• Title/Summary/Keyword: National Carrier

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A Basic Study on the Maritime Performing Party System and the Difference between the Maritime System and China's system

  • Liu, Xiaoxian;Noh, Chang-Kyun
    • Journal of Navigation and Port Research
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    • v.36 no.4
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    • pp.299-303
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    • 2012
  • "United Nations Convention on Contracts for the International Carriage of Goods Wholly or Partly by Sea" was passed in July 3, 2008. on September 23, 2009 signing ceremony was held in Rotterdam. The system of maritime performing party is a special system in the transport convention, and constitutes an integral part of the Convention. Maritime performing party system is not the first system which brings in the carrier's independent contractor, but it is the most comprehensive and thorough one. It unified the duty of carrier's independent contractor in the maritime segment, and it is also an important progress in the developing process of international maritime legal system. There are some differences between the maritime performing party and China's current related system, i.e, the port maritime performing party and the intermediate performing party are included in the maritime performing party, and they can enjoy the carrier's exception clause and limitation of liability.

Effect of Carrier Gases on the Microstructure and Properties of Ti Coating Layers Manufactured by Cold Spraying (저온 분사 공정으로 제조된 Ti 코팅층의 미세조직 및 물성에 미치는 송급 가스의 영향)

  • Lee, Myeong-Ju;Kim, Hyung-Jun;Oh, Ik-Hyun;Lee, Kee-Ahn
    • Journal of Powder Materials
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    • v.20 no.1
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    • pp.24-32
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    • 2013
  • The effect of carrier gases (He, $N_2$) on the properties of Ti coating layers were investigated to manufacture high-density Ti coating layers. Cold spray coating layers manufactured using He gas had denser and more homogenous structures than those using $N_2$ gas. The He gas coating layers showed porosity value of 0.02% and hardness value of Hv 229.1, indicating more excellent properties than the porosity and hardness of $N_2$ gas coating layers. Bond strengths were examined, and coating layers manufactured using He recorded a value of 74.3 MPa; those manufactured using $N_2$ gas had a value of 64.6 MPa. The aforementioned results were associated with the fact that, when coating layers were manufactured using He gas, the powder could be easily deposited because of its high particle impact velocity. When Ti coating layers were manufactured by the cold spray process, He carrier gas was more suitable than $N_2$ gas for manufacturing excellent coating layers.

Controlled Charge Carrier Transport and Recombination for Efficient Electrophosphorescent OLED

  • Chin, Byung-Doo;Choi, Yu-Ri;Eo, Yong-Seok;Yu, Jai-Woong;Baek, Heume-Il;Lee, Chang-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1418-1420
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    • 2008
  • In this paper, the light emitting efficiency, spectrum, and the lifetime of the phosphorescent devices, whose emission characteristics are strongly dominated not only by the energy transfer but also by the charge carrier trapping induced by the emissive dopant, are explained by differences in the energy levels of the host, dopant, and nearby transport layers. On the basis of our finding on device performance and photocurrent measurement data by time-of-flight (TOF), we investigated the effect of the difference of carrier trapping dopant and properties of the host materials on the efficiency roll-off of phosphorescent organic light emitting diode (OLED), along with a physical interpretation and practical design scheme, such as a multiple host system, for improving the efficiency and lifetime of devices.

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An Improved Phase-Shifted Carrier Pulse Width Modulation Based on the Artificial Bee Colony Algorithm for Cascaded H-Bridge Multilevel Inverters

  • Cai, Xinjian;Wu, Zhenxing;Li, Quanfeng;Wang, Shuxiu
    • Journal of Power Electronics
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    • v.16 no.2
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    • pp.512-521
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    • 2016
  • Cascaded H-bridge multilevel (CHBML) inverters usually include a large number of isolated dc-voltage sources. Some faults in the dc-voltage sources result in unequal cell dc voltages. Unfortunately, the conventional phase-shifted carrier (PSC) PWM method that is widely used for CHBML inverters cannot eliminate low frequency sideband harmonics when the cell dc voltages are not equal. This paper analyzes the principle of sideband harmonic elimination, and proposes an improved PSCPWM that can eliminate low frequency sideband harmonics under the condition of unequal dc voltages. In order to calculate the carrier phases, it is necessary to solve transcendental equations for low frequency sideband harmonic elimination. Therefore, an approach based on the artificial bee colony (ABC) algorithm is presented in this paper. The proposed PSCPWM method enhances the reliability of CHBML inverters. The proposed PSCPWM is not limited to CHBML inverters. It can also be applied to other types of multilevel inverters. Simulation and experimental result obtained from a prototype CHBML inverter verify the theoretical analysis and the achievements made in this paper.

