• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.43.1-43.1
• /
• 2011

The detail simulation modeling of fully-fed induction generator is investigated through PC based MATLAB/Simulink environment. Generator's stator currents are controlled by indirect vector control method. In this method, generator side converter controls the maximum excitation (air gap flux) by stator d-axis current and controls generator torque by stator q-axis current. Induction generator speed is controlled by tip speed ratio (TSR) upon the wind speed variations in order to generate the maximum output power. The generator torque model is specified as a 3-blade wind turbine with rating, then, the model is simulated under normal operating condition and three different fault conditions. The matlab model designed for fully-fed induction generator based wind farm provides good performance under normal and grid fault conditions. It provides good results for different pwm techniques and fault conditions except the single-phase line to ground fault, which should be verified with real time data from wind farms.

• Proceedings of the KIEE Conference
• /
• 2000.11c
• /
• pp.446-448
• /
• 2000

Organic semiconductors based on vacuum-deposited films of fused-ring polycyclic aromatic hydrocarbon have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, pentacene thin films and electrode materials were deposited by Organic Molecular Beam Deposition (OMBD) and vacuum evaporation respectively. For the gate dielectric layer, OPTMER PC403 photo acryl (JSR Coporation.) was spin-coated and cured at $220^{\circ}C$. Electrical characteristics of the devices were investigated, where the channel length and width was $50{\mu}m$ and 5 mm. It was found that field effect mobility was $0.039\;cm^2V^{-1}s^{-1}$, threshold voltage was -7 V, and on/off current ratio was $10^6$.

• Journal of the Korean Applied Science and Technology
• /
• v.18 no.3
• /
• pp.191-196
• /
• 2001

Organic semiconductors based on vacuum-deposited films of fused-ring polycyclic aromatic hydrocarbon have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, pentacene thin films and electrode materials were deposited by Organic Molecular Beam Deposition (OMBD) and vacuum evaporation respectively. For the gate dielectric layer, photoacryl (OPTMER PC403 from JSR Co.) was spin-coated and cured at $220^{\circ}C$. Electrical characteristics of the device were investigated, where the channel length and width was 50 ${\mu}m$ and 5 mm. It was found that field effect mobility was 0.039 $cm^{2}V^{-1}s^{-1}$, threshold voltage was -8 V, and on/off current ratio was $10^{6}$. Further details will be discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.585-588
• /
• 2010

Recently, there is increasing concern about smart phone due to the release of Iphone and Android phone. Like the normal desktop application, using multimedia contents will have important role for smart phone application. The multimedia contents mentioned here mean Image and Video. The famous codecs for Image and video are Jpeg Mpeg and h.264, which is popular recently as a vedeo codec because of its high compression ratio compared with the other video codecs. In this paper, we will use Jpeg and H.264 encoded raw sequences. This paper will suggest how to decode and display effectively Jpeg and H.264 raw sequences arrived from socket stream. And we will show you the simulation result.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.8
• /
• pp.874-880
• /
• 1997

Various classes of phospholipids were investigated for the structural determination of fatty acyl groups by fast atom bombardment tandem mass spectrometry (FAB-MS/MS). Phospholipids were desorbed by FAB as molecules chelated with sodium ion (or ions). Collision-induced dissociation (CID) of intact sodium adduct molecular ions ([M+Na]+, [M-H+2Na]+ or [M+Na-2H]-) produced a series of homologous fragment ions via the charge-remote fragmentation along the fatty acid chains. These ions were found useful to locate the double bond positions even for the polyunsaturated fatty acid chains. The regiospecificity of the acyl chain linkages in phosphatidylcholine (PC) could also be determined based on the ratio of relative abundance of the product ions (i.e., [M+Na-85-R2COOH]+ vs [M+Na-85-R1COOH]+) in CID-MS/MS of [M+Na]+. These are generated by the loss of fatty acyl groups at sn-1 and sn-2, respectively, together with the choline group. In all the phospholipid compounds investigated, loss of the fatty acid at the sn-2 position was dominant. The present method was applied to the structural determination of molecular species of phosphatidylglycerols (PG) isolated from cyanobacterium Synechocystis sp. PCC 6803.

