• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.2
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• pp.1-10
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• 2010

Mapping virtual process topology to physical processor topology is one of the most important design issues in parallel programming. However, the mapping problem is complicated due to the topology irregularity and routing complexity. This paper proposes a new process mapping scheme called adjacency-based mapping (AM) for irregular cluster systems assuming that the two-dimensional mesh process topology is specified as an interprocess communication pattern. The cluster systems have been studied and developed for many years since they provide high interconnection flexibility, scalability, and expandability which are not attainable in traditional regular networks. The proposed AM tries to map neighboring processes in virtual process topology to adjacent processors in physical processor topology. Simulation study shows that the proposed AM results in better mapping quality and shorter interprocess latency compared to the conventional approaches.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.149-157
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• 2012

In WSN environment, the sensor nodes collect sensed data, and transmit data to the BS. BS is difficult to trust the data from unauthenticated nodes. Therefore, many papers have been proposed about the node authentication and the safety of data. In the AM-E paper, data is delivered after node authentication. In this time, the sensor nodes are directly communicated to BS the AREQ/AREP message for authentication. Therefore, the sensor nodes consume more energy for authentication. Also, noes communicate directly with the BS for authentication will have problem due to the limited energy of nodes. In this paper, the same security with AM-E is supported, Furthermore, to minimize the energy consumption, IDE based hierarchical node authentication protocol is proposed. Compared with AM-E, the number of alive nodes is increased about 39%. Thus, the entire network life time is extended and energy efficiency is improved.

• Journal of Korea Port Economic Association
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• v.27 no.4
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• pp.51-71
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• 2011

The purpose of this study is to use DEA modeling to make an analysis on 12 ODCYs in the hinterland of Busan North Port, so that it may propose possible ways to efficiently operate them. For analysis, this study adopted 3 input factors such as CY area, number of employees and number of cargo work equipments and also adopted 1 output factor, i.e. container throughput. According to the analysis DEA-CCR model, it was found that Chunil(YongDang CY) was the most efficient one among companies engaged in the operation of ODCY. And it was found that KCTC(YongDang CY), Kukbo(U-Am CY), KORAIL(BusanJin CY) and Hanjin (JaeSong CY) would need to boost the container throughput 5 or more times higher than current throughput with a view to improving cargo handling efficiency, while Sebang(U-Am CY), KCTC(U-Am CY), KCTC(YongDang CY), Hyopsung(YongDang CY) and Kukbo(U-Am CY) need to work on personnel restructuring targeted to current employees. Based on the analysis DEA-BCC model, it was found that Chunil(YongDang CY), Dongbu(ShinYoung GamMan CY), Intergis(GamMan CY) and Sebang(U-Am CY) were efficient companies, but KCTC(YongDang CY), Kukbo(U-Am CY), KORAIL(BusanJin CY) and Hanjin(JaeSong CY) were inefficient companies. Particularly, it was found that both KCTC(U-Am CY) and Kukbo(U-Am CY) would need to try harder to carry out personnel reshuffle than other comparable companies.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.224-230
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• 2010

Purpose: We designed the aft-multiple-slit (AMS) system to reduce scatter in cone-beam computed tomography (CBCT). As a preliminary study, we performed a Monte Carlo N-Particle Transport Code (MCNP) simulation to verify the effectiveness of this system. Materials and Methods: The MCNPX code was used to build the AMS geometry. An AMS is an equi-angled arc to consider beam divergence. The scatter-reduced projection images were compared with the primary images only and the primary plus scatter radiation images with and without AMS to evaluate the effectiveness of scatter reduction. To obtain the full 2 dimensional (2D) projection image, the whole AMS system was moved to obtain closed septa of the AMS after the first image acquisition. Results: The primary radiation with and without AMS is identical to all the slit widths, but the profiles of the primary plus scattered radiation varied according to the slit widths in the 2D projection image. The average scatter reduction factors were 29%, 15%, 9%, and 8% when the slit widths were 5 mm, 10 mm, 15 mm, and 20 mm, respectively. Conclusion: We have evaluated the scatter reduction effect of the AMS in CBCT imaging using the Monte Carlo (MC) simulations. A preliminary study based on the MCNP simulations showed a mount of scatter reduction with the proposed system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.8
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• pp.3529-3550
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• 2016

In heterogeneous networks (HetNets), energy saving is vital for a sustainable network development. Many techniques, such as spectrum allocation, network planning, etc., are used to improve the network energy efficiency (EE). In this paper, micro BSs utilizing cell range expansion (CRE) and spectrum allocation are considered in multi-channel heterogeneous networks to improve EE. Hotspot region is assumed to be covered by micro BSs which can ensure that the hotspot capacity is greater than the average demand of hotspot users. The expressions of network energy efficiency are derived under shared, orthogonal and hybrid subchannel allocation schemes, respectively. Particle swarm optimization (PSO) algorithm is used to solve the optimal ratio of subchannel allocation in orthogonal and hybrid schemes. Based on the results of the optimal analysis, we propose three service control strategies on the basis of large-scale user behaviors, i.e., adjust micro cell rang expansion (AmCRE), adjust micro BSs density (AmBD) and adjust micro BSs transmit power (AmBTP). Both theoretical and simulation results show that using shared subchannel allocation scheme in AmBD strategies can obtain maximal EE with a very small area ratio. Using orthogonal subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is larger. Using hybrid subchannel allocation scheme in AmCRE strategies can obtain maximal EE when area ratio is large enough. No matter which service control strategy is used, orthogonal spectrum scheme can obtain the maximal hotspot user rates.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.531-538
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• 1998

In this paper the system performance degradation resulting from nonlinear transmitter power amplifier which is essential to increase the efficiency is analysed in a CDMA system. The power amplifier is modeled by its AM-AM, AM-PM characteristics. The effects of power amplifier's nonlinearity such as intersymbol interference, phase distonion on the RF system performance were visualized by examining the distorted time domain waveforms, signal vector constellation. And through the investigation of the power spectrum density of the transmitted signal, spectral regrowth or sideband regrowth which is result from amplitude distortion can be seen. All these characteristics result in BER performance degradation due to other user interferences and intersymbol interference. The analysis technique described here applies not only to power amplifier but also to any other nonlinear components such as mixers and switches. Also the effects of adjacent channel interference and supurious emission can be analysed between different systems.

