• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.67-72
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• 2020

The fifth generation (5G) mobile communication has an impact on the human life over the whole world, nowadays, through the artificial intelligence (AI) and the internet of things (IoT). The low latency of the 5G new radio (NR) access is implemented by the state-of-the art technologies, such as non-orthogonal multiple access (NOMA). This paper investigates a practical issue that in NOMA, for the practical channel models, such as fading channel environments, the successive interference cancellation (SIC) should be performed on the stronger channel users with low power allocation. Only if the SIC is performed on the user with the stronger channel gain, NOMA performs better than orthogonal multiple access (OMA). Otherwise, NOMA performs worse than OMA. Such the superiority requirement can be easily implemented for the channel being static or slow varying, compared to the block interval time. However, most mobile channels experience fading. And symbol by symbol channel estimations and in turn each symbol time, selections of the SIC-performing user look infeasible in the practical environments. Then practically the block of symbols uses the single channel estimation, which is obtained by the training sequence at the head of the block. In this case, not all the symbol times the SIC is performed on the stronger channel user. Sometimes, we do perform the SIC on the weaker channel user; such cases, NOMA performs worse than OMA. Thus, we can say that by what percent NOMA is better than OMA. This paper calculates analytically the percentage by which NOMA performs better than OMA in the practical mobile communication systems. We show analytically that the percentage for NOMA being better than OMA is only the function of the ratio of the stronger channel gain variance to weaker. In result, not always, but almost time, NOMA could perform better than OMA.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.3
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• pp.345-352
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• 2009

The purpose of inlet baffle is to distribute the flow uniformly over the entire cross-sectional area of the sedimentation basin. The goal when designing this baffle is to achieve some head loss while keeping the velocity gradients through the ports equal to the velocity gradient in the end of the flocculator, so as to not break up the flocs. Sedimentation tank performance is strongly influenced by hydrodynamic and physical effects such as inlet design. This study was conducted to evaluate the effect of open ratio of the inlet baffle on hydraulic behavior within a rectangular sedimentation basin using CFD simulation and ADV technique. In order to verify the CFD simulation, we measured the factual velocity at 18 points in the full-scale sedimentation basin at Y water treatment plant. Good agreement was obtained between the CFD predictions and the experimentally measured data. From the simulation results of the existing basin with 7.4 % open ratio, it was investigated that extreme decrease in velocity occurred in the middle of basin. Since then, flow features was unstable. The region which the velocity decrease rapidly moved forward to the flow direction in proportion to the increase of inflow velocity. Also, it was investigated that the flow characteristic of 6.0 % open ratio was significantly different from 7.4 % open ratio at the same configuration condition. These results are a clear indication that inflow momentum and open ratio are the parameters affecting the characteristics of hydraulic patterns. The influence of these parameters on the sedimentation performance requires further study.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.299-303
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• 2022

The article examines the stage of verification of a crime report from the standpoint of the need for its legislative regulation. Moreover, it investigates the international experience in this field. The existing procedural models are described in detail on the example of the neighboring and faraway countries. An analysis of the provisions of the current criminal procedure law of Russia and foreign experience allowed the authors to identify existing problems in the implementation of departmental control and prosecutorial supervision at the stage of verifying a crime report. The aim of the study is to develop theoretical provisions and recommendations regarding the implementation of departmental procedural control and prosecutorial supervision over the activities of the investigator during the verification of reports of crimes, based on the study of experience, both in Russia and in a number of countries of the near and far abroad, which could find their reflection in law enforcement practice, as well as aimed at improving the current criminal procedure legislation. The authors substantiated the theory that a detailed examination of the foreign procedural foundations of checking a crime report will allow us to form the most suitable model for checking a crime report for our state, taking into account all possible features and successfully implement it into the current criminal procedural law of the Russian Federation.

