• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4112-4112
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• 2001

The feasibility of NIR spectroscopy as a quick and nondestructive method for quality control of uniformity of coating thickness of pharmaceutical tablets was investigated. Near infrared spectra of a set of pharmaceutical tablets with varying coating thickness were measured with a diffuse reflectance fiber optic probe connected to a Broker IFS 28/N FT-NIR spectrometer. The challenging issues encountered in this study included: 1. The similarity of the formulation of the core and coating materials, 2. The lack of sufficient calibration samples and 3. The non-linear relationship between the NIR spectral intensity and coating: thickness. A peak at 7184 $cm^{-1}$ was identified that differed for the coating material and the core material when M spectra were collected at 2 $cm^{-1}$ resolution (0.4 nm at 7184 $cm^{-1}$). The study showed that the coating thickness can be analyzed by polynomial fitting of the peak area of the selected peak, while least squares calibration of the same data failed due to the lack of availability of sufficient calibration samples. Samples of coal powder and solid pieces of coal were analyzed by FT-NIR diffuse reflectance spectroscopy with the goal of predicting their ash content, percentage of volatile components, and energy content. The measurements were performed on a Broker Vector 22N spectrometer with a fiber optic probe. A partial least squares model was constructed for each of the parameters of interest for solid and powdered sample forms separately. Calibration models varied in size from 4 to 10 PLS ranks. Correlation coefficients for these models ranged from 86.6 to 95.0%, with root-mean-square errors of cross validation comparable to the corresponding reference measurement methods. The use of FT-NIR diffuse reflectance measurement techniques was found to be a significant improvement over existing measurement methodologies in terms of speed and ease of use, while maintaining the desired accuracy for all parameters and sample forms.(Figure Omitted).

• 한국결정학회지
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• 제6권2호
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• pp.80-87
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• 1995

Tetrapropionyloxycalix[4]arene(C40H40O8)의 결정 및 분자를 X-선 회절법으로 연구하였다. 이 결정은 단사정계이고 공간군은 P21/n이다. 단위세포 길이는 a=13.921(3), b=13.552(2), c=19.840(5)Å이며, β=110.38(2)°, Z=4이다. 회절반점들의 세기는 흑연단색화 장치가 있는 Enraf-Nonius CAD-4 Diffractometer로 얻었으며, Mo-Kα X-선(λ=0.7107Å)을 사용하였다. 분자구조는 직접법으로 풀었으며 최소자승법으로 정밀화하였다. 최종 신뢰도 R값은 2514개의 회절반점에 대하여 0.06이었다. 본 Calixarene은 partial cone conformation을 이루고 있어 세 개의 phenyl group들과 나머지 한 개의 phenyl group사이에 서로 다른 배향을 가지고 있다. 세 개의 phenyl group들은 macrocycle로 된 cavity 바깥쪽을 향하여 배열되어 있다.

• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1108-1112
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• 1994

25-Acetoxy-26,27,28-trimethoxycalix[4]arene was synthesized by the treatment of calix[4]arene trimethyl ether with acetyl chloride in the presence of NaH. The solution conformation was inferred as a partial cone conformation based on the $^1H$-and $^{13}C$ NMR spectra. The crystal structure has been determined by X-ray diffraction method. The crystals are monoclinic, space group $P2_1$/n, a=8.186 (1), b=17.137 (2), c=19.878 (3) ${\AA}$, ${\beta}$=95.67 (1)$^{\circ}$, Z=4, V=2774.90 ${\AA}^3$, $D_c$= 1.22 g $cm^{-3}$, $D_m$=1.23 g $cm^{-3}$. The intensity data were collected on an Enraf-Noninus CAD-4 Diffractometer with a graphite monochromated $Cu-K{\alpha}$ radiation. The structure was solved by direct method and refined by full-matrix least-squares methods to a final R value of 0.054 for 3675 observed reflections. The molecule possesses a partial cone conformation with one flattened phenyl unit, in which one anisol ring, distal to the ester ring, is inverted. The acetoxyphenyl ring is flattened.

