• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.94-106
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• 2022

In order to increase timber self-sufficiency, Korea's 6th Basic Forest Plan aims to increase the density of forest roads to 12.8 m ha^-1 by 2037. However, due to rapid re-forestation, current management infrastructure is insufficient, with just 4.8 m ha^-1 of forest roads in 2017. This is partly due to time and cost limitations on the process of forest road feasibility evaluation, which considers factors such as topography and forest conditions. To solve this problem, we propose an eco-friendly and efficient forest road network planning method using a geographic information system (GIS), which can evaluate a potential road site remotely based on spatial information. To facilitate such planning, this study identifies forest road construction priorities that can be evaluated using spatial information, such as topography, forest type and forest disasters. A method of predicting the optimal route to connect a forest road with existing roads is also derived. Overlapping analysis was performed using GIS-MCE (which combines GIS with multi-criteria evaluation), targeting the areas of Cheongsong-gun and Buk-gu, Pohang-si, which have a low forest-road density. Each factor affecting the suitability of a proposed new forest road site was assigned a cost, creating a cost surface that facilitates prioritization for each forest type. The forest path's optimal route was then derived using least-cost path analysis. The results of this process were 30 forestry site recommendations in Cheongsong-gun and one in Buk-gu, Pohang-si; this would increase forest road density for the managed forest sites in Cheongsong-gun from 1.58 m ha^-1 to 2.55 m ha^-1. This evaluation method can contribute to the policy of increasing timber self-sufficiency by providing clear guidelines for selecting forest road construction sites and predicting optimal connections to the existing road network.

• Journal of Korea Water Resources Association
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• v.55 no.8
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• pp.603-611
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• 2022

In urban areas, the impermeable area continues to increase due to urbanization, which interferes with the surface penetrating and infiltrating of rainwater, causing most rainwater runoff to the surface, deepening the distortion of water circulation. Distortion of water circulation affects not only flood disasters caused by rainfall and runoff, but also various aspects such as dry stream phenomenon, deterioration of water quality, and destruction of ecosystem balance, and the Ministry of Environment strongly recommends the use of Low Impact development (LID) techniques. In order to apply the LID technique, it is necessary to set a rainwater management target to handle the increase in outflow after the development of the target site, and the current standard sets the rainwater management target using the 10-year daily rainfall. In this study, the difference from the current standards was analyzed through statistical analysis and classification of independent rainfall ideas using inter-event time definition (IETD) in setting the target amount of rainwater management to improve water circulation. Using 30-year rainfall data from 1991 to 2020, methods such as autocorrelation coefficient (AC) analysis, variation coefficient (VC) analysis, and annual average number of rainfall event (NRE) analysis were applied, and IETD was selected according to the target rainfall period. The more samples the population had, the more IETD tended to increase. In addition, by analyzing the duration and time distribution of independent rainfall according to the IETD, a plan was proposed to calculate the standard design rainfall according to the rainwater management target amount. Therefore, it is expected that it will be possible to set an improved rainwater management target amount if sufficient samples of independent rainfall ideas are used through the selection of IETD as in this study.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.239-247
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• 2023

The FIDIC Red Book is an international standard contract condition in which the Employer designs and the Contractor performs the construction. The Engineer of FIDIC Red Book shall agree or determine any matter or Claim in accordance with Sub-Clause 3.7 neutrally, not as an agent of the Employer. This study aimed to derive Key Risk Sub-Clauses out of 49 Sub-Clauses that the Engineer of FIDIC Red Book recently revised in 18 years shall agree or determine according to Sub-Clause 3.7 using the Delphi method. A panel of 35 experts with more than 10 years of experience and expertise in international construction contracts was formed, and through total three Delphi surveys, errors and biases were prevented in the judgment process to improve reliability. As for the research method, 49 Sub-Clauses that engineers shall agree on or determine according to Sub-Clause 3.7 of the FIDIC Red Book were investigated through the analysis of contract conditions. In order to evaluate the probability and impact of contractual risk for each 49 Sub-Clause, the Delphi survey conducted repeatedly a closed-type survey three times on a Likert 10-point scale. The results of the first Delphi survey were delivered during the second survey, and the results of the second survey were delivered to the third survey, which was re-evaluated in the direction of increasing the consensus of experts' opinions. The reliability of the Delphi 3rd survey results was verified with the COV value of the coefficient of variation. The PI Risk Matrix was applied to the average value of risk probability and impact of each of the 49 Sub-Clauses and finally, 9 Key Risk Sub-Clauses that fell within the extreme risk range were derived.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.4
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• pp.1-10
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• 2019

