• Journal of Microbiology and Biotechnology
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• v.9 no.4
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• pp.464-468
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• 1999

The effectiveness of current biodegradation test methods for degradable polymers under controlled composting conditions was studied in regards to the test temperature and compost condition. When biodegradability tests for the natural (starch, cellulose, PHB/HV) and synthetic (PCL, SG, PLA) polymers were conducted at temperature levels of 35 and $55^{\circ}C$ with compost cured at ambient temperature, the degradations of cellulose and starch were higher at $35^{\circ}C$ because of the priming effect. On the other hand, degradations of other polymers were higher at $55^{\circ}C$. In the biodegradation test at $55^{\circ}C$, compost harvested right after the thermophilic degradation stage showed higher biodegradation activities than the cured compost for both the synthetic aliphatic polyester (SG) and a natural polymer, cellulose. These results suggest that the biodegradation test conducted at $55^{\circ}C$ with the compost, harvested right after the thermophilic degradation stage during composting, showed the highest biodegradation activity under controlled composting conditions.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.801-809
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• 2013

We investigate sensitivity and limit of detection (LOD) of trace copper (Cu) metal using pristine carbon nanotube (CNT) and acidified CNT (ACNT) electrodes. Squarewave based anodic stripping voltammetry (SWASV) is used to determine the stripped Cu concentration. Prior to performing the SWASV measurements, its optimal conditions are determined and with that, effects of potential scan rate and $Cu^{2+}$ concentration on stripping current are evaluated. The measurements indicate that (1) ACNT electrode shows better results than CNT electrode and (2) stripping is controlled by surface reaction. In the given $Cu^{2+}$ concentration range of 25-150 ppb, peak stripping current has linearity with $Cu^{2+}$ concentration. Quantitatively, sensitivity and LOD of Cu in ACNT electrode are 9.36 ${\mu}A\;{\mu}M^{-1}$ and 3 ppb, while their values are 3.99 ${\mu}A\;{\mu}M^{-1}$ and 3 ppb with CNT electrode. We evaluate the effect of three different water solutions (deionized water, tap water and river water) on stripping current and the confirm types of water don't affect the sensitivity of Cu. It turns out by optical inspection and cyclic voltammetry that superiority of ACNT electrode to CNT electrode is attributed to exfoliation of CNT bundles and improved interfacial adhesion occurring during oxidation of CNTs.

• Journal of the Korean Ceramic Society
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• v.52 no.1
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• pp.13-18
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• 2015

The fabrication method used for mineral hydrate is similar to that of ALC (autoclaved lightweight concrete), but the fabrication of normal slurry with a considerable amount of a foaming agent is difficult due to material separation and collapse of the slurry. Therefore, the development of fabrication methods for normal slurry is necessary. The final product, mineral hydrate insulation, has excellent thermal properties but poor strength characteristic given the many pores. In this study, in order to fabricate normal slurry, the viscosity and foaming time of the slurry were controlled. The mixing ratio of the starting material and the polypropylene fiber was controlled to improve the strength. Mineral hydrate with polypropylene fiber showed a higher strength than that without this type of fiber. Specifically, the compressive strength of mineral hydrate with 2% polypropylene fiber added to it was more than 40% higher than that without the fiber.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1215-1221
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• 2023

According to the study and experiments performed on the Improvement of Maintaining Temperature of Aviation Dangerous Goods, a conclusion was drawn that clear technical guidelines should be established from the design and assembly stage of temperature-controlled packaging, taking into account actual transportation environment. In particular, profiles consisting of only two types of summer and winter are difficult to adjust flexibly in transportation process with severe weather and temperature changes such as spring and fall. To this end, there is a need to establish a compromise profile configuration for summer and winter. It was also found that the condition of the refrigerant, temperature control, and the speed of the packaging operation have a significant impact on maintaining constant temperature. Therefore, all packing operations need to be completed within a short period of time in the environment close to the target temperature. The current packing instructions provided by packaging manufacturers do not provide precise instructions on post-conditioning, but the experiments in this study confirmed that post-conditioning is very important for maintaining the target temperature, so it is necessary to provide precise legal packing technical instructions.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.591-596
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• 2002

