• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.666-671
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• 2018

A honeycomb panel is a plate made by attaching two surface plateson eitherside of a honeycomb core. The honeycomb plate hasexcellent specific strength and energy absorption and is suitable for use in regions where good impact resistance is required. Recently, with the increasing the need for a lightweight design to facilitate transportation, numerous studies have been conducted using aluminum honeycomb plates as body materials for vehicles such as automobiles and high-speed trains. In addition, honeycomb plates have excellent sound deadening properties, as well as excellent heat insulation and durability. Savings in weight using lightweight materials such as aluminum alloy for honeycomb panel's skin can lead to increase fuel economy and reduction in air pollution. In this study, in order to improve the design technology of the honeycomb plate material, the manufacturing technology of the aluminum honeycomb core and honeycomb plate material and various mechanical properties of the honeycomb plate were evaluated. From the results, it was found that the design of the manufacturing process of the aluminum honeycomb plate, as well as itsproduction and characteristics, were improved. The resulting excellent energy absorption capability of the honeycomb plate was due to the repetitive core buckling, indicating that the higher the compressive strength, the higher the strength per bonded area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.688-698
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• 2018

The government has recognized the importance of smart city indicators and prepared the legal grounds for the certification of smart cities in the recently revised "Act on Smart City Development and Industrial Promotion." This study derived smart city indicators adequate for the domestic conditions and compatible with the overseas trends by examining and complementing the indicators through an AHP analysis based on consultations and interviews (surveys) with experts and local government officials, who are actually carrying out related projects. In addition, the adequacy and reliability of the indicators were confirmed by verifying and certifying the Korean local governments' smart city plans through demand surveys on a trial basis. This study is meaningful in that it systematically studies the smart city indicators that have gained in importance and reviews their application. The findings of this study can be used as a basis for implementing a smart cities certification system in the future. Recently, the Special Committee on Smart Cities was established under the Committee for the Fourth Industrial Revolution. This committee is composed of civilian members and is working with the Ministry of Land, Infrastructure, and Transport, the Ministry of Science and ICT, etc., to promote the creation of smart cities. It is expected that smart city indicators that include the levels of both domestic and overseas smart cities will boost the active spread of such cities in Korea.

• Journal of Conservation Science
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• v.31 no.4
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• pp.411-427
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• 2015

The purpose of the present study is to examine the objects excavated from the archaeological site of the Nogye Village in terms of their relationships with the iron production facilities such as 1ho smithing hearth and 2ho smelting furnace. 32 samples including slags, iron ores, and wall were analyzed to identify the mineralogical and chemical characterization. In addition, in the case of the 1ho smithing hearth slag, differing points of the cross-section were analyzed to examine its formation in depth. The analysis results suggest that the slags from the each site adjacent to the 1ho smithing hearth and 2ho furnace are related to smithing and smelting process respectively. Furthermore, it is possible to draw some conclusions that the aspects of the increased contents of nonferrous elements such as CaO in the slags in comparison with those of the iron ores are due to various factors such as charcoal ash and analytical reasons rather than an addition of CaO as flux.

• Journal of Korea Technology Innovation Society
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• v.17 no.1
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• pp.95-123
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• 2014

Recently, as the role of science and technology in social domain is more increased and the creative economy becomes a important matter in national development strategy, it is necessary that the improvement of legal system on science and technology for efficiently responding to paradigm shift into Innovation driven science and technology policy. Especially, The Framework Act On Science And Technology as a general and basic norm on science and technology policy is necessary to revise in systematic and substantial aspect in order to correspond with changed environment and current of the times. The Framework Act On Science And Technology was established in 2001 and revised several times, but substantial amendment reflecting the political facts as the need to demand was insufficient because it was revised only related with restructuring the government organization and changing the S&T Policy Coordinating Committee system. And therefore, this paper aims to review the problems and complementary factors and suggest the improvement draft on The Framework Act On Science And Technology. According to study, the revision methodologies are following : first, the Chapter and Paragraph of the law should be restructured to improve the systemicity, next the comprehensiveness, effectiveness, connections with related special laws and compatibility of the law should be complemented by adding the new provision or amending the inadequate provision to improve the position and function as a general and basic norm.

