• Journal of Digital Convergence
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• v.17 no.8
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• pp.95-104
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• 2019

Recently, software education has been emphasized as a key element of the fourth industrial revolution. Many universities are strengthening the software education for all students according to the needs of the times. The use of online content is an effective way to introduce SW education for all students. However, the provision of uniform online contents has limitations in that it does not consider individual characteristics(major, sw interest, comprehension, interests, etc.) of students. In this study, we propose a recommendation method that utilizes the directional similarity between contents in the boolean view history data environment. We propose a new item-based recommendation formula that uses the confidence value of association rule analysis as the similarity level and apply it to the data of domestic paid contents site. Experimental results show that the recommendation accuracy is improved than when using the traditional collaborative recommendation using cosine or jaccard for similarity measurements.

• Journal of Elementary Mathematics Education in Korea
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• v.22 no.2
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• pp.161-181
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• 2018

This study involved an investigation of prospective elementary teachers' preconceptions and experiences of diagrams and their ability to draw diagrams in solving math word problems. A questionnaire and two math word problems were administered to prospective elementary teachers who began to taking an introductory mathematics education course. The results from the analysis of their responses to the questionnaire items indicate that prospective elementary teachers appreciate the value of diagrams as tools for problem solving and communication. In addition, prospective elementary teachers have the will not only to teach their future students how to use diagrams but also to encourage them to draw diagrams in solving math word problems. However, the results also indicates that prospective elementary teachers neither use diagrams spontaneously in their math problem solving activities nor have confidence in drawing useful diagrams. Prospective elementary teachers also manifested low scores on the questionnaire items asking whether they were taught how to draw useful diagrams or encouraged by their teachers to use diagrams in their previous learning experiences. The results from the analysis of the diagrams that prospective elementary teachers drew in solving math word problems showed that most of them had difficulty drawing diagrams that represent their reasoning and solving process.

• Journal of Gastric Cancer
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• v.19 no.2
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• pp.183-192
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• 2019

Purpose: Due to adverse events, dose reduction or withdrawal of adjuvant chemotherapy is required for some patients. To identify the predictive factors for tolerability to postoperative adjuvant S-1 monotherapy in gastric cancer (GC) patients, we evaluated the predictive values of blood indicators. Materials and Methods: We analyzed 98 patients with pStage II/III GC who underwent postoperative adjuvant S-1 monotherapy. We retrospectively analyzed correlations between 14 parameters obtained from perioperative routine blood tests to assess their influence on the withdrawal of postoperative adjuvant S-1 monotherapy, within 6 months after discontinuation. Results: Postoperative adjuvant chemotherapy was discontinued in 21 patients (21.4%) within 6 months. Univariable analysis revealed that high preoperative albumin-bilirubin (ALBI) scores had the highest odds ratio (OR) for predicting the failure of adjuvant S-1 chemotherapy (OR, 6.47; 95% confidence interval [CI], 2.08-20.1; cutoff value, -2.696). The high ALBI group had a significantly shorter time to failure of postoperative adjuvant S-1monotherapy (hazard ratio, 3.48; 95% CI, 1.69-7.25; P=0.001). Multivariable analysis identified high preoperative ALBI score as an independent prognostic factor for tolerability (OR, 10.3; 95% CI, 2.33-45.8; P=0.002). Conclusions: Preoperative ALBI shows promise as an indicator associated with the tolerability of adjuvant S-1 monotherapy in patients with pStage II/III GC.

• Journal of Yeungnam Medical Science
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• v.35 no.2
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• pp.179-186
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• 2018

Background: To evaluate the success rate of balloon dilation and the factors possibly influencing the outcomes of balloon dilation for the ureteric strictured portion of ureteroureterostomy (UUS) site in patients with post-gynecologic surgeries. Methods: A single institution data base was screened for the patients who received balloon dilation for a treatment of ureteral stricture diagnosed after gynecologic surgery. Overall 114 patients underwent primary intra-operative UUS due to ureteral injury during gynecologic surgery. Among them, 102 patients received balloon dilation, and their medical records were retrospectively reviewed. Success of balloon dilation was defined as the condition that requires no further clinical interventions after 6 months from balloon dilation. Results: The ureter injury rate of women treated with open radical abdominal hysterectomy was highest (32 cases, 31.4%). 60 patients (60.8%) showed successful outcomes regarding dilation. All patients underwent technically successful dilation with a full expansion of balloon during the procedure, but 40 patients (39.2%) were clinically unsuccessful as they showed a recurrence of ureteral stricture on the previous balloon dilation site after the first dilation procedure. Univariate logistic regression analyses showed that stricture length >2 cm was a significant predictor of successful dilation (odds ratio, 0.751; 95% confidence interval, 0.634-0.901; p-value, 0.030), but it failed to achieve independent predictor status in multivariate analysis. Conclusion: Balloon dilation can an effective alternative treatment option for strictured portion of the primary UUS in post-gynecologic surgery patients when its length is <2 cm.

