알루미늄(Ⅲ)의 2염기카르복실산 배위자 착물로부터의 질화알루미늄 분말의 합성

鄭宇軾 嶺南大學校 工業技術硏究所 1993 工業技術硏究所論文集 Vol.21 No.2

Aluminum(Ⅲ) complex with a dibasic carboxylate ligand, (hydroxo)(succinato)Al(Ⅲ), was used as a precursor of aluminum nitride (AlN). The AlN powder was obtained by calcining the complex under nitrogen atmosphere. The carbon source requisite for the carbothermal reduction of γ-Al₂O₃ is provided by pyrolysis of the succinate ligand. The purity and flow rate of nitrogen gas affected on the degree of nitridation. The fact that the nitridation reaction proceeds via an intermediate of γ-Al₂O₃ was evidenced by infrared spectra and powder X-ray diffraction patterns of calcinated samples. Gases evolved during the calcination step were analyzed by infrared spectroscopy.

골격성 Ⅲ급 부정교합자에서 상악골 전진술을 동반한 양악 수술 시 중안면 연조직 형태의 변화

정종현,김성식,손우성,박수병 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.2

본 연구는 중안면 함몰이 있는 골격성 III급 부정교합자의 중안면의 형태를 정상 표본과 비교하고, 악교정수술에 의하여 연조직이 어떤 변화를 보이는지를 알아보기 위하여 시행하였다. 골격성 III급 부정교합으로 진단받고 상악 전진술과 하악 후퇴술을 시행받은 환자 34명 (남자:15명, 여자:19명)을 대상으로 수술 전후 측모 두부방사선 계측사진을 분석하였다. 골격성 III급 부정교합자의 중안면의 경조직 계측치 S'-Or, Or⊥NA, S'Or/SN, ∠SNOr에서 남녀 모두에서 정상 교합자와 큰 차이가 있었다. 상악골이 평균 5.03 mm 전방이동 될 때 연조직 Orbitale는 2.26 mm 전방으로 이동하였으며 상관계수는 0.599였다(p < 0.05). 상악 평면각의 변화(시계방향으로 회전)와 상악골의 수직 이동은 연조직 Orbitale의 전방이동과 유의성있는 상관관계가 없었다. 상악골 전방이동에 대한 연조직 Orbitale와 Subnasale의 전방이동 비율은 각각 43.57%, 81.54%였다. 이상의 결과에서 중안면 함몰이 있는 환자는 상악골 전방이동시 상순과 비부 외에도 연조직 Orbitale를 포함한 중안면 연조직이 전방으로 이동하지만, 상악골의 회전이동 및 수직이동에 대해서는 연조직의 변화량이 적었다는 것을 알 수 있었다. 이는 상악골의 수술에 따른 중안면 함몰의 해소를 예측하는 데 도움이 될 것이다. Purpose: The first objective of this study was to compare the upper midface morpholgy, focusing on the soft tissues, between skeletal Class III maloccusion patients with midfacial depression and the norm. The second objective was to estimate and analyze the change in the upper midface soft tissues following surgical correction with maxillary advancement by Lefort I osteotomy and mandibular setback by bilateral sagittal split osteotomy (BSSRO). Methods: The samples consisted of 34 adult patients (15 males and 12 females) with an average age of 21 years, who had severe anteroposterior discrepancy with midfacial depression. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of simultaneous Lefort I osteotomy and BSSRO. Results: The correlation coefficient between changes in maxillary advancement and changes in Or' (soft tissue orbitale) was 0.599 (P < 0.05). Change in maxillary plane angle and vertical change of the maxilla were not correlated with the change in Or' (P < 0.05). The ratio of soft tissue change in Or' to maxillary advancement was 43.57 %, and 81.54 % in Sn. Regression equations between maxillary movement and Or' were devised. The r² value was 0.476. Conclusions: The majority of measurements in the upper midface in skeletal Class III maloccusions when compared to the norm, showed significant differences. In Class III malocclusion with midfacial depression, maxillary advancement produces soft tissue change in the upper midface.

