백제 복성(複姓)의 출현과 그 정치적 배경

오택현(Oh, Taek?hyun) 한국역사연구회 2013 역사와 현실 Vol.- No.88

Two?lettered family names only appear in the history of the Baekje Dynasty, and not in Goguryeo and Shilla. Baekje"s acceptance of family names seems to have been during the Hanseong period, and it is highly possibile that they came through the Nakrang and Daebang troops in 313. Accepting Chinese culture, the Baekje royal families used "Buyeo" family names. Such fact contains several meanings. First, it indicates the direct connection between the practice of using a family name and the embracement of Chinese culture. Second, it shows the Baekje people"s consciousness of a Bu"yeo heritage. Family name was first used by the Baekje royal family but the practice spreaded to the nobility class. Various one and two?lettered family names can be found in diplomatic letters, like the one?lettered names in the letter King Gae"ro?wang sent to China as shown in Nihon Shogi, as well as two?lettered family names recorded in Samguk Sagi. It should be noted that most of the family names in Baekje were two?lettered ones. The reason behind such fashion is unclear. The first letter might have been the result of taking the "King"s name" as family name, and the second letter might have been a regional name. Such phenomenon seemed to have had a relation with the situation in which Baekje"s national power was weakened or in disorder. Actually, since Baekje established a structure of coexistence between the central and the districts, since the end of the Hanseong period, the appearance of two?lettered family names increased. The political interests and privileges of the community led to a system of coexistence with the central line. The "King?Jwa"pyeong?Dal"sol" system, the system of mutual political balance sustained by triangular antipodes, was formed. However, in the late Sabi period this structure of coexistence was destroyed during the reigns of King Mu"wang and Eui"ja?wang. In that time, new families with one?lettered last names appeared, in conflicts within the Jwa"pyeong groups, in the Crown?prince investiture, foreign relationships with China, and during wartime. King Eui"ja?wang designed a new reform policy, in response to this emergence of new factions. He tried to reorganize the power structure and centralize the governing power. As a result, the Jwa"pyeong?Dal"sol system was seriously changed, and so was the structure of coexistence between the central and the districts. This directly contributed to the fall of Baekje.

용해성 poly(dimethy-co-diphenylsilane)공중합체의 특성과 열분해에 관한 연구

강필현,양현수,황택성,김봉만,권오현 忠南大學校 産業技術硏究所 1993 산업기술연구논문집 Vol.8 No.2

Soluble poly(dimethyl-co-diphenylsilane)copolymer,[(SiMe₂)x(SiPh₂)1-x]n where x=0.5 to 0.9., was synthesized by condensation polymerization of dimethyldichlorosilane and diphenyldichlorosilane in xylene. In the TG analysis of the copolymer, weight loss started at 170℃ and the weight residue at 1000℃ was 32%. The copolymer was stabilized by thermal oxidation at 80 to 110℃ for 5 hr. in air, and its thermal stability increased as the temperature increased. The copolymer heat treated above 700℃ showed no organic bonds of C-H and Si-CH₃. while Si-C, and Si-O large bonds were observed. Amorphous SiC was obtained by pyrolysis at 1000℃ and β-SiC at 1200 to 1400℃, in which a better crystallinity of β-SiC was observed at a higher temperature.

제주도 지하수 질산염 농도의 시·공간적 변화 특성: 장기(1993-2015) 모니터링 자료의 평가

김호림(Ho-Rim Kim),오준섭(Junseop Oh),도현권(Hyun-Kwon Do),이경진(Kyung-Jin Lee),현익현(Ik-Hyun Hyun),오상실(Sang-Sil Oh),감상규(Sang-Kyu Kam),윤성택(Seong-Taek Yun) 대한자원환경지질학회 2018 자원환경지질 Vol.51 No.1