A STUDY ON THE PREVALENCE AND INTRA-ORAL DISTRIBUTION OF CANDIDA ALBICANS (캔디다 알비칸스의 구강내 빈도 및 분포도에 관한 연구)

  • Lee, Cheol-Gyu;Kim, Chang-Whe
    • The Journal of Korean Academy of Prosthodontics
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    • v.24 no.1
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    • pp.91-103
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    • 1986
  • Using imprint cultures and epithelial smears, the density and prevalence of colonization of oral mucosal sites and denture surfaces by Candida albicans has been determined in 28 healthy dentate subjects and 20 denture wearers. With questionnaire, oral and denture examination, the relationship between the carrier rates and several factors; DMFT, oral hygiene index, salivary pH & denture plaque score were studied. But these factors have not significant relationship to the carrier rates. Imprint culture appears to be sensitive technique for detecting candidal carriers and be useful for distinguishing between the healthy carrier state and candidal infection. Cigarette smokers had a significantly increased carrier state (P<0.05) compared with nonsmoker in male dentate subjects. Female were more frequent carriers than male in dentate and denture group, but these differences were not significant. In denture wearers, there was a higher density and frequency of candidal colonization of all mucosal sites sampled, compared with that of healthy dentate group especially anterior palate and posterior palate showed highly significant differences in frequency of candidal colonization (P<0.05). The distribution of Candida albicans is not uniform throughout the mouth. The tongue in the healthy dentate subjects and the impression surfaces of upper dentures are the primary oral reservoirs for the fungus. Overnight wearing of dentures was associated with increased density and frequency of candidal colonization and density.

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Precise attitude determination using GPS carrier phase measurements (GPS 반송파 위상을 이용한 정밀 자세 측정)

  • Park, Chan-Sik;Lee, Jang-Gyu;Jee, Gyu-In;Lee, Young-Jae
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.6
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    • pp.602-612
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    • 1997
  • With GPS carrier phase measurements from more than two antenna which attached to the vehicle, precise attitude can be easily obtained if the integer ambiguity included in carrier phase measurement is resolved. Recently some special products which use dual frequencies or has one receiver engine with multiple antenna are announced. But there are still strong requirements for the conventional single frequency off-the-shelf receiver. To meet these requirements, an efficient integer ambiguity resolution technique is indispensable. In this paper, a new technique to resolve integer imbiguity with single frequency receivers is proposed. The proposed method utilize the known baseline length as a constraint of independent elements of integer ambiguities. With this constraints, the size of search volume can be greatly reduced. Thus the true integer ambiguity can be easily determined with less computational burden and number of measurements. The proposed method is applied to real data to show its effectiveness.

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Three-Temperature Modeling of Carrier-Phonon Interactions in Thin GaAs Film Structures Irradiated by Picosecond Pulse Lasers

  • Lee Seong-Hyuk;Lee Jung-Hee;Kang Kwan-Gu;Lee Joon-Sik
    • Journal of Mechanical Science and Technology
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    • v.20 no.8
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    • pp.1292-1301
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    • 2006
  • This article investigates numerically the carrier-phonon interactions in thin gallium arsenide (GaAs) film structures irradiated by subpicosecond laser pulses to figure out the role of several recombination processes on the energy transport during laser pulses and to examine the effects of laser fluences and pulses on non-equilibrium energy transfer characteristics in thin film structures. The self-consistent hydrodynamic equations derived from the Boltzmann transport equations are established for carriers and two different types of phonons, i.e., acoustic phonons and longitudinal optical (LO) phonons. From the results, it is found that the two-peak structure of carrier temperatures depends mainly on the pulse durations, laser fluences, and nonradiative recombination processes, two different phonons are in nonequilibrium state within such lagging times, and this lagging effect can be neglected for longer pulses. Finally, at the initial stage of laser irradiation, SRH recombination rates increases sufficiently because the abrupt increase in carrier number density no longer permits Auger recombination to be activated. For thin GaAs film structures, it is thus seen that Auger recombination is negligible even at high temperature during laser irradiation.

