• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.10
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• pp.883-891
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• 2016

In this paper, we propose an asymmetric dipole antenna utilizing the metal case as a ground radiator for a pen-type wireless presenter which operates in the ISM frequency band(2.4~2.48 GHz). A normal mode helix mounted on the top end of the long metallic cylinder case which acts as the ground plane takes the form of the asymmetric dipole structure in the proposed antenna. The metallic cylinder case which performs as a radiating element increases the inherent narrow bandwidth and low gain of the helix. The effects of the hand contacts with the metal case on the antenna performance are measured and analyzed with a specially designed human phantom. Experimental results show that the -10 dB return loss bandwidth of the proposed antenna in free space(no hand contact) is 200 MHz that ranges from 2.3 to 2.5 GHz and the maximum gain is measured to be 5 dBi. Under the normal operating condition where the metal case is contacted with a human hand, the bandwidth is 480 MHz from 2.24 to 2.72 GHz. The maximum gain is 2 dBi, lowered by 3 dB due to the hand contact.

• Korean Journal of Remote Sensing
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• v.37 no.6_3
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• pp.1975-1984
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• 2021

Urban expansion results in raising the temperature in the city, which can cause social, economic and physical damage. In order to prevent the urban heat island and reduce the urban land surface temperature, it is important to quantify the cooling effect of the features of the urban space. Therefore, in order to understand the relationship between each object of land cover and the land surface temperature in Seoul, the land cover map was classified into 6 classes. And the correlation and multiple regression analysis between land surface temperature and the area of objects, perimeter/area, and normalized difference vegetation index was analyzed. As a result of the analysis, the normalized difference vegetation index showed a high correlation with the land surface temperature. Also, in multiple regression analysis, the normalized difference vegetation index exerted a higher influence on the land surface temperature prediction than other coefficients. However, the explanatory power of the derived models as a result of multiple regression analysis was low. In the future, if continuous monitoring is performed using high-resolution MIR Image from KOMPSAT-3A, it will be possible to improve the explanatory power of the model. By utilizing the relationship between such various land cover types considering vegetation vitality of green areas with that of land surface temperature within urban spaces for urban planning, it is expected to contribute in reducing the land surface temperature in urban spaces.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.199-207
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• 2010

This research was conducted to determine the influence of physiological and chemical properties of root substrates on the growth of the daughter plants of 'Maehyang' strawberry produced by bag culture. The daughter plants produced by stock plants during bag culture were individually separated and grown in 10-cm diameter plastic pots containing six different formulations of root substrates: a) 50% peatmoss plus 50% vermiculite (5:5 by volume, A), b) 70% peatmoss plus 30% perlite (7:3, B), c) 70% coir dust plus 30% perlite (7:3, C), d) mixture of 35% coir dust, 35% peatmoss, and 30% perlite (3.5:3.5:3.0, D), e) mixture of 20% rice hull, 70% coir dust, and 10% perlite (2:7:1, E), and f) 30% rice hull plus 70% coir dust (30:70, F). The container capacity and air filled porosity of the growing medium varied greatly among the six substrate formulations evaluated. The substrates E and F had less container capacity and higher air-holding spaces than the rest of the formulations. Therefore, these two formulations (E and F) may cause a problem in water management during the production of healthy daughter plants. The substrate formulations A, B, and D retained higher nitrogen (N) concentrations than other formulations containing coir dust or rice hull. The substrate formulations E and F which contained rice hull had lower N, phosphorus (P), and potassium(K) concentrations than other substrate formulations containing coir. The quality of the daughter plants grown in all six different substrate formulations was good with the crown diameters at around 10 mm. Fresh weights of the daughter plants grown in substrate formulations A, C, and D were higher than those obtained from B, E, and F. Dry weights of the daughter plants showed a similar trend. The daughter plants having high fresh and dry weights and increased crown diameter are in demand by the industry. For this reason, the substrate formulations A, C and D can readily be used as potting mixes during the production of 'Maehyang' strawberry transplants utilizing the bag culture system.

