• Title/Summary/Keyword: harmful components

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An Enhancement Scheme of Dynamic Analysis for Evasive Android Malware (분석 회피 기능을 갖는 안드로이드 악성코드 동적 분석 기능 향상 기법)

  • Ahn, Jinung;Yoon, Hongsun;Jung, Souhwan
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.29 no.3
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    • pp.519-529
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    • 2019
  • Nowadays, intelligent Android malware applies anti-analysis techniques to hide malicious behaviors and make it difficult for anti-virus vendors to detect its presence. Malware can use background components to hide harmful operations, use activity-alias to get around with automation script, or wipe the logcat to avoid forensics. During our study, several static analysis tools can not extract these hidden components like main activity, and dynamic analysis tools also have problem with code coverage due to partial execution of android malware. In this paper, we design and implement a system to analyze intelligent malware that uses anti-analysis techniques to improve detection rate of evasive malware. It extracts the hidden components of malware, runs background components like service, and generates all the intent events defined in the app. We also implemented a real-time logging system that uses modified logcat to block deleting logs from malware. As a result, we improve detection rate from 70.9% to 89.6% comparing other container based dynamic analysis platform with proposed system.

Effective Components of Bovine Colostrum and Its Applications (소 초유의 유효성분과 산업적 활용)

  • Seo, Sang-Ah;Seo, Hye-Ryoung;Heo, Young-Tae
    • Journal of Embryo Transfer
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    • v.33 no.3
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    • pp.159-168
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    • 2018
  • Bovine colostrum is necessary for newborn calves to survive, grow and receive immunity from their mother. Cows in Korea produce about 35kg of colostrum, 4Kg of which is fed to the calf, and the rest is discarded. The bovine colostrum causes the harmful side effects to human, such as allergies and digestive problems; so, it is prohibited by law to consume colostrum itself as a food. However, many scientific research data have suggested that components in the colostrum can improve human health and has the ability to help treat diseases. In line with the trend of food and pharmacy industries using natural product materials, which attract positive attention, recently, some ingredients in colostrum have been used in the production of food supplements, and it has been used in its raw form in some cosmetics. This review introduces the active ingredients and physiologically active substances contained in bovine colostrum, summarizes the efficacy of physiological enhancement of the colostrum, which has been proven by scientific methods to date, and also suggests the possibility of industrial applications of colostrum as an animal-derived natural material.

Analysis of computational fluid dynamics on design of nozzle for integrated cryogenic gas and MQL(minimum quantity lubrication) (극저온 가스와 MQL(minimum quantity lubrication)의 복합 분사를 위한 하이브리드 노즐 설계에 관한 전산유체역학 해석)

  • Song, Ki-Hyeok;Shin, Bong-Cheol;Yoon, Gil-Sang;Ha, Seok-Jae
    • Design & Manufacturing
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    • v.13 no.3
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    • pp.41-47
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    • 2019
  • In conventional machining, the use of cutting fluid is essential to reduce cutting heat and to improve machining quality. However, to increase the performance of cutting fluids, various chemical components have been added. However, these chemical components during machining have a negative impact on the health of workers and cutting environment. In current machining, environment-friendly machining is conducted using MQL (minimum quantity lubrication) or cryogenic air spraying to minimize the harmful effects. In this study, the injection nozzle that can combined injecting minimum quantity lubrication(MQL) and cryogenic gas was designed and the shape optimization was performed by using computational fluid dynamics(CFD) and design of experiment(DOE). Performance verification was performed for the designed nozzle. The diameter of the sprayed fluid at a distance of 30 mm from the nozzle was analyzed to be 21 mm. It was also analyzed to lower the aerosol temperature to about 260~270K.

A Study on the Design of Transmission Oil-Seal Using 2D Finite Element Analysis (2D 유한요소해석을 이용한 트랜스미션 오일 씰 설계에 관한 연구)

  • Yoon, Hyun-cheol;Jeon, Gi Hyun;Choi, Ju Yong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.1
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    • pp.85-93
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    • 2019
  • Oil seals are most essential parts in mechanical lubrication system to maintain the close gaps between stationary and high rotating components, and to help prevent oil leakages. Oil seals also can prevent harmful contaminants entering from outside to machinery, especially in severe environments. Therefore, the oil seals have an important performance in the machinery components. The performance of the oil seals are influenced by the design variables such as amount of interference gap between the main lip and shaft, the angle of main lip at air and oil sides and the distance between the garter spring and main lip. In the present study, a finite element analysis was performed to evaluate the oil seal performance with the considerations of number of oil seal dust lips and angle of the lip at oil side with the different design variables. As a result from the FEM analysis, the stress and contact pressure distributions was derived, based on this, performance of the sealing and durability were determined.