• Journal of Korean Home Economics Education Association
• /
• v.10 no.2
• /
• pp.131-144
• /
• 1998

The lack of characteristical understanding of the Home Economics Education will have difficulty in achieving the goal of the Home Economics Education. To allow the Home Economics Education class in school contribute toward the enhancement of the quality of life, it is inevitable to reinforce the recognition of the importance and necessity of the Home Economics Education and to newly propose a directional guidance forward the coming 21st century. The purpose of this study was to provide basic data for planners of the future Home Economics Education by surveying research administrators in charge of programming the overall school curriculum. This study was conducted under the following procedure to have the outcome as follows ; 1. Answers from respondents of age over 50 or careers over 16 years tended to grasp the goal of Home Economics Education in relation to the enhancement of quality of life rather than to the accumulation of knowledge, skill or capacity. 2. Of all the surveyed, 9.64% regarded Home Economics Education as an essential part of school education and the positive ratio was higher with younger respondents. 3. To the question asking if the high school Home Economics Education could have influence on one's capacity, 97.2% of the answerers said yes. The respondents with career under 15 year showed 100% of positive agreement in this matter and of age under 40 marked much higher ratio of 98.84% than the elders. 4. The overall recognition of the necessity for separate sections in Home Economics Education programmed in accordance with the 6th Revision of High School Curriculum displayed a considerably high ratio, with a little differences among age and job groups. The purpose of this study is to analyze and understand adolescents'culture, thereby to provide fundamental information for Preventive Education for Adolescents'Problems in Home Economic Education. 745 articles collected in computer communication service were used for the analysis. The data were analyzed by frequency and percentage using the SPSS/PC+computer program. The most important results of this study were as follows ; 1) Concerning 'Adolescent's Problems's, problems such as violence, homicide and robbery were treated with the greatest frequency. It was also analyzed that the older generations are highly inclined to understand adolescents'culture as a negative one, for example, 'delinquency'or 'immaturity'. 2) Although the area of 'Adolescents'Education'was treated most frequently reflecting the high educational concern in our society, the significant part of those articles were on wrongful educational administration. As much as 70.6% of the articles analyzed were on 'Education'and 'Problems'. Thereby it may be concluded that the other areas such as health, activities, worries, values and harmful environments ere treated respectively as only a 'subculture'or'fragmentary culture'. The articles containing correlations and interactions among them and certain alternative proposals were very rare. 3) The areas such as 'Worries and Counselling'and 'Health'were occupying only a small portion of the articles. The articles which were treating the practical worries and their resolutions were even rarer. 4) 'Values'of the adolescents tended to be viewed by the older generations very negatively. It was also found that the older generations gave the tendency to see the 'consumption culture'of the adolescents as a kind of 'counter culture'or'subculture'.

• Clean Technology
• /
• v.26 no.2
• /
• pp.116-121
• /
• 2020

In this paper, the recycling of waste Ni-MH battery by-products for electric vehicle is studied. Although rare earths elements still exist in waste Ni-MH battery by-products, they are not valuable as materials in the form of by-products (such as an insoluble substance). This study investigates the recovering of rare earth oxide for solvent extraction A/O ratio, substitution reaction, and reaction temperature, and scrubbing of the rare earth elements for high purity separation. The by-product (in the form of rare earth elements insoluble powder) is converted into hydroxide form using 30% sodium hydroxide solution. The remaining impurities are purified using the difference in solubility of oxalic acid. Subsequently, Yttrium is isolated by means of D2EHPA (Di-[2-ethylhexyl] phosphoric acid). After cerium is separated using potassium permanganate, lanthanum and neodymium are separated using PC88A (2-ethylhexylphosphonic acid mono-2-ethylhexyl ester) and it is calcinated at a temperature of 800 ℃. As a result of the physical and chemical measurement of the calcined lanthanum and neodymium powder, it is confirmed that the powder is a microsized porous powder in an oxide form of 99.9% or more. Rare earth oxides are recovered from Ni-MH battery by-products through two solvent extraction processes and one oxidation process. This study has regenerated lanthanum and neodymium oxide as a useful material.

