• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.26 no.2
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• pp.88-98
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• 2023

Purpose: Children with inflammatory bowel disease (IBD) frequently undergo clinical assessments, involving triadic communication between clinician, parent, and child. During such encounters parents are traditionally the main communicator of information on their child's IBD, including subjective symptom reports. The level of agreement between children and their parents for IBD symptoms is poorly understood, and this study aimed to examine this factor. Methods: This was a cross-sectional study among children with IBD, and one parent. A validated paediatric IBD symptom report tool (IBDnow) enabled children and their parent to rate seven pain, well-being, and stool metrics, with dyads completing the tool concurrently. Results were assessed using: Individual agreement: proportion of identical symptom reports by each dyad (ideal score >0.7); Category agreement: percentage of identical reports for IBDnow metrics for the cohort; Inter-rater reliability: Gwet's AC1 coefficient with higher scores indicating better reliability (maximum=1). Results: Seventy-four parent/child dyads participated; child's mean age 12.2 years (standard deviation [SD] 2.9, range 6-16), mean time since diagnosis 2.8 years (SD 3), 54% female, 73% had Crohn's Disease. Mean individual agreement level was 0.6, with 27% of dyads agreeing on ≥6/7 IBDnow metrics. Category agreement was reported by 61% of dyads, 20% of parents overestimated, and 19% underestimated, their child's symptoms. Inter-rater reliability ranged from fair to good. Conclusion: These results should improve clinician awareness of how IBD symptom reports from parents may introduce bias. Children should be considered the most important source of symptom reports, and tools such as IBDnow utilised to enhance communication.

• Computers and Concrete
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• v.30 no.5
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• pp.311-321
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• 2022

The interfacial bond strength of partially encased composite (PEC) structure tends to 0, therefore, the cast-in-place concrete theoretically cannot embody better composite effect than the fabricated structure. A total of 12 specimens were designed and experimented to investigate the energy dissipation and damage of fabricated PEC beam through unidirectional cyclic loading test. Because the concrete on both sides of the web was relatively independent, some specimens showed obvious asymmetric concrete damage, which led to specimens bearing torsion effect at the later stage of loading. Based on the concept of the ideal elastoplastic model of uniaxial tensile steel and the principle of equivalent energy dissipation, the energy dissipation ductility coefficient is proposed, which can simultaneously reflect the deformability and bearing capacity. In view of the whole deformation of the beam, the calculation formula of energy dissipation is put forward, and the energy dissipation and its proportion of shear-bending region and pure bending region are calculated respectively. The energy dissipation efficiency of the pure bending region is significantly higher than that of the shear-bending region. The setting of the screw arbors is conducive to improving the energy dissipation capacity of the specimens. Under the condition of setting the screw arbors and meeting the reasonable shear span ratio, reducing the concrete pouring thickness can lighten the deadweight of the component and improve the comprehensive benefit, and will not have an adverse impact on the energy dissipation capacity of the beam. A damage model is proposed to quantify the damage changes of PEC beams under cyclic load, which can accurately reflect the load damage and deformation damage.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.442-453
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• 2021

Artificial intelligence (AI) will likely affect various fields of medicine. This article aims to explain the fundamental principles of clinical validation, device approval, and insurance coverage decisions of AI algorithms for medical diagnosis and prediction. Discrimination accuracy of AI algorithms is often evaluated with the Dice similarity coefficient, sensitivity, specificity, and traditional or free-response receiver operating characteristic curves. Calibration accuracy should also be assessed, especially for algorithms that provide probabilities to users. As current AI algorithms have limited generalizability to real-world practice, clinical validation of AI should put it to proper external testing and assisting roles. External testing could adopt diagnostic case-control or diagnostic cohort designs. A diagnostic case-control study evaluates the technical validity/accuracy of AI while the latter tests the clinical validity/accuracy of AI in samples representing target patients in real-world clinical scenarios. Ultimate clinical validation of AI requires evaluations of its impact on patient outcomes, referred to as clinical utility, and for which randomized clinical trials are ideal. Device approval of AI is typically granted with proof of technical validity/accuracy and thus does not intend to directly indicate if AI is beneficial for patient care or if it improves patient outcomes. Neither can it categorically address the issue of limited generalizability of AI. After achieving device approval, it is up to medical professionals to determine if the approved AI algorithms are beneficial for real-world patient care. Insurance coverage decisions generally require a demonstration of clinical utility that the use of AI has improved patient outcomes.

