• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.873-881
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• 2023

The evolution of civil engineering technology, exemplified by recent milestones like the completion of the Gangnam Global Business Center (GBC), has fostered the construction of expansive civil and architectural structures both above and below the earth's surface. This surge in construction necessitates a commensurate advancement in research and technology pertaining to safety protocols applicable to these vast edifices. Such protocols encompass a spectrum of concerns, ranging from the preemptive mitigation of accidents to the effective management of exigencies such as fires. As the trajectory of construction endeavors continues unabated, encompassing both subterranean and elevated domains, a concomitant imperative emerges to refine the methodologies underpinning precise indoor positioning. To address this need, an innovative web-based simulator has been devised to emulate indoor positioning scenarios for rigorous testing. This research further entails the development of an indoor positioning data Application Programming Interface (API) fortified by Geographic Information System (GIS) spatial operation techniques. This API is anchored in the construction of intricate test data, centered on the spatial layout of building 13 at the Electronics and Telecommunications Research Institute (ETRI). Consequently, the study renders feasible the expeditious provisioning of diverse signal-based and image-based spatial information, pivotal for enhancing the navigational acumen of mobile devices. Path delineation, cellular signal mapping, landmark identification, and ancillary navigational aids are among the manifold datasets promptly furnished by the indoor positioning data API. In summation, this study engenders a crucial leap towards the fortification of safety protocols and navigational precision within the expansive confines of modern architectural wonders.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.21-25
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• 2010

Purpose: For better PET imaging with accuracy the transmission scanning is inevitably required for attenuation correction. The attenuation is affected by condition of acquisition and patient position, consequently quantitative accuracy may be decreased in emission scan imaging. In this paper, the present study aims at providing the measurement for attenuation varying with the positions of the patient's arm in whole body PET/CT, further performing the comparative analysis over its SUV changes. Materials and Methods: NEMA 1994 PET phantom was filled with $^{18}F$-FDG and the concentration ratio of insert cylinder and background water fit to 4:1. Phantom images were acquired through emission scanning for 4min after conducting transmission scanning by using CT. In an attempt to acquire image at the state that the arm of the patient was positioned at the lower of ahead, image was acquired in away that two pieces of Teflon inserts were used additionally by fixing phantoms at both sides of phantom. The acquired imaged at a were reconstructed by applying the iterative reconstruction method (iteration: 2, subset: 28) as well as attenuation correction using the CT, and then VOI was drawn on each image plane so as to measure CT number and SUV and comparatively analyze axial uniformity (A.U=Standard deviation/Average SUV) of PET images. Results: It was found from the above phantom test that, when comparing two cases of whether Teflon insert was fixed or removed, the CT number of cylinder increased from -5.76 HU to 0 HU, while SUV decreased from 24.64 to 24.29 and A.U from 0.064 to 0.052. And the CT number of background water was identified to increase from -6.14 HU to -0.43 HU, whereas SUV decreased from 6.3 to 5.6 and A.U also decreased from 0.12 to 0.10. In addition, as for the patient image, CT number was verified to increase from 53.09 HU to 58.31 HU and SUV decreased from 24.96 to 21.81 when the patient's arm was positioned over the head rather than when it was lowered. Conclusion: When arms up protocol was applied, the SUV of phantom and patient image was decreased by 1.4% and 9.2% respectively. With the present study it was concluded that in case of PET/CT scanning against the whole body of a patient the position of patient's arm was not so much significant. Especially, the scanning under the condition that the arm is raised over to the head gives rise to more probability that the patient is likely to move due to long scanning time that causes the increase of uptake of $^{18}F$-FDG of brown fat at the shoulder part together with increased pain imposing to the shoulder and discomfort to a patient. As regarding consideration all of such factors, it could be rationally drawn that PET/CT scanning could be made with the arm of the subject lowered.

