• 한국전산유체공학회지
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• 제17권2호
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• pp.42-52
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• 2012

Direct Numerical Simulation(DNS) of turbulent mass transfer in fully developed turbulent pipe flow has been performed to study the effect of wall boundary conditions on the concentration fields at $Re_{\tau}$=180 based on friction velocity and pipe radius. Fully developed turbulent pipe flows for Sc=0.71 are studied with two different wall boundary conditions, namely, constant mass flux and constant wall concentration. The mean concentration profiles and turbulent mass fluxes obtained from the present DNS are in good agreement with the previous numerical results currently available. To investigate the effects of wall boundary condition on the turbulent mass transfer, the mean concentration profile, root-mean-square of concentration fluctuation, turbulent mass fluxes and higher-order statistics(Skewness and Flatness factor) are compared for the two cases. Furthermore, the budgets of turbulent mass fluxes and concentration variance were computed and analyzed to elucidate the effects of wall boundary conditions on the turbulent mass transfer.

• 대한건축학회논문집:구조계
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• 제34권11호
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• pp.27-35
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• 2018

The purpose of this study is to examine the effects of boundary RC frame(composed of one tie-beam and two tie-columns) on seismic performance of unreinforced masonry walls to suggest alternative way for seismic design of unreinforced masonry wall structures. Two test specimens are prepared, one is a typical unreinforced masonry wall and another is alternative unreinforced masonry wall with additional boundary RC frame. The structural experiments were carried out to evaluate the difference of seismic resistance performance between two test specimens with or without the boundary RC frames. From the test results, it was found that the failure mode of unreinforced masonry wall fundamentally changed from 'brittle' to 'ductile' by the installing of boundary RC frames. And, the maximum load and energy dissipation capacity of the test specimen with boundary RC frame was increased about 1.6~1.7 and 2~3 times respectively compared with a typical unreinforced masonry wall specimen.

• 대한건축학회논문집:구조계
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• 제35권3호
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• pp.11-18
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• 2019

The purpose of this study was to estimate the resistance capacity of a traditional wooden house with shear walls made of wood panel. In order to achieve the purpose of the study, the load - displacement test was carried out and the resistance moment values of the shear walls were proposed. The shear walls were made by placing studs with a nominal dimension of $38mm{\times}89mm$ at intervals of 600 mm, and attaching 12 mm thick plywood with 8-d size pegs at intervals of 150 mm. The type of traditional building wall was classified and showed the moment resistance ability of each wall type. This value is expressed as a proportional value divided by the moment resisting capacity of the standard size shear walls not divided into the divided small frames. Although some frames have proportional values larger than 1.0 even though they have openings, most of them show values smaller than 1.0. Also, even without the openings, it showed a smaller value than 1, such as 0.84 and 0.67.

• Asian Pacific Journal of Cancer Prevention
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• 제17권10호
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• pp.4577-4581
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• 2016

Objective: The aim of this study was to assess thyroid function in breast cancer patients exposed to therapeutic external beam radiation. The focus was on possible progressive changes and any relationships between the incidence of primary hypothyroidism, the time required to become hypothyroid, and factors such as chemotherapy, hormonotherapy and immunotherapy. Materials and Methods: Seventy females undergoing 3D conformal and IMRT radiation therapy for breast cancers were enrolled in a non-randomized prospective study. The patients was divided into two groups: those after mastectomy or breast conserving surgery (BCS) were irradiated to a scar of the chest wall/breast and the ipsilateral supraclavicular and the axillary areas (supraclavicular radiotherapy group - SC-RT group - 32 patients) and the control group receiving adjuvant chest wall/breast RT only (BCT group - 38 patients).The total doses were 50.0 to 70 Gy in 5 to 7 weeks. The median follow-up term was 24 months (range, 1-40 months). Thyroid function was evaluated by measuring thyroid stimulating hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3) levels. The minimum, maximum and mean thyroid gland doses for 20 Gy (V20) were calculated for all patients. Results: Statistically significant results were obtained for the SC-RT group. Two yearsa fter the end of RT the chance of an event was increased in 6% of the population (p=0.009) in the SC-RT group. In the BCT group no significance was noted. No statistically significant differences were found for V20, chemio-, immunotherapy and hormonotherapy or Ki67 values (p=0.12). No significant results were obtained for development of hypothyroidism and clinical factors (age, thyroid volume, treatment modalities). Conclusion: Radiotherapy is associated with a higher incidence of thyroid toxicity in breast cancer patients. Routine thyroid function monitoring should be recommended in such cases.

