• Journal of Korea Multimedia Society
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• v.14 no.2
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• pp.153-170
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• 2011

OMTP (Open Mobile Terminal Platform) is a global forum made by telecommunications providers to promote user-oriented mobile services and data business. Devised by OMTP, BONDI is a browser-based application or a mobile web run-time platform to help widgets make good use of functions of mobile devices in a secure way. BONDI enables applications programmed with web standard technologies such as HTML, JavaScript, CSS, and AJAX to reach the internal functions of mobile devices. Since BONDI, which is not just a simple network application, can reach the internal resources of devices in standard ways, it enables the application and widgets to be developed regardless of tile OS or platform. Web browser-based widgets are vulnerable to the network environment, and their exeeution speed can be slowed as the operations of the widgets or applications become heavy. However, those web widgets will be continuously used thanks to the user-friendly simple interface and the faster speed in using web resources more than the native widgets inside the device. This study suggested a method to effectively operate and manage the resource of OMTP BONDI web widget and then provided an improved result based on a running performance evaluation experiment. The experiment was carried to improve the entire operating time by enhancing the module-loading speed. In this regard, only indispensable modules were allowed to be loaded while the BONDI widget was underway. For the purpose, the widget resource list, able to make the operating speed of the BONDI widget faster, was redefined while a widget cache was employed. In addition, the widget box, a management tool for removed widgets, was devised to store temporarily idle widgets.

• Journal of Energy Engineering
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• v.19 no.2
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• pp.103-115
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• 2010

Currently, many nations in the world make a strong effort to exploit the new and renewable energy. Tidal energy is the constant and regular power sources with higher and more stable quality compared to other renewable sources. The present paper reports the status of tidal energy analyzing its latest technology and development. In addition, a feasibility study on two types of tidal power plant(TPP) systems is conducted based on many assumptions, conditions and data involved in the Korea environment. The Sihwa and Uldolmok TPP are considered as the reference of tidal barrage(TB) and tidal in stream energy conversion(TISEC) type, respectively. While TB technology is currently mature and reliable, there still remain many environmental issues. Whereas, TISEC is recently received more attention due to its environmental friendly aspect. Therefore, the TISEC is believed to be very promising technology as the TPP. The unit electricity generation cost of Sihwa TPP is approximately 67.3 KRW/kWh. However, considering additional cost of Sihwa lake construction, it increases to 254 KRW/kWh. In Uldolmok, the unit electricity generation cost is calculated to be about 400 KRW/kWh, which is even higher than that of Sihwa TPP. This is ascribed to high cost of TISEC device and construction cost due to its technological infancy as well as relatively small power capacity. Nevertheless, the TISEC technology would be substantially developed in the future due to its many advantageous features.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.2
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• pp.47-52
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• 2015

A microbial fuel cell (MFC) is a device that can be obtained electricity from a variety of organic through the catalytic reaction of the microorganism. The MFC can be applied to various fields, and research is required to promote the performance of the microbial fuel cell for commercialization. The lower performance of an MFC is due to oxygen reduction at the cathode and the longer time of microbial degradation at anode. The MFC amount of power is sufficient but, in consideration of many factors, as a renewable energy, now commonly power density as compared to Nafion117 it is an ion exchange membrane used is PP (Poly Propylene) from 80 to about 11 fold higher, while reducing the cost to process wastewater is changed to a microporous non-woven fabric of a low cost, it may be energy-friendly environment to generate electricity. All waste, in that it can act as a bait for microorganisms, sustainability of the microbial fuel cell is limitless. The latest research on the optimization and performance of the operating parameters are surveyed and through the SSaM-GG(Smart, Shared, and Mutual- Green Growth) or GG-SSaM(Green Growth - Smart, Shared, and Mutual) as the concept of sustainable development in MFC, the middle indices are developed in this study.

