• Journal of Korean Library and Information Science Society
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• v.44 no.3
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• pp.447-470
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• 2013

The purpose of this study is to examine how the cultural aspects of the publication of literary collections have been changed from its time throughout the entire Joseon Dynasty. At the royal court in the early Joseon Dynasty, the need for publication of the literary collections has consistently arisen to preserve writings of the noted sages, and the Joseon government was also taking the lead and promoting the publication of the literary collections. From the 16th to the early 18th century, the publication was intensively made at the local governments led by local governors. From the 17th to the early to middle of the 18th century, the finances of local governments were limited with the changed taxation system, and there had been a dramatic decrease in the number of literary publication projects. On the other hand, with the sudden increase of the number of Seowons during the reign of King Sukjong, the focus of the literary publication was moved to Seowon from the 18th to the 19th century. After the enforcement of the Seowon Abolition Decree, the collections were still published at Seowons, however from the end of 19th century, the publication of literary collections had been explosively made by aristocrats who did not belong to the institution of Seowon or could not receive Seowon's support, which spreaded over the entire Yangban culture.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.143-150
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• 2018

With the rapid development of RF based high speed wireless communication technology, devices that can be applied to IoT networks based on RF bandwidth are rapidly spreading, nevertheless, the development speed of the RF communication is not possible to keep up with the spread of the RF band for wireless communication. In this situation, OWC technology that uses visible light source as a transmitter is attracting attention as a technology that can overcome the band exhaustion problem of RF based wireless communication technology. Although, due to the distortion of the LED illumination shape by camera exposure time and LED blinking period, the LED illumination detection rate is degraded and the RoI setting is inaccurate. In this paper, we propose an adaptive median filter applied LED illumination detection algorithm for low rate CamCom, it is possible to detect a clear RoI and LED illumination. This research will be able to play a role as a complementary material of RF based wireless communication technology efficiently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.503-510
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• 2020

Eco-friendly mountain railways operate on concrete rack tracks embedded on existing sharp curved and steep roads to preserve the environment in mountainous areas. Owing to the narrow roads, single lines are inevitable, and many branches are required. In branches, previous switchers and heating devices cannot be applied, because of the limited spacing for the rack and the slow removal of thick ice. To solve these problems, a switch and a heating device have been developed. The switcher changes the line by moving the block of concrete track with hydraulic actuators. The lack of discontinuity reduces the derailment risk and makes locking simple. The heating device uses high frequency induction coils to increase the efficiency and melt the thick ice rapidly. The prototype switcher and heating device were produced and operated to prove their performance. The heating device yielded a 10 times greater efficiency than the previous one. The switcher and heating device are the essential core technologies for the operation of mountain trams in winter and contribute to the spread of mountain railways to domestic or foreign resort areas by enhancing safety and efficiency. In addition, they can provide transportation rights to local residents in poor winter traffic, and bring about tourism and local economic growth.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.610-620
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• 2022

An acoustic vector sensor can simultaneously receive vector quantities, such as particle velocity and acceleration, as well as acoustic pressure at one location, and thus it can be used as a single input multiple output receiver in underwater acoustic communication systems. On the other hand, vector signals received by a single vector sensor have different channel characteristics due to the azimuth angle between the source and receiver and the difference in propagation angle of multipath in each component, producing different communication performances. In this paper, we propose a channel parameter-based weighting method to improve the performance of an acoustic communication system using a single vector sensor. To verify the proposed method, we used communication data collected from the experiment conducted during the KOREX-17 (Korea Reverberation Experiment). For communication demodulation, block-based time reversal technique which is robust against time-varying channels were utilized. Finally, the communication results showed that the effectiveness of the channel parameter-based weighting method for the underwater communication system using a single vector sensor was verified.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.33-43
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• 2007

