• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.214-224
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• 2008

Member force, strain and stress distribution of a section are obtained for optimized standard 25m~45m PSSC composite bridge subjected to dead and live load in order to interpret the effect of prestressing and deformation of tendon. The stress and strain distribution and moment capacity are obtained for both noncomposite and composite section and for allowable stress limit state, yield limit state and strength limit state. Reliability analysis is conducted after assuming limit states for stress and flexural strength. The reliability index for standard PSSC composite bridge which is designed to satisfy the allowable stress for flexural strength are higher than 3.5 which is required reliability indexes on American code for LRFD. Reliability of PSSC girder which is designed based on allowable stress of bridge design code is high for flexural strength.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.12
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• pp.1186-1192
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• 2008

The reliability of gas turbine engine blades was studied. Yield strength, Young’s modulus, engine speed and gas temperature were considered as statistically independent random variables. The failure probability was calculated using five different methods. Advanced Mean Value Method was the most efficient without significant loss in accuracy. When random variables were assumed to have normal, lognormal and Weibull distributions with the same means and standard deviations, the CDF of limit state equation did not change significantly with the distribution functions of random variables. The normalized sensitivity of failure probability with respect to standard deviations of random variables was the largest with gas temperature. The effect of means and standard deviations of random variables was studied. The increase in the mean of gas temperature and the standard deviation of engine speed increased the failure probability the most significantly.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.199-206
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• 2017

Embedded control system is widely spreaded and used in various fields including military defence, aviation, medical, etc. due to extended use of smart phones, connected car, IoT. Increasing examples are introduced where embedded control system that perform their unique role such as smart phone and network system organically configure to create new system. According to this trend, organic interface and reliability of each embedded control system are becoming important evaluation factors. The purpose of this paper is to develop quality evaluation criteria method for automobile embedded system, among the fields that use embedded control systems. In order to satisfy high quality level requirements of automobile embedded control system, we surveyed latest trend of automobile embedded control system, analyzed structure and application technology of embedded control system, to establish quality evaluation criteria and method for automobile embedded control system by referring international standard for software (ISO/IEC 9126), and international standard for electric & electronic products (ISO 26262).

• The Korean Journal of Archival Studies
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• no.10
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• pp.3-26
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• 2004

ISO 15489:2001 addresses the principles and requirements with which organizations, both public and private, should comply on the management of their records to ensure that adequate records are created, captured and managed. The standard defines the characteristics that a record should have through records management system as follows: authenticity, reliability, integrity, and usability. Authenticity means that records can be proven to be what it purports to be, to have been created or sent by the person purported to have created or sent it, and to have been created or sent at the time purported. Reliability means that the contents of the records can be trusted as a full and accurate representation of the transactions, activities or facts to which they attest and can be depended upon in the course of subsequent transactions or activities. Integrity refers to ensuring that a record is complete and unaltered. Usability means that records can be located, retrieved, presented and interpreted. In order to have these characteristics, a record should be persistently linked to the metadata necessary to document a transaction. Metadata is "data describing context, content and structure of records and their management through time." Metadata ensure the creation and maintenance of authentic, reliable and usable records and the protection of the integrity of those records. It could be implemented by creating and capturing records management metadata in systems that create and manage records. There have been some projects and standard initiatives to identify a core set of records management metadata. Included are the Australian Recordkeeping Metadata Standard and the British Metadata Standard which is part of the Requirements for Electronic Records Management System. Recently ISO/TS 23081-1 is published to implement metadata requirements within the framework of ISO 15489. Public records management system in Korea is ruled by the Act on the Management of Archives by Public Agencies and Administrative Records Management Regulation. This article evaluates records and their descriptive elements captured and maintained by the records management system in Korea on the basis of the international metadata standards.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.4
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• pp.407-414
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• 2002

The inherent reliability of a product is primarily determined in the design stage, and therefore, design engineers should be able to design reliability into the product in an efficient manner. Especially, the product should be designed such that its reliability is robust to various noise factors encountered in production and field environments. The Taguchi method can be effectively used for this purpose. However, there exist only a few attempts to integrate the Taguchi method with reliability design, and in addition, the existing works do not sufficiently consider the robustness and/or the distinction between noise and acceleration factors. This paper develops a unified approach to robust reliability design assuming that accelerated life tests are conducted at each combination of design and noise conditions. First, an experimental structure for assigning not only acceleration but also noise factors is presented. Second, the reliability at the use condition is estimated using the assumed accelerated life test model. Third, reliabilities are transformed into 'efforts' using an effort function which reflects the degree of difficulty involved in improving the reliability. Finally, an optimal setting of design parameters is determined based on the mean and standard deviation of the effort values. The above approach is illustrated with an example of a paper feeder design.

