• Title/Summary/Keyword: shallow depth

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First record of Hirtomurex nakamurai (Muricidae: Gastropoda) from Korean waters

  • Lee, Sang-Hwa;Kil, Hyun-Jong;Park, Taeseo
    • Journal of Species Research
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    • v.5 no.3
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    • pp.530-532
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    • 2016
  • A single specimen in the subfamily Coralliophilinae in Family Muricidae was collected from Jeju-do by SCUBA diving survey. It was identified as Hirtomurex nakamurai Kosuge, 1985 based on external morphological characteristics. The Coralliophilinae species, commonly known as coral snails, are broadly distributed in tropical and temperate oceans from shallow subtidal zones up to 1,000 m in depth. To date, only four Coralliophila species in the subfamily Coralliophilinae have been reported from Korean waters. Prior to this report, Hirtomurex species has not been reported from Korean waters yet. As a result of this study, a total of five species in two genera of subfamily Coralliophilinae are recorded as Korean mollusk fauna.

ANALYSIS OF TRANSIENT TEMPERATURE DISTRIBUTION IN ROTATING ARC GMA ELDING BY CONSIDERING DROPLET DEFLECTION

  • Kim, Cheolhee;Na, Suck-Joo
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.763-768
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    • 2002
  • This paper presents a mathematical model predicting the temperature distribution in rotating GMA welding. The bead width increases with rotation frequency at the same rotation diameter because the molten droplets are deflected by centrifugal force. The numerical solution is obtained by solving the transient three-dimensional heat conduction equation considering the heat input from the welding arc, cathode heating and molten droplets. Generally in GMA welding the heat input may be assumed as a normally distributed source, but the droplet deflection causes some changes in the heat input distribution. To estimate the heat flux distribution due to the molten droplet, the contact point where the droplet is transferred on the weld pool surface is calculated from the flight trajectory of the droplets under the arc plasma velocity field obtained from the arc plasma analysis. The numerical analysis shows a tendency of broadened bead width and shallow penetration depth with the increase of rotating frequency. The simulation results are in good agreement with those obtained by the experiments under various welding conditions.

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A Study on the Characteristics of PSA Bipolar Transistor with Thin Base Width of 1100 ${\AA}$ (1100 ${\AA}$의 베이스 폭을 갖는 다결정 실리콘 자기정렬 트랜지스터 특성 연구)

  • Koo, Yong-Seo;An, Chul
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.10
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    • pp.41-50
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    • 1993
  • This paper describes the fabrication process and electrical characteristics of PSA (Polysilicon Self-Align) bipolar transistors with a thin base width of 1100.angs.. To realize this shallow junction depth, one-step rapid thermal annealing(RTA) technology has been applied instead of conventional furnace annealing process. It has been shown that the series resistances and parasitic capacitances are significantly reduced in the device with emitter area of 1${\times}4{\mu}m^{2}$. The switching speed of 2.4ns/gate was obtained by measuring the minimum propagation delay time in the I$^{2}$L ring oscillator with 31 stages.

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Analysis on the concept design of the nuclear waste disposal site in foreign country (해외 방사성 폐기물 처분장 개념 설계 분석)

  • Seo, Kyoung-Won;Kim, Woong-Ku;Baek, Ki-Hyun;Jun, Seong-Keun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.791-800
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    • 2010
  • This paper presents the construction status and the conceptual designs of midium and high level radioactive waste disposal facilities from all around world. For the midium radioactive waste, a shallow disposal using trench or a deep depth disposal are adopted. However, these are rather focusing on the social and cultural point of view than the technical. Meanwhile, the high level radioactive waste is basically disposed in the deep underground. The corresponding ground conditions are usually dense and composed of sedimentary and crystalline rocks mainly with low permeability. A barrier system is made of canister which consists of copper, titanium, and tin. The inner and outer side of the canister are composed of different materials respectively.

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A Experimental Study on the Hydroelastic Behavior of Large Floating Offshore Structures (대형부체구조물(大型浮體構造物)의 유(流).탄성(彈性) 연성거동에 관한 실험적 고찰)

  • Lee, Sang-Yeob
    • Journal of Korean Association for Spatial Structures
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    • v.1 no.2 s.2
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    • pp.101-110
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    • 2001
  • A large floating structure is attracting great attention in recent years from the view of ocean space utilization. Its huge scale in the horizontal directions compared with the wavelength and relatively shallow depth make this type of floating structure flexible and its wave-induced motion be characterized by the elastic deformation. In this paper, a boundary integral equation method is proposed to predict the wave-induced dynamic response mat-like floating offshore structure. The structure is modeled as an elastic plate and its elastic deformation is expressed as a superposition of free-vibration modes in air. This makes it straightforward to expand the well-established boundary integral technique for rigid floating bodies to include the hydroelastic effects. In order to validate the theoretical analysis, we compare with the experimental result of reduced model test. Satisfactory agreement is found between theory and experiment.

