쾌속조형재료의 강도예측모델 - Fused Deposition Modeling (FDM)

안성훈 ( Sung Hoon Ahn ),이선영 ( Sun Young Lee ),백창일 ( Chang Il Baek ),추원식 ( Won Shik Chu ) 한국복합재료학회 2002 Composites research Vol.15 No.6

Rapid Prototyping(RP) technologies provide the ability to fabricate initial prototypes from various model materials. Stratasys` Fused Deposition Modeling(FDM) is a typical 게 process that can fabricate prototypes out of plastic materials, and the parts made from FDM were often used as load-carrying elements. Because FDM deposits materials in about 300㎛ thin filament with designated orientation, parts made from FDM show anisotropic material properties. In this paper an analytic model was proposed to predict the tensile strength of FDM parts. Applying the Classical Lamination Theory, which was developed for laminated composite materials, a computer code was implemented. Tsai-Wu failure criterion was added to the code to predict the failure of the FDM parts. The tensile strengths predicted by the analytic model were compared with experimental data. The data and prediction agreed reasonably well to prove the validity of the model. In addition, a web-based advisory service(FDMAS) was developed to provide strength prediction and design rules for FDM parts.

간경변증환자에서 고농도 분지형 아미노산제제 투여후 혈중 아미노산과 간기능 검사상의 변화 - 일반 아미노산제제와 비교조사 -

안성훈 ( Sung Hoon Ahn ),박승국 ( Soong Kook Park ),박원대 ( Won Dae Park ),한승범 ( Seung Beum Han ),이수형 ( Soo Hyeong Lee ),허정욱 ( Jeug Wook Hur ) 대한소화기학회 1987 대한소화기학회지 Vol.19 No.1

N/A This study was done to compare the therapeutic effect of enriched branched chain amino acid (BCAA) infusion to regular amino acid infusion for the decompensated liver cirrhosis. Enriched BCAA solution (Pamisol) was given to 30 patients and regular amino acid solution (Salviamine) was given to 8 patints. The changes of plasma amino acid concentrations and liver profiles in before and 7 days after amino acid infusion daily 1,000 ml were compared. The results were as follow. 1) In the group of patients given enriched BCAA infusion, the plasma concentrations of valine, leucine, isoleucine (BCAA) increased (p<0.001), while the phenylalanine, tyrosine (aromatic amino acid: AAA) decreased (p<0.001). 2) In the group of patients given regular amino acid infusion, both BCAA and AAA concentrations increased (p+0.001). 3) In the group of patients given enriched BCAA infusion, total protein increased (p<=0.01), total bilirubin decreased (p<=0.01), prothrombin time shortened (p<0.05), and blood ammonia decreased (p< 0.01). 4) In the group of patients given regular amino acid infusion, only total protein increased (p < 0.01) but, bilirubin, prothromoin time and blood ammonia remained no significant changes. 5) The molar ratio of BCAA/AAA more improved in the enriched BCAA infusion than regular amino acid.

상부 위장관 이물에 대한 임상적 고찰 : 내시경적 진단과 적출

안성훈(Sung Hoon Ahn),허정욱(Jung Wook Hur),강영우(Young Woo Kang),이준호(Jun Ho Lee),박승국(Seoung Kook Park),박태원(Tae Won Park),강진무(Chin Moo Kang) 대한소화기학회 1993 대한소화기학회지 Vol.25 No.5

Today upper gastrointestinal (UGI) endoscopy is widely used in diagnosis and management of foreign bodies. A clinical study of 76 cases with the foreign bodies in the upper gastrointestinal tract diagnosed by flexible UGI endoscopy in Dangsan Hospital from January 1982 to December 1992 was performed. Foreign bodies were common in male (rate 1,6: 1) and in 6th decade (28 cases, 36.8%). Bezoar was the most common foreign body (57 cases, 75.0%) and foreign bodies were mostly lodged in stomach (50 cases, 65.8%). Endosopic removal or destruction was successful in 31 cases (35.4%) including all 19 cases other than bezoar. 52 cases (68.4%) hacl combined diseases, 17 cases (22.4%) had past history of operation and 9 cases (11.8%) had history nf ingestion of foreign bodies. In conclusion, UGI endoscopy and endoscopic removal is required to diagnose and manage foreign bodies in UGI tract

