• Journal of Ocean Engineering and Technology
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• 제29권3호
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• pp.270-282
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• 2015

A submerged body moving near the free surface needs to maintain its attitude and position to accomplish missions. It is necessary to validate the performance of a designed controller before a sea trial. The hydrodynamic coefficients of maneuvering are generally obtained by experiments or computational fluid dynamics, but these coefficients have uncertainty. Environmental loads such as the wave exciting force and suction force act on the submerged body when it moves near the free surface. Thus, a controller for the submerged body should be robust to parameter uncertainty and environmental loads. In this paper, the six-degree-of-freedom equations of motions for the submerged body are constructed. The suction force is calculated using the double Rankine body method. An adaptive control method based on an artificial neural network and proportional-integral-derivative control are used for the depth controller. Simulations are performed under various depth and speed conditions, and the results show the effectiveness of the designed controller.

• Journal of Korean Port Research
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• 제7권2호
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• pp.37-60
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• 1993

Because of the rapid growing traffic volumes of cargo, especially between Seoul and Inchon, and lack of investment into transport infrastructure in the past, in Kyong-in area have suffered from the serious traffic congestion in the public-road and the express-way network, But the further expansion of the traffic volume in near future is difficult due to burden of the higher expansion of the traffic volume in near future is difficult due to burden of the higher construction cost. Although the traffic congestion on the Kyung-in railway, is not very serious comparing with the road sector, the shortage of capacity on some main lines becomes emerged as a problem as railway traffic has increased. Unlike these two modes, the water transport, which has been paid relatively less attention for commodity transport in Kyong-in area, has not any constaint in this respect. Han river has been used as a water transport route in Chosun Dynasty which is called Cho-wun. This paper therefore aims to propose the availability of Han river as the alternative water transportation mode, in order to decrease the congestion between Seoul-Inchon by considering the construction of Kyong-in artificial water channel in near future. In this paper, we investigate the availability of Nanji-do as the physical distribution depot connecting with the circulation express way in the national capital distribution depot connecting with the circulation express way in the national capital. We also estimate the traffic volume by using the push-barge carrier (300DWT) in the same channel through the simulation under some assumptions such as ship's turnaround time, speed, etc.

• Journal of Environmental Health Sciences
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• 제50권2호
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• pp.83-92
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• 2024

Background: In this study, we investigate the rapid increase in environmental odors and notable rise in civil complaints near Dorim Stream in the Gwanak-gu area of Seoul. Objectives: This study aims to identify the causal compounds responsible for environmental odors in the Dorim Stream and investigate the structural characteristics of the stream that influence odor generation. Methods: The research methodology involved setting up 41 sampling points, selecting panels for direct sensory evaluation to assess odor intensity, measuring dissolved oxygen and hydrogen sulfide concentrations, and using all-in-one low-temperature desorption gas chromatography (ATD-GC) and thermal desorption-gas chromatography-mass spectrometry (TD-GC/MS) analysis to identify odor-causing compounds. Results: The evaluation of Dorim Stream revealed that in areas with complete meandering, there were lower dissolved oxygen levels (4.5±2.67 mg/L) and higher odor intensity (4.0±0.92), while in partially meandering sections, higher dissolved oxygen levels (7.8±1.15 mg/L) and lower odor intensity (2.8±1.06) were observed. Hydrogen sulfide levels measured with sensors increased with higher temperatures, especially in the afternoon hours (12:00~14:00). Acetaldehyde was the dominant odor compound detected in both the Bonglim Bridge (0.4 ppm) area and Guro Bridge area (0.867 ppm), with concentrations more than twice as high near Guro Bridge. Odor-causing compounds identified by TD-GC/MS indicated a pungent, sulfurous odor in the Guro Bridge area and a musty odor in the Bonglim Bridge area. Conclusions: This study categorizes and analyzes the sources of odor in Dorim Stream in Seoul based on meandering patterns and the distribution of sewage facilities, highlighting the potential odor issues associated with combined sewage systems and sewer junctions and suggesting policy improvements.

