• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.3
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• pp.61-68
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• 2009

The objective of this study was to examine the possibility of utilizing the immersion stereoscopic image with a curved-screen-display as a tool for evaluating the landscape. The curved-screen-display ensures the continuity of the image and can be simultaneously evaluated by many people. Fifty-meter-wide Gangnamdaero Boulevard in Seoul was selected for this study, and the simulation was done using computer graphics. With the computer simulation, a questionnaire on landscape preferences was conducted according to different visual environments (immersion, non-immersion) and different projection types(stereoscopic or plane image). In the results of this study, the landscape preference was largely dependent on the immersion environment. Using the immersion-type simulation, the observer can easily evaluate the preference with higher judgment power. The stereoscope or plane projection type does not have any significant result in terms of its judgment power. This result implies that it is very important to strengthen the sense of immersion by expanding the screen into an angled view in which the observer can become immersed while making and projecting the simulation to evaluate the landscape. As a landscape evaluation tool for examining the efficiency and usefulness of immersion simulation, this study has limitations in that it controls many factors in street landscape that adversely affect judgment. Accordingly, a detailed comparison and verification of the stereoscopic image in various environments, including street width and building height ratio, must be conducted.

• Spatial Information Research
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• v.23 no.5
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• pp.1-7
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• 2015

Twitter has the fast propagation and diffusion of information compare to other SNS. Therefore, many researches about detecting real-time event using twitter are progressing. Twitter real-time event detecting system assumes every twitter user as a sensor and analyzes their written tweet in order to detect the event. Researches that are related to this twitter have already obtained good results but confronted the limits because of some problems. Especially, many existing researches are using the method that can trace an event location by using GPS coordinate. However, it can be suggested a definite limitation through the present user's skeptical responses about making personal location information public. Therefore, this paper suggests the method that traces the location information in tweet contents text without using the provided location information from twitter. Associated words were grouped by using the keyword that extracted in tweet contents text. The place that the events have occurred and whether the events have surely occurred are detected by this experiment using this algorithm. Furthermore, this experiment demonstrated the necessity of the suggested methods by showing faster detection compare to the other existing media.

• Land and Housing Review
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• v.1 no.1
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• pp.103-111
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• 2010

The purpose of the paper is to research issues and implications on a large-scale enlargement of urban area in city management plan. This study investigated laws and regulations in force and carried out case study for three cities such as Yangju-si, Gimpo-si, Whaseong-si. As a result of analysis, three points at issue were abstracted and improvement ideas for each of them were suggested as follows. First, to set up adequate size of urban area, it is necessary to consider resonable planning for population, spatial structure, zone of life and land use in city comprehensive plan and city management plan. Second, to decrease arguments about scope and bounds of urban area, it is important to make general and specific guidelines to set up them. Third, to manage new urban area and its surroundings efficiently, it is necessary to subdivide zoning of non-urban area strictly, to restraint individual location of factories or cattle sheds, to make a proper infrastructure plan in advance, to administer strongly the permission of development behavior and to control strictly consecutive and joining development in non-urban area.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.173-179
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• 2021

Scattered x-ray generated by digital radiography systems also have the advantage of increasing signals, but ultimately detectability is reduced by decreasing resolution and increasing noise of x-ray images transmitted objects. An indirect method of measuring scattered x-ray in a modulation-transfer function (MTF) for evaluating resolution in a spatial-frequency domain can be considered as a drop in the MTF value corresponding to zero-frequency. In this study, polymethyl methacrylate (PMMA) was used as a patient tissue equivalent, and MTFs were obtained for various thicknesses to quantify the effect of scattered x-ray on resolution. X-ray image signals were observed to decrease by 35 ~ 83% with PMMA thickness increasing, which is determined by the absorption or scattering of x-rays in PMMA, resulting in reduced MTF and increased scatter fraction. The method to compensate for MTF degradation by PMMA resulted in the MTF inflation without considering the optical spreading generated by the indirect-conversion type detector. Data fitting or zero-padding are needed to compensate for MTF more reasonably on edge-spread function or line-spread function.

