• 펄프종이기술
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• 제34권5호
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• pp.49-55
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• 2002

A new method is proposed for the on-line measurement of the fiber orientation of sheet materials. The measurement of fiber orientation is very important in manufacturing paper sheets, non-woven fabrics, and glass sheets, because fiber orientation strongly affects product properties represented by, for example, dimensional stability of paper. A method developed in this research utilizes anisotropy of dielectric constants of sheet materials as a key characteristic to determine the fiber orientation. The new on-line sensor, consisting of 5 microwave dielectric resonators set in different directions, was designed to detect the fiber orientation while paper is running with high speed on a paper machine. This sensor can determine the direction and the degree of fiber orientation from the measured direction of the maximal dielectric constant and its variation, respectively. The fundamental performance of this system was examined by the static measurement of printing grade paper, which gave a satisfactory result. Then, the dynamic measurements were done at a speed of 1,000 m/min by using a high-speed test-coating machine.

• 한국콘텐츠학회지
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• 제13권2호
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• pp.47-52
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• 2015

• Restorative Dentistry and Endodontics
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• 제38권1호
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• pp.31-35
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• 2013

Objectives: This study compared the cyclic fatigue resistance of nickel-titanium (NiTi) files obtained in a conventional test using a simulated canal with a newly developed method that allows the application of constant fatigue load conditions. Materials and Methods: ProFile and K3 files of #25/.06, #30/.06, and #40/.04 were selected. Two types of testing devices were built to test their fatigue performance. The first (conventional) device prescribed curvature inside a simulated canal (C-test), the second new device exerted a constant load (L-test) whilst allowing any resulting curvature. Ten new instruments of each size and brand were tested with each device. The files were rotated until fracture and the number of cycles to failure (NCF) was determined. The NCF were subjected to one-way ANOVA and Duncan's post-hoc test for each method. Spearman's rank correlation coefficient was computed to examine any association between methods. Results: Spearman's rank correlation coefficient (${\rho}$ = -0.905) showed a significant negative correlation between methods. Groups with significant difference after the L-test divided into 4 clusters, whilst the C-test gave just 2 clusters. From the L-test, considering the negative correlation of NCF, K3 gave a significantly lower fatigue resistance than ProFile as in the C-test. K3 #30/.06 showed a lower fatigue resistance than K3 #25/.06, which was not found by the C-test. Variation in fatigue test methodology resulted in different cyclic fatigue resistance rankings for various NiTi files. Conclusions: The new methodology standardized the load during fatigue testing, allowing determination fatigue behavior under constant load conditions.

• 산경연구논집
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• 제9권5호
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• pp.47-62
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• 2018

Purpose - Based on preceding studies, this thesis focuses on the finding of the definition and category of mobile tourism application and deriving out its characteristics. And after looking for how they make influences on continuous intention to use, we make empirical study with TAM model. Research design, data, and methodology - There are many Chinese tourist who visit Korea with user's constant intention to use of tourism application. This study is to find out the definition and category of mobile tourism application through research of preceding study and to fomulate the research model and hypothesis that how tourism application attributes (convenience, interaction, accessibility, local basis, security) affect constant intention to use of mobile tourism application. In order to verify a hypothesis, we conducted a survey for Chinese users of tourism application. In empirical study, we analyzed a structure model for frequency analysis, reliability analysis, exploratory factor analysis, validity analysis through IBM SPSS Statistics 21.0 and IBM SPSS AMOS 21.0 Results - Among tourism applications, convenience, interaction, accessibility and local basis have positive effects on both perceived usefulness and perceived easiness respectively. But security does not. Also perceived easiness has a positive effect on perceived usefulness. Finally, perceived usefulness and perceived easiness have positive effect on constant intent to use. Conclusions - Tourism application enterprises should put emphasis on design such as menu or function in order to simplify the operation of new services for new customers. Therefore, comfortable user interface and development of useful function can improve tourism application. Consequently, it leads to the promotion of tourism application. Also, when users perceive tourism application as a useful media which is easy, comfortable and useful content, the degree of constant intention to use becomes increased. It is important to provide plentiful and useful contents for customers and to develop user interface such as easy operation because these factors have positive effects on constant demand and use of tourism application.

