Electrical Properties of MoS2 Field-Effect Transistors in Contact with Layered CrPS4

Minjeong Shin,이미정,Ji Hye Lee,박배호,Sungmin Lee,박제근 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.8

We report the enhanced electrical performance of a MoS2 field-effect transistor (FET) by using a contact with a layered CrPS4. Our transport measurements revealed that MoS2 channel with CrPS4 junction showed higher mobility of 33.9 cm^2/Vs than that without CrPS4 junction on SiO2/Si substrate. We also fabricated a MoS2 FET with a top gate insulator, CrPS4, which showed low leakage current of 10^-11 A and high on/off ratio of 10^5. In a dual-gated FET with SiO2 bottom gate insulator and CrPS4 top gate insulator, much decreased sub-threshold swing of 0.70 V/dec was obtained.

The study on the impact of diversification & differentiation in platform technology business in Korea: The case of Kakaotalk platform

Minjeong Shin 한국인적자원개발학회 2019 한국인적자원개발학회 학술연구발표회 발표논문집 Vol.2019 No.06

As the invention of fundamental science develops, new technologies extend into new application and markets. Some of them are principally “dead ends’, whereas others are evolve over time into a lot of derived technologies products and services. It can be called a technological trajectory, which is the pattern of branching and evolution of platform technology business. Because of the knowledge properties, platform firms that originate in industrial fields based on a platform technology attain the technological skills to diversify and differentiate the branching based on technology trajectory. However, these strategies of platform business are not always positive effect to firms, because of use’s side, such as affective, cognitive emotion. In this vein we conduct propositions and case study with the Korea messenger KaKaoTalk.

A Study of Mg Capping Inside p-tert-butylcalix[4]arene Adsorbed on a Ge(100) Surface

Minjeong Shin,Myungjin Lee,Hangil Lee 한국진공학회 2013 한국진공학회 학술발표회초록집 Vol.2013 No.8

Attitudes towards Parenthood and Fertility Awareness in Female and Male University Students in South Korea

Shin, Hyewon,Lee, Jungmin,Kim, Shin Jeong,Jo, Minjeong Korean Academy of Child Health Nursing 2020 Child Health Nursing Research Vol.26 No.3

Purpose: This study investigated intentions and attitudes towards future parenthood and awareness of fertility among university students in South Korea. Methods: The participants comprised 166 female and male undergraduate students enrolled at five universities. A cross-sectional survey was conducted from May to July 2019 using the Korean version of the Fertility Awareness Questionnaire and Attitudes of Parenthood. The data were analyzed using descriptive statistics based on participants' general characteristics, the χ² test to identify differences in intentions, and the t-test to evaluate attitudes towards parenthood and awareness of fertility in female and male students. Results: Both female and male students desired to have two children, but they lacked awareness about fertility. The possibility of combining work and having children, along with the availability of childcare resources, impacted the desire for parenthood. Male students tended to consider parenthood as less impactful on their lives and careers than female students. Social structures might also impact the decision to have children. Conclusion: It is important to provide health education emphasizing fertility awareness and parenthood in young adulthood so participants can consider these facts in advance. In addition, the government should provide resources for couples making parenthood decisions.

Charge-trapping memory device based on a heterostructure of MoS2 and CrPS4

Shin Minjeong,이미정,윤찬수,Kim Sohwi,Park Bae Ho,이성민,박재근 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.78 No.9

Atomically thin two-dimensional (2D) materials have emerged as promising candidates for flexible and transparent electronic applications. Here, we introduce non-volatile charge trapping memory devices, based on the 2D heterostructure field-effect transistor consisting of a few-layer MoS2 channel and CrPS4 charge-trapping gate stack. Clockwise hysteresis behaviors in transfer curves measured at room temperature show strong dependence on the thickness of CrPS4, which are attributed to charge trapping at trap sites in the CrPS4 layers. Our heterostructure memory device with 75 nm-thick CrPS4 layer exhibits both large memory windows up to 100 V and a high on/of current ratio (3 × 105 ) with good endurance during 625 cycles because of excellent trapping ability of trap sites in the CrPS4. Especially, the memory window size can be effectively tuned from 7.6 to 100 V by changing the sweep range of gate voltage. Such high performances of the charge-trapping memory device with a simple heterostructure provide a promising route towards next-generation memory devices utilizing 2D materials.

