• Journal of IKEEE
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• v.25 no.4
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• pp.721-727
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• 2021

This paper proposes a UWB (Ultar-wideband) impulse generator using the gated ring oscillator. The oscillator and PLL circuits which generate a several GHz LO signal for the conventional architecture are replaced with the gated ring oscillator. Therefore, the system complexity is decreased. The proposed architecture controls the duty of enable signal, which is used for the head switch of ring oscillator. The control of the duty enables to tun off the oscillator during the guard interval and stop wasting the power consumption. The pulse shaping method using the counter makes the small side lobe and preserves the bandwidth regardless of the change on the center frequency. Designed UWB impulse generator could change the center frequency from 6.0 GHz to 8.8 GHz with a digital bit control, while it preserves the bandwidth as about 1.5 GHz.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.78-88
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• 2023

Medication safety and medicine delivery challenge the well-being of the elderly and the management of the elderly center. With the outbreak of COVID-19, the elderly in the care center were challenged by the inconvenience of the medication restocking. The purpose of this paper accentuates the importance of the design and development of an UAV-based Smart Medicine Case (UAV-SMC) to improve the performance of medication management and medicine delivery in the elderly center. The researchers came up with the design of UAV-SMC in the light of the UAV and IoT technology to improve the performance of both Medication Practice Management (MPM) and Low Inventory Detection and Delivery (LIDD). Based on the result, with UAV-SMC, the performance of both MPM and LIDD was significantly improved. The UAV-SMC improves the efficacy of medication management in the elderly center by 26.97 to 149.83 seconds for each medication practice and 9.03 mins for each time of medicine delivery in Subang Jaya Malaysia. This paper only investigates the adoption of UAV-SMC in the content of elderly center rather than other industries. The authors consider integrating the UAV-SMC with the e-pharmacy system in the future. In conclusion, the UAV-SMC has significantly improved the medication management and guard the safety of elderly and caretaker in the elderly in the post-pandemic times.

• Journal of the Korean Institute of Gas
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• v.27 no.1
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• pp.13-22
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• 2023

As an alternative to environmental pollution generated from fossil fuels currently in use, research is being actively conducted to use hydrogen that does not cause air pollution. As fire and explosion accidents caused by hydrogen leakage have occurred until recently, research on safety is needed to commercialize hydrogen on ships, which are special environments. In this study, a seasonal alternative scenario for each season and the worst scenario were assumed in the event of a leakage accident while a hydrogen fuel cell propulsion ship equipped with a hydrogen storage tank was navigating at JangSaengPo port in Ulsan. In order to consider environmental variables, the damage impact range was derived through ALOHA and probit analysis based on the annual average weather data for 2021 by the Korea Meteorological Administration and on geographic information data from the National Statistical Office. Radiation showed a wider damage range than that of Overpressure and Flame in both the alternative and worst-case scenarios, and as a result of probit analysis, a fatality rate of 99% was confirmed in all areas.

• FOCUS: LIFE SCIENCE
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• no.1
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• pp.1.1-1.4
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• 2024

This article provides comprehensive guidance on the maintenance, cleaning, regeneration, and storage of silica-based HPLC (High-Performance Liquid Chromatography) columns. The general considerations emphasize the importance of using in-line filters and guard cartridges to protect columns from blockage and irreversible sample adsorption. While these measures help, contamination by strongly adsorbed sample components can still occur over time, leading to an increase in back pressure, loss of efficiency, and other issues. To maximize column lifetime, especially with UHPLC (Ultra-High Performance Liquid Chromatography) columns, it is advisable to use ultra-pure solvents, freshly prepared aqueous mobile phases, and to filter all samples, standards, and mobile phases. Additionally, an in-line filter system and sample clean-up on dirty samples are recommended. However, in cases of irreversible compound adsorption or column voiding, regeneration may not be possible. The document also provides specific recommendations for column cleaning procedures, including the flushing procedures for various types of columns such as reversed phase, unbonded silica, bonded normal phase, anion exchange, cation exchange, and size exclusion columns for proteins. The flushing procedures involve using specific solvents in a series to clean and regenerate the columns. It is emphasized that the flow rate during flushing should not exceed the specified limit for the particular column, and the last solvent used should be compatible with the mobile phase. Furthermore, the article outlines the storage conditions for silica based HPLC columns, highlighting the impact of storage conditions on the column's lifetime. It is recommended to flush all buffers, salts, and ion-pairing reagents from the column before storage. The storage solvent should ideally match the one used in the initial column test chromatogram provided by the manufacturer, and column end plugs should be fitted to prevent solvent evaporation and drying out of the packing bed.

• Convergence Security Journal
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• v.14 no.6_1
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• pp.89-98
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• 2014

Simultaneously with the founding of the Joseon military system was reformed. On the basis of Koryo's '2gun 6wie(二軍 六衛)' reorganized into '10wie 50ryong(10衛 50領)'. But the de facto central military power was in Euhungqingunwie(義興親軍衛) that is Lee Seong-gye's Elite Guard. In addition to these make up the backbone of the central forces that were Siwiepae(侍衛牌). Also a anti-legislation Seongzhongaima(成衆愛馬) was also presented. But soon the military command and military systems will start to repair. First, reform of military command system of the unified command system shall be established for the Euhungqingunwie(義興親軍衛). And Jeongdojeon has strengthened the military education and training. But, for the establishment of Military command system the most important was the reform of the private soldier. Military systems also have been systematized. shipwie(十衛) was changed to the shipsa(十司) in Taejo. After, they are expanded to shipyisa(十二司) in Sejong. And, the Gabsa(甲士) were returned. In addition, various special branch of the army, Byelsiwie(別侍衛), Naegumewie(內禁衛), gyumsabok(兼司僕) etc, are increased and founded.

