• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.932-940
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• 1999

Object-oriented programming is often touted as promoting software reuse. However it is recognized that objected-oriented software often need to be restructured before it can be reused. refactoring is the process that changes the software structure to make it more reusable, easier to maintain and easire to be enhanced wit new functionalities. This paper desirbes experience gained and lessons learned from restructuring OODesigner, a Computer Aided Software Engineering(CASE) tool that supports Objects Modeling Technique(OMT). this tool supports a wide range of features such as constructing object modeler of OMT, managing information repository, documenting class resources, automatical generating C++ and java code, reverse engineering of C++ and Java cod, searching and reusing classes in the corresponding repository and collecting metrics data. although the version 1.x was developed using OMT(i.e the tool has been designed using OMT) and C++, we recognized that the potential maintenance problem originated from the ill-designed class architecture. Thus this version was totally restructured, resulting in a new version that is easier to maintain than the old version. In this paper, we briefly describe its restructuring process, emphasizing the fact that the Refactoring of the tool is conducted using the tool itself. Then we discuss lessons learned from these processes and we exhibit some comparative measurements of the developed version.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.180-187
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• 2013

The dinger in solar generation is the amount of sunlight which the solar cells absorb. Various types of solar trackers, which rotate themselves in order to make the solar cells face the sun as much as possible, have been developed, and especially the method of tracking with two axes has greatly contributed in increasing the generation amount at work sites. Among theses 2-axis solar trackers, the inclination-dependent 2-axis solar tracker are widely utilized for its advantages of requiring less initial investment and easy maintenance due to a solid structure. However, the drawback is that the generation efficiency is relatively low because of the structural restriction that limits the rotation angle, thus making it less efficient when tracking the sun. This paper proposes a method to increase the generation efficiency of the inclination-dependent 2-axis solar tracker. It also contains the derived equations needed for precise controlling along with a method to keep tracking with the other axis even when one has reached its angle limit. To confirm that the proposed method increases the amount of incidence onto the solar cells, formulas needed for operation on the proposed method and tracking the exact position of the sun are derived, and applying this to the quarterly data of Korea Astronomy and Space Science Institute it shows maximum over 11.1% more incidence compared to existing methods.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.582-591
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• 2019

This study was conducted to develop low-cost, simplified slope stabilization methods for the continuous utilization of skid trails, and to analyze the effect of the developed methods. Slope stabilization methods were created on the fill slopes of skid trails in the Forest Technology and Management Research Center of the National Institute of Forest Science.We measured the settlement and bearing capacity of skid trail surfaces, and the displacement of slope stabilization methods with respect to the number of passes (maximum 100 passes) by a logging truck weighing 17 tons. The constancy of slope stabilization methods was determined by measuring displacement of the stabilization structure with respect to the number of logging truck passes. Results showed that the bearing capacity in most cases was insufficient, but that the settlement of skid trails was less than 150 mm, which was considered reasonable. In addition, the stability of root staking wallswas somewhat low, but the average displacements of all slope stabilization methods were generally around 20 mm or less, indicating no issues regarding structural stability. By applying the simplified stabilization methods to skid trail maintenance following timber harvesting, efficient timber harvesting can be achieved. Additionally, these methods can be utilized as permanent forest management infrastructures and complement insufficient forest road facilities.

• Journal of the Korea Concrete Institute
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• v.29 no.1
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• pp.3-10
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• 2017

In case of Korea highways, about 60% of highways are paved by concrete and more than 50% of them were repaired due to reduction in required performance such as damage in pave or joint and delamination of cover pavement. However, repairing old material in such structure generally costs a lot of money and induces difficulty in maintenance. Thus, enhanced material for ensuring economic efficiency should be developed. The present study designed concrete mixtures with 3 levels of replacement using OPC (0, 10, 20%) in calcium aluminate cement and to evaluate material performance for load pavement, experimental works for setting time, compressive strength and flexural strength were carried out on those materials. As a result, 20% replacement for OPC was determined as an optimized material in terms of required physical performance and its unit price. Moreover, to determine cost in load pavement economy analysis using a program (CA4PRS) was conducted with widely used paving materials. Result showed that application for 20% replacement for OPC was the most efficient in economical aspect, arising from 4.052 and 1.577 billion won for total construction and user cost, respectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.3 s.39
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• pp.171-190
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• 1990

