• Steel and Composite Structures
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• 제49권3호
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• pp.337-348
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• 2023

Successive wetting and drying cycles of concrete due to weather changes can endanger the safety of engineering structures over time. Considering wetting and drying cycles in concrete tests can lead to a more correct and reliable design of engineering structures. This study aims to provide a model that can be used to estimate the resistance properties of concrete under different wetting and drying cycles. Complex sample preparation methods, the necessity for highly accurate and sensitive instruments, early sample failure, and brittle samples all contribute to the difficulty of measuring the strength of concrete in the laboratory. To address these problems, in this study, the potential ability of six machine learning techniques, including ANN, SVM, RF, KNN, XGBoost, and NB, to predict the concrete's tensile strength was investigated by applying 240 datasets obtained using the Brazilian test (80% for training and 20% for test). In conducting the test, the effect of additives such as glass and polypropylene, as well as the effect of wetting and drying cycles on the tensile strength of concrete, was investigated. Finally, the statistical analysis results revealed that the XGBoost model was the most robust one with R2 = 0.9155, mean absolute error (MAE) = 0.1080 Mpa, and variance accounted for (VAF) = 91.54% to predict the concrete tensile strength. This work's significance is that it allows civil engineers to accurately estimate the tensile strength of different types of concrete. In this way, the high time and cost required for the laboratory tests can be eliminated.

• 한국운동역학회지
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• 제34권2호
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• pp.53-62
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• 2024

Objective: The purpose of this study was to analyze the differences in kinematic factors according to stretching treatment, myofascial release treatment, and static stretching treatment conditions during squat. Method: Twelve males with resistance training experience participated in this study. Participants performed squats without treatment (Pre-Test), and performed squats after treatment with the myofascial release technique (MRT) and static stretching (SS) on different days (post-test). Squat movements were captured using eight motion capture cameras (sampling rate: 250 Hz), and the peak joint angles of the ankle, knee, hip, and pelvis were calculated for each direction. One-way repeated ANOVA and Bonferroni post hoc analyses using SPSS 27 (IBM Corp. Armonk NY, USA) were used to compare the peak joint angle of the lower extremity joints and pelvis among the normal condition (squat without treatment), MRT condition (squat after MRT treatment) and SS condition (squat after static stretching). The statistical significance level was set at .05. Results: It was observed that the maximum ankle joint flexion angle during squats was statistically reduced under conditions of myofascial release and static stretching (p<.05), in comparison to the scenario where no stretching was performed. Furthermore, static stretching was found to enhance the maximum hip flexion angle during squat (p<.05), whereas the myofascial release stretching technique resulted in the minimal posterior pelvic tilt angle (p<.05). Conclusion: Employing myofascial release stretching as a preparatory exercise proved to be more efficacious in maintaining body stability throughout the execution of high-intensity squat movements by effectively managing the posterior tilt of the pelvis, as opposed to foregoing stretching or engaging in static stretching.

• 한국운동역학회지
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• 제34권1호
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• pp.25-33
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• 2024

Objective: The purpose of this study was to compare the lower extremity muscle activity and knee joint load according to movement speed conditions during the barbell back squat. Method: Nine males with resistance training experience participated in this study. Participants performed the barbell back squat in three conditions (Standard, Fast, and Slow) differing movement speed. During the barbell back squat, muscle activity of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris long head (BFL), semitendinosus (ST), gluteus maximus (GM), gastrocnemius (GCN), and tibialis anterior (TA) was collected using an 8 channel wireless EMG system. The peak flexion angle of the lower extremity joints and the peak resultant joint force in each direction of the knee joint were calculated using eight motion capture cameras and ground reaction force plates. This study was to used the Friedman test and the Wilcoxon signed rank test, to compare lower extremity muscle activity and peak resultant joint force at knee joint according to movement speed conditions during the barbell back squat, and the statistical significance level was set at .01. Results: In the downward phase of the barbell back squat, the RF and TA showed the higher muscle activity in the fast condition, and in the upward phase, RF, VL, VM, BFL, ST, GM, and TA showed the higher muscle activity in the fast condition. As a results, analyzing of the load on the knee joint, in the downward phase, and in the upward phase, the higher peak compressive force of the knee joint was showed in the fast condition. Conclusion: The barbell back squat with fast movement speed was more effective due to increased muscle activity of lower extremity, but one must be careful of knee joint injuries because the load on the knee joint may increase during the barbell back squat with fast movement speed.

