• Journal of the Korea Society for Simulation
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• v.25 no.3
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• pp.53-63
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• 2016

We consider simulation study combining static and mobile decoys for survivability of a surface warship against torpedo attack. It is assumed that an enemy torpedo is a passive acoustic homing torpedo and detects a target within its maximum target detection range and search beam angle by computing signal excess via passive sonar equation, and a warship conducts an evasive maneuvering with deploying static and mobile decoys simultaneously to counteract a torpedo attack. Suggesting the four different decoy deployment plans to achieve the best plan, we analyze an effectiveness for a warship's survival probability through Monte Carlo simulation, given a certain experimental environment. Furthermore, changing the speed and the source level of decoys, the maximum torpedo detection range of warship, and the maximum target detection range of torpedo, we observe the corresponding survival probabilities, which can provide the operational capabilities of an underwater defense system.

• Journal of the Korean Solar Energy Society
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• v.36 no.1
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• pp.39-47
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• 2016

Geographic information system (GIS) based renewable energy resource map including potential analysis can play a crucial role not only to develop the national plan for renewable energy deployment but also to make strategic investment decision in the private sector. Korea Institute of Energy Research (KIER) has been developing domestic maps about several resources such as solar, wind, hydro, biomass, and geothermal, as well as conducting research on methodologies for potential analysis. Furthermore, the institute is trying to transfer related technologies and know-how to foreign countries, recently. In this context, the main purpose of this study is to introduce the business model of renewable energy resource map. From the value chain analysis, we focus on the government-side market in foreign countries, such as the development of the national level renewable energy resource map and the support of the national renewable energy plan. For about 180 countries, we segment the customers according to the consideration of economic capacity, renewable energy resource capacity, existence of renewable resource map, current portion of renewable energy facility capacity, and renewable energy policies, and we conclude that the target customers are non-Organization for Economic Co-operation and Development (non-OECD) countries or some OECD countries, their per capita GDP are under the average among OECD countries, that do not have renewable resource map yet. We segment the target customers into four groups, and suggest different strategies for market positioning and financing strategy based on Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis. This study can help to develop the business strategy about the development of renewable energy resource map in foreign countries.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.27-34
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• 2013

In wireless sensor networks, sensors need to communicate with each other to send their sensing data to the administration node and so they are susceptible to many attacks like garbage packet injection that cannot be prevented by using traditional cryptographic approaches. A behavior-based detection is used to defend against such attacks in which some specialized monitoring nodes overhear the communications of their neighbors to detect bad packets. As monitoring nodes use more energy, it is desirable to use the minimal number of monitoring nodes to cover the whole or maximal part of the network. The monitoring nodes can either be selected among the deployed normal nodes or differ in type from normal nodes. In this study, we have developed an algorithm for selecting the predefined number of monitoring nodes needed to cover the maximum number of normal nodes when the different types of normal nodes and monitoring nodes are deployed. We also have investigated experimentally how the number of monitoring nodes and their transmission range affect the connection ratio of the monitoring nodes and the coverage of the normal nodes.

• Journal of the Korean Society for Computer Game
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• v.31 no.4
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• pp.167-174
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• 2018

The homogeneous key arrangement is a method of consistently arranging notes in a tile-shaped keyboard musical instrument, and arranging them in the same direction in the same direction on the neighboring keys in the same direction to enable a consistent musical arrangement. It has been used for a long time, but recently it has attracted attention by applying it to various modern musical instrument design and software instrument interface. There have been many different methods of deployment, but there are few studies on the existence of some or none of them. In this paper, we propose a classification method for such a key arrangement and analyze the relationship between them. This shows that there are far fewer types of homologous key arrangement than the known ones, and provided the basis of the study on the homogeneous key arrangement by providing a classification framework. Based on this, it is expected that more systematic analysis and research will be done and it will be used to develop various music interfaces. These studies will play a very important role in training students to understand the basic elements of pitch, harmony, harmony, and scales in music education games.

• The Journal of Korean Medical History
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• v.34 no.2
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• pp.1-10
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• 2021