• Journal of the Korean Society of Radiology
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• v.7 no.5
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• pp.321-331
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• 2013

The purpose of this study was to investigate factors of perception by inpatients of the radiology department about exposure to radioactivity at the time of radioactive examination, providing basic information for making educational materials aimed to change their perception. Most of those patients, 65.5% responded that CT was a type of radioactive examination bringing highest exposure to radiosensitivity. Most of the subjects, 56.1% said that a body part most vulnerable to exposure to radiosensitivity was the genital gland at the time of radiosensitivity examination. And most of the participants, or 26.3% responded that they obtained information about radiation from TVs or newspapers. Among the surveyed patients, men were higher in scores for factors of the perception of radiation such as recognition of radiation, harmfulness of radiation, psychological state at the time of radioactive examination, prevention of exposure to radioactivity and necessity of radiation that women were, with statistically significant differences between the two groups. These findings suggest that it is urgently needed to develop an education program which helps patients better perceive exposure to radioactivity and that radiologists should be very careful to reduce the does of that exposure. If patients better perceive radiation, they would be less anxious and less exposed to radioactivity when receiving the radioactive examination.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.353-363
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• 2018

According to the Digi Capital forecast, the global augmented reality market is expected to grow rapidly by 2020 to reach 150 billion dollars. In particular, high value added effects are expected in education. As ICT advances, digital textbooks are also leading innovative education by adding interactive functions. Advanced countries, including the U.S., are already using digital textbooks that use augmented reality technology in their classes. In line with this technological outlook, the ministry proposed a design plan that applies augmented reality technology to middle school science 1 digital textbooks. A study on middle school science 1 digital textbooks showed that each unit provided short videos. In addition, an investigation into the augmented reality class case showed that it was difficult to establish experimental equipment, lack of equipment (devices), and 3D design contents that did not continue despite the excellence of learning effects. Based on this demand, we designed an augmented reality scenario and system configuration to be applied to the instrument-specific experiments of middle school science 1 digital textbooks to explore and explore the contents of augmented reality by students. This research will replace the dangerous experiments and time consuming experiments for teachers and students by applying augmented reality to science subjects that are essential for the development of digital textbooks.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.88-89
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• 2010

