• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.506-525
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• 2007

Incision into bedrock channel is the primary control of landform evolution, but research into bedrock incision process stagnated for long time. Due to the scaling problem of the application of results from flume studies to bedrock channel, there is a strong need to simulate the bedrock incision process with more realistic models. As a part of investigation into controls of bedrock channel incision, three-dimensional changes of rock surface with abrasion was investigated with physical modelling. 18 rock plates were abraded with various sediment particle size and sediment load and abraded surfaces of the plates were scanned with high resolution 3-D scanner. To identify the spatial pattern of erosion of the rock plates, various methods were used. There was no synthetic or holistic method that showed all features of bedrock plate produced by abrasion, so each plate was analyzed using some available methods. Contour maps, shaded relief maps and profiles show that abrasion concentrated on the centre of plate (cross profile) and upstream and downstream edges (longitudinal profile) and eroded area extended inwards. It also found that the cracks and boundaries of forming materials easily eroded than other parts. Changing patterns of surface roughness were investigated with profiles, regression analysis and spectral analysis. Majority of plates showed decrease in small-scale roughness, but it depends on microstructures of the plates rather than general hardness or other factors. SEM inspection results supported this idea.

• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.101-109
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• 2011

As climate change is becoming the main issue, various efforts are focused on saving building energy consumption both at home and abroad. In particular, it is very important to save energy by maintenance, repair and rehabilitation of existing multi-family housing complex, because energy consumption in residential buildings is not only forming a great part of gross energy consumption in Korea but the number of deteriorated complexes is also sharply increasing. However, energy saving is not considered as a main factor in decision making on rehabilitation project. Also, any supporting tool is not appropriately prepared in existing process. As the first step for development of decision support system on rehabilitation, this paper developed a breakdown structure, which makes clusters of multi-family housing complexes. Decision tree, one of data mining methods, was used to make clusters based on the characteristics and energy consumption data of multi-family housing complexes. Energy saving and CO2 reduction will be maximized by considering energy consumption during rehabilitation process of multi-family housing complex, based on these results and following research.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.288-299
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• 2010

Recently, scientific literacy means not only the acquisition of scientific knowledge but also the linguistic ability to participate in a scientific discourse community. Keeping this in mind, this study investigated middle school students' writings about phase transitions of water in air. Sixty seven students at 9th grade (age 15) students participated in this study and wrote two individual short texts. The result of text analysis can be summarized as follows: (1) students had problems with familiar scientific terms such as 'water vapor' and 'steam' as well as unfamiliar ones like 'dew point'. (2) Students described right semantic relations and at the same time wrong ones more in the idea formed from everyday experience than those from school instruction. (3) While students showed action and process centered writing in text about everyday phenomenon, they showed more preference for technical words and nouns in text about school science. This study suggest that students could develop linguistic ability of science from both spontaneous process based on experience and formal and theoretical learning; the former in forming various semantic relations, the latter in technical and abstract aspect of scientific writing.

• Journal of Korea Foresty Energy
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• v.24 no.2
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• pp.1-9
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• 2005

After manufacturing fermentation system for degrading pig manure using environmentally friendly technique, performance of the system and characteristics of wood chips and pig manure fermented in the system were analyzed. Results from this study shows that proper fermentation temperature($55{\sim}60^{\circ}C$) reached 3days after the system started and degradation rate, which expresses fermentation performance of system, was $180{\iota}$/day. Even as progressing the fermentation of wood chips and pig manure mixture, the amount of extractives drawn out by alkali, and alcohol-benzene and lignin content was not varied. However, ash content in wood was increased. The inorganic compounds in pig manure seem to be transferred into wood chip. On the other hand holocellulose contents in wood were decreased a little. Holocellulose seems to be consumed as the second carbon source in fermentation process. Results through analysis of inorganic- and heavy metal elements contents in wood chips and pig manure fermented in long term process shows that inorganic elements($Ca^{2+},\;Mg^{2+},\;K^+,\;Na^+$ etc.) contents were increased with fermentation time and heavy metal elements(Cd, As, Cu etc.) which cause environmental pollution were not detected. Number of microorganisms including bacteria, actinomycetes, and fungi, the number of C.F.U(Colony Forming Unit) was increased while temperature in fermentation system was abruptly increased.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.3
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• pp.49-53
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• 2018

Since various methods to form well-aligned nano-/micro- patterns are underlying technologies to fabricate next generation wearable electronic devices, many efforts have been made to realize finer patterns in recent years. Among lots of patterning methods, the present invention includes a nano-transfer printing (n-TP) process which is advantageous in that a processing cost is low and high-resolution patterns can be formed within a short processing time. We successfully achieved pattern formation of highly ordered Pt lines with line-width of 250 nm, 500 nm, and $1{\mu}m$ on transparent and flexible substrates. In addition, we analyzed the durability of the patterns, showing excellent stability of line-shape even after a physical and repeated bending test of 500 times using a bending machine. As a result, it is expected that a n-TP process is very useful for forming various metal patterns, and it is also expected to be applied to wiring and interconnection technology of next generation flexible electronic devices.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.2
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• pp.52-60
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• 2002

Line heating is a forming process which makes the curved surface with the residual strain created by applying heat source of high temperature to steel plate. in order to control the residual strain, it is necessary to understand not only conductive heat transfer between heat source and steel plate, but also temperature distribution of steel plate. In this paper we attempted to analyze is temperature distribution of steel plate by simplifying a line heating process to collision-effusive flux of high temperature and high velocity, and conductive heat transfer phenomenon. To analyze this, combustion in the torch is simplified to collision effusive phenomenon before analyzing turbulent heat flux. The distribution of temperature field between the torch and steel plate is computed through turbulent heat flux analysis, and the convective heat transfer coefficient between effusive flux and steel plate is calculated using approximate empirical Nusselt formula. The velocity of heat flux into steel plate is computed using the temperature distribution and convective heat transfer coefficient, and temperature field in the steel plate is obtained through conductive heat transfer analysis in which the traction is induced by velocity of heat flux. In this study, Finite Element Method is used to accomplish turbulent heat flux analysis and conductive heat transfer analysis. FEA results are compared with empirical data to verify results.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.5
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• pp.11-22
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• 2004

