• Journal of Navigation and Port Research
• /
• v.44 no.4
• /
• pp.347-353
• /
• 2020

Aids to Navigation (AtoN) contribute to preventing marine accidents and protecting marine environment by providing various information such as location information etc. to ships. Recognizing the importance of the AtoN, a 24 won of the AtoN service fee is charged for ships entering and leaving international trade ports. However, while the 24 won of the AtoN service fee has been maintained since its establishment in 1999, the demand for new roles of the AtoN service for autonomous shipping and smart port operations, etc. has gradually increasing with the change of shipping and port 4.0. Thus the purpose of this study was to estimate the appropriate level of the AtoN service fee in accordance with such changes in the shipping and port industries. To accomplish this, a method of recovering the total cost was introduced to the PROOF (Pyeongtaek Regional Office of Ocean and Fisheries). It is estimated that there are four cases in which estimation of the AtoN service fee is estimated in two cases year by year and conversion year, the AtoNs of PROOF are classified into the all and part of a ship using the trade port. As a result of the estimation, the AtoN service fee of PROOF is estimated at 53.78-71.62 won (as of 2019), and 29.78-47.62 won is higher than the today at 24 won. The results of this study can be used as useful basic data for the operation of budgets and policy management considering the role of the AtoN.

• Journal of the Korea Convergence Society
• /
• v.11 no.7
• /
• pp.35-40
• /
• 2020

Recently, devices such as smart watches capable of measuring small biosignals have been released. Body composition, blood pressure, heart rate, and oxygen saturation can be easily obtained. However, the part that is not trusted by the user is accuracy. These biosignals are sensitive to the external environment and have large fluctuations depending on the conditions inside the subject's body. Blood pressure measurements, in particular, still give different results, depending on how the conditions in the body are handled. Therefore, in this study, PPG was analyzed to measure PTT at two points of 80% and 100%, the highest in PTT measurement. The effect of the measured value on SBP and DBP was analyzed and a method was proposed to increase the accuracy. As a result of the study, the measured value of PTT at 80% of the peak PPG is more effective in estimating blood pressure of SBP and DBP than the value measured at 100%. In the regression analysis of the rate of change blood pressure estimation, the coefficient of determination of SBP (80%) was 0.6946, and DBP (100%) was 0.547.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.6
• /
• pp.63-70
• /
• 2011

A bicycle is different from vehicles in the structure that a rider is fully exposed to the surrounding environment. Therefore, it needs to make use of prior information about local weather, air quality, trail road condition. Moreover, since it depends on human power for moving, it should acquire route property such as hill slope, winding, and road surface to improve its efficiency in everyday use. Recent mobile applications which are to be used during bicycle riding let us aware of the necessity of development of intelligent bicycles. This study aims to develop a riding state (up-hill, down-hill, accelerating, braking) recognition algorithm using a low-power wrist watch type embedded system which has 3-axis accelerometer and wireless communication capability. The developed algorithm was applied to 19 experimental riding data and showed more than 95% of correct recognition over 83.3% of the total dataset. The altitude and temperature sensor also in the embedded system mounted on the bicycle is being used to improve the accuracy of the algorithm. The developed riding state recognition algorithm is expected to be a platform technology for intelligent bicycle interface system.

• Journal of the Korean earth science society
• /
• v.41 no.1
• /
• pp.31-39
• /
• 2020

Cheonji, the largest caldera lake in Asia, is located at the summit of Baekdu Mountain. Cheonji is covered with snow and ice for about six months of the year due to its high altitude and its surrounding environment. Since most of the sources of water are from groundwater, the water temperature is closely related to the volcanic activity. However, in the 2000s, many volcanic activities have been monitored on the mountain. In this study, we analyzed the dimension of ice produced during winter in Baekdu Mountain using Sentinel-1 satellite image data provided by the European Space Agency (ESA). In order to calculate the dimension of ice from the backscatter image of the Sentinel-1 satellite, 20 Gray-Level Co-occurrence Matrix (GLCM) layers were generated from two polarization images using texture analysis. The method used in calculating the area was utilized with the Support Vector Machine (SVM) algorithm to classify the GLCM layer which is to calculate the dimension of ice in the image. Also, the calculated area was correlated with temperature data obtained from Samjiyeon weather station. This study could be used as a basis for suggesting an alternative to the new method of calculating the area of ice before using a long-term time series analysis on a full scale.

• The Journal of the Korea Contents Association
• /
• v.11 no.1
• /
• pp.34-41
• /
• 2011

At present wireless internet access service is available through the 3G network, mobile WiMAX and WiFi anytime and anywhere. In this environment where there are various networks, users should be able to select specific networks depending on different situations. And it is necessary to provide mobility support between homogeneous and between heterogenous networks. Given this situation, the many proposals have been presented to link 3G, which has the largest service area among various networks, with mobile WiMAX(IEEE 802.16e), or with WiFi(IEEE 802.11). But, recently, with the increasing volume of wireless internet use and wireless internet data, due to the advents of net-book, e-book and smart phone, the service area of WiFi and mobile WiMAX has rapidly expanded. Especially, the availability of real-time application such as internet phone has led to the relative shrinking of the proportion of 3G mobile communication network giving conventional voice service, and enlargement of those of wireless internet access networks like WiFi and mobile WiMAX. This paper suggests a handover scheme based on PMIPv6, whitch support mobility between WiFi and mobile WiMAX, and minimizes handover delay. In this scheme, the mobile node has a dual stack structure composed of two interfaces-WiFi and mobile WiMAX. Since WiFi dose not support mobility, it is suggested that the mobile node have the capacity to deal with handover signaling between gateway in case of handover between homogeneous networks. This handover scheme, suggested comparing with current handovers between homogeneous networks, has proved, in its analytic evaluation, to be able to reduce handover, transmission, and signaling overhead.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.7
• /
• pp.52-60
• /
• 2010

