• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.1.1-1.1
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• 2011

Printed electronics based on the direct writing of solution processable functional materials have been of paramount interest and importance. In this talk, the synthesis of printable inorganic functional materials (conductors and semiconductors) for thin-film transistors (TFTs) and photovoltaic devices, device fabrication based on a printing technique, and specific characteristics of devices are presented. For printable conductor materials, Ag ink is designed to achieve the long-term dispersion stability and good adhesion property on a glass substrate, and Cu ink is sophisticatedly formulated to endow the oxidation stability in air and even aqueous solvent system. The both inks were successfully printed onto either polymer or glass substrate, exhibiting the superior conductivity comparable to that of bulk one. In addition, the organic thin-film transistor based on the printed metal source/drain electrode exhibits the electrical performance comparable to that of a transistor based on a vacuum deposited Au electrode. For printable amorphous oxide semiconductors (AOSs), I introduce the noble ways to resolve the critical problems, a high processing temperature above $400^{\circ}C$ and low mobility of AOSs annealed at a low temperature below $400^{\circ}C$. The dependency of TFT performances on the chemical structure of AOSs is compared and contrasted to clarify which factor should be considered to realize the low temperature annealed, high performance AOSs. For photovoltaic application, CI(G)S nanoparticle ink for solution processable high performance solar cells is presented. By overcoming the critical drawbacks of conventional solution processed CI(G)S absorber layers, the device quality dense CI(G)S layer is obtained, affording 7.3% efficiency CI(G)S photovoltaic device.

• 대한치과교정학회지
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• 제42권1호
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• pp.47-54
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• 2012

Objective: To determine and compare the frequency distribution of various arch shapes in ethnic Malays and Malaysian Aborigines in Peninsular Malaysia and to investigate the morphological differences of arch form between these two ethnic groups. Methods: We examined 120 ethnic Malay study models (60 maxillary, 60 mandibular) and 129 Malaysian Aboriginal study models (66 maxillary, 63 mandibular). We marked 18 buccal tips and incisor line angles on each model, and digitized them using 2-dimensional coordinate system. Dental arches were classified as square, ovoid, or tapered by printing the scanned images and superimposing Orthoform arch templates on them. Results: The most common maxillary arch shape in both ethnic groups was ovoid, as was the most common mandibular arch shape among ethnic Malay females. The rarest arch shape was square. Chi-square tests, indicated that only the distribution of the mandibular arch shape was significantly different between groups (p = 0.040). However, when compared using independent t-tests, there was no difference in the mean value of arch width between groups. Arch shape distribution was not different between genders of either ethnic group, except for the mandibular arch of ethnic Malays. Conclusions: Ethnic Malays and Malaysian Aborigines have similar dental arch dimensions and shapes.

• International Journal of Internet, Broadcasting and Communication
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• 제7권2호
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• pp.16-27
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• 2015

Holography technology which was developed by Dennis Gabor (1900~1979) in 1948 is a technology to record wave planes of actual 3D objects. It is known as the only technology which can express 3D information most perfectly close to human-friendly. Holography technology is widely used in advertisement, architecture and arts as well as science technology areas. Especially, digital holographic print which is an applied area is greatly used in military map, architecture map and cultural asset restoration by printing and reproducing 3D information. Holography is realized by recording and reproducing the amplitude and phase information on high resolution film using coherent light like laser. Recording materials for digital holographic printer are silver halide, photoresist and photopolymer. Because the materials have different diffraction efficiency according to film characteristics of each manufacturer, appropriate guide lines should be suggested through efficiency analysis of each film. This paper suggests appropriate guide lines through the diffraction efficiency measurement of silver halide which is a holographic printer recording medium. And the objective of this study is to suggest appropriate guide lines through diffraction efficiency analysis of Ultimate 08-C and PFG-03C which are commercially used. The experiment was prepared by self-diffraction efficiency system which measures the strength with the defector by penetrating RGB recording medium and concentrating diffracted beams through collimating lens. The experiment showed Geola's PFG-03C which is a silver halide for full color has price/performance advantage in optical hologram recording, but recording angles and reproduction angles are irregular for digital holographic printer recording. Ultimate's Ultimate08-C for full color shows its diffraction efficiency is relatively stable and high according to recording angles and laser wavelength.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.421-421
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• 2008

