• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.61.2-61.2
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• 2015

In the past decades, green energy, such as solar energy, wind power, hydropower, biomass energy, geothermal energy, and so on, has been widely investigated and developed to solve energy shortage. Recently, organic solar cells have attracted much attention, because they have many advantages, including low-cost, flexibility, light weight, and easy fabrication [1-3]. Organic solar cells are as a potential candidate of the next generation solar cells. In this abstract, to improve the power conversion efficiency and the stability, the inverted polymer solar cells with various structures were developed [4-6]. The novel cell structures included the P3HT:PCBM inverted polymer solar cells with AZO nanorods array, with pentacene-doped active layer, and with extra P3HT interfacial layer and PCBM interfacial layer. These three difference structures could respectively improve the performance of the P3HT:PCBM inverted polymer solar cells. For the inverted polymer solar cells with AZO nanorods array as the electronic transportation layer, by using the nanorod structure, the improvement of carrier collection and carrier extraction capabilities could be expected due to an increase in contact area between the nanorod array and the active layer. For the inverted polymer solar cells with pentacene-doped active layer, the hole-electron mobility in the active layer could be balanced by doping pentacene contents. The active layer with the balanced hole-electron mobility could reduce the carrier recombination in the active layers to enhance the photocurrent of the resulting inverted polymer solar cells. For the inverted polymer solar cells with extra P3HT and PCBM interfacial layers, the extra PCBM and P3HT interfacial layers could respectively improve the electron transport and hole transport. The extra PCBM interfacial layer served another function was that led more P3HT moving to the top side of the absorption layer, which reduced the non-continuous pathways of P3HT. It indicated that the recombination centers could be further reduced in the absorption layer. The extra P3HT interfacial layer could let the hole be more easily transported to the MoO3 hole transport layer. The high performance of the novel P3HT:PCBM inverted polymer solar cells with various structures were obtained.

• 대한안전경영과학회지
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• 제15권4호
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• pp.233-243
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• 2013

As companies were concerned with developing green logistics and environment, most logistics concerned functions like packaging, loading, storage, transportation and IT studies are active in study. Even if active in research studies, companies still recognized that logistics cost increases as green concepts are applied. For the efficient execution of green logistics management, it is absolutely necessary but difficult to build an optimal logistics system where each function is smoothly interacted through the proper integration and the link of various logistics functions and partners. This study aims to development of green logistics through integration of supply chain functions and partners. With this aim of study, case studies with analysis of embodiment, planning and operations for supply chain of companies are carried out.

• 펄프종이기술
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• 제33권2호
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• pp.81-86
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• 2001

The functions of food packaging are not only prevention from physical damage and loss during carrying and transportation, but also extension of shelf-life by adding antimicrobial substrate in packaging materials. Consumption of active packaging is gradually increasing. With different dosage of potassium sorbate(P.S.), the food preservative agent, antimicrobial papers were made by internal and external application of starch. The antimicrobial action of the paper was analyzed by the halo test and the shake flask method. The mechanical properties and strength were also measured. Antimicrobial papers adding P.S. showed higher values in tensile index than adding starch. The antimicrobial paper using starch showed similar microbe decreasing rate as that using P.S. Though microbe decreasing rate was 21.9%, it showed possibility to make antimicrobial paper using food preservative.

• 전기학회논문지
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• 제62권8호
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• pp.1157-1162
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• 2013

This thesis describes the active cruise control which is a part of AVHS(Advanced Vehicle and Highway System) in the ITS(Intelligent Transportation Systems). The active cruise control is a system which recognizes some obstructions and vehicles in front, drives in safe speed and puts on the brake in dangerous situations as the driver simply turns on the switch without stepping on the accelerator and brake. PID controller is used in the speed-control by linearizing the longitudinal model of the vehicle, obstacle detecting algorithm which makes use of the laser scanner is proposed to recognize the situation in front and the system's performance is tested.

• 전기학회논문지P
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• 제57권3호
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• pp.215-224
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• 2008

In this paper, we introduced a linear motor-based transfer system with an active pid controller which can be replaced with an automated guided vehicle (AGV) for the port automation. This system, which is named LMCTS(liner motor-based container transfer system), is based on PMLSM (permanent magnetic linear synchronous motor) which basically consists of stator modules on the rail and shuttle car. Therefore more progressive and adaptive control mechanisms should be required to control a system with large variation of container weight, the difference of each characteristic of stator modules, a stator module's trouble etc. We introduced an active control mechanism with an online tuning scheme using modified evolutionary strategy. Some computer simulations are implemented to assess the robustness of the proposed system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.630-635
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• 2008

