• Journal of Applied Reliability
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• v.9 no.3
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• pp.165-176
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• 2009

The risk management case is an organization's formal arrangement to ensure the safety of its work activity within risk management system. It allows an organization to demonstrate its capability in achieving its safety objectives and in meeting regulatory requirements. This paper presents how the safety assessments are described, prepared and maintained to meet the criteria specified by the upcoming safety regulations. We propose the elements of risk management system that include arrangements for the ongoing identification of hazards, assessment of risks and the implementation of necessary control measures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.583-584
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• 2006

• Journal of KIISE:Software and Applications
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• v.26 no.8
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• pp.955-963
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• 1999

다단계 보안 실시간 데이타베이스 시스템은 데이타베이스의 일관성 유지와 실시간 요구인 마감시간의 만족, 그리고 기밀성을 띤 데이타가 노출될 수 있는 비밀채널(covert-channel)의 방지라는 요구사항을 모두 만족해야 한다. 기존의 SRT-2PL(Secure Real-Time 2 Phase Locking)은 원본과 복사본으로 데이타 객체를 분리시켜 다른 등급간에 불간섭(non-interference)을 유지하여 비밀채널의 방지를 가능하게 하였으나, 복사본이 모든 데이타 객체에 대해 항상 존재하므로 메모리의 낭비가 있을 수 있고, 복사본의 갱신을 위한 갱신 큐의 관리에 따르는 오버헤드와 그에 따른 예측성 결여라는 문제점을 갖고 있다. 이를 개선하기 위하여 본 논문에서는 다단계 보안 실시간 데이타베이스 시스템의 요구사항을 모두 만족하는 동적 복사 프로토콜을 제안한다. 동적 복사 프로토콜은 로킹 기법을 기초로 동작하고, 트랜잭션의 작업에 따라 동적으로 복사본을 생성하고 삭제한다. 모의 실험 결과 제안한 동적 복사 프로토콜은 비밀채널을 방지하고 동적인 복사본의 생성으로 SRT-2PL의 단점인 메모리 낭비를 줄일 수 있으며, 예측성을 높여 마감시간 오류율을 감소시켰다.Abstract Concurrency control of real-time secure database system must satisfy not only logical data consistency but also timing constraints and security requirements associated with transactions. These conflicting natures between timing constraints and security requirements are often resolved by maintaining several versions(or secondary copies) on the same data items. In this paper, we propose a new lock-based concurrency control protocol, Dynamic Copy Security Protocol, ensuring both two conflicting requirements. Our protocol aims for reducing the storage overhead of maintaining secondary copies and minimizing the processing overhead of update history. Main idea of our protocol is to keep a secondary copy only when it is needed to resolve the conflicting read/write operations in real time secure database systems. For doing this, a secondary copy is dynamically created and removed during a transaction's read/write operations according to our protocol. We have also examined the performance characteristics of our protocol through simulation under different workloads while comparing the existing real time security protocol. The results show that our protocol consumed less storage and decreased the missing deadline transactions.

• Journal of KIISE
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• v.43 no.6
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• pp.662-667
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• 2016

As electric and electronic control systems have sharply increased in vehicles, safety accident has emerged as an important issue. Therefore, in order to ensure safety of the vehicle, engineers are required to identify the hazards utilizing PHA and HAZOP, etc. in the early phase of development and implement safety mechanisms to prevent them. HAZOP has been widely used in a systematic manner based on guidewords. However, HAZOP identifies malfunctions from the top-level functionality provided by the system, so it cannot sufficiently identify hazards during the system operation. This leads to restrictions in designing testcases, because the safety requirements are derived from only some of the hazards. This research aimed to provide a hazard identification method utilizing Use case description, which defines operation procedure of the system and HAZOP and a testcase design method based on safety requirements. We introduced a case study on Smart Key Control System in vehicles and compared with hazards identification results based on HAZOP, to demonstrate the effectiveness of this study. The result of this study could potentially reduce development cost and increase system quality by adequately identifying hazards and safety requirements and designing the related testcase.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.80-91
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• 2010

Due to the convergence of broadcasting and communications, IPTV services are spotlighted as the that next-generation multimedia services. IPTV services should have functionality such as unlimited channel capacity, extension of media, QoS awareness and are required increasing traffic and quality control technology to adapt the attributes of IPTV service. Consequently, flow based quality control techniques are needed. Therefore, many studies for providing Internet QoS are performed at IETF (Internet Engineering Task Force). As the buffer management mechanism among IP QoS methods, active queue management method such as RED(Random Early Detection) and modified RED algorithms have proposed. However, these algorithms have difficulties to satisfy the requirements of various Internet user QoS. Therefore, in this paper we propose the Flow based AQM(Active Queue Management) algorithm for the multimedia services that request various QoS requirements. The proposed algorithm can converge the packet loss ratio to the target packet loss ratio of required QoS requirements. And we present a performance evaluation by the simulations using the ns-2.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1070-1088
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• 2017