• Membrane and Water Treatment
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• v.15 no.2
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• pp.67-78
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• 2024

In this study, a nickel hexacyanoferrate and manganese dioxide-polyacrylonitrile (NM-PAN) composite was synthesized and used for the sorptive removal of Co²⁺, Sr²⁺, and Cs⁺ Cs⁺ in radioactive laundry wastewater. Single- and multi-solute competitive sorptions onto NM-PAN were investigated. The Freundlich (Fr), Langmuir (Lang), Kargi-Ozmıhci (K-O), Koble-Corrigan (K-C), and Langmuir-Freundlich (Lang-Fr) models satisfactorily predicted all the single sorption data. The sorption isotherms were nonlinearly favorable (Freundlich coefficient, N_F = 0.385-0.426). Cs⁺ has the highest maximum sorption capacity (q_mL = 0.855 mmol g^-1) for NM-PAN compared to Co²⁺ and Sr²⁺, wherein the primary mechanism was the physical process (mainly ion-exchange). The competition between the metal ions in the binary and ternary systems reduced the respective sorption capacities. Binary and ternary sorption models, such as the ideal adsorbed solution theory (IAST) model coupled with single sorption models of IAST-Fr, IAST-K-O, IAST-K-C and IAST-Lang-Fr, were fitted to the experimental data; among these, the IAST-Freundlich model showed the most satisfactory prediction for the binary and ternary systems. The presence of cationic surfactants highly affected the sorption on NM-PAN due to the increase in distribution coefficients (K_d) of Co²⁺ and Cs⁺.

• Clean Technology
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• v.26 no.3
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• pp.161-167
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• 2020

For the design of the prevention and mitigation measures in process industries involving flammable substances, reliable safety data are required. An important property used to estimate the risk of fire and explosion for a flammable liquid is the flash point. Flammability is an important factor to consider when developing safe methods for storing and handling solids and liquids. In this study, the flash point data were measured for the binary systems {2-butanol + 2,2,4-trimethylpentane}, {2-butanol + methylcyclohexane} and {2-butanol + toluene} at 101.3 kPa. Experiments were performed according to the standard test method (ASTM D 3278) using a Stanhope-Seta closed cup flash point tester. A minimum flash point behavior was observed in the binary systems as in the many cases for the hydrocarbon and alcohol mixture that were observed. The measured flash points were compared with the predicted values calculated via the following activity coefficient (GE) models: Wilson, Non-Random Two-Liquid (NRTL), and UNIversal QUAsiChemical (UNIQUAC) models. The predicted data were only adequate for the data determined by the closed-cup test method and may not be appropriate for the data obtained from the open-cup test method because of its deviation from the vapor liquid equilibrium. The predicted results of this work can be used to design safe petrochemical processes, such as the identification of safe storage conditions for non-ideal solutions containing flammable components.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.144.2-144.2
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• 2016