• Proceedings of the Korean Society of Computer Information Conference
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• 한국컴퓨터정보학회 2014년도 제49차 동계학술대회논문집 22권1호
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• pp.127-130
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• 2014

여행지에서 제공하고 있는 스탬프 투어링 서비스는 여행객들에게 특별한 기념이 되어주고 있지만, 스탬프를 받기 위한 장소를 찾기 어려운 점과 여행지의 주변 정보를 얻기 위해서는 여행자의 별도의 노력이 필요하다는 단점이 있다. 이러한 문제를 해결하기 위해 유명 관광지 및 추천 명소 등에 NFC 태그를 설치하고 간단한 태깅만으로 스탬프를 수집할 수 있는 어플리케이션을 제안한다. 또한 이 어플리케이션에 저장되는 정보와 평가를 이용해 사용자별 맞춤 여행 코스를 제공하고 사용자가 좀 더 편리하고 재미있는 여행을 즐길 수 있도록 돕고자 한다.

• Animal cells and systems
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• 제7권1호
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• pp.81-87
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• 2003

While screening proteins that interact with DnaA protein, the initiator protein for Escherichia coil chromosomal DNA replication, we found a 52-kD sized protein which bound to DnaA protein in a salt-dependent manner. This protein was identified as trigger factor, a ribosome-associated peptidyl-prolyl- cisltrans isomerase with chaperone activity. Trigger factor was overproduced and purified to near homogeneity, and its effect on the function of DnaA protein was examined, Enhanced binding of DnaA protein to DnaA box with no apparent supershift in the gel-shift experiments suggested that trigger factor, by virtue of its chaperone activity, exerts a change on DnaA protein thus increasing its binding affinity for DnaA box.

• Architectural research
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• 제21권2호
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• pp.31-39
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• 2019

Inspired by the success of the High-line project in New York, The Seoul Metropolitan Government launched a project to convert an overpass near Seoul station into a pedestrian park. Seoullo 7017 went through instant success after its opening in May 2017; however, there is a continuous controversy over its long-term impact as shown in the exemplary cases like the High-line project. This study aims for quantitative investigation through the comparative analysis between Seoullo 7017 and the High-Line in the perspectives of spatial configuration. Space Syntax was chosen as the analysis method for this research. Integration (3) in Space Syntax is known to have a high correlation with pedestrian volume; thus, by using this method, spatial structure was analyzed by comparing the statistically verified results of changes in the spatial structure of the Highline with those in Seoul. The results indicated that the influence of Seoullo 7017 was less than that of the High-line in terms of spatial configuration. The reason for this difference is spatial configuration between Manhattan and Seoul. The High-line is located in Manhattan which has an urban grid structure, whereas Seoul has non-geometric urban structure, the neighborhood unit in Korea. Also the center of the overpass isn't connected well with its surroundings.

• The Journal of the Korea institute of electronic communication sciences
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• 제11권2호
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• pp.159-164
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• 2016

A wireless communication system is required to be implemented with the low power circuits because it uses a battery having a limited energy. Therefore, the current mode circuit has been studied because it consumes constant power regardless of the frequency change. However, the clock-feedthrough problem is happened by leak of stored energy in memory operation. In this paper, we suggest the current memory circuit to minimize the clock-feedthrough problem and introduce a technique for ultra low power operation by inducing dynamic voltage scaling. The current memory circuit was designed with BSIM3 model of $0.35{\mu}m$ process and was operated in the near-threshold region. From the simulation result, the clock-feedthrough could be minimized when designing the memory MOS Width of $2{\mu}m$, the switch MOS Width of $0.3{\mu}m$ and dummy MOS Width of $13{\mu}m$ in 1MHz switching operation. The power consumption was calculated with $3.7{\mu}W$ at the supply voltage of 1.2 V, near-threshold voltage.

