항공기 부품국산화 진흥방안 - 항공기 엔진 국산화 방안

이대성,Lee, Dae-Seong 한국항공우주산업진흥협회 1995 航空宇宙 Vol.29 No.-

전라남도(全羅南道) 해남층군(海南層群) 우항리층(牛項里層)에 흡재(夾在)된 흑색(黑色)셰일의 유기지구화학적(有機地球化學的) 연구(硏究)

이대성,시마다 이쿠로,하야시다 노부오,Lee, Dai Sung,Shimada, Ikuro,Hayashida, Nobuo 대한자원환경지질학회 1976 자원환경지질 Vol.9 No.3

In this study, the oil bearing rock-sequence, U-hand-ri Formation (D.S. Lee et al., 1976), was subdivided into three members; the lower, the intermediate and the upper. The lower consists mainly of reddish purple tuff and sandy calcareous shales, the intermediate of an alternation of tuffs, sandstons, calcareous black shales, cherts and limestone and the upper of coarse grained variegated tuff and agglomerate. Oily matter was found from the black shales of the intermediate. Ten samples of black shales from drilled cores, 8 samples of black shales from different outcrops of the member, and 1 sample of grease-like seeping oil from black shales at U-hang-ri coast were chemically analyized. Among them, 9 samples contain remarkable amount of organic carbon (0.96~1.60%) and E.O.M. extract (0.176~0.718%), and mostly the bituminous material is saturated hydrocarbons as well as shown in infared spectroscopic analyses. The elemental analyses of MAE extracts and asphaltenes of some of thoese samples indicate that the transformation of organic material to crude oil is highly progressed. The authors suggest that the seeping oil and oily tinges in black shale layers are the products of natural cracking related with the igneous activities in the area nearby.

기체 유량 측정에서 몬테 카를로 모사를 이용한 측정불확도 평가

이대성,양인영,김춘택,양수석,Lee, Dae-Sung,Yang, In-Young,Kim, Chun-Taek,Yang, Soo-Seok 대한기계학회 2003 大韓機械學會論文集B Vol.27 No.12

Monte Carlo simulation(MC) method was used as an uncertainty assessment tool for gas flow measurement in this paper. Uncertainty sources for gas flow measurement were analyzed, and probability distribution characteristics of each source were discussed. Detailed MC methodology was described including the effect of the number of simulation. The uncertainty result was compared with that of the conventional sensitivity coefficient method, and it was revealed that the results were different from each other for this particular gas flow measurement case of which the modelling equation was nonlinear. The MC was comparatively simple, convenient and accurate as an uncertainty assessment method, especially in cases of complex, nonlinear measurement modelling equations. It was noted that the uncertainty assessment method should be selected carefully according to the mathematical characteristics of the measurement.

중재 쓰레드와 지연 캐싱에 의한 스퀴드 프록시 서버 성능 향상에 관한 연구

이대성,김유성,김기창,Lee, Dae-Sung,Kim, Yoo-Sung,Kim, Ki-Chang 한국정보처리학회 2003 정보처리학회논문지 C : 정보통신,정보보안 Vol.10 No.1

인터넷 사용자의 폭발적인 증가로 인해 캐시 서버의 사용이 대두되고 있다. 이에 따라 캐시 서버의 성능을 향상시키기 위한 많은 연구들이 진행되었다. 본 논문에서는 캐시 서버의 병목 현상을 유발하는 원인을 분석하고 그에 대한 해결책으로 중재 쓰레드와 지연 캐싱을 제안한다. 중재 쓰레드를 사용함으로써 캐시 서버가 디스크 쓰기 연산 시에 준비된 다중 쓰레드를 탐색해야 하는 문제점을 없애고 즉시 사용자의 서비스 요청에 응답함으로써 보다 빠른 서비스를 제공할 수 있도록 한다. 또한 준비된 다중 쓰레드가 없는 경우에는 지연 캐싱을 이용해 과부하 상태의 디스크 연산을 피하고 큐가 안정화될 때 캐싱을 하도록 하여 시스템이 안정성 있게 동작하도록 하였다. 제안된 캐시 서버는 스퀴드(SQUID) 캐시 서버를 변형하여 구현되었고 실험을 통해 기존 스퀴드 캐시 서버의 성능과 비교한 결과, 응답 시간의 향상을 관찰할 수 있었다. As the number of the Internet users increases explosively, a solution for this problem is web caching. So, many techniques on improving cache server performance have been suggested. In this paper, we analyze the cause of the bottleneck in cache servers, and propose an arbitral thread and delayed caching mechanism as a solution. We use an arbitral thread in order to provide a quick service to user requests through eliminating the ready multi-thread search problem in case of disk writing operation. We also use delayed caching in order to provide stable system operation through avoiding overloaded disk operation and queue threshold. Proposed cache server is implemented through modification on SQUlD cache server, and we compare its performance with the original SQUID cache server.

