• Elastomers and Composites
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• v.49 no.2
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• pp.110-116
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• 2014

We investigated the effect of the concentration of stannous 2-ethylhexanoate catalyst on the esterification rate between adipic acid (AA) and each of two PEG oligomers, diethylene glycol (DEG) and polyethylene glycol (PEG600). The concentration of the catalyst was varied from 0.15 to 2.0 wt.%. To attach hydroxy group to each end of the poly(oxyethylene-co-adipate) synthesized from AA and the PEGs, the esterification was performed with excessive PEG oligomers ([PEG]/[AA]=2) at $170^{\circ}C$. The degree of polymerization of the poly(oxyethylene-co-adipate)diol products were three. The apparent rate constant ($k_{app}$) of the esterification between AA and DEG shows the first order dependency on the catalyst concentration ($k_{app}=0.88[C_{cat}]$), whereas the $k_{app}$ of the esterification between AA and PEG600 has a relation of $k_{app}=0.123[C_{cat}]^{0.55}$ with the catalyst concentration. It is expected that the rate of esterification between AA and DEG has a non-linear dependency on the catalyst concentration as the catalyst concentration approaches to 0.22M.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.85.3-86
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• 1976

Sudden deafness requires immediate investigation and treat if there is to be any prospect of salvaging the hearing. It present an otological emergency and a diagnostic challenge. Sn Sudden sensorineural deafness can be caused by a wide variety of pathologies. A battery of tests and investigations must be performed forthwith if treatment is to be started without further delay. The concept that nothing can be done for the patient with sensori-neural deafness must be abandoned. Some pathologies causing sudden deafness are not amenable to therapy or can show only partial reversibility. But there are several causes, showing little or no spontaneous recovery, which do responed to appropriate treatment. It is important to identify them and concentrate on their management. The age and sex ratios and the unilaterral or bilateral nature of the lesion are related to the etiology and depend upon which type of case is included in the series. Though individually rare, collecting for about 2.5 per cent of new otoloical patients. Some 70 per cent of cases are unilateral. Viral, bacterial and treponemal infections accounted for about 30 per cent of the cases. Some 16 per cent were due to vascular lesions of the cochlea. In almost 22 per cent there was no obvious cause (idiopathic), they occurred in young adult and were either sensory or neural. About 12 per cent were traumatic and 9 per cent were ototoxic in origin. The remaining 11 per cent were due to a group of rarities. The two vital factors are the site of the lesion and the duration of the hearing loss. The earlier these are diagnosed and treated the better the response. The etiology, pathology and treatment are reviewed.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.255-264
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• 2013

This research was conducted to analyze parents' attitudes on the issues related to the Smart Education Initiative Korea. The questions included the usefulness of major digital tools for educational purposes, knowledge on the Smart Education, necessity for better educational methods, and Bring Your Own Devices (BYOD) policy. A total of 432 response cases from the parents were analyzed considering the parents' age, academic level, and income. As a result, parents regarded desktop PCs as more effective tools for learning when compared to tablet PCs. Meanwhile, mobile devices and SNSs were hardly considered as instructional tools. Second, familarity and understanding of the Smart Education were proportional to household income and mothers' education levels. Third, parents needed for the change in educational methods and agreed with the importance of students' self-regulated learning, collaboration, inquiry ability and creativity. Fourth, regarding BYOD, parents were willing to buy devices with a reasonable price. In conclusion, it is required to reflect the results of the study when implementing the Smart Education throughout the nation.

• Journal of Sericultural and Entomological Science
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• v.3
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• pp.61-67
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• 1963

This report is prepared to find how the filament of cocoon bave size deviation relates with the raw silk made by them which are intensively cultured in this country. Three recommended hybrid varieties and two varieties under working at Suwon Sericultural Experiment Station were selected as specimens. The cocoons were reeled as an individual filament of every fifty meters long skein with a wrap reel to weigh the denier and to investigate the relationship of the above statement so that it may be used for the quality estimation before processing it into raw silk. The conclusions obtained are as follows. (1) The variation of Pk${\times}$Sn was found as best cocoon for 21 denier raw silk use, but the number of cocoon to make the denier has to be eight which might cause more labor cost. (2) Baektoo-Kumkang and Myohiang-Chongchon were found as economical varieties for 21 denier use. (3) Seulak-Soyang is a proper variety for the use of 14 or 28 denier silk use. (4) Myohiang-Chongchon did not confirm a good property from the aspect of denier deviation. (5) It was found that there was a fairly strong corelationship between the mean cocoon bave size deviation as indicated by Ono's report. (6) Three graphs were prepared to estimate the cocoon quality before processing into various sizes of raw silk using the mean cocoon bave size and the raw silk size to be prepared. (7) Mean time, the graph which is able to estimate the expectable grade of the raw silk size deviation was designed for the practical use. (8) The expectable grade of the varieties used in this report were found as following data. Notice (A......cocoon number to make raw silk (B......total cocoon bave size deviation (C......expectable silk grade (9) The result of the work concerning the expectable denier deviation on 21 denier silk was the same with the statistical actual testing result as 1.25 D while the distribution showed farther necessity of improvement in technically.

