• Journal of Internet Computing and Services
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• v.25 no.3
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• pp.43-54
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• 2024

This study employs text mining techniques to compare user responses across various Over-The-Top (OTT) service platforms. The primary objective of the research is to understand user satisfaction with OTT service platforms and contribute to the formulation of more effective review strategies. The key questions addressed in this study involve identifying prominent topics and keywords in user reviews of different OTT services and comprehending platform-specific user reactions. TF-IDF is utilized to extract significant words from positive and negative reviews, while BERTopic, an advanced topic modeling technique, is employed for a more nuanced and comprehensive analysis of intricate user reviews. The results from TF-IDF analysis reveal that positive app reviews exhibit a high frequency of content-related words, whereas negative reviews display a high frequency of words associated with potential issues during app usage. Through the utilization of BERTopic, we were able to extract keywords related to content diversity, app performance components, payment, and compatibility, by associating them with content attributes. This enabled us to verify that the distinguishing attributes of the platforms vary among themselves. The findings of this study offer significant insights into user behavior and preferences, which OTT service providers can leverage to improve user experience and satisfaction. We also anticipate that researchers exploring deep learning models will find our study results valuable for conducting analyses on user review text data.

• Radiation Oncology Journal
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• v.23 no.3
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• pp.143-156
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• 2005

Background: The best dose-fractionation regimen of the definitive radiotherapy for cervix cancer remains to be clearly determined. It seems to be partially attributed to the complexity of the affecting factors and the lack of detailed information on external and intra-cavitary fractionation. To find optimal practice guidelines, our experiences of the combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) were reviewed with detailed information of the various treatment parameters obtained from a large cohort of women treated homogeneously at a single institute. Materials and Methods: The subjects were 743 cervical cancer patients (Stage IB 198, IIA 77, IIB 364, IIIA 7, IIIB 89 and IVA 8) treated by radiotherapy alone, between 1990 and 1996. A total external beam radiotherapy (EBRT) dose of $23.4\~59.4$ Gy (Median 45.0) was delivered to the whole pelvis. High-dose-rate intracavitary brachytherapy (HDR-IBT) was also peformed using various fractionation schemes. A Midline block (MLB) was initiated after the delivery of $14.4\~43.2$ Gy (Median 36.0) of EBRT in 495 patients, while In the other 248 patients EBRT could not be used due to slow tumor regression or the huge initial bulk of tumor. The point A, actual bladder & rectal doses were individually assessed in all patients. The biologically effective dose (BED) to the tumor ($\alpha/\beta$=10) and late-responding tissues ($\alpha/\beta$=3) for both EBRT and HDR-ICBT were calculated. The total BED values to point A, the actual bladder and rectal reference points were the summation of the EBRT and HDR-ICBT. In addition to all the details on dose-fractionation, the other factors (i.e. the overall treatment time, physicians preference) that can affect the schedule of the definitive radiotherapy were also thoroughly analyzed. The association between MD-BED $Gy_3$ and the risk of complication was assessed using serial multiple logistic regression models. The associations between R-BED $Gy_3$ and rectal complications and between V-BED $Gy_3$ and bladder complications were assessed using multiple logistic regression models after adjustment for age, stage, tumor size and treatment duration. Serial Coxs proportional hazard regression models were used to estimate the relative risks of recurrence due to MD-BED $Gy_{10}$, and the treatment duration. Results: The overall complication rate for RTOG Grades $1\~4$ toxicities was $33.1\%$. The 5-year actuarial pelvic control rate for ail 743 patients was $83\%$. The midline cumulative BED dose, which is the sum of external midline BED and HDR-ICBT point A BED, ranged from 62.0 to 121.9 $Gy_{10}$ (median 93.0) for tumors and from 93.6 to 187.3 $Gy_3$ (median 137.6) for late responding tissues. The median cumulative values of actual rectal (R-BED $Gy_3$) and bladder Point BED (V-BED $Gy_3$) were 118.7 $Gy_3$ (range $48.8\~265.2$) and 126.1 $Gy_3$ (range: $54.9\~267.5$), respectively. MD-BED $Gy_3$ showed a good correlation with rectal (p=0.003), but not with bladder complications (p=0.095). R-BED $Gy_3$ had a very strong association (p=<0.0001), and was more predictive of rectal complications than A-BED $Gy_3$. B-BED $Gy_3$ also showed significance in the prediction of bladder complications in a trend test (p=0.0298). No statistically significant dose-response relationship for pelvic control was observed. The Sandwich and Continuous techniques, which differ according to when the ICR was inserted during the EBRT and due to the physicians preference, showed no differences in the local control and complication rates; there were also no differences in the 3 vs. 5 Gy fraction size of HDR-ICBT. Conclusion: The main reasons optimal dose-fractionation guidelines are not easily established is due to the absence of a dose-response relationship for tumor control as a result of the high-dose gradient of HDR-ICBT, individual differences In tumor responses to radiation therapy and the complexity of affecting factors. Therefore, in our opinion, there is a necessity for individualized tailored therapy, along with general guidelines, in the definitive radiation treatment for cervix cancer. This study also demonstrated the strong predictive value of actual rectal and bladder reference dosing therefore, vaginal gauze packing might be very Important. To maintain the BED dose to less than the threshold resulting in complication, early midline shielding, the HDR-ICBT total dose and fractional dose reduction should be considered.

