• Annual Conference on Human and Language Technology
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• 1999.10d
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• pp.76-86
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• 1999

본 논문에서는 포항공과대학교 지식 및 언어공학연구실에서 개발한 한국어 형태소 분석기 및 품사 태거에 대하여 설명한다. 먼저, 음운 축약 현상이 많은 한국어에 적합한 음절단위 CYK 알고리즘을 제안한다. 그리고, 복합명사 및 복합동사에 대한 처리와 실제 문서에서 빈번히 발생하는 띄어쓰기 오류 처리에 대한 방법론을 설명하고 미등록어에 대한 처리 방안을 제시한다. 품사 태거에서 사용된 방법론과 태그 집합간 매핑, 그리고 명사 추출기에 대해 기술한 후 마지막으로 MATEC'99를 위한 준비과정에서 발생한 표준안과 우리 시스템 사이의 차이점을 나열 및 분석하고 간단히 MATEC'99를 통해 얻은 실험 결과와 평가를 하고자 한다.

• Annual Conference on Human and Language Technology
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• 2001.10d
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• pp.41-47
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• 2001

본 논문에서는 한국어 형태소 해석기에 다중 스레드 기법을 도입하여 다중 처리가 가능하도륵 하였다. 기존의 여러 형태소 해석기들은 언어 분석에만 관심이 있었기 때문에 다량의 문서를 동시에 처리하는 기능을 고려하지 않았다. 그러나 형태소 해석기가 정보 검색 시스템 분야에서 사용되기 시작하면서, 다수의 사용자가 대량의 문서를 처리해야 하는 필요성이 생겼다. 스레드 간에는 메모리 영역과 같은 자원을 공유한다. 이러한 특징 때문에 자칫하면 예상치 못한 결과가 야기될 수 있다. 따라서, 다중 스레드 기법을 사용하기 위해서는 스레드의 특징을 고려한 조치가 필요하다 기존의 한국어 형태소 해석기의 소스 코드를 분석하여 자주 사용되는 전역 변수는 하나의 구조체로 구성하였다. 그리고 이러한 전역 변수와 크기가 큰 지역 변수를 사용할 때 메모리를 동적으로 할당하였다. 또한, 파일에서 입력값을 읽어오거나 파일에 결과값을 쓰는 등 여러 스레드가 접근할 때 값이 변경될 위험이 있는 부분은 조건 변수를 이용하여 동기화 시켰다. 구현된 시스템의 검증을 위하여, 단일 스레드 방식으로 순차적인 처리를 하는 원래의 형태소 해석기와 비교 실험을 실시하였다. 35Kbyte 문서 30개를 처리하는 경우, 다중 처리가 가능한 형태소 해석기가 단일 스레드 방식의 형태소 해석기보다 처리속도가 약 12% 향상되었다.

• Textile Coloration and Finishing
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• v.22 no.3
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• pp.229-238
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• 2010

Poly($\varepsilon$-caprolactone) nano/microcapsules(nmcPCL) containing phytoncide oil were synthesized by emulsion diffusion method using ethyl acetate and poly(vinyl alcohol) (PVA) as an organic solvent and an emulsion stabilizer respectively. The influence of the degree of saponofication of the PVA and the weight ratio of core to wall materials was investigated to design nanocapsules in terms of particle size, morphology, and emulsion stability. The encapsulated nmcPCL were characterized by FT-IR spectrometry, particle size analyzer and scanning electron microscope. Mean size of nanocapsules prepared with PVA with a degree of saponofication of 87% was smaller than those of PVA with a degree of saponofication of 98.5% and the mean particle size of the capsules decreased with increasing core/shell ratio.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.29-34
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• 2014

Nanogels are internally cross-linked particles of sub-micrometer size made of hydrophilic polymers and are considered a distinct type of macromolecules, compared with linear and branched polymers or macroscopic gels. In this study, we studied a method of radiation induced synthesis of nanogels, which allows us to obtain tailored intra-molecularly crosslinked macromolecules of independently chosen molecular weight and dimensions. Thus, we report the possibility of applying the prepared nanogels using poly(acrylic acid) through electron beam irradiation for potential application as biomaterials. The nanogels were characterized by scanning electron microscopy (SEM). In addition, the size and zeta-potential of nanogels were measured by a particle size analyzer (PSA). The nanogels were prepared at an approximate size of 180 nm at 100 kGy and were spherical in shapes. The size of the nanogels decreased with increasing irradiation doses, and the absolute value of zeta potential increased with increasing irradiation doses.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.102-110
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• 2001

