• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.112-120
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• 2008

Today, the use of a vacuum cleaner gave us the higher quality of life than past time, but sometimes made us w1comfortable in the house because of the specific noise that is annoying. So we need to study how sound absorbtion materials affect sound power level and sound quality with sound metrics. In this paper, we will measure and calculate sound power level for vacuum cleaner and analyze characteristics of the noise for 10 Signals according to materials positioned in vacuum cleaner. The multiple regression analysis can estimate the nonlinear characteristics of relation between subjective evaluation and sound metrics. So we will develop sound quality index for vacuum sound.

• 한국자동차공학회논문집
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• 제20권4호
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• pp.39-45
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• 2012

Today gasoline engines for vehicular application are not only faced with stringent emission regulation but also with increasing requirements to better fuel economy, while guaranteeing power density. The spray-guided type gasoline direct injection (GDI) engine has an advantage of improved thermal efficiency and lower harmful emissions. Centrally mounted high pressure injector and adjacent spark plug allow stable lean combustion due to the flexible mixture stratification. In the present study, the performance and emissions characteristics of developed spray-guided type GDI combustion system were evaluated at various excess air ratio conditions. The specific fuel consumption and nitrogen oxides ($NO_x$) emissions were reduced due to the achievement of stable lean combustion under flammability limit. Multiple injection strategy was not helpful to improve fuel consumption while further reduction of $NO_x$ emissions was possible.

• 대한임상검사과학회지
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• 제39권3호
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• pp.201-209
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• 2007

Among the inhalant and foods which caused allergy, which is increasing nowaday, this research has a purpose of studying allergy-causing materials (allergen) which most frequently cause allergy. In order to conduct this research, we selected 100 hundred patients (M : F = 65 : 35) from in Kwangju Christian Hospital, who were tested through allergy multiple antigen simultaneous test (MAST) immunoblot assay (RIDA$^{(R)}$ X-Screen; r-Biopharm Co., Darmstadt, Germany). According to the test, the total IgE positive rate (above Class 2) from the inhalant is 58.3%, and that from food is 35%, respectively. This research showed that the first most allergen was the tick (Derm. farinae/Derm. pteronyssinus), the second most was housedust, and the third was the hair of pets such as cats and dogs; 65%, 35%, 26.3% in inhalant panel, and 52.5%, 40%, 50% in food panel, respectively. Thease allergens newly added to inhalant and food panels were not contributable to the detection of specifical allergen. We needs further improvement to be used as primary screening or quantitative test for allergy.

• 한국정밀공학회지
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• 제28권8호
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• pp.1000-1007
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• 2011

For enlarging the applications of microstereolithography, the use of diverse materials is required. In this study, the material switching system (MSS) for projection microstereolithography apparatus is proposed. The MSS consists of three part; resin level control, resin dispensing control, and vat level control. Curing characteristic of materials used in fabrication has been identified. Through repeated fabrication of test models, the critical fabrication error is investigated and a possible solution to this error is suggested. The developed system can be applied to improve the strength of microstructure and extended to fabricate an array of microstructures with multiple materials.

• 한국자동차공학회논문집
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• 제16권6호
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• pp.176-183
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• 2008

Performance of electrostatic diesel PM filtration systems (E-DPS) with different types has been tested using the carbon particles generated by spark discharge in laboratory. Among the five electrostatic precipitators, the multiple wires cylindrical E-DPS with the highest collection efficiency and relatively lower differential pressure at the flow rate of $1\;m^3$/min, as an applicable device to diesel engine as an after treatment system, has been combined with another collection cylinder to improve the collection efficiency of diesel particulate matters generated from diesel engines. The multiple wires cylindrical E-DPS combined with the cylindrical collector showed the collection efficiency of more than 60% at the engine speed of 2,000 rpm with the engine loads of 25 and 50%.

