• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.8
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• pp.694-699
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• 2000

S $r_{0.9}$/B $i_{2.1}$/T $a_{2}$/ $O_{9}$ solutions was synthesized by MOD (metalorganic decomposition) method. SBT thin films with 2000$\AA$ thickness were prepared on Ir $O_2$/ $SiO_2$/Si and Pt/Ti/ $SiO_2$/Si substrates using the spin coating process and then investigated the dielectric and electrical properties of them. In the case of using Ir $O_2$bottom electrode the hysteresis loop was saturated at lower temperature than Pt/Ti electrode but the breakdown phenomenon was occurred at low voltage because of the rough surface morphology and porous microstructure of SBT thin films. As the results of the fatigue and imprint characteristics related to the lifetime and reliability of devices after 10$^{10}$ cycles the fatigue rates were about 10% at the Ir $O_2$and Pt/Ti bottom electrodes. Both SBT thin films with Ir $O_2$ and with Pt/Ti bottom electrodes show a slight tendency to imprint after 10$^{9}$ cycles but do not lead to a failure.e.e.

• Ocean Science Journal
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• v.43 no.2
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• pp.67-79
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• 2008

We investigated the relationship between mesoscale spatial distribution of environmental parameters (temperature, salinity, and sigma-t), chlorophyll-a concentration and mesozooplankton in the Yellow Sea during May 1996, 1997, and 1998, with special reference to Yellow Sea Bottom Cold Water (YSBCW). Adult calanoid copepods, Calanus sinicus, Paracalanus parvus s.l., Acartia omorii, and Centropages abdominalis were isolated by BVSTEP analysis based on the consistent explainable percentage (-32.3%) of the total mesozooplankton distributional pattern. The copepods, which accounted for 60 to 87% of the total abundances, occupied 73-78% of the copepod community. The YSBCW consistently remained in the northern part of the study area and influenced the spatial distribution of the calanoid copepods during the study periods. Abundances of C. sinicus and P. parvus s.l., which were high outside the YSBCW, were positively correlated with the whole water average temperature (p<0.01). In contrast, the abundances of C. abdominalis and A. omorii, which were relatively high in the YSBCW, were associated with the integrated chl-a concentration based on factor analysis. These results indicate that the YSBCW influenced the mesoscale spatial heterogeneity of average temperature and integrated chl-a concentration through the water column. This consequently affected the spatial distribution pattern of the dominant copepods in association with their respective preferences for environmental and biological parameters in the Yellow Sea during spring.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1633-1638
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• 2003

In case that in-leakage through the valve disk occurs, a numerical study is performed to estimate on thermal stratification phenomenon in the Safety Injection piping connected with the Reactor Coolant System piping of Nuclear Power Plant. As the leakage flow rate increases, the temperature difference between top and bottom of horizontal piping has the inflection point. In the connection point of valve and piping, the maximum temperature difference between top and bottom was 185K and occurred in the condition of 10 times of standard leakage flow rate. In the connection point of elbow and horizontal piping, the maximum temperature difference was 145K and occurred in the condition of 15 times of standard leakage flow rate. In the vertical piping of Safety Injection piping, the near of connection point between elbow and vertical piping showed the outstanding thermal stratification phenomenon in comparison with another region because of turbulent penetration from Reactor Coolant System piping. In order to prevent damage of piping due to the thermal stratification when in-leakage through the valve disk occurs, the connection points between valve and piping, and the connection points between elbow and piping need to be inspected continually.

• Carbon letters
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• v.9 no.4
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• pp.289-293
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• 2008

Naphtha Cracking Bottom (NCB) oil was heat reformed at various reforming temperature and time, and the volatile extracts were characterized including yields, molecular weight distributions, and representative compounds. The yield of extract increased as the increase of reforming temperature ($360{\sim}420^{\circ}C)$ and time (1~4 hr). Molecular weight of the as-received NCB oil was under 200, and those of extracts were distributed in the range of 100-250, and far smaller than those of precursor pitches of 380-550. Naphtalene-based compounds were more than 70% in the as-received NCB oil, and most of them were isomers of compounds bonding functional groups, such as methyl ($CH_{3^-}$) and ethyl ($C_2H_{5^-}$). When the as-received NCB oil was reformed at $360^{\circ}C$ for 1 hr, the most prominent compound was 1,2-Butadien, 3-phenyl- (24.57%), while naphthalene became main component again as increasing the reforming temperature.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.1
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• pp.23-30
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• 1993

Hydrogenation on the top gate and bottom gate Poly-Si TET's was performed by using Nh$_{3}$ plasma and annealing SiN film deposited by PECVD and then the electric characteristics on Poly-Si TET were investigated. As the time of NA$_{3}$ plasma treatment increaes, on/off current ratio gradually increases and the swing value decreases. The trap densities of graim boundaries in Poly-Si decrease very much during the inital 20min of hydrogenation time, and the decreasing scale becomes smaller after 20 min. The electric characteristics of the top gate TFT are better than those of the bottom gate TFT, it is considered due to the defects at the interface between the Poly-Si and the underlayer, SiO$_{2}$. After NH$_{3}$ plasma was treated for 2 hours for the top gate TFT, as the aging time atroon temperature increases on current was not scacely changed and off current decreases more than 1 order. Gate current density recovers to original value after the aging treatment for 8 days and then the electric characteristics are finally improved. It is suggested that the degraded characteristics of gate oxide are improved, from the variations of C-V characteristics with aging time. For the hydrogenation of isothermal and isochronal annealing SiN film deposited by PECVD, the characteristics of Poly-Si TFT are improved with increasing annealing temperature and are not largely changed with increasing annealing time. This results is good in agreement with the hydrogen reduction in Sin film as variations of annealing temperature and time.

