• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2508-2519
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• 1994

In this thesis, two possible schemes for power feeding are considered. The first one is the network power feeding, and the other is the power feeding from the rechargeable battery. Though each scheme has its merits and demerits, the domestic network operator has proposed the latter due to the large deviation of line resistance, high power loss, and safety. This scheme, however, has several problems. The usage is limited by the life of battery leading to the failure of minimal voice service for many hours. The space occupation of that battery is another serious problem. Moreover, the network opeator should have overhead of maintenance and repair. In order to alleviate such the difficulties, the sealing current is introduced through the subscriber loop. Flowing the current into the loop prevents from rusting. This thesis designs a power controller using PEB2025 to control various amount, duration, and period of this sealing current, to achieve the optimum current supply for sealing.

• Journal of Digital Contents Society
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• v.18 no.3
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• pp.607-612
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• 2017

The use of RaspberryPi in building an embedded system may be difficult for users in understanding the circuit and the hardware cost. This paper proposes a solution that can test the systems virtually. The solution consists of three elements; (i) editor, (ii) interpreter and (iii) simulator and provides nine full modules and also allows the users to configure/run/test their own circuits like real environment. The task of abstraction for modules through the actual circuit test was carried out on the basis of the data sheet and the specification provided by the manufacturer. If we can improve the level of quality of our solution, it can be useful in terms of cost reduction and easy learning. To achieve this end, the electrical physics engine, the level of interpreter that can be ported to the actual board, and a generalization of the simulation logic are required.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.2
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• pp.42-49
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• 2014

A broadband antenna using a main and a sub antenna for the mobile communication terminal such as mobile phone and ITS terminal is designed. Two antennas are based on the hybrid antenna that is operating both a monopole and a IFA(Inverted F Antenna). It's applied the transmission line to connect both antennas. Sub antenna located in small space of the terminal allows space usability for the terminal design. Antenna for the hexa-frequency band of LTE700, CDMA, GSM, DCS, PCS and WCDMA is designed and implemented on the bare PC board that is same size of the mobile phone. This antenna was measured 3 : 1 VSWR over the whole design band. And average gains and efficiencies were-3.78 ~ -2.62dBi and 41.9 ~ 54.73% for LTE700/CDMA/GSM frequency band, -3.75 ~ -1.84dBi and 42.19 ~ 65.46% for DCS/PCS/WCDMA frequency band.

• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.39-47
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• 2012

Currently, most of the frequency spectrum resources are allocated and due to the lack of frequency, low frequency band, optimal for wireless communication environment is not used. Therefore, Cognitive Radio (CR) is a critical issue to solve the spectrum scarcity and to improve frequency spectrum utilization in wireless communication. In this paper, we implement data transmission and receive in a real CR system using the USRP(Universal Software Radio Peripheral) board and GNU Radio package of an open source development kit. Concretely, we detect the Primary User by spectrum sensing, and then we send Primary User information to the database. After receiving the information, because the database already sent optimal transmit power, bandwidth and channel information to CR equipment, CR can communicate without any interference to Primary User.

• The KIPS Transactions:PartD
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• v.15D no.5
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• pp.691-698
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• 2008

Web designers generally use a story board, a site map, a flow chart or the combination of these for representing web sites. But these methods are difficult to represent the entire architecture of a web site, and may be not adaptive for describing the detail flow of web pages. To solve these problems to some degree, there were works using EMFG(Extended Mark Flow Graph) recently. However the conventional EMFG representation method is not adaptive to represent the dynamic interface of web sites because that cover only the static parts of a web site. Internet utilization is rapidly growing in our life and we cannot imagine the worlds of work, study and business without internet. And web sites recently have not only more complex and various architecture but also web pages containing the dynamic interface. Therefore we propose the representation method of these web sites - for example, a web site containing varying pages with time and varying page status or contents with mouse operations - using EMFG. We expect our work to be help the design and maintenance of web sites.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.2
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• pp.165-176
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• 2021

To solve environmental problems, research and efforts are required to reduce leather waste that is generated in large quantities during the leather manufacturing process. Leatherboard is a plate-like material that is made by crushing leather waste, such as trimming or shaving scraps and mixing fibers, pulp, rubber, and adhesives. The aim of this study is to provide basic data on the localization of leatherboard manufacturing technology for outsoles, which are increasingly in demand due to their excellent performance and price competitiveness. Interviews with experts and related organizations were conducted to investigate the related global technology trends. Also, the performance of three products that can be used as reference materials were evaluated and compared. As part of the research and efforts to reduce the amount of leather waste generated, high-performance materials using leather waste were developed and commercialized by major western companies. In Korea, various efforts have been made since 2000, and some companies have produced leatherboard for interior uses. However, the amount of waste recycled relative to that generated is not large due to the limited demand. Natural leather soles perform better than leatherboard soles in all evaluation aspects. In the case of leatherboard, performance varied by manufacturer. German products showed flexibility resistance and dimensional stability, thereby meeting performance requirements. However, abrasion resistance and cleavage resistance were slightly below the required performance standards, and research and development is needed to improve performance in those areas. Currently, it is impossible to evaluate the performance of domestic products due to underdevelopment. However, if the development of process technology continues based on the performance evaluation results of the best leatherboard in the shoe industry, materials for outsoles will be able to be produced domestically with prices competitiveness while realizing natural leather materials performance to some extent.

