• Title/Summary/Keyword: current science issue

Search Result 392, Processing Time 0.028 seconds

The improvement of electrical properties of InGaZnO (IGZO)4(IGZO) TFT by treating post-annealing process in different temperatures.

  • Kim, Soon-Jae;Lee, Hoo-Jeong;Yoo, Hee-Jun;Park, Gum-Hee;Kim, Tae-Wook;Roh, Yong-Han
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.08a
    • /
    • pp.169-169
    • /
    • 2010
  • As display industry requires various applications for future display technology, which can guarantees high level of flexibility and transparency on display panel, oxide semiconductor materials are regarded as one of the best candidates. $InGaZnO_4$(IGZO) has gathered much attention as a post-transition metal oxide used in active layer in thin-film transistor. Due to its high mobility fabricated at low temperature fabrication process, which is proper for application to display backplanes and use in flexible and/or transparent electronics. Electrical performance of amorphous oxide semiconductors depends on the resistance of the interface between source/drain metal contact and active layer. It is also affected by sheet resistance on IGZO thin film. Controlling contact/sheet resistance has been a hot issue for improving electrical properties of AOS(Amorphous oxide semiconductor). To overcome this problem, post-annealing has been introduced. In other words, through post-annealing process, saturation mobility, on/off ratio, drain current of the device all increase. In this research, we studied on the relation between device's resistance and post-annealing temperature. So far as many post-annealing effects have been reported, this research especially analyzed the change of electrical properties by increasing post-annealing temperature. We fabricated 6 main samples. After a-IGZO deposition, Samples were post-annealed in 5 different temperatures; as-deposited, $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$ and $500^{\circ}C$. Metal deposition was done on these samples by using Mo through E-beam evaporation. For analysis, three analysis methods were used; IV-characteristics by probe station, surface roughness by AFM, metal oxidation by FE-SEM. Experimental results say that contact resistance increased because of the metal oxidation on metal contact and rough surface of a-IGZO layer. we can suggest some of the possible solutions to overcome resistance effect for the improvement of TFT electrical performances.

  • PDF

Current Research Trends in Hospice-Related Domestic Nursing Research Theses (1998~2017) (호스피스 관련 국내 간호연구 논문 동향(1998~2017))

  • Kim, Won Soon
    • Journal of Hospice and Palliative Care
    • /
    • v.22 no.1
    • /
    • pp.19-29
    • /
    • 2019
  • Purpose: In this study, the hospice nursing research trend in 1998~2017 was investigated by analyzing research articles on hospice nursing. Methods: Literature search was performed with keywords of 'nursing' and 'hospice on an academic research information service. Also reviewed were all articles published in the Korean Journal of Nursing Science and its 8 subcategory journals, the Korean Journal of Hospice and Palliative Care and the Korean Hospice Association from 1998 through 2017, except thesis papers. Results: In 2013~2017, 79 articles (31.0%) were relevant, up over 7% from 61 articles (23.9%) in 2008~2012. The most studied field was psychology (92 papers, 36.2%) in the Korean Journal of Hospice and Palliative Care. Enrolled in most papers were patients with end-stage cancer (75, 29.5%), which is overwhelmingly high. Most studies used quantitative methods (183, 72.0%). Recognition was the most studied theme (62, 24.4%), and 16 of them focused on recognition of death (6.3%). Intervention studies totaled 34 (13.4%), and most of them (7, 2.8%) were conducted for palliative education. Conclusion: Most hospice nursing studies were quantitative studies, conducted with patients, and hospice nursing intervention programs were similar to each other. Thus, more studies with hospice patients and their families are needed. And more experimental and qualitative studies are needed to build an evidence-based nursing study environment. Considering how most studies examined psychological factors, physiological factors such as pain, a major issue in hospice care, should be analyzed in experimental studies to construct a pain intervention program for hospice patients.

