보문 : Polyethylene Film포장이 포도 Sheridan의 저장력에 미치는 영향

남상영(Sang Young Nam),김경미(Kyoung Mi Kim),박종천(Jong Chun Park),주선종(Seon Jong Joo),정재현(Jai Hyun Jung) 한국식품저장유통학회(구 한국농산물저장유통학회) 1997 한국식품저장유통학회지 Vol.4 No.1

Vertical pattern of interconnects to bypass high strain near a hard die on a flexible substrate under mechanical bending

Jong-Sung Lee,Young-Joo Lee,Jaegeun Seol,Young-Chang Joo,Byoung-Joon Kim 대한금속·재료학회 2024 ELECTRONIC MATERIALS LETTERS Vol.20 No.2

The distinguishing feature of a fl exible electronic device is that it maintains its function even when the shape changes repeatedly. As the degree of integration of fl exible devices increases, revealing failure mechanisms and extending the lifetime ofthe fl exible devices are getting more diffi cult. One of the potential damage zones is the interface of heterogeneous materialcomponents, where strain can be localized due to the mismatch of mechanical properties. In this study, we investigate themechanically reliable interconnect design of the fl exible printed circuit board (FPCB) system in which the packaging chipis integrated. When the FPCB was bent, folding occurred at the edge of the packaging chip due to the high bending rigiditycompared with the plastic substrate and resulted in high strain concentration. By introducing interconnect architecture thatbypassed the strain concentration area around the packaging chip, mechanical damage of the interconnects was successfullyreduced. Through fi nite element simulation, the strain applied to the interconnect crossing the strain-concentrated regionwas predicted to be 2 times larger than that bypassing the strain-concentrated region, from 8.32 to 4.64%. In addition, thestrain gap of these two interconnects could be increased as the Young’s modulus mismatch between the packaging chip andthe substrate increased. This study is expected to improve the design guidelines to mechanically reliable interconnects inhighly integrated fl exible electronics.

한국리듬운동학회지 저자 네트워크 분석

박성건 ( Sung-geon Park ),박주영 ( Joo Young Park ) 한국리듬운동학회 2016 한국리듬운동학회지 Vol.9 No.1

This study aims to find out the network structure, influence and progress of the network, by analyzing the network of Korean Society for Rhythmic Exercise(KSRE) using the social network analysis structure. For this study, we collected the text data of the titles and authors(affiliations) of 65 papers in 2010-2015 published on the KSRE online journal web site. The data analysis and visualization were performed by social network analysis tool, Node XL, by Microsoft. Also, the influences of authors and their groups were investigated by applying the weight factors depending on the importance of authors, and the network size was analyzed by Eigenvector Centrality, Betweenness Centrality and Closeness Centrality. The results show that the influence under the application of the weight factors is bigger in the ‘Kim, Eunhye" and "Kangwon National University" than the other authors and their affiliations. In terms of the network size, "Choi, Young-jun" and "Dongnam Health College" was the biggest. "Seo, Han-kyo" and "Shinhan University" was doing the role of the midium connecting authors. In conclusion, since the research performance of KSRE is low compared to other academic societies, the efforts to expand the authors and their affiliations are required in the future.

금 박막의 기계적 물성에 끼치는 두께와 미세조직의 영향

전영선(Young-Sun Jeon),이상주(Sang-Joo Lee),현승민(Seung-Min Hyun),이학주(Hak-Joo Lee) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

We have used Visual Image Tracing(VIT) strain measurement system coupled with a micro tensile testing unit to test thickness and microstructure dependent mechanical behavior of Au film. The advantage using this method is to monitor the real time images of specimen during the test in order to determine its Young’s modulus, yield strength and tensile strength. 0.5, 1 and 2 ㎛ thick films were deposited by sputtering system. Free standing films were prepared through lithography and etching processes. Au films were annealed at 300℃ and 350℃ to achieve microstructure evolution and Focus ion beam (FIB SEM) and transmission electron microscopy (TEM) were employed to characterize grain sizes of films. Thickness and grain sizes dependent mechanical behavior such as stress-strain curve, Young’s modulus and yield strength of Au thin film will be presented.

Effect of Ultrasound on the Properties of Biodegradable Polymer Blends of Poly(lactic acid) with Poly(butylene adipate-co-terephthalate)

Lee, Sang-Mook,Lee, Young-Joo,Lee, Jae-Wook The Polymer Society of Korea 2007 Macromolecular Research Vol.15 No.1

