• Title/Summary/Keyword: fundamental relation

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A Study on the Fundamental Surge Frequencies in Multi-Stage Axial Flow Compressor Systems

  • Yamaguchi, Nobuyuki
    • International Journal of Fluid Machinery and Systems
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    • v.7 no.4
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    • pp.160-173
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    • 2014
  • Surge phenomena in multi-stage axial flow compressors were studied with attention to the frequency behaviors. A new parameter "volume-modified reduced surge frequency" was introduced, which took into consideration the essential surge process, i.e., emptying and filling of the working gas in the delivery plenum. The behaviors of the relative surge frequencies at the stall stagnation boundaries, compared with the corresponding duct resonance frequencies, have demonstrated the existence of two types of surges; i.e., a near-resonant surge and a subharmonic surge. The former, which has fundamentally a near-resonance frequency, occurs predominantly at the stall stagnation boundary for the short -and-fat plenum delivery flow-path and the long-and-narrow delivery duct flow-path, and possibly in the intermediate conditions. The latter, which has a subharmonic frequency of the fundamental near-resonant one and occurs mainly in the intermediate zone, is considered to be caused by the reduced frequency restricted to a limited range. In relation with those dimensionless frequencies at the stall stagnation boundary, the surge frequency behaviors in more general situations away from the boundaries could be estimated, though very roughly.

Identification of the Properties of Soils and Defect Detection of Buried Pipes Using Torsional Guided Waves (비틀림 유도파를 이용한 토양 특성 규명 및 지하매설 배관 결함 검출)

  • Park, Kyung-Jo;Kim, Chung-Yup
    • Journal of Power System Engineering
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    • v.17 no.2
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    • pp.56-62
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    • 2013
  • A technique is presented that uses a circular waveguide for the measurement of the bulk shear (S-wave) velocities of unconsolidated, saturated media, with particular application to near surface soils. The technique requires the measurement of the attenuation characteristics of the fundamental torsional mode that propagate along an embedded pipe, from which the acoustic properties of the surrounding medium are inferred. From the dispersion curve analysis, the feasibility of using fundamental torsional mode which is non-dispersive and have constant attenuation over all frequency range is discussed. The principles behind the technique are discussed and the results of an experimental laboratory validation are presented. The experimental data are best fitted for the different depths of wetted sand and the shear velocities are evaluated as a function of depths. Also the characteristics of the reflected signal from the defects are examined and the reflection coefficients are calculated for identifying the relation between defect sizes and the magnitude of the reflected signal.

The Exchange of Reduced Sulfur Gases Across the Atmosphere-Teerrestrial Biosphere Interface

  • Kim, Ki-Hyun;Zhen Yand;Shiming Wang
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.E
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    • pp.1-18
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    • 1996
  • In this review, the significance of terrestrial ecosystems in the global sulfur budget has been reviewed based on the currently available databases covering the topic. In the section 1, we describe our current understanding of natural sulfur cycle in relation to most well-known natural reservoir, oceanic environment. The sections 2 and 3 provide the fundamental pictures of the rerrestrial sulfur cycle with respect to the relative importance of its individe the fundamental pictures of the terrestrial sulfur cycle with respect to the section 3, previously reported flux values for several major sulfur gases are presented for each reservoir and are intercompared to derive representative fluxes for the respective environment. In the section 4, source mechanisms for volatile sulfur species are dealt for both microscale and macroscale processes leading to their productions. In the section 5, environmental factors controlling the exchange of biogenic sulfur gases across the air-surface have been discussed. In the section 6, environmental fate of sulfur gases released into the atmosphere has been described. Finally in tie section 7, as concluding remarksm we discuss directions and suggestions to overcome various limitations encountered from previous measurement investigations of natural sulfur cycle in diverse natural ecological systems.