• Journal of Korea Spatial Information System Society
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• v.10 no.4
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• pp.77-88
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• 2008

There has been growing demands to manage the water quality of west coastal region due to the large scale urbanization along the coastal zone, the possibility of application of TMDL(Total Maximum Daily Loadings) to Han river, and the natural disaster such as oil spill incident in Taean, Chungnam. However, no system has been developed for such purposes. In this background, the demand of GIS based effective water quality management has been increased to monitor water quality environment and propose best management alternatives for Han river and Kyeonggi bay. This study mainly focused on the development of integrated water quality management system for Han river bas in and its estuary are a connected to Kyeonggi bay to support integrated water quality management and its plan. Integration was made based on GIS by spatial linking between water quality attributes and location information. A GIS DB was built to estimate the amount of generated and discharged water pollutants according to TMDL technical guide and it included input data to use two different water quality models--W ASP7 for Han river and EFDC for coastal area--to forecast water quality and to suggest BMP(Best management Practices). The results of BOD, TN, and TP from WASP7 were used as the input to run EFDC. Based on the study results, some critical areas which have relatively higher pollutant loadings were identified, and it was also identified that the locations discharging water pollutant loadings to river and seasonal factor affected water quality. And the relationship of water quality between river and its estuary area was quantitatively verified. The results showed that GIS based integrated system could be used as a tool for estimating status-quo of water quality and proposing economically effective BMPs to mitigate water pollution. Further studies need to be made for improving system's capabilities such as adding decision making function as well as cost-benefit analysis, etc. Also, the concrete methodology for water quality management using the system need to be developed.

• Tuberculosis and Respiratory Diseases
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• v.67 no.2
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• pp.95-104
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• 2009

Background: The pathophysiologic mechanisms of early acute lung injury (ALI) differ according to the type of primary insult. It is important to differentiate between direct and indirect pathophysiologic pathways, and this may influence the approach to treatment strategies. NF-$\kappa$B decoy oligodeoxynucleotide (ODN) is a useful tool for the blockade of the expression of NF-$\kappa$B-dependent proinflammatory mediators and has been reported to be effective in indirect ALI. The purpose of this study was to investigate the effect of NF-$\kappa$B decoy ODN in the lipopolysaccharide (LPS)-induced direct ALI model. Methods: Five-week-old specific pathogen-free male BALB/c mice were used for the experiment. In the preliminary studies, tumor necrosis factor (TNF)-$\alpha$, interleukine (IL)-6 and NF-$\kappa$B activity peaked at 6 hours after LPS administration. Myeloperoxidase (MPO) activity and ALI score were highest at 36 and 48 hours, respectively. Therefore, it was decided to measure each parameter at the time of its highest level. The study mice were randomly divided into three experimental groups: (1) control group which was administered 50 ${\mu}L$ of saline and treated with intratracheal administration of 200 ${\mu}L$ DW containing only hemagglutinating virus of Japan (HVJ) vector (n=24); (2) LPS group in which LPS-induced ALI mice were treated with intratracheal administration of 200 ${\mu}L$ DW containing only HVJ vector (n=24); (3) LPS+ODN group in which LPS-induced ALI mice were treated with intratracheal administration of 200 ${\mu}L$ DW containing 160 ${\mu}g$ of NF-$\kappa$B decoy ODN and HVJ vector (n=24). Each group was subdivided into four experimental subgroups: (1) tissue subgroup for histopathological examination for ALI at 48 hours (n=6); (2) 6-hour bronchoalveolar lavage (BAL) subgroup for measurement of TNF-$\alpha$ and IL-6 in BAL fluid (BALF) (n=6); (3) 36-hour BAL subgroup for MPO activity assays in BALF (n=6); and (4) tissue homogenate subgroup for measurement of NF-$\kappa$B activity in lung tissue homogenates at 6 hours (n=6). Results: NF-$\kappa$B decoy ODN treatment significantly decreased NF-$\kappa$B activity in lung tissues. However, it failed to improve the parameters of LPS-induced direct ALI, including the concentrations of tumor necrosis factor-$\alpha$ and interleukin-6 in BALF, myeloperoxidase activity in BALF and histopathologic changes measured by the ALI score. Conclusion: NF-$\kappa$B decoy ODN, which has been proven to be effective in indirect models, had no effect in the direct ALI model.