• Asia pacific journal of information systems
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• 제17권3호
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• pp.105-130
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• 2007

Recently, there is a substantial interest in implementing Business Process Management System(BPMS) among enterprises with the purpose of business process innovation. BPMS redesigns and coordinates business processes in terms of both automated steps and human involvement in order to maximize the value of both involved people and systems. The reason why BPMS is getting attention from top managers is that it has the possibility to optimize the business processes by cycling the process of modeling, execution, monitoring, evaluation, and redesigning work processes. Thus, it has created high expectations about not only productivity improvement but also business process innovation. However. having an innovative nature, which is used for process innovation, BPMS implementation has great potential to stir up employee resistance. The analysis and the discussion about the prevention of the resistance against IS(Information Systems) is important because IS change the way people work and also alter the power structure within the organization, in general. The purpose of this study is to investigate factors that have an impact on the effective adoption of BPMS at the enterprise level. To find out these factors, this study considers two characteristics of BPMS: First. BPMS shares some characteristics with other enterprise-wide IS such as ERP. Second, it has special BPMS-specific characteristics. Due to the lack of previous research on BPMS adoption, interviews were carried out with IT-consultants and CIOs who conducted BPMS projects previously to find out BPMS-specific features that would make BPMS unique when compared to other enterprise-wide IS. As a result, the monitoring function was chosen as the main BPMS-specific factor. Thus, this paper reviewed studies both on enterprise-wide IS adoptions, which applied Technology Acceptance Model (TAM) and secondly on computer based monitoring to find out factors that would influence the employees' perception on the monitoring function of BPMS. Based on the literature review, the study suggested three factors that would have an impact on the employee's perception of the monitoring function: fairness of enterprise evaluation system, fairness of the boss, and self-efficacy of their work. Three factors that would impact the enterprise-wide IS adoption were also set: the shared belief in the benefit of BPMS, training, and communication. Then, these factors were integrated with TAM. Structural equation modeling was used to test hypotheses, out factors that would impact the employees' perception on the monitoring function of BPMS. Based on the literature review the study suggested three factors that would have an impact on the employee's perception of the monitoring function: fairness of enterprise evaluation system, fairness of the boss, and self-efficacy of their work. Three factors that would impact the enterprise-wide IS adoption were also set: the shared belief in the benefit of BPMS, training, and communication. Then, these factors were integrated with TAM. Structural equation modeling was used to test hypotheses. The data analysis results showed that two among three monitoring function related factors - enterprise evaluation system and fairness of the boss - were significant. This implies that employees would worry less about the BPMS implementation as long as they perceive the monitoring results will be used fairly for their performance evaluation. However, employees' high self-efficacy on their job was not a significant factor in their perception of the usefulness of BPMS. This is related to cases that showed employees resisted against the information systems because they automated their works (Markus, 1983). One specific case was an electronic company, where the accounting department workers were requested to redefine their job because their working processes were automated due to BPMS implementation.

• 한국운동역학회지
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• 제27권3호
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• pp.197-203
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• 2017

Objective: The purpose of this study was to determine how exercise intensity affects muscle activity and kinematic variables during squat. Method: Fifteen trainers with >5 years of experience were recruited. For the electromyography (EMG) measurements, four surface electrodes were attached to both sides of the lower extremity to monitor the rectus femoris (RF) and biceps femoris. Three digital camcorders were used to obtain three-dimensional kinematics of the body. Each subject performed a squat in different conditions (40% one-repetition maximum [40%1RM], 60%1RM, and 80%1RM). For each trial being analyzed, three critical instants and two phases were identified from the video recording. For each dependent variable, one-way analysis of variance with repeated measures was used to determine whether there were significant differences among the three different conditions (p<.05). When a significant difference was found, post hoc analyses were performed using the contrast procedure. Results: The results showed that the average integrated EMG values of the RF were significantly greater in 80%1RM than in 40%1RM during the extension phase. The temporal parameter was significantly longer in 80%1RM than in 40%1RM and 60%1RM during the extension phase. The joint angle of the knee was significantly greater in 80%1RM than in 40%1RM at flexion. The range of motion of the knee was significantly less in 80%1RM than in 40%1RM and 60%1RM during the flexion phase and the extension phase. The angular velocity was significantly less in 80%1RM than in 40%1RM and 60%1RM during the extension phase. Conclusion: Generally, the increase of muscle strength decreases the pace of motion based on the relation between the strength and speed of muscle. In this study, we also found that the increase of exercise intensity may contribute to the increase of the muscle activity of the RF and the running time in the extension phase during squat motion. We observed that increased exercise intensity may hinder the regulation of the range of motion and joint angle. It is suitable to perform consistent movements while controlling the proper range of motion to maximize the benefit of resistance training.

