• Title/Summary/Keyword: dependencies

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Human Error Analysis in a Permit to Work System: A Case Study in a Chemical Plant

  • Jahangiri, Mehdi;Hoboubi, Naser;Rostamabadi, Akbar;Keshavarzi, Sareh;Hosseini, Ali Akbar
    • Safety and Health at Work
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    • v.7 no.1
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    • pp.6-11
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    • 2016
  • Background: A permit to work (PTW) is a formal written system to control certain types of work which are identified as potentially hazardous. However, human error in PTW processes can lead to an accident. Methods: This cross-sectional, descriptive study was conducted to estimate the probability of human errors in PTWprocesses in a chemical plant in Iran. In the first stage, through interviewing the personnel and studying the procedure in the plant, the PTW process was analyzed using the hierarchical task analysis technique. In doing so, PTWwas considered as a goal and detailed tasks to achieve the goal were analyzed. In the next step, the standardized plant analysis risk-human (SPAR-H) reliability analysis method was applied for estimation of human error probability. Results: The mean probability of human error in the PTW system was estimated to be 0.11. The highest probability of human error in the PTW process was related to flammable gas testing (50.7%). Conclusion: The SPAR-H method applied in this study could analyze and quantify the potential human errors and extract the required measures for reducing the error probabilities in PTW system. Some suggestions to reduce the likelihood of errors, especially in the field of modifying the performance shaping factors and dependencies among tasks are provided.

ABox Realization Reasoning in Distributed In-Memory System (분산 메모리 환경에서의 ABox 실체화 추론)

  • Lee, Wan-Gon;Park, Young-Tack
    • Journal of KIISE
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    • v.42 no.7
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    • pp.852-859
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    • 2015
  • As the amount of knowledge information significantly increases, a lot of progress has been made in the studies focusing on how to reason large scale ontology effectively at the level of RDFS or OWL. These reasoning methods are divided into TBox classifications and ABox realizations. A TBox classification mainly deals with integrity and dependencies in schema, whereas an ABox realization mainly handles a variety of issues in instances. Therefore, the ABox realization is very important in practical applications. In this paper, we propose a realization method for analyzing the constraint of the specified class, so that the reasoning system automatically infers the classes to which instances belong. Unlike conventional methods that take advantage of the object oriented language based distributed file system, we propose a large scale ontology reasoning method using spark, which is a functional programming-based in-memory system. To verify the effectiveness of the proposed method, we used instances created from the Wine ontology by W3C(120 to 600 million triples). The proposed system processed the largest 600 million triples and generated 951 million triples in 51 minutes (696 K triple / sec) in our largest experiment.

Aspectual Implementation Patterns for Feature-Oriented Product Line Engineering (특성 지향의 제품계열공학을 위한 애스팩트 구현 패턴)

  • Lee, Kwan-Woo
    • The KIPS Transactions:PartD
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    • v.16D no.1
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    • pp.93-104
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    • 2009
  • Modular implementation of a feature is a first step toward feature-oriented product line engineering, which develops and then utilizes core assets to configure products in terms of features. Aspect-oriented programming provides effective mechanisms for improving the modularity of feature implementations. However, as features in general are not independent of each other, changes in the implementation of one feature may cause changes to or side effects in the implementation of other features. Moreover, since the time at which a feature is incorporated into products, called feature binding time, may be various from compile time through load time to run time, a feature may have to be implemented differently depending on when the feature is bound into a product. To make each feature implementation module as independent as possible, this paper proposes aspectual implementation patterns that can effectively separate feature dependencies as well as feature binding time from feature implementation modules. These patterns enable flexible composition of feature implementation modules without affecting other modules according to feature selection. The approaches are demonstrated and evaluated based on a product line of scientific calculator applications.