최근 인간의 활동범위와 영역이 확대되고 산업이 발전하면서 인간의 삶과 지속가능한 발전 등 도시 기후에 관한 관심도 높아지고 있다. 산업혁명 이후 도시화와 산업화로 인해 인구가 증가하고 도시지역으로 집중됨으로써 도시 열섬화 현상에 대한 도시환경문제가 부각되고 있다. 이는 최근까지도 도시개발에 있어서 기능과 효율성이 우선시 되어 도시기후에 대한 배려가 이루어지지 못하고 있으며, 오히려 과도한 냉난방을 가동하는 등 쾌적한 실내 환경 조성을 위한 노력만을 행해왔다. 도시화에 따른 도시의 열환경 구조의 변화는 토지이용의 변화에 따른 피복상태와 밀접한 관련이 있다는 연구들이 수행된 바 있다. 이렇듯 도시화가 진행됨에 따라서 도심 지표면을 덮고 있는 포장재도 변하고 있다. 대표적인 토지피복재로는 콘크리트와 아스팔트 등의 인공포장재, 수계, 삼림 등으로 크게 나누어 볼 수 있다. 최근 도심의 발달로 인해 도심의 표면은 점차 인공포장재인 아스팔트와 콘크리트로 덮여지고 있다. 인공포장재는 맑은 여름철 낮에 받아들인 열을 야간에도 머금고 있어 도시열섬현상의 주요원인이 된다. 도시화가 진행됨에 따라 토지이용형태가 변화하고 있으며 이러한 토지피복의 변화는 그 지역의 기온과 풍향, 풍속뿐만 아니라 지표온도도 변화시키므로 도시 열환경 구조에 적지 않은 영향을 미치고 있다. 과거에는 자연 환경과 도시공간에 대한 인식이 다른 분야로 나누어져서 다루었지만 현재 위성영상 기술의 발달로 많은 공간 정보를 파악할 수 있게 된 바 도시기후변화에 더욱 직접적이고 근본적인 접근이 쉬워졌다. 원격탐사기법의 활용은 위성자료를 이용하여 동시간대 평면적인 열구조를 정량적으로 파악하는데에 중요한 자료를 제공하여 도시지역을 덮고 있는 인공자재의 존재가 도시열섬의 형성과 밀접하게 연관이 있다는 사실을 짐작할 수 있다. 따라서 도시기후변화의 문제점을 더욱 적극적으로 해결하기 위해서는 토지이용에 따른 지표면 온도 상승의 현황을 파악하고 이를 저감 시킬 수 있는 대책들이 수립되어야 한다. 본 연구는 보다 세분화된 도시 열환경을 정량적으로 분석 평가하기 위해서 토지피복별 분류를 3가지로 대구시 중구 경북대학교 부속 고등학교(이하 사대부고 지점)를 도심지역으로, 경상남도 창녕군 창녕읍 우포늪(이하 우포지점)을 수계지점으로, 경상북도 안동시 길안면 만음리(이하 안동지점) 지점과 대구시 칠곡군 동명면 득명리 팔공산 한티재 도립공원(이하 팔공지점)을 산림으로 분류하여 연구하였다. 대구 계명대학교 기후환경연구실에서 보유하고 있는 AWS(Automatic Weather Station) 자료로 기상요소를 분석하였으며, MODIS Terra 위성영상을 이용하여 지표온도를 추출하고 분석하였다. 또 기상요소와 지표온도를 이용해 회귀식을 도출하여 추정기온을 산출하였다. 그 결과 첫째, 계절에 따른 기온의 시간변화는 여름의 평균기온이 $25.13^{\circ}C$와 $24.12^{\circ}C$로 사대지점과 우포지점의 평균기온이 가장 높게 나타났으며, 이는 도심에서 발생되는 인공열의 영향으로, 우포지점은 수계의 특징이 반영된 결과라 할 수 있다. 둘째, 계절에 따른 풍속의 시간변화는 여름의 경우 우포지점의 풍속이 1.63m/s로 가장 높은 반면 안동지점의 풍속이 0.27m/s로 가장 낮은 것으로 나타났다. 겨울의 경우 팔공지점의 풍속이 1.82m/s로 가장 높게 나타났다. 토지피복에 따른 지표면의 변화가 도시기후에 미치는 영향을 정량적으로 평가하고, 또 지표면 온도와 기온과의 차이를 알아보기 위하여 MODIS 위성 영상을 이용하여 세 지점을 대상으로 토지피복에 따른 열환경을 평가 분석하여 다음과 같은 결론을 얻을 수 있었다. 첫째, MODIS 위성영상을 이용하여 산출한 지표면 온도는 여름철 주간에 안동지점의 경우 주변지역에 비해 지표면 온도가 약 $26^{\circ}C$로 낮게 나타났으며 우포지점의 경우 수계가 가지는 열 완충능력으로 약 $27^{\circ}C$의 낮은 지표면 온도를 나타내었다. 사대지점의 경우 약 $34^{\circ}C$이상의 높은 지표면 온도를 나타내었다. 둘째, MODIS 위성영상을 이용하여 산출한 지표면 온도와 관측된 기온과의 회귀식을 도출하여 상관분석 한 결과, 모든 지점의 값에서 상관성 및 신뢰도가 높은 것으로 나타났다. 셋째, 상관분석의 결과를 통하여 추정한 기온은 지표면 온도와의 차이가 있지만 유사한 패턴의 결과로 추출되었다. 이러한 결과로 볼 때 도시의 인공자재를 이용한 건축과 개발이 도시열섬현상을 유발하는데 중요한 역할을 하는 것을 정량적으로 평가할 수 있었다. 따라서 본 논문의 연구결과를 바탕으로 도시계획에 있어서 인공구조물에 의한 기온과 풍속이 받는 영향을 고려하여 도심의 인공구조물의 배치나 자재에 대한 개발이 이루어져야 할 것이며 열교환의 방해 및 바람순환이 확보되는 구조로 개선되어야 할 것이다.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.57-69
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• 2004

This study developed an ecological mapping technique with GIS database using the analyses of existing ecological survey reports and the change detection on the Nakdong river estuary. The data which are used to establish GIS DB include 2 Landsat TM images on Nov. 31, 1984 and May 17, 1997, 1:25,000 topographical maps established by National Geography Institution and various ecological survey reports published by Busan metropolitan city government. The details for producing ecological map are as follows. At first, the current methods of ecomapping efforts and previous ecological surveys of Nakdong river estuary were carefully examined. Secondly, the land cover maps were created from the classified Landsat images of 1984 and 1997 for the spatiotemporal ecosystem analysis. Thirdly, the ecosystem was evaluated by using GIS ecological database based on the criteria of botany, zoology and water quality etc. Each criteria was reclassified into 3 stages which describe the overall quality of ecological condition. At last, the comprehensive ecological map was suggested as a prototype of ecosystem assesment and management tool with the discussion of further study. The findings of this study would be a milestone for preserving and managing the ecosystem.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.1
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• pp.100-108
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• 2003

