• Education of Primary School Mathematics
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• v.25 no.1
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• pp.57-79
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• 2022

Current mathematics It is necessary to ensure that ratio and proportion concept is not distorted or broken while being treated as if they were easy to teach and learn in school. Therefore, the purpose of this study is to analyze the activities presented in the textbook. Based on prior work, this study reinterpreted the proportional reasoning task from the proportional perspective of Beckmann and Izsak(2015) to the multiplicative structure of Vergnaud(1996) in four ways. This compared how they interpreted the multiplicative structure and relationships between two measurement spaces of ratio and rate units and proportional expression and proportional distribution units presented in the revised textbooks of 2007, 2009, and 2015 curriculum. First, the study found that the proportional reasoning task presented in the ratio and rate section varied by increasing both the ratio structure type and the proportional reasoning activity during the 2009 curriculum, but simplified the content by decreasing both the percentage structure type and the proportional reasoning activity. In addition, during the 2015 curriculum, the content was simplified by decreasing both the type of multiplicative structure of ratio and rate and the type of proportional reasoning, but both the type of multiplicative structure of percentage and the content varied. Second, the study found that, the proportional reasoning task presented in the proportional expression and proportional distribute sections was similar to the previous one, as both the type of multiplicative structure and the type of proportional reasoning strategy increased during the 2009 curriculum. In addition, during the 2015 curriculum, both the type of multiplicative structure and the activity of proportional reasoning increased, but the proportional distribution were similar to the previous one as there was no significant change in the type of multiplicative structure and proportional reasoning. Therefore, teachers need to make efforts to analyze the multiplicative structure and proportional reasoning strategies of the activities presented in the textbook and reconstruct them according to the concepts to teach them so that students can experience proportional reasoning in various situations.

• Herbal Formula Science
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• v.30 no.2
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• pp.95-100
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• 2022

Objectives : Recent studies reported that Dokwhalkisaeng-tang (DHJST) could relieve the clinical rheumatoid arthritis (RA) symptoms and the level of RA-related blood test. However, evidence-based review on effectiveness and safety of DHJST with medication on RA was not yet provided. Methods : Searching randomized controlled trials on the use of DHJST for RA will be performed using multiple electronic databases, manual search, and contact to author. Studies will be selected according to the pre-defined criteria and collected data on study participants, interventions, control groups, outcome measurements, the results, adverse events, and risk of bias will be summarized. Primary outcome will be the disease activity score (including effective rate, swollen joint count, tender joint count, and morning stiffness), and the secondary outcomes will be RA-related blood test and adverse events. We will use Review Manager software to perform a meta-analysis, Cochrane Collaboration "risk of bias" tool for assessing the risk of bias, and Grades of Recommendation, Assessment, Development and Evaluation for the determination of quality of evidence. Results : We are going to investigate the effectiveness and safety of DHJST with medication for RA. Conclusion : This study will provide reliable evidence on whether DHJST combined with medicine is more effective on RA than medicine monotherapy.

• Korean Journal of Optics and Photonics
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• v.34 no.1
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• pp.22-30
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• 2023

The use of segmented mirrors is one of the ways to make the primary mirror of a spaceborne satellite larger, where several small mirrors are combined into a large monolithic mirror. To align multiple segmented mirrors as one large mirror, there must be no discontinuity in the x, y-axis (tilt) and axial alignment error (piston) between adjacent mirrors. When the tilt and piston are removed, we can collect the light in one direction and get an expected clear image. Therefore, we need a precise wavefront sensor that can measure the alignment error of the segmented mirrors in nm scale. The tilt error can be easily detected by the point spread image of the segmented mirrors, while the piston error is hard to detect because of the absence of apparent features, but makes a downgraded image. In this paper we used an optical testing interferometer such as a Fizeau interferometer, which has various advantages when aligning the segmented mirror on the ground, and focused on measuring the axial displacement error of a segmented mirror as the basic research of measuring the piston errors between adjacent mirrors. First, we calculated the relationship between the axial displacement error of the segmented mirror and the surface defocus error of the interferometer and verified the calculated formula through experiments. Using the experimental results, we analyzed the measurement uncertainty and obtained the limitation of the Fizeau interferometer in detecting axial displacement errors.

