• 정보관리학회지
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• 제28권2호
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• pp.37-51
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• 2011

디지털도서관 분야는 컨텐츠, 운영, 기반 기술 관련하여 다양한 분야를 포함하고 있는 학제적 학문분야 중 하나로 여겨진다. 이 연구의 목적은 기존의 문헌정보학 범주 내에서 파악되었던 디지털도서관의 하위분야 규명을 넘어서 다양한 학문 분야에서 다루고 있는 디지털도서관을 학제적 공동연구의 관점에서 분석하고자 하였다. 1997년부터 2010년까지 게재된 디지털도서관 주제의 논문 1,394편을 대상으로 다양한 분야의 공동저자 분석을 수행하였다. 그 분석결과 문헌정보학, 컴퓨터학, 공학 분야가 공동연구의 중심 역할을 수행하였음을 밝혔다. 또한 디지털도서관의 세부영역은 핵심디지털도서관영역, 자연과학영역, 의학관련 영역, 생물학 및 의학영역으로 파악되었다. 이러한 결과는 디지털도서관은 다양한 학문 분야에서 다루고 있으며, 이론중심의 연구뿐만 아니라 구축과 운영과 관련된 실무 영역이 함께 발전된 특징을 지니고 있기 때문인 것으로 파악되었다.

• 보건행정학회지
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• 제18권2호
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• pp.86-106
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• 2008

This research analyzed. knowledge structure and its effect factor by analysis of co-author and keyword network in Korea's health policy and administration sector. The data was extracted from 339 articles listed in the Korean Journal of Health Policy and Administration, and was transformed into a co-author and keyword matrix. In this matrix the existence of a link was defined by impact factors which were calculated by the weight value of what the role was and the rate of how many authors contributed. We demonstrated that the research achievement was dependent on the author's status and network index. Analysis methods were neighborhood degree, correspondence analysis, multiple regression and the difference of weight distribution by research fields. Co-author networks were developed as closeness centrality as well as degree centrality by a few high productivity researchers. In particular, power law distribution was discovered in impact factor and research productivity. The effect of the author's role was significant in both the impact factor calculated by the participatory rate and the number of listed articles. Especially, this journal shared its major researchers who had a licensed physician with the Journal of Preventive Medicine and Public Health. Therefore, social scientists were likely to be small co-author network differently from natural scientists. It was so called 'two cultures' phenomenon. This study showed how can we verified academic research structure existed in the unit of journal like as citation networks. The co-author networks in the field of health policy and administration had more differentiated and clustered than preventive medicine and epidemiology fields.

• 마이크로전자및패키징학회지
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• 제27권4호
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• pp.11-17
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• 2020

Copper has been proved to be the best catalyst for electrochemical CO2 reduction reaction, however, for optimal efficiency and selectivity, its performance requires improvements. Electrochemical CO2 reduction reaction (RR) using CuO nanowire electrode was performed with different concentrations of KHCO3 electrolyte (0.1 M, 0.5 M, and 1 M). Cu(OH)2 was formed on Cu foil, followed by thermal-treatment at 200℃ under the air atmosphere for 2 hrs to transform it to the crystalline phase of CuO. We evaluated the effects of different KHCO3 electrolyte concentrations on electrochemical CO2 reduction reaction (RR) using the CuO nanowire electrode. At a constant current (5mA), low concentrated bicarbonate exhibited a more negative potential -0.77 V vs. Reversible Hydrogen Electrode (RHE) (briefly abbreviated as VRHE), while the negative potential reduced to -0.33 VRHE in the high concentration of bicarbonate solution. Production of H2 and CH4 increased with an increased concentration of electrolyte (KHCO3). CH4 production efficiency was high at low negative potential whereas HCOOH was not influenced by bicarbonate concentration. Our study provides insights into efficient, economically viable, and sustainable methods of mitigating the harmful environmental effects of CO2 emission.

