• Radiation Oncology Journal
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• v.27 no.1
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• pp.10-14
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• 2009

Purpose: This study was designed to evaluate the effectiveness and prognostic factors for patients treated with postoperative radiation therapy following surgery or with radiation therapy alone for squamous cell carcinoma of the esophagus. Materials and Methods: We retrospectively analyzed 132 esophageal cancer patients treated with postoperative radiation therapy following surgery or patients who were treated with radiation therapy alone at our institution from 1989 to 2006. Thirty-five patients had stage II disease, 88 patients had stage III disease and nine patients had stage IV disease. Tumors were located at the upper esophagus in 18 patients, the mid esophagus in 81 patients and the distal esophagus in 33 patients. Sixty patients were treated with radiation therapy alone and 72 patients were treated with postoperative radiation therapy following surgery. Eight patients received a dose less than 40 Gy and 78 patients received a dose of 40 to 50 Gy. The remaining 46 patients received a dose of 50 to 60 Gy. The majority of patients who underwent postoperative radiation therapy received a dose of 45 Gy. Results: Actuarial survival rates for all of the patients at two years and five years were 24% and 5%, respectively. The median survival time was 11 months. Survival rates for patients who underwent postoperative RT at two years and five years were 29% and 8%, respectively. The corresponding survival rates for patients who received radiation alone were 18% and 2%, respectively. Survival rates at two years and five years were 43% and 15% for stage II disease, 22% and 2% for stage III disease and 0% and 0% for stage IV disease, respectively; these findings were statistically significant. Two-year survival rates for patients with upper, middle and distal esophageal cancer were 19, 29% and 22%, respectively. Although there was a trend of slightly better survival for middle esophageal tumors, this finding was not statistically significant. Complete response to radiation was achieved in 13 patients (22%) and partial response to radiation was achieved in 40 patients (67%) who received radiation alone. No response to radiation was noted in seven patients (12%). A statistically significant difference in survival rates was seen between patients that had a complete response and patients that had a partial response. Two-year survival rates for patients that had a complete response versus patients that had a partial response were 31% and 17%, respectively. There were no survivors for patients with no response as determined at two-year follow-up. Conclusion: We conclude that radiation therapy is an effective treatment for esophageal cancer. Stage and response to radiation therapy were noted to be prognostic factors. A more effective treatment modality is needed to improve long term survival because of the relatively dismal prognosis for this tumor.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.249-259
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• 2018

This research had intended to find out regarding the present influences of the Smart Work on the intention to use continuously with the staff members working in the small- and medium-sized enterprises as the subject. And, finally, it had intended to find out about the Smart Work environments of the IT corporations and the non-IT corporations. For this research, the questionnaire survey data were collected from the staff members working at the small- and medium-sized enterprises. Through the questionnaire survey data that were collected, an empirical analysis was carried out. And, through the reliability analysis, the feasibility analysis, the discriminatory feasibility analysis, and the inspection of the degree of suitableness of the structural equation model, finally, the research model was verified and, finally, a difference analysis of the IT corporations and the non-IT corporations was carried out. Regarding the results of the analysis of the research, it appeared that the factors of the job efficiency and the job autonomy of the special characteristics of the job had the positive influences on the usefulness and the job satisfaction, which were the parameters and which were perceived. And it appeared that the time flexibility of the job form could not have any influences on the usefulness and the job satisfaction, which were the parameters and which were perceived. And it appeared that the spatial flexibility had the influences on the job satisfaction only. The perceived usefulness, which was a parameter, had the positive influences on the job satisfaction and the intention to use continuously. And, finally, the job satisfaction had the positive influences on the intention to use continuously. And it appeared that there were the differences, too, between the IT corporations and the non-IT corporations. It is thought that, through the results of this research and through the Smart Work environment, the positive influences on the workers and the organizations could be induced and that a better working environment than previously can be provided to the workers to fit the special characteristics of the corporations.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.171-179
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• 2006

