscript in Chinese characters and the author and the date of writing is unknown. The book Seung Aeh Ill Chan begins with the song of division table so called Guguiga(九歸歌). We first investigate and compare the writing pattern of this with other old Korean mathematical books. Next, we investigate typical expression and calculation methods of mathematical contents and terminologies used in Su Hak Ip Mun and also figure out oddities of writing pattern of mathematical expression and cultural circumference of several problems dealt in the book. From these analysis and investigation, we estimate the writing date of Su Hak Ip Mun later than the year 1723 on which Su Ri Jeong On(數理精蘊) was first published. And we presumably guess that Guguiga and Su Hak Ip Mun are made not for practical use or theoretical purpose but for text to teach students.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.959-962
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• 2002

This paper presents a method of constructing the universal multiple processing element unit(UMPEU) based on De Bruijn Graph. The proposed method is as following. Firstly we propose transformation operators in order to construct the De Bruijn graph using properties of graph. Secondly we construct the transformation table of De Bruijn graph using above transformation operators. Finally we construct the De Bruijn graph using transformation table. The proposed UMPEU is capable of constructing the De Bruijn geraph for any prime number and integer value of finite fields. Also the UMPEU is applied to fault-tolerant computing system, pipeline class, parallel processing network, switching function and its circuits.

• The Journal of Engineering Research
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• v.4 no.1
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• pp.35-45
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• 2002

This paper deals with the scheduling problems which are the most important subtask in High-Level Synthesis. Especially, we have concentrated our attentions on the data-path scheduling which can get the structural informations from the behavioral algorithm as a first step in synthesis procedure. Suggest Forward scheduling methode is executed the ASAP and ALAP scheduling to use the fifth – order elliptic wave filter of a standard benchmark model, and then it is drawing up T.N matrix table by the number of resource and control-step, using the table extract of the simple than down-limit value of the control-step for the number of given resource to use this table. All of existing list scheduling techniques determine the priority functions first, and then do the operation scheduling, But, the suggested forward scheduling technique does the schedule first, and determines the priority functions if needed in scheduling process.

• Journal of Korean Medical classics
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• v.25 no.4
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• pp.105-113
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• 2012

Objectives : Acquiring information from symptoms is one of the important method to gain clinically available information in korean medicine. Therefore, up to now, study of symptom terms was frequently implemented in promotion of various information project. In data extraction methods using symptom information from DB, information search using synonym and method using ontology is studied and utilized. However, considering concept of symptom has essential information of appeared body area and phenomenon we think that extending synonym and ontology relationship in symptom terms can be useful for search and set to this study. Methods : We collect terms relevant to human body area and structure described in Donguibogam. Synonymous relationship between collected terms is organized. Relationship between collected terms is build to human-body-knowledge table which has form of Concept+Relation+Concept. Type of relationship is limited on a range of expressing content about parts of human body. Result & Conclusion : Search condition is generated automatically using relationship of the upper area in knowledge table contents. Information of next and previous acupuncture point, upper and lower acupuncture point, left and right acupuncture point can be searched using information of acupuncture point location, order, relative position in area, direction in knowledge table contents.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.121-133
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• 2007

The CMS(color management system) software was to enable consistent color reproduction from original to reproduction. The CMS was to create RGB monitor and printer characterization profiles and then use the profiles for device independent color transformation. The implemented CMM(color management module) used the CIELAB color space for the profile connection. Various monitor characterization model was evaluated for proper color transformation. To construct output device profile, SLI(sequential linear interpolation) method was used for the color conversion from CMYK device color to device independent CIELAB color space and tetrahedral interpolation method was used for backward transformation. UCR(under color removal) based black generation algorithm was used to construct CIELAB to CMYK LUT(lookup table). When transforming the CIE Lab colour space to CMYK, it was possible to involve the gray revision method regularized in the brightness into colour transformation process and optimize the colour transformation by black generation method based on UCR technique. For soft copy colour proofing, evaluating several monitor specialism methods showed that LUT algorithm was useful. And it was possible to simplify colour gamut mapping by constructing both the look-up table and the colour gamut mapping algorithm to a reference table.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.4
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• pp.761-766
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• 2013

A precision linear motion table plays a crucial role in manufacturing systems used in various industries such as machine tools, semiconductors, and nanofabrication. In particular, one of the most typical mechanisms for a linear motion table is to use a ballscrew and LM guides. However, this mechanism is inevitably influenced by friction because of the relative motion in its joint regions. One of the most complex phenomena in friction is the hysteresis behavior of dynamic friction, which was compared with the steady dynamic friction that was presented using a Stribeck curve in this study. Therefore, we investigated the dynamic friction and its hysteresis behavior using a miniaturized linear table equipped with a ballscrew and LM guides that were lubricated with grease. Subsequently, it could be seen that hysteresis could be considered a time delay after zero-velocity crossing and that it was influenced by acceleration.

• Korean Journal of Agricultural Science
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• v.31 no.1
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• pp.1-8
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• 2004

This study was carried out to identify the effects of seaweed extracts(GA14) on growth of two rice cultivars, Junambyo and Donganbyo. Seedling qualities of two cultivars were better in all items including heading dates at early stage treated at seedling plus 2-3 leaf stages than at single treatment of seedling. Ripening ratio of Junambyo in paddy field was increased 0.3% by seaweed extracts(GA14) treatment, but that of Donganbyo decreased 0.5%. 1,000 grain weight of Junambyo and Donanbyo by seaweed extracts(GA14) treatment was two to four grams higher and the yield of two cultivars was also higher by three to four percent. Appearance characters of two rice cultivars was high in head, while damaged, chalky and crack rate were low at seaweed extracts(GA14) treatment. Protein, moisture and amylose characteristics related to table quality of Junambyo were not different by seaweed extracts treatment, but table values was high in only treatment. Donganbyo was also similar to Junambyo, but table quality was slightly high at non-treatment.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.77-78
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• 2006

This paper presents a signal quality estimation technique for QAM modulation systems. By making a LUT(Look-up table) putting the number of N enough, we can derive estimated SNR from LUT even though N is small. That is so called MOTM algorithm. In 16-QAM, the distance $d_a$, between adjacent symbols is always invariable, so absolute value of R(the amplitude of signal) minus $d_a$ has a always same signal distribution value. This value does not form a Gaussian shape but, by making a little bit correction, we can make this symmetrical. So, from the received symbol value, by using LUT we can easily derive the estimated SNR. By considering this, we introduce a signal quality estimation technique for QAM schemes. This proposed method can be applicable to high order modulation schemes and wide range of signal to noise ratio.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.12
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• pp.1303-1312
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• 2013

We report an ultra-precision lathe designed to machine micron-scale features on a large-area roll mold. The lathe can machine rolls up to 600 mm in diameter and 2,500 mm in length. All axes use hydrostatic oil bearings to exploit the high-precision, stiffness, and damping characteristics. The headstock spindle and rotary tooling table are driven by frameless direct drive motors, while coreless linear motors are used for the two linear axes. Finite element method modeling reveals that the effects of structural deformation on the machining accuracy are less than $1{\mu}m$. The results of thermal testing show that the maximum temperature rise at the spindle outer surface is approximately $0.5^{\circ}C$. Finally, performance evaluations of the error motion, micro-positioning capability, and fine-pitch machining demonstrate that the lathe is capable of producing optical-quality surfaces with micron-scale patterns with feature sizes as small as $20{\mu}m$ on a large-area roll mold.