• Journal of the Korean Society of Safety
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• v.36 no.5
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• pp.27-35
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• 2021

This study investigated the change in stiffness and deflection of a scaffold working plate caused by damage to a cross-beam in the plate. Experiments were conducted considering various load and damage conditions of cross-beams. A cross-beam falling off from the working plate was considered damaged. The load-displacement curves of specimens at the center of the uniform load showed that the working plate stiffness decreased by 14.66%-1.89%, depending on the load interval due to the damage of one cross-beam. A reduction in the stiffness of 33.94%-40.76% resulted from the damage of two cross-beams. Moreover, the displacement increased by an average of 25% when one cross-beam was damaged and an average of 65% when two cross-beams were damaged. Therefore, damage to the cross-beam in the working plate can potentially cause accidents and harm workers. As the load increases, the risk of an accident due to the aforementioned damage also increases because the stiffness remarkably decreases with the load increase. Further, the damage to the cross-beam mainly reduces the stiffness but increases the displacement rather than the strength of the working scaffold plate.

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.40.1-40.1
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• 1998

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.41.2-41.2
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• 1998

• Plant Resources
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• v.2 no.1
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• pp.22-25
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• 1999

Molecular markers are useful to confirm the hybridity of F1 plant derived from cross of two homozygous parents with similar morphological traits. RAPD markers were used to test F1 hybrid plant obtained from cross of two homozygous soybean (Glycine max) parents. Fl plant for cross I was made from the mating of Hobbit87 (female) and L63-1889 (male) and Fl plant for cross II was obtained from the mating of H1053 (female) and L63-1889 (male). Selfing plant per each cross was also obtained. Among 20 Operon primers used, OPA04 and OPA09 show polymorphism between cross I and II parent. Band in size 1Kb of OPA04 and 2.1Kb of OPA09 primer was polymorphic band. This fragment identified Fl hybrid plant and selfing plant in cross I and II. Female parent Hobbit87 in cross I and H1053 in cross II has no this fragment (recessive allele). However, male parent L63-1889 and Fl hybrid plant in cross I and II has this size of polymorphic band (dominant allele). This indicated that Fl hybrid and selfing plants were detected by RAPD marker before phenotypic marker would be used to identify Fl hybridity. Amplification products of selfing plant for cross I and II were completely same to the those of female parent. When mature, flower color of Fl hybrid plant in cross I and II was purple and flower color of selfing plant in cross I and II was white. Purple flower is dominant trait. Fl hybridity was successfully detected at very early growth stage using RAPD marker. Therefore, RAPD marker can be used broadly to confirm Fl hybridity in many crops.

• Journal of Korea Trade
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• v.24 no.5
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• pp.87-105
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• 2020

Purpose - The purpose of the study is to propose a theoretical framework of cross-border e-commerce ecosystems based on blockchain technology. The ecosystem includes five systems, namely, crossborder supply chain intelligent system, cross-border logistics system, cross-border payment system, cross-border product quality traceability system and cross-border customs supervision system. Design/methodology - This study firstly derived the main improvement factors for the new ecosystem based on blockchain through prior research and expert interviews on cross-border e-commerce. Then explored the use of virtue of decentralization, anti-counterfeiting traceability, consensus mechanism, smart contract and other means of the core technology of blockchain to overcome the bottleneck of cross-border e-commerce development among Korea, China, and Japan. Finally, proposed valuable implications in both theoretical and practical perspectives. Findings - As a result, we combined with the problems existing in cross-border e-commerce among Korea, China and Japan, this paper proposes a solution based on blockchain. On this basis, it constructs a cross-border e-commerce ecosystem among these three countries, including five systems. In addition, we discuss the main problems existing in the current blockchain, such as low transaction concurrency, security loopholes, and inconsistent standards, the corresponding countermeasures are proposed from the technical level, security level and industry standards. Originality/value - This study is the first to apply the blockchain technology to solve the cross-border e-commerce problems in Korea, China and Japan, which is of pioneering significance in both literature and practice. Block chain technology is in the ascendency. This study provides technical solutions for promoting the development of cross-border e-commerce import and export trade between Korea, China and Japan.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.426-432
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• 2012

In this paper, we investigate the signal to noise ratio (SNR) estimation performance of Cross quadrature amplitude modulation (QAM), which is being used for asymmetric digital subscriber line (ADSL), very high bit rate digital subscriber line (VDSL), and digital video broadcasting - cable (DVB-C), and has been found to be useful in adaptive modulation and blind equalization. At first, the symbol error rate (SER) performance of Cross QAM is analyzed in Rayleigh fading channel. Then we suggest error vector magnitude (EVM) based SNR estimation utilizing the selected constellation points having different types of decision region from one another, and verify that SNR estimation performance of each points have different performance pattern through simulation. From the simulation results, it has been found that when suggested selected constellation points are used for SNR estimation in Cross QAM, estimation performance is enhanced in additive white Gaussian noise (AWGN) channel or Ricean fading channel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.272-276
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• 2000

