下水 處理場의 最適處理工程에 關한 實驗的 硏究

조정석,한양수 대구대학교 과학기술연구소 1995 科學技術硏究 Vol.2 No.1

The growth of population and industrialzation has been increasing the discharge of wastewater and requiring more intensive eater treatment processes. This study was carried out to determine the optimal design conditions of a sewage treatmentplant in the small city of An-jung. Also, we set out to find the operation guide data pertaining to the activated sludge process required by a city of this size. The biological reactors were operated with hydraulic retention time of 4hrs, 6hrs, 8hrs, 10hrs, and 12hrs respectively, using a mixture of raw wastewater. From the results of the experiments, we found that the removal efficiency increased as the F/M ratio decreased. From this conclusion we found that we could get the BOD removal eficiency above 90% if the F/M ratio was 0.13 to 0.27 KgBOD/Kg MLSSday.

QUAL2E 모형을 이용한 하천 수질예측

조정석,한양수 大邱大學校 科學技術硏究所 1996 科學技術硏究 Vol.3 No.2

The purpose of this study predict to the water quality of Sum-Jin river watershed using QUAL2E model. In order to predict water puality, the upstream of Sum-Jin estimated flow and variation of water quality by main stream. The model is applicable to dendritic streams those are well mixed. It assumes that the major trasport mechanisms, advection and disperssion, are significant only along the main direction of flow. By operating the model dynamically, there can study the effects of diurnal variations in meteorological data on water quality and also can study diurnal dissolved oxygen variations due to algal growth and respiration. The result of the QUAL2E model simulation in Seom-Jin river basin have shown that. First, BOD concentration before confluent Hang-Jong stream was 1∼1.5ppm as a second class water quality. Second, the water quality simulation rusults using QUALM model, BOD intake southseas was 1.4ppm and the prediction of BOD in 2002 and 2012 turn out 1.8ppm and 2.6ppm. There was high increased concentration for BOD variation by purposed year(2002, 2012)

역전파 신경회로망을 이용한 복수 결함 패턴 인식에 관한 연구

양협,조석수,이성룡 三陟大學校 2000 論文集 Vol.33 No.1

Ultrasonic inspection of defects has been focused on the existence of defect in structural material and need has much time and expenses in inspecting all the coordinates (x, y) on material surface. Neural networks is information processing system modeling human brain and can have an application to coordinates (x, y) of defects by multi-point inspection method. Ultrasonic inspection modeling is optimized by neural networks which makes defect echo, back-well echo and ultrasonic transducer units of input layer and absolute and relative coordinates of defects and defect pattern units of output layer. This method can predict coordinates (x, y) of defects within engineering estimated mean error ψ.

자동차압연강의 X선 잔류응력 특성에 관한 연구

양협,조석수,이성룡 三陟大學校 2000 論文集 Vol.33 No.1

In textured material, diffraction angle 2 θusually shows a nonlinear relation against sin²ψdue to the elastic anisotropy to crystals. SPCD and SOCD steel is cold rolled carbon steel for automobile. The characteristic X-ray for stress measurement is Cr-Kα and Mo-Kα characteristics X-ray. The 2 θsin²ψdiagram under elastic strain seems to have a linear behavior but has nonlinear behavior in distribution o data Cr-Kα characteristics X-ray. As the plastic strain of specimen increases, the nonlinearity of 2 θwith respect to sin²ψincrease remarkably. On the other hand the diffraction angle 2 θby Mo-Kα characteristic X-ray shows a good linearity on 2 θ-sin²ψdiagram plastic strain as well as elastic strain. This results from deep penetration depth and multiplicity factor of crystal diffraction plane in Mo-Kα characteristic X-ray.

Box-Jenkins法을 利用한 河川水質의 時系列 豫測

趙廷錫,韓陽洙,金喜洛 大邱大學校 科學技術硏究所 1997 科學技術硏究 Vol.4 No.2

This study was carried out to develop the stochastic stream water quality model for the intaking station of Taejoun City waterworks in the Keum River system. The monthly water dissolved oxygen with periodicity and trend were forcasted by multiplicative ARIMA models and then the applicability of the models was tested based on 13years of the historical monthly water quality data at Taejoun City intaking site. The parameter estimation was made with the monthly observed data. The last one year data was used to compare the forcasted water quality by ARIMA model with the observed. The models are ARIMA(2.0.2)x(2.1.1)_(12) for dissolved oxygen. The forecasting results showed a good agreement with the observed. It is implying the applicability of multiplicative ARIMA model for forecasting monthly water quality at the Taechoung site.

신경회로망을 이용한 Al 2024-T3합금의 피로손상예측에 관한 연구

조석수,양협,이성룡 三陟大學校 産業科學技術硏究所 2000 産業科學技術硏究論文集 Vol.5 No.-

Fatigue crack growth and life is estimated by various fracture mechanical parameters but affected by load, material and environment. Fatigue character of component without surface notch cannot be evaluated by above-mentioned parameters due to microstructure of in-service material. Single fracture mechanical parameter of nondestructive parameter cannot predict fatigue damage in arbitray boundary condition but multiple fracture mechanical parameters or nondestructive parameters can. Fatigue crack growth modelling with three point representation scheme uses this merit but has limit on realtime monitoring. Therefore, this study shows fatigue damage model by backpropagation neural networks on the basis of X-ray half breadth ratio ??, fractal dimension ?? and fracture mechanical parameters can predict fatigue crack growth rate da/dN and cycle ratio ?? at the same time within engineering estimated mean error(5%).

