• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.23-29
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• 2002

Five and more leg intersections have been still in operation in many urban areas. The number of conflicts in five leg intersection is more than four leg intersection. The signal timing design in the five leg intersection should be performed not only to reduce delay but also to increase safety. This paper suggests safety enhanced signal phase sequence design of a rotary with five leg intersection such as phase sequence minimizing the number of conflict points at the rotary with five leg intersections and the phase-length-design procedure by utilizing the Traffic Network Study Tool(TRANSYT). Field data was collected from Gonguptap five leg intersection in Ulsan and TRANSYT-7F was applied for signal timing design model. Optimal signal phase length and sequence of TRANSYT-7F is rearranged based on the Principal of "two moving traffic flows per phase". In conclusion, proposed signal phase design increased delay by 6.2% compared with the optimal signal phase of TRANSYT-7F. However, it could decrease the number of conflict in the five leg intersection by 61.5%.

• Korean Journal of Computational Design and Engineering
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• v.3 no.4
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• pp.211-222
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• 1998

Parametric design is an important modeling paradigm in CAD/CAM applications, enabling efficient design modifications and variations. One of the major issues in parametric design is to develop a geometric constraint solver that can handle a large set of geometric configurations efficiently and robustly. In this appear, we propose a new approach to geometric constraint solving that employs a graph-based method to solve the ruler-and-compass constructible configurations and a numerical method to solve the ruler-and-compass non-constructible configurations, in a way that combines the advantages of both methods. The geometric constraint solving process consists of two phases: 1) planning phase and 2) execution phase. In the planning phase, a sequence of construction steps is generated by clustering the constrained geometric entities and reducing the constraint graph in sequence. in the execution phase, each construction step is evaluated to determine the geometric entities, using both approaches. By combining the advantages of the graph-based constructive approach with the universality of the numerical approach, the proposed approach can maximize the efficiency, robustness, and extensibility of geometric constraint solver.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.6
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• pp.15-20
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• 2016

In this paper, we consider selective mapping (SLM) based OFDM systems without side information, where SLM is one of the promising peak-to-average power ratio (PAPR) reduction techniques due to its simplicity and no distortion in the transmitted signal. First, we construct a new phase sequence where a part of phase sequence is replaced by an orthogonal sequence. Based on the proposed phase sequence, we propose a new scheme for detecting coherently the index of the phase sequence used in transmitter without side information. Computer simulation shows that the proposed detection scheme performs well in SLM-based OFDM systems, and specifically outperforms the existing ones when channel variation is relatively small between sub-carriers used in phase sequence detection.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.3
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• pp.81-86
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• 2010

Since CORDIC (COordinate Rotation DIgital Computer) is able to carry out the phase operation, such as vector to phase conversion or rotation of vectors, with adders and shifters, it is well suited for the design of the frequency synchronization unit in OFDM receivers. It is not easy, however, to fully utilize the CORDIC in the OFDM demodulator because of the non-linear characteristics of the direction sequence (DS), which is the representation of the phase in CORDIC. In this paper a new representation method is proposed to linearize the direction sequence approximately. The maximum phase error of the linearized binary direction sequence (LBDS) is also discussed. For the purpose of designing the hardware, the architectures for the binary DS (BDS) to LBDS converter and the LBDS to BDS inverse converter are illustrated. Adopting LBDS, the overall frequency synchronization hardware for OFDM receivers can be implemented fully utilizing CORDIC and general arithmetic operators, such as adders and multipliers, for the phase estimation, loop filtering of the frequency offset, derotation for the frequency offset correction. An example of the design of 22 bit LBDS for the T-DMB demodulator is also presented.