Low-voltage Pentacene Field-Effect Transistors Based on P(S-r-BCB-r-MMA) Gate Dielectrics (P(S-r-BCB-r-MMA) 게이트 절연체를 이용한 저전압 구동용 펜타센 유기박막트랜지스터)

  • Koo, Song Hee;Russell, Thomas P.;Hawker, Craig J.;Ryu, Du Yeol;Lee, Hwa Sung;Cho, Jeong Ho
    • Applied Chemistry for Engineering
    • /
    • v.22 no.5
    • /
    • pp.551-554
    • /
    • 2011
  • One of the key issues in the research of organic field-effect transistors (OFETs) is the low-voltage operation. To address this issue, we synthesized poly(styrene-r-benzocyclobutene-r-methyl methacrylate) (P(S-r-BCB-r-MMA)) as a thermally cross-linkable gate dielectrics. The P(S-r-BCB-r-MMA) showed high quality dielectric properties due to the negligible volume change during the cross-linking. The pentacene FETs based on the 34 nm-thick P(S-r-BCB-r-MMA) gate dielectrics operate below 5 V. The P(S-r-BCB-r-MMA) gate dielectrics yielded high device performance, i.e. a field-effect mobility of $0.25cm^2/Vs$, a threshold voltage of -2 V, an sub-threshold slope of 400 mV/decade, and an on/off current ratio of ${\sim}10^5$. The thermally cross-linkable P(S-r-BCB-r-MMA) will provide an attractive candidate for solution-processable gate dielectrics for low-voltage OFETs.

Quality Evaluation of Long-Term Shipboard Salinity Data Obtained by NIFS (국립수산과학원 장기 정선 관측 염분 자료의 정확성 평가)

  • PARK, JONGJIN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.26 no.1
    • /
    • pp.49-61
    • /
    • 2021
  • The repeated shipboard measurements that have been conducted by the National Institute of Fisheries Science (NIFS) for more than a half century, provide the valuable long-term hydrographic data with high spatial-temporal resolution. However, this unprecedent dataset has been rarely used for oceanic climate sciences because of its reliability issue. In this study, temporal variability of salinity error in the NIFS data was quantified by means of extremely small variability of salinity in the deep layer of the south-western East Sea, in order to contribute to studies on long-term variability of the East Sea. The NIFS salinity errors estimated on the isothermal surfaces of 1℃ have a remarkable temporal variation, such as ~0.160 g/kg in the year of 1961~1980, ~0.060 g/kg in 1981~1994,~0.020 g/kg in 1995~2002, and ~0.010 g/kg in 2003~2014 on average, which basically represent bias error. In the recent years, even though the quality of salinity has been improved, there still remain relatively large bias errors in salinity data presumably due to failure of salinity sensor managements, especially in 2011, 2013, and 2014. On the contrary, the salinity in the year of 2012 was very accurate and stable, whose error was estimated as about 0.001 g/kg comparable to the salinity sensor accuracy. Thus, as long as developing proper data quality control procedures and sensor management systems, I expect that the NIFS shipboard hydrographic data could have good enough quality to support various studies on ocean response to climate variabilities. Additionally, a few points to improve the current NIFS shipboard measurements were suggested in the discussion section.

Legal Issues for the Implementation of Non-Face-to-Face Treatment (비대면진료 실행을 위한 법적 쟁점)

  • Kwon, Ohtak
    • The Korean Society of Law and Medicine
    • /
    • v.23 no.3
    • /
    • pp.47-87
    • /
    • 2022
  • Due to the COVID-19 pandemic, non-face-to-face treatment was temporarily permitted. A lot of consensus has been formed on the need to continuous non-face-to-face treatment. However, the current 「Medical Service Act」 only permits telemedicine between doctors and medical personnel. On the other hand, as a result of legal interpretation, there is an opinion that non-face-to-face treatment is allowed. But considering the overall legal system, non-face-to-face treatment is not allowed. Nevertheless, we have to consider the reality such as the development of science and technology and the outbreak of infectious diseases. Therefore, it is not advisable to allow face-to-face treatment only. Ultimately, it is necessary to find ways to ensure that non-foce-to-face treatment can be performed in a safe and effective manner. And it should be institutionalized. This is strategically necessary and important. Therefore, we must look over ahead legal issues to be discussed. First of all, the scope, the target disease and the subject of implement have to be clear. Also, structurally, the standards of facilities and equipment must be prepared for non-face-to-face treatment to be implemented. Functionally, communication and information exchange between doctors and patients should be well conducted. In addition, the information protection management system that occurs in the process of non-face-to-face treatment should be materialized. Lastly, the issue of responsibility and cost of non-face-to-face treatment should be decided in detail. When these problems materialize, it can be expected that a safe non-face-to-face treatment environment will be established.

