• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.212-213
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• 2006

Polymer thick film resistor paste was fabricated using various materials. Inorganic materials of carbon black and graphite were selected as fillers and epoxy resin was selected as organic material. Solvent with high boiling temperature was applied to adjust viscosity. A designed test coupon pattern was used to evaluate fabricated resistors. Aspect ratio of 1 was selected for evaluating resistor values. Electrical properties of fabricated resistors were measured and their values analyzed in relation to paste composition. PTF fabricated using carbon black as fillers achieved resistor value of $530{\Omega}/sq$.

• 한국의류학회지
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• 제24권2호
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• pp.277-285
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• 2000

The purpose of this study was to quantify the relationship between the sense of touch and mechanical properties of man-made leather. The first was to develop the five conversion equations which convert mechanical properties of man-made leather into five factor scores, which express five factors of the sense of touch(surface property, stretchiness, thickness & weight, thermal property(warmth & coolness), and moisture property(sticky & clingy)). The second was to develop the conversion equation which converts five factor scores into score of the sense of touch. Five factor scores were predicted by the following mechanical properties; surface property factor by log2HB and (log2HB)2, stretchiness factor by logEM, thickness & weight factor by logT, log2HB, logW, thermal property factor by logT, logHB, logSMd, and moisture property factor by logMMD, RC, RC2, (logEM)2, RT2. Subsequently, these five factor scores were converted into score of the sense of touch. The predictive abilities of the developed equations were satisfied.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.443-448
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• 2012

Ferrocenyl chalcones (Fc-C(O)CH=CH-Ar: Fc-Ar) with mono- and di-1-naphthalenyl moieties (Fc-1Naph and Fc-d1Naph) were prepared and spectroscopically characterized. The enone bridge was in the s-cis conformation and the $\pi$-electrons on the C=C bond were further delocalized on the bridge. The naphthalenyl moiety deviates greatly from the enone-Cp plane by $26.9(1)^{\circ}$. Cyclic voltammetry measurements for Fc-1Naph exhibit one reversible cycle for the redox of the ferrocenyl moiety at a lower potential, and one irreversible oxidation peak at the higher potential region. For Fc-d1Naph, the cyclic voltammogram is more featureless. Fluorescence properties for both compounds are active in polar solvents with $\lambda_{em}$ = 500 nm (EtOH) and $\lambda_{em}$ = 512 nm (MeOH) for Fc-1Naph and $\lambda_{em}$ = 496 nm (EtOH) and $\lambda_{em}$ = 508 nm (MeOH) for Fc-d1Naph. The intensity of Fc-d1Naph is more than twice than that of Fc-1Naph. The fluorescence properties for both compounds are inactive in the less polar solvents such as $CH_3CN$, $CH_2Cl_2$ and $CHCl_3$.

• 한국치위생학회지
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• 제1권2호
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• pp.171-180
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• 2001

The purpose of this study was to compared with the properties of commercial polyvinyl siloxane impression materials on the Korean product and the other country one. The materials used in this study were 5 hydrophilic polvinyly siloxane impression materials of light body automixing type (Perfect-F, Handae Chemical, Korea; Examix, GC, Japan; Contrast, VOCO, Germany; Express, 3M, U.S.A; Extrude, Kerr, U.S.A.). Specimens of each impression material were fabricated from a mold with dimensions identical to that specified in ASTM D624-91 and were subjected to tensile lode at 500 mm/min until failure for tear strength. Properties of consistency, strain in compression, recovery from deformation, detail reproduction and linear dimensional change were tested according to the testing methods of the ISO specification no.4823(1992). From this study, the follow ing results were obtained 1. The tear strength values were high ET(3.4kN/m), EP(3.4kN/m), PF(3.0kN/m), CT(3.0kN/m), but the lowest was EM(2.2kN/m)(p<0.05). 2. In the consistency, CT(47 mm) had the highest value, followed by PF(42.1 mm), ET(41.2 mm), and EM(39.6 mm), EP(39.2 mm)(p<0.05). It means more flow that the consistency value is high. 3. The strain in compression values were high followed by EM(5.8%), PF(52%), CT(4.6%), ET(4.1%), EP(2.9%)(p<0.05). 4. In the recovery from deformation, ET(99.95%) and PF(99.90%) had the highest value, followed by EP(99.75%), EM(99.74%) without statistical signification, CT(99.64%) had the lowest value(p<0.05). 5. Detail reproduction reappeared to line $20{\mu}m$ all products. 6. The linear dimensional change was a little shrinked all products. and there were not statistical signification (p>0.05). All products were satisfied the ISO specification.