• The Korean Journal of Food And Nutrition
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• v.19 no.2
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• pp.183-192
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• 2006

The purpose of this study was to investigate the performance of elementary school dietitians in terms of nutrition education in the northern portion of Gyeonggi province. Self-administered questionnaires were given to 50 dietitians who have worked in elementary schools with self-operation food service, and 35(70%) dietitians returned the questionnaires. The results are summarized as follows: no students took part in nutrition education as a regular course, but all dietitians performed nutrition education in passive ways, such as 'using home correspondence'(39.0%), 'bulletin board/poster'(22.0%), 'using the internet'(13.4%) and 'indirectly through a classroom teacher'(12.2%). Most respondents performed nutrition education 'one time/month'(66.0%) or 'one time/week'(20.0%). The respondents thought that suitable teaching times for nutrition education were 'during a related subject'(35.5%), 'during lunch time'(22.6%) rather than 'during an independent subject'(16.1%). Most of the dietitians(94.3%) did not perform nutrition counseling because of 'a lack of opportunity'(72.7%) and 'workload'(27.3%). Additionally 88.6% of respondents did not have the time of for nutrition counseling for parents because 'am not a teacher'(56.7%) and 'workload'(30,0%). Information sources for nutrition education were mainly 'internet'(71.4%) and 're-educationa1 materials'(17.1%). They possessed instructional materials in the forms of 'printed materials'(35.1 %), 'exhibition/bulletin board'(31.2%), and 'electrical materials'(33.8%), 'but did not have 'solid materials' such as food models and dolls. Generally they had mostly 'leaflets'(82.9%), 'bulletins'(68.6%), 'internet'(57.1%), and 'CDs'(57.1%). Preferences for instructional materials used were 'printed materials'(46.2%), 'exhibition/bulletin board'(36.5%), and 'electrical materials'(17.3%) 'Leaflets'(80.0%) were mainly used; 'CD'(17.1 %) use was low compared to the proportion possessing CDs. The topics frequently chosen by the subjects for nutrition education were 'table manners'(82.9%), 'basic concepts of food and nutrition'(80.0%), and 'proper food habits'(80.0%), but the topics helpful for practical use, such as 'how much do I eat'(20.0%) and 'nutrition labeling'(37.1%), were not included frequently. The respondents thought that 'eating only what they like'(60.0 %), 'intake of processed foods'(17.8%), and 'obesity'(17.8%) were the most common nutritional problems among elementary school children. They also thought that establishing a regular course for nutrition education was an effective way to cut down on these nutritional problems. In conclusion, nutrition education programs that are combined with effective instructional materials and practical topics should be developed. Additionally, it is recommended that dietitians act as teachers who participate in regular courses as soon as possible.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.298-309
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• 2000

Background : The antitumor effects of herpes simplex virus thymidine kinase (HSV-tk) and ganciclovir (GCV) strategies for cancer gene therapy have a the following advantages : 1) a direct cytotoxicity to HSV-tk modified cancer cells by GCV 2) a cell death by the local transfer of toxic metabolites from the HSV-tk modified cells to nearby unmodified tumor cells (bystander effect), and 3) in vivo bystander effect such as antitumor-immunity. Retroviral and adenoviral sequences can silence transgene expression in cells and mice. In this study, we investigated the above described advantages of HSV-tk/GCV strategy in Lewis lung cell and mouse lung cancer model using retroviral vector and adenoviral vector. Also, we observed whether the expression of a silenced gene can be reactivated by treating cells with butyrate. Methods : Retrovirus-HSV-tk and adenovirus-HSV-tk vectors were used for the transduction of Lewis lung carcinoma (LLC) cells. The change of HSV-tk expression by butyrate was measured by Western blol The antitumor activities containing bystander effect were observed in vivo (by MTT assay) and in vivo tumor models of various combinations of LLC and LLC-tk. Results : 1. Butyrate induced the enhancement of HSV-tk expression from adenovirally transduced cells but not from retrovirally transduced cells. 2. Both retrovirus-HSV-tk and adenovirus-HSV-tk vectors with GCV treatment were effective for killing of tumor cell in vitro and suppression of LLC tumorigenicity. Bystander effect was responsible for killing of mixture of LLC-tk and LLC in vitro and in vivo-tumorigenicity model. Conclusion : Butyrate could augment adenovirus-mediated HSV -tk gene expression. Cancer gene therapy with HSV-tk suicide gene by retroviral and adenoviral vector seems to be an effective approach for lung cancer therapy.

