• Journal of the Institute of Convergence Signal Processing
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• v.24 no.4
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• pp.249-254
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• 2023

Recently, the distribution of drones is being activated by saving farmers' working time and protecting them from harmful human bodies from pesticides due to the mission of spraying pesticides using drones. It is possible to compensate for various shortcomings derived from the existing pesticide spraying method, wide-area control and helicopter control. Recently, the smart farm expansion policy has actively used it to generate profits for farmers by increasing harvests by monitoring growth information of various crops based on IoT in real time and collecting big data on key variables, and related drone industry technologies are also being developed. In this study, drones were applied to the work of shading greenhouses to secure diversity in agricultural application fields, and basic research on the greenhouse environment was conducted to materialize the technology related to shading. In order to provide high-quality light in consideration of the internal and external environment of the green house, basic research was conducted to enable light-shielding missions using drones through nozzle design for uniform spraying of nozzles of drones, light-transmitting rate analysis of green houses, and light-shielding agent application experiments.

• Nuclear Engineering and Technology
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• v.56 no.9
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• pp.3644-3653
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• 2024

Enhancing the capabilities of unmanned space exploration, such as satellite monitoring and space science missions, requires efficient and reliable nuclear power systems. A viable solution is found in the 1-10 kWe power level of space nuclear reactor power systems, offering advantages such as a manageable research and development process, and relatively low investment requirements. This paper introduces a conceptual design for a 5 kWe space nuclear reactor power system, outlining its components and characteristics. The study includes a thorough analysis of potential challenges, encompassing heat pipe failure accidents, re-entry scenarios, and weight estimation considerations. The results demonstrate that the proposed space nuclear reactor power system effectively meets the safety requirements. The total mass of the power system is estimated at approximately 1.5 tons, with a specific mass of around 300 kg/kWe. This research contributes valuable insights for the design of space nuclear reactor power systems operating within a similar power range.

• Journal of Space Technology and Applications
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• v.4 no.3
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• pp.232-243
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• 2024

In order to perform various missions in space, including planetary exploration, estimating the position of a satellite in orbit is a very important factor because it is directly related to the success rate of mission performance. As a study for autonomous satellite navigation, this study estimated the satellite's attitude and real time orbital position using a star sensor algorithm with two star trackers and earth sensor. To implement the star sensor algorithm, a simulator was constructed and the position error of the satellite estimated through the technique presented in the paper was analyzed. Due to lens distortion and errors in the center point finding algorithm, the average attitude estimation error was at the level of 2.6 rad in the roll direction. And the position error was confirmed by attitude error, so average error in altitude direction was 516 m. It is expected that the proposed satellite attitude and position estimation technique will contribute to analyzing star sensor performance and improving position estimation accuracy.

• Journal of IKEEE
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• v.28 no.3
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• pp.382-389
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• 2024

In this paper, a design of dynamic braking resistor for stationary mode of azimuth driving equipment (ADE) for multi-function radar (MFR) is presented. The ADE carries out missions which is the rotation mode for all directions and the stationary mode for tracing a subject with standstill. The ADE has to transfer the operation mode in demand time from rotation mode to stationary mode for precise target tracing. During the transition with deceleration, it may cause the fault of input power device due to back-electromotive force (back-EMF) of PMSM with generator mode. To protect the power device, a design of dynamic braking resistor is essential for consuming back-EMF. This paper presents the development of dynamic braking resistor for consuming back-EMF of ADE with deceleration mode. The validity and effect of the design is verified using simulation results.

• Journal of agricultural medicine and community health
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• v.42 no.1
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• pp.1-12
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• 2017

Objectives: In this study, we analyzed vision statements of the 6th community health plan of local government in Korea. Methods: We examined vision statements letters, missions and strategy plans, and long-term missions of 6th community health plans of 229 local government in Korea. We also analyzed the numbers of vision letters, sentence examination, word frequency, each vision statement with frequency analysis, chi-square test, and one-way ANOVA. Results: Among 229 local government, 172(75.1%) of local government had the number of letters (Korean) less than 17 of vision statements, and there were a significant differences according to type of community health centers (p<0.05). Figuration (37.1%) were the most used in an expression of vision statement sentence, and special characters (43.2%) were the most used language except Korean. The most commonly used words of vision statement in order of frequency were 'health', 'happiness', 'with', 'citizen', 'city', '100 years old' etc. Chungcheong provinces and Daejeon metropolitan city had a highest score in directionality on phrase evaluation, and there were a significant differences according to regional classes of local government (p<0.01). Gyeongsang provinces, Ulsan, Daegu, and Busan metropolitan cities had a highest score in future orientation and sharing possibilities on phrase evaluation, and there were a significant differences according to regional classes of local government (p<0.01). Conclusions: Vision is one of the most important component of community health plan. We need more detailed 'vision statement guideline' and the community health care centers of local government should effort to make more clear and complete their vision.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.351-360
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• 2004

