• Journal of The Korean Society For Urban Railway
• /
• v.6 no.4
• /
• pp.259-268
• /
• 2018

To reduce conducted a survey on human error risk factors and related experience frequency to drivers of Seoulmetro and Korail. The human error arising from systems operating urban railway aimed at eliminating and reducing the fundamental causes of urban rail accidents is based on research from a factorial point of view, since it contains problems dealing with the types and situations of accident generation. It is required to contribute to reducing human error so that urban railway accidents may be reduced and safe operation will be continuedly seared.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.16 no.6
• /
• pp.73-80
• /
• 2006

Recently, Sun et el. proposed a three-party authenticated key exchange protocol using the public key of the server and the derived verifier from the Password of a user. This paper proposes a password-based three-party authenticated key exchange protocol using smartcards. Since the proposed protocol has very low computation cost by using XOR and hash function operation instead of the public key operation, and reduces the count of message transmission to 20% compared with the protocol of Sun et el., it can execute an effective authenticated key exchange. Furthermore, the proposed protocol is safe from password guessing attack by not saving passwords in the server, and it is also safe from server compromise attack because the server cannot know the shared session key between the two users.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.5
• /
• pp.476-482
• /
• 2013

This study aims to enhance the effectivity of VTS(Vessel Traffic Service) control by investigating the minimum safe distance between vessel and vessel, vessel and land(obstacle) for the vessel's safe navigation within the VTS control area. In addition, to suggest basic data for the safe navigation, this study has done survey and analysis to each VTS center, and individual on the minimum safe distance to VTS operators of each ports of korea. Through ocean voyage by training ship, Singapore and Malacca strait's congested vessel traffic zone's control distance was compared and investigated the difference on safe distance by the different VTS operators. As a result, there was huge difference of minimum safe distance between the VTS operators belong to the same center. Over all, the port with gentle coastline, like donghae, the safe distance was wider than the other port. On the other hand, port with complex coastline and frequent entry and departure of the vessel, like mokpo, the safe distance was the shortest of all. Therefore, development of module suitable to port's natural conditions and traffic volume's necessity is required, for the operators affiliated to the same VTS center control according to formal method. Lastly, the full discussion by the expert group about establishment of standard control procedure in the future should be considered as well.

• Journal of Biosystems Engineering
• /
• v.2 no.1
• /
• pp.33-48
• /
• 1977

Transporting agricultural products and the other material by the two-wheel-tractor (power-tiler)and trailer system may be one of its most widely used farming functions.The safety and hitching load for all the previaling performing conditions may be the general concern over the operation of the tiller-trailer system. In this study, a mathematical model to determine the static and dynamic forces excerting on the hitch point were developed . Based on the analysis of the model and the field measurements. the limiting hitching load and critical slope were analyzed. The results of the study are summarized as follows ; 1) The limit angle of slope land for the safety steering that two-wheel tractor-single axle trailer system was able to transport agricultural products was the direct angle (${\gamma}$) = 8 ; the cross angle$\beta$) 15 ; and it was decreased in accordance with the increase of carrying load ($W_4). 2) The critical velocity for safe operation in case of running on downward hill road was about 1.08m/sec. 3) The limiting carrying load for the safe steering was W$_4$=600kg. The degree of the safe steering for different braking methods was given in order as follows ; Simulataneous braking the tractor and trailer , braking the trailer only, and braking tractor only. 4) Among the three components of impact loads excerting on the hitch point, the component in the lateral direction ($P_{Vy}$) was near zero in spite of increase of hitching load ($W_4) , while the components in the other two mutually perpedicular directions ($P_{Vx}$ and ($P_{Vz}$) ) had larger values in horizontal plane than those in the slope lands. 5) Moment of forces on the lateral direction (M$y$) had the largest value among the three components of impact moment acting on the hitch point, however all the components were sharply increased in accordance with the increase of hitching loads ($W_4. Three components of the moment were the negative values.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.25 no.2
• /
• pp.271-278
• /
• 2015

We use various types of cryptographic algorithms for the protection of personal and sensitive informations in the application environments, such as an internet banking and an electronic commerce. However, recent researches were introduced that if we implement modes of operation, padding method and other cryptographic implementations in a wrong way, then the critical information can be leaked even though the underlying cryptographic algorithms are secure. Among these attacking techniques, the padding oracle attack is representative. In this paper, we analyze the possibility of padding oracle attacks of 12 kinds of padding techniques that can be applied to the CBC operation mode of a block cipher. As a result, we discovered that 3 kinds were safe padding techniques and 9 kinds were unsafe padding techniques. We propose 5 considerations when designing a safe padding techniques to have a resistance to the padding oracle attack through the analysis of three kinds of safe padding techniques.