• 한국진공학회지
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• 제11권4호
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• pp.194-200
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• 2002

MOCVD(metal-organic chemical vapor deposition) Cu 박막을 여러 조건에서 열처리를 행하여 그 전기적 특성과 미세구조의 변화를 통해 적절한 열처리 조건을 찾고 그 효과를 조사하였다. Ar 1 torr, $400^{\circ}C$에서 열처리를 거친 Cu 박막의 비저항이 1.98 $\mu$Ω.cm로 가장 낮게 나타났으며, 결정성의 경우도 $I_{(111)}/I_{(200)}$의 비가 2.03에서 3.11로 열 처리를 거치지 않았을 경우와 비교해서 약 50% 정도 향상된 값을 나타내었다. 열처리 후의electromigration(EM) 테스트에서는 Ar 1 torr, $400^{\circ}C$에서 열처리를 거친 배선이 EM에 대한 가장 높은 저항성을 보였다. 이것은 열처리 후 낮은 비저항, (111) 결정면의 성장, 그리고 표면 거칠기의 감소에서 기인한 것이다.

• 한국항해항만학회지
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• 제28권6호
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• pp.503-507
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• 2004

폐 처리된 스토론튬(Sr) 페라이트를 사용하여 GHz 대역용 전파흡수체를 개발하였다. 도전손실재인 카본의 첨가에 따른 전파흡수능의 변화와 시편 제작시 제작온도 변화에 따른 전파흡수능의 변화를 조사하였다. 이와 같은 실험을 실시하여 스토론튬(Sr) 페라이트 : 실리콘 (slicone)고무 : 카본 (carbon)=80 : 13.6 : 6.4 wt%인 시편을 7$0^{\circ}C$에서 제작하여 두께 2mm인 시편에 대하여 9.4 GHz에서 -24 dB, 두께 3mm인 시편에 대하여 5.5 GHz에서 -23 dB인 우수한 전파흡수체를 개발하였다.

• 로봇학회논문지
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• 제11권3호
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• pp.156-162
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• 2016

For the underwater localization, acoustic sensor systems are widely used due to greater penetration properties of acoustic signals in underwater environments. On the other hand, the good penetration property causes multipath and interference effects in structured environment too. To overcome this demerit, a localization method using the attenuation of electro-magnetic(EM) waves was proposed in several literatures, in which distance estimation and 2D-localization experiments show remarkable results. However, in 3D-localization application, the estimation difficulties increase due to the nonuniform (doughnut like) radiation pattern of an omni-directional antenna related to the depth direction. For solving this problem, we added a depth sensor for improving underwater 3D-localization with the EM wave method. A micro scale pressure sensor is located in the mobile node antenna, and the depth data from the pressure sensor is calibrated by the curve fitting algorithm. We adapted the depth(z) data to 3D EM wave pattern model for the error reduction of the localization. Finally, some experiments were executed for 3D localization with the fast calculation and less errors.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
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• pp.271-276
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• 1999

This study was carried out to investigate the relationship between sound color and physical propertiessuiting fabrics. Rustling sounds of 23 suiting fabrics by sound generator developed for this study were recorded and analysed through FFT analysis. Three sound color factor(ΔL Δf. LPT) were obtained.Physical properties of specimens were measured by KES-FB. Level range(L) showed significant correlation with tensile resilience(RT) and thickness (T). Frequency difference(Δf) showed significant correlation with tensile linearity(LT), shear properties(G, 2HG, 2HG5), compressional energy(WC), and weight(W). Total sound pressure (LPT) showed significant correlation with elongation at maximum load (EM), tensile linearity(LY), and tesile energy(WT). By stepwise regression LPT was found to be explained by EM, MIU, RC, LT significantly.

