• Kyungpook Mathematical Journal
• /
• v.53 no.4
• /
• pp.541-552
• /
• 2013

This research is a continuation of a recent paper due to the first author in [9]. Different from previous results, we investigate the value distribution of difference polynomials of moromorphic functions in this paper. In particular, we are interested in the existence of zeros of $f(z)^n({\lambda}f(z+c)^m+{\mu}f(z)^m)-a$, where f is a moromorphic function, n, m are two non-negative integers, and ${\lambda}$, ${\mu}$ are non-zero complex numbers. However, the proof here is obviously different to the one in [9]. We also study difference polynomials of entire functions sharing a common value, which improves the result in [10, 13].

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.557-558
• /
• 2006

In this paper, the hysteresis characteristics by bias stress in organic thin film transistors using inkjet printing were investigated. Electron trapping increased threshold voltage for positive gate bias stress and hole trapping decreased threshold voltage for negative gate bias stress. From these phenomena, highly reproducible measurement method which minimized threshold voltage shift by choosing the proper range of gate voltage was suggested. Using this measurement method, we found that electron trapping as well as hole trapping had important influence on hysteresis characteristics.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.904-906
• /
• 2009

Organic field-effect transistor (OFET) memory is an emerging device for its potential to realize light-weight, low cost flexible charge storage media. Here we report on a solution-processed poly[9,9-dioctylfluorenyl-2,7-diyl]-co-(bithiophene)] (F8T2) nano floating-gate memory (NFGM) with top-gate/bottom-contact device configuration. A reversible shift in the threshold voltage ($V_{Th}$) and the reliable memory characteristics were achieved by incorporation of thin Au nanoparticles (NPs) as charge storage sites for negative electrons at the interface between polystyrene and cross-linked poly(4-vinylphenol).

• Korean Medical Education Review
• /
• v.20 no.1
• /
• pp.1-5
• /
• 2018

A traditional clerkship consists of a series of short rotations in specialty disciplines and is usually based in tertiary, urban teaching hospitals. Shortened inpatient stays and the shift toward ambulatory management have had a negative impact on student learning. There have been growing concerns that the traditional specialty-based clerkship in fragmented and highly specialized clinical environments may not be the optimal choice for basic clinical education. As a result, a new model of clinical clerkship called longitudinal integrated clerkships (LICs) has emerged. There is increased interest in LICs due to the growing evidence of positive outcomes for students, patients, and supervising clinicians. Emphasizing continuity as one of the main organizing principles of an LIC, this article reviews the introduction of LICs into medical education, the key concepts and educational theories which underpin LICs, and the typology of LICs. The author also offers some personal suggestions for contemplation before clerkship programs in Korea adopt LICs.

• Journal of the Korean Institute of Educational Facilities
• /
• v.11 no.3
• /
• pp.5-15
• /
• 2004

This study aims to review the reality of local educational officials in technical post, to investigate their needs and awareness for newly changing social environment, and to inspire them with alternatives and strategies for reforming and restructuring their organization. It examines and analyses the strong points and weak points of the organization, the methods for improving the operation systems and organizational structures and the problems in the personnel management in officialdom, especially unfairness between the executive and the technical officials through a questionnaire and interview. This study ascertains that most of the technical officials consider expert knowledge and experience as their strong point and think the negative image against its group as their weak point for the organizational development. Specially this article indicates that they are not satisfied with the job conditions and want to shift to the official in executive post.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.23 no.2
• /
• pp.128-132
• /
• 2010

Photonic crystal is dielectric materials or a set of different dielectric materials with periodic structure. Line defect is obtained by leaving out a row of rods along the $\Gamma$-X direction. We showed the change of group velocity in waveguide mode and found resultant small group velocity. Characteristics of the small group velocity were described by electric field distribution. Investigating the phase shift, it is confirmed if small group velocity is positive or negative.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.117-117
• /
• 2007

The physical and electrical properties of nitrided Hf-silicate films, incorporated by NO gas annealing, were investigated by XPS, NEXAFS, TEM and C-V measurement. We confirmed the nitrogen incorporation during NO gas annealing treatment effectively enhances the thermal stability of Hf-silicate. The suppression of phase separation was observed in Hf-silicate films with high nitrogen contents. The negative shift of threshold voltage is caused by the incorporation of nitrogen in the hafnium silicate films.

• Transactions on Electrical and Electronic Materials
• /
• v.13 no.1
• /
• pp.47-49
• /
• 2012

In this paper, we investigated the anomalous hump in the bottom gate staggered a-IGZO TFTs. During the positive bias stress, a positive threshold voltage shift was observed in the transfer curve and an anomalous hump occurred as the stress time increased. The hump became more serious in higher gate bias stress while it was not observed under the negative bias stress. The analysis of constant gate bias stress indicated that the anomalous hump was influenced by the migration of positively charged mobile interstitial zinc ion towards the top side of the a-IGZO channel layer.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.12
• /
• pp.1154-1157
• /
• 1996

The growth and electronic properties of ultrathin silver films deposited onto Pt(211) surface were studied using Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and x-ray photoelectron spectroscopy. The AES and LEED results indicate that the silver grows by a layer by layer growth followed by three dimensional islands growth. The XPS results show that the Ag 3d core-level binding energy of Ag overlayers on Pt(211) shifts toward lower binding energy relative to the bulk value at lower Ag coverage. This negative binding energy shift of the Ag 3d core level is explained by the reduced coordination number of the overlayer atoms and the resulting initial state band narrowing effect suggested by Wertheim and Citrin [Phys. Rev. Lett. 1978, 41, 1425].

• Journal of the Korean Mathematical Society
• /
• v.60 no.2
• /
• pp.255-271
• /
• 2023

In this paper, we deal with random attractors for dynamical systems forced by a deterministic noise. These kind of systems are modeled as skew products where the dynamics of the forcing process are described by the base transformation. Here, we consider skew products over the Bernoulli shift with the unit interval fiber. We study the geometric structure of maximal attractors, the orbit stability and stability of mixing of these skew products under random perturbations of the fiber maps. We show that there exists an open set U in the space of such skew products so that any skew product belonging to this set admits an attractor which is either a continuous invariant graph or a bony graph attractor. These skew products have negative fiber Lyapunov exponents and their fiber maps are non-uniformly contracting, hence the non-uniform contraction rates are measured by Lyapnnov exponents. Furthermore, each skew product of U admits an invariant ergodic measure whose support is contained in that attractor. Additionally, we show that the invariant measure for the perturbed system is continuous in the Hutchinson metric.