This study investigated the effect of ultrasound irradiation on the blend of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT). The blends of PLA/PBAT(50/50) (PBAT50) were prepared in a melt mixer with an ultrasonic device attached. Thermal, rheological, and mechanical properties, morphology, and biodegradability of the sonicated blends were analysed. The viscosity of the sonicated blends was increased by the ultrasound irradiation owing to the strong interaction. The morphology of the sonicated blends was significantly dependent on the duration o the ultrasound irradiation. For PBAT50, the phase size reduction was maximized when the blends were ultrasonically irradiated for 30 sec. At longer duration of ultrasound irradiation, the PBAT phase underwent flocculation. Measurement of the tensile properties showed an increased breakage tensile stress and an enhanced Young's modulus when the blends were properly irradiated. This improvement was ascribed to better adhesion between the PLA matrix and the PBAT domain and to better dispersion of the PBAT phase. However, the tensile properties were maximized after excessive energy irradiation, which was ascribed to an emulsifying effect leading to coalescence of the PBAT phase. Impact strength was increased to reach a peak with the ultrasound irradiation, and was higher than the untreated sample for all sonicated samples due to the difference of failure mechanism between the tensile test and the impact test.

수종의 실란처리 유리섬유를 첨가한 의치상용 레진의 강도변화 및 마모전.후 표면성상분석

이상일,김창회,임영준,김명주,윤석대,Lee, Sang-Il,Kim, Chang-Whe,Lim, Young-Jun,Kim, Myung-Joo,Yun, Suk-Dae 대한치과보철학회 2007 대한치과보철학회지 Vol.45 No.4

Statements of problem: The fracture of acrylic resin dentures remains an unsolved problem. Therefore, many investigations have been performed and various approaches to strengthening acrylic resin, for example, the reinforcement of heat-cured acrylic resin using glass fibers, have been suggested over the years. Silane is important for bonding between glass fiber and resin. Purpose: The aim of the present study was to investigate the effect of various silane on the strength of PMMA resin and roughness of resin-glass fiber complex after abrasion test. Material and methods: 3mm glass fiber (Chopped strand, Hankuk fiber Co., Milyang, Korea) was treated with 3 kinds of silane (MPS, EPS, APS) (Sila-ace, Chisso chemical, Tokyo, Japan) and mixed with PMMA resin(Vertex RS, Vertex Dental B.V., Zeist, Netherlands). Transverse strength and Young's modulus was measured using Instron (Instron model 4466, Instron, Massachusetts, USA). After abrasion test (The 858 Mini Bionix II Test System, MTS System Co., Minnesota, USA) surface roughness was evaluated using tester (Form Talysurf plus, Taylor Hopson Ltd., Leicester England). Examination of scanning electron microscope was also performed. Results: Within this study, the following conclusions were drawn. 1. Surface treatment of glass fiber with MPS and APS increased transverse strength of PMMA resin complex, but surface treatment with EPS decreased transverse strength of PMMA resin complex (p<0.05). 2. Silane treated glass fiber increased Young's modulus of PMMA resin complex compared to desized glass fiber (p<0.05). 3. Roughness increased after abrasion test in case of PMMA resin reinforced with desized glass fiber (p<0.05). 4. Roughness change was not observed after abrasion test in case of PMMA resin reinforced with silane treated glass fiber (p>0.05).

Effect of gel spinning accompanied with cross-linking using boric acid on the structure and properties of high-molecular-weight poly(vinyl alcohol) fiber

Jo, Yong Gu,Shin, Eun Joo,Lee, Young Jae,Yoon, Won Sik,Han, Sung Soo,Lee, Yang Hun,Lee, Yong Rok,Noh, Seok Kyun,Gal, Yeong Soon,Lyoo, Won Seok Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of applied polymer science Vol.113 No.3

<P>To enhance the thermal stability of poly(vinyl alcohol) (PVA) fiber, the fiber was prepared from the gel spinning of high molecular weight (HMW) PVA by using dimethyl sulfoxide/water (8/2, v/v) as a solvent, accompanied with the cross-link by boric acid (B-PVA). In addition, the structure and properties of the B-PVA fiber were compared with those of the HMW PVA fiber obtained by using the same spinning system without cross-linking (NB-PVA). Through a series of experiments, it turned out that cross-linking actualized by an optimum amount of boric acid (0.3 wt % based on PVA) and zone drawing caused significant changes in the properties of HMW PVA gel fiber. That is, cross-linking increased thermal degradation temperatures at each degradation step and amounts of final residues, resulting in improving thermal properties of the PVA fiber. On the contrary, it was found that in the case of the B-PVA fiber, some broadening of the original PVA unit cell occurred, which was identified by the peak shift to lower angle in X-ray diffractogram. The tensile strength and Young's modulus of B-PVA fiber with draw ratio of 15 are 23.1 and 308.3 g/d, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009</P>

Real-World National Colonoscopy Volume in Korea: A Nationwide Population-Based Study over 12 Years

Jae Myung Cha,Min Seob Kwak,Hyun-Soo Kim,Su Young Kim,Sohee Park,Geun U Park,Jung Kuk Lee,Soo Jin Kim,Hun Hee Lee,Joo Sung Kim,Won Ho Kim,Big Data Research Group of the Korean Society of Gastroenterol 거트앤리버 소화기연관학회협의회 2020 Gut and Liver Vol.14 No.3

