• Journal of Advanced Navigation Technology
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• v.27 no.2
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• pp.197-202
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• 2023

This paper presents the design method and electrical characteristics of a high-efficiency power amplifier for a 50 Watts class repeater applied to a 5G system and used in in-building, subway, and tunnel. GaN was used for the termination transistor of the power amplifier designed here, and intermodulation signals were removed using DPD to satisfy linearity. In addition, in order to handle various requirements such as amplifier gain control and alarm processing required in the 5G system, the microprocessor is designed to exist inside the power amplifier. The amplifier manufactured to confirm the electrical performance of the power amplifier satisfying these conditions satisfied 46.5 dBm and the overall efficiency of the amplifier was 37%, and it was confirmed that it satisfied various alarm conditions and electrical characteristics required by telecommunication companies.

• Korean Journal of Remote Sensing
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• v.33 no.6_2
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• pp.1151-1157
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• 2017

Street Trees is an important object for urban environment improvement. Especially the height of the trees needs to be precisely measured as a factor that greatly influences the removal of air pollutants in the Urban Street Canyons. In this study, we extracted the height of the tree based on the stereo image using the precisely adjusted UAV Images of the target area. The adjustment of UAV image was applied photogrammetric SfM (Structure from motion) based on the collinear condition. We measured the height of the trees on the Street Canyon using stereoscopic vision on stereo plotting system. We also acquired the height of the building adjacent to the street trees and the average height of the road surface was calculated for accurate measurement of the height of each object. Through the visual analysis with the plotting operation system, it was possible to measure height of the tree and to calculate the relative height difference value with building quickly. This means that the height of buildings and trees can be calculated without making a 3D point cloud of UAV and it has the advantage of being able to utilize non-experts. In the future, further studies for semiautomatic/automation of this technique should be performed. The development and research of these technologies is expected to help to understand the current status of environmental policies and roadside trees in urban areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.662-671
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• 2020

The uplift force acts directly on the foundation and causes a building to float to the upper ground. To examine the stability of a structure according to the uplift force, four sites (Paju, Anyang, Osan, and Gangneung) were selected, and sensors were installed on the foundations for the field tests. The rainfall characteristics were analyzed around June~September, and the changes in the water level of the adjacent river were considered. The maximum uplift force except for Gangneung did not exceed 72% of the water pressure when the groundwater level was up to the surface. On the other hand, the maximum uplift force in Osan was approximately 67%, but the reliability was slightly inferior because the difference from the average (46%) was large. The minimum uplift force was within 10% except for Anyang (~ 41%). At the Gangneung site on soft rock where the permanent drainage facility was installed before the measurement, the maximum and minimum uplift force was approximately 14% and 3.5%, respectively. Based on the measurement results, the possibility of overdesigning or underdesigning comes from the design by the hydrostatic pressure when the groundwater level is up to the surface.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.1
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• pp.87-97
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• 2013

This study was carried out to find the prototype of the rear garden in Changdeok Palace during King Jungjo's reign through Gang Sehwang's "Record of Strolling with King in the Forbidden Garden", and the site of this study included the whole areas of Ongnyucheon(玉流川), Mansongjeong(萬松亭), Mangchunjeong(望春亭), Jondeokjeong(尊德亭), Pyemwoosa and Taichungmun(太淸門). The characteristics of the area of Ongnyucheon described in Record of Strolling with King in the Forbidden Garden was the shape of Wiyiam expressed three-dimensional mountain such as the fence surrounding Soyojeong(逍遙亭) and the painting techniques of Fu Pi' ts'un and pond in front of Taegeukjeong(太極亭). The pond in front of Taegeukjeong(which was described by Gang Sewhang) is also identified in Donggwoldo(東闕圖) and this study judged that the pond was removed during the maintenance process of Ongnyucheon, where was scheduled as the place of entertainment when Chinggyong-Yesik(稱慶禮式: Royal court rites) was held to celebrate the 40th anniversary of King Gojong's reign. The characteristics of the whole area of Mangchunjeong where was the attraction point for flower viewing in the forbidden garden was surrounded by the sculptured fence, and Mangchunjeong which was hexagonal structure was located in the inside of the structure on both sides of the main building. The cornerstone was carved with white jade. Also a corridor assumed as Chunhyanggak(天香閣) was adjacent to Mangchunjeong. Gang Sehwang confirmed the space organization appeared in Donggwoldo by describing the attached building of Pyemwoosa, Taichungmun, and surrounding fence in detail.

