• Journal of Communications and Networks
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• v.18 no.2
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• pp.150-161
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• 2016

Coordinated multi-point transmission (CoMP) techniques are being touted as enabling technologies for interference mitigation in next generation heterogeneous wireless networks (HetNets). In this paper, we present a comparative performance study of uplink (UL) CoMP algorithms for the 3GPP LTE HetNets. Focusing on a distributed and functionally-split architecture, we consider six distinct UL-CoMP algorithms: 1. Joint reception in the frequency-domain (JRFD) 2. Two-stage equalization (TSEQ) 3. Log-likelihood ratio exchange (LLR-E) 4. Symmetric TSEQ (S-TSEQ) 5. Transport block selection diversity (TBSD) 6. Coordinated scheduling with adaptive interference mitigation (CS-AIM) where JRFD, TSEQ, S-TSEQ, TBSD and CS-AIM are our main contributions in this paper, and quantify their relative performances via the post-processing signal-to-interference-plus-noise ratio distributions.We also compare the CoMP-specific front-haul rate requirements for all the schemes considered in this paper. Our results indicate that, with a linear minimum mean-square error receiver, the JRFD and TSEQ have identical performances, whereas S-TSEQ relaxes the front-haul latency requirements while approaching the performance of TSEQ. Furthermore, in a HetNet environment, we find that CS-AIM provides an attractive alternative to TBSD and LLR-E with a significantly reduced CoMP-specific front-haul rate requirement.

• The Journal of Korean Medical History
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• v.30 no.1
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• pp.43-50
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• 2017

In the United States, California is well known for its rigorous education and licensing system regarding East Asian Medicine and acupuncture. As in most other states in America, the State government controls the practice of acupuncture, massage, acupressure therapy, food therapy, and natural therapy using a board established to set, maintain, and uphold licensing credentials for acupuncturists and practitioners of East Asian medicine. In California the system started in the 1970s when the State Legislature passed a bill to measure competency, and license acupuncturists. This study briefly describes the California Acupuncture Board (CAB), which is authorized to control the related education, examination, continuing education, and management of licenses already awarded. This study addresses the essential and minimum educational requirement established by the CAB for licensure, that is mandate classroom lecture with additional 950 hours clinic training, and the 50 hours of continuing education credits earned every two years, for maintaining the license.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.1
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• pp.1-21
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• 2011

Because of high demand of color quality of the prints, proof prints are more important for end-user to predict and correct the final prints directly as an intermediate. Thus, proof prints can be used as a reference to take minimum ${\Delta}E^*ab$between the originals and finals in the field. The advantage of proof prints is to predict and correct color easily through the RIP(Raster Image Processor) without printing plates and plate making steps. While, it is thought that the proof systems are almost equivalent to the press in the past, present proof systems are more simple to take proof prints more easily due to the automation and digitalization. This paper addresses a method to perform an accurate profiling according to proof paper types and find optimal proof papers which meet proofing requirement. Although proof papers are matched with ISO 12647-7, we were trying to reduce ${\Delta}E^*ab$, In addition to the above, through the Gamut Mapping and Iteration, We were trying to find optimal proofing conditions.

• Journal of Environmental Impact Assessment
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• v.19 no.2
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• pp.205-213
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• 2010

The purpose of this research is to analysis the application of the ISG(Index of Streetscape Greenness) in EIA through case study of Seoul. ISG is a new index which directly expresses human's perceptions of plants in a street and is defined as the area ratio of which leaves of plants occupy an eye-level view of a person standing on the center line of a street. In this research the 42 cases of 3 step reports such as plans, drafts, and final reports which had been passed through the EIA procedure of Seoul were analyzed. The results are as follows: In the drafts frequent mistakes or errors such as unsuitable picture composition, unsuitable sample points, inconsistency of the simulation result with the planting plan, and insufficient numbers of analysis were found, but almost of them were corrected in the final reports. In the most of final reports, the 30% of minimum requirement was satisfied. At all cases the changes of the ISG values were clearly positive. Finally the average current ISG was 19.6%, meanwhile the average proposed ISG was 35.4%. It was verified that the ISG is very practical index to promote green streetscape, but in order to guarantee an achievement a thorough investigation of reports are needed.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.574-575
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• 2007

This paper proposes a method for choosing the best transmission system expansion plan using nodal/bus delivery marginal rate criterion ($BMR_k$) defined newly in this paper. The objective method minimizes a total cost which is an investment budget for constructing new transmission lines subject to the $BMR_k$ which means a nodal deterministic reliability level requirement at specified load point. The proposed method models the transmission system expansion problem as an integer programming problem. It solves for the optimal strategy using a branch and bound method that utilizes a network flow approach and the maximum flow-minimum cut set theorem. Test results on an existing 21-bus system are included in the paper. It demonstrated the suitability of the proposed method for solving the transmission system expansion planning problem in competitive electricity market environment.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.314-314
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• 2010