• 보존과학연구
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• s.26
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• pp.141-164
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• 2005

Most of the stone cultural properties is exposed to the weathering factor(rain, windetc.), so the shelter is constructed for reduction of its direct effect. But the shelter is indicated some problems that inharmoniousness of the surroundings, in section disturbance for insufficiency of light, the loss about the value of cultural properties and so on. So we have investigated on environmental condition (temperature, relative humidity, wind etc.) at the Standing Stone Buddhist Triad in Bae-ri, Gyeongju and Rock-carved Triad Buddha in Seosan because check the effect of the shelter. As the result, the Standing Stone Buddhist Triad in Bae-ri, Gyeongju is located a pine wood and a lot of bamboo grow naturally in nearing. Environmental difference on inside and outside of the shelter is not found because opened on all sides. But there is so dim for the direction of the sunlight that can't see the Standing Stone Buddhist. The base rock of Rock-carved Triad Buddha in Seosan well develop with crack and break, and the vegetation(trees, moss, lichen etc.) grow naturally in surroundings. Environmental difference on inside and outside of the shelter is found because closed on all sides and opened the front gate only inspection time. Inside of the shelter was too calm(air-velocity not detected) and humid(over 75%RH). Also the surface is occurred the dew(at 2-4 pm) and the efflorescence for effect of the water(rain, dew etc.). Besides the head of the central Buddhist is so dangerous for crack.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.27-32
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• 2009

This paper presents the stress and deformation behaviors using the finite element method as a function of the thickness of the helmets without the bead frames on the top of the shell structure. The helmet that would provide head and neck protections without causing discomfort to the user when it was worn for long periods of time should be manufactured for increasing the safety and impact energy absorption. The FEM computed results show that when the impulsive force is applied on the top surface of a helmet, the maximum stress and strain have been occurred around the position of an applied impact force, which may lead to the initial failure on the top surface of the helmet shell. As the helmet thickness is decreased from 4mm to 2mm, the impact energy absorbing rate is radically increased, and the maximum stress of the helmet is increased over the tensile strength, 54.3MPa of the thermoplastic material. Thus, the top surface of the helmet should be supported by a bead frame and increased thickness of the shell structure.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.6
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• pp.678-687
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• 2012

Concentration fields of solid powder in a liquid fuel were quantitatively measured by a visualization technique. The measurement system consists of a camcoder and three LCD monitors. The solid powder (glass powder) were filled in a head tank which was installed over a main mixing tank ($D{\times}H$, $310{\times}370mm$). The main mixing tank was filled with JetA1 fuel oil. With a sudden opening of the upper tank by pressurized nitrogen gas with 1.9 bar, the solid powder were poured into the JetA1 oil. An impeller type agitator was being rotated in the mixing with 700 rpm for the enhancements of mixing. Uniform visualization for the mixing flow field was made by the light from the three LCD monitors, and the visualized images were captured by the camcoder. The color images captured by the camcoder The color information of the captured images was decoded into three principle colors R, G, and B to get quantitattive relations between the concentrations of the solid powder and the colors. To get better fitting for the strong non-linearity between the concentration and the color, a neural network which has strong fitting performances was used. Analyses on the transient mixing of the solid powders were quantitatively made.

• Journal of the Korean Society of Costume
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• v.66 no.1
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• pp.122-134
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• 2016