성인원외폐렴의 원인미생물에대한 전향적 다기관 연구 : 성인원외폐렴의 원인으로 세균의 역할을 중심으로

우준희,강재명,김양수,신완식,류진홍,최정현,김양리,정희진,어수택,박춘식,정문현,정기석,이찬주,류지소 대한감염학회 2001 감염 Vol.33 No.1

Background : Communite-acquired peumonia (CAP) is one of the leading causes of mortality and morbidity. Despite progress in diagnostic techniques and treatments, management of pneumonia remains challenging, because the precise etiology remains uncertain in as many as 49% of cases. The limitaions of identifying etiologic agents make it necessary to use empiric antibiotics in almost all patients, and furthermore emergence of antibiotic-resistant organisms pose difficulties to the selection of an empiric antibiotic regimen. For the optimal choice of empirical antibiotics, we should know the frequency of etiologic agents and antimicrobial resistance rates in the community. Methods : A prospective multicenter study of community-acquired pneumonia in Korea was carried out between May 1997 and April 2000. The microbiologic diagnosis was based on the results of sputum culture, blood culture and pleural culture. Results : Five hundred eighty eight cases of community-acquired peumonia in 562 patients admitted to the hospitals. The mean age was 59.9 with male predominance (58.3%), and 370 (63%) had underlyin gillness. The etiologic agents were identified in 38.3%, and the list of individual agents, in decreasing order, was Streprococcus pneumoniae (21.7%), Klebsiella pneumoniae (14.8%) Pseudomonas aeruginosa (9.8%), Staphylococcus aureus (9.5%), viridans group streptococci (5.7%), Enterobacter cloacae (4.2%), Hemophillus Influenza (3.8%), The rates of admission to the intensive care unit was 10.4%. The motality was 7.1%. Susceptible rates of S. pneumoniae to penicillin was 36.6% and showed multidrug resistant. Forty percents of S. aureus were methicillin-resistant S. aureus. K. penumoniae were susceptible to cephalosporin and quinolone. Conclusion : In Korea, S.pneumoniae is the most important agent causing community-acquired pneumonia. Susceptible rates of S. pneumoniae to penicillin was 36.6% and showed multidrug resistant. Gram negative bacteria such as K. pneumoniae, P. aeruginosa showed high incidence when compared with that of other countries. Most of them had underlying diseases including bronchiectasis and chronic obstructive pulmonary diseases. (Korean J Infect Dis 33:1∼7, 2001)

원고지 상에 쓰여진 온라인 필기 제스쳐 인식기 구현

정우식,권영빈 중앙대학교 정보통신연구소 2000 정보통신연구소논문집 Vol.2 No.2

본 논문에서는 원고지 상에 작성된 문자들의 교정을 위한 제스쳐 인식 방법을 제안하고 있다. 원고지의 교정용으로 제시된 13개의 정의된 제스쳐를 중심으로 흘려 쓴 원고의 내용을 수정할 수 있도록 하였다. 이때, 인식을 위하여 제시된 프리미티브로는 직선, 곡선 및 원을 사용하였으며 이들은 벡터 세크먼트들의 조합에 의한 결합과정에 따라 한글 오토마타에 의해 정의되도록 하였다. 제시된 방법의 인식율은 40명의 다른 필기자가 작성한 520개의 샘플에 대하여 92%를 나타내어 실용화가 가능함을 보여주고 있다. In this paper, a method on handwriting gesture recognition for the oriental manuscript paper form is proposed. The pre-defined 13 different kinds of gestures are introduced on the boxed type manuscript paper on which the cursive handwrithing characters are already written. To detect the pre-defined gestures, primitives of line,curve, and circle are defined from the pre-calculated vector segments and its calculation using line merging process and automata. The recognition ratio of the proposed method is obtained at 92% among 520 samples with 40 different writers.

지형적 특징이 해풍시작에 미치는 영향에 대한 연구

정우식,이화운 한국대기환경학회 2003 한국대기환경학회지 Vol.19 No.6

We simulate the geographical effects on the onset time of sea breeze at Suyoung and Haeundae districts by using the LCM (Local Circulation Model). The following can be found out from the numerical simulation on Case I (real terrain) which considered the real geography of Busan metropolitan area. Especially, as a result of analyzing the land breeze path, it could be found along the coastline as it flows out through low land coastal area. To find out more about the effects of terrain and geography on the onset time of sea breeze, the results of numerical simulation of virtual geography are as follows. In Case II (flat terrain), to find out how the terrain slope affects the onset of sea breeze, flat land and the ocean was considered. As a result, convergence of nighttime air mass at a Suyoung area and nighttime strong wind speed phenomenon was not shown. In Case III (modified flat terrain), to find out the effects of the irregularity of coastline affecting the onset of sea breeze, numerical simulation was carried out by simplifying the complex coastline into segments of straight coastline. So land breeze system and changing process of sea breeze after sunrise at Suyoung and Haeundae was simulated almost in a similar manner. Through this we could find the effects of coastal irregularities on onset of sea breeze.

