• Structural Engineering and Mechanics
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• 제45권6호
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• pp.837-851
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• 2013

In construction industry, strength is a primary criterion in selecting a concrete for a particular application. The concrete used for construction gains strength over a long period of time after pouring the concrete. The characteristic strength of concrete is defined as the compressive strength of a sample that has been aged for 28 days. Neither waiting for 28 days for such a test would serve the rapidity of construction, nor would neglecting it serve the quality control process on concrete in large construction sites. Therefore, rapid and reliable prediction of the strength of concrete would be of great significance. On this backdrop, the method is proposed to establish a predictive relationship between properties and proportions of ingredients of concrete, compaction factor, weight of concrete cubes and strength of concrete whereby the strength of concrete can be predicted at early age. Multiple regression analysis was carried out for predicting the compressive strength of concrete containing Portland Pozolana cement using statistical analysis for the concrete data obtained from the experimental work done in this study. The multiple linear regression models yielded fairly good correlation coefficient for the prediction of compressive strength for 7, 28 and 40 days curing. The results indicate that the proposed regression models are effectively capable of evaluating the compressive strength of the concrete containing Portaland Pozolana Cement. The derived formulas are very simple, straightforward and provide an effective analysis tool accessible to practicing engineers.

• Journal of Information Processing Systems
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• 제14권3호
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• pp.655-665
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• 2018

In efforts to increase its agricultural productivity, the Indonesian Center for Agricultural Biotechnology and Genetic Resources Research and Development has conducted a variety of genomic studies using high-throughput DNA genotyping and sequencing. The large quantity of data (big data) produced by these biotechnologies require high performance data management system to store, backup, and secure data. Additionally, these genetic studies are computationally demanding, requiring high performance processors and memory for data processing and analysis. Reliable network connectivity with large bandwidth to transfer data is essential as well as database applications and statistical tools that include cleaning, quality control, querying based on specific criteria, and exporting to various formats that are important for generating high yield varieties of crops and improving future agricultural strategies. This manuscript presents a reliable, secure, and scalable information technology infrastructure tailored to Indonesian agriculture genotyping studies.

• 열처리공학회지
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• 제3권2호
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• pp.10-19
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• 1990

The tempering behavoirs of 0.45% carbon steel treated by automatic progressive high frequency induction hardening equipment have been investigated. In order to examine the correlation of hardness with both tempering temperature and time, simple regression analysis has been made using the statistical quality control package. The maximum surface hardness value of induction hardened zone and its effective hardening depth have been determined to be Hv 810 and 0.76mm, respectively. The hardness obtained after tempering has been shown to vary lineary with tempering time at six different temperatures. The activation energies during tempering have been calculated to be 25.34kcal/mole, 32.73kcal/mole and 49.24kcal/mole for HRcs 60, 50 and 40, respectively, showing that tempering process occurs by a complex mechanism, The tempering hardness equation of $H=90.113{\sim}4.531{\times}10^{-3}$ [T(11.996+log t)] has proved to be in a reasonably good agreement with experimently determined data and it is also expected to be useful for the determination of tempering treatment conditions to obtain a required hardness value.

• International Journal of Internet, Broadcasting and Communication
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• 제13권4호
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• pp.121-128
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• 2021

In order to design a real time big data collection and analysis system of manufacturing data in a smart factory, it is important to establish an appropriate wired/wireless communication system and protocol. This paper introduces the latest communication protocol, OPC-UA (Open Platform Communication Unified Architecture) based client/server function, applied user interface technology to configure a network for real-time data collection through IoT Integration. Then, Database is designed in MES (Manufacturing Execution System) based on the analysis table that reflects the user's requirements among the data extracted from the new cutting process automation process, bush inner diameter indentation measurement system and tool monitoring/inspection system. In summary, big data analysis system introduced in this paper performs SPC (statistical Process Control) analysis and visualization analysis with interface of OPC-UA-based wired/wireless communication. Through AI learning modeling with XGBoost (eXtream Gradient Boosting) and LR (Linear Regression) algorithm, quality and visualization analysis is carried out the storage and connection to the cloud.