• Korean Journal of Optics and Photonics
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• v.19 no.2
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• pp.87-94
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• 2008

We present a new design for an endoscope objective lens composed of a lexible fiber bundle with 30,000 core, and a gradient-index (GRIN) objective lens with an optical adaptor. The characteristic of this objective lens is to be minimally-invasive to be able to insert easily in the internal organs of live animals. The GRIN lens has a small diameter and a very simple construction, which is selected with the diameter of 1.0 mm and numerical aperture of 0.5 to achieve a minimally-invasive outer diameter and a high resolution. The resultant designed lens shows the performance as follows; a lateral resolution of 1.63 um and diameters of 100% encircled energy of $0.3\;{\mu}m$ and $0.83\;{\mu}m$ for the on-axis and the off-axis image point, respectively. Also, we can present a cheap solution with a lateral resolution of 1.74 um and diameters of 100% encircled energy of $1.10\;{\mu}m$ and $2.84\;{\mu}m$ for the on-axis and the off-axis image point, respectively.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.75-78
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• 2006

Development of pellet-type artificial diet for insect was tried by using a twin screw extruder(TSE). Screws were arranged several times and two reverse screws were equipped on the foreparts of 2 axes of TSE. Pellet-type diet could be produced successfully under conditions of TSE set as the following. : 300 rpm of main motor speed, 228 rpm of feed motor speed, $75m{\ell}/min$ of running water speed and 5 mm of extrusion diameter. The optimum adding quantity of water to the manufactured diet was $1.2{\sim}1.5$ times of dry diet. On the rearing results of beet armyworm, Spodoptera exigua and common cutworm, Spedoptera litura with the pellet-type diet, the final survival ratio (emergence rate) of these two species was over than 50%, and so it was concluded that the manufactured pellet-type artificial diet was sufficient dietetically to rear those insects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.653-659
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• 2008

In this study, the optimum pre-heating condition was investigated to improve water extraction yield of Phelinus linteus tea. Pre-heating was carried out using drying oven or hot plate at different temperatures and times, and extraction yield was estimated by measuring optical density at 370 nm and soluble solid content. The highest optical density and soluble solid content of Phelinus linteus tea were observed when pre-heated at $70{\sim}80^{\circ}C$ for 30 minutes in drying oven. Pre-heating in drying oven resulted in also faster color changes of Phelinus linteus tea at lower temperature. According to the organoleptic evaluation, pre-heated Phelinus linteus tea in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was preferred compared to the non-treated. In conclusion, pre-heating in drying oven at $70{\sim}80^{\circ}C$ for 30 minutes was found to be the most efficient conditions to increase extraction yield of Phelinus linteus tea.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.235-243
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• 2008

Construction projects have unique characteristics that these may be carried out by contractors thus, cost should be estimated before execution. The importance of cost estimation and cost check has become increasingly emphasized in all phases of construction project that would be performed numerously. It is needed that owner have to estimate reasonable budget, and contractor should predict the bid price. However, there are lack of standard cost estimation method before quantity takeoff, cost analysis method, and cost database thus, the method of area cost, such as square foot method, is as used as ever in Korea. Therefore, this research suggested standard cost database structure CUBE, and analysis method of item quantity per one household categorized by area type. Whereafter, database of all item quantity of finish work has been built with 90 building cost data, and validated it's availability. In this respect, the suggested method and the findings from this research are expected to help enhancing the efficiency and productivity of cost estimation in Korea.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.297-317
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• 2006

This article is aimed to find a more successful way to build a metropolitan-wide governance for enhancing industrial cluster in South-East region, Korea. We begin a research with reviewing a current study of regional cluster and its governance. New industrial system and agglomeration changed regional growth theory and urban system. In traditional system, a central city dominated economy of the metropolitan area. However, with development of new transportation and communication technology, a central city lost their superiority to suburban cities. In other words, growing competition between central and suburban cities changed traditional concentration and diffusion theory of urbanization which dominated urban geography for last decades. Next, current situation of development of industrial cluster in South-East region is examined to suggest policy for more competitiveness. South-East region has grown as the most prominent cluster of mechanical engineering and metal industry in Korea since the late 1970s. In the form of agglomeration and network of a specific and its related industry, South-East region has formed a linear industrial belt along with the inter-regional South Coast Highway and contain about ten industrial cities. Accompanying with this growing South-East region, a problem has risen from geographic mismatch between metropolitan-wide industrial cluster and its administrative boundary. Since industrial cluster has no specific administrative boundary, adequate government support for developing industrial cluster has not been provided. Responding to the problem, academics and policy makers maintain need in establishing a metropolitan-wide governance for supporting a cluster. At the end, this paper provides some implication to planners and policy makers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1267-1274
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• 2012

A guide vane plays a key role in controlling the flow rate of water supplied to the turbine of a hydropower plant. It has been reported that guide vane bearing bushings are subjected to considerable wear, which requires them to be maintained. An ancillary service such as frequency control and black start causes cyclic low opening operation of the guide vanes. It is empirically well known that such operation increases the wear rate of the guide vane bearing bushing. In this study, the effect of low opening operation on the increasing wear of the guide vane bearing bushing is quantitatively assessed via finite element flow analysis, finite element stress analysis, and relative wear evaluation. As a result of the assessment, it is identified that the pressure applied on the guide vane surface increases and the contact length between the outer surface of the guide vane stem and the inner surface of the bearing bushing decreases with a decrease in the opening of the guide vane. In addition, low opening of the guide vanes results in an increase in the relative wear owing to the generation of high contact pressure on the bearing bushing surfaces.