B+트리를 위한 벌크로드

황환규,김상욱 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

In this paper, we propose a bulk-load algorithm for B' -trees, the most widely used index structures in database systems. The main characteristic of our algorithm is to simultaneously process all the keys to be placed on each B' -tree page when accessing the page. This avoids the overhead for accessing the same page multiple times, which results from applying the B' -tree insertion algorithm repeatedly. For performance evaluation, we analyze our algorithm in terms of the number of disk accesses. The results show that the number of disk accesses excluding those in the redistribution process in identical to the number of B' -tree pages. Considering that the redistribution process is an unavoidable preprocessing step for bulk-loading, our algorithm requires just one disk access per B' -tree page, and therefore turns out to be optimal. We also present performance tendancy according to the changes of parameter values via simulation.

펄스-스텝 標的에 의한 Saccadic 運動系의 잠복기 測定

황헌민,박상희 연세대학교 산업기술연구소 1975 논문집 Vol.6 No.1

The purpose of this study is to verify the saccadic eye-movement system which is the part of visual system. Conclusions of this study are (1) The probability of pulse tracking decreases as the pulse duration decreases. (2) The visual system is able to cancel the response to an initial target (pulse) based upon new visual information(step) to the system. (3) The average time needed by the visual system to cancel the original response (pulse) and to produce a new one (step) is about 40 msec longer than the latent period to the response (step only) would have been. The result from this study rules out the possibility that the saccadic eye-movement system is a biological sampled-data system having a sampling period of the order of one latent period.

Oxymetholone의 造血促進效果

黃基錫,鄭聖洙 慶北大學校 醫科大學 1980 慶北醫大誌 Vol.21 No.2

著者는 흰 숫쥐에 蛋白同化 스테로이드인 oxymetholone을 經口的으로 投與하고 投與量에 따르는 赤血球系 造血能의 變動과 好中球, 血小板, 그리고 其他 造血細胞成分에 미치는 影響을 檢討하기 위해 이 實驗을 企圖했으며 다음과 같은 結果를 얻었다. 卽, 體重 ㎏雷 2㎎을 每日 4週間 投與한 實驗群에서는 實驗後 2週부터 網赤血球數가 增加하기 시작하였으며, 對照群에 比하여 骨髓赤芽球 絶對數 및 赤血球 ^59Fe 利用率의 有意한 增加가 있었다. 그리고, 體童 ㎏當 10㎎을 每日 4週間 投與한 實驗群에서는 實驗後 綱赤血球數뿐 아니라 血色素値, hematocrit値 및 赤血球數의 增加도 있었다. 또, 骨髓赤芽球 絶對數와 赤血球 ^59Fe 利用率에 있어서도 2㎎ 投與群보다 多少 높은 增加率을 보여 주었다. 그리고, 體重 ㎏當 20㎎을 每日 4過間 投與한 實驗群에서는 10㎎ 投與群과 大差없는 血色素値, hematocrit値, 赤血球數 및 網赤血球數의 增加가 있었다. 그러나, 10㎎ 投與群에서 볼 수 없었던 好中球 絶對數와 單球 絶封數의 增加를 볼 수 있었으며 아울러 骨隨에 있어서도 亦是 好中球 絶對數와 單球絶 對數의 增加가 있었다. 骨隨赤芽球數의 增加와 赤血球 ^59Fe 利用率의 士昇에 있어서는 10㎎ 投與群과는 큰 差가 없는 것 같았다. The hematopoietic effects of oxymetholone in the albino male rats was studied with the following results. In rats administered oxymetholone orally at a dose of 2㎎/㎏ daily for 4 weeks, reticulocyte count began to rise significantly at second week after the medication. Futrhermore, a marrow absolute erythroid cell count as well as erythrocyte ^59Fe incorporation were appreciably increased as compared with those of the control group. The peripheral blood of the rats treated with an oral administration of oxymetholone at a dose of 10㎎/㎏ daily for 4 weeks, revealed a significant and gradual enhancement of the reticulocyte, hemoglobin, hematocrit and erythrocytc count at the first week after the administration of the drug. The marrow absolute erythroid cell count and erythrocyto ^59Fe incorporation also were noticeably increased and their increment were much greater than those of the 2㎎/㎏ group. In the rats given oxymetholone orally at a dose of 20㎎/㎏ daily for 4 weeks, there were pronounced elevation of the hemoglobin, henlatocrit, erythrocyte count, reticulocyte count, marrow absolute erythroid cell count as well as erythrocyte ^59Fe incorporation. However, their increment were not much different from those of the 10mg/kg group. It was noteworthy that the absolute neutrophil and monocyte count in the peripheral blood as well as the marrow were characteristically enhanced in this particular massive dosage group.