• Fire Science and Engineering
• /
• v.32 no.1
• /
• pp.57-65
• /
• 2018

In this study, a post-fire safe shutdown analysis (PFSSA) including multiple spurious operation (MSO) treatments for cables was conducted with an imaginary nuclear power plant for training using a deterministic fire analysis code. The imaginary nuclear power plant for the training consisted of a reactor containment building and an auxiliary building, including a total of 22 fire areas. The equipment including valves, pumps, emergency diesel generators, switch gears, motor control centers, and logic controllers were located in each fire area of the imaginary plant. It was assumed that each equipment is connected with two cables and that each cable passes through the fire areas along the cable trays. A database containing the information on the equipment and cables for the imaginary plant was constructed for the fire area analysis. The fire area analysis was performed for several assumed MSO scenarios, equipment logics, and cable logics. A mitigation measure using a three hour rated wrap was applied to the failed cables and cable trays after the fire area analysis.

• Journal of Navigation and Port Research
• /
• v.33 no.5
• /
• pp.345-352
• /
• 2009

The issues of environmental pollution and labor safety on ship recycling in the undeveloped countries such as India, Bangladesh, etc have been proclaimed. For this, IMO has been actively participated in resolving such problems since 1998 and then finally the International Convention for the Safe and Environmentally Sound Recycling of Ships is going to be adopted in this year. The convention provides the design, construction, operation and preparation of ships in order to facilitate safe and environmentally sound recycling as well as the safe and environmentally sound operation of ship recycling facilities. Therefore, the purposes of this study are to introduce the major contents of ship recycling convention and its time of entry into force and to analyse stakeholders' strategies toward it so that Korea will have a better position for the establishment of a mechanism regarding regulation stringency on environmentally sound ship recycling.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.2
• /
• pp.219-228
• /
• 2001

This paper presents the implementation of comparator which are Fail-Safe with respect to faults caused by any single physical defect likely to occur in NMOS and CMOS integrated circuit. The goal is to use it at the Fail-Safe system. First, a new fault model for PLA(Programmable Logic Array) is presented. This model reflects several physical defects in VLSI circuits. It focuses on designs based on PLA because VLSI chips are far too complex to allow detailed analysis of all the possible physical defects that can occur and of the effects on the operation of the circuit. Second, this paper show that these design, which was implemented with 2 level AND_ORor NOR-NOR circuit, are optimal in term of size. And it also present a formal proof that a comparator implemented as NOR-NOR PLA, based on these design, is self-testing with respect to most single faults in the presented fault model. Finally, it discuss the application of the self-testing comparator as a building block for implementing Fail-Safe Adder.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.6
• /
• pp.314-324
• /
• 2006

In recent years, having the advantages of being small, low in cost and high in efficiency, Half-wave resonant type, (having only one output diode), is used in ZVS Half-Bridge DC/DC converter. This paper presents the operation mode by multi-resonant factors in the Half-wave type multi-resonant converter with direct Buck chopper circuit operated in discontinuous current mode. To study the characteristics of a multi-resonant operation in steady-state, the characteristic impedances in each mode and safe operation-region(S.O.R) are reported. Computer simulation and experimental data are also riven to verify the theoretical results.

• Journal of Korean Academy of Nursing Administration
• /
• v.22 no.5
• /
• pp.415-423
• /
• 2016

Purpose: The purpose of this research was to provide patients with safe preoperative preparatory procedures by removing any risk factors from the preparatory procedures by using failure mode and effects analysis, which is a prospective risk-managing tool. Methods: This was a research design in which before and after conditions of a single group were studied, Failure mode and effects analysis were applied for the preparatory procedures done before operations. Results: The preparation omission rate before the operation decreased from 2.70% to 0.04%, and operation cancellation rate decreased from 0.48% to 0.08%. Conclusion: Failure mode and effects analysis which remove any risk factors for patients in advance of the operation is effective in preventing any negligent accidents.