• Steel and Composite Structures
• /
• v.48 no.1
• /
• pp.43-57
• /
• 2023

The impacts of waste tire rubber (WTR) on the bending conduct of reinforced concrete beams (RCBs) are investigated in visualization of experimental tests and 3D finite element model (FEM) using both ANSYS and SAP2000. Several WTR rates are used in total 4 various full scale RCBs to observe the impact of WTR rate on the rupture and bending conduct of RCBs. For this purpose, the volumetric ratios (Vf) of WTR were chosen to change to 0%, 2.5%, 5% and 7.5% in the whole concrete. In relation to experimental test consequences, bending and rupture behaviors of the RCBs are observed. The best performance among the beams was observed in the beams with 2.5% WTR. Furthermore, as stated by test consequences, it is noticed that while WTR rate in the RCBs is improved, max. bending in the RCBs rises. For test consequences, it is clearly recognized as WTR rate in the RCB mixture is improved from 0% to 2.5%, deformation value in the RCB remarkably rises from 3.89 cm to 7.69 cm. This consequence is markedly recognized that WTR rates have a favorable result on deformation values in the RCBs. Furthermore, experimental tests are compared to 3D FEM consequences via using ANSYS software. In the ANSYS, special element types are formed and nonlinear multilinear misses plasticity material model and bilinear misses plasticity material model are chosen for concrete and compression and tension elements. As a consequence, it is noticed that each WTR rates in the RCBs mixture have dissimilar bending and rupture impacts on the RCBs. Then, to observe the impacts of WTR rate on the constructions under near-fault ground motions, a reinforced-concrete building was modelled via using SAP2000 software using 3-D model of the construction to complete nonlinear static analysis. Beam, column, steel haunch elements are modeled as nonlinear frame elements. Consequently, the seismic impacts of WTR rate on the lateral motions of each floor are obviously investigated particularly. Considering reduction in weight of structure and capacity of the members with using waste tire rubber, 2.5% of WTR resulted in the best performance while the construction is subjected to near fault earthquakes. Moreover, it is noticeably recognized that WTR rate has opposing influences on the seismic displacement behavior of the RC constructions.

• Journal of the Korea Convergence Society
• /
• v.12 no.12
• /
• pp.287-294
• /
• 2021

A near miss is an unplanned event that did not result in injury/illness, or property damage, but had potentials to do so. The importance of the near miss has been emphasized by many researchers and organizations. However, only a few studies have quantitatively approached the near miss from the viewpoint of safety culture. The purpose of this study is to investigate the current status of near miss reporting activities in manufacturing workplaces in Korea. It also aims to understand how the activities related with the safety culture and the occurrence of industrial accidents. To this end, a survey was conducted on manufacturing workplaces and the results were analyzed. As a result, there was a marked difference in the perception on near miss according to whether or not the near miss reporting activity was conducted. However, it was found that only 56% of the workplaces were carrying out the reporting activities. It was found that the number of near misses reported varied depending on the reward. Although no correlation could be found between whether or not the near miss reporting activities were carried out and the history of industrial accidents occurred, it was found that safety culture level was hier at the workplaces conducting the activities.

• Journal of Agricultural Extension & Community Development
• /
• v.8 no.2
• /
• pp.179-190
• /
• 2001

The purpose of this study was to analysis the education effects of web-based on-line cyber program mesaured by Kirkpatrick’s evaluation process. The average score on satisfaction of the program was 4.28(.59), which was designed to evaluate the level 1, reaction. To test level 2, learning, the average score that students achieved was calculated and it was 86.87(std.=7.05) in the term examinations. The level 3, job months. It was reported that most employees who took the course are utilizing the knowledge that they acquired from the course(mean=3.80, std.=.77). To identify the level 4, business results, the mean score of the number of accidents and near misses that happened in their factories for 3 months before and after the course were compared. There was statistically significant difference between the number of accidents that happened 3 months before the course and 3 months after the course, at the significance level of .01, which was tested by Paired t-test.

• Journal of the Korean Society of Safety
• /
• v.39 no.2
• /
• pp.54-64
• /
• 2024

This study investigated the impact of a safety coaching program on the safety behavior and safety climate among expressway safety patrols. Four to seven patrols from each of the three branches participated in this study. The safety coaching program was developed based on the GROW model, with main contents including recognizing individual differences, exploring safety values, communicating near-misses, providing effective and efficient feedback, employing non-violent communication, and fostering commitment toward safety behaviors. Additionally, each session included self-monitoring and peer review of each item based on a critical behavior checklist developed for this study, with challenging goals set based on the monitoring and review. The safety coaching program comprised six sessions in three branches, while three other branches were assigned as a control group. A non-equivalent control group experimental design was applied. Dependent variables included observed and perceived safety behavior, safety climate, psychological safety, and feedback. The results indicated that the safety coaching program effectively increased patrols' safety behavior and safety climate. Furthermore, psychological safety and feedback improved. These findings suggest that the developed safety coaching program could serve as an alternative method to enhance safety management for expressway safety patrols. Finally, the implications, limitations, and directions for future research are discussed.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.36 no.3
• /
• pp.195-201
• /
• 2000

