• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.8
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• pp.975-980
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• 2019

In this paper, we propose a deep learning-based scheduling scheme for user selection in multi-user multi-antenna networks which is considered one of key technologies for the next generation mobile communication systems. We obtained 90,000 data samples from the conventional optimal scheme to train the proposed neural network and verified the trained neural network to check if the trained neural network is over-fitted. Although the proposed neural network-based scheduling algorithm requires considerable complexity and time for training in the initial stage, it does not cause any extra complexity once it has been trained successfully. On the other hand, the conventional optimal scheme continuously requires the same complexity of computations for every scheduling. According to extensive computer-simulations, the proposed deep learning-based scheduling algorithm yields about 88~96% average sum-rates of the conventional scheme for SNRs lower than 10dB, while it can achieve optimal average sum-rates for SNRs higher than 10dB.

• Physical Therapy Rehabilitation Science
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• v.8 no.3
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• pp.146-151
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• 2019

Objective: The purpose of this study was to investigate the test-retest reliability and concurrent validity of the joint angle of the lower extremities during sit-to-stand movements with wearable sensors based on a portable gait analysis system (PGAS), and the results were compared with a analysis system (MAS) to predict the clinical potential of it. Design: Cross-sectional study. Methods: Sixteen persons with stroke (9 males, 7 females) participated in this study. All subjects had the MAS and designed PGS applied simultaneously and eight sensor units of designed PGAS were placed in a position to avoid overlap with the reflexive markers from MAS. The initial position of the subjects was 90º of hip, knee, and ankle joint flexion while sitting on a chair that was armless and backless. The height of the chair was adjusted to each individual. After each trial, the test administrator checked the quality of data from both systems that measured sit-to-stand for test-retest reliability and concurrent validity. Results: As a result, wearable sensor based designed PGAS and MAS demonstrated reasonable test-retest reliability for the assessment of joint angle in the lower extremities during sit-to-stand performance. The intra-class correlation coefficients (ICCs) for wearable sensor based designed PGAS showed an acceptable test-retest reliability, with ICCs ranging from 0.759 to 0.959. In contrast, the MAS showed good to excellent test-retest reliability, with ICCS ranging from 0.811 to 0.950. In concurrent validity, a significant positive relationship was observed between PGAS and MAS for variation of joint angle during sit-to-stand movements (p<0.01). A moderate to high relationship was found in the affected hip (r=0.665), unaffected hip (r=0.767), affected knee (r=0.876), unaffected knee (r=0.886), affected ankle (r=0.943) and unaffected ankle (r=0.823) respectively. Conclusions: The results of this study indicated that wearable sensor based designed PGAS showed acceptable test-retest reliability and concurrent validity in persons with stroke for sit-to-stand movements and wearable sensors based on developed PGAS may be a useful tool for clinical assessment of functional movement.

• Nutrition Research and Practice
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• v.13 no.5
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• pp.410-414
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• 2019

BACKGROUND/OBJECTIVES: Several nutritional screening tools were recently developed to screen the risk of malnutrition in hospitalized children, but have not been validated in Asia. We compared four nutritional screening tools for pediatric patients in evaluating nutritional risks in newly hospitalized children. SUBJECTS/METHODS: Medical records of newly admitted pediatric patients between June 2016 and May 2017 at two tertiary hospitals were reviewed. Initial information by nurses and hospital records by doctors on baseline demographic, clinical, and anthropometric data at admission were collected in all subjects. Nutritional risks were evaluated using four nutritional screening tools including the pediatric nutritional risk score (PNRS), the screening tool for the assessment of malnutrition in pediatrics (STAMP), the paediatric Yorkhill malnutrition score (PYMS), and the screening tools for risk of nutritional status and growth (STRONGkids). RESULTS: A total of 559 patients (310 boys and 249 girls, mean age $6.3{\pm}5.5years$) were recruited. Patients in medical and surgical departments were 469 (83.9%) and 90 (16.1%), respectively. The prevalence of patients at risk of malnutrition were 31.1% for low risk, 52.2% for medium risk, and 16.6% for high risk by PNRS; 11.4%, 39.7%, and 48.8% by STAMP; 26.5%, 25.4%, and 48.1% by PYMS; and 35.6%, 58.9%, and 5.5% by STRONGkids. PNRS versus STRONGkids and STAMP versus PYMS showed moderate agreement (kappa = 0.566 and kappa = 0.495, respectively). PYMS and STAMP revealed a relatively high sensitivity of 87.8% and 77.6% for wasting. CONCLUSION: Different nutritional screening tools revealed considerably different results in evaluating nutritional risks in newly hospitalized children. Since pediatric patients are at risk of malnutrition at admission and during hospitalization, screening tools should be applied properly according to the situation of each hospital.

• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.104-113
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• 2019

There are keen competitions among the air operators to recruit competent pilots, which could be adversely affect the safe operation of aircraft. This study is aimed to identify the correlation between the flight experience of the pilot of the air transport operator and competency on visual approach operation. About 2,400 sets of flight training data of several pilots of an air transport operator was analysed for this study. The analysis showed that most captains were able to make stabilized visual approach regardless of his/her flight experience of any type of aircraft, while the first officers were able to make a stabilized visual approach with more than 1,500 hours of flight experience for each rated type of aircraft. This should be considered during making policies for the supply and demand of pilots for the safe operation of air transport.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.281-286
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• 2019

This study, which checked diagnostic agreement at the femoral region and lumbar region during diagnosis of osteoporosis and surveyed errors related with choosing measured parts, aimed at providing basic date for right diagnosis of osteoporosis. The study, using the first, second years of the fifth period from initial data from National Nutrition Survey, surveyed 1,637 men and 2,128 women at the age of 50 years or older. The study used kappa test to grasp the agreement between the occurrence of osteoporosis at the femoral region and lumbar region and whether or not received doctor's diagnosis. Women showed diagnostic agreement of osteoporosis at all of the femoral region and lumbar region, with diagnostic agreement of the lumbar region being higher than that of the femoral region. While, men showed diagnostic agreement of osteoporosis only at the lumbar region. Bone density changes with the age and varies depending on parts, and so, the study believes, measuring bone density should conduct all of the femoral region and lumbar region and diagnosis had better be made focused on the lumbar region.

• Applied Chemistry for Engineering
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• v.30 no.2
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• pp.190-197
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• 2019

The adsorption of methyl green dye using an activated carbon from an aqueous solution was investigated. Adsorption experiments were carried out as a function of the adsorbent dose, initial concentration, contact time and temperature. The Langmuir isotherm model showed a good fit to the equilibrium adsorption data. Based on the estimated Langmuir separation factor, ($R_L=0.02{\sim}0.106$), this process could be employed as the effective treatment (0 < $R_L$ < 1). It was found that the adsorption was a physical process with the adsorption energy (E) value range between 316.869 and 340.049 J/mol obtained using Dubinin-Radushkevich equation. The isothermal saturation capacity obtained from brunauer emmett teller (BET) model increased with increasing the temperature. The kinetics of adsorption followed a pseudo second order model. The free energy and enthalphy values of -5.421~-7.889 and 31.915 kJ/mol, respectively indicated that the adsorption process follows spontaneous endothermic reaction. The isosteric heat of adsorption increased with the increase of equilibrium adsorption amounts, and the total interaction of the adsorbent - adsorbate increased as the surface coverage increased.

• Clinics in Shoulder and Elbow
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• v.22 no.2
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• pp.70-78
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• 2019