Charge Trapping Memory Device Based on MoS₂ FET with CrPS₄

Minjeong Shin,Mi Jung Lee,Chansoo Yoon,Gwangtak Oh,Woohyeon Ryu,Sungmin Lee,Je-Geun Park,Bae Ho Park 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1

Atomically thin two-dimensional (2D) materials have emerged as promising candidates for flexible and transparent electronic applications [1, 2]. Here, we introduce non-volatile charge trapping memory devices, based on the 2D heterostructure field-effect transistor consisting of a few-layer MoS₂ channel and CrPS4 charge-trapping gate stack. Clockwise hysteresis behaviors in transfer curves measured at room temperature show a strong dependence on the thickness of CrPS4, which are attributed to charge trapping at trap sites in the CrPS4 layers. Our heterostructure memory device with 75 nm-thick CrPS4 layer exhibits both large memory windows up to 99.7 V and a high on/off current ratio (3x10⁵) with good endurance during 625 cycles because of its excellent trapping ability of trap sites in the CrPS4. Especially, the memory window size can be effectively tuned from 7.6 V to 99.7 V by changing the sweep range of gate voltage. Such high performances of the charge trapping memory device with a simple heterostructure provide a promising route towards next-generation memory devices utilizing 2D materials.

피아노 리사이틀의 원류와 변천에 관한 역사적 고찰

신민정 ( Minjeong Shin ) (사)음악사연구회 2018 음악사연구 Vol.7 No.-

피아노 리사이틀은 19세기에 리스트(Franz Liszt, 1811-1886)가 창시한 것으로 알려진다. 이에 본 논문은 최초의 리사이틀이 탄생한 배경, 리스트의 리사이틀을 둘러싼 19세기 피아니스트들의 다양한 견해, 당시의 음악회 프로그램과 이들이 향유된 문화를 세밀하게 고찰한다. 영국의 산업혁명과 프랑스의 시민혁명 이후 19세기에 이르러 대중음악회가 본격화 되고, 각계각층의 관객들이 한 데 모여 음악을 감상하는 이러한 행사는 사회적으로 분명 새롭게 경험되는 문화였다. 대중음악회가 발달하는 과정에서 여러 과도기적인 시각들이 공존할 수밖에 없었는데, 진보와 보수의 양단간에 음악회가 어떤 미학적 관점을 고수해야 할 것인지 끊임없는 논쟁이 대두되었다. 결국, 음악을 창조한 위대한 작곡가의 작법을 감식하고 이를 숭배하는 의례가 고착화 되면서 20세기의 피아노 리사이틀은 본질적인 변화를 거부하고 관습에 안주하는 추세를 보였으나, 21세기에 들어서는 참신한 시도를 접목한 리사이틀들이 점차 기획 및 양산되기 시작했다. 이로서 과거지향적인 견지로부터, 현대의 관객들이 이해하고 공유하며 즐길 수 있는 문화적 트렌드로 거듭나려 했던 여러 시도와 시대적 흐름을 읽어볼 수 있다. It is well known that piano recitals was created by Franz Liszt (1811-1886) in the 19th century. To this, this dissertation will consider in detail, the background of how the first recital was born, the diverse opinions of 19th century pianists regarding Liszt's recital, the music concert programs of the time and the culture that these possessed. After Britain's Industrial Revolution and the France's Civil Revolution, in the 19th century, popular music concerts became full-fledged and events where audiences from all levels of society gathered to listen to music was a culture being newly experienced by the society. There had to be many transitional views coexisting during the process of popular music concerts developing and endless debate about which aesthetic perspective the music concert had to adhere was hotly discussed between the liberals and the conservatives. Ultimately, with the ritual of identifying and worshipping the composition methods of great composers who created music becoming the norm, the piano recital of the 20th century exhibited the trend of setting with the convention and rejecting intrinsic change. However, in the 21st century, recitals that grafted fresh attempts gradually began to be planned and produced. Therefore, one could experience many attempts and flow of the time that tried to make it re-born as a cultural trend that could be understood, shared and enjoyed by the contemporary audience, away from the past-oriented perspective.

