• Title/Summary/Keyword: physical faults

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A Study on Human Engineering for Human Ability (인간능력에 대한 인간공학연구)

  • 이근희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.1 no.1
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    • pp.3-10
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    • 1978
  • Human Engineering has an intention of design to keep the best condition of man-machine system. Hitherto the conception of design has been used to include existing engineering, as mechanical engineering and electric engineering. But the manufactured goods which to be made these process seem to be fully equipped on physical function, but faults come out discountent repeatedly to users. Accordingly, the development of industrial design has been demanded for improving functional design. It is considered that industrial design has aesthetical sensation. In actually, it must be 1. to provide for utility and safety, 2. easy for maintenance, 3. cheap at cost. 4. possible for sales appeal, 5. and good on appearance. As taking into consideration above five conditions, however, for 삯e sake of comprehend to human being about operating method of machinery and equipment, it should be reflected to design what kind of training way will be needed. Also, it must be considered what a certain extent would be occurred tiredness to human being. in other words. it should be considered the design to be possible the reflect to principle of motion economy, It should not be made adoption of human ability for the designed machinery, it must be adopted the method to consider the design on presuppose about human ability. For study of these actual fact, this paper is summarized the essence of human engineering, and also to find out the methodology as humanistic engineering, It is, Particularly, subdivisionization of operation in flow operation is essential direction of mechanization. Generally. as developing the subdivisionization of operation, it will be lack of satisfaction on operation which worker take charge of. The subdivisionization of operation makes the operation to simple-repetitive, to lose the interest of worker and will be also come into question to the feeling of worker's livelihood. It is human's fundamental desire to have get skilful function or special technique. But the subdivisionization of operation hold in those human's fundamental desire and so that it will likely to lose the sorority of living by this fact. Accordingly, this paper have an operation to hold out the methodology on presuppose about human ability.

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A study on the Site Survey and Detection Efficiency for Kepco Lightning Detection and Information Network (낙뢰측정 네트워크(KLDNet)를 위한 감지기 사이트서베이와 낙뢰 감지율 검토)

  • Woo, J.W.;Kwak, J.S.;Moon, J.D.
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.11
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    • pp.532-537
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    • 2006
  • Lightning induced faults accounts for more than 66% at the transmission lines of KEPCO. The lightning causes damages to power system equipments including transmission line, the blackout of electricity and the electro-magnetic interference. Because of this reason, we need the real time lightning information for the optimal operation of power system. And, it is required to obtain and accumulate the lightning current parameters for the insulation design. In 2005, KEPRI constructed a lightning detection network, the KLDNet (i.e. Kepco Lightning Detection & Information System) and launched a lightning information service for KEPCO customers. It is intended to provide data service on the operation of transmission lines and collect lightning-related data, which is the most important factor regulating power system design and operation. The new system will replace LPATS, the old detection system, which has been operating since 1995 and is rapidly failing in terms of both detection performance and location accuracy. The purpose of this paper is to explain the work performed and the results of that work in performing a site survey of several locations. The purpose of the site survey is to find locations acceptable for the installation of a lightning location receiver in support of a Lightning detection system(LDS). A restriction was placed on the surveyed locations, as they must belong to the Korea Electric Power Company. This requirement was made to facilitate the communication needs of the LDS network. Total of 15 sites were evaluated as possible LDS sensor sites. Some of the sites were rejected for physical reasons and therefore no electrical testing was performed. Of the 15 sites, total of 10 sites were considered acceptable and 5 sites were rejected for various reason. In this paper, we would like to explain the site survey and detection efficiency for LDS.

A Proposal for Unit Testing Procedure of Embedded Software Complied with Safety Assessment Criteria (안정성평가 기준에 적합한 내장형 소프트웨어 단위시험 절차 방안)

  • Jang, Jeong-Hoon;Lee, Won-Taek;Jang, Ju-Su
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.2223-2231
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    • 2010
  • Recently, an important physical device of transportation, such as car, railroad, ship and aircraft has changed into electronic control unit. According to accident reports, the most of car accidents are caused by faults of embedded software loaded to computer control unit. The facts implies that the test to find defects in embedded software haven't performed sufficiently. As a result, it is necessary to establish the test procedures of embedded software based on safety assessment criteria. The objective of this proposal is to provide a unit test procedure complied with the safety assessment criteria for the embedded software. In addition, an effective unit testing procedure and defect analysis methods are proposed and a testing procedure using a safety criteria built-in tool is presented.

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Proactive Network Optimizer for Critical Applications (크리티컬한 응용을 위한 능동형 네트워크 최적화기)

  • Park, Bongsang;Park, Pangun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.9
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    • pp.1250-1256
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    • 2018
  • Recently, wireless networks are becoming an important infrastructure for the critical large-scale applications such as cyber-physical systems and next generation industrial automations. However, the fundamental performance uncertainty of wireless networks may incur the serious instability problem of the overall systems. This paper proposes the proactive network optimizer to guarantee the application demands without any real-time link monitoring information of the networks. In particularly, the proposed proactive optimizer is the cross-layer approach to jointly optimize the routing path and traffic distribution in order to guarantee the performance demand within a maximum k number of link faults. Through the simulations, the proposed proactive network optimizer provides better robustness than the traditional existing reactive networks. Furthermore, the proactive network does not expose to the major weakness of the reactive networks such as the performance degradation due to the erroneous link monitoring information and the network reconfiguration cost.