1993년부터 2015년까지 관측된 제주도 지하수 장기모니터링 관측정(N = 4,835)에서 수집된 지하수 수질자료(N = 21,568)를 기반으로 질산성질소의 시공간적 변동 특성을 평가하였다. 제주도 지하수의 질산성질소 농도의 중앙값은 2.5 mg/L로서 다른 국가나 대륙의 조사 결과에 비해 다소 높거나 유사한 것으로 나타났다. 또한 지하수 용도, 행정구역 및 고도 별로 유의한 차이를 보였다. 특히, 산간 지역에 비해 저지대 해안가에 위치한 농업 및 주거지역에서 농도가 높음을 확인하였다. Mann-Kendall 및 Sen’s slope 분석을 활용한 질산성질소 농도의 추세 분석 결과, 하류 저지 대에 비해 중산간지역에서의 질산성질소 농도 증가 경향이 뚜렷하였다. 제주도 내 토지 피복의 시계열 변화 특성과 결부 지어 보면, 중산간지역의 오염 증가 추세는 농업지역의 확장 등 인위적 활동 증가에 기인한 결과로 판단된다. 반면,기지정된 지하수자원특별관리구역에서는 전반적으로 질산성질소 농도의 감소 경향이 나타났는데, 이는 지하수 관리 측면에서 수질관리를 위한 적극적인 정책이 유효함을 시사한다. 본 연구에서는 제주도 지하수의 질산성질소 오염관리를 위한 적정 방안을 제안한다. The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of NO 3 -N is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen’s slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

전해응집공정을 이용한 염색폐수의 처리

이용택,한승우,조영개,이현문,김태근,손인식,양병수 한국환경과학회 2000 한국환경과학회지 Vol.9 No.4

This research studied the characteristics and applicability of electrocoagulation using aluminium electrode for the color and COD removal in textile wastewater. Electrocoagulation reactor used two different electrode, Fe and Al, since in the general chemical wastewater treatment, aluminium and ferrous salts were used as coagulants. Aluminium electrode showed higher removal efficiency of color and COD than ferrous electrode did. The COD and color removal efficiency improved at the 0.192A/dm^2 current density. Thus, the electrocoagulation process with bipolar aluminium electrode showed better efficiency in the decolorization and COD removal rate of textile wastewater effluent than custom coagulants did.

대칭형 보에 의해 보강된 등방성 평판의 음향방사에 관한 연구

김택현,오택열,김종태 한국공작기계학회 1998 한국생산제조학회지 Vol.7 No.1

The determination of sound pressure radiated from peoriodic plate structures is fundamental in the estimation of noise levels in aircraft fuselages and ship hull structures. As a robust approach to this problem, here a very general and comprehensive analytical model for predicting the sound radiated by a vibrating plate stiffened by periodically spaced orthogonal symmetric beams subjected to a sinusoidally time varying point load is developed. The plate is assumed to be infinite in extent, and the beams are considered to exert both line force and moment reactions on it. Structural damping is included in both plate and beam materials. A space harmonic series representation of the spatial variables is used in conjunction with the Fourier transform to find the sound pressure in terms of harmonic coefficients. From this theoretical model, The sound pressure levels on axis in a semi-infinite fluid (water) bounded by the plate with the variation in the loactions of an external time harmonic point force on the plate can be calculated efficiently using three numerical tools such as the Gauss-Jordan method, the LU decomposition method and the IMSL numerical package.

炭素鋼의 龜裂不成長 條件 및 SHORT CRACK 擧動에 關한 硏究

金澤鉉,李相鎬 조선대학교 동력자원연구소 1988 動力資源硏究所誌 Vol.10 No.1

This study were carried out fatigue test under the constant stress cyclic with smooth specimens of SM 45C and has considered the behavior of short crack and the critical condition of non-propagation. The main conclusions obtained are as follows. 1) In this test results under the constant stress cycle elasticity are lower than static strength, and are estimated bellow the fatigue limit. 2) Short-crack to initiate and propagate under a constant stress cyclic is stopped due to the closure of crack tip by the residual pressive stress when the fatigue load is acted. 3) Cyclic stress below fatigue limit is able to neglect an effect on shore crack to continuously grow.