Because usually signal controllers on the crosswalks of mid-block provide pedestrian signals every cycle based on the fixed signal plan, pedestrian signals are provided even when there is no pedestrian demand. Consequently, signal is operated inefficiently and this may cause drivels to experience useless delay or violate the signal. Even though recently pushbuttons have been installed to improve the efficiency of pedestrian signal control in the crosswalks of mid-block and the pedestrian safety. they are not spread out national-wide in Korea because of the cost of the pushbutton equipments and the lack of an acknowledgement of the efficiency of the pushbutton. In this study, the effectiveness of the pushbutton on saving the vehicle delay was verified through before and after study in 4 study sites using a traffic micro-simulation model, VISSIM. To evaluate the viability of the pushbutton, a benefit/cost analysis was also performed for 4 study sites. It was found that B/C ratio of all of 4 study sites was greater than 1. The sensitivity analysis for the traffic volume and pedestrian volume were performed to identify the impact of the both volume on the operation of pushbutton. And, a benefit/cost analysis was performed for all scenarios. It was found that when the pedestrian volume is greater than 90ped/h, the pedestrian signal was operated same as the fixed signal plan. That is, there is no benefit of pushbutton at all once the pedestrian volume is greater than 90ped/h. When the pedestrian volume is equal to or less than 90ped/h and the traffic volume is greater than 2,500veh/h, B/C ratio is greater than 1. Also it was found that as traffic volume increases and pedestrian volume decreases, the benefit increases. In this study, the criteria for installation of pushbutton on the crosswalks of mid-block are developed through the sensitivity analysis and benefit/cost analysis. The results of this study may be used as a criteria for expansion of pushbutton system.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.1
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• pp.1-9
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• 2011

In order to investigate the cause and magnitude of scale effect occurring in the model experiments of fishing nets, five pairs of Nylon pyramid nets and one pair of PE ones in which all the two nets paired were equal each other in the factors determining their flow resistance, i. e., the ratio d/l of diameter d to length l of bars, the angle f between two adjacent bars, the attack angle q of nettings to the water flow, and the wall area S of nets, and different in the values of d and l were prepared. Then, the nets were attached to the circular steel frame alternately and their flow resistances with shapes in water were measured on the sea ascribing no turbulent flows by using the tension meter made of a block bearing for the experiment. All the Nylon nets were spreads out easily in water to form a circular cone at relatively low velocity of water and showed the resistance smaller a little in the nets with larger d and l than them with smaller d and l, because the filtration of water through meshes become easier in nets especially with larger l. But PE nettings were not spread out sufficiently on account of their small flexibility and showed higher resistance especially in them with thicker twines. Therefore, the difference in bar length or mesh size and flexibility of nettings between prototype and model nets are regarded to become factors ascribing scale effect. Especially the influence of the difference in mesh size may become large significantly in actual model experiments because the mesh size of model nets is decided at much larger value than that given by scale ratio and so the difference of mesh size between the two nets become much larger than that between nets used in this experiment.

• Journal of Forest and Environmental Science
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• v.38 no.2
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• pp.128-132
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• 2022

Wild boars (Sus scrofa) not only cause crop damage and human casualties, but also facilitate the spread of many infectious diseases in domestic animals and humans. To determine the efficiency of a fencing system in blocking the movement of wild boars, long-term monitoring was performed in a fenced area in Bukhansan National Park using camera traps. Upon monitoring for a period of 46 months, there was a 72.6% reduction in the number of wild boar appearances in the fence-enclosed area, compared to that in the unenclosed area. For 20 months after the fence installation, the blocking effect of the fence was effective enough to reduce the appearance of wild boars by 92.6% in the fence-enclosed area, compared to that in the unenclosed area. The blocking effect of the fence remained effective for 20 months after its installation, after which its effectiveness decreased. Maintaining a fence for a long time is likely to lead to habitat fragmentation. It can also block the movement of other wild animals, including the endangered species - the long-tailed goral. This study suggests a 20-month retention period for the fences installed to inhibit the movement of wild boars in wide forests such as Gangwon-do in South Korea. To identify how long the blocking effect of the fences lasts, further studies are needed focusing on the length and height of the fence, and the conditions of the ground surface.