• The Korean Journal of Emergency Medical Services
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• v.6 no.1
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• pp.103-128
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• 2002

As a result of trying the various manufacturing methods considering the reality of manpower and equipments with this manual, the following standardized procedures and contents can be suggested. (1) Since tools presenting Rock-Drill data must formalize the order of explanation although explainers are different, it will be valid that it is configured by existing power point method rather than by web document type. Composition of contents are selected on the basis of defence card and survey and then 8 items including initial screen, peripheral conditions, mobilization route, general conditions, use and structure by floor, department of vehicle consideration in activities and end screen are included. (2) Making methods and cautions of data included and used in power point are as follows ; - It was most effective that objects of fire fighting and location of neighboring fire fighting water were expressed by electronic map and drawing of inner building was made by scanning it after paining general architecture drawing(plan by each floor) rather than using drawing tools of EXCEL program or CAD drawing. And it was helpful to simplify contents of architecture drawing to wall, stairs and gate in understanding them. - Photographing of video data should be taken to show available fire fighting facilities in fire, use of planned space and the whole inner structure of each floor from the inside of fire fighting buildings and to display play time between 10 sec. and 1 min, for obstacles to distance from adjacent buildings or passage of special vehicles and fire fighting water from the outside of the building. - File format of video data taken in this way is most suitable to use wmv(window media video) or asf(advanced streaming format) type in consideration of time required for export, screen quality, file capacity and play type in Rock-Drill through network. - Still screen(photo) is more effective to express the department of fire fighting vehicles or other equipments than using video. (3) In configuration work of power point, hyper link was used most and configured to see any part at any situation like web document and then uniformity of presentation order of power point was complemented. (4) In case of sales facilities with the area of $35.557m^2$, the time of 22 hours and 30 minutes for five days was taken with five persons. Therefore, when eight-hour works a day were calculated, the whole process of video work for Rock-Drill can be finished with three day works.

• Fire Science and Engineering
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• v.33 no.3
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• pp.105-111
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• 2019

In Korea, the results of a field survey on the construction of flammable exterior materials implemented in 2018 revealed that 147,559 buildings belong to this category. It was found that the fire spreading cases in upper and adjacent constructions are about 3,500 per year, the fires of starting in flammable exterior material are about 1,500 per year. In this study, we investigated the repair method of buildings constructed by flammable exterior material and conducted performance verification of each repair materials for prevention of similar fire. In the case of the repair method, a method of reinforcing with a repair material after removing the existing building finishing material and a method of attaching the repair material after performing the face finishing are proposed. In addition, we conducted cone calorimeter tests of 6 materials such as fireproof gypsum board, mineral wool, hard urethane foam, ceramic board and ALC panel as dryvit and repairing materials, and investigated basic combustion performance of that materials.

• Fire Science and Engineering
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• v.26 no.4
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• pp.48-54
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• 2012

In order to study on the evacuation risk when connate fires caused by vertical fire spread of the exterior occurs, the egress simulations based on the relevant scenarios has carried out. As a result of it, ASET (permitted evacuation time) was reached in between 550 to 650 seconds in entire floors after vertical smoke spread from fire of combustible exteriors. In particular, ASET was 358 seconds in the first floor, 490 seconds in the six floor and 473 seconds in the tenth floor. In addition, five floors of all levels, the 1st floor, the 6th floor and the 28th floor ~30th floor, show RSET (minimum evacuation time) which is bigger than ASET as evacuation risk. This result presents occupants in high rise buildings with more than 15 floors might not be able to egress of them using staircases due to huge population attempting to evacuate simultaneously. Particularly, 699 people in the upper levels by smoke from the first floor are having difficulty escaping this building since ASET on the first floor adjacent to the ignition point was 358 seconds which is relatively reached fast. Considering a prevention method of the fire and smoke spread, architects have to use non-combustible exterior in the building's facade to be required as an active fire protection system.