An orbit propagation software for the Mars orbiting spacecraft has been developed and verified in preparations for the future Korean Mars missions. Dynamic model for Mars orbiting spacecraft has been studied, and Mars centered coordinate systems are utilized to express spacecraft state vectors. Coordinate corrections to the Mars centered coordinate system have been made to adjust the effects caused by Mars precession and nutation. After spacecraft enters Sphere of Influence (SOI) of the Mars, the spacecraft experiences various perturbation effects as it approaches to Mars. Every possible perturbation effect is considered during integrations of spacecraft state vectors. The Mars50c gravity field model and the Mars-GRAM 2001 model are used to compute perturbation effects due to Mars gravity field and Mars atmospheric drag, respectively. To compute exact locations of other planets, JPL's DE405 ephemerides are used. Phobos and Deimos's ephemeris are computed using analytical method because their informations are not released with DE405. Mars Global Surveyor's mapping orbital data are used to verify the developed propagator performances. After one Martian day propagation (12 orbital periods), the results show about maximum ${\pm}5$ meter errors, in every position state components(radial, cross-track and along-track), when compared to these from the Astrogator propagation in the Satellite Tool Kit. This result shows high reliability of the developed software which can be used to design near Mars missions for Korea, in future.

• Atmosphere
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• v.12 no.4
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• pp.20-42
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• 2002

Based on the "Mid to Long Term Plan for Space Development", a project to launch COMeS (Communication, Oceanography, and Meteorological Satellite) into the geostationary orbit is undergoing. Accordingly, KMA (Korea Meteorological Administration) has defined the meteorological missions and prepared the user requirements to fulfill the missions. To make a realistic user requirements, we prepared a first draft based on the ideal meteorological products derivable from a geostationary platform and sent the RFI (request for information) to the sensor manufacturers. Based on the responses to the RFI and other considerations, we revised the user requirement to be a realistic plan for the 2008 launch of the satellite. This manuscript introduces the revised user requirements briefly. The major mission defined in the revised user requirement is the augmentation of the detection and prediction ability of the severe weather phenomena, especially around the Korean Peninsula. The required payload is an enhanced Imager, which includes the major observation channels of the current geostationary sounder. To derive the required meteorological products from the Imager, at least 12 channels are required with the optimum of 16 channels. The minimum 12 channels are 6 wavelength bands used for current geostationary satellite, and additional channels in two visible bands, a near infrared band, two water vapor bands and one ozone absorption band. From these enhanced channel observation, we are going to derive and utilize the information of water vapor, stability index, wind field, and analysis of special weather phenomena such as the yellow sand event in addition to the standard derived products from the current geostationary Imager data. For a better temporal coverage, the Imager is required to acquire the full disk data within 15 minutes and to have the rapid scan mode for the limited area coverage. The required thresholds of spatial resolutions are 1 km and 2 km for visible and infrared channels, respectively, while the target resolutions are 0.5 km and 1 km.

• Strategy21
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• s.46
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• pp.89-122
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• 2020

The longing for submarine manufacture and the fear of her power had exited for a long time, but submarine that could submerge and attack was built from 20th century by science technology development. The question, 'Submarine can exercise her power in naval warfare?' had exited before World War I, but the effective value of submarine was shown in the procedure of a chain of naval warfare during World War I and World War II. Germany and the United States made the best use of submarines at that time. The submarines of these nations mounted fierce attack on the enemy's battleships and merchant ships and blocked the sea lanes for war material. These fierce attack on ships became impossible After World War II, and the major powers reduced and coordinated the defence budget, so they considered the role of submarine. However, submarine is still powerful weapon system because she can secretly navigate under the water, and one of the most important force in the navy. The aim of this thesis is analyzing submarine roles in each naval warfare and integrating maritime strategy and weapon system technology into her roles. First, the research about represent submarine roles like anti-surfaceship warfare, anti-submarine warfare, intelligence gathering, land attack, supporting special operation and mine landing warfare will be presented, then the major naval warfare where submarine participated(during ex-World War I, World War I, World War II, The Cold War Era and post Cold War) and the analyzing of submarine roles by time will be presented. Submarine was developed for anti-surfaceship warfare during ex-World War I but could not make remarkable military gain in naval warfare because her performance and weapon was inadequate. However, the effective value of submarine in the procedure of a chain of naval warfare was shown during World War I and World War II. The major powers put battleships into naval warfare undiscriminatingly to command the sea power and submarines did massive damage to enemy navy power, so put a restraint the maritime power of enemy, and blocked the sea lanes for war material. After World War II, the battlefield situation changed rapidly and the concept of preemption became difficult to apply in naval warfare. Therefore, the submarine was unable to concentrate on anti-surfaceship mission. Especially during the Cold War era, nuclear submarine came to appear and her weapon system developed rapidly. These development gave submarines special missions: anti-submarine warfare and intelligence gathering. At that time, United States and Soviet submarines tracked other nation's submarines loaded with nuclear weapons and departing from naval their base. The submarines also collected information on the volume of ships and a coastal missile launching site in company with this mission. After Cold War, the major powers despatched forces to major troubled regions to maintain world peace, their submarines approached the shores of these regions and attacked key enemy installations with cruise missiles. At that time, the United States eased the concept of preemption and made the concept of Bush doctrine because of possible 911 terrorism. The missiles fired from submarines and surface battleships accurately attacked key enemy installations. Many nations be strategically successful depending on what kind of mission a submarine is assigned. The patterns of future naval warfare that my country will provide against will be military power projection and coalition/joint operations. These suggest much more about what future missions we should assign to submarines.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.285-303
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• 2020

