딥러닝 알고리즘을 이용한 콘크리트 압축강도 예측 모델 개발을 위한 기초적 연구

박동진(Park, Dong Jin),손영준(Son, Young Jun),김용권(Kim, Yong Kwon),노홍래(Lo, Hong Lea),임채용(Lim, Chae Yong),정연식(Jung, Youn Shik) 한국콘크리트학회 2019 한국콘크리트학회 학술대회 논문집 Vol.31 No.2

용융법과 졸겔법으로 제조된 Cordierite 계 유리와 겔의 결정화 거동

박원규,Park, Won-Gyu 배재대학교 공학연구소 1997 공학논문집 Vol.1 No.1

코디어라이트(2MgO.$2Al_2 O_3$.$5SiO_2$)계 유리와 겔을 일반 용융법과 졸겔법으로 제조하여 그 결정화 거동을 비교하여 보았다. 졸겔법으로 제조되는 겔의 치밀화 온도는 $810^{\circ}C$이었으며, IR결과 용융유리와 같은 구조를 가짐을 알 수 있었다. 겔의 결정화 개시온도는 $965^{\circ}C$이었으며, 핵형성제로서 10wt%의 $TiO_2$를 첨가한 용융유리의 $978^{\circ}C$ 보다 낮았다. 겔로부터의 결정상의 변화는 스피넬, $\beta$-석영고용 결정에서 $\alpha$-코디어라이트결정으로, 핵형성제로서 $TiO_2$를 넣은 용융유리에서는 (Mg,Al)TiOn 고용결정상과 $\beta$-석영고용결정에서 $\alpha$-코디어라이트로 전이하여감을 알 수 있었다. 핵형성제를 첨가한 용융유리의 결정화는 핵형성제로부터의 체적결정화였으며, 첨가하지 않은 경우는 $\beta$-석영고용결정으로부터의 표면결정화에 의해 결정화가 일어났으며, 겔로부터의 결정화는 치밀화과정에서 미립자사이에 생겨난 계면으로부터의 표면핵형성에 의한 내부 결정화과정을 거쳐 일어남을 알 수 있었다. The crystallization behaviours of cordierite gel derived from sol-gel method and glass prepared from conventional melting method with or without $TiO_2$ as nucleants are compared. The densification temperature of gel is $810^{\circ}C$ and its chemical structure identified by IR analysis is same as that of glass melted by conventional method. The beginning crystallization temperature of gel is $965^{\circ}C$ lower than that of melted glass with 10wt% $TiO_2$, which is $978^{\circ}C$. The crystalline phases developed from gel during heat treatment are identified as spinel, $\beta$-quartz solid solution and $\alpha$-cordierite crystal and crystalline phases in case of glass are (Mg,Al)TiOn and $\beta$-quartz solid solution and $\alpha$-cordierite crystal, respectively. The crystallization in melted glass with nucleants occurs through bulk crystallization and in case of that without nucleants surface crystallization occurs, while the crystallization in gel is internal crystallization from interface between particles formed after densification.

연마방법에 따른 금속의 활택도에 관한 연구 - Atomic Force Microscope를 이용한 -

박원규,우이형,최부병,이성복,Park Won-Kyu,Woo Yi-Hyung,Choi Boo-Byung,Lee Sung-Bok 대한치과보철학회 2003 대한치과보철학회지 Vol.41 No.1