• Journal of KIISE:Computing Practices and Letters
• /
• v.11 no.2
• /
• pp.149-156
• /
• 2005

The HLA is the simulation architecture standard that the civilian and military simulation communities are deeply interested in. We can find various successful practices applying HLA to constructive simulations such as war games in domestics and overseas. However, any case of real-time distributed simulations has not been reported. The reason is that a message transmission period via RTI in a network layer varies according to computing power, simulation nodes, transmission types, and packet size; further a message processing time in an application layer depends on its processing methods, thus too difficult to set up real-time constraints for the enhancement of a real-time resolution. Hence, in this paper we have studied the real-time constraints of RTI for the development of the M-SAM simulator. Thus we have developed a HLA based pilot simulator using 6 PC's in LAN and then measured and analysed the performance of the RTI. As the results of our work, we could obtain the quantitative values for message delay, RTI overhead and RTI packet transmission ratio by a real operation scenario and loads, which are not shown in the previous works. We also expect that the results can be used as a guideline to set up the number of targets, transmission frequency and message processing method in the development of the M-SAM simulator and similar applications.

• Applied Biological Chemistry
• /
• v.47 no.3
• /
• pp.300-306
• /
• 2004

Eight cation or anion-responsive polymer membranes were prepared by a casting procedure employing polyvinyl chloride, Bis (2-ethylhexyl)sebacate and each electroactive material in the ratio of 66 : 33 : 1. The resulting membranes were separately installed onto the sensitive area of the ionic electrodes to produce an 8-channel taste sensor array. The taste sensors of the array were connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a PC via an A/D converter. The taste evaluation system was applied to a discriminant analysis on six groups of marketed beverages like sikhye, sujunggwa, tangerine juice, ume juice, ionic drink and green tea. When the signal data from the sensor array were analyzed by principal component analysis after normalization, the 1st, 2nd and 3rd principal component explained most of the total data variance. The six groups of the analyzed beverages were discriminated well in the three dimensional principal component space. The half of the five groups of the analyzed beverages was also discriminated in the two dimensional principal component plane.

• Polymer(Korea)
• /
• v.37 no.6
• /
• pp.694-701
• /
• 2013

A new copolymer named T-TI24T (poly((5,5-(2-butyl-5,6-bisdecyloxy-4,7-di-thiophen-2-yl-isoindole-1,3-dione))- alt-(2,5-thiophene))) based on phthalimide derivative and thiophene is synthesized by the Stille-coupling reaction. The polymer shows relatively high number average molecular weight of 86500 g/mol with good solubility in common organic solvents such as chloroform, 1,2-dichlorobenzene, and toluene and is thermally stable up to $380^{\circ}C$. Besides, it possesses a relatively low highest occupied molecular orbital (HOMO) energy level of -5.33 eV, promising the high open circuit voltage ($V_{oc}$) for photovoltaic applications. Active layer solution of polymer T-TI24T-as a donor and (6)-1-(3-(methoxycarbonyl)- {5}-1-phenyl[5,6]-fullerene (PCBM)-as an acceptor in different weight ratios is applied to fabricate the polymer solar cell devices. The ratio of polymer/PCBM affects the solar cell efficiency and the best performance exhibits in the device with polymer/PCBM = 1:3 (w/w), which shows a power conversion efficiency (PCE) of 0.199% and a $V_{oc}$ of 0.99 V, respectively. Even though the device shows the very low PCE, the $V_{oc}$ is higher than that of well known bulk heterojunction type solar cell based on P3HT:PC61BM (c.a. 0.5 V).