• 고문화
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• 50호
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• pp.297-315
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• 1997

Chronology, Paleolithic typology and ecology in Pleistocene East and Southeast Asia have been a constant source of debate and controversy. However, recent significant advances in the fields above-mentioned have improved this condition greatly. The 'ultima

• Asian-Australasian Journal of Animal Sciences
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• 제27권12호
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• pp.1763-1772
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• 2014

The objective of this study was to assess the effects of constant high ambient temperatures on meat quality, antioxidant capacity, and carnosine expression in longissimus dorsi muscle of finishing pigs. Castrated 24 male DLY (crossbreeds between Landrace${\times}$Yorkshire sows and Duroc boars) pigs were allocated to one of three treatments: constant ambient temperature at $22^{\circ}C$ and ad libitum feeding (CON, n = 8); constant high ambient temperature at $30^{\circ}C$ and ad libitum feeding (H30, n = 8); and constant ambient temperature at $22^{\circ}C$ and pair-fed with H30 (PF, n = 8). Meat quality, malondialdehyde (MDA) content, antioxidant capacity, carnosine content, and carnosine synthetase (CARNS1) mRNA expression in longissimus dorsi muscle were measured after three weeks. The results revealed that H30 had lower $pH_{24h}$, redness at 45 min, and yellowness at 24 h post-mortem (p<0.05), and higher drip loss at 48 h and lightness at 24 h post-mortem (p<0.01). Constant heat stress disrupted the pro-oxidant/antioxidant balance in longissimus dorsi muscle with higher MDA content (p<0.01) and lower antioxidant capacity (p<0.01). Carnosine content and CARNS1 mRNA expression in longissimus dorsi muscle of H30 pigs were significantly decreased (p<0.01) after three weeks at $30^{\circ}C$. In conclusion, constant high ambient temperatures affect meat quality and antioxidant capacity negatively, and the reduction of muscle carnosine content is one of the probable reasons.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.1124-1129
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• 2009

골절 후 골 유합에 대한 미세직류전류 자극의 효과를 관찰하기 위하여 체중 2.5~3 ㎏내외의 6개월 령 뉴질랜드 웅성토끼 24마리를 대상으로 경골 골절 후 미세전류 자극을 적용한 실험군과 비적용군인 대조군으로 나누어 3일, 7일, 14일 및 28일 후 BMP-4에 대한 면역조직화학적 염색을 실행하여 다음과 같은 결론을 얻었다. BMP-4의 발현은 비침습식 미세전류를 적용한 실험군과 자연치유군인 대조군 모두 시간이 경과함에 따라 통계학적으로 유의하게 증가하다가 감소되었다. 그러나 실험군에서 경골 골절 3일 후 대조군은 하버씨계의 간질층판을 중심으로 약한 갈색의 면역양성반응(+)을 보였으나 실험군의 경우 중등도의 면역양성반응(++)을 보였다. 경골 골절 7일 후 대조군은 하버씨계의 동심원과 간질층판을 중심으로 중등도의 갈색의 면역양성반응(++)을 보였으나 실험군의 경우 바깥층판을 포함하여 매우 강한 갈색의 면역양성반응(++++)을 보였다. 경골 골절 14일 후 대조군은 하버씨계의 간질층판과 동심원을 중심으로 강한 갈색의 면역양성반응(+++)을 보였으며 실험군 또한 강한 면역양성반응(+++)을 보였다. 그 후 점차 감소하여 경골 골절 28일 후 대조군은 하버씨계의 간질층판을 중심으로 약한 갈색의 면역양성반응(+)을 보였으나 실험군의 경우 중등도의 면역양성반응(++)을 보였다. 위의 결과로 보면 골절 후 미세전류를 비침습적으로 적용할 때 치유과정 초기에 골형성단백질인 BMP-4의 발현을 증가시켜 골절 치유를 촉진시킴을 알 수 있다.