A Novel Method for Compensating Phase Voltage Based on Online Calculating Compensation Time

  • Wang, Mingyu;Wang, Dafang;Zhou, Chuanwei;Liang, Xiu;Dong, Guanglin
    • Journal of Power Electronics
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    • v.19 no.2
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    • pp.333-343
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    • 2019
  • Dead time and the nonideal characteristics of components all lead to phase voltage distortions. In order to eliminate the harmful effects caused by distortion, numerous methods have been proposed. The efficacy of a method mainly depends on two factors, the compensation voltage amplitude and the phase current polarity. Theoretical derivations and experiments are given to explain that both of these key factors can be deduced from the compensation time, which is defined as the error time between the ideal phase voltage duration and the actual phase voltage duration in one Pulse Width Modulation (PWM) period. Based on this regularity, a novel method for compensating phase voltage has been proposed. A simple circuit is constructed to realize the real-time feedback of the phase voltage. Utilizing the actual phase voltage, the compensation time is calculated online. Then the compensation voltage is derived. Simulation and experimental results show the feasibility and effectivity of the proposed method. They also show that the error voltage is decreased and that the waveform is improved.

The Trend of Cigarette Design and Tobacco Flavor System Development

  • Wu, Jimmy Z.
    • Journal of the Korean Society of Tobacco Science
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    • v.24 no.1
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    • pp.67-73
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    • 2002
  • In light of addressing consumer health concern, coping with anti-tobacco movement, and promoting new product, tobacco industry is actively pursuing to make a new generation of cigarettes with low tar and nicotine deliveries, and less harmful substances. Low tar and low nicotine cigarettes increases their market shares dramatically world wide, especially in KT&G, multinational tobacco companies, EU countries, even in China regulated by CNTC to set up yearly target to lower tar and nicotine deliveries. On the other hand, to design a new cigarette with reduced harmful substances begins to gain speed. The "modified Hoffmann list" publishes thirty plus substances in tobacco leaf and main smoke stream, which is the prime suspect causing health problems. Various ways and means are developed to reduce such components including new tobacco breeds, new curing method, tobacco leaf treatment before processing, selected filtration system, innovated casing system to reduce free radicals, as well as some non conventional cigarette products. In TSRC held this year, the main topic is related to reduce tobacco specific nitrosamines in tobacco leaf. The new generation of cigarette is in the horizon. It still needs a lot help to produce commercial products with satisfied taste and aroma characters. The flavor industry is not regulated by many governments demanding which ingredients might or might not be for tobacco use. However, most of the cigarette companies self impose a list of ingredients to guide flavor suppliers to design flavors. Unfortunately, the number of ingredients in those lists is getting shorter every year. It is understandable that the health is not the only reason. Some cigarette companies are playing safe to protect the company from potential lawsuit, while others are just copying from their competitors. Moreover, it is obvious that it needs more assistance from casings and flavors to design new generation of cigarettes with missing certain flavor components in tobacco leaf and main smoke stream. These flavor components are either non-existed or at lower level at new form of cured tobacco leaf or filtered in the main smoke stream along with reduced harmful substances. The use of carbon filters and other selected filtration system poses another tough task for flavor system design. Specific flavor components are missing from the smoke analysis data, which brings a notion of "carbon taste" and "dryness" of mouth feel. It is ever more demanded by cigarette industry to flavor suppliers to produce flavors as body enhancer, tobacco notes, salivating agents, harshness reducer, and various of aromatic notes provided they are safe to use. Another trend is that water based flavor or flavor with reduced ethanol as solvent is gaining popularity. It is preferred by some cigarette companies that the flavor is compounded with all natural ingredients or all ingredients should he GMO free. The new generation of cigarettes demands many ways of new thinking process. It is also vital for tobacco industry. It reflects the real needs for the consumers that the cigarette product should be safe to use as well as bearing the taste and aroma characters smokers always enjoyed. An effective tobacco flavor system is definitely a part of the equation. The global trend of tobacco industry is like trends of any other industries lead by consumer needs, benefited with new technology availability, affected by the global economy, and subjected for various rules and regulations. Anti-tobacco organizations and media exceptionally scrutinize cigarette, as a legal commercial product. Cigarette is probably the most studied commercial product for its composition, structure, deliveries, effects, as well as its new developmental trend. Therefore, any new trend of cigarette development would be within these boundaries. This paper is trying to point out what it would be like for tobacco industry in the next few yews and what concerns the tobacco industry. It focuses mostly on the efforts to produce safer cigarettes. It is such a vital task for the tobacco industry and its affiliate industries such as cigarette papers, filters, flavors, and other materials. The facts and knowledge presented in this paper might be well known for the public. Some of the comments and predictions are very much personal opinion for a further discussion.

