Tabu 탐색법을 이용한 PI 제어기 설계

원태현,황기현,문경준,이용길 동의공업대학 2000 論文集 Vol.26 No.1

We propose an adaptive Tabu search method changing neighbor solution's range to be searched each iteration according to an objective function and design a PI controller using the proposed Tabu search. We apply it to a time-delay system to evaluate the usefulness of the proposed method. overshoot, rising time, and settling time.

p-Anisaldehyde가 조골세포 분화에 미치는 영향

김경민 ․ 이도원 ․ 김현준 ․ 김아랑 ․ 장원구 대구대학교 산업기술연구소 2018 産業技術硏究 Vol.29 No.2

p-Anisaldehyde is a natural fragrance extracted from Pimpinella anisum L., and used as a preservative. This study examined the effect of p-anisaldehyde on osteoblast differentiation. First, cytotoxicity tests were carried out after examining the concentrations that did not show toxicity to the cells. The expression of osteoblast differentiation marker gene was confirmed by RT-PCR and was not effective in the treatment with p-anisaldehyde alone. However, p-anisaldehyde decreased the expression levels of inhibitor of differentiation-1 (Id1), distalless related homeobox (Dlx5), and runt-related transcription factor 2 (Runx2), which are osteogenic differentiation marker genes, which are increased in osteogenic condition. alkaline phosphatase (ALP) activity was also confirmed by ALP staining that p-anisaldehyde reduced ALP activity. These results show that p-anisaldehyde is effective in reducing osteoblast differentiation.

탄소 나노튜브의 전계방출 특성

이경원,김은미,권민철,김용,이재열,박홍준 동아대학교 기초과학연구소 2000 基礎科學硏究論文集 Vol.17 No.1

본 연구에서는 emitter와 collector 사이의 간격과 current density 대 electric field (J-K)특성을 초점으로 카본나노튜브의 전계방출 특성을 조사하였다. 카본 소스로 CH4, 촉매 및 희석가스로서 NH3를 사용하고 HFCVD를 이용하여 실리콘 위에 카본나노튜브를 성장하였다. 나노튜브의 지름이 20-40nm이고 길이는 15㎛이다. I-V곡선에서 onset voltage는 Vons=3.36V/㎛이고, 2.5V/㎛ 의 전기장에서 8mA/cm2이상의 높은 전류밀도 특성을 보였다. Fowler-Nordheim 그래프를 그려서 팁의 특성을 나타내는 β값을 계산하였다. We report the field emission properties of carbon nanotube, focusing on current density versus electric field (J-F) characteristics and the spacing between the emitter and collector. We grow carbon nanotubes on sillicon using hot-fillament chemical vapor deposition, using CH4 gas as the carbon source and NH3 gas as the catalyst and dilution gas. Nanotubes are distributed from 20 to 40nm in diameter and 15㎛ long. Onset field of the field emission is 3.36V/㎛ and the current density is 8mA/cm2 at an electric field of 2.5V/㎛. A Fowler-Nordheim plot was made. Field enhancement factor β is calculated.

초내열합금 Inconel의 가공성 평가

정경효,원종식,정윤교 國立 昌原大學校 産業技術硏究所 1996 産技硏論文集 Vol.10 No.-

Inconel, super heat-resistant alloy is superior in the toughness and the creep strength. It can especially endure high temperature and corrosion. It has been, therefore, broadly used in the various fields of atomic industry, aerospace, industrial mechanics and automobile etc. But such inherent properties as high temperature strength, an affinity with tool materials and low heat-conductivity etc. of Inconel alloy 600 degrade machinability. As a result, they cause many problems in the cutting process. In this study, machinability of Inconel alloy 600 was estimated on stand points of cutting force, tool wear and welding of chip for the cutting edge. Inconel alloy 600 was cut by precision high-speed lathe and tool material was used coated tungsten carbide insert(CTCI) and ceramic insert(CI) to be done in general. Cutting force is measured by the piezo type tool dynamometer and cutting edge is observed by scanning electron microscope(SEM). As a experiment result, obtained conclusions as follows. (1) In the case of cutting Inconel alloy 600 with CTCI, value of cutting force is similar its of SM45C. In this case, however, we can not avoid the cutting trobles that is ; the large width of fluctuations for cutting force and welding of cutting chips for cutting edge because of the toughness of the material. (2) In the case of using CI, the brittleness of the tool resulted in chipping. (3) Available cutting conditions of Inconel alloy 600 for CTCI and CI were established.

