[논문]Operational Characteristics of CO2 Laser Adopted by Superposing-Discharge

Hee-Je Kim,Hyun-Ju Chung,Byoung-Dae Min,Jong-Han Joung,Sung- lun Park 釜山大學校生産技術硏究所 2003 生産技術硏究所論文集 Vol.62 No.-

오늘날 현저한 CO2 레이저의 응용 추세에 발맞추어 보다 다양한 형태의 출력 제어 기술이 대두되고 있다. 본연구에서는multi-Pulse Superposing-Discharge 기술을 이용하여 다양한형태의 CO2 레이저의 펄스를 성형 하였다. 펄스 성형을 위한 방법으로 PIC one-chip microprocessor를 이용하여 삼중 PFN 모률의 SCR을 각각 고유의 지연시간을 가지도록 제어하였다. 실험에 사용된 삼중 PFN 모률의 전원 회로는 각각 캐패시터 인덕터,SCR,고압 펄스 트랜스 그리고 고압 트랜스 2차측에 브릿지 정류기로 구성 하였다. 고압 펼스 트랜스의 1차측을 제어하므로서 PFN 모률의 동작을 저 전압에서 수행 할 수 있다. 트랜스의 2차측에 연결된 전파 정류기는 펄스 에너지를 부하에 지속적으로 전달한다. 본 연구에서는 삼중 PFN 모률의 각각의 SCR을 다른 시간 가격을 두고 트리거 하므로서 다양한 Long pulse shaping을 실현하였다. 또한 약 250-1000μs 의 주기를 가지는 다양한 펄스형 레이저 빔을 얻었다.

기술금융기관의 효율성 분석사례

한상대(Sang-Dae Han),홍재범(Jae-Bum Hong) 한국인터넷전자상거래학회 2016 인터넷전자상거래연구 Vol.16 No.4

This case was to assess the efficiency of 26 technology appraisal centers(TAC) of Korea Technology Finance Corporation(KOTEC) and improve the efficiency. The research is based on the analysis of data collected from 2011 to 2013 with Data Envelopment Analysis(DEA). As the number of employees and business administrative expenses were used as input variables, leveraging the number of technology appraisal cases, the amount of technology credit guarantee provision and the amount of debt collection through exercising indemnity rights as well as revenues accruing from the technology appraisals were used as output variables. The purpose of those variables are aimed at representing the differentiated features of KOTEC from other conventional credit guarantee institutions. The analysis result showed that the efficiencies of TACs were high overall and improving in the way that their efficiency values show mostly over 0.9 on average. CCR model showed that the number of effective DMUs –represented as Technology Efficiency(TE) Value was 1 – was 7 in 2011 and 13 in 2013 while BCC model showed that the number of DMUs, whose values of Pure Technology Efficiency(PTE) was 1, was 15 in 2011 and 17 in 2013 respectively. The number of DMUs, whose value of Scale Efficiency(SE) is 1, had also been increased from 7 in 2011 to 13 in 2013. The number of DMUs was to show the status of “Constant Returns to Scale(CRS)” increased from 7 in 2011 to 13 in 2013. The number of DMUs was to show the status of “Increasing Returns to Scale(IRS)” was 16 in 2011 and 11 in 2013. The number on “Decreasing Returns to Scale(DRS)” had decreased from 3 in 2011 to 2 in 2013 respectively. Therefore, the number of efficient DMUs whose input was proportional to output –signaling the optimal efficient status- increased by 6. The number of DMUs which still had inefficiency and needed to step up the input had been decreased by 4 while the number of DMU which need to be scaled back the input is decreased by 1. Overall, efficiency of TACs has been increased. The result implies there are many DMUs which could increase the size efficiency, not through removing the inefficiencies by decreasing the input, but through scaling up the total size of output, leveraged by the consolidation of the internal analogous operation in order to make a synergy effect as well as the reduction of outsourcing tasks which have been related with claim collection process and hiring external technology appraisal experts. The benchmarked DMUs which could be the reference group were An-san, Sa-Sang and Sung-Nam TACs. They were located near to the industry complexes. So, their geographical conditions were well positioned to access to the technology-innovative corporations and venture startups, solidifying the fundamental to provide supply in accordance with the increasing demand of technology finance. The value of this study was that it analyses the efficiency of KOTEC takes the key role of technology financing based on technology appraisal. This research was distinctive in that it defined the input and output variables to measure the efficiency of credit guarantee institutions while earlier studies, most of which researched credit-evaluation based guarantee institutions, did not deal with those variables. It has implications which could be applied to evaluate the efficiency of public technology appraisal institution in the future.

