• Kyungpook Mathematical Journal
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• 제60권1호
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• pp.45-51
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• 2020

A module M is called FI-extending if every fully invariant submodule of M is essential in a direct summand of M. In this work, we define a module M to be generalized FI-extending (GFI-extending) if for any fully invariant submodule N of M, there exists a direct summand D of M such that N ≤ D and that D/N is singular. The classes of FI-extending modules and singular modules are properly contained in the class of GFI-extending modules. We first develop basic properties of this newly defined class of modules in the general module setting. Then, the GFI-extending property is shown to carry over to matrix rings. Finally, we show that the class of GFI-extending modules is closed under direct sums but not under direct summands. However, it is proved that direct summands are GFI-extending under certain restrictions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.1037-1041
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• 2005

It is well-known that the corrosive behavior of PMC (polymer matrix composite) structure is much better than the metal structure in the marine environment. The understanding of fracture behavior of PMC in the deep-sea environment is essential to expand its use in the marine industry. For a present study, fracture tests have been performed under four different pressure levels such as 0.1 MPa, 100 MPa, 200 MPa, and 270 MPa using the seawater-absorbed carbon/epoxy composite samples. Fracture toughness was determined from the work factor approach as a function of hydrostatic pressure. It was found that fracture behavior was a linear elastic for all pressure levels. The fracture toughness increased with increasing pressure.

• 소음진동
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• 제9권2호
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• pp.401-408
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• 1999

A method is presented for the vibration analysis of steam turbine-generator rotor system based on the component mode synthesis method. The motion of each component of the system is described by superposing constraint mode associated with boundary coordinates and constrained normal modes associated with internal coordinates. This method using real fixed-interface modes allows for significant reduction in system model size while retaining the essential dynamic characteristics of the lower modes. The capability of this method is demonstrated in the natural frequency and unbalance response analysis of the steam turbine-generator rotor system in which the dynamics of the pedestal is considered. The results by the present method are compared with finite element method and trnasfer matrix method in terms of the accuracy and computing time.

• 한국컴퓨터정보학회논문지
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• 제7권3호
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• pp.16-22
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• 2002

컴포넌트의 효율적인 검색은 컴포넌트에 기반한 소프트웨어 개발에 필수적이다. 패싯 방식은 컴포넌트 검색 방법의 하나로 많은 연구의 대상이다. 이 논문에서 여러 개의 패싯값에 대한 논리 부정 검색에 사용되는 가중치 신경 접속 행렬을 효율적으로 만드는 새로운 알고리즘을 제안한다. 이 알고리즘을 사용하여 연산에 드는 복잡도를 향상할 수 있다. 또한 여러 개의 서로 다른 패싯을 사용하는 경우 이에 대한 논리적인 검색이 가능하도록 새로운 연산 방법을 제안하다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권3호
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• pp.1-12
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• 2019

Plastics have become essential materials in human life for several decades. Meanwhile, the inadvertent spread of plastic debris from the use of many plastic products has raised global environmental concerns. The risk of microplastics in subsurface environment has received little attention because soil is considered to confine microplastics within the matrix. However, the concentration of microplastics in soil unavoidably increased as a result of an increase in plastic production and use. Based on lab experiments, several researches claimed that microplastics possibly penentrate soil layers. Recently, a few researches reported the occurrence of microplastics in groundwater. This study reviewed the recent reports of microplastic occurrences in soil and groundwater, and the modeling studies for simulating transport of microplastics. Additionally, the difficulties and limits in microplastics researches in soil and groundwater are discussed. Finally, several perspectives on microplastic studies in subsurface environment are suggested.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.133.1-133.1
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• 2003

Cathepsin K (CK) is a cysteine protease that plays a major and essential role in osteoclast-mediated degradation of collagen matrix of bone. Its tissue-limited distribution and pivotal contribution to bone resorption meet the requirements as the potential therapeutic target of the disease with excessive bone loss such as osteoporosis. In a search for potent CK inhibitors. we found OST-5440 that effectively inhibited bone resorption in vivo as well as in vitro. (omitted)

• 아태비즈니스연구
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• 제10권4호
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• pp.181-195
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• 2019

This study aims to investigate the influencing attributes on price fairness in the domain of fast food service context. As the research subject, this research selects McDonald's business because of its market share in the fast food market. Five attributes are examined to account for price fairness. The attributes are advertising attitude, employee service, waiting, convenience, and brand love. This study performed survey to collect the data. The survey participants are university students because they are essential market segment for fast food business. The number of observation is 299 for the data analysis. To analyze the data, this research used various statistical instruments (e.g., frequency analysis, mean and standard computation, exploratory factor analysis, reliability test, correlation matrix, and multiple regression analysis). Regarding the results, this research identified advertising attitude, employee service, and brand love are influential attributes to establish price fairness of university students. This research could inform the marketing director of food service business to understand university students target better.

• Coupled systems mechanics
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• 제11권2호
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• pp.133-149
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• 2022

The accurate prediction of elastoplasticity under prescribed workloads is essential in the optimization of engineering structures. Mechanical experiments are carried out with the goal of obtaining reliable sets of material parameters for a chosen constitutive law via inverse identification. In this work, two sample geometries made of high strength steel plates were evaluated to determine the optimal configuration for the identification of Ludwik's nonlinear isotropic hardening law. Finite element model updating(FEMU) was used to calibrate the material parameters. FEMU computes the parameter changes based on the Hessian matrix, and the sensitivity fields that report changes of computed fields with respect to material parameter changes. A sensitivity analysis was performed to determine the influence of the sample geometry on parameter identifiability. It was concluded that the sample with thinned gauge region with a large curvature radius provided more reliable material parameters.

• Archives of Plastic Surgery
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• 제50권4호
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• pp.331-334
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• 2023

Historically, the approach to any reconstructive challenge, whether intentionally or intuitively, can be seen to follow distinct guidelines that could aptly be called "reconstructive metaphors." These have been intended to inform us as to the "what, "when" and "where" this attempt can best be achieved. Yet the "how" or means to accomplish this goal, usually also intuitively well understood, in a similar vein can now be expressed to be within our "reconstructive toolbox." The latter will distinctly mirror our individuality and contain not only the various hardware that we deem essential, but also the means to access whatever technology we may be comfortable with. No toolbox, even if overflowing will ever be full, as potential options and the diversity they represent surely approaches infinity. But the truly excellent reconstructive surgeon will know when their toolbox is in any way lacking, and fears not remedying that deficiency even if the talents of another colleague must be sought, so as always to ensure that the patient will obtain the best appropriate treatment!

• 한국초전도ㆍ저온공학회논문지
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• 제10권1호
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• pp.32-36
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• 2008

An HTS conductor with parallel HTS tapes is essential for a large power HTS device to flow a large current. One of the most important factor for this conductor is a current distribution. Non-uniform current distribution in parallel tapes makes the critical current of the conductor low and the AC losses high. In this paper we proposed a non-contact method which measured each current in parallel tapes by using an array of Hall sensors. A matrix can be derived from this array for calibration. The current distributions of 4 and 6 parallel tapes were measured.