• Magazine of the Korea Concrete Institute
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• v.7 no.2
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• pp.146-154
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• 1995

I n this paper, an experimental research was carried out to investigate the confinement effect of spiral reinforcements in concrete column specimens subjected to t.he concentric axial corn pressive loads. Main variables were the compressive strengths of concrete of 27.2, 62.4 and 81.2 MPa, and the spacings of spirals of 120, 60, 40, 30, 25 and 20mm. and the yield strengths of spir als of 451 and 1375MPa, respectively. For the same volumetric ratio and yield strength of spir als, it was shown that the strength increment of confined concrete was almost same regardless of the strength of unconfined concrete, however, the axial stram at maximum stress was decreas ed with increasing of the compressive strength of unconfined concrete.

• Journal of Korean Society of Steel Construction
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• v.13 no.3
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• pp.223-232
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• 2001

Column tests subjected to compressive loading were carried out for the estimation of compression buckling strength of steel plate SM570 in beam-column member under high axial load. It was found that the maximum strength of column member was determined by local buckling when satisfied with a limit of width-to-thickness ratio in current steel structure design specifications, but decreased suddenly by local buckling before the maximum strength in case of not satisfying with that ratio. Also, the compression buckling strength of SM570 plate was higher than the design specification value of 4$4.1tonf/cm^2$.

• Journal of Korean Society of Steel Construction
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• v.26 no.1
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• pp.31-42
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• 2014

In this paper, concrete-filled steel tubular columns encased with precast reinforced concrete were studied. Four eccentrically loaded columns and a concentrically loaded column were tested to investigate the axial load-carrying capacity. The test parameters were the use of fiber reinforcement for cover concrete, eccentricity, column length, and lateral reinforcement. The maximum axial loads of the specimens agreed with the nominal strengths predicted by KBC 2009. However, in some specimens, the load carrying capacity quickly decreased after the peak strength due to spalling of the cover concrete.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.39-54
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• 2012

Picture Archiving and Communication System (PACS) has been planted as one of the key infrastructures with an overall improvement in standards of medical informationization and the stream of digital hospitalization in recent days. The kind and data of digital medical imagery are also increasing rapidly in volume. This trend emphasizes the medical image compression for storing large-scale medical image data. Digital Imaging and Communications in Medicine (DICOM), de facto standard in digital medical imagery, specifies Run Length Encode (RLE), which is the typical lossless data compressing technique, for the medical image compression. However, the RLE is not appropriate approach for medical image data with bilateral symmetry of the human organism. we suggest two preprocessing algorithms that detect interested area, the minimum bounding rectangle, in a medical image to enhance data compression efficiency and that re-code image pixel values to reduce data size according to the symmetry characteristics in the interested area, and also presents an improved image compression technique for brain CT imagery with high bilateral symmetry. As the result of experiment, the suggested approach shows higher data compression ratio than the RLE compression in the DICOM standard without detecting interested area in images.

• The Journal of the Korea Contents Association
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• v.10 no.11
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• pp.58-67
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• 2010

Data-centric storage schemes(DCS) are one of representative researches that efficiently store and manage sensor readings in sensor nodes in the sensor networks. In DCS, a sensor sends the sensed data to a specific node in order to store them. However, it has a problem that sensor nodes consume a lot of energy for transmitting their readings to remote sensor node. In this paper, we propose a novel sensor data compression algorithm to reduce communication costs for DCS. The proposed algorithm establishes a safe region and transmits the sensed data only when current measurement is out of the safe region, As a result, the proposed algorithm extends network life time and reduces data transmission. It is shown through performance evaluation that our proposed algorithm reduces energy consumption by about 60% over the conventional algorithm.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.207-216
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• 2005

The maximum strength of the stainless steel square and the circular hollow section columns, which are cold-formed and TIG welded, is experimented on and analyzed. The paper presents centrally compressed experiments, including stub column tests and coupon tests, on stainless steel pipe columns. A total of 24 stainless steel pipe column experiments are conducted, using the slenderness ratios ($L_k/r$ = 20, 30, 40, 50, 60, 70) as parameters. The experimental results were compared with the design standard curves, AIK-LSD and AISC-LRFD, AIJ-LSD, SIJ-ASD curves, and multiple column curves.

• Journal of Korean Society of Steel Construction
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• v.22 no.6
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• pp.609-616
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• 2010

The objective of this study is to investigate the structural character of the buckling strength of 600MPa-class high-strength steel compression members. The buckling strength of circular hollow-section columns is evaluated by a numerical analysis of the stress-strain curves of the tension test results. The numerical analysis was based on the beam-column theory and the tangent modulus theory. It was considered possible to enlarge the nominal yield strength of the 600MPa-class steel.

• Journal of Korean Society of Steel Construction
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• v.29 no.2
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• pp.147-158
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• 2017

The present study focused on the structural performance of newly developed prefabricated composite columns (PSRC composite column) using bolt-connected steel angles. Concentric axial loading tests were performed for four 2/3 scaled PSRC column specimens and two conventional SRC column specimens. The test parameters were the spacing and sectional configurations of lateral reinforcement, and width-to-thickness ratio of steel angles. The test results showed that the axial load-carrying capacity and deformation capacity of the PSRC column specimens were comparable to those of the conventional SRC column specimens. Closely spaced steel plates and Z-shaped steel plates for lateral reinforcement increased the deformation capacity of the PSRC column specimens. The load-carrying capacity was greater than the prediction by current design codes. Numerical analysis was performed for the specimens. The results agreed well with the test results in terms of initial stiffness, load-carrying capacity, except for strength degradation due to cover concrete spalling.

• Annual Conference of KIPS
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• 2008.11a
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• pp.774-777
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• 2008

지리정보는 여러 분야에서 활용되고 그 데이터 양도 방대하여 효율적으로 저장하여 관리해야 할 필요가 있다. 본 논문은 균등 분할 방식과 비균등분할 방식에 의한 두 가지 지리정보 표현 및 압축방법을 수행하는 연산회수와 자료의 효율성 등을 중심으로 비교하였다. 두 가지 방법 모두 효율적인 활용이 가능하며 상황에 따라 기본 방법에서 수정을 가하여 사용할 수도 있다.

• Journal of Korean Society of Steel Construction
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• v.12 no.1 s.44
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• pp.9-16
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• 2000

The model of load-strain relations for CFT stub columns subjected to centrally compressive axial load is shown in this paper. The modified model of concrete and steel is obtained by using the experimental data and the formulas of that is based on the foreign researcher's result. The purpose of this paper is to suggest the basic data for evaluating the behavior of CFT stub columns to be variable to the strength of concrete and steel.