Background : Despite the emerging danger of MDR-TB to human beings, there have only been a limited number of drugs developed to treat MDR-TB since 1970. This study investigated the cross-resistance rate between rifampicin (RFP) and rifabutin (RBU) in order to determine the efficacy of rifabutin in treating MDR-TB. In addition, the results of rifabutin were correlated with the rpoB mutations, which are believed to be markers for MDR-TB and RFP resistance. Methods : The MICs of RBU were tested against 126 clinical isolates of MDR-TB submitted to the clinical laboratory of National Masan TB Hospital in 2004. Five different concentrations ($10-160{\mu}g/ml$) were used for the MICs. The detection of the rpoB mutations was performed using a RFP resistance detection kit with a line probe assay(LiPA), which contains the oligonucleotide probes for 5 wide type and 3 specific mutations (513CCA, 516GTC, and 531TTG) The rpoB mutation was determined by direct sequencing. Results : The rate of cross-resistance between RFP and RBU was 70.5%(74/105) at $20{\mu}g/ml$ RBU(ed note: How much RFP?) Most mutations (86.3%) occurred in the 524~534 codons. The His526Gln, His526Leu, Leu533Pro, Gln513Glu, and Leu511Pro mutations(Ed note: Is this correct?) were associated with the susceptibilty to RBU. Conclusion : Based on the cross-resistance rate between RFP and RBU, RBU may be used effectively in some MDR-TB patients. Therefore, a conventional drug susceptibility test for RBU and a determination of the critical concentration are needed. However, rpoB gene mutation test may be have limited clinical applications in detecting RBU resistance.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.152-157
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• 2008

The customer satisfaction of WAP service greatly relies on the usability of the service due to the limited display size of a mobile phone and limitation in realizing UI (User Interface) for function keys, browser, and OS (operating system) Currently, a number of contents providers develop and deliver varying services, and thus, it is critical to control quality level of UI in consistent standards and manner. This study suggests usability index evaluation system to achieve consistent UI quality control of various WAP services. The system adopts both top-down and bottom-up approaches. The former concerns deriving UI design components and evaluation checklists for the WAP, based on the usability attributes and UI principles. The latter concerns deriving usability-related evaluation checklists from the established UI design features, and then grouping them from the viewpoint of usability principles and attributes. This bidirectional approach has two outstanding advantages: it allows thorough examination of potential elements that can cause usability problems from the standpoint of usability attributes, and also derives specific evaluation elements from the perspective of UI design components that are relevant to the real service environment. The evaluation system constitutes a hierarchical structure by networking usability attributes, UI guideline which indicates usability principles for each attribute, and usability evaluation checklist for each UI component that enables specific evaluation. Especially, each evaluation checklist contains concrete contents and format so that it can be readily marked in O/X. The score is based on the ratio of number of items that received positive answer to the number of total items. This enables a quantitative evaluation of the usability of mobile WAP service. The validity of the proposed evaluation system has been proved through comparative analysis with the real usability problems based on the user test. A software was developed that provides guideline for evaluation objects, criteria and examples for each checklist, and automatically calculates a score. The software was applied to evaluating and improving the real mobile WAP service.

• The Korean Journal of Financial Management
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• v.24 no.2
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• pp.1-40
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• 2007

We test a model of investment-cashflow-growth opportunities relationship in order to estimate the sensitivities to investments. In this study, we use a new proxy variable for the value of growth opportunities(hereafter "VGO"), which is based on the seminal papers of M&M(1958:1961:1963) and Lee(2006;2007). The empirical findings on the sensitivities of cashflow and growth opportunities are as follows. First, when the traditional proxy variables for the growth opportunities such as Tobin's Q, MBR and sales growth are included with the new proxy VGO in the estimation, their coefficients are turned out to be insignificant. Second, only the new proxy variable VGO shows a statistically significant positive sensitibity to investment, which can be regarded that the growth opportunities hold the positive influences to investments. Third, the Tobin's Q can be decomposed into three factors such as the value of growth opportunities(VGO), the value of asset-in-place and valuation errors. It turns out that only the VGO shows a statistically significant positive relationship with investment among others. This means that the new variable VGO is a good proxy variable for the growth opportunities in the investment-cashflow sensitivity analysis. In sum, thanks to the above findings in this study, we can say that it will not be proper to choose a proxy variable for the growth opportunities from the traditional set of proxies such as Tobin's Q, MBR, or sales growth rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1673-1681
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• 2013

