• Applied Chemistry for Engineering
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• v.10 no.8
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• pp.1169-1174
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• 1999

2-Diazo-1-naphthoquinone-5-sulfonyl chloride(NQD-Cl) was synthesized from sodium 2-diazo-naphthoquinone-5-sulfonate by chlorination. NQD-Cl was esterified with hydroxybenzophenones to give several 1,2-naphthoquinone-(2)-diazide-5-sulfonic acid ester derivatives(NQD-esters). We have compared benzophenone derivatives with methoxy group to benzophenone derivatives with hydroxy group. Solubility of each NQD-ester was studied. Each of NQD-esters was formulated with novolac base resin and PS plates were manufactured. Photosensitivity, bleachability, compatible exposed time and relative sensitivity were determined by UV spectrophotometry, imaged by UV lithographic techniques, and the gray scale method. According to the number of substituted NQD group, it showed that relative sensitivity was different from gray scale method. NQD-esters with methoxy group showed a good solubility and higher sensitivity than commercial PS ones.

• Journal of the Korean Graphic Arts Communication Society
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• v.12 no.1
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• pp.17-34
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• 1994

Recently, the photopolymer made of novolak resin as the base and the naphthoquinonediazide(NQD) as the photoreactive compound is used for the presensitized plate(PS plate). The reaction mechanism of the NQD-novolak resin on light exposure is considered. Upon exposure it undergoes a Wolff rearrangement, via ketene intermediate which react with water ti form an 3-indene carboxylic acid. It was also found that NQD type resin in this experiment shows a high relative sensitivity compared with imported sample from Japan.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.106-106
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• 2012

Strategies to facilitate carrier transfer/transport while preserving confined characteristics of isolated nanocrystal quantum dots (NQDs) will be discussed. Specifically, synthesis and characterizations of 1) the fabrication of neat NQD solids (assembled NQD films) with modified surfaces by attaching ligands or by applying physical processes such as heat annealing [J. Phys. Chem. C (2011), 115(3), 607] and 2) coupling NQDs to one-dimensional nanostructures such as single-walled carbon nanotubes (SWNTs) [ACS Nano, (2010) 4(1), 324] will be presented. Further, recent achievement ours of fabricating NQDs assemblies into photovoltaic devices for elucidating transfer mechanism witll be discussed.

• Journal of applied mathematics & informatics
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• v.10 no.1_2
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• pp.235-243
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• 2002

In this paper, we show that NQD ordering is preserved under mixture, limits in distribution, invariant under transformation of increasing functions. Finally, we explore the characterization and limit in distribution of RTD(LTI) ordering and some properties.

• Journal of the Korean Mathematical Society
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• v.56 no.2
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• pp.457-473
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• 2019

In this paper, we investigate weak laws of large numbers for weighted coordinatewise pairwise negative quadrant dependence random vectors in Hilbert spaces in the case that the decay order of tail probability is r for some 0 < r < 2. Moreover, we extend results concerning Pareto-Zipf distributions and St. Petersburg game.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.93-93
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• 2010

Semiconductor nanocrystal quantum dots (NQDs) have recently attracted considerable interest for use in photovoltaics. Band gaps of NQDs can be tuned over a considerable range by varying the particle size thereby allowing enhance absorption of solar spectrum. NQDs, synthesized using colloidal routes, are solution processable and promise for a large-area fabrication. Recent advancements in multiple-exciton generation in NQD solutions have afforded possible efficiency improvements. Various architectures have attempted to utilize the NQDs in photovoltaics, such as NQD-sensitized solar cell, NQD-bulk-heterojuction solar cell and etc. Here we have fabricated CdSe NQDs with the band gap of 1.8 eV to 2.1 eV on thin-layers of p-type organic crystallites (1.61 eV) to realize a donor-acceptor type heterojuction solar cell. Simple structure as it was, we could control the interface of electrode-p-layer, and n-p-layer and monitor the following efficiency changes. Specifically, surface molecules adsorbed on the NQDs were critical to enhance the carrier transfer among the n-layer where we could verify by measuring the photo-response from the NQD layers only. Further modifying the annealing temperature after the deposition of NQDs on p-layers allowed higher conversion efficiencies in the device.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.63-63
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• 2010

Ability to transport extracted carriers from NQDs is essential for the development of most NQD based applications. Strategies to facilitate carrier transport while preserving NQDs' optical characteristics include: 1) Fabricating neat films of NQDs with modified surfaces either by adapting series of ligands with certain limitations or by applying physical processes such as heat annealing 2) Coupling of NQDs to one-dimensional nanostructures such as single walled carbon nanotubes (SWNTs) or various types of nanowires. NQD-nanowire hybrid nanostructures are expected to facilitate selective wavelength absorption, charge transfer to 1-D nanostructures, and efficient carrier transport. Even with the vast interests in using NQD-SWNT hybrid materials in optoelectric applications, still, no reports so far have clearly elucidated the optoelectric behavior when they were assembled on the FET mainly because the complexity involving in both components in their preparation and characterization. We have monitored the optical properties of both components (NQDs, SWNTs) from the synthesis, to the assembly, and to the device. More importantly, by using pyridine molecules as a linker to non-covalently attach NQDs to SWNTs, we were able to assemble NQDs on SWNTs with precise density control without harming their electronic structures. Furthermore, by measuring electrical signals from the fabricated aligned SWNTs-FET using dielectrophoresis (DEP), we were able to elucidate the charge transfer mechanism.

• Journal of the Korean Statistical Society
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• v.29 no.3
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• pp.261-268
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• 2000

Let {Xn,n$\geq$1} be a sequence of pairwise negative quadrant dependent(NQD) random variables and let {an,n$\geq$1} and {bn,n$\geq$1} be sequencesof constants such that an$\neq$0 and 0$\infty$. In this note, for pairwise NQD random varibles, a general weak law of alrge numbers of the form(∑│aj│Xj-$\upsilon$n)/bnlongrightarrow0) is established, where {νn,n$\geq$1} is a suitable sequence. AMS 2000 subject classifications ; 60F05

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.85-95
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• 2012

In this paper we define extended negative quadrant dependence which is weaker negative quadrant dependence and show conditions for having extended negative quadrant dependence property. We also derive generalized Farlie-Gumbel-Morgenstern uniform distributions that possess the extended quadrant dependence property.

• Journal of applied mathematics & informatics
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• v.6 no.3
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• pp.959-968
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• 1999

In this paper we are obtained new results for bivariate pro-cesses which help us to tell the dependent structure among hitting times of the processes. We are proposed both dependence properties and the-oretical results among the processes and certain kinds of dependence properties when we are imposed on processes are reflected as analo-gous properties of corresponding hitting times. Finlly we are given some examples to illustrate these concepts.