• Journal of the Economic Geographical Society of Korea
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• v.23 no.1
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• pp.56-70
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• 2020

This study identifies the impact of social network service (SNS) on the spatial characteristics of retail stores locations in the hyper-connected society, which have been closely related to the everyday lives of urban residents. In particular, we focus on the changes in the spatial distribution of restaurants since the information retrieval process was added to the decision-making process of a consumer's restaurant selection. Empirically, we analyze restaurants in Seoul, Korea since the smart-phone was introduced. By applying the kernel density estimation and Moran's I index, we examine the changes in the spatial distribution pattern of restaurants during the last ten years for running, newly-open and closed restaurants as well as SNS popular ones. Finally, we develop a spatial regression model to identify geographic features affecting their locations. As the results, we identified geographical variables and online factors that influence the location of restaurants. The results of this study could provide important groundwork for food and beverage location planning and policy formulation.

• Resources Recycling
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• v.7 no.4
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• pp.27-34
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• 1998

In this research, the processing control of NiCuZn Ferrite (NCZF) had been studied. NiCuZn Ferrite, which calcined at $700^{\circ}C$ for 3 bours, was ball milled for about 60 hours to ill김ke a size of $0.5\mu\;extrm{m}$ followed by granulation using spray dryer Apparent densincatioo rate and initial permeability of NiCuZn Ferrite with an initial packing density had been investigated as f follows. 1.The relative packing density of NCZF green body increas$\xi$d in the range of 48.6-56.8% with an increased forming pressure of 20-170 MPa. 2. The higher the relative pac퍼ng density of NCZF and the sintering temperature are, the higher the initial densification rate. The increased bulk rlcnsity of NCZF was attributed to the densification rate with decreased open pore and increased closed pore as the relative packing density, sintering temperature, and sinteriog tim$\xi$ increased. 3. The initial P permeability of NCZF with constant composition is logarithmically proportional to the bulk density of NCZF sintered at $875~925^{\circ}C$ for 0-5h, and strongly depended on the relative packing density of NCZF green body. The empirical equation is as f follows; log $\mu$i=$G1{\times}BD$+$G2{\times}RPD$+b(0);where, G1, G2; gradient, B.D: bulk density, RPD; relative packing density, b(0); intercept.

• Journal of Digital Contents Society
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• v.13 no.1
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• pp.1-11
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• 2012

The BBS of Web Site is a space of informational communication to share information. At the moment, countless information is shared through various kinds of BBS. The shared information through the Web BBS can be gains to someone and losses to the other. Thus, for a long time, there have been many researches about technologies, which monitor information uploaded to Web BBS in real-time and inform the results to subjects. For BBS monitoring, existing methods have utilized direct approaches to DB or open API. Also, e-mail addresses have been utilized to inform results to subjects. However, there are two main problems for these methods. The one is a problem on closed BBS, which cannot be accessed, and the other is impossibility of supporting real-time alarm to e-mail. Especially, the real-time support for services, such as monitoring, is extremely important, since the main purpose of monitoring is based on the counter action for the result. The mobile Web has a merit to be accessed in anywhere, so that it is quite suitable for services requiring real-time support. However, the real-time support of mobile device has not been utilized enough, because each mobile phone has different standards of contents so that the contents should be pre-created. This paper suggests a technology that overcomes pitfalls of mobile Web while it is out of standard, and shows how the effect can be maximized through services such as monitoring, which requires the real-time support.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.76-81
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• 2018

The Internet of Things (IoT), which is emerging as a future economic growth engine, has been actively introduced in areas close to our daily lives. However, there are still IoT security threats that need to be resolved. In particular, with the spread of smart homes and smart cities, an explosive amount of closed-circuit televisions (CCTVs) have been installed. The Internet protocol (IP) information and even port numbers assigned to CCTVs are open to the public via search engines of web portals or on social media platforms, such as Facebook and Twitter; even with simple tools these pieces of information can be easily hacked. For this reason, a big-data analytics system is needed, capable of supporting quick responses against data, that can potentially contain risk factors to security or illegal websites that may cause social problems, by assisting in analyzing data collected by search engines and social media platforms, frequently utilized by Internet users, as well as data on illegal websites.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.1
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• pp.54-59
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• 2009

It was difficult for the existing rotary kiln to fabricate the fine aggregates under 3 mm due to the sticking phenomenon between specimens. In this study, the vertical type fluidizing furnace was designed and manufactured by which the lightweight fine aggregates of specific gravity $1.1{\sim}1.7$, water absorption $11{\sim}19%$ could be fabricated from the green body of clay: stone sludge: spent bleaching clay = 60 : 30 : 10 (wt%) without sticking-together happening. The minimum sintering temperature for bloating of aggregates was $1130^{\circ}C$. The specimens sintered over $1140^{\circ}C$ showed the typical bloating characteristics of lightweight aggregates and an inner layer was discovered due to widened cracks on a surface. But the crack on a surface did not propagate into a black core area so had no effect on a water absorption of aggregates. The sintering temperature made the thickness of shell and the black core area thin and expanded respectively but the sintering time did not affect the microsturcture of aggregates. The water absorption of aggregates decreased with increasing temperature owing to increased amount of liquid formed on a surface. Also sintering time affected a lot on a water absorption because it takes a time to form a liquid, which change the open pores to closed pores by blocking.

