A Study on Vehicle-based Durability Evaluation for Weight-reduced Valve Parts of the Dual Clutch Transmission

김찬욱,김찬욱 한국트라이볼로지학회 2024 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.40 No.1

A monotype valve body for a dual clutch transmission has the potential to reduce costs, weight, and manufacturing time by modularizing various parts, including those of existing solenoid packs and valve bodies, into one through the application of super-precision die casting technology. However, this approach may lead to challenges such as reduced rigidity and increased interference due to modularization and compactness, impacting both product performance due to the reduced weight as well as durability and reliability. Unlike existing products, this approach requires a high-precision thin-wall block to avoid more complicated flow line formation, interference between flow lines, and leaks, as well as a strict quality requirement standard and precise inspections including detection of internal defects. To conduct precise inspections, we built an equivalent model corresponding to a driving distance of 300,000 km. Testing involved simulating actual road loads using a real vehicle and a chassis dynamometer in the FTP-75 mode (EPA Federal Test Procedure). The aim of the study was to establish a vehicle load-based part durability model for manufacturing a mono-type valve body and to develop fundamental technology for part weight reduction through preliminary design by introducing analytical weight reduction technology based on the derived results.

Clinicopathologic Characteristics, Surgical Treatment and Outcomes for Splenic Flexure Colon Cancer

김찬욱,신의섭,유창식,김진천 대한암학회 2010 Cancer Research and Treatment Vol.42 No.2

Purpose This current study examined the clinicopathologic characteristics of patients with splenic flexure (SF) colon cancer and the association with the surgical outcomes to find the optimal procedure to treat this malady. Materials and Methods A total of 167 operated patients with SF colon cancer were consecutively recruited between 1993 and 2003. The clinicopathological, operative and survival data was reviewed and analyzed. Results For the SF colon cancer patients, the proportion of males was higher than that for the rightsided colon patients or the sigmoid-descending junction & sigmoid (SD & S) colon patients (p≤0.05, respectively) and the age at the time of diagnosis was younger (p≤0.05). Obstruction was more frequent in the patients with SF colon cancer than that for the patients with colon cancer at other sites (p≤0.001). The incidence of mucinous adenocarcinoma for the SF patients was similar to that for the patients with right-sided colon cancer, but it was higher than that for the patients with SD & S colon cancer (11.4% vs. 6.5%, p=0.248 or 2.5%, respectively, p=0.001). Disease-free and overall survival did not differ between the patients who underwent a left hemicolectomy and extended surgery such as combined splenectomy or subtotal colectomy. Multivariate analysis showed that old age (≥60 years) and a N1-2 and M1 status were the independent risk factors for overall survival. Conclusion The SF colon cancers exhibited exclusively different characteristics as compared to colon cancers at other site colon cancers. It appears that left hemicolectomy was generally sufficient for a satisfactory oncological outcome, obviating concurrent splenectomy.

저급 망간광석의 광물학적 특성에 관한 연구

김찬욱,석한길,홍성진 한국자원공학회 2012 한국자원공학회지 Vol.49 No.3

To investigate the possibility of upgrading low-grade manganese ores, the mineralogical characteristics of two kinds of low-grade manganese ores was studied by analyzing the fracture behavior, mineral texture and thermal decomposition. The crushing behavior of low-grade manganese ores based on a study on the fragmentation kinetics of them was examined. The efficiency of grinding was checked up. It was identified that the minerals of the low-grade manganese ores were MnO2, MnSiO3, SiO2 and CaCO3. The mineral liberation effect by grinding was observed in the ground manganese ores. And it was observed that the results showed that Mn3O4 phase was obtained without reducing agents. The ground manganese ores were divided into various particle size group. The composition analysis showed that the most Mn-poored and gangue-riched particles were below 100 μm-sized. Therefore, it might be concluded that upgrading low-grade manganese ores is possible, if they are removed. 본 연구에서는 경제적 가치가 낮은 저급 망간광석 A 및 B를 대상으로 광석의 파쇄거동 분석, 조직학적 분석 및 열분해 곡선 분석을 통해 광석의 광물학적 특성에 대해서 알아보았으며, 분급선별공정으로써 목적원소인 Mn의 함량을 증가시킬 수 있는 가능성을 제시하고자 한다. 먼저 저급 망간광석의 파쇄거동 특성을 광석의 파쇄 속도론적 고찰로 접근하였으며, 이를 토대로 분쇄과정에서의 효율성에 대해 알아보았다. 망간광석을 구성하고 있는 각각의 성분들은 Mn의 경우 MnO2와 망간실리케이트로 존재하며, 맥석의 경우 복합 산화물형태로 광석 내에 존재함을 알 수 있었다. 또한 미분쇄된 망간광석은 각각의 성분이 독립된 입자로 분화되어 분쇄에 의한 Mineral Liberation효과가 나타남을 확인하였다. 이러한 망간광석은 열분해 되어 별도의 환원제를 사용하지 않아도 Mn3O4상태의 망간산화물을 얻을 수 있는 것을 확인 할 수 있었다. 미분쇄된 광석을 입단별로 분급한 후 조성을 분석한 결과, 맥석이 집중되는 -100 μm 이하의 입단을 선별 제거함으로써 목적원소인 Mn을 농축시킬 수 있는 가능성을 가늠할 수 있었다.