A military is not an organization that seeks profits, such as a company, or a research institute whose results and outcomes can produce. Therefore, it can be said that the nature of the bureaucracy is stronger than any other organizations, which perform the task centered based on ranks. In addition, as military missions deal with national and operation security which is closed with each other and more conservative compare to other organization. In this circumstance, the role of military organization and leaders is to carry out their duties with the cost of people's lives, and indeed, leades and leadership in military are more important than those of any organizations. However, many researches are lacking or focused on leadership research in a limited field, especially positive field, developmental, constructive leadership research and researches that are not focused on that area are limited. Already in the United States, research on negative leadership has been actively conducted under the direction of the Secretary of US Army Thomas E. White in 2003, how toxic leadership is serving in military organizations and on the battlefield. Now they realize how toxic leadership had impact on missions in military organizations and on the battlefield. The purpose of this study is to collect and analyze qualitative and quantitative data on the negative leadership of military organizations that have not been studied. The aim of this study was to establish a literature study on the scope and behavior of toxic leadership among negative leadership and to build empirical data on toxic leaders of current military organizations, and to create occupations that occur when subordinates work with toxic leaders. This study analyzes changes in satisfaction and organizational cohesion that mediates results and causes. This study will be more urgent and important for groups that prioritize groups and organizations over individuals, and it may provide new directions for the role and impact of military leaders from attempting these studies.

• Maritime Security
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• v.4 no.1
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• pp.57-82
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• 2022

The objective of this treatise is to explore the limitations of the current navy manpower utilization system and the ways to improve it from the perspective of Generation Z. As Generation Z, following Millennials, has finally come of age, this new group is constituting a gradually greater proportion of military personnel. Due to the typical characteristics of naval operations, the harmony between Millennials and Generation Z, which is differentiated from Generation X in view of dispositions and traits, is one of the essential issues to be discussed. Generally, in a naval vessel, there are numerous pieces of equipment necessary to carry out a wide range of missions and a large number of crew members who operate them with consistent levels of fighting power. This is all while members are living together within the narrow space throughout the 24 hours of each day. Under such particular circumstances, any inter-generational conflicts may have a disruptive effect on the successful accomplishment of naval missions. Currently, new generations of military personnel are facing social difficulties in different aspects compared with the previous generations, and also have different viewpoints on the military. In this regard, in order to foster true harmony between generations, it is considered necessary to take a closer look at the inter-generational differences from their respective standpoints and to examine whether the military organization has taken adequate steps to respond to such changes. Accordingly, Chapters 1 and 2 cover the environments in which Millennials and Generation Z were raised during their childhood to young adulthood, which are distinct from those of older generations, their viewpoints formed based on such backgrounds, and the need to resolve various conflicts between generations. In Chapter 3, the current actions taken by overseas military powers to enhance the coexistence with Generation MZ are analyzed to find the significant implications they had. Chapter 4 examines the operation environments specific to the navy; identifies the potential barriers to achieving harmony between generations by assessing the current status of personnel utilization in the Korean navy in terms of the seaman, petty officer, and the officer, as well as policy; and outlines the solutions to drive harmony. Finally, Chapter 5 emphasizes the need to establish a genuine empathy between generations based on the understanding of unique inter-generational characteristics. This section also discusses the importance of addressing difficulties in utilizing technology-centered naval manpower, and forecasts a scenario of a naval organization that resolves the problem of utilizing naval personnel and the inter-generational conflicts in the future.