• Journal of Korea Game Society
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• v.15 no.5
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• pp.57-78
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• 2015

This Study is the effect of the inclusive institution on a nation's economic development. Therefore, we focused on the gaming industry as an index that can drive the economic growth in the future. The reason to compare the game institution in South Korea and Germany is that both countries began to develop the game by the State, but the game institution in South Korea and Germany at the present time are sharply opposed, because the institutions can focus on the main points that are experiencing this difference. The results of this study, first, open/closed network in institutionalized aspect affects the social status of the game. This second, game workers in the legal institution has been classified as artists in Germany, as addicts in South Korea. And, Germany also has incentives to creators protected profits reinvested in the gaming industry, Korea leads to punitive exploitation is being transferred to the group for addiction treatment that revenue. Third, this exclusive and inclusive institutional system could affect the stable growth of the game market. As a result, South Korea's state institutions will notice that you get a result away from opportunities for economic development due to the loss of inclusiveness.

• Composites Research
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• v.32 no.6
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• pp.301-306
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• 2019

Triboelectric nanogenerator (TENG) is one of the energy harvesting methods in spotlight that can convert mechanical energy into electricity. As TENGs produce high electrical output, previous studies have shown TENGs that can power small electronics independently. However, recent studies have reported limitations of TENG due to air breakdown and field emission. In this study, we developed a triboelectric nanogenerator that utilizes the metal-to-metal surface contact to induce ion-enhanced field emission and electron avalanche for electrons to flow directly between two electrodes. The average peak open-circuit voltage of this TENG was measured as 340 V, and average peak closed-circuit current was measured as 10 mA. The electrical output of this TENG has shown different value depending on the surface charge of surface charge generation layer. The TENG developed in this study have produced RMS power of 0.9 mW, which is 2.4 times higher compared to conventional TENGs. The TENG developed in this study can be utilized in charging batteries and capacitors to power portable electronics and sensors independently.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.601-609
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• 2016

This study evaluated the dynamic balance and pain after 12 weeks aquatic exercise in old osteoarthritis patients. The dynamic balances were assessed using 2 different experimental conditions (Open Eye Condition; OEC, Closed Eye Condition; CEC). Twenty-two subjects were assigned one of the two experimental groups: arthritis group (ART, age=$65.25{\pm}5.9$, n=11), control group(CON, age=$64.50{\pm}7$, n=11). All subjects participated in the aquatic exercise program three times a week for 12 weeks. The dynamic balances (OEC (p<.001), CEC (p<.05)) capability were improved significantly in the ART group after 12 week aquatic exercise. Visual Analogue Scale (VAS) was decreased significantly [Factor 10(Soft chair, p<0.01), 11 (Lying down, p<0.05), 12(Handicap, p<0.05), 13 (Work interference, p<0.01)] in the ART group. In conclusion, aquatic exercise was effective in improving the overall health status and the capacity of dynamic balances and reducing the degree of pain in osteoarthritis patients.

• Sijohaknonchong
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• v.20
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• pp.75-96
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• 2004

A pavilion is located in the place with beautiful scenery, which maximizes the poetical features of nature. So a scholar in the Chosun Dynasty had the dream of possessing it. This trends of the Chosun scholar resulted in producing lots of literary works related with the pavilion. In this thesis, I researched the characters of Pavilion Si-Jo in accordance with the function of pavilion. First, the pavilion, which is surrounded by the beautiful scenery, is a good place to see the beauty of nature. It is needless to walk around to see the scenery thanks to its open structure. So the feeling in the pavilion Si-Jo is distinguished from other sightseeing Si-Jos: those show the way of seeing the scenery walking here and there, but this shows the way of seeing the scenery only just looking up, looking down, and looking in the distance. Second, the pavilion functions as an academic place. In this case, it can be said that it functions like a lecture hall. It is more effective to study in the pavilion than in the closed structure, a lecture hall. Furthermore, the scholar studying in the pavilion understand the principle of nature with seeing the beautiful mountain and river, and it can be a place for growing a vast-flowing spirit. This kind of poetry has been handed down with the Chinese poetry, and the character who operated the pavilion often appears in the work. Third, the pavilion functions as a space for a fraternity or poetry circles. The poetic exchange was conducted by host of pavilion. which is the key ingredient for organizing a poetry circles. Finally, the pavilion functions as an entertainment. Although it is a space for an entertainment, there is no deviation as a man of novel birth. If the pavilion has the feature of closeness, there are sometimes works which shows the deviation of them.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.915-921
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• 2020

Thermoacoustic instability caused by air conditioning in a combustion chamber has emerged as a problem that must be solved to establish a stable combustion system. Thermoacoustic instability is largely divided into primary and secondary acoustic instability. In this study, an experimental study of the effects of heat losses was conducted to investigate the mechanism of secondary acoustic instability. To generate the secondary acoustic instability, a quarter-wavelength resonator with one open end and one closed end was used, and the inside of the resonator was filled with premixed gases. Subsequently, secondary acoustic instability with downward-propagating flames could be realized via thermal expansion on the burnt side. To control heat losses qualitatively, an additional co-axial tube was installed in the resonator with air or nitrogen supply. Therefore, additional diffusion flames can be formed at the top of the resonator depending on the injection of the oxidizer into the co-axial tube when rich premixed flames are used. Consequently, secondary acoustic instability could not be achieved by increasing heat losses to the ambient when the additional diffusion flame was not formed, and the opposite result was obtained with the additional diffusion flame.