• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.1
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• pp.44-53
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• 2006

The expansion of near shore aquaculture is feasibility of moving aquaculture facilities into the open ocean. Numerical modeling technique using finite element method was used to enable the optimum design and evaluation of submersible aquaculture cage system. The characteristics of mooring loads response in mooring lines under waves and current and their response amplitude operators were calculated for single and three point mooring configuration at the surface condition and submerged one. The static mooring loads without wave and current loading were similar for both the surface and submerged configuration. It was calculated that three point mooring was more adequate than single point mooring for the mooring configuration of submersible aquaculture cage system. The wave induced response amplitude operators for the single point mooring configuration with the influence of currents were identical to those without the influence of currents.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.778-780
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• 1999

Arithmetic unit speed depends strongly on the algorithms employed to realize the basic arithmetic operations.(add, subtract multiply, and divide) and on the logic design. Recent advances in VLSI have increased the feasibility of hardware implementation of floating point arithmetic units and microprocessors require a powerful floating-point processing unit as a standard option. This paper describes the design of floating-point multiplier for IEEE 754-1985 Single-Precision operation. Booth encoding algorithm method to reduce partial products and a Wallace tree of 4-2 CSA is adopted in fraction multiplication part to generate the $32{\times}32$ single-precision product. New scheme of rounding and sticky-bit generation is adopted to reduce area and timing. Also there is a true sign generator in this design. This multiplier have been implemented in a ALTERA FLEX EPF10K70RC240-4.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.629-633
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• 2006

We investigated a new longitudinal acceleration wave decomposition method in time domain. The proposed method separates up- and down-stream waves with an axial strain and axial acceleration measured at a single point on the transmission path. The advantages such as low computation load and easy implementation would be possible by developing time domain under the following assumptions; low frequency range, uniform cross sectional area and elastic wave propagation. We confirmed the feasibility and performance of the method through experiment using Split Hopkinson Pressure Bar (SHPB). The method can be effective in several applications, including active vibration control with wave view point, where real time wave decomposition is necessary.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.10
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• pp.72-81
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• 2011

In this paper, we proposed and designed a novel floating point converter which supports single and double precisions of IEEE754 standard. The proposed convertor supports conversions between floating point number single/double precision and signed fixed point number(32bits/64bits) as well as conversions between signed integer(32bits/64bits) and floating point number single/double precision and conversions between floating point number single and double precisions. We defined a new internal format to convert various input types into one type so that overflow checking could be conducted easily according to range of output types. The internal format is similar to the extended format of floating point double precision defined in IEEE754 2008 standard. This standard specifies that minimum exponent bit-width of the extended format of floating point double precision is 15bits, but 11bits are enough to implement the proposed converting unit. Also, we optimized rounding stage of the convertor unit so that we could make it possible to operate rounding and represent correct negative numbers using an incrementer instead an adder. We designed single cycle data path and 5 cycles data path. After describing the HDL model for two data paths of the convertor, we synthesized them with TSMC 180nm technology library using Synopsys design compiler. Cell area of synthesis result occupies 12,886 gates(2 input NAND gate), and maximum operating frequency is 411MHz.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1115-1116
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• 2010

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.143-145
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• 2006

In this paper, single phase induction motor achieved improvement in efficiency by adapting the condition of Balanced operation and Quasi-balanced operation. Also, the process of efficiency improvement to find the optimum point of secondary resistance and running capacitor for working single phase induction motor is performed in order to attain the conclusion to put out the maximum efficiency at the rated operation point with meeting the starting torque.

• Journal of the Chungcheong Mathematical Society
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• v.25 no.4
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• pp.617-631
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• 2012

In this paper, we will consider some existence theorems of common fixed points for a countable family of non-self multi-valued mappings defined on a closed subset of a complete metrically convex space, and give more generalized common fixed point theorems for a countable family of single-valued mappings. The main results in this paper generalize and improve many common fixed point theorems for single valued or multi-valued mappings with contractive type conditions.

• East Asian mathematical journal
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• v.32 no.5
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• pp.677-684
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• 2016

In this paper, the notion of S-metric spaces will be introduced. We present some fixed point theorems for two maps on complete S-metric spaces and an illustrative example is given for the single-valued case. By using the similar method as in [4], a common fixed point theorem for two single-valued mappings is obtained in S-metric spaces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3632-3637
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• 2009

In this paper, we describe the performance results of the field installation test which is required to practicalize the single-phase MJ81 Switch Point Machine. This product has passed the certified test through performance improvement of driving parts in order to use 3 phase MJ81 Switch Point Machine, which is localized by taking over technology from Alstom and Cogifer when constructing Seoul-Busan rapid-transit railway, without change of the electrical equipment at track-side in domestic existing lines which single-phase 220V is used. KRRI and Samsung SDS have localized the single-phase MJ81 Switch Point Machine to improve the speed and safety of the conventional lines through the existing railway technology development project. For practicalization of this, we should, however, verify the performance through not only field installation test in real lines but also interface test with the interlocking. In this paper we verify the practicality of the domestic single-phase MJ81 Switch Point Machine through analysis on the performance result of the field installation test as well as the research contents for this test. Thereby, in Feb 2009 we have received an order from the Korea Rail Network Authority and are currently installing the single-phase MJ81 Switch Point Machine.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.773-778
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• 2014

Aircraft communication system which provides internal communications between pilots in an aircraft and external communications between pilots and operators in ground tower with them. It is very important equipment in terms of mission and safety. It wouldn't meet performance requirements with only functions of transmission and receiving of signals. It should provide highly clear voice quality without any noise. This paper analyzes the cause of noise during internal communications and summarizes the design changes applying single point ground concept to solve the problem. It also describes the results of fight test to verify the design changes.