• 자동차안전학회지
• /
• 제13권2호
• /
• pp.35-41
• /
• 2021

In this study, improved path tracking control algorithm based on pure pursuit algorithm is newly proposed by using improved lane detection algorithm through real time post-processing with interpolation methodology. Since the original pure pursuit works well only at speeds below 20 km/h, the look-ahead distance is implemented as a sigmoid function to work well at an average speed of 45 km/h to improve tracking performance. In addition, a smoothing filter was added to reduce the steering angle vibration of the original algorithm, and the stability of the steering angle was improved. The post-processing algorithm presented has implemented more robust lane recognition system using real-time pre/post processing method with deep learning and estimated interpolation. Real time processing is more cost-effective than the method using lots of computing resources and building abundant datasets for improving the performance of deep learning networks. Therefore, this paper also presents improved lane detection performance by using the final results with naive computer vision codes and pre/post processing. Firstly, the pre-processing was newly designed for real-time processing and robust recognition performance of augmentation. Secondly, the post-processing was designed to detect lanes by receiving the segmentation results based on the estimated interpolation in consideration of the properties of the continuous lanes. Consequently, experimental results by utilizing driving guidance line information from processing parts show that the improved lane detection algorithm is effective to minimize the lateral offset error in the diverse maneuvering roads.

• 공업화학
• /
• 제32권3호
• /
• pp.229-236
• /
• 2021

금속 유기 골격체는 최근 20년간 센서, 촉매, 에너지 저장과 같은 많은 응용분야에서 관심을 받아온 물질이다. 이 물질을 합성하기 위해 수열 합성, 유기용매열과 같은 합성법이 제시되어 왔으나, 그 공정이 복잡하면서 고비용·장시간이 소요된다는 문제점이 제기되어 왔다. 이를 해결하기 위한 전기화학적 합성법이 새롭게 제시되었는데, 간단한 준비절차와 특정한 온도·압력 조건 없이 합성할 수 있어 기존 합성법의 단점을 보완한다는 특징이 있다. 이에 본 총설논문에서는 전기화학적으로 합성 가능한 금속 유기 골격체의 종류와 전기화학적 합성 메커니즘을 다루고 있다. 전기화학적 합성법을 통해 형성된 금속 유기 골격체를 적용한 응용분야 연구동향을 정리하였다.

• 한국염색가공학회지
• /
• 제34권1호
• /
• pp.68-75
• /
• 2022

The breathable film refers to a high-functional film that allows gas and water vapor to pass through very fine and sophisticated pores but not liquid. In this research, the breathable film was prepared based on linear low-density polyethylene (LLDPE) and CaCO₃ particles by extrude method. The LLDPE composite film containing CaCO₃ particles had excellent mechanical properties and functionalties. The drawing is a technologically simple and excellent method for improving the mechanical properties of composite films. In this work, the effects of draw ratio on morphology, crystallinity, pore size distribution, mechanical properties, and water vapor permeability of the films were examined. The results revealed that both surface morphology and breathability were affected by the influence of chain orientation and crystal growth with increasing the draw ratio. The mechanical properties were improved with increasing the draw ratio.

• 한국염색가공학회지
• /
• 제34권1호
• /
• pp.20-26
• /
• 2022

Centrifugal spinning is an emerging technique for fabricating micro-to-nano-fibers in recent years. To obtain fibers with the desired size and morphology, it is necessary to configure and optimize the parameters used in centrifugal spinning. In this study, it was controlled by changing the solution's concentration (7.5, 10, and 12.5 wt.%) and disk's rotational velocity (6,000, 8,000, and 10,000 rpm) to prepare centrifugal spun nano-filter. The morphological property, air permeability, and dust collection efficiency of the PVA/PP bi-layer nanoweb prepared by centrifugal spun PVA on the PP micron nonwoven substrate are studied using a field emission scanning electron microscope, an air permeability tester, and a filter tester equipment, and the analysis results indicate that it is suitable as a nano-filter when the concentration of PVA solution is 10 wt.% and the rotational velocity of the disk is 8,000 rpm. The resultant reduced diameter and uniform fibers also proved that an excellent dust collection efficiency filter could be made.

• 대한정형외과학회지
• /
• 제56권2호
• /
• pp.117-124
• /
• 2021

비록 수술적 치료의 발전에 의해 부정유합의 발생은 감소하였으나 복합적 골절 또는 동반된 손상 등으로 인하여 드물지 않은 합병증이다. 관절 연골에 과한 하중이나 관절의 불안정성이 예상되는 부정유합이 있다면 교정 절골술이 필요하다. 부정유합에 대한 절골술을 시행하기 위해서는 수술 전 계획이 매우 중요하다. 적절한 계획이 없을 경우 의인성 부정정렬, 수술중 골절, 변형의 재발, 연부조직의 손상과 같은 심각한 합병증이 따르게 된다. 또한 적절한 환자를 선택하지 않았을 경우 불량한 기능적 결과가 나타날 수 있다. 본 종설은 부정유합을 치료하기 위하여 수술적 적응증, 수술 전 계획, 그리고 수술방법과 고정물 종류에 따른 다양한 교정 절골술의 방법에 대하여 기술하였다.