High-ionic-strength pre-concentration via ion concentration polarization for blood-based biofluids

Han, Sung Il,Yoo, Yong Kyoung,Lee, Junwoo,Kim, Cheonjung,Lee, Kyungjae,Lee, Tae Hoon,Kim, Hyungsuk,Yoon, Dae Sung,Hwang, Kyo Seon,Kwak, Rhokyun,Lee, Jeong Hoon Elsevier 2018 Sensors and actuators. B Chemical Vol.268 No.-

<P><B>Abstract</B></P> <P>Ion concentration polarization (ICP) preconcentration is a pretreatment method that is actively utilized in the analysis of low-abundance biomolecules. In biofluids (e.g. urine, sweat, blood, serum, plasma, saliva, etc.), low-concentrated target analytes presented among large number of background molecules under a high ionic concentration, there still exist several hurdles in the utilization of ICP preconcentration in the such high ionic fluids. This is especially true in the case of blood-based biofluids, such as plasma and serum, wherein on account of the abundance biomolecules as well as high ionic buffer concentration makes the ICP preconcentration process difficult to realize. In this study, we have demonstrated the realization of ICP preconcentration of blood-based biofluids (serum) using a paper-based preconcentrator. We acquired preconcentration factors (PF) for 25.5, 127.5 and 255 mM of human serum were 40, 10, and 5.5 within 20 min. The squared fluorescence intensity is also found to be inversely proportional to ionic concentration, showing that the PF are strongly correlated to the Debye length of the buffer solution. Using the paper-based preconcentrator, we were able to acquire effective preconcentration factor (PF<SUB>eff</SUB>) of 5.17, 4.88, 4.58, and 4.23 for the 1X, 0.75X, 0.5X, and 0.1X diluted solutions, demonstrating approximately 5 times increase in PF<SUB>eff</SUB> for all prepared human serum samples.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ion concentration polarization (ICP) preconcentration platform of high-ionic-concentration sample is demonstrated for blood-based samples. </LI> <LI> The squared fluorescence intensity is inversely proportional to ionic concentration, showing that the PFs are correlated to the Debye length. </LI> <LI> We demonstrated approximately 5 times increase in effective preconcentration factor (PF<SUB>eff</SUB>) for all prepared human serum samples. </LI> </UL> </P>

Effect of hypertension on coronary flow reserve in controlled diabetes mellitus With normal coronary arteries

( Sung Il Choi ),( Jeong Hyun Kim ),( Jae Hee Yoon ),( Dae Hee Shin ),( Han Pay Cho ),( Sook Jin Lee ),( Sahng Lee ),( Jae Ung Lee ),( Sun Gil Kim ),( Kyung Soo Kim ),( Heon Kil Lim ),( Bang Hun Lee ) 대한내과학회 2001 대한내과학회 추계학술대회 Vol.61 No.-

The Flavonoid Jaceosidin from <i> Artemisia princeps</i> Induces Apoptotic Cell Death and Inhibits the Akt Pathway in Oral Cancer Cells

Han, Hye-Yeon,Kim, Hyung Joon,Jeong, Seung-Hwa,Kim, Jiyeon,Jeong, Sung-Hee,Kim, Gyoo Cheon,Hwang, Dae-Seok,Kim, Uk-Kyu,Ryu, Mi Heon Hindawi 2018 Evidence-based Complementary and Alternative Medic Vol.2018 No.-

