• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.319-325
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• 2017

Marine algal flora and community structures were examined seasonally at three sites around the Shingori Nuclear Power Plant, Korea from February to November 2016. A total of 76 species were identified, including 9 green, 14 brown and 53 red algae. The greatest number of species occurred at Daesongri (51 species) followed by Sinamri (43 species) and at the discharge area (38 species) during the study period. Of the 76 seaweeds, 59 annuals and 17 warm tolerant species were recorded. Annual average biomass in dry weight varied from $168.02g/m^2$ at the discharge area to $222.53g/m^2$ at Sinamri. The coarsely branched form was the dominant functional form of seaweeds at the three sites. Seaweed community structures at the discharge site were distinguishable by decreasing species richness, biomass, species diversity index, richness index, and evenness index. The ratio of warm tolerance species and the dominance index values were remarkably higher at the discharge than those at the other sites.

• Journal of the Korean Society of Safety
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• v.23 no.4
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• pp.53-58
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• 2008

This paper presents the findings obtained from the investigation of fatal disasters occurred by small-sized construction firms which have been accepted as to provide lower safety performance other than large-sized construction enterprises and cause more than half of the safety accidents in average. The study identifies the current status of safety performance provided by the small-sized construction contractors in details, find the issues involved with lack of safety performance, and suggest the improvement measures derived from the findings. A survey questionnaire was administered to the construction contractors, which are listed in the database of Construction Association of Korea as to fall into rank between 501st and 1000th in construction capacity. Safety issues such as the performance of safety management system, safety control structure, safety cost relative to safety control, education devoted to safety improvement, usage of safety garments or individual protective tools, and activities to maintain safety performance on site, etc were investigated from the study.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1380-1383
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• 2007

The secondary electron emission coefficient (${\gamma}$) of the cathode is an important factor for improving the discharge characteristics of AC-PDP, because of its close relationship to discharge voltage. In this experiment, we have investigated the electronic structure of the energy band in the MgO layer responsible for the high ${\gamma}$. We used three kinds of MgO pellet that have another component, and each MgO layers have been deposited by electron beam evaporation method. The work-functions of MgO layer have been investigated from their ion-induced secondary electron emission coefficient (${\gamma}$), respectively, using various ions with different ionization energies in a ${\gamma}-FIB$ (Focused Ion Beam) system. We have compared work-function with ${\gamma}-FIB$ system current signal for measurement defect energy level in MgO layer. MgO-A in the three types has lowest work-function value (4.12eV) and there are two defect energy levels.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1281-1283
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• 2007

In this paper, the properties of n-channel poly-Si TFTs with different channel widths are reported. Poly-Si fabricated using ELA on glass substrates has high quality as a material for applications such as TFT-LCDs. The fabricated n-channel TFTs have a double stack structure of oxide-nitride which acts as an insulator layer. The results show that the small channel TFTs exhibited a lower $V_{TH}$ and the wide channel TFTs had a higher $I_{DSAT}$. The nchannel poly-Si TFTs with an $I_{ON}/I_{OFF}$ value of more than $10^4$ can be reliable switching devices for AMOLED displays.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1284-1287
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• 2007

Titanium dioxide ($TiO_2$) is promising candidate for fabricating blocking layer of gate dielectrics in non-volatile memory (NVM). In this work, we investigated $TiO_2$ as high dielectric constant material instead of silicon dioxide ($SiO_2$), which is generally used as blocking layer for NVM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.644-647
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• 2001

Amorphous As-Ge-Se-S thin films have been studied with the aim of identifying optimum etching condition which can be used to produce holographic grating structure for use as diffractive optical elements. In this study, holographic gratings have been formed using He-Ne laser(632.8nm), and fabricated by the method of wet etching using NaOH etchant with various concentration(0.26N, 0.33N, 0.40N). The diffraction efficiency was obtained by +1st order intensity of the diffracted beam. The formed grating profiles were observed by atomic force microscope and showed that the expected grating profile could be achieved by controlling the etching time. Over-etching resulted in under-cutting of the grating lines. The highest 1st order diffraction efficiency for these gratings was about 5.05%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.6
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• pp.428-435
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• 1998

