• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.4 s.334
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• pp.1-8
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• 2005

The increased effective impurity due to the pocket ion implantation is well blown to give rise to a reduction of the effective mobility of halo MOSFETs. However, further decrease of the effective mobility can be observed in pocket implanted MOSFETs above the mobility reduction due to the Coulomb impurity scattering and the gate bias dependency of the effective mobility can also differ from the simple model describing the mobility behavior in terms of the effective impurity. Phonon scattering and surface scattering as well as impurity Coulomb scattering are also shown to be effective in the degradation of the carrier mobility of pocket implanted MOSFETs. Using the 1-D regional approximation the effect of the distribution of the inversion charge density along the channel on the drain current is investigated. The inhomogeneous channel charge distribution due to pocket implantation is also shown to contribute to the further reduction of the effective mobility in halo MOSFETs.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.796-801
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• 2011

The objective of this work presented here was focused on analysis of development trend for the integrated power system of naval vessels to perform the high-power and energy mission load platform. These mission loads are affected by the high level of military technologies, digitalization of the ocean battlefield, high power sensor system for maximization of the ship survivability. All electric power including propulsion power for ship should be controlled by integrated single system in order to carry various high power density weapon system such as Electromagnetic Aircraft Launch System, Electromagnetic Rail Gun[feasible precision striking at long distance 200NM(370km) or over]. As the analyzing the present state of things, mechanical propulsion system is shifted into hybrid or fully electric propulsion systems to realize integrated power system at the developed countries. Such challenges include reduced dependency on foreign-supplied fossil fuel, increasing demand for installed ship power, controlling life-cycle costs.

• Journal of Environmental Policy
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• v.9 no.4
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• pp.53-76
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• 2010

This paper attempts to estimate and compare environmental Kuznets curves (EKC) for$CO_2$ emissions of five regions constituting South Korea. For this, panel data of $CO_2$ emission for these regions are constucted for the period 1990 - 2007. Close inter-dependency among these five regions is considered by using a seemingly unrelated regression (SUR) model. In addition to real per-capita income, price index of energy sources and population dens ity are included as control variables. Results of estimates show the robust existence of EKC's in all these regions. EKC turning points of five regions range between 13.7 and 21.6 million Korean Won, showing a large variation. This difference among regions should be conisidered for the effective implementation of policies targeting the reduction of $CO_2$ emmission. In addition, the increase of energy price is found help reduce the $CO_2$ emmision while the rise of population density seems to lead to the increase of $CO_2$ emission.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1157-1163
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• 2002

This experimental research has been done to study the effects of Gmibojungikgi-tang(GBJIKT) on the anti-allergic reaction. We found the several important results from the research which has been performed by two experiments toward immediately type and delayed type in order to study the effects of GBJIKT on hypersensitivity response to mice. The results obtained from our research are as following: The survival rate of one group to which we injected only the compound 48/80 is almost 0% according to its density and timing test. In the other hand, the survival rates of the other group to which we injected both of the compound 48/80 and GBJIKT are 10%, 10%, 20%, 30%, 20%, and 40% according to 0.025, 0.05, 0.1, 0.25 0.5 and 1(mg/g) of compound 48/80. Time dependency test also shows the 0% survival rates in 5 and 10 minutes. GBJIKT revealed the significantly inhibitory effect on Compound 48/80 induced Mast cell degranulation. GBJIKT showed the significantly inhibitory effect in the delayed type hypersensitivity response to picry1 chloride GBJIKT showed the significantly inhibitory effect in the delayed type hypersensitivity response to sheep red blood cell. Our research provides the important evidence that GBJIKT is benificial to the prevention and treatment of allergy related diseases.

• Journal of the Korean Ceramic Society
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• v.45 no.7
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• pp.411-417
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• 2008

Aerosol Deposition Method (ADM) is a novel technique to grow ceramic thick films with high density and nano-crystal structure at room temperature. $^{1,2)}$ For these unique advantages of ADM, it would be applied to the fabrication process of 3-D integration ceramic modules effectively. However, it is critical to control the properties of starting powders, because a film formation through ADM is achieved by impaction and consolidation of starting powders on the substrates. We fabricated alumina thick films by ADM for the application to integral substrates for RF modules. When the as-received alumina powders were used as a starting material without any treatments, it was observed that the dielectric properties of as-deposited alumina films, such as relative permittivity and loss tangent, showed high dependency on the frequency. In this study, some techniques of powder pre-treatments to improve the dielectric properties of alumina thick films will be shown and the effects of starting powders on the properties of AD films will be discussed.

• The Journal of the Acoustical Society of Korea
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• v.28 no.1E
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• pp.9-15
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• 2009

In this paper, FSTL (Field Sound Transmission Loss) measured in a mock-up simulating ship cabins is studied. A mock-up is built by using 6 mm steel plate, and two identical cabins are made where 25 mm or 50 mm sandwich panel is used to construct wall and ceiling inside the steel structure. Various wall panels and ceilings are tested, where effects of wall and ceiling panel thickness, and presence of a unit toilet on FSTL are investigated. It is found that the effect of unit toilet on FSTL is at most 1 dB. From the comparison of FSTL for panels of the same thickness of 50 mm, it is observed that panel having inside air cavity of 10 mm shows higher STL than that of the panel without air cavity. Comparison of FSTL for panels of 50 mm and 25 mm thickness shows that dependency on surface density predicted by mass law is not observed. The sandwich panels act as a mass-spring system, which shows a resonant mode that cannot be explained by the mass law. It is also found that STL from laboratory test is higher than FSTL by 5- 10 dB, which can be explained by flanking structure-borne noise transmission path such as ceiling, floor and corridor-facing wall.