질소-프로판-공기 분위기에서 유동상 침탄 특성

黃龍吉,李相和,金榮熙 동아대학교 공과대학 부설 한국자원개발연구소 1992 硏究報告 Vol.16 No.1

The effect of air : propane ratios on the microstructure of carburized layers, internal oxidation characteristics and carburizing atmospheres during fluidized-bed carburizing under the nitrogen-6% propane base atmosphere were investigated At air : propane ratios less then 3 : 1 carbon potential of fluidized bed carburizing at mosphere was shown to be settled down to good carburizing condition, while carbon potential was shown to be decreased abruptly and CO₂ content increased exceedingly at air : propane ratios greater than 3 : 1. Under the same carburizing condition, the effective case depth of the carburized specimens decreased with Nicontent. At the given ratio of air to propane, the depths of internal oxidation layer appered to be increased almost linearly as carburizing time and the total contents of Si, Mn and Cr of steel increased. For air : propane ratios less than 3 : 1 at 930℃ it was concluded that the most effective carburizing condition and the control of internal oxidation could be obtained easily.

다형홍반증에서 각질형성세포의 ICAM-1, TNF-α 및 IL-1α 발현에 관한 연구

황규왕,정현,이종석,박준홍,부태성,이성열 순천향의학연구소 1998 Journal of Soonchunhyang Medical Science Vol.4 No.1

The pathogenetic mechanisms involved in the developement of erythema multiforme(EM) are still largely unknown. The histologic and immunopathologic changes in erythema appear to be due in part to cellular immune mechanisms with the cytotoxic T cell. Especially cytotoxic T cell/ICAM-1 positive-keratinocyte adherence plays an important role in the pathogenesis of EM. In this study, we investigated the expression of TNF-a, IL-1 a by immunohistochemical stain and ELISA. In skin tissue of EM, strong basal cell expression of ICAM-1, TNF-a and IL-1 a was found, and we detected more TNF-a from supernatants of cultured human keratinocytes with serum of EM patient than normal control. Our results may suggest possible relationship between the pathogenesis of EM and cytokine from keratinocyte.

동적 선택률 추정 기법을 위한 오차 분석

황환규,김상욱 강원대학교 정보통신연구소 1997 정보통신논문지 Vol.1 No.-

In this paper, we analyze the errors occurred in a selectivity estimation method based on dynamic maintenance of data distribution, which employs the mulitilevel grid file(MLGF), a multidimensional file structure. We first demonstrate that the estimation errors stem from the uniformity assumption that records are uniformly distributed in their belonging region represented by an entry in a level of an MLGF directory. Based on this demonstration, we then investigate five factors affecting the accuracy of estimation: (1) the data distribution in a region, (2) the number of records stored in an MLGF, (3) the page size, (4) the query region size, and (5) the level of an MLGF directory. Next, we present the tendency of estimation errors according to the change of values for each factor through experiments. The results show that the errors decrease when (1) the distribution of records in a region becomes closer to the uniform one, (2) the number of records in an MLGF increases, (3) the page size decreases, (4) the query region size increases, and (5) the level of an MLGF directory employed as data distribution information becomes lower.