마이크로 가공을 위한 웹 기반 설계 가공 시스템

안성훈(Sung-Hoon Ahn),김형중(Hyung-Jung Kim) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.11

In this paper a web-based micro fabrication system is discussed. A commercial CAD and a web browser were used as its user interfaces. In these user interfaces the concepts of Design for Manufacturing (DFM) was implemented providing the fabrication knowledge of micro machining to the designers. Simple databases were constructed to store the fabrication knowledge of materials, tools, and micro machining know-how. The part geometry was uploaded to the web server of this system as an STL (Stereo Lithography) format with process parameters for 3-axis micro milling. A Slice-based process planner automatically provides NC codes for controlling micro stages. A couple of micro parts were fabricated using the system with micro endmills. This design and manufacturing system enables network users to obtain micro-scale prototypes in a rapid manner.

복강경검사로 진단된 복막암종증

안성훈(Sung Hoon Ahn),박승국(Soong Kook Park),강영우(Young Woo Kang),이상곤(Sang Gon Lee),박경아(Kyung Ah Park),허정욱(Jeong Wook Hur) 대한소화기학회 1993 대한소화기학회지 Vol.25 No.4

With developement of noninvasive diagnostic test such as computed tomography (CT), ultrasongraphy and image-guided biopsies, the role of peritoneoscopy for the diagnosis of peritoneal carcinomatosis has been questioned. Retrospective study including 42 patients who were diagnosed as carcinomatosis peritonei by peritoneoscopic biopsy from July, 1980 to July, 1992 at Dongsan Hospital was done. Sixth decade was the most common age and sex distribution was relatively equal. The most common chief complaint was abdorninal distension (57.1%) and the nature of ascitic fluid was exudate in all cases. Of the 19 cases who were examined ascitic cytology, 13 cases (68.5%) were aborre class 3. 18 case.; (72%) were diagnosed as carcinomatosis peritonei on abdominal CT, while 7 cases (28%) as benign among 25 cases. The latter percent was similar to the poercent of the cases with even sized multiple small miliary nodules or flat lesions on peritoneoscopy which could be missed on abclominal CT. In conclusion, peritoneoscopy is still the precedure of choice for diagnosing carcinomatosis peritonei with a negative finding an imaging diagnostic test.

지방간 진단을 위한 복부 초음파 촬영술의 유용성

안성훈(Sung Hoon Ahn),박승국(Soong Kook Park),허정욱(Jung Wook Hur),허규찬(Kyu Chan Huh),정우진(Woo Jin Chung),황재석(Jae Suck Hwang),우성구(Seong Gu Woo) 대한소화기학회 1998 대한소화기학회지 Vol.31 No.1

Background/Aims: For the diagnosis of fatty liver, physical examination, biochemical test, radiological study and histological examination are being used. Among the various diagnostics, liver biopsy is essential for the confirmative diagnosis. The authors studied the accuracy of ultrasonography in the diagnosis of fatty liver in comparison with a histologic diagnosis. Methods: We perfonned ultrasonography and liver biopsy in 19 patients with suspected fatty liver. The criteria for the diagnosis of fatty liver on ultrasonography is diffusely increased echogenicity of the liver and the criteria for diagnosis of fatty liver on liver biopsy is based on degree of fatty metamor- phosis. We compared a sonographic finding with the histologic grade of fatty liver. Also, we investigated liver function test and lipid profile. Results: The sensitivity of ultrasonography in diagnosis of fatty liver was 100 percent. The correlation of fatty liver in ultrasonography and histology was 73.6%. Therefore, the degree of fatty infiltration in ultrasonography was significantly correlated with degree of fatty accumulation of liver (p<0.05). Liver enzyme titer revealed an increase slighter than normal but cholesterol, triglyceride, and total lipid level were in the normal range. Conclusions: The degree of fatty infiltration in ultrasonography was significantly correlated with that in the liver biopsy and the sensitivity of ultrasonography in the diagnosis of fatty liver was high. Therefore we have concluded that abdominal ultrasonography with a liver biopsy is useful in the diagnosis of fatty liver and follow-up. (Korean J Gastroenterol 1998; 31: 64 - 72)