A Study on the Supply of First/Last Mile Transportation Methods Based on ABATA Travel Patterns Analysis for the Provision of MaaS (MaaS 제공을 위한 ABATA 통행 분석 기반의 First/Last Mile 이동 수단 공급 방안 연구)

  • Choi, Jaeon;Song, Jaein;Kang, Min Hee;Eom, Jinki;Hwang, Kee Yeon
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.21 no.1
    • /
    • pp.159-181
    • /
    • 2022
  • Today, people in cities use differentthe types of transportation that rangepeople use in cities have diversified from existing public transportation, cars, taxis to shared bicycles and shared electric kickboards. In addition, with the development of mobile platform -based search, order, and payment services, and transportation services have also begun to change into platform-based integrated services. In particular, MaaS, which has emerged as an integrated mobile service and, is currently being studied and operated worldwide., However, MaaS but remains at the level of the integrated provision of the existing public transportation. As a result of Specifically, the results of a literature review on this issue reveal that, the First/Last Mile problem raised at the current level of MaaS is likely to be solved by establishing an improved policy incorporating new means of transportation. Therefore, this study aims to establish a First/Last Mile transportation supply plan for successful MaaS provision. This establishment is realized by analyzing the traffic patterns of urban populations usingbased on the ABATA system,, an activity-based traffic analysis model withevaluated as having higher analysis power on people's traffic.

Study on the Feasibility of Space Weapon Development Utilizing Active Debris Removal Techniques and Understanding of Space Maneuver Warfare (우주 쓰레기 제거기술을 활용한 우주무기 개발 개연성 고찰 및 우주기동전(Space Maneuver Warfare)의 이해)

  • Seonghwan Choi
    • Journal of Space Technology and Applications
    • /
    • v.3 no.2
    • /
    • pp.165-198
    • /
    • 2023
  • According to the studies recently published through advanced maui optical and space surveillance technologies (AMOS) Conference 2021, LEO conjunction assessment revolves around not on operating satellites but space debris such as rocket bodies and non-operational satellites, hence suggesting a solution through space traffic management. Against this backdrop, the issue of active debris removal (ADR) has emerged to the surface as an international challenge throughout the globe. In step with this, the United Nations General Assembly approved a resolution calling on nations to halt tests of direct-ascent anti-satellites, to which U.S. and twelve other nations included Republic of Korea were original signatories. ADR techniques are also actively being researched in the civil sector, and these commercial services, if successfully developed, could possibly be utilized for military use as well. As such, this paper will help readers' understanding for the current status of ADR techniques, space threat assessments, on-orbit rendezvous and proximity operations by looking at previous cases, reflecting on space-faring nations' ADR techniques and its development probability in relation to space weapons. As a conclusion, this study will propose the needs of developing space propulsion system by understanding Space Maneuver Warfare in preparation for the future space battlefield.

Explaining Variance in Children's Recall of a Stressful Experience: Influence of Cognitive and Emotional Individual Differences (스트레스적 경험에 대한 아동 기억의 신뢰성과 인지 및 정서적 개인차 특성들과의 관계)

  • Seungjin Lee
    • Korean Journal of Culture and Social Issue
    • /
    • v.19 no.3
    • /
    • pp.343-365
    • /
    • 2013
  • This study examined the effects of various individual differences on children's memory of a stressful experience. The participants for the current study were children (N=85) aged 4-9 years those who experienced a naturally occurring stressful experience from a dental procedure. There was overall negative relation between the level of stress and children's memory performance. However, more interestingly, the results of this study provided some further evidence that several cognitive (i.e., receptive language ability and working memory capacity) and emotional (i.e., children's general anxiety condition, children's self-report of pain and anxiety about the event) individual difference factors were associated with variations in children's remembering across ages. The results suggest that the relation between stress and children's memory might be impacted in part by children's various individual characteristics. Furthermore, the findings are discussed in the applied context that based on the results clinical and legal professionals can tailor interviews to best meet children's needs and capabilities, and create developmentally and individually sensitive guidelines for interviewing children in the legal system.

