• Design & Manufacturing
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• 제12권2호
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• pp.27-33
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• 2018

Korea's automobile industry, which has grown rapidly to become the world's fifth-largest automobile producer, To cope with environmental pollution and energy problems in order to prevail competitive edge in global market We are investing a lot of research personnel and costs. Among them, for realizing alternative light weight It is a part of the automobile module system that has achieved the technological development before the breakthrough in the injection molding process in the press process. Door module PNL was the subject of research. The door module PNL is expected to cause warpage before the mold production due to the thin and flat product characteristics and fiber orientation characteristic of the material. In this paper, CAE analysis and reverse correction tool Design. CAE analysis to obtain the results of weld line position, bending position and deformation value Through the correction tool, think3, the original product was modified before the mold production to improve the completeness of the parts. In fiber orientation, the position and size of the cooling channel in the mold, the position and size of the gate, Temperature, pressure, time, and work environment. Compared with the result of CAE analysis, the product that was reverse-corrected by Think3 was manufactured, and injection molding was performed. Injection molding products were tested 24 hours later. 3.5 mm to 7.0 mm, and under the fixed condition, the deviation was from 1.1 mm to 1.5 mm. Unlike the CAE analysis, the deviation of the actual injection pressure and the cooling temperature, the fiber orientation of the material, In order to solve this problem, it is necessary to compare the injection conditions with the database, I knew I had to catch the standard.

• 정보보호학회논문지
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• 제27권5호
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• pp.1049-1058
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• 2017

최근 무선 네트워크 및 모바일 기술의 발전으로 인해 모바일 기기를 통한 다양한 종류의 서비스가 개발 및 제공되고 있다. 이와 더불어 모바일 광고(mobile advertisement) 형태도 다양한 형태로 확대되고 있다. 이에 유선 환경에서 발생하였던 광고 인젝션(advertisement injection; ad injection)이 모바일 환경으로 확장되고 있다. 특히 모바일 환경에서는 원하지 않는 광고의 노출로 인하여 사용자에게 불편함을 초래함과 동시에 모바일 데이터 사용량을 증가시킬 수 있다. 이렇게 광고 인젝션으로 인한 피해가 발생함에도 불구하고, PC 환경에서와 마찬가지로 아직까지 모바일 환경에서의 광고 인젝션 유형 및 특성에 관한 연구는 거의 진행되지 않았다. 따라서 본 논문에서는 국내 인터넷 포털 사이트 네이버를 대상으로 한 모바일 앱(mobile app)의 광고 인젝션 사례를 살펴보고, 이를 통하여 모바일 광고 인젝션의 유형 및 특성 분석을 수행하고자 한다. 본 연구에서는 2개의 모바일 앱을 대상으로 역공학(reverse engineering) 기법을 통하여 광고 인젝션 코드 및 행위에 대한 정적 동적 분석을 수행하였고 기존 PC 환경에서의 광고 인젝션과 비교 분석하였다.

• 한국정밀공학회지
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• 제19권10호
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• pp.99-106
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• 2002

This paper proposes an error compensation method that improves accuracy with geometry information of injection molding parts. Geometric information can give an improved accuracy in reverse engineering. Measuring data can not lead to get accurate geometric model, including errors of physical parts and measuring machines. Measuring data include errors which can be classified into two types. One is molding error in product, the other is measuring error. Measuring error includes optical error of laser scanner, deformation by probe forces of CMM and machine error. It is important to compensate these in reverse engineering. Least square method (LSM) provides the cloud data with a geometry compensation, improving accuracy of geometry. Also, the functional shape of a part and design concept can be reconstructed by error compensation using geometry information.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.1-11
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• 2004

Combustion and fuel distribution characteristics of heavy duty engine with the liquid phase LPG injection(LPLI) were studied in a single cylinder engine, Swirl ratio were varied between 1.2, 2.3, and 3.4 following Ricardo swirl number(Rs) definition, Rs=2.3 showed the best results with lower cycle-by-cycle variation and shorter burning duration in the lean region while strong swirl(Rs=3.4) made these worse for combustion enhancement. Excessive swirl resulted in reverse effects due to high heat transfer and initial flame kernel quenching. Fuel injection timings were categorized with open valve injection(OVI) and closed valve injection(CVI). Open valve injection showed shorter combustion duration and extended lean limit. The formation of rich mixture in the spark plug vicinity was achieved by open valve injection. With higher swirl strength(Rs=3.4) and open valve injection, the cloud of fuel followed the flow direction and the radial air/fuel mixing was limited by strong swirl flow. It was expected that axial stratification was maintained with open-valve injection if the radial component of the swirling motion was stronger than the axial components. The axial fuel stratification and concentration were sensitive to fuel injection timing in case of Rs=3.4 while those were relatively independent of the injection timing in case of Rs=2.3.

