• Journal of the Korean Chemical Society
• /
• v.17 no.3
• /
• pp.207-212
• /
• 1973

The mechanical degradation of poly (-vinylacetate) in several mixed solvents (dioxane-n-butanol, dioxane-sec-butanol, dioxane-ethyleneglycol, dioxane-kerosene.) was studied using the capillary flow method. The velocity constant of scission reaction (k) and the limited degree of polymerization (g) were compared at the same value of [${\eta}$], which is considered as the parameter of molecular dimension of polymers in solution. As result, (k) did not change much, even if the species and the volume fraction of poor (non-) solvents changed, while the value of (g) changed according to the species of poor solvents and the value of [${\eta}$]. From the facts described above, It follows that the limited degree of polymerization (g) were affected by the composition and distribution of mixed solvent molecules around the polymer chain, and the value of $\alpha$ (at [${\eta}$] = $KM^a$) in the polymer solution.

• Journal of Information Processing Systems
• /
• v.10 no.3
• /
• pp.395-411
• /
• 2014

Temporal medical data is often collected during patient treatments that require personal analysis. Each observation recorded in the temporal medical data is associated with measurements and time treatments. A major problem in the analysis of temporal medical data are the missing values that are caused, for example, by patients dropping out of a study before completion. Therefore, the imputation of missing data is an important step during pre-processing and can provide useful information before the data is mined. For each patient and each variable, this imputation replaces the missing data with a value drawn from an estimated distribution of that variable. In this paper, we propose a new method, called Newton's finite divided difference polynomial interpolation with condition order degree, for dealing with missing values in temporal medical data related to obesity. We compared the new imputation method with three existing subspace estimation techniques, including the k-nearest neighbor, local least squares, and natural cubic spline approaches. The performance of each approach was then evaluated by using the normalized root mean square error and the statistically significant test results. The experimental results have demonstrated that the proposed method provides the best fit with the smallest error and is more accurate than the other methods.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.10C
• /
• pp.935-941
• /
• 2007

In this paper, we suggest the power allocation method which enhances the performance in high SNR for LDPC codes. In this method, bit power is unequally allocated proportionally to the difference of the degree distributions of variable and check nodes of Tanner graph between practically used codes and the codes optimized by density evolution. Simulation is performed to the codes in IEEE 802.16e standards, and the results show that the proposed method works well in high SNR.

• Journal of the Korean Society for information Management
• /
• v.20 no.1
• /
• pp.165-198
• /
• 2003

This study analyzed authors' use of theory in 654 articles that appeared in two core library and information science journals during last three decades. In order to analyze degree of theory use of LIS, such as, publication productivity, growth and distribution of theory in subfields. name and origin of theory, usability of each theory, subfields and journals, and so on, content analysis of LIS theories was performed through conceptual and empirical study. For the purpose of this study, we suggested a couple of new analytical methods, so called, ‘Subfield Classification Scheme’ within LIS, and ‘5 Degrees of Theory Use’ model for the first time.

• The Journal of Internal Korean Medicine
• /
• v.39 no.5
• /
• pp.914-928
• /
• 2018

Objectives: This case report examines the effects of traditional Korean medicine for unspecified tremor with xerostomia caused by psychometric drug intake. Methods: A patient who suffered from unspecified tremor with xerostomia caused by psychometric drug intake was treated with acupuncture, pharmacopuncture, and traditional Korean medicine for 30 days. We provided the patient with herbal medicines including Ondam-tang-gagam (溫膽湯加減), Pumsimgieum-gagam (忿心氣陰加減), and Hoichunyanggyeok-san-gami (回春凉隔散加味). Symptoms were charted and evaluated using the Yin-deficiency questionnaire score, Yin-deficiency scale score, dry mouth symptom questionnaire, and visual analogue scale. Results: After treatment with Korean Medicine and pharmacopuncture, the frequency and degree of tremor has decreased, and degree of Xerostomia also improved. The Scores of Yin-deficiency questionnaire score, Yin-deficiency scale score, dry mouth symptom questionnaire, and visual analogue scale were also improved. And we could see reduction in the level of distribution of gastrointestinal heat at Digital Infrared Thermal Imaging test. The patient's Symtoms (Xerostomia as well as unspecified tremor) were improved after treated with Korean Medicine and pharmacopuncture. Conclusion: Korean medicine treatments may be valuable for xerostomia caused by psychometric drug intake.

• Journal of Welding and Joining
• /
• v.30 no.5
• /
• pp.51-56
• /
• 2012

The purpose of this study is to evaluate the distortion and the residual stress of GTA tubular welds between tube and head. In order to do it, the heat input model for GTA welding process was first developed by experiment and FE analyses. The welding distortion and the residual stress distribution of the tubular welds according to welding pass and various restraint degrees were evaluated by using FEA with the heat input model. From FEA results, it was found that the residual stress and the radial distortion at the weld toe of tube part decrease with a decrease in the number of welding pass. However, the maximum residual stresses in each direction of tubular welds are almost constant regardless of the external restraint degree. It was mainly due to the high internal restraint of the welds.

• Journal of Korean Physical Therapy Science
• /
• v.10 no.1
• /
• pp.122-129
• /
• 2003

In this study, a group of 25 patients between the ages of $22{\sim}55$ received acupuncture treatments for tennis elbow. The variance has some high value. 1. The distribution of an age group in 22 to 55 and the average age of men is $40.9{\pm}9.3$ and the average age of women is $39.5{\pm}3.6$. Total average age is $40.4{\pm}8.4$. 2. Before the acupuncture treatments the average pain degree for the group is $4.72{\pm}0.6$ and after treatments, it is $2.36{\pm}1.6$. Statistically, the variance has some high value. 3. There were statistically significant difference in the pain degree before and after the acupuncture treatment according to the age. By these results, acupuncture treatments will be useful to the first-line treatment for tennis elbow.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.7C
• /
• pp.587-593
• /
• 2010

In this paper we design an irregular low-density parity-check (LDPC) code for multiple-input multiple-output (MIMO) system, using a simple extrinsic information transfer (EXIT) chart method. The MIMO systems considered are optimal maximum a posteriori probability (MAP) detector. The MIMO detector and the LDPC decoder exchange soft information and form a turbo iterative receiver. The EXIT charts are used to obtain the edge degree distribution of the irregular LDPC code which is optimized for the MIMO detector. It is shown that the performance of the designed LDPC code is better than that of conventional LDPC code which was optimized for either the Additive White Gaussian Noise (AWGN) channel or the MIMO channel.

• Journal of the Korean Wood Science and Technology
• /
• v.20 no.2
• /
• pp.81-90
• /
• 1992

The effect of acid treatment of cellulose on the substitution charateristics of carboxymethylation was studied in this paper. Five samples of hydrocellulose(HC), all prepared from ${\alpha}$-cellulose by hydrolysis with five reaction times and determined on average molecular weight and polydispersity, were carboxymethylated to carboxymethyl cellulose (CMC). The CMCs from HCs were examined upon degree of substitution(DS), distribution of carboxymethyl groups in anhydroglucose units of the cellulose, and unsubstituted anhydroglucose(USAG) content. The DS of CMCs increased with increasing the hydrolysis time except CMC from HC at 1 hour hydrolysis time. In carboxymethylation the availability of hydroxyl groups on anhydroglucose units in HCs was the highest on OH(2), and the relative availability of OH(6) increased with the increasing of the hydrolysis time. The USAG contents were more deviated than that calculated based on Spurlin's model, and had a strong tendency of decreasing with increasing the hydrolysis time. The reactivity of HC was lower than that of ${\alpha}$-cellulose and the relative availability of OH(6) in HC increased with the hydrolysis time.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.11
• /
• pp.195-204
• /
• 2020

The aim of this study is to estimate the impact of ownership structure on the performance of listed firms in transition economy. Buiding upon agency theory, hypotheses on such relationship are proposed. A detailed panel data of 502 non-financial companies listed on Ho Chi Minh Stock Exchange and Hanoi Stock Exchange over the period from 2013 to 2018, and the system generalized method of moment estimation are employed to test the proposed hypotheses. To ensure the reliability of data, this study excludes companies that violate information disclosure regulations or that are subject to special supervision by the State Securities Commission of Vietnam. Some firms with inadequate information, firms that lack the financial data required for creating variable or firms that have inconsistent construction are also re-screened. We only collect the data of enterprises that have ownership structure of two or more components. Estimation results reveal that state ownership has an U-shaped relationship with the performance of Vietnamese listed firms, while foreign ownership and the degree of ownership concentration have an inverted U-shaped relationship with listed firms' performance. The article provides governance implications that Vietnamese listed firms should decrease state ownership and foreign ownership to improve firm performance in order to boost investors' confidence.