• Journal of Convergence for Information Technology
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• v.10 no.7
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• pp.1-6
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• 2020

A new resource management algorithm is proposed for 5G networks which have a coordinated network architecture. By sharing the contol information among multiple neighbor cells and managing in centralized structure, the propsed algorithm fully utilizes the benefits of network coordination to increase fairness and throughput at the same time. This optimization of network performance is achieved while operating within a tolerable amount of signaling overhead and computational complexity. Simulation results confirm that the proposed scheme improve the network capacity up to 40% for cell edge users and provide network-wise fairness as much as 23% in terms of the well-knwon Jain's Fainess Index.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.4
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• pp.1-6
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• 2004

This study was carried out to investigate the effects of light intensities on the growth and net photosynthesis of Piper kauzura under different shading levels : 0％, 50％, 70％ and 90％ of sunlight. Mortality rate was lowest under a 70％ shading level but 0％ and 90％ shading levels were about 46％ and 53％ each respectively. Plant height was shorter and leaf size was smaller and yellowish under a 0％ shading level but increased when light intensity was decreased. However, under a 90％ shading level, growth of Piper kauzura was inferior to other treatments. Top fresh weight was about 11.24g under a 50％ shading level and about two times higher than that observed in about 6.6g under a 90％ shading level. Root fresh weight was about 7.7g under a 0％ shading level and was about two times higher than that showed in about 3.84g and 3.64g under 90％ and 70％ respectively. Total chlorophyll content and chlorophyll a/b rate were increased when light intensity was decreased. Net Photosynthesis achieved the highest under a 70％ shading level and maximum photosynthetic photon flux density was 150 molㆍm/sup -2/ㆍs/sup -1/. Therefore, growth of Piper kauzura was good under 50∼70％ shading, Meaning that it is an indoor plant that could be highly utilized.

• Journal of Intelligence and Information Systems
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• v.22 no.1
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• pp.107-118
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• 2016

The advent of 5G mobile communications, which is expected in 2020, will provide many services such as Internet of Things (IoT) and vehicle-to-infra/vehicle/nomadic (V2X) communication. There are many requirements to realizing these services: reduced latency, high data rate and reliability, and real-time service. In particular, a high level of reliability and delay sensitivity with an increased data rate are very important for M2M, IoT, and Factory 4.0. Around the world, 5G standardization organizations have considered these services and grouped them to finally derive the technical requirements and service scenarios. The first scenario is broadcast services that use a high data rate for multiple cases of sporting events or emergencies. The second scenario is as support for e-Health, car reliability, etc.; the third scenario is related to VR games with delay sensitivity and real-time techniques. Recently, these groups have been forming agreements on the requirements for such scenarios and the target level. Various techniques are being studied to satisfy such requirements and are being discussed in the context of software-defined networking (SDN) as the next-generation network architecture. SDN is being used to standardize ONF and basically refers to a structure that separates signals for the control plane from the packets for the data plane. One of the best examples for low latency and high reliability is an intelligent traffic system (ITS) using V2X. Because a car passes a small cell of the 5G network very rapidly, the messages to be delivered in the event of an emergency have to be transported in a very short time. This is a typical example requiring high delay sensitivity. 5G has to support a high reliability and delay sensitivity requirements for V2X in the field of traffic control. For these reasons, V2X is a major application of critical delay. V2X (vehicle-to-infra/vehicle/nomadic) represents all types of communication methods applicable to road and vehicles. It refers to a connected or networked vehicle. V2X can be divided into three kinds of communications. First is the communication between a vehicle and infrastructure (vehicle-to-infrastructure; V2I). Second is the communication between a vehicle and another vehicle (vehicle-to-vehicle; V2V). Third is the communication between a vehicle and mobile equipment (vehicle-to-nomadic devices; V2N). This will be added in the future in various fields. Because the SDN structure is under consideration as the next-generation network architecture, the SDN architecture is significant. However, the centralized architecture of SDN can be considered as an unfavorable structure for delay-sensitive services because a centralized architecture is needed to communicate with many nodes and provide processing power. Therefore, in the case of emergency V2X communications, delay-related control functions require a tree supporting structure. For such a scenario, the architecture of the network processing the vehicle information is a major variable affecting delay. Because it is difficult to meet the desired level of delay sensitivity with a typical fully centralized SDN structure, research on the optimal size of an SDN for processing information is needed. This study examined the SDN architecture considering the V2X emergency delay requirements of a 5G network in the worst-case scenario and performed a system-level simulation on the speed of the car, radius, and cell tier to derive a range of cells for information transfer in SDN network. In the simulation, because 5G provides a sufficiently high data rate, the information for neighboring vehicle support to the car was assumed to be without errors. Furthermore, the 5G small cell was assumed to have a cell radius of 50-100 m, and the maximum speed of the vehicle was considered to be 30-200 km/h in order to examine the network architecture to minimize the delay.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.23-28
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• 1999

