內燃機關 燃燒室내의 壓力測定에 관한 硏究

鄭性植,李湘石,朴基龍 동아대학교 공과대학 부설 한국자원개발연구소 1990 硏究報告 Vol.14 No.1

In the present study, the influence of the measuring apparatus to the analysis of the combustion is clarified. T재 measuring system used are ; 8-bit system and 12-bit system (composed of 12-bit A/D converter and 16-bit AT grade computer). It was shown that the 12-bit system gave more accurate and more reliable data for the combustion analysis than the 8-bit system.

D. I. Diesel Engine에서 Cavity形狀이 出力性能과 排出微粒子에 미치는 영향

鄭性植,河鐘律,李湘石 동아대학교 공과대학 부설 한국자원개발연구소 1990 硏究報告 Vol.14 No.1

Dish, Toroidal and Reflex combustion chamber piston types of direct-injection Diesel engine were compared in order to investigate the effect of gas flow in cylinder associated with the combustion chamber geometry on combustion characteristics engine performance and exhaust gas emissions ; and as the results Relfex type has superior performance compares with Dish and Toroidal type.

Cyclophosphamide 투여 흰쥐에서 비타민 A가 창상파열력에 미치는 영향에 관한 실험적 연구

조해석,정상훈,임풍,김진철,안상태 大韓成形外科學會 1985 Archives of Plastic Surgery Vol.12 No.1

Cyclophosphamide lays restraints upon production of fibroblast and collagen fiber and reduce wound burst strength by acting on fibroblast in acute inflammatory phase. Vitamin A is known to increase inflammatory reaction by exerting an effect upon inflammatory cells in the beginning of the wound healing process. It shows contrary effect to cyclophosphamide. In order to study the influence of vitamin A over wound healing delay induced by cyclophosphamide in rats, we observed and compared the wound burst strength of cyclophosphamide and vitamin A combined treated group with those of control and cyclophosphamide treated group. Wound burst strength of each group was measured in the skin segments of 2×4cm obtained from the operation sites at the 3rd, 5th, 7th and 14th postoperative days after making 5cm incision and suture at the back of 72 rats. Results of the experiment are as follows; 1. Wound burst strength in control group increases slowly as days go by and shows trends of sudden increase between the 5th and 7th postoperative days. 2. Wound burst strength in cyclophosphamide treated group is markedly less than that in control group. 3. Wound burst strength in cyclophosphamide and vitamin a combined treated group shows similar level to that in control group. 4. Body weight in cyclophosphamide treated group reduces gradually as days go by. But there's no weight reduction in cyclophosphamide and vitamin A combined treated group. Judging from these results, we found the fact that vitamin A could prevent or recuperate the side effects of cyclophosphamide, delay of wound healing and worsening of general condition.

분산분석에 대한 통계소프트웨어 활용 : SAS, SPSS/PC+ 와 S-PLUS를 중심으로 SAS, SPSS/PC+ and S-PLUS

김성수,정성석 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

The Analysis of Variance(ANOVA) is a general tool for analysing desinged experiments. Among the many statistical softwares on ANOVA available in personal computers, we will review SAS(version 6.04), SPSS/PC+(version 4.0) and S-PLUS(version 2.0). SAS and SPSS/PC+are popular data analysis systems, and S-PLUS is an interactive graphical data analysis system. Statistical graphics give many informations aobut the main effects and the interaction effects in experimental data, and diagnostics about the model design. S-PLUS is very useful in these respects. Combining the analysis by SAS ans SPSS/PC+ with graphical displays of S-PLUS will give good interpretation of designed experiments.

Li₂O-B₂0₃-SiO₂계 유리의 유전특성

정순영,정석종,남상탁 慶尙大學校 1986 論文集 Vol.25 No.2

The one K-family of 5 glasses was fabricated to study the dielectric properties. Room temperature measurements of the real (εreal) and imaginary (εimag.) parts of the dielectric constant for the Li₂O-B₂0₃-SiO₂₃ glass system were obtained over a frequency range from 102 to 2×104Hz. The dielectric constants were increased with decreasing frequency and increasing molar fraction of Li₂O, which could be interpreted by a bistable model of Debye's theory.

방광이행상피세포암에서 p53유전자의 변화

김법완,권태균,노기석,정성광,장세국,정운복,김정완 경북대학교 병원 1997 경북대학교병원의학연구소논문집 Vol.1 No.1

The objective of this study was to characterise the pattern of p53 mutations in bladder turmor. In this study, 25 bladder transitional cell carcinomas were analyed by immunohistochemistry (IHC) for p53 nuclear overexpression, and the results were compared with those of polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis in exon 5-8 of the p53 gene and DNA sequencing analysis. 15 out of 20 cases (75%) showed p53 nuclear immunoreactivities on IHC. On PCR-SSCP analysis, 10 out of 25 cases(40%) had abnormal shifts on mobility. 62% of the mutations were in exon 8. Direct DNA sequencing analysis were performed in these 10 cases to confirm the presence of mutated p53 genes and to determine the type of mutations. Sixteen point mutations were detected in 10 cases. Tow specimens had double mutations and another two had triple mutations. G:C→A:T transitions were the most frequent patterns (62.5%). One mutation was a premature stop codon and two were silent mutations. There out of 10 had a point mutation at codon 285 (GAG/Glu→AAG/Lys) and two had at codon 280(GAG/Glu→AAG/Lys). One of 16 mutations was transition at hot spot codon 273 with CpG site. These results suggest that altered expressions and point mutations of p53 occured in all grade of bladder cancer, but are more associated with hight grade bladder tumors. To elucidate the carcinogenesis of bladder cancer, further studies should be carried out.

