• Economic and Environmental Geology
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• v.24 no.4
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• pp.447-463
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• 1991

Petrological and chemical studies of Precambrian dikes in the southern Lake Superior region were conducted with the objects of evaluating magma source and constraining models for the paleo-tectonic environment. Forty-six samples were analyzed for major, trace, and rare earth elements. Chemical data of the studied dikes are typical of continental tholeiites and showing iron-enrichment fractionation trend. With wallrock contamination carefully evaluated, a series of tectonic discriminating methods utilizing immobile trace elements indicate that the source magma was a high-Ti tholeiitic basalt similar to present-day T-type MORB. Effect of chemical contamination from wallrock assimilation accmulates with increasing differentiation. Evolved rocks show LREE enriched patterns and have enhanced levels of LIL elements (e.g., Rb, K, Ba, Th), but low levels of high field strength elements (e.g., Nb, P, Ti) with respect to their neighboring elements. It is suggested from this study that this enrichment possibly due to a combination of a feature inherited from the subcontinental lithosphere and crustal contamination. Geochemical signatures of these rocks are distinctively different from those of arc-related volcanics. Comparisons with chemistries of modern magmas show a pattern of overlap between Within-plate and ocean-floor characteristics, and chemical signatures of these rocks favor a model of intrusion into a crustal environment undergoing lithospheric attenuation.

• Progress in Superconductivity
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• v.12 no.2
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• pp.82-87
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• 2011

We studied the trapped field properties of bulk Y-Ba-Cu-O superconductors by applying 3 T of the permanent or $Nb_3Ti$ superconducting magnet. The 28 mm circular type of YBCO bulk superconductor was prepared and then hole at the center of bulk, parallel to the c-axis, was mechanically drilled. Typical size of hole in YBCO bulk was 10 mm in diameter. In order to examine the trapped field variation in terms of different impregnated materials, a hole in YBCO bulk was filled with resin and indium respectively. The trapped field decay due to flux flow was determined in terms of time. Our preliminary result indicates the trapped field value measured on the YBCO without hole after 30 minute by applying 3 T, was 6,500 G, which is much higher than that, 4,500 G, measured on YBCO with hole. Also, we confirmed that the tendency of a trapped field decrement with time was almost the same regardless of the impregnated materials in YBCO.

• ETRI Journal
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• v.38 no.6
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• pp.1064-1073
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• 2016

An adaptive speech streaming method to improve the perceived speech quality of a software-based multipoint control unit (SW-based MCU) over IP networks is proposed. First, the proposed method predicts whether the speech packet to be transmitted is lost. To this end, the proposed method learns the pattern of packet losses in the IP network, and then predicts the loss of the packet to be transmitted over that IP network. The proposed method classifies the speech signal into different classes of silence, unvoiced, speech onset, or voiced frame. Based on the results of packet loss prediction and speech classification, the proposed method determines the proper amount and bitrate of redundant speech data (RSD) that are sent with primary speech data (PSD) in order to assist the speech decoder to restore the speech signals of lost packets. Specifically, when a packet is predicted to be lost, the amount and bitrate of the RSD must be increased through a reduction in the bitrate of the PSD. The effectiveness of the proposed method for learning the packet loss pattern and assigning a different speech coding rate is then demonstrated using a support vector machine and adaptive multirate-narrowband, respectively. The results show that as compared with conventional methods that restore lost speech signals, the proposed method remarkably improves the perceived speech quality of an SW-based MCU under various packet loss conditions in an IP network.