Estimating Domain Scores for Mixed-Format Tests under Item response theory and Generalizability theory Approaches

신민정(MinJeong Shin),이규민(Guemin Lee) 한국교육평가학회 2011 교육평가연구 Vol.24 No.2

이 연구에서는 영역점수를 추정하기 위해 문항반응이론과 일반화 가능도이론을 활용한 추정 방법을 적용해 보았다. 그리고 관찰 점수와 두 이론을 적용하여 산출한 점수를 비교해 보고, 가장 정확한 결과를 도출하는 방법이 무엇인지 알아보았다. 선행 연구와 다른 점은 이 연구에서는 혼합형 검사를 사용했다는 것과 개인 수준과 집단 수준에서의 추정치를 모두 포함하였다는 것이다. 이 연구를 위해 크게 두 가지 조건을 사용하였다. 본 연구에서 사용한 조건은 문항 수와 집단 안에 포함된 피험자 수이다. 문항 수를 13, 26, 51 문항으로 하여 각각 세 가지 검사형을 구성하였고, 집단 내 피험자 수는 25, 50, 100명으로 세 개의 다른 집단을 가정하였다. 연구 결과, 일반화 가능도이론과 문항반응이론을 적용한 방법이 관찰점수 방법보다 더 정확한 결과를 산출한다는 사실을 확인할 수 있었다. 개인 수준에서는 최대우도추정치 방법이 모든 조건에서 가장 작은 평균제곱오차를 보였다. 문항 수가 증가함에 따라 평균제곱오차는 줄어들었으나, 13 문항에서 26 문항으로 증가할 때에는 평균제곱오차의 감소폭이 크지 않았다. 집단 수준에서의 결과에서도 역시 관찰점수 방법보다는 일반화 가능도이론과 문항반응이론을 적용한 방법이 더 나은 결과를 보였다. 문항 수가 13일 때에는 최대우도추정치 방법이 가장 작은 평균 제곱오차를 보였고, 26 문항으로 이루어진 검사형에서는 집단 내 피험자수에 상관없이 문항반응이론방법이 일반화 가능도이론 방법보다 더 나은 결과를 보였다. 문항 수가 51문항으로 증가함에 따라 관찰점수를 제외한 각 방법의 추정치가 비슷한 결과를 보였다. 이 연구에서는 비록 감소되는 폭이 각 조건에 따라 다르긴 하지만, 집단 내 피험자 수와 문항수가 커짐에 따라 평균제곱오차는 점차 줄어든다는 사실을 확인할 수 있었다. This study was conducted to investigate the relative appropriateness of several estimation methods for domain scores under item response theory (IRT) and generalizability theory (G-theory) approaches. Both individual and group level domain score estimates were examined with mixed-format data. Several simulation conditions were formulated by considering and combining the number of items within a separate domain (13, 26, and 51) and the number of examinees within a specified group (25, 50, and 100). Based on the results, both G-theory and IRT-based approaches produced better estimates for domain scores than did using observed scores for all conditions. At the individual level, IRT-MLE method showed the smallest mean square error (MSE). As the number of items increased, MSE decreased as expected. When the number of items increased from 13 to 26, the decrease in MSEs did not seem to be large. At the group level, the GT-Searle method produced the largest MSEs. As the number of items within a domain and examinees within a group increased, MSEs decreased to some extent.

군집 드론망을 통한 IoT 서비스를 위한 보안 프레임워크 연구

신민정(Minjeong Shin),김성운(Sungun Kim) 한국멀티미디어학회 2018 멀티미디어학회논문지 Vol.21 No.8

커피 찌꺼기의 카페인 용출 및 산화분해 특성

신민정 ( Minjeong Shin ),김영훈 ( Young-hun Kim ) 한국환경과학회 2018 한국환경과학회지 Vol.27 No.12

During the past few decades, significant increase in the consumption of coffee has led to rapid increase in the production of coffee waste in South Korea. Spent coffee waste is often treated as a general waste and is directly disposed without the necessary treatment. Spent Coffee Grounds (SCGs) can release several organic contaminants, including caffeine. In this study, leaching tests were conducted for SCGs and oxidative degradation of caffeine were also conducted. The tested SCGs contained approximately 4.4 mg caffeine per gram of coffee waste. Results from the leaching tests show that approximately 90% of the caffeine can be extracted at each step during sequential extraction. Advanced oxidation methods for the degradation of caffeine, such as UV/H₂O₂, photo-Fenton reaction, and UV/O₃, were tested. UV radiation has a limited effect on the degradation of caffeine. In particular, UV-A and UV-B radiations present in sunlight cause marginal degradation, thereby indicating that natural degradation of caffeine is minimal. However, O₃ can cause rapid degradation of caffeine, and the values of pseudo-first order rate constants were found to be ranging from 0.817min^-1 to 1.506 min^-1 when the ozone generation rate was 37.1 g/㎥. Additionally, the degradation rate of caffeine is dependent on the wavelength of irradiation.