• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.266-271
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• 2009

We have investigated the lasing characteristics of GaAs-based 1300 nm wavelength region InAs Quantum Dot Laser Diode grown by Migration Enhanced Molecular Beam Epitaxy. Under a pulsed and CW operation, we observed the state switching of lasing wavelength from ground state (1302 nm) to excited state (1206 nm) due to the gain saturation of ground state. Under a pulsed operation, $J_{th}=92A/cm^2$, $\lambda_L=1311\;nm$ and under a CW operation, $J_{th}=247A/cm^2$, $\lambda_L=1320\;nm$.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.1
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• pp.13-25
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• 2005

In order to technical analysis of the Newspaper printing press, the printability such as, dot gain, contrast and printing density change according to the amount of ink and damping water feeding were experimented. t도 Printability assurance in printing aims at a correct and constant color reproduction throughout the whole print-run. And the checked values were checked from densitometer and colorimeter instead of conventional subjective method. In this research, we could propose the range of driving in printing of domestic Newspaper printing press as well as the limits of ink feed speed and damping water feed speed.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.1
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• pp.1-12
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• 2006

The rheological characteristics of an ink relate to its performance on the press and to the printing quality such as ink stability, transfer characteristics, mottle, squash, misting, dot gain, and so on. For lithographic print, the emulsification of ink is an important factor to determine the product. And also the rheological characteristics of the emulsified ink should be investigated. Thus, in this study, the effects of the changing molecular weight of rosin modified phenolic resin on the water-pickup ratio of neat inks were studied. And then rheological properties of neat inks and emulsified inks with changing molecular weight of rosin modified phenolic resin were analyzed by using rotational rheometer.

• Asia pacific journal of information systems
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• v.11 no.3
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• pp.185-208
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• 2001

A growing number of firms are competitively entering into e-business because they see the high potential of e-business growth as an opportunity. The positive expectation of e-business market leads most firms to go into e-business, but it is not clarified what kinds of benefits firms gain through e-business. In this paper, we examine whether firms' economic benefits are related to e-business activities. For this purpose, we employ event study methodology and assess the cumulative abnormal returns for 782 e-business initiatives made by firms listed in Korean capital markets. The well-known "Dot Com Effect" is empirically verified through this study. The results of this study indicate that the e-business potential is highly evaluated in the capital market, and e-business firms are expected to create significant benefits in the future period.

• International Journal of Control, Automation, and Systems
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• v.3 no.1
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• pp.56-69
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• 2005

In this paper, it is clearly shown that the two well-known necessary and sufficient conditions mp n as generic static output feedback pole-assignment and mp + d(m+p) n+d as generic minimum d-th order dynamic output feedback pole-assignment on complex field, unbelievably, do not match up each other in strictly proper linear systems. For the analysis, a diagram analysis is newly created (which is defined by the analysis of 'convoluted rectangular/dot diagrams' constructed via node-branch conversion of the signal flow graphs of output feedback gain loops). Under this diagram analysis, it is proved that the minimum d-th order dynamic output feedback compensator for pole-assignment in m-input, p-output, n-th order systems is quantitatively decomposed into static output feedback compensator and its associated d number of arbitrary 1st order dynamic elements in augmented (m+d)-input, (p+d)-output, (n+d)-th order systems. Total configuration of the mismatched data is presented in a Table.

• Journal of the Korean Graphic Arts Communication Society
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• v.20 no.2
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• pp.31-43
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• 2002

Screen printing is a stencil process whereby ink is transferred to the substrate through a stencil supported by a fine fabric mesh. Therefore screen had a tendency to distort and swell, as ink was deposited between the fibers, and were difficult to clean. The tow importance of stencil parameters that affect print quality are stencil thread diameter and the fabric thickness because of their influence on both ink deposit and print definition. Since screen printing inks can be formulated to adhere to almost any surface, and the printing process itself can be handled almost any substrate in a wide variety of shape, screen printing is a very versatile process. The small size pronting is reproduced image used screen printing because the surface of substrates is not suited at screen printing method. In screen printing, the need of high definition printing is gradually increasing according to developing special inks. A conventional haftone, so called AM screening, is simple and easy to implement, but the haftone dot patterns by using this method are not free for the moire fringe. This paper is used densitometry and image analysis to investigate relation with printing according to screen mesh, opening size and resolution of copy in image reproduction used FM screen. We had the good result of dot gain and tone reproduction on the screen printing of high definition using FM screen.