• Composites Research
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• v.35 no.6
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• pp.371-377
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• 2022

Triboelectric nanogenerator (TENG) devices have generated a lot of interest in recent decades. TENG technology, which is one of the technologies for harvesting mechanical energy among the energy wasted in the environment, is obtained by the dual effect of electrostatic induction and triboelectric charging. Recently, a multilayer thin film stacking method (or layer-by-layer (LbL) self-assembly technique) is being considered as a method to improve the performance of TENG and apply it to new fields. This LbL assembly technology can not only improve the performance of TENG and successfully overcome the thickness problem in applications, but also present an inexpensive, environmentally friendly process and be used for large-scale and mass production. In this review, recent studies in the accomplishment of LbL-based materials for TENG devices are reviewed, and the potential for energy harvesting devices reviewed so far is checked. The advantages of the TENG device fabricated by applying the LbL technology are discussed, and finally, the direction and perspective of this fabrication technology for the implementation of various ultra-thin TENGs are briefly presented.

• Journal of Animal Environmental Science
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• v.17 no.2
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• pp.81-92
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• 2011

When we bury the infected poultry into the ground, we have many problems such as the difficulty of making sufficient area for burying, environmental contamination by the leachate, unpleasant ordor. Also, in case of burning the carcass of the infected poultry, there are some problems such as high cost, dust, unpleasant odor, etc. It could cause environmental contamination which many peoples and environmental organization complains about. In this study, we develop a treating system which treats the infected poultry carcass in a environmental method preventing the environment contamination. This system is composed of many processes. The euthanasia system uses rigid vinyl to trap and to do a euthanasia the infected poultry with lethal gas, carbon dioxide. And then, with the tractor attached grappler infected poultry carcass could be put into the carcass treating system. The euthanasia system uses rigid vinyl to trap the infected birds and to confine lethal gas, carbon dioxide. Infected poultry carcass are moved to carcass disposal system by collecting device which is attached at tractor. The carcass treatment system (capacity of disposal : 6.3 $m^3$) is installed on a truck and do one pass work, which is input, crush, stir, sterilize, and discharge treated carcass. 1,000 chickens was killed within 9.7min by $CO_2$ (300L/min) in the tent (10 $m^3$). The collecting device could carry 142 chickens at a time, and the movable carcass treatment system could sterilize 2 tons carcass per hour (at one time). This treatment systems was eco-friendly because it reduced the volume of carcass by 31.9% with no wastewater generation.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.83-89
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• 2020

For the past few decades, as part of efforts to protect the environment where fossil fuels, which have been a key energy resource for mankind, are becoming increasingly depleted and pollution due to industrial development, ecofriendly secondary batteries, hydrogen generating energy devices, energy storage systems, and many other new energy technologies are being developed. Among them, the lithium-ion battery (LIB) is considered to be a next-generation energy device suitable for application as a large-capacity battery and capable of industrial application due to its high energy density and long lifespan. However, considering the growing battery market such as eco-friendly electric vehicles and drones, it is expected that a large amount of battery waste will spill out from some point due to the end of life. In order to prepare for this situation, development of a process for recovering lithium and various valuable metals from waste batteries is required, and at the same time, a plan to recycle them is socially required. In this study, we introduce a nanoscale pattern transfer printing (NTP) process of Li2CO3, a representative anode material for lithium ion batteries, one of the strategic materials for recycling waste batteries. First, Li2CO3 powder was formed by pressing in a vacuum, and a 3-inch sputter target for very pure Li2CO3 thin film deposition was successfully produced through high-temperature sintering. The target was mounted on a sputtering device, and a well-ordered Li2CO3 line pattern with a width of 250 nm was successfully obtained on the Si substrate using the NTP process. In addition, based on the nTP method, the periodic Li2CO3 line patterns were formed on the surfaces of metal, glass, flexible polymer substrates, and even curved goggles. These results are expected to be applied to the thin films of various functional materials used in battery devices in the future, and is also expected to be particularly helpful in improving the performance of lithium-ion battery devices on various substrates.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.131-145
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• 2020