• Korean Security Journal
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• no.10
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• pp.243-272
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• 2005

All measures related to the safety of the casino facilities guarantee safety of facilities that are targets of security guards, protect lives and properties, minimize risks of artificial and natural disaster and crimes. In summary, plan for responding to safety and accidents should be developed not only for the casino facilities but also for the facilities of annexed buildings, and lives and properties of customers and employees. Determine areas in the casino facilities that are prone to accidents and set around-the-clock guard in the areas or maintain surveillance with CCTV and prevent accidents through continuous patrol. These are the most basic and the most important requirements in safety. In addition, casinos which prompt gambling are causing economic and psychological treats to families. To resolve these social issues, casinos have adopted limited entrance system. To support this system, new forms of machine security systems such as video automatic recognition system of fingerprint pattern recognition system should be adopted too. In addition, security guards in casino facilities need to instill themselves with a sense of ownership as well as a strong sense of mission to do the best for customer security and to protect the company assets and employees and manage accidents that could occur without notice. Security guards should do their best to enable manage accidents that could occur without notice. Security guards should do their best to enable tourists who are on the rise due to increase in advanced country-style tourism and leisurely activities to get the utmost satisfaction from the casinos, and as a leader of private security company, establish the foundation for security based on the characteristics of security in Korea.

• Korean Security Journal
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• no.59
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• pp.71-90
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• 2019

As the demand for national security and national safety is gradually increasing in accordance with the trend of the times and social environment, and the use of private areas for effective prevention and supply required for the demand for safety services, this paper analyzed the Japanese private security testing system for the introduction of the Korea security certification system as a way to secure expertise in the private security industry and drew the following conclusion. First, certificate segmentation should be carried out according to the clearly divided field and scope of the expense operation. Second, it is necessary to distinguish the qualification of the private security qualification according to the level. Third, it is necessary to utilize the combined evaluation method through the departmental and practical tests. Fourth, an assessment should be made through the link between departments and practical subjects. Fifth, the diversity of the acquisition methods should be placed to ensure the gainer's accessibility. Finally, the use of professional and visible use of professional personnel should be achieved through benefit assessment for those who are qualified for

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.803-815
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• 2016

In this paper, we design a direct radio frequency (RF) sampling receiver for multiband GNSS signals and demonstrate its performance. The direct RF sampling is a technique that does not use an analog mixer, but samples the passband signal directly, and all receiver processes are done in digital domain, whereas the conventional intermediate frequency (IF) receiver samples the IF band signals. In contrast to the IF sampling receiver, the RF sampling receiver is less complex in hardware, reconfigurable, and simultaneously converts multiband signals to digital signals with an analog-to-digital (AD) converter. The reconfigurability and simultaneous reception are very important in military applications where rapid change to other system is needed when a system is jammed by an enemy. For simultaneous reception of multiband signals, the sampling frequency should be selected with caution by considering the carrier frequencies, bandwidths, desired intermediate frequencies, and guard bands. In this paper, we select a sampling frequency and design a direct RF sampling receiver to receive multiband global navigation satellite system (GNSS) signals such as GPS L1, GLONASS G1 and G2 signals. The receiver is implemented with a commercial AD converter and software. The receiver performance is demonstrated by receiving the real signals.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.841-850
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• 2019

The Korean government has designated speed-limit zones and speed limits in 19 ports and 3 routes to ensure safe navigation and transportation. However, the speed limit differs from port to port, no practical means of management exist. This often leads to violation of the speed limit. Additionally, ship collisions due to human error continue to occur. First, the study analyzed marine accidents that occurred at trade ports and fairways. The result of the analysis revealed the occurrence of 1344 accidents (average 269 cases per year) from 2014 to 2018. Five hundred sixty three accidents involved fishing boats, whereas, merchant vessels were involved in 508 cases. Second, the efficacy of the application of voice and message warnings to GPS plotters and electronic chart display and information system (ECDIS) was reviewed, and these were proposed as measures to inform vessel operators of the hazards of speed limit violation. Third, experts' opinions from relevant agencies and navigation system manufacturers were consulted and it was found that the proposed warning function was technically implementable. The findings are expected to help reduce human error among ship operators and establish a Korean e-navigation system.

• Journal of Navigation and Port Research
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• v.45 no.1
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• pp.26-32
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• 2021

In ocean field, the spread of the Fourth Industrial Revolution based on information and communication technology requires high precision and stable PNT&D (Position, Navigation, Timing and Data). As the IMO (International Maritime Organization) and IALA (The International Association of Marine Aids to Navigation and Lighthouse Authorities) are requiring backup systems due to mitigate vulnerabilities and the increase of dependency on GNSS (Global Navigation Satellite System), Korea is conducting a research & development of R-Mode. An DGPS (Differentiate Global Positioning System) reference station that uses MF, an existing maritime infrastructure, and AIS (Automatic Identification System) base stations that use 34 integrity station and VHF will be utilized in this study to avoid redundant investment. Because there are radio shadow areas that display low signal levels in the west sea, the establishment of new R-Mode reference and integrity station will be intended to resolve problems regrading the radio shadow area. Because the frequency has a characteristic in that radio wave transmits well along the ground (water surface) in low frequency band, simulation and measurement were conducted therefore this paper to propose candidate sites for R-Mode reference and integrity station resulted through p wave's propagation characteristics analysis. Using this paper, R-Mode reference and integrity station can be established at appropriate locations to resolve radio shadow areas in other regions.