• 디지털융복합연구
• /
• 제6권3호
• /
• pp.35-43
• /
• 2008

This research was to analyze information network which contributed Anyang Venture Valley's development. And mutual communication between regional innovated companies was the essential factor of this growth. Anyang city with its Knowledge Industry Promotion Agency, KIPA, has first set up communication network, facility and other structures to create basis of communication. For that, they were able to operate various networking and promotion of communication which led to the enforcement of regional innovation in venture businesses. During its innovation, KIPA played a key role as a link between regional Innovated companies, which enabled active interactions between them. Government can verify significance of establishing network base with mediation function for lively communication for promoting innovation capability through Anyang Venture Valley's case.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.198-202
• /
• 2001

This paper presents a novel prototype version of ZCS-PWM forward DC-DC power converter using power MOSFETs which is designed for application specific low voltage large current conversion operation. The soft-switching forward power converter with a high frequency isolated transformer link which can efficiency operate over wide load ranges under two conditions of ZCS as well as active voltage clamped switching is evaluated and discussed on the basis of the simulation and experimental results.

• 전자공학회논문지C
• /
• 제34C권4호
• /
• pp.1-15
• /
• 1997

This paper proposes CMOS on-chip voltage and current reference circuits that operate at supply voltages between 2.5V and 5.5V without using a vonventional bandgap voltage structure. The proposed reference circuits based on enhancement-type MOS transistors show low cost, compatibility with other on-chip MOS circuits, low-power consumption, and small-chip size. The prototype was implemented in a 0.6 um n-well single-poly double-metal CMOS process and occupies an active die area of $710 um \times 190 um$. The proposed voltage reference realizes a mean value of 0.97 V with a standard deviation of $\pm0.39 mV$, and a temperature coefficient of $8.2 ppm/^{\circ}C$ over an extended temeprature range from TEX>$-25^{\circ}C$ to $75^{\circ}C$. A measured PSRR (power supply rejection ratio) is about -67 dB at 50kHz.

• 신재생에너지
• /
• 제2권2호
• /
• pp.23-27
• /
• 2006

The power split hybrid powertrain is considered to be one of the most prospective configuration for the hybrid electric vehicle (HEV). Toyota Prius, representing this type of vehicle, showed outstanding performances in fuel efficiency, emission reduction and acceleration. The excellence is largely due to the fact that it utilizes almost all operation modes of HEV. Those modes include ZEV (Zero Emission Vehicle) driving, idle stop, fuel cut-off, power assist, active charging, regenerative braking and so forth. In this paper, a few of the mode operations were simulated using AVL Cruise. Also, control logics to operate the powertrain in each mode were developed. The states of powertrain components were displayed and analyzed. By controlling the three components (engine, motor and generator), it was possible to run the powertrain in several hybrid operation modes.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.127-132
• /
• 2000

This paper describes a 3-phase Line-Interactive APF system and analyzes its operating characteristics considering LC Filter output characteristics. Topology of APF is similar to that of Off-Line UPS in the point of parallelly operating inverter system. So it is possible to be multi-functioned active compensating system according to power condition. Likewise this actively operating system from APF to UPS and vice versa is often to be called Line-Interactive system. And more than that Line-Interactive system needs precise design of LC filter on converter output side to make this system fully operate in both APF and UPS modes. The problem in this point is how to design LC Filter to be contented with two different system characteristics so this paper analyzes this problem and proposes its design procedures. Then suggested filter design is verified to be contented by the simulations and experimental results

• Journal of Power Electronics
• /
• 제9권6호
• /
• pp.835-844
• /
• 2009

In this paper a new buck-boost type DC-DC converter is presented. Its voltage gain is positive, all active elements operate under soft-switching condition independent of loading, magnetic isolation and self output short-circuit protection exist, and very fast dynamic operation is achievable by a simple bang-bang controller. This converter also exhibits appropriate PFC characteristics since its input current is inherently proportional to the source voltage. When the voltage source is off-line, it is sufficient to add an inductor after the rectifier, then near unity power factor is achievable. All essential guidelines to design the converter as a DC-DC and a PFC regulator are presented. Simulation and experimental results verify the developed theoretical analysis.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 A
• /
• pp.136-139
• /
• 1997

The active-clamped double forward-flyback converter is studied in this paper. The converter reduces the voltage stress of the switches and decreases switching loss, EMI. The energy stored in the magnetic core is transferred to both the input voltage source and the flyback output. This makes it possible the output circuit of the flyback to operate at CCM without complex control circuit. The MOSFET is used at output stage, which decreases switching loss.

• 한국IT서비스학회지
• /
• 제13권2호
• /
• pp.55-69
• /
• 2014

As Korea's global IT sourcing is sluggish and supply of qualified IT personnel does not meet the demand, IT developers currently do not worry about their job security. The sluggish global sourcing is attributed to the lack of system design and analysis skills as well as lack of communication skills of IT personnel. Most of big Korean IT service firms operate in captive market. This is also attributed to the cause of the sluggish global sourcing. Some IT managers, especially in global IT service firms, concerned about the negative long term effect of the sluggish global sourcing on competitiveness and human infra capability of Korea's IT service industry. Managers in IT service firms expect skill requirement changes in the future when global sourcing becomes active. The skills and knowledge that they wish to retain in-house is business knowledge, system analysis and design knowledge, customer relation management skills, project management skills and industry knowledge. The jobs with the above knowledge usually involve customers.

• 한국태양에너지학회 논문집
• /
• 제30권4호
• /
• pp.63-70
• /
• 2010

This study introduce a architectural design process by the changes of sustainable design guidelines in public project. First of all, this study examines existing integrated design process studies performed by Rhee & U.B.C. Also, this study examines sustainable guidelines which demanded by public building projects. Then, this study introduces sustainable design process using existing sustainable design process, and shows that how to operate and proceed integrated design to satisfy the sustainable guidelines in practice. The results of this study are as follows. (1) Since 2007, sustainable design guidelines of bidding projects have been highlighted. (2) In public buildings, energy saving is very important issue. Especially energy certification demands 1st degree(under $300kWh/m^2{\cdot}yr$). (3) Inp ractice, integrated design team performed sustainable design using the sustainable design process to improve sustainable in public buildings.

• Tribology and Lubricants
• /
• 제11권1호
• /
• pp.20-26
• /
• 1995

Most magnetic bearings are based on the attractive force between the magnets and ferrous materials. One of the disadvantages of such attractive type magnetic bearings is the instability so that an active control device is necessary to operate bearing successfully. In this study a repulsive type magnetic bearing is analyzed which uses eddy current as a force source. The load capacities are analyzed for the various gap sizes, the rotor velocities and the frequencies of current supplied to electromagnet. Analytic Results show that as the gap size decreases, the levitation and drag forces increase, while the number of poles increasqs, the drag force decreases in the higher linear velocity region. Experimental results show that as the gap size decreases the levitation and the drag force increase, and as the velocity of rotor increases, the drag is larger than the levitation force up to certain velocity. But after that, the levitation is larger than the drag force. As the frequency of the current increases the levitation and drag decreases while the thickness of rotor gets thicker the forces decrease because of increase in eddy current loss.