• ETRI Journal
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• v.41 no.1
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• pp.23-31
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• 2019

Since the late 20th century, there has been rapid development in the display industry. Only 30 years ago, we used big cathode ray tube displays with poor resolution, but now most people use televisions or smartphones with very high-quality displays. People now want images that are more realistic, beyond the two-dimensional images that exist on the flat screen, and digital holography-one of the next-generation displaysis expected to meet that need. The most important parameter that determines the performance of a digital hologram is the pixel pitch. The smaller the pixel pitch, the higher the level of hologram implementation possible. In this study, we fabricated the world-smallest $3-{\mu}m$-pixel-pitch holographic backplane based on the spatial light modulator technology. This panel could display images with a viewing angle of more than $10^{\circ}$. Furthermore, a comparative study was conducted on the fabrication processes and the corresponding holographic results from the large to the small pixel-pitch panels.

• Convergence Security Journal
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• v.17 no.5
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• pp.27-34
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• 2017

Network security visualization technique using security alerts provide the administrator with intuitive network security situation by efficiently visualizing a large number of security alerts occurring from the security devices. However, most of these visualization techniques represent events using overlap the timelines of the alerts or Top-N analysis by their frequencies resulting in failing to provide information such as the attack trend, the relationship between attacks, the point of occurrence of attack, and the continuity of the attack. In this paper, we propose an effective visualization technique which intuitively explains the transition of the whole attack and the continuity of individual attacks by arranging the events spirally according to timeline and marking occurrence point and attack type. Furthermore, the relationship between attackers and victims is provided through a single screen view, so that it is possible to comprehensively monitor not only the entire attack situation but also attack type and attack point.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1445-1450
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• 2020

Recently, a hologram-like system to provide a realistic experience has been serviced in performances, exhibitions, education. The constructing method for the hologram-like system can be configured in various forms such as a pyramid-typed, a semi-transparent large screen form. However, in various types of hologram-like systems, it is difficult to provide adjustment by changing and revising the content according to the configured hardware characteristics. In this paper, we propose a novel technique that can automatically visualize virtual contents running on heterogeneous hologram-like systems. To change the content to a given hardware configuration, we receive pre-built simple text-based configuration data, and correcting process was performed. According to the results of this paper, we found automatically and easily corrected visualization with the given configuration of the hologram-like system. Also, the problem of reducing the time by manual control in various types of heterogeneous hologram systems was solved.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.78-91
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• 2022

The importance of emotional intelligence education in the development of children's augmented reality education content is overlooked. Therefore, in-depth research is needed to develop children's emotional intelligence. This study was conducted through theoretical consideration and case analysis. The proposal of this paper is that the augmented reality type for children aged 2 to 7 is suitable for indoor activities with marking recognition technology. To promote an understanding of emotions, a large screen is selected, and emoticon dolls or emoticon books are recommended for learning content. Children aged 7 to 11 are suitable for indoor activities of non-marker recognition technology, and can induce emotional control and emotional recognition through active manipulation. For the learning content, "3D art teaching content" and "Online Classic Musical" are recommended. Children after the age of 11 are suitable for non-marker recognition technology outdoor activities and improve each element of emotional intelligence through interaction with nature and society. For the learning content, 'Forest Play Activity through Art' and 'EQ Theater Play' are recommended. Through this paper, we intend to promote the development of children's augmented reality emotional intelligence education.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.157-166
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• 2022

In the case of a die-casting process, defects that are difficult to confirm by visual inspection, such as shrinkage bubbles, may occur due to an error in maintaining a vacuum state. Since these casting defects are discovered during post-processing operations such as heat treatment or finishing work, they cannot be taken in advance at the casting time, which can cause a large number of defects. In this study, we propose an approach that can predict the occurrence of casting defects by defect type using machine learning technology based on casting parameter data collected from equipment in the die casting process in real time. Die-casting parameter data can basically be collected through the casting equipment controller. In order to perform classification analysis for predicting defects by defect type, labeling of casting parameters must be performed. In this study, first, the defective data set is separated by performing the primary clustering based on the total defect rate obtained during the post-processing. Second, the secondary cluster analysis is performed using the defect rate by type for the separated defect data set, and the labeling task is performed by defect type using the cluster analysis result. Finally, a classification learning model is created by collecting the entire labeled data set, and a real-time monitoring system for defect prediction using LabView and Python was implemented. When a defect is predicted, notification is performed so that the operator can cope with it, such as displaying on the monitoring screen and alarm notification.

• Journal of the Korean Society of Floral Art and Design
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• no.41
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• pp.61-92
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• 2019

We attempted to find the style of flower arrangement from the drawings of Uigwe and paintings of folding screens for the royal ceremonies of the late Joseon dynasty. In the pictures of the Uigwe and folding screens, we could see the linear, circular, and oval types Junhwa used to decorate the left and right sides of the throne placed in the center of main parish at the national banquet. There were also identified the Sanghwa which was used to decorate food on it, Jamhwa which was used to decorate head to be worn on the caps or hats, and Hwaga which was used to decorate the style supporting the large awnings at the national banquet. Hwaga was found, in the Musin Jinchan Dobyeong. In 1795, it was found that decorations on the floor, which are quite similar to the table decorations and modern space decorations, and flower shoot presented by king and flower decorations which were bound to the stick which was presented by king to country old men from Wonhaeng Eulmyo Jeongri Uigwe and Hwaseong Reunghaengdobyeong

• Journal of architectural history
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• v.32 no.5
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• pp.81-94
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• 2023

