자기펄스 성형 및 방전 플라즈마 소결 공정으로 제조한 텅스텐 소결체의 특성

이의선,변종민,정영근,오승탁,Lee, Eui Seon,Byun, Jongmin,Jeong, Young-Keun,Oh, Sung-Tag 한국재료학회 2020 한국재료학회지 Vol.30 No.6

The present study demonstrates the effect of magnetic pulse compaction and spark plasma sintering on the microstructure and mechanical property of a sintered W body. The relative density of green specimens prepared by magnetic pulse compaction increases with increase in applied pressure, but when the applied pressure is 3.4 GPa or more, some cracks in the specimen are observed. The pressureless-sintered W shows neck growth between W particles, but there are still many pores. The sintered body fabricated by spark plasma sintering exhibits a relative density of above 90 %, and the specimen sintered at 1,600 ℃ after magnetic pulse compaction shows the highest density, with a relative density of 93.6 %. Compared to the specimen for which the W powder is directly sintered, the specimen sintered after magnetic pulse compaction shows a smaller crystal grain size, which is explained by the reduced W particle size and microstructure homogenization during the magnetic pulse compaction process. Sintering at 1,600 ℃ led to the largest Vickers hardness value, but the value is slightly lower than that of the conventional W sintered body, which is attributed mainly to the increased grain size and low sintering density.

동결건조 공정에서 Tert-butyl alcohol 기공형성제가 텅스텐 다공체의 기공구조에 미치는 영향

이의선,허연지,고윤택,박진경,좌용호,오승탁,Lee, Eui Seon,Heo, Youn Ji,Ko, Yun Taek,Park, Jin Gyeong,Cho, Yong-Ho,Oh, Sung-Tag 한국분말재료학회 (*구 분말야금학회) 2021 한국분말재료학회지 (KPMI) Vol.28 No.3

The effect of tert-butyl alcohol (TBA) as a freezing solvent on the pore structure of a porous tungsten body prepared by freeze-drying is analyzed. TBA slurries with a WO3 content of 10 vol% are prepared by mixing with a small amount of dispersant and binder at 30℃. The slurries are frozen at -25℃, and pores are formed in the frozen specimens by the sublimation of TBA during drying in air. After hydrogen reduction at 800℃ and sintering at 1000℃, the green body of WO₃ is completely converted to porous W with various pore structures. Directional pores from the center of the specimen to the outside are observed in the sintered bodies because of the columnar growth of TBA. A decrease in pore directionality and porosity is observed in the specimens prepared by long-duration drying and sintering. The change in pore structure is explained by the growth of the freezing solvent and densification.

WO₃/tert-butyl alcohol 슬러리의 동결건조 조건이 다공체의 미세구조 특성에 미치는 영향

이의선,허연지,석명진,오승탁,Lee, Eui Seon,Heo, Youn Ji,Suk, Myung-Jin,Oh, Sung-Tag 한국분말재료학회 (*구 분말야금학회) 2021 한국분말재료학회지 (KPMI) Vol.28 No.4

The effects of drying temperature on the microstructure of porous W fabricated by the freeze-casting process of tert-butyl alcohol slurry with WO₃ powder was investigated. Green bodies were hydrogen-reduced at 800℃ for 1 h and sintered at 1000℃ for 6 h. X-ray diffraction analysis revealed that WO₃ powders were completely converted to W without any reaction phases by hydrogen reduction. The sintered body showed pores aligned in the direction of tert-butyl alcohol growth, and the porosity and pore size decreased as the amount of WO₃ increased from 5 to 10vol%. As the drying temperature of the frozen body increased from -25℃ to -10℃, the pore size and thickness of the struts increased. The change in microstructural characteristics based on the amount of powder added and the drying temperature was explained by the growth behavior of the freezing agent and the degree of rearrangement of the solid powder during the solidification of the slurry.