Chemical Composition of Petrographic Assemblages of Igneous and Related Rocks in South Korea

이대성,Lee, Dai Sung The Korean Society of Economic and Environmental G 1977 자원환경지질 Vol.10 No.2

남한(南韓)에 분포(分布)하는 화성암류(火成岩類)의 화학성분(化學成分)과 그 암석화학적성질(岩石化學的性質)을 개략적(槪略的)으로 알기 위해서 35개(個) 문헌(文獻)에서 359개(個) 화성암류(火成岩類) 및 화성기원(火成起源)으로 인정(認定)되는 암석류(岩石類)의 화학분석치(化學分析値)를 인용(引用)하였다. 분석치(分析値)들은 27개암석조합(個岩石組合)으로 구분(區分)하고 이들은 다음의 5개암석구(個岩石區)로 갈라서 처리(處理)하였다. (1) 경기지괴(京機地塊), (2) 영남지괴(嶺南地塊)(도표(圖表)에서는 이들을 합(合)쳐서 하나의 지괴(地塊)로 묶음). (3) 옥천대(沃川帶), (4) 경상분지(慶尙盆地), 및 (5) 알카리암구(岩區), 분석치(分析値)는 $SiO_2$대(對) $Na_2O+K_2O$ 및 CaO, D. I. 대(對)산화물류(酸化物類), AFM 삼각도(三角圖), AKF삼각도(三角圖), An-Ab-Or 노름삼각도(三角圖), 및 Q-Or-Ab 노름삼각도(三角圖)로 처리(處理)하였다. 이에 의(依)하면 (1) (2) (3) (4) 는 모두 칼식암계열(岩系列)에 (5)는 알카리암계열(岩系列)에 속(屬)한다. 또한 (1)-(2)와 (3)의 분화경로(分化經路)는 세계(世界)칼크알카리암계열(岩系列)에 (4) 는 Karoo dolerite에, (5)는 Mull 화산(火山) 및 알카리감람석현무암태지(橄攬石玄武岩台地)에서의 분화경(分化經)들과 유사(類似)하다. 지각내(地殼內) 점상질암(粘上質岩)과의 동화정도(同化程度)는 (1)-(2) 및 (3)에서는 매우 높고 (4)에서도 높으며 (5)에서는 낮다. $K_2O$ : $Na_2O$는 대체(大體)로 $K_2O$ < $Na_2O$이고 (3)에서만 $K_2O{\approx}Na_2O$를 보이고 있다. 노름치(値)에 의한 도표(圖表)에 의하면 지질시대(地質時代)의 차이(差異)는 있으나 남한(南韓)의 화성암류(火成岩類)는 일본(日本)의 화성암류(火成岩類)와 유근사(類近似)하다. Results of 359 chemical analyses of igneous and related rocks of the south Korea were collected from 35 papers to see preliminarily some trends of chemical properties of spatial igneous rock assemblages according to five geotectonic provinces: (1) Kyonggi land, (2) Ryongnam land (on diagram these are jointed together as a massif), (3) Ogcheon zone, (4) Kyongsang basin and (5) Alkali rock province. The data were plotted on the diagrams; $SiO_2$ vs. $Na_2O+K_2O$ and CaO, D. I. vs. oxides, AFM triangle, AKF triangle, and normative An-Ab-Or and Q-Or-Ab triangles for each rock assemblages of individual provinces.

해남지역(海南地域)에 분포(分布)된 우항리층내(牛項里層內) 흑색(黑色)셰일의 유기지화학적(有機地化學的) 연구(硏究)