• Journal of Radiation Protection and Research
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• v.47 no.2
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• pp.99-106
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• 2022

Background: The radionuclide inventory calculation codes such as ORIGEN and FISPACT collapse neutron reaction libraries with energy spectra and generate an effective one-group cross-section. Since the nuclear cross-section data, energy group (g) structure, and other input details used by the two codes are different, there may be differences in each code's activation inventory calculation results. In this study, the calculation results of neutron-induced activation inventory using ORIGEN and FISPACT were compared and analyzed regarding radioactive waste classification and worker exposure during nuclear decommissioning. Materials and Methods: Two neutron spectra were used to obtain the comparison results: Watt fission spectrum and thermalized energy spectrum. The effective one-group cross-sections were generated for each type of energy group structure provided in ORIGEN and FISPACT. Then, the effective one-group cross-sections were analyzed by focusing on ⁵⁹Ni, ⁶³Ni, ⁹⁴Nb, ⁶⁰Co, ¹⁵²Eu, and ¹⁵⁴Eu, which are the main radionuclides of stainless steel, carbon steel, zircalloy, and concrete for decommissioning nuclear power plant (NPP). Results and Discussion: As a result of the analysis, ¹⁵⁴Eu and ⁵⁹Ni may be overestimated or underestimated depending on the code selection by up to 30%, because the cross-section library used for each code is different. When ORIGEN-44g, -49g, and -238g structures are selected, the differences of the calculation results of effective one-group cross-section according to group structure selection were less than 1% for the six nuclides applied in this study, and when FISPACT-69g, -172g, and -315g were applied, the difference was less than 1%, too. Conclusion: ORIGEN and FISPACT codes can be applied to activation calculations with their own built-in energy group structures for decommissioning NPP. Since the differences in calculation results may occur depending on the selection of codes and energy group structures, it is appropriate to properly select the energy group structure according to the accuracy required in the calculation and the characteristics of the problem.

• Journal of Korean Library and Information Science Society
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• v.39 no.3
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• pp.479-500
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• 2008

This study investigates Kim Inhue's view of reading through the analysis of reference books in Haseo-Chunjib(하서전집). As the result, he had read 123 different books ar least. He had quoted frequently $Sish{\bar{u}}$ $S{\bar{a}}nj{\bar{i}}ng$(사서삼경), $Sh{\check{i}}ji$(사기), $H{\grave{a}}nsh{\bar{u}}$(한서), $Zhu{\bar{a}}ngz{\check{i}}$(장자), $G{\check{u}}wenzh{\bar{e}}nb{\check{a}}o$(고문진보), $Ch{\check{u}}c{\acute{i}}$(초사), $W{\acute{e}}nxu{\check{a}}n$(문선). He had read books beyond the contemporary(sixteen centurtry) scholar's common list, and had enjoyed reading over the boundaries of stereotyped idea. While he had emphasized on the scripture of Confucian, had earned more knowledges for usefulness and the bases of scholarly writings by reading a wide spectrum of books.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.100-102
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• 2001

In this paper, the piezoelectric and dielectric properties of $Pb(Zr_xTi_{1-x)O_3$ - $Pb(Co_{1/3}Nb_{1/3})O_3)$ piezoelectric ceramics have been investigated as a function of Zr/Ti mole ratio. From the results, when Zr/Ti mole ratio is 49/51, electromechanical coupling coefficient($k_p$), piezoelectric strain constant($d_{33}$) mechanical quality factor($Q_m$), and Permittivity(${{\varepsilon}_{33}}^T/{\varepsilon}_0$) is 64[%], 469[PC/N], 360 and 2000, respectively. Morphotropic Phase Boundary is Zr/Ti mole ratio(49/51) from XRD analysis. Also. From SEM observation, when sintering temperature is 1150[$^{\circ}C$], grain size is about $1{\sim}2[{\mu}m]$ and maximum sintering density is 7.85[$g/cm^3$].