『심벌린(Cymbeline)』 구조의 담론적 분석

이의선 ( Catherine E. Lee ) 한국드라마학회 2002 드라마연구 Vol.- No.19

Shakespeare wrote his last plays from 1609 to 1611 after King James’s accession. As we know, James’s early years as King of England represent the period of the continentalization of English art. And the wealth of James’ national coffers was spread prodigiously in many directions and settled upon many persons whom King James de lighted to honor. The fine arts indirectly benefited from this generosity and Stuart Court gathered to see the epitomic courtly art form―masque―in a banquet hall. It seems to me that during this time Shakespeare might have been affected by the new fashions, and I will also observe the influence of new Jacobean aesthetics in the arts upon Shakespeare’s working environment and then upon his late palys. From this viewpoint, I wish to discuss here some dominating elements of aesthetics reflected in the dramtic structure of Shakespeare’s late plays under the following aesthetics in the dramatic structure of Cymbeline. In the first place it seems to me that Shakespeare inherited the Renaissance belief in dance and music as reflection of the cosmic order. For the purpose of interpreting Cymbeline structurally, we are to understand the meaning of the structure as a whole. The dramatic structure can be divided into five ―plot structure; therefore Cymbeline followed the dramatic pattern established in Pericles, although it inherited the classic Greek romance properties. In the first place, Shakespeare intentionally deconstructs the dramatic action in order to materialize the disintegration of Cymbeline’s court. Shakespeare splits the focus of dramatic actions into the hero and the heroine. The play develops into the parallel actions-Posthumus in Rome and Imogen in Britain-with Iachimo as the link between these lovers. Form this moment the two protagonists are resolved separately into the strucyure of the play. The separation and unwitting encounter delineate the dramatic action of Imogen, who is unknowingly united with her two lost brothers-Guiderius and Arviragus-in Wales. There is a structural deficiency during this Welsh scene where Posthumus is off-stage from the dramatic action. The fact that Imogen is off-stage during following scenes demonstrates the conflict between inner virtue and outward appearance which begins with the first battle cry, progresses through Posthumus’ achievements on the battlefield. Lastly the dichotomous structure is resolved by the harmonic conclusion of the play Cymbeline where Posthumus and Imogen are reunited with true love. At the center of this conclusion is the reunion of two protagonists which is linked symbolically bu love and it prefigures the return to cosmic order of Cymbeline’s court

일반논문 : 금융교육프로그램이 금융역량에 미치는 효과 연구

이의선 ( Lee Eui Sun ),문정숙 ( Moon Chung Sook ) 한국여성경제학회 2014 여성경제연구 Vol.11 No.1

현재 우리나라 금융교육이 금융소비자의 합리적 금융행동을 수반할 수 있는가에 대하여 다양한 의문이 제기된다. 본 연구에서는 금융교육 형식요소의 개선을 위하여 지식전달형, 효율적학습형, 학습자주도형 교육프로그램을 개발하여 각 프로그램이 금융소비자의 금융이해력함양과 비합리적 투자행동의 변화에 유의미한 변화를 주었는지 알아보았다. 그 결과 학습자 주도형 프로그램이 금융이해력 함양에 가장 긍정적인 효과를 주었고, 일시적이고 미약하지만 비합리적 투자행동에도 변화를 보이는 것으로 확인되었다. 본 연구에서는 금융이해력의 함양이 직접적으로 학습자의 행동의 변화를 이끌어낸다는 증거를 찾아내지는 못했으나, 금융교육의 내용 및 형식요소를 모두 학습자 중심으로 강화한 집단의 경우 상승효과가 있음을 확인하였다. It is controversial whether contemporary financial education brings about rational action of consumers. This study aimed to examine the effect of the educational programs on consumers’ financial literacy and investment behaviors. The programs were developed for the improvement of formal elements, such as teaching method, learning method and scale of students, in financial education and consisted of three types: Knowledge- delivery type, effective learning-applied type and learner-centered type programs. As a result, learner-centered program was most positive about financial literacy and contributed to change irrational investment behaviors, limited though. This study did not reveal that enhancing financial literacy was related to the change of action to the consumers, but that learner-centered program was significantly positive result.

블록체인에 대한 소비자 인지도와 수용, 저항 분석

이의선 ( Lee Euisun ),옥경영 ( Ohk Kyungyoung ),문정숙 ( Moon Chung Sook ) 한국소비자학회 2019 소비자학연구 Vol.30 No.3