Development of Campus Facility Management System using GIS - Focused on Kyungpook National University - (GIS를 이용한 대학시설물 관리시스템 개발 - 경북대학교를 중심으로 -)

  • Lee, Seung-Yeob;Im, Yong-Ho;Choi, Hyun-Sang
    • Journal of the Korean Association of Geographic Information Studies
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    • v.1 no.1
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    • pp.18-27
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    • 1998
  • This paper, deals with the developmental result of university facility management system using GIS, is to explain the developmental process of this system and the merits and the faults of GIS facility management system. Facility management, as a discipline, is the practice of coordinating the people and the work of an organization into the physical workplace. According to rising costs for the facility management and effective management for the existing facility, the organization need to optimize the use of existing facilities and equipment to prevent unnecessary investments in facilities and equipment. The purpose of this study is to build GIS based university facility management system using GIS. Based on 1/5,000 from national geography institute and 1/600 map, we construct base map for study and, using genasys genius program, we made facility management system. This system includes geographic management, infrastructure management and building management, and, using each attribute information, it is possible to use not only for effective management for existing facilities but also available to future decision making.

An XML-based Digital Mock-Up System for Heterogeneous Multi-CAD Assembly (XML을 이용한 이기종 CAD 조립체 DMU시스템의 설계)

  • Song, In-Ho;Chung, Sung-Chong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.6 s.261
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    • pp.635-643
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    • 2007
  • As many engineers and technicians are involved in the design process of large scale and/or complex products, there are a lot of miss matches and interferences due to designers' faults and several kinds of CAD systems. Recently, CAD systems are applied to verify and check the assembly process. Digital Mock-Up(DMU) system, a tool to build a virtual mock-up in the design stage, has been used to prevent the interferences and miss matches during precision design processes. Using the virtual assembly tool, engineers are able to design precision and interference free parts without physical mock-ups. Instead of a single CAD source, several CAD systems are used to design a complex product. Several organizations are involved in the distributed design environment for heterogeneous multi-CAD assembly. XML and the lightweight CAD file are proposed for the multi-CAD assembly. XML data contains hierarchy of the heterogenenous multi-CAD assembly. STEP PDM schema and STEP ISO 10303-28 formations are applied to construct the XML data. The lightweight CAD file produced from various CAD files through ACIS kernel and InterOp not only contains mesn, B-Rep and topological data, but also is used to visualize CAD data and to verify dimensions. Developed system is executed on the desktop computers. It does not require commercial CAD systems to visualize 3D assembly data. Real-time interference and fitness checks, dimensional verification, and design and assembly verification are performed on the developed system. Assembly of heterogeneous models for a car is conducted to verify the effectiveness of the developed DMU system on the Internet.

Characteristics of South Korea's Geothermal Water in Relation to Its Geological and Geochemical Feature

  • Lee, Chung-Mo;Hamm, Se-Yeong;Lee, Cholwoo;Choi, Sung-Ja;Chung, Sang Yong
    • Journal of Soil and Groundwater Environment
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    • v.19 no.2
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    • pp.25-37
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    • 2014
  • The volcanic type of geothermal water is linked intimately to active or potentially active volcanoes and takes place near the plate boundaries. In contrast to the volcanic type, the geothermal water in Korea has a non-volcanic origin. Korea's geothermal water is classified into the residual magma (RM) type and deep groundwater (DG) type according to the criterion of $35^{\circ}C$. This study reviewed the relationship between the physical and chemical features of the 281 geothermal water sources in South Korea in terms of the specific capacity, water temperature, and chemical compositions of two different basements (igneous rock and metamorphic rock) as well as the geological structures. According to the spatial relationship between the geothermal holes and geological faults, the length of the major fault is considered a key parameter determining the movement to a deeper place and the temperature of geothermal water. A negligible relationship between the specific capacity (Q/s) and temperature was found for both the RM type and DG type with the greater specific capacities of the RM- and DG-igneous types than the RM- and DG-metamorphic types. No relationship was observed between Q/s and the chemical constituents ($K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$, $Zn^{2+}$, $Cl^-$, $SO_4{^{2-}}$, $HCO_3{^-}$, and $SiO_2$) in the DG-igneous and DG-metamorphic types. Furthermore, weak relationship between temperature and chemical constituents was found for both the RM type and DG type.