• Journal of Mechanical Science and Technology
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• 제16권4호
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• pp.557-563
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• 2002

In this paper, the characteristics of flow and spray motions affected by from piston head configurations were investigated numerically. Calculations were carried out from intake process to the end of compression. GTT (Generalized Tank and Tube method) code, which includes a third order upwind Chakravarthy-Osher TVD scheme and k-$\varepsilon$ turbulence model with fuel spray analysis was used for the calculations. As a results, piston heads with smaller radii of curvature were found to give stronger reverse tumble than those with larger radii of curvature. Similar results are shown in the convection and diffusion of fuel sprays.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.22-30
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• 1999

Optimization of in-cylinder flow is regarded as one of the most important factors to realize stable stratified charge combustion in a Spark-ignited Direct Injection(SDI) engine. Therefore, Computational Fluid Dynamic(CFD) simulation technique were used to clarify the characteristics of in-cylinder flow of a SDI engine with top entry intake port. Also, CFD results were compared to experimental results using Laser Doppler Velocimetry(LDV), Particle Image Velocimetry(PIV) and good validations were met. As the results reverse tumble flow generated during intake process was preserved by configuration of curved piston while base and reverse tumbles were diminished at the end of compression stroke in case of flat top piston. In addition, it will be needed to optimize the fuel mixture distribution based on these results.

• Archives of Reconstructive Microsurgery
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• 제3권1호
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• pp.40-44
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• 1994

Microsurgery has advanced beyond its nascent stages reaching success rates of 90% to 95%. However, this means that even in the best circumstances, 5% to 10% of free flaps and replants fail. Almost all failures are due to vessel thrombosis, resulting in ischemia of the transplanted tissue. Many attemps have been undertaken to treat and reverse its effects. Zdeblick and colleagues noted an improvement in the viability of amputated limbs replanted after an extended period of ischemia following intraarterial infusion of urokinase. Subsequent studies have investigated many modalities of urokinase administration in various animal models by differing ischemic periods. These studies, however, have failed to establish a definitive, generally accepted protocol for administration of urokinase in the salvage of tissue subjected to prolonged ischemia. Our clinical observations suggest that a bolus of urokinase delivered under pressure may increase the thromoblytic effect of the drug, probably by means of increased delivery to microvasculature. We intend to investigate the role of selective pressure perfusion of ischemic flaps as a new means for increasing the effectiveness of urokinase in the treatment of the "no-reflow" phenomenon. A total of 32 male New Zealand rabbits were used and divided into the four groups according to the method of infusion. After 12 hours of ischemia the flaps were injected with Hartmann's solution or with urokinase and the percent survival of the flap was determined at 7 days following flap reperfusion. As the result, the flap survival rate was highest in the pressure injection of urokinase group.

• Animal cells and systems
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• 제14권2호
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• pp.91-98
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• 2010

Male rats were given a single injection of iron, and temporal changes in iron content and iron-induced effects were examined in heart cellular fractions. Over a period of 72 h, the contents of total and labile iron, reactive oxygen species, and NO in tissue homogenate, nuclear debris, and postmitochondrial fractions were mostly constant, but in mitochondria they continuously increased. An abrupt decrease in membrane potential and NAD(P)H at 12 h was also found in mitochondria. The respiratory control ratio was reduced slowly with a slight recovery at 72 h, suggesting uncoupling by iron.While the ATP content of tissue homogenate decreased steadily until 72 h, it showed a prominent increase in mitochondria at 12 h. Total iron and calcium concentration also progressively increased in mitochondria over 72 h. Enzyme activity of the oxidative phosphorylation system was significantly altered by iron injection: activities of complexes I, III, and IV were reduced considerably, but complex II activity and the ATPase activity of complex V were enhanced. A reversal of activity in complexes I and II at 12 h suggested reverse electron transfer due to iron overload. These results support the argument that mitochondrial activities including oxidative phosphorylation are modulated by excessive iron.

• 대한미세수술학회:학술대회논문집
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• 대한미세수술학회 1994년도 제14차 학술대회
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• pp.102.2-103
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• 1994

• 한국전기전자재료학회논문지
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• 제16권9호
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• pp.771-774
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• 2003

In this paper, the programming characteristics of the multi-bit devices based on SONOS structure are investigated. Our devices have been fabricated by 0.35 $\mu\textrm{m}$ complementary metal-oxide-semiconductor (CMOS) process with LOCOS isolation. In order to achieve the multi-bit operation per cell, charges must be locally frapped in the nitride layer above the channel near the source-drain junction. Programming method is selected by Channel Hot Electron (CUE) injection which is available for localized trap in nitride film. To demonstrate CHE injection, substrate current (Isub) and one-shot programming curve are investigated. The multi-bit operation which stores two-bit per cell is investigated. Also, Hot Hole(HH) injection for fast erasing is used. The fabricated SONOS devices have ultra-thinner gate dielectrics and then have lower programming voltage, simpler process and better scalability compared to any other multi-bit storage Flash memory. Our programming characteristics are shown to be the most promising for the multi-bit flash memory.