The design of the blanket and shield play a key role in determining the size of a reactor since it has an impact on the various reactor components. The blanket should produce enough tritium for tritium self-sufficiency and the shield should provide sufficient protection for the superconducting TF coil. Neutronic optimization of the blanket and the shield is necessary, and we coupled the system analysis with a neutronic calculation to account for the interrelation of the blanket and shield with the plasma performance of a reactor system in a self-consistent manner. By using the coupled system analysis code, the operational space for a low aspect ratio (LAR) tokamak reactor with a superconducting toroidal field (TF) coil is investigated with an spect ratio in the range of 1.5 - 2.5. The minimum major radius which satisfies all the physics and engineering requirements increases with the magnetic field at the magnetic axis. A required inboard shield thickness is mainly determined by the requirement on the protection of the TF coil against radiation damage. It is shown that to have a fusion power bigger than 3,000 MW in the LAR tokamak with a superconducting TF coil, a major radius bigger than 4.0 m is required.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.461-464
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• 2004

The reduction effect of floor impact noise depends on the various factors such as stiffness and thickness of the concrete slab, finishing If ceiling materials and the composition method. Among the rest it is well known that floating floor system is more effective. Standard floating floor(SFF) type-2 consisted of 50mm lightweight aerated concrete(LAC) and 20mm damping material has been widely used. But LAC construction problem on dry damping material occurred and the reduction effect of floor impact noise has bare minimum qualifications. Thus the aim of this study is to develop 40mm composite damping material(Soundzero Plus) for SFF type-5 which substitute LAC and damping material. 'Soundzero Plus' is satisfied with quality requirement for damping material for SFF. The heat transition rate, $0.45W/m^2{\cdot}K$ is more effective 55% about than the regulation. The test results of floor impact noise by using 'Soundzero Plus' are showed good improvement about 12dB (tested by tapping machine) and 4dB (tested by bang machine) between before and after.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.241-269
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• 2012

Wireless networks composed of multimedia-enabled resource-constrained sensor nodes have enriched a large set of monitoring sensing applications. In such communication scenario, however, new challenges in data transmission and energy-efficiency have arisen due to the stringent requirements of those sensor networks. Generally, congested nodes may deplete the energy of the active congested paths toward the sink and incur in undesired communication delay and packet dropping, while bit errors during transmission may negatively impact the end-to-end quality of the received data. Many approaches have been proposed to face congestion and provide reliable communications in wireless sensor networks, usually employing some transport protocol that address one or both of these issues. Nevertheless, due to the unique characteristics of multimedia-based wireless sensor networks, notably minimum bandwidth demand, bounded delay and reduced energy consumption requirement, communication protocols from traditional scalar wireless sensor networks are not suitable for multimedia sensor networks. In the last decade, such requirements have fostered research in adapting existing protocols or proposing new protocols from scratch. We survey the state of the art of transport protocols for wireless multimedia sensor networks, addressing the recent developments and proposed strategies for congestion control and loss recovery. Future research directions are also discussed, outlining the remaining challenges and promising investigation areas.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1736-1746
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• 2008

Because present road traffic reaches to the limitation of its faculty, Korean tilting train was developed to find the solution by increasing the speed of rail road. A tilting train can run on a curved rail at high speed so it improves a speed of a rail transit without constructing a new line. Only minimum modification is necessary for a existing line. According to above requirement, Korean tilting train was developed in 2007 and the try run has been executing since April, 2007 in order to validate its safety and reliability in a service lines. And this test and estimation will be completed in 2009. After completing a try run, main parts of tilting train will be studied again to commercialize and localize including a bogie and its commercial model design will be finalized by 2012. In order to achieve the development target as mentioned above, the study have been done to improve the bogie system. As the first step to design commercialized bogie system, measurements from the try run and a dynamic analysis were used to find problems of present bogie system well. So this project is performed to decide what parts of the bogie should be modified in basis of this result.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.1
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• pp.40-48
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• 2019

Hybrid electric propulsion systems (H-EPSs) are an intermediate step for integrated full electric propulsion warships. H-EPSs are a dynamic combination of mechanical and electrical propulsion systems to achieve the required mission performances. The system modes could adapt to meet the requirement of the various operation conditions of a warship. This paper presents a configuration and operating modes of H-EPSs considering the operation conditions of a destroyer class warship. The system has three propulsion modes, namely, motoring mode, generating mode [power take off (PTO) mode], and mechanical mode. The PTO mode requires a careful fuel efficiency analysis because the fuel consumption rate of propulsion engines may be low compared with the generator's engines depending on the loading power. Therefore, the calculation of fuel consumption according to the operating modes is performed in this study. Although the economics of the PTO mode depends on system cases, it has an advantage in that it ensures the reliability of electric power in case of blackout or minimum generator operation.