• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.77-83
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• 2018

A modular robot that memorizes motion can be easily created and operated because it expresses by hand. However, since there is not enough storage space in the module to store the user-created operation, it is impossible to reuse the created operation, and when the modular robot again memorizes the operation, it changes to another operation. There is no main controller capable of operating a plurality of modular robots at the same time, and thus there is a disadvantage that the user must input directly to the modular robot. To overcome these disadvantages, a remote controller has been proposed that can be operated in the surrounding smart devices by designing web server and component based software using wired and wireless network. In the proposed method, various types of structures are created by connecting to a modular robot, and the reconstructed operation is performed again after storing, and the usefulness is confirmed by regenerating the stored operation effectively. In addition, the reliability of the downloaded trajectory data is verified by analyzing the difference between the trajectory data and the actual trajectory. In the future, the trajectory stored in the remote controller will be standardized using the artificial intelligence technique, so that the operation of the modular robot will be easily implemented.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.49-59
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• 2017

Smart sensing plays a key role in a variety of IoT applications, and its importance is growing more and more together with the development of artificial intelligence. Therefore the importance of smart sensors cannot be overemphasized. However, most studies related to smart sensors have been focusing on specific application purposes, for example, security, energy saving, monitoring, and there are not much effort on researches on how to efficiently configure various types of smart sensors to be needed in the future. In this paper, a component-based framework with hierarchical structure for efficient construction of smart sensor is proposed and its application to smart home is designed and implemented. The proposed method shows that various types of smart sensors to be appeared in the near future can be configured through the design and development of necessary components within the proposed software framework. In addition, since it has a layered architecture, the configuration of the smart sensor can be expanded by inserting the internal or external layers. In particular, it is possible to independently design the internal and external modules when designing an IoT application service through connection with the external device layer. A small-scale smart home system is designed and implemented using the proposed method, and a home cloud operating as an external layer, is further designed to accommodate and manage multiple smart homes. By developing and thus adding the components of each layer, it will be possible to efficiently extend the range of applications such as smart cars, smart buildings, smart factories an so on.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.195-202
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• 2010

Cooling air-conditioning of APC (Agricultural Products processing Center) workplace is important to improve the working environment in the summer season. As existing cooling systems for air-conditioning of whole workplace are inefficient because of their high equipment operating costs, relatively inexpensive cooling system is required. The objectives of this study were to simulate the thermal flow fields in APC workplace having the positive and negative pressure type fan and pad systems and spot cooling system by using CFD software (FLUENT, 6.2) and estimate the cooling effectiveness of respective cooling systems. The results showed that the negative pressure type fan and pad system was inappropriate for the present APC workplace because of excessive outside air influx from open gateway and the positive pressure type fan and pad system created relatively low temperature field but non-uniform velocity field at worker positions. The spot cooling system could supply cool air to worker positions with relatively constant air velocity and temperature.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1261-1265
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• 2003

Axial piston pumps of bent axis have been commonly used in hydraulic systems because of high pressure level. best efficiency, low shear force on pistons and low operating costs. The other side, they have a few demerits like that they have the relatively high number of moving parts and more discharge pressure ripples. Especially, the discharge pressure ripples bring about vibrations and noises in hydraulic system components such as connecting pipes and control valves, so that these deteriorate the stability and accuracy of the systems. Therefore, the hydraulic systems having the axial piston pumps of bent axis require the methods to reduce the discharge pressure ripples. So, the purpose of this paper is to reduce the discharge pressure ripples by the phase interference of pressure wave and to develope the analysis model of the pumps to predict the discharge pressure ripples. In this paper, the analysis model of the axial piston pumps of bent axis was developed using the AMESim software, and the reliability of that was verified by the comparison with the experimental results. The hydraulic pipeline with a parallel line was used as the method to generate the phase interference of pressure wave. the dynamics characteristics of the hydraulic pipeline with a parallel line were analyzed by a transfer matrix method. the usefulness of the phase interference of pressure wave was investigated through the experiment and simulation. The results from the experiment and simulation said that the phase interference of pressure wave by the hydraulic pipeline with a paralle linel could reduce the discharge pressure wave of the pump well. The analysis model of the axial piston pumps of bent axis developed in this paper and the method of the phase interference by the hydraulic pipeline with a parallel line are expected to be helpful to achieve the design of the pump and to reduce the discharge pressure wave of the pump effectively.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.786-789
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• 1996

An image processing system was built to evaluate the color properties of apple and meat. The system consisted of video camera, video card, 32 bit microcomputer and an optical illuminator. The operating software was developed to carry out capturing, analyzing, displaying and storing of the 8 bit digitized images of food. The images of apples at various maturing stages were investigated to obtain the color histogram of R, G, B and Hunter value. RGB histogram showed a major difference in G value, 35.01, the minor change in R value, 6.16, and the negligible difference in B value. The image of beef cut was separated into two parts, fat and lean tissue, by applying threshold value method based on the digital value of color. The threshold value for fat was over 240 and for lean under 230 in R value, respectively. The resulting non fat image showed 2% decreased color difference value, ${\Delta}E$, than whole meat cut.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.109-115
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• 2020

