• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.6
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• pp.45-58
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• 2005

The objective of this study is to the integrated evaluation of the present condition and satisfaction of visitors of rooftop greening area using quantitative and qualitative method. The thirteen green roofs were selected to investigate environmental variables as like building structure, soil, water, atmosphere and climate environment and questionnaire survey for investigate the satisfaction of visitors was conducted. The results of this study are as follows : remove of the hazardous inflow of species, install rain water recycling facility, install outdoor unit of air condition where not to affect plants in green roof, install safety facilities in the case of making resting place, plant variable vegetation and so on. The result of questionnaire survey are that visitors want to make more comfortable resting space. The more bigger the resting space and privacy, the more satisfaction of visitor became high. In conclusion, green roofs implementation should be considered reduction of temperature and delay of runoff, insulation effect and ecological restoration as well as rooftop greening is focused on the development of resting space nowadays.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.10
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• pp.467-473
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• 2014

Since the operating conditions of HVAC systems are different from those for which they are designed, on-going commissioning is required to optimize the energy consumed and the environment in the building. This study presents a methodology to analyze operational data and its applications. A predicted operation model is to be produced through a statistical data analysis using multiple regressions in SPSS. In this model, the dependent variable is the pre-cooling time, and the independent variables include the power output of the supply air inverter during pre-cooling, the supply air set temperature during pre-cooling, the indoor temperature-indoor set temperature just before pre-cooling, supply heat capacity, and the lowest outdoor air temperature during non-cooling/non-heating hours. The correlation coefficient R2 of the multiple regression model between the pre-cooling hour and the internal/external factors is of 0.612, and this could be used to provide information related to energy conservation and operating guidance.

• Land and Housing Review
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• v.10 no.3
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• pp.77-87
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• 2019

In Korea, the modular construction method was applied to the construction of facilities such as military barracks and school dormitories, beginning with the pilot project of Seoul New Elementary School in 2003. In 2017, public modular houses were supplied to Busan(Yongho-dong) and Seoul(Gayang-dong), and modular housing is expected to continue to be supplied in the future. However, there is no clear construction standard for the modular housing construction yet, and there are few cases where the infill modular system is applied. Therefore, this study established the work breakdown structure and proposed a standard process focusing on the infill modular system applied to the construction of Dujeong-dong modular house in Cheonan. Level 1 of the work breakdown structure by construction stage of Infill modular was defined as modular manufacturing, assembly, and finishing process. Level 2 was defined as preparation, modular production, modular infill, modular fixing, floor plastering, building finishing, and other site finishing. Level 3 is defined as 57 detailed unit work of infill modular construction. The standard process of infill modular is proposed for the assembly stage that is commonly applicable to infill modular housing construction. The results of this study can be used for the process plan, transportation plan, lifting plan of modular housing construction.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.27-32
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• 2008

The present study has been conducted economic analysis of heat storage type ground source heat pump system(HSGSHP) and normal ground source heat pump (GSHP) which are installed at the same building in the shared an apartment house. Cost items, such as initial cost, annual energy cost and maintenance cost of each system are considered to analyze life cycle cost (LCC) and simple payback period (SPP) with initial cost different are compared. The initial cost is a rule to the Government basic unit cost of production. LCC applied present value method is used to assess economical profit of both of them. Variables used to LCC analysis are prices escalation rate and interest rate mean values of during latest 10 years. The LCC result shows that HSGSHP (1,050,910,000won) is more profitable than GSHP by 68.9% initial cost. And SPP appeared 3.0 year overcome the different initial cost by different annual energy cost.

• Current Optics and Photonics
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• v.7 no.3
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• pp.254-262
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• 2023

Novel thermo-optically focus-switchable Fresnel zone plates based on phase-change metafilms are designed and analyzed at a visible wavelength (660 nm). By virtue of the large thermo-optic response of vanadium dioxide (VO₂) thin film, a phase-change material, four different plasmonic phase-change absorbers are numerically designed as actively tunable Gires-Tournois Al-VO₂ metafilms in two and three dimensions. The designed phase-change metafilm unit cells are used as the building blocks of actively focus-switchable Fresnel zone plates with strong focus switching contrast (40%, 83%) and high numerical apertures (1.52, 1.70). The Fresnel zone plates designed in two and three dimensions work as cylindrical and spherical lenses in reflection type, respectively. The coupling between the thermo-optic effect of VO₂ and localized plasmonic resonances in the Al nanostructures offer a large degree of freedom in design and high-contrast focus-switching performance based on largely tunable absorption resonances. The proposed method may have great potential in photothermal and electrothermal active optical devices for nonlinear optics, microscopy, 3D scanning, optical trapping, and holographic displays over a wide spectral range including the visible and infrared regimes.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.71-78
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• 2024