To establish an accurate asbestos analysis method for workplace samples, chrysotile, amosite, crocidolite, tremolite, actinolite, and anthophyllite asbestos fibers were analyzed for their morphology, atomic content and electron diffraction patterns. The morphology of asbestos fiber was evaluated in $10,000{\times}$ magnification. The atomic contents was analyzed by X-ray analyzer (TEM-EDX). Asbestos fibers were further assessed using electron diffraction (ED) patterns to provide an additional criterion for classifying the asbestos fibers. Twenty asbestos fibers were initially randomly selected for morphological evaluation; based on an aspect ratio (length : diameter = 3:1). Then the fibers were determined for their EDX spectrums and ED patterns. Our results showed that only chrysotile fiber has a hollow tube structure to be distinguished from other asbestos fibers. Although asbestos fibers had similar morphology, they had different EDX spectrums and ED patterns. Our results on the atomic content of asbestos fibers were very similar to those of other researchers, but amosite and crocidolite had a little difference in atomic content compared with the results from other researchers. The difference may be due to the difference in equipment or asbestos sample selection. A study on asbestos samples from biological specimens to establish a criterion for determining occupational asbestos exposed diseases should be done in the near future.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.214-220
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• 2013

Hydrophobic coating on a silicate-based yellow phosphor ($Sr_2SiO_4:Eu^{2+}$) was carried out by using hexamethyldisiloxane (HMDSO) precursor in an atmospheric pressure dielectric barrier discharge plasma reactor, eventually to improve the long-term stability and reliability of the phosphor. The phosphor powder samples were characterized by a scanning electron microscope (SEM), a transmission electron microscope (TEM), a fluorescence spectrophotometer and a contact angle analyzer. After the coating was prepared, the contact angle of the phosphor powder increased to $133.0^{\circ}$ for water and to $140.5^{\circ}$ for glycerol, indicating that a hydrophobic layer was formed on its surface. The phosphor coated with HMDSO exhibited photoluminescence enhancement up to 7.8%. The SEM and TEM images of the phosphor powder revealed that the plasma coating led to a morphological change from grain-like structure to smooth surface with 31~46 nm thick hydrophobic layer. The light emitting diode (3528 1 chip LED) fabricated with the coated phosphor showed a substantial enhancement in the reliability under a special test condition at $85^{\circ}C$ and 85% relative humidity for 1,000 h (85/85 testing). The plasma-mediated method proposed in this work may be applicable to the formation of 3-dimensional coating layer on irregular-shaped phosphor powder, thereby improving the reliability.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.305-312
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• 2005

Poly(urethane-imide)s were prepared by reaction between crosslinkable endgroup containing soluble polyimide (PI) by chemical imidization and acrylate end-capped polyurethane (PU). Poly (amic acid) was prepared from 2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) and 4,4'-oxydianiline (ODA) and then end-capped with maleic anhydride (MA). The PU prepolymers were prepared by the reaction of polycaprolactone diol, tolylene 2,4-diisocyanate and end-capped with hydroxyl ethyl acrylate. The effect of PU content on the residual stress behavior, morphology and thermal property was studied. The poly(urethane-imide)s were characterized by thin film stress analyzer (TFSA), XRD, TGA and DMTA. Low residual stress and slope in cooling curve were achieved by higher PU content. Compared to typical polyurethane, these polymers exhibited better thermal stability due to the presence of the imide groups. Finally the residual stress of poly(urethane-imide)s was strongly affected by the morphological structure.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1014-1019
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• 1999