During the Joseon Dynasty, Jeju had a unique aspect that differentiated it from other regions in terms of their medical system, such as the exclusive deployment of shimyak dispatched to Gamyeong and Barracks units due to the uniqueness of being an island. This study uses various historical sources to verify that these differences existed throughout the medical system and procedures of Jeju in the late Joseon Dynasty. The following significant conclusions were drawn: 1) Looking at the work and characters of Jejushimyak reveals the inherent limitations of Jeju medical care in the Joseon Dynasty. Compared to other regions' shimyak, Jejushimyak had two limitations: it was difficult to engage in only medicine and the quality of medical doctors declined due to the avoidance of major medical doctors' households. 2) The establishment of public health care in Jeju through Medical Cadets failed. Jeju medical science obviously played an essential role in public health care in the early 18th century. However, there was no continuity in the garden, etc. Hyangri, who was in charge of Medical Cadets, was in charge of various fragrances as needed. Thus expertise in medicine was lacking. 3) The cultivated herbs of Jeju's herb field show the failure to supply herbs for institutional medicine. It was impossible to supply enough herbs to implement institutional medicine in Jeju. In that case, it would have been necessary to discover alternative local herbs or to bring them in from outside, but there was barely any such effort. In conclusion, in the late Joseon Dynasty, Jeju failed to establish a foundation for centrally administered institutional medicine. There was a lack of all the entities that provided medical care and herbs that could be used for medical care. The reason that Jeju continued to follow traditional shaman medicine in the late Joseon Dynasty was because there was no other alternative.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.165-173
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• 2021

The purpose of this study was to provide directions to help enter and expand long-distance routes by analyzing the characteristics of AirAsia X's network construction with Malaysia Airlines. To this end, long-distance route data was extracted from the OAG Schedule Analyzer and the network was analyzed on a two-period basis using SNA. Since AirAsia X's entry into long-range routes, Malaysia Airlines has steadily reduced its routes across the entire region. On the other hand, it is analyzed that AirAsia X is building an expanded network by increasing its network in Northeast Asia instead of ultra-long range routes. Studies have shown that LCCs also have potential growth in the long-distance route market of less than 7,000 km. The results of this study may help LCC establish a long-distance market entry and network deployment strategy.

• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.53-58
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• 2021

The number of patients with cardiovascular diseases who experience an out-of-hospital cardiac arrest (OHCA) are increasing among young adults as well as the aged population. An automated external defibrillator (AED) is vital in improving survival rates of OHCA victims. Survival rates of OHCA were shown to decline exponentially in time to defibrillation, yet studies in Korea are uncommon that captures the properties of their survival rates in examining optimal locations of AEDs. In this study, we worked on the maximal gradual coverage location problem (MGCLP) with exponential decay coverage function to decide on their optimal locations. The exponential decay coverage function mitigates the drawback of over-estimating survival rates of OHCA patients. It is expected that a more sophisticated facility location problem will be developed to identify the "emergent" characteristics of pedestrians who responds to the OHCA occurrence by incorporating random pedestrian locations and movement through simulation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.4
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• pp.314-319
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• 2019

In this study, we propose a W-band frequency modulated continuous wave(FMCW) radar altimeter that can measure the altitude based on the frequency differences of transmitted and received signals. This W-band FMCW system is powered by an altitude control algorithm, which we propose to help prevent collisions of drones with obstacles in real deployment by measuring the relative altitude. It is shown that this algorithm enables the drone to be positioned within a 3 % error of altitude from the desired input height. The chip used in the W-band transmitter and receiver was fabricated using a 65-nm CMOS process, and a horn antenna was directly fed by incorporating an embedded waveguide feeder into the chip. The clutter spectra observed in terrains including soil, grass, and calm lake water were measured and compared, confirming the reflectivity characteristics of various surfaces of different water contents.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.217-223
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• 2018

Real-time controllability has been a major challenge that should be addressed to ascertain the practical usage of the management systems. In this regards, for the first time, we proposed and implemented an IoT(Internet of Things)-based water tank system to improve convenience and efficiency. The reservoir can be effectively controlled by notifying the user if the condition of the reservoir is unstable. The proposed system consists of embedded H/W unit for sensor data measuring and controling, application S/W for deployment of management server via web and mobile app, and efficient database structure for managing and monitoring statistics. And machine learning algorithms can be applied for further improvements of efficiency in practice.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.3
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• pp.63-82
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• 2019

Libraries are recently emerging as the core institutions designed to resolve the information equality that is forecasted to further deepen with the arrival of the fourth industry revolution era. This study thus analyzed the trends of studies on the library services offered to people suffering information inequality in Korea, and proposed measures for the activation of the research and future studies so as to strengthen the domestic library services targeting the people suffering information equality and to promote the research. As a result, proposed as measures for the activation of research were (1) Policy support and project expansion at the national level, (2) Various approaches and research environment creation at the academic level, (3) Strengthening of services for the various levels of people suffering information inequality and deployment of professional librarians at the level of libraries, and (4) Encouraging librarians to enroll with graduate schools and to conduct research. Further, proposed were the future studies that can be approached according to the various levels of people suffering information inequality, such as disabled people, multicultural family members, elderly people, children, youth, agricultural and fishing areas, low-income people, and refugees(North Korea defectors).