By choosing Multicast for transmission of educational contents in the Remote Educational System, we can reduce the server load and increase network bandwidth utilization. We design and implement Multicast Middleware for the Remote Educational System in this paper. There are three characteristics in this Multicast Middleware: 1) Through Centralized Multicast Group Management for passive members, it allows a host to make multicast group, which is composed of receivers, called Group Member and who are chosen by the host, called group Maker. Because, all groups are created by the Group Maker in Centralized Group Management, Group Member's join action will be passive 2) Maintenance and recovery of multicast group information in order to restore from exception and crash; the maintenance and recovery mechanism of Group Maker is distinct from that of Group Member. 3) The mechanism which enables to transmit large size multimedia data through multicasting and remove additional copy operation through shared buffer. Fragmentation/de-fragmentation for large data delivery results in additional copy operation in user level. But by using user level shared buffer, it can be done without user Bevel copy operation. By applying to Remote Educational environment which consists of 30 PCs and Fast Ethernet, we can examine the efficiency of this middleware, which can transmit 18frames/sec movie which resolution 320 $\times$ 120 pixels, 128Kbps encoded sound data and some text data.

• Journal of Broadcast Engineering
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• v.15 no.2
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• pp.248-264
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• 2010

In this paper, we presents an efficient rich media framework based on MPEG-4 LASeR PMSI. Rich media provides distinctive features such as dynamic updates and object-based interactivity over the conventional AV centric media service. It rapidly gains its popularity as the convergent multimedia services between broadcasting and telecommunication. MPEG-4 LASeR is an international standard which provides specifications for such rich media services. Recently MPEG added an extension to LASeR called PMSI. It provides an efficient technique to present SI on a scene by referencing specific portions of SI from PI. The presented rich media application is using PMSI of MPEG-4 LASeR standard to provide users a widget-like rich media application. This application utilizes MPEG-4 LASeR with PMSI technique as PI, and this PI references SI to present information that resides in SI on a scene. In this paper, we provide descriptions of technical ingredients used to build the presented application. The framework is presented followed by the implementation result. Possible impacts and applicable services are described in the conclusion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.243-246
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• 2013

Recently, the 4th generation of mobile communications in Korea with anyone supports was supported high speed multimedia communication services. With the launch of Apple iPhone, there is an explosion of interest in Smartphone itself as well as Internet-based services using Smartphone are being revitalized. Smartphone users, opinion experts almost of the economically active population is using, it has reached the saturation past the early stages of formation. In 1989, the 1st generation mobile communication service has been started with the analog voice service. After this, the 2nd generation mobile communication service for short messages and digital voices has been developed. And, the 3rd generation service of low speed data and low quality videos has been realized in 2000s. The very high speed data service of LTE (long term evolution), which is the 4th generation mobile communication service standards, had been in July 2011. and the subscribers are increasing constantly. However, changes in communication technology, has given an economical cost to Smartphone users. Therefore, the purposes of this study was trending of the communication cost according to the change in the communication technology of the mobile communication industry.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.3
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• pp.100-119
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• 2020

During recent years, the heat environment and particulate matter (PM₁₀) have become serious environmental problems, as increases in heat waves due to rising global temperature interact with weakening atmospheric wind speeds. There exist urban heat islands and urban pollution islands with higher temperatures and air pollution concentrations than other areas. However, few studies have examined these issues together because of a lack of micro-scale data, which can be constructed from spatial data. Today, with the help of satellite images and big data collected by private telecommunication companies, detailed spatial distribution analyses are possible. Therefore, this study aimed to examine the spatial distribution patterns of urban heat islands and urban pollution islands within Busan Metropolitan City and to compare the distributions of the two phenomena. In this study, the land surface temperature of Landsat 8 satellite images, air temperature and particulate matter concentration data derived from a private automated meteorological observation system were gridded in 30m × 30m units, and spatial analysis was performed. Analysis showed that simultaneous zones of urban heat islands and urban pollution islands included some vulnerable residential areas and industrial areas. The political migration areas such as Seo-dong and Bansong-dong, representative vulnerable residential areas in Busan, were included in the co-occurring areas. The areas have a high density of buildings and poor ventilation, most of whose residents are vulnerable to heat waves and air pollution; thus, these areas must be considered first when establishing related policies. In the industrial areas included in the co-occurring areas, concrete or asphalt concrete-based impervious surfaces accounted for an absolute majority, and not only was the proportion of vegetation insufficient, there was also considerable vehicular traffic. A hot-spot analysis examining the reliability of the analysis confirmed that more than 99.96% of the regions corresponded to hot-spot areas at a 99% confidence level.