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.

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.

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.

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.

성능을 고려한 집적회로 설계에서의 계층적 배치 기법

김기택,김원종,신현철 漢陽大學校 工學技術硏究所 1996 工學技術論文集 Vol.5 No.1

An effective hierarchical placement technique leas been developed for performance-driven integrated circuit design. To minimize delays on critical paths, a net-weight-based method is used. For efficiency, the placement refinement is performed using multiple levels of hierarchy and "closely connected" cells are clustered using an improved clustering function. The physicall layout area containing cells is hierarchically partitioned into bins. In the region refinement algorithm, each bin becomes the active bin by turns and the placement is optimized by moving cells between the active bin and its neighbor bins. To obtain optimal placement results, partitioning and region refinement algorithms are performed several times at each hierarchy level. Several standard cell benchmark circuits from MCNC are placed using the suggested refinement technique and superior results are obtained.

원자흡수분광법과 발광분광법에 의한 마그네슘의 분석

한현택,정창웅 순천향대학교 기초과학연구소 1998 순천향자연과학연구 논문집 Vol.4 No.2

Atomic absorption method has been compared with atomic emission spectrometry for the determination of magnesium. Atomic absorption method are shown to be serious diverse ions and acidities effect, therefore these effects are eliminated by the addition of LaCl3. Atomic emission method are not shown interference effects in the analysis of magnesium.

순막반응의 조건화에 관여하는 신경회로에서의 부외전핵의 역할

김현택,이두현,최준식,김기석 한국심리학회 1990 한국심리학회지 생물 및 생리 Vol.2 No.1

토끼의 소뇌 중간핵에서 순막조건화 기간동안 다단위 기록을 하였다. 다단위 활동은 학습의 초기에는 조건자극과 무조건자극에 대한 유발반응만을 보였으나 학습이 진행됨에 따라 증가하였다. 이 다단위 활동을 회기별로 16msec bin 히스토그램을 작성하여 회기별 순막반응 평균치와 교차 상관값을 구하니 상당한 정도의 상관을 보였으며 더우기 다단위 활동의 히스토그램이 평균화된 순막반응을 수십 msec 앞섰다. 이런 결과는 중간핵의 다단위 활동이 학습의 신경적 지표가 되며 중간핵은 순막조건화의 신경적 근저가 될 수 있음을 보여주었다. 몇몇 연구에서는 부외전핵 또는 외전핵에 무조건 자극으로 전기자극을 주어 순막조건화가 가능하였다고 보고하고 있으므로 본 연구는 이 부외전핵이 단순한 반응의 출력핵에 불과한지 또는 습득된 순막조건화의 파지에 필요한지를 밝히고자 하였다. 그래서 조건화정도의 지표로서 행동적 순막반응과 중간핵 다단위 활동의 히스토그램을 관찰하면서 학습이 진행된후 부외전핵을 손상시켰다. 손상후 행동적 순막반응은 크게 감소하거나 사라졌지만 중간핵에서의 다단위 활동은 여전히 형성된 순막조건화가 건재함을 보여 주었다. 이 결과로서 부외전핵은 단순운동출력핵이며 순막조건화의 파지에 관여하는 부위가 아니라고 결론지었다. Multiple unit activity(MUA) was recorded from the cerebellar dentato-interpositus nucleus during classical conditioning of the nictitating membrane response(NMR) in the rabbit with a tone conditioned stimulus(CS) and an airpuff unconditioned stimulus(US). The MUA was processed to 16msec bin histogram and the NMR was averaged in each session respectively. The result showed that The averaged NMR was highly correlated with the histogram and that the histogram of MUA preceded the averaged NMR by several tens millisecond. This supports the previous reports that dentato-interpositus nucleus may be the neural substrate of the NMR conditioning. In some studies, it was reported that the stimulation of accessory abducens nucleus as US can support the NMR conditioning. So, one purpose of this study was the examination of the role of accessory abducens nucleus in the NMR conditioning. Following days of aquisition, the nucleus was lesioned electrolytically. The result showed that the lesion abolished both conditioned and unconditioned responses, but MUA recorded from deutatointerpositus nucleus maintains the same level as it prior to lesion. Results suggest that accessory abducens nucleus is merely motor output nucleus and isn't involved in the retention of the NMR conditioning.