Haeju was home to the Hwanghae-do Provincial Office and a hub for supporting the northwestern regions of Korea. Local commerce expanded in Haeju during the late Joseon period based on its abundant resources and regional products, leading it to evolve into a large city. King Seonjo temporarily resided in Haeju while seeking refuge from the Japanese Invasions of Korea, and Yi Yi (sobriquet: Yulgok) secluded himself in Seokdam in Haeju in his later years. King Seonjo's residence in Haeju and Yi Yi's retirement there boosted interest in the city among the literati and influenced its places of scenic beauty. The development of its local history and literary achievements were documented in a wide variety of historical records and visual materials. Eight scenic views in Haeju became famous through a poem written by Seong Su-ik in the late sixteenth century. Around the mid-eighteenth century, eight new scenic views became popular. Local officials and travelers from other regions produced a vast body of prose and poetry focusing on the landscape and society of Haeju, playing a crucial role in raising awareness of its scenic attractions. Most surviving visual materials related to Haeju were created in and after the nineteenth century. Many of them illustrate both landscapes and the everyday lives of people. Among them, paintings of scenic spots created by Jeong Seon (sobriquet: Gyeomjae), who never actually visited Haeju in person, raises some of the issues posed by relying on indirect materials. In contrast, Eight Scenic Views of Haeju, which is presumed to have been produced by a local painter, appears to have accurately highlighted the characteristics of each scenic spot. Moreover, Haejudo, a folding screen presenting a panoramic view of Haeju, incorporates content from paintings depicting eight scenic views, in this case Eight Scenic views of Haeju. This practice can be observed in visual materials of other provincial cities.

• Journal of KIISE:Software and Applications
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• v.37 no.5
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• pp.341-353
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• 2010

Mobile Internet Device (MID) allows users to flexibly use various forms of wireless internet such as Wi-Fi, GSM, CDMA, and 3G. Using such Internet, MID users can utilize application services. MID usage is expected to grow due to the benefits of portability, Internet accessibility, and other convenience. However, it has resource constraints such as limited CPU power, small memory size, limited battery life, and small screen size. Consequently, MIDs are not capable to hold large-sized complex applications and to process a large amount of data in memory. An effective solution to remedy these limitations is to develop cloud services for the required application functionality, to deploy them on the server side, and to let MID users access the services through internet. A major concern on running cloud services for MIDs is the potential problems with low Quality of Service (QoS) due to the characteristics of MIDs. Even measuring the QoS of such services is more technically challenging than conventional quality measurements. In this paper, we first identify the characteristics of MIDs and cloud services for MIDs. Based on these observations, we derive a number of quality attributes and their metrics for measuring QoS of mobile services. A case study of applying the proposed quality model is presented to show its effectiveness and applicability.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.75-82
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• 2015

Major corporations and portals have implemented a link server that connects Content Management Systems (CMS) to the physical address of content in a database (DB) to support efficient content use in web-based environments. In particular, a link server automatically connects the physical address of content in a DB to the content URL shown through a web browser screen, and re-connects the URL and the physical address when either is modified. In recent years, the number of users of digital content over the web has increased significantly because of the advent of the Big Data environment, which has also increased the number of link validity checks that should be performed in a CMS and a link server. If the link validity check is performed through an existing URL-based sequential method instead of petabyte or even etabyte environments, the identification rate of dead links decreases because of the degradation of validity check performance; moreover, frequent link checks add a large amount of workload to the DB. Hence, this study is aimed at providing a link server that can recognize URL link deletion or addition through analysis on the B-tree-based Information Identifier count per interval based on a large amount of URLs in order to resolve the existing problems. Through this study, the dead link check that is faster and adds lower loads than the existing method can be performed.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.39-48
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• 2009

Previous studies on the effects of speaking rate on voice onset time (VOT) of stops in English, French, Icelandic, and Thai indicate that speaking rate asymmetrically affects VOT values. That is, pre-voiced and long-lag stops vary due to the rate factor more than short-lag stops do. One suggested explanation for this asymmetry is that it is due to the necessity of maintaining phonetic contrasts among the stop categories. Since pre-voiced and long-lag stops represent the ends of the VOT scale, they encompass broad swathes of that range and consequently allow for large variations. On the other hand, the VOT variations of short-lag stops may result in overlap with the VOTs of long-lag stops. This study aimed to explore the effects of speaking rate on the VOTs of Korean stops and see whether Korean fortis and lenis stops are limited in the degrees of variation as a function of rates due to the existence of stops with larger VOT values, lenis and aspirated stops respectively. Conversely, aspirated stops were expected to show more variation since there are no other categories with longer VOTs. Fortis, lenis, and aspirated stops in /CVn/ words (C = bilabial or velar stop, V = /i/ or /a/) were examined in isolation, and at normal and fast rates in a carrier sentence. Speaking rates were controlled by alternating words or sentences on a computer screen at intervals of two seconds for the isolation- and normal-rate conditions and one second for the fast-rate condition. This study found that while the VOTs of fortis stops did not change significantly, those of lenis and aspirated stops showed considerable changes as a function of speaking rates. Also, overlap between lenis and aspirated stops occurred considerably at all speaking rates. These phenomena were interpreted to relate to the fact that VOT contrasts between lenis and aspirated stops in Korean are currently being collapsed. Large variations of lenis stops as a function of rates seem to occur due to a weak motivation to limit the degree of variations for the purpose of maintaining phonetic contrasts. The significant overlap between lenis and aspirated stops at all rates was interpreted to occur because the VOT merger between the two categories became considerably fixed. Also the percentage of correctly-classified VOTs by optimal-boundary values between lenis and aspirated stops turned out to be lower than in previously-studied languages. This was interpreted to be further evidence that VOTs are losing their role in contrasting the two stop categories in Korean.