• 한국결정성장학회지
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• 제6권2호
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• pp.155-165
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• 1996

Growth of $LiNbO_3$ single crystal by Czochralski method was carried out to study the piezoelectric effects. Piezoelectric coefficients and elastic compliances of the $LiNbO_3$ single crystal were determined by the resonance method of length-extentional mode of bar resonator from the room temperature up to $100^{\circ}C$. Two dielectric constants of $LiNbO_3$ were also determined by measuring the capacitance of the plate specimen. Measured constants were piezoelectric coefficients $d_{15},d_{22},d_{31},d_{33}$ elastic compliances $s^E_{11},s^E_{33},2s^E_{13}+2s^E_{44},s^E_{14}$ and dielectric constants $K^T_{11},K^T_{33}$. As temperature increased, elastic compliances changed very slowly while piezoelectric coeffiecients and dielectric constant $K^T_{33}$ changed very rapidly. Electromechanical coupling constant of zyw ($45^{\circ}C$)-bar was as high as 0.51 in room temperature and nearly constant up to $1000^{\circ}C$. The increase of piezoelectric coefficients was mainly due to the increase of dielectric permittivity.

• 한국결정성장학회지
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• 제10권3호
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• pp.205-210
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• 2000

초음파분무를 이용한 MOCVD법으로 강유전체 $PbTiO_3$박막을 Si(100) wafer와 ITO-coated glass위에 제조하였다 Si 기판 위에 증착된 박막으로부터, 출발원료의 농도비(Ti/Pb)가 1.2일 때, 단일 perovskite 상을 얻을 수 있었다. ITO-coated glass 위에 증착된 박막은 Si기판 위에 제조된 박막보다 박막의 성장속도가 더 빠르며, 기판온도를 $530^{\circ}C$부터 $570^{\circ}C$까지 증가시켰을 때, 결절성과 입자 크기의 증가에 의해 유전상수는 증가하였다. $570^{\circ}C$에서의 유전상수 및 유전손실 값은 각각 205, 0.016을 나타내었다. 기판온도가 $600^{\circ}C$ 이상인 경우, 유전상수가 감소되는 경향을 보였다.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.718-724
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• 2006

The heterogeneous association behaviour of various concentration binary mixtures of mono alkyl ethers of ethylene glycol with ethyl alcohol were investigated by dielectric measurement in benzene solutions over the entire concentration range at 25 ${^{\circ}C}$. The values of static dielectric constant $\epsilon_0$ of the mixtures were measured at 1 MHz using a four terminal dielectric liquid test fixture and precision LCR meter. The high frequency limiting dielectric constant $\epsilon_\infty$ values were determined by measurement of refractive index $n_D$ ($\epsilon_\infty\;=\;n_D\;^2$). The measured values of $\epsilon_0$ and $\epsilon_\infty$ were used to evaluate the values of excess dielectric constant $\epsilon^E$, effective Kirkwood correlation factor $g^{eff}$ and corrective correlation factor $g_f$ of the binary polar mixtures to obtain qualitative and quantitative information about the H-bond complex formation. The non-linear behaviour of the observed $\epsilon_0$ values of the polar molecules and their mixtures in benzene solvent confirms the variation in the associated structures with change in polar mixture constituents concentration and also by dilution in non-polar solvents. Appearance of the maximum in $\epsilon^E$ values at different concentration of the polar mixtures suggest the formation of stable adduct complex, which depends on the molecular size of the mono alkyl ethers of ethylene glycol. Further, the observed $\epsilon^E$ < 0 also confirms the heterogeneous H-bond complex formation reduces the effective number of dipoles in these polar binary mixtures. In benzene solutions these polar molecules shows the maximum reduce in effective number of dipoles at 50 percent dilutions. But ethyl alcohol rich binary polar mixtures in benzene solvent show the maximum reduce in effective number of dipoles in benzene rich solutions.