• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권1호
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• pp.299-322
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• 2020

Vehicular ad hoc networks (VANETs) enable wireless communication between vehicles and roadside infrastructure to provide a safer and more efficient driving environment. However, due to VANETs wireless nature, vehicles are exposed to several security attacks when they join the network. In order to protect VANETs against misbehaviours, one of the vital security requirements is to revoke the misbehaved vehicles from the network. Some existing revocation protocols have been proposed to enhance security in VANETs. However, most of the protocols do not efficiently address revocation issues associated with group signature-based schemes. In this paper, we address the problem by constructing a revocation protocol particularly for group signatures in VANETs. We show that this protocol can be securely and efficiently solve the issue of revocation in group signature schemes. The theoretical analysis and simulation results demonstrate our work is secure against adversaries and achieves performance efficiency and scalability.

• 한국항공운항학회지
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• 제18권2호
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• pp.54-59
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• 2010

The flight deck crew must manage complexity during daily flight operations. The Airline may obtain data regarding threats and errors through LOSA(Line Operations Safety Audits) on normal flights as predictive safety tool in Safety Management System of the Airline to actively improve the systems such as SOP(Standard Operation Procedure), training, evaluation and the TEM(Threat and Error Management) for the flight deck crew. The flight deck crew make errors when they fail managing threats. The crew mismanage around ten percent of threats and commit errors. The major mismanaged threats are aircraft malfunction, ATC(Air Traffic Communication), and wether threats. The effective countermeasures of TEM for manageing threats are leadership, workload management, monitor & cross check, Vigilance, communication environment and cooperation of the crew. It is important that organizations must monitor for the hazards of threats and improve system for the safer TEM environments.

• 해양환경안전학회지
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• 제8권1호
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• pp.109-125
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• 2002

This paper has dealt with the efficiency of maritime safety administrative system in the APEC region. under the hypothesis that officient maritime safety and marine environment. Many factors affect administrative structures, which generate various types of administration. The factors include social, economical and political factors. Further, the addition of historical factors to these factors makes it tougher to draw out an optimal model for maritime safety administration. In this regard, the result of this study will be within the extent of volition capable of accepting it under the existing maritime safety administration system. The result of the study to help APEC member states(economies) to compare their own system with those of other economies and finally to help to improve their maritime safety administrative structure for safer shipping.

• The Korean Journal of Pain
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• 제10권1호
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• pp.93-96
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• 1997

Block of superior hypogastric plexus has been advocated as a useful technique in the palliation of various of pelvic pain syndromes. This technique has been performed under fluroscopic or CT guidance using bilateral placement of needles. We performed a modification of transdiscal approach with the patient in oblique position permitting successful superior hypogastric plexus block using a single needle placed under fluoroscopic guidance. Our experience suggest transdiscal approach performed in oblique position allows easier, safer, and more accurate needle placement for superior hypogastric plexus block.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 1997년도 추계 학술논문발표회 논문집
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• pp.157-164
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• 1997

Construction accident happens all of the process in work and contains materials types of causes. Especially, temporary work material in the great problem in industrial accident. Because temporary work In essential to build the main structure. The most frequent type of accident by the temporary work is the falling and so on. Its causes were the failure of scaffolding, imperfection of temporary material etc. These accident properties the Primitive and repetitive accident. The prevention counterplan of construction accident by temporary material work in need to protect worker and make more safer construction site. Therefore in this paper analyzed of the serious accident of construction by the temporary work material and present reasonable solution method to reduce the construction accident by the temporary work material.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.1023-1030
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• 2002

From the early 1980s, the New Austrian Tunnelling Method (NATM) has been developed as a one of the standard tunneling method in Korea. Approximately 10 years ago, wet-mix shotcrete with sodium silicate accelerator (waterglass) was introduced and widely used to tunnel lining and underground support. However, this accelerator had some disadvantages due to the decrease of long-term strength compared to plain concrete (without accelerator) and low quality of the hardened shotcrete. In order to compensate for these disadvantages, recently developed alkali-free accelerator has been successfully demonstrated in numerous projects and applications as a new material to make tunnels more durable and safer. An experimental investigation was carried out in order to verify the strength behavior of wet-mix Steel Fiber Reinforced Shotcrete (SFRS) with alkali-free accelerator. Compressive strength, flexural strength and equivalent flexural strength were measured by testing specimens extracted from the shotcrete panels. From the results, wet-mix SFRS with alkali-free accelerator exhibited excellent strength improvement compared to the conventional shotcrete accelerator.

• 전기학회논문지
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• 제59권3호
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• pp.614-622
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• 2010

The goal of this paper is to develope the control program based on model which can be applied to 1000MW class coal fired thermal power plant. 1000MW class power plant has the higher efficiency and lower cost because the steam conditions of the ultra super-critical process are higher than them of the previous power plants in temperature and pressure. The program includes the state variable controls which have the desired characteristics for the higher temperature and pressure. The program had been developed successfully using advanced process control. The simulation results using the new control program showed the better performance and safer control than them of the previous control program and we could verify the application possibility of the new program for the actual power plant through the load test, comparison, analysis and tuning.

• Journal of Korean Neurosurgical Society
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• 제51권3호
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• pp.182-186
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• 2012

In conventional percutaneous disc surgery, introducing instruments into disc space starts by inserting a guide needle into the triangular working zone. However, landing the guide needle tip on the annular window is a challenging step in endoscopic discectomy. Surgeons tend to repeat the needling procedure to reach an optimal position on the annular target. Obturator guiding technique is a modification of standard endoscopic lumbar discectomy, in which, obturator is used to access triangular working zone instead of a guide needle. Obturator guiding technique provides more vivid feedback and easy manipulation. This technique decreases the steps of inserting instruments and takes safer route from the peritoneum.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 춘계학술대회
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• pp.205-207
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• 2015

The purpose of this paper is to analyze maritime piracy and its economic implications with particular attention to attacks registered in the Gulf of Aden, and to investigate in theory what is the rationale behind engaging in criminal behavior. The paper also aims to investigate how the International community along with Sovereign States should allocate resources in order to make the seas a safer place and describe how closely inter-related maritime piracy, preventive and punitive measure put in place by Governments are. Elements of economics and ergonomics are taken into account in order to properly investigate the major legal issues relating to maritime security.

• International Journal of Safety
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• 제4권2호
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• pp.36-42
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• 2005

A study on fire phenomena in a subway transit mass station has been carried out as a part of disaster prevention plan at the subway station. The ventilation facilities installed in both the platform and the trackway are designed to convert into a smoke exhaust system in emergency situation, creating an environment necessary for evacuation. 3 dimensional Numerical Simulations based on the CFD are carried out using a simulation tool, Fire Dynamic Simulator. Total of six different cases are made and performances are compared each other to find optimal vents operation to ensure safer environment for evacuation at the platform area considering the installation of platform screen door.