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A Study on the Effective Construction and Use of Cadastral Information Database (지적정보데이터베이스의 효율적 구축과 활용에 관한 연구)

  • Kang, Joon-Mook;Lee, Hyung-Seok
    • Journal of Korean Society for Geospatial Information Science
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    • v.8 no.2 s.16
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    • pp.71-78
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    • 2000
  • In these days, the attributes data recorded in computerization of cadastral maps is just written in its own format, not considered the relation with graphic data. Therefore, digital information linked attribute data to graphic data is necessary to be performed as fundamental data of graphic information and analysis of various spatial information. This study is to present the possibility of GIS application by constructing cadastral information related to graphic and attribute Information based on the cadastral map. Attribute information was constructed as a relational database form using data modeling and entity-relationship diagram. Thus, this study is expected to be used as a fundamental data for various public planning and design including the effective management of cadastral information and building parcel based land information system by presenting various spatial analysis and application methods.

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The Rules of Law on Passing of Risk in Contracts for the International Sale of Goods (국제물품매매계약에서 위험이전에 관한 법리)

  • Hong, Sung Kyu
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.64
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    • pp.3-37
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    • 2014
  • The purpose of this paper is to examine thoroughly on passing of risk in contracts for the international sale of goods. Articles 66~70 of the CISG contain provisions on passing of risk. Article 66 states the main effect of passing risk to the buyer. Article 67~69 determine the decisive point in time which the risk passes from the seller to the buyer and article 70 attempts to explain the relation between passing of risk and fundamental breach of contract by the seller. As in the case corresponding Incoterms rules, the main issue to be resolved is which party should bear the economic consequences in the event that the goods are accidentally lost, damages or destroyed. Many cases also apply CISG articles 66~70 to contracts in which parties not agree on the use of trade terms such as CIF, CFR, FOB and FCA in Incoterms[R] 2010 Rule that provide for when the risk passes. In order to minimize disputes that may arise under contract, when drawing up a contracts for the international sale of goods, the specifics of agreement should be clearly stipulated. Consequently, the parties of contracts for the international sale of goods should take adequate measures, and it is required to prepare the contracts clearly as the specific terms to prevent and resolve contractual disputes on passing of risk.

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Embodiment of living body measure system modelling for rehalibitation treatment of positive simulation for HRV algorithm analysis interface of Mobile base (모바일기반의 HRV 인터페이스에 처리에 대한 생체계측 시스템 모델링의 구현)

  • Kim, Whi-Young
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.1013-1014
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    • 2006
  • Mobilecomputer offers more fundamental role than role assistance enemy of modern technology equipment and new Information Technology can reconsider, and reconstruct creatively accuracy of physiological concept. That military register symptoms are developed of disease, before far before rehalibitation, offer possibility that can intervene in process that motive change of military register symptoms after rehalibitation. But, that many parameters become analysis target and mathematical settlement and equalization system of neted data of that is huge, same time collection of all datas can lift difficulty etc.. These main weakness puts in structural relation between elements that compose system. Therefore, dynamics research that time urea of systematic adjustment has selected method code Tuesday nerve dynamics enemy who groping of approach that become analysis point is proper and do with recycling bioelectricity signal. Nature model of do living body signal digital analysis chapter as research result could be developed and scientific foundation groping could apply HSS (Hardware-software system) by rehalibitation purpose. Special quality that is done radish form Tuesday of bioelectricity signal formation furthermore studied, and by the result, fundamental process of bodysignal in do structure circuit form of analog - digital water supply height modelling do can

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Relationship among Essentials of Fundamental Nursing Skills Performance, Stress from Work and Work Capability of New Clinical Nurses (신규간호사의 핵심기본간호술 수행과 업무스트레스 및 업무수행능력과의 관계)

  • Bang, Soon Sik;Kim, Il-Ok
    • The Journal of Korean Academic Society of Nursing Education
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    • v.20 no.4
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    • pp.628-638
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    • 2014
  • Purpose: This study identifies the relation among the essentials of fundamental nursing skills performance (EFNSP), work capability and stress from work experienced by new clinical nurses. Method: This is a cross-sectional descriptive study with a self-reported questionnaire. The subjects were 224 new clinical nurses employed by general hospitals having more than 400 beds. The data, collected from February 10 to March 7, 2014, were analyzed using descriptive statistics, t-tests, ANCOVA, Pearson's correlation analysis and hierarchical linear regression. Results: The highest frequency of EFNSP of new clinical nurses was vital sign measurement (4.74, ${\pm}.89$) and the lowest frequency of performance was Basic CPR & defibrillator application (1.81, ${\pm}.94$). There were significant positive correlations between frequency and confidence of EFNSP (r=.64, p<.001), frequency and work capability (r=.34, p<.001), and confidence of EFNSP and work capability (r=.48, p<.001), but negative correlation stress from work and work capability (r=-.17, p=.009). General characteristics, stress from work, frequency and confidence in EFNSP and stress from work explain 25.1% of work capability. Conclusion: This result suggests the importance of EFNSP education in nursing schools and availability of opportunities to practice EFNSP during the post-graduation waiting period until assignment to a hospital.