妊娠中督症을 同伴한 妊婦의 胎盤內 免疫globulins, 補體(C₃) 및 纖維素源 沈着에 關한 免疫組織化學的 硏究

黃仁奎,金善行,洪性鳳 고려대학교 의과대학 1985 고려대 의대 잡지 Vol.22 No.1

Nowadays, it is generally accepted that immunological mechanisms are relevant in the materno-fetal relationship. And the abnormal deviation of maternal immune response to paternally derived or organ specific antigens is proposed as the pathogenesis of toxemia. The primary site of antigen-antibody reaction will be the choriodecidual junction because it is the area of direct contact and exchange between mother and feto-placental unit. Therefore this investigation has focused on the term placenta of toxemic women and demonstrated more heavier deposits of IgG, IgM, and fibrinogen in the villi of toxemic placenta than that of normal placenta by the treatment of deparaffinized specimen with anti-immunoglobulins antiserum and avidin-biotinylated peroxidase. The most striking reactions were produced by anti-IgG, anti-IgM, and anti-fibrinogen antiserum in this series. The followings are more detailed results. 1. Anti-IgG antiserum routinely reacted within the syncytiotrophoblast, the peripheral surface of the chorionic villi, as segmental or linear fashion. The staining was not seen in all villi and the pattern was granular or smooth with some areas of villi being more intensively stained than others. The degree and extent of staining were more dense and wide-spread in the placenta of toxemia than that of normal. 2.Anti-IgA antiserum reacted weakly and focally along with the surface of villi as segmental fashion. No difference of staining was noted between toxemic and normal placenta. 3. One of the most striking reaction was produced by anti-IgM antiserum. The pattern and distribution of staining were similar to anti-IgG antiserum treated specimen. There was noticeable difference in the degree and extent of staining between the placenta of toxemia and normal. 4. Generally, anti-complement (C₃) antiserum reacted weakly and focally. This finding stressed the immunological concept of toxemia. 5. One of the prominent reaction was also produced by anti-fibrinogen antiserum. The densely and homogeneously stained areas along the peripheral surface of the chorionic villi were impressive. The widely spreaded staining areas were also noted in the inter-villous spaces and fibrinoid(degeneration) areas which was connected to trophoblastic basement membrane as interrupted fashion. The degree and extent of staining produced by anti-fibrinogen antiserum had the most striking difference between the placenta of toxemia and normal. Above results may allow the conclusion that the more intense immunohistologic or histochemical changes in the placenta of toxemic pregnancy imply that toxemia has definite immunologic background different from that of normal pregnancy.

변단면 H-형강보의 탄성처짐에 관한 연구

황상진,최선규,홍영균,홍기섭 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

Tapered H-shaped beams are often used in the structures with large spans and roof crane running beams; for the purpose of member self-weight reduction and appropriately architectural representation. The purpose of this study is to represent an accurate calculation method for tapered beam deformations, based on elastic theories. In this study, equations for beam deformation calculation of whole span tapered or partly tapered beams are represented and compared with structural analysis results of generally used commercial computer program. The equations of Moment of Inertia for tapered H-shaped beams, which may have different width and thickness of their flanges or top and bottom flanges, are induced as well. Compared with the result of generally used structural analysis program, the results of this study will be confirmed for practical use.

GIS에서의 공간 조인 기법의 관한 고찰

황환규,김상욱 강원대학교 정보통신연구소 1998 정보통신논문지 Vol.2 No.-

The spatial join operation is one of the fundamental spatial database query operations. It facilitates the retrieval of information from two different spatial objects based on spatial relationships. The join is one of the most difficult operations to implement efficiently in spaital database systems, as it was with relational database ststems. In this paper, different kinds of spatial joins and various implementation techniques are surveyed. We investigate the basic idea, algorithms, and performance of the various spatial join techniques. In addiotion, we discuss the issues of the different spatial join techniques.

새로운 데이타베이스 응용을 위한 대형 데이타 관리 기법에 관한 고찰

황환규,김상욱 강원대학교 정보통신연구소 1997 정보통신논문지 Vol.1 No.-

Previous DBMSs have been built based on the simple assumption that a date item can reside on a disk page since traditional database applications such as bank service systems, business automation systems, and office automation systems have dealt with only small data items. However, with the advent of new advanced multimedia applications frequently dealing with large data items, this assumption is no longer acceptable. For supporting such new applications, DBMSs have to provide the additional facilities for managing large data items whose size are larger than that of a page. Recently, some researches have been performed aiming at this issue through developing advanced DBMSs and storage systems. In this paper, we discuss recent research results on large data management. We first present design considerations for large data management techniques. Next, we introduce the five techniques employed in commercial DBMSs and advanced storage systems such as WiSS, Exodus, Starburst, and EOS, and then compare those techniques focusing on (1) data structures, (2) algorithms, and (3) advantages and disadvantages. We also introduce domestic research activities, and finally suggest future research directions related to this issue.