• Tunnel and Underground Space
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• v.13 no.1
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• pp.33-43
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• 2003

Field investigations of the orientations of discontinuity planes inside the borehole for designing the underground rock structures have been depend solely on the borehole image-taking techniques. But, borehole image-taking has to be processed after the completion of drilling operation and also requires the handling of highly expensive apparatus so that practical application is very restricted. In this study Discontinuity Orientation Measurement (DOM) drilling system and discontinuity analysis model RoSA-DOM are developed to acquire the reliable information of rock structure by analyzing the characteristics of joint distribution. DOM drilling system retrieves the rock core on which the reference line of pre-fixed drilling orientation is engraved. Coordinates of three arbitrary points on the joint surface relative to the position of reference line are assessed to determine the orientation of joint plane. The position of joint plane is also allocated by calculating the location of core axis at which joint plane is intersected. Then, the formation of joint set is analyzed by utilizing the clustering algorithm. Total and set spacings are calculated by considering the borehole axis as the scanline. Engineering applicability of in-situ rock mass around the borehole is also estimated by calculating the total and regional RQDs along the borehole axis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6630-6638
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• 2014

The concerns for higher returns among investors in Korea are increasing as local interest rates lag behind the global market. The aim of this study was to provide a basis for estimating the precise return on investment to private investors and stakeholders of office buildings by identifying the optimal scale estimation of office building space, derived from managerial expenses. The literature on the economies theories of scales were reviewed, and the average administrative costs on an appropriate scale were assessed by cross-analysis and regression analysis using the U-shaped quadratic and cubic function. The findings suggest that the average office building managerial costs are approximately 6-11% according to the region, 10-13% according to the grade, and 8-9% according to size. Corporate-owned buildings represent the highest in terms of the average managerial costs, and there is an approximately 11.5% difference when it comes to outsourcing. In addition, the elapsed year showed that approximately 5.3 years to meet the lowest U-shaped curve of the average managerial cost. The 'Total floor area' variable shows a ${\bigcap}$-shape as it continue to increase to 72,000-Pyung then decrease gradually. This study presents the fundamental proposition of efficient and practical management of cost, lease and operation for real estate management firms by utilizing LCC.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.94-106
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• 2020

Recently, the radio navigation method utilizing the GPS(Global Positioning System) satellite information is widely used as the method to measure the position of objects. As GPS applications become wider and fields based on various positioning information emerge, new methods for achieving higher accuracy are required. In the case of autonomous vehicles, the INS(Inertial Navigation System) using the IMU(Inertial Measurement Unit), and the DR(Dead Reckoning) algorithm using the in-vehicle sensor, are used for the purpose of preventing degradation of accuracy of the GPS and to measure the position in the shadow area. However, these positioning methods have many elements of problems due not only to the existence of various shaded areas such as building areas that are continually enlarged, tunnels, underground parking lots and but also to the limitations of accumulation-based location estimation methods that increase in error over time. In this paper, an efficient positioning method in a large underground parking space using Fingerprint method is proposed by placing the AP(Access Points) and directional antennas in the form of four anchors using WLAN, a popular means of wireless communication, for positioning the vehicle in the GPS shadow area. The proposed method is proved to be able to produce unchanged positioning results even in an environment where parked vehicles are moved as time passes.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.39-46
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• 2015