Diamond-like carbon (DLC) coatings have been widely applied to the mechanical components, cutting tools due to properties of high hardness and wear resistance. Among them, hydrogenated amorphous carbon (a-C:H) coatings are well-known for their low friction properties, stable production of thin and thick film, they were reported to be easily worn away under high temperature. Non-hydrogenated tetrahedral amorphous carbon (ta-C) is an ideal for industrial applicability due to good thermal stability from high $sp^3$-bonding fraction ranging from 70 to 80 %. However, the large compressive stress of ta-C coating limits to apply thick ta-C coating. In this study, the thick ta-C coating was deposited onto Inconel alloy disk by the FCVA technique. The thickness of the ta-C coating was about $3.5{\mu}m$. The tribological behaviors of ta-C coated disks sliding against $Si_3N_4$ balls were examined under elevated temperature divided into 23, 100, 200 and $300^{\circ}C$. The range of temperature was setting up until peel off observed. The experimental results showed that the friction coefficient was decreased from 0.14 to 0.05 with increasing temperature up to $200^{\circ}C$. At $300^{\circ}C$, the friction coefficient was dramatically increased over 5,000 cycles and then delaminated. These phenomenon was summarized two kinds of reasons: (1) Thermal degradation and (2) graphitization of ta-C coating. At first, the reason of thermal degradation was demonstrated by wear rate calculation. The wear rate of ta-C coatings showed an increasing trend with elevated temperature. For investigation of relationship between hardness and graphitization, thick ta-C coatings(2, 3 and $5{\mu}m$) were additionally deposited. As the thickness of ta-C coating was increased, hardness decreased from 58 to 49 GPa, which means that graphitization was accelerated. Therefore, now we are trying to increase $sp^3$ fraction of ta-C coating and control the coating parameters for thermal stability of thick ta-C at high temperatures.

• Journal of Technologic Dentistry
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• v.19 no.1
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• pp.91-111
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• 1997

An aim of this study is to find out influenced factors of satisfaction degree on the clinical practice for the dental technology student and it can be provided the basic necessary data for the educational planning of the curriculum for the clinical practice. The target of study are selected form 7 junior health college students and colleges are located in around seoul form 14 junior health college throughout the nation. The questionnaries were distributed between 24th Feb to 30th July in 1997 to the 100 dental technicians who finished clinical practice and entered profession in 1997. All collected data were analysed by using SPSS/PC, Technical Statistic, One-Way ANOVA, Ttest, Person Correnlation Coefficient, Chrobach Alpha Coefficient and the result of the study is follow. 1) The satisfaction degree were classificated as 7 aspect and overall average score was 3.042. During that period satisfaction of personal relation aspect(M=3.737) shows highest level. Satsfiaction of clinical parctice(M=3.571) shows as second, Satisfiaction of environment(M=3.028), Satisfaction of guidance(M=2.915), satisfaction of subject are ordered of their scores. According to above study satisfaction's degree of subject show lowest level. 2) According to the result of verification of study. general character of student and satisfiaction degree has not much relation with sex, location of college, religion, period for enrolling college, teaching method of clinical practice. But the result show similar relation with following items. Satisfaction if subject and satisfaction of clinical practice(P=0.000), place of clinical practice and satisfaction of clinical practice(P=0.002), Academic record of college and satisfaction of clinical practice(P=0.000). 3) The relation of satisfaction(Subject, method of teaching, environment, period, rating, personal relation) of clinical practice and age of investigation's target Older student show higher satisfaction(P=0.040). Also method of teaching, environments, period, rating, personal relation has similarities with satisfaction. Therefore student who has higher satisfaction of clinical practice they also have higher rate for subject, environment, period, personal relation. 4) The result fo investigation, most interesting subject was crown & bridge and most difficult factor was too many simple-works to the student. One of ideal factor was discussing with counselor before they choose place for clinical practice. Third grade and first semester is most efficient time for clinical practice and 8 week is proper period for clinical practice. Clinical practice is absilutory mecessary and we find out most student rated positively. However we need more specific study about satisfcation of each subject. Because it shows lowest level and we need more pay attention for planning of clinical practice.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.506-510
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• 2004

