• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.487-492
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• 2007

The enhancement of the service life of damaged or cracked structures is a major issue for researchers and engineers. The hierarchical void element with the integrals of Legend polynomials is used to characterize the fracture behavior of unpatched crack as well as repaired crack with bonded composite patches by computing the stress intensity factors and stress contours at the crack tip. The numerical approach is based on the v-version degenerate shell element including the theory of anisotropic laminated composites. Since the equivalent single layer approach is adopted in this study, the proposed element is necessary to represent a discontinuous crack part as a continuum body with zero stiffness of materials. Thus the aspect ratio of this element to represent the crack should be extremely slender. The sensitivity of numerical solution with respect to energy release rate, displacement and stress has been tested to show the robustness of hierarchical void element as the aspect ratio is increased up to 2000. The stiffness derivative method and displacement extrapolation method have been applied to calculate the stress intensity factors of Mode I problem.

• 한국항해항만학회지
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• 제33권5호
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• pp.309-314
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• 2009

Manta형 무인잠수정(MUUTV)을 대상으로 회류수조에서의 모형실험을 통해 동일한 동체 모형에 대해 형상이 서로 다른 부가물을 부착했을 때의 동유체력 특성을 실험적으로 검토하였으며, 동유체력 측정 결과를 이론계산치와 비교하였다. 아울러 이를 바탕으로 운동안정성을 검토하여 최적의 부가물 형상 결정의 이론적 근거를 확립하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.5-6
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• 2009

Manta형 무인잠수정(MUUTV)을 대상으로 회류수조에서의 모형실험을 통해 동일한 동체 모형에 대해 형상이 서로 다른 부가물을 부착했을 때의 동유체력 특성을 실험적으로 검토하였으며, 동유체력 측정 결과를 이론계산치와 비교하였다. 아울러 이를 바탕으로 운동안정성을 검토하여 최적의 부가물 형상 결정의 이론적 근거를 확립하였다.

• 한국정밀공학회지
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• 제33권9호
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• pp.707-714
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• 2016

This paper describes analysis results of vibration characteristics and modal test for a small-scale quad-rotor drone. The rotor arm has a slender body with a propeller and motor at its tip. Rotor system generates excitation for an unbalanced mass. Therefore, the drone platform is involved in the possibility of resonance. For advance identification of the possibility of resonance, confirmation of eigen-mode being closest to the propeller operation range is necessary. Material properties of CFRP tubes used for the rotor arm were acquired by finding the natural frequency based on Rayleigh method. A simplified quad-rotor FE model consisting of rotor arm assembly with tip mass was built to perform numerical analysis, and a free-free boundary condition was applied to provide flight status. Modal tests for the actual platform with impact hammer instrument were performed to verify analysis results. Separation margin from hazardous eigen-mode was checked on the propeller operation range.

• 한국소음진동공학회논문집
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• 제20권3호
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• pp.215-222
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• 2010

Long and slender body, like a fuel rod, oscillating in axial flow can be unstabilized even by the small cross flow which can be activated by the flow mixer or turbulent generator. It is important to include these effects of flow disturbance in dynamic stability analysis of nuclear fuel rod. This work shows how eigen frequency of a multi-span fuel rod can be changed by the swirl flow, which is discretely generated by a flow mixer. By solving a state-space form of the eigenvalue equation for a multi-span fuel rod system, the critical velocity at which a fuel rod becomes unstable was calculated. Based on the simulation results, we evaluated how stability of a multi-spanned nuclear fuel rod with mixing vanes can be affected by the coolant flow in an operating reactor core.

• Ocean Systems Engineering
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• 제9권1호
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• pp.21-42
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• 2019

In this paper, the Finite-Analytic Navier-Stokes (FANS) code is coupled with an in-house finite-element code to study the dynamic interaction between a floating buoy and its mooring system. Hydrodynamic loads on the buoy are predicted with the FANS module, in which Large Eddy Simulation (LES) is used as the turbulence model. The mooring lines are modeled based on a slender body theory. Their dynamic responses are simulated with a nonlinear finite element module, MOORING3D. The two modules are coupled by transferring the forces and displacements of the buoy and its mooring system at their connections through an interface module. A free-decay model test was used to calibrate the coupled method. In addition, to investigate the capability of the present coupled method, numerical simulations of two degree-of-freedom vortex-induced motion of a CALM buoy in uniform currents were performed. With the study it can be verified that accurate predictions of the motion responses and tension responses of the CALM buoy system can be made with the coupling CFD-FEM method.