• Bulletin of the Korean Chemical Society
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• 제17권7호
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• pp.643-647
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• 1996

1,2-Disubstituted chiral calix[4]arene "25-(3,5-dinitrobenzoyloxy)-26-methoxy-27,28-dihydroxycalix[4]arene" was synthesized by the reaction of 25-(3,5-dinitrobenzoyloxy)-calix[4]arene with methyl iodide in the presence of K2CO3. Methylation was occurred at the 26-position of calix[4]arene. The partial cone conformation and 1,2-substitution were characterized based on the 1H NMR, 13C NMR and X-ray diffraction analysis. The crystal structure has been determined by X-ray diffraction method. The crystals are orthorhombic, Pbca, a=10.652(1), b=17.687(1), c=32.247(3) Å, Z=8, V=6075.4(9) Å3, Dc=1.38gcm-3. The intensity data were collected on an Enraf-Nonius CAD-4 Diffractometer with a graphite monochromated Cu-Kα radiation. The structure was solved by direct method and refined by full-matrix least-squares methods to a final R value of 0.050 for 2368 observed reflections. The molecule is in the partial cone conformation. It has two strong intramolecular hydrogen bonds of O(1D)-H…O(1C)-H…O(1B).

• Metals and materials international
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• 제24권6호
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• pp.1386-1393
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• 2018

The solubility of $TiO_2$ in $NaF-CaF_2-BaF_2$ ternary eutectic melts was investigated at the temperature range of $1025-1150^{\circ}C$. The least-squares equation was obtained from the relationship between the reciprocal temperature and the natural logarithm of the titanium concentration in the melts saturated with $TiO_2$. The corresponding partial molar enthalpy of dissolution of $TiO_2$ was found to be 188 kJ/mol. The titanium saturation concentration was 3.73 wt% at $1100^{\circ}C$. From the titanium concentration change with the added amount of $TiO_2$ at different holding time after a final stirring, it was found that not only complete dissolution of $TiO_2$ but also enough sedimentation of excessive $TiO_2$ should be guaranteed to obtain more reliable solubility data. The holding time of 10 h was found to be enough for the excessive $TiO_2$ particles to settle down in our experimental conditions. It is noteworthy that in case of adding $TiO_2$ in excess of its solubility, the $Ba_{1.12}(Ti_8O_{16})$ phase was observed at the lower and bottom of the solidified salt ingots.

• 한국자동차공학회논문집
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• 제21권6호
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• pp.175-182
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• 2013

Lately, customers think highly of the emotional satisfaction and as a result, issues on odor are matters of concern. The cases are odor of interior material and air-conditioner of vehicles. In particualar, with respect to the odor of air-conditioner, customers strongly claimed defects with provocative comments : "It smells like something rotten," "It smells like a foot odor," "It stinks like a rag." Generally, it is known that mold of evaporator core in the air-conditioning system decays and this produce VOCs which causes the odor to occur. In this study, partial least squares regression model is applied to predict the strength of the odor and select of important VOCs which affect car air conditioning smell. The PLS method is basically a particular multilinear regression algorithm which can handle correlated inputs and limited data. The number of latent variable is determined by the point which is stabilized mean absolute deviations of VOCs data. Also multiple linear regression is carried out to confirm the validity of PLS method.

• 약학회지
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• 제60권2호
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• pp.85-91
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• 2016

Drying of granules for tablet formulation is one of the important unit operations. The loss on drying method is traditionally used for this purpose. However, it is a time-consuming method, requiring at least 1 h. Moreover, it is ineffective in monitoring the moisture content of granules during the drying process. In this study, online real-time monitoring of moisture content during the drying process was successfully performed using near-infrared (NIR) spectroscopy. NIR spectra were collected during 15 different drying batches for developing a reliable NIR spectroscopic method. Such a large number of batches were used to develop a more robust partial least squares (PLS) model. NIR spectra collected from 12 batches were used for developing the model that was validated by predicting the moisture content of the samples in the remaining 3 batches. The standard errors of predictions (SEPs) in the measurement of batch 1, batch 2, and batch 3 were 0.52%, 0.57%, and 0.56%, respectively. The online NIR spectroscopic method developed in this study was reliable and accurate in monitoring the moisture content during the drying process.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1267-1274
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• 2021