• Journal of Veterinary Clinics
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• v.18 no.3
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• pp.257-264
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• 2001

This study was performed to investigate the effects of chitosan-trimer (CT) on the prevention of postoperative adhesion formation in the rate model. All animals divided into PBS (control), 1% CT, 3% CT, and chitin treated group. The mean adhesion score in 1% CT group (1.03$\pm$0.63), 3% CT group (0.64$\pm$0.53) and chitin group (1.67$\pm$0.71) was found to be lower than that in control group (2.07$\pm$0.81). More favorable adhesion prevention was achieved in 3% CT group (0.64$\pm$0.53) in comparison with the control group, 1% CT group, and chitin group without any hemorrhagic complications. A statistically significant difference was observed in adhesion formation between control group and 3% CT group (p<0.001). In control group, 44 of 45 sites (97.7%) formed adhesions between the intestine defects. In contrast, 3% CT was effective in reducing the incidence of adhesion formation to 17 to 45 sites (62.2%) (p<0.05). The locations of adhesions were observed in serosa-serosa (60%), serosa-mesentery (13.3%), serosa-connective tissue of testis (10%), omentum-liver (10%), serosa-omentum (3.3%), serosa-cecum (3.3%), and serosa-incision (0%). On the results of histological analysis, grade of inflammation and fibrosis at the sites of postoperative peritoneal adhesion formation were not significantly different in all groups. But, 3% CT showed the lowest score of inflammation and fibrosis. In 3% CT group, the rate of increase of plasma fibrinogen was significantly lower compared with that in control group from pre-operation to 10 days later (p<0.05). There were no appreciable difference in the CBC, leukocyte differential counts and total protein concentrations among four groups. In conclusion, our data suggested that CT should be effective on reducing adhesion formation in experimental rat models. The results also showed that 3% CT does not adversely affect normal wound healing and healthy recovery after operation.

• Journal of Life Science
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• v.23 no.4
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• pp.501-509
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• 2013

Formaldehyde (FA) is widely used in industries, and it is an indoor and outdoor pollutant. Exposure to FA may cause inflammation and respiratory oxidative stress. Studies have demonstrated that FA can cause cancer in animal models. During the regeneration process of injured starfish (Asterina pectinifera), several changes have been observed in the expression of cytokines. In particular, higher TGF-${\beta}1$ expression has been detected in arm cut starfish extract after eight days. The current study was designed to elucidate the in-vitro and the in-vivo pharmacological effects of starfish extract on FA exposure. We investigated the protective effects of intact starfish extract and arm cut starfish extract on an IMR-90 cell line and on mouse lung injury in response to FA exposure. In the presence of FA, inhalation of the arm cut starfish extract was associated with more promising cell proliferation, TNF-${\alpha}$, NF-${\kappa}B$ decrement, and $I{\kappa}-B{\alpha}$ increment. In the experimental group, the pulmonary structure of the arm cut starfish extract-treated group in the presence of FA exposure was similar to the control group, whereas the FA exposure group showed damage to the pulmonary structure. Moreover, the arm cut starfish extracts was more effective than the intact starfish extracts in terms of the expression of TNF-${\alpha}$, NF-${\kappa}B$, $I{\kappa}-B{\alpha}$, and surfactant protein A. The results obtained in this study demonstrate that arm cut starfish extracts are more effective in protecting pulmonary structure and function against FA exposure than intact starfish extracts.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.29-46
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• 2004