It is the purpose of this study to address how to manage the urban vegitation using the concept of Urban Forestry which is relatively new to Korea. When we consider the Urban Forestry as a science, We should understand it interdisciplinary subject which includes Forestry, Horticulture, Urban Planning, Landscape Design, Landuse Planning, Business and Humanities. It may say that people and tree are the fundermental components of Urban Forestry. So there are two ways of Urban Forestry Applications-How people care for trees and How trees care for People-. For the application, this study places the focus on the monetary valuation, tree inventory system and traditional forestry application to urban forest management. Pubic Relation, Communication, Ordinances and Budget are also mentioned as a part of Urban Forestry Policy. Monetary valuation of trees and forests is very important for the proper cognition of their real value. So that, they may be equated and weighed against conflicting uses which would cause to be removed or severely mutilated. A tree inventory system which is the essential part of urban tree management can provide the pertinent information about the present condition of urban tree resource. It may aid in reducing the subjectivity of tree management decisions and stimulate them to be made rapidly and can help reduce potential municipal liability by identifying serious problems in time for corrective maintenance practices to be applied for the maximize community benefits and minimimize public nuisances or hazards. Managers can derive the information from the inventory and use it for the various management plan. When we see the structure of tree inventory system as one of the data base management system, Computer is the best equipment for the efficient management plan. Public relation and communication is also important factors to care the people for urban vegetation management. Volunteer management system is a good example for the public relation and communication. Those skills are need to develop for using the priceless, valuable human resources. Budget holds the key to the execution of Urban Forestry. Good inventory can provide for efficient budgeting stratiges through it's scientific analysis for the way of maximum benefits and minimum costs. Forest can be play a vital role for the aesthetic improvement and recreation in the city. This study suggests that the traditional sivicultural application not only improve the quality of scenic beauty and recreation but also the products of timber. So it is more needed to study for strong and scientific application to urban forest management.

• Resources Recycling
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• v.27 no.2
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• pp.24-31
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• 2018

In this study, waste ITO target is dissolved into hydrochloric acid to generate a complex indium-tin chloride solution. Nano sized ITO powder with an average particle size below 30 nm are generated from these raw material solutions by spray pyrolysis process. Also, in this study, thermodynamic equations for the formation of indium-tin oxide (ITO) are established. As the reaction temperature increased from $800^{\circ}C$ to $900^{\circ}C$, the proportion and size of the spherical droplet shape in which nano sized particles aggregated gradually decreased, and the surface structure gradually became densified. When the reaction temperature was $800^{\circ}C$, the average particle size of the generated powder was about 20 nm, and no significant sintering was observed. At a reaction temperature of $900^{\circ}C$, the split of the droplet was more severe than at $800^{\circ}C$, and the rate of maintenance of the initial atomized droplet shape decreased sharply. The average particle size of the powder formed was about 25 nm. The ITO particles were composed of single solid crystals, regardless of reaction temperature. XRD analysis showed that only the ITO phase was formed. Remarkably, the specific surface area decreased by about 30% as the reaction temperature increased from $800^{\circ}C$ to $900^{\circ}C$.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.57-63
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• 2010

The bearing wall apartments which occupy the majority of multi-residential apartment buildings built in Korea, are known for having limited architectural plan flexibility, posing challenges in terms of maintenance and remodeling. The economic losses and environmental issues resulting from the reconstruction of bearing wall apartments are now accumulating to the extent that they are becoming a national concern. Multi-residential apartment buildings, which are now the dominant form of residence in Korea, must accommodate diverse customer needs and changes in life style. A new concept of Rahmen structure with architectural flexibility is Green Frame. GF multi-residence housing is expected to reduce construction costs and shorten the construction schedule by overcoming the shortcomings of conventional bearing wall apartments. This goal is consistent with the national policies that target the reduction of resource and energy consumption. In addition, GF will be established as a core contributor to achieving a reduction in $CO_2$ emissions, which will enable the sustainable growth of domestic construction industry, and address the low-carbon green growth drive implemented by the government.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.188-201
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• 2017

