• Journal of Korea Spatial Information System Society
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• v.9 no.3
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• pp.17-24
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• 2007

The noise problem is one of the major problems associated with large cities and is considered important factor not only in maintenance but also in development of cities. Accordingly, the noise map is being increasingly used in city planning and design. However, the existing two-dimensional noise maps only show regional, planar distribution of noise. This study presented a method to build a data model for analyzing and visualizing noise levels at fine scale considering the vertical distribution of noise in a building. By expanding the 2D topology concept used in conventional GIS to 3D, it suggested a 3D GIS data model that makes 3D spatial queries, analyses and visualization possible and applied the proposed approach to building a 3D noise information system. By building and testing the system, the study showed different functionalities including 3D spatial queries and 3D visualization of noise levels varying temporally or according as the height of sound-proof walls. In each case, the population exposed to noise was quantitatively computed to illustrate the potential in the areas of city planning and design.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.278-285
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• 1991

This study was conducted to manufacture a good qualified organic fertilizer with cow dung through rapid composting process, and the proposal guideline of the degree of maturity could be estimated with the measurement of final product. It included total nitrogen content of above 2% on an oven-dry material basis, C/N ratio of below 20, CEC of more than about 60 me/100g, ratio of carbon in reducing sugar to the total carbon of below 35%, and temperature in pile of above $60^{\circ}C$. The total nitrogen content, the C/N ratio, and the Paper Chromatographic method couldn't be the guideline to evalute the maturity of cow dung compost. CEC was increased in increased fermentation and it was high in the high fermented temperature plots which were cow dung+ shredded bark in 1988, cow+dung+wood chips in 1989, and cow dung+rice straws in 1990. The ratio of carbon in reducing sugar to total carbon in 1990 was lower in cow dung+saw dust than cow dung+rice straws that was the highest temperature in pile. Generally cow dung was mixed well with saw dust and thus the total carbon of the product was high. The measurement of the temperature in pile seems to be a indirect guideline of maturity.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.884-889
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• 2015

Appropriate evaluation of thermal insulation property of structural member and valid control of cooling/heating energy are important for improving building's energy efficiency. The typical heating system of house in Korea is the floor heating one. The radiation heating system is not only appropriate to climate and geographic conditions of Korea, but also advantageous to provide emotional comfort by the warm feeling of floor. Based on living conditions in Korea, scaled models of the wooden house and concrete house were designed. The ceiling was made of styrofoam insulation and the four sided walls and bottom were made of plywood and concrete, respectively. The floor was heated by heating film. Indoor vertical temperature distributions by floor heating system were measured by thermocouple, and surface temperatures on walls were measured by infrared thermography. Also, thermal insulation property of wooden wall was evaluated to build database for improving energy efficiency of wooden building. It is expected that collected data during tests of various types of floor and wall composition could be referenced for evaluating thermal environment of actual conditions of houses.

• Journal of the Korea Institute of Building Construction
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• v.16 no.5
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• pp.429-436
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• 2016

Because of the shortage of construction workers due to The rising labor costs and an aging labor force, construction time has been extended. As a solution, The construction time of high-rise buildings can be reduced by adopting precast concrete construction methods. Most relevant studies have focused on the development and structural analysis of such methods and not on their construction management. Therefore, this study focused on the construction management of the hollow precast concrete column (HPC) method. The objective of this study was to evaluate the performance of HPC formulations through the analytic hierarchy process and benefit-cost analysis. After a gap analysis of the available literature and expert interviews, the evaluation criteria were selected. A questionnaire survey was administered to professionals with ample experience in precast concrete construction for the pair-wise evaluation of the benefit and costs of the HPC method. The results show that the benefits of the HPC method outweighed its costs. Therefore, the HPC method is a suitable substitute for the half-slab method.

• Journal of the Korea Institute of Building Construction
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• v.20 no.2
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• pp.147-153
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• 2020

It is important to estimate the optimal construction cost at the early stage of the project. In this regard, conceptual cost estimate is an important factor for estimate optimal construction cost. However, domestic conceptual cost estimate are only used as cost per unit area according to the building type, and it's accuracy is not high. Hence, the purpose of this study is to calculate the approximate quantity and cost for reinforcing bars, concrete, and formwork by presenting a regression formula based on the total floor area of the common work items in the frame work. In order to verify the accuracy and validity of the regression formula presented in this study, a comparative analysis was performed by applying the regression formula and the traditional approximate quantity take-off method to real cases. As a result, the estimated error rate of the traditional method was -102~+55%, and exceeded the estimated conceptual cost estimate accuracy range of -50~+100% suggested by AACE(American Association of Cost Engineering). On the other hand, the error rate of the regression formula method presented in this study was -6.4~+11.62%. This can be used not only for conceptual cost estimate range of accuracy, but also for detailed estimates. However, it is necessary to analyze the factors that affect the unit price as well as quantity in order to calculate the appropriate cost.