It is important to identify geometries of fracture that act as a conduit of fluid flow for characterization of ground water flow in fractured rock. Fracture geometries control hydraulic conductivity and stream lines in a rock mass. However, we have difficulties to acquire whole geometric data of fractures in a field scale because of discontinuous distribution of outcrops and impossibility of continuous collecting of subsurface data. Therefore, it is needed to develop a method to describe whole feature of a target fracture geometry. This study suggests a new approach to develop a method to characterize on the whole feature of a target fracture geometry based on the Fourier transform. After sampling of specimens along a target fracture from borehole cores, effective frequencies among roughness components were selected by the Fourier transform on each specimen. Then, the selected effective frequencies were averaged on each frequency. Because the averaged spectrum includes all the frequency profiles of each specimen, it shows the representative components of the fracture roughness of the target fracture. The inverse Fourier transform is conducted to reconstruct an averaged whole roughness feature after low pass filtering. The reconstructed roughness feature also shows the representative roughness of the target subsurface fracture including the geometrical characteristics of each specimen. It also means that overall roughness feature by scaling up of a fracture. In order to identify the characteristics of permeability coefficients along the target fracture, fracture models were constructed based on the reconstructed roughness feature. The computation of permeability coefficient was performed by the homogenization analysis that can calculate accurate permeability coefficients with full consideration of fracture geometry. The results show a range between $10^{-4}{\;}and{\;}10^{-3}{\;}cm/sec$, indicating reasonable values of permeability coefficient along a large fracture. This approach will be effectively applied to the analysis of permeability characteristics along a large fracture as well as identification of the whole feature of a fracture in a field scale.

• Journal of Elementary Mathematics Education in Korea
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• v.10 no.1
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• pp.67-87
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• 2006

This study is to recognize a problem in the practice of performance assessment in elementary school, and to find out some suggestive points for improvement of teaching·learning method in elementary mathematics through assessment by reducing time restriction according to assessment through the practice of self-assessment, peer-assessment and observation, and then by reflecting the results of assessment on teaching learning plan. For that, the questions of study set up are as follows ; 1. How should self-assessment and peer-assessment be applied to in elementary mathematics assessment? 2. How should the time for 'let's play an interesting game' be managed for assessment of elementary mathematics? 3. How should the results of assessment be reflected on the Process of teaching and learning of mathematics? To solve these problems, a researcher of this thesis performed self-assessment, peer-assessment on 40 students of second grade under her charge as a class teacher, and applied observation in the time management process for 'let's play an interesting game' for a semester. self-assessment was made by mathematics journal, self-assessment chart, peer-assessment was by the analysis of conversation record among students in the situations of assessment, and observation was by observation of activity when playing with the results data of play analyzed. the concrete methods of application as follows ; First, mathematics journal was applied $1{\sim}2$ times by each unit with reconstruction into the level of second grade on the basis of the preceding-study models. Second, peer-assessment was applied to the unit-assessment time and the play-activities time by the method of recording·analyzing the contents of conversation among students in the process of assessment. Third, mathematical attitude & dispositions of students making use of the self- assessment table were examined referring to the teaching learning plan. Fourth, the time management for 'let's play an interesting game' was made through the prior recognition of play method and the joyful play-activities by use of the play-plate. Assessment depended on analysis of play-activities results of students making use of an observation form. Fifth, the results of self-assessment, peer-assessment, and observation were analyzed, and then they were made use of as self-observation data, of teacher her/his self, or teaching·learning improvement data. Students' self-assessment datum (mathematics diary, self-assessment sheets, conversation contents in the process of assessment) and observation materials (check lists, Play-activity result materials, conversation contents in the process of play) obtained in the process of application was analyzed as follows ; 1. From the practice of self-assessment in form of mathematics journal, I could obtain not only datum showing how much students was understanding the learning aims by unit time and to any degree they reached but also information about their response to learning datum and favorable type of learning. 2. Assessment by self-assessment chart was useful in planning the mathematics teaching learning process because it helps ascertain mathematical attitude & dispositions of students. 3. Through the application of peer-assessment, students had the opportunity of communicating with other students looking back on his/her explaining process, and teachers could obtain basic materials for assessment of students. 4, In case of time management for 'let's play an interesting game', there was natural extension of play made through time-security by prior looking into the method of play-activity, and then, for a remained time, by making children play a new game. 5, I could easily record the activities of students by use of the observation. form, and make use of it as basic data for descriptive assessment. 6, Each kinds of data obtained from the results of assessment was helpful for securing self-observation materials in the process of teaching learning and for their betterment in mathematics subject. However, because they were in the second grade of elementary school and there was an individual difference, some students could not make use of mathematics diary or self-assessment form properly. In case of these students, assessment data would be obtained through interview or observation. And for effective operation of play, its purpose & method and matters that demand special attention when play-acting should be clearly guided. Also, when applying an effective play in addition to play activities in textbook, to lessons, interesting mathematics lessons could be guided.