• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.1048-1057
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• 2004

WCDMA system is 3rd generation wireless mobile system specified by 3GPP. In WCDMA downlink, two power control schemes are operated. One is inner loop power control operated m every slot Another is outer loop power control based on one frame time. Base staion (BS) can estimate proper transmission power by these two power control schemes. However, because each MS's transmission power makes a severe effect on BS's performance, BS cannot give excessive transmission power to the speclfic user 3GPP defined Power Control Dynamic Range (PCDR) to guarantee proper BS's performance. In this paper, we propose Adaptive PCDR algorithm. By APCDR algorithm, Radio Network Controller (RNC) can estimate each MS's current state using received signal to interference ratio (SIR) APCDR algorithm changes MS's maximum code channel power based on frame. By proposed scheme, each MS can reduce wireless channel effect and endure outages in cell edge. Therefore, each MS can obtain better QoS. Simulation result indicate that APCDR algorithm show more attractive output than fixed PCDR algorithm.

• Journal of Astronomy and Space Sciences
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• v.34 no.4
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• pp.237-244
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• 2017

Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker (~7.4 nT) than that of MCs (~10.6 nT). Also, the average duration time and expansion speed of SMFRs are ~2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of ~10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.994-1005
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• 2016

Expansion and spreading of marine telemedicine is rather restricted due to the conflict of laws relating to medical service and lack of provisions in the Seafarers' Act, Medical Service Act, etc. Thus, this study is intended to reveal the current status and problems of marine emergency medical advice system for the furtherance of health care of seafarers and emergency medical assistance conditions and deduce relevant proposals for legislative improvements thereof in order to resolve underlying problems and issues. The results of this study can be summated as follows. First, in respect of directions to provide marine emergency service based on marine telemedicine system, emergency radio medical advice system needs to be strengthened to meet domestic and international instrument, marine telemedicine system needs to be provided through integrating u-Health technology and special marine medical center needs to be established. Second, regarding directions to provide health promotion service based on the marine telemedicine system, a new process of health care service for seafarers needs to be devised and provided involving seafarers' life cycle covering from prior to boarding to after leaving a ship. The conclusions of this study can be given as follows. First, the following new provisions need to be introduced in the Seafarers' Act. (1) The Minister of Oceans and Fisheries and a shipowner shall conduct matters pertaining to preventive health promotion and care for seafarers; (2) a provisions regarding establishment of seafarers' health promotion center by the Minister; (3) a special exemption permitting marine telemedicine service and qualification requirements for marine telemedicine assistant; (4) shipowner's obligation of carrying seafarers' health measuring equipment on board. Second, the relevant provisions regarding medical care persons needs to be revised in such a way that master or chief officer shall be appointed to be in charge of medical care on board. Last but not least, it is also essential to amend and update the minimum standards on drug and medicines to be carried on board and medicine chest and equipment on board.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.47-56
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• 2012

Bicycle has a large amount of kinetic energy available for energy harvesting technology in its speedy and balanced riding movement. Systematic and realistic analysis of its dynamic property is essential to improve the efficiency of energy harvester. However, there has not been enough researches about precise measurement or analysis of bicycle dynamics on real roads. This study aims to investigate the characteristics of vibrational movement of bicycle using MEMS-based accelerometer and to develop a prototype of electromagnetic energy harvester with nonlinear behavior which is proper to the random vibrations accompanied in bicycle riding. The vibrational components have average magnitude of 1 g and turn out to be independent of riding speed. The developed prototype of energy harvester was installed on a front port of a bicycle to use this ambient vibration and generated an average electrical power of 1.5 mW which is enough to support power for most of portable sensors and short range radio-frequency communication. Further study about isolation of vibration from a rider and conversion efficiency is ongoing. The developed energy harvester is expected to be a platform technology for sustainable portable power supply for various smart IT devices and applications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1352-1370
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• 2010

In this paper, we investigated the shadow area of radio programs which are currently being broadcast via FM 102.5 MHz in Jeollabuk-do consisting of 6 cities and 8-guns. The field strength data of FM 102.5 MHz was used with criterion of shadow area. As a result, the field strength of the eastern mountainous area in Jeollabuk-do was very low. We also measured, compared and analyzed the field strength of 102.5 MHz(TBN-Jeonju), 100.7 MHz(KBS) and 99.1 MHz (MBC) in Jeollabuk-do. Based on the field strength data, we tried to find what correlation exists and how much influence is between difference of antenna output power and solution of shadow area. In result, enhancement of antenna output power is not solution in terms of reducing the shadow Area of 102.5 MHz(TBN-Jeonju). In addition, we measured, compared and analyzed the field strength of 102.5 MHz(TBN-Jeonju) and 106.9 MHz(EBS). In fact, the relay stations with 104.1 MHz, 104.9 MHz, 105.3 MHz and 107.5 MHz of EBS FM has a number of FM relay stations in the eastern mountainous area of Jeollabuk-do. As a result, we confirmed that EBS almost did not have shadow area in the eastern mountainous area of Jeollabuk-do based on the field strength data. As in the case of EBS and KBS, we suggest installing TBN-Jeonju FM relay station with the best solution to reducing the shadow area to extend the audible range of TBN-Jeonju.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.62-62
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• 2008