An urban transit is representative public transportation which lots of people take everyday. Especially, the station of urban transit is one of the very important public civil infrastructures. From the teachings of subway fire disaster occurred at Daegu on 2003, a certain incident might create large numbers of deaths or injuries and a lot of damages to the subway station without having an accurate grasp of emergency situation and doing proper action on the situation. Therefore, the passive surveillance system, which means the present CCTV based system, needs to be changed into the active one. The active surveillance system is the CCTV based system with intelligent softwares which affords to prevent a certain incident or trouble and its aggravation. In this paper, the state of the art of the representative companies developing intelligent softwares and its application sites of Australia and Hong Kong are briefly introduced. Finally, with the consideration of its recent trends, some technical contents for the intelligent surveillance system of domestic urban transit are briefly described.

• Journal of Power Electronics
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• 제16권1호
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• pp.102-110
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• 2016

Contactless power transfer technology is gaining increasing attention in city transportation applications because of its high mobility and flexibility in charging and its commensurate power level with conductive power transfer method. In this study, an inductively coupled contactless charging system for a 48 V light electric vehicle is proposed. Although this study does not focus on system efficiency, the generic problems in an inductively coupled contactless power transfer system without ferromagnetic structure are discussed. An active load matching method is also proposed to control the power transfer on the receiving side through a load matching converter. Small signal modeling and linear control technology are applied to the load matching converter for port voltage regulation, which effectively controls the power flow into the load. A prototype is built, and experiments are conducted to reveal the intrinsic characteristics of a series-series resonant inductive power charger in terms of frequency, air gap length, power flow control, coil misalignment, and efficiency issues.

• International Journal of Automotive Technology
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• 제5권2호
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• pp.77-88
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• 2004

Narrow commuter vehicles can address many congestion, parking and pollution issues associated with urban transportation. In making narrow vehicles safe, comfortable and acceptable to the public, active tilt control systems are likely to playa crucial role. This paper focuses on the development of an active direct tilt control system for a narrow vehicle that utilizes an actuator in the vehicle suspension. A simple PD controller can stabilize the tilt dynamics of the vehicle to any desired tilt angle. However, the challenges in the tilt control system design arise in determining the desired lean angle in real-time and in minimizing tilt actuator torque requirements. Minimizing torque requirements requires the tilting and turning of the vehicle to be synchronized as closely as possible. This paper explores two different control design approaches to meet these challenges. A Receding Horizon Controller (RHC) is first developed so as to systematically incorporate preview on road curvature and synchronize tilting with driver initiated turning. Second, a nonlinear control system that utilizes feedback linearization is developed and found to be effective in reducing torque. A close analysis of the complex feedback linearization controller provides insight into which terms are important for reducing actuator effort. This is used to reduce controller complexity and obtain a simple nonlinear controller that provides good performance.

• International Journal of Control, Automation, and Systems
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• 제2권4호
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• pp.450-462
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• 2004

In this paper, we describe a system for controlling the perceptual processes of two cooperative mobile robots that addresses the issue of enhancing perceptual awareness. We define awareness here as knowing the location of other robots in the environment. The proposed system benefits from a formalism called perceptual anchoring. Here, perceptual anchoring enhances the awareness of the system by employing an anchor-based active gaze control strategy or active perceptual anchoring to control the perceptual effort according to what is important at a given time. By anchoring we extend the notion of awareness as knowing what the symbols in the control module represent to by connecting them to the objects or features in the environment. We demonstrate the present system through a simulation of two nonholonomic mobile robots performing a cooperative transportation by carrying a cargo to a target location where there are two other robots moving about. The system is able to efficiently focus the perceptual effort and thus able to safely carry the cargo to the target position.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권3호
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• pp.41-49
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• 2022

This study utilized citric acid as a floating agent in biological denitrification process and assessed its role under different carbon supplying conditions. Several microcosm tests including citric acid active (CAA), precipitating tablet release active (PTRA) and floating tablet release active (FTRA) were conducted to evaluate nitrate denitrification efficacy. In CAA reactors, nitrate removal was accompanied by the formation of denitrification by-products such as nitrite and nitrous oxide, with the extent of nitrate removal being proportional to citric acid concentration. These results suggest that citric acid induced heterotrophic biological denitrification. PTRA reactor that incorporated CAA and the same electron donor showed a similar denitrification efficiency to CAA reactor. FTRA reactor, which contained the same amount of fumarate as PTRA, enhanced denitrification by 7% as compared to the PTRA reactor. The overall results of this work indicate that surplus citric acid can be efficiently utilized in heterotrophic denitrification.