• 수산해양교육연구
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• 제27권5호
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• pp.1334-1342
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• 2015

본 연구에서는 연어 오일의 미세캡슐화를 위해 다양한 피복물질을 사용해 보았다. 피복물질의 종류가 미세캡슐화 수율에 큰 영향을 미쳤으며, 피복물질로 사용한 MD/SC/WPI 혼합 처리구에서 수율이 82.55%로 가장 우수한 성능을 보였다. SEM 분석 결과 입자의 분포가 균일하고 섬유 표면의 질감이 매끄럽게 나타났으며, 저장성 실험결과 pH, 산가, 과산화물가에서 안정한 수치를 나타내었기에 제품화 시 유통기한 30일까지는 실온저장에서 안전할 것으로 사료된다. 또한 MD/SC/WPI를 이용하여 분말화 한 연어 오일은 유화안정성이 높고, 제품의 취급이 쉽게 이용 될 수 있을 것이다. 이에 본 연구에서의 캡슐화 방법이 연어 오일과 유사한 특성을 지닌 물질의 캡슐화에 응용 될 수 있을 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.812-818
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• 2009

This study evaluated the effects of live yeast and yeast cell-wall mannan-oligosaccharide supplementation onperformance and nutrient digestibility during early lactation in cows fed a diet based on a mixture of corn silage and alfalfa hay as forage sources. Eight multiparous Holstein dairy cows (average days in milk, 27${\pm}$6) were used in a replicated 4${\times}$4 Latin square design. Diets contained 45% forage and 55% concentrate on a dry matter (DM) basis and treatments were: i) basal diet without additive (Control), ii) basal diet with 32 g/d of mannan-oligosaccharides (MOS), iii) basal diet with $1.2{\times}10^{10}$ colony forming units per day (cfu/d) of live yeast (Saccharomyces cerevisiae CNCM 1-1077; SC), and iv) basal diet with a mixture of MOS (32 g/d) and SC ($1.2{\times}10^{10}$ cfu/d; MOS+SC). Treatments had no effect (p>0.05) on DM intake and yields of milk, 3.5% fat-(FCM) and energy-corrected milk (ECM), and on milk fat percentage, body condition score and blood metabolites. Compared with the Control, only supplementation of SC resulted in numerically higher yields of FCM (41.9 vs. 40.1 kg/d) and ECM (41.8 vs. 40.3 kg/d), and milk fat percentage (3.64 vs. 3.43%). While the MOS diet had no effects on performance compared to the Control, the combination treatment MOS+SC increased milk protein percentage (p<0.05). Also, the MOS supplementation, both alone or in combination with SC, numerically increased milk fat percentage. The SC supplementation increased apparent digestibility of DM and crude protein while the MOS supplementation did not affect digestibility. Concentrations of total volatile fatty acids (VFA) and ruminal pH were similar across treatments. Overall results indicated that supplementation of MOS produced variable and inconsistent effects on rumen metabolism and performance, whereas SC supplementation improved nutrient digestibility and numerically increased FCM and ECM yields, which could not be enhanced by the combined supplementation of MOS+SC. According to our experimental condition, there was no effect of MOS alone or in combination with SC on dairy cow performance.

