• Journal of the Institute of Convergence Signal Processing
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• v.21 no.4
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• pp.202-208
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• 2020

Recently, the importance of non-face-to-face has been emphasized due to COVID-19, and the use of sharing spaces is also expanding. The use of uncontact check-in technology for access control of sharing spaces reduces waiting time and optimizes workers' efficiency, resulting in operational cost savings. In this paper, we propose a sharing space access management system based on a mobile key and RCU (Room Control Unit), access to the facility using a mobile key, and monitor the facility using an RCU. Proposal system is for shared accommodation, rental field (residence, sale-selling hotel), shared office, etc. when there is a one-time visitor on a specific day and time, the corresponding password is delivered to the mobile platform to expose and key the existing password. It is supported by a field-adaptive system that can reduce discomfort such as delivery. In order to test the operation of the proposed integrated system, tests were conducted according to scenarios to understand the overall status of the user's reservation, check-in, and check-out, and a 100% success rate was derived for each item by setting performance indicators to prove test reliability.

• International Journal of Aeronautical and Space Sciences
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• v.5 no.1
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• pp.64-74
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• 2004

The Grid is a communication service that collaborates dispersed highperformance computers so that those can be shared and worked together. It enablesthe analysis of large-scale problem with the reduction of computation time bycollaborating high performance computing resources in dispersed organizations. Thus,the present paper focuses on the efficient flow calculation using the Grid. To increaseparallel efficiency, a simple load balance algorithm for the Grid computing is proposedand applied to various aerodynamic problems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.167-171
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• 2002

As a channel of a DS-CDMA system is shared among several users, the receivers face the problem of MAI. Also the multipath scenario leads to ISI. Both components are undesired, but unlike the additive noise process, which is usually completely unpredictable, their space-time structure helps to estimate and remove them. This paper investigates a DS-CDMA system with a fading multipath channel. The investigations have been separated into a channel estimation part and a reception part. In the first part, the estimation of multipath parameters(DOA, TOA) are considered, space-time beamformers(Decorrelating, Match-Filter, Wiener-Hopf) are performed in the second part. To assess many different estimation techniques and beamformers, the simulation compared with theoretical values is performed.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.3
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• pp.136-142
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• 2006

Existing buffer management schemes for shared-memory output queueing switches can be classified into two types: In the first type, some constant amount of memory space is guaranteed to each virtual queue using static queue thresholds. The static threshold method (ST) belongs to this type. On the other hand, the second type of approach tries to maximize the buffer utilization in 머 locating buffer memories. The complete sharing (CS) method is classified into this type. In the case of CS, it is very hard to protect regular traffic from mis-behaving traffic flows while in the case of ST the thresholds can not be adjusted according to varying traffic conditions. In this paper, we propose a new buffer management method called weighted dynamic thresholds (WDT) which can process packet flows based on loss priorities for quality-of-service (QoS) functionalities with fairly high memory utilization factors. We verified the performance of the proposed scheme through computer simulations.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.8
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• pp.33-44
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• 2011

In this paper, we presents a hybrid on-chip bus architecture based on the AMBA 3.0 AXI protocol for MPSoC with high performance and low power. Among AXI channels, data channels with a lot of traffic are designed by crossbar-switch architecture for massively parallel processing. On the other hand, addressing and write-response channels having a few of traffic is handled by shared-bus architecture due to the overheads of (areas, interconnection wires and power consumption) reduction. In experiments, the comparisons are carried out in terms of time, space and power domains for the verification of proposed hybrid on-chip bus architecture. For $16{\times}16$ bus configuration, the hybrid on-chip bus architecture has almost similar performance in time domain with respect to crossbar on-chip bus architecture, as the masters's latency is differenced about 9% and the total execution time is only about 4%. Furthermore, the hybrid on-chip bus architecture is very effective on the overhead reduction, such as it reduced about 47% of areas, and about 52% of interconnection wires, as well as about 66% of dynamic power consumption. Thus, the presented hybrid on-chip bus architecture is shown to be very effective for the MPSoC interconnection design aiming at high performance and low power.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.2
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• pp.55-67
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• 2005