• Journal of information and communication convergence engineering
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• 제20권3호
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• pp.204-211
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• 2022

This study evaluated the completeness of patient care report (PCR). A retrospective quality analysis was conducted using raw data of 122,140 EMS activity reports prepared by paramedics in Gyeonggi-do from April 1 to May 31, 2021. In all, 67,830 cases of normal transfers were statistically analyzed using IBM SPSS Statistics version 22, and statistical significance was set at p<0.5. The 119EMT_2 certificate was omitted in 50,037 (73.8%) cases, followed by time-related items in 1,227 (1.8%) cases. In the primary assessment of vital signs, systolic blood pressure was omitted and erroneous in 1,218 (1.9%) and 1,129 (1.8%) cases, respectively. In the secondary assessment, the completeness of all vital sign items was approximately 70%. Advanced emergency care and online medical control (OLMC) reporting showed discrepancies in all items. As the severity of the patient's condition increased, the errors in the Patient care report (PCR) also increased, at a significant level (p= .00). Paramedics must be aware of the importance of completing the activity report.

• 한국응급구조학회지
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• 제28권1호
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• pp.21-34
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• 2024

Purpose: This study aimed to observe change in factors over time in the first cohort of the 2018 Children and Adolescent Panel Middle School. In addition, this study attempted to examine the causal relationship and influence between variables by setting a time gap between independent and dependent variables. Methods: Frequency and descriptive statistical analyses were conducted to determine the general characteristics of the study participants. Hierarchical regression analysis was conducted to analyze the effects of smartphone dependence on health, sleep quality, and depression. After inputting the control variables (Model 2), the influence of the variables was identified based on the input model. Results: Smartphone dependence positively impacted depression in both male and female students and negatively impacted sleep and health. Conclusion: Smartphones are closely associated with teenagers' lives. Additionally, as adolescents experience various psychological anxieties owing to rapid physical changes, there are concerns that psychological dependence may increase, considering that adolescence is the most emotionally unstable period. Therefore, the results of this study consistently prove that smartphone dependence has a causal relationship with emotion-related variables, such as emotional stress, depression, and anxiety.

• 생물환경조절학회지
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• 제4권2호
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• pp.144-151
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• 1995

본 실험은 겨울철 파의 양액재배시 배양액 온도를 13, 18, 23$^{\circ}C$로 처리하여 잎파의 생육 및 품질에 미치는 영향을 살펴보고자 수행하였다. 13-23$^{\circ}C$ 범위 내에서 배양액 온도가 증가할수록 생체중도 증가하였다. 초장도 13$^{\circ}C$보다 18, 23$^{\circ}C$ 처리구에서 더 길었으며, 지상부, 지하부 건물율은 18$^{\circ}C$ 처리구에서 가장 무거웠다. 식물체내 K의 함량은 18$^{\circ}C$ 처리구에서 가장 높았으며, Ca, Mg의 함량은 23$^{\circ}C$보다 13, 18$^{\circ}C$ 처리구에서 더 높았다. 비타민 C의 함량은 배양액 온도가 증가할수록 감소하였으나, 유의성은 인정되지 않았다. Pyruvic acid 함량은 13, 18$^{\circ}C$ 처리구에서 높았으며, nitrate의 함량은 반대로 23$^{\circ}C$ 처리구보다 13, 18$^{\circ}C$ 처리구에서 낮았다. 따라서 파의 생육과 품질을 고려한다면, 겨울철 파의 양액 재배시 적절한 배양액 온도는 18$^{\circ}C$ 내외로 생각된다.

