• Journal of the Korean Chemical Society
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• v.46 no.5
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• pp.437-471
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• 2002

The photosensitivity enhancement of photoresist achieved by the addition of acid amplifiers stems from the autocatalytic decomposition of the acid amplifiers triggered by acidic species generated from a photoacid gen-erator. In this research we synthesized and evaluated 4-hydroxy-4'-p-styrenesulfonyloxy isopropylidene dicyclohex-ane(1), 4,4'-di-p-styrenesulfonyloxy isopropylidene dicyclohexane(2) and 4-p-styrenesulfonyloxy-4'-tosyloxy isopropylidene dicyclohexane(3) as novel acid amplifiers. These acid amplifiers(1-3) showed reasonable thermal stability for resist pro-cessing temperature. As estimated by the sensitivity curve, 1-3 were 2X-12X sensitive than poly(tert-butyl meth-acrylate) film in the presence of a photoacid generator and, therefore, provides practical applicability for photoimaging.

• Polymer(Korea)
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• v.28 no.3
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• pp.273-280
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• 2004

Acrylic resins (ethyl methacrylate-2-hydroxypropyl methacrylate-n-butyl acrylate-acrylic acid EHBCs) containing 80％ of solid were synthesized. Then, high-solid coatings (ethyl methacrylate-2-hydroxypropyl methacrylate-n-butyl acrylate-acrylic acid/hexamethylene diisocyanate-biuret : EHBCNs) were prepared by curing of the acrylic resin with curing agent hexamethylene diisocyanate-biuret at room temperature. The cure time of prepared coatings EHBCN-4 (EHBC-4 : $T_{g}$ = $0^{\circ}C$) and EHBCN-7 (EHBC-7 : $T_{g}$ = 3$0^{\circ}C$), measured by rigid-body pendulum method, was recorded 6.2 hours and 4.5 hours, respectively. Dynamic viscoelastic experiment revealed the glass transition temperature of EHBCN-4 and EHBCN-7 to be $14^{\circ}C$ and $39^{\circ}C$, respectively. It was found that the adhesion and flexural properties among various properties of coatings were enhanced by the incorporation of caprolactone acrylate monomer into the acrylic resins.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.47-55
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• 2010

UV-screening agents have some adverse effects that raise consumers' concern. The organic agents often cause irritation and may penetrate into human body while the inorganic agents raise aesthetic issues because they often turn opaque. Organic agents with high molecular weights and nano-sized inorganic agents have been developed respectively to minimize transdermal intrusion into human body and suppress turning opaque. Recently, we reported preparation of powdery UV-screening agents made of polysilsesquioxane, an organic-inorganic hybrid material. Powders would not penetrate into epidermis and organic-inorganic hybrid nature would suppress the opaqueness problem. In this study, we continued our research on this powdery polysilsesquioxane UV-screening agent, SESQUV, regarding its chemical composition, its synergic UV-screening effects when mixed with other organic agents, and its applicability in practical formulation. Results showed SESQUV was promising UV-screening agents useful in sunscreen formulation.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.799-804
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• 2018

The separation and purification of 2,6-dimethylnaphthalene (2,6-DMN) present in the light cycle oil (LCO) fraction was investigated by a crystallization operation. Solute crystallization (SC) was performed using LCO fraction and iso-propyl alcohol as a raw material and a SC solvent, respectively. Increasing the operation temperature and volume ratio of the solvent to the raw material (S/F) resulted in improving the purity of 2,6-DMN, whereas the yield decreased. As a result of the crystallization operation in three steps containing the SC using LCO fraction (13.9% 2,6-DMN) and isopropyl alcohol, the re-crystallization 1 (RC 1) using the crystals recovered by SC and methyl acetate, and RC 2 using the crystals recovered by RC 1 and methyl acetate, the crystal with 99.9% 2,6-DMN was recovered with 19.5% yield. Furthermore, the separation and purification process of 2,6-DMN present in the LCO fraction was reevaluated by using the experimental results obtained through each operations of SC, RC 1, and RC 2.