Prognostic Implications of Extranodal Extension in Relation to Colorectal Cancer Location

김찬욱,김지훈,박양순,조동형,이종률,윤용식,박인자,임석병,유창식,김진천 대한암학회 2019 Cancer Research and Treatment Vol.51 No.3

Purpose Extranodal extension (ENE) is closely associated with the aggressiveness of both colon and rectal cancer. This study evaluated the clinicopathologic significance and prognostic impact of ENE in separate populations of patients with colon and rectal cancers. Materials and Methods The medical records of 2,346 patients with colorectal cancer (CRC) who underwent curative surgery at our institution between January 2003 and December 2011 were clinically and histologically reviewed. Results ENE was associated with younger age, advanced tumor stage, lymphovascular invasion (LVI), and perineural invasion (PNI) in both colon and rectal cancer. ENE rates differed significantly in patients with right colon (36.9%), left colon (42.6%), and rectal (48.7%) cancers (right vs. left, p=0.037; left vs. rectum, p=0.009). The 5-year disease-free survival (DFS) rate according to ENE status and primary tumor site differed significantly in patients with ENE-negative colon cancer (80.5%), ENE-negative rectal cancer (77.4%), ENE-positive colon cancer (68.6%), and ENE-positive rectal cancer (64.2%) (p < 0.001). Multivariate analysis showed that advanced tumor stage, ENE, LVI, PNI, and absence of adjuvant chemotherapy were independently prognostic of reduced DFS in colon and rectal cancer patients. Conclusion ENE is closely associated with the aggressiveness of colon and rectal cancers, with its frequency increasing from the right colon to the left colon to the rectum. ENE status is a significant independent predictor of DFS in CRC patients irrespective of tumor location. ENE might be more related with distally located CRC.

연구발표논문초록 - 특별강연 ( 기술과장 · 공정과장협의회 ) : 엘리트기술사원의 경영직 진출

김찬욱 한국화학공학회 1988 춘계학술발표회 Vol.- No.-

3차원 자기장해석을 이용한 자기차폐 연구

김찬욱,이동창,Kim, Chan-Uk,Lee, Dong-Chang 한국재료학회 1999 한국재료학회지 Vol.9 No.3

대전력을 사용하는 제강공장의 L/F설비에서 발생되는 강자계를 효율적으로 차폐하기 위하여 L/F주위의 자기장 분포를 유한해석법을 이용한 사용해석도구인 ANSYS 5.3 3차원 자기장해석기를 통해 해석하고 그 결과를 평판형태의 차폐체에 적용시키고자 하였다. 분석결과, L1 및 L2가 각각 2.7 및 2.9m 이려 높이가 3.5m인 2중차폐체(1차측 차폐: 1mmt의 전기강판, 2차측차폐: 1mmt의 Fe-Ni alloy sheet)를 설치하는 거싱 최적의 처폐방안으로 도출되었다.

