• Title/Summary/Keyword: severe environments

Search Result 329, Processing Time 0.026 seconds

Feasibility Study for Wear Resistance of Rails (레일의 내마모성에 대한 타당성 연구)

  • Chang, Seky;Pyun, Young Sik
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.23 no.6
    • /
    • pp.576-579
    • /
    • 2014
  • Rails are continuously exposed to severe environments due to increases in train service frequency, passing tonnage, and speed. Wear is one of the most common types of damage observed on rails. The surface of railsis heat treated to secure safety at critical sites, such as curved tracks or turnouts. Ultrasonic nanocrystal surface modification (UNSM), a new approach for rails, was examined to strengthen the rail surface. The effect of UNSM on the wear resistance of rail specimens was compared with that of heat treatment. Wear resistance was improved after UNSM treatment due to increased hardness and surface compressive residual stress.

Human Cutaneous Injuries Following Jellyfish Stings in Dolphin Performance Pool (돌고래 공연 풀에서 해파리 자상에 의한 피부상해)

  • Eo, Kyung-Yeon;Kwon, Oh-Deog
    • Journal of Veterinary Clinics
    • /
    • v.27 no.4
    • /
    • pp.497-499
    • /
    • 2010
  • Cutaneous injuries stung by jellyfish are not uncommon in human exposed to marine environments. Most of the cases occur to scuba divers, fishermen, and travelers swimming at the beach. The symptoms vary from mild dermatosis to fatal systemic reaction. Some group of jellyfish like Atlantic Portuguese man-of-war (Physalia physalis) provokes acute severe skin injuries with systemic symptoms of nausea, bradycardia, and rarely anaphylaxis. But it is unusual case that allergic dermatitis caused by Scyphistoma which is polyp stage of jellyfish (Aurelia aurita) happened to zoo keepers working at indoor dolphin pool. This case report is about dermatosis with symptoms such as painful, irritant, itching, and erupted skin lesions on the neck and face of zoo keepers working at dolphinarium in Seoul zoo, Korea.

Studies on the Occurrence of Corn Sheath Blight Caused by Rhizoctonia solsni I. Influence of growth season and cultural environment on the occurrence of sheath blight disease. (담근먹이 옥수수의 잎집무늬마름병 발생에 관한 연구 I. 생육시기 및 재배환경과 잎집무늬 마름병 발생)

  • 이상범;김정갑;한민수;한흥전
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.9 no.3
    • /
    • pp.174-178
    • /
    • 1989
  • The investigation was carried out to identify the main pathogen infected with sheath blight in corn plant during 1986-1987. The main fungi of sheath blight isolated from corn plant was identified as Rhizoctonia sobni. Sheath blight in corn plant was first found in early July and infected extremely from late July to end August. Severe sheath blight disease was observed in Gyeongido (Yeoju and Suweon) and Jeonnam (Kwangju) area. The rate of attack was associatied with management and cultural environments of corn plant. Dense planting increased sheath blight, but application of cattle compost reduced the rate of infection. A positive correlation was found between infection rate of shealth blight and concentration of soluble carbohydrate in corn plant (r=0.96). The varieties of Jinjuok, Suweon 83, Suweon 87, Suweon 89, P.3055, P.3160, DK689 and XCG 51 showed remarkable tolerance to sheath blight disease.

  • PDF

Blind Algorithms with Decision Feedback based on Zero-Error Probability for Constant Modulus Errors

  • Kim, Nam-Yong;Kang, Sung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.36 no.12C
    • /
    • pp.753-758
    • /
    • 2011
  • The constant modulus algorithm (CMA) widely used in blind equalization applications minimizes the averaged power of constant modulus error (CME) defined as the difference between an instant output power and a constant modulus. In this paper, a decision feedback version of the linear blind algorithm based on maximization of the zero-error probability for CME is proposed. The Gaussian kernel of the maximum zero-error criterion is analyzed to have the property to cut out excessive CMEs that may be induced from severely distorted channel characteristics. Decision feedback approach to the maximum zero-error criterion for CME is developed based on the characteristic that the Gaussian kernel suppresses the outliers and this prevents error propagation to some extent. Compared to the linear algorithm based on maximum zero-error probability for CME in the simulation of blind equalization environments, the proposed decision feedback version has superior performance enhancement particularly in cases of severe channel distortions.

A Framework of Web-based Inventory System using a RFID in Plastic Injection Molding Industry (플라스틱 사출산업의 RFID를 이용한 웹기반 재고관리시스템 프레임웤)

  • Lim, Seok-Jin;Song, Jae-Ho;Ko, Young-Uk;Park, Byong-Tae
    • Proceedings of the Safety Management and Science Conference
    • /
    • 2010.04a
    • /
    • pp.189-197
    • /
    • 2010
  • Recently, industrial business environments have rapidly changed and face severe competitive challenges. The effective inventory system enables to product and deliver the products quickly for meeting due date of customer's order in this environment. This study have developed a web-based inventory system framework using RFID for a plastic injection molding industry. The system analysis inventory problem issues such as inventory planning, warehouse assignment. In this study, web-based inventory system using Java language is proposed and implemented. As the result of implementation of the system, we expected that it manages to inventory planning continually and systematically.