纖維强化 Plastics의 切削加工에 관한 硏究

金元鎰,李允景,姜渭民 慶南大學校 附設 工業技術硏究所 1991 硏究論文集 Vol.9 No.-

本 硏究에서는 유리纖維 强化樹脂의 旋消時 각 切削 條件에 따른 超音波 振動切削과 常用切削時 나타나는 加工特性을 考察하기 위하여 眞圓度, 表面粗度을 中心으로 比較, 檢討한 結果 다음과 같은 結論을 얻을 수 있었다. 1. 眞圓度의 값은 切削條件 및 振幅에는 많은 影響을 받지 않고, 纖維角이 60˚인 경우 V=60m/min, f=0.08mm/rev, t=0.05mm일때 眞圓度 값이 10㎛로 가장 良好하였고, 纖維角이 90˚인 경우에는 振動切削에서는 19㎛, 常用切削에서는 37㎛로 가장 높은 값이 나타났으며, 振動切削이 常用切削 보다 약 2배 改善되었다. 2. 表面眺度는 纖維角이 60˚인 경우가 가장 良好하고, V=20m/min에서는 振動切削과 常用切削의 값은 거의 變化가 없으며 V=30m/min이상에서는 振動切削이 顯著하게 改善되었다. 3. 工具傾斜角은 眞圓度에는 많은 影響을 미치지 않지만 表面粗度는 0˚보다 6˚가 약간 改善됨을 알 수 있다. 4. 振動切削은 硏削에서 얻을 수 있는 加工精度를 旋削에서도 쉽게 얻을 수 있어 精密度와 生産性을 向上시키는 加工法이라 할 수 있다. In this paper, under different cutting condition on G.F.R.P, ultrasonic vibration cutting and the characteristics in conventional cutting have been studied. So the following conclusion centered on comparison, examination of roundess, surface roughness has been reached. 1. The value of surface roundess doesn't get much effect from amplitude as well as cutting conditions. With 60˚of fiber angle, v=60m/min, f=0.08mm/rev, t=0.05mm, the value of surface roundess, 10㎛, was the best. In case of 90˚, the highest value was 19㎛ in vibration cutting and 37㎛ in conventional cutting vibration cutting has improved about twice as high as conventional cutting. 2. In case the fiber angle was 60˚, surface roundess was little difference between vibeation and conventional cutting. Under v=30m/min and above, vibration cutting has remarkably improved. 3. Even if the tool rake angle doesn't affect the roundess, surface roughness has improved a little more at 6˚than at 0˚. 4. Vibration cutting helps to gain as lathe turing working precision as in grinding, Consequently, it's considered a good working method to improve precision and productivity.

원통 연삭에서 가공 능률 향상을 위한 연삭 저항의 측정에 관한 연구

김원일,이진,이윤경,왕덕현,이상복,이관철,문원길 경남대학교 공업기술연구소 2000 硏究論文集 Vol.18 No.-

본 연구에서는 원통 연삭 가공에서 가공 능률 향상을 위한 연삭 저항을 측정하고자 연삭 가공 중에 발생하는 연삭 저항의 추이를 확인하였고 다음과 같은 결과를 얻었다. 숫돌과 공작물간의 연삭 강성은 공작 속도의 증가에 따라 지지계의 강성이 높은 경우 증가하였고 절삭 깊이와 연삭 숫돌의 속도에는 연삭 강성이 감소하는 경향을 보였다. 또한 총합 강성은 공작 속도, 절삭 깊이 및 연삭 숫돌의 속도 증가에 따라 지지계의 강성이 높을 수록 증가하였다. 연삭기의 강성 변형과 가공 능률에 영향을 주는 값으로 연삭 강성비는 지지계의 강성이 높을 수록 감소하였다. In this study, the measurement of grinding resistance to improve grinding efficiency in cylindrical grinding was studied and the following conclusions could be obtained. Relation grinding wheel and workpiece, grinding stiffness increases according to increase of work speed for high machine stiffness and decreases depth of cut and grinding wheel speed. Also, resultant stiffness increases high machine stiffness according to increase work speed, depth of cut and grinding wheel speed. The values of the effect stiffness deflection in grinding machine, grinding stiffness ratio decrease according to high machine stiffness.