A torque transmission system composed of several gears and couplings is flexible. In order to get an exact response of motor, the torsional vibration due to an unexpected change of motor speed must be suppressed. Therefore, it is very important that motor control suppress vibration. Various methods to control it including dual inertia system are proposed. Specially, the method of vibration suppression is that vibration can be suppressed to fee㏈ack the estimated torsion torque via the disturbance observer filter being of normal filter. The suitable Proportional controller and coefficient parameter can be designed using CDM and the torsional vibration also be suppressed, but it has a low degree of adaptability to disturbance. The PID controller can be designed easily, but makes the excessive overshoot and oscillation for system response in the early period. To resolve these problems, simple and practical PID controller with two degree of freedom is proposed recently that it ran improve performance of obeying the reference unconcerned in any disturbance by changing the proportional gain by two degree of freedom parameter. But it has also the defect that parameter a must be changed to obtain the ideal Proportional parameter. On this paper, we design the controller which automatically adjusts parameter u using fuzzy Algorithm to overcome such defects. Also, we compare the proposed method with established one and evaluate them to confirm performance of the designed controller.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.332-338
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• 2016

This study examined the posttraumatic growth of North Korean defectors, the relation between their characteristics and posttraumatic growth and the factors influencing their posttraumatic growth, and explored methods of improving their mental health status. 145 North Korean defectors, who were trained in B city and G city, participated in the survey from February 1 to March 10, 2016. The posttraumatic growth, resilience, self-esteem, deliberate rumination, and impact of the (traumatic) event were measured using the PTGI (Posttraumatic Growth Inventory), RS (Rumination Scale, Resilience Scale), SES (Self-esteem Scale) and ISR (Impact of Event). The data were analyzed using the t-test, ANOVA, Pearson correlation coefficient and stepwise multiple regression. The mean scores were 29.64 for posttraumatic growth. There were significant positive correlations between posttraumatic growth and resilience and between posttraumatic growth and rumination. The influence of the independent variables on the total posttraumatic growth was examined using regression analysis. Models including the variables (resilience, positive self-esteem, and rumination) explained 54.2% of the variance for the posttraumatic growth. These findings demonstrate that it is essential for nurses to continuously intervene and help North Korean defectors so as to promote their posttraumatic growth and resilience. Furthermore, it is also necessary for nurses to find ways to develop ideal interventions in order to activate deliberate rumination.

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.653-658
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• 2016

Poly(ether-block-amide)(PEBAX$_{(R)}$) resin is a thermoplastic elastomer combining linear chains of hard-rigid polyamide block interspaced soft-flexible polyether block. It was believed that the hard polyamide block provides the mechanical strength and permselectivity, whereas gas transport occurs primarily through the soft polyether block. The objective of this work was to investigate the gas permeation properties of carbon dioxide and methane for PEBAX$^{(R)}$-1657 membrane, and compare with those obtained for other grade of pure PEBAX$^{(R)}$, PEBAX$^{(R)}$-2533 and PEBAX$^{(R)}$ based hybrid membranes. The hybrid membranes based PEBAX$^{(R)}$ were obtained by a sol-gel process using GPTMS ((3-glycidoxypropyl) trimethoxysilane) as the only inorganic precursor. Molecular structure and morphology of membrane were analyzed by $^{29}Si$-NMR, DSC and SEM. PEBAX$_{(R)}$-2533 membrane exhibited higher gas permeability coefficients than PEBAX$^{(R)}$-1657 membrane. This was explained by the increase of chain mobility. In contrast, ideal separation factor of $CO_2/CH_4$ for PEBAX$^{(R)}$-1657 membrane was higher than PEBAX$^{(R)}$-2533 membrane. It was explained by the decrease of diffusion selectivity caused by increase of chain mobility. For PEBAX$^{(R)}$/GPTMS hybrid membrane, gas permeability coefficients were decreased with reaction time. Gas permeability coefficient of $CH_4$ was more significantly decreased than $CO_2$. It can be explained by the reduction of chain mobility caused by the sol-gel process, and strong affinity of PEO segment with $CO_2$. Comparing with pure PEBAX$^{(R)}$-1657 membrane, ideal separation factor of $CO_2/CH_4$ for PEBAX$^{(R)}$/GPTMS hybrid membrane has decreased to 4.5%, and gas permeability coefficient of $CO_2$ has increased 3.5 times.