• 대한통합의학회지
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• 제9권3호
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• pp.87-97
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• 2021

Purpose : The purpose of this meta-analysis was to evaluate the effects of transcranial direct current stimulation on the lower extremity function of stroke patients. Methods : Domestic data were gathered from studies that conducted clinical trials associated with transcranial direct current stimulation and its impact on lower extremity function of stroke patients. A total of 592 studies published between 2012 and 2020 were identified, with 7 studies satisfying the inclusion data. The studies consisted of patient, intervention, comparison, and outcome (PICO) data. The search outcomes were items associated with muscle activity, balance, muscle strength and walking ability. Cochrane risk of bias (ROB) was used to evaluate the quality of 3 randomized control trials. The quality of 4 non-randomized control trials was evaluated using risk of bias assessment tool for non-randomized studies (RoBANS). Effect sizes in this study were computed as the corrected standard mean difference (SMD). A random-effect model was used to analyze the effect size because of the high heterogeneity among the studies. Egger's regression and 'trim-and-fill' tests were carried out to analyze the publishing bias. Results : The following factors had a large total effect size (Hedges's g=2.10, 95 %CI=1.54~2.66) involving transcranial direct current stimulation on stroke patients: muscle activity (Hedges's g=2.38, 95 %CI=1.08~3.68), balance (Hedges's g4=2.41, 95 %CI=1.33~3.60), walking ability (Hedges's g=1.54, 95 %CI=0.49~2.59), and muscle strength (Hedges's g=2.45, 95 % CI: 0.85~4.05). Egger's regression test showed that the publishing bias had statistically significant differences but 'trim-and-fill' test showed that there was still statistical difference. Conclusion : This study provides evidence for the effectiveness of transcranial direct current stimulation on the lower extremity in terms of muscle activity, balance, walking ability, and muscle strength in stroke patients. However, due to the low quality of studies and high heterogeneity factors, the results of our study should be interpreted cautiously.

• 치위생과학회지
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• 제21권4호
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• pp.233-242
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• 2021

Background: The importance of infection with COVID-19 is being emphasized in dentistry with high risks such as aerosols. The purpose of this study is to investigate the knowledge and practice of infection control, stress and coping, and turnover of dental hygienists. Methods: Questionnaire was conducted knowledge and practice of infection control, occupational stress and coping, turnover. Survey data was investigated about 149 dental hygienists from February to March 2021 Data were analyzed t-test, ANOVA, Pearson's correlation using statistical programs of PASW Statistics ver. 21.0. Results: Regarding occupational stress, relationship conflict was higher in the group with less than 2 years of experience (p<0.05). Job anxiety, organizational system, inadequate compensation, and workplace culture were highly surveyed in the 3 to 5 year of experience. The group with more than 6 years of experience had the highest perception of lack of job autonomy (p<0.05). The group with higher knowledge of infection control had lower mean inappropriate rewards and stress (p<0.05). The group with high infection control performance had a lower average in items such as job instability, organizational system, inadequate compensation, workplace culture, and stress. And problem-focused coping ability was found to be high (p<0.05). Infection control knowledge and performance were positively correlated (r=0.251, p<0.01), infection control practice and stress were negatively correlated (r=-0.264, p<0.01), and stress and emotional coping were positively correlated (r=0.367, p<0.01). Stress was positively correlated with turnover rate (r=0.549, p<0.01). Conclusion: Infection control training was required to reduce occupational stress. Occupational stress was highly correlated with turnover, a holistic and systemic organizational operation and improvement of the quality of medical care were required to reduce stress.

• Journal of Welding and Joining
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• 제32권6호
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• pp.8-13
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• 2014

One of the main challenges of the automatic arc welding process which has been widely used in various constructions such as steel structures, bridges, autos, motorcycles, construction machinery, ships, offshore structures, pressure vessels, and pipelines is to create specific welding knowledge and techniques with high quality and productivity of the production-based industry. Commercially available automated arc welding systems use simple control techniques that focus on linear system models with a small subset of the larger set of welding parameters, thereby limiting the number of applications that can be automated. However, the correlations of welding parameters and bead geometry as welding quality have mostly been linked by a trial and error method to adjust the welding parameters. In addition, the systematic correlation between these parameters have not been identified yet. To solve such problems, a new or modified models to determine the welding parameters for tandem GMA (Gas Metal Arc) welding process is required. In this study, A new predictive model called STACO model, has been proposed. Based on the experimental results, STACO model was developed with the help of a standard statistical package program, MINITAB software and MATLAB software. Cross-comparative analysis has been applied to verify the reliability of the developed model.