Reverse engineering refers to the process that creates a physical part from acquiring the surface data of an existing part using a scanning device. In recent years, as the non-contact type scanning devices become more popular, the huge amount of point data can be obtained with high speed. The point data handling process, therefore, becomes more important since the scan data need to be refined for the efficiency of subsequent tasks such as mesh generation and surface fitting. As one of point handling functions, the cross-sectioning function is still frequently used for extracting the necessary data from the point cloud. The commercial reverse engineering software supports cross-sectioning functions, however, these are only for cross-sectioning the point cloud with the constant spacing and direction. In this paper, adaptive cross-sectioning point cloud which allow the changes of the spacing and directions of cross-sections according to the constant spacing and direction. In this paper, adaptive cross-sectioning algorithms which allow the changes of the spacing and directions of cross-sections according to the curvature difference of the point cloud data are proposed.

• Steel and Composite Structures
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• v.35 no.1
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• pp.29-41
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• 2020

Cross-beams of modern through truss bridges are connected to truss chord at its nodes and between them. It results in variable rotational end restraint for cross-beams, thus variable bending moment distribution. This feature is captured in three-dimensional modelling of through truss bridge structure. However, for preliminary design or rapid assessment of service load effects such technique of analysis may not be available. So an analytical method of assessment of rotational end restraint for cross-beam of through truss bridges was worked out. Two cases - nodal cross-beam and inter-nodal cross-beam - were analyzed. Flexural and torsional stiffness of truss members, flexural stiffness of deck members and axial stiffness of wind bracing members in the vicinity of the analyzed cross-beam were taken into account. The provision for reduced stiffness of the X-type wind bracing was made. Finally, general formula for assessment of rotational end restraint was given. Rotational end restraints for cross-beams of three railway through truss bridges were assessed basing on the analytical method and the finite element method (three-dimensional beam-element modelling). Results of both methods show good agreement. The analytical method is able to reflect effects of some structural irregularities. On the basis of the obtained results the general values of rotational end restraint for nodal and inter-nodal cross-beams of railway through truss bridges were suggested.

• Geophysics and Geophysical Exploration
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• v.7 no.1
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• pp.7-13
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• 2004

In this paper, we demonstrate that Common Mid-Point (CMP) cross-correlation gathers of multi-channel and multi-shot surface waves give accurate phase-velocity curves, and enable us to reconstruct two-dimensional (2D) velocity structures with high resolution. Data acquisition for CMP cross-correlation analysis is similar to acquisition for a 2D seismic reflection survey. Data processing seems similar to Common Depth-Point (CDP) analysis of 2D seismic reflection survey data, but differs in that the cross-correlation of the original waveform is calculated before making CMP gathers. Data processing in CMP cross-correlation analysis consists of the following four steps: First, cross-correlations are calculated for every pair of traces in each shot gather. Second, correlation traces having a common mid-point are gathered, and those traces that have equal spacing are stacked in the time domain. The resultant cross-correlation gathers resemble shot gathers and are referred to as CMP cross-correlation gathers. Third, a multi-channel analysis is applied to the CMP cross-correlation gathers for calculating phase velocities of surface waves. Finally, a 2D S-wave velocity profile is reconstructed through non-linear least squares inversion. Analyses of waveform data from numerical modelling and field observations indicate that the new method could greatly improve the accuracy and resolution of subsurface S-velocity structure, compared with conventional surface-wave methods.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.9-17
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• 1999

This investigation is the result of the structural analysis by finite element method for optimal design of the cross beam with circular holes of the electric car-body. in order to install the air pipe and electric wire pipe that correspond signal between electric machines for the control system and to reduce the weight of the electric car-body, several circular areas from a cross beam should be taken off. What we want to perform is the optimal design of a cross beam with circular holes to posses equal stress in comparison with no hole cross beam. first, no hole cross beam as basic modal be chosen, executing the analysis, reviewing the distribution of stress and displacement at each location. several parameter should be adopted from the cross beam geometry like the location and shape of the hole to affect the maximum stress and displacement. So the analysis was executed by finite element analysis for finding optimal design parameter to the change of the location and shape of the circular hole. finally, the optimal design of the cross beam with circular holes was obtained and the maximum equivalent stress was compared with no hole cross beam at each location.