In indoor environments, since global positioning system (GPS) signals can be blocked by obstacles, such as building structure. the performance of GPS-based positioning methods can be degraded because of the loss of GPS signals. To solve this problem, various localization schemes using inertial measurement unit (IMU) sensors, such as gyroscope, accelerometer, and magnetometer, have been proposed to enhance the positioning accuracy in indoor environments. IMU-based positioning methods can estimate the location of the user by calculating the velocity and heading angle of the user without the help of GPS. However, low-cost MEMS IMUs may lead to drift error and large bias. In addition, positioning errors in IMU-based positioning approaches can be caused by the irrelevant motion of the pedestrian. In this study, we propose an enhanced indoor positioning method that provides more reliable localization results by using the camera, light detection and right (LiDAR), and ARKit framework on the iPhone. Through reliable positioning results and augmented reality (AR) experiences, our indoor positioning system can provide indoor space guidance services.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.38-53
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• 2022

In this article, I have summarized and reviewed the concepts and terms surrounding the stamped construction technique, focusing on earthen walls in the Three Kingdoms period. This is because confusion is caused by defining the nature of the earthen walls by using various concepts and terms for each researcher regarding the substance and construction method of the earthen walls. The stamped earth method is a representative ancient civil engineering or construction technique in which a frame is made of plates to form a fortress wall, a fence, and the base of a building, and then soil or sand is poured into it layer by layer and then stamped with a bat to make it solid. Therefore, in order to prove that the earthen wall was built by the stamped earth method, evidence such as a narrow plate, a column for fixing it, long horizontal and vertical wood pieces to support the narrow plate, and traces of pounding the soil must be detected. However, in Korea, there are very few cases where such evidence has been fully excavated, so it is necessary to agree on how strictly the standards for the stamped earth method will be applied. The terms related to the stamped technique mobilized for the construction of the earthen walls were explained with actual examples by dividing the terms related to the concept into terms related to the principle and unit of the stamped plate, and the specific stamped technology. In particular, in Pungnabtoseong Earthen wall, a variety of typical and diverse methods of building the ancient stamped earthen wall were identified so that decisive data could be secured to understand the principles and techniques of the stamped earthen wall. In the future, a more general understanding of the stamped technique will be possible only when more evidence related to it is found in relics other than Pungnabtoseong Earthen wall.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.5
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• pp.431-437
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• 2006

In this paper vector code correlation(VCC) method and an algorithm to promote the image-processing performance in building an effective measurement system using cameras are described far automatically berthing and controlling the ship equipped with side-thrusters. In order to realize automatic ship berthing, it is indispensable that the berthing assistant system on the ship should continuously trace a target in the berth to measure the distance to the target and the ship attitude, such that we can make the ship move to the specified location. The considered system is made up of 4 apparatuses compounded from a CCD camera, a camera direction controller, a popular PC with a built-in image processing board and a signal conversion unit connected to parallel port of the PC. The object of this paper is to reduce the image-processing time so that the berthing system is able to ensure the safety schedule against risks during approaching to the berth. It could be achieved by composing the vector code image to utilize the gradient of an approximated plane found with the brightness of pixels forming a certain region in an image and verifying the effectiveness on a commonly used PC. From experimental results, it is clear that the proposed method can be applied to the measurement system for automatic ship berthing and has the image-processing time of fourfold as compared with the typical template matching method.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.153-161
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• 2011

As the problem of GOSST building belongs to NP compete domain, heuristics for the problem ask for immense amount execution time and computations in large scale inputs. In this paper, we propose an efficient mechanism for GOSST construction using space locality PTAS. For 40,000 input nodes with maximum weight 100, the proposed space locality PTAS GOSST with 16 unit areas can reduce about 4.00% of connection cost and 89.26% of execution time less than weighted minimum spanning tree method. Though the proposed method increases 0.03% of connection cost more, but cuts down 96.39% of execution time less than approximate GOSST method (SGOSST) without PTAS. Therefore the proposed space locality PTAS GOSST mechanism can work moderately well to many useful applications where a greate number of weighted inputs should be connected in short time with approximate minimum connection cost.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.1
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• pp.1-15
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• 2012

Marine scientific monitoring, including monitoring of oil pollution, marine ecosystems, and the marine environment in general, has been being carried out continuously in order to assess the impact of oil pollution since the Hebei Spirit oil spill in December 2007. GIS thematic maps containing visual and summarized information are very useful for conducting exploratory analyses on the spatio-temporal variability of the marine environment and marine ecosystems due to oil pollution. Defining map types and building a legend in accordance with data characteristics are essential elements for mapping. In the present study, map types were defined according to the data attributes and GIS data types for each data item and classification of data intervals for the legend was defined by using two data distribution types through a histogram analysis. The data interval method was defined as follows: If the histogram of data has a uniform distribution, an equal interval method is applied; in the case of a normal distribution, a standard deviation method is applied. In addition, thematic map templates were made for each map type through the definition of marginal elements. Through the establishment of systematic mapping methods and procedures in this study, it was possible to effectively make standardized thematic maps for various kinds of marine scientific data.