  • PDF

Toward A Totally Solving Interference Problem for Ultrasound Localization System (초음파 위치인지 시스템의 간섭 문제의 해결을 위한 연구)

  • Song, Byung-Hun;Ham, Kyung-Sun;Lee, Hyung-Su
    • Proceedings of the IEEK Conference
    • /
    • 2006.06a
    • /
    • pp.177-178
    • /
    • 2006
  • The real-time tracking system is an essential factor for the development of low cost sensor networks for use in pervasive computing and ubiquitous networking. In this paper, we address the interference problems of the sensor network platform with ultrasonic for location tracking system. Ubiquitous indoor environments often contain substantial amounts of metal and other such reflective materials that affect the propagation of radio frequency signals in non-trivial ways, causing severe multi-path effects, dead-spots, noise, and interference. Especially we present a novel reducing interference location system that is particularly well suited to support context-aware computing. The system called Pharos, aims to combine the advantages of real-time tracking systems that implement distributed environment with regardless of infrastructure or infrastructure-less wireless sensor networks.

  • PDF

COMPUTATIONAL INTELLIGENCE IN NUCLEAR ENGINEERING

  • UHRIG ROBERT E.;HINES J. WESLEY
    • Nuclear Engineering and Technology
    • /
    • v.37 no.2
    • /
    • pp.127-138
    • /
    • 2005
  • Approaches to several recent issues in the operation of nuclear power plants using computational intelligence are discussed. These issues include 1) noise analysis techniques, 2) on-line monitoring and sensor validation, 3) regularization of ill-posed surveillance and diagnostic measurements, 4) transient identification, 5) artificial intelligence-based core monitoring and diagnostic system, 6) continuous efficiency improvement of nuclear power plants, and 7) autonomous anticipatory control and intelligent-agents. Several changes to the focus of Computational Intelligence in Nuclear Engineering have occurred in the past few years. With earlier activities focusing on the development of condition monitoring and diagnostic techniques for current nuclear power plants, recent activities have focused on the implementation of those methods and the development of methods for next generation plants and space reactors. These advanced techniques are expected to become increasingly important as current generation nuclear power plants have their licenses extended to 60 years and next generation reactors are being designed to operate for extended fuel cycles (up to 25 years), with less operator oversight, and especially for nuclear plants operating in severe environments such as space or ice-bound locations.

The Evaluation of 2-25Cr-lMo Steels Degradation by the Electrochemical Polarization Method (전기화학적 분극특성을 이용한 2.25Cr-lMo 강의 열화도 평가)

  • 김지수;현양기;이재도;오세규
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • 2001.05a
    • /
    • pp.314-319
    • /
    • 2001
  • Most parts of facilities in domestic petroleum plants and power plants are needed to be abandoned, repaired or replaced, because in Korea they were built in the 1960s and, they have been used under severe conditions and exposed corrosive environments. 2.25Cr- lMo steels have excellent high-temperature mechanical properties. Therefore, the material have been widely used as heat exchanger tubes, boiler headers and its tubes in such industries. But, those microstructural evolutions in high temperature such as precipitation and carbide coarsening give a reason to degrade the material. Especially, in case of this material, carbides induced embrittlement(CIE) is the primary reason for degrading mechanical properties at over 50$0^{\circ}C$. In this paper, we introduce a electrochemical polarization method for detecting CIE quantitatively.

  • PDF

A Development of Web-based Inventory System using a RFID in Injection Molding Industry (RFID를 이용한 사출산업에서의 웹기반 재고관리시스템 개발)

  • Lim, Seok-Jin
    • Journal of the Korea Safety Management & Science
    • /
    • v.12 no.3
    • /
    • pp.177-182
    • /
    • 2010
  • Industrial business environments have rapidly changed and face severe competitive challenges. The effective inventory system enables to product and deliver the products quickly for meeting due date of customer's order in this environment. This study have developed a web-based inventory system using RFID for an injection molding industry. The system analysis inventory problem issues such as inventory planning, warehouse assignment and assist to develop production scheduling. In this study, web-based inventory system using Java language and RFID technology is proposed and implemented. As the result of implementation of the system, we expected that it manages to inventory planning continually and systematically.

A Dual Radiation Monitoring System Ror Robot Working in High Radiation Field (고방사선장내 작업 로봇용 이중 방사선 감지 시스템)

  • Lee Nam-Ho;Cho Jai-Wan;Kim Seung-Ho
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.54 no.9
    • /
    • pp.556-558
    • /
    • 2005
  • The effect of high irradiation on inspection systems in a nuclear power plant can be severe, especially to electronic components such as control hoards. The effect may lead to a critical malfunction or trouble to a underwater robot for inspection and maintenance of nuclear reactor. However, if information on the total accumulated dose on the sensitive parts of the robot is available, a prediction of robot's behavior in radiation environments becomes possible. To know how much radiation the robot has encountered, a dosimeter to measure the total accumulated dose is necessary. This paper describes the development effort of a dual radiation monitoring system using a SiC diode as a dose-rate meter and a p-type power MOSFET as a dose meter. This attempt using two sensors which detect same radiation improves reliability and stability at high intensity radiation detection in nuclear facilities. It uses the concept of diversity and redundancy.