• Title/Summary/Keyword: Transport functions

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An Extended SNMP Scheme for a Digital Convergence Device with Control Functions (제어 기능을 갖는 디지털 컨버전스 장비를 위한 SNMP 확장에 관한 연구)

  • Heo, Gil;Kim, Eun-Hoe;Choi, Jae-Young
    • The KIPS Transactions:PartA
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    • v.16A no.5
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    • pp.369-380
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    • 2009
  • SNMP (Simple Network Management Protocol) is a standard protocol for management of network devices, and it provides excellent features such as scalability, information management, authentication, encryption, and access control. However, SNMP has a structural weakness to fully support control functions for integrated management of digital convergence devices, and it has a limitation of message length in SNMP communication. In this paper, we present an extended SNMP scheme for integrated management of digital convergence devices with control functions. We modified the SNMP architecture by adding DDS (Device Driver Subsystem) to SNMP engine for controlling different devices and by defining CADM (Control Agent Driver Model), therefore we solved the ambiguity problem between 'set' and 'control' of SNMP. And the extended SNMP made it easy for SNMP applications to use various control functions. The extended SNMP can transport massive high-level information by adding three new SNMP commands which eliminate the limit of message length.

Effect of Chewlical Transport on Stability of Earth Embankment

  • Ahn, Tae bong
    • Geotechnical Engineering
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    • v.12 no.3
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    • pp.109-126
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    • 1996
  • In this study, the chemical fluid considered is sodium chloride sloutions. The concentrations for the sodium chloride solutions are varied from 0 to 20%. A series of lab oratory triaxial tests are performed on the cylindrical specimens of sand bentonite mixture with different (5, 10, 15%) sodium chloride content solutions. Deformation(elastic modulus, E) and strength (cohesion, c', and angle of friction, f') parameters are obtained from the triaxial tests and they are expressed as functions of conf'ming pressure and sodium chloride solution concentrations. The stress-strain-strength behavior based on the above strength parameters is introduced to the finite element method with a residual flow procedure (RFP). By integrating a slope stability (limit equilibrium) procedure in the finite element method, factors of safety with time are computed.

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The Conceptual Design of Semi-submersible Type Mobile Harbor Using Axiomatic Design Principles (공리설계를 이용한 반잠수식 모바일하버의 개념설계)

  • Lee, Joo-Hee;Yoon, Seong-Jin;Chung, Hyun;Lee, Phill-Seung
    • Korean Journal of Computational Design and Engineering
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    • v.15 no.3
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    • pp.189-203
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    • 2010
  • The axiomatic design principles are applied to the conceptual design of semi-submersible type mobile harbor (B1). The process of how the design of mobile harbor is elaborated, evaluated and improved from the very beginning is presented in this paper. The concept of mobile harbor is a functional harbor, which can move to a container ship anchoring out of ports in the deep water to load/unload containers on sea and transfer them to their destination ports. This floating system will innovate the maritime transport and distribution since it will greatly enhance the accessibility of super-sized container ships to existing harbors and harbors without enough infrastructures. Designing a mobile system which can perform the functions of traditional harbors on the floating system requires innovative ideas as well as rigorous validations of each sub systems. In order to enhance the chance of design success, we try to satisfy the design axioms in early stage of conceptual design. We use the zigzagging process for defining Functional Requirements (FR)-Design Parameters (DP) hierarchy due to the complexity of the system. In other words, we decomposed the complexity of the design by FR-DP hierarchy and reduced coupled design logically and systematically. This paper shows applicability of the axiomatic design principles to the field of ocean systems engineering.

Transport Properties of Ar-Kr Mixtures: A Molecular Dynamics Simulation Study

  • Min, Sun-Hong;Son, Chang-Mo;Lee, Song-Hi
    • Bulletin of the Korean Chemical Society
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    • v.28 no.10
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    • pp.1689-1696
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    • 2007
  • Equilibrium molecular dynamics (EMD) simulations are used to evaluate the transport coefficients of argonkrypton mixtures at two liquid states (state A: 94.4 K and 1 atm; state B: 135 K and 39.5 atm) via modified Green-Kubo formulas. The composition dependency of the volume at state A obeys close to the linear model for ideal liquid mixture, while that at state B differs from the linear model probably due to the high pressure. The radial distribution functions for the Ar-Kr mixture (x = 2/3) show a mixing effect: the first peak of g11 is higher than that of g(r) for pure Ar and the first peak of g22 is lower than that of g(r) for pure Kr. An exponential model of engineering correlation for diffusion coefficient (D) and shear viscosity (η) is superior to the simple linear model for ideal liquid mixtures. All three components of thermal conductivity (λpm, λtm, and λti) at state A and hence the total thermal conductivity decrease with the increase of x. At state B, the change in λtm is dominant over those in λpm and λti, and hence the total thermal conductivity decrease with the increase of x.