A Comparative Study on Transformation Methods In Kernel Density Estimation

Chung, Sung-Suck 全北大學校 1993 論文集 Vol.35 No.-

커널형 밀도함수의 추정에 관한 기존의 방법들은 전 구간에서 같은 띠폭을 가지기 때문에 첨도가 큰 자료에서는 잘 맞지 않는다. 이러한 단점을 보완하기 위하여 데이터의 변화를 이용하는 방법들이 제안되었다. 본 논문에서는 최근 제안된 Ruppert and Wand(1991)과 Ruppert and Cline(1991)의 방법을 이용하여 소표본 모의실험을 통하여 기존의 방법과 비교하였다. 모의실험 결과, Ruppert and Wand의 방법은 첨도가 큰 자료에, Ruppert and Cline의 방법은 bimodal 형태의 자료에 잘 적용되었다.

두개저 재건에 대한 임상적 경험

정복성,윤근철,고경석,정호균 大韓成形外科學會 1996 Archives of Plastic Surgery Vol.23 No.1

Skull base surgery has developed through the convergent evolution of imaging, anatomic research and reconstructive techniques. Indications for reconstruction have included obliteration of paranasal sinuses, coverage of tenuous dural repair or dural grafts and seperation of the nasopharynx from the dura of the frontal and temporal lobes and posterior fossa to prevent CSF leakage and meningitis. We experienced 11 cases of skull base reconstruction by a multidisciplinary team consisting of a neurosurgeon, ENT surgeon, radiologist and plastic surgeon after tumor resection or trauma. The resultant defects of the skull base have been reconstructed using three galeal flaps, two temporalis muscle flaps, one serratus anterior muscle free flap and five rectus abdominis muscle free flaps. There was no significant complication such as flap necrosis, CSf leakage or meningitis. We believe that the rectus abdominis muscle free flap is a good alternative for reconstruction of cranial base defects when local tissue flaps cannot be used because of previous craniotomy and high dose radiation therapy, or when the defect is extensive.

Wall-Following Control of a Two-Wheeled Mobile Robot

Chung, Tan-Lam,Bui, Trong-Hieu,Kim, Sang-Bong,Oh, Myung-Suck,Nguyen, Tan-Tien The Korean Society of Mechanical Engineers 2004 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.18 No.8

Wall-following control problem for a mobile robot is to move it along a wall at a constant speed and keep a specified distance to the wall. This paper proposes wall-following controllers based on Lyapunov function candidate for a two-wheeled mobile robot (MR) to follow an unknown wall. The mobile robot is considered in terms of kinematic model in Cartesian coordinate system. Two wall-following feedback controllers are designed: full state feedback controller and observer-based controller. To design the former controller, the errors of distance and orientation of the mobile robot to the wall are defined, and the feedback controller based on Lyapunov function candidate is designed to guarantee that the errors converge to zero asymptotically. The latter controller is designed based on Busawon's observer as only the distance error is measured. Additionally, the simulation and experimental results are included to illustrate the effectiveness of the proposed controllers.

Feasibility of the Mucosa-Tracking Technique in Precut Papillotomy with the Iso-Tome as an Alternative to the Needle-Knife Technique

( Sang Heum Park ),( Do Hyun Park ),( Tae Hoon Lee ),( Ho Sung Lee ),( Yong Sub Lee ),( Sae Hwan Lee ),( Chang Kyun Lee ),( Suck Ho Lee ),( Il Kwun Chung ),( Hong Soo Kim ),( Hyo Jin Lee ),( Sun Joo K 대한소화기기능성질환·운동학회 2010 Gut and Liver Vol.4 No.1

Background/Aims: The aim of this study was to evaluate whether the mucosa-tracking technique is effective for improving precutting-related pancreatitis and the sustained failure of bile duct cannulation in precut papillotomy (PP) with the Iso-Tome (MTW Endoskopie). Methods: From September 2004 to June 2006, PP was performed with the Iso-Tome if biliary cannulation failed by conventional methods for approximately 5 minutes. The pink intrapapillary mucosa (PIPM) exposed by PP was tracked and classified into four groups: fully exposed and oriented to the direction of the bile duct (group A) or the pancreatic duct (group B), partially exposed (group C), or unexposed (group D). The success rate of bile duct cannulation (SRBC), the procedure time required for successful bile duct cannulation (PTBC), and the complications in the first session were compared between the mucosa-exposed groups (MEGs; group A, B, and C) and the mucosa-unexposed group (MUEG; group D). Results: A total of 59 patients (25 females, 34 males) with a mean age of 65.2 years were enrolled. The MEGs and MUEG comprised 52 (88.1%) and 7 (11.9%) patients, respectively. SRBC in the first session was 86.4% (51/59) in total and 92.3% (48/52) in the MEGs, compared to only 42.9% (3/7) in the MUEG (p=0.005). The mean PTBC in the MEGs and MUEG was 8.7 minutes and 16.3 minutes, respectively (p=0.23). Complications occurred in 6.8% of the patients (4/59; all pancreatitis); there were no differences between the MEGs (5.8%, 3/52) and MUEG (14.3%, 1/7; p=0.41). All four patients with pancreatitis were managed medically. Conclusions: The mucosa-tracking technique in PP with the Iso-Tome is a feasible and useful method of enhancing SRBC. PIPM is an important endoscopic landmark for successful PP. (Gut Liver 2010;4:76-83)