• Journal of the Korean Graphic Arts Communication Society
• /
• v.15 no.1
• /
• pp.71-83
• /
• 1997

In recent years, various kinds of organic photoreceptors have been used for copy machines based on electrophotography. Most of them are constructed into layered devices in which a photogeneration layer is separated from a charge transport layer. They are usually used with application of negative charges. Organic pigment have received considerable attention with phthalocyanine, squaraine, and azo compounds being used to construct zerograpgic photoreceptors with enhanced long wavelength sensitivity, residual potential and zerograpgic gain of squaraine photoconductor were measured from the photoinduced discharge curve. Most of synthesized squaraine derivative couldn`t use for CGM(charge generation material), but it knew that a part of one was able to use it within the possibility. A few appliance is used it know about dependence on CTM(charge transport material) of squaraine derivative. It could know that experiment`s result is 2.5-bis(4-N-N`-diethylaminophenyl)-1,3,4-oxadiazole(OXD) is the bestproduct.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.820-822
• /
• 2008

Pentacene has excellent semi-conducting characteristics. But pentacene practically used in OTFTs gives rise to problems mainly due to its sensitivity to oxygen and its very low solubility. In order to make up the problems, 6,13-disubstituted pentacene derivative was synthesized and characterized. The properties of the compound were characterized by FT-IR, NMR and we measured the charge transport mobility and the on/off current ratios.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.370-372
• /
• 1997

In this paper, magnetic fields produced by lightning return strokes were investigated and analyzed Magnetic field and its derivatives were measured with two crossed loop antennas. Frequency bandwidths of the magnetic field and its derivative measuring systems are in the range of $270\;[Hz]\;{\sim}\;2.3\;[MHz]$ and $450\;[Hz]\;{\sim}\;2.5\;[MHz]$, and their response sensitivity are 128 [mV/${\mu}T$] and 4.12 [mV/nT//${\mu}s$], respectively. Signals are digitized every 500 [ns], data are automatically recorded by transient signal analyzer(Nicolet Pro. 30) having the resolution of 12 - bit and the length of 5 kilowords, and they are registered at personal computer. Magnetic field and its derivative waveforms associated with lightning return strokes were observed since the summer of 1997 at Inha University in Inchon.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.623-624
• /
• 2008

We present a level set method for numerical shape optimization of electromagnetic systems. The level set method does not only lead to efficient computational schemes, but also is able to handle topological changes such as merging, splitting and even disappearing of connected components. The velocity field on boundaries is obtained by a shape derivative of continuum sensitivity analysis using the material derivative concept and an adjoint variable technique. Two numerical results of dielectric optimization between electrodes showed that the level set method is feasible and effective in solving shape optimization problems of electromagnetic systems.

• The Korean Journal of Applied Statistics
• /
• v.7 no.2
• /
• pp.21-34
• /
• 1994

In this paper we consider the M/M/1 Queue with mean inter arrival time $\theta$. We derive a sample path estimator for the derivative of steady state mean system time with respect to $\theta$. We also show that the derived sample path estimate can be expressed as a sum of the IPA estimate and the other effect. We have a similar result for the derivative of limiting probability $P_k$ with respect to $\theta$.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.7
• /
• pp.2359-2364
• /
• 2012

Two new chemosensors, rhodamine 6G derivative bearing hydroxyethyl group (1) and rhodamine base derivative bearing 15-crown-5 group (2) were synthesized and their sensing behaviors toward various metal ions were investigated by UV/Vis and fluorescence spectroscopies. Addition of $Hg^{2+}$ ion to a $CH_3CN$ solution of 1 and 2 gave visual color changes as well as fluorescent OFF-ON observations. Selectivity and sensitivity of 1 towards $Hg^{2+}$ are excellent enough to detect micromolar level of $Hg^{2+}$ ion, even in equeous media and biological sample (HeLa cell).