DEPENDENCY OF SINGLE-PHASE FAC OF CARBON AND LOW-ALLOY STEELS FOR NPP SYSTEM PIPING ON PH, ORIFICE DISTANCE AND MATERIAL

  • Moon, Jeong-Ho;Chung, Hung-Ho;Sung, Ki-Woung;Kim, Uh-Chul;Rho, Jae-Seong
    • Nuclear Engineering and Technology
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    • v.37 no.4
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    • pp.375-384
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    • 2005
  • To investigate the flow-accelerated corrosion (FAC) dependency of carbon steel (A106 Gr. B) and low-alloy steels (1Cr-1/2Mo, 21/4Cr-1Mo) on pH, orifice distance, and material, experiments were carried out. These experiments were performed using a flow velocity of 4 m/sec (partly 9 m/sec) at pH $8.0\~10.0$ in an oxygen-free aqueous solution re-circulated in an Erosion-Corrosion Test Loop at $130^{\circ}\;{\ldots}$ for 500 hours. The weight loss of the carbon steel specimens appeared to be positively dependent on the flow velocity. That of the carbon and low-alloy steel specimens also showed to be distinguishably dependent on the pH. At pH levels of $8.0\~9.5$ it decreased, but increased from 9.5 to 10.0. Utility water chemistry personnel should carefully consider this kind of pH dependency to control the water system pH to mitigate FAC of the piping system material. The weight loss of the specimens located further from the orifice in the distance range of $6.8\~27.2$ mm was shown to be greater, except for 21/4Cr-1Mo, which showed no orifice distance dependency. Low alloy steel specimens exhibited a factor of two times better resistance to FAC than that of the carbon steel. Based on this kind of FAC dependency of the carbon and low-alloy steels on the orifice distance and material, we conclude that it is necessary to alternate the composition of the secondary piping system material of NPPs, using low-alloy steels, such as 21/4Cr-1Mo, particularly when the system piping has to be replaced.

Determination of optical properties of Pr3+-doped selenide glasses of Ge-Sb-Se system using spectroscopic ellipsometry (분광타원법을 이용한 Pr 첨가 Ge-Sb-Se 계열 셀레나이드 유리의 굴절률 결정)

  • 신상균;김상준;김상열;최용규;박봉제;서홍석
    • Korean Journal of Optics and Photonics
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    • v.14 no.6
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    • pp.594-599
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    • 2003
  • By using the spectroscopic ellipsometry, we have measured and analyzed the optical characteristics of P $r^3$$^{+}$-doped selenide glasses of Ge-Sb-Se system, a strong candidate material for U band fiber amplifiers. The ellipsometric spectra measured in the transparent wavelengths range of the material were all fitted to a model consisting of ambient/roughness/thin fil $m_strate structures to obtain simultaneously the optical properties such as refractive index, in terms of Sellmeier parameters and film structure of P $r^3$$^{+}$-doped selenide glasses. Repeated measurements on different positions in both polished faces rendered to verify positional dependence of measured spectre-ellipsometric data. Hence, the model made possible the analysis of the optical characteristics of the glasses. Even though surface roughness was mainly responsible for the position dependencies, the averaged refractive indexes were as precise as to reflect the minute compositional change tantamount to 1 mol%. The measured refractive indexes are useful for design of core and clad compositions of single-mode selenide optical fibers.

The Possible Signs of Hydrogen and Helium Accretion from Interstellar Medium on the Atmospheres of F-K Giants in the Local Region of the Galaxy

  • Yushchenko, Alexander;Kim, Seunghyun;Jeong, Yeuncheol;Demessinova, Aizat;Yushchenko, Volodymyr;Doikov, Dmytry;Gopka, Vira;Jeong, Kyung Sook;Rittipruk, Pakakaew
    • Journal of Astronomy and Space Sciences
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    • v.38 no.3
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    • pp.175-183
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    • 2021
  • The dependencies of the chemical element abundances in stellar atmospheres with respect to solar abundances on the second ionization potentials of the same elements were investigated using the published stellar abundance patterns for 1,149 G and K giants in the Local Region of the Galaxy. The correlations between the relative abundances of chemical elements and their second ionization potentials were calculated for groups of stars with effective temperatures between 3,764 and 7,725 K. Correlations were identified for chemical elements with second ionization potentials of 12.5 eV to 20 eV and for elements with second ionization potentials higher than 20 eV. For the first group of elements, the correlation coefficients were positive for stars with effective temperatures lower than 5,300 K and negative for stars with effective temperatures from 5,300 K to 7,725 K. The results of this study and the comparison with earlier results for hotter stars confirm the variations in these correlations with the effective temperature. A possible explanation for the observed effects is the accretion of hydrogen and helium atoms from the interstellar medium.