The Mural Tomb of Xu Xianxiu(AD 571), a high ranking official in Northern Qi period, is located in Taiyuan, Shanxi province, China. Despite having been raided, it was still discovered to contain over 530 pieces, such as artifacts and murals, in excellent state of preservation. These murals are noteworthy for their high level of detail compared to other murals from the same era, and are important for understanding the historical context of active East-West and Han-Hu cultural exchange in the $6^{th}$ to $7^{th}$ century. The murals of Xu Xianxiu's tomb depict round-collared and narrow-sleeved garments as well as straight collared robes typical of the Xianbei tribe's attire. Notable are the ermine fur overcoat and a headwear with flares on the left and right thought to be unique to the Xianbei. The wife and female servants show female attire of the Xianbei at the time; this attire can be characterized by narrow-sleeved long gowns and asymmetrical flying-bird buns. Despite the anti-Han policy of Northern Qi, influences such as the right sided gathering of the robes and embellished hair styles remain. The procession also depicts the three-cornered headdress and long-tailed hood of the Xianbei men, which have been recorded in documents. The large rounded pearl pattern containing the palmette, the divine animal, and bodhisattva's head motifs show the influence of the Western China [Xi'yu]. Considering that Northern Qi had more active interactions with the three ancient kingdoms of Korea than with the Southern Kingdoms[Nanchao], the findings of this study call for further research on the correlation between the attire of ancient Korea and Northern Qi.

• Journal of the Korean Home Economics Association
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• v.38 no.3
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• pp.85-97
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• 2000

The goal of this study is mainly to improve the quality of life for the elderly by understanding the actual condition of the home management which includes their family relationship, family finance, and household work carried out in their domestic lives and diagnosing problems possibly restated from the condition. The result includes the following. The characteristics of rural elderly living alone: They have lived in rural area since their marriage which is over 40 years long in average, The tend to be satisfied with living apart themselves. The majority of the families are the first son in their family. In home management regard: First, in family relationship, the way the elderly in their nuclear family state communicate with their spouse is limited, and they hardly speaks together. So it is encouraged for couples to forge their own specific relationship and to plan for their odd age in their younger age. Also, they tend to be satisfied with living separated from their children, but at the same time, the closer they live in distance from their children, the more often they meet their children as well as they talk on the phone. They especially depend on their first son for offerings for ancestors and matters to occur after their death, while they get emotional support from daughters. Second, in family finance, their income varies in range from 200,000 to 3,000,000 won. In the majority f the famines, the wives are in charge of finance. The cost of living is mainly spent on flood, clothing, and housing, or the cost of offerings for ancestors if they are the head family. Third, Meanwhile, the housewives under 70 years old are positive about household work and tend to consider it pleasant for their children and their husband. Generally, the older they are, the more they dislike household labor. For example, food preparation is especially considered a major problem. Community dinning rooms, food delivery service, volunteers, and home helper and neighborhood could be help.

• Korean Journal of Legislative Studies
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• v.24 no.1
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• pp.31-66
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• 2018

The purpose of this study is to analyze the institutional factors and the political environment in which the influence of the president is limited in South Korea's decision making process of the policy toward North Korea. Although the president has the highest decision-making power over policy toward North Korea as a head of state, the president's influence is not always absolute. Many reasons, such as bureaucratic government through the separation of power, the political environment such as divided government or the remaining term of the president,and the specificity of policy act as factors limiting the president's influence on policy toward North Korea. This study analyzed the dynamics of the decision making process of the 'Special Zone for Peace and Cooperation in the West Sea' which was planned by the agreement between the two Koreas in 2007, and examined the influence of the president, limited by the institutional environment and political conditions in the process.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.460-472
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• 2023

This study was conducted based on the case of an accident (excessive deformation) that occurred during the hydraulic test of a shipboard tank manufactured in accordance with the design regulations. Over-pressure phenomenon was noted as the main cause of accidents in the process of testing tanks without physical damage, which can be found in external factors such as cross-sectional difference between inlet pipe and air pipe and higher water filling rate than the recommended one. The main goal of this paper is to establish a safe water filling rate according to the range of sectional area ratio(SAR) reduced below the regulations for each test situation. The simulation was conducted in accordance with the hydraulic test procedure specified in the Ship Safety Act, and the main situation was divided into two types: filling the tank with water and increasing the water head to the test pressure. The structural safety evaluation of the pressure generated inside the tank and the effect on the structure during the test was reviewed according to the SAR range. Based on the results, guidelines for the optimal filling rate applicable according to SAR during the hydraulic test were presented for the shipboard tanks used in this study.