블록체인은 분산형 데이터 저장기술로서, 소비자의 개인정보 거래와 관련한 혁신적인 기술로 주목받고 있다. 블록체인기술을 적용한 소비자 대상 서비스의 상용화는 대기업을 중심으로 활발하게 논의되고 있으며, 올해 들어 블록체인 기반 비즈니스 모델을 개발하는 등 사업화에 본격착수하고 있어 시장의 확대를 기대하게 한다. 그러나 일반 소비자들이 경험할 수 있는 서비스의 대중화까지는 다소 시간이 소요될 수 있을 뿐 아니라 암호화화폐에 대한 부정적 인식은 소비자들의 신기술 수용을 저해할 수 있는 환경적 요소로 지목되고 있다. 본 연구를 위하여 국내의 일반소비자를 대상으로 블록체인에 대한 인식과 수용과 저항 등을 조사하였다. 분석결과 국내 소비자들의 블록체인에 대한 인지도는 낮은 편이었다. 또한 블록체인의 소비자의 수용에 영향을 주는 요인은 소득, 인지도, 지각된 위험 및 지각된 혜택이었으나, 저항에 영향을 미치는 요인은 연령, 인지도 및 지각된 위험인 것으로 분석되었다. 본 연구는 블록체인의 상용화가 이루어질 것으로 예상되는 현재시점에서, 블록체인에 대한 일반 소비자의 인지도를 확인하고, 블록체인에 대한 소비자의 긍정적 요인과 부정적 요인을 확인한 데에 의의가 있다. 연구결과를 통해 블록체인 시장형성을 위한 시사점을 도출하고, 소비자와 사업자의 신뢰도 구축을 위한 방안을 제시해보고자 한다. Blockchain is a distributed data storage technology that is attracting attention as an innovative technology related to consumers' personal information transactions. Commercialization of consumer oriented services using blockchain technology has been actively discussed mainly by major companies. Futhermore, they are developing a blockchain-based business model this year, and it is expected to expand the market. However, it may take some time to commercialize services that consumers can experience, as well as consumers' negative perception of encrypted currency is an environmental factor that can obstruct the acceptance of new technologies. As such, there are both positive and negative issues about the commercialization of the blockchain now, it is timely to examine consumer perceptions. For this study, we investigated the awareness, acceptance and resistance of blockchain among the general consumers in Korea. As the first result of the analysis, consumers' awareness of the blockchain was low. The second, income, awareness, perceived risk and subjective reliability were the factors influencing consumers' acceptance of the blockchain, but age, awareness, and perceived risk are factors affacting blockchain resistance. The significance of this study is to confirm the general consumers' awareness of the blockchain at this point and to identify the positive and negative factors for the blockchain of the consumers. Through the results of this study, we will draw implications for blockchain market formation and suggest ways to build credibility of consumers and businesses.

소비자의 주관적 금융지식과 객관적 금융지식이 금융태도 및행동에 미치는 영향력 연구: 금융 상품군 별 경로를 중심으로

이의선(Lee, Euisun) 한국소비문화학회 2016 소비문화연구 Vol.19 No.4

본 연구는 객관적 금융지식과 주관적 금융지식이 금융소비자의 긍정적 금융태도 및 합리적 금융행동에 미치는 영향력을 규명하기 위한 연구이다. 이를 규명하기 위해 첫 번째로 금융지식자신감을 중심으로 소비자 집단을 구분하여 각 집단별 금융태도 및 금융행동에 미치는 영향력을 분석했다. 그 결과 지식에 대한 자신감이 높은 소비자가 긍정적 금융태도를 형성하고 있었으며, 합리적 금융 행동을 하고 있었다. 두 번째로는 주관적 금융지식과 객관적 금융지식이 금융태도 및 행동에 미치는 전달경로를 규명하였는데, 객관적 금융지식은 주관적 금융지식 및 금융태도의 선행변수였고, 주관적 금융지식은 금융태도 및 금융행동의 선행변수인 것으로 나타났다. 다만 객관적 금융지식은 금융행동에 직접적 영향변수는 아니었다. 세 번째로 저축, 투자, 대출상품군의 금융지식의 전달경로를 비교한 결과, 저축 및 투자상품군의 지식전달경로는 영향력의 크기차이는 존재하나, 그 경로에는 큰 차이가 없었다. 그러나 대출상품의 경우 주관적 금융지식이 태도나 행동에 미치는 영향력이 유의하지 않은 것으로 나타났다. 마지막으로 설정된 지식전달경로가 성별 차이가 있는지를 알아본 결과, 유의한 차이를 발견할 수 없었다. 본 연구의 결과는 주관적 금융지식이나 금융지식자신감은 금융태도 및 금융행동에 긍정적인 영향을 주는 선행 변수라는 사실을 보여준다. 연구에서 새롭게 규명한 것은 금융상품군에 따라 지식의 전달경로가 상이할 수 있음을 제시한 것이다. This study aimed to present the influence of objective financial knowledge and subjective financial knowledge on positive financial attitude and behavior of financial consumers. It established four kinds of research topics in order to examine the path of financial knowledge. First, we analyzed an impact on the financial attitudes and financial behaviors dividing by the level of confidence in financial knowledge, which is substituted with the gap of objective knowledge and subjective knowledge. The result of this analysis shows that group of the consumers which ‘higher confidence in the financial knowledge’ leads positive financial attitude and a rational financial behavior. The second research topic was to identify the pathways of subjective financial knowledge and objective financial knowledge to financial attitude and behavior. The result shows that objective financial knowledge was a predictor of subjective financial knowledge and financial attitude, but it was not a direct predictor in financial behavior. The result also shows subjective financial knowledge was a predictor of financial attitude and behavior. Third, we examined the paths of knowledges by categories of financial product such as savings, investment and bank loan product. The result comparing between the pathways of savings & investment knowledge toward attitude and behavior were not significant differences. However we could find some differences in the path of the bank loan product.The results of this study show that subjective financial knowledge and confidence in financial knowledge are the leading variables positively affecting financial attitudes and behaviors. The new findings are that the path of knowledge may be different depending on the type of financial product.