Separation between computation and communication in system design allows the system designer to explore the communication architecture independently of component selection and mapping. In this paper we present an iterative two-step exploration methodology for bus-based on-chip communication architecture and memory allocation, assuming that memory traces from the processing elements are given from the mapping stage. The proposed method uses a static performance estimation technique to reduce the large design space drastically and quickly, and applies a trace-driven simulation technique to the reduced set of design candidates for accurate Performance estimation. Since local memory traffics as well as shared memory traffics are involved in bus contention, memory allocation is considered as an important axis of the design space in our technique. The viability and efficiency of the proposed methodology arc validated by two real -life examples, 4-channel digital video recorder (DVR) and an equalizer for OFDM DVB-T receiver.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.104-110
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• 2008

In this paper, a novel 2-level-search sphere decoding algorithm for multiple-input multiple-output (MIMO) detection and its VLSI implementation are presented. The proposed algorithm extends the search space by concurrently performing symbol detection on 2 level of the tree search. Therefore, the possibility of discarding good candidates can be avoided. Simulation results demonstrate the good performance of the proposed algorithm in terms of bit-error-rate (BER). From the proposed algorithm, an efficient very large scale integration (VLSI) architecture which incorporates low-complexity and fixed throughput features is proposed. The proposed architecture supports many modulation techniques such as BPSK, QPSK, 16-QAM and 64-QAM. The sorting block, which occupies a large portion of hardware utilization, is shared for different operating modes to reduce the area. The proposed hardware implementation results show the improvement in terms of area and BER performance compared with existing architectures.

• Journal of Drive and Control
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• v.18 no.4
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• pp.19-27
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• 2021

A bunker bed is a type of furniture that efficiently utilizes a narrow indoor space by having a high bed and using the empty space below as a living and storage space. The demand for multi-purpose furniture is increasing due to the recent increase in single-person households and wide-spread shared accommodation. According to the consumer research, one of the major drawbacks of a bunker bed was to get on and off the bed through a ladder or stairs. In order to overcome these problems, it was confirmed that the height adjustment function that can easily adjust the minimum and maximum heights of the bed was necessary. In this study, a height adjustable bunker bed was designed by using a gas spring that generates a repulsive force by the compressed gas inside. The design process consisted of the following three steps: Firstly, the hysteresis characteristics due to a friction and spring constant of a commercial gas spring were confirmed by measuring the repulsive force vs. compressed displacement. Secondly, requirements of the vertical lifting force exerted on the bed against gravity force were derived. Finally, the height-adjustable bed using the four-bar link mechanism was designed with 4 parameters so that the bed weight of 60-70 kgf could be adjusted to 800 mm in height by an affordable initial operation force. The performance was verified through prototype production and the results of vertical displacement and force to move were nearly the same as designed. In addition, an electrically operated height-adjustable bed was also designed with linear actuators and the performance was proved with the prototype.

• Annual Conference on Human and Language Technology
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• 2018.10a
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• pp.305-309
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• 2018

딥러닝에서 층을 공유하여 작업에 따라 변하지 않는 정보를 사용하는 multi-task learning이 다양한 자연어 처리 문제에 훌륭하게 사용되었다. 그렇지만 우리가 아는 한 공유 공간의 상태와 성능과의 관계를 조사한 연구는 없었다. 본 연구에서는 공유 공간과 task 의존 공간의 자질의 수와 오염 정도가 성능에 미치는 영향도 조사하여 공유 공간과 성능 관계에 대해서 탐구한다. 이 결과는 multi-task를 진행하는 실험에서 공유 공간의 역할과 성능의 관계를 밝혀서 시스템의 성능 향상에 도움이 될 것이다.

• Journal of Information Processing Systems
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• v.9 no.3
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• pp.489-498
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• 2013

In this paper, we propose a common simulation model that can be reused for different performance evaluations of networked virtual environments. To this end, we analyzed the common features of NVEs, in which multiple regions compose a shared space, and where a user has his/her own interest area. Communication architecture can be client-server or peer-server models. In usual simulations, users move around the world while the number of users varies with the system. Our model provides various simulation parameters to customize the region configuration and user movement pattern. Furthermore, our model introduces a way to mimic a lot of users in a minimal experiment environment. The proposed model is integrated with our network framework, which supports various scalability approaches. We specifically applied our model to the interest management and load distribution schemes to evaluate communication overhead. With the proposed simulation model, a new simulation can be easily designed in a large-scale environment.