이대성,윤현수,Lee, Dai Sung,Yun, Hyun Soo 대한자원환경지질학회 1979 자원환경지질 Vol.12 No.4

The studied area occupies the southern part of Haenam peninsula located in the southwestern corner of Korea. The stratigraphic sequences of the area are grouped into following three units in ascending order. (1) Late Cretaceous sedimentary rocks of Uhangri Formation which consist of the alternative beds of black shales and tuffaceous sediments, Hwangsan acidic fine grained tuffs and Jindo rhyolite flows. (2) Late Cretaceous biotite granite and acidic porphyries which intruded the Late Cretaceous sedimentary rocks. (3) Tertiary(?) pitchstone. The study purposes to delineate any of geochemical aspects on the deposition of the sequences, the average amounts of organic materials and the effect to the maturation of hydrocarbonization which has been occured by the intrusives. Sixty nine black shale samples were collected from Uhangri Formation in the northern and southern coasts of the peninsula. Organic carbons, total extracted organic matters and hydrocarbons were mainly determined by the Soxhlet extraction method, together with C-H-N elemental analyses. Based on the field and laboratory studies, the following interpretations have been obtained. (1) The paleohydrostatic condition of the sedimentation which took place was relatively calm and stable to delineate a lacustrine environment. (2) The amounts of organic material were more or less constant throughout the period of the deposition of the sediments. (3) The degree of hydrocarbonization of the Uhangri Formation in the northern coast was taken place higher than that in the southern coast due to the differences of thermal effect by the biotite granite which is assumed to be as a heat source in the area. Among the northern coast, some black shales in Uhangri and Mogsam areas which had been under the most moderate temperature environment snow symptomatic oily material, whereas, those in Sinseongri area do not, which were presumably to be intensive thermal alteration by the later acidic porphyries.

석질문화재에 미치는 자연환경 조사

이대성,Lee, Dae-Seong 국립문화재연구소 1980 保存科學硏究 Vol.1 No.-

옥천대(沃川帶)에서의 화성활동(火成活動) -특(特)히 옥천대동북부(沃川帶東北部)에서의 화성활동(火成活動)-

이대성,김용준,Lee, Dai Sung,Kim, Yong Jun 대한자원환경지질학회 1985 자원환경지질 Vol.18 No.1

The northeastern part of Ogcheon zone which consisted mainly of Cambro-Ordovician arenaceous, argillaceous and calcareous formations and Carboni-Triassic arenaceous and argillaceous formations is delineated as the eastern mass of a thrust fault along Choongju-Moongyong-Cheongsan in the middle of the zone. The present study proposes a geotectonic line, Imgye-Samchog fault(see, figure 1) which divides the northeastern part into two blocks, Hambacksan block in the west and East coast block in the east. The igneous rocks in the Hambacksan block ranging from granite to gabbro are distributed in a symmetrical zones parallel to general direction of Ogcheon zone as follows (Fig. 2 and Table 2). Southeast igneous rock zone: it aligns Jurassic granites in its south and Precambrian leucocratic granites in its north. Central igneous rock zone: it aligns Cretaceous granites in its south and Jurassic granites, and some of diorite and gabbro in its north. Northwest igneous rock zone: aligns Jurassic granites in its south and huge batholithic granodiorite in its north. The distribution of the igneous rocks in the East coast block shows an entirely different features from those of Hanbacksan block. In the southern part of the block they assemble in a narrow area ranging in age from Early Proterozoic, through Middle to Late Proterozoic, Devonian, Jurassic, Cretaceous to Tertiary, whereas, the igneous rocks in the northern part of the block gathered to a restricted area, in ages of Middle Proterozoic and Cretaceous. The assemblage of the igneous rocks in the studied area shows a compositionally restricted, mixed S-type and I-type granites, $^{87}Sr/^{86}Sr$ > 0.706, rare volcanics and shortening with upright folding. These lithologic and structural features suggest that the igneous activity in this part related intimately to Hercynotype Orogeny of Pitcher(1979). Chronological episodes of igneous activity from Early Proterozoic to Early Tertiary in the northeastern part are figured.

옥천대(沃川帶) 우라늄광층(鑛層)의 구조규제(構造規制) 및 지구화학적(地球化學的) 특성연구(特性硏究)

이대성,윤석규,이종혁,김정택,Lee, Dai Sung,Yun, Suckew,Lee, Jong Hyeog,Kim, Jeong Taeg 대한자원환경지질학회 1986 자원환경지질 Vol.19 No.no.spc