파종시기가 다른 일미찰의 등숙 중 호화 특성 비교

김미정, 박효진, 이유영, 김선림, 김정태, 우관식, 권영업, 정일민 忠北大學校 農業科學硏究所 2014 農業科學硏究 Vol.30 No.2

This study was conducted to investigate the pasting properties of waxy corn ‘Ilmichal’ during ripening with different sowing date. Starch content of Ilmichal was increased as matured (p<0.05). Analysis of pasting properties with waxy corn starch using a rapid visco analyser (RVA) showed linear changes in peak viscosity, trough viscosity, final viscosity, breakdown and consistency according to ripening. There were significantly positive correlation between starch content of Ilmichal and peak viscosity (0.39*), trough viscosity (0.58***), final viscosity (0.58***), and consistency (0.57**). Differential scanning calorimerty (DSC). The enthalpy of gelatinization was increased as ripening. But onset and peak temperature were decreased. There were significantly positive correlation between starch content of Ilmichal and onset temperature (0.44*), peak temperature (0.38*), and completion temperature (0.59***), on the other hand, crude protein content presented significantly negative correlation between completion temperature (-0.41*).

해풍시작에 영향을 미치는 지형성 강풍현상에 대한 고찰 : 관측자료 분석 Analysis of Observation Data

정우식,이화운 한국환경과학회 2002 한국환경과학회지 Vol.11 No.4

We would like to investigate the strong wind phenomenon effecting to the onset of a sea breeze. It is general the fact that the onset time of a sea breeze is mainly affected according to the distance from the coastline but we find the reversal fact. The onset time at Suyoung is faster than that at Haeundae in spite of the observation site of Suyoung is 5 m and that of Haeundae is 1 ㎞ away from the coastline. This is the reason that the nighttime air is converged the lower area by surface cooling and then it is strongly drained onto the lowest area, Suyoung river until the sunrise, it is porved by observation data at Suyoung and Haeundae.

골격성 III급 부정교합자의 수직적 안면골격형태와 교합평면과의 관계

정우준,김성식,손우성,김용덕 대한치과교정학회 2007 대한치과교정학회지 Vol.37 No.4

암모니아 분위기에서 질산갈륨 염으로부터 질화갈륨 분말의 합성

정우식,한승훈 嶺南大學校 工業技術硏究所 2003 工業技術硏究所論文集 Vol.31 No.1

Gallium nitride (GaN) powder was prepared by using a gallium(Ⅲ) nitrate salt in flowing ammonia in the temperature range 600-1050℃. The process of conversion of the salt to GaN was monitored by X-ray diffraction, IR, and ^71Ga MAS (magic-angle spinning) NMR spectroscopy. The salt decomposed to r-Ga_2O_3 and then converted to GaN without r-β Ga_2O_3 phase transition. It is most likely that the conversion of r-Ga_2O_3 to GaN does not proceed through Ga_2O but stepwise via amorphous gallium oxynitride (GaO_xN_y) as intermediates. Room-temperature photoluminescence spectra showed the emission peak at 363㎚. The GaN powders prepared were fused, with its primary particle size being 30-50㎚.

암모니아 분위기에서 갈륨(Ⅲ) 착물으로부터 질화갈륨 분말의 합성

정우식,김진호 嶺南大學校 工業技術硏究所 2004 工業技術硏究所論文集 Vol.32 No.1

Gallium nitride (GaN) powders were prepared by using tris(N,N-dimethyldithiocarbamato)-gallium(III)(Ga(DmDTC)₃) as a new precursor. The GaN powders were obtained by reaction of the complex with ammonia in the temperature ranging from 500 to 1100℃. The process of conversion of the complex to GaN was monitored by X-ray diffraction and ^(71)Ga MAS (magic-angle spinning) NMR spectroscopy. The complex decomposed to γ-Ga₂S₃ and then converted to GaN via amorphous gallium thionitride (GaS_(x)N_(y)). Room-temperature photoluminescence spectra of as-prepared GaN powders exhibited the emission peak at 363 nm. The GaN powders prepared were fused, with their primary particle size being ca. 60 nm.