• BMB Reports
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• v.37 no.4
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• pp.460-465
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• 2004

A 16-residue polypeptide model with the sequence acetyl-YALSLAATLLKEAASL-OH was derived by rational de novo peptide design. The designed sequence consists of amino acid residues with high propensity to adopt an alpha helical conformation, and sequential order was arranged to produce an amphipathic surface. The designed sequence was chemically synthesized using a solid-phase method and the polypeptide was purified by reverse-phase liquid chromatography. Molecular mass analysis by electro-spray ionization mass spectroscopy confirmed the correct designed sequence. Structural characterization by circular dichroism spectroscopy demonstrated that the peptide adopts the expected alpha helical conformation in 50% acetonitrile solution. Liposome binding assay using Small Unilamellar Vesicle (SUV) showed a marked release of entrapped glucose by interaction between the lipid membrane and the tested peptide. The channel-forming activity of the peptide was revealed by a planar lipid bilayer experiment. An analysis of the conducting current at various applied potentials suggested that the peptide forms a cationic ion channel with an intrinsic conductance of 188 pS. These results demonstrate that a simple rational de novo design can be successfully employed to create short peptides with desired structures and functions.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1104-1107
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• 2005

This paper presents a comparison of core losses for the four cases of Switched Reluctance Motors (SRM) with different winding method and switching sequence. With concentrated winding SRM, two kinds of switching sequence are considered for one-phase exciting and two-phase simultaneously exciting driving. With both distributed winding and toroidal winding, two-phase exciting driving is considered. The ratio of calculated core losses to input power is able to be used a guide or reference for deciding the winding method and switching sequence of in the initial design stage of SRM.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.5
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• pp.22-29
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• 2012

By using the cyclic properties of symmetric balance incomplete block design(BIBD) codes and arrayed-waveguide grating(AWG) routers, a compact optical CDMA network coder-decoder(codec) can be constructed. It can be observed that the various code families obtained by BIBD improve the BER performance compared to M-sequence code.

• Journal of the Korean Magnetic Resonance Society
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• v.2 no.1
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• pp.59-65
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• 1998

The correction of image artifacts due to misadjustment in tuning of RF coils (tip angle) and in the RF single sideband spectrometer was investigated using phase cycling of the $\pi$/2 and $\pi$ pulses in spin-echo sequences. A general procedure was developed for the systematic design of phase cycles that select desirable coherence transfer pathways. To analyze a phase cycling sequence, changes in the coherence level and phase factor for each RF pulse in the spin-echo cycle must be determined. Four different phase cycling schemes (FIXED, ALTERNATE, FORWARD, REVERSED) to suppress unwanted signal components such as mirror and ghost images were evaluated using two signal acquisitions. When the receiver phase factor is cycled counter-clockwise (REVERSED), these artifacts are completely removed.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.1
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• pp.19-30
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• 2015

A static synchronous compensator (STATCOM) applied to rapidly changing, highly unbalanced loads such as electric arc furnaces (EAFs), requires both positive-sequence and negative-sequence current control, which indicates fast response characteristics and can be controlled independently. Furthermore, a delta-connected STATCOM with cascaded H-bridge configuration accompanying multiple separate DC-sides, should have high performance zero-sequence current control to suppress a phase-to-phase imbalance in DC-side voltages when compensating for unbalanced load. In this paper, actual EAF data is analyzed to reflect on the design of current controllers and a pioneering zero-sequence current controller with a superb transient performance is devised, which generates an imaginary -axis component from the presumed response of forwarded reference. Via simulation and experiments, the performance of the positive, negative, and zero-sequence current control of a cascaded H-bridge STATCOM for EAF is verified.

• IE interfaces
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• v.16 no.2
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• pp.268-279
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• 2003

This paper presents critical steps in building client/server application with UML and Visual Basic, which are derived from the implementation case of a typical order processing system. To begin with, we briefly review the software architecture, the diagrams and the object-oriened building process in the UML. In the inception phase, it is critical to define the project charter, to draw use case diagrams, and to construct a preliminary architecture of the application. In the elaboration phase, it is critical to identify classes to be displayed in the class diagram, to develop user interface prototypes for each use case, to construct sequence diagram for each use case, and finally to design an implementation architecture. Steps to construct implementation architecture are given. In the construction phase, it is critical to design both the database and components. Steps to design these components are described in detail. Additionally the way to create the Internet interface is suggested.