• 대한건축학회논문집:구조계
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• 제35권3호
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• pp.19-25
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• 2019

The purpose of this study was to evaluate bending performance of concrete filled soldier pile for temporary retaining wall. Structural performance tests were conducted on total number of four specimens. Each specimen had a unique characteristics with combination of the following variables, existence of reinforcing bar and locations of reinforcing steel plates. The results of this study were as follows; concrete filled steel tubes with being reinforced bar and flange rather than non-bar showed better performance. Higher yield, tensile strength and sufficient plastic strain were archived and maximum moment observed in experiments exceeded theoretical maximum moment in both allowable stress design and limit state design at all specimens.

• 대한건축학회논문집:구조계
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• 제35권10호
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• pp.155-162
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• 2019

Hybrid precast concrete panel is a wall element that is able to quickly construct the core wall structure for moderate-rise modular buildings. Hybrid precast concrete panel has unique characteristics which is a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, In this study, an improved anchorage detail for vertical rebar is proposed to ensure the lateral force resistance performance of hybrid precast concrete panel emulating monolithic concrete wall. Also, the structural performance of horizontal connection is investigated experimentally with the bolt spacing parameter. And the behavior of hybrid precast concrete panel with the improved detail is compared with the monolithic concrete wall tested in a previous study. Finally, the required thickness of C-shaped steel beam to eliminate or minimize the deformation in horizontal connection is calculated by prying action equation.

• 헤리티지:역사와 과학
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• 제45권4호
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• pp.114-125
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• 2012

본 연구에서는 풍납토성 동성벽 내부토양을 대상으로 색도색차계, XRD, 입도분석기 등을 이용하여 색도, 입도, 주요화학조성, 광물결정구조 등을 분석하였다. 성벽토양은 황갈색, 회황색의 모래 또는 실트질 모래(SW~SC)로 분류되고, 입도와 화학 광물학적 특성이 유사하며, 도로나 활주로 등의 성토재료로 적합한 특성임이 확인되었다. 색도, 입도, 화학조성, 강열감량의 4인자를 기준으로 비교분석한 결과, 풍납토성이 위치한 지역의 대조군 토양(PNS)은 성벽축조에 사용되지 않았던 것으로 판단한다. 모든 토양은 풍납토성이 위치한 지역과 지질학적으로 유사한 곳에서 채굴되었던 것으로 추정되지만, 성벽 축조 이전에 분포했던 구지표면의 토양과는 다른 특성을 나타내기 때문에, 유적 주변에 대량채굴이 가능했던 토양분포지가 존재할 것으로 추정된다. 향후 성벽 축조재료의 여러 특성들을 비교 분석하면, 성벽 내부토양의 산지, 축조방법, 보수방법 및 시기 등을 보다 종합적으로 이해할 수 있는 계기가 마련될 것으로 기대한다.

• 대한건축학회논문집:구조계
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• 제34권9호
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• pp.3-10
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• 2018

While computer environments have been dramatically developed in recent years, as the building structures become larger, the structural analysis models are also becoming more complex. So there is still a need to model one shear wall with one finite element. From the viewpoint of the concept of FEA, if one shear wall is modeled by one finite element, the result of analysis is not likely accurate. Shear wall may be modelled with various finite elements. Among them, considering the displacement compatibility condition with the beam element connected to the shear wall, plane stress element with in-plane rotational stiffness is preferred. Therefore, in order to analyze one shear wall with one finite element accurately, it is necessary to evaluate finite elements developed for the shear wall analysis and to develop various plane stress elements with rotational stiffness continuously. According to the above mentioned need, in this study, the theory about a plane stress element using hierarchical interpolation equation is reviewed and stiffness matrix is derived. And then, a computer program using this theory is developed. Developed computer program is used for numerical experiments to evaluate the analysis results using commercial programs such as SAP2000, ETABS, PERFORM-3D and MIDAS. Finally, the deflection equation of a cantilever beam with narrow rectangular section and bent by an end load P is derived according to the elasticity theory, and it is used to for comparison with theoretical solution.