• 정보관리학회지
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• 제33권2호
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• pp.201-225
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• 2016

학제적 분야의 연구 전선을 분석하는 새로운 기법으로 인용 이미지 구축자 프로파일링 기법을 제안하였다. 인용 이미지 구축자 프로파일링은 해당 문헌을 인용한 문헌의 표제어를 단서로 사용하여 문헌 간의 주제관계를 파악하는 방법이다. 이 연구에서는 시험적으로 국내 여성학 연구를 대상으로 인용 이미지 구축자 프로파일링 기법을 적용하여 연구 전선과 주요 연구 주제를 파악해보았다. 분석 대상은 KCI의 2015년 기준 여성학분야 인용빈도 10회 이상에 해당하는 핵심문헌 집합이다. 여성학 분야에 문헌동시인용 기법을 적용한 결과 인용 데이터 부족 때문에 어려움이 있었던 반면에, 인용 이미지 구축자 프로파일링 기법을 적용한 결과 성공적으로 2개 대분야 및 6개 소분야를 파악할 수 있었다. 이 연구에서 제안한 인용 이미지 구축자 프로파일링 기법은 학제적 연구분야의 동향을 파악하는데 기여할 수 있을 것으로 기대된다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.22-24
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• 1996

Small size DC motor control method for portable drug delivery system has been developed to be used for the actuator of insulins pump. The control method gives the controllabilities both in high speed(40-50 revolution per second(rps)) DC motor drive and also in low speed(0.5-1rps). In low speed mode DC motor is controlled to act like stepping motor and in high speed to optimize power consumption. To control both mode modified bang bang control is suggested. Using this method small size DC motor(spec.) speed is controlled from 0.2 rps to 50 rps. Experimental setup is developed using micro-processor(PIC16C73, Micro Chips co., USA), motor turns checking circuitry, small size DC motor for pager(SM1012, Samhong co., Korea) and gear box. Results from experiment meet need for vailable load condition which is require for portable drug delivery system.

• Safety and Health at Work
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• 제13권1호
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• pp.66-72
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• 2022

Background: The aim of the present study was to evaluate the psychological well-being (PWB) during the coronavirus disease (COVID-19) pandemic in workers of a multinational company. Methods: Employees (aged ≥18 years) were recruited from Latin American, North American, New Zealand, and European sites of a multinational company operative during all the pandemic period. The self-reported Psychological General Well-Being Index was used to assess the global PWB and the effects on six subdomains: anxiety, depressed mood, positive well-being, self-control, general health, and vitality. The influencing role of age, gender, geographical location, COVID-19 epidemiology, and restrictive measures adopted to control the pandemic was explored. Results: A total of 1335 workers completed the survey. The aggregate median PWB global score was in a positive range, with significantly better outcomes detected in the Mexican and Colombian Latin American sites compared with the other worldwide countries (p < 0.001). Among the European locations, a significantly higher PWB score was determined in Spain compared with the German and French sites (p < 0.05). Comparable geographical trends were demonstrated for all the PWB subdomains. Male workers had a significantly better PWB compared with females (p < 0.05), whereas a negative correlation emerged with aging (p = 0.01). COVID-19 epidemiology and pandemic control measures had no clear effects on PWB. Conclusion: Monitoring PWB and the impact of individual and pandemic-related variables may be helpful to clarify the mental health effects of pandemic, define targeted psychological-supporting measures, also in the workplace, to face such a complex situation in a more constructive way.

• 한국비블리아학회지
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• 제22권3호
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• pp.353-371
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• 2011

