• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.205.2-205.2
• /
• 2011

Micro hydraulic turbines take a growing interest because of its small and simple structure as well as high possibility of applying to micro and small hydropower resources. The differential pressure exiting within the city water pipelines can be used efficiently to generate electricity like the energy generated through gravitational potential energy in dams. In order to reduce water pressure at the inlet of water cleaning centers, pressure reducing valves are used widely. Therefore, pressure energy is wasted. Instead of using the pressure reduction valve, a micro counter-rotating hydraulic turbine can be replaced to get energy caused by the large differential pressure found in the city water pipelines. In this study, in order to acquire design data of counter-rotating tubular type micro-turbine, output power, head, and efficiency characteristics due to the diffuser.

• Proceedings of the Korea Contents Association Conference
• /
• 2006.05a
• /
• pp.405-408
• /
• 2006

Design of appropriate control schemes that can satisfy the cell loss, delay requirements with various traffic specification for B-ISDN is an extremely important challenging problem. In this paper, we proposes a priority control scheme with a window counter and a cell counter per each type of class. The priority control for satisfying required service quality is performed with delay/loss factor obtained by comparing window counter with cell counter. The performance of proposed control scheme is estimated by computer simulation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.305-310
• /
• 2007

For the understanding of the complex flow characteristics in the counter-rotating axial flow fan, it is necessary to investigate the three-dimensional unsteady flow fields in the counter-rotating axial flow fan. This information is also essential for the prediction of the aerodynamic and acoustical characteristics of the counter-rotating axial flow fan. Experimental study on the three-dimensional unsteady flow in the counter-rotating axial flow fan is carried out at the design point(operating condition). Three-dimensional unsteady flow fields in the counter rotating axial flow fan are measured at the cross-sectional planes of the upstream and downstream of each rotor using the $45^{\circ}$ inclined hot-wire. Three-dimensional unsteady flow fields in the counter-rotating axial flow such as the wake, the tip vortex and the tip leakage flow are shown the form of the velocity vectors and the velocity contours.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.12
• /
• pp.148-161
• /
• 1998

We investigate a design methodology for master arm which is employed in remote-site control. Though counter-balancing has been employed for the purpose of lessening the actuator loads, it results in the increase of dynamic load at the task position. Therefore, there exists a trade-off between counter-balancing and dynamic performance. The concept of a composite index is introduced to simultaneously consider those two effects in the design of master arms. Several alternative designs of master arms are suggested.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.39-42
• /
• 2008

In the case of the general helicopter among rotorcraft, length of the rotor blade for thrust-generation is longer than that of fuselage and tail rotor is required in order to compensate moment of the fuselage. For those reasons, enough space for take-off and landing should be secured and an accessibility for building is low. Also, the accidents caused by tail rotor occur frequently. However, the case of counter-rotating has merits that tail rotor is unnecessary as well as length of the rotor blade can be shortened but has a weakness that the weight of body is increased. In the present study, aerodynamic force measurement on single rotor system equipped with NACA0012 airfoil, which has aspect ratio of 6 and chord length of 35.5 mm, was carried out. And measurement was conducted with blade which has a half size of the former blade by using single motor counter-rotating. Aerodynamic force measurement was acquired by using 6-component balances and coefficients of thrust and power were derived along the pitch angle varying from 0$^{\circ}$ to 90$^{\circ}$ with the increment of 10$^{\circ}$. Those aerodynamic force data will be utilized for the design and production of brand-new counter-rotating rotor blade system which has same thrust with single blade system and provides a good accessibility to building by reducing its blade length.