Fused deposition(FD) modeling by Stratasys Inc., is one of the material deposition subfamilies of solid freefrom fabrication(SFF) technologies. In this process, build material in the form of a flexible filament, is heated to a semi-liquid state and extruded from a controlled deposition head onto a fixtureless table in a temperature controlled environment. The position of nozzle is computer controlled relative to the base, which allows geometric complex models to be made to precise dimensions. FDM provide what the part was directly tested by the worker. It provide believable data. This Study is identify to surface roughness by build orientation adjustment. So, the paper is the study on surface roughness by build orientation at FDM.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.977-983
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• 2005

In this paper, novel ubiquitous concept of real reality robot game controlled by a mobile server robot is proposed. Real reality robot game means that two real robots controlled by humans/computers through the internet are playing a boxing game. The mobile server robot captures playing images of the boxing game and sends them to GUI on the screen of human operators' PC. The human operator can login to the boxing game from any computer in any place if he/she is permitted. Remote control of a boxing robot by a motion capture system through network is implemented. Successful motion control of a boxing robot remotely controlled by a motion capture system through network can be achieved. In addition, real boxing games between a human and a computer are demonstrated.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.387-392
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• 2001

Fused deposition(FD) modeling by Stratasys Inc., is one of the material deposition subfamilies of solid freeform fabrication(SFF) technologies. In this process, build material in the form of a flexible filament, is heated to a semi-liquid state and extruded from a robotically controlled deposition head onto a fixtureless table in a temperature controlled environment. The position of nozzle is computer controlled relative to the base, which allows geometric complex models to be made to precise dimensions. FDM provide what the part was directly tested by the worker. It provide believable data. This study is experiment on surface roughness of part at FDM

• Journal of Power Electronics
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• v.6 no.2
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• pp.146-162
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• 2006

This paper deals with the analysis, design and implementation of an AC-DC Zeta converter in discontinuous current mode (DCM) of operation used for power quality improvement at AC mains in direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drives. The designed Zeta converter feeds a direct torque controlled PMSM drive system. Modeling and simulation is carried out in a standard PSIM software environment. Test results are obtained on the developed prototype Zeta converter using DSP ADMC401. The results obtained demonstrate the effectiveness of the Zeta converter in improving power quality at AC mains in the PMSM drive system.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.1
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• pp.1-6
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• 2008

The ubiquitous sensor network technique is widely applied to variety of information fields such as home automations, logistics, traffic controls, public administrations, health and environment monitoring and etc. It is particularly useful in the areas where energy consumption is minimal and where continuous monitoring of the surrounding environments, which generates streams of data, are required. In this study, we have designed and implemented a living environment automatic control system which collects the streams of temperature, humidity, light and noise data of a simulated house setting in real-time fashion, then controls the home environment based on the collected data according to the users favorites. In order to differentiate the proposed system from the currently existing similar system, we have demonstrated not only the feasibility of collecting data using sensor network in the controlled environment but also the ability to control the various household equipments through wireless communications.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2337-2340
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• 2002

This paper presents the method of AGV(Automatic guided vehicle)'s moving environment(plane, corner, edge) recognition using SONAR sensor configuration. As for the SONAR sensor, the Crosstalk effect has been generally considered as an inevitable noisy phenomenon in the indoor environment. However, this effect can be used as a clue for classifying and localizing targets in the indoor environment if those can be controlled and used well. EERUF(error eliminate rapid ultrasonic firing) is a method for firing multiple ultrasonic sensors in mobile robot application and multi-echo mode of POLARIOD Device can reduce the Crosstalk effect. Here, Crosstalk effect was reduced using EERUF and applied to the AGV with a simple wall-following algorithm in the indoor environment. This method was tesed by a typical AGV with multi SONAR sensors in the laboratory environment.