• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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• pp.73-73
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• 2000

Shear strength of BGA solder joints on Cu pad was studied for Cu-contained Sn n.5 a and 2.5wt.% Cu) and Sn-Pb (o.5wt.% Cu) solders, with emphasis on the roles of the C Cu-Sn intermetallic layer thickness and the roughness of the interface between the i intermetallic layer and solder. The shear strength test was performed both for a as-soldered s이der joints with soldering reaction times of 1, 2, 4 min and for aged s이der j joints at 170 C up to 16 days. The Cu addition to both pure Sn and eutectic Sn-Pb s solders increased the intermetallic layer thickness at both soldering and aging t temperatures. The Cu addition also resulted in changes in the roughness of the interface b between the intermetallic layer and solder at as-soldered states. With increasing Cu c content. the interface roughened for Sn-Cu solders whereas it flattened for Sn-Pb-Cu s solders. The shear fractures in all solder joints investigated were confined in the bulk s solder rather than through the intermetallic layer. Therefore, the effect of Cu content in s solders on the shear strength of the solder joints was primarily attributed to its i influence on the micros$\sigma$ucture of bulk solder, such as the size and spatial distributions of CU6Sn5 precipitates. In addition, the critical intermetallic layer thickness for a m maximum shear strength seemed to depend on the Cu content in bulk solder.older.

• 인터넷정보학회논문지
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• 제14권3호
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• pp.1-13
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• 2013

최근 등장한 다양한 플랫폼 기반의 스마트폰과 iPad와 같은 미디어 디바이스의 등장은 전세계 소비자의 관심을 불러일으켰다. 이러한 관심은 종이책의 디지털화를 가져오게 되었고 국내외 전자출판물 산업의 가파른 성장을 가져왔다. 하지만 다양한 디바이스와 콘텐츠들이 생겨나면서 호환성 문제가 대두되었고 전자출판물과 관련한 콘텐츠의 교환 및 공유를 위한 표준화의 필요성과 수요를 만들어 냈다. 본 연구는 전자출판물 표준화와 관계된 산 학 연 관 이해관계자 16명의 의견 수렴을 통해 향후 전자출판분야의 콘텐츠 및 유통, 디바이스, 표준화, 기술적 보호조치, 저해요인 등에 대한 미래에 예측되는 변화들을 살펴보고 이를 기반으로 추후 표준 개발을 위한 영역 및 요소를 도출해보고자 한다.

• Ocean and Polar Research
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• 제38권2호
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• pp.129-137
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• 2016

This study aimed to isolate and characterize sulfated polysaccharides (SPs) from Iridaea cordata and evaluate their anticancer activity. SPs of the Antarctic red seaweed were obtained by $CaCl_2$ (SP1) and ethanol precipitations (SP2) following diluted acid extraction at room temperature. Yields of SP1 and SP2 were approximately 14% and 23%, respectively, of the dry weight of red seaweed. The average molecular mass of the SP1 and SP2 was estimated about $1.84{\times}10^3$ and $1.42{\times}10^3kDa$, respectively, by size-fractionation High-Performance Liquid Chromatography (HPLC). From the High-Performance Anion-Exchange Chromatography-Pulsed Amperometric Detection (HPAEC-PAD) analysis, the main monosaccharide was galactose with glucose and fucose as minor components. The sulfate content of SP2 (40.4%) was slightly higher than that of SP1 (33.8%). The FT-IR spectra also showed characteristic band of carrageenan-like sulfated polysaccharides. Taken together the SPs are thought to be carrageenan-like sulfated galactan. The polysaccharides (SPs) from I. cordata exhibited weak antitumor activity against PC-3 (prostate cancer), HeLa (cervical cancer), and HT-29 (human colon adenocarcinoma). To our knowledge, this is the first data on biological activity of the Antarctic red seaweed I. cordata.