• 한국실내디자인학회논문집
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• 제15권3호
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• pp.24-32
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• 2006

Through the increasing of social economies and cultural activities, the Food service industry have been growing up steadily in spite of low economic activity. This is owing to increasing income, participation of women in public affairs and a dual-income family, automobile culture, desire for healthful food, shorten working hours, changing of cultural style. Moreover, the recent importance of Interior finishing materials by means of fire in the Restaurant, legal fractional multiple use business establishment are recognized of publicity. Therefore, This Study aim object at probing into the characteristic of Interior finishing material and then analysing the characteristics of space and material according to the typical distribution. In the Interior planning of Restaurant, firstly it is need to probe the Characteristics of interior finishing material at the basic element. This study is going to apprehend the constitution of space and difference of proportion or a point of sameness in the characteristics of material. Moreover, the recent importance of Interior finishing materials by means of fire in the Restaurant, legal fractional multiple use business establishment are recognized of publicity. Throughout probe and analysing, it can append more efficiency and elasticity in the usage of interior finishing material.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2006년도 춘계 학술발표회 논문집
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• pp.61-64
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• 2006

Soft materials, such as polymer solutions, gels and filamentous protein materials in cells, show complicated behavior due to their complex structures and dynamics with multiple characteristic time and length scales. Several complementary techniques have been developed to measure viscoelastic of soft materials. Especially, particle tracking microrheology, using the Brownian motion of particles in a medium to get rheological properties, has recently been improved both theoretically and experimentally. Compared to other conventional methods, video particle tracking microrheology has some advantages such as small sample volume, detecting spatial variation of local rheological properties, and less damage to sample materials. With these advantages, microrheology is more suitable to measure the properties of complex materials than other mechanical rheometries.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2006년도 제31회 학술논문발표회 초록집
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• pp.135-135
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• 2006

• 한국지반환경공학회 논문집
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• 제15권11호
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• pp.13-19
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• 2014

투수성 반응벽체 공법은 지하수 오염을 정화하는 대표적인 방법 중의 하나이다. 영양염류와 중금속 등 여러 가지 오염물질이 동시에 존재하는 경우 두 가지 이상의 반응성 매질을 적용한 반응벽체공법으로 복합오염물질의 제거가 가능하다. 본 연구에서는 반응성 매질로 제올라이트와 제강슬래그를 함께 사용하는 경우 복합오염물질의 제거능을 평가하였다. 영양염류인 암모늄과 인산염, 중금속인 카드뮴이 혼합된 복합오염물질에 대하여 연속회분식실험을 통하여 제올라이트 및 제강슬래그와의 반응순서에 따른 오염물질 제거능을 분석하였다. 연속회분식실험 결과에 의하면 제올라이트-제강슬래그 순서로 반응하는 경우 영양염류와 중금속의 복합오염물질에 대한 제거능이 더 좋은 것으로 나타났다.

• 한국세라믹학회지
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• 제47권1호
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• pp.54-60
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• 2010

This paper shortly reviews our recent work on filled skutterudites, which are considered to be one of the most promising thermoelectric (TE) materials due to their excellent power factors and relatively low thermal conductivities. The filled skutterudite system also provides a platform for studying void filling physics/chemistry in compounds with intrinsic lattice voids. By using ab initio calculations and thermodynamic analysis, our group has made progresses in understanding the filling fraction limit (FFL) for single fillers in $CoSb_3$, and ultra-high FFLs in a few alkali-metal-filled $CoSb_3$ have been predicted and then been confirmed experimentally. FFLs in multiple-element-filled $CoSb_3$ are also investigated and anonymous filling behavior is found in a few specific systems. The calculated and measured FFLs, in both single and multiple-filled $CoSb_3$ systems, show good accordance so far. The thermal transport properties can be understood qualitatively by a phonon resonance scattering model, and it seems that a scaling rule may exist between the lattice thermal resistivity and the resonance frequency of filler atoms in filled system. Even though a few things become clear now, there are still many unsolved issues that call for further work.