<P>Jaceosidin is a single compound from the Japanese mugwort<I> Artemisia princeps</I>, which is used as a food and a traditional medicinal herb.<I> A. princeps</I> extracts and flavonoid components have been shown to have antihyperglycaemic, antioxidant, and anti-inflammatory properties. Although the anticancer properties of these extracts were recently demonstrated, the related mechanisms have not been characterised. In this study, we investigated the effects of jaceosidin in oral squamous cell carcinoma (OSCC) cells and initially showed selective suppression of proliferation (IC<SUB>50</SUB> = 82.1 <I>μ</I>M in HSC-3 cells and 97.5 <I>μ</I>M in Ca9.22 cells) and accumulation of cells at the sub-G1 stage of the cell cycle. In addition, jaceosidin increased cleavage of caspase-9 and caspase-3 in OSCC cells, although caspase-8 was not detected. In further experiments, jaceosidin downregulated Akt phosphorylation and ectopic activation of Akt blocked the antiproliferative effects of jaceosidin. Finally, we showed that jaceosidin has no effects on HaCaT normal epithelial cell viability, indicating selective chemotherapeutic potential of jaceosidin and that tumour-specific downregulation of Akt increases apoptosis and inhibits growth in OSCC cells.</P>

Fabrication of recyclable superhydrophobic cotton fabrics

Han, Sang Wook,Park, Eun Ji,Jeong, Myung-Geun,Kim, Il Hee,Seo, Hyun Ook,Kim, Ju Hwan,Kim, Kwang-Dae,Kim, Young Dok Elsevier 2017 APPLIED SURFACE SCIENCE - Vol.400 No.-

<P><B>Abstract</B></P> <P>Commercial cotton fabric was coated with SiO<SUB>2</SUB> nanoparticles wrapped with a polydimethylsiloxane (PDMS) layer, and the resulting material surface showed a water contact angle greater than 160°. The superhydrophobic fabric showed resistance to water-soluble contaminants and maintained its original superhydrophobic properties with almost no alteration even after many times of absorption-washing cycles of oil. Moreover, superhydrophobic fabric can be used as a filter to separate oil from water. We demonstrated a simple method of fabrication of superhydrophobic fabric with potential interest for use in a variety of applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly stable superhydrophobic fabric was fabricated using PDMS coated SiO<SUB>2</SUB> nanoparticles. </LI> <LI> The superhydrophobic fabric showed resistance to water-soluble contaminants. </LI> <LI> The prepared sample selectively absorbed oil while repelling water. </LI> <LI> It maintained its superhydrophobicity after many times of oil absorption-washing cycles. </LI> <LI> We showed that the fabric can be used as an effective filter for oil-water separation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Feasibility of dynamic stress 201Tl/rest 99mTc-tetrofosmin single photon emission computed tomography for quantification of myocardial perfusion reserve in patients with stable coronary artery disease

Han, Sangwon,Kim, Young-Hak,Ahn, Jung-Min,Kang, Soo-Jin,Oh, Jungsu S.,Shin, Eonwoo,Sung, Changhwan,Chae, Sun Young,Park, Seung-Jung,Grimberg, Gillan,Kovalski, Gil,Moon, Dae Hyuk Springer-Verlag 2018 European journal of nuclear medicine and molecular Vol.45 No.12

Korean Multicenter Registry Study of EPIC Stents for the Treatment of Iliac Artery Disease: K-EPIC Registry

Dae-Young Kim,Young-Guk Ko,Seung-Jun Lee,Chul-Min Ahn,Seung-Woon Rha,Cheol Ung Choi,Jong Kwan Park,Chang-Hwan Yoon,Seung-Hyuk Choi,Pil-Ki Min,Jang-Whan Bae,Jung-Kyu Han,Sang Ho Park,최동훈 대한심장학회 2021 Korean Circulation Journal Vol.51 No.5