This study measured transpiration rate of urban trees and albedos of urban surfaces, and examined the function of microclimate amelioration by urban greenspace. Transpiration rates of trees were highest in July and August of growing months. Transpiration per unit leaf area for the two months was 300-350 g/$m^2$/h for Platanus occidentalis, 210-270 g/$m^2$/h for Ginkgo biloba and Zelkova serrata, and 130-140 g/$m^2$/h for Acer palmatum. Surface albedos were 0.09 for asphalt paving and 0.68 for white wall, which reveals that light-colored surfaces are better than dark-colored ones to lower the heat build-up. Due to lack of evapotranspiration, concrete surfaces were, at t midafternoon maximum, 8$^{\circ}C$ hotter than grass ones, though the albedo of concrete paving was higher thant that of grass and trees. Summer air temperatures at places with 12% and 22% cover of woody plants were, respectively, 0.6$^{\circ}C$ and 1.4$^{\circ}C$ cooler than a place with no vegetation. To mitigate the impacts of urban heat islands, required are minimization of hard surfaces, light-coloring for building surfaces, and greenspace enlargement including more plantings.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.403-414
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• 2020

Gradient concentrations of Tithonia diversifolia green leaves and phosphate rocks were used to investigate their contributions as a fertilizer to the yield and quality improvement of a rainfed rice cultivar. Six treatments were compared: (1) T0, no fertilization (control); (2) T1, 1.28 g of phosphate rocks; (3) T2, 250 g of organic matter; (4) T3, 500 g of organic matter; (5) T4, 250 g of organic matter + 1.28 g of phosphate rocks; (6) T5, 500 g of organic matter + 1.28 g of phosphate rocks. The results showed that the germination percentage recorded 15 days after sowing varied from 58 - 76% between T0 and T5. The number of panicles ranged between 2 (T0) to 6.3 (T5). Moreover, the recorded length of the panicles ranged between 7.5 (T1) to 15.8 cm (T2), and the number of grains per panicle ranged between 25.5 (T1) to 273.5 (T3). The plant height was significantly increased in the T5 (79.27 cm) group compared to the T1 (33.63 cm) and control treatment (T0) (40.08 cm) groups. Although the plant height in the T2, T3, and T4 groups was slightly lower than the T5 group, the difference was not statistically significant. The average of the grain number per plant was high in the T3 (273.6 grains) group compared to the T1 and T0 (25.5 and 32.8 grains) groups, respectively. These results suggest that the combination of T. diversifolia leaves and phosphate rocks as a natural fertilizer would be beneficial when integrated into soil fertility management strategies and would contribute to improving crop yield and quality.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.4
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• pp.254-262
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• 2011

This study aims to optimize an arrangement of ship compartments with knowledge-based systems. Though great attention has been shown to the optimization of hull forms in recent years, the study on arrangement design optimization has received relatively little attention. A ship is both an engineering system and a kind of assembly of many spaces. This means that, to design an arrangement of ship compartments, it is necessary to treat not only geometric data but also knowledge on topological relations between spaces and components of a ship. In this regard, we select a suitable knowledge representation scheme for describing ship compartments and their relations, and then develop a knowledge-based system using expert system shell. This new approach is applied to create design variations for optimization on an arrangement of a pressure hull of a submerged vehicle. Finally, we explicate how our approach improves the design process.

