• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1926-1933
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• 2013

Many localization algorithms have been proposed for Wireless Sensor Networks (WSNs). The IEEE 802.15.4a-based location-aware-system can provide precise ranging distance between two mobile nodes. The mobile nodes can obtain their exact locations by using accurate ranging distances. However, the indoor environments contain various obstacles which cause non-line-of-sight (NLOS) conditions. In NLOS condition, the IEEE 802.15.4a-based location-aware system has a large scale location error. To solve the problem, we propose location error compensation in indoor environment by using MST-based topology control. Experimental and simulation results show that the proposed algorithm improves location accuracy in NLOS conditions.

• IMMUNE NETWORK
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• v.20 no.5
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• pp.36.1-36.13
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• 2020

Hippo signaling pathways are evolutionarily conserved signal transduction mechanisms mainly involved in organ size control, tissue regeneration, and tumor suppression. However, in mammals, the primary role of Hippo signaling seems to be regulation of immunity. As such, humans with null mutations in STK4 (mammalian homologue of Drosophila Hippo; also known as MST1) suffer from recurrent infections and autoimmune symptoms. Although dysregulated T cell homeostasis and functions have been identified in MST1-deficient human patients and mouse models, detailed cellular and molecular bases of the immune dysfunction remain to be elucidated. Although the canonical Hippo signaling pathway involves transcriptional co-activator Yes-associated protein (YAP) or transcriptional coactivator with PDZ motif (TAZ), the major Hippo downstream signaling pathways in T cells are YAP/TAZ-independent and they widely differ between T cell subsets. Here we will review Hippo signaling mechanisms in T cell immunity and describe their implications for immune defects found in MST1-deficient patients and animals. Further, we propose that mutual inhibition of Mst and Akt kinases and their opposing roles on the stability and function of forkhead box O and β-catenin may explain various immune defects discovered in mutant mice lacking Hippo signaling components. Understanding these diverse Hippo signaling pathways and their interplay with other evolutionarily-conserved signaling components in T cells may uncover molecular targets relevant to vaccination, autoimmune diseases, and cancer immunotherapies.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.4
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• pp.11-33
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• 2013

We analyzed the structures and properties of the global financial market networks using social network analysis approach. The Minimum Spanning Tree (MST) lengths and networks of the global financial markets based on the correlation coefficients have been analyzed. Firstly, similar to the previous studies on the global stock indices using MST length, the diversification effects in the global multi-asset portfolio can disappear during the crisis as the correlations among the asset class and within the asset class increase due to the system risks. Second, through the network visualization, we found the clustering of the asset class in the global financial markets network, which confirms the possible diversification effect in the global multi-asset portfolio. Meanwhile, we found the changes in the structure of the network during the crisis. For the last one, in terms of the degree centrality, the stock indices were the most influential to other assets in the global financial markets network, while in terms of the betweenness centrality, Gold, Silver and AUD. In the practical perspective, we propose the methods such as MST length and network visualization to monitor the change of the correlation risk for the risk management of the multi-asset portfolio.

• Korean Journal of Biological Psychiatry
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• v.9 no.2
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• pp.112-119
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• 2002

Object:This study was to investigate the difference of speech perception ability in schizophrenic patients, and depression patients in order to explore trait-dependent speech perception ability of each disorder. Methods:The speech perception ability was assessed with masked speech tracking test(MST) in schizophrenic patients(N=31), depression patients(N=25), and normal controls(N=21). The continuous performance test(CPT) and sentence repetition test(SRT) were also used for assessment of attention and working memory. Results:The schizophrenic patients showed significant impaired MST performance, compared with depressive patients and normal controls. The performances of CPT and SRT were also more impaired in schizophrenic patients. The difference of MST performances between two patient group was cancelled out after consideration of differences in CPT & SRT performances. Conclusions:These results imply that schizophrenic patients have the impaired speech perception ability compared with depressive patients and normal controls. But speech perception ability was significantly influenced with CPT and SRT. For evaluation of pure speech perception ability, the more elaborate controlled study that excluded factors such as attention, working memory and intelligence is needed.

