• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.1-7
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• 1999

An innovative concept for a passive reactor shutdown system, so called self-actuated shutdown system(SASS), is inevitably required for the inherent safety in liquid metal reactor, which is designed with the totally different concept from the usual reactor shutdown system in LWR. SASS using Curie point electromagnet(CPEM) was selected as the passive reactor shutdown system for KALIMER (Korea Advanced Liquid MEtal Reactor). A mock-up of the SASS was designed, fabricated and tested. From the test it was confirmed that the mockup was self-actuated at the Curie point of the temperature sensing material used in the mockup. An articulated control rod was also fabricated and assembled with the CPEM to confirm that the control rod can be inserted into core even when the control rod guide tube is deformed due to earthquake. The operability of SASS in the actual sodium environment should be confirmed in the future. All the design and test data will be applied to the KALIMER design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.717-720
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• 2000

Event-driven communication protocols such as CAN(Controller Area Network) have inherent packet delays due to the contention process for the use of network medium. These delays are stochastic in nature because most packets arrive at random time instants. The stochastic property of the delay adversely influences the control system's performance in terms of stability, responsiveness and steady-state error. Another problem for safety-critical application such as brake-by-wire systems is the reliability of the communication modules that can fail abruptly. This paper deals with two methods to overcome the above problems : (i) scheduling method that can maintain packet delays under some acceptable level, and (ii) redundancy management of communication modules that prescribes dual-redundancy modules' behavior when one of them fails.

• IMMUNE NETWORK
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• v.12 no.4
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• pp.139-147
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• 2012

Although adoptive T cell therapy (ACT) has become a promising immunotherapeutic regime for cancer treatment, its effectiveness has been hindered by several inherent shortcomings regarding safety and efficacy. During the past few decades, several strategies for enhancing the efficacy of ACT have been developed and introduced in clinic. This review will summarize not only the past approaches but also the latest strategies which have been shown to enhance the anticancer activity of ACT.

• KSTLE International Journal
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• v.4 no.1
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• pp.27-30
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• 2003

The basic principles of tribo-systems and study method based on tribe-systems are introduced in the paper, Based on the viewpoint of tribe-systems, the experiment on tribology characteristics of friction lining material in multi-rope friction hoist is carried out. The research result shows: tribology characteristics of friction material are not its inherent characteristic but system characteristics of the tribo-systems, the“sliding-rope”of multi-rope friction hoist can be divided into“safety sliding-rope”and“fault sliding-rope”, study on friction material only based on characteristic of system where friction material exists possesses practical significance.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.15 no.3
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• pp.70-76
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• 2007

The benefits for using reduced takeoff thrust are many, ranging from lower maintenance and operating costs to improved engine and dispatch reliabilities. Some pilots, however, are apprehensive about using reduced thrust. They are particularly reluctant to use the maximum permissible level of reduced thrust. Two common arguments are (1)If reduced thrust is used, then the airplane will not be able to clear the obstacles if an engine fails during takeoff, and (2)If the maximum allowable assumed temperature is used, then there will be no stopping margin left if the takeoff is aborted. There is the notion that using reduced thrust sacrifices safety. The intent of this discussion is to: (1)Show that reduced thrust performance meets all regulatory requirements (2)Show that the Assumed Temperature method includes inherent extra performance margins (3)Show how to maximize performance margins while maximizing thrust reduction.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.321-324
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• 2001

The accidents in a railway level crossing where passengers or vehicles pass on the track went through by the train with a inherent high rate on incidents lead to a vast economic damage on people and material resources. So, many protection equipments are placed on the railway crossing to prevent those kind of accidents. But there is a limit to control driver's rough activity, passenger's careless or an intentional accident. This study is trying to ensure the safety in railway crossing by providing the information on train's speed and expected passing time on the railroad to a road traffic control system or car driver. Additionally, this system has been studying the railway level crossing system concerning ITS to support harmonious traffic flow.

• Nuclear Engineering and Technology
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• v.34 no.2
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• pp.117-131
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• 2002

Core disruptive accidents have been investigated at Korea Atomic Energy Research Institute(KAERI) as part of the work to demonstrate the inherent and ultimate safety of conceptual design of the Korea Advanced Liquid Metal Reactor(KALIMER), a 150 MWe pool- type sodium cooled prototype fast reactor that uses U-Pu-Zr metallic fuel. In this study, a simple method and associated computer program, SCHAMBETA, was developed using a modified Bethe-Tait method to simulate the kinetics and thermodynamic behavior of a homogeneous spherical core over the period of the super-prompt critical power excursion induced by the ramp reactivity insertion. Calculations of the energy release during excursions in the sodium-voided core of the KALIMER were subsequently performed using the SCHAMBETA code for various reactivity insertion rates up to 100 S/s, which has been widely considered to be the upper limit of ramp rates due to fuel compaction. Benchmark calculations were made to compare with the results of more detailed analysis for core meltdown energetics of the oxide fuelled fast reactor. A set of parametric studies were also performed to investigate the sensitivity of the results on the various thermodynamics and reactor parameters.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.845-855
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• 2019

Synthetic biology builds programmed biological systems for a wide range of purposes such as improving human health, remedying the environment, and boosting the production of valuable chemical substances. In recent years, the rapid development of synthetic biology has enabled synthetic bacterium-based diagnoses and therapeutics superior to traditional methodologies by engaging bacterial sensing of and response to environmental signals inherent in these complex biological systems. Biosynthetic systems have opened a new avenue of disease diagnosis and treatment. In this review, we introduce designed synthetic bacterial systems acting as living therapeutics in the diagnosis and treatment of several diseases. We also discuss the safety and robustness of genetically modified synthetic bacteria inside the human body.

• Nuclear Engineering and Technology
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• v.50 no.7
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• pp.1099-1105
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• 2018

How to choose defaults in risk-informed regulations depends on the conservatism implicated in regulatory defaults. Without a universal agreement on the approaches dealing with the conservatism of defaults, however, the desirability of conservatism in regulatory risk analyses has long been controversial. The opponent views it as needlessly costly and irrational, and the proponent as a form of protection against possible omissions or underestimation of risks. Moreover, the inherent ambiguity of risk makes it difficult to set suitable defaults in terms of risk. This paper, the extension of the previous work [1], focuses on the effects of different levels of conservatism implicated in regulatory defaults on the estimates of risk. According to the postulated behaviors of regulated parties and the diversity of interests of regulators, in particular, various measures for evaluating the effect of conservatism in defaults are developed and their properties are explored. In addition, a simple decision model for setting regulatory defaults is formulated, based on the understanding of the effect of conservatism implicated in them. It can help decision makers evaluate the levels of safety likely to result from their regulatory policies.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.636-642
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• 2021

Vehicular Ad hoc Networks (VANET's) are gaining popularity in research community with every passing year due to the key role they play in Intelligent Transportation System. Their primary objective is to provide safety, but their potential to offer a variety of user-oriented services makes them more attractive. The biggest challenge in providing all these services is the inherent characteristics of VANET itself such as highly dynamic topology due to which maintaining continuous communication among vehicles is extremely difficult. Here comes the importance of routing solutions which traditionally are designed using strict layered architecture but fail to address stringent QoS requirements. The paradigm of cross-layer design for routing has shown remarkable performance improvements. This paper aims to highlight routing challenges in VANET, limitations of single-layer solutions and presents a survey of cross-layer routing solutions that utilize the information from the MAC layer to improve routing performance in VANET.