The purpose of this study is to examine the design ＆ construction methods of the traditional landscape space of the past and the repair and maintenance of cultural heritages to maintain it today. To this end, the method of narrative description, process extraction and construction related to traditional landscaping were compared to each other based on the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages'. The results are as follows; First, to analyze at the description methods of the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages' and related processes in the field of traditional landscaping. 『Imwongyeongjeji』 「Seomyongji」 was an encyclopedia of the overall construction method of the living space, describing the location, effect, and advantages and disadvantages of each component and presenting quantitative figures to institutionalize the construction of traditional landscaping spaces. 'Standard Specification for Repairing Cultural Heritages' presented the entire process of repairing cultural heritages, and it is becoming a kind of guide for reference at the site. Among them, foundation construction, roof construction, landscape construction, and fence construction were drawn as items that could be applied to traditional landscaping areas. Second, the traditional landscape space construction method was divided into the processes of foundation construction, roof construction, landscaping construction, and fence construction. Foundation construction is a way of repeating the process of land-tramping. During the construction of the roof, the tile-roofed building was built on top of the rafters and roofed with tiles. And thatched roof was made to a number of rice straws bundles to cover the roof one after the other. Instead of tiles, the stone roof was made of thin and wide stones, and the wooden boards were used for the single roof and the bark roof were constructed with many layers of dried corrugations. Landscape construction mainly consists of the Paving technique through tramping rubble and the construction of terraced flower by planting stone, plants, and shrubs on the top. According to the building materials, the wall construction was derived from the earth-stacked earthen wall, stone walls using stone and clay, marble walls made of tile patterns, and the construction of a board wall using a wood board as a wall. Third, comparing the construction methods of the 『Imwongyeongjeji』 「Seomyongji」 and 'Standard Specification for Repairing Cultural Heritages', 『Imwongyeongjeji』 「Seomyongji」 focuses on standardizing the construction methods to create a new traditional space. There is a difference in the setting of the scope of the 『Imwongyeongjeji』 「Seomyongji」 and the construction because 'Standard Specification for Repairing Cultural Heritages' provides the overall construction procedure considering the diversity of the cultural heritages. In addition, the traditional landscape space used to be a residential space in the past, but today, the maintenance process of the already established facilities as designated cultural heritages has been carried out, and construction methods have been added to create viewing conditions. In terms of the succession of traditional knowledge, some similar methods were found in the repair of cultural assets today, and some cases were also confirmed in the reconstruction of traditional technologies such as application of some materials or mix, separation of added facilities and introduction of efficient construction methods.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.1
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• pp.98-106
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• 2009

This work proposes a 1280-RGB $\times$ 800-Dot 70.78mW 0.l3um CMOS LCD driver IC (LDI) for high-performance 16M-color low temperature poly silicon (LTPS) thin film transistor liquid crystal display (TFT-LCD) systems such as ultra mobile PC (UMPC) and mobile applications simultaneously requiring high resolution, low power, and small size at high speed. The proposed LDI optimizes power consumption and chip area at high resolution based on a resistor-string based architecture. The single column driver employing a 1:12 MUX architecture drives 12 channels simultaneously to minimize chip area. The implemented class-AB amplifier achieves a rail-to-rail operation with high gain and low power while minimizing the effect of offset and output deviations for high definition. The supply- and temperature-insensitive current reference is implemented on chip with a small number of MOS transistors. A slew enhancement technique applicable to next-generation source drivers, not implemented on this prototype chip, is proposed to reduce power consumption further. The prototype LDI implemented in a 0.13um CMOS technology demonstrates a measured settling time of source driver amplifiers within 1.016us and 1.072us during high-to-low and low-to-high transitions, respectively. The output voltage of source drivers shows a maximum deviation of 11mV. The LDI with an active die area of $12,203um{\times}1500um$ consumes 70.78mW at 1.5V/5.5V.

• Journal of the Korean Electrochemical Society
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• v.23 no.2
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• pp.39-46
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• 2020

Composite electrodes for rechargeable batteries generally consist of active material, electric conductor, and polymeric binder. And their composition and distribution within the composite electrode determine the electrochemical activity in the electrochemical systems. However, it is not easy to quantify the physical properties of composite electrodes themselves using conventional experimental analysis tools. So, 3D structural modeling and simulation can be an efficient design tool by looking into the contact areas between particles and electric conductivity within the composite electrode. In this study, while maintaining the composition (LiCoO₂ : Super P Li^® : Polyvinylidene Fluoride (PVdF) = 93 : 3 : 4 by wt%) and loading level (13 mg cm^-2) of the composite electrode, the effects of LiCoO₂ size (10 ㎛ and 20 ㎛) and electrode density (2.8 g cm^-3, 3.0 g cm^-3, 3.2 g cm^-3, 3.5 g cm^-3, 4.0 g cm^-3) on the physical properties are investigated using a GeoDict software. With this tool, the composite electrode can be efficiently designed to optimize the contact area and electric conductivity.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.717-729
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• 2005

Peak cooling load of large buildings is generally greater than their peak heating load. Internal and solar heat gains are used fur selection of adquate equipment in large building in cold winter climate like Canada and even Korea. The cost of geothermal heat exchanger to meet the cooling loads can increase the initial cost of ground source heat pump system to the extend less costly conventional system often chosen. Thermal ice storage system has been used for many years in Korea to reduce chiller capacity and shift Peak electrical time and demand. A distribution system designed to take advantage of heat extracted from the ice, and use of geothermal loop (geothermal heat exchanger) to heat as an alternate heat source and sink is well known to provide many benifits. The use of thermal energy storage (TES) reduces the heat pump capacity and peak cooling load needed in large building by as much as 40 to $60\%$ with less mechanical equipment and less space for mechanical room. Additionally TES can reduce the size and cost of the geothermal loop by 1/3 to 1/4 compared to ground coupled heat pump system that is designed to meet the peak heating and cooling load and also can eliminate difficuties of geothermal loop installation such as space requirements and thermal conditions of soil and rock at the urban area.

