• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.21 no.2
• /
• pp.17-32
• /
• 2022

This study explored an approach to estimate a flow-density diagram(FD) on a link in highway traffic environment by utilizing probe vehicles' time headway records. To study empirical flow-density diagram(EFD), the probe vehicles with vision sensors were recruited for collecting driving records for nine months and the vision sensor data pre-processing and GIS-based map matching were implemented. Then, we examined the new EFDs to evaluate validity with reference diagrams which is derived from loop detection traffic data. The probability distributions of time headway and distance headway as well as standard deviation of flow and density were utilized in examination. As a result, it turned out that the main factors for estimation errors are the limited number of probe vehicles and bias of flow status. We finally suggest a method to improve the accuracy of EFD model.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.3
• /
• pp.389-395
• /
• 2022

Because of improvement of deep learning techniques, deep learning using computer vision such as classification, detection and segmentation has also been used widely at many fields. Expecially, automatic driving is one of the major fields that applies computer vision systems. Also there are a lot of works and researches to combine multiple tasks in a single network. In this study, we propose the network that predicts the individual depth of pedestrians and vehicles. Proposed model is constructed based on YOLOv3 for object detection and Monodepth for depth estimation, and it process object detection and depth estimation consequently using encoder and decoder based on hard parameter sharing. We also used attention module to improve the accuracy of both object detection and depth estimation. Depth is predicted with monocular image, and is trained using self-supervised training method.

• International Journal of Computer Science & Network Security
• /
• v.22 no.8
• /
• pp.222-234
• /
• 2022

Background: Within the framework of the new Saudi Vision 2030, the education system is keen on developing Early Childhood (EC) curricula to meet the needs of children from diverse cultural and linguistic backgrounds, in addition to preparing teachers to be the main driving forces in this field. To achieve these strategic goals, the professional development of teachers has taken the lead in terms of their continuous professional achievements. Purpose: The recent study tended to explore the promotion of Cultural and Linguistic Competence (CLC) of teachers in preschool institutions in different sectors in the Kingdom of Saudi Arabia (KSA) include public, private and international. Method: In the current study, (n=300) of preschool female teachers, who had experience teaching children from diverse language and cultural backgrounds, participated voluntarily by filling out the exploratory questionnaire. It was designed on a five-point Likert scale. The credibility of the scale and the validity of the questionnaire were ascertained, and the content for which it was designed verified in terms of the purposes of the current investigation. Results: The results revealed that preschool female teachers in the private preschool settings have a higher level of CLC compared to those who were teaching in public and international preschools in KSA. In the private sector, preschool female teachers showed create abilities to provide culturally responsive environments for diverse students, applying various communication styles, and showing proper attitudes and values toward diversity. Implication: The current study provided key implications for policy makers regarding the promotion of CLC for all teachers, particularly preschool in government settings in KSA. It contributed to revealing the cultural awareness of preschool teachers' values and attitudes toward diversity.

• KIPS Transactions on Computer and Communication Systems
• /
• v.11 no.5
• /
• pp.139-146
• /
• 2022

With the recent development of the Internet of Things (IoT) and the convergence of vehicles and IT technologies, high-performance applications such as autonomous driving are emerging, and multi-access edge computing (MEC) has attracted lots of attentions as next-generation technologies. In order to provide service to these computation-intensive tasks in low latency, many methods have been proposed to partition tasks so that they can be performed through cooperation of multiple MEC servers(MECSs). Conventional methods related to task partitioning have proposed methods for partitioning tasks on vehicles as mobile devices and offloading them to multiple MECSs, and methods for offloading them from vehicles to MECSs and then partitioning and migrating them to other MECSs. In this paper, the performance of task partitioning methods using offloading and migration is compared and analyzed in terms of service delay, blocking rate and energy consumption according to the method of selecting partitioning targets and the number of partitioning. As the number of partitioning increases, the performance of the service delay improves, but the performance of the blocking rate and energy consumption decreases.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.4
• /
• pp.10-16
• /
• 2021

This paper proposes a model that considers the parity-time symmetric structure as a state detection circuit for sensor applications using a stretchable inductor. In particular, to obtain a more practical computer simulation result, the stretchable inductor model was applied to this study model by referring to previously reported experimental results. The resistance component and phase component were controlled through the negative differential resistance circuit used in this study. In addition, the imbalance of the circuit caused by a change in the characteristics of the stretchable inductor could be compensated for using a negative differential resistance circuit. In particular, an analysis of the frequency characteristics of the sensor driving circuit of the parity-time symmetric structure proposed in this study confirmed that the Q-factor could be increased up to 20 times compared to the conventional resonant circuit.

