고유 불안정한 도립진자 시스템의 최적 안정화 제어에 관한 연구

최부귀,박영식,안기형,이취중 동아대학교 공과대학 부설 한국자원개발연구소 1990 硏究報告 Vol.14 No.1

This paper proposes a design techinque of dynamic stabilization controller for the intrinsic unstable inverted pendulum system. Mathematical modelling with the more complex nonlineaity and the stabilized control theory presented by C.D. Johnson are adapted to this system by using the stage-space approach. And the stabilized controller with the designed optimal regulator type which can be fastly tracked and can be accurately counteracted against all effects of the constant disturbances and the parameteric variations is sumulated and is implemented successfully on the microcomputer.

Fusobacterium nucleatum의 테트라사이클린 내성여부를 검사하기 위한 세균배양법과 중합효소연쇄반응법의 비교

최재흥,성진효,국중기,김동기 대한구강보건학회 2003 大韓口腔保健學會誌 Vol.27 No.4

The purposes of this study were to identify the detection and incidence of tetracycline resistance determinant tet(M) by PCR method and to evaluate the availability of PCR method guided for clinical use of antibiotics in dentistry. Subgingival plaque samples were collected from 172 sites of 29 patients. Both original sample and subculturd sample, PCR amplification was used to detect tet(M) in Fusobacterium nucleatum. The percentage of tet(M)-positive subjects and sites in original samples were 100%, 95.9%, respectively. And the percentage of tet(M)-positive subjects and sites in subcultured samples were 17.2%, 3.5%, respectively. In subcultured samples, probing pocket depth and clinical attachment level in tet(M)-positive sites were higher than in negative sites (p<0.05). The sensitivity and specificity of PCR method compared with broth dilution method as a gold standard were 0.91 and 0.86, respectively. The results suggested that tet(M) assay using PCR method was available to detect the tetracycline-resistant F. nucleatum.

壓挫시킨 家兎 軟骨의 生存

최동원,송중원,한기환,강진성,정재홍 大韓成形外科學會 1990 Archives of Plastic Surgery Vol.17 No.2

The deviated nose regardless whether it is due to traumatic or congenital origin results in troublesome symptoms coming from airway obstruction. Numerous methods for straightening the severely deviated septum have been described by many authors but none is wholly satisfactory. A new method that the crooked septal cartilage is being flattened by crushing and reimplanting into the septal pocket is introduced. The authors are desirous of knowing about the fate of the crushed cartilage graft. Forty rabbits weighing 2 to 3 kg were divided into 2 groups, septal group and conchal group. The cartilages were obtained from the nasal septum and ear; these cartilages were placed under the paraspinal subcutaneous tissue. Prior to paraspinal iplantation the obtained cartilage was halved; one piece of cartilage being crushed by Cottle's cartilage crusher before its placement into the recipient site and the other was placed without crushing. The cartilage specimens were removed at 6 and 12 weeks postoperatively and these were examined by the naked eyes and light microscope. The results were as follows: 1. The fissures and cleavages of cartilage developed during crushing process are restored to normal by 6 weeks postoperatively. 2. All of the ujncrushed cartilages remained viable in the subcutaneous pockets. The crushed cartilages not only appeared viable but also induced a new cartilage formation beneath the perihondrium at 12 weeks postoperatively and the thickness being increased compaired to the cartilage before crushing. 3. Crushed cartilage remained flat at 12 weeks postoperatively. 4. The degree of strength of the crushed cartilage is increased due to new cartilage formation and fibrosis of perichondrium at 12 weeks postoperatively. These findings support the clinical impression that the crushed autogenous cartilage is viable and can be reshaped according to the contour of the recipient site.

압좌시킨 이개 연골을 이용한 안저 골결손의 재건

최동원,송중원,한기환,강진성 大韓成形外科學會 1990 Archives of Plastic Surgery Vol.17 No.5

A numerous materials have been used for reestablishing continuity of the orbital floor in orbital floor fracture. Traditionally autogeneous bone has been utilized for reconstructing orbital floor defect but autogeneous bone has criticized for unpredictable resorption, donor site morbidity and difficulty in shaping and fixation. Alloplastic materials have gained some popularity because of their availability and ease of use but they disadvantages like infection. extrusion and implant displacement. There is an alternative to bone grafts and inorganic implants fir reconstruction of orbital floor defect; auricular conchal cartilage, however, has convolution so the authors have made the conchal cartilage flat and malleable by crusher. Crushed autogenuous conchal cartilage has proved to be a material that is easy to obtain and shape and can reliably support the orbit without evidence of resorption. Crushed autogeneous conchal cartilage offers an attractive alternative to inorganic implants and bone grafts in properly selected patient for orbital floor reconstruction.

치과용 니켈-티타늄 합금의 갈바닉 부식

최창혁,최기열,이중배 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.1

The purpose of this study was to evaluate the galvanic corrosion behavior of NT by coupling with other dental alloys in artificial saliva. The variation of galvanic current and common potential (mixed potential) were monitored as a function of time, and interpreted in terms of the electrochemical properties of each alloy. The effects of adding some constituents such as acid or chloride to the ordinary composition of artificial saliva were also estimated. For most cases of coupling, the significant current was observed only at early stage for several seconds or several minutes, then gradually diminished. The current value was affected by the excessive amount of acid or chloride added to artificial saliva, depending on their aggressiveness on each alloy ; the current was increased in the couples with HG, LG, VT, and decreased in the couples with AM and G2. The results were more complicated in the couples with AP and TC, where some mixed reaction occurred. The common potential was always between two corrosion potentials of alloys involved in the couple, and did not exceed the breakdown potential of alloy acted as anode except the case of coupling with AM in acid-containing artificial saliva. The coupling with AM was found to be the most susceptible to galvanic corrosion.