• Journal of Korean Society of Forest Science
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• 제52권1호
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• pp.31-36
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• 1981

The infrared specta of wood powders have been recorded both in the untreated stste and after treatment through 1%-NaOH extraction(2hrs) and alcohol-benzene mixture extraction. Differences between the spectra of 3 species(Pinus densiflora, Populus alba x glandulosa and Quercus mongolica) can be explained chiefly in terms of theirs chemical compositions through comparisions of the spectra of pure cellulose powders. 1. The peak near $3400cm^{-1}$ from wood powders appeared at $3420cm^{-1}$, which was shifted to left compared with pure cellulose powders. 2. Many new peaks appeared at 2725, 1730, 1660, 1640, 1600, 1510, 1500, 1460, 1385, 1270, 830 and $810cm^{-1}$ etc., which were not appeared in pure cellulose powders. 3. Pinus densiflora spectra of untreated powders showed small peak appeared at $2840cm^{-1}$, which was the most characteristic band. There were peaks at $1240cm^{-1}$ in Populus alba x glandulosa and Quercus mongolica spectra of untreated wood powders. 4. Treated wood powder spectra showed weak or no peaks at near $1730cm^{-1}$ and also at near $2920cm^{-1}$. $2840cm^{-1}$, near $1385-1365cm^{-1}$, near $1235cm^{-1}$ and $1110-1095cm^{-1}$ etc. 5. The Alcohol-benzene extractive spectrum from Pinus densiflora showed many peaks at $3600-2300cm^{-1}$, $3100-2800cm^{-1}$, $1700cm^{-1}$, $1450cm^{-1}$ and $1375cm^{-1}$ etc. The most characteristic band of the extractives appeared at $3100-2900cm^{-1}$.

• The Bulletin of The Korean Astronomical Society
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• 제40권1호
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• pp.54.3-54.3
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• 2015

To probe the star formation in local and early Universe, the NISS with a capability of imaging spectroscopy in the near-infrared is being developed by KASI. The main scientific targets are nearby galaxies, galaxy clusters, star-forming regions and low background regions. The off-axis optical design of the NISS with 15cm aperture was optimized to obtain a wide field of view (FoV) of $2deg.{\times}2deg.$ as well as a wide spectral coverage from 0.9 to $3.8{\mu}m$. The opto-mechanical structure was designed to be safe enough to endure in both the launching condition and the space environment. The dewar will operate $1k{\times}1k$ infrared sensor at 80K stage. The NISS will be launched in 2017 and explore the large areal near-infrared sky up to $200deg.^2$ in order to get both spatial and spectral information for astronomical objects. As an extension of the NISS, KASI is planning to participate in a new small space mission together with NASA. The promising candidate, SPHEREx (Spectro-Photometer for the History of the Universe Epoch of Reionization, and Ices Explorer) is an all-sky survey satellite designed to reveal the origin of the Universe and water in the planetary systems and to explore the evolution of galaxies. Though the survey concept is similar to that of the NISS, the SPHEREx will perform the first near-infrared all-sky imaging spectroscopic survey with the wider spectral range from 0.7 to $5{\mu}m$ and the wider FoV of $3.5deg.{\times}7deg.$ Here, we report the current status of the NISS and introduce new mission for the near-infrared imaging spectroscopic survey.

• Journal of the Korean Association of Geographic Information Studies
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• 제23권3호
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• pp.236-251
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• 2020

As remote sensing technologies are evolving, and more satellites are orbited, the demand for using satellite data for disaster monitoring is rapidly increasing. Although natural and social disasters have been monitored using satellite data, constraints on establishing an integrated satellite-based near real-time disaster monitoring system have not been identified yet, and thus a novel framework for establishing such system remains to be presented. This research identifies constraints on establishing satellite data-based near real-time disaster monitoring systems by devising and testing a new conceptual framework of disaster monitoring, and then presents a feasible disaster monitoring system that relies mainly on acquirable satellite data. Implementing near real-time disaster monitoring by satellite remote sensing is constrained by technological and economic factors, and more significantly, it is also limited by interactions between organisations and policy that hamper timely acquiring appropriate satellite data for the purpose, and institutional factors that are related to satellite data analyses. Such constraints could be eased by employing an integrated computing platform, such as Amazon Web Services(AWS), which enables obtaining, storing and analysing satellite data, and by developing a toolkit by which appropriate satellites'sensors that are required for monitoring specific types of disaster, and their orbits, can be analysed. It is anticipated that the findings of this research could be used as meaningful reference when trying to establishing a satellite-based near real-time disaster monitoring system in any country.