Generally, the polymer thick-film resistors for embedded organic or hybrid substrate are patterned by screen printing so that the accuracy of resistor pattern is not good and the tolerance of resistance is too high(${\pm}$20~30%). To reform these demerits, a method using Fodel$^{(R)}$ technology, which is the patterning method using a photosensitive resin to be developable by aqueous alkali-solution as a base polymer for thick-film pastes, was recently incorporated for the patterning of thermosetting thick-film resistor paste. Alkali-solution developable photosensitive resin system has a merit that the precise patterns can be obtained by UV exposure and aqueous development, so the essential point is to get the composition similar to PSR(photo solder resist) used for PCB process. In present research, we made the photopatternable resistor pastes using 8 kinds of epoxy acrylates and a conductive carbonblack (CDX-7055 Ultra), evaluated their developing performance, and then measured the resistance after final curing. To become developable by alkali-solution, epoxy acrylate oligomers with carboxyl group were prepared. Test coupons were fabricated by patterning copper foil on FR-4 CCL board, plating Ni/Au on the patterned copper electrode, applying the resistor paste on the board, exposing the applied paste to UV through Cr mask with resistor patterns, developing the exposed paste with aqueous alkali-solution (1wt% $Na_2CO_3$), drying the patterned paste at $80^{\circ}C$ oven, and then curing it at $200^{\circ}C$ during 1 hour. As a result, some test compositions couldn't be developed according to the kind of oligomer and, in the developed compositions, the measured resistance showed different results depending on the paste compositions though they had the same amount of carbonblack.

• 공업화학
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• 제8권3호
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• pp.510-516
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• 1997

Cetyl alcohol과 polyoxyethylene(20) sorbitan monooleate를 혼합한 유화제와 양친매성 resin을 용매에 용해시킨 분산상에 분산매인 물을 첨가하여 O/W 에멀젼을 제조하여 HLB(Hydrophilic Lipophilic Balance) 값과 온도변화에 따른 상변화를 관찰하였다. 양친매성 resin을 함유한 에멀젼은 이를 함유하지 않는 에멀젼보다 온도변화에 따른 상안정성이 좋다는 것을 알 수 있었다. 또한 양친매성 resin이 에멀젼 안정성에 미치는 영향을 파악하기 위해 양친매성 resin에 함유되어 있는 작용기중 하나의 작용기를 갖는 resin을 model compound로 하여 HLB값과 온도변화에 따른 에멀전 상거동을 관찰한 결과, Poly(acrylic acid)

• 한국문헌정보학회지
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• 제27권
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• pp.99-124
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• 1994

This study examines the establishment of Sea-po (서포) in the opening period of Korea at the end of the 19th century. The role they played, the particular situations and their geographical characteristics are researched, The earliest sea-po was Koh-je-hong sea-po, which was established in Tae­kwang-kyo at the end of 1880s. Around 1905, a specialised book distribution system was set up with establishement of Chu-han-yung book store, Kim-sang-man book store, Jesuit book store, Tae-dong su-si, Kae-myung sea-kwan, Tong-wha seo-kwan. The owners of the seo-pos were pioneers in introducing modern culture with nationalistic consciousness, although they were primarily businessmen and their social origins varied. The primary role of seo-pos was selling a variety of books but some combined printing and publication of books as well. It seems that publication business took roots around 1908, though it is difficult to know the accurate dates of first attempts. Some sea-pas offered book rental services for poor people who could not easily afford to purchase books. A certain amount of deposit had to be paid to benefit from the services. Jesuit Bookstore in Pyungyang had a library facility with a large stock or books in the same building open to public for free. These sea-pas started mainly in Seoul and Pyungyang, which were traditional centers for economic and cultural affairs. Early introduction of foreign cultures and commercial developments in these areas contributed to the establishment of sea-pos. The sea-po which took charge of book distribution in the provinces was set up around 1906. One of the important findings of this study is that the geographical distribution of sea-po shows the following three characteristics. First is that the area such as Seoul, Taegu and Chunju were the traditional centers of publishing culture from which Pang­gak-bon(방각본) emerged. Second characteristic is Pyungyang and the surrounding Pyungbuk province, and harbors like Inchon and Pusan, which had the benefits of early spread of modem cultures. Third characteristic is Kaesung and the surrounding Hwanghae province which bridged Pyungyang and Seoul. The reception of foreign cultures stimulated the commercial spirits traditionally attributed to Kaesung to establish sea-pas most actively.

• Toxicological Research
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• 제18권4호
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• pp.401-409
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• 2002