Recently, the applications of Internet of Things (IoTs) are growing rapidly. Wireless Sensor Network (WSN) becomes an emerging technology to provide the low power wireless connectivity for IoTs. The IPv6 over low-power wireless personal area networks (6LoWPAN) has been proposed by IETF, which gives each WSN device an IPv6 address to connect with the Internet. The transmission congestion in IoTs could be a problem when a large numbers of sensors are deployed in the field. Therefore, it is important to consider whether the WSN devices have be completely integrated into the Internet with proper quality of service (QoS) requirements. The Software Defined Network (SDN) is a new architecture of network decoupling the data and control planes, and using the logical centralized control to manage the forwarding issues in large-scale networks. In this research, the SDN-based 6LoWPAN Border Router (6LBR) is proposed to integrate the transmission from WSNs to Internet. The proposed SDN-based 6LBR communicating between WSNs and the Internet will bring forward the requirements of end-to-end QoS with bandwidth guarantee. Based on our experimental results, we have observed that the selected 6LoWPAN traffic flows achieve lower packet loss rate in the Internet. Therefore, the 6LoWPAN traffic flows classified by SDN-based 6LBR can be reserved for the required bandwidth in the Internet to meet the QoS requirements.

• Health Policy and Management
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• v.31 no.3
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• pp.244-254
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• 2021

The management of emerging infectious diseases cannot help but completely depend on non-pharmaceutical interventions in the early stages of the outbreak. Consequently, South Korea has developed and implemented the 3T (test-trace-treat) models, non-pharmaceutical infection prevention and control (IPC) measures, in response to the coronavirus disease 2019 (COVID-19) pandemic. The IPC measures have gained global attention, rendering them to be essential in the development of a shareable, reusable, and applicable protocol for future pandemics. This study was conducted to identify the requirements necessary for standardizing the IPC measures. Three new work items of the 18 3T models were proposed to ISO/TC 304 (International Organization for Standardization/Technical Committee 304; healthcare organization management). Requirements for each IPC measure, identified by participating members (P-members) countries during the ISO ballots, were analyzed in this study. The three new work items were approved by the P-members countries after a 3-month ballot. There was a consensus that the three IPC measure models should be International Standards (IS). Other comments include (1) the models should include not only COVID-19 but also any respiratory pandemic; and (2) keep donning of level D protection at screening sites as an optional protocol, in consideration for the lack of personal protective equipment. Standardization is a systematic process of developing internationally agreed-upon wisdom and knowledge that consider and respect the diversity and universality of each country. It is expected that such standardized applicable IPC measure models contribute to global efforts to rapidly respond to a public health emergency of international concern during its early stages.

• Journal of Advanced Navigation Technology
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• v.27 no.3
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• pp.314-322
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• 2023

The use of unmanned aerial vehicles is rapidly increasing in order to effectively utilize limited manpower and minimize casualties on the battlefield. The requirements for ground control equipment vary depending on the operating concept and environment of the unmanned aerial system, but there are still common requirements. However, the lack of standardized system configurations to meet these common requirements makes it difficult to reuse common functions, leading to continuous acquisition costs. To solve this problem, this paper develops a Korean version of the UCS model using the UCS architecture. Furthermore, after designing elements related to service development not specified in the architecture (such as framework, communication middleware, service structure, etc.), we develop a Boilerplate to enhance developers' work efficiency based on this. The results of this study will serve as a foundation for effectively and economically carrying out the development of ground control equipment for unmanned aerial systems.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.144-150
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• 2008

Bogie(The Launch vehicle transporter) is the special land transportation vehicle for the LV (Launch vehicle) which is used for not only the transportation-means of LV from LVAB(Launch Vehicle Assembly Building) to LP(Launch Pad) but also one of principal tools for launch operation sequence. Due to the multi-role of Bogie, The technical requirements of bogie are very complicated. Especially launch operation has performed with not only bogie but also many ground support equipments. So, it is impossible to establish technical requirements of bogie without whole understanding of launch operation. This paper was made for arranging whole launch operation sequence and technical requirements of bogie based on the this sequence.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.249-255
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• 2001

Different kinds of information are used when solving tasks that arise in the life cycle of an applied knowledge based system (KBS). Many of these tasks are still under investigation. Their solving methods are often researched independently of each other due to complexity of the tasks. As a result, systems that realize these methods turn out to be incompatible and therefore could not be used together in the lifecycle of a KBS. The following problem arises here: how to support the full life cycle of a KBS. This paper introduces a class of computer knowledge banks that are intended to support the full life cycle of KBSs. Primary tasks that arise in the full life cycle of a KBS are analyzed. The architecture of a knowledge bank of the introduced class is presented, including an Information Content, a Shell of the Information Content and a Software Content. General requirements on these components are formulated on the basis of the analysis. These requirements depend on the current state of understanding in the life cycle of KBSs.