• Journal of Korean Home Economics Education Association
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• v.21 no.3
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• pp.45-64
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• 2009

The purpose of this study was to develope issue-centered teaching learning process plan for environment-friendly housing education and to apply it to the housing section of Technology Home Economics in a middle school. PRO-CON cooperative group model was used for the teaching learning process plans of 2-session lessons according to the ADDIE model. In the development stage, 7 activity materials and 20 teaching learning materials (4 reading texts, 12 pictures and photos, & 5 moving pictures) were developed for 2-session lessons. The plans applied to the 7 classes, 222 students, in the third grade of the G middle school in Gyeonggi-do during July 10th-17th, 2008. The results showed that the final pro-con was influenced by the rationals of juries' pro-con of each team and the representative's discussion besides one's environmental perspective. The intention to implement environment-friendly housing activities was significantly increased between before and after the lessons. The contents, methods, goals, and process of the 2-session lessons were evaluated over medium to somewhat higher levels. Those evaluations except methods and general satisfaction with the lessons were differed by sex, students' and their families' interests in environments but not by the type of housing. These results might support that pro-con cooperative group model of controversial issues on parking lot would be appropriate to environment-friendly housing lessons and could apply to broad issues on housing and various schools in other areas.

• Archives of design research
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• v.17 no.2
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• pp.95-104
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• 2004

Creativity is a important keyword for users as well as for main design organization who needs it. But little attention has been given to the aspect of user's creativity, also there has been a few attempt to apply it into design development until now. Nowadays in design areas, user's experiences and actions are changing the passive states receiving meanings into the active states creating meanings voluntarily. It is resonable to suppose that creative stage is important for users and they have the possibility of new ideas of uses and creating new productions. User's experiences of objects includes that of being formed or supported previously and that of voluntary interpretations acquired for himself, which it may be the possibilities predicted in design process or unknown user's action areas. It is likely that creative use process by themselves are the actions applied and deviated from usability and function by main design organization, also creative productions are arranged and made by users. These have a scope of examination and research in probability that is occurs frequently in user. In this research, approaching with a term, 'User gestures', User gestures are the characteristic action areas based on user's voluntary behaviors, where are revealed a unessential and non-operational function as a action itself and various transformation and creation of products as a outcome of action. This fact proves clearly that user gestures have a worth of alive spectrum to observe aspects of user culture and could be a attractive approach to seek easily new design concept for designer and developer. A further direction of this study will be following areas, Ethnography methods research of user gestures, Cultural research to phenomenon of user design and UGSBD(User gesture scenario based design) research. And it seems probable that they are applied in design development as follows, User initiative customization products, User participatory recycling products and creativity-experience design.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.203-218
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• 2010

The site categorization and corresponding site amplification factors in the current Korean seismic design guideline are based on provisions for the western United States (US), although the site effects resulting in the amplification of earthquake ground motions are directly dependent on the regional and local site characteristic conditions. In these seismic codes, two amplification factors called site coefficients, $F_a$ and $F_v$, for the short-period band and midperiod band, respectively, are listed according to a criterion, mean shear wave velocity ($V_S$) to a depth of 30 m, into five classes composed of A to E. To suggest a site classification system reflecting Korean site conditions, in this study, systematic site characterization was carried out at four regional areas, Gyeongju, Hongsung, Haemi and Sacheon, to obtain the $V_S$ profiles from surface to bedrock in field and the non-linear soil properties in laboratory. The soil deposits in Korea, which were shallower and stiffer than those in the western US, were examined, and thus the site period in Korea was distributed in the low and narrow band comparing with those in western US. Based on the geotechnical characteristic properties obtained in the field and laboratory, various site-specific seismic response analyses were conducted for total 75 sites by adopting both equivalent-linear and non-linear methods. The analysis results showed that the site coefficients specified in the current Korean provision underestimate the ground motion in the short-period range and overestimate in the mid-period range. These differences can be explained by the differences in the local site characteristics including the depth to bedrock between Korea and western US. Based on the analysis results in this study and the prior research results for the Korean peninsula, new site classification system was developed by introducing the site period as representative criterion and the mean $V_S$ to a depth of shallower than 30 m as additional criterion, to reliably determine the ground motions and the corresponding design spectra taking into account the regional site characteristics in Korea.