A few years ago, many people proposed that a plaza be added to Seoul City Hall. The proposal, however, did not materialize because of traffic confusion. The June 2002 World Cup cheering in front of Seoul City Hall has prodded the public to reconsider the plaza. Even though the exercise failed to gain support, many democratic procedures, opening a Web page and design competitions, and so on were attempted while the design and management of Seoul City Hall Plaza was being deliberated. In the future, the need for proper communication and democratic procedures in the process of making decisions regarding public spaces is expected to increase because of the strengthening of the requirement of participatory and deliberative democracy. An examination of the nature and extent of the communication that has been carried out in relation to the plan to add a plaza to Seoul City Hall will be very helpful in gathering feedback to guide decision-making in regards to the use of other public spaces. Thus, this study has a three-fold purpose. : (1) to examine the theories that may justify the need for public input in relation to decisions made regarding the use of public spaces, and to propose the criteria to be used for the methods of communication (2) to examine the contents and conflicts of communication in relation to the decision made regarding the design and management of Seoul City Hall Plaza and (3) to examine the potential distortion of that communication by analyzing the communication according to the criteria previously proposed. The study method that is used herein is the analysis of articles about the subject matter, which have been posted on the Seoul City Hall Plaza Website and which have been published in newspapers such as the Chosun ilbo, Donga ilbo, the Jungang ilbo, and the Hankyoreh. Diverse article contents are also discussed. As result, there are many differences in the contents and viewpoints of the newspapers that are included in this study. In addition, the related Internet bulletin board has not been used actively, but has contributed to forming public opinion on this issue. Finally, the public demanded to be given acceptable reasons for the results of the design competition, and for the decision to make the grass plaza, which ignores the chosen design in the newspapers or on the Web page. However, their demand was rejected. The communication therefore became distorted and consequently did not become successful in bringing about its intended result.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1367-1372
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• 2014

As the awareness of the environmental crisis has recently increased around the world, numerous studies in the transport industry have been conducted to solve this problem through lightweight car bodies. The hot-stamping process has been presented as solution to achieve a light weight. Hot-stamping is a method that is used to obtain ultra-high strength steel (1,500 MPa or greater) by simultaneously forming and cooling boron steel in a press die after heating it to a temperature of $900^{\circ}C$ or above. This study involved a, fundamental examination of laser parameters to investigate the laser weldability of boron steel. As a result, the following optimum parameters for the shielding gas were found: Q = 20 l/min, ${\alpha}=40^{\circ}$, d = 20mm, and l = 0 mm. The hardness of butt weldment increasesed sharply as a result of martensite formation at the fusion zone.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.4
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• pp.37-49
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• 2014

This paper aims to interpret the transformation process of town plan of Gosan-up(高山), which was provincial administrative focus town in Josun dynasty, basing on morphological viewpoint. Morphological concepts, such as morphological frame, urban plan, kernel, colonization, route system, fixation line, fringe belt, plan unit & plan division, morphological period derived from the study of Conzen, M.R.G. and Caniggia, G. epidome district, break point, broken plot, urban fallow, privatization are adopted for the interpretation of urban form. Morphological period of Gosan can be divided in four ; formation of kernel & morphological structure, disintegration & redevelopment of the kernel, augmentative development of the kernel & formation of modern epidome district, outwards expanding of urbanized area, transition & reorganization of epidome district. Especially public leading projects such as construction of new regional connection road and public facilities such as myeon(township) office, agricultural cooperatives federation office, market, are main factors of morphological transformation of townplan. In the early stage, under the Japanese imperialism, construction of the new matrix route(Gosan-ro) through the kernel and followed planned routes gave way to disintegrating traditional areal plan unit and forming small block plan units in administrative facilities area. And linear plan units with commercial buildings were formed along the new matrix route and planned route adjacent to periodical market. In the latter stage, with development of public facilities, private sectors' large circulation institution and terminal outside the kernel with planned routes formed areal block based plan units with commercial and public buildings. And part of the spatial area with the linear plan unit were turned into urban fallow. With the transformation of town plan, new roads outside the kernel have substituted for traditional fixation line of waterway with road and topographical feature. Fringe belts were made successively along the new road and around the major intersections outside of existing urbanized area. Land use in fringe belts, constituting of outer locational tendency early on formation, was gradually replaced with commercial & business buildings.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.27-36
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• 2019

The demand for a low dispersion lens with a small refractive index and a high refractive index is increasing, and accordingly, there is an increasing need for a releasable protective film with high heat resistance and abrasion resistance. On the other hand, the optical industry has not yet established a clear standard for the manufacturing process and quality standards for mold-releasing protective films used in aspheric glass lens molding. Optical lens manufacturers treat this technology as proprietary information. In this study, an experiment was conducted regarding the optimization of ion etching, magnetron, and arc current at each source and filter part, and bias voltage in FCVA (filtered cathode vacuum arc)-based Ta-C thin film coatings. This study found that compared to iridium-rhenium alloy thin film sputtering products, the coating conditions were improved by approximately 50%, 20%, and 40% in terms of thickness, hardness, and adhesive strength of the film, respectively. The thin-film coating process proposed in this study is expected to contribute significantly to the development and utilization of glass lenses, which will help enhance the minimum mechanical properties and quality of the mold-release thin film layer required for glass mold surface forming technology.