• 대한수학회논문집
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• 제24권4호
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• pp.501-508
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• 2009

This paper presents a new representation algorithm which computes the representation for elements of a free group generated by two linear fractional transformations and also the justification of the algorithm in order to show how it operates correctly and efficiently according to inputs.

• 공학교육연구
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• 제22권1호
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• pp.48-54
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• 2019

This study examined the effects of free writing in writing class targeted for engineering students on their writing skills. To assess the effects, we have asked 100 engineering students from writing class to write free writing, classifying them as the test group(N=50) and the control group(N=50). We have also compared their learning effect, their writing ability, and learning satisfaction via pre and post intervention surveys. The results showed higher change in learning effect, interest in writing, learning attitude, writing ability, learning satisfaction in the test group compared to the control group. This positive change proves that free writing is a significant teaching method in writing class for engineering and science students.

• 한국식품영양과학회지
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• 제5권1호
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• pp.1-9
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• 1976

The variations of growth gain and the composition of free amino acid levels in plasma and erythrocytes of young rats(wistar strain male) were determined by microbioassay method, feeding diets of rice group and 7% casein group as a control for three weeks. The results were as follows; 1. The growth gain of control diet group was higher than the rice diet group. 2. The contents of free tryptophan, lysine, and threonine levels in plasma and erythrocytes on rats of 7% casein group were higher than the rice group. 3. In the 7% casein diet group and the rice group, these free amino acids were included more in erythrocytes than in plasma. 4. Therefore, generally feeding by high protein score diet was included more Try, Lys, Thr in plasma and erythrocytes than feeding by low protein score diet. So the high and low of protein score was assumed by the contents of Try, Lys, Thr in plasma and erythrocytes on rats.

• Journal of Ginseng Research
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• 제32권2호
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• pp.150-154
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• 2008

Twenty five albino rats were divided into five groups for conducting this experiment. The first group was for positive control (Vitamin C, ascorbic acid), the second group was of Panax ginseng (10 mg/kg body weight) treated group after bio-activity assay, the third group was of mercuric chloride treated group (0.033 mg/kg body weight) based on calculating $LD_{50}$ 9.26 mg/kg body weight by probit analysis, the fourth group was of mercuric chloride (0.033 mg/kg body weight) followed by Panax ginseng (10 mg/kg body weight) and the fifth group was Panax ginseng (10 mg/kg body weight) followed by mercuric chloride (0.033 mg/kg body weight) treated group. The interval between intake of Panax ginseng and mercuric chloride was of 2 hours in groups, fourth and fifth respectively. Comparative free radical scavenging property of Panax ginseng was studied under three in vitro models (role model for calculating scavenging activity) viz. DPPH method (hydroxyl free radicals), Nitric oxide method (nitrile free radicals) and Lipid peroxidation (mercury free radicals).

• 대한수학회보
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• 제47권5호
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• pp.997-1000
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• 2010

We prove that the reduced free product of $k\;{\times}\;k$ matrix algebras over abelian $C^*$-algebras is not the minimal tensor product of reduced free products of $k\;{\times}\;k$ matrix algebras over abelian $C^*$-algebras. It is shown that the reduced group $C^*$-algebra associated with a group having the property T of Kazhdan is not isomorphic to a reduced free product of abelian $C^*$-algebras or the minimal tensor product of such reduced free products. The infinite tensor product of reduced free products of abelian $C^*$-algebras is not isomorphic to the tensor product of a nuclear $C^*$-algebra and a reduced free product of abelian $C^*$-algebra. We discuss the freeness of free product $II_1$-factors and solidity of free product $II_1$-factors weaker than that of Ozawa. We show that the freeness in a free product is related to the existence of Cartan subalgebras in free product $II_1$-factors. Finally, we give a free product factor which is not solid in the weak sense.

• 한국운동역학회지
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• 제22권2호
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• pp.183-191
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• 2012

The objective of this study was to evaluate the plantar foot pressure of skilled and unskilled players during a free throw. The experiment performed here in measured the movement route of the mean foot pressure, maximum foot pressure, and center of pressure in four event zones (ready, maximum knee flexion, release event, and maximum knee extension) for both groups while they were wearing the plantar foot pressure measurement equipment under identical conditions. The major findings are as follows. When getting ready (RD) during a free throw, the skilled player group had higher mean and maximum foot pressures, although neither variable showed significant differences statistically. For the maximum knee flexion (MF) during a free throw, the skilled player group had higher mean and maximum foot pressures, but only the mean foot pressure significantly differed statistically. For the release event (RE) during a free throw, the unskilled player group had higher mean and maximum foot pressures, but only the mean foot pressure significantly differed statistically. During the maximum knee extension (ME) of a free throw, the unskilled player group had a higher mean foot pressure, and the skilled player group had a higher maximum foot pressure. No significant correlation was found between the two groups. For the skilled player group, movement towards the center of pressure showed a stable form that moved from the rear to the front and from side to side during a free throw. For the unskilled player group, movement towards the center of pressure was unstable, which made it impossible to move from the rear to the front and from left to right.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.5811-5816
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• 2013

Background: Breast cancer is the most common cancer among women. Molecular subtypes are important in determining prognosis. This study evaluated five-year disease-free survival among four molecular subtypes in patients with early stages of breast cancer. Materials and Methods: In this retrospective descriptive-analytical study, information on patients with breast cancer between 2001-2010 was evaluated. Five hundred ninety two patients in the early stages of breast cancer (stages 1 and 2) were selected to undergo anthracycline-based chemotherapy. Relapse, death or absence (censor) were considered as the end of the study. Patients based on ER, PR and HER-2 expression were divided into four subtypes (luminal A, luminal B, HER-2 enriched and triple negative). Information based upon questionnaire was analysed. To show the patients survival rate, life table and Kaplan-Meyer methods were used, and for comparing mean survival among different groups, the Log-Rank test was utilized. Results: Mean age at diagnosis was $47.9{\pm}9.6$. Out of the 592 patients, 586 were female (99%) and 6 were male (1%). Considering breast cancer molecular subtypes, 361 patients were in the luminal A group (61%), 49 patients in the luminal B group (8.3%), 48 patients in the HER-2 enriched group (8.1%) and 134 in the triple negative group (22.6%). Mean disease-free survival was 53.7 months overall, 55.4 months for the luminal A group, 48.3 months for the luminal B group, 43 months for the HER-2enriched group and 54.6 months for the triple negatives. Disease free survival differed significantly among the molecular subtypes (p value=0.0001). Conclusions: The best disease-free survival rate was among the luminal A subgroup and the worst disease-free survival rate was among the HER-2 enriched subgroup. Disease free survival rate in the HER-2 positive groups (luminal B and HER-2 enriched) was worse than the HER-2 negative groups (luminal A and triple negative).

• Archives of Plastic Surgery
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• 제42권5호
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• pp.608-613
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• 2015

Background The purpose of this study was to compare postoperative morbidities and functional outcomes of pectoralis major myocutaneous (PMMC) flap and cutaneous free flap reconstruction approaches in hypopharyngeal squamous cell carcinoma patients. Methods We retrospectively reviewed records from 99 patients who underwent hypopharyngeal reconstruction with a cutaneous free flap (n=85) or PMMC flap (n=14) between 1995 and 2013. Morbidity was classified into hospitalization, medical, or flap-related complications. Functional outcomes were classified into oral re-alimentation and decannulation time. Results The overall flap-related complication rate was higher in the PMMC flap group (n=8, 57.1%; P=0.019), but the medical morbidity rate was higher in the cutaneous free flap group (n=68, 80%; P=0.006). The rate of pneumonia was higher in the cutaneous free flap group (n=48, 56.5%; P=0.020). Pulmonary premorbidity was the variable most significantly associated with pneumonia (odds ratio=3.012, P=0.012). There was no statistically significant difference in oral re-alimentation and decannulation time between the two groups. Conclusions Although the functional superiority of free flaps has been reported in many studies, our results do not support this hypothesis. One limitation of our study is the relatively smaller flap size and fewer PMMC flap cases compared with the cutaneous free flap group. The low postoperative medical morbidity incidence rate in the PMMC flap group was clinically significant; however, the free flap group had more flap-related complications. Thus, PMMC flaps should be considered a viable option, especially for patients with pulmonary premorbidities.

• Bulletin of the Korean Chemical Society
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• 제11권2호
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• pp.144-149
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• 1990

Conformational free energy calculations using an empirical potential function (ECEPP/2) and the hydration shell model were carried out on the sulfonylurea herbicides of bensulfuron methyl (Londax) and metsulfuron methyl (Ally). The conformational energy was minimized from starting conformations which included possible combinations of torsion angles in the molecule. The conformational entropy of each conformation was computed using a harmonic approximation. To understand the hydration effect on the conformation of the molecule in aqueous solution, the hydration free energy of each group was calculated and compared each other. It was found that the low-free-energy conformations of two molecules in aqueous solution prefer the overall folded structure, in which an interaction between the carbonyl group of ester in aryl ring and the first amido group of urea bridge plays an important role. From the analysis of total free energy, the hydration and conformational entropy are known to be essential in stabilizing low-free-energy conformations of Londax, whereas the conformational energy is proved to be a major contribution to the total free energy of low-free-energy conformations of Ally.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제17권2호
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• pp.109-129
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• 1995

Many patients with malignancies of the head and neck undergo radiation therapy, either as the only method of treatment or in combination with surgery. Radiation therapy has great effect in the case of fairly advanced malignancies which can't be operated radically. But the complication of radiation therapy arise because of damage to the peri- and operated area. It is fully known that irradiated tissue shows retarded healing process in the skin, mucosa and especially vascuslar tissue. The purpose of this study was to observe the healing process of irradiated free or island flap after operation. As Experimental Models, Femoral arterial and venous anastomosis (Group 1), Epigastric-island flap (Group 2) and free Epigastric falp(Group 3) with irradiated postoperative 24 hrs were made on 30 rats/group. As Control Model(Group 4), Free Epigastric flap was not irradiated after operation was chosen on 30 rats. The amount of irradiation was single fraction of 20 Gy using as linear megavoltage accelerator. Difference between Experimental and Control group was evaluated by the method of clinical examination, histopatholoical findings, biochemical analysis and DNA activity at postoperative 1, 3, 7, 14 and 28 days. The results were as follows, 1. Skin color and new epithelization in group 2 and 3 was similar to control group clinically. 2. Postoperarive patency of femoral artery and vien showed 5% and 22% of ischemity. 3. The externa, media and intima of irradiated femoral artery and vein were similar to control group histopathlogically. 4. Granulation and collagen tissue accumulation of irradiated groups were more active due to degenerative and fibrotic changes than control group at postoperative 7 days histopathologically. 5. The hydroxyproline content of all experimental groups were reduced till 14 days and the group 2 was most prominent at postoperative 7 and 28 days(p<0.05). 6. DNA activities of all groups were reduced till 3 days, but begun to recover at 7 days and more activities in control group than irradiated group(p<0.05). Based on the above results, the clinical healing process of free flaps with irradiated postoperative 24 hrs little difference from control group without complications.