중이기형을 동반한 안이척수이형성 증후군에서 시행한 난원창 개창술 1예

조양선,정유석,이종찬,추광철 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.12

轉移函數 雜音模型을 利用한 月流出量 豫測

趙廷錫,韓良洙,金喜洛 대구대학교 과학기술연구소 1999 科學技術硏究 Vol.5 No.5

This model was based on the theory of Box-Jenkins multiplicative ARIMA (SARIMA) and the Transfer function to simulate changes of monthly runoff. The forecasting of Runoff from the pair of observed value of effective rainfall and runoff (X_(t), Y_(t)) in the uniform interval will gives less standard error then the analysis only by Y_(t), so the object of this study is more rational forecasting by the use of (X_(t) , Y_(t)). I analyzed the records of monthly runoff and effective rainfall, and applied the multiplicative ARIMA model and Transfer function-noise model. so I made it possible to do the long-term forecasting and got following results.

Long-term Stability after Reduction of Mandible Fracture by Keyhole Plate: Evaluation at the Time of Plate Removal

Cheon, Kyeong-Jun,Cho, Seoung-Won,Jang, Won-Seok,Kim, Ju-Won,Yang, Byoung-Eun Korean Association of Maxillofacial Plastic and Re 2020 Maxillofacial Plastic Reconstructive Surgery Vol.42 No.-

Background: Various types of miniplates have been developed and used for the reduction of facial bone fractures. We introduced Yang's Keyhole (YK) plate, and reported on its short-term stability. The purpose of this study was to evaluate the long-term stability of the YK plate, as a follow-up study, by examining the patients who had used the YK plate among the patients with the reduction of mandible fractures and who visited for plate removal. Methods: We reviewed the medical records of 16 patients who underwent mandibular fracture fixation using a YK plate (group I) and 17 patients who underwent mandibular fracture fixation using a conventional plate (group II). Assessment was then made on malunion, occlusal stability, discomfort during the application, and clinical symptoms. Results: From January 2015 to December 2017, a total of 36 patients underwent mandibular fracture surgery using a YK plate. A total of 16 patients received plate removal. Among them, 15 were male and 1 female. The average age was 26 years. The applied surgical sites were the 12 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of YK plate was an average of 335 days. During the same period, 45 people underwent surgery on the conventional plate. A total of 17 patients received plate removal. Among them, 15 were male and 2 females. The average age was 36 years. The applied surgical sites were the 8 on mandibular angle, 4 on mandibular symphysis, and 2 on subcondyle. The application period of the conventional plate was an average of 349 days. No malocclusion occurred at the time of removal, and occlusion was stable. No patient complained of joint disease or discomfort. Conclusion: The YK plate system, in which the screw was first inserted and the plate was applied, for clinical convenience did not cause any particular problem and no significant difference from the conventional plate.

CD28Ig 및 CTLA4Ig 융합단백 생산 포유동물 세포주 수립에 관한 연구

유양석,정용훈,최용,임대철,조양자 한양대학교 의과대학 1998 한양의대 학술지 Vol.18 No.2

CTLA-4, which is homologous to CD28, recognizes the same coutner-receptors B7.1 and B7.2. Although initial researches implied that these molecules may act to each other synergistically, recent data suggest that CTLA-4 may acts as a negative regulator of T cell activation. In this study human CD28 and CTLA-4 cDNAs were amplified from PHA-stimulated human peripheral blood lymphocytes mRNAs by using RT-PCR method. IgG1 Fc portion cDNA was amplified from human peripheral blood lymphocytes of patients with febrile illness and fused to C"-terminal parts of CD28 and CTLA-4 extracellular domains. The fusion constructs were subcloned into pCI-neo vector and then transfected into Sp-2/0murine myeloma cell. Stable cell lines were established by geneticin selection and cloning. In the sequence of CTLA-4 cDNA from 3 different healthy persons it was found that 2 sites of bases were different from that published in original paper and submitted to genbank database. The 49th and 331st bases of open reading frame were changed from adenine to guanine and from guanine to adenine respectively. It was confirmed that the 17th and 111th amino acid of human CTLA-4 were alanine and threonine respectively, 5 different human CTLA-4 clones with serial N'-terminal deletion were constructed. CTLA4/L_1 was intact CTLA-4 gene of native form without any form of mutation. CTLA4/L_2 was a mutatn with deletion in gene coding N'-termial 6 amino acids. CTLA4/L_3 was a mutant with deletion in gene coding N'-termial 11 amino acids. CTLA4/L_4 was a mutant with deletion in gene coding N'-termial 16 amino acids. CTLA4/L_5 was a mutant with deletion in gene coding N'-termial 22 amino acids. Level of surface expression of CTLA4Ig on L_1, L_2, L_3, L_4 and L_5 transfectant cell lines were 5%, 3%, -1.5%, 8%, and 6% respectively. These 2 fusion proteins, CD28Ig and CTLA4Ig, would be useful tools for further researches on role of the costimulations in T cell activation.