X선회절에 의한 Pt/Co 인공격자 다층막의 구조평가

김찬욱,조남웅 한국결정성장학회 1997 한국결정성장학회지 Vol.7 No.2

2원동시 RF magnetron 방법을 이용하여 조건별(sputtering gas압력, buffer충 유무 및 etching여부 등)로 제작된 Pt/co 인공격자 다층막 ([$Pt10.7\AA/Co2.8{\AA}{\times}{12}$])의 구조정보에 대하여 알아보았다. 다층막 구조평가는 X선 회절측정을 이용하여 행하였으며 구조에 대한 정보를 보다 면밀하게 평가하기 위해서 다층막 모델을 제작하여 얻어진 결과를 실험결과와 비교분석 하였다. 제작된 다층막 구조모델의 계산결과를 실측치와 비교하면 peak의 위치나 회절강도가 상당히 일치하였으며 이것은 구조모델이 실제의 Pt/Co 인공격자 다층막구조를 잘 반영하고 있음을 알 수 있었다. X-ray diffraction patterns of Pt/Co modulated films prepared by RF comagnetron sputtering method was investigated. Modulated films ([$Pt10.7\AA/Co2.8{\AA}{\times}{12}$]) were deposited on glass substrate with various sputtering conditions : sputtering with variations of gas pressures, sputtering with Xe instead Ar gas, and etching of the buffer layers. In order to obtain the structural information of Pt/Co modulated films, the structural model was constructed and calculated data of the model were compared with experimental ones. Comparison results showed that there were good agreements in satellite peak position and its intensity between them. This suggests that the realistic Pt/Co modulated film can be reproduced by our structure model.

식용곤충 갈색거저리의 장기저장 및 생육 조절 연구

김찬욱,지상민,장규동,김소윤,송정훈 한국환경과학회 2024 한국환경과학회지 Vol.33 No.1

We introduce a method for preserving yellow mealworm (Tenebrio molitor Linnaeus) larvae for an extended period and show that a high percentage of larvae can survive in good health under low-temperature storage conditions combined with specific diapause termination conditions. Our study revealed that we can regulate important development stages such as pupation, emergence, and larval duration by adjusting these termination conditions. When storing larvae aged 6–8 weeks for 140 days, the storage temperature can be varied based on our goals, giving us control over yellow mealworm production to meet specific demands. To produce adult beetles, storing larvae at 15 ℃ with wheat bran and ending diapause at 30 ℃ resulted in 90% pupation rate, with 60% becoming adults in 21 days. If our aim is larvae production, storing them at 10–12 ℃ with wheat bran and ending diapause at 25–30 ℃ allows the larvae to reach a suitable weight for processing. This straightforward approach ensures long-term storage of yellow mealworm larvae and provides a practical way to control their development, allowing efficient mass production tailored to market demands.

좌각차단을 동반한 심부전증 환자에 실시한 양심실 심박조율기 치료 -증례 보고-

김찬욱,차태준,김성만,김민대,권성일,서수홍,최병주,주승재,이재우 고신대학교(의대) 고신대학교 의과대학 학술지 2002 고신대학교 의과대학 학술지 Vol.17 No.1

Epidemiological studies suggest that 30-50% of patients diagnosed with symptomatic congestive heart failure (CHF) have electrocardiographic evidence of a major intraventricular conduction delay, which may worsen left ventricular systolic and diastolic dysfunction through asynchronous ventricular contraction and paradoxical interventricular septal wall motion. Biventricular pacing is an emerging therapy allowing simultaneous electrical stimulation of the both ventricles with an implantable pacing system and it improves hemodynamics and well-being of patient by reducing ventricular asynchrony. Recently, we underwent biventricular DDD pacemaker implantation in a patient with CHF and Left bundle branch block and was significantly improved exercise tolerance and quality of life in that patient.

유한요소법을 이용한 Arc로의 자기장분포 해석연구

김찬욱,임종인,Kim, Chan-Uk,Im, Jong-In 한국재료학회 2001 한국재료학회지 Vol.11 No.12

Finite element analysis showed that strong magnetic fields were distributed around the arc furnace where the strongest magnetic field was generated around the three phase cables, and followed by the electrodes and the mast arm in decreasing order. Magnetic field decay patterns around the arc furnace could be fitted by introducing exponential formula,$Y=Y_0+Ae^{\frac-{x}{t}}$. These results showed that magnetic field intensities around the arc furnace could be estimated at any 3-dimensional positions using the finite element method (FEM).