Background/Aims: Little is known about the national colonoscopy volume in Asian countries. This study aimed to assess the national colonoscopy volume in Korea over a 12-year period on the basis of a nationwide population-based database. Methods: We conducted a population-based study for colonoscopy claims (14,511,158 colonoscopies performed on 13,219,781 patients) on the basis of the Korean National Health Insurance Service database from 2002 to 2013. The 12-year national colonoscopy burden was analyzed according to patient age, patient sex, and healthcare facility type. Results: The overall volume of colonoscopy increased 8-fold over the 12-year period. The annual colonoscopic polypectomy rate significantly increased in all patient sex and age groups over the 12-years period (all p<0.001). The yearly colonoscopic polypectomy rate for men was significantly increased compared with that for women (2.3% vs 1.7%, p<0.001) and for the screening-age group compared with that for the young-age group (2.0% vs 1.6%, p<0.001). The yearly colonoscopic polypectomy rate relative to the total colonoscopy volume significantly increased in primary, secondary, and tertiary facilities by 2.4%, 1.9%, and 1.4% during the 12-year period (all p<0.001). In addition, the annual colonoscopy volume covered by high-volume facilities significantly increased by 1.8% in primary healthcare facilities over the 12-year period (p<0.001). Conclusions: Healthcare resources should be prioritized to allow adequate colonoscopic capacity, especially for men, individuals in the screening-age group, and at primary healthcare facilities. Cost-effective strategies to improve the quality of colonoscopy may focus on primary healthcare facilities and high-volume facilities in Korea.

Clinical and microbiological features of nontuberculous mycobacteria infection in young adult : experience at a tertiary hospital

( Eun Hye Lee ),( Ah Young Leem ),( Sang Hoon Lee ),( Joo Han Song ),( Song Yee Kim ),( Kyung Soo Chung ),( Ji Ye Jung ),( Moo Suk Park ),( Young Sam Kim ),( Joon Chang ),( Young Ae Kang ) 대한결핵 및 호흡기학회 2018 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.126 No.-

Background: The prevalence of nontuberculous mycobacteria lung disease (NTM-LD) is increasing worldwide. However, there is limited information about the NTM-LD of young age people. Methods: Patients diagnosed with NTM-LD at severance hospital between January 2006 and December 2016 were retrospectively reviewed. Clinical characteristics and microbiologic features of patients under 40 years were compared with patients over 40 years. Results: Total 906 patients were identified NTM-LD. Of these, 29 patients (3.2%) were under 40 years of age (young age group) and the remaining 877 were over 40 years of age (old age group). Mean age of the two groups were 32 (IQR 24-33) and 64 (IQR 56-72), respectively. Female was predominant in both groups and about half of the patients had a history of tuberculosis (51.7% vs.51.5%, p=0.984). 7 patients (24.1%) of the young age group had malignancy history and among them, 6 patients were hematologic cancer who subsequently received bone marrow transplantation. The proportion of the nodular bronchiectatic form of NTM-LD is significantly higher in old age group (67.5%) compared to young age group (31.0%) (p=<0.001). M.avium complex (MAC) was the most common etiologic organism in both groups, however, it was less common in the young age group (44.8% vs. 65.3%, p=0.023). Identification of M.abscessus complex (MABC) was higher in young age group although statistically insignificant (24.1% vs. 17.0%, p=0.318). Conclusion: This study could help to better understand the characteristics and microbial features of NTM-LD of young age people.

Comprehensive analysis of microRNA-mRNA co-expression in circadian rhythm

Young-Ji Na,Jung Hwan Sung,이석찬,Young-Ju Lee,Yeun Joo Choi,박웅양,Hee Sup Shin,김주한 생화학분자생물학회 2009 Experimental and molecular medicine Vol.41 No.9

To investigate the potential role of microRNA (miRNA) in the regulation of circadian rhythm, we performed microarray-based expression profiling study of both miRNA and mRNA in mouse liver for 48 h at 4-hour intervals. Circadian miRNA-mRNA target pair is defined as the pair both elements of which show circadian expression patterns and the sequence-based target relationship of which can be predicted. Circadian initiators, Clock and Bmal1, showed inversely correlated circadian expression patterns against their corresponding miRNAs, miR-181d and miR-191, targeting them. In contrast, circadian suppressors, Per, Cry, CKIe and Rev-erba, exhibited positively correlated circadian expression patterns to their corresponding miRNAs. Genomic location analysis revealed that intronic region showed higher abundance of cyclic than non-cyclic miRNAs targeting circadian genes while other (i.e., 3'-UTR, exon and intergenic) regions showed no difference. It is suggested that miRNAs are involved in the regulation of peripheral circadian rhythm in mouse liver by modulating Clock:Bmal1 complex. Identifying specific miRNAs and their targets that are critically involved in circadian rhythm will provide a better understanding of the regulation of circadian-clock system.