Five different chopped frozen garlic products samples, three from Chinese and two from Korean origins being commercially available products in Korean market, were used to confirm their pre-pasteurization or pre-irradiation status by screening (direct epifluorescent filter technique/aerobic plate counts, DEFT/APC; electronic nose, E-nose; photostimulated luminescence, PSL) and identification (thermoluminescence, TL; electron spin resonance, ESR) techniques. Some parts of samples were gamma-irradiated at 1 kGy to be used as control samples in irradiation history identification. DEFT/APC and e-nose successfully showed distinct results between the domestic and imported samples. The PSL photon counts of all the unknown samples were less than 700 (negative), while most of 1 kGy-irradiated samples gave PSL photon counts more than 5,000 (positive). The domestic unknown samples produced the TL glow peaks after $300^{\circ}C$ or more, whereas the imported samples showed TL peaks at the range of $240{\sim}250^{\circ}C$. A clear TL glow peak was obtained from all irradiated samples at $150{\sim}250^{\circ}C$. The unknown samples of Chinese origin gave radiation-specific cellulose ESR signal that was not shown by domestic samples. A multiple step of applying the physical analytical methods is recommended for the effective identification of irradiation status on chopped frozen garlic products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1560-1566
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• 2013

This study was conducted to find out the effects of aqueous extract from the leaves of Artemisia capillaris (AA) on the reduction of hepatotoxicity induced by ethanol in rats. In this experiment, Sprague Dawley rats were used in the experimental groups, which were divided into 5 groups; normal group, ethanol+UDCA (ursodeoxycholic acid)-treated group (positive control), ethanol-treated group (control), ethanol+Artemisia capillaris aqueous extract-treated group (200 mg/kg of BW) and ethanol+Artemisia capillaris aqueous extract-treated group (400 mg/kg of BW). AST (aspartate aminotransferase), ALT (alanine aminotransferase), GGT (gamma(${\gamma}$)-glutamyl transferase) and LDH (lactate dehydrogenase) activities of the ethanol+Artemisia capillaris aqueous extract-treated group (400 mg/kg of BW) were significantly decreased compared to that of the ethanol-treated group (P<0.05). The triglyceride level of the ethanol-treated group was significantly increased and the HDL-cholesterol level was significantly decreased compared to the normal group (P<0.05). On the other hand, the triglyceride level was significantly decreased (P<0.05) and the HDL-cholesterol level was significantly increased (P<0.05) in the ethanol+Artemisia capillaris aqueous extract-treated groups. Superoxide dismutase (SOD) activity was enhanced significantly (P<0.05) in the ethanol+Artemisia capillaris aqueous extract-treated groups. Also, malondialdehyde contents were decreased in this group (P<0.05). Histologically, in the control group, there was a mild degenerative change around central venule. The AA treated group showed well preserved lobular architectures with no evidence of steatosis or liver damage in aqueous extract from the leaves of Artemisia capillaris treated group (H&E, ${\times}20$). As the results of this study, it is thought that Artemisia capillaris aqueous extract may have effects on the improvement of hepatic damage by ethanol.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.281-287
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• 2005