• International Journal of Knowledge Content Development & Technology
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• 제7권3호
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• pp.67-86
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• 2017

The emergence of smart devices such as smartphones (e.g., iPhone) and tablets (e.g., iPad) may enhance e-learning by increasing communication and collaborative learning outside the classroom. These devices also facilitate the use of online technologies such as Facebook. However, the adaptation of Learning Management System (LMS) services to mobile devices took longer than social networks or online tools such as Facebook and Twitter have already been long used via smartphone. The main purposes of this study are to explore students' skill levels of LMS (Moodle) and their knowledge of online tools or technologies and then examine if there is a correlation between smartphone use and using of online tools and Moodle in learning. The study conducted among 173 students in the Department of Information Studies (DIS) in Oman, using online survey. The study found that most students demonstrated high levels of accessing course/subject materials and regularly engaging with studies of using LMSs. YouTube, Wikipedia and Facebook were clearly recorded as the most popular sites among students while LinkedIn and Academia.edu were two online tools that had never been heard of by over half of the 142 participants. Emailing and searching are recorded the most popular online learning activities among students. The study concluded that students prefer to use smartphone for accessing these tools rather than using it to access LMSs, while a positive correlation was found between the use of these tools and smartphones, but there was no correlation between smartphones and using LMSs.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.316-322
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• 2014

본 연구는 TRPV1 채널의 활성화가 염증성 통증반응 조절에 관여하는지에 관해 조사하였다. 수컷의 Sprague-Dawley계 흰 쥐 (220-260g)을 사용하였으며, 통증행위반응은 약물 주입 후 총 45분간 안면부를 긁거나 문지르는 행위를 지표로 간주하였다. 5% formalin($25{\mu}L$)을 단독투여 한 그룹에서는 유의한 통증행위반응을 관찰할 수 있었으나, capsaicin($0.1{\mu}g$, $1{\mu}g/10{\mu}L$)의 단독 투여한 그룹에서는 통증행위반응의 변화가 나타나지 않았다. 실험동물의 안면부에 TRPV1 채널의 효현제인 capsaicin 을 1시간 전에 주입한 후 동일 부위로 5% formalin 을 투여하게 되면 유의하게 증가된 통증행위반응을 관찰할 수 있었다. 증가된 통증행위반응은 TRPV1의 억제제인 I-RTX의 전처리에 의해 효과적으로 경감되었다(p<0.05). 이상의 결과들은 5% formalin으로 유발된 안면부 염증성 통증행위반응에 TRPV1의 활성화가 통증전도에 영향을 미칠 수 있음을 제시한다.

• 동의생리병리학회지
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• 제18권2호
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• pp.419-426
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• 2004

This experimental study was designed to investigate the effects of Yukgunja-tang(YGJT) on the inhibition of cerebral ischemia in rats. And We measured regional cerebral blood f1ow(rCBF) and pial arterial diameter(PAD) in cerebral ischemic rats, and cytokines production in serum Of cerebral ischemic rats. The results were as follows; Both rCBF and PAD were significantly and stably increased by YGJT(10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. In cytokine production of serum by drawing from femoral arterial blood after middle cerebral arterial occlusion(MCAO) 1 hr, IL-1β and TGF-β production of sample group were similar to that of control group, but sample group was decreased TNF-α production compared with control group, and was significantly increased IL-10 production in compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 1 hr, sample group was significantly decreased IL-1β and TNF-α production compared with control group, but TGF-β production of sample group was similar to that of control group, and sample group was significantly increased IL-10 production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 4 hrs, sample group was significantly decreased IL-1β production compared with control group, and sample group was decreased TNF-α production in compared with control group, but TGF-β production of sample group was similar to that of control group, and sample group was increased IL-10 production compared with control group. This results were suggested that YGJT has inhibitive effect on the brain damage by inhibited IL-1β production and TNF-α production, but accelerated IL-10 production. We thought that YGJT should have an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