  • PDF

The Effect of Collectivism on Anxiety Perception and Mental Health in Youth Unemployment (집합주의 문화가 청년실업에 대한 불안 지각 및 정신건강에 미치는 영향)

  • Minjung Cha;So Young Park;Hyun-joo Song;Younhee Roh
    • Korean Journal of Culture and Social Issue
    • /
    • v.18 no.1
    • /
    • pp.27-51
    • /
    • 2012
  • The current paper examines the effect of collectivism on perceived youth unemployment anxiety as well as mental health and the mediating effects of employment self-efficacy; self-esteem; and the frequency of upward and downward social comparisons. In Study 1, data were gathered from 179 university students in upper-ranking schools and middle-ranking schools in Seoul, Korea. Our results indicated that (a) collectivism was positively correlated to, and also an significant predictor of perceived youth unemployment anxiety and mental health and (b) employment self-efficacy and self-esteem had mediating effects on the relationship between collectivism and perceived youth unemployment anxiety and mental health. In Study 2, data were gathered from 118 students in upper-ranking schools in Seoul, Korea. Our results indicated that (c) upward social comparison had mediating effects on the relationship between collectivism and perceived youth unemployment anxiety and mental health, while downward social comparison did not. The findings are discussed in terms of their general implications for understanding the importance of culture in employment seeking settings.

  • PDF

Water-Blooms (Green-Tide) Dynamics of Algae Alert System and Rainfall-Hydrological Effects in Daecheong Reservoir, Korea (대청호 조류경보제의 녹조현상 동태와 강우-수문학적 영향)

  • Shin, Jae-Ki;Kang, Bok-Gyoo;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
    • /
    • v.49 no.3
    • /
    • pp.153-175
    • /
    • 2016
  • Daecheong Reservoir has suffered eutrophication and water-blooms by blue-green algae from initial impoundment, and algae alert system (AAS) was introduced in 1997. The purpose of this study was to investigate the effect of rainfall and hydrological factors in increase or decrease variability of green-tide and prolonged AAS, studied and analyzed the current situation of AAS has been operating for 19 years (1997~2015) in Daecheong Reservoir. The total issued number of AAS was 46 times, the most frequent period in August and September were 22 times (752 days) and 16 times (431 days), respectively, it accounted for 82.6%. Many number and frequency during this period were significantly associated with rainfall, various discharge and water level. Rainfall and hydrological events are associated with the rainy season of monsoon-Changma and the typhoon, it was concentrated in June~September, total rainfall in this period accounted for 69.9% of the annual rainfall. An increase in inflows was dependent on the intensity, frequency and the amount of rainfall. Accounted for 68.4% of the total annual inflow, it was a time when the most rapidly changing hydrological variability in the reservoir. The total outflow was closely related to rainfall, and compared the distinctive characteristics of hydropower generation and watergate-spillway discharge. In addition, the upreservoir zone of Daecheong Reservoir could be vulnerable to green-tide by regulating discharge of the upstream dam. The issue of AAS was strongly related to the with and without of watergate-spillway discharge. The watergate-spillway discharge had a total of 25 times, it was maximum 17 days from July to September in the year. And the opening times and each duration of the watergate were 1~4 times and the range of 3~37 days, respectively. When the watergate opened, the issue of AAS was maintained to 13 years and the movement of water bodies and green-tide was great about five times than that of non-open, had a profound effect on prolonged AAS within reservoir. In Daecheong Reservoir, Chusori (CHU) area of the So-ok Stream was still showing serious symptoms green-tide levels in the summer, but Janggye (JAN) waters of the main reservoir was pointed out that more important. AAS will be operated by an absolutely consider the rainfall and hydrological effects around the watergate-spillway discharge. The measures of green-tide will be included in the limnological studies more suited to the characteristics of the watershed and reservoir of the our country. Finally, from now on, we will prepare the systematic management and guidelines for vulnerable zone water-blooms that are the source within the reservoir before the monsoon rather than waiting for the arrival of green-tide on the operating stations of AAS.