• Journal of Internet Computing and Services
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• v.7 no.2
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• pp.151-160
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• 2006

Software quality evaluation system and software evaluation criterion have to be defined to evaluate software reliability. In this study, we develop software reliability quality metrics for evaluating of software reliability and research for testing of suitable criteria of software reliability. To accomplish a study successfully, we have to estimate the failure time of software using the number of software bugs. Software reliability is very important in software quality. We propose the estimation of software reliability. We propose the software reliability metrics and the software testing method that the basis of international standard ISO/IEC 9126 in software testing metrics.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.1
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• pp.48-54
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• 2023

Guided missiles are a one-shot system that finishes their purpose after being used once, and due to the long-term storage until launch, the storage reliability is calculated during development, and performance is maintained through periodic inspections until the life cycle arrives. However, the reliability standards applied in the development of guided missiles were established by analyzing data accumulated by the United States during long-term operation in the country, and since they are different from our environment, the 00 guided missiles that have been deployed in the armed forces for more than 10 years under the premise that there is a difference from actual reliability. As a result of verifying the appropriateness of the current inspection cycle by analyzing the actual reliability of the missile, the necessity of changing the inspection period was derived because it was higher than the predicted reliability. It is proposed to build and utilize a lifespan management system that can systematically collect all data such as shooting and maintenance results by classification, and to establish a reliable reliability standard based on the accumulated data.

• Journal of the Korean Society for Library and Information Science
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• v.37 no.4
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• pp.131-149
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• 2003

Scientific/technical data whose reliability is authorized have to include physical/chemical constants, authorized property value or authorized scientific statistical values so that the scientists in the same field use them continuously and repeatedly for their research. The data also have to be managed as Standard Reference Data that will be used in other area nationwide by analyzing, evaluating and authorizing the accuracy and reliability of the information with scientific methods. This study suggests a plan for establishing the National Center for Standard Reference Data as well as a necessity for managing the data produced in research process as a national Standard Reference Data. Also, a prototype of research information system for measurement standards is developed and described in detail for research information for measurement standard to be used as a reference data, then a plan to managing national reference data is suggested, in addition.

• Journal of Korea Multimedia Society
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• v.23 no.8
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• pp.1030-1039
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• 2020

The biggest feature of the online environment is anonymity. So it is difficult to identify the sender accurately in Email. So we use PGP to enhance the security of email. PGP is an e-mail encryption program that has become the standard for email security worldwide. But PGP has a weak point in security. PGP can identify users, but it is difficult to verify reliability. In PGP, the more reliable other users guarantee that user are, the more reliable they are. In the previous study, the PGP structure was implemented by utilizing the block chain to lay the foundation, and in this paper, the structure of the previous article is applied to the e-mail environment to measure up the sender's reliability, and a system is proposed that allows users to distinguish the reliability of the message.

• Journal of Korean Society for Quality Management
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• v.20 no.1
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• pp.158-167
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• 1992

This paper represents the new techniques for optimal sampling plans of reliability applying the mathematical complex number(real and imaginary number) in the complex system of reliability. The research formulation represent a mathematical model Which preserves all essential aspects of the main and auxiliary factors of the research objectives. It is important to formule the problem in good agreement with the objective of the research considering the main and auxilary factors which affect the system performance. This model was repeatedly tested to determine the required statistical chatacteristics which in themselves determine the actual and standard distributions. The evaluation programs and techniques are developed for establishing criteria for sampling plans of reliability effectiveness, and the evaluation of system performance was based on the complex stochastic process(derived by the Runge-Kutta method. by kolmogorv's criterion and the transform of a solution to a Sturon-Liouville equation.) The special structure of this mathematical model is exploited to develop the optimal sampling plans of reliability in the complex system.