• Journal of Korean Neurosurgical Society
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• v.37 no.2
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• pp.116-123
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• 2005

Objective: Percutaneous kyphoplasty using a balloon-catheter is an widely accepted method which achieves the restoration of vertebral height and the correction of kyphotic deformity with little complication in osteoporotic vertebral compression fractures. The authors assess the results of 59 patients who underwent kyphoplasty, and analyze the factors that could affect the prognosis. Methods: From December 2001 to May 2003, fifty-nine patients underwent kyphoplasty. The patients included 49 women and 10 men aged 52-85 years. Average t-score on bone marrow density was -3.58. About 7cc of polymethylmethacrylate(PMMA) was injected into the fractured vertebral body using $Kyphon^{(R)}$ under local anesthesia. The vertical height of all fractured vertebrae was measured both before and after surgery. Outcome data were obtained by comparing pre- and post-operative VAS score and by assessing postoperative satisfaction, drug dependency and activity. Various clinical factors were analyzed to assess the relationship with the outcome. Results: The VAS score improved significantly, and the mean percentage of restored vertebral height was 53%. The mean improvement in kyphosis was $3.6^{\circ}$. Eighty-nine percent of the patients gained excellent or good results. Any of the clinical factors including the interval between fracture and operation, the degree of height loss, the degree of the vertebral height restoration or the correction rate of kyphosis did not affect the clinical results. Conclusion: Kyphoplasty is associated with a statistically significant improvement in pain and function with little complication. The clinical results are not affected by any clinical parameters. Further follow-up study is needed to determine whether the restoration affects the long-term clinical results.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.308-315
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• 2003

This experimental research has been done to study the effects of Sipjeondaebo-tang(SOT) on the anti-allergic reaction. We found the several important results from the research which has been performed by two experiments toward immediately type and delayed type in order to study the effects of SDT on hypersensitivity response to mice. The results obtained from our research are as following. The survival rate of one group to which we injected only the compound 48/80 is almost 0% according to its density and timing test. In the other hand, the survival rates of the other group to which we injected both of the compound 48/80 and SDT are 20%, 10%, 30%, 10%, 40% and 70% according to 0.025, 0.05, 0.1, 0.25 0.5 and 1 (mg/g) of compound 48/80. Time dependency test also shows the 30% and 20% survival rates in 5 and 10 minutes. SDT revealed the significantly inhibitory effect on Compound 48/80 induced Mast cell degranulation. SDT showed the significantly inhibitory effect in the delayed type hypersensitivity response to picry1 chloride. SDT showed the significantly inhibitory effect in the delayed type hypersensitivity response to sheep red blood cell. Our research provides the important evidence that SDT is benificial to the prevention and treatment of allergy related diseases.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.4
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• pp.295-300
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• 2015

The precise determination of the activity for each radionuclide in environmental samples requires the self-absorption correction factor. In this research, we derived the self-absorption correction factor for three p-type high purity germanium detectors using the Monte Carlo code MCNPX. These detectors have different characteristics such as crystal diameter, height and size of the core. We compared the calculated full-energy peak efficiency with the experimental value using a standard sample with $1g/m^3$ density and verified the modeling. We simulated the dependency of the full-energy peak efficiency on the 0.3, 0.6, 0.9, 1.0, 1.2 and $1.5g/m^3$ samples and obtained the corresponding self-absorption correction factor. The self-absorption correction factors calculated for the three detectors differ by less than 1% over most of the energy range and sample densities considered. This indicates that the self-absorption correction factors are independent of the crystal characteristics of HPGe detector.

• Korean Journal of Materials Research
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• v.30 no.2
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• pp.61-67
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• 2020

BiFeO₃ with perovskite structure is a well-known material that has both ferroelectric and antiferromagnetic properties called multiferroics. However, leaky electrical properties and difficulty of controlling stoichiometry due to Bi volatility and difficulty of obtaining high relative density due to high dependency on the ceramic process are issues for BiFeO₃ applications. In this work we investigated the sintering behavior of samples with different stoichiometries and sintering conditions. To understand the optimum sintering conditions, nonstoichiometric Bi_1±xFeO_3±δ ceramics and Ti-doped Bi_1.03Fe_1-4x/3Ti_xO₃ ceramics were synthesized by a conventional solid-state route. Dense single phase BiFeO₃ ceramics were successfully fabricated using a two-step sintering and quenching process. The effects of Bi volatility on microstructure were determined by Bi-excess and Ti doping. Bi-excess increased grain size, and Ti doping increased sintering temperature and decreased grain size. It should be noted that Ti-doping suppressed Bi volatility and stabilized the BiFeO₃ phase.