Piperine 誘導體[5-(3-methoxy-4-hydroxyphenyl)-2,4-pentadienoic acid amides]의 合成 硏究

林中基,咸元勳,崔然喆 성균관대학교 약학연구소 1990 成均藥硏論文集 Vol.2 No.1

Abstract-Some 5-(3-methoxy-4-hydroxyphenyl)-2,4-pentadienoic acid amides were synthesized for searching new anticonvulsant agents. The amides could be synthesized by condensation of protected vaniline with crotonic acid amides in the presence of sodium amide. A MOM Ether(methoxymethyl ether) was used to protect one phenolic hydroxyl group of vaniline. MOM Ether was selectively cleaved on exposure to 1 : 1 THF-6N hydrochloric acid.

유동층을 이용한 탈황제의 마모특성에 관한 연구

오광중,김형국,최은화,조기철 부산대학교 환경문제연구소 1999 環境硏究報 Vol.17 No.1

For the efficient energy use and the protection of environmental pollution, attrition characteristics, depending on the component and the condition of sorbent for the purification of fuel gas, were analyzed by a fluidized-bed tester. Results of these studies can be summarized follows. 1) When Mn-based sorbent(M, MT, MFT) prepared with varying addictives and induration conditions was compared in terms of particle size distribution and AI(Attrition Index), MT and MFT possessing TiO2 and Fe203 had much higher attrition resistance than M. Attrition resistance of M, MT and MFT increased as bentonite contents and induration temperature increased, when bentonite contents induration temperature were changed from 2 to 5% and from 1000 to 1100℃, respectively. Therefore when powdery catalysts are prepared, the attrition rate can be considerably affected by the controls of addictive, binder and induration temperature. 2) Attrition tests using MT1100-5 were performed under the conditions that particle size distribution was uniform and had much more over +270mesh and under -325mesh. AI due to attrition was 8.83, 21.54 and 1.67%, respectively. Thus, initial particle size distribution showed a great influence on both produced fines distribution and attrition loss. Therefore, the size distribution of particles injected initially and the particle size that carried over showed be considered to reduce the loss of particulate materials and the replacement cost due to attrition. 3) An experiment using MT1100-5 sorbent was also carried out to predict AI as a function of time and particle size distribution during 23hr. AI of prepared sorbent was 4.54, 7.73, 9.08, 11.35 and 12.48 after 1.5, 3, 5, 9 and 23hr. respectively. Thus, it was shown that the amount of produced fines during the same time was shorten with the increase of time. The operating condition of dust capturing equipment and the rate of powder exchange needs to be considered because most of the fines due to fluidization of particulate material was generated at initial operation.

폐렴으로 병발된 범발성 혈관내 응고증의 Antithrombin III 치험 1례

서중산,최호열,김현수,이록윤,오흥국,박영석,정기석,박근칠,선덕제 한림대학교의료원 1994 人間科學 Vol.18 No.9

포스트-텐션 프리캐스트 외부 넓은 보-기둥 접합부의 비탄성 거동

박상욱,최윤철,김영찬,김대중,임재형,권기혁,문정호,이리형 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

Experimental results from the cycle lateral load tests for post-tensioned precast wide beam-column connections were presented. Six exterior beam-column assemblages of half scale were tested in the laboratory. The specimens consist of U-shaped precast wide beams and concrete columns. The continuity at the beam-column joint is achieved with the topping concrete and post-tensioning. The specimens were designed with parameters of the beam-to-column depth ration and the number of tendons within column core. The test results showed that the post-tensioned precast wide beam-column connection satisfied the provisional standard by ACI of acceptance criteria for concrete special moment frames.

Development of Sediment Assessment Tool for Effective Erosion Control(SATEEC) in Small Small Scale Watershed

임경재,최중대,김기성,사공 명,버나드 엥겔 江原大學校 附設 環境硏究所 2003 環境硏究 Vol.20 No.-

The Revised Universal Soil Loss Equation (RUSLE) has been used in over 100 countries to estimate potential long-term soil erosion from the field. However, the RUSLE estimated soil erosion cannot be used to estimate the sediment delivered to the stream networks. For an effective erosion control, it is necessary to compute sediment delivery ratio (SDR) for watershed and sediment yield at watershed outlet. Thus, the Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed in this study to compute the sediment yield at any point in the watershed. To compute spatially distributed sediment yield map, the RUSLE was first integrated with the ArcView GIS and three area based sediment delivery ratio methods were incorporated in the SATEEC. The SATEEC was applied to the Bangdong watershed, Chuncheon, Gangwon Province to demonstrate how it can be used to estimate soil loss and sediment yield for a watershed. The sediment yield using USDA SDR method is 8,544 ton/year and 4,949 ton/year with the method by Boyce. Thus, use of watershed specific SDR is highly recommended when comparing the estimated sediment yield with the measured sediment data. The SATEEC was applied with hypothetical cropping scenario and it was found that the SATEEC can be used to assess the impacts of different management on the sediment delivered to the stream networks and to find the sediment source areas for a reach of interest. The SATEEC is an efficient tool to find the best erosion control practices with its easy-to-use interface.