• Polymer(Korea)
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• v.38 no.5
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• pp.620-625
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• 2014

The effect of polyvinyl alcohol/polyamide-epichlorohydrin (PVA/PAE) complex strengthening additive on dry and wet strength and surface properties of paper was investigated. The enhancements of dry and wet strength and dimensional stability were found when PVA/PAE was applied as a complex strengthening additive compared with the cases of applying individual PVA or PAE. This was understood as physical crosslinking between PVA and PAE in the PVA/PAE complex strength additive. This complex strengthening additive also lowered surface roughness and increased sizing. As a result, PVA/PAE complex strengthening additive provided the distinctive gain dot in printed papers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.232-238
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• 2013

In this paper we describe the maximum energy transfer of CSA(Capacitive Switching Antenna). CSA which is radiated antenna system contain energy storage and switch, antenna needs to high voltage source for electrical field radiation experiment. In this experiment we employed Marx generator as a charging source. CSA can radiate electrical field more efficiently by varying antenna capacitance. The electromagnetic generation system which was using CSA has some advantages which are more simple and more effective compared to exist system. We evaluated the performance of electromagnetic wave generating system using CSA. As a result UWB gain of system is 0.47, It is higher level than exist system is 0.3. Radiated electrical field strength at 1m is 70kV/m. It is measured by D-dot sensor and gap distance is 20mm. Center frequency of CSA is approximately 25MHz. When vary the antenna gap distance from 50mm to 20mm, we can find the radiation field strength is decrease and antenna center frequency is increased. We also simulated the energy transfer efficiency to compare with experiment result. Consequentially, CSA needs to appropriate capacitance which is similar value from marx generator for maximum energy transfer, and gap is less than 1mm to increase the CSA capacitance.

• Safety and Health at Work
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• v.12 no.3
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• pp.346-350
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• 2021

Background: The high sensitivity of individuals toward safety information in production activities, that is, attentional bias toward safety (ABS), can positively predict safe behaviors. It has become a hot topic in current organizational safety behavior research. However, there is no literature on its modification method. Methods: Based on the modified dot-probe task, we designed a modification training method of ABS. The training method required subjects to respond to the location of detection points that presented after safety stimulus and neutral stimulus pictures. Subjects' attentional bias values of safety and neutral pictures were measured during the experiment. Twenty-one students were selected and divided into a control group and training group to gain comparable results. Results: A novel training method was developed in this study to promote the efficacy of safety stimulus by activating ABS of the subjects. Moreover, repeated trainings and preacquired relative knowledge can enhance this effect. Conclusion: This study develops an experimental approach to evaluate the effectiveness of safety education and safety training, and also provides a new research idea for accident prevention.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.50-56
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• 2022

Change Orders generally impact cost and schedule performance of highway projects. However, highway projects that do not have any change orders also face cost growth and schedule delays. This study seeks to determine the cost and schedule performance of Texas DOT projects by collecting project data for 120 highway projects completed between 2016 to 2020. For the study, we selected project data that has zero or negative change orders which were then grouped and analyzed based on their Project Types i.e., maintenance works; structural works; restoration and rehabilitation works; and safety works. The study found that performance of Maintenance and Safety type projects had less cost and schedule growth among the data analyzed. Statistical tests also found that even though the projects have no change orders, Rehabilitation and Restoration type projects experienced significant schedule growth compared to others. However, the data did not show any significant cost and schedule growth for the projects when statistical tests were performed on overall data. The study concluded that highway projects are experiencing schedule growth even though the projects had no change orders. Results from the study can help planners, engineers, and administrators to gain better insight on how different types of highway projects are performing in terms of cost and schedule and eventually derive appropriate solutions to minimize cost and schedule growth in such projects.