In this paper, we propose a dynamic power management framework for multi-core systems. We reduced the power consumption of multi-core processors such as Intel Centrino Duo and ARM11 MPCore, which have been used at the consumer electronics and personal computer market. Each processor uses a different technique to save its power usage, but there is no embedded multi-core processor which has a precise power control mechanism such as dynamic voltage scaling technique. The proposed dynamic power management framework is suitable for smart phones which have an operating system to provide multi-processing capability. Basically, our framework follows an intuitive idea that reducing the power consumption of idle cores is the most effective way to save the overall power consumption of a multi-core processor. We could minimize the energy consumption used by idle cores with application-targeted policies that reflect the characteristics of active workloads. We defined some properties of an application to analyze the performance requirement in real time and automated the management process to verify the result quickly. We tested the proposed framework with popular processors such as Intel Centrino Duo and ARM11 MPCore, and were able to find that our framework dynamically reduced the power consumption of multi-core processors and satisfied the performance requirement of each program.

• Applied Chemistry for Engineering
• /
• v.24 no.3
• /
• pp.219-226
• /
• 2013

Organic semiconductor-based soft electronics has potential advantages for next-generation electronics and displays, which request mobile convenience, flexibility, light-weight, large area, etc. Organic field-effect transistors (OFET) are core elements for soft electronic applications, such as e-paper, e-book, smart card, RFID tag, photovoltaics, portable computer, sensor, memory, etc. An optimal multi-layered structure of organic semiconductor, insulator, and electrodes is required to achieve high-performance OFET. Since most organic semiconductors are self-assembled structures with weak van der Waals forces during film formation, their crystalline structures and orientation are significantly affected by environmental conditions, specifically, substrate properties of surface energy and roughness, changing the corresponding OFET. Organo-compatible insulators and surface treatments can induce the crystal structure and orientation of solution- or vacuum-processable organic semiconductors preferential to the charge-carrier transport in OFET.

• Journal of Korean Society for Geospatial Information Science
• /
• v.25 no.2
• /
• pp.13-19
• /
• 2017

This paper analyzed MODIS data from 2006 to 2013 to determine relationship between meteorological changes and vegetation index. The experimental area was divided into the northern, central and southern regions according to the regional characteristics, and the smoothed MODIS LAI and NDVI were obtained using Timesat. In the case of precipitation, MODIS NDVI had correlation coefficients of 0.66, 0.44 and 0.35 in the northern, central and southern regions and the correlation was the highest in the northern region. In the case of temperature, MODIS LAI had correlation coefficients of 0.66, 0.64 and 0.68, and MODIS NDVI had 0.89, 0.89 and 0.80. The correlation of MODIS NDVI was higher and showed similar positive correlation regardless of region. In addition, The accuracy between Timesat plant seasonal start and actual plant seasonal start in MODIS NDVI was higher than MODIS LAI. The average error in MODIS LAI was 19 days in the central region and 20 days in the southern region. And the average error in MODIS NDVI was 6 days in the central region and 8 days in the southern region.

• Journal of Internet of Things and Convergence
• /
• v.6 no.3
• /
• pp.21-30
• /
• 2020

The purpose of this paper is to verify the differences of the effect of the support between the number of employment of those who have experienced employment and the unemployment period of those who have not experienced employment for the participants of the Jeollanam-do Youth Job Search Allowance Support Project. In addition, this study attempted to find out the ways to develop the system using the Internet of Things by figure out how to use the allowance, the field of help, the average investment time per day, the average monthly expenditure, the difficulties of job search activities, and the differences in the youth job search activities for the required programs. In this study, 602 people who participated in the Jeollanam-do Youth Job Search Allowance Support Project from February 19 to March 9, 2020 are surveyed. The collected data was processed using the SPSS 21.0 program. The research results are as follows. First, there was a difference in satisfaction according to the number of jobs employed. Second, there was a difference in the effectiveness according to the number of employment. Third, there was a difference in satisfaction according to the period of unemployment. Fourth, there was a difference in effectiveness according to the period of unemployment. In order to enhance the effectiveness of the youth job search allowance support project, the Edutech industry and technology that can share various information using the Internet of Things environment in the untact era must be improved together.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.2
• /
• pp.383-395
• /
• 2017

Brainwave-based user authentication technology has advantages such as changeability, shoulder-surfing resistance, and etc. comparing with conventional biometric authentications, fingerprint recognition for instance which are widely used for smart phone and finance user authentication. Despite these advantages, brainwave-based authentication technology has not been used in practice because of the price for EEG (electroencephalography) collecting devices and inconvenience to use those devices. However, according to the development of simple and convenient EEG collecting devices which are portable and communicative by the recent advances in hardware technology, relevant researches have been actively performed. However, according to the experiment based on EEG samples collected by using a single-channel EEG measurement device which is the most simplified one, the authentication accuracy decreases as the number of channels to measure and collect EEG decreases. Therefore, in this paper, we analyze technical problems that need to be solved for practical use of brainwave-based use authentication and propose an incremental elimination method of collected EEG samples for each user to consist a set of EEG samples which are effective to authentication users.