• Korean Journal of Culture and Social Issue
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• v.21 no.3
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• pp.317-338
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• 2015

The main purpose of this research is to examine the relation of variables related to the worker's stress symptoms and coping. The influence of emotional support(from family, colleague, and boss), self-efficacy (self-regulatory, social, relational, resiliency, and management of work), job-satisfaction, and job-performance on worker's stress symptoms and coping is analyzed. Participants were 559 teachers (elementary 205, junior high 203, senior high 151; male 132, female 427). The results were as follows: There were no significant differences in stress symptoms and coping among primary, junior and senior high school teachers. On the other hand, there were significant differences in stress symptoms and coping between male and female teachers. Female teachers experienced more stress symptoms than male teachers. At the same time female teachers coped more efficiently in stress situation than male teachers. With emotional support, self-efficacy, job-performance and job-satisfaction as independent variables, the result of multiple regression showed that job-satisfaction has a negative influence on stress symptoms. Positive influences on stress coping was found for resiliency of self-efficacy in case of male teachers, and in case of female teachers resiliency of self-efficacy, emotional support from colleague, job-performance, and emotional support from family. Therefore, regardless of the gender of the teachers, high job-satisfaction decreased stress symptoms and high resiliency of self-efficacy increased efficient stress coping. As for female teachers, not only resiliency of self-efficacy but also emotional support from colleague and family, job-performance contributed to coping with stress.

• Tunnel and Underground Space
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• v.33 no.3
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• pp.189-207
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• 2023

In the present study, the thermoshearing experiment on a rough rock fracture were modeled using a three-dimensional grain-based distinct element model (GBDEM). The experiment was conducted by the Korea Institute of Construction Technology to investigate the progressive shear failure of fracture under the influence of thermal stress in a critical stress state. The numerical model employs an assembly of multiple polyhedral grains and their interfaces to represent the rock sample, and calculates the coupled thermo-mechanical behavior of the grains (blocks) and the interfaces (contacts) using 3DEC, a DEM code. The primary focus was on simulating the temperature evolution, generation of thermal stress, and shear and normal displacements of the fracture. Two fracture models, namely the mated fracture model and the unmated fracture model, were constructed based on the degree of surface matedness, and their respective behaviors were compared and analyzed. By leveraging the advantage of the DEM, the contact area between the fracture surfaces was continuously monitored during the simulation, enabling an examination of its influence on shear behavior. The numerical results demonstrated distinct differences depending on the degree of the surface matedness at the initial stage. In the mated fracture model, where the surfaces were in almost full contact, the characteristic stages of peak stress and residual stress commonly observed in shear behavior of natural rock joints were reasonably replicated, despite exhibiting discrepancies with the experimental results. The analysis of contact area variation over time confirmed that our numerical model effectively simulated the abrupt normal dilation and shear slip, stress softening phenomenon, and transition to the residual state that occur during the peak stress stage. The unmated fracture model, which closely resembled the experimental specimen, showed qualitative agreement with the experimental observations, including heat transfer characteristics, the progressive shear failure process induced by heating, and the increase in thermal stress. However, there were some mismatches between the numerical and experimental results regarding the onset of fracture slip and the magnitudes of fracture stress and displacement. This research was conducted as part of DECOVALEX-2023 Task G, and we expect the numerical model to be enhanced through continued collaboration with other research teams and validated in further studies.

• Journal of Digestive Cancer Research
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• v.2 no.2
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• pp.72-74
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• 2014

Pancreatic cancer is well known to have a poor prognosis and poor responses to both of chemotherapy and radiation therapy. We report a metastatic pancreatic cancer treated successfully with chemotherapy and radiation therapy. A 71-year-old female with epigastric pain and weight loss was diagnosed as advanced pancreatic cancer with main vessels invasion and multiple mesenteric lymph node's metastasis. She was taken chemotherapy of gemcitabine single regimen and radiation therapy. Although she experienced one recurrence and concomitant primary lung cancer, she has survived for over 7 years with no symptoms. The authors report this case of long term survival in metastatic pancreatic cancer after chemoradiation therapy.

• Journal of Digestive Cancer Research
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• v.1 no.2
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• pp.104-107
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• 2013

Gallbladder (GB) cancer is highly malignant neoplasm found in advanced stage and chemotherapy commonly plays a palliative role in GB cancer. We report a case of unresectable GB cancer treated with chemotherapy followed by extended cholecystectomy. Fifty-six-year-old male visited our hospital with weight loss and dyspnea on exertion. Computed tomography detected pulmonary embolism and diffuse GB wall thickening with para-aortic lymph node enlargement. The length of common channel was 23mm at magnetic resonance cholangiopancreatography which stands for anomalous union of the pancreaticobiliary duct. Anticoagulation was started for pulmonary embolism. GB wall mass was regarded as unresectable GB cancer with distant lymph node metastasis. Gemcitabine and cisplatin combination chemotherapy was carried out for 6 cycles. Primary tumor was stationary but multiple enlarged lymphnodes were almost completely disappeared. Extended cholecystectomy with hepaticojejunostomy was performed. Post-operative tumor stage was T3N1 (stage IIIB) and R0 resection was achieved. After operation he has no evidence of disease recurrence for 6 months.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1185-1193
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• 2021