• 한국간호교육학회지
• /
• 제28권1호
• /
• pp.101-112
• /
• 2022

Purpose: The purpose of this study was to investigate the association of faculty-student interaction, psychological well-being, and the image of nurses with nursing professionalism in the COVID-19 pandemic situation. Methods: The participants of the study were 243 nursing college students located in Daegu, Kyungpook. Data collection was performed between August 11 and 20, 2021. Data were analyzed with descriptive statistics, independent t-test, ANOVA, Pearson's correlation coefficient, and stepwise multiple regression using the IBM SPSS 21.0 program. Results: The multiple regression showed that nursing professionalism was associated with a positive image of nurses (β=.71, p<.001) and higher faculty-student interaction (β=.11, p=.023). Additionally, a negative impression about nurses during the COVID-19 pandemic was negatively associated with nursing professionalism (β=-.12, p=.003). The explanatory power of the factors was 67 percent of the total variances on nursing professionalism; however, psychological well-being was not an associated factor. Conclusion: This study suggested that, to improve nursing student's nursing professionalism in the COVID-19 pandemic situation, nursing colleges should systemize curricular and non-curricular programs to improve awareness of nurses' efforts and faculty-student interaction.

• 한국치위생학회지
• /
• 제23권4호
• /
• pp.269-276
• /
• 2023

Objectives: This study aimed to analyze the official Instagram accounts of dental hygiene departments, focusing on the relationship between the number of posts and the number of followers. Additionally, the study sought to determine the status of these Instagram accounts through classifying posts by type. Methods: A total of 49 official Instagram accounts from Korean dental hygiene departments were selected as subjects. Correlation and regression analyses were conducted using SPSS ver. 26.0 Statistics software to determine the correlation between the total number of posts and the number of followers. Results: The results indicated a statistically significant difference in follower numbers between 3 year colleges (Mean: 284.11) and 4 year universities (Mean: 167.86), based on university classification (p=0.035). Correlation analysis demonstrated that the number of posts had a significant effect on the number of followers (r=0.338, p=0.017). Conclusions: The findings showed that the differences in Instagram follower numbers and the number of posts among different university classifications significantly influenced the number of followers.

• 자동차안전학회지
• /
• 제15권2호
• /
• pp.42-48
• /
• 2023

In recent years, automated vehicles have garnered attention in the multidisciplinary research field, promising increased safety on the road and new opportunities for passengers. High-Definition (HD) maps have been in development for many years as they offer roadmaps with inch-perfect accuracy and high environmental fidelity, containing precise information about pedestrian crossings, traffic lights/signs, barriers, and more. Demonstrating autonomous driving requires verification of driving on actual roads, but this can be challenging, time-consuming, and costly. To overcome these obstacles, creating HD maps of real roads in a simulation and conducting virtual driving has become an alternative solution. However, existing HD maps using high-precision data are expensive and time-consuming to build, which limits their verification in various environments and on different roads. Thus, it is challenging to demonstrate autonomous driving on anything other than extremely limited roads and environments. In this paper, we propose a new and simple method for implementing HD maps that are more accessible for autonomous driving demonstrations. Our HD map combines the CARLA simulator and OpenStreetMap (OSM) data, which are both open-source, allowing for the creation of HD maps containing high-accuracy road information globally with minimal dependence. Our results show that our easily accessible HD map has an accuracy of 98.28% for longitudinal length on straight roads and 98.42% on curved roads. Moreover, the accuracy for the lateral direction for the road width represented 100% compared to the manual method reflected with the exact road data. The proposed method can contribute to the advancement of autonomous driving and enable its demonstration in diverse environments and on various roads.

• 한국분말재료학회지
• /
• 제30권6호
• /
• pp.521-527
• /
• 2023

Piezoelectric technology, which converts mechanical energy into electrical energy, has recently attracted drawn considerable attention in the industry. Among the many kinds of piezoelectric materials, BaTiO₃ nanotube arrays, which have outstanding uniformity and anisotropic orientation compared to nanowire-based arrays, can be fabricated using a simple synthesis process. In this study, we developed a flexible piezoelectric energy harvester (f-PEH) based on a composite film with PVDF-coated BaTiO₃ nanotube arrays through sequential anodization and hydrothermal synthesis processes. The f-PEH fabricated using the piezoelectric composite film exhibited excellent piezoelectric performance and high flexibility compared to the previously reported BaTiO₃ nanotube array-based energy harvester. These results demonstrate the possibility for widely application with high performance by our advanced f-PEH technique based on BaTiO₃ nanotube arrays.

• 한국염색가공학회지
• /
• 제35권4호
• /
• pp.214-220
• /
• 2023

Poly(vinyl alcohol) (PVA) is a common hydrophilic polymer that is synthesized through the saponification reaction of poly(vinyl ester)-based polymers, mostly using poly(vinyl acetate) (PVAc) as a precursor. The heterogeneous saponification reaction of poly(vinyl ester)-based films leads to PVA films with new surface properties. Cellulose acetate (CA), in which the hydroxyl group of cellulose is replaced by an acetyl group, is a typical cellulose derivative capable of overcoming the low processability of cellulose due to strong hydrogen bonding. In this study, P(VAc/VPi)/CA blended films were prepared by the solvent casting, and then PVA/Cellulose blended films with improved surface properties were prepared by heterogeneous saponification. The structural changes caused by heterogeneous saponification were confirmed by FT-IR analysis, where both saponification and deacetylation reactions occurred in the saponification solution. In addition, the surface property changes were analyzed by FE-SEM and contact angle analyses, and the transmittance changes of the modified films were also assessed.