• Journal of the Korean Ceramic Society
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• v.55 no.3
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• pp.290-298
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• 2018

In order to investigate the effect of thickness on the dielectric and piezoelectric properties of (001) PMN-29PT single crystals, three different types of PMN-29PT samples were prepared using the solid-state single crystal growth (SSCG) method: high density crystal [99%], low density crystal [95%], and high density crystal doped with Mn [98.5%]. When their thickness decreased from 0.5 mm to 0.05 mm, their dielectric constant ($K_3{^T}$), piezoelectric constants ($d_{33}$ and $g_{33}$), and electromechanical coupling factor ($k_t$) decreased continuously. However, their dielectric loss (tan ${\delta}$) increased. The addition of Mn to PMN-PT induced an internal bias electric field ($E_I$), increased the coercive electric field ($E_C$), and prevented local depoling. Therefore, Mn-doped PMN-PT crystals show high stability as well as high performance, even in the form of very thin plates (< 0.2 mm), and thus are suitable for application to high frequency composites, medical ultrasound probes, non-destructive testing devices (NDT), and flexible devices.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.43-49
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• 2004

Ten promising polyvoltine mulberry silkworm strains(SDMGl, SDMG2, SDMG3, SDMG4, SDMWl, SDMW2, RMWl, RMW2, RMW3 and RMW4) that are superior in quantitative and qualitative traits have been synthesized in the polyvoltine breeding laboratory of Andhra Pradesh State Sericulture Research ＆ Development Institute, Hindupur through systematic hybridization and appropriate selection methods. After the genotypes were found homozygous for the desired traits, they have been crossed with 3 bivoltine testers $(APS8, APS4 and {NB_2}{D_4})$ and thirty new hybrid combinations were developed for the assessment of their hybrid performance. Phenotypic expressions of economically important quantitative and qualitative traits of fist filial generation were measured and subjected for statistical analysis. Evaluation Index and Subordinate Function methods were employed for the assessment of hybrid performance since they are widely used in silkworm hybrid evaluation. Total of seven poly${\times}$bivoltine combinations, which ranked high in both the methods, were selected as potential combinations for further field test. These combinations also ranked significantly higher than the control hybrid (APMl${\times}$APS8).

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.154-161
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• 2014

Demands for Korean Traditional Residence Complexes as a more humane resident space have recently been increasing for the purposes of users' health and convenience, built with the purpose of reflecting various trends. This study is aimed at examining the physical characteristics of design in residence complexes by analyzing the physical characteristics of the sound environment as auditory elements of Hanok Complexes and the relationship between spatial and visual test values. The results were shown as follows: In subjective evaluation at Hanok, Natural sounds were recognized higher but artificial sounds were lower. According to the interrelationship analysis between subjective evaluation and physical measurement values, entrance (regular-StdDev), yard (regular-NbEm, friendly-G), waterside (regular-articulation index(rooms), StdDev, $L_{min}$, Rem), etc had been shown highly related.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.207-207
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• 2003

최근 광촉매 재료로 각광받고 있는 TiO$_2$는 band gap 에너지가 3.0-3.2eV로 자외선 영역과 일부 가시광선 영역에서 활성을 갖는 것으로 알려져 있다. 따라서 용액 중에 결정화 및 안정화 되어있는 TiO$_2$의 band gap 에너지를 낮춘다면 가시광 영역의 광반응을 얻을 수 있다. 이에 본 연구는 G. Sato등이 제안한 방법으로 TiO$_2$ sol을 제조할 때 band gap 에너지를 낮추고자 천이 금속원소를 첨가하여 복합 및 담지된 TiO$_2$계 복합 sol을 합성하고자 하였다 출발원료는 TiC1$_4$를 가수분해하여 제조한 TiOCl$_2$에 천이금속원소인 V, Cr, Fe, Ni, Nb 등의 chloride 화합물을 첨가하여 중화 및 세척과정을 거친 후, 과산화수소수에 용해하여 전구체 용액인 titania peroxo용액을 제조하였다 제조된 전구체 용액은 온도와 시간을 변수로 각각 열처리하여 TiO$_2$계 복합 sol을 합성하였다. 제조된 시편은 X-선 회절 분석, 투과전자현미경, particle size analyzer, ζ-potential analyzer 및 UV-VIS Spectrometer 통을 이용하여 천이금속 첨가에 따른 TiO$_2$계 복합 sol의 형성과정과 특성변화를 관찰하였다.