• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.73-81
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• 2008

The current electrical safety plan developed for the national electricity system has been playing an important role in handling a variety of electrical accidents. However, it can be more effective to prevent or reduce those accidents if a preventive electrical safety plan is available. In this paper, an approach to developing the safety plan is described. We first discuss the contents that should be included in the plan. Noting that an effective plan requires the system level consideration of all the factors affecting the safety issues, an operation concept document (OCD) is considered. The OCD can allow us to understand the behavior of the safety system based on the operation environment, the system functions, the performance requirements, all at the system level of the safety system. Thus, the OCD can be useful in developing the safety plan. A detailed description then follows on how the OCD is developed for the electrical safety system under study. Finally, we discuss how the developed OCD can be used in deriving the preventive electrical safety plan.

• Journal of Environmental Science International
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• v.14 no.7
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• pp.639-647
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• 2005

The aim of this study is to determine the outbreaks of nontoxic Gonyaulax polygramma Stein in Yeosu waters in place of harmful Cochlodinium polykrikoides Margalef, which has occurred annually in the same region since 1995. The observation of cellular arrangement and structure by electron microscopy showed that G. polygramma isolated from Yeosu waters had a few spines connecting with membranes and prominent longitudinal ridges on the cell surface, with a cingular displacement 1.5 times their cell width. Furthermore, the location of the nucleus was posterior of large oval formation according to electron microscopy. On 6 August, 2004, the first bloom of G. polygramma occurred, the date of its disappearance was with a maximum cell density of 8,000 cells $ml^{-1}$ on 21 August, 2004. During the period of this study, the horizontal distribution of sea water temperature and salinity showed a strong coastal front, whereas the front of DIN (Dissolved Inorganic Nitrogen) was significantly different between the occurrence and disappearance of G. polygramma blooms. These results suggested that the process of the breakdown of stratification by wind and a low level of inorganic nitrogen play important roles in the rapid growth of G. polygramma, which is associated with a greater robustness in growth against DIN than that of C. polykrikoides in nature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.84-84
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• 2008

A multidimensional ZnO light-emitting diode LEDstructure comprising film/nanorods/substrate was fabricated on a p-type Si substrate using metal organic chemical vapor deposition at relatively low growth temperature. The filmlike top layer used for the metal contact was continuously formed on the ZnO nanorods by varying the growth conditions and the resulting structure allowed us to utilize the nanorods with intense emission as an active layer. We investigated the performance of the resulting multidimensional LED. An extremely high breakdown voltage and low reverse leakage current as well as typical rectification behavior were observed in the I-V characteristics.

• The Journal of Information Technology
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• v.7 no.3
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• pp.127-137
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• 2004

A Project planning is one of the most important processes that determines success and failure of a project. Scope management for a project planning is also essential job in system integration project. However project planning is very difficult because lots of factors and their relationships should be considered. Therefore project planning of system integration project has been done by project manager's own knowledge and experience. It is necessary to develop an algorithm of WBS(Work Breakdown Structure) identification & document selection along to project's specificity in project management system using AI technique. This study presents a methodology to cope with the limitations of the existing studies that have uniformly been customizing the methodology by only project complexity. We propose PPSM(Project planning support module) based on determination rules regarding route maps and document levels, and CBR(Case-Based Reasoning) for WBS identification.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1497-1499
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• 2000

We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 30 [mN/m]. LB layers of Arac. acid deposited by LB method were deposited onto y-type silicon wafer as y-type film. In processing of a device manufacture. we can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/arachidic acid/Al. the number of accumulated layers are 9$\sim$21. Also. we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.9
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• pp.20-28
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• 1992

Dielectric thin film of N/O ($Si_{3]N_{4}/SiO_{2}$) for high density stacked dynamic-RAM cell was formed by LPCVD and oxidation(dry & pyrogenic oxidation methods) of the top 7nm $Si_{3]N_{4}$ film. The thickness, structure and composition of this film were measured by ellipsometer, high resolution TEM, AES and SIMS. The insulating characteristics(I-V characteristics) were investigated by HP 4145, and the characteristics of TDDB (Time Dependent Dielectric Breakdown) were evaluated by using CCST(Current Constant Stress Time) method. In this experiment, The optimum oxidation condition for preparation of good insulating and TDDB characteristics of N/O film was pyrogenic oxidation at 85$0^{\circ}C$ for 30 minutes. The leakage current was reduced from 400pA to 7.5pA when SiO$_{2}$ film with thickness of 2nm was formed on the top of $Si_{3]N_{4}$ film by the pyrogenic oxidation method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.1
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• pp.1-12
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• 2001

Based on mixed-mode transient analyses utilizing a 2-dimensional device simulator, we have suggested the methodology to analyze the HBM ESD phenomena in CMOS chips utilizing NMOS transistors for ESD protection, and have analyzes the HBM discharge mechanisms in detail. Also the second breakdown characteristics in the protection device have been successfully simulated based on mixed-mode simulations, to explain the discharge mechanisms leading to device failure. To analyze the effects of the device structure changes on the discharge characteristics, we have compared the results of DC analyses and mixed-mode transient analyses, and have discussed about more robust designs of NMOS transistor structures against HBM ESD based on the analyses.

• Korean Journal of Construction Engineering and Management
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• v.8 no.4
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• pp.119-127
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• 2007

Cost and Schedule is the most important information, and how efficiently manage this information is the key issue for Construction Project Management. Domestically, systematic scheduling method such as CPM network is not only used widely but integration of time and cost information also is. In order to effectively integrate and use the time and cost information, it is suggested that WBS(Work Breakdown Structure) based QDB(Quantity Database) should be generated from the design phase and, WBS and QDB related system tool should be supported. It could be helpful to relate and integrate other construction project information.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.29-32
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• 1999

$GaF_3$ films were directly grown on p' and p-type GaAs(100) substrates using a $SF_6$ plasma discharge system. GaAs MIS(Meta1-Insulator-Semiconductor) capacitor was successfully fabricated for about 1 hour at temperature $290^{\circ}C$ using the as-grown $GaF_3$ films. The as-grown films on p'-GaAs exhibited a current density of less than 6.68 $\times$ $1O^{-9}$ A/$cm^2$ at a breakdown field of 500kV/cm and a refractive index of 2.0 ~ 2.3 at a wavelength of 632.8 nm. The dielectric constant was about 5 derived from 1 MHz capacitance-voltage (C-V) measurements. Dielectric dispersion of the fluoridated films on p'-GaAs measured ranged from 100 Hz to 10 MHz was not observed.

• Journal of the Korean Ceramic Society
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• v.35 no.11
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• pp.1121-1129
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• 1998

Reactions between Ag-Pd internal electrode materials and{{{{ { {Bi }_{2 }O }_{3 } }} in multilayer chip varistor were in-vestigated. For more than 1 mol%{{{{ { {Bi }_{2 }O }_{3 } }} in varistor composition internal electrode structure was destroyed due to the reaction between internal electrode and{{{{ { {Bi }_{2 }O }_{3 } }} But for typical varistor compositions (below 1 mol% of{{{{ { {Bi }_{2 }O }_{3 } }} content) microstructural changes around the internal electrode were not observed. However SEM-EDS and TEM-EDS analysis showed the uneven distribution of{{{{ { {Bi }_{2 }O }_{3 } }} in the internal electrode which was due to the migration of{{{{ { {Bi }_{2 }O }_{3 } }} to the electorde during sintering. As a results the nonlinear coefficient of multilayer varistor showed very large distribution as well as the breakdown voltage.