• Korean Journal of Crystallography
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• v.7 no.1
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• pp.8-19
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• 1996

Cholestryl Methyl and Propyl Carbonate(CH3OCOOC27H45, C3H7OCOOC27H45) are monoclinic, space group P21, with a=17.014(1), b=7.682(1), c=10.612(1)Å, β=103.05(1)°, Z=2, V=1351.16Å3, Dc=1.09 g/cm3 for methyl carbonate, and with a=13.683(1), b=11.864(2), c=18.904(2)Å, β=106.30(1)°, Z=4, V=2945.4Å3, Dc=1.06 g/cm3, Dm=1.06 g/cm3 for propyl carbonate. The intensity data were collected on an Enraf-Nonius CAD-4 diffractometer with a graphite monochromated Cu-Kα radiation. The structure was solved by direct methods and refined by full matrix least-squares methods. The final R factor was 0.051 for 2323 observed reflections for methyl carbonate and 0.074 for 3323 observed reflections for propyl carbonate. Compared with other cholesteryl derivatives, the cholesteryl ring and tail region of the molecules are normal. The molecules are stacked in clearly separated layers. At center of the layer, there are cholesteryl-C(17) side chain interactions. The interface region between layers is occupied by the loosely packed methyl carbonate chains. The structure of cholesteryl propyl carbonates have two propyl carbonates have two molecules(A, B) that are not related by crystal symmetry and have their tetracyclic system almost parallel to each other. Cholesteryl-cholesteryl interactions between symmetry related A-molecules, and cholesteryl-C(17) side chain interactions between symmetry related B-molecules occur at the center of the layers and these molecules stack along 2₁ screw axes. There are also C(17)chain-carbonate chain and C(17)chain-C(17)chain interactions in the interface region between layers. There is efficient packing between cholesteryl ring systems in propyl carbonates. Temperature ranges of cholesteric mesophases of cholesteryl alkyl cargonates are narrow for methyl, pentyl and hexyl carbonates, and rather broader for ethyl and propyl carbonates. Cholesteryl-isotropic transitions change very little with chain length.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.5
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• pp.77-90
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• 2023

This study aims to investigate the potential of alternative credit assessment through Social Networking Sites (SNS) as a complementary tool to conventional loan review processes. It seeks to discern the impact of SNS usage characteristics and loan product attributes on credit loan repayment. To achieve this objective, we conducted a binomial logistic regression analysis examining the influence of SNS usage patterns, loan characteristics, and personal attributes on credit loan conditions, utilizing data from Company A's credit loan program, which integrates SNS data into its actual loan review processes. Our findings reveal several noteworthy insights. Firstly, with respect to profile photos that reflect users' personalities and individual characteristics, individuals who choose to upload photos directly connected to their personal lives, such as images of themselves, their private circles (e.g., family and friends), and photos depicting social activities like hobbies, which tend to be favored by individuals with extroverted tendencies, as well as character and humor-themed photos, which are typically favored by individuals with conscientious traits, demonstrate a higher propensity for diligently repaying credit loans. Conversely, the utilization of photos like landscapes or images concealing one's identity did not exhibit a statistically significant causal relationship with loan repayment. Furthermore, a positive correlation was observed between the extent of SNS usage and the likelihood of loan repayment. However, the level of SNS interaction did not exert a significant effect on the probability of loan repayment. This observation may be attributed to the passive nature of the interaction variable, which primarily involves expressing sympathy for other users' comments rather than generating original content. The study also unveiled the statistical significance of loan duration and the number of loans, representing key characteristics of loan portfolios, in influencing credit loan repayment. This underscores the importance of considering loan duration and the quantity of loans as crucial determinants in the design of microcredit products. Among the personal characteristic variables examined, only gender emerged as a significant factor. This implies that the loan program scrutinized in this analysis does not exhibit substantial discrimination based on age and credit scores, as its customer base predominantly consists of individuals in their twenties and thirties with low credit scores, who encounter challenges in securing loans from traditional financial institutions. This research stands out from prior studies by empirically exploring the relationship between SNS usage and credit loan repayment while incorporating variables not typically addressed in existing credit rating research, such as profile pictures. It underscores the significance of harnessing subjective, unstructured information from SNS for loan screening, offering the potential to mitigate the financial disadvantages faced by borrowers with low credit scores or those ensnared in short-term liquidity constraints due to limited credit history a group often referred to as "thin filers." By utilizing such information, these individuals can potentially reduce their credit costs, whereas they are supposed to accrue a more substantial financial history through credit transactions under conventional credit assessment system.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.793-795
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• 2002