• Physical Therapy Korea
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• v.14 no.2
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• pp.76-84
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• 2007

This study was designed to determine the efficacy of ultrasound and laser therapy for sub-acute lower back pain. Twenty-seven patients with sub-acute low back pain were recruited, who were randomly assigned to three groups: Ultrasound group (actual ultrasound, 1.1 MHz, $1.0W/cm^2$, duty cycle 100%, 10 min/session, n=9), laser group (actual laser, 904 nm, 155 ns, 13.5 W, 12 mW, 90 sec/point, n=9), and control group (placebo ultrasound or placebo laser, n=9). All of treatments including placebo procedures were applied to patients over a period of 2 weeks, five times a week. Visual Analogue Scale (VAS), Modified Schober's Test (MST), and Modified Oswestry Disability Questionnaire (MODQ) were used by the clinical and functional evaluations before and after intervention. At post-hoc, significant differences were observed in all groups with respect to VAS, MST (p<.05), except MODQ. VAS and MST score were more significantly improved in the ultrasound group than the laser and control group (p<.0167). However, no significant difference was present between the laser group and the control group. Therefore, this study revealed that ultrasound therapy was effective in pain relief and improvement of lumbar mobility in patients with sub-acute lower back pain. However, laser therapy did not show the effects for sub-acute lower back pain.

• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.111-117
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• 2019

We categorize the model of simple payment into Magnetic Secure Transmission, Near Filed Communication, and App Card based on the Focus Group Interview. We also define the key drivers for the diffusion of simple payment services based on the literature review with the experts. Through Analytic Hierarchy Process our finding suggests that the degree of acceptance at the stores is the most critical factor which decides the diffusion of simple payment service model. Security is also the important driver but due to the fact that service providers should follow the information security rule and supervisory guidance, it actually did not make a big difference in terms of assessing competence of each model.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.208-215
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• 2021

Cosmic-ray muon scattering tomography (MST) technology is a new radiation imaging technology with unique advantages. As the performance of its image reconstruction algorithm has a crucial influence on the imaging quality, researches on this algorithm are of great significance to the development and application of this technology. In this paper, a fast inspection algorithm based on clustering analysis for the identification of the existence of nuclear materials is studied and optimized. Firstly, the principles of MST technology and a binned clustering algorithm were introduced, and then several simulation experiments were carried out using Geant4 toolkit to test the effects of exposure time, algorithm parameter, the size and structure of object on the performance of the algorithm. Based on these, we proposed two optimization methods for the clustering algorithm: the optimization of vertical distance coefficient and the displacement of sub-volumes. Finally, several sets of experiments were designed to validate the optimization effect, and the results showed that these two optimization methods could significantly enhance the distinguishing ability of the algorithm for different materials, help to obtain more details in practical applications, and was therefore of great importance to the development and application of the MST technology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.346-355
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• 2005

To investigate the application of biochemical markers' and small-sample methods using whole-wheat flours for screening in early generation in Korean wheat breeding system, 74 Korean wheats, including cultivars, local breeding lines and experimental lines, were analyzed. Seed storage protein and amylose contents of grains were evaluated. Biochemical makers, including granule bound starch synthase (GBSS), high molecular weigh glutenin subunits (HMW-GS) and friabilin were also evaluated by using one-dimensional sodium dodecyl sulfate-polyacryla-mide gel electrophoresis with a single kernel. The small­sample methods, including modified SDS-sedimentation test (MST), micro-alkaline water retention capacity (AWRC) and whole-wheat flour swelling volume (WSV) were also tested in this study. Protein content, MST and AWRC was $11.0 - 15.8\%$, 2.7 - 26.2 ml and $71.9 - 109.7\%$, respectively. Apparent and total amylose content and WSV was $20.6 - 25.0\%$, $26.1 - 32.4\%$ and 9.0 - 16.9 ml, respectively. There were highly significant correlations between MST and AWRC (r=0.592, P<0.001), but Korean wheats showed no significant difference in protein content, amylose content and small-sample methods. In the biochemical markers, Korean wheats contained all three GBSS encoded by Wx loci, except for Suwon 252. Korean wheats showed the high frequency ($58.1\%$) of 1Dx2.2 + 1Dy12 subunits of HMW-GS. Friabilin band was present in 46 lines ($62.2\%$) and absent in 28 lines ($37.8\%$). Friabilin-absence lines showed the higher MST (14.9 ml) and AWRC ($92.1\%$) value than friabilin-presence lines (8.5 ml and $82.4\%$, respectively).

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.5 no.3
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• pp.27-45
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• 2010

It is strongly believed that multicast will become one of the most promising services on internet for the next generation. Multicast service can be deployed either on network-layer or application-layer. IP multicast (network-layer multicast) is implemented by network nodes (i.e., routers) and avoids multiple copies of the same datagram on the same link. Despite the conceptual simplicity of IP multicast and its obvious benefits, it has not been widely deployed since there remain many unresolved issues. As an alternative to IP multicast, overlay multicast (application-layer multicast) implