• Management & Information Systems Review
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• v.28 no.3
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• pp.191-210
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• 2009

Internet was first designed only for sending data, but as the time passed, internet started to evolve into a broadband multi-media web that is capable of transmitting sound, video, high-capacity data and more due to the demands of internet users and the rapid changing internet-communication technology. Domestically, in January, 2000 Saerom C&T, launched a free VoIP, but due to limited ways of conversation(PC to PC) and absence of a revenue model, and bad speech quality, it had hit it's growth limit. This research studied VoIP based on technological enhancement in super-speed internet. According to IDC, domestic internet market's size was 80,800 million in 2008, and it formed a percentage of 12.5% out of the whole sound-communication market. in case of VoIP, it is able to maximize it's profit by connecting cable and wireless network, also it has a chance of becoming firm-concentrated monopoly market by fusing with IPTV. Considering the fact that our country is insignificant in MVNO revitalization, regulating organizations will play a significant roll on regulating profit between large and small businesses. Further research should be done to give VoIP a secure footing to prosper and become popularized.

• Journal of Korean Home Economics Education Association
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• v.32 no.2
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• pp.179-192
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• 2020

High school credit system refers to a system in which a student selects the desired content according to his/her subject and completes accumulated credits to reach graduation when a certain standard is reached. The purpose of this study is to identify the advantages and disadvantages to the technology and home economics education after the introduction of the high school credit system by analyzing the status of high school elective subjects in technology and home economics areas, and the perceptions and needs of teachers and experts as the introduction of the high school credit system approaches. A survey was conducted to all professors in the Department of Home Economics Education or Technology Education, along with a national sample of the secondary school teachers of Home Economics and Technology, and responses of 282 teachers and 36 experts were analyzed. Results are as follows: First, in general high schools, the formation and operation of elective courses in technical and home economics were very insufficient. Second, there was a large number of requests for the expansion of elective courses in technology and home economics among the high school teachers. Third, in order to take advantage of the high school credit system, it was recognized that elective courses in technology and home economics should be established not only in consideration of secondary school education, but in relation to their connections with majors in universities. Improving the structure of electives in this direction is expected to play a positive role in allowing elective courses in technology and home economics to contribute to ensuring students' free choice.

• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.597-606
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• 1994

Oxygen derived radicals($O_2\;^-$, $H_2O_2$, and $OH^-$) are thought to play a role in a lot of human diseases. And it has been believed that antioxidant enzymes such as superoxide dismutase(SOD) and catalase could protect the tissues from damage resulting from the oxygen derived free radicals. The purpose of this study was performed to investigate the activity of the SOD(CuZn- and Mn-SOD) and catalase in inflammatory gingival tissues and the correlation between boold glucose level and antioxidants and age in non-insulin dependent diabetes mellitus(NI- DDM) patients. For this study, the patients were classified into normal, inflammatory, and diabetic, and ten their papillary bleeding index(PBI) and gingival index were checked. Subjects consisted of 11 healthy patients with no inflammatroy gingiva, 20 adult periodontitis patients, and 8 diabetic patients, aged 33 to 66(average: 44.62). The blood glucose level of diabetic group was ranged from 120ml/dl to 160ml/dl(physical status 0 : averge : 135.67ml/dl). Gingival tissues were surgically obtained from the patients during periodontal surgery, extraction, and clinical corwn lenghening procedure. The activity of CuZn and Mn- SOD and catalase in the gingival tissues was measured by using UV-spectrophotometer by the same methods that Crapo et al. And Aebi did, respectively. The results were as follows : 1. The Mn-SOD activity was significantly lower in inflammatory group in comparison to normal group(P<0.05), and the activities of antioxidants in diabetic group were not significant in comparison to normal inflammatory group(P>0.05). 2. The activities of antioxidants showed little variation among individuals of different ages (P>0.05). 3. The higher blood glucose level was, the higher gingival index was(P<0.05). 4. There was no correlation between blood glucoe level and activity of antioxidant in inflammatory gingival tissues of NIDDM patients(P>0.05). In conclusion, these results, within the limits of the present experiment, suggest that the activity of Mn-SOD might reflect the inflammatory status of gingival tissue, and the activity of antioxidants was independent of blood glucose level of diabetic patients in physical status 0.