Electron Mean Energy in CF4, CH4, Ar mixtures (CF4, CH4, Ar 혼합기체의 전자 평균에너지)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.64 no.4
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    • pp.241-245
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    • 2015
  • Energy Distribution Function in pure $CH_4$, $CF_4$ and mixtures of $CF_4$ and Ar, have been analyzed over a range of the reduced electric field strength between 0.1 and 350[Td] by the two-term approximation of the Boltzmann equation (BEq.) method and the Monte Carlo simulation (MCS). The calculations of electron swarm parameters require the knowledge of several collision cross-sections of electron beam. Thus, published momentum transfer, ionization, vibration, attachment, electronic excitation, and dissociation cross-sections of electrons for $CH_4$, $CF_4$ and Ar, were used. The differences of the transport coefficients of electrons in $CH_4$, mixtures of $CH_4$ and Ar, have been explained by the deduced energy distribution functions for electrons and the complete collision cross-sections for electrons. The results of the Boltzmann equation and the Monte Carlo simulation have been compared with the data presented by several workers. The deduced transport coefficients for electrons agree reasonably well with the experimental and simulation data obtained by Nakamura and Hayashi. The energy distribution function of electrons in $CF_4$-Ar mixtures shows the Maxwellian distribution for energy. That is, $f({\varepsilon})$ has the symmetrical shape whose axis of symmetry is a most probably energy.

Development of Application Service for Secure Container Transport Based on CSD (CSD 기반의 컨테이너 안전운송 응용 서비스 개발)

  • Choo, Young-Yeol;Choi, Su-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.10
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    • pp.2203-2208
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    • 2011
  • In this paper, we describe application service development for secure land and marine transport based on CSD (Conveyance Security Device) systems. Based on CSD systems, we present application service and security service according to relevant standards as well as test procedure of developed services. Exploiting temperature, moisture, impact sensors, state monitoring function of container freight was developed to prevent disaster during transportation in addition to security function with CSD. For confidentiality of messages exchanged among application service entity and CSD systems, Encryption and decryption functions going by RC5 and AES-128 algorithms were implemented at desktop PC and 8 bit CPU environments, respectively. Measuring the elapsed time during encryption and decryption shows that two algorithms are allowable for the application service.

Design of a Safe-driving Assistant System based on the IEEE WAVE (IEEE WAVE 기반 안전운전 지원 시스템의 설계)

  • Ko, Jae-Cheol;Lee, Hyuk-Joon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.1
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    • pp.55-68
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    • 2010
  • IEEE WAVE is going through the final standardization process as the wireless access technology which provides drivers in high-speed vehicles with safety-related information and commercial services This paper presents an application-layer protocol for safe driving assistant service and a service system emulator based on this protocol. The safe driving assistant system includes a construction zone information service and a vehicle crash notification service, an emergency vehicle notification service, a probing service and a dilemma zone decision assistant service. Emulator System design for verifying functions of system, The emulator consists of an emulator server that models the movement of all vehicles and road states and a number of clients that models functional units for OBUs, RSUs, and a traffic control center).

The Implementation of an IPv4 over IPv6 Tunnel of the DSTM for Next-Generation Internet Service (차세대 인터넷 서비스를 위한 DSTM의 IPv4 over IPv6 터널 구현)

  • Lee, Seung-Min;Min, Sang-Won;Kim, Yong-Jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.1
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    • pp.75-83
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    • 2008
  • In this paper, we propose an efficient algorithm that assigns single temporary IPv4 address and port number to improve efficiency of IPv4 address that is allocated in DSTM service. And, we have analyzed the elementary functions for DSTM and have designed the functional modules. Also, we have implemented the DTI interface for encapsulation and decapsulation of IPv6 packets. The performance analysis and comparison are investigated whether the appropriate interworking service is possible or not. Our observation results show that the performance of IPv4 over IPv6 tunneling is suitable to DSTM service due to the reduction of delay by eliminating checksum calculations in the header of IPv6 tunneling.

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Analysis of the Mean Energy in $SiH_4-Ar$ Mixture Gases ($SiH_4-Ar$ 혼합기체의 평균 에너지에 관한 연구)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.55 no.2
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    • pp.57-61
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    • 2006
  • This paper calculates and gives the analysis of mean energy in pure $SiH_4,\;Ar-SiH_4$ mixture gases ($SiH_4-0.5[%],\;5[%]$) over the range of $E/N =0.01{\sim}300[Td]$, p = 0.1, 1, 5.0 [Torr] by Monte Carlo the Backward prolongation method of the Boltzmann equation using computer simulation without using expensive equipment. The results have been obtained by using the electron collision cross sections by TOF, PT, SST sampling, compared with the experimental data determined by the other author. It also proved the reliability of the electron collision cross sections and shows the practical values of computer simulation. The calculations of electron swarm parameters require the knowledge of several collision cross-sections of electron beam. Thus, published momentum transfer, ionization, vibration, attachment, electronic excitation, and dissociation cross-sections of electrons for $SiH_4$ and Ar, were used. The differences of the transport coefficients of electrons in $SiH_4$, mixtures of $SiH_4$ and Ar, have been explained by the deduced energy distribution functions for electrons and the complete collision cross-sections for electrons. A two-term approximation of the Boltzmann equation analysis and Monte Carlo simulation have been used to study electron transport coefficients.

Power Transmission Line Hazardous Material Surveillance System Implemented Laser Scanning (레이저를 이용한 송전선 위해물질 감지시스템)

  • Park, Gang-Sook;Son, Tae-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.4
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    • pp.95-103
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    • 2012
  • In this paper, we implemented a surveillance system for the power transmission line protection from heavy-duty fender-bender. Laser scanning technology was applied for system design. It was analyzed detailed functions for designed system. Measured detection rate and error rate that are monitoring parameters for both studied system and conventional system were 100%, 0% and 95.8%, 2.1%, respectively. Measurement showed that studied system is almost perfect and better than conventional system. Because this system provides the information to frontline workers with managers of heavy equipments that have possibility of accident, it can be applied to surveillance system for the transmission line protection.