• Physical Therapy Rehabilitation Science
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• v.7 no.4
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• pp.186-190
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• 2018

Objective: Deep neck flexor muscle endurance (DNFET) is important to cervical pain patients. However, there is no normative data of the DNFET hold time of Korean university students. The purpose of this study was to provide normative data and the reliability of the DNFET times of Korean university students and to compare the DNFET hold times between male and female subjects. Design: Cross-sectional study. Methods: The participants included 39 male and 39 female students with no cervical pain. Each DNFET was measured while the subjects kept their chin tucked in while in a supine (hook-lying) position and with the head lifted 2.5 cm off the bed. The DNFET was conducted on each subject twice and the mean values were obtained. After each measurement, the participants rested for 5 minutes. Inter-rater reliability was measured by intraclass correlation coefficient (ICC) by three separate evaluators. Results: The inter-rater reliability was good, showing an ICC (2,3) value = 0.785 (95% confidence interval, 0.370-0.942). The DNFET time scores for men and women were $25.14{\pm}9.96$ seconds and $15.23{\pm}6.10$ seconds, respectively, in which the time scores of the men were significantly longer compared to women (p<0.05). Conclusions: Asymptomatic men displayed higher DNFET scores than women. This study can help clinicians test cervical function of patients and set an interventional goal. These findings serve as a basis that insists Korean women to increase their amount of physical activity.

• Acute and Critical Care
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• v.33 no.4
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• pp.222-229
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• 2018

Background: The diagnosis of pediatric acute respiratory distress syndrome (PARDS) is a pragmatic decision based on the degree of hypoxia at the time of onset. We aimed to determine whether reclassification using oxygenation metrics 24 hours after diagnosis could provide prognostic ability for outcomes in PARDS. Methods: Two hundred and eighty-eight pediatric patients admitted between January 1, 2010 and January 30, 2017, who met the inclusion criteria for PARDS were retrospectively analyzed. Reclassification based on data measured 24 hours after diagnosis was compared with the initial classification, and changes in pressure parameters and oxygenation were investigated for their prognostic value with respect to mortality. Results: PARDS severity varied widely in the first 24 hours; 52.4% of patients showed an improvement, 35.4% showed no change, and 12.2% either showed progression of PARDS or died. Multivariate analysis revealed that mortality risk significantly increased for the severe group, based on classification using metrics collected 24 hours after diagnosis (adjusted odds ratio, 26.84; 95% confidence interval [CI], 3.43 to 209.89; P=0.002). Compared to changes in pressure variables (peak inspiratory pressure and driving pressure), changes in oxygenation (arterial partial pressure of oxygen to fraction of inspired oxygen) over the first 24 hours showed statistically better discriminative power for mortality (area under the receiver operating characteristic curve, 0.701; 95% CI, 0.636 to 0.766; P<0.001). Conclusions: Implementation of reclassification based on oxygenation metrics 24 hours after diagnosis effectively stratified outcomes in PARDS. Progress within the first 24 hours was significantly associated with outcomes in PARDS, and oxygenation response was the most discernable surrogate metric for mortality.

• Yonsei Medical Journal
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• v.59 no.9
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• pp.1115-1122
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• 2018

