• Journal of the Korean Magnetics Society
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• v.16 no.6
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• pp.287-292
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• 2006

Al substituted $CoAl_{0.5}Fe_{1.5}O_{4}$ has been studied with x-ray and neutron diffraction, $M\"{o}ssbauer$ spectroscopy and magnetization measurements. $CoAl_{0.5}Fe_{1.5}O_{4}$ revealed a cubic spinel structure of ferrinmagnetic long range ordering at room temperature, with magnetic moments of $Fe^{3+}(A)(-2.29{\mu}_{B}),\;Fe^{3+}(B)(3.81\;{\mu}_{B}),\;Co^{2+}(B)(2.66{\mu}_{B})$, respectively. The temperature dependence of the magnetic hyperfine field in $^{57}Fe$ nuclei at the tetrahedral (A) and octahedral (B) sites was analyzed based on the $N\'{e}el$ theory of magnetism. In the sample of $CoAl_{0.5}Fe_{1.5}O_{4}$, the interaction A-B interaction and intrasublattice A-A superexchange interaction were antiferromagnetic with strengths of $J_{A-B}=-19.3{\pm}0.2k_{B}\;and\;J_{A-A}=-21.6{\pm}0.2k_{B}$, respectively, while the intrasublattice B-B superexchange interaction was found to be ferromagnetic with a strength of $J_{B-B}=3.8{\pm}0.2k_{B}$.

• Journal of the Korea Computer Industry Society
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• v.2 no.7
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• pp.895-904
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• 2001

In this study, gain can be high because an active double balance mixer was used. Receiving system II was made with receiving system I of low IIP3, a passive double balance mixer which has low gain and high IIP3, and an intermediate frequency amplifier for enhancing the low gain. The result of simulating receiving parameter is as follows： the total NF of receiving system I was 6.4382dB, gain was 53.5dB, and IIP3 was -6.6352dB m. As for the receiving system II, the total NF was 9.70672dB, gain was 47dB, and IIP3 was 3.66729dB m.

• Journal of the Korean Ceramic Society
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• v.27 no.5
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• pp.583-588
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• 1990

Glass films in the binary system B2O3-SiO2 and Al2O3-SiO2 were prepared on soda-lime-silica slide glass by the dip-coating technique from TEOS and boric acid or aluminum nitrate. Thickness of the films varying with viscosity and withdrawal speed were measured and effect of composition and firing temperature on the properties such as transmittance and refractive index were investigated. nM2O3.(100-n)SiO2(M=B or Al) films containing up to 20mol% B2O3 and 40mol% Al2O3 were transparent. Maximum transmittance at visible range were obtained for the sample containing 15mol% Ba2O3 and 32.5mol% Al2O3 and heat-treated at 50$0^{\circ}C$, respectively. Refractive index of the film containing 15mol% B2O3 was mininum in the B2O3-SiO2 binary system and minimal refractive index was appeared at the film containing 32.5mol% Al2O3. In IP spectra, addition of B2O3 were increased absorption peak intensity of B-O and Si-O-B bond and addition of Al2O3 were decreased absorption peak intensity of Si-O bond, respectively.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.792-796
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• 2003

Polychlorinated dibenzo-p-dioxins (PCDDs) are extremely toxic and persistent environmental pollutants. Their chemical reactivities and other physicochemical/biological properties show a strong dependence on the chlorination pattern. With increasing the number of chlorines, dioxin congeners become more electronegative and gain higher electron affinities. The vertical electron affinities (VEA) are related with the LUMO energies of neutral molecules. LUMO energies of all PCDD congeners were calculated at the B3LYP/6-31G** level and those of some selected congeners at the level of B3LYP/6-311G**//B3LYP/6-31G** and B3LYP/cc-pvtz/ /B3LYP/6-31G**. The total energies of neutral and anionic species for dibenzo-p-dioxins (DD), 1469-TCDD, 2378-TCDD, and OCDD were calculated at the level of B3LYP/6-31G**, B3LYP/aug-cc-pvdz, and B3LYP/ aug-cc-pvtz//B3LYP/6-31G**. By using the four congeners with D2h symmetry as reference molecules, we could estimate VEA (B3LYP/aug-cc-pvdz) of 75 PCDD congeners based on the linear correlations between LUMO energy and VEA (B3LYP/6-31G**) and between VEA (B3LYP/6-31G**) and VEA (B3LYP/aug-ccpvtz// B3LYP/6-31G**). Results show that all PCDDs with the number of Cl ≥ 3 have positive electron affinities. The PCDD electron affinity values provided in this work can be a useful data set in understanding the congener-specific reactivities of dioxins in various environmental media.

• Journal of Acupuncture Research
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• v.27 no.3
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• pp.1-13
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• 2010

