• ETRI Journal
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• v.45 no.3
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• pp.418-432
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• 2023

In this work, we proposed a low-complexity hybrid layered tabu-likelihood ascent search (LTLAS) algorithm for large multiple-input multiple-output (MIMO) system. The conventional layered tabu search (LTS) approach involves many partial reactive tabu searches (RTSs), and each RTS requires an initialization and searching phase. In the proposed algorithm, we restricted the upper limit of the number of RTS operations. Once RTS operations exceed the limit, RTS will be replaced by low-complexity likelihood ascent search (LAS) operations. The block-based detection approach is considered to maintain a higher signal-to-noise ratio (SNR) detection performance. An efficient precomputation technique is derived, which can suppress redundant computations. The simulation results show that the bit error rate (BER) performance of the proposed detection method is close to the conventional LTS method. The complexity analysis shows that the proposed method has significantly lower computational complexity than conventional methods. Also, the proposed method can reduce almost 50% of real operations to achieve a BER of 10^-3.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.12
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• pp.633-638
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• 2015

This study evaluates the capacity of night purging in office buildings to reduce the cooling load. RTS-SAREK is used to estimate the performance of night purging on the steady state. To overcome steady state RTS program limitations, we added unsteady heat transfer equations. When the ACH (Air Change per Hour) increases, the wall temperature decreases in both the steady and unsteady states. The unsteady heat transfer rate is different from the steady transfer rate, which validates the unsteady calculation. When ACH is low, the heat transfer rate increases continuously with time. When ACH becomes higher, the heat transfer rate increases and decreases with time. When ACH is quite high, there exists a large difference in the heat transfer rate between the steady and unsteady calculations, which emphasizes the importance of the unsteady calculation.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.525-530
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• 2006

• Economic and Environmental Geology
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• v.43 no.4
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• pp.343-348
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• 2010

Gravity anomalies observed in shipborne survey are usually distorted by bad weather conditions and unexpected vessel movement. These distorted data should be removed because they may mislead the data interpretation. However, it is not possible to perfectly remove all erroneous data. Cross-over point correction, which is generally used, only reduces the errors at cross-over points, and thus the data still contain error values. To resolve this drawback, Rauch-Tung-Striebel(RTS) filter was adopted to minimize all errors in the data and at cross-over points. After applying this method, the range of anomaly variation is reduced from 15 mGal to less than 2 mGal, and errors at the cross-over points are minimized from 4.21 mGal to 2.95 mGal. The results imply that RTS filter is very useful to reduce errors in the data and corss-over points.

• 전자공학회논문지 IE
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• v.48 no.2
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• pp.61-70
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• 2011

IEEE 802.11 wireless network supports control frames like RTS/CTS(Request To Send / Clear To Send). Because they is defend to frame collection problems. It helps to solve the frame collection problem but decreases the throughput rate. Also, control frame makes False Node Problem. This problem is makes to other wireless nodes don't work and don't find channels in the same cell and near cells. We proposed a reformed new control frame for efficiency throughput rate and solution of False Node Problem. New control frame is to have added to 4 bytes of channel detection ability at the RTS frames. Channel detection ability supported to check channel at the wireless node start to transmit data frame, We expect that channel detection ability make prevent False Node Problem for increase to access number to channel. We perform comparative analysis in terms of delay(sec) and load(bits/sec) with reform RTS/CTS method which proves the efficiency of the proposed method.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.252-259
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• 2017

In this paper, we propose a novel method for extracting an accurate depth of a trap that causes RTS(Random Telegraph Signal) noise. The error rates of the trap depth rely on the mean time constants and its ratio. Here, we determined how many data of the capture and emission time constant are necessary in order to reduce the trap depth error caused by an inaccurate mean time constant. We measured the capture and emission time constants up to 100,000 times in order to ensure that the samples had statistical meaning. As a result, we demonstrated that at least 1,000 samples are necessary to satisfy less than 10% error for trap depth. This result could be used to improve the accuracy of RTS noise analysis.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.2
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• pp.7-16
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• 2000

In this paper, IEEE 802.11 MAC layer protocol is modeled by p-persistent CSMA method. And We introduce performance analysis model based on Basic CSMA/CA protocol, CTS/RTS protocol and hidden node effect reflected Basic CSMA/CA Protocol, Which is mathematically assayed by renewal theory. In this throughput, the result shown that Basic CSMA/CA protocol is profitable when the number of active node is smaller, or the length of packet is shorter, and CTS/RTS protocol is lucrative when the number of active node is larger, or the length of packet is longer. Also the result shown that hidden node less affected when the active node has small one, rather than when the active node has larger one.

• Journal of Korean Society for Quality Management
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• v.38 no.3
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• pp.463-474
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• 2010

In this study, we evaluate the efficiency of Construction Industry using Data Envelopment Analysis(DEA). Since the Construction Industry has been traditionally operated through competition, it is important to measure the efficiency. In this paper, we empirically analyze the Efficiency of the 50 Korean Construction Industry. In detail, we used the scale of efficiency in order that efficiency cannot be affected by the total technical efficiency of each company and the scale of DMU by applying CCR or BBC model. Also, we analyzed the changes of measurement DEA model score. we adopted the basic DEA, RTS Region and MPSS(Most Productive Scale Size) method which are combined with efficiency measurement model in order to analyze the operational status. Furthermore, by complementing the shortfalls of the scale efficiency value of the DEA Model, RTS Region Model can be recommended to be appropriate in the evaluation of ideal input/output Quantity. In particular, input variables are total assets, construction capacity, the technical staff and output variables are sales volume, operating income. The result of RTS Region and MPSS shows that 9 DMUs of the efficiency frontier in the Construction Industry are analyzed to be relatively efficient DMUs, and 41 DMUs are analyzed to be inefficient DMUs, and finally inefficient DMUs are separated with Region 1 and Region 6.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.1
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• pp.13-19
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• 2015

This paper presents the performance improvement of an EQS (Eradic Quake System) device applied to a nuclear power plant. For the nuclear facility, the EQS device needs to be ensured to have high quality, flexibility of design and reliability. To improve the reliability of the design, the hysteresis of the device must be exactly predicted. The friction coefficient of PTFE (PolyTetraFluoroEthylene) and the stiffness of the MER-Spring are considered as the factors influencing the hysteresis curve. In this paper, those factors are analysed to predict the behavior of the device and to improve the equipment of the EQS device. The results of the improved EQS device have been verified via a tests to be comparable with the predicted results. The estimation results indicate that considering those factors is more appropriate than the results of the previous design and method.

• Korean Journal of Materials Research
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• v.34 no.2
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• pp.105-110
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• 2024

Scanning probe microscopy (SPM) has become an indispensable tool in efforts to develop the next generation of nanoelectronic devices, given its achievable nanometer spatial resolution and highly versatile ability to measure a variety of properties. Recently a new scanning probe microscope was developed to overcome the tip degradation problem of the classic SPM. The main advantage of this new method, called Reverse tip sample (RTS) SPM, is that a single tip can be replaced by a chip containing hundreds to thousands of tips. Generally for use in RTS SPM, pyramid-shaped diamond tips are made by molding on a silicon substrate. Combining RTS SPM with Scanning spreading resistance microscopy (SSRM) using the diamond tip offers the potential to perform 3D profiling of semiconductor materials. However, damage frequently occurs to the completed tips because of the complex manufacturing process. In this work, we design, fabricate, and evaluate an RTS tip chip prototype to simplify the complex manufacturing process, prevent tip damage, and shorten manufacturing time.