Morphological classification of the moderator band and its relationship with the anterior papillary muscle

  • Lee, Ju-Young;Hur, Mi-Sun
    • Anatomy and Cell Biology
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    • v.52 no.1
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    • pp.38-42
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    • 2019
  • This study investigated and classified the various types of moderator band (MB) in relation to the anterior papillary muscle, with the aim of providing anatomical reference information and fundamental knowledge for use when repairing the congenital defects and understanding the conduction system. The study investigated 38 formalin-fixed human hearts of both sexes obtained from donors aged 38-90 years. The MB was evident in 36 of the 38 specimens (94.7%). The morphology of the MB and its connection with the APM took various forms. The MBs that had a distinct shape were classified into three types according to their shape: cylindrical column, long and thin column, and wide and flat column. Types 2 and 3 were the most common, appearing in 15 (41.7%) and 14 (38.9%) of the 36 specimens, respectively, while type 1 was observed in seven specimens (19.4%). Type 3 was divided into subtypes based on their length. The MB usually originated from a single root (91.7%), with the remainder exhibiting double roots. The pairs of roots in the latter cases had different shapes. The originating point of the MB ranged from the supraventricular crest to the apex of the ventricle. The most-common originating point was in the middle (25 of 36 specimens, 69.4%), followed by the upper third (13.9%), the lower third (11.1%), and the top fifth (5.6%) of the interventricular septum. This study has produced fundamental anatomical and clinical information that will be useful when designing cardiac surgical procedures.

A Study on Buyer's Obligation in Relation to the Letter of Credit in a Sales Contract

  • Eun-Hee JANG;Joon-Pyo LEE;Ki-Moon HAN
    • Journal of Distribution Science
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    • v.21 no.9
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    • pp.115-121
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    • 2023
  • Purpose: This study aimed to deal with disputes between the seller and the buyer in connection with the Letter of Credit (LC) in a sales contract. The Contracts for the International Sale of Goods (CISG) provides the rules on the fundamental breaches which can lead to termination of the sales contract but the CISG is not enough to govern issues arising from the LC disputes when the sales contract is not clear about the payment terms. This paper tried to find some solutions to the disputes by considering international rules, such as the Principles of European Contract Law (PECL). Research design, data and methodology: The methodology applied in this study was an analysis of some court decisions and extended literature review. Results: The study revealed that in contracts for the sale of international goods, the buyer was obliged to open an LC as manner of payment. If the buyer failed to open an LC or amend the terms of the LC, the seller could avoid the contract because this could deprive the seller's expected interest. Conclusions: Few studies in Korea have been comprehensively analyzed in terms of the obligations of regarding the LC with respect to the CISG in court cases. This study suggests safeguarding the buyer and seller when the LC is considered absolute or conditional.

Dislocation-oxide interaction in Y2O3 embedded Fe: A molecular dynamics simulation study

  • Azeem, M. Mustafa;Wang, Qingyu;Li, Zhongyu;Zhang, Yue
    • Nuclear Engineering and Technology
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    • v.52 no.2
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    • pp.337-343
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    • 2020
  • Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. It was found that higher shear deformation rates produce more fine-tuned stress-strain curve. Both molecular dynamics (MD) simulations and BKS (Bacon-Knocks-Scattergood) model display similar characteristics whereby establishing an inverse relation between the depinning stress and the obstacle distance. It was found that (110)oxide || (111)Fe (oriented oxide) also had similar characteristics as that of (100)oxide || (111)Fe but resulted in an increased depinning stress thereby providing greater resistance to dislocation bypass. Our simulation results concluded that critical depinning stress depends significantly on the size and orientation of the oxide.