• 디지털융복합연구
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• 제11권11호
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• pp.29-36
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• 2013

전자상거래 시장이 삐르게 증가하고 관련 산업이 발달하고 있다. 전자상거래의 특징인 비대면 거래 방식규모의 증가와 더불어 다양한 결제수단 등장으로 전자상거래에서 소비자 피해도 증가하고 있는 추세이다. 본 연구는 구매안전서비스라는 제도측면에서 소비자 보호방안에 대하여 살펴보았다. 구매안전서비스의 대표적인 결제대금예치 제도와 소비자피해보상보험 등의 한계점을 살펴보고 개선방안을 제시하였다. 불법적인 구매안전서비스 홍보를 방지하기 위해서는 소비자의 포상신고제를 운영하고 결제대금예치제도의 예치기간 악용에 대해서는 차감정산제도와 결제 대금예치사업자에게 분쟁중재역할 제공에 대한 검토가 필요하다. 결제대금예치를 통한 거래발생시 증서형태로 소비자에게 전달하고 구매안전서비스의 적극적인 홍보와 지속적인 제도개선 노력이 필요하다.

• Structural Engineering and Mechanics
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• 제80권5호
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• pp.491-501
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• 2021

A difference in subgrade settlement between two rails of a track manifests as lateral differential subgrade settlement. This settlement causes unsteadiness in the motion of trains passing through the corresponding area. To illustrate the effect of lateral differential subgrade settlement on the dynamic response of a vehicle-track coupling system, a three-dimensional vehicle-track-subgrade coupling model was formulated by combining the vehicle-track dynamics theory and the finite element method. The wheel/rail force, car body acceleration, and derailment factor are chosen as evaluation indices of the system dynamic response. The effects of the amplitude and wavelength of lateral differential subgrade settlement as well as the driving speed of the vehicle are analyzed. The study reveals the following: The dynamic responses of the vehicle-track system generally increase linearly with the driving speed when the train passes through a lateral subgrade settlement area. The wheel/rail force acting on a rail with a large settlement exceeds that on a rail with a small settlement. The dynamic responses of the vehicle-track system increase with the amplitude of the lateral differential subgrade settlement. For a 250-km/h train speed, the proposed maximum amplitude for a lateral differential settlement with a wavelength of 20 m is 10 mm. The dynamic responses of the vehicle-track system decrease with an increase in the wavelength of the lateral differential subgrade settlement. To achieve a good operation quality of a train at a 250-km/h driving speed, the wavelength of a lateral differential subgrade settlement with an amplitude of 20 mm should not be less than 15 m. Monitoring lateral differential settlements should be given more emphasis in routine high-speed railway maintenance and repairs.

• 한국환경농학회지
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• 제33권1호
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• pp.63-67
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• 2014

BACKGROUND: The present study is an exploratory research to establish national biosafety regulation systems through a survey on the recognition of safety regulation systems for the living modified organism(LMO). METHODS AND RESULTS: We have conducted a survey on an awareness of LMO safety regulation systems in scientific working groups. The data of 235 respondents were analyzed using various statistical methods. As a result, 72.8% of the respondents were male; 27.2% were female, and 43.4% of them work in the university. A total of 33.2% of the respondents majored in general biology, and their most common job position was the laboratory safety manager. The difference of an awareness on LMO law and regulatory system was not statistically significant by either work places or job positions. CONCLUSION: For the rapid settlement and the efficient implementation of LMO safety management policy, we conclude that it is required to reduce the gap between the recognition and fulfillment of safety management. Furthermore, the mutual exchanges of information among researchers are needed with the settlement of the safety management system and the harmony of policy with improvement of the absurd regulations. The ongoing and specialized training, inspections, and the strengthening of public relations are also required along with the efforts to improve the absurd regulations.

• Geomechanics and Engineering
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• 제34권6호
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• pp.649-664
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• 2023

Structural inertial interaction is a representative the effect of dynamic soil-foundation-structure interaction (SFSI), which leads to a relative displacement between soil and foundation, period lengthening, and damping increasing phenomena. However, for a system with a significantly heavy foundation, the dynamic inertia of the foundation influences and interacts with the structural seismic response. The structure-to-foundation mass ratio (MR) quantifies the distribution of mass between the structure and foundation for a structure on a shallow foundation. Although both systems exhibit the same vertical factor of safety (FS_v), the MR and corresponding seismic responses attributed to the structure and foundation masses may differ. This study explored the influence of MR on the permanent deformation and seismic response of soil-foundation-structure system considering SFSI via numerical simulations. Given that numerous dimensionless parameters of SFSI described its influence on the structural seismic response, the parameters, except for MR and FS_v, were fixed for the sensitivity analysis. The results demonstrated that the foundation inertia of heavier foundations induced more settlement due to sliding behavior of heavily-loaded systems. Moreover, the structural inertia of heavier structures evidently exhibited foundation rocking behavior, which results in a more elongated natural period of the structure for lightly-loaded systems.

• 한국안전학회지
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• 제21권4호
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• pp.85-94
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• 2006

In this study, in order to evaluate the effect of two types of connector systems in reinforced retaining wall, the centrifugal tests for the conventional connector and new settlement connector system were performed. In the centrifugal tests, the aluminum plate for the face was used and the aluminum foil was used as a reinforcement. The granite soil was adopted as a fill. As a result, The settlement reinforced retaining wall reached to the failure at 80g-level. In contrast, the conventional reinforced retaining wall was collapsed at 69g-level. It means that the settlement reinforced retaining wall has the stronger stability than the conventional reinforced retaining wall. In addition, it was shown that the settlement connector system is more effective to release the stress concentration occurred at the face of reinforced retaining wall than the conventional connector system.