This study aims to analyze the effect of corporate communication and service quality on loyalty mediating satisfaction. The population of this study is 384 Islamic bank customers in North Sumatra. This research is quantitative research using the survey method. The number of research samples was 384 customers. Characteristics of this research sample were (1) Savings customers who actively carried out transactions in Islamic banks (2) Savings customers who had used bank services for at least 1 year (3) Savings customers who used services directly and individually. The data analysis technique used in this study was the Partial Least Squares-Structural Equation Model (SEM-PLS) analysis technique, using Warp-PLS 3.0 software. This study investigates the largest Islamic banks in North Sumatra, namely Bank Syariah Mandiri, Bank BNI Syariah, and Bank BRI Syariah. The results show that company communication has a positive and significant effect on satisfaction, service quality has a positive and significant effect on satisfaction, company communication has a positive and significant effect on loyalty, service quality has a positive and significant effect on loyalty, satisfaction has a positive and significant effect on loyalty. There is also a significant effect of satisfaction on the relationship between company communication and loyalty, and the relationship between service quality and loyalty. This study contributes to Islamic banking to increase customer loyalty.

• 대한수학회보
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• 제59권1호
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• pp.119-139
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• 2022

This paper deals with the λ-labeling and L(2, 1)-coloring of simple graphs. A λ-labeling of a graph G is any labeling of the vertices of G with different labels such that any two adjacent vertices receive labels which differ at least two. Also an L(2, 1)-coloring of G is any labeling of the vertices of G such that any two adjacent vertices receive labels which differ at least two and any two vertices with distance two receive distinct labels. Assume that a partial λ-labeling f is given in a graph G. A general question is whether f can be extended to a λ-labeling of G. We show that the extension is feasible if and only if a Hamiltonian path consistent with some distance constraints exists in the complement of G. Then we consider line graph of bipartite multigraphs and determine the minimum number of labels in L(2, 1)-coloring and λ-labeling of these graphs. In fact we obtain easily computable formulas for the path covering number and the maximum path of the complement of these graphs. We obtain a polynomial time algorithm which generates all Hamiltonian paths in the related graphs. A special case is the Cartesian product graph K_n☐K_n and the generation of λ-squares.

• 한국측량학회지
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• 제27권4호
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• pp.437-444
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• 2009

동역학적 방법을 이용한 GPS(Global Positioning System) 위성궤도 결정을 위해 양방향 적분이 가능한 multi-step 방식의 수치적분기를 개발하였으며, 이는 GPS 위성 고도에서 마이크로미터 수준의 정확도를 보였다. 가속도 모델링에서 달, 태양 이외의 천체에 의한 인력은 매우 작으므로 태양복사압에서 경험적 모델로 대체하였다. 위성궤도 미지수는 수치적분된 위성궤도와 IGS(International GNSS Service) 정밀궤도를 이용하여 최소제곱방법으로 결정했다. 이를 위해서는 수치적분기에서 가속도와 함께 미지수에 대한 편미분값을 동시에 적분해야 한다. 추정된 위성궤도 미지수를 이용하여 계산한 잔차의 RMS(Root Mean Squares error)로 부터 위성궤도의 정확도를 검증했다. 2009년 3월 한달의 평균적인 궤도오차 RMS는 5.2mm 였으며, 궤도오차의 절대적인 크기는 위성체의 종류 및 위성진행방향기준 좌표계 상에서 특별히 편향된 형태를 보이지는 않는 것으로 나타났다. 본 연구에서 적용한 태양복사압 모델은 상수항 및 궤도당 1주기에 대한 변화만을 포함하고 있으므로, 궤도당 2주기에 해당하는 궤도오차 양상을 크게 보이고 있으며 이에 대한 추가적인 연구가 필요할 것으로 판단된다.