• Title/Summary/Keyword: Mission Reliability

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Study on Developing the Scale of Korea Citizen's Intentionality out of Inborn Ability and Mission (한국 도시민의 목적지향 성향 척도 개발을 위한 연구)

  • Sohnn, Jou-Hwan;Ha, Kyu-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.10
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    • pp.6056-6065
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    • 2014
  • The aim of this study was to develop a scale of the Korea citizen's intentionality out of their inborn ability and mission. To set up the concept of the above intentionality, there have been many academic and religious studies for reference in addition to the existing productivity, Korea elderly successful aging scale, and the scale of life qualities for review. The first 57 items for questionnaires were created thereafter. The final 27 items were confirmed, which were constantly modified by a professor of statistics and corresponding author in effective response and in removing the redundant items after the first items had been reduced to 44 preliminary items through the many an item-by-item discussions with pastors, theologians and social workers. A survey was conducted around the metropolitan area and 380 records were collected. Factor analysis to verify the validity of the measurement tool was completed, and showed that there were 6 sub-factors; "recognition of being", "autonomous life", "self-completion", "initiative", "acceptance", and "economic feasibility". In addition, reliability analysis was implemented and found to be reliable because the Cronbach's ${\alpha}$ value was 0.6 or more.

A Study on Design for Reliability for the PBA of Warship based on Reliability Physics Analysis (신뢰성 물리학 분석 기반 함정탑재 PBA 신뢰성 설계에 대한 연구)

  • Cha, Jong-Han;Park, Kyoung-Deok;Lee, Ki-Won;Bak, Byeong-Ho;Kim, Hee-Earn;Kwon, Hyeong-Ahn
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.12
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    • pp.535-545
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    • 2019
  • The PBA of ship weapon system should be installed and operated under harsh environmental conditions and so it should be highly reliable to endure the mission profiles during its entire lifetime. In the case of PBA failure during operation, rapid maintenance is highly likely to be difficult due to problems such as supply of parts, which can have a devastating effect on the mission. In order to validate the reliability of PBA, a series of tests are performed with PBA samples, but they require time, testing facilities, samples, expenses and failure analysis if failed. The reliability of PBA is predicted on the basis of specifications such as MIL-HDBK-217F, but this specification does not take into account failure mechanisms for specific design details, environment and usage, interconnects and its characteristics that drive many failures of PBA in the field. Therefore, this study predicts the reliability of PBA using an RPA tool and proposes the RPA methodology as a validation process at the design stage. With RPA, it is now possible to achieve design validation including inherent failure mechanism, identification of weakest link, alternative design options, and test plan development.

A Comparative Study on Software Reliability Model for NHPP Intensity Function Following a Decreasing Pattern (강도함수가 감소패턴을 따르는 NHPP 소프트웨어 신뢰모형에 관한 비교 연구)

  • Kim, Hee Cheul;Kim, Jong Buam;Moon, Song Chul
    • Journal of Information Technology Applications and Management
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    • v.23 no.4
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    • pp.117-125
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    • 2016
  • Software reliability in the software development process is an important issue. In infinite failure non-homogeneous Poisson process software reliability models, the failure occurrence rates per fault. can be presented constant, monotonic increasing or monotonic decreasing pattern. In this paper, the reliability software cost model considering decreasing intensity function was studied in the software product testing process. The decreasing intensity function that can be widely used in the field of reliability using power law process, log-linear processes and Musal-Okumoto process were studied and the parameter estimation method was used for maximum likelihood estimation. In this paper, from the software model analysis, we was compared by applying a software failure interval failure data considering the decreasing intensity function The decreasing intensity function model is also efficient in terms of reliability in the arena of the conservative model can be used as an alternating model can be established. From this paper, the software developers have to consider life distribution by preceding information of the software to classify failure modes which can be gifted to support.

The Design of Fault Tolerant Dual System and Real Time Fault Detection for Countdown Time Generating System

  • Kim, Jeong-Seok;Han, Yoo-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.10
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    • pp.125-133
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    • 2016
  • In this paper, we propose a real-time fault monitoring and dual system design of the countdown time-generating system, which is the main component of the mission control system. The countdown time-generating system produces a countdown signal that is distributed to mission control system devices. The stability of the countdown signal is essential for the main launch-related devices because they perform reserved functions based on the countdown time information received from the countdown time-generating system. Therefore, a reliable and fault-tolerant design is required for the countdown time-generating system. To ensure system reliability, component devices should be redundant and faults should be monitored in real time to manage the device changeover from Active mode to Standby mode upon fault detection. In addition, designing different methods for mode changeover based on fault classification is necessary for appropriate changeover. This study presents a real-time fault monitoring and changeover system, which is based on the dual system design of countdown time-generating devices, as well as experiment on real-time fault monitoring and changeover based on fault inputs.