• International Journal of Oral Biology
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• 제34권1호
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• pp.1-6
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• 2009

The purpose of the present study was to examine the role of peripheral nitric oxide (NO) pathways in the onset of interleukin (IL)-1$\beta$-induced mechanical allodynia in the orofacial area. Experiments were carried out on male Sprague-Dawley rats weighing 230-280 gm and surgical procedures were performed under pentobarbital sodium (40 mg/kg, i.p.). Under anesthesia, a polyethylene tube (PE10) was implanted into the subcutaneous area of one vibrissa pad, which enabled the injection of IL-1$\beta$ or other chemicals. We subcutaneously injected 50 ${\mu}L$ of IL-1$\beta$ into a vibrissa pad through the implanted polyethylene tube with a 100 ${\mu}L$ Hamilton syringe. After the administration of 0.01, 0.1, 1, or 10 pg of IL-1$\beta$, withdrawal behavioral responses were examined. The subcutaneous injection of saline had no effects on the air-puff thresholds. Following the subcutaneous injection of 0.01, 0.1, 1, or 10 pg of IL-1$\beta$, the threshold of air puffs decreased significantly to 12 $\pm$ 3, 7 $\pm$ 2, 5 $\pm$ 1, or 5 $\pm$ 1 psi, respectively, in a dose dependent manner. Pretreatment with L-NAME, a nitric oxide synthase (NOS) inhibitor, blocked IL-1$\beta$-induced mechanical allodynia. However, neither D-NAME, an inactive isomer of L-NAME, nor vehicle affected the IL-1$\beta$-induced mechanical allodynia. Subcutaneous injection of IL-1$\beta$ increased the number of c-fos-like immunoreactive neurons, whereas pretreatment with L-NAME decreased this number, in the trigeminal caudal nucleus. These results suggest that pro-inflammatory cytokines and NO are important contributors to the pathogenesis of persistent and exaggerated IL-1$\beta$-induced pain states. Based on these observations, peripheral application of NOS inhibitors may be of therapeutic value in treating pain disorders in the clinic.

• 마이크로전자및패키징학회지
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• 제30권3호
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• pp.40-50
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• 2023

최근 스마트폰의 부품 수는 급격히 증가하고 있는 반면, PCB 기판의 크기는 지속적으로 감소하고 있다. 따라서 부품의 실장밀도를 개선하기 위해 PCB를 쌓아서 올리는 stacked PCB 구조의 3D 실장 기술이 개발되어 적용되고 있다. Stacked PCB에서 PCB 간 솔더 접합 품질을 확보하는 것이 매우 중요하다. 본 연구에서는 stacked PCB의 신뢰성을 향상시키기 위하여, 인터포저(interposer) PCB 및 sub PCB의 프리프레그의 물성, PCB 두께, 층수에 대한 휨의 영향을 실험과 수치해석을 통해 분석하였다. 또한 솔더 접합부의 응력을 최소화하기 위해 인터포저 패드 설계 구조에 따른 접합강도를 분석하였다. 인터포저 PCB의 휨은 프리프레그의 열팽창계수가 적을수록 감소하였으며, 유리전이온도(Tg)가 높을수록 감소하였다. 그러나 온도가 240℃ 이상이면 휨의 개선 효과는 크지 비교적 크지 않다. 또한 FR-4 프리프레그에 비하여 FR-5을 적용할 경우에 휨은 더 감소하였으며, 프리프레그의 층수와 두께가 높을수록 휨은 감소하였다. 한편 sub PCB의 경우, 휨은 프리프레그의 Tg 보다 열팽창계수가 더 중요한 변수임을 확인하였고, 두께를 증가시키는 것이 휨 감소에 효과적이었다. 솔더 접합력을 향상시키기 위하여 다양한 인터포저 패드 디자인을 적용하여 전단력 시험을 수행한 결과, 더미 패드를 추가하면 접합강도가 증가하였다. 또한 텀블 시험 결과, 더미 패드가 없을 때의 크랙 발생율은 26.8%이며, 더미 패드가 있으면 크랙 발생율은 0.6%로 크게 감소하였다. 본 연구의 결과는 stacked PCB의 설계 가이드라인 제시를 위한 유용한 결과로 판단된다.