• Nonlinear Functional Analysis and Applications
• /
• v.29 no.2
• /
• pp.597-620
• /
• 2024

In this study, the conformable fractional derivative(CFD) of order 𝝔 in conjunction with the LC operator of orderρ is used to develop the model of the transmission of the A(H1N1) influenza infection. A brand-new A(H1N1) influenza infection model is presented, with a population split into four different compartments. Fixed point theorems were used to prove the existence of the solutions and uniqueness of this model. The basic reproduction number R₀ was determined. The least and most sensitive variables that could alter R₀ were then determined using normalized forward sensitivity indices. Through numerical simulations carried out with the aid of the Adams-Moulton approach, the study also investigated the effects of numerous biological characteristics on the system. The findings demonstrated that if 𝝔 < 1 and ρ < 1 under the CFD, also the findings demonstrated that if 𝝔 = 1 and ρ = 1 under the CFD, the A(H1N1) influenza infection will not vanish.

• International Journal of Precision Engineering and Manufacturing
• /
• v.2 no.3
• /
• pp.54-60
• /
• 2001

A newly designed inductive micro displacement detecting system is presented. The proposed inductive system consists of driving coils, position-detecting coils, cores, and closed-loop formed magnetic blocks. The cores and magnetic blocks are made of Mn-Zn ferrite. When AC sine wave is applied to the driving coils, the time derivative flux is generated within the system, and then induced voltages arise in the position-detecting coils according to the core\`s position. Putting the cores to be moved proportionally to the input displacement, the induced voltage is proportional to input displacement. The parameters that affect the system characteristics are turn ratio, air-gap size, excitation frequency, overlap area, load resistance, capacitance effect, and so forth. Based on the experimental results, the system parameters are selected in such a way as to have high sensitivity ad stable responses. The sensitivity of the proposed inductive displacement-detecting system is greater than 2800mV.V-1mm-1 and the linearity error is below $\pm$0.10% in the range of $\pm$200㎛.

• Journal of Navigation and Port Research
• /
• v.44 no.2
• /
• pp.98-109
• /
• 2020

In recent years, there have been concerted efforts toward predicting ship maneuvering in shallow water since the majority of ship's accidents near harbors commonly occur in shallow and restricted waters. Enhancement of ship maneuverability at the design stage is crucial in ensuring that a ship navigates safely. However, though challenging, establishing the mathematical model of ship maneuvering motion is recognized as crucial toward accurately predicting the assessment of maneuverability. This paper focused on a study on sensitivity analysis of the hydrodynamic coefficients on the maneuverability prediction of KVLCC2 in shallow waters. Hydrodynamic coefficients at different water depths were estimated from the experimental results conducted in the square tank at Changwon National University (CWNU). The simulation of standard maneuvering of KVLLC2 in shallow waters was compared with the results of the Free Running Model Test (FRMT) in shallow waters from other institutes. Additionally the sensitivity analysis of all hydrodynamic coefficients was conducted by deviating each hydrodynamic derivative from the experimental results. The standard maneuvering parameters including turning tests and zig-zag maneuvers were conducted at different water depths and their effects on the standard maneuvering parameters were assessed to understand the importance of different derivatives in ship maneuvering in shallow waters.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.34 no.3
• /
• pp.328-338
• /
• 1998

It is main objective of this approach to present a method to analyse stochastic design sensitivity for problems of structural dynamics with randomness in design parameters. A combination of the adjoint variable approach and the second oder perturbation method is used in the finite element approach. An alternative form of the constant functional that holds for all times is introduced to consider the time response of dynamic sensitivity. The terminal problem of the adjoint system is solved using equivalent homogeneous equations excited by initial velocities. The numerical procedures are shown to be much more efficient when based on the fold superposition method : the generalized co-ordinates are normalized and the correlated random variables are transformed to uncorrelated variables, where as the secularities are eliminated by the fast Fourier transform of complex valued sequences. Numerical algorithms have been worked out and proved to be accurate and efficient : they codes whose element derivative matrices can be explicitly generated. The numerical results of two cases - 2-dimensional portal frame and 3/4-cylindrical shell structure - for the deterministic and stochastic sensitivity analysis illustrates in this paper.