• Transactions of the Korean hydrogen and new energy society
• /
• v.20 no.3
• /
• pp.238-244
• /
• 2009

We investigated the electrochemical properties of lithium/molybdenum sulfide(Li/MoS$_2$) using tetra (ethylene glycol) dimethyl ether(TEGDME) electrolyte. The Li/TEGDME/MoS$_2$ cell showed the first discharge capacity of 288mAhg$^{-1}$. From the XRD, SEM results of the MOS$_2$ electrode in various cut-off voltage during charge-discharge process, MoS$_2$ partly changed into Li$_2$S and Mo during discharge and Li$_2$S partly recovered into MOS$_2$ and Li during charge. Full charged MOS$_2$ electrode showed lump shape of big size, which might be related to agglomerate of MoS$_2$ particles. Therefore, the degradation might be related to decrease of active material for electrochemical reaction by agglomeration of MOS$_2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.8
• /
• pp.699-705
• /
• 2008

Capacitance versus voltage (C-V) characteristics of Ge-nanocrystal (NC)-embedded metal-oxide-semiconductor (MOS) capacitors with $HfO_2$ gate material were investigated in this work. The current versus voltage (I-V) curves obtained from Ge-NC-embedded MOS capacitors fabricated with the $NH_3$ annealed $HfO_2$ gate material reveal the reduction of leakage current, compared with those of MOS capacitors fabricated with the $O_2$ annealed $HfO_2$ gate material. The C-V curves of the Ge-NC-embedded MOS capacitor with $HfO_2$ gate material annealed in $NH_3$ ambient exhibit counterclockwise hysteresis loop of about 3.45 V memory window when bias voltage was varied from -10 to + 10 V. The observed hysteresis loop indicates the presence of charge storages in the Ge NCs caused by the Fowler-Nordheim (F-N) tunneling. In addition, capacitance versus time characteristics of Ge-NC-embedded MOS capacitors with $HfO_2$ gate material were analyzed to investigate their retention property.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.349-350
• /
• 2006

정부의 배전분할 유보결정에 따라 전력거래소에서는 현행 발전경쟁시장의 효율성 향상을 위한 많은 사업을 추진하고 있다. 그중 우선적으로 추진하였던 사업이 도매전력시장을 대비해 구축한 시장운영시스템(MOS; Market Operation System)을 현행 계통운영을 담당하고 있는 급전 자동화시스템(EMS; Energy Management System)과의 연계활동이다. 이는 시장운영시스템(MOS)에 내재되어 있는 최첨단 기능중에서 일부를 현행 전력시장에 적용함으로써 계통운영의 효율성 향상뿐만 아니라 계통운영기술을 선진화하는 것이다. 특히, 기존 급전시스템에 비해 가장 두드러지는 점은 발전기들에 대한 에너지 및 예비력 급전계획을 사전적으로 5분단위로 최적화하여 수립하고 이를 발전기들에게 송신함으로써 경제적이며 안정적인 전력계통운영을 가능하게 해 줄 수 있는 것이다. 이를 가능하게 하기 위해서는 바로 정확한 미래 수요수준의 결정이 필수불가결한 요소이다. 따라서 본 논문에서는 MOS-EMS 연계활용에서의 실시간 수요예측의 중요성과 기존 제작사의 알고리즘과 국내 전력수요특성간의 불일치점 그리고 이를 해결하고자 모색했던 방안들에 대하여 설명하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.9-10
• /
• 2007

In this paper, Thin films of $HfO_2$/Hf were deposited on p-type wafer by Atomic Layer Deposition(ALD). And we studied the electrical characterization of $HfO_2$/Hf/Si MOS capacitor depending on thickness of Hf metal layer. $HfO_2$ films were deposited using TEMAH and $O_3\;at\;350^{\circ}C$. Samples were then annealed using furnace heating to $500^{\circ}C$. The MOS capacitor of round-type was fabricated on Si substrates. Through TEM(Transmission Electron Microscope), XRD(X-ray Diffraction), capacitance-voltage(C-V) and current-voltage(I-V) analysis, the role of thin Hf metal layer for the better $HfO_2$/Si interface property was investigated.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.6
• /
• pp.812-818
• /
• 2009

This study evaluated the effects of live yeast and yeast cell-wall mannan-oligosaccharide supplementation onperformance and nutrient digestibility during early lactation in cows fed a diet based on a mixture of corn silage and alfalfa hay as forage sources. Eight multiparous Holstein dairy cows (average days in milk, 27${\pm}$6) were used in a replicated 4${\times}$4 Latin square design. Diets contained 45% forage and 55% concentrate on a dry matter (DM) basis and treatments were: i) basal diet without additive (Control), ii) basal diet with 32 g/d of mannan-oligosaccharides (MOS), iii) basal diet with $1.2{\times}10^{10}$ colony forming units per day (cfu/d) of live yeast (Saccharomyces cerevisiae CNCM 1-1077; SC), and iv) basal diet with a mixture of MOS (32 g/d) and SC ($1.2{\times}10^{10}$ cfu/d; MOS+SC). Treatments had no effect (p>0.05) on DM intake and yields of milk, 3.5% fat-(FCM) and energy-corrected milk (ECM), and on milk fat percentage, body condition score and blood metabolites. Compared with the Control, only supplementation of SC resulted in numerically higher yields of FCM (41.9 vs. 40.1 kg/d) and ECM (41.8 vs. 40.3 kg/d), and milk fat percentage (3.64 vs. 3.43%). While the MOS diet had no effects on performance compared to the Control, the combination treatment MOS+SC increased milk protein percentage (p<0.05). Also, the MOS supplementation, both alone or in combination with SC, numerically increased milk fat percentage. The SC supplementation increased apparent digestibility of DM and crude protein while the MOS supplementation did not affect digestibility. Concentrations of total volatile fatty acids (VFA) and ruminal pH were similar across treatments. Overall results indicated that supplementation of MOS produced variable and inconsistent effects on rumen metabolism and performance, whereas SC supplementation improved nutrient digestibility and numerically increased FCM and ECM yields, which could not be enhanced by the combined supplementation of MOS+SC. According to our experimental condition, there was no effect of MOS alone or in combination with SC on dairy cow performance.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.5
• /
• pp.1109-1116
• /
• 2010