인터넷에서 비지니스 파트너 사이에 보안 정보를 교환하는 XML 프레임워크인 SAML (SecurityAssertions Markup Language)은 국제적 컨소시엄인 OASIS(the Organization for the Advancement of Structured Information Standards)에 의해 제정된 표준이다. SAML은 S2ML(Security Services Markup Language)의 원리와 구조를 재사용하고, 신뢰할 수 있는 Single Sign-On, 인증 서비스, B2B이션 서버, XML 메시징 프레임워크와 다양한 오퍼레이팅 플렛폼사이에 인증, 승인과 함께 프로필 정보를 교환하기 위해 사용된다. 본 논문에서는 SAML의 기반으로 인터넷에서 여러 기업들이 보안문서를 교환할 때 여러 가지 솔루션과 함께 쓰고 공유하는 안전한 언어에 대해서 논한다

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.597-599
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• 1992

A calculation method for predicting the instantaneous torques by the inductance profiles of a switched reluctance motor (SRM) is presented. The method considers saturation and nonlinearities in the magnetic circuits. The inductance of SRM varies complex according to the input current waveforms and rotor position angle, thus the accurate calculation technique is needed to estimate the inductance value at arbitary input current and rotor position angle. This paper describes how the inductance profiles influence the torque produced by the input current of SRM and, proposes a calculation technique of the permeabilities, reluctances, current waveforms and torques of a 6/4 3-phase SRM.

• Proceedings of the Korean Society for Information Management Conference
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• 2012.08a
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• pp.25-28
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• 2012

최근 스마트폰 열풍과 함께 트위터, 페이스북 등으로 대표되는 SNS의 이용이 크게 확대되었다. SNS가 개인간 네트워크 유지 및 확대를 위한 소통의 도구로 자리매김함에 따라 기업들도 고객과의 관계 강화를 위한 마케팅 도구로 SNS를 활용하고 있다. 그러나 개인 프로필을 기반으로 하는 정보의 공개 및 공유가 특징인 SNS는 개인정보 노출이나 퍼블리시티권 침해, 저작권 침해 등 여러 가지 사회적 이슈를 야기하고 있다. 이에 SNS 이용자들은 정보의 공유에 대한 범위 설정 등을 통해 자신의 권리는 물론, 타인의 권리도 보호해야 할 필요가 있다. 따라서 이 연구는 SNS 상에서 발생하는 권리침해 문제들을 개괄하고, 주요 SNS의 이용약관을 살펴봄으로써 SNS 이용자의 정보공유 및 권리보호를 위한 권한과 책무를 파악하고자 한다.

• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.1
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• pp.11-20
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• 2003

Equilibrium swelling curves of N-isopropyl acrylamide(NIPA) gel and its ionized copolymer gels were obtained as a function of temperature. Discontinuous volume changes of the gels were observed. Phase transition temperature was increased with the ionized counter parts of the gels. Equilibrium swelling of ionized copolymer gel cylinder was found to depend strongly on their diameters. Crosslinking density of NIPA gel was adjusted by increasing N,N'-methylenebisacrylamide(BIS). Phase transition temperature was increased with the crosslinking density.