Background and Objectives: The EPIC™ stent is a self-expanding, nitinol stent that has been designed to enhance flexibility and provide expansion within vessels. The aim of the present study was to investigate the clinical efficacy and safety of the EPIC™ stent when used to treat iliac artery diseases in a prospective Korean multicenter registry. Methods: A total of 138 patients with iliac artery diseases who received endovascular treatment with EPIC™ stents at 9 Korean sites were enrolled in a prospective cohort and followed for 1 year. The primary endpoint was the 1-year freedom from target lesion revascularization (TLR). The secondary endpoints were 1-year clinical patency and freedom from major adverse events (MAEs). Results: The mean age of the study subjects was 66.8±8.5 years and most subjects were male (86.2%). The most frequent lesion type was Trans-Atlantic Inter-Society Consensus B (43.5%) and the majority (56.5%) of the target lesions were located in the common iliac artery. Procedural success was obtained in 99.3% of patients. The freedom from TLR and the clinical patency at 1-year follow-up were 94.9% and 92.3%, respectively. The 1-year rate of MAEs was 5.1%. Combined coronary artery disease (hazard ratio [HR], 5.91; 95% confidence interval [CI], 1.13–30.89; p=0.035) and smaller stent diameter (HR, 0.38; 95% CI, 0.17–0.88; p=0.023) were identified as independent risk factors of TLR after EPIC™ stent implantation. Conclusions: The EPIC™ stents demonstrated excellent immediate and 1-year efficacy and safety outcomes in iliac artery lesions in this multicenter, prospective, registry-based study.

Serum interferon-γ and urinary monocyte chemoattractant peptide-1 are important factors in the pathogenesis of immunoglobulin A nephropathy

( Sang Youb Han ),( Kyung Hwan Jeong ),( Chun-gyoo Ihm ),( Young Sun Kang ),( Dae Ryong Cha ) 대한신장학회 2021 Kidney Research and Clinical Practice Vol.40 No.1

Background: Imbalance of T helper (Th) 1/2 cells has been shown to contribute to the development of immunoglobulin A nephropathy (IgAN). To address the inconsistent results on the role of Th1/Th2 polarization, we evaluated the levels of Th1/Th2 cytokines in various samples from patients with IgAN. Methods: Thirty-one patients with biopsy-proven IgAN (age, 34.48 ± 12.10 years) and 25 healthy controls (age, 44.84 ± 13.72 years) were enrolled. We evaluated the relationship between the levels of Th1/Th2 cytokines and the response to glucocorticoid treatment. Results: The levels of serum interferon-gamma (IFNγ) and urinary monocyte chemoattractant peptide (MCP)-1 were higher in the IgAN group than in the control group. The levels of MCP-1 in urine and secreted by peripheral blood mononuclear cells (PBMCs) were significantly different among three groups categorized based on daily proteinuria. The level of urinary MCP-1 was significantly correlated with proteinuria. The levels of urinary MCP-1, serum interleukin (IL)-4, IFNγ, and IL-2 secreted by PBMCs and intrarenal IL-1 messenger RNA (mRNA) were significantly correlated with the ratio of proteinuria at 6 months to baseline proteinuria in patients undergoing glucocorticoid treatment. MCP-1 mRNA and protein levels were significantly upregulated in mesangial cells stimulated with IFNγ among representative Th1/Th2 cytokines. Conclusion: IFNγ was shown to be a key cytokine in the pathogenic processes underlying IgAN, and its upregulation induced an increase in urinary MCP-1 production. These findings suggest that Th1 cytokines may play an important role in the development of IgAN.

Gastric Angiolipoma Resected with Endoscopic Submucosal Dissection

Sang Myung Yeo,Jae Kwang Lee,Hyun Soo Kim,Chang Geun Park,Jae Kwon Jung,Dae Jin Kim,Yun Jin Chung,Han Jun Ryu 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.3

Angiolipoma is a benign fatty neoplasm that has components of proliferating blood vessels. These types of lesions commonly occurin the subcutaneous tissue of the limbs and trunk. Angiolipoma in the gastrointestinal tract is extremely rare, and the final diagnosisgenerally depends on histological examination of the excised biopsy. In most previously reported cases, the lesions were diagnosedand treated with surgical management. In this study, we report a case of gastric angiolipoma of approximately 4 cm in size that wasdiagnosed and treated with endoscopic submucosal dissection.