Impact of Organizational Culture on the Accounting Information System and Operational Performance of Small and Medium Sized Enterprises in Ho Chi Minh City

  • HA, Van Dung
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.2
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    • pp.301-308
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    • 2020
  • This study focuses on determining the impacts of organizational culture on the accounting information system and the operational performance of small and medium-sized enterprises in Ho Chi Minh City. The paper is organized in five parts: introduction, literature review, research methodology, research results, and conclusion and policy implications. Based on the samples of 353 respondents working in small and mediumsized enterprises in Ho Chi Minh City, the research employs both qualitative and quantitative methods to find the answers for research questions. Group discussion, which yields final observed variables of the factors of organizational culture is used for qualitative method. Statistics, assessment of the reliability of Cronbach's Alpha scale, exploratory factor analysis (EFA), confirmatory factor analysis (CFA) and structural equation modeling (SEM) are used for quantitative procedure. The results show that mission, involvement and inconsistency in organizational culture positively affect the accounting information system of small and medium-sized firms in Vietnam. In addition, mission, involvement, adaptability and consistency in organizational culture are found to have positive impacts on the firm operational performance. Another finding of the study is that the accounting information system has a positive effect on operational performance of small and medium-sized firms in Vietnam.

A Suggestion of Common Analysts' Guidance and it's Utilisation (국방모델 개발을 위한 공통 모의논리 제안과 활용방안에 관한 연구)

  • Kwon, Hyog-Lae;Ku, Bonim;Lee, Tae-Eog;Lim, Jong Won
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.6
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    • pp.754-760
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    • 2012
  • To improve the efficiency and economics of national defence, the needs for defence M&S systems are greatly increased, but the lack of interoperability and reusability lowers the level of reliability in the existing simulations models. Recently, many research activities have been performed and some conceptual models, such as CMMS, DCMF, and KAMA, were introduced. However, these models don't support the whole process of defence M&S system development nor provide integrated domain knowledge and up-to-date data. In this paper, we analyzed the analysts' guidances and doctrines, which are the basic ingredients for the simulation system development, and proposed a systematic structure for all the defence M&S stakeholders to share the standardized domain knowledge, modeling algorithm and data. This will be a logical bridge between Mission Space and Simulation Space, and provide substantial data sets to build simulation systems.

Reliability Analysis of Interconnected Dynamical Systems with Reconfigurable Control

  • Matsumoto, Satoshi;Kohda, Takehisa
    • International Journal of Safety
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    • v.10 no.2
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    • pp.10-15
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    • 2011
  • The reconfigurable control systems based on feedback controls are utilized to compensate for damages of actuators in control systems. Such systems have multiple feedback controls and switch them in accordance with the degrees of the failures of the actuators. In order to be able to assess those systems, this paper develops a method to obtain reliabilities of reconfigurable dynamical systems which are interconnected in parallel / series configuration. By calculating reliabilities of interconnected dynamical systems, it is possible to assess many dynamical systems by comparing their reliabilities. Firstly, reliabilities of subsystems are obtained according to the definitions of the failures in terms of robust reliability for each subsystem. Then, the reliability of overall system is calculated from reliabilities of subsystems, using the methodology employed for probabilistic safety assessment. Failure rates of subsystems with feedbacks for reconfiguration change in certain time periods because of the switching of feedback controls. In order to deal with this, combinations of subsystems which compose overall system for each time period are derived by the methodology mentioned above and then integrated to calculate the reliability of overall system for a specific time. An illustrative example shows the validity and details of the proposed method.

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Establishing Method of RAM Objective Considering Combat Readiness and Field Data of Similarity Equipment (전투준비태세 및 유사장비 운용자료를 활용한 RAM 목표 값 설정방법에 관한 연구)

  • Kim, Kyung-Yong;Bae, Suk-Joo
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.32 no.3
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    • pp.127-134
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    • 2009
  • RAM(Reliability, Availability, Maintainability) is important performance factor to keep combat readiness and optimize operational and maintenance cost of weapon systems. This paper discusses the method to establish RAM for combat readiness by using field failure data from similarity equipments. Operational availability is estimated from a binomial distribution function of user's operational conditions such as combat readiness preservation probability, operational rate, operational availability and total number of equipment. Reliability and maintainability is estimated from field failure data from similarity equipment to accomplish operational availability. The effectiveness of established RAM is verified through analysis of combat readiness preservation probability and mission reliability. A case study of weapon system illustrates the process of the proposed method.

AUV hull lines optimization with uncertainty parameters based on six sigma reliability design

  • Hou, Yuan hang;Liang, Xiao;Mu, Xu yang
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.4
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    • pp.499-507
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    • 2018
  • Autonomous Underwater Vehicle (AUV), which are becoming more and more important in ocean exploitation tasks, needs energy conservation urgently when sailing the complex mission path in long time cruise. As hull lines optimization design becomes the key factor, which closely related with resistance, in AUV preliminary design stage, uncertainty parameters need to be considered seriously. In this research, Myring axial symmetry revolution body with parameterized expression is assumed as AUV hull lines, and its travelling resistance is obtained via modified DATCOM formula. The problems of AUV hull lines design for the minimum travelling resistance with uncertain parameters are studied. Based on reliability-based optimization design technology, Design For Six Sigma (DFSS) for high quality level is conducted, and is proved more reliability for the actual environment disturbance.

A Study on the Improvement of RAM Objective Considering Method for Weapon System (무기체계 RAM 목표값 설정 관련 개선방안 고찰)

  • Hwang, Kyeong Hwan;Hur, Jangwook
    • Journal of Applied Reliability
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    • v.17 no.2
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    • pp.150-158
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    • 2017
  • Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.