• Journal of The Korea Institute of Healthcare Architecture
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• v.7 no.1
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• pp.33-44
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• 2001

This study is about the Spatial Composition and Area Calculation in Plastic Surgical Clinics. 1. The space of the plastic surgical clinics are divided into 4 sections; exam, exam support, the staffs, and waiting and reception area. 2. The average G/N ratio of width was 1.46. The Plastic surgical clinics which had great deviation in the ratio showed these characteristics; first, when they were planned at first, the operation rooms were not assigned enough space; second. space for supporting exam and the activities of staffs was given too little consideration in their first drafts. 3. The average size of operation rooms was $21.76m^2$. The most desirable size was found to be $26.4m^2$ when we put the number of staffs, the movement area of stretcher, and the movement lines of operation room into consideration.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.718-724
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• 2012

Sugars play important roles in petal senescence of cut flowers. In the Expt. 1 of this study, the effects of different concentrations of glucose (60, 90, and $120g{\cdot}L^{-1}$) and sucrose (30, 60, and $90g{\cdot}L^{-1}$) application on the vase life, rate of flower diameter increase, rate of flower weight increase and ethylene production of cut tree peony (Paeonia suffruticosa 'Luoyang Hong') were evaluated. At the earlier stage, treatments of different concentrations of glucose and sucrose all retarded the process of flower opening and inhibited the increase of flower diameter and weight, while senescence of flowers fed with different concentrations of glucose was delayed at later stage. Flowers treated with $90g{\cdot}L^{-1}$ glucose displayed the longest vase life, which showed significant difference (P < 0.05) from those of flowers with the control and sucrose treatments. All treatments with glucose or sucrose not only retarded the decrease of flower diameter and weight, but also suppressed the ethylene production at the earlier stage and delayed the peak of ethylene evolution. In order to study the effect of exogenous sugar on the postharvest response of cut tree peony to ethylene, Expt. 2 was conducted. Cut flowers were treated with $90g{\cdot}L^{-1}$ glucose for 4 hours before (GE) or after (EG) exposed to $10{\mu}L{\cdot}L^{-1}$ ethylene for 4 hours. Generally, the opening process of flowers with GE and EG treatments was similar to that of the control, however GE treatment delayed flower senescence. Both GE and EG treatments improved flower diameter and weight, and GE treatment delayed the time of flower weight decrease. Besides, GE delayed climacteric ethylene evolution for 8 hours. All above suggest that exogenous sugars delay tree peony 'Luoyang Hong' cut flower senescence and extend flower vase life through their roles in the decrease of water loss and the suppression of sensitivity to ethylene and ethylene production.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.896-914
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• 2020

With the rapid growth of network traffic, a large number of connected devices, and higher application services, the traditional network is facing several challenges. In addition to improving the current network architecture and hardware specifications, effective resource management means the development trend of 5G. Although many existing potential technologies have been proposed to solve the some of 5G challenges, such as multiple-input multiple-output (MIMO), software-defined networking (SDN), network functions virtualization (NFV), edge computing, millimeter-wave, etc., research studies in 5G continue to enrich its function and move toward B5G mobile networks. In this paper, focusing on the resource allocation issues of 5G core networks and radio access networks, we address the latest technological developments and discuss the current challenges for resource management in 5G.

• The Journal of Korea Robotics Society
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• v.17 no.2
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• pp.118-123
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• 2022

We implemented a real-time cloud robotics application by offloading robot navigation engine over to 5G Mobile Edge Computing (MEC) sever. We also ran a fleet management system (FMS) in the server and controlled the movements of multiple robots at the same time. The mobile robots under the test were connected to the server through 5G SA network. Public 5G network, which is already commercialized, has been temporarily modified to support this validation by the network operator. Robot engines are containerized based on micro-service architecture and have been deployed using Kubernetes - a container orchestration tool. We successfully demonstrated that mobile robots are able to avoid obstacles in real-time when the engines are remotely running in 5G MEC server. Test results are compared with 5G Public Cloud and 4G (LTE) Public Cloud as well.