Synthesis of Organized TiO₂ Electrodes Using Graft Copolymer and Their Applications to Dye-Sensitized Solar Cells

안성훈(Ahn, Sung Hoon),고주환(Koh, Joo Hwan),박정태(Park, Jung Tae),김종학(Kim, Jong Hak) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

The morphology of mesoporous TiO₂ films plays an important role in the operation of a DSSC. For example, the energy conversion efficiency of DSSCs with well-organized mesoporous TiO₂ films is much higher than those with traditional films possessing a random morphology. In previous research, well-organized mesoporous TiO₂ films have mainly been synthesized using an amphiphilic block copolymer, e.g., a poly(ethylene oxide) (PEO)-based template. A graft copolymer is more attractive than a block copolymer due to its low cost and the ease with which it can be synthesized. In this work, we provide the first report on the successful synthesis of well-organized mesoporous TiO₂ films templated by an organized graft copolymer as a structure directing agent. Well-organized mesoporous TiO₂ films with excellent channel connectivities were developed via the sol gel processusing an organized PVC-g-POEM graft copolymer synthesized by one-pot ATRP. The careful adjustment of copolymer composition and solvent affinity using a THF/H₂O/HCl mixture was used to systematically vary the material structure. The influence of the material structure on solar cell performance was then investigated. A solid-state DSSC employing both the graft copolymer templated organized 700 nm-thick TiO₂ films and graft copolymer electrolytes exhibited a solar conversion efficiency of 2.2% at 100 mW/cm². This value was approximately two-fold higher than that attained from a DSSC employing a random mesoporous TiO₂ film. The solar cell performance was maximized at 4.6% when the film thickness was increased to 2.5{mu}m. We believe that this graft copolymer-directed approach introduces a new and simple route toward the synthesis of well-organized metal oxide films as an alternative to a conventional block copolymer-based template.

항공기 보수용 복합재의 호환성

안성훈(Sung-Hoon Ahn) 한국항공우주학회 2001 韓國航空宇宙學會誌 Vol.29 No.6

전투차량용 세라믹 복합장갑의 개발추세

안성훈(Sung-Hoon Ahn),정우균(Woo-Kyun Jung),김희재(Hee-Jae Kim) Korean Society for Precision Engineering 2005 한국정밀공학회지 Vol.22 No.7

전이성 거세 저항 전립선암에서 Docetaxel 전신 화학요법의 최적의 횟수

안성훈(Sung Hoon Ahn),박승철(Seung Chol Park) 대한비뇨기종양학회 2013 대한비뇨기종양학회지 Vol.11 No.2

Metastatic prostate cancer is initially treated with androgen deprivation therapy, which induces rapid decrease in bone pain and decrease in serum prostate specific antigen level. However, most of cases with prostate cancer eventually progress to castration-resistant prostate cancer within a median of 18-24 months. Docetaxel-based systemic chemotherapy is now the standard treatment for CRPC, based on the results of 2 phase III studies. However, the optimal cycles of docetaxel-based systemic chemotherapy for CRPC has not been defined. Herein, we present two cases of castration-resistant prostate cancer treated by docetaxel-based systemic chemotherapy and reviewed recent literatures.