• Smart Structures and Systems
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• 제33권1호
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• pp.17-26
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• 2024

The new metro crossing the existing metro will cause the settlement or floating of the existing structures, which will have safety problems for the operation of the existing metro and the construction of the new metro. Therefore, it is necessary to monitor and predict the settlement of the existing metro caused by the construction of the new metro in real time. Considering the complexity and uncertainty of metro settlement, a Gaussian Prior Bayesian Emulator (GPBE) probability prediction model based on Bayesian optimization (BO) is proposed, that is, BO-GPBE. Firstly, the settlement monitoring data are analyzed to get the influence of the new metro on the settlement of the existing metro. Then, five different acquisition functions, that is, expected improvement (EI), expected improvement per second (EIPS), expected improvement per second plus (EIPSP), lower confidence bound (LCB), probability of improvement (PI) are selected to construct BO model, and then BO-GPBE model is established. Finally, three years settlement monitoring data were collected by structural health monitoring (SHM) system installed on Nanjing Metro Line 10 are employed to demonstrate the effectiveness of BO-GPBE for forecasting the settlement.

• 한국철도학회논문집
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• 제10권3호
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• pp.355-364
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• 2007

Recently a concrete slab tracks are being constructed on roadbed in the Gyoeng-bu 2nd phase high speed railways. In respdnding to this trend, new design standards and track materials maintenance systems, based on the slab track material safety and usage perspective, are needed. This research provides a roadbed design criteria and the maintenance system. The proposed roadbed design criteria and the maintenance system are based on the developed analysis meathod of train/slab-track interaction. where the roadbed settlement and train speed are utilized as mediating variables. In the analysis, the dynamic response of train/slab-track interaction apply to various speeds and settlements. the roadbed settlement is shown in a sinusoidal shape of wave, the scope of the settlement occurrence presented in its wavelengths, include 6meters, 10meters, 15merwes, 20meters, 30meters. The train speeds involved are 50, 100, 150, 200, 250, 300, 350, 400kilometers per hour.

• Geomechanics and Engineering
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• 제21권4호
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• pp.379-390
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• 2020

The behavior of a piled raft system in multi-layered soil subjected to vertical loading has been studied numerically using 3D finite element analysis. Initially, the 3D finite element model has been validated by analytically simulating the field experiments conducted on vertically loaded instrumented piled raft. Subsequently, a comprehensive parametric study has been conducted to assess the performance of a combined piled raft system in terms of optimum pile spacing and settlement of raft and piles, in multi-layered soil stratum subjected to vertical loading. It has been found that a combined pile raft system can significantly reduce the total settlement as well as the differential settlement of the raft in comparison to the raft alone. Two different arrangements below the piled raft with the same pile numbers show a significant amount of increase of load transfer of piled raft system, which is in line with the load transfer mechanism of a piled raft. A methodology for the factor of safety assessment of a combined pile raft foundation has been presented to improve the performance of piled raft based on its serviceability requirements. The findings of this study could be used as guidelines for achieving economical design for combined piled raft systems.

• 산업경영시스템학회지
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• 제17권31호
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• pp.187-201
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• 1994

For settlement of safety supervision and prevention agains industry's accident, first, it needs to design and manufacture for safety of machines and tools, second, it must safety foundation of machines and tolls and sticking of safety facilities, third, it must be wear of protective device in operations. Then it needs to fit countermeasure founding and continuous safety education and itself inspection control that analysis and study the point at issue of safety.

• 한국철도학회논문집
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• 제13권2호
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• pp.229-235
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• 2010

공공교통기관인 철도에 요구되는 가장 기본적인 요건은 수송의 안전을 확보하는 것이다. 타 교통수단보다 철도가 비록 안전하지만 대량교통수단에서 일단 사고가 발생하면 그 피해규모는 크다. 철도운영자 및 국가에서는 이러한 철도의 사고발생을 사전에 방지하기 위하여 많은 노력을 기울이지만, 사고를 근절시키는 것은 불가능하다. 따라서 사고발생을 최대한 줄이기 위하여 다양한 방안들이 강구되고 있는데, 본 논문에서는 최근 들어 그 중요성이 부각되고 있는 인시던트 보고제도와 안전문화에 대하여 살펴보고자 한다. 본 논문에서는 미국 및 영국 등 선진외국에서 항공분야에서의 인시던트 보고 제도에 대한 사례를 분석하여 보았으며, 또한 철도분야에서도 인시던트 보고 제도가 도입된 영국사례를 중심으로 이에 대한 분석을 통하여 우리나라에서의 철도분야 인시던트 보고 제도의 필요성과 방향에 대하여 논의하였다. 또한, 사고방지 및 안전향상을 위하여 필요한 것이 철도운영회사 및 관련기관의 철도안전에 대한 문화의식이다. 올바른 철도안전문화의 정착이야말로 가장 확실하게 철도사고를 예방하고 철도안전을 향상시킬 수 있는 방안인 것이다. 따라서 철도기업에서의 철도안전문화에 대한 이해 등에 대하여 본 논문에서 검토하고자 한다.