For-To 구문과 Of-To 구문의 의미론적 차이점에 대하여

권경원 한국현대영어영문학회 2002 현대영어영문학 Vol.46 No.2

The purpose of this paper is to find the semantic difference between for-to construction and of-to construction. In this paper the semantic differences of these constructions have been studied based on (1) the historical change of infinitives, (2) the meaning of prepositions such as for and of, (3) the relation between adjectives in the main clause and the subject of infinitive clause, (4) the relation between the adjective and the action of the infinitive clause. We observed that the infinitive with to was originally a noun in the dative governed by the preposition to, hence was in the first stages of its development a prepositional object modifying the verb. Now this to is not felt as a preposition but rather as a part of the infinitive itself. In the fourteenth century there arose a desire to extend the use of the convenient infinitive construction and people began to give the infinitive a subject of its own when there was no noun or pronoun in the principal proposition which could serve as a subject. The subject was put before the to infinitive and for was used as a formal sign of the introduction of this new subject. While the preposition of represents the inherent relation between two objects in X of Y, the preposition for represents the exchange between two objects in X for X. It is found that the adjective in the of-to construction modifies both the subject and the action of the infinitive clause based on the meaning of preposition of. So the of-to construction can be used as an euphemistic expression. What is important here is that the adjective primarily describes the subject of the infinitive clause. The adjective of the for-to construction does not describe the subject of the infinitive clause but primarily modifies the action of the infinitive clause. The properties of adjectives are [+noun], [+verb]. In other words adjectives are between nouns and verbs. Generally the properties of nouns are permanent, the properties of adjectives are stable and the properties of verbs can be changed rapidly. We found that the adjectives with nominal properties are used in for-to construction and the adjectives with verbal properties are used in of-to construction through these properties. In conclusion, the adjective in the matrix clause modifies the proposition of the infinitive clause in for-to construction. Those adjectives do not describe the subject of the infinitive clause but primarily describe the action of the infinitive clause. In contrast with for-to construction, the adjective in of-to construction modifies both the subject and the action of the infinitive clause. However those adjectives primarily describe the subject of the infinitive clause.