Effect of Ce0.9Gd0.1O1.95 as a promoter upon the oxygen transfer properties of MgMnO3-δ-Ce0.9Gd0.1O1.95 composite oxygen carrier materials for chemical looping combustion

  • Hwang, Jong Ha;Lee, Ki-Tae
    • Journal of Ceramic Processing Research
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    • v.20 no.1
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    • pp.18-23
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    • 2019
  • Chemical looping combustion (CLC) is a promising carbon capture and storage (CCS) technology whose efficiency and cost primarily relies on the oxygen carrier materials used. In this paper, gadolinium-doped ceria (GDC, Ce0.9Gd0.1O1.95) was added as a promoter to improve the oxygen transfer rate of MgMnO3-δ oxygen carrier materials. Increasing GDC content significantly increased the oxygen transfer rate of MgMnO3-δ-GDC composites for the reduction reaction due to an increase in the surface adsorption of CH4 via oxygen vacancies formed on the surface of the GDC. On the other hand, the oxygen transfer rate for the oxidation reaction decreased linearly with increasing GDC content due to the oxygen storage ability of GDC. Adsorbed oxygen molecules preferentially insert themselves into oxygen vacancies of the GDC lattice rather than reacting with (Mg,Mn)O to form MgMnO3-δ during the oxidation reaction.

Effect of Reduction Temperature on the Microstructure and Thermoelectric Properties of TAGS-85 Compounds

  • Madavali, Babu;Han, Seung-Tek;Shin, Dong-Won;Hong, Soon-Jik;Lee, Kap-Ho
    • Korean Journal of Materials Research
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    • v.27 no.8
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    • pp.438-444
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    • 2017
  • In this work, the effects of hydrogen reduction on the microstructure and thermoelectric properties of $(GeTe)_{0.85}(AgSbTe_2)_{0.15}$ (TAGS-85) were studied by a combination of gas atomization and spark plasma sintering. The crystal structure and microstructure of TAGS-85 were characterized by X-ray diffraction(XRD) and scanning electron microscopy (SEM). The oxygen content of both powders and bulk samples were found to decrease with increasing reduction temperature. The grain size gradually increased with increasing reduction temperature due to adhesion of fine grains in a temperature range of 350 to $450^{\circ}C$. The electrical resistivity was found to increase with reduction temperature due to a decrease in carrier concentration. The Seebeck coefficient decreased with increasing reduction temperature and was in good agreement with the carrier concentration and carrier mobility. The maximum power factor, $3.3{\times}10^{-3}W/mK^2$, was measured for the non-reduction bulk TAGS-85 at $450^{\circ}C$.

Characteristic as a Gene Delivery System of Water Soluble Chitosan Conjugated with Cationic Peptide (양이온 펩타이드가 컨쥬게이트된 수용성 키토산의 유전자 전달체로서의 특성)

  • Kim, Young-Min;Kim, Ji-Ho;Park, Seong-Cheol;Park, Yung-Hoon;Jang, Mi-Kyeong
    • KSBB Journal
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    • v.31 no.4
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    • pp.300-311
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    • 2016
  • Recently gene delivery has been designed newly using bioactive biomaterial and applied in the various field by many researchers. In this study, we proposed a new gene delivery system which has the capability of targeting effect in the specific tissue and remarkably enhanced transfection efficiency. We investigated $^1H-NMR$ spectroscopy, particle size analyzer and gel retardation to confirm the correct preparation of gene delivery. Also, we identified the hemo-compatibility of gene delivery by hemolysis assay, non-cytotoxicity by MTT test and transfection efficiency. The uptake mechanism of the gene carrier was confirmed using inhibitor agent such as sodium azide, indomethacin, quercetin, colchicine, and chloropromazine. As a results, it was identified that gene carrier prepared by in this study entered in the cell by the microtubule-dependent, energy-dependent and clathrin-mediated endocytosis pathway.