Structural, radioactive, petrological, petrochemical, mineralogical and stable isotopic study as well as the review of previous studies of the uranium-bearing slates in the Ogcheon sequence were carried out to examine the lithological and structural controls, and geochemical environment in the uranium deposition in the sequence. And the study was extended to the coal-bearing formation (Jangseong Series-Permian) to compare the geochemical and sedimentologic aspects of uranium chemistry between Ogcheon and Hambaegsan areas. The results obtained are as follows: 1. The uranium mineralization occurs in the carbonaceous black slates of the middle to lower Guryongsan formation and its equivalents in the Ogcheon sequence. In general, two or three uranium-bearing carbonaceous beds are found with about 1 to 1.5km stratigraphic interval and they extend from Chungju to Jinsan for 90km in distance, with intermittent igneous intrusions and structural Jisturbances. Average thickness of the beds ranges from 20 to 1,500m. 2. These carbonaceous slate beds were folded by a strong $F_1$-fold and were refolded by subsequent $F_1$-fold, nearly co-axial with the $F_1$, resulting in a repeated occurrence of similar slate. The carbonaceous beds were swelled in hing zones and were shrinked or thined out in limb by the these foldings. Minor faulting and brecciation of the carbonaceous beds were followed causing metamorphism of these beds and secondary migration and alteration of uranium minerals and their close associations. 3. Uranium-rich zones with high radioactive anomalies are found in Chungju, Deogpyong-Yongyuri, MiwonBoun, Daejeon-Geumsan areas in the range of 500~3,700 cps (corresponds to 0.017~0.087%U). These zones continue along strike of the beds for several tens to a few hundred meters but also discontinue with swelling and pinches at places that should be analogously developed toward underground in their vertical extentions. The drilling surveyings in those area, more than 120 holes, indicate that the depth-frequency to uranium rich bed ranging 40~160 meter is greater. 4. The features that higher radioactive anomalies occur particularly from the carbonaceous beds among the argillaceous lithologic units, are well demonstrated on the cross sections of the lithology and radioactive values of the major uranium deposits in the Ogcheon zone. However, one anomalous radioactive zone is found in a l:ornfels bed in Samgoe, near Daejeon city. This is interpreted as a thermal metamorphic effect by which original uranium contents in the underlying black slate were migrated into the hornfels bed. 5. Principal minerals of the uranium-bearing black slates are quartz, sericite, biotite and chlorite, and as to chemical composition of the black slates, $Al_2O_3$ contents appear to be much lower than the average values by its clarke suggesting that the Changri basin has rather proximal to its source area. 6. The uranium-bearing carbonaceous beds contain minor amounts of phosphorite minerals, pyrite, pyrrhotite and other sulfides but not contain iron oxides. Vanadium. Molybdenum, Barium, Nickel, Zirconium, Lead, Cromium and fixed Carbon, and some other heavy metals appear to be positive by correlative with uranium in their concentrations, suggesting a possibility of their genetic relationships. The estimated pH and Eh of the slate suggests an euxenic marine to organic-rich saline water environment during uranium was deposited in the middle part of Ogcheon zone. 7. The Carboniferous shale of Jangseong Series(Sadong Series) of Permian in Hambaegsan area having low radioactivity and in fluvial to beach deposits is entirely different in geochemical property and depositional environment from the middle part of Ogcheon zone, so-called "Pibanryong-Type Ogcheon Zone". 8. Synthesizing various data obtained by several aspects of research on uranium mineralization in the studied sequence, it is concluded that the processes of ur

구봉석회석광산의 지질조사보고(地質調査報告)

이대성,Lee, Dai Sung 대한자원환경지질학회 1970 자원환경지질 Vol.3 No.1

The purpose of this report is to prepare a data for the economic evaluation on the Goobong Limestone Mine which is located at the south-eastern corner of the Yongchun Quadrangle scaled in 1:50,000. The accessibility from the mine to railroad was considered in two ways. One is to Dodam Station on Central Railway Line and the other is to reach Songjung-ni village which is near Sangyong Station on Hamback Railway Line. The distance of the former way is 26.7km and the later is 24.2km. Geologically the mine is situated near the base of the Greast Limestone Series which strikes generally $N25^{\circ}{\sim}30^{\circ}E$. The series comprises six different formations from older to younger; Pungchon Limestone Formation and Whajol Formation of Cambrian age, and Dongjum Quartzite Formation, Dumudong Formation, Maggol Limestone Formation and Goseong Formation of lower to middle Ordovician age. 82 samples; 48 from Pungchon Limestone Formation, 11 from Dumudong Formation, 15 from Maggol Limestone Formation and 8 from Goseong Formation, were taken from the series in the crossed direction to the general trend of the series as shown in geological map. They were chemically analyzed on the components of CaO, MgO, $SiO_2$, $R_2O_3(Al_2O_3+Fe_2O_3)$ and ignition loss as shown in table 2, table 3, table 4, and table 5. As seen from the tables, among the formations of the series, middle to upper parts of the Pungchon Limestone Formation and middle and upper parts of the Dumudong Formation have chemical composition as available source for the raw material of cement industry, not only that but also the part of the Pungchon Formation was highly evaluated as source for the flux of iron smelting and the raw material of carbide manufacturing because of its high purity of calcium carbonate.