This paper presents an automatic method to detect and count the cells from microorganism images based on mobile environments. Cell counting is an important process in the field of biological and pathological image analysis. In the past, cell counting is done manually, which is known as tedious and time consuming process. Moreover, the manual cell counting can lead inconsistent and imprecise results. Therefore, it is necessary to make an automatic method to detect and count cells from biological images to obtain accurate and consistent results. The proposed multi-step cell counting method automatically segments the cells from the image of cultivated microorganism and labels the cells by utilizing topological analysis of the segmented cells. To improve the accuracy of the cell counting, we adopt watershed algorithm in separating agglomerated cells from each other and morphological operation in enhancing the individual cell object from the image. The system is developed by considering the availability in mobile environments. Therefore, the cell images can be obtained by a mobile phone and the processed statistical data of microorganism can be delivered by mobile devices in ubiquitous smart space. From the experiments, by comparing the results between manual and the proposed automatic cell counting we can prove the efficiency of the developed system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.277-280
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• 2016

Currently, systems for finding missing children are composed of using communication between a QR code and RFID chip, as the use of a smartphone. However, the current systems for finding missing children have limitations in that children can only be found if there are people in the surrounding area; there is an economic burden on parents required to purchase a smartphone for their children; along with difficulties in finding the missing children without the assistance of those in the surrounding area in critical situations such as a kidnapping, due to the limited duration of the battery life. In order to solve such problems, approaches need to be made from two perspectives: having someone in the surrounding area; and absence of anyone in the surrounding area. This thesis is centered on the development of a IoT (Internet of Things) system for finding missing children that combines two methods, namely, the method of finding missing children without a guardian in the surrounding area -within the limited space in which AP is installed by using a beacon and open source hardware being highlighted as the IoT technology - and the method of finding missing children with the smartphone application in which each individual becomes the Access Point (AP). The Main purpose is to provide accurate information of missing children's location for the 2situations and it is found that the accuracy of smartphones APP is 97.7% and security device AP is 91.1%.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.495-505
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• 2019

This study reported the treatment of a patient with excessive worn dentition and limited maxillo-mandibular space for restoration, utilizing the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. After the thorough examination of the patient's occlusal vertical dimension (OVD), full mouth rehabilitation was planned with increase of the OVD. The patient was satisfied with the provisional restorations establishing the increased OVD. The horizontal and vertical data of the patient's jaw relation that the provisional restorations contained were transferred to the definitive metal ceramic fixed prostheses by double scanning and three-dimensional printing. After the fixed restorations were cemented to the abutments, electronic surveying and three-dimensional printing were used to fabricate metal frameworks for the patient's removable partial dentures. The mandibular definitive removable prostheses were delivered to the patient's mouth and the full mouth rehabilitation procedures were completed. The digital technologies used for this case produced fixed and removable restorations satisfactory in masticatory, phonetic and aesthetic functions to both the patient and the dental clinician.

• Archives of design research
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• v.19 no.5 s.67
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• pp.55-64
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• 2006

As digital systems were introduced to automotive design in the mid 1980s, the design process has adopted many digital programs to save time compared to the conventional hand drafting. Digital technology was introduced not only to satisfy the reeds of the global environment, as the number of automobiles exported to many different parts of the world has increased, but also to save time and effort in developing several models of quality automobiles. Therefore, every automotive manufacturer in the world has expanded its virtual reality(VR) studio to establish visualization systems that visualize automobiles in the actual size and a co-operation system that enables simultaneous feedback from all of its design studios around the world. Unlike the existing design reviewing methos, the new improved feedback system is assessed as a reasonable method to evaluates and understand how the automobiles are actually manufactured in simulation. It is especially helpful when advanced products and concept cars require fast results. Other strengths of the new system include shorter development period, cost efficiency, no more manual labor, various designs within a short period of time, and realistic visualization of concepts. Large-scale products, including automobiles, need to be projected in the actual size and high clarity through the Power-wall System and are examined in a virtual space called a Cave. Therefore, it took much time to establish digital infrastructure. An infrastructure would constantly require system improvement and performance enhancement, but it is certain that now is the right time for the take-off to utilizing the strengths of digital design and improve the weaknesses. In this respect, this study provided an understanding of the importance of digital design based on digital reinforcements and examined an effective utilization of digital technology for an efficient development of automobiles in the future.