• 대한영양사협회학술지
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• 제14권1호
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• pp.64-76
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• 2008

The purpose of this study was to investigate the change of body composition, biochemical index level, resting metabolic rate and daily activities by the public health center's health-promoted program in overweight middle aged women. The workout program of 12 subjects constituted by exercise(aerobic exercise & resistance training) and nutritional education for 10 weeks. As the results, there was a significant decrease in all the weight(59.0$\pm$8.9 vs 57.2$\pm$8.3kg, p<0.05), body fat percentage(33.4$\pm$4.3 vs 30.5$\pm$4.5%, p<0.05) and body fat mass(19.8$\pm$5.4 vs 17.7$\pm$4.9kg, p<0.05) after program. Fat free mass and RMR which tend to be higher after than before program were found not to be significantly. In addition, the serum HDL-cholesterol(54.3$\pm$8.1 vs 59.7$\pm$13.9mg/dl, p<0.05) and TG level(65.2$\pm$418 vs 89.4$\pm$65.6mg/dl, p<0.05) of the subjects increased at the end of the study significantly and significant correlation found between total-cholesterol and TG before program. When the other laboratory parameter were compared before and after program, hematocrit(35.1$\pm$3.3 vs 39.7$\pm$3.3%, p<0.001), platelet(225.9$\pm$49.6 vs 244.3$\pm$49.7cell/ul, p<0.05) and fasting glucose(88.0$\pm$6.5 vs 76.6$\pm$9.7mg/dl, p<0.001) increased significantly but hemoglobin(13.3$\pm$1.3 vs 12.9$\pm$1.3mg/dl, p<0.01) decreased. And in activities analysis, 'moderate activity(18.8 vs 5.8minutes, p<0.05)' clearly showed a significant decrease but 'severe activity(17.7 vs 11.4minutes, p<0.05)' showed a increase. These results suggest that continuous health-promoted program involved exercise and nutritional education at the public health center are effective to reduce body fat and to improve resting metabolic rate(RMR). Further research is required to develop more effective public health program for the middle aged women in community.

• 생명과학회지
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• 제18권2호
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• pp.193-199
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• 2008

본 연구의 목적은 운동프로그램이 과체중 및 비만아동의 시기에 따른 C-반응성단백질 및 심혈관질환 위험인자의 변화에 미치는 영향을 알아보고자 과체중 및 비만 아동을 대상으로 12주 간의 걷기와 밴드운동을 실시하고, 운동전, 4주 후, 12주 후의 신체조성, 혈중지질, 인슬린, C-반응성단백질를 측정 분석하였다. 연구의 대상자는 연령과 성별에 따른 체질량지수 백분위 수 85 이상(BMI${\geq}$21.3)인 과체중 및 비만아동 16명을 프로그램에 참여하는 운동군에 8명, 대조군에 8명으로 무선배치 하였다. 운동군은 주 2회의 걷기운동 50분과 주 2회의 밴드저항운동을 12주 동안 실시하였다. 연구결과 운동군 내 에서는 체중(p<0.001), BMI (p<0.001), 체지방량(p<0.001), 체지방률(p<0.001), TC (p<0.05), 인슐린(p<0.05), HOMA-IR (p<0.05)이 감소하였고, 제지방률(p<0.001), HDL-C (p<0.01)는 증가하였다. 측정시기를 고려하여 집단간의 차이를 분석한 결과 체중(p<0.001), BMI (p<0.001), 체지방량(p<0.001), 체지방률(p<0.001), 제지방량(p<0.05), 제지방률(p<0.001), 인슐린(p<0.05), HOMA-IR (p<0.05)에서 통계적으로 유의한 차이가 있는 것으로 나타났다. 이상의 연구결과 12주 걷기와 밴드운동에 의해 과체중 및 비만아동의 심혈관질환 위험인자를 일부 개선되지만, C-반응성단백질 농도는 개선되지 않음을 알 수 있었다.

• 한국전자통신학회논문지
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• 제13권3호
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• pp.661-668
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• 2018

피부 저항을 이용한 생체 신호는 스트레스성 질환에 따라 각각 다른 특성을 보이고 있으며 이 특성을 이용하여 스트레스성 질환을 진단하는 생체진단 장비들이 개발 되었으며, 장비들은 피부 저항 측정기에서 측정한 신호를 해석하기 쉽게 출력해주며, 그 분야의 전문가는 출력 신호를 직접 보고 어떤 스트레스성 질환의 가능성이 높은지를 판단하게 된다. 하지만 각 측정 대상자에게서 측정된 생체 신호를 분석하여 측정 대상자가 어떤 스트레스성 질환을 가지고 있는지를 사람이 정확히 판단하기는 매우 어려울 뿐만 아니라 판단의 결과가 잘못될 가능성도 매우 높다. 이런 문제점을 해결하기 위하여 본 연구에서는 머신러닝 기법을 이용하여 측정된 신호가 어떤 스트레스성 질환의 신호에 해당하는지를 판단하는 기능을 구현하였다. 측정 장비의 낮은 컴퓨팅 능력을 고려하여 분류 기법은 SVM을 사용하였으며, 훈련 데이터와 테스트 데이터는 13개의 질환을 중심으로 오차범위 5를 사용하여 각 질환 당 1,000개를 랜덤하게 생성하여 사용하였다. 모의실험 결과에서 90% 이상의 판단 정확도를 보였으며 앞으로 측정 장비가 실제로 환자들에게 적용되면 다시 생성된 데이터로 분류기를 재훈련 할 수 있게 구성하였다.

