• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2085-2090
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• 2007

This paper describes the possible way to improve the capacity, the efficiency and the pressure drop of $CO_2$ system. It is considered the use of an internal heat exchanger (IHX) to improve the performance of the $CO_2$ system. Experiment was performed by changing a tube shape, a tube number and a tube length of IHX to investigate the performance of IHX for $CO_2$ system. The focus of the present study is to obtain the concept on IHX optimal design. Experimental results show that design parameters are closely related with the capacity and the pressure drop of $CO_2$ system. In the transcritical $CO_2$ cycle, the system performance is very sensitive to the IHX design. System performance on operation condition and shape of IHX is also introduced.

• Structural Engineering and Mechanics
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• 제28권1호
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• pp.69-88
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• 2008

A number of construction practices, implemented during the design process of a reinforced concrete (RC) structural system, may have significant consequences on the behaviour of the structural system in the case of earthquake loading. Although a number of provisions are imposed by the contemporary Greek national design codes for the seismic design of RC structures, in order to reduce the consequences, the influence of the construction practices on the seismic behaviour of the structural system remains significant. The objective of this work is to perform a comparative study in order to examine the influence of three, often encountered, construction practices namely weak ground storey, short and floating columns and two combinations on the seismic performance of the structural system with respect to the structural capacity and the maximum interstorey drifts in three earthquake hazard levels.

• 한국산업융합학회 논문집
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• 제10권4호
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• pp.227-233
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• 2007

In case of design of a rectifier to supply high current, To select switching frequency of semiconductor switches affect absolutely the design of the LC filter value in an power conversion circuit. The conventional rectifier by using MOSFET is no use in high current equipments because of small drain-source current. To solve this problem, this paper proposes to design of high capacity rectifier by parallel driving of MOSFET in the single half bridge DC-DC converter. This method can be able to develop high current rectifier by distributed drain-source current. The proposed scheme is able to expect a decrease in size, weight and cost of production by decreasing the LC filter value and increasing maximumly the switching frequency. The validity of the proposed parallel driving strategy is verified through computer-aided simulations and experimental results.

• Structural Engineering and Mechanics
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• 제43권6호
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• pp.795-821
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• 2012

The size and topology of geometrically nonlinear dome structures are optimized thereby minimizing both its entire weight & joint (node) displacements and maximizing load-carrying capacity. Design constraints are implemented from provisions of American Petroleum Institute specification (API RP2A-LRFD). In accordance with the proposed design constraints, the member responses computed by use of arc-length technique as a nonlinear structural analysis method are checked at each load increment. Thus, a penalization process utilized for inclusion of unfeasible designations to genetic search is correspondingly neglected. In order to solve this complex design optimization problem with multiple objective functions, Non-dominated Sorting Genetic Algorithm II (NSGA II) approach is employed as a multi-objective optimization tool. Furthermore, the flexibility of proposed optimization is enhanced thereby integrating an automatic dome generating tool. Thus, it is possible to generate three distinct sphere-shaped dome configurations with varying topologies. It is demonstrated that the inclusion of brace (diagonal) members into the geometrical configuration of dome structure provides a weight-saving dome designation with higher load-carrying capacity. The proposed optimization approach is recommended for the design optimization of geometrically nonlinear dome structures.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1251-1253
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• 2001

This paper presents on capacity design of DC-fed-traction system. The system is introduced including a characteristics of train, feeding network configuration, and design method of substation arrangements. Optimal design procedures is described, and program for capacity computation of the system is presented using the nodal equation, K.C.L, K.V.L, Ohm's law and superposition theory. For the proof of the proposed algorithm, we accomplished the simulation of DC traction system for HA-Nam LRT. By considering whole component in DC traction system the conclusion will be much precise.

• 한국지진공학회논문집
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• 제19권3호
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• pp.93-102
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• 2015

This study evaluates collapse probabilities of structures which are designed according to a domestic seismic design code, KBC2009. In evaluating their collapse probabilities, to do this, probabilistic distribution models for seismic hazard and structural capacity are required. In this paper, eight major cities in Korea are selected and the demand probabilistic distribution of each city is obtained from the uniform seismic hazard. The probabilistic distribution for the structural capacity is assumed to follow a underlying design philosophy implicitly defined in ASCE 7-10. With the assumptions, the structural collapse probability in 50 years is evaluated based on the concept of a risk integral. This paper then defines an mean value of the collapse probabilities in 50 years of the selected major cities as the target risk. Risk-targeted spectral accelerations are finally suggested by modifying a current mapped spectral acceleration to meet the target risk.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.521-528
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• 2005

In our previous study, we have developed a preliminary design procedure of MR dampers for controlling seismic response of building structures. In this paper, the effectiveness the proposed method is verified through the numerical analysis of the structures with various period and story number, and twenty earthquake loads are used for statistical assessment. The comparison between the proposed method and simplified sequential search algorithm indicates that the capacity, number and the placement of the MR damper which can achieve the given performance objective are reasonably determined using the proposed design procedure.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1654-1660
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• 2000

Recently, the regulations from the government and the concerns of people give rise to the interest in exhaust and intake noise of passenger car as much as other vehicles. In these demands, performance prediction software was developed in the previous study. In this study, Robust design was used for improving the noise reduction capacity of intake system with the performance prediction software. On the basis of the existing design, length and radius of each component that was thought to effect to capacity of intake system was selected. At first factors are arranged by using $L_{18}$ table of orthogonal array and then optimum value can be obtained by $L_{16}$ table of orthogonal array.

• 산업공학
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• 제14권4호
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• pp.348-355
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• 2001

This paper suggests a detailed design of APS(Advanced Planning & Scheduling) system using the DBR (Drum-Buffer-Rope) which is a finite capacity scheduling logic of TOC(Theory of Constraints). Our design is composed of four modules; Network, Buffer, Drum and Subordination. The Network module defines the Product Network which is built from BOM and routings. The Buffer module inserts the Buffers into the Product Network. The Drum module describes detail procedures to create Drum Schedule on the CCR(Capacity Constraint Resource). The Subordination module synchronizes all non-constraints to the constraints by determining the length of Rope. This design documented by ARIS.

• Journal of Power Electronics
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• 제13권3호
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• pp.437-446
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• 2013

This paper proposes a design scheme for an LCL-filter used for the three-parallel operation of the power converters in high-capacity wind turbines. The designs of the power devices and grid connected filter are difficult due to the high level voltages and currents in huge-capacity wind turbines. To solve these problem, this paper presents three-parallel operation and LCL-filter design techniques optimized by parallel operation. Furthermore, the design of an inverter side inductance of the LCL-filter is discussed in detail considering the switching modulation method. Simulation and experimental results demonstrate the validity of the designed filter and wind turbines.