• Korean Journal of Heritage: History & Science
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• v.45 no.4
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• pp.38-53
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• 2012

This paper investigated the construction year of 'Jeongnimsa(定林寺)temple in Buyeo(扶餘) through the recent archaeological records. First, the composition of land for the construction of temple was linked with Gwanbukri(官北里) sites which is estimated as palace. The composition of land for the palace was formed at late 6th century. Second, the several furnace sites was discovered under the foundation soil layers for the construction of temple. Reference to the pottery excavated from the previous surface indicates that the workshops having been operated a period of time after the transfer of the capital to Sabi(泗?). These workshops having been operated before the construction of roof-tile buildings which were followed by the large-scale composition of land for the palace at Gwanbukri sites adjacent to the north of 'Jeongnimsa. The pottery, roof-tiles and chinese porcelain which were included in the earth laid on the ground for the construction of temple also indicates that the construction year of temple do not go up to shortly after the transfer of the capital to Sabi. This is related with that wooden pagoda would have been present before stone pagoda and the foundation of the wooden pagoda would have soared into the ground. Last, the building layout of temple is familiar to Iksan(益山) Mireuksa(彌勒寺址) temple site than the temples of Buyeo such as Wangheungsa(王興寺址) temple site. This imply that Jeongnimsa temple was not constructed shortly after the transfer of the capital to Sabi like the opinion of the existing. Jeongnimsa temple was probably constructed at late 6th century when composition of the Sabi city was actively made.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.693-702
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• 2022

The purpose of this study is to present the problems of urban ecosystem imbalance in Seoul and the need to restore housing functions through comparison with Manhattan, New York, which grew earlier than Seoul and has been striving to solve urban problems and restore urban ecosystems. The residential status in urban commercial use areas was investigated through analysis of the total amount of residential space, characteristics of each type of residential building, and distribution of residential buildings. Through this, it can be seen that most of the space in Seoul's historic city center is biased toward commercial roads, and there are significantly insufficient high- and high-density mixed-use buildings suitable for urban dwellings compared to Manhattan's. In addition, it can be seen that the complex building in the historical city center of Seoul is located adjacent to the outskirts of the target site. In conclusion, Seoul's historical city center does not provide an appropriate residential space for creating an urban ecosystem, and it is necessary to come up with measures to restore housing functions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.225-227
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• 2022

Now In Seoul, about 75,000 CCTVs are installed in 25 district offices. Each ward office in Seoul has built a control center for CCTV control and is building information such as people, vehicle types, license plate recognition and color classification into big data through 24-hour artificial intelligence intelligent image analysis. Seoul Metropolitan Government has signed MOUs with the Ministry of Land, Infrastructure and Transport, the National Police Agency, the Fire Service, the Ministry of Justice, and the military base to enable rapid response to emergency/emergency situations. In other words, we are building a smart city that is safe and can prevent disasters by providing CCTV images of each ward office. In this paper, the CCTV image is designed to extract the characteristics of the vehicle and personnel when an incident occurs through artificial intelligence, and based on this, predict the escape route and enable continuous tracking. It is designed so that the AI automatically selects and displays the CCTV image of the route. It is designed to expand the smart city integration platform by providing image information and extracted information to the adjacent ward office when the escape route of a person or vehicle related to an incident is expected to an area other than the relevant jurisdiction. This paper will contribute as basic data to the development of smart city integrated platform research.