As the maritime targets that threaten allies become lower, smaller, and faster, the need for analysis and modeling of clutter according to sea state increases. Clutter according to the sea state has a great influence on radar performance, such as lowering the probability of detection of low-altitude small maritime targets. In this paper, to analyze the detection performance of a multi function radar for a ship, a sea clutter model suitable for the radar operating environment is selected from several sea clutter models, and analysis of low-altitude, small target detection under a clutter is performed. By using the actual data of the already mounted radar for maritime target detection, four known clutter models have been implemented for each sea state and compared with the actual data. Through this, by selecting a clutter model that best reflects the actual radar environment, reliability of the clutter model is improved. Subsequently, the selected model is used to detect the detectable distance to the low-altitude small target.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.497-506
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• 2020

A chameleonic surface proposed in this study was a pin-art and 3D display device for generating arbitrary shapes. A smooth and continuous surface was formed using slim telescopic actuators and high-elasticity composite material. Realistic 3D shapes were continuously generated by projecting dynamic mapping images on the surface. A slim telescopic actuator was designed to show long strokes and minimize area for staking. A 3D shape was formed by thrusting and extruding the high-elasticity material using multiple telescopic actuators. This structure was advantageous for generating arbitrary continuous surface, projecting dynamic images and lightening weight. Because of real-time synchronization, a distributed controller based on EtherCAT was applied to operate hundreds of telescopic actuators smoothly. Integrated operating software consecutively generated realistic scenes by coordinating extruded shapes and projecting 3D image from multiple projectors. An opera content was optimized for the chameleon surface and showed to an audience in an actual concert.

• Nutrition Research and Practice
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• v.14 no.1
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• pp.20-24
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• 2020

BACKGROUND/OBJECTIVES: Malnutrition has multiple impacts on surgical success, postoperative complications, duration of hospital stay, and costs, particularly for cancer patients. There are various nutrition risk screening tools available for clinical use. Herein, we aim to determine the most appropriate nutritional risk screening system for esophageal cancer (EC) patients in China. SUBJECTS/METHODS: In total, 138 EC patients were enrolled in this study and evaluated by experienced nurses using three different nutritional screening tools, the Nutrition Risk Screening 2002 tool (NRS2002), the Patient-generated Subjective Globe Assessment (PG-SGA), and the Nutrition Risk Index (NRI).We compared sensitivity, specificity, positive and negative likelihood ratios, and Youden index generated by each of the three screening tools. Finally, cut-off points for all three tools were re-defined to optimize and validate the best nutritional risk screening tool for assessing EC patients. RESULTS: Our data suggested that all three screening tools were 100% sensitive for EC patients, while the specificities were 44.4%, 2.96%, and 59.26% for NRS 2002, PG-SGA, and NRI, respectively. NRI had a higher positive likelihood ratio as well as a higher area under the receiver operating characteristic curve compared to those of NRS 2002 and PG-SGA; although, all three tools had null negative likelihood ratios. After adjusting the cut-off points, the specificity and accuracy for all tools were significantly improved, however, the NRI remained the most appropriate nutritional risk screening system for EC patients. CONCLUSIONS: The NRI is the most suitable (highest sensitivity and accuracy) nutritional risk screening tool for EC patients. The performance of the NRI can be significantly improved if the cut-off point is modified according to the results obtained using MedCalc software.

• Investigative Magnetic Resonance Imaging
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• v.4 no.2
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• pp.128-135
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• 2000

Purpose : The aim of this study is to develope the Magnetic Resonance Spectroscopy(MRS) data processing S/W which plays an important role as a diagnostic tool in clinical field. Materials and methods : Post-processing software of MRS based on graphical user interface(GUI) under windows operating system of personal computer(PC) was developed using MATLAB(Mathwork, U.S.A.). This tool contains many functions to increase the quality of spectrum data such as DC correction, zero filling, line broadening, Gauss-Lorentzian filtering, phase correction, etc. And we obtained the normal human brain $^1H$ MRS data from parietal white matter, basal ganglia and occipital grey matter region using 1.5T Gyroscan ACS-NT R6 (philips, Amsterdam, Netherland) MRS package. The analysis of the MRS peaks were performed by obtaining the ratio of peak area. Results : The peak ratios of NAA/Cr, Cho/Cr, MI/Cr for the different MRS machines have a little different values. But these peak ratios were not significantly different between different echo time MRS peak ratios in the same machine (p<0.05). Conclusion : MRS post-processing S/W based on GUI using PC was developed and applied to the analysis of normal human brain $^1H$ MRS. This independent MRS processing job increases the performance and throughput of patient scan of main console. Finally, we suggest that the database for normal in-yivo human MRS data should be obtained before clinical applications.

• Membrane Journal
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• v.24 no.3
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• pp.223-230
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• 2014

A numerical analysis was performed for concentration of methane from the biogas using a polysulfone hollow fiber membrane permeator. Governing equations were derived for the countercurrent flow and numerically solved by using the Compaq Visual Fortran 6.6 software. When the methane mole fraction of feed was 0.5, the mole fraction of retentate increased from 0.5 to 0.8; the normalized retentate flow rate to the feed flow rate decreased from 1.0 to 0.57 at the given typical operating condition as the feed gas flowed from the inlet to the outlet of the membrane. As the methane mole fraction of feed was changed to 0.9, the methane mole fraction of retentate became 0.93 and the normalized retentate flow rate was changed to 0.91. When the pressure ratio of the permeate to the feed was varied from 0.33 to 0.17, there was a little difference in the methane mole fraction of retentate for the low stage cut of 0.1, whereas there was an significant increment for the high stage cut of 0.3. The retentate methane mole fraction remained relatively high despite the change of a stage cut as the area of the membrane increased from $1.14m^2$ to $2.57m^2$.