Temperature and Concentration Dependencies of Chemical Equilibrium for Reductive Dissolution of Magnetite Using Oxalic Acid

  • Lee, Byung-Chul;Oh, Wonzin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.2
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    • pp.187-196
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    • 2021
  • Chemical equilibrium calculations for multicomponent aqueous systems involving the reductive dissolution of magnetite (Fe3O4) with oxalic acid (H2C2O4) were performed using the HSC Chemistry® version 9. They were conducted with an aqueous solution model based on the Pitzer's approach of one molality aqueous solution. The change in the amounts and activity coefficients of species and ions involved in the reactions as well as the solution pH at equilibrium was calculated while changing the amounts of raw materials (Fe3O4 and H2C2O4) and the system temperature from 25℃ to 125℃. In particular, the conditions under which Fe3O4 is completely dissolved at high temperatures were determined by varying the raw amount of H2C2O4 and the temperature for a given raw amount of Fe3O4 fed into the aqueous solution. When the raw amount of H2C2O4 added was small for a given raw amount of Fe3O4, no undissolved Fe3O4 was present in the solution and the pH of the solution increased significantly. The formation of ferrous oxalate complex (FeC2O4) was observed. The equilibrium amount of FeC2O4 decreased as the raw amount of H2C2O4 increased.

The Development of the Standard Framework of Sports Event Process Management System (스포츠이벤트 프로세스 관리시스템 표준 프레임워크 개발)

  • Kim, Joo-Hak;Cho, Sun-Mi
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.9 no.1
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    • pp.815-824
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    • 2019
  • It is not easy to present a generalized operating model because the operating environment of a sport event is composed of a complex matrix structure. In this study, we propose 'standardization' which provides guidance of concept and process of sport event management to solve this sports event management problem. To purpose complete of this study, the frame was developed by the international standard ISO 9001: 2015 is applied. The standards framework for sports event process management system structure proposed in this study consists of scope of application, citing standard, Terms and definitions, organizational situation, leadership, planning, support, operation, performance evaluation, and improvement. This sport event process management system standard can be applied to any organization that wants to host, prepare, and operate sport events regardless of the form or scale of the sport event. In addition, this standard was focused on process management of life-cycle stages of sporting events, therefor it was possible to manage interrelationships and dependencies between processes and processes.

The ICT Operation Performance by a New ICT Investment and Policy Consistency of Government Organizations (정부조직의 신규 ICT 투자와 정책 일관성에 따른 ICT 운영 성과)

  • Jung, Byoungho
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.15 no.2
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    • pp.87-99
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    • 2019
  • The purpose of this study is to examine an organizational ICT(Information and Communication Technology) performance by ICT investment and policy consistency of government organizations. As the rapid development of ICT is becoming an essential element of social culture, the ICT operation of bureaucratic government also is becoming important. The central government has invested substantially new ICT for improving the quality of nationwide service and to promote administrative efficiency. However, various departments of government occur frequently duplication investments of ICT, and budget conflicts between organizations caused difficulties in maximizing ICT competency. I will confirm the ICT operational performance by ICT investment behavior and organizational work competency as well as the significance of ICT policy consistency. The method of study used a structural equation. The research model set ICT investment behavior as independent variables, organizational work competencies and policy consistency as mediations, and operational performance as dependencies. As a result of the research, New ICT interests show negative effects that caused work change between government organizations and government-funded body. But, New ICT convergence shows positive effects on increasing the two competency variables. The two competency variables show negative effects that caused changes in ICT policy consistency and show no impact on the ICT operational performance. The ICT policy consistency shows a positive effect on enhancing ICT operational performance. The study contribution explain updated the contingency theory and because the ICT policy consistency is essential, negotiation between government organizations will be important. Future research will require a qualitative study through interviews in government organizations about consistency enhance of ICT policy.

Design and Implementation of Software-Defined Storage Autoconfiguration Module for Integrated Use of Cloud File/Block/Object Storage (클라우드 파일/블록/객체 스토리지의 통합사용을 위한 소프트웨어 정의 스토리지 자동 설정 모듈의 설계 및 구현)

  • Park, Sun;Cha, ByungRae;Kim, Jongwon
    • Smart Media Journal
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    • v.7 no.4
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    • pp.9-16
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    • 2018
  • In order to improve the economics and flexibility of cloud computing, tendency to automate the operation and management of cloud resources has become complicated. However, while automation for cloud storage depends on the manufacturer's storage hardware, it cannot flexibly support the storage type in accordance with users' needs. In this paper, we propose an automatic configuration module that supports block/file/object storages suitable for user environment. In order to automatically install ceph, a cloud storage, we propose an automatic installation and configuration module based on the Chef configuration management tool. In addition to that, we also propose an automatic configuration module based on a shell programming in pursuit of enabling users to use ceph storage of block/file/object. The proposed method can automatically set up and manage shared file, block, and object storages in a virtual or physical user environment with no hardware dependencies.