• Journal of the Semiconductor & Display Technology
• /
• v.20 no.4
• /
• pp.29-37
• /
• 2021

A 7 nm technology node using extreme ultraviolet lithography with a wavelength of 13.5 nm has been recently developed and applied to the semiconductor manufacturing process. Furthermore, the development of sub-3 nm technology nodes continues to be required. In this study, design factors of an electrostatic deflector for an ultra-miniaturized microcolumn system that can realize an electron wavelength of below 1.23 nm with an acceleration voltage of above 1 eV were investigated using a three-dimensional simulator. Particularly, the optimal design of the electrostatic octupole floating deflector was derived by optimizing the design elements and improving the driving method of the 1 keV low energy ultra-miniaturized microcolumn deflector. As a result, the entire wide field of view greater than 330 ㎛ at a working distance of 4 mm was realized with an ultra-high-resolution electron beam spot smaller than 10 nm. The results of this study are expected to be a basis technology for realizing a wafer-scale multi-array microcolumn system, which is expected to innovatively improve the throughput per unit time, which is the biggest drawback of electron beam lithography.

• The Journal of the Korea Contents Association
• /
• v.21 no.11
• /
• pp.657-679
• /
• 2021

This study aimed to explore the experience and nature of emotional care for elderly parent living alone for middle-aged adult who formed initial insecure attachment with his or her parent. To this end, 12 middle-aged people aged 45 to 60 (3 males and 9 females) were recruited as subjects of the study, interviewed in-depth, and analyzed using Colaizzi's phenomenological research method. As a result of the study, 60 constitutive meanings, 18 themes, and 4 thematic groups were derived for the experience of middle-aged adult who experienced insecure attachment to his or her parent and caring for the emotional needs of elderly parent living alone. Thematic groups included "negative experiences that caused emotional exhaustion," "emotional driving force in emotional care," "the role of helper in parental care," and "economic and physical content in emotional care". This study is meaningful in that it revealed the phenomenon of experiences of emotional care for parent living alone by middle-aged adult who had an initial unstable attachment with his or her parent to understand them and contributed to the provision of counseling data.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.1
• /
• pp.209-214
• /
• 2023

In the future, as autonomous vehicles become popular at home and abroad, the frequency of accidents involving autonomous vehicles is also expected to increase. In particular, when a fully autonomous vehicle is operated, various criminal/civil problems such as sexual violence, assault, and fraud between passengers may occur as well as the vehicle accident itself. In this case, forensics for accidents involving autonomous vehicles and accidents involving passengers in the vehicles are also about to change. This paper reviewed the types of security threats of autonomous vehicles, methods for maintaining the integrity of evidence data using blockchain technology, and research on digital forensics. Through this, it was possible to describe threats that would occur in autonomous vehicles using blockchain technology and forensic techniques for each type of accident in a scenario-type manner. Through this study, a block that helps forensics of self-driving vehicles before and after accidents by investigating forensic security technology of domestic and foreign websites to respond to vulnerabilities and attacks of autonomous vehicles, and research on block chain security of research institutes and information security companies. A chain method was proposed.

• Membrane Journal
• /
• v.32 no.2
• /
• pp.91-99
• /
• 2022

It is a global challenge to fulfill the demand for clean water at an affordable cost to all the strata of the population. Desalination of seawater as well as brackish water by the membrane separation process is a well-established and cost-efficient method. However, there is still inherent problem of membrane fouling, disposal of the reject as well as a capital-intensive process. While electrodialysis (ED) is a membrane-based separation process in which a driving force is the potential difference. The advantages of ED process are excellent efficiency and low operation cost. Ion exchange membrane (IEM) used in the ED process needs to have higher chemical and thermal stability along with excellent mechanical strength for long-term use without losing its efficiency. The ion exchange capacity of the ED membrane is largely dependent on the conductivity of IEMs. In this review, the modification strategy of the pristine membrane to enhance the stability and ion conductivity of cation exchange membrane (CEM) and anion exchange membrane (AEM) is discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.22 no.3
• /
• pp.133-138
• /
• 2022

Digital radiation inspection equipment is a medical device that deals with human life and requires stability and high reliability. However, this system is currently the most advanced technology and the domestic market is almost occupied by European products including Japan. Therefore, research and development are needed not only to replace domestic medical devices, which are largely dependent on expensive imported products, but also to develop more economical and user-oriented products that are easy to operate and produce devices that lead to accurate diagnosis. In particular, among the digital X-ray systems, the motor driving technology and the mechatronics technology related to the development of mechanical devices have matured to some extent in Korea. In this paper, selection of AC servomotor for digital radiation inspection suitable for imaging purpose, and application of conversion device and control method to check performance and improve problems.