This paper discusses methods for the stable bottom detection and the optimum bottom offset which enable to separate the fish echoes from the bottom echoes with echo integration of demersal fish. In preprocessing of the echo signal, the bottom detection has to be done stably against the fluctuation of echo level and the bottom offset has to be set to a minimum height such that near bottom fish echoes are included Two methods of bottom detection, namely echo level threshold method and maximum echo slope method were compared and analyzed. The echo level method works well if the ideal threshold level was given but it sometimes misses the bottom because of the fluctuation of the echo. Another method to detect the bottom which uses maximum echo slope indicates the simple and stable bottom detection. In addition, the bottom offset has to be set near to the bottom but not to include the bottom echo. Optimum bottom offset should be set a few samples before the detected bottom echo which relates the beginning of pulse shape and acoustic beam pattern to the bottom feature.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.6
• /
• pp.105-114
• /
• 2011

The snake algorithm is widely adopted to track objects by extracting the active contour of the object from background. However, it fails to track the target converging to the background if there exists background whose gradient is greater than that of the pixels on the contour. Also, the contour may shrink when the target moves fast and the snake algorithm misses the boundary of the object in its searching window. To alleviate these problems, we propose an improved algorithm that can track object contour more robustly. Firstly, we propose two external energy functions, the edge energy and the contrast energy. One is designed to give more weight to the gradient on the boundary and the other to reflect the contrast difference between the object and background. Secondly, by computing the motion vector of the contour from the difference of the two consecutive frames, we can move the snake pointers of the previous frame near the region where the object boundary is probable at the current frame. Computer experiments show that the proposed method is more robust to the complicated background than the previously known methods and can track the object with fast movement.

• The Journal of Korean Academy of Prosthodontics
• /
• v.42 no.1
• /
• pp.58-72
• /
• 2004

Statement of problem : Clinically, maxillary first premolar has a high risk of fracture. This is thought to be caused by the susceptible figure which the maxillary first premolar has In other words, sharp cusp angles of the premolar is thought to influence this situation. Purpose : This study was to know stress distribution of all-ceramic crown according to the cusp angle. Material and Method : It was manufactured a three dimensional finite element model simplified maxillary first premolar, and then analyzed stress distribution when cusp angle was each $80^{\circ}$, $90^{\circ}$, $100^{\circ}$, $110^{\circ}$ and $120^{\circ}$. Results and conclusion : 1. The von Misses stress showed that stress decreases as cusp angle increases in the central groove of the occlusal surface. 2. It showed that maximum principal stress was centered at the region of the central groove of the occlusal surface and a region which the force was inflicted. And also it appeared high on the lingual and buccal side of finish line. 3. The X axis of normal stress was focused in the central groove of the occlusal surface. The Y axis normal stress appeared high in the central groove of the occlusal surface, buccal and lingual side. 4. The Stress near the finish line showed a low value compared with stress in the region of the central groove of the occlusal surface. 5. It shows that the most dangerous angle for tooth fracture was on $80^{\circ}$ of the cusp angle and low on $120^{\circ}$ of its.

• Journal of the Korean Society for Railway
• /
• v.16 no.4
• /
• pp.331-339
• /
• 2013

This study highlights the theme of human error emerging as a critical issue in the railroad industry, conducting exploratory research on the effects of health, cognition, and safety climates on safety behavior and accidents using an empirical method. The statistical results based on questionnaires received from 204 train drivers indicate that psychological fatigue, cognitive failure, and internal locus of control as individual variables and CEO philosophy and behavior of immediate boss as organizational variables have significant relationships with safety behavior, while cognitive failure, CEO philosophy, behavior of immediate boss, and education were found to be significant variables with respect to accidents. Furthermore, unsafe behavior such as mistakes and violations showed negative effects on near misses and responsibility accidents, respectively. Based on these results, effective alternatives and countermeasures needed to mitigate human error were posited.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.2
• /
• pp.27-34
• /
• 2001

Utterance verification is used in variable vocabulary word recognition to reject the word that does not belong to in-vocabulary word or does not belong to correctly recognized word. Utterance verification is an important technology to design a user-friendly speech recognition system. We propose a new utterance verification algorithm for no-training utterance verification system based on the minimum verification error. First, using PBW (Phonetically Balanced Words) DB (445 words), we create no-training anti-phoneme models which include many PLUs(Phoneme Like Units), so anti-phoneme models have the minimum verification error. Then, for OOV (Out-Of-Vocabulary) rejection, the phoneme-based confidence measure which uses the likelihood between phoneme model (null hypothesis) and anti-phoneme model (alternative hypothesis) is normalized by null hypothesis, so the phoneme-based confidence measure tends to be more robust to OOV rejection. And, the word-based confidence measure which uses the phoneme-based confidence measure has been shown to provide improved detection of near-misses in speech recognition as well as better discrimination between in-vocabularys and OOVs. Using our proposed anti-model and confidence measure, we achieve significant performance improvement; CA (Correctly Accept for In-Vocabulary) is about 89％, and CR (Correctly Reject for OOV) is about 90％, improving about 15-21％ in ERR (Error Reduction Rate).