A Study on the Design of the Output ESD Protection Circuits and their Electrical Characteristics (출력단 ESD 보호회로의 설계 및 그 전기적 특성에 관한 연구)

  • 김흥식;송한정;김기홍;최민성;최승철
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.11
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    • pp.97-106
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    • 1992
  • In integrated circuits, protection circuits are required to protect the internal nodes from the harmful ESD(Electrostatic discharge). This paper discusses the characteristics of the circuit components in ESD protection circuitry in order to analyze the ESD phenomina, and the design methodalogy of ESD protection circuits, using test pattern with a variation of the number of diode and transistor. The test devices are fabricated using a 0.8$\mu$m CMOS process. SPICE simulation was also carried out to relate output node voltage and measured ESD voltage. With increasing number of diodes and transistors in protection circuit, the ESD voltage also increases. The ESD voltage of the bi-directional circuit for both input and output was 100-300[V], which in higher than that of only output(uni-directional) circuit. In addition, the ESD protection circuit with the diode under the pad region was useful for the reduction of chip size and parasitic resistance. In this case, ESD voltage was improved to a value about 400[V].

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Die design for HIP'ing of Nickel-base Superalloys (초내열합금 HIP 성형을 위한 금형설계)

  • Lim J.S.;Yeom J.T.;Hou Bongliang;Park N.K.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.05a
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    • pp.139-142
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    • 2004
  • Nickel base superalloys are widely used for high temperature applications due to heat resisting capability and corrosion resistance at high temperatures. Superalloys with many strengthening alloying elements are frequently used in powder form to alleviate harmful effects of alloy segregation. HIP (hot isostatic pressing) and DB (diffusion bonding) as a form of solid-state bonding process is used to make turbine components, such as integrated turbine rotors. HIP/DB process requires many technical overcomes related to dimensional changes as well as microstructural control. In this research, HIP/DB process for nickel base superalloys, Udimet 720 and MM 247, were investigated with a view to control the dimensional change during the consolidation process. Simple disc-shaped cans were used to select the conceptual die design for the control of the dimensional change especially in radial direction. The change in the shape of consolidated shape was investigated using commercial FE code with constitutive equations fur low temperature plasticity deformation.

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An Experimental Study on Application of Biodiesel Fuel in Direct Injection Diesel Engine (직접 분사식 디젤기관에서 바이오디젤유의 적용에 관한 실험적 연구)

  • Oh, Y.I.;Choi, S.H.
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.818-823
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    • 2001
  • Because the exhaust emissions from automobiles are increased, our environment is faced with very serious problems related to the air pollution in these days. In particular, the exhaust emissions of diesel engine are recognized main cause which influenced environment strong. Lots of researcher have been attempted to develop various alternative fuel on purpose to reduce these harmful emissions. In this study, the potential possibility of esterfied rice bran oil which is a kind of biodiesel fuel was investigated as an alternative fuel for diesel engine. And, we tried to analysis not only total hydrocarbon but hydrocarbon components from $C_1$ to $C_6$ in exhaust gas using gas chromatography to seek the reason for remarkable reduction of exhaust emission. Individual hydrocarbon$(C_1\simC_6)$ as well as total hydrocarbon of biodiesel fuel is reduced remarkably than that of diesel fuel in this experiment.

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Regulations of Food Packaging in Korea, Europe and USA (우리나라, 유럽 및 미국의 식품용 용기포장재 기준규격 관리제도 연구)

  • Jeon, Dae-Hoon;Lee, Young-Ja
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.13 no.2
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    • pp.75-78
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    • 2007
  • Regulation of food packaging in Korea, Eurpoe and USA are surveyed. Food packaging manufacturer or converter has a responsibility to evaluate the safety of migration of harmful materials from typical finished packaging items. The 'overall migration limit' of all components from the packaging and 'specific migration limits(SML)' of monomers or additives are evaluated with food simulants, water, acetic acid, ethanol and n-heptane, based on the regulations of the countries. A substance not regulated has to be authorized with the technical data required, information on chemical identity, physical chemical and other properties, the intended use, migration studies and toxicological studies.

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