Paleoseismological implications of liquefaction-induced structures caused by the 2017 Pohang Earthquake

  • Gihm, Yong Sik;Kim, Sung Won;Ko, Kyoungtae;Choi, Jin-Hyuck;Bae, Hankyung;Hong, Paul S.;Lee, Yuyoung;Lee, Hoil;Jin, Kwangmin;Choi, Sung-ja;Kim, Jin Cheul;Choi, Min Seok;Lee, Seung Ryeol
    • Geosciences Journal
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    • v.22 no.6
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    • pp.871-880
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    • 2018
  • During and shortly after the 2017 Pohang Earthquake ($M_w$ 5.4), sand blows were observed around the epicenter for the first time since the beginning of instrumental seismic recording in South Korea. We carried out field surveys plus satellite and drone imagery analyses, resulting in observation of approximately 600 sand blows on Quaternary sediment cover in this area. Most were observed within 3 km of the epicenter, with the farthest being 15 km away. In order to investigate the ground's susceptibility to liquefaction, we conducted a trench study of a 30 m-long sand blow in a rice field 1 km from the earthquake epicenter. The physical characteristics of the liquified sediments (grain size, impermeable barriers, saturation, and low overburden pressure) closely matched the optimum ground conditions for liquefaction. Additionally, we found a series of soft sediment deformation structures (SSDSs) within the trench walls, such as load structures and water-escaped structures. The latter were vertically connected to sand blows on the surface, reflecting seismogenic liquefaction involving subsurface deformation during sand blow formation. This genetic linkage suggests that SSDS research would be useful for identifying prehistoric damage-inducing earthquakes ($M_w$ > 5.0) in South Korea because SSDSs have a lower formation threshold and higher preservational potential than geomorphic markers formed by surface ruptures. Thus, future combined studies of Quaternary surface faults and SSDSs are required to provide reliable paleoseismological information in Korea.

Shear behavior of non-persistent joints in concrete and gypsum specimens using combined experimental and numerical approaches

  • Haeri, Hadi;Sarfarazi, V.;Zhu, Zheming;Hokmabadi, N. Nohekhan;Moshrefifar, MR.;Hedayat, A.
    • Structural Engineering and Mechanics
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    • v.69 no.2
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    • pp.221-230
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    • 2019
  • In this paper, shear behavior of non-persistent joint surrounded in concrete and gypsum layers has been investigated using experimental test and numerical simulation. Two types of mixture were prepared for this study. The first type consists of water and gypsum that were mixed with a ratio of water/gypsum of 0.6. The second type of mixture, water, sand and cement were mixed with a ratio of 27%, 33% and 40% by weight. Shear behavior of a non-persistent joint embedded in these specimens is studied. Physical models consisting of two edge concrete layers with dimensions of 160 mm by 130 mm by 60 mm and one internal gypsum layer with the dimension of 16 mm by 13 mm by 6 mm were made. Two horizontal edge joints were embedded in concrete beams and one angled joint was created in gypsum layer. Several analyses with joints with angles of $0^{\circ}$, $30^{\circ}$, and $60^{\circ}$ degree were conducted. The central fault places in 3 different positions. Along the edge joints, 1.5 cm vertically far from the edge joint face and 3 cm vertically far from the edge joint face. All samples were tested in compression using a universal loading machine and the shear load was induced because of the specimen geometry. Concurrent with the experiments, the extended finite element method (XFEM) was employed to analyze the fracture processes occurring in a non-persistent joint embedded in concrete and gypsum layers using Abaqus, a finite element software platform. The failure pattern of non-persistent cracks (faults) was found to be affected mostly by the central crack and its configuration and the shear strength was found to be related to the failure pattern. Comparison between experimental and corresponding numerical results showed a great agreement. XFEM was found as a capable tool for investigating the fracturing mechanism of rock specimens with non-persistent joint.

Adaptive Design Techniques for High-speed Toggle 2.0 NAND Flash Interface Considering Dynamic Internal Voltage Fluctuations (고속 Toggle 2.0 낸드 플래시 인터페이스에서 동적 전압 변동성을 고려한 설계 방법)

  • Yi, Hyun Ju;Han, Tae Hee
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.251-258
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    • 2012
  • Recently, NAND Flash memory structure is evolving from SDR (Single Data Rate) to high speed DDR(Double Data Rate) to fulfill the high performance requirement of SSD and SSS. Accordingly, the proper ways of transferring data that latches valid data stably and minimizing data skew between pins by using PHY(Physical layer) circuit techniques have became new issues. Also, rapid growth of speed in NAND flash increases the operating frequency and power consumption of NAND flash controller. Internal voltage variation margin of NAND flash controller will be narrowed through the smaller geometry and lower internal operating voltage below 1.5V. Therefore, the increase of power budge deviation limits the normal operation range of internal circuit. Affection of OCV(On Chip Variation) deteriorates the voltage variation problem and thus causes internal logic errors. In this case, it is too hard to debug, because it is not functional faults. In this paper, we propose new architecture that maintains the valid timing window in cost effective way under sudden power fluctuation cases. Simulation results show that the proposed technique minimizes the data skew by 379% with reduced area by 20% compared to using PHY circuits.