• 한국전자파학회논문지
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• 제14권4호
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• pp.377-383
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• 2003

동(copper) 케이블을 이용한 xDSL 초고속서비스가 널리 보급됨에 따라 외부 전자파에 의한 통신케이블의 전자파 결합특성을 해hi하기 위해 케이블 쉴드층의 전달임피던스가 중요하게 되었다. 본 논문에서는 xDSL 서비스를 제공하기 위해 사용되는 대표적인 형태의 통신케이블에 대해 IEC 96-1의 line injection method를 이용하여 전달임피던스를 측정하였다. 또한 injection line의 위치, 내부 도체의 위치가 전달임피던스에 어떻게 영향을 주는지를 분석하였으며, 이를 근거로 통신케이블의 전달임피던스 특성 모델을 제시하였다.

• 폴리머
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• 제28권3호
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• pp.263-272
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• 2004

자동차 계기판을 제조하는 기체 사출 성형의 공정에 있어서 전산 모사를 통한 공정성 및 제조된 제품의 물성 향상에 관한 연구를 수행하였다. ABS 삼원공중합체의 P-V-T 자료를 이용하여 기체 사출 공정을 적용하였으며 시간에 따른 금형 충전 효과를 예측하였다. 또한 기체 사출 성형에 있어서 압력, 충전 시간, 기체의 주입 통로 및 런너의 위치 등 다양한 가공 인자들을 변화시킴으로서 공정의 최적 조건을 찾을 수 있었다. 이러한 전산 모사를 통하여 확립된 공정을 통해 제조된 계기판은 일반적인 사출 성형법에 의해 제조되어진 제품에 비해서 우수한 치수 및 변형 안정성이 개선되었다.

• 한국동물위생학회지
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• 제41권4호
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• pp.251-255
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• 2018

Bordetella bronchiseptica and Pasteurella multocida are two main pathogens responsible for atrophic rhinitis (AR), which causes considerable economic losses in swine industry worldwide. Commercial vaccine has been widely used to prevent the damage from AR in Korea. Adverse effects of vaccination at the injection site have been reported, which results in the numerous complaint from farms. However, data on about local reaction at the injection site remains limited. In this study, we compared the local adverse effects of three commercial vaccines following intramuscular injection. The results showed that no gross lesion was founded at the injection sites of all three vaccines. In histopathologic examination, a various level of lesions was identified. Especially, the local reaction of vaccine including saponin as an adjuvant showed the lowest level of histopathological lesions, when compared to those of oil-based and vitamin E-based vaccines. Therefore, this study would provide the information about the extent of local reaction at the injection site and help the farmer to select AR vaccine in order to avoid adverse reaction due to vaccination.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.141-145
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• 2008

Wireless sensor network (WSN) is expected to be used in many applications. However, sensor nodes still have some secure problems to use them in the real applications. They are typically deployed on open, wide, and unattended environments. An adversary using these features can easily compromise the deployed sensor nodes and use compromised sensor nodes to inject fabricated data to the sensor network (false data injection attack). The injected fabricated data drains much energy of them and causes a false alarm. To detect and drop the injected fabricated data, a filtering-based security method and adaptive methods are proposed. The number of different partitions is important to make event report since they can make a correctness event report if the representative node does not receive message authentication codes made by the different partition keys. The proposed methods cannot guarantee the detection power since they do not consider the filtering scheme. We proposed clustering method for filtering-based secure methods. Our proposed method uses fuzzy system to enhance the detection power of a cluster.

• 한국동물위생학회지
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• 제43권3호
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• pp.129-137
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• 2020

In this study, we applied biodegradable drug delivery carries (BDDC) for food-and-mouth (FMD) vaccination. After FMD vaccination using BDDC, we estimated the percentage inhibition (PI) of antibody, decomposed patterns, and histopathologic features of BDDC. PI of antibody was higher than 50 at two weeks after injection and sustained positive PI until 10 weeks after injection. BBDC injection group showed significantly an increased pattern of blood monocyte at two and three weeks after injection. According to the Micro CT, micro-cracks were observed at two weeks after injection and the morphology of BDDC was lost at four weeks after injection. For histopathological examination, acute inflammation with neutrophil infiltration and micro-metallic residues were observed around BDDC until four weeks after injection and inflammatory responses gradually decreased at 10 weeks. Based on our experiment, BDDC is considered as an alternative way to vaccine injection for veterinary applications. Our study can be used as basic data for the drug delivery system using biodegradable metals in the future.