In this paper, some performance characteristics of VoIP(Voice over Internet Protocol) for MANET(Mobile Ad-hoc Networks) with simulation is studied and appropriate condition for implementation of VoIP service is suggested. VoIP simulator is implemented with NS(Network Simulator)-2. VoIP traffic for simulation is generated with some codecs of G.711, G.723.1, G.726-32, G.729A, GSM.AMR and iLBC. As simulation results for traffic transmission under $670{\times}670m$ 50node MANET environment, performance data for MOS(Mean Opinion Score), network delay, packet loss rate and transmission bandwidth are measured. Normalized analysis about measured results shows that maximum VoIP connection satisfying VoIP service quality condition is 15.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.10
• /
• pp.1034-1040
• /
• 2004

The latch-up current and switching characteristics of MOS-Controlled Thyristor(MCT) are studied with variation of the channel length and impurity concentration. The proposed MCT power device has the lateral structure and P-epitaxial layer in substrate. Two dimensional MEDICI simulator is used to study the latch-up current and forward voltage-drop from the characteristics of I-V and the switching characteristics with variation of impurity concentration. The channel length and impurity concentration of the proposed MCT power device show the strong affect on the anode current and turn-off time. The increase of impurity concentration in P and N channels is found to give the increase of latch-up current and forward voltage-drop.

• Electrical & Electronic Materials
• /
• v.1 no.3
• /
• pp.269-277
• /
• 1988

P형 Si(100)로 제작한 MOS 커패시터에 $Co^{60}$-.gamma.선을 주사한 후 고주파 C-V특성 곡선으로 부터 방사선 조사에 의해 유발된 산화막안의 트랩전하의 거동 및 Si- $SiO_{2}$계면에서의 트랩밀도 분포의 변화를 검토하였다. 산화막 느랩전하는 .gamma.선 흡수선량 증가와 더불어 증가하다가 $10^{7}$ rad 부근에서부터 서서히 포화하는 경향이 나타났으며 게면트랩밀도의 분포모양은 흡수선량의 증가와 더불어 전형적인 이그러진 W자형에서 넓혀진 V자형 분포로 변화하였으나 최소값은 항상 진성페르미준위( $E_{i}$)부근에 있었으며 그 밀도는 1.0*$10^{11}$~7.5*$10^{11}$[개/$cm^{2}$/eV]로 계산되었다. 또한, 일정 바이어스전압하에서의 조사선량에 따른 $V_{fb}$ 의 변화는 현저하지는 않았으나 바이어스 전압을 +12V로 인가할 때 변화방향의 반전상태가 관측되었다. 그 이유로는 Si측의 계면 부근에서 일어난 눈사태 전자가 산화막내로 주입됨에 따라 도너형 양전하의 수가 감소되기 때문으로 추정되었다.되었다.

• The Journal of the Korea Contents Association
• /
• v.5 no.4
• /
• pp.254-264
• /
• 2005

In this paper, an advanced E-Model was proposed in order to overcome disadvantages of conventional method. A new model makes the accurate VoIP call quality assessment possible by applying the burst packet loss and recency effect. In order to assess the performance of this advanced E-Model, we gained the estimated MOS value from NR(Network R) value and UR(User R) value resulted from the burst packet loss values by Gilbert Model. Through simulations and comparisons with conventional models such as MOS, PESQ, and I-Model, we reach a conclusion that advanced E-Model is more accurate and reliable method than conventional models.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.4
• /
• pp.559-563
• /
• 2001

The effects of feeding a mannan oligosaccharide (Bio-Mos) from 0 to 3 g/kg diet and vaccination program on 1- to 35-day performance (growth and feed efficiency), metabolizable energy, nitrogen utilization and carcass composition of meat chickens were investigated. A general vaccination program was used against IB, IBD and ND with half of the birds per diet receiving a booster dose of IB and ND vaccines at 12 days of age. Dietary supplementation of Bio-Mos (BM) did not influence body weight gain, feed efficiency and nutrient utilization. The highest dietary BM (3 versus 1.5 or 0 g/kg) increased carcass abdominal fat and reduced the proportion of drumstick in the carcass of meat chickens. The booster dose reduced the performance of birds. It was concluded that the addition of BM to the diet of chickens did not significantly influence the performance and nutrient utilization of meat chickens.