The surface of metals should be as smooth as possible for optimum comfort, oral hygiene, low plaque retention, and resistance to corrosion. In this study five specimens of each precious metal(type III gold alloy, ceramic gold alloy, and Ag-Pd alloy) were divided into five groups according to finishing and polishing procedures : group 1(sandblaster), group 2(group 1+stone), group 3(group 2+brown rubber), group 4(group 3+green rubber), and group 5(group 4+rouge). Six specimens of each non-precious metal(Co-Cr alloy, Ni-Cr alloy, and Co-Cr-Ti alloy) were divided into six groups: group 1(sandblaster), group 2(group 1+hard stone), group 3(group 2+electrolytic polisher), group 4(group 3+brown hard rubber point), group 5(group 4+green hard rubber point), and group 6(group 5+rouge). Considering factors affecting the rate of abrasion, the same dentist applied each finishing and polishing procedure. In addition, the surface roughness of enamel, resin, and porcelain was evaluated. The effect of finishing and polishing procedures on surface roughness of precious and non-precious metals, enamel, resin, and porcelain was evaluated by means of Atomic Force Microscope(AutoProbe CP. Park Scientific Instruments, U.S.A.) that can image the three dimensional surface profile and measure average surface roughness values of each sample at the same time. The obtained results were as follows : 1. According to finishing and polishing procedures, the surface roughness of type III gold alloy, ceramic gold alloy, and Ag-Pd alloy was decreased in the order of group 1, 2, 3, 4, and 5 (P<0.01). 2. According to finishing and polishing procedures. the surface roughness of Co-Cr alloy, Ni-Cr alloy, and Co-Cr-Ti alloy was decreased in the order of group 1, 2, 3, 4, 5, and 6 (p<0.01). 3. There was not statistically significant difference in the surface roughness among three metals of precious metals in group 1 but was significant difference in group 2, 3, 4, and 5 (P<0.05). 4. There was not statistically significant difference in the surface roughness among three metals of non-precious metals in all groups. 5. When the surface roughness of the smoothest surface of each metal, enamel. porcelain, and resin was compared, porcelain was the smoothest and the surface roughness was decreased in the order of Ni-Cr alloy. Co-Cr alloy. Co-Cr-Ti alloy, resin. Ag-Pd alloy, ceramic gold alloy type III gold alloy, and enamel (P<0.01). The results of this study indicate that the finishing and polishing procedures should be carried out in a logical, systematic sequence of steps and the harder non-precious metals may be less resistance to abrasion than are the softer precious metals.

창경궁 통명전 목부재의 연륜연대 측정 -방에서 마루로 변형된 시기규명을 중심으로-

박원규,손병화,한상효,Park, Won-Kyu,Son, Byung-Wha,Han, Sang-Hyo 한국건축역사학회 2003 건축역사연구 Vol.12 No.3

Tree-ring chronologies can be used to date historical buildings by matching them with the chronologies of living trees or previously dated samples. Tree-ring dating gives a calendar year to each tree ring and produces the felling dates of logs or woods which had been used for buildings. In Korea, several chronologies of Japanese red pine(Pinus densiflora Sieb. et Zucc., 'sonamu' in Korean), a major species for the wooden building materials, have been developed and used for dating historical buildings. In this study, Tongmyungjeon Hall of Changkyung Palace in Seoul was dated by tree rings. The present Tongmyungjeon Hall was known to be reconstructed in A.D. 1834 after burned-out in A.D. 1790. We sampled total of 122 wood samples which were replaced during the repair process in 2002-2003. Felling dates of the samples were determined by the dendrochronological crossdating method. Crossdating method employs graphic comparison of the master patterns (ring-width chronologies of known dates) with those of the sample chronologies of unknown dates. Tree-ring dates confirmed that the reconstruction of 1834 utilized second-handed timbers as well as fresh-cut ones. The felling dates of wooden floor frames were mostly A.D. 1913, indicating the 'Ondol' floors were changed to the wooden floors around 1914 when the Japanese rulers brutally destroyed the royal Korean Palaces and transformed palace buildings to their offices or exhibition halls after occupying Korea in 1910. This study proved that tree-ring dating was a useful and accurate method to identify the critical dates for the history of Korean traditional buildings.