• 한국치위생학회지
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• 제11권1호
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• pp.59-68
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• 2011

Objectives : To investigate the knowledge and recognition level of fluorine by teaching career among class teachers, who are primarily responsible for oral health education, despite lack of expertise in oral health, by playing a model role for students through continuous contacts with them, and provide basic elementary data about accurate knowledge and how to correctly use fluorine remarkably effective in preventing dental caries. Methods : A self-administered survey was conducted with 539 teachers at 21 elementary schools in Jinhae City from September 1 to October 15, 2010, drawing the following conclusions. Results : 1. As for the channel for acquiring knowledge of oral health, the highest frequency was found in health programs for respondents with less than 9 years of career, in dental clinics for those with 20 to 29 years of career, and in PR booklets for those with 10 to 19 years and 30 years and longer of career. 2. Use of fluorine-containing toothpaste and fluorine spread is very effective and effective in preventing dental caries got 64.9%, 72.2%, 72.3%, 77.7% and 54.0%, 63.1%, 62.2%, 69.7%, respectively, among elementary school teachers with less than 9 years, 10 to 19 years, 20 to 29 years, and 30 years and longer of career. 3. Intake of fluoride and toothbrushing with fluoric solution is very effective and effective in preventing dental caries got 33.3%, 40.1%, 39.5%, 55.3% and 50.0%, 54.9%, 48.8%, 69.7%, respectively, among elementary school teachers with less than 9 years, 10 to 19 years, 20 to 29 years, and 30 years and longer of career. 4. Use of fluoric tablets is very effective and effective in preventing dental caries got 32.9%, 36.0%, 36.1%, 47.3%, respectively, among elementary school teachers with less than 9 years, 10 to 19 years, 20 to 29 years, and 30 years and longer of career. 5. Most of the elementary school teachers knew the fact that fluorine increases dental resistance to cavity and prevents bacterial growth but gave incorrect responses to properties of becoming basic nutrients or inducing recalcification. Conclusions : Various types of application of fluorine during the elementary-level childhood experiencing the most frequent dental caries will be very useful in improving oral health in the future. It is necessary to enable class teachers to get correct recognition of fluorine through supplementary and job training based on technical knowledge and various educational materials so that they, who are directly responsible for health management through continuous contacts with students, can understand how to correctly use fluorine and get accurate knowledge.

• 한국지역지리학회지
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• 제10권2호
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• pp.267-285
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• 2004

국제사회는 세계화의 소용돌이에 휩싸여 있다. 정치, 경제, 문화, 생태의 다양한 영역에서 전개되고 있는 세계화는 신자유주의의 이념적 토대 위에 신보수주의자 주도로 진행되고 있는 미국의 패권확대 과정, 즉 미국화로 달리 해석되기도 한다. 그러나 헤게모니의 일방적 강요는 현실적으로 불가능한데, 지역정체성을 근간으로 하는 상향적 운동으로 지방화가 존재하기 때문이다. 세계화와 지방화가 양립하는 상황에서 지방에 대한 세계적인 인식과 세계에 대한 지방적 인식이 요구되고 있으며, 이를 위해 지리학계는 한국지리는 물론 해외지역연구에 적극적으로 나서야 할 것으로 보인다. 세계화의 중심에 있는 미국을 포함한 아메리카에 대한 연구는 그간 정치학, 경제학, 경영학, 법학, 사회학 등 일부 학문에 의해 그 본질이 왜곡되면서 지역 자체에 대한 분석은 거의 이루어지지 못했다. 학계의 패전구도에서 소외되어온 지리학의 경우 지역연구를 학문의 존재이유로 내걸고는 있지만 위상에 걸맞는 역할을 다하지 못하고 주변적인 분야로 남아있었다. 다행스럽게도 1990년대 중반을 넘기면서 아메리카지역에 대한 연구가 양과 질 양면에서 꾸준한 신장세를 보였다. 이는 아메리카지역에 대한 사회적인 관심의 증대와 지리학계의 연구역량의 강화로 인한 결과이다. 향후 아메리카지역 연구의 내실을 기하기 위해서는 전문 연구인력의 양성, 연구설비의 확충, 재원조달의 측면에서 획기적인 조치가 마련되어야 할 것이다.