• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.2
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• pp.310-323
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• 1990

A three-noded, with three degree-of-freedom at each node, in-plane curved beam element is formulated and employed in eigen-analysis of constant curvature beam. The conventional quadratic shape functions used in a three noded C .deg. type curved beam element produce such an undesirable large stiffness that a significant error is introduced in displacements and stresses. These phenomena are called 'Stiffness Locking Phenomena', which result from spurious strain energy due to inappropriate assumptions on independent isoparametric quadratic interpolation functions. Stiffness locking phenomena can be alleviated by using modified interpolation functions which get rid of spurious constraints of conventional interpolation functions. Eigenvalues and their modes as well as displacements and stresses may be locked because they are related to stiffness. Using modified curved beam element in eigenvalue problem of cantilever and arch, the property and performance of modified curved beam element are examined by numerical experimentations. In these eigen-analyses, mass matrices are calculated by using both modified and unmodified curved beam element, are compared with theoretical solutions. These comparisons show that the performance of the modified curved beam element is better than that of the unmodified curved beam element.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.112-126
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• 1993

In this paper, unified requirements of IACS on longitudinal strength of ships are investigated using nonlinear wave loads analyses under short term irregular waves. Also, analyses on IACS wave data were carried out for the purpose of presenting the guideline for future use. While keeping theoretical consistensy, the rule requirements for horizontal shear force, bending moment and torsional moment are newly proposed for the ships of large deck openings bases on the calculation results for 17 sample ships. The requirements for side shell hydrodynamic pressure are also presented. All the calculated results are compared with other Societies and present KR rules. These formula will be checked when corresponding requirements of structural scantling are determined.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1129-1137
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• 2007

50kg NSI PCT(Prestress Concrete Timber, sleeper) is developed for the purpose of low maintenance cost, Extend life cycle, Track stability, Friendly Environment, Good running quality. In this study, as a part of research which is to make renovated NSI turnout, the main objective of this study is the optimization of PC sleeper's section, the number of PS tension wire. For this purpose, the finite element analysis was conducted to evaluate the serviceability and the safety of NSI PC sleeper developed.

• Clinics in Shoulder and Elbow
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• v.11 no.1
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• pp.62-65
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• 2008

Isolated acromial fracture is not common and it frequently accompanies fractures to the coracoid process and glenoid bone and also injuries to the acromioclavicular joint. Furthermore, most of these combined acromial fractures have minimal displacement, which needs no additional treatment other than protection for a certain period of time. We have experienced a case of isolated fracture of the posterolateral angle of the acromion, which we reduced and fixated using K-wire and cannulated screws. We report on the technical aspects and clinical results of this reduction and fixation, along with a review of the literature.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.602-605
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• 2003

통신업계의 사업자간 성과를 평가할 때 흔히 사용되는 지표가 ARPU(Average revenue per user) 이다. ARPU란 가입자당 수익으로 사업자의 총 수익을 가입자 수로 나누어 산출된다. 그러나 최근 통신 선진국 등지에서 ARPU적용의 문제점들을 제시하면서 새로운 지표인 AMPU(Average margin per user)를 사용하자는 주장이 일고 있다. AMPU란 가입자당 이익으로 사업자의 순이익을 가입자 수로 나누어 산출된 수치를 말한다. ARPU는 그 산정 메카니즘 상 변수인 수익과 가입자수에 대한 통일된 개념정립이 없으므로 사업자마다 각기 다른 회계처리를 할 수 있다. 특히 수익의 경우는 단말기 매출의 포함여부와 CP들에게 지불될 제3자수익에 대한 처리에 따라 수익수준이 달라지게 되며, 가입자수의 경우 가입자에 대한 정의가 명확하지 않기 때문에 실제 서비스를 이용하고 있지 않은 inactive가입자들의 포함여부에 따라 ARPU수치에 영향을 주게 된다. 따라서 사업자간 일률적이지 않은 회계처리에 따른 ARPU수치를 비교하는 것은 의미 없는 일이 될 수 있고 궁극적으로 이해 관계자들의 의사결정을 왜곡시킬 수 있는 요인이 된다. 따라서 수익과 비용을 모두 고려하는 개념인 AMPU의 사용은 ARPU로 인한 문제점을 해소시킬 수 있을 것이다. 따라서 보다 정확하고 비교가능한 정보를 제공하기 위해서는 통신산업의 사업자들과 이해관계자들이 AMPU지표의 공시에 협조해야 하며, 근본적으로 공시되는 수익이나 가입자수에 대한 개념의 정립이 시급할 것이다.

• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.91-94
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• 2009

Metatarsal head and neck fractures are injuries that often result from a direct blow of a heavy objects to the metatarsal head. The head is often impacted or displaced to the plantar aspect that if not treated may cause malunion which later induces painful plantar calluses. If the fracture fragment is large enough, closed reduction may be successfully performed, but when the fragment is small or closed reduction is unsuccessful, open reduction is needed. We present our reduction and fixation technique for the metatarsal head and neck fractures using antegrade intramedullary Kirschner wire (K-wire) without opening the fracture site or infringing the metatarsophalangeal (MTP) joint which allows immediate motion of the joint and partial weight bearing in a stiff soled shoe.

• Journal of the Korean Society of Combustion
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• v.5 no.1
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• pp.43-53
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• 2000

Experimental studies on determination of the supply leading time of propellants to combustion chamber have been made to stably and efficiently guarantee the ignition process with liquid rocket engine. The propellant used is a Jet A-1 as fuel and a liquid oxygen as oxidizer. Unlike impinging FOOF type of injectors are arranged radially and the designed O/F ratio is 2.34. The present experiment program also includes the stability on the quadlet type of ignitor using the triethylalumimum as an ignition source and injector life tests. Experimental results clarifies that the propellant supply through LOx leading to combustion chamber is proper for stable ignition and combustion processes based on the fuel and oxidizer manifold pressures, combustion chamber pressure, and the variation of flame length from the nozzle exit with lapse time, and shows that the leading supply time of propellants affects the engine performance little. The effect of positioning cooling holes is remarkable to protect the injector face.

• Clinics in Shoulder and Elbow
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• v.9 no.1
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• pp.124-129
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• 2006

Distal clavicular fracture frequently requires operative treatment due to high rate of non-union. The operative technique includes the tension band wiring, K- wire fixation, and cerclage wiring etc. Each method has disadvantages somewhat like pin migration or acromioclavicular joint injury and so on. For the distal clavicular fracture type 2a, because of its oblique fracture line, the cerclage wiring is suitable. We performed the cerclage wiring percutaneously under minimal incision without injury to periosteum for the patient who had the distal clavicular fracture type 2a, and the result was favorable.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.4
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• pp.378-384
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• 2011

During the flight test of KSLV-I, various sensors are installed in the launch pad and the flame deflector to measure the flame characteristics and their influences on the launch complex when a launch vehicle lifts off. Parameter Measurement System is responsible for acquiring the above flight test data. The measurement methodology such as the configuration of measurement system, sensor locations and data acquisition procedures are presented. And this paper compares and explains the characteristics of data sets measured during two flight tests.

• Journal of the Korean Society of Food Culture
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• v.30 no.3
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• pp.370-376
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• 2015

In this study, we compared the organoleptic and other qualities of fermented milk containing 10 or 15% purple carrot extract that had either been previously fermented with Aspergillus oryzae or not fermented. Fermentation characteristics, pH, chromaticity, viscosity, viable cell counts, and sensory evaluations were measured. The pH and acid values did not differ between purple carrot extract fermented with Aspergillus oryzae and non-fermented extract. Viable cell counts were significantly higher in 15% purple carrot extract fermented with Aspergillus oryzae compared to the control after fermentation. Regarding characteristic changes, purple carrot extract fermented with Aspergillus oryzae group showed a lower red value but higher yellow value compared with non-fermented purple carrot extract due to heat-sterilization. Both fermented and non-fermented extract groups showed significantly increased viscosity compared to control. In the sensory evaluation, 15% purple carrot extract fermented with Aspergillus oryzae showed the highest score. In conclusion, addition of 15% purple carrot extract fermented with Aspergillus oryzae resulted in a superior fermented milk product.