• The Korean Journal of Pain
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• v.28 no.2
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• pp.122-128
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• 2015

Background: Caudal epidural injections have been commonly performed in patients with low back pain and radiculopathy. Although caudal injection has generally been accepted as a safe procedure, serious complications such as inadvertent intravascular injection and dural puncture can occur. The present prospective study was designed to investigate the influence of the depth of the inserted needle on the success rate of caudal epidural blocks. Methods: A total of 49 adults scheduled to receive caudal epidural injections were randomly divided into 2 groups: Group 1 to receive the caudal injection through a conventional method, i.e., caudal injection after advancement of the needle 1 cm into the sacral canal (n = 25), and Group 2 to receive the injection through a new method, i.e., injection right after penetrating the sacrococcygeal ligament (n = 24). Ultrasound was used to identify the sacral hiatus and to achieve accurate needle placement according to the allocated groups. Contrast dyed fluoroscopy was obtained to evaluate the epidural spread of injected materials and to monitor the possible complications. Results: The success rates of the caudal injections were 68.0% in Group 1 and 95.8% in Group 2 (P = 0.023). The incidences of intravascular injections were 24.0% in Group 1 and 0% in Group 2 (P = 0.022). No intrathecal injection was found in either of the two groups. Conclusions: The new caudal epidural injection technique tested in this study is a reliable alternative, with a higher success rate and lower risk of accidental intravascular injection than the conventional technique.

• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.125-134
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• 2011

Art Deco is a decorative and eclectic design style, popularized at the interwar period. The term Art Deco derives from the Exposition Internationale des Arts D$\acute{e}$coratils et Industriels Modernes held in Paris in 1925. The aim of the exposition was to create new modern aesthetics. This exposition introduced the modern decorative and industrial art to the world and influenced all designers of area, including architects, interior designers, industrial designers, craftsmen, fashion designers, etc. Art Deco designers applied inspirations from a variety of sources and movements such as the Cubist abstract, the Neoclassical refinement, Egyptian exotic elements, Babylonian and Aztec temples, the machine aesthetic, avant-garde movements, etc to their modern works. Art Deco style rapidly spread all over the design areas nationwide in America. In Art Deco architecture, in particular, its inception was French but its domination was American. Skyscrapers, airplanes, automobiles, ocean liners, jazz, Hollywood film, streamline, and native Indian symbols are the defining features of American Art Deco. This study began from questions on how these features are expressed and stylized to decoration elements as the modern aesthetics in American Art Deco architecture. Thus, the purpose of the study is to find out the ornamental and eclectic factors of Art Deco style and to define a concept of the modernity and the regionalism of Art Deco architecture in America. This article provides an overview of the decoration style of Art Deco architecture in America through the analysis of ornamental and eclectic factors reflecting diverse roots. It also analyzes the wide variety of building examples of American Art Deco which represent regionalism. In addition, this study focuses on Art Deco architecture in Miami, Florida. Miami is one of typical cities that has the most unique regional aspects of 1920's to 1940's in Art Deco architecture. Miami Art Deco architecture reveals the tropical and nautical references such as streamlined and curved walls, exotic animal motifs, flora and fauna motifs, and marine motifs: use of glass block, porthole window, terra-cotta, and pastel color stucco.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.69-76
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• 2007

The blocking of malicious traffic in groupware network system is used to prevent the spread and distribution of malicious traffic. The method protecting from malicious traffic in groupware system is designed to handle the malicious traffic of various routes with the internal course of groupware, which leads to lighten the load of security and traffic. It was impossible to block this kind of traffic at the traditional structure. When the protection of the proposed groupware system is performed, there appears to be a great change for the rate of a load factor at the CPU of Backbone Switch which is connected to the internal gateway. The load factor of CPU, which was increased with the traffic, is now remarkably reduced after the internal gateway is set up. This is to show that a lot of malicious traffic pass through the internal network and that network environment is faced to the menace of many malicious traffics. This paper is to show the efficiency of protection of internal gateway proposed in this study, for the rate of CPU of Backbone Switch was about 17% a day, but was dropped up to the 4% after the malicious traffic was removed.