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Fabrication of deep submicron PMOSFET with the source/drain formed by the mothod of As-Preamorphization though the predeposited amorphous Si layer (증착된 비정질 실리콘층을 통한 As-Preamorphization 방법으로 형성된 소오스/드레인을 갖는 deep submicron PMOSFET의 제작)

  • 권상직;김여환;신영화;김종준;이종덕
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.6
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    • pp.51-58
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    • 1995
  • Major limiting factors in the linear scaling down of the shallow source/drain junction are the boron channeling effect and the Si cosumption phenomenon during silicidation. We can solve these problems by As preamorphization of the predeposited amorphous Si layer. The predeposited amorphous Si layer made the junction depth decrease to nearly the thickness value of the layer and was effectively utilized as the cosumed Si source during Ti silicidation. This method was applied to the actual fabrication of PMOSFET through SES (selectricely etched Si) techology.

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Rapid Thermal Alloy of Fabricated Diode by Rapid Thermal Diffusion (고속 열확산에 의해 제작된 다이오드의 Rapid Thermal Alloy)

  • 이동엽;이영희
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.2
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    • pp.63-67
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    • 1992
  • Shallow $p^{+}-n,n^{+}-p$ diodes have been fabricated using rapid thermal diffusion by solid diffusion source and rapid thermal alloying with pure Aluminum. Diode area and junction depth are designed about 2.83$[\times}10^{-3}cm^{2}$ and 250nm, respectively. Electrical characteristics of $p^{+}-n$ diode show that the ideality factor is 1.04 and reverse current density is 29.3nA/$cm^{2}$, respectively. On the other hand, those of $n^{+}-p$ diode show that the ideality factor is 1.05 and reverse current density is 85.2pA/$cm^{2}$. The reverse currents are measured at 5V reverse bias after rapid thermal alloying for all the measurement.

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Development of a Fixing Apparatus Available to Mount-and-detach ADCP on a Small Vessel (소형선박용 착.탈식 ADCP 고정장치 개발)

  • Hwang, Sang-Chul;Jeon, Dong-Chull;Kang, Jae-Hoon;Kim, Cheol-Soo
    • Ocean and Polar Research
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    • v.26 no.3
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    • pp.481-486
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    • 2004
  • A portable apparatus mounting Acoustic Doppler Current Profilers (ADCP) to any small boat was developed to effectively measure currents in shallow and narrow coastal seas like the west coasts of Korea. Characteristics of the apparatus is that an underwater fish-shaped body protecting an ADCP is designed to reduce the drag during the cruise, which can be freely mounted and detached from a boat with a clamp. Several cruise outputs prove themselves that the apparatus is properly designed for the intended purpose, to minimize air bubbles and to control the submerged depth of the sensor.

Two Cases of Primary Localized Amyloidosis of Larynx (원발성 국소 후두아밀로이드증 2례)

  • 김형태;조승호;전범조;김민식
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.9 no.2
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    • pp.147-151
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    • 1998
  • Primary localized laryngeal amyloidosis is an uncommon disorder of unknown cause that occurs in the absence of systemic amyloidosis or associated disease. There is a risk of either missing concomitant systemic amyloidosis or exhaustively investigating for this when it is not present through failure to appreciate the nature of the disease. We present 2 cases of primary localized laryngeal amyloidosis in supraglottic region. Biopsy of the mass of patients revealed findings consistent with amyloidosis, which were Congo red reaction with a apple green birefringence in polarized light fluorescence microscopy. An extensive workup for systemic amyloidosis was negative. All of two cases were treated by vaporization via $CO_2$ LASER using "Swiftlase Flshscan" for creating a wide, shallow char-free treatment site by precisely controlling ablation depth without causing residual thermal damage to tissue. The postoperative recovery of all cases was uneventful with good vocal quality and no aspiration. At the present time, the patients have no evidence of disease, recurrence and complication.

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Noncontact techniques for monitoring of tunnel linings

  • White, Joshua;Hurlebaus, Stefan;Shokouhi, Parisa;Wittwer, Andreas;Wimsatt, Andrew
    • Structural Monitoring and Maintenance
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    • v.1 no.2
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    • pp.197-211
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    • 2014
  • An investigation of tunnel linings is performed at two tunnels in the US using complimentary noncontact techniques: air-coupled ground penetrating radar (GPR), and a vehicle-mounted scanning system (SPACETEC) that combines laser, visual, and infrared thermography scanning methods. This paper shows that a combination of such techniques can maximize inspection coverage in a comprehensive and efficient manner. Since ground-truth is typically not available in public tunnel field evaluations, the noncontact techniques used are compared with two reliable in-depth contact nondestructive testing methods: ground-coupled GPR and ultrasonic tomography. The noncontact techniques are used to identify and locate the reinforcement mesh, structural steel ribs, internal layer interfaces, shallow delamination, and tile debonding. It is shown that this combination of methods can be used synergistically to provide tunnel owners with a comprehensive and efficient approach for monitoring tunnel lining conditions.