• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.823-827
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• 2004

Antimicrobial effect of Lithospermum erythrorhizon extracts against food-borne pathogens was investigated. L. erythrorhizon was extracted with methanol at room temperature, and the extraction was sequentially fractionated using petroleum ether, chloroform, ethyl acetate, and methanol. Antimicrobial activity of L. erythrorhizon extracts was determined using paper disc method against food-borne pathogens and food spoilage bacteria. Ethyl acetate extracts of L. erythrorhizon showed the highest activity against Staphylococcus aureus and Shigella dysenteriae. Synergistic effect was found in combined extracts of L. erythrorhizon and Sophora subprostrata as compared with each extract alone. Growth inhibition curve was determined using ethyl acetate extracts of L. erythrorhizon, against S. aureus and S. dysenteriae. Ethyl acetate extract of L. erythrorhizon, showed strong antimicrobial activity against S. aureus at 4,000 ppm, retarding growth of S. aureus more than 48 hr and S. dysenteriae up to 12 hr.

• The Journal of Society for e-Business Studies
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• v.16 no.4
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• pp.155-172
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• 2011

The purpose of this study is to examine factors affecting an individual's acceptance of mobile banking, which is a typical example of smartphone based self-service. We derive three personal traits(positive technology readiness, negative technology readiness and individual's expertise) as antecedent variables that affect intention to use mobile banking from previous studies, and adopt a technology readiness and acceptance model(TRAM) to investigate factors that determine an individual's intention to use mobile banking. TRAM, which integrates technology readiness index(TRI) into the technology acceptance model (TAM) in the context of consumer adoption of e-service systems, is adopted to examine personal traits influencing on the factors forming the attitude of mobile banking. The new findings of this study are as follows. First, individual's expertise and positive technology readiness(ptr) have significant effect on both perceived usefulness and perceived easy of use. However, negative technology readiness(ntr) has significant effect on only perceived easy of use.

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.861-866
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• 1993

In general, the concentration of constituents can be more accurately measured in x-ray fluorescence analysis of Fe-Ni-Cr alloy by reducing and correcting the matrix effect with standard ingot samples. Because of the difficult the treatment at a high temperature in preparing the ingot samples of various concentrations, several standard specimens were prepared by mixing the powders of the metallic oxides in certain proportions and pressing them with a costant pressure. With the metallic oxide specimens thus obtained, different matrix coefficients were calculate from the intensities of the strength of the x-ray fluorescence and the concentration of the substances. It is found that effects of Fe and Cr on Ni are absorption rich and effects of Fe and Ni on Cr are enhancement rich, whereas Ni enhances Fe Fluorescence but Cr absorves Fe K${\alpha}$ line. And the x-ray fluorescence intensities were compared and analyzed between the metallic oxides and the ingot samples.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.1-8
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• 2020

Ghosted illustration is an effective tool to simultaneously visualize interior and exterior structures while preserving clear shape cues. We propose a novel framework that combines 3D blending technique, which uses depth information of the target structure, with the conventional ghosted illustration framework. This combination facilitates natural blending effects tailored to the needs of ghosted illustration. Furthermore, we present how common manipulation techniques (e.g., masking) and illustrative rendering effects (e.g., silhouette mapping) can be integrated into the proposed framework to preserve both clear shape cues and depth cues. For the compositing techniques, we show and discuss the visual results obtained from various combinations of them. This demonstrates that the proposed framework can be an effective tool for ghost illustration.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.5
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• pp.70-79
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• 2013

The isothermal flow structure and mixing characteristics of a hybrid/dual swirl jet combustor for micro-gas turbine (MGT) were numerically investigated. Location of pilot burner, swirl angle and direction were varied as main parameters with the identical thermal load. As a result, the variations in location of pilot nozzle, swirl angle and direction resulted in the significant change in turbulent flow field near burner exit, in particular, center toroidal recirculation zone (CTRZ) as well as turbulent intensity, and thus the flame stability and emission performance might be significantly changed. With the comparison of experimental results, the case of swirl angle $45^{\circ}$ and co-swirl flow including optimum location of pilot burner were chosen in terms of the flame stability and emissions for the development of hybrid/dual swirl jet combustor.

• Computational Structural Engineering
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• v.10 no.2
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• pp.255-263
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• 1997

The optimum design of most structural systems used in practice requires considering design variables as discrete quantities. The present paper shows that the linear approximation method is very effective as a tool for the discrete optimum designs of unsymmetric composite laminates. The formulated design problem is subjected to a multiple in-plane loading condition due to shear and axial forces, bending and twisting moments, which is controlled by maximum strain criterion for each of the plys of a composite laminate. As an initial approach, the process of continuous variable optimization by FDM is required only once in operating discrete optimization. The nonlinear discrete optimization problem that has the discrete and continuous variables is transformed into the mixed integer programming problem by SLDP. In numerical examples, the discrete optimum solutions for the unsymmetric composite laminates consisted of six plys according to rotated stacking sequence were found, and then compared the results with the nonlinear branch and bound method to verify the efficiency of present method.

• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1440-1446
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• 1997

The radiologically detectable pulmonary involvement of NHL at diagnosis is about 4%. The commonest intrathoracic manifestations of secondary pulmonary lymphoma are mediastinal or hilar lymph node enlargement And the most frequent manifestations of pulmonary parenchymal lymphoma are lymphomatous nodules. But, when patients with newly diagnosed lymphoma exhibit rapidly progressive parenchymal lesions, an infection, such as pneumonia, is usually suspected. We present a report of a patient who developed rapidly progressive pulmonary involvement with T cell lymphoma, which was considered to be pneumonia because of high fever and rapidly progressive radiologic findings.

• Journal of the Korean Chemical Society
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• v.21 no.3
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• pp.180-186
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• 1977

The preparation of 1-chloro-2-iodoperfluorocycloalkenes was achieved with a short reaction time and a high yield when the starting compound was iodinated via the metalation process using an alkyllithium reagent. Especially, the high yield of 1-chloro-2-iodo-perfluorocyclohexene was obtained when 1,2-dichloroperfluorocyclohexene was iodinated via the same reaction conditions. The coupling reaction of 1,2-dihaloperfluorocycloalkenes was also achieved with a lower reaction temperature and a shorter reaction time when the equal slurry mixture of fluorocycloolefines and DMF was reacted at a high pressure in a sublimer. The yield of the coupling product was greatly improved by this process. For a typical example, the coupling reaction of the 1-chloro-2-iodotetrafluorocyclobutene was proceeded with a higher yield of the product than that of the reported reaction, when the present method was adopted. A plausible reaction mechanism of the present coupling reactiont was proposed and the physical characteristics of the coupling product were confirmed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.17-17
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• 1998

연소반응을 가지는 후류(wake)는 가스터빈 연소실의 flame holder 등에서 발생한다. 후류유동의 안정성 혹은 불안정성은 이러한 유동에 있어서 많은 영향을 끼치므로 상당히 중요하다. 본 연구는 위와 같이 연소 반응에 의한 밀도구배를 가지는 후류유동에 대하여 불안정성 해석을 수행하였다. 교란에 대한 지배방정식은 Navier-Stokes 방정식에서 점성항을 제외한 Euler 방정식을 고려하였다. 충류유동의 압력은 일정하다고 가정하였다. 교란 방정식을 유도하기 위하여 충류 유동이 평행하여 유동 방향에 수직한 방향의 구배만이 존재한다고 가정하였다. 모든 변수들은 충류 유동의 값과 움직이는 파장의 형태를 가지는 작은 교란의 합으로 생각하여 압력에 대한 교란방정식을 구하며, shooting법과 Newton-Raphson법에 근거를 두는 반복법을 사용하여 풀었다. 불안정성 해석을 수행하는 기본 유동의 속도장 및 온도장은 불안정성 해석을 수행하는 기본 유동의 속도장 및 온도장은 비압축성의 경우 우선 Gaussian Profile 가정함과 동시에 연소반응을 포함하는 유동장을 보다 정확히 구하기 위하여 Navier-Stokes 방정식으로부터 구한 결과를 사용하였다. 연소반응을 포함하는 유동장을 구할 때에는 해석상 편의를 위해 예혼합물질은 이상기체로, 화학반응은 1단계의 비가역반응으로 가정하였으며, 반응열로 인한 부력의 효과는 무시하였다. 위와 같은 유동장을 가지고 불안정성 해석을 수행한 결과 후류유동은 두 개의 변곡점을 가지며 sinuous 모드와 varicose모드의 두 개의 불안정성 모드가 있음을 보였다. 밀도 변화가 있는 경우나 밀도 변화가 없는 경우 모두 sinuous 모드의 가장 불안정한 모드가 varicose 모드의 가장 불안정한 모드보다 더 불안정함을 보여주어 후류 유동은 자유 유동에 가까운 위상 속도를 가지는 sinuous 모드에 의해 지배될 것임을 예측할 수 있다. 연소반응이 완전연소에 가까울수록 그리고 압축성 효과가 클수록 유동내부의 온도가 증가하고 점성 또한 증가하여 후류유동은 안정됨을 알 수 있었다 유동변수들의 contour로부터 유동의 특성을 예측한 결과 baroclinic 항이 dilatational 항보다 상대적으로 크며, 중심선 상하에 생기는 vortex를 더욱 성장시킬 것으로 생각된다.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.642-647
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• 2005

Lonicerae Flos was extracted with methanol and successively fractionated with petroleum ether, chloroform, ethyl acetate, and methanol to investigate their antimicrobial effects against food-borne pathogens and food spoilage bacteria using paper disc method. Ethyl acetate extracts of L. Flos showed highest antimicrobial activity against Shigella dysenteriae. Synergistic effect in inhibition was observed when L. Flos extract was mixed with Artemisa capillaris extract as compared to using each extract alone. Growth inhibition curves were determined using ethyl acetate extracts of L. Flos against Staphylococcus epidermidis and S. dysenteriae. Ethyl acetate extract of L. Flos had antimicrobial activity against S. dysenteriae at 3,000 ppm, retarding growth of S. dysenteriae up to 12 hr.