• 한국자동차공학회논문집
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• 제12권6호
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• pp.60-65
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• 2004

Numerical simulations and experiments have been carried out to investigate the effect of fuel injection nozzles on the combustion and NOx formation processes in a medium-speed marine diesel engine. Spray visualization experiment was performed in the constant-volume high-pressure chamber to verify the numerical results on the spray characteristics such as spray angle and spray tip penetration. Time-resolved spray behaviors were captured by high-speed digital camera and analyzed to extract the information on the spray parameters. Spray and combustion phenomena were examined numerically using FIRE code. Wave breakup and Zeldovich models were adopted to describe the atomization characteristics and NOx formation processes. Numerical results were verified with experimental data such as cylinder pressure, heat release rate and NOx emission. Finally, the effects of fuel injection nozzles on the engine performance were investigated numerically to find the optimum nozzle parameters such as fuel injection angle, nozzle hole diameter and number of nozzle holes. From this study, the optimum fuel injection nozzle (nozzle hole diameter, 0.32 mm, number of nozzle holes, 8 and fuel injection angle, $148^{\circ}$) was selected to reduce both the fuel consumption and NOx emission. The reason for this selection could be explained from the highest fuel-air mixing in the early phase of injection due to the longest spray tip penetration and the highest heat release rate after $19^{\circ}$ ATDC due to the increased injection duration.

• 동서간호학연구지
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• 제11권2호
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• pp.137-145
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• 2005

Purpose: This study has been attempted as one of the Quality Improvement activities in order to provide with intravenous injection control and to confirm the evaluation from the patients and their guardians, and also from nurses themselves. Method: The subject of this intravenous injection control was a control group of 239 patients and 176 nurses, a comparison group of 128 patients and 146 nurses. The tool consisted of hospitality (towards patients), explanation, and infection prevention activities. The collected data were analysed using SPSS Windows 11.0 program for percentage, $X^2$-test and t-test. Result: 1) The nurses who were instructed in standardised intravenous injection control received more satisfactory evaluation from the patients(t=-2.89, p=.004) than the nurses who were not. However, in the subdivisions, the explanation field was the only one to receive a more satisfactory evaluation(t=-1.14, p=.255). 2) The nurses who were instructed in standardised intravenous injection control showed higher performances in intravenous injection control (t=-4.21, p=.000) than the nurses who were not. In the subdivisions, hospitality, explanation, and infection prevention activities all showed effectiveness ($t=-2.35{\sim}3.90$, $p=.020{\sim}.000$). Conclusion: From the results stated above, it can be concluded that standardised intravenous injection control instruction for nurses brought out better evaluation, i.e. satisfaction, from the patients and their guardians, and the nurses who received the instruction showed better performances in intravenous injection control.

• 한국가스학회지
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• 제22권6호
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• pp.90-103
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• 2018

본 연구에서는 초크크기와 가스주입량을 조절함으로써 일반 유정이나 가스리프트가 적용된 유정에서 최적생산량을 산출할 수 있는 두 가지 인공신경망 모델을 개발하였다. 개발된 모델들의 입력자료는 용해가스-오일비, 물 생산 비율, 저류층압력, 초크크기 또는 가스주입량이고 출력자료는 정두압력과 오일 생산량으로 구성하였다. 먼저 육상 유정 시스템에 대하여 입력자료의 민감도 분석을 통해 각 변수의 범위를 결정하였고, 노달분석을 수행하여 초크크기 선정 모델에 1,715개, 가스주입량 선정 모델에 1,225개의 훈련자료를 각각 생성하였다. 동일한 저류층 자료에 대해 노달분석과 인공신경망 모델 결과를 비교해보면 두 모델 모두 결정계수 값이 0.99 이상으로 상관관계가 매우 높은 것으로 확인되었다. 또한 초크크기 선정 모델의 정두압력과 오일 생산량의 평균절대백분율오차는 각각 0.55%, 1.05%이고, 가스주입량 선정 모델의 정두압력과 오일 생산량의 평균절대백분율오차는 각각 1.23%, 2.67%로 개발된 모델의 정확도가 높은 것으로 확인되었다.

• 대한기계학회논문집B
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• 제24권1호
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• pp.1-8
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• 2000

A modified low-Reynolds-number Reynolds stress model is developed for the calculation of drag-reducing turbulent flows induced by polymer injection. The results without polymer injection are compared with the results of direct numerical simulation to ensure the validity of the basic model. In case of drag reduction, profiles of mean velocity and Reynolds stress components, in two-dimensional channel flow, obtained with a proper value of viscosity ratio are presented and discussed. Computed mean velocity profile is in very good agreement with experimental data. And, the qualitative behavior of Reynolds stress components with the viscosity ratio is also reasonable.

• 한국생산제조학회지
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• 제23권3호
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• pp.291-298
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• 2014

This study uses two numerical approaches to analyze the filling behavior of micro patterns on micro-injection molding for V-grooves pattern which cannot be simulated with conventional CAE packages. The parametric studies have been performed to examine the fidelity of micro patterns with respect to temperature, pressure, inlet velocity and pattern location on the mold according to the boundary condition from the macro pressure and velocity data which can be obtained by conventional CAE packages. Through these numerical approaches, the filling behavior of polymer melt in micro patterns can be understood, the quality of replication can be predicted, and the V-groove pattern can be shaped uniformly during the process of injection molding.