• Korean Journal of Construction Engineering and Management
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• v.12 no.3
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• pp.42-52
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• 2011

As environmental issues are rising recently efforts to reduce environmental stress are emerging in all industry segments. Especially environmental impact of buildings occupy a critical portion, so each country is operating green building rating system for life cycle of buildings. Accordingly green building rating system for every facility is operating in Korea. And acquisition of grade I for building energy efficiency is mandatory for every new public buildings since 2010. To design green building efficiently and systematically eco-friendly elements should be considered and checked from the schematic design phase. But in many cases eco-friendly elements are checked at the end of constructed design phase. So applying eco-friendly elements at the value engineering process, which is performing through schematic and constructed design phase, could make a efficient and systematic green building design. Value engineering process is divided into pre workshop, workshop and post workshop stages. And subject selection in pre workshop stage is the step that finds out the subjects which has the great possibility to be improved to perform efficient value engineering workshop. So this study present the Green VE subject selection model to select the most considerable eco-friendly subjects in projects.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.221-228
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• 1994

Respitation and growth rates of leaves, branches, stems and roots of 2 to 11-yr-old red pine trees(Pinus densiflora) were examined and applied to Thornley's growth equation, $$R=(\frac{1-Yg}{Yg})\frac{dW}{dt}+mW$$. The conversion efficiency of substrates(Yg), maintenance respiration coefficients(m), relative growth rates(${\mu}$) were estimated. The efficiency of conversion of substrates (Yg) was 0.3637g/g dw/yr and the maintenance respiration coefficient(m0 was 0.094g/g dw/yr. The relative growth rate(${\mu}$) was remarkably reduced with age from 0.90(2-year-old) to 0.33:11 year-old). The Ratio of gross respiration(R) per gross photosynthesis(Pg), R/Pg showed the range of 0.6~0.7 and annually 64% of Pg was spent for constructive respiration. The 3.4% of dry weight of whole tree was spent for maintenance respiration.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.10-20
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• 2014

The purpose of this study is to define criteria for landscape restoration of palace gardens. The case study on Gyeongbokgung and Changdeokgung was used not only to evaluate effectiveness of the criteria, but also to propose solutions to issues of current restoration process of both palace gardens. Following three pairs of different concepts were chosen as criteria to determine on the original form: Diachrony vs. Synchrony, Originality vs. Contemporary Characteristics, and Invariance vs. Deformability. Gyeongbokgung has been restored based on its contemporary characteristics of Year 1888 and the main focus is on its architectural features rather than both architecture and landscape. However, in-depth complementary work on landscape restoration is necessary to restore its originality in Year 1395 such as analyzing photos of Gyeongbokgung taken in modern era. In case of Changdeokgung, we analyzed separately by region or landmark such as Jondeok-Pavilion(尊德亭), Yeonkyung-Hall(演慶堂), and Okryu-Stream(玉流川). Original form of Jondeok-Pavilion Area was changed in 1884. Since diachronic invariance that lasted for 240 years is more important criterion than its contemporary characteristics, it should be restored as how it was painted in Donggwoldo(東闕圖). In Yeonkyung-Hall Area, both original characteristics at the time of Hyomyung Crown Prince and contemporary characteristics of Emperor Kojong Era appear. Therefore, different solution is required for such area to be restored appropriately. Starting from era of King Injo(1636), diachrony and invariance of Okryu-Stream Area were continued throughout the era of King Sukjong and King Jeongjo(1800). It is more than 250 years before Okryu-Stream Area was altered under the rule of Emperor Kojong in 1884. In fact, alterations made to Okryu-Stream Area after 1884 doesn't hold much significance. Therefore, water landscape of Okryu-Stream Area, which was altered in the era of Emperor Kojong, needs to be restored based on Donggwoldo.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.13-20
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• 2017

Unreinforced masonry buildings are vulnerable to lateral forces, such as earthquakes, owing to the nature of the building materials, yet numerous masonry buildings remain in South Korea. Since the majority of the existing masonry buildings were constructed more than 20 years ago, it is necessary to develop economical reinforcement methods for disaster reduction. In this study, external reinforcement of masonry walls using adhesive stiffeners was proposed as a reinforcement method for such age-old masonry buildings. Six specimens were fabricated with different aspect ratios (L/H = 1.0, 1.3, and 2.0) and used in static load tests to verify the reinforcement effect. The experimental results showed that the masonry walls before and after reinforcement were ruptured by rigid body rotation and slip. In addition, the maximum strength, maximum displacement, and dissipated energy of the walls were shown to increase after applying the adhesive stiffeners, thereby verifying the excellent reinforcement effect. Furthermore, an adhesive stiffener design for unreinforced masonry walls was proposed based on the increased shear strength achieved by using conventional glass fibers. The proposed design can be used as a basis for the application of adhesive stiffeners for unreinforced masonry walls.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.175-181
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• 2009

Intelligent Transportation Systems(ITS) enables road users to enhance efficiency of their trips in a variety of traffic conditions. As a significant part of ITS, information communication technology among vehicles and between vehicles and infrastructure has been being developed to upgrade current traffic data collection technology through location-based traffic surveillance systems. A wider and detailed range of traffic data can be acquired with ease by the technology. However, its performance level falls with environmental impediments such as large vehicles, buildings, harsh weather, which often bring about wireless communication failure. For imputation of vehicle trajectory data discontinued by the failure, several potential existing methods were reviewed and a new method to complement them was devised. AIMSUN API(Application Programming Interface) software was utilized to simulate vehicle trajectories data and missing vehicle trajectories data was randomly generated for the verification of the method. The method was proven to yield more accurate and reliable traffic data than the existing ones.