범죄 청소년의 성격특성에 따른 군집분석

원호택,이훈진,박현순 서울大學校 社會科學大學 心理科學硏究所 1992 心理科學 Vol.1 No.-

본 연구에서는 범죄 청소년의 성격특성을 알아보고, 군집분석을 통하여 성격특성에 따르는 하위유형을 구분하고 각 하위유형간에 교육정도, 범죄유형, 가정, 성장배경이나, 범법 전의 스트레스 경험과 대처방식에서 어떤 차이가 있는지를 밝히고자 하였다. 그 결과 범죄 청소년 집단은 성격특성에 따라 세유형의 하위집단으로 구분되었다. 첫번째 하위집단은 긍정적 자아집단으로, 이들은 긍정적 자아개념을 지니고 있고 충동을 잘 억압하면서 방어적 경향을 보인다. 두번째 하위집단은 부정적 자아집단으로 자아개념이 부정적이고 충동통제를 못하며, 실패를 추구하는 경향이 두드러 진다. 세번째 하위집단은 강인한 충동집단으로 냉담하고, 반사회적인 성격특성과 유사한 양상을 드러냈다. 각 하위 집단간에는 부모 양육방식과 스트레스 경험, 그리고 대처방식에서 차이가 나타났다. 그러나 범죄유형이나 교육수준에서는 유의미한 차이가 없었다. In this study, we examined psychological characteristics of juvenile criminals using various personality qestionaires such as self-concepts, Eysenk personality test, locus of control and etc. Multivariate cluster analysis was performed to derive three subgroups of juvenile criminals for 18 personality variables. The first subgroup consisted of crimianls characteristic of a positive self concept with highly repressive and defensive tendancy while the second subgroup appeared to have negative self concept with poor impulse control. The third subgroup was characterized by the tough-mindedness with emotional insecurity and poor impulse control. These three subgroups showed differences in family enviroments. The first subgroup had better family enviroments than the other two subgroups. Especially, the second subgroup appeared to have had the poorest family enviroments. Also, there were differences in strees coping styles among subgroups. The first subgroup showed more active coping and social support seeking than the other groups.

고전적 순막 조건화 동안의 해마 뇌전도와 다단위 활동

이두현,김현택,류재욱,김기석 한국심리학회 1990 한국심리학회지 생물 및 생리 Vol.2 No.1

해마에서만 발견되는 뇌전도는 낮은 주파수, 높은 진폭의 특징을 갖고 동기화가 잘 이루어져 마치 정현파에 가까운 형태를 보인다. 이러한 뇌전도에 대해 서파리듬 또는 θ파라 부르고 전기 생리학적인 연구가 많이 진행되고 있다. θ파의 주파수 특성, 발생기전, 행동과의 관련성 등에 대해 집중적 연구가 이루어졌고, 그러한 연구를 기초로 θ파의 기능에 관한 여러가설이 도출되었다. 본 연구에서는 이러한 해마의 서파리듬이 행동과 어떤 관계를 갖고 있는지를 알아보기 위하여 토끼의 순막반응을 고전적으로 조건화시키는 동안에 미리 해마에 삽입한 전극으로부터 뇌전도와 다단위활동을 기록하였다. 해마 서파리듬에 대해서는 주파수 분석을 실시하고 다단위 활동은 시간단위당 발화 횟수를 측정하여 조건화과정과의 관련성을 살펴보았다. 실험 결과, 해마의 다단위 활동은 순막의 조건 반응과 높은 상관관계를 보여주었다. 해마 서파리듬은 조건화 절차와 관계없이 조건자극, 무조건자극 제시 기간에 제2유형인 4,5㎐의 감소와 제1유형인 7,8㎐의 증가를 보였다. 이는 해마 서파리듬의 기능이 조건화된 반응보다는 조건자극과 무조건자극의 제시와 관련이 있음을 시사하는 것이었다. 이러한 결과를 해마 θ파의 기능에 관한 여러 가설에 비추어 논의하였다. This study was investigated to hippocampal θ rhythm and multiple unit response during classical conditioning of rabbit's nictitating membrane response. Hippocampal θ rhythm usually was classified into type 1 and type 2. According to various electrophysiological researches, type 1 θ rhythm was highly correlated with voluntary behavior and type 2 θ rhythm with automatic behavior, but there were studies which assert that type 1 θ rhythm was correlated with sensory information processing. So, this study was an attempt to investigate those results as compared paired conditioning group with unpaired control group. Paired group was presented 500msec tone CS followed 100msec air puff US after 400msec interstimulus interval. But unpaired group was presented 500msec tone and 100msec air puff independently. There was no difference in distinction of θ rhythm between the two group. Again, there was no correlation between θ rhythm and conditioned response. But, there was high correlation between multiple unit response and conditioned response. The result indicated that type 1 θ rhythm was highly correlated with presentation of tone and air puff in both group, this result suggest that type 1 θ rhythm is correlated with subject's information processing.

輕量콘크리트블록의 製造에 關한 硏究

申鉉澤 慶尙大學校 1985 論文集 Vol.24 No.1

Expanded polystyrene beads used as aggregate instead of natural gravel for the manufacture of light weight hollow concrete block. These granules are spherical, hydrophobic and have a closed cell structure. But they do not absorb water. Steam-cured lightweight plastic aggregate concrete block prepared from portland cement, natural sand and expanded polystyrene beads were investigated by means of test of compressive strength and measurement of specific gravity.