• 한국유기농업학회지
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• 제27권1호
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• pp.87-100
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• 2019

본 시험은 유기오이(Cucumis sativus L.) 선도농가에서 자가제조 액비를 장기간 연용하고 있는 순천과 김천지역의 농가를 선정하여 작물의 생산성을 비교하고자 수행되었다. 순천농가는 EM(EM 액비; 유용미생물)을 1년 및 15년간 연용한 곳을 각각 EM 1년차와 EM 15년차로 명명하였다. 김천농가의 재배구는 토착미생물(Microbes)을 4년 및 5년간 연용한 곳을 각각 Micro 4년차와 Micro 5년차 재배구로 분류하여 명명하였다. 액비 내 pH 수준은 EM 액비에서 약 7.7로 높았으며 EC는 Micro 액비에서 EM 액비 대비 0.1 dS/m 이상 높게 나타났으며, 기타 대량 무기성분은 두 액비 자재 간에 비슷하였다. 토양 EC는 EM 1년차 재배구에서 약 10.0 dS/m으로 매우 높았으며 나머지 재배구에서는 1.5 dS/m 이하의 수준을 보였다. 토양유기물 함량은 Micro 재배구에서 20 g/kg 이하의 수준으로 EM구보다 2배 이상 낮은 수준을 보였다. 토양미생물상은 재배구 간에 통계적으로 유의성 있는 차이가 관찰되지 않았다. 재배구간 SPAD와 광계II 활성은 토양 내 유기물함량과 EC 수준이 비교적 높았던 EM 15년차 재배구에서 통계적으로 유의성 있게 높게 나타났다. EM 1년차 재배구에서 작물의 전질소와 칼슘 및 나트륨 농도는 통계적으로 유의성 있게 높게 나타났지만 인산과 마그네슘의 흡수는 저하되었고, 특히 칼륨농도는 약 1.2%로 오이생육을 위한 적정 수준보다 2배 이상 낮게 관찰되었다. 염류가 과잉으로 집적되었던 EM 1년차 재배구에서 수량이 가장 적었다. EM 15년차 재배구에서는 생육후기에 수관이 가장 크게 확대되어 수량 증대효과가 관찰되어서, 10년 이상 장기간 유기액비를 연용하면 토양 안정성과 작물의 생산성을 지속적으로 향상시킬 수 있을 것으로 기대되었다.

• Geomechanics and Engineering
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• 제37권3호
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• pp.213-222
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• 2024

Determination of jointed rock mass properties plays a significant role in the design and construction of underground structures such as tunneling and mining. Rock mass classification systems such as Rock Mass Rating (RMR), Rock Mass Index (RMi), Rock Mass Quality (Q), and deformation modulus (Em) are determined from the jointed rock masses. However, parameters of jointed rock masses can be affected by the tunnel depth below the surface due to the effect of the in situ stresses. In addition, the geomechanical properties of rocks change due to the effect of metamorphism. Therefore, the main objective of this study is to apply correlation analysis to investigate the relationships between rock mass properties and some parameters related to the depth of the tunnel studied. For this purpose, the field work consisted of determining rock mass parameters in a tunnel alignment (~7.1 km) at varying depths from 21 m to 431 m below ground surface. At the same excavation depths, thirty-seven rock types were also sampled and tested in the laboratory. Correlations were made between vertical stress and depth, horizontal/vertical stress ratio (k) and depth, k and Em, k and RMi, k and point load index (PLI), k and Brazilian tensile strength (BTS), Em and uniaxial compressive strength (UCS), UCS and PLI, UCS and BTS. Relationships were significant (significance level=0.000) at the confidence interval of 95% (r = 0.77-0.88) between the data pairs for the rocks taken from depths greater than 166 m where the ratio of horizontal to vertical stress is between 0.6 and 1.2. The in-situ stress parameters affected rock mass properties as well as metamorphism which affected the geomechanical properties of rock materials by affecting the behavior of minerals and textures within rocks. This study revealed that in-situ stress parameters and metamorphism should be reviewed when tunnel studies are carried out.