• Journal of Acupuncture Research
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• v.24 no.4
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• pp.13-23
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• 2007

Objectives : The aim of the present study was to assess the effects of Sa-am acupuncture (Damjeonggyeok) on autonomic nervous system in night nurses by heart rate variability. Methods : Five night nurses were divided into two groups. We checked their HRV once after sleeping for night and 5 times after working for night, 4 times after operation. We operate Sa-am acupuncture (Damjeonggyeok) and sham acupuncture twice by turns for group A and in reverse order for group B. We checked responses of HRV change after operations. Statistical analysis was performed by using the SPSS Win. Ver. 13.0 for analysis about correlation between data, and Baysian analysis using WinBUGS(Ver. 1.4) for comparison between Sa-am acupuncture (Damjeonggyeok) and sham acupuncture. Results : The median overall decrease for difference in responses of low-frequency power in normalized units (LF (NU)) was -16.56 (-28.88, -6.446), the median overall increase for difference in responses to high-frequency power in normalized units (HF (NU)) was 16.25 (8.104, 28.6) and for the median overall decrease for difference in responses to the ratio of low- to high-frequency power (LF/HF) was -1.846 (-3.922, -0.069), 95% credibility intervals being shown in brackets. VAS of stress was correlated with LF (NU) and HF (NU), LF/HF (p<0.0l). Conclusion : Sa-am acupuncture (Damjeonggyeok) might have sympatholytic and parasympathomimetic effects.

• Journal of Acupuncture Research
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• v.19 no.1
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• pp.24-38
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• 2002

This study was undertaken to examine the effects of acupuncture at LI4 on temperature changes of the facial surface randomly divided into 17 areas. The volunteers who participating in this study had taken rest for 20 - 30 min in room temperature ($23-25^{\circ}C$) before acupuncture and informed them what to prohibit smoking, drinking and drug for the previous one day. The Temperature of facial surface was measured by using Digital Thermography IR 2000 (Meridian Co., Korea) at 5 min before and immediately, 5, 10, and 15 min after acupuncture on LI4. The results of this study showed that there was no significancy in thermal changes of facial surface randomly divided into 17 areas, but different significantly in the aggregate changes at the difference of the thermal changes on facial surface (p < 0.001). The difference of aggregate change was increased time-dependent and the changes at 1st, 3rd, and 13th area were comparatively smaller than the other areas. However, the changes at 6th, 8th, 10th and 15th area were more increased than the others. This study suggests that acupuncture at LI 4 help human being increase the reaction to maintain thermal homeostasis in facial surface and the ability to treat at these area's disease.

• Journal of Pharmacopuncture
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• v.21 no.4
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• pp.268-276
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• 2018

Objectives: The purpose of this study is to investigate the anti-cancer effects of different fractions of Astragalus membranaceus (AM) in human non-small cell lung cancer (NSCLC) cells. Methods: We isolated hexane, ethyl acetate, and butanol fractions from crude ethanol extract of AM. The cell death was examined by MTT assay and trypan blue exclusion assay. Apoptosis was detected by DAPI staining, annexin V-PI double staining and cell cycle analysis. The expression of apoptosis-related proteins and mitogen-activated protein kinases (MAPKs) was examined by western blot. Results: Among various fractions of AM, the ethyl acetate fraction of AM (EAM) showed the strongest cytotoxic effect in NSCLC cells. EAM reduced the cell proliferation in a time- and dose-dependent manner in NSCLC cells. In addition, EAM induced the chromatin condensation, and increased the population of sub-G1 phase and annexin V-positive cells in a time-dependent manner, indicating that EAM induced apoptosis in NSCLC cells. Consistently, EAM enhanced the expression of cleaved caspase-8 and -9, and induced the accumulation of cleaved- poly (ADP-ribose) polymerase (PARP). Among MAPK proteins, only ERK was dephosphorylated by EAM, suggesting that ERK might be related with EAM-induced apoptosis. Conclusion: Our results clearly demonstrate that EAM exhibited anti-cancer effects in NSCLC cells by induction of apoptosis. We provide a valuable evidence which suggests that AM could be a desirable therapeutic option for treatment of NSCLC.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.407-408
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• 2009

In this work, a quantitative method of the sequential separation of $^{90}Pu,\;^{90}Sr$ and $^{241}Am$ nuclides was developed in environmental soil samples using by an anion exchange resin connected with a Sr Spec resin. The sequential methods of Pu, $^{90}Sr$ and $^{241}Am$ nuclides can reduce analysis cost and time. With the sequential methodupdated in this study, the activity concentrations of $^{239,240}Pu,\;^{90}Sr$ and $^{241}Am$ in the IAEA reference materials were close to the reference values reported by the IAEA.