목적 : 이 연구는 봉약침의 봉독과 그 주요성분인 멜리틴이 NF-${\kappa}B$의 활성억제와 세포자멸사 관련 단백질의 발현 조절을 통하여 세포자멸사를 유도함으로써 전립선 암세포주인 PC-3 세포의 성장을 억제하는지를 확인하고 해당 기전을 살펴보고자 하였다. 방법 : 봉독이나 멜리틴을 처리한 후 PC-3의 성장억제를 관찰하기 위해 WST-1 assay, CCK-8 assay를 시행하였고, 세포자멸사 조절단백질의 변동 관찰에는 western blot analysis를 시행하였고, 세포자멸사와 연관된 NF-${\kappa}B$의 활성 변화를 관찰하기 위해 EMSA를 시행하였으며, PC-3에서 봉독이나 멜리틴과 NF-${\kappa}B$의 상호작용을 관찰하기 위해 transient transfection assay를 시행하여 세포생존율과 NF-${\kappa}B$의 활성 변동을 측정하였다. 결과 : PC-3 세포에 봉독이나 멜리틴을 처리한 후, 전립선암세포의 성장, 세포자멸사의 유발, 세포자멸사 관련 단백질의 발현, NF-${\kappa}B$의 활성, NF-${\kappa}B$의 p50, $IKK{\alpha}$, $IKK{\beta}$ 치환 후 NF-${\kappa}B$의 활성과 PC-3 세포 증식에 미치는 영향을 관찰하여 다음과 같은 결과를 얻었다. 1. PC-3 세포에서 봉독이나 멜리틴을 처리한 후 세포자멸사가 유도되어 세포성장이 억제되었고, 세포자멸사 관련 단백질 중 분리된 PARP, caspase-3, -9는 유의한 증가를, Bcl-2, XIAP, cXIAP2는 유의한 감소를 나타내었다. 2. PC-3 세포에서 봉독이나 멜리틴을 처리한 후 NF-${\kappa}B$의 활성은 유의한 감소를 나타내었다. 3. PC-3 세포에서 NF-${\kappa}B$의 p50, $IKK{\alpha}$, $IKK{\beta}$를 치환하여 작용기를 없애고 봉독이나 멜리틴을 처리하였을 경우에도 NF-${\kappa}B$의 활성이 유의한 감소를 나타내었다. 결론 : 이상의 결과는 봉독이나 멜리틴이 NF-${\kappa}B$의 활성 억제를 통하여 인간 전립선암세포주인 PC-3의 세포자멸사를 유발함으로써 증식억제 효과가 있음을 입증한 것으로, 전립선암의 예방과 치료에 대한 효과적인 치료제 개발에 도움이 될 것으로 기대된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1687-1693
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• 2015

Recently, demand for digital image processing devices increases rapidly, more clear images have been required. But, in the process of digital image acquisition, processing and transmission, image degradation occurs due to various external reasons and researches about noise reduction are on the rise. Therefore, this study suggested the algorithm to process AWGN(additive white Gaussian noise) by separately processing as three levels according to the pixel distribution in the mask in order to remove AWGN(additive white Gaussian noise) which is added in the image. Regarding the processed results by applying Barbara images which were damaged by AWGN(σ = 15), suggested algorithm showed the improvement by 2.87[dB], 2.95[dB], 2.88[dB], 1.52[dB], 1.49[dB], 1.58[dB] and 1.25[dB] respectively compared with the existing MF(5 × 5), A-TMF(5 × 5), AWMF(5 × 5), MF(3 × 3), A-TMF(3 × 3), AWMF(3 × 3), GF(5 × 5).

• Journal of the Korean Magnetics Society
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• v.6 no.2
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• pp.80-85
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• 1996

An externally applied magnetic field during annealing the $Nd_{2}Fe_{14}B/Fe_{3}B$ based spring magnet was found to enhance the exchange coupling between the hard and soft magnetic grains. More than 30 % increase in remanence values for melt-spun $Nd_{4}Fe_{73.5}Co_{3}(Hf_{1-x}-Ga_{x})B_{18.5}$(x=0, 0.5, 1.0) alloys was resulted from uniform distribution of $Fe_{3}B$, $\alpha$-Fe as well as $(Nd_{2}Fe_{14}B)$, and also from reduced grain size of those phases by 20 %. The result also showed that there is an optimum grain size exhibiting a high coercivity value which will be discussed in terms of previously simulated exchange coupling parameter.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1415-1423
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• 2007

Total efficiency of transmitter system was improved by developing combinational 2-Way Isohybrid for GSM1900 base station in this paper. The size of product was decreased and the characteristics were stabilized. The isohybrid transmitter combiner of chip coupler type and hybrid coupler type were designed and fabricated. Insertion loss for chip coupler type isohybrid was $3.17\;dB{\sim}3.47\;dB$. On the other hand, insertion loss for hybrid coupler type was $3.17\;dB{\sim}3.42\;dB$. Isolations between ANT and port were $24.23\;dB{\sim}29.98\;dB$ in case of chip coupler type Isohybrid and were $26.28\;dB{\sim}36.91\;dB$ in case of hybrid coupler type, respectively.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2255-2260
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• 2010

In this study, some novel thiosubstituted butenyne (3a-d, 7b, 15b), butadiene (4a-b, 4d, 5a, 5c, 6b, 8e, 9c, 10b, 16b, 18e) and [3]cumulene (11a-b with isomer 3a-b, 12a with isomer 13a, 14b, 17e) compounds were synthesized from the reaction of 2H-pentachloro-1,3-butadiene with thiols. The new compounds were characterized by elemental analysis, mass spectrometry, UV-vis, IR, 1H NMR, NMR ($^{13}C$ or APT) spectroscopy.

• Journal of Life Science
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• v.8 no.3
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• pp.272-278
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• 1998

To investigate the effects of different UV-B levels on plant growth, cucumber plants were subjected to three levels of biologically effective ultraviolet-B(UV--$B^{BE}$ radiation [daily dose : 0.03(No UV-B), 6.40(Low UV-B) and 11.30 (High UV-B) kJ $m^{-2}$, UV--$B^{BE}$] in the growth chambers for 3 weeks during the early growth period. High and low levels of UV-B irradiation drastically decreased both dry weight and leaf area, but increased specific leaf weight of cucumber. Plants subjected to UV-B resulted in 30% and 20% reduction of photosynthesis rate by high and low UV-B, respectively. However, respiration rate was not affected by the UV-B. With increasing UV-B intensity, total chlorophyll contents were decreased linearly, while the contents of flavonoid were increased linearly. These results suggest that the present levels of UV-B may affect the growth of cucumber plant compared with a UV-B-free condition. It is likely that the growth of cucumber will be affected by enhanced UV-B due to ozone depletion in the near future.