• Parasites, Hosts and Diseases
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• 제60권6호
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• pp.419-421
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• 2022

To improve our understanding of the migration of sparganum in humans, we report a case of ocular sparganosis having the migratory episode from the muscle cone to the subconjunctiva. A 34-year-old woman was admitted to the Hospital of Anhui Medical University (Hefei, China), in December 2019. She presented with conjunctival hemorrhage and recurrent pain in the left eye. A foreign body was found in the muscle cone of the eye. Two months later, a ribbon-like white material was found under the conjunctiva on slit-lamp examination. A long and slender, actively moving parasite was extracted by surgery. The extracted worm was approximately 8 cm long and 2 mm wide. The worm was whitish, wrinkled, ribbon shaped, and had a slightly enlarged scolex. The worm sample was morphologically identified as a plerocercoid larva (sparganum) of the Spirometra tapeworm. Her conjunctival blood suffusion and eye pain ceased within 1 week after operation. She has been in good health without any symptoms during the 2-year follow-up. A case of ocular sparganosis, in which larval worm migrated from the muscle cone to the subconjunctiva is reported from China.

• 한국의류학회지
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• 제31권2호
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• pp.177-188
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• 2007

The purpose of this study was to provide basic materials for the brief patterns and design development for the elderly women to select number 1 to 3 brands according to their brand preference surveying the elderly women with average shapes, and to compare and analyze the exterior fit and functionality. Accordingly, this study proposed basic materials needed for panty pattern suitable for average shapes of the elderly women. The results of the study are as follows: 1 . Looking into the style, they preferred white the best. Regarding the patterns, almost half preferred patterns and rest of them did not. With the panty with patterns, they wanted small and implicit flower patterns. The design they liked was midi, maxi and then mini in order. When looking into the brands, they preferred 'Company B', 'Company SS', 'Company SY', and then market products. The reason why they selected those panty was feeling of fitness, price and then material. 2. To classify the figures of elderly women, we grouped the subjects with strata method using minimal dispersion method. Type 1 is the average, type 2 is for obese women and type 3 is slender women. 3. 3 brands were selected that were produced using CM 40's and elderly women preferred best. When executing wearing test on two elderly women who have average figure according to the body measures in previous study and body measure of Size Korea total exterior evaluation score was Company A, B and C in order.

• 한국어류학회지
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• 제11권1호
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• pp.1-11
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• 1999

한국산 모래주사속(Genus Microphysogobio)5종 배가사리 M. longidorsalis, 됭경모치 M. jeoni, 모래주사 M. koreensis, 돌마자 M. yaluensis, 여울마자 M. rapidus를 분류학적으로 재검토하여 검색표와 그림을 제시하고 지리적 변이에 대하여 논의하였다. 그 가운데 됭경모치의 학명은 지금까지 Microphysogobio sp. Uchida, 1939와 M. tungtingensis uchidai Banarescu and Nalbant, 1973로 사용되어 왔으나, 본 조사에서 M. t. uchidai는 모식표본의 확인결과 M. yaluensis의 동종이명임이 확인되었다. 그리고 됭경모치는 중국산 M. tungtingensis나 M. linghensis와 아주 비슷하지만 등지느러미 기점이 훨씬 뒤에 있고, 상순 유두돌기가 민틋하며, 흉복부에 비늘이 배열되어 있어 이들과는 잘 구별되므로 별종인 M. jeoni로 기재하였다. 우리나라에 널리 분포하는 돌마자는 측선비늘수와 척추골수에 있어서 clinal variation을 보여주어 지리적으로 주목되었다. 됭경모치는 상순유두돌기와 흉부비늘의 배열상태가 집단간에 약간의 변이를 보였다. 돌마자와 됭경모치는 비교적 널리 분포하나 배가사리는 서한아지역에만 출현하고 모래주사와 여울마자는 남한아지역에만 제한 분포한다.

• Parasites, Hosts and Diseases
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• 제55권1호
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• pp.39-45
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• 2017

The present study was performed to reveal the morphological characteristics and molecular phylogenetic position of Platynosomum fastosum Kossack, 1910. A total 167 specimens of P. fastosum were collected in 8 (4.9%) out of 163 sets of gall-bladders and bile ducts of cats. The number of worms was 1-105 per infected cat. This species was characterized by having a long and slender body, slightly larger ventral sucker than the oral sucker, indistinct prepharynx, small pharynx, short esophagus, bifurcation midway between 2 suckers, and ceca extending to the posterior end of the body. The length of the partial sequences of ITS1 and 5.8S rDNA of P. fastosum were 990 bp, GC-rich. AT/GC ratio was 0.9, there were 9 polymorphic sites, and intraspecific variations ranged from 0.1% to 0.9%. Phylogenetic analyses by neighbor-joining phylogram inferred from ITS1 rDNA sequences revealed that the genetic distance between P. fastosum specimens ranged from 0.3 to 1.5% while the smallest interspecific distance among dicrocoeliid species was 20.9 %. The redescription and genetic characters of P. fastosum are taxonomically important to recognize future different species of the genus Platynosomum showing high intraspecific and morphological variability.