Copolyamic acid PMDA/6FDA-PDA(PAA) and homopolyamic acids PMDA-PDA(PAA) and 6FDA-PDA(PAA) were synthesized from 1,2,4,5-benzenetetracarboxylic dianhydride(PMDA) and 2,2'-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride(6FDA) as the dianhydride and 1,4-phenylenediamine (PDA) as the diamine. Residual stresses were detected in-situ during thermal imidization of the co- and homopolyimide precursors as a function of processing temperature over the range of $25{\sim}400^{\circ}C$ using thin film stress analyzer(TFSA), and morphological structures were investigated by WAXD. In comparison, the resultant residual stress of polyimide films composed of different compositions decreased with the increasing content of PMDA unit in the chain and was about 5 Mpa in compression mode for PMDA-PDA. In this study, the synthesis of random PMDA/6FDA-PDA copolyimide could be completed and compensate for the difficulty of process due to high $T_g$ of PMDA-PDA and relatively higher stress of 6FDA-PDA. It showed that we can make a low level stress copolyimied having excellent mechanical properties by incorporating appropriate rod-like rigid structure PMDA-PDA unit into 6FDA-PDA polyimide backbone which generally shows higher stress due to rotational hinges such as bulky di(trifluoromethyl). Specially, PMDA/6FDA-PDA(0.9:0.1:1.0) satisfied excellent mechanical property and low level stress as an inter layer showing low dielectric constant.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.44-51
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• 1998

In this work, the in-situ viscoelastic characteristics of electropolymerized polypyrrole (PPy) thin film were investigated in the electrolyte solutions of $NaClO_4$, $LiClO_4$, and $KClO_4$ by using quartz crystal analyzer (QCA). One side of quartz crystal was used as a working electrode mounted in a special fabricated QCA electrochemical ceil. The resonant frequency and resonant resistance diagram (F-R diagram) was used to interpret the viscoelastic characteristics of Pby thin film and compared with AFM photograph. The resonant frequency, resonant resistance, and current were measured to analyze the redox reaction behaviors when the cyclic voltammetry was performed using AT-cut quartz crystal electrode coated with galvanostatically polymerized Ppy film. The result suggests that the Ppy film polymerized onto the crystal behaves as a rigid elastic layer at the initial stage of electropolymerization, while the film becomes a viscoelastic layer the polymerization proceeds further. At the same time, the film thickness increases and some morphological changes take place due to the penetration of electrolyte solution into the film. These phenomena take place when cyclic voltammetry was performed using different electrolyte solution compared with polymerization process.

• Journal of Korean Academy of Nursing
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• v.44 no.3
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• pp.328-338
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• 2014

Purpose: This study was done to explore experiences of persons living through the periods of cancer diagnosis, treatment, and self-care. Methods: With permission, texts of 29 cancer survival narratives (8 men and 21 women, winners in contests sponsored by two institutes), were analyzed using Kang's Korean-Computerized-Text-Analysis-Program where the commonly used Korean-Morphological-Analyzer and the 21st-century-Sejong-Modern-Korean-Corpora representing laymen's Korean-language-use are connected. Experiences were explored based on words included in 100 highly-used-morphemes. For interpretation, we used 'categorizing words by meaning', 'comparing use-rate by periods and to the 21st-century-Sejong-Modern-Korean-Corpora', and highly-used-morphemes that appeared only in a specific period. Results: The most highly-used-word-morpheme was first-person-pronouns followed by, diagnosis treatment-related- words, mind-expression-words, cancer, persons-in-meaningful-interaction, living and eating, information-related-verbs, emotion-expression- words, with 240 to 0.8 times for layman use-rate. 'Diagnosis-process', 'cancer-thought', 'things-to-come-after-diagnosis', 'physician husband', 'result-related-information', 'meaningful-things before diagnosis-period', and 'locus-of-cause' dominated the life of the diagnosis-period. 'Treatment', 'unreliable-body', 'husband people mother physician', 'treatment-related-uncertainty', 'hard-time', and 'waiting-time represented experiences in the treatment-period. Themes of living in the self-care-period were complex and included 'living-as-a-human', 'self-managing-of-diseased-body', 'positive-emotion', and 'connecting past present future'. Conclusion: The results show that the experience of living for persons with cancer is influenced by each period's own situational-characteristics. Experiences of the diagnosis and treatment-period are negative disease-oriented while that of the self-care period is positive present-oriented.