Phthalate esters have possible effects on the endocrine system. Di-n-butyl phthalate (DBP) is one of the most commonly wed phthalic acid esters (PAEs). It is extensively wed as a plasticizer in elastomers, as a solvent for printing inks and resins, and as a textile lubricating agent. It is also present in the formulations of various cosmetic products. DBP has been identified as a reproductive toxicant in several animal species and also know as a endocrine disruptor. The objective of this study was to investigate the effect of DBP on developmental immune Junction wing rat pups as experimental animals. Timed-bred pregnant SD rats were orally dosed with 0, 250, 500, or 750 mg DBP/kg body weight once a day from gestational day (GD) 5 to 18 and postpartum day (PD) 3 to 18. On PD22, the dams and their pups were euthanized and examined for alteration in parameters associated to immune function. The results showed no significant changes in body weight, thymus weight, thymus and spleen cellularities, the polyclonal activation respones of splenocyte with ConA and LPS, and also the distribution of arterial blood cells and thymocyto subsets in both rat dam and pups. However DBP exposure on rat dam resulted in increases of liver weights of dam and their pups except 750 mg DBP/kg, and body and spleen weights in pups except 750 mg DBP/kg. On the other hands, distribution rates of CD8+ T cells at 500 mg DBP/kg and B cells at 750 mg DBP/kg among splenocyte subsets were significantly increased in rat pups, unlike dams. Reasons of these distribution alterations of CD8+ T cells and B cells in rat pups are under study.

• 펄프종이기술
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• 제34권2호
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• pp.1-12
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• 2002

Starch dissolved in paper-mill wastes, either as a result of poor retention on the paper web or recycling of surface-treated broke, was a major pollutant Laboratory tests were performed by using different kinds of starch as a surface treatment. It was concluded that the use of cationic starch can positively affect the level of starch dissolved in liquid effluents. When cationically modified starches were used for surface sizing, the starch was tightly bound to the paper fibers, it was not removed during the repulping of broke. The result of mill trial in fine paper manufacture for the application of low-viscosity cationic starches used in size press reduced COD load in the effluents and increased One Pass Retention. It had been found that when cationic starch used as a surface sizing agent, more starch was retained on or near the surface of the sheet than with conventional oxidized starches. Thus surface strengths and quality were improved. In addition it is possible to maintain the desired level of starch penetration into the fiber net and improve porosity, opacity and brightness. In contrast, in most cases, dusting problems are notably eliminated. Cationic surface sized starch improved black and color ink-jet print quality in terms of feathering and optical density of the print image. These improved properties were believed to be due to a combination of fiber bonding and surface orientation more uniform starch concentration on the paper surface was resulted. Moreover cationic charges in the paper surface lend themselves excellently to fix ink jet ink anionic in nature.

• 한국언론정보학보
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• 제27권
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• pp.153-181
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• 2004

이 논문은 한국사회에서 근대 공론장과 신문의 형성과정에 대해 '학문연계적 연구'를 시도했다. 근대사회가 형성되는 과정에서 공론장은, 중세 유럽의 신분제적 정치체제를 허물고 시민사회를 등장시킨 조건이었다. 유럽에서 근대 신문은 아래로부터 여론을 모아나가면서 공론장을 형성하는 데 핵심적 구실을 했다. 한국에서도 18세기 이후 조선 시대 내부에서 아래로부터 문예적 공론장과 정치적 공론장이 발전해나가고 있었다. 농업에서 생산력 발전에 따른 신분제 질서의 동요와 부의 축적에 따른 상업과 수공업, 광업의 활성화는 그에 걸맞은 커뮤니케이션 체계를 요구할 수밖에 없었다. 하지만 그것이 신문이라는 인쇄미디어를 만들기 전에 개항이 이루어졌다. 그 결과 한국의 근대 신문은 공론장과 갈등구조를 이루게 되었다. 근대언론의 생성문제를 두고 언론학계에서 논의해 온 이식론(移植論)이나 접목잡종론(接木雜種論)과 달리, 이 논문에서 제안한 '갈등구조론'을 통해 우리는 한국 저널리즘의 위기가 어디서부터 연유하는지 구조적으로 파악할 수 있다.

• Transactions on Electrical and Electronic Materials
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• 제18권5호
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• pp.261-264
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• 2017

$Ni_{0.79}Co_{0.15-x}Cu_xMn_{2.06}O_4$ ($0{\leq}x{\leq}0.09$) thick films were fabricated using the conventional solid-state reaction method and screen-printing method. Structural and electrical properties of specimens based on the amount of Cu were observed in order to investigate their applicability in the infrared detector. All specimens showed a single spinel phase with a homogeneous cubic structure. As the amount of Cu increased, the average grain size increased and was found to be approximately $5.01{\mu}m$ for the $Ni_{0.79}Co_{0.06}Cu_{0.09}Mn_{2.06}O_4$ specimen. The thickness of all specimens was approximately $55{\sim}56{\mu}m$. As Cu content increased, the resistivity and TCR properties at room temperature decreased, and these values for the $Ni_{0.79}Co_{0.06}Cu_{0.09}Mn_{2.06}O_4$ specimen were $502{\Omega}-cm$ and $-3.32%/^{\circ}C$, respectively. The responsivity and noise properties decreased with an increase in Cu content, with the specimen with a Cu content of x=0.09 showing 0.0183 V/W and $5.21{\times}10^{-5}V$, respectively.