• 한국신재생에너지학회:학술대회논문집
• /
• 2006.06a
• /
• pp.154-157
• /
• 2006

The counter electrode widely used in DSCs (Dye-sensitized Solar Cells) is constructed of conducting glass substrates coated with Pt films, where the platium acts as a catalyst. Pt counter electrodes in DSCs are one important component. It is expected that characteristics of Pt electrodes strongly depend on fabrication process and its surface condition. In this study, Pt counter electrode surface of DSC is deposited by reactive RF magnetron sputtering under the conditions of Ar 5mtorr, RF power of 120w and substrate temperature of $100^{\circ}C$. Surface morphology of Pt electrodes was investigated by FE-SEM and AFM. And this paper shows our recent results and technology to fabricate the new designed cell with Pt electrodes deposited by sputtering method. We have achieved fill factor 65% and photoelectric conversion efficiency around 2.6% as the best results of new designed DSCs structure.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.05a
• /
• pp.678-681
• /
• 2009

A single-pixel photon counter is designed using a folded cascode CMOS operational amplifier which is self-biased. Since there is no need for a voltage bias circuit, the layout area and power consumption of the designed counter are reduced. The signal voltage of the designed charge sensitive amplifier (CSA) with the MagnaChip $0.18{\mu}m$ CMOS process is simulated to be 138mv, near the theoretical voltage of 151mV. And the layout area of the designed counter is $100{\mu}m{\times}100{\mu}m$.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.05a
• /
• pp.982-986
• /
• 2000

Perpendicular guideway mechanism has a different behavior with horizontal guideway mechanism due to the slider weight. So, to decrease its weight effect, counter balances such as weight type and hydraulic cylinder type are used. But it can also make another motion behavior by weight rate of slider and counter balance, its connected position. Therefore, it is necessary to find design parameters and analyze their effect. This paper dealt with the optimal design of perpendicular guideway mechanism. For analysis, the theoretic model as same as real machine tool and sib plate to adjust the clearance was used. Rotational angle and displacement of slider, pressure distribution, friction distribution were calculated. Stick slip, intermittent motion of slider according to friction change was adapted to the perpendicular guideway mechanism.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.14 no.3
• /
• pp.217-233
• /
• 2012

Placeness forms the traits unique to certain areas inducing people to visit there and purchase goods related to the place. The purpose of this study is to survey fashion images linked with placeness, by examining on-line and off-line fashion goods which claim the placeness. Hong-dae area in Seoul is selected for the case study, and the fashion goods claiming Hong-dae style or Hong-dae fashion are selected in order to analyze the fashion images. Hong-dae area, which was known for its art scenes and small restaurants in the 1980s, has been flourished its postmodern style cafes formed as yuppies-style consumer space in the 1990s. Foreign influenced subcultures were adopted, mimicked and mixed. Afterwards, dance clubs and live clubs gathered around this area. Recently, various local events to enhance the place identity such as "freemarket" and festivals are hosted by the local community. Based on the historical and regional background, the placeness of Hong-dae area is characterized with its artistry, counter-culturalism, and commercialism. The fashion images related of Hong-dae area fashion can be characterized as avant-garde image, art & craft image, kitsch image, vintage image, sexy casual image, and pop art image. The avant-garde image and the art & craft image are related with altistry and counter-culturalism. Kitsch image is related with the artistry, counter-culturalism, and the commercialism. Vintage image is related with artistry, counter-culturalism and commercialism. Sexy casual image is known to have commercialism of Hong-dae area, while Pop art image has its artistry and commercialism.

• The KIPS Transactions:PartA
• /
• v.12A no.3 s.93
• /
• pp.263-272
• /
• 2005

The addressing mode for data is performed by the software in yon Neumann-concept(SISD) computer a priori without hardware design of an address counter for operands. Therefore, in the addressing mode for the vector the corresponding variables as much as the number of the elements should be specified and used also in the software method. This is because not for operand but only for an instructions, quasi PC(program counter) is designed in hardware physically. A vector has a characteristic of a structural dimension. In this paper we propose to design a hardware unit physically external to the CPU for addressing only the elements of a vector unit with the structure and dimension. Because of the high speed performance for a vector processing it should be designed in the SIMD pipeline mechanics. The proposed mechanics is evaluated through a simulation. Our result shows $12\%$ to $30\%$ performance enhancement over CRAY architecture under the same hardware consideration(processing unit).