재관류에 의한 간소엽 손상과 DMSO의 보호효과에 대한 형태학적 연구

송인환,이융창 대한해부학회 1996 Anatomy & Cell Biology Vol.29 No.4

남원시 생활하수가 요천 수질오염에 미치는 영향에 관한 연구

김환기,김태근,이영우 全北大學校 附設 都市및環境硏究所 1995 都市 및 環境硏究 Vol.10 No.1

The Yo stream(drainage area: 526.08㎢, length: 52.0㎞) is one of the branchs of the Seom Jin river. In order to evaluate effects of the sewage in Nam-Won City(I) on the water pollution of the Yo stream, water qulity analysis and estimate the pollutant discharge rate were carried out at six sites in the Yo stream basin from December 1994 to September 1995. The results of research are summarized as follow: 1. According to the water quality of six sites evaluated by BOD, ST1 is classified into I grade, ST2 and ST3 are II grade, ST4∼ST6 sites are III grade. 2. Amount of total BOD load from the Yo stream basin was estimated 11,810㎏/day of which 13.9% was contributed by land, 0.1%, was contributed by industrial waste water, 43% was contributed by population and livestock, respectively. 3. As Nam-Won city(I), discharge rate and effluence rate of BOD, SS were estimated 28.4%, 10.6% and 20.6%, respectively. 4. Since Nam-Won city sewage treatment plant started operation, BOD, SS reduction rate of Nam-Won city(I) were forecasted 36.1% and 20.6%, respectively.

광통신 수신기의 Transimpedence 궤환 증폭기에 관한 연구

姜英鎭,金煥溶 圓光大學校 1986 論文集 Vol.20 No.2

광통신 시스템 설계요건중 중효한 것의 하나는 수신기에서 최소의 S/N비를 갖도록 하는 것이다. 이 논문에서는 수신기에서의 여러 가지 잡음소오스를 알아보고 이중 transimpedancer궤환 증폭기 형태의 수신기에서 S/N비를 계산하고 평가한다. 수신기 입력에서 큰입력저항을 사용하며 증폭전압잡음과 열잡음이 감소됨을 알 수 있다. 또한 등화과정이 생략되며 고이득의 APD를 사용하면 증배 shot 잡음은 극히 작아지고 양호한 S/N비를 얻을 수 있다. 또한 매우 높은 주파수대에서는 입력소자로 G?A?/ - MESFET를 사용해야 함을 알 수 있고 수신 증폭기를 I.C화 하는 것이 요구됨을 알 수 있다. The need to preserve a certain minimum S/N ratio at the receiver input represents one of the chief design criteria of an optical communication system. In this paper the various sonrces of noise in the receiver are discussed, and shall attempt to calculated the S/N ratio as a function of the received power level for transimpedance feed back amplifier. The use of a large input resistance reduces the amplifier voltage noise and the thermal noise components. Unless the transimpedance feedback configuration is used, equalization may then be needed and dynamic range is reduced. When a high gain APD is used, multiplied shot noise normally dominates, as it does also when large S/N ratio are required.

λ-경쇄형 다발성 골수종 1예

박용관,김태원,장영,김진호,강정원,천영욱,박유환,정춘해 조선대학교 1995 The Medical Journal of Chosun University Vol.20 No.1

Multiple myeloma is a disease caused by neoplastic plasma cells that synthesize abnormal amouts of immunoglobulin or immunoglobulin fragments. Light chain myeloma are regarded as a separate category characterized by a more malignant clinical course. Light chain myelomas are said to grow fastest of all and are associated with more osteolytic lesions, more hypercalcemia, and a higher incidence of renal failure and amyloidsis than either the IgG, IgA varienties The authors experienced a case of patients with λ-light chain myeloma. A 43-year-old male patient admitted to our hospital with the chief complaint of both rib and lower back pain. The radiologic findings showed multiple pathologic fracture in ribs. osteolytic lesions in 2nd, 3rd cervical spineimmuture plasma cells. Serum electrophoresis showed normal finding. Urine electrophoresis evealed an M-spike. Urine immunoelectrophoress demonstrated λ-monoclonal protein. With the cycle of melphalan, prednisone and α-interferon chemotherapy improved of pain was observed. So we reported the case with brief review of previous literature.

수치해석을 도입한 파괴역학의 기하학적 고찰과 응력확대계수의 합성에 관한 연구

박영환 東洋大學校 産業技術硏究所 1999 東洋大學校 産業技術硏究所 論文集 Vol.1 No.1

Stress intensity factor is one of the most important factors in analysing fracture mechanics. To access fracture mechanics easily, the geometric consideration of fracture mechanics, particularly in stress intensity factor calculation, is studied. When geometric consideration of crack tip opening for the stress intensity factor ?? of opening mode case and for the stress intensity factor ?? of sliding mode case is successfully set up, the combined mode stress intensity factor ?? can be interpreted from the geometrically introduced ?? and ??. As the ??, ?? and ?? can be calculated from the physical displacement calculation in the consideration of the crack opening geometry, we can obtain each stress intensity factor by adopting displacement or stress value from the numerical analysis calculation for the various configurations of the geometry we need to analyse.