GPR을 이용한 세종시 특정 지역 지하 맵핑 연구

이형(Hyoung Lee),김현우(Hyun-Woo Kim),김정,이의선(Eui-Sun Lee),손정영(Jung-Young Son),허광희(Gwang-Hee Heo) 대한토목학회 2019 대한토목학회 학술대회 Vol.2019 No.10

의사와 간호사의 환자안전교육 경험에 관한 포커스 그룹 연구

박정윤,이유라,이의선,이재호,Park, Jeong-Yun,Lee, Yu-Ra,Lee, Eu-Sun,Lee, Jae-Ho 한국의료질향상학회 2020 한국의료질향상학회지 Vol.26 No.2

Purpose:This study aims to understand and explore the subjective experiences of patient safety education among health care professionals in developing a patient safety curriculum in South Korea. Methods: A qualitative descriptive study was conducted through two focus group interviews in the period October-December 2018. Eleven participants who underwent patient safety education participated in each session. All interviews were recorded and transcribed as spoken, and qualitative content analysis was used to identify categories of discussion depicting participants' subjective experience with patient safety education. Results: A total of three categories and seven themes were identified out of 77 units of analysis. Topics were identified in the dimensions of a patient safety curriculum, as follows: (1) activities for patient safety; (2) principle of patient safety (five rights, ethics, patient participation) and patient participation; (3) leadership, teamwork, and communication; and (4) reporting and learning system for patient safety events. In the dimension of methods, (5) case and evidence-based education and (6) multidisciplinary and small group teaching were identified. Finally, in the dimension of the system, (7) policies for patient safety education were identified. Conclusion: Our findings indicate that patient safety education is a significant area for health care professionals. Health care professionals suggested that a systematic patient safety curriculum would improve their knowledge and attitude toward patient safety. Moreover, it enables them to better construct a safety environment in a hospital.

HG-AAS법에 의한 요중 비소의 최적 분석법에 관한 연구

이종화,이의선,홍성철,장봉기,Lee, Jong-Wha,Lee, Ui-Seon,Hong, Sung-Chul,Jang, Bong-Ki 한국환경보건학회 2009 한국환경보건학회지 Vol.35 No.5

This study was carried out to examine the optimal analytical method for determination of urinary toxic arsenic (inorganic arsenic and its metabolites) by HG-AAS (hydride generation-atomic absorption spectrometry). In the analysis of SRMs (standard reference materials), method E (addition of 0.4% L-cysteine to pre-reductant and use 0.04M HCl as carrier acid) showed the most accurate results compared with the reference values. In the analysis of 30 urinary samples, analytical results were significantly different depend on the component of pre-reductant and the concentration of carrier acid. When the concentration of carrier acid was higher, the analytical result was lower. The recovery rates of MMA (monomethylarsonic acid) and DMA (dimethylarsenic acid) were varied by the concentration of pre-treatment acid and carrier acid and hydride generation reagents. When the concentration of carrier acid was 1.62 M (5% HCl), the recovery rates of DMA was 1%. The recovery rates of MMA and DMA in method E (=V) were 102% and 100%, respectively. The results of this study suggest that the component and concentration of pre-reductant and carrier acid must be carefully adjusted in the analysis of urinary arsenic, and method E is recommendable as the most precise analytical method for determination of urinary toxic arsenic.