• Information Systems Review
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• v.18 no.1
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• pp.125-140
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• 2016

Mobile applications (apps) play a significant role in the proliferation of smartphones. According to statistics from Apple, 100 million apps were downloaded in 2008. Since then, the number of cumulative app downloads have increased exponentially. By October 2014, 85 billion apps had been downloaded worldwide. Many studies have attempted to determine the factors that drive app downloads. However, unlike previous studies, we examine the effects of app updates on app rankings. To achieve this goal, we collected data on rankings (gross rankings and category rankings), update contents, reviewer ratings, and number of reviews on apps listed in the App Store. We then categorized app updates into functionality, reliability, and convenience updates following the buying hierarchy model. We found that functionality updates had a positive effect on app gross ranking whereas reliability updates had a positive effect on category ranking. Our study is the first to explore the effects of update content on app ranking. Moreover, our study provides a practical implication for mobile app developers, who should consider app updates in their product development strategy.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1147-1151
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• 2007

The human skin is constantly exposed to environmental irritants such as ultraviolet, smoke and chemicals. Free radicals and reactive oxygen species caused by them play critical roles in cellular damage. They not only injure the skin structure but also participate in the immensely complex inflammatory reaction. Anti-wrinkle effects of the Oriental herb extracts(OHE) were evaluated by the determination of anti-oxidation, collagenase inhibition and collagen synthesis in normal human fibroblast. OHE showed antioxidative activity as high as vitamin C, trolox and DL-penicillamine. Also OHE showed promotive effect on collagen synthesis and inhibitory effect on collagenase activity. These results demonstrated that OHE could be useful as an anti-wrinkle cosmetic ingredient.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1137-1144
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• 2012

Introduction: Recent studies have shown that circulating tumor cells (CTCs) play potential roles as diagnostic and prognostic biomarkers with various cancer types. The aim of this study was to comprehensively and quantitatively summarize the evidence for the use of CTCs to predict the survival outcome of lung cancer patients. Materials and Methods: Relevant literature was identified using Medline and EMBASE. Patients' clinical characteristics, overall survival (OS) and progression-free survival (PFS) together with CTC positive rates at different time points (before, during and after treatment) were extracted. A meta-analysis was performed to clarify the prognostic role of CTCs and the correlation between the CTC appearance and clinical characteristics. Results: A total of 12 articles containing survival outcomes and clinical characteristics and 15 articles containing only clinical characteristics were included for the global meta-analysis. The hazard ratio (HR) for OS predicted by pro-treatment CTCs was 2.61 [1.82, 3.74], while the HR for PFS was 2.37 [1.41, 3.99]. The HR for OS predicted by post-treatment CTCs was 4.19 [2.92, 6.00], while the HR for PFS was 4.97 [3.05, 8.11]. Subgroup analyses were conducted according to histological classification and detection method. Odds ratio (OR) showed the appearance of pro-treatment CTCs correlated with the lymph node status, distant metastasis, and TNM staging, while post-treatment CTCs correlated with TNM staging only. Conclusion: Detection of CTCs in the peripheral blood indicates a poor prognosis in patients with lung cancer.

• The Journal of the Convergence on Culture Technology
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• v.6 no.3
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• pp.193-204
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• 2020

According to science technology development, information society has progressed rapidly in the 21st century. Our consciousness and tradition have become entangled in the tide of Westernization. Therefore, the education of Chinese characters was neglected, and Chinese poetry literature was naturally neglected. This led to the abundance of material civilization, however, from the mental aspects, the daily life of modern people became insecure. There is a poet who has lived a lonely life of creation of Chinese poetry in this era. He is a Geasan Kwon Seung Geun(1940~) who writes only poem while being friends with nature. His Chinese poems were revealed through life experiences in nature, which is inspiring sympathy. The origin of his theme is nature. The poetry obtained from nature is rustic simple and pure. Therefore His poems have the style and taste of nature. The Chinese poetry literature of Geasan has been embodied the elements of self-interest, self-satisfaction, self-contentment and living in free at his literatue. On its basis, his Chinese literature has aesthetic boundary of remaining aloofness(自然而然的 超然)·rambling talk, living peacfully and play around with leisure·(閒遠物遊的 閑淡)·deviation rhyme of vividly and beautifully(生趣淸遠的 逸韻) The aesthetic boundary of Chinese poetry of Geasan can be seen as having a depth. This is the aesthetic boundary of Chinese poetry written by this generation in the 21st century.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.1213-1217
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• 2015

Background: Gastric cancer is the second most common cause of cancer- related deaths worldwide and ranks $11^{th}$ or $14^{th}$ among all deaths. Patients with advanced disease require supportive care along with the medical and/or surgical treatment. Aim: To assess the need for palliative care for patients with advanced tumours along with standard clinical therapy. Materials and Methods: Eighty-four patients with metastatic (stage 4) gastric cancer, including both patients who had received surgical treatment or not, were followed up in Bagcilar Training and Research Hospital, Division of Medical Oncology between 2011 and 2014. They were categorised as supportive care (-) (Group 1, n=37) and (+) groups (Group 2, n=47) and evaluated retrospectively. Results: Demographic characteristics of the patients were as follows: mean age, Group 1, $65.2{\pm}10.5$ years, Group $2,63.7{\pm}11.3$ years; male/female ratio, Group 1, 21/16, Group 2, 28/19; distribution of Eastern Cooperative Oncology Group (ECOG) performance scores of 0 and 1, Group 1, ECOG 0 (n=9) and 1 (n=14), Group 2, ECOG 0 (34) and 1 (n=13) (p<0.0001); patients receiving second-line, Group 1 (n=7) and Group 2 (n=22) (p<0.008) or third - line chemotherapy,Group 2 (n=6) (p<0.02); mortality rates, Group 1, (n=28; 75.6%) and Group 2 (n=30; 63.8%); progression-free survival (PFS) rates, Group 1, $17.4{\pm}6$ weeks, Group 2, $28.3{\pm}16.2$ weeks; statistically significant overall survival rates, Group 1, $20.8{\pm}8.2$ weeks and Group 2, $28.3{\pm}162$ weeks (p<0.01). Conclusions: The supportive care team (medical oncologist, general surgeon, internal medicine specialist, algologist, psychiatrist and radiologist) can play a role in the treatment of metastatic gastric tumours, with improvements shown in terms of the performance status of cases, eligibility of patients to be on chemotherapy programmes for longer duration and overall survival rates in Turkey.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.641-650
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• 2010

The concrete cracking from the restrained stress caused by the shrinkage may play significant cause of deterioration of concrete structures by allowing the permeation of sulphate and chloride ions which in turn triggers corrosion of steel reinforcement. In particular, the cracking becomes more critical as water binder ratio (W/B) is reduced and concrete strength increases. Therefore, it needs to evaluate correctly the comprehensive shrinkage behavior of concrete with high strength: high-strength concrete (HSC), ultra-highstrength concrete (UHSC). The unrestrained shrinkage tests, however, cannot estimate the net shrinkage effectively which affects cracking after full development of strength and stiffness because it does not consider the degree of restraint, strength development, stress relaxation, and so on. Therefore, in this study, both free and restrained shrinkage tests with variables of W/B (W/B of 30, 25 and 16%) and admixtures (fly ash (FA) and granulated blast-furnace slag (BFS)) for HSC, very-high-strength concrete (VHSC) and UHSC were performed. The test results indicated that the autogenous shrinkage and total shrinkage at drying condition were reduced as W/B increased and FA, BFS were added, and the cracking behavior was suppressed as W/B increased and FA was added.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.4
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• pp.413-423
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• 1997

The importance of the kidney in the development of hypertension was first demonstrated by Goldblatt and his colleagues more than fifty years ago. Many hormones and other regulatory factors have been proposed to play a major role in the development of hypertension. Among these factors angiotensia II (ANG II) is closely involved in renal hypertension development since it directly regulates $Na^+$ reabsorption in the renal proximal tubule. Thus the aim of the present study was to examine signaling pathways of low dose of ANC II on the $Na^+$ uptake of primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined seum-free medium. The results were as follows: 1) $10^{-11}$ M ANG II has a significant stimulatory effect on growth as compared with control. Alkaline phosphatase exhibited significantly increased activity. However, leucine aminopeptidase and ${\gamma}-glutamyl$ transpeptidase activity were not significant as compared with control. In contrast to $10^{-11}$ M ANG II stimulated $Na^+$ uptake $(108.03{\pm}2.16% of that of control)$, $10^{-9}$ M ANG II inhibited ($92.42{\mu}2.23%$ of that of control). The stimulatory effect of ANG II on $Na^+$ uptake was amiloride-sensitive and inhibited by losartan (ANG II receptor subtype 1 antagonist) and not by PD123319 (ANG II receptor subtype 2 antagonist). 2) Pertussis toxin (PTX) alone inhibited $Na^+$ uptake by $85.52{\pm}3.52%$ of that of control. In addition, PTX pretreatment prevented the AMG II-induced stimulation of $Na^+$ uptake. 8-Bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP), forskolin, and isobutylmethylxanthine (IBMX) alone inhibited $Na^+$ uptake by $88.79{\pm}2.56,\;80.63{\pm}4.38,\;and\;84.47{\pm}4.74%$ of that of control, respectively, and prevented the ANG II-induced stimulation of $Na^+$ uptake. However, $10^{-11}$ M ANG II did not stimulate cAMP production. 3) The addition of 12-O-te-tradecanoylphorbol-13-acetate (TPA, 0.01 ng/ml) to the PTCs produced significant increase in $Na^+$ uptake ($114.43{\pm}4.05%$ of that of control). When ANG II and TPA were added together to the PTCs, there was no additive effect on $Na^+$ uptake. Staurosporine alone had no effect on $Na^+$ uptake, but led to a complete inhibition of ANG II- or TPA-induced stimulation of Na'uptake. ANG II treatment resulted in a $111.83{\mu}4.51%$ increase in total protein kinase C (PKC) activity. In conclusion, the PTX-sensitive PKC pathway is the main signaling cascade involved in the stimulatory effects of ANG II on $Na^+$ uptake in the PTCs.