• Tunnel and Underground Space
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• v.31 no.5
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• pp.333-359
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• 2021

Gases such as hydrogen and radon can be generated around the canister in high-level radioactive waste disposal systems due to several reasons including the corrosion of metal materials. When the gas generation rate exceeds the gas diffusion rate in the low-permeability bentonite buffer, the gas phase will form and accumulate in the engineered barrier system. If the gas pressure exceeds the gas entry pressure, gas can migrate into the bentonite buffer, resulting in pathway dilation flow and advective flow. Because a sudden occurrence of dilation flow can cause radionuclide leakage out of the engineered barrier of the radioactive waste disposal system, it is necessary to understand the gas migration behavior in the bentonite buffer to quantitatively evaluate the long-term safety of the engineered barrier. Experimental research investigating the characteristics of gas migration in saturated bentonite and research developing numerical models capable of simulating such behaviors are being actively conducted worldwide. In this technical note, previous gas injection experiments and the numerical models proposed to verify such behaviors are introduced, and the future challenges necessary for the investigation of gas migration are summarized.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1089-1098
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• 2020

In this study, we propose a method to detect red tide Cochlodinium Polykrikoide using by machine learning and geostationary marine satellite images. To learn the machine learning model, GOCI Level 2 data were used, and the red tide location data of the National Fisheries Research and Development Institute was used. The machine learning model used logistic regression model, decision tree model, and random forest model. As a result of the performance evaluation, compared to the traditional GOCI image-based red tide detection algorithm without machine learning (Son et al., 2012) (75%), it was confirmed that the accuracy was improved by about 13~22%p (88~98%). In addition, as a result of comparing and analyzing the detection performance between machine learning models, the random forest model (98%) showed the highest detection accuracy.It is believed that this machine learning-based red tide detection algorithm can be used to detect red tide early in the future and track and monitor its movement and spread.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.4
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• pp.145-152
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• 2023

The average Nusselt numbers in the source and crystal region for the variation of thermal Grashof number (Gr_t) in the range of 2.31 × 10⁴ ≤ Gr_t ≤ 4.68 × 10⁴ are obtained through numerical simulations. It is shown the average Nusselt number in the crystal region is more than twice as large as the average Nusselt number in the source region. The average Nusselt number in the source region shows an increasing tendency with increasing the thermal Grashof number, Gr_t, while the average Nusselt number in the crystal region shows a decreasing tendency with increasing thermal Grashof number, Gr_t. For the variation of the solutal Grashof number (Gr_s) in the ran ge of 3.28 × 10⁵ ≤ Gr_s ≤ 4.43 × 10⁵, the average Sherwood number in the source region and crystal region tends to decrease as the solutal Grashof number, Gr_s increases. The average Sherwood number in the crystal region is about four times greater than the average Sherwood number in the source region.

• Design Convergence Study
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• v.15 no.1
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• pp.135-150
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• 2016

Due to the development of communication technology and expansion of Intelligent Transport System (ITS), the car is changing from a simple mechanical device to second living space which has comprehensive convenience function and is evolved into the platform which is playing as an interface for this role. As the interface area to provide various information to the passenger is being expanded, the research importance about smart car based user experience is rising. This study has a research objective to propose the guidelines regarding the smart car user experience elements. In order to conduct this study, smart car user experience elements were defined as function, interaction, and surface and through the discussions of UX/UI experts, 8 representative techniques, 14 representative techniques, and 8 locations of the glass windows were specified for each element. Following, the smart car users' priorities of the experience elements, which were defined through targeting 100 drivers, were analyzed in the form of questionnaire survey. The analysis showed that the users' priorities in applying the main techniques were in the order of safety, distance, and sensibility. The priorities of the production method were in the order of voice recognition, touch, gesture, physical button, and eye tracking. Furthermore, regarding the glass window locations, users prioritized the front of the driver's seat to the back. According to the demographic analysis on gender, there were no significant differences except for two functions. Therefore this showed that the guidelines of male and female can be commonly applied. Through user requirement analysis about individual elements, this study provides the guides about the requirement in each element to be applied to commercialized product with priority.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.62-62
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• 2021

