• Membrane Journal
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• v.24 no.6
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• pp.417-422
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• 2014

The poly(ethylene oxide) (PEO)/Ag Nanoparticles (NPs)/7,7,8,8-Tetracyanoquinodimethane (TCNQ) membrane was fabricated to obtain highly permeable facilitated olefin transport nanocomposite membrane, compared with PEO/Ag NPs/p-Benzoquinone (p-BQ) membrane. Polymer matrix, PEO and silver nanoparticle precursor $AgBF_4$ were fixed at 1 : 0.4 mole ratio and electron acceptor TCNQ content was controlled variously. And the best olefin separation performance was obtained at 1/0.4/0.004 mole ratio, and long-term separation performance was measured at this ratio. As a result, mixed-gas permeance decreased from 23 to 6 GPU, and selectivity decreased from 6 to 2 (propylene/propane) after 32 hours.

• Industry Promotion Research
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• v.2 no.2
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• pp.1-6
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• 2017

SCADA (Supervisory Control and Data Acquisition) System was first introduced to the Seoul Electricity Authority, which manages the transportation part among the three business fields that produce, transport and supply electric power in Korea. Has been using the data link with 1200 bps and 9600 bps in 5 protocols such as HARRIS 6000, BSC, HDLC, L & N and Toshiba by configuring 3 layers of EMS, SCADA and RTU computer equipments in 1: N radial form. This paper presents the OSI standard network packet flow, analyzing DataLink and Network Layer, and presents a KEPCO SCADA network model composed of X.25 high - speed communication network using 3 layers of network. We proposed a future SCADA communication structure that improved the current SCADA communication structure, defined the SCADA DB structure, introduced the concept of the remote SCADA gateway to the SCADA functional structure, applied the standard communication protocol, Multiplexing of surveillance and control in other local facilities and ensuring communication openness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.74-79
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• 2016

The Seoul Metropolitan Subway, which started operating in 1974, plays a major role in transporting 7,289 thousands passengers daily. This trend of a steadily increase in passengers from 2012 has increased the congestion rate because of the limited capacity and time. To solve this problem, Seoul city is consistently working on improving the subway facilities, such as the construction of a detour path. This project, however, has only a slight effect on improving the congestion rate and is too expensive to construct the facilities. Hence, this study suggests The Congestion Standardization System based on the IoT for improving the subway congestion rate. Based on the system, the expected effect analysis was performed, which resulted in a decrease in ride passengers from 34 to 20. In addition, this expected effect analysis shows that the number of subway vehicles can increase from 20 to 24. The suggested system will have a significant effect on the efficiency of the management system.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.69-72
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• 2021

Various studies for QLEDs using inkjet printing has been actively conducted. Multilayers in QLEDs need an orthogonal process inevitably using different solvents and it makes the inkjet printing process more difficult and expensive. Therefore, coating two layers in a single process can reduce the fabrication step, resulting in the process time. In this study, we fabricated QLEDs of standard structure using a mixture of emission layer and hole transport layer. The mixed layer was fabricated by dissolving TFB and QDs in chlorobenzene, and the maximum luminance of the device was 45,850 cd/m². It shows the bright future of the electroluminescence devices applied with inkjet printing process.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4D
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• pp.323-330
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• 2010

The time in port for vessels is one of the important factors for analyzing the operation status and the capacity of ports. In addition, the time in port for vessels can be directly used for estimating the greenhouse gas emissions resulted from vessels in port. However, it is unclear which variables can affect the time in port for vessels and what the marginal effect of each variable is. With these challenges in mind, the study analyzes the time in port for vessels arriving and departing port of Busan by using a parametric survival model. The results show that the log-logistic accelerated failure time model is appropriate to explain the time in port for 19,167 vessels arriving and departing port of Busan in 2008, in which the time in port is significantly affected by gross tonnage of vessels, service capacity of terminal, and vessel type. This study also shows that the greenhouse gas emission resulted from full-container vessels, which accounted for about 61% of all vessels with loading/unloading purpose arriving and departing port of Busan in 2008, is about "17 ton/vessel" in the boundary of port of Busan. However, the hotelling greenhouse gas emissions resulted from non-container vessels (3,774 vessels; 20%) are greater than those from the full-container vessels. Hence, it is necessary to take into account more efficient port management polices and technologies to reduce the service time of non-container vessels in port of Busan.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.5
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• pp.217-227
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• 2017

The object of this study is to estimate the net volume transport and the residual flow that changed by space and time at southern part of Yeomha channel, Gyeonggi Bay. The cross-section observation was conducted at the mid-part (Line2) and the southern end (Line1) of Yeomha channel for 13 hours during neap and spring-tides, respectively. The Lagrange flux is calculated as the sum of Eulerian flux and Stokes drift, and the residual flow is calculated by using least square method. It is necessary to unify the spatial area of the observed cross-section and average time during the tidal cycle. In order to unify the cross-sectional area containing such a large vertical tidal variation, it was necessary to convert into sigma coordinate system by horizontally and vertically for every hour. The converted sigma coordinate system is estimated to be 3~5% error when compared with the z-level coordinate system which shows that there is no problem for analyzing the data. As a result, the cross-sectional residual flow shows a southward flow pattern in both spring and neap tides at Line2, and also have characteristic of the spatial residual flow fluctuation: it northwards in the main line direction and southwards at the end of both side of the waterway. It was confirmed that the residual flow characteristics at Line2 were changed by the net pressure due to the sea level difference. The analysis of the net volume transport showed that it tends to southwards at $576m^3s^{-1}$, $67m^3s^{-1}$ in each spring tide and neap tide at Line2. On the other hand, in the control Line1, it has tendency to northwards at $359m^3s^{-1}$ and $248m^3s^{-1}$. Based on the difference between the two observation lines, it is estimated that net volume transport will be out flow about $935m^3s^{-1}$ at spring tide stage and about $315m^3s^{-1}$ at neap tide stage as the intertidal zone between Yeongjong Island and Ganghwa Island. In other words, the difference of pressure gradient and Stokes drift during spring and neap tide is main causes of variation for residual current and net volume transport.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.346-349
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• 2007