• Journal of the Korean Geotechnical Society
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• v.27 no.5
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• pp.61-74
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• 2011

This is a fundamental research on use as fill material of lightweight waste such as bottom ash and tire shred. We carried out the test for particle size distribution, specific gravity, density, shear strength, permeability and vertical compression settlement, considering water content change and temperature effect of several waste materials. Bottom ash, which is lighter than soils, has similar permeability and particle size distribution to those of weathered soils. But permeability may differ depending on the particle size distribution. The shear strength aspect of bottom ash and tire shred mixed materials are similar to that of natural fill materials. In the 1-D vertical compression settlement test, we could be assured that bottom ash and tire shred mixed materials showed similar compression settlement to that of sand under actual vertical stress. Furthermore, materials including bottom ash showed smaller compression settlement than that of weathered soils in the long-term settlement test under wetting and freezing-thawing condition.

• 한국해양학회지
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• v.14 no.2
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• pp.54-60
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• 1979

Distribution of drifting larvae of scallop, Patinopecten yessoensis, was studied in the Yeong-il Bay in 1973, 1978, and 1979. The range of the bottom water temperature was 10∼19$^{\circ}C$ and that of salinity was 32.58∼34.55 . The larvae appeared from early March to mid-July with maximum abundance from mid- April to early June. Drifting period of larvae is about a month, and then the larvae begin to settle on the substratum. In the Yeong-il Bay setting period was from early Arpil to late June with maximum abundance from mid-May to eary June. The highest density of drifting larvae was found in the vicinity of Dae-dong-bae(Station H) among the observed stations, and the density was much higher in 1979 than in the other years observed. Vertical distribution of the larvae is closely related to the depth of the water column. High density of the larvae was observed in the bottom layer. The larvae were most abundant in the bottom-most layer, and in the place where the water depth is 24m, 42% appeared in the 4m layer from the bottom, and 80% in the 8m layer from the bottom, and where the water depth is 16m, 50% in the bottom-most 4m, and 90% in the layer up to 8m.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.4
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• pp.397-409
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• 2024

To evaluate the recent trophic state of Jinhae Bay, field campaigns were conducted in June and August during 2020-2023, measuring environmental factors in both the surface and bottom layers. Temperature differences between layers were greater in August than in June. Surface salinity was decreased in August, probably due to runoff, while bottom salinity remained stable. Dissolved oxygen levels showed a more pronounced stratification in August, leading to hypoxic conditions in the bottom layer. Chemical oxygen demand (COD) was higher at the surface, with rainfall contributing to elevated levels. The eutrophication index (EI) was consistently higher at the bottom across all stations, driven by dissolved inorganic nitrogen (DIN) and phosphate (DIP), with a notable increase in August due to organic matter decomposition. The trophic index (TRIX) was also higher in the bottom layer, with surface TRIX influenced by DIN and salinity, and bottom TRIX by salinity, rainfall, COD, and DIN. The average TRIX for Jinhae Bay was 4.21±1.30, classified as "poor", but comparable to values from other regions. Continuous monitoring of the trophic state is essential for the sustainable management of Jinhae Bay's fisheries.

• Journal of fish pathology
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• v.21 no.1
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• pp.35-43
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• 2008

Pathological symptoms and hematological parameters of red sea bream, Pagrus major and water temperature in the culture ground was investigated to clarlify the cause of winter moratility. Dead fish showed green liver and accumulation of ascites in the cavity. A few Bivagina tai were also found on the gill but either bacteria or virus were not. When hematological parameters from fish taken before/after the winter mortality were compared, blood glucose, serum AST and ALT, and total cholesterol, trigyceride and total protein were significantly decreased in the fish after the winter mortality. These results may explain that the nutritional level of fish was decreased because fish could not fed during winter season. According to the CORI monitoring system operating by KODC, NFRDI a long term water temperature from Dec. 25, 2005 to Feb. 24, 2006 (60 days) were exposed the low water temperature environments to the red sea bream. First of all, mass mortality began at Sarayngdo where low temperature below 8℃ continued for 42 days. The winter mortality did not occured in the depths of 9 m to 19.2 m where difference of water temperature in the surface and bottom was only within 0.1℃. But in the depth of 7.5 m to 11 m winter mortality occured where water temperature in the surface and bottom showed much variation ranged from 0.2℃ to 1.4℃. From these results, great difference of water temperature in the surface and bottom of the culturing area might results in winter mortality of red sea bream.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.2
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• pp.61-68
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• 2015

Warpage analysis has been performed for top and bottom packages of thin package-on-packages processed with different epoxy molding compounds (EMCs). Warpage deviation was measured for packages molded with the same EMCs and also the warpage deviations of top and bottom substrates themselves were characterized in order to identify the major factor causing the package warpage. For the top and bottom packages processed with thin substrates, the warpage deviation of the substrates was large, which made it difficult to figure out the effect of EMC properties on the package warpage. Top packages, where the molding area of $13mm{\times}13mm$ covered the most of the substrate area ($14mm{\times}14mm$), exhibited similar warpage behavior with changing the temperature. On the other hand, bottom packages, where the molding area was only $8mm{\times}8mm$, exhibited the complex warpage behavior due to simultaneous occurrence of (+) and (-) warpages on the same package. Accordingly, the bottom packages showed dissimilar temperature-warpage behavior even being processed with the same EMCs.