만경강 상류 수질 및 식생분포와 토양환경에 따른 하천식생의 종 다양성

이경보,김창환,이덕배,김종구,박찬원,나승용 한국환경농학회 2003 한국환경농학회지 Vol.22 No.2

만경강 상류유역 수질 및 하천식생 군락 변화를 조사 분석하여 수질에 따른 하천식생의 종 다양성 및 토양요인에 따른 종 다양성의 변화를 평가하기 위하여 2001년 6월부터 2002년 9월까지 만경강 상류유역 5개 조사지점을 선정한 후 조사를 실시하였다. 수질중 T-N의 농도는 전주천과 삼천에서 높았으며, 겨울철에 전주천에서 7.45 mg/L로 가장 높았다. 무기태 질소 성분벽 함량은 NH₄-N 경우 고산천과 소양천 유역은 0.01~0.06 mg/L 범위로 계절별 커다란 차이가 없는 낮은 농도를 나타냈으나, 생활하수가 유입되는 전주천과 삼천에서는 0.77~3.01 mg/L로 계절별로 큰 차이를 보였다. T-P의 농도는 계절별로 비슷하였으나 전주천에서 겨울천에 0.89 mg/L로 가장 높았다. 계절별 BOD의 농도는 고산천과 소양천 유역에서 0.92~2.14 mg/L를 나타내었으나 생활하수가 유입되는 유역에서는 2.01~7.65 mg/L범위를 보였다. SO₄²^(-)의 농도는 농업용수 수질기준인 50 mg/L를 초과하는 지역은 없었으며 소양천에서 다소 높았다. 만경강 지류인 고산천에서 조사된 식물은 59과 과 129속 165종 20변종으로 총 185종류가 조사되었으며, 소양천에서 조사된 식물은 53과 111속 141종 19변종으로 총 160종이었고, 전주천 하류에서 조사된 식물은 37과 68속 86종 15변종으로 총 103종이었다. 그리고 삼천에서 조사된 식물은 32과 92속 110종 18변종으로 총 128종류 조사되었으며, 만경강 본류인 하리유역에서 조사된 식물은 73과 134속 218종 33변종으로 총 251종류가 조사되었는데 식물의 생활형에 따라 분류하면 침수식물이 13종, 부엽식물이 5종, 부유식물이 2종, 추수식물이 26종, 수생식물이 46종, 습생식물이 47종으로 조사지점중 이 지역의 식생이 가장 다양하였다. 식물사회학적 방법에 따라 분류된 하천식생의 식물군락은 10개의 수생식물 군락과 2개의 습생 및 수변식물 군락으로 대별되어졌다. 이들 군락들에 대한 4종류(종수, 종의 풍부도지수, 종의 이질성지수, 종의 균등도지수)의 종 다양성과 토양요인(pH, EC, 유기물 함량, 전질소, 인삭)과의 관계를 분석한 결과 pH가 높을수록 4종류의 종 다양성 지수는 높아 졌으며, EC는 값이 높을수록 종수(SN), 종의 풍부도지수(SR), 종의 이질성지수(H'), 종의 균등도지수(J')가 낮아 졌다. 또한 유기물 함량(OM)과 전질소(T-N)의 경우도 4종류의 다양성지수와는 부의 상관관계를 나타내었다. 인산(P₂O_(5))은 4종류의 다양성 지수의 변화에 영향을 미치지 않았다. This study was conducted to evaluate influence of chemical properties in the riparian on the species diversity and to get plant information for enhancement of natural purification in Mankyeong River. The concentration of total nitrogen was high in Jeonju and Sam stream, while that of total nitrogen showed the highest peak in Winter. Concentrations of NH₄-N was 0.01-0.06 ㎎/L in Gosan and Soyang stream. The water quality of upstream along with Mankyeong River was suitable for the imgation source. The riparian vegetation was investigated by Zurich-Montpellier school's method from June, 2001 to September, 2002. The number of riparian plants were 59 families, 129 genera, 165 species, 20 varieties in Gosancheon, on the while 53 families, 111 genera, 141 species, 19 varieties in Soyangcheon The number of riparian plants in Hari basin was higher than that of other sites namely, 73 families, 134 genera, 218 species, 33 varieties. Riparian vegetation was consisted of 12 plant communities. The contents of organic matter, total nitrogen and electrical conductivity had negative relationship with species diversity (Species richness index, Heterogeneity index, Species evenness index, Species number). On the while, species diversity had positive relationship with soil pH. Species diversity of the plant communities were affected by topography and disturbance.

유방의 과립구성 육종으로 재발한 급성 골수성 백혈병 1 례

박경배,서원석,신상만 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Granulocytic sarcoma is a malignant neoplasm composed of poorly differentiated cells of the myelogenous series. Granulocytic sarcoma are reported in 3.1-9.1% of patients with myelogenous leukemia and occur concomitantly, following or rarely antedating the onset of leukemia. Granulocytic sarcomas can occur at various sites of the body and frequently at multiple sites. Involvement of the breast is uncommon. We experienced a case of acute myelogenous leukemia. 12 months earlier, she was diagnosed as acute myelogenous leukemia(M2) and acheived complete remission with KSPHOG ANL regimen. The patient was treated with KSPHOG ANL regimen without radiation therapy. An 20th day, left breast lesion disappeared and complete remission was obtained.

육류영양소의 소비자수요

정경수,박창원 建國大學校 經濟經營硏究所 2000 商經硏究 Vol.24 No.2