우리나라 건축물에 사용된 목재 수종의 변천

박원규,이광희,Park, Won-Kyu,Lee, Kwang-Hee 한국건축역사학회 2007 건축역사연구 Vol.16 No.1

We investigated the changes in the species of the woods used for Korean ancient and historic architectures, which include prehistoric excavated relics and existing wooden buildings in South Korea. The species data were collected from various sources such as excavation and repair reports, journal papers, and a few unpublished documents. We divided the building Periods as Paleolithic, Neolitic, Bronze Ages, Iron Age/Three Kingdoms, Koryo, Joseon (early, middle, late) and modem periods. In prehistoric periods, hardwoods were major species. Oak (Quercus spp.) woods dominated (94 percent in average); the others (5%) were Juglans mandshurica, Platycarya strobilacea, Castanea crenata, and few softwoods(1%). During Iron Age and Three Kingdom periods, oaks remained as a major species (57%) and others Platycarya strobilacea(21%), Castanea crenata(13%), and Pinus spp. (6%). The oak woods decreased in Koryo period and they occupied only 1.1%. Instead of oaks, pine (Pinus spp., 71%) and Zelkova serrata (22%) dominated in Koryo. In early and middle Joseon periods, pine woods (73%) remain as a major species and the others were oaks (14%) and Zelkova serrata (9%). As late Joseon came, the pine woods occupied more than 88%. In the late 19th and early 20th centuries, a few boreal species such as larch (Larix spp.) and spruce (Picea spp.), which grow in cold area, were found. We believe they were transported from northern Korea. The existing buildings in Korea are mainly from Joseon period and a few from late Koryo periods. During these periods, pine woods were used for most buildings. For such reason, pine woods were known as 'representative materials for historic buildings'. but earlier times, broad-leaved trees, i.e., oak and Zelkova woods were major materials. The changes in building materials resulted from both climate and human impacts. The dry climate and disturbed forests induce more pines in the mountains. We also compared the wood qualities of the species and found that Zelkova woods were superior ones and deserved more planting for future demands in the repair for historic buildings.

공동주택단지 외부공간의 친환경 수준에 따른 주민의 거주만족도와 친환경 의식 비교 연구 - 광주광역시 아파트 단지를 대상으로 -

박원규,임선화,Park, Won-Kyu,Im, Sun-Hwa 한국주거학회 2009 한국주거학회 논문집 Vol.20 No.6

This study focused on the analysis of residential satisfaction and environment awareness depending on the environment-friendly level on the outdoor space of the housing complexes. The purpose of this study is to present basic materials of the environment-friendly outdoor space planning of housing complexes. The major findings of the study are as follows. First, the results of the comparative analysis of the satisfaction of the outdoor space of apartment complexes show that the complexes with the most application of environment-friendly elements had higher residential satisfaction. But there was no meaningful statistical difference between the complexes with the higher level of application of the environment-friendly elements and the complexes with medium level of application. Secondly, according to a comparative analysis, the overall residential satisfaction of the apartment complexes was the same as the residential satisfaction of the outdoor space. Thirdly, the results of the correlative analysis of residential satisfaction and environmental awareness showed that the satisfaction of the apartment complexes decreases as the awareness of the environment-friendly apartment complex increases. The results of this study can be used as basic materials for environment-friendly outdoor space planning of apartment complexes.

송풍기 분야 연구동향

박원규,Park, Won-Gyoo 한국유체기계학회 2004 한국유체기계학회 논문집 Vol.7 No.1

아미드옥심화 PAN 나노섬유 웹의 중금속 흡착 특성

박원규,장미화,양혜연,최창남,Park, Won-Kyu,Jang, Mi-Hwa,Yang, Hye-Youn,Choi, Chang-Nam 한국섬유공학회 2007 한국섬유공학회지 Vol.44 No.6

In order to prepare the heavy metal adsorbent, PAN nano fiber web was prepared by electro spinning and subsequently amidoximated with hydroxyl amine. The diameter of fiber depended on the polymer concentration and the applied voltage. The average diameter increased with an increase of the polymer concentration and decreased with the applied voltage. Both the prepared nano fiber web and PAN fiber for weaving were amidoximated by the reaction of PAN with hydroxylamine. The formation of amidoxime groups was identified by FT-IR spectra and elemental analyses. The degree of amidoximation of PAN nano fiber was increased with increasing temperature. Amidoximated PAN nano fiber web had an excellent adsorption capacity for heavy metal ions, especially $Cu^{+2}$, compared with the amidoximated PAN fiber for weaving due to the relatively large specific surface area.

대학순례-코넬대학의 특성과 교육환경

박원규,Park, Won-Gyu 한국대학교육협의회 1990 大學敎育 Vol.45 No.-

송풍기 분야 연구동향

박원규,Park, Won-Gyoo 한국유체기계학회 2005 한국유체기계학회 논문집 Vol.8 No.1