Objective: Clear cell sarcoma of the kidney (CCSK) is the second-most common but extremely rare primary renal malignancy in children after Wilms' tumor. The aims of this study were to evaluate the imaging features that could distinguish between CCSK and Wilms' tumor and to assess the features with diagnostic value for identifying CCSK. Materials and Methods: We reviewed the initial contrast-enhanced abdominal-pelvic CT scans of children with CCSK and Wilms' tumor between 2010 to 2019. Fifty-eight children (32 males and 26 females; age, 0.3-10 years), 7 with CCSK, and 51 with Wilms' tumor, were included. The maximum tumor diameter, presence of engorged perinephric vessels, maximum density of the tumor (Tmax) of the enhancing solid portion, paraspinal muscle, contralateral renal vein density, and density ratios (Tmax/muscle and Tmax/vein) were analyzed on the renal parenchymal phase of contrast-enhanced CT. Fisher's exact tests and Mann-Whitney U tests were conducted to analyze the categorical and continuous variables, respectively. Logistic regression and receiver operating characteristic curve analyses were also performed. Results: The age, sex, and tumor diameter did not differ between the two groups. Engorged perinephric vessels were more common in patients in the CCSK group (71% [5/7] vs. 16% [8/51], p = 0.005). Tmax (median, 148.0 vs. 111.0 Hounsfield unit, p = 0.004), Tmax/muscle (median, 2.64 vs. 1.67, p = 0.002), and Tmax/vein (median, 0.94 vs. 0.59, p = 0.002) were higher in the CCSK compared to the Wilms' group. Multiple logistic regression revealed that engorged vessels (odds ratio 13.615; 95% confidence interval [CI], 1.770-104.730) and Tmax/muscle (odds ratio 5.881; 95% CI, 1.337-25.871) were significant predictors of CCSK. The cutoff values of Tmax/muscle (86% sensitivity, 77% specificity) and Tmax/vein (71% sensitivity, 86% specificity) for the diagnosis of CCSK were 1.97 and 0.76, respectively. Conclusion: Perinephric vessel engorgement and greater tumor enhancement (Tmax/muscle > 1.97 or Tmax/vein > 0.76) are helpful for differentiating between CCSK and Wilms' tumor in children aged below 10 years.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.4
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• pp.176-183
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• 2010

In order to understand the temporal variations and species composition of tintinnids, at two stations of the Korea Strait, this study was carried out from January to December 2007 (n=17). Fifty-one species from 22 genera were encountered: 27 neritic species (9 genera) and 24 oceanic species (14 genera). The species composition was different between two stations, and neritic species frequently appeared at St. 1, while oceanic species more frequently appeared at St. 2. According to the frequency in appearance of species, the most dominant species were neritic species such as Stenosemella nivalis and S. pacifica, that appeared in all seasons. Also, Acanthostomella norvegica, Amphorellopsis acuta, Epilpocyloides ralumensis, Protorhabdonella curta and other many oceanic species appeared intensively during the low salinity (${\leqq}33\;psu$) and high water temperature (${\geqq}24^{\circ}C$) period (July~October). The abundance of tintinnids ranged from 0 to 1,845 cells $L^{-1}$. It was higher in the seasons (summer and autumn) of low salinity and high water temperature than in other seasons. The abundance was relatively higher at St. 1 than at St. 2. On the basis of correlation and multiple regression analyses, the tintinnid abundance was not correlated with chi-a, but significantly correlated with water temperature and salinity, suggesting to be the primary abiotic factors influencing the abundance. This study suggests that the complex hydrographic conditions of the study area might influence the temporal distribution and species composition of tintinnids.

• Journal of Korean Medicine Rehabilitation
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• v.34 no.2
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• pp.165-172
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• 2024

Objectives This study aims to report current status and strategies of thread embedding acupuncture (TEA) on face through survey of Korean medicine doctors. Methods The survey was conducted online via e-mail to certified Korean medicine doctors. The questionnaire is developed by Korean medicine doctors in Kyung-Hee Korean Medicine Hospital at Gangdong. The survey mainly consisted with multiple-choice questions on the current status, cost, and adverse reactions. Results TEA was predominantly utilized for cosmetic purposes, and the billing cost was commonly determined based on the number of threads used. The reported incidence of adverse reactions during TEA was 69.9%. The most frequent self-resolving adverse reaction was bruising, while the most common adverse reaction requiring medical intervention or resulting in sequelae was the 'dimple phenomenon'. According to the questionnaire, the primary factor associated with adverse reactions was the treatment area. Conclusions This study provided insights into the practical use of TEA on face in Korean medical clinic.