Purpose: To investigate biomechanical properties of the cornea using a dynamic Scheimpflug analyzer according to age. Materials and Methods: In this prospective, cross-sectional, observational study, participants underwent ophthalmic investigations including corneal biomechanical properties, keratometric values, intraocular pressure (IOP), and manifest refraction spherical equivalent (MRSE). We determined the relationship of biomechanical parameters and ocular/systemic variables (participant's age, MRSE, IOP, and mean keratometric values) by piecewise regression analysis, association of biomechanical parameters with variables by Spearman's correlation and stepwise multiple regression analyses, and reference intervals (RI) by the bootstrap method. Results: This study included 217 eyes of 118 participants (20-81 years of age). Piecewise regression analysis between Corvis-central corneal thickness (CCT) and participant's age revealed that the optimal cut-off value of age was 45 years. No clear breakpoints were detected between the corneal biomechanical parameters and MRSE, IOP, and mean keratometric values. Corneal velocity, deformation amplitude, radius, maximal concave power, Corvis-CCT, and Corvis-IOP exhibited correlations with IOP, regardless of age (all ages, 20-44 years, and over 44 years). With smaller deformation amplitude and corneal velocity as well as increased CorvisIOP and Corvis-CCT, IOP became significantly increased. We provided the results of determination of confidence interval from RI data using bootstrap method in three separate age groups (all ages, 20-44 years, and over 44 years). Conclusion: We demonstrated multiple corneal biomechanical parameters according to age, and reported that the corneal biomechanical parameters are influenced by IOP.

• Kosin Medical Journal
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• v.33 no.3
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• pp.297-306
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• 2018

Objectives: Identification of axillary metastases in breast cancer is important for staging disease and planning treatment, but current techniques are associated with a number of adverse events. This report evaluates the diagnostic accuracy of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) techniques for identification of axillary metastases in breast cancer patients. Methods: We performed a meta-analysis of previous studies that compared SPIO enhanced MRI with histological diagnosis after surgery or biopsy. We searched PubMed, Ovid, Springer Link, and Cochrane library to identify studies reporting data for SPIO enhanced MRI for detection of axillary lymph node metastases in breast cancer until December 2013. The following keywords were used: "magnetic resonance imaging AND axilla" and "superparamagnetic iron oxide AND axilla". Eligible studies were those that compared SPIO enhanced MRI with histological diagnosis. Sensitivity and specificity were calculated for every study; summary receiver operating characteristic and subgroup analyses were done. Study quality and heterogeneity were also assessed. Results: There were 7 publications that met the criteria for inclusion in our meta-analysis. SROC curve analysis for per patient data showed an overall sensitivity of 0.83 (95% Confidence interval (CI): 0.75-0.89) and overall specificity of 0.97 (95% CI: 0.94-0.98). Overall weighted area under the curve was 0.9563. Conclusions: SPIO enhanced MRI showed a trend toward high diagnostic accuracy in detection of lymph node metastases for breast cancer. So, when the breast cancer patients has axillary metastases histologically, SPIO enhanced MRI may be effective diagnostic imaging modality for axillary metastases.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.264-271
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• 2019

Currently, teenagers value the beauty of appearance due to the proximity of the media. Therefore, acne on the skin is not a serious disease, but if it is managed incorrectly, it will leave scars and marks on the face, which leads to students' depression, stress and loss of confidence. Therefore, this study analyzed how acne skin afects adolescent's stress, depression and self-esteem and recognized that acne is not a simple skin disease but is closely related to mental health. And three hypotheses were established to be more effective in managing acne skin and to be used as basic data for skin care. As a result, it was found that acne development of junior high school students had an actual effect on stress and depression. Acne skin care is considered to be necessary for mental health, not superficial management.

• Journal of Soil and Groundwater Environment
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• v.24 no.5
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• pp.11-16
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• 2019

In this study, a reliable number of soil samples for TPH fractionation was investigated in order to perform risk assessment. TPH was fractionated into volatile petroleum hydrocarbons (VPH) with three subgroups and extractable petroleum hydrocarbons (EPH) with four subgroups. At the study site, concentrations of each fraction were determined at 18 sampling points, and the 95% upper confidence limit (UCL) value was used as an exposure concentration of each fraction. And then, 5 sampling points were randomly selected out of the 18 points, and an exposure concentration was calculated. This process was repeated 30 times, and the results were compared statistically. Exposure concentrations of EPH obtained from 18 points were 99.9, 339.1, 27.3, and 85.9 mg/kg for aliphatic $C_9-C_{18}$, $C_{19}-C_{36}$, $C_{37}-C_{40}$, and aromatic $C_{11}-C_{22}$, respectively. The corresponding exposure concentrations obtained from 5 points were 139.8, 462.8, 35.1 and 119.4 mg/kg, which were significantly higher than those from 18 points results (p <0.05). Our results suggest that limited number of samples for TPH fractionation may bias estimation of exposure concentration of TPH fractions. Also, it is recommended that more than 30 samples need to be analyzed for TPH fractionation in performing risk assessment.