As micro-system move toward higher speed and miniaturization, requirements for embedding the passive components into printed circuit boards (PCBs) grow consistently. They should be fabricated in smaller size with maintaining and even improving the overall performance. Miniaturization potential steps from the replacement of surface-mount components and the subsequent reduction of the required wiring-board real estate. Among the embedded passive components, capacitors are most widely studied because they are the major components in terms of size and number. Embedding of passive components such as capacitors into polymer-based PCB is becoming an important strategy for electronics miniaturization, device reliability, and manufacturing cost reduction Now days, the dielectric films deposited directly on the polymer substrate are also studied widely. The processing temperature below $200^{\circ}C$ is required for polymer substrates. For a low temperature deposition, bismuth-based pyrochlore materials are known as promising candidate for capacitor $B_2Mg_{2/3}Nb_{4/3}O_7$ ($B_2MN$) multi layers were deposited on Pt/$TiO_2/SiO_2$/Si substrates by radio frequency magnetron sputtering system at room temperature. The physical and structural properties of them are investigated by SEM, AFM, TEM, XPS. The dielectric properties of MIM structured capacitors were evaluated by impedance analyzer (Agilent HP4194A). The leakage current characteristics of MIM structured capacitor were measured by semiconductor parameter analysis (Agilent HP4145B). 200 nm-thick $B_2MN$ muti layer were deposited at room temperature had capacitance density about $1{\mu}F/cm^2$ at 100kHz, dissipation factor of < 1% and dielectric constant of > 100 at 100kHz.

• Progress in Medical Physics
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• v.17 no.1
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• pp.6-16
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• 2006

The goal of this study was to develop new indices for effectively evaluating the dose coverage and homogeneity based on the target-volume dose-volume histogram (TV-DVH) of intensity-modulated radio-therapy treatment plans. A new coverage Index and a new homogeneity index were developed by integrating a modified TV-DVH and by fitting a TV-DVH with a modified step function, respectively. The coverage index, named the l-index, indicates whether the dose coverage for the target volume is adequate based on user-defined criteria. A lower l-index indicates higher dose coverage of the tumor volume. The index for assessing dose homogeneity in a target volume, named the n-index, is more accurate than the conventional method in evaluating the dose homogeneity in a tumor volume. The baseline treatment plan for a target volume coverage and homogeneity is discussed. The proposed simple indices have been demonstrated to be effective in evaluating the dose coverage and homogeneity for TV-DVHs.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.147-157
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• 2017

Recently, ICT Retail Convergence(IRC) has been rapidly increasing to improve consumer satisfaction and consumer experience. In this paper, we aim to diagnose IRC from consumers' point of view by reviewing the present status and value of IRC according to consumer purchase decision making process. Based on the previous studies in retail industry, we classified IRC into 4 types: Experience-specific tech(Virtual Reality and Augmented Reality); Information-specific tech(Artificial Intelligence and Big Data); Location-based tech(Radio Frequency Identification and Beacon); Payment-related tech(Fin-tech and Biometrics). Next, we found that there is a difference in value provided to consumers according to the type of technology, analysing the value by consumer purchase decision making process. This study can be useful to introduce IRC for improving consumer satisfaction as well as ICT and Retail. Also, it can be basic data for future technology studies with a consumer perspective.

• Journal of Agricultural Extension & Community Development
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• v.18 no.3
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• pp.591-629
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• 2011

The purpose of this research is to examine how the village community centers are being used and find how to improve leisure activities of elders in rural areas by using them. In order to achieve the purpose of this research, we did convenience sampling from elders using 92 village community centers in one of the counties in Gyeong-gi province, and did field survey to 343 persons. The collected data was analyzed by SPSS 18 program, and the results are as follows: The survey on population sociological peculiarity of elders using village community centers shows that most of elders are over 70 years old. As for health conditions, there are more elders who are physically weaker than healthy elders. And the survey shows that most of the elders are suffering from illness such as hypertension, arthritis, neuralgia, and indigestion so such programs related to health are critically required. First, the survey on using village community centers by elders in rural areas shows that they think the village community centers are important for them and use them often. Most of respondents said that they use the village community center so as to meet friends, to enjoy leisure, and to spend time in rural areas where they have difficulty enjoying cultural facilities. Meanwhile, some people dislike to use the village community centers mainly because there is few programs for leisure or each one has a different personality or they don't have enough money to pay for the membership fee. Second, according to the survey on leisure for the elders in village community centers, there are few leisure programs. For men, they spend time by playing Baduk, Janggi, Hwatu and drinking. Meanwhile, women spend time by meeting with friends, listening to radio and TV watching. There are almost nothing to improve leisure activities such as hobby, recreation and health etc. Male elders using centers are suffering from health problems, economic difficulty, and lack of leisure activities, meanwhile, female elders are suffering from loneliness, health problems, and economic difficulty. Third, according to the survey on improving the leisure program of village community center, elders preferred health related programs to improve leisure activities. The most necessary leisure activities in village community center are hobby classrooms, health programs and group travelling. They preferred health related programs for leisure in village community center. Based upon the reality described above, improving the village community centers as leisure facilities is considered to be important for the welfare well of elders in rural areas.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.588-594
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• 2015

Although GPS technology for location positioning system has been widely used, it is difficult to be used in intelligent transport systems, due to the large positioning error and limited area for receiving radio signals. Thanks to the rapid development of LED technology, LED lights become popular in many applications. Especially, visible light communications (VLC) has raised a lot of interests because of the simultaneous functioning of LED illumination and communication. Recent studies on positioning system using VLC mainly focused on indoor environments and still difficult to satisfy positioning accuracy and simple implementation simultaneously. In this paper, we propose a positioning system based on VLC using the coordinate information of LEDs installed on the road infrastructure. Extracting the LED signal, obtained through VLC, from the easily accessible camera image, it is possible to estimate the position of the car on the road. Simulation results show that the proposed scheme can achieve a high positioning accuracy of 1 m when large number of pixels is utilized and the distance from the LED light is close.