산업 고도화로 인하여 복잡하고 다양한 유기물의 사용량이 증가하였으며, 공공수역 내 새로운 오염물질이 유입됨에 따라 생화학적 산소요구량(BOD) 중심의 수질평가에 한계를 나타내었다. 이후 난분해성 물질을 고려한 유기물관리 정책과 총량관리의 필요성이 제기되었고 국내 하천과 호소에서는 총 유기탄소(TOC)를 유기물 관리지표로 설정하였다. 그러나 부영양 하천과 호소에서 TOC는 외부 부하뿐만아니라 식물플랑크톤의 과잉성장에 의해 증가할 수 있는 항목이므로 TOC 관리정책 추진을 위해서는 유기물의 기원에 대한 파악이 필요하다. 특히, 국내 하천에서 나타나고 있는 난분해성 유기물 오염도의 증가 추세에 대응한 실효성 있는 유기물 오염관리 정책을 수립하기 위해서는 다양한 유기물의 근원을 정확하게 파악하는 것이 매우 중요하다. 본 연구의 목적은 금강 수계 최대 상수원인 대청호를 대상으로 3차원 수리-수질 모델을 적용하여 유기탄소 성분 별 유입과 유출, 내부생성 및 소멸량을 평가하고 저수지시스템에서의 유기탄소 물질수지를 해석하는 데 있다. 유기탄소 물질수지 해석을 위해 AEM3D 모델을 사용하였으며 2017년을 대상으로 입력자료를 구축한 후 보정을 수행하였고 2018년을 대상으로 모델을 검정하였다. 모델은 유기탄소를 입자성, 용존성, 그리고 난분해성과 생분해성으로 구분하여 모의하며 유기물질 성상별 실험결과를 이용하여 입력자료를 구축하였다. 유기탄소 물질수지 해석을 위해 4가지의 탄소성분과 조류 세포 내 탄소의 질량 변화율을 계산하였다. 이를 위해 외부 유입·유출부하율, 수체 내 생성(일차생산, 재부상, 퇴적물과 수체 간 확산) 및 소멸률(POC 및 조류 침강, DOC 무기화, 탈질)을 고려하였다. 모델은 2017년과 2018년의 물수지를 적절히 재현하였으며 저수지의 성층구조를 잘 재현해내면서 전반적인 수온, 수질을 적절하게 모의하였다. 연간 TOC 부하량 중 내부기원 부하량은 2017년 68.4 %, 2018년은 높은 강우량의 영향으로 55.0%로 산정되었다. 내부 소멸 기작 중 침전으로 인한 손실이 가장 높은 것으로 나타났으며, 2017년과 2018년 각각 31.3%, 29.0%로 나타났다. TOC의 공간분포는 Chl-a 농도 분포와 유사하게 나타났으며, 댐 설치로 형성된 정체수역은 유역의 유기물 순환에 많은 영향을 미치는 것으로 평가되었다. TOC 관리 정책 기초자료 확보를 위해서는 향후 유역-저수지 시스템을 연계한 유기물 물질순환 심층 연구가 필요하다.

• Korean Journal of Culture and Social Issue
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• v.19 no.2
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• pp.109-131
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• 2013

It is expected that expanded use of smartphone and enhanced information technology will enable smartwork to change individuals and organizations. Smartwork is expected to allow people to perform their roles without barriers of time and space. However, people tend not to accept and actively utilize smartwork. The present study is to examine how important flexibility-willingness is for performance outcome in the context of smartwork. It was hypothesized that flexibility-willingness mediates between perceived smartwork usefulness and work-family conflict. It was also hypothesized based on technology acceptance model that task interdependence and process control moderates the relationship between flexibility-willingness and work-family conflict because the relationship is not consistent. The results show that the mediation effect of the flexibility-willingness is statistically significant. The moderator effects of task interdependence was marginal proved but process control wasn't. From these results, we discussed the theoretical implications of findings, limitations, suggestions for future research in discussion.