• Journal of the Korea Society of Computer and Information
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• v.27 no.6
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• pp.117-122
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• 2022

In this paper, we developed a vehicle control terminal using IoT and low-power long-distance communication (NB-IoT) technology. This system collects information on the location and status of a parked vehicle, and transmits the vehicle status to the vehicle owner's terminal in real time with low power to prevent vehicle theft, and in the case of a vehicle in motion, When primary information about the vehicle, such as an impact, is collected and transmitted to the server, the server analyzes the relevant data to generate secondary information on traffic congestion, road damage, and safety accidents. By sending it, you can know the exact arrival time of the vehicle at its destination. This terminal device is an IoT gateway for a vehicle and can be connected to various wired and wireless sensors inside the vehicle. In addition, the data collected from vehicle maintenance, efficient operation, and vehicles can be usefully used in the private or public sector.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.38-47
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• 1997

A new weighing sensor for the automatic diameter control system of the crystal growth is developed in this study. This weighing sensor measures the frequency of the vibrating element which is lineally changing with respect to weight. The signal and the power of this system are transmitted without any physical contact, so that this sensor offers high accuracy and resolution. This system consists of a string, a sinusoidal wave generator, an automatic amplification adjusting circuit, signal transformers and a PCB. 4 kinds of programs are developed for checking DAC, weight calibration and controlling growth process. The measurements of the standard deviation and the resolution show $\pm0.10g$(measured at every second) and $5{\times}10^{-5}$, respectively, This weighing sensor is effective under high pres-sure of 200 atm, high temperature and vacuum condition. The weighing system can control the temperature in the accuracy of $\pm0.025^{\circ}C$ with the 'signal divider'. The optical quality single crystals of $(YGd)_3Sc_2Ga_3O_{12},\;Er-Y_3Sc_2Al_3O_{12},\;and\;Bi_{12}GeO_{20}$ have been grown by Czo-chralski method using this auto-diameter control system.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1159-1166
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• 2009

The use of cone-beam computed tomography(CBCT) has been proposed for guiding the delivery of radiation therapy. A kilovoltage imaging system capable of radiography, fluoroscopy, and cone-beam computed tomography(CT) has been integrated with a medical linear accelerator. A standard clinical linear accelerator, operating in arc therapy mode, and an amorphous-silicon (a-Si) with an on-board electronic portal imager can be used to treat palliative patient and verify the patient's position prior to treatment. On-board CBCT images are used to generate patient geometric models to assist patient setup. The image data can also, potentially, be used for dose reconstruction in combination with the fluence maps from treatment plan. In this study, the accuracy of Hounsfield Units of CBCT images as well as the accuracy of dose calculations based on CBCT images of a phantom and compared the results with those of using CT simulator images. Phantom and patient studies were carried out to evaluate the achievable accuracy in using CBCT and CT stimulator for dose calculation. Relative electron density as a function of HU was obtained for both planning CT stimulator and CBCT using a Catphan-600 (The Phantom Laboratory, USA) calibration phantom. A clinical treatment planning system was employed for CT stimulator and CBCT based dose calculations and subsequent comparisons. The dosimetric consequence as the result of HU variation in CBCT was evaluated by comparing MU/cCy. The differences were about 2.7% (3-4MU/100cGy) in phantom and 2.5% (1-3MU/100cGy) in patients. The difference in HU values in Catphan was small. However, the magnitude of scatter and artifacts in CBCT images are affected by limitation of detector's FOV and patient's involuntary motions. CBCT images included scatters and artifacts due to In addition to guide the patient setup process, CBCT data acquired prior to the treatment be used to recalculate or verify the treatment plan based on the patient anatomy of the treatment area. And the CBCT has potential to become a very useful tool for on-line ART.)

• Trans-
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• v.5
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• pp.1-27
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• 2018

What is 'analyzing a movie'? And, what is 'its role in film studies'? The question required a systematic and scholarly answer, and filmologie was making a clear place for itself. Through psychology, aesthetics, text theories and of course semiotics, the conceptualization of 'film' has been formed. Deleuze, who has been continually writing about 'movies' in his philosophical essays, ended the debate in defining the relationship between 'image and essence' when he released 《Movie 1, Movement-Image》 in 1983. 'Film' rapidly became the topic of the century and became a 'device' that leads the way of thinking. The reason why Jean-Louis Boissier labeled this 'film' as 'device (le dispositif)' was not part of film studies. What should be noted is that the mention of 'film' became a key part of the debate of 'reproduction', which was the most popular subject of philosophy and humanities. In the digital era, the film is once again questioned about its definition. In retrospect, themes of core debates of 'History of cinema' have always been driven by simple and superficial technological changes. With the emergence of CG (Computer Graphics), the question of 'cinema' in the 21st century is not only a philosophical discussion on the problem of 'reproduction', but also a crucial change that shifted the focus of the debate on the nature of the film from 'production' to 'distribution'.