Background: This study evaluated postoperative changes in the supraspinatus from time-zero to 6 months, using magnetic resonance imaging (MRI). We hypothesized that restoration of the musculotendinous unit of the rotator cuff by tendon repair immediately improves the rotator cuff muscle status, and maintains it months after surgery. Methods: Totally, 76 patients (29 men, 47 women) with rotator cuff tears involving the supraspinatus tendon who underwent arthroscopic rotator cuff repairs were examined. MRI evaluation showed complete repair with intact integrity of the torn tendon at both time-zero and at 6 months follow-up. All patients underwent standardized MRI at our institution preoperatively, at 1 or 2 days postoperative, and at 6 months after surgery. Supraspinatus muscular (SSP) atrophy (Thomazeau grade) and fatty infiltrations (Goutallier stage) were evaluated by MRI. The cross-sectional area of SSP in the fossa was also measured. Results: As determined by MRI, the cross-sectional area of SSP significantly decreased 11.41% from time-zero (immediate repair) to 6 months post-surgery, whereas the Goutallier stage and Thomazeau grade showed no significant changes (p<0.01). Furthermore, compared to the preoperative MRI, the postoperative MRI at 6 months showed a no statistically significant increase of 8.03% in the cross-sectional area. In addition, morphological improvements were observed in patients with high grade Goutallier and Thomazeau at time-zero, whereas morphology of patients with low grade factors were almost similar to before surgery. Conclusions: Our results indicate that cross-sectional area of the initial repair appears to decrease after a few months postoperatively, possibly due to medial retraction or strained muscle.

• 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.

• Journal of Cardiovascular Imaging
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• v.26 no.4
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• pp.229-237
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• 2018

BACKGROUND: Statins are thought to have little effect on the progression of aortic stenosis, but the data on their role in patients with aortic valve sclerosis (AVS) are limited and inconsistent. METHODS: We retrospectively analyzed 541 consecutive patients (214 men, age: $70{\pm}11$ years) with AVS. Each patient underwent two or more electrocardiography examinations at least 6 months apart at Kangwon National University Hospital from August 2010 to August 2015. AVS is defined as irregular thickening of the leaflets, focal increases in echogenicity and minimal elevation of the peak aortic valve velocity (> 1.5 and < 2 m/s). The progression rate of AVS was expressed as the increase in peak velocity per year (m/s/yr). RESULTS: The mean follow-up duration was $24.9{\pm}13.3$ months in the statin-treated group and $24.1{\pm}12.4$ months in the non-statin-treated group (p = 0.460). There were no differences between the statin-treated and non-statin-treated groups in mean age, gender or smoking status. Relative to the non-statin-treated group, a higher number of patients in the statin-treated group had hypertension, diabetes, ischemic heart disease, and stroke. The progression rate of AVS did not differ between the statin-treated and non-statin-treated groups ($0.012{\pm}0.340m/s/yr$ vs. $0.014{\pm}0.245m/s/yr$, p = 0.956). Multivariate analysis showed initial peak aortic jet velocity was significantly associated with AVS progression (${\beta}=0.153$, p = 0.009). CONCLUSIONS: Our study demonstrated that statins had no effect on the progression of AVS. However, well-designed studies are needed to define the prognosis and management of AVS.

• Korean journal of medical education
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• v.30 no.4
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• pp.327-337
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• 2018

Purpose: Patient education is a dynamic and continuous process that should be implemented during the entire time of hospital stay and even afterward. Studies have shown the typically poor quality of patient education in Iran and its failure to convey the required knowledge and skills to patients. The purpose of this study was to survey the experience of nursing students in regard to the challenges of patient education in hospitals. Methods: This qualitative study was conducted using the conventional qualitative content analysis approach on a sample of 21 undergraduate nursing students (4th semester and beyond), which was drawn from the Qom Nursing and Midwifery School through purposive sampling with maximum variation. Data were collected through semi-structured interviews conducted over a period of 45 to 75 minutes, and were analyzed using the conventional qualitative content analysis. Results: Results were derived from the experiences of 21 nursing students (nine males, 12 females) about the research subject. The primary themes identified in the study were the student-related, patient-related, instructor-related, education environment-related, and curriculum-related barriers to patient educations. Conclusion: Participants believed that patient education in Iranian hospitals is faced with many challenges. Nursing instructors and curriculum planners should ensure more emphasis on patient education at the initial semesters of nursing education curriculum and make sure that it is included in the evaluation of students. Hospital officials should provide a dedicated education environment with suitable facilities, tools, and atmosphere for patient education. Also, special education programs need to be developed for less educated patients.