• Journal of the Korean Applied Science and Technology
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• v.38 no.4
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• pp.1070-1080
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• 2021

This study is a descriptive survey research on social network service addiction tendency and interpersonal relationships on college life adaptation among nursing students. The study period was from October 1 to 4, 2019, the survey was conducted for 228 first and third year nursing students located in G city. The collected data were analyzed with the SPSS 23.0 program using descriptive statistics, ANOVA, Pearson correlation coefficients, and multiple regression. The results of the study showed that there were differences in the subjects' college life adaptation depending on their gender (t=5.26, p<.001), daily average duration of using social network service (F=8.07, p<.001), and friends in real life (F=2.87, p=.037). College life adaptation had a significant correlation with social network service addiction tendency (r=-.31, p<.001) and interpersonal relationships (r=.52, p<.001), and social network service addiction tendency with interpersonal relationships had a significant correlation (r=-.17, p=.011). Factors that affected college life adaptation included interpersonal relationships (𝛽=.477, p<.001), gender (𝛽=-.198, p=.001), and daily average duration of using social network service (𝛽=-.177, p=.003), and the explanatory power of these factors was 37.8%. Based on the results of this study, it is thought that it is necessary to develop a program for a positive interpersonal relationship formation using social network service in order to improve the college life adaptation of nursing students.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.403-411
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• 2018

Purpose : The purpose of this study is to analyze how the certain efforts of the optical shops affect on opticians' job satisfaction and organizational commitment, and to analyze how opticians' job satisfaction and organizational commitment affect on the customer orientation and to suggest the method of maintaining competitiveness. Methods : Two hundred opticians took participations on the surveys via the Internet survey method and social network system (SNS), and SPSS 18.0 statistics program was used for data analysis; frequency analysis, T-test, factor analysis, reliability analysis, and multiple linear regression analysis were conducted. Results : It is analyzed the differences on the job satisfaction and organizational commitment in accordance with type of optical shops, conducting 5 working days/week and flexible time. As a result, higher job satisfaction is presented with 5 working days/week. Relationships with co-workers statistically affect on job satisfaction positively and emotional labor and work overload statistically affect on job satisfaction negatively. In addition, relationships with co-workers and reward statistically affect on organizational commitment positively and emotional labor and work overload statistically affect on organizational commitment negatively. And opticians' job satisfaction and organizational commitment statistically affect on customer satisfaction positively. Conclusion : It is necessary for the optical shops to make an effort for their opticians to improve the job satisfaction and organizational commitment. And to do so, it is needed to form trusting and respecting relationships with co-workers or superiors. In addition, it is necessary to have continuous communication and education for opticians' self-management. Also, it is needed to establish an effective reward system.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.1
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• pp.18-25
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• 2019

2-Nitroimidazole derivatives have been reported to accumulate in hypoxic tissue. We prepared a novel $^{99m}Tc-MAG_3$-2-nitroimidazole and evaluated the feasibility for hypoxia imaging agent. $Bz-MAG_3$-2-nitroimidazole was synthesized by direct coupling of $Bz-MAG_3$ and 2-nitroimidazole using dicyclohexylcarbodiimide. $Bz-MAG_3$-2-nitroimidazole was labeled with $^{99m}Tc$ in the presence of tartaric acid and $SnCl_2-2H_2O$ at $100^{\circ}C$ for 30 min. And the reaction mixture was purified by $C_{18}$ Sep-pak cartridge. The labeling efficiency and the radiochemical purity were checked by ITLC-SG/acetonitrile. The tumor was grown in balb/c mice for 8~13 days after the subcutaneous injection of tumor cells, CT-26 (murine colon adenocarcinoma cell). Biodistribution study and tumor autoradiography were performed in the xenografted mice after i.v injection of 74 kBq/0.1 mL and 19 MBq/0.1 mL of $^{99m}Tc-MAG_3$-2-nitroimidazole, respectively. In vivo images of $^{99m}Tc-MAG_3$-2-nitroimidazole in tumor bearing mice were obtained 1.5 hr post injection. The labeling efficiency was $45{\pm}20%$ and the radiochemical purity after purification was over 95%. Paper electrophoresis confirmed negative charge of $^{99m}Tc-MAG_3$-2-nitroimidazole. $^{99m}Tc-MAG_3$-2-nitroimidazole was very stable at room temperature and its protein binding was 53%. The $^{99m}Tc-MAG_3$-2-nitroimidazole exhibited high uptake in the liver, stomach and intestine. In biodistribution study using tumor bearing mice, the uptakes (% ID/g) of the tumor were $0.5{\pm}0.1$, $0.4{\pm}0.0$, $0.2{\pm}0.1$ and $0.1{\pm}0.1$ at 5, 15, 30 min and 4 hrs. Tumor/muscle ratio were $1.4{\pm}0.1$, $2.2{\pm}0.83$, $3.0{\pm}0.9$, and 3.7 (n=2) for 5, 15, 30 min and 4 hrs. The uptake in hypoxic area was found higher than in non-hypoxic area of tumor tissue by autoradiography. In vivo images showed the relatively faint uptake to the hypoxic tumor region. $^{99m}Tc-MAG_3$-2-nitroimidazole was successfully synthesized and found feasible for imaging hypoxia.

• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.43-59
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• 2019

Today, with the spread of smartphones and the development of social networking services, structured and unstructured big data have stored exponentially. If we analyze them well, we will get useful information to be able to predict data for the future. Large amounts of data need to be collected first in order to analyze big data. The web is repository where these data are most stored. However, because the data size is large, there are also many data that have information that is not needed as much as there are data that have useful information. This has made it important to collect data efficiently, where data with unnecessary information is filtered and only collected data with useful information. Web crawlers cannot download all pages due to some constraints such as network bandwidth, operational time, and data storage. This is why we should avoid visiting many pages that are not relevant to what we want and download only important pages as soon as possible. This paper seeks to help resolve the above issues. First, We introduce basic web-crawling algorithms. For each algorithm, the time-complexity and pros and cons are described, and compared and analyzed. Next, we introduce the state-of-the-art web crawling algorithms that have improved the shortcomings of the basic web crawling algorithms. In addition, recent research trends show that the web crawling algorithms with special purposes such as collecting sentiment words are actively studied. We will one of the introduce Sentiment-aware web crawling techniques that is a proactive web crawling technique as a study of web crawling algorithms with special purpose. The result showed that the larger the data are, the higher the performance is and the more space is saved.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.118-129
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• 2018

In AI chatbot service via a messenger, a profile image of the chatbot is the first thing that users see to communicate with the chatbot. This profile image not only manages an impression about the profile owner in SNS on followers, but also makes an important impression about chatbot services on users. Thus motivated, this study investigates proper profile images tailored for the types of chatbot services and users. Specifically, I reviewed the preferred images and expressions of chatbots for each purpose of chatbot service. Then, in a case study, I collected and analyzed the representative chatbot profile images for the purpose of fun and counseling. The profile images are categorized as robot, human, animal, and abstract images. Based on these categories, I surveyed the preferred profile image of the chatbot service in either the text type or image type alternatives. For the purpose of fun, in the text version, I found that both men and women preferred a human image to others. However, in the image version, men preferred woman and robot images while women preferred cute animation character and robot images. For counseling services, both men and women preferred woman and animal images most, which is similar to the results of the text version of questionnaires as well. While both genders consistently preferred real photo images, women tend to like abstract images more than men do. I expect that the results of this study would be useful to develop the proper profile images of AI chatbot for each service purpose.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.30-37
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• 2018

The social media data and the broadcasting data related to onion as well as agri-food consumer panel data were collected and investigated if the amount of money spent to purchase onion in year 2014 when onion price plunged latest were correlated with the frequencies of onion-related keywords in the social media data and the broadcasting programs because onion price in year 2018 is expected to plunge due to overproduction and there has been needs to analyze impacts of social media and broadcasting program on onion purchase in the previous similar events, and identify potential factors that can promote onion consumption in advance. What we identified from our study include a) broadcasting news programs mentioning words "onion," were correlated with onion purchase with 3 - 6 weeks in advance; b) broadcasting entertainment programs mentioning words "onion and health," were correlated with onion purchase with 11 weeks in advance; c) blog mentioning words "onion and efficacy," were correlated with onion purchase with 5 weeks in advance. Our study provided a case on how social media and broadcasting programs could be analyzed for their effects on consumer purchase behavior using big data collection and analysis in the field of agriculture. We propose to use the findings from the study may be applied to promote onion consumption.