치밀한 $CuInSe_{2}$ (CIS) 태양전지용 광흡수층을 제조하기 위해 상용되는 출발물질을 이용하여 비진공방식인 paste coating 법으로 CIS 막을 제조하였다. 먼저 치밀한 CIS 막 제조를 위해 $Cu_{2}Se$의 액상 거동을 관찰하였다. 이러한 $Cu_{2}Se_{2}$의 액상거동을 위해 Se 분위기에서 Se 증발온도, 기판온도, 열처리시간 등을 다양하게 변화 시켰으며, Se 증발온도 $450^{\circ}C$, 기판온도 $550^{\circ}C$, 열처리시간 30분 그리고 수송가스 ($N_{2}$)를 20 sccm으로 최적조건을 형성하였다. 이러한 최적조건을 바탕으로 치밀한 CIS막을 위해 two-zone RIP (rapid temperature process) 방법으로 Se 분위기 안에서 셀렌화를 위한 열처리를 행하였다. 셀렌화를 위해 다양한 열처리시간에 따라 형성된 CIS 막은 CIS 광흡수층과 Mo 박막 사이에서 $MoSe_{2}$ 층이 형성되었지만, 균일한 CIS 막을 얻었으며 업자성장과 치밀화 거동을 관찰 하였다. 또한, CIS 막의 치밀화를 위해 Se 증발온도와 열처리시간을 고정하고 기판온도를 $600^{\circ}C$로 증가시켜 $Cu_{2}Se$의 액상거동을 관찰하였다. $600^{\circ}C$에서 형성된 CIS 막은 기판온도 $500^{\circ}C$의 시편보다 입자성장과 치밀화가 되었으나 기판으로 사용하는 soda-lime glass의 휨 현상이 발생하였다.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.280-292
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• 2014

A tram has been the focus of a new public transportation that can solve a traffic jam, decreasing of public transit usage and environmental problem in recent years. This study aims to develop a signal optimization model for considering the traffic signal progression of tram and vehicles, when they are operated simultaneously in the same signalized intersections. This research developed the KS-SIGNAL-Tram model to obtain a minimum tram bandwidth and to minimize a vehicle's delay to perform a tram passive signal priority, it is based on the KS-SIGNAL model and is added to the properties of a tram and it's system. We conducted a micro simulation test to evaluate the KS-SIGNAL-Tram model, it showed that the developed optimization model is effective to prevent a tram's stop on intersection, to reduce a tram's travel time and vehicle's delay.

• Fire Science and Engineering
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• v.31 no.5
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• pp.1-6
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• 2017

The fire and explosion properties of combustible materials are necessary for the safe handling, storage, transportation and disposal. Typical combustion characteristics for process safety include auto ignition temperature(AIT). The AIT is an important index for the safe handling of combustible liquids. The AIT is the lowest temperature at which the material will spontaneously ignite. In this study, the AITs and ignition delay times of n-pentanol and p-xylene mixture were measured by using ASTM E659 apparatus. The AITs of n-pentanol and p-xylene which constituted binary system were $285^{\circ}C$ and $557^{\circ}C$, respectively. The experimental AITs and ignition delay times of n-pentanol and p-xylene mixture were a good agreement with the calculated AITs and ignition delay times by the proposed equations with a few A.A.D. (average absolute deviation). Therefore, it is possible to estimate the AITs and ignition delay times in other compositions of n-pentanol and p-xylene mixture by using the predictive equations which presented in this study.

• Proceedings of The KACE
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• 2017.08a
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• pp.189-192
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• 2017

던지기는 시간 효율이 높은 물체 수송 방법이나 그 정확성을 위해서는 다양한 물리적인 변인들을 고려해야 한다. 따라서 본 연구에서는 정확한 던지기에 영향을 주는 변인들을 설정하여 물체를 정확하게 던지는 해를 찾는 유전 알고리즘을 설계하고, 이를 4자유도 로봇팔에 적용시켰다. 하드웨어는 TETRIX와 EV3 플랫폼을 이용하여 설계하였고, 소프트웨어는 LabVIEW 2014를 이용하여 구현하였다. 또한 물체가 던져질 때마다 위치와 각 변인들의 값을 수집하고, 이를 통계적으로 분석하여 던지기의 정확성에 대한 각 관절의 기여도를 분석하였다. 본 연구의 결과는 물체를 정확히 던지는 기계를 설계하거나 사람의 던지는 동작을 이해하는 데 도움이 될 것으로 기대된다.