In line with the trend of industrial innovation, IoT technology utilized in a variety of fields is emerging as a key element in creation of new business models and the provision of user-friendly services through the combination of big data. The accumulated data from devices with the Internet-of-Things (IoT) is being used in many ways to build a convenience-based smart system as it can provide customized intelligent systems through user environment and pattern analysis. Recently, it has been applied to innovation in the public domain and has been using it for smart city and smart transportation, such as solving traffic and crime problems using CCTV. In particular, it is necessary to comprehensively consider the easiness of securing real-time service data and the stability of security when planning underground services or establishing movement amount control information system to enhance citizens' or commuters' convenience in circumstances with the congestion of public transportation such as subways, urban railways, etc. However, previous studies that utilize image data have limitations in reducing the performance of object detection under private issue and abnormal conditions. The IoT device-based sensor data used in this study is free from private issue because it does not require identification for individuals, and can be effectively utilized to build intelligent public services for unspecified people. Especially, sensor data stored by the IoT device need not be identified to an individual, and can be effectively utilized for constructing intelligent public services for many and unspecified people as data free form private issue. We utilize the IoT-based infrared sensor devices for an intelligent pedestrian tracking system in metro service which many people use on a daily basis and temperature data measured by sensors are therein transmitted in real time. The experimental environment for collecting data detected in real time from sensors was established for the equally-spaced midpoints of 4×4 upper parts in the ceiling of subway entrances where the actual movement amount of passengers is high, and it measured the temperature change for objects entering and leaving the detection spots. The measured data have gone through a preprocessing in which the reference values for 16 different areas are set and the difference values between the temperatures in 16 distinct areas and their reference values per unit of time are calculated. This corresponds to the methodology that maximizes movement within the detection area. In addition, the size of the data was increased by 10 times in order to more sensitively reflect the difference in temperature by area. For example, if the temperature data collected from the sensor at a given time were 28.5℃, the data analysis was conducted by changing the value to 285. As above, the data collected from sensors have the characteristics of time series data and image data with 4×4 resolution. Reflecting the characteristics of the measured, preprocessed data, we finally propose a hybrid algorithm that combines CNN in superior performance for image classification and LSTM, especially suitable for analyzing time series data, as referred to CNN-LSTM (Convolutional Neural Network-Long Short Term Memory). In the study, the CNN-LSTM algorithm is used to predict the number of passing persons in one of 4×4 detection areas. We verified the validation of the proposed model by taking performance comparison with other artificial intelligence algorithms such as Multi-Layer Perceptron (MLP), Long Short Term Memory (LSTM) and RNN-LSTM (Recurrent Neural Network-Long Short Term Memory). As a result of the experiment, proposed CNN-LSTM hybrid model compared to MLP, LSTM and RNN-LSTM has the best predictive performance. By utilizing the proposed devices and models, it is expected various metro services will be provided with no illegal issue about the personal information such as real-time monitoring of public transport facilities and emergency situation response services on the basis of congestion. However, the data have been collected by selecting one side of the entrances as the subject of analysis, and the data collected for a short period of time have been applied to the prediction. There exists the limitation that the verification of application in other environments needs to be carried out. In the future, it is expected that more reliability will be provided for the proposed model if experimental data is sufficiently collected in various environments or if learning data is further configured by measuring data in other sensors.

• Science of Emotion and Sensibility
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• v.16 no.1
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• pp.125-132
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• 2013

Recently, the consciousness of energy crisis is rapidly growing and sustainable eco-friendly energy sources are becoming issue. Therefore the portable electronic device requires new energy sources for providing continuous power supply and the power energy harvesting system of the human body that enables the power-harvesting research requests anytime, anywhere. One of the sources for energy harvesting is heat energy, which is the difference in temperature of the body and the surrounding environment. We tried to analyze the temperature difference between the environmental temperature and the temperature inside clothing according to the structure of the closed portion. And we examined the temperature difference between the environmental temperature and the temperature inside clothing according to the material of the clothing. The analysis showed that we have been able to get different results at parts of the body in the temperature inside clothing according to the structure of clothing. In upper torso of the chest and back, the temperature inside clothing of 'closed structure' was higher than the temperature inside clothing of 'opened structure'. In the section of arm and leg, it was reduced the difference of temperature inside clothing between 'closed structure' and 'opened structure'. It was particularly noticeable in the section of leg. The results of analysis of the difference between the environmental temperature and the temperature inside clothing according to the material of the clothing, in both cases of the two materials, 'closed structure' was higher than the 'opened structure' in the difference value between the environmental temperature and the temperature inside clothing. There was a difference according to the material in the section of leg. In this study, we outlined the basic guidelines for developing heat energy harvesting clothing by exploring the structure and material of clothing suitable for the heat energy harvesting.