Based on a total of 272 vegetation data collected by the ZM school phytosociological study method, the composition and structural characteristics of the forest vegetation in the Sogwang-ri forest genetic resource reservoir located in Uljin-gun, Gyeongsangbuk-do were compared using the table comparison method and the TWINSPAN method, And their ecological characteristics were analyzed. The types of forest vegetation were classified into 7 types, and it was divided into two major groups, 'Slope and Ridge type', which characterized by Quercus mongolica, Pinus densiflora for. erecta, Lespedeza bicolor etc. and 'valley and concave slope', which characterized by Cornus controversa, Fraxinus mandshurica, Morus bombycis, Hydrangea serrata for. acuminata etc. The hierarchy of the vegetation unit was 2 community groups, 4 communities, and 6 subcommunities. The structural characteristics such as the total percent cover, species importance value, species diversity of the constituent species per unit area($/100m^2$) of each type of forest vegetation were also identified. In order to understand the spatial distribution of forest vegetation, 1/5,000 large-scale physiognomic vegetation map was created by the uppermost dominant species. The composition and structural characteristics of Geumgang pine(P. densiflora for. erecta) forest, which is a core community of protected area by natural and anthropogenic influences, appear as a subtype of Quercus mongolica forest, which is a potential natural vegetation, Appropriate maintenance measures seemed urgently needed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.295-302
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• 2011

Ubiquitous is an information communication environment which peoples could connect on network without being conscious of the network and computer condition at anytime and anywhere. Presently, advanced technology, digital cities and eco-friendly cities using Ubiquitous technology are being focused through out the world. As recent information industry and communication technology have developed remarkably, studies on intelligent structures and structural maintenance methods by combining a general idea of connecting all objects on network by interpolating computers which is called Ubiquitous Computing, and USN(Ubiquitous Sensor Network) are being attempted. In this paper, a basic experiment on penetration of RF(Radio Frequency) sensor nodes using an experimental sample setting concrete and reinforcing bar as variables is studied to estimate the possibility of applying wireless sensor networks in structures. The spring of reinforcing bars, concrete thickness, intensity of radio frequency were set up as variables, transmitting and receiving distance were checked vertically and horizontally. Moreover, Spectrum Analyzer was used for checking the magnitude of the frequency used in order to measure the reduction of radio wave exactly. The radio wave reduction was numerically analyzed, and the influence of the wavelength was analysed as well. As a result, the penetration depth in concrete without reinforcing bars was 45cm, and in reinforced concretes which reinforcing bars placed at spacing of 5cm and 15cm, the penetration depth were 37cm and 45cm each. No influence on radio wave penetration depth were found when the spacing of reinforcing bars in the reinforced concrete structures becomes over 15cm.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.7
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• pp.449-455
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• 2016

Fog causes economic losses in transportation. It also results in health problems when it is combined with air pollutants. Considerable research efforts have focused on developing fog removal systems. However, most systems operate themselves after monitoring the fog. Additionally, continuous energy supply and maintenance are required to retain the fog-removal efficiency of the system. This study included the demonstration of a moss filter (a polyolefin mesh interlaced with moss) as a fog-removal method overcoming the limitations of the fog removal system. Three types of mosses with different surface structures were investigated to elucidate the relation between the moisture absorption rate and the structures. Among the different moss types, Hypopterygium japinicum showed the highest efficiency based on the smallest pore diameter and the largest total pore area. The visibilities with the moss filter and the polyolefin mesh were compared to perform the fog removal tests. The moss filter could provide a cost-effective and eco-friendly fog removal system with sustainability.