본 연구의 목적은 국내 연구자들의 연구 성과물인 학술지 논문에 나타난 학문분야의 상호관계성과 연관성에 대한 연구로 연구동향에 대한 시사점을 제시하는 것이다. 학술논문을 이용한 계량적 연구는 주로 논문의 초록, 자동추출 키워드, 논문의 풀텍스트를 활용하는 것이 일반적이나 본 연구는 실험대상 학술논문의 저자가 제시한 주제어에 초점을 두었다. 실험대상 자료는 2009년도 한국연구재단 등재학술지 80종으로 학술논문 7,616건, 주제어 58,143건이다. 자료 분석결과 공학, 농수해양, 복합학, 사회, 예술체육, 의약학, 인문, 자연과학 등의 8개 각 연구분야는 주제어 사용에서 차이점을 보였다. 특히 공학분야의 주제어가 다른 연구 분야에서도 주제어로 많이 사용되고 있었다. 또한 주제어 네트워크를 통해 연구분야를 클러스터링 한 결과, 3개 클러스터를 얻을 수 있었다. 클러스터A는 '공학', '자연과학', '사회', '복합학', '인문', 클러스터B는 '의약학', '예술체육', 클러스터C는 '농수해양'이었다.

• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.293-300
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• 2023

The global energy storage markets have gravitated to high-energy-density and low cost of lithium-ion batteries (LIBs) as the predominant system for energy storage such as electric vehicles (EVs). High-Ni layered oxides are considered promising next-generation cathode materials for LIBs owing to their significant advantages in terms of high energy density. However, the practical application of high-Ni cathodes remains challenging, because of their structural and surface instability. Although extensive studies have been conducted to mitigate these inherent instabilities, a two-step process involving the synthesis of the cathode and a dry/wet coating is essential. This study evaluates a one-step β-Li₂SnO₃ layer coating on the surface of LiNi_0.8Co_0.2O₂ (NC82) via the thermal segregation of Sn owing to the solubility limit with respect to the synthesis temperature. The doping, segregation, and phase transition of Sn were systematically revealed by structural analyses. Moreover, surface-engineered 5 mol% Sn-coated LiNi_0.8Co_0.2O₂ (NC82_Sn5%) exhibited superior capacity retention compared to bare NC82 owing to the stable surface coating layer. Thus, the developed one-step coating method is suitable for improving the properties of high-Ni layered oxide cathode materials for application in LIBs.

• 한국농림기상학회지
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• 제20권1호
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• pp.34-46
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• 2018

온실가스 배출로 인한 기후변화는 되먹임 고리의 형태로 연결되어 공진화 하는 자연생태계와 사회시스템의 지속가능성을 저해하는 위험요소가 되었다. 기후변화가 인위적인 온실가스 배출량의 상승에 의한 것으로 지적됨에 따라, 온실가스 배출원과 대기 간의 에너지 및 물질 교환과정에 대한 관심이 고조되었다. 본 고찰에서는 온실가스 모니터링의 배경에 대한 역사와 특별히 농업에서 배출되는 온실가스 관측을 위한 챔버법의 개발에 대해 요약하였다. 챔버를 이용하여 온실가스의 방출 특성을 분석한 국내 선행 연구들의 검토를 기반으로, 기후변화 적응을 위해 보다 나은 과학적 기초자료를 구축할 수 있도록 국내 챔버 관측의 문제점과 개선 방향을 간략히 논의하였다.

• 센서학회지
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• 제29권4호
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• pp.215-219
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• 2020

MnCo₂S₄/CoS₂ electrode with highly accessible electroactive sites is prepared using the hydrothermal method. The electrode exhibits an areal capacitance of 0.75 Fcm^-2 at 6 mAcm^-2 in 1 M KOH. The capacitance is further increased to 2.06 Fcm^-2 by adding K₃Fe(CN)₆ and K₄Fe(CN)₆ (a redox couple) to KOH. This increment is associated with the redox-active properties of cobalt and manganese transition metals, as well as the ion pair of [Fe(CN)₆]^-3/[Fe(CN)₆]^-4. The capacitance retention of the MnCo₂S₄/CoS₂ electrode is 87.5% for successive 4000 charge-discharge cycles at 10 mAcm^-2 in a composite electrolyte system of KOH and ferri/ferrocyanide. The capacitance enhancement is supported by the lowest equivalent series resistance (0.62 Ωcm^-2) of MnCo₂S₄/CoS₂ in the presence of redox additive couple compared with the bare KOH electrolyte.