Purpose: This study was conducted to evaluate the effectiveness and the role of post-operative adjuvant chemoradiation therapy in a stage-II (UICC, 1997) primary gastric cancer. Materials and Methods: From September 1994 to December 2004, 954 stage-II gastric-cancer patients were seen, and all of them underwent a curative resection with extensive (D2) lymph-node dissection. The chemotherapy consisted of fluorouracil $(400mg/m^2)$ plus leucovorin $(20mg/m^2)$ for 5 days, followed by 4,500 cGy of radiotherapy for 5 weeks with fluorourcil and leucovorin on the first 4 days and the last 3 days of radiotherapy. Two five-day cycles of chemotherapy were given four weeks after the completion of radiotherapy. The Kaplan-Meier method was used to estimate the survival rates. To assess the importance of potential prognostic factors, we performed univariate and multivariate analyses using a log-rank test and Cox's proportional hazards regression model. A P value <0.05 was considered significant. Results: Univariate analysis revealed that age, tumor size, gross type, surgical method, and postoperative adjuvant therapy had statistical significance. Among these factors, age, surgical method, tumor size, surgical method, and postoperative adjuvant therapy were found to be independent prognostic factors by using a multivariate analysis. The postoperative adjuvant chemotherapy group and the chemoradiation therapy group had survival benefit compared to the surgery-only group. However the chemoradiation therapy group had no significant survival benefit compared to the chemotherapy group. Conclusion: The postoperative adjuvant therapy in stage-II gastric-cancer patients had significant benefit. Therefore, postoperative adjuvant chemoradiation therapy has an acceptable effect. A large-scale, randomized study is needed to evaluate the effectiveness and the role of postoperative radiation therapy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.235-249
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• 2011

A new form of I-type PSC bridge girder, which has hole in the web, is proposed in this paper. Three different concepts were combined and implemented in the design. First of all, a girder was precast at a manufacturing plant as divided pieces and assembled at the construction site using post-tensioning method, and the construction period at the site will be reduced dramatically. In this way, the quality of concrete can be assured at the manufacturing factory and concrete curing can be well controlled, and the spliced girder segments can be moved to the construction site without a transportation problem. Secondly, a numerous number of holes was made in the web of the girder. This reduces the self-weight of the girder. But more important thing related to the holes is that about half of the total anchorages can be moved from the girder ends into individual holes. The magnitude of negative moment developed at girder ends will be reduced. Also, since the longitudinal compressive stresses are reduced at ends, thick end diaphragm is not necessary. Thirdly, Prestressing force was introduced into the member through multiple stages. This concept of multi-stage prestressing method overcomes the prestressing force limit restrained by the allowable stresses at each loading stage, and maximizes the magnitude of applicable prestressing force. It makes the girder longer and shallower. Two 50 meter long full scale girders were fabricated and tested. One of them was non-spliced, or monolithic girder, made as one piece from the beginning, and the other one was assembled using post-tensioning method from five pieces of segments. It was found from the result that monolithic and spliced girder show similar load-deflection relationships and crack patterns. Girders satisfied specific girder design specification in flexural strength, deflection, and live load deflection control limit. Both spliced and monolithic holed web post-tensioned girders can be used to achieve span lengths of more than 50m with the girder height of 2 m.

• Communications of Mathematical Education
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• v.27 no.1
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• pp.39-62
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• 2013

On the standards or elements of teaching evaluation, the Korea Institute of Curriculum and Evaluation(KICE) has carried out the following research such as : 1) development of the standards on teaching evaluation between 2004 and 2006, and 2) investigation on the elements of Teacher Knowledge. The purposes of development of evaluation standards for mathematics teaching through those studies were to improve not only mathematics teachers' professionalism but also their own teaching methods or strategies. In this study, the standards were revised and modified by analyzing the results of those studies focused on the knowledge of subject matter knowledge, knowledge of learners' understanding, teaching and learning methods and assessments, and teaching contexts. For this purpose, according to those evaluation domains of each teacher knowledge, elements on teaching evaluation focused on the teacher's knowledge were established using the instructional evaluation framework, which is developed in this study, including the four areas of knowledge obtaining, instructional planning, instructional implementation, and instructional reflection. In this study, 1st and 2nd pilot studies was accomplished for revising evaluation standards and as a result, the procedure for implementing mathematics teaching using evaluation standards was changed to evaluate teachers own teaching using the standards focused on instructional reflection and according to the degree of satisfaction on reflecting their own teaching, standards on knowledge obtaining, instructional planning, instructional implementation would be utilized. Teacher survey is accomplished two times, by the subject of seven teachers. According ot the result of the first teacher questionnaire which was consisted of the essay type of questions on the degree of understanding the content of standards, the evaluation standards were revised. According ot the result of the second teacher questionnaire which was consisted of the essay type of questions on the application of standards, the evaluation standards were revised finally and the way of how to use the standards efficiently was suggested.