고속 광무선 LAN 시스템 개발 연구

김준환,김영권,홍권의 건국대학교 산업기술연구원 1997 건국기술연구논문지 Vol.22 No.-

Optical communications through the atmosphere offer the potential of relatively inexpensive high speed line-of-sight communications. Furthermore, the performance of any gound-to-ground or satellite-to-ground optical link will be affected by the atmosphere. The atmosphere is an imperfect medium for transmission of optical communications signals. It is not homogeneous and further, it is dynamic in its behavior. The atmosphere can be considered as producing some effects on transmission of light. These effects are turbulence, absorption, and scattering. All three can reudce the amount of light energy that is collected at the receiver and corrupt the data being sent. Although the effect of attenuation due to absorption/scattering can be overpowering in a link design, and can be compensated with judicious choice of wavelength of light signal, the fluctuations in amplitude and phase due to turbulence give rise to a number of important effects.

극초음속 실험장치의 구동부 특성에 관한 연구

변영환,허철준 건국대학교 산업기술연구원 1997 건국기술연구논문지 Vol.22 No.-

There are shock tunnel, gun tunnel, piston tunnel and expansion tube as ground-based hypersonic test facilities. Performances of these facilities depend on many things, but mainly characteristics of driver. These drivers are very important impulse facilities but hardly known for lack of theoretical analysis. Most of knowledges about drivers are based on facility developer's own experiences and experimental data. Characteristics of shock wave compression and piston compression have been studied in this reseach to study characteries of drivers of impulse test facilities. Change of ratio of driver pressure to stagnation pressure has been compared to well known results of other researches and it shows very similar trend. Shock wave compression is more effective than piston compression in low pressure, but piston compression is more effective than shock wave compression in high pressure. Results of our gas gun tests show that piston compression is more effective to get higher stagnation pressure in the region of the above 72 of driver pressue ratio.

매체를 활용한 초등 영어 수업 설계

권영환,김정희 부산교육대학교 교육대학원 2000 논문집 Vol.2 No.-

This paper deals with the utilization of multimedia that helps Korean elementary school students develop their language learning by using a variety of language teaching methods. These methods include lessons based upon the student's interests, student centeredness, and meaningful activities. In order to provide efficient educational software program to language teaching/learning, the educational materials designed by educational goals according to the characteristics of learners are necessarily needed. Therefore, the individualized media lesson could possibly sustain the learner's interests and reinforce his/her language learning with lots of feedback and thorough assessment. Finally, for the development of multimedia language teaching/learning, the computerized program needs to be evaluated by the professional expert on the points of the validity of educatonal goal, the appropriateness of the contents, the pertinence of communication delivery, and the trust of programming technology.

고등학교 통계적 추측 단원의 신뢰구간 지도

김응환 공주대학교 사범대학 과학교육연구소 1997 과학교육연구 Vol.28 No.1

신뢰구간의 지도는 고등학교의 수학교육분야에서 추측의 한 방법으로서 매우 중요한 위치를 점하고 있다. 또한 신뢰구간의 개념이 이해하기 어려운 특성을 지니고 있다. 본 연구에서는 현행 12종의 고등학교 수학교과서를 분석 검토하여 그 결과를 논하였으며 이를 바탕으로 보다 효과적인 신뢰구간의 지도를 위한 방법을 제안한다. The teaching of the confidence interval is very important in mathematics education at highschool as a method of the statistical inference. It is hard to understand that the concept of the confidence interval. In this paper, I discuss and compare with the context of the confidence interval in the 12 textbooks of mathematics used at highschool. And I propose more effective teaching method of the confidence interval.

치아회분과 석고를 혼합하여 제작한 block의 inlay 매식후 치유과정에 관한 실험적 연구

김영균,여환호,박인순,조재오 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.2

The purpose of this investigation was to determine the possibility of clinical use of toothash-plaster block implant material with ratio of 2 : 1 weight. We made 1cm diameter round partial thickness defect at both sides of calvaria. Right side was implanted with block and left side was not implanted as a control site. The following results were obtained : 1. In gross examinations, the implanted site had a hardness on palpation and the margin with host bone was not identified clearly at 12 weeks after operation. But control site contained the fibrous tissue. 2. In the light microscopic examinations, most of the implanted sites were repaired by newly-formed bone at 12 weeks postoperatively. 3. At 8 weeks postoperatively, the implanted particles were divided into small granules and the amount was decreased gradually. Some remained particles were united directly with newly-formed bone. But the implanted particles still remained partly at 24 weeks postoperatively. 4. There was no significnat difference between the experimental and control site at 24 weeks postoperatively.