SOI-like-bulk CMOS device is proposed, which having the advantages of SOI(Silicon On Insulator) and protects short channel effects efficiently with adding partial epitaxial process at standard CMOS process. SOI-like-bulk NMOS and PMOS with 0.25${\mu}{\textrm}{m}$ gate length have designed and optimized through analyzing the characteristics of these devices and applying again to the design of processes. The threshold voltages of the designed NMOS and PMOS are 0.3[V], -0.35[V] respectively and those have shown the stable characteristics under 1.5[V] gate and drain voltages. The leakage current of typical bulk-CMOS increase with shortening the channel length, but the proposed structures on this a study reduce the leakage current and improve the subthreshold characteristics at the same time. In addition, subthreshold swing value, S is 70.91[mV/decade] in SOI-like-bulk NMOS and 63.37[mV/ decade] SOI-like-bulk PMOS. And the characteristics of SOI-like-bulk CMOS are better than those of standard bulk CMOS. To validate the circuit application, CMOS inverter circuit has designed and transient & DC transfer characteristics are analyzed with mixed mode simulation.

• Archives of Pharmacal Research
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• v.29 no.9
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• pp.721-727
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• 2006

To continue exploration of structure activity relationship of novel 1-(indoline-5-sulfonyl)-4-phenylimidazolidinones (1) reported as anticancer agent with broad spectrum, three 1-(arylsulfonyl)-4-vinylimidazolidinones (2) were synthesized from methyl serinate (3) in 8 steps. Reaction of intermediate 2-phenoxycarbonylaminobut-3-enyl p-toluenesulfonate (10) with arylsulfonamide in the presence of potassium carbonate produced corresponding 2 and N-(4-vinyloxazolidin-2-yl)arylsulfonamide 11 in approximately equal ratio. This reaction is believed to undergo through urea intermediate 16 as shown in scheme 3. 1-Arylsufonyl-4-vinylimidazolidinones 2 show much reduced activity against human colon carcinoma (Colo205), human chronic myelogenous leukemia (K562), and human ovarian adenocarcinoma (SK-OV-3) and compatible activity against human lung carcinoma (A549) compared to 1. Therefore phenyl at 4-position should be the optimum planar motif for the activity of 1.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.587-597
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• 2001

The structural system that discreterized continuous shells is frequently used to make dome-type structures and these structures show the unstable phenomena by snap-through or bifurcation when a load level reaches certain critical value. The characteristic structural behaviour of a cable dome shows a strong nonlinearity and very sensitive according to the initial imperfection. In this study the shape finding problem by applying initial tension stress is investigated and using this the unstable phenomena of perfectly shaped and initially imperfected shape model by external forces are examined to grasp the unstable behavior of cable dome using the Geiger-type model.

• Selected Papers of The Society of Naval Architects of Korea
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• v.2 no.1
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• pp.79-105
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• 1994

A ship in waves is suffered from the various wave loads that comes from its motion throughout its life. Because these loads are dynamic, the analysis of a ship structure must be considered as the dynamic problem precisely. In the rationally-based design, the dynamic structural analysis is carried out using dynamic wave loads provided from the results of the ship motion calculation as a rigid body. This method is based on the linear theory assumed low wave height and small amplitude of motion. But at the rough sea condition, high wave height, compared with ship's depth, induce the large ship motion, so the ship section configuration under waterline is rapidly changed at each time. This results in a non-linear problem. Considering above situation in this paper, a strength analysis method is introduced for the hull girder among waves considering non-linear hydrodynamic forces. This paper evaluates the overall or primary level of the ship structural dynamic loading and dynamic response provided from the non-linear wave forces, and bottom flare impact forces by momentum slamming theory. For numerical calculation a ship is idealized as a hollow thin-walled box beam using thin walled beam theory and the finite element method is used. This method applied to a 40,000 ton double hull tanker and attention is paid to the influence of the response of the ship's speed, wave length and wave height compared with the linear strip theory.