• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2015년도 제46회 하계학술대회
• /
• pp.155-156
• /
• 2015

Recently, electricity consumption has rapidly increased along with economic growth. The operating strategy using emergency generator is aimed, to resolve a demand response management. For strategy of peak shedding using emergency generator, it is essential to introduce the fast transfer switching device. One of the most effective solutions is to use a static transfer switch (STS) based on thyristor. However, the characteristic of natural commutated SCR thyristor should anticipate short duration voltage sag. STS system thus requires more than a quarter cycle to successfully complete transfer process. This paper proposes the operation scheme of the STS system using the forced-commutation technique to mitigate instantaneous voltage sag during peak transfer process. Proposed STS system improved turn-off characteristic thus accomplishes the peak load shedding satisfied power quality. Performance of the proposed STS system is evaluated using electromagnetic transient program (EMTP) to confirm the effectiveness.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2006년도 전력전자학술대회 논문집
• /
• pp.43-45
• /
• 2006

대부분의 컨버터들은 초기 기동시에 MOSFET 전류와 전압의 과도한 상승을 막아주기 위해서 Soft Start 기능을 갖고 있다. 하지만 제어기 내부의 지연시간이나 LEB(Leading Edge Blanking) 시간 등으로 인해 MOSFET은 무시할 수 없는 상당한 기간의 최소 턴온 시간(Minimum Turn-on Time)을 갖게 되고, 이로 인해 드레인 전류가 과도하게 상승하는 현상을 보이게 된다. 본 논문에서는 이런 현상이 발생할 수 있는 초기 기동이나 출력단 단락시에 과도한 드레인 전류의 상승을 막아주는 방법을 제시하고자 한다.

• 한국정밀공학회지
• /
• 제15권10호
• /
• pp.103-112
• /
• 1998

The evolution of semiconductor manufacturing technology has accelerated the reduction of device dimensions and the increase of integrated circuit density. In order to improve yield within a short turn around time and maintain it at high level, a system that can rapidly determine problematic processing steps is needed. The statistical process control detects abnormal process variation of key parameters. Expert systems in SPC can serve as a valuable tool to automate the analysis and interpretation of control charts. A set of IF-THEN rules was used to formalize knowledge base of special causes. This research proposes a strategy to apply expert system to SPC in semiconductor manufacturing. In analysis, the expert system accomplishes the instability detection of process parameter, In diagnosis, an engineer is supported by process analyzer program. An example has been used to demonstrate the expert system and the process analyzer.

• 한국인쇄학회지
• /
• 제19권1호
• /
• pp.42-54
• /
• 2001

The combination of a silicone surfaced plate and high viscosity ink produced a waterless printing system that worked well, but had limitation. The limitation was that this system was restricted to relatively short run lengths. In the waterless printing process, the press tended to heat up rapidly. Heat in turn, broke down the resins in the inks, causing them to become more fluid. When the ink is heated, the viscosity will drop, the ink will become too liquid and the plate will no longer be able to resist it. The ink will adhere to the non-print portions of the plate, and will print as a very fine mist or speckle pattern in the non-image area. On the other hand, when the ink gets too cold, viscosity will increase until ink transfer is impeded. This study carried otu to investigate the effect of temperature variations of the inks on the print quality in waterless lithography and to examine the adaptability of waterless lithography to conventional offset press without cooling system.

• 패션비즈니스
• /
• 제10권3호
• /
• pp.1-22
• /
• 2006

This study aims at strengthening the national competitiveness of Korea's clothing industry as it provides substantial information on type characteristics and body types for Chinese women and improves the fitness of clothing, considering human proportion in the production of clothing products for export to China. This study measured for 1,381 women between 19 and 50 aged residing in Beijing and Shanghai, China from June 23 to August 7, 2004 by the simple random sampling. Data was analyzed by used SPSS/WIN 10.0 Program. As for the of method of this study, the technical statistical analysis, F-test, and Duncan-test were made. The results of this study are as follows. As age increases, the shoulders seem higher with less curvature on waist, while the front has turned into the straight silhouette with the side turned into the flat silhouette without curvature, and waist and belly turn into the body type of short and thick.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2008년도 춘계학술대회 논문집
• /
• pp.2035-2039
• /
• 2008

This paper described an on-line condition monitoring device for rotating machines by measurement of unbalance current due to insulation deterioration. The device consists of a zero-phase current transformer (ZCT), a low-noise amplifying circuit, and a microprocessor unit. The prototype device measures current of $500\;{\mu}A\;{\sim}\;30\;mA$ in frequency ranges from 10 Hz to 3 kHz. An application experiment was carried out on 3-phase induction motors and we could measure current changes caused by a short-circuited turn.

• 복식문화연구
• /
• 제7권5호
• /
• pp.56-67
• /
• 1999

At the turn of the 19C, the first development, spreading to the all classes that peculiar attitude of mind associated with the term prudery. The second changes of habit which affected both sexes and their undergarments were the novel idea of personal cleanliness. Drawers appear to have been of two lengths, short, when worn under breeches, and long when worn under pantaloons and trousers. The dandy wore corsets for beauty. In the early part of the 19C, the differences between day and evening style came to be accentuated. Not only the beau, but the soldier and hunting man were addicted to stays. The high standing collars of the early 1800s became fairly low in the middle of the century. in mid of the 19C, a woolen under-vest was worn next to the skin and studs were an usual fashion. At about 1850 the bottom of the shirt was cut in a curve. For evening dress the elliptic collar was introduced.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
• /
• pp.1049-1052
• /
• 2007

Extremely sharp and uniform Transfer Mold FEAs with thin film low work function TiN emitter material have been fabricated by controlling the thickness of the coated emitter materials to realize high efficient, high reliable and low-cost vacuum nanoelectronic devices..Their tip radii are 8.3-13.8 nm. Turn-on electric fields of the Ni FEAs and TiN-FEAs resulted in the low electric field values of $31.6\;V/{\mu}m$ and $44.2V/{\mu}m$,respectively, at the short emitter/anode distance: less than $30\;{\mu}m$, which are lower than those of conventional FE As such as Spindt type FEAs and carbon nan otube FEAs The Transfer Metal Mold fabrication method is one of the best methods of changing emit ter materials with sharp and uniform emit ter shapes.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2003년도 The 4th Korea-Italy Workshop
• /
• pp.51-55
• /
• 2003

Membranes made with perfluorinated polymers are of particular interest due to the unique features demonstrated by these materials. Both highly hydrophobic and hydrophilic membranes have been developed from appropriate perfluoropolymers, which were in turn obtained by copolymerization of TFE with special monomers available at the industrial scale. Highly hydrophobic membranes obtained from the glassy copolymers of TFE and 2,2,4 trifluoro-5 trifluoromethoxy-1,3 dioxole (Hyflo $n^{ }$ AD) show properties which make them particularly suited for use in the field of gas-liquid contactors and membrane distillation. Hydrophylic highly conductive proton exchange membranes obtained from the copolymer of TFE and a short-side-chain (SSC) perfluorosulfonylfluoridevinylether (Hyflo $n^{ }$ Ion) find interesting application in the field of fuel cells, especially in view of the current tendency to move to high temperature operation.n.

• Journal of Power Electronics
• /
• 제2권2호
• /
• pp.88-94
• /
• 2002

The demand for protection of power electronic application has during the last couple of vears increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight inductance over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection of adding inductance of existing High-speed and new Typower Fuse protection. First, the problem of adding inductance of exiting High-speed and new Typower Fuse DC-link circuit is treated, second a short discussion of protection of the IGBT module is done, and finally, the impect of the high frwquency loading on the currying capability of the fuses is presented.