無定形 실리카(왕겨재 및 실리카 흄)를 添加한 슬래그 시멘트의 蒸氣 養生에 의한 機械的 性質

申鉉澤,鄭喜天 慶尙大學校 1991 論文集 Vol.30 No.2

슬래그 시멘트에 무정형 실리카로서 왕겨재 및 실리카홈을 혼화재로 첨가한 조합물을 양생온도 90℃, 120℃, 양생시간 6,9,12hrs.로 변화시켜 증기양생한 경화체의 압축강도 및 미세조직을 관찰한 실험 결과는 다음과 같다. 1. 슬래그 시멘트에 왕겨재 또는 실리카 홈 0,3,5,7we.% 양생 조건 120℃-6,9,12hrs. 일때 9시간 증기양생시 가장 높은 압축강도를 나타낸다. 2. 동일한 상기 조건에서 혼합재료로서 왕겨재가 실리카 홈보다 높은 압축강도를 나타낸다. 3. 왕겨재 5%첨가시 120℃-9hrs 양생조건 일때 최고 압축강도는 793kg/㎠을 나타내었다. 4. SEM 미세조직 관찰에서 최고 압축강도가 높은 왕겨재의 경우는 미세기공이 적고 조직이 치밀함을 보여주었다. The mechanical properties and SEM micrograph of portland slag cement-amorphous silica(rice husk ash and silia fume) systems were studied with various compositions. Samples were steam cured at 90 and 120℃ for 6, 9, and 12hrs., respectively. The highest compressive strength (793 kg/ ㎠) was abtained the composition in weight ratio of portland slag cement : rice husk ash = 95 : 5 at 120℃-9hr steam curing. SEM micregraphs of the specimens with 5 wt.% RHA steam curing at 120℃-9hrs were more dense than specimen with 5 wt.% SF.

경량기포 콘크리트의 고방수 특성에 관한 연구

신현택 경상대학교 생산기술연구소 2000 生産技術硏究所論文集 Vol.16 No.-

The result of the addition of silicone and polymer with high waterproofing properties on the autoclaved lightweight concrete were studied by varying the contents of the waterproofing agent. ALC specimens were autoclave cured at 180℃ for 6 hrs under saturated steam pressure. The major experimental results are as follows. 1. The water absorbtion of waterproofing ALC specimens with 1.5 % waterproofing agent was smaller than that of control ALC specimens by 42.46%. 2. The compressive strength after freezing and thawing for 16days of control ALC specimen was 40 Kg/㎠, but in case of waterproofing ALC specimen with 1.5% waterproofing agent was 43.2 Kg/㎠. Therefore the performance for freezing and thawing of waterproofing ALC specimen was increased to 108 %. 3. The final hydrate material are 11 Å tobermolite and unreacted quartz as result of X-ray diffraction and SEM examination.

사람 뇨 속의 스테로이드 정량에 관한 연구

장현경,김수경,박택규 建國大學校基礎科學硏究所 1990 理學論集 Vol.15 No.-

사람 뇨 속의 15개 endogenous steroid를 β-glucuronidase(from E. Coli)로 가수분해시켜서 XAD-2 수치를 사용하여 추출하고 N-methly silyl heptafluoro butylamide/trimethyl silylimidazole/trimethyl chloro silane 혼합물로 유도체화시킨 다음, GC/MSD로 동시 분석하였다. endocrine disease의 진단용으로 사용되어질 수 있는 15개의 endogenous steroid 농도는 정상인 뇨에서 0.01∼100㎍/ml로 나타났다. The fifteen endogenous steroids in human urine were simultaneously analyzed by selected ion monitoring(SIM) method of GC/MS. Urinary steroids were extracted by using XAD-2 resin and hydrolyzed with β-glucuronidase from E. Coli. The urinary steroids were quantitatively derivatized by N-methyl heptafluoro butylamide/trimethyl silylimidazole/trimethylchloro silane mixture. Concentrations of the fifteen steroids were in the range of 0.01∼100㎍/ml in the urine of twenty-four males and twenty-four females. The quantitative results of steroids can be used as a diagnostic tool for endocrine disease.

CaO-SiO₂계 保溫材에 關한 硏究

申鉉澤,李詳珪 경상대학교 생산기술연구소 2001 工學硏究院論文集 Vol.1 No.-

The Experiments are carried out to make and improve the calcium silicate insulators which have properties of more light weight, good insulation, high compressive strength and high stability by using the available Korean raw materials. It used the X-ray diffraction and TGA-DTA to observe the chemical reaction and products among CaO-SiO2-H20 systems for the original body, and examined gel condition, molding pressure and autoclaving condition to get the more resonable manufacturing method. In this study, The result were as follow: 1.The suitable molding pressure was 2㎏/㎠ and the best autoclaving condition of samples was at the temperature of 200˚ for 5 hours. 2.The properties of resistance in hot water was all good. 3.According as rock wool as reinforcing material was appendixed at the rate of 5%, approximately bulk specific gravity increased at the rate of 0.03 and compressive strength 3 ㎏/㎠. 4.According as quartz or silica and was appendixes at the rate of 10%, approximately bulk speccific gravity increased at the rate of 0.03 and compressive strength 7 ㎏/㎠.