• Journal of Acupuncture Research
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• 제24권2호
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• pp.141-153
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• 2007

Objectives: The purpose of this report is to examine the effect of $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and LIl ${\cdot}$ $GB_{44}$ draining in acupuncture for cerebral apoplexy treatment. Methods : I designed to investigate whether $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture affects cerebral hemodynamics [regional cerebral blood flow(rCBF), mean arterial blood pressure(MABP)] in normal rats, and to make manifest whether $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture is mediated by cyclooxygenase or guanylate cyclase. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF). Results : 1. $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and LI1 ${\cdot}$ $GB_{44}$ draining in acupuncture increased rCBF significantly, but decreased MABP. These results suggest that $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture increased significantly rCBF by dilating pial arterial diameter(PAD). 2. By pretreatment with indomethacin(1 mg/kg, i.p.), the effect of $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture induced increase of rCBF was significantly inhibited, the decreased MABP by treatment with $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture was increased. 3. By pretreatment with methylene blue($10{\mu}/kg$, i.p.), the increased rCBF by treatment with $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture was decreased conversely, the decreased MABP by treatment with $BL_{66}$ ${\cdot}$ $GB_{43}$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture was decreased. and then increased. Conclusion : I suggest that $BL_{66}$ ${\cdot}$ $GB_43$ supplement and $LI_1$ ${\cdot}$ $GB_{44}$ draining in acupuncture has an anti-ischemic effect through the improvement of cerebral hemodynamics.

• 디자인학연구
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• 제18권4호
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• pp.129-138
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• 2005

1990년대 초까지 자동차 제조사는 인테리어 디자인을 중요하게 생각하지 않았다. 주로 설계, 구동방식, 크기 등 기술적 구조를 체계화하기 위한 시도를 중점으로 발전을 거듭하였고 단순히 의장디자인과 비교하면서 인테리어를 개발하였다. 그러나 1990년대에 이러한 상황은 바뀌기 시작하는데 이유는 소비자가 차안에서 보내는 시간이 많아지면서 고객에게 편안함을 주고 기능적으로도 만족할 수 있는 기술을 개발하려는 의지를 보이기 시작했기 때문이다. 인간이 자동차 안에서 어떻게 하루를 보내며 사용하는지 관찰하고, 그 결과 인테리어를 새롭게 하는 트렌드가 무엇인지를 고려하는 즉, 전략적으로 브랜드 아이덴티티를 갖도록 인테리어의 개성을 강화하고 소비자의 감성적인 부분을 고려하는 사용자 중심의 가치관 전환을 가져온 중요 요인이 되었다. 오늘날 자동차 인테리어 디자인 은 다양한 요소 변화를 반영하는 컨셉트카를 매 해 선보이고 있는데, 향후에는 감지기능과 네비게이션 적용의 무인주행을 실현시킬 수 있는 첨단 기술을 반영한 디자인 적용이 미래 디자인의 핵심적 트렌드로 제기되고 있다. 또한 제품디자인, 패션, 가구 등 타 분야에서의 직접적인 영향으로 인테리어 디자인인의 다각적 컨셉트 적용을 시도하고 있는 현 시점에서 객관적인 관점으로 시대적 배경에 따라 자동차 인테리어 디자인 변화와 조형적 특징을 조사, 분석해야 함을 강조하고자 한다. 본 연구에서는 시대적 배경과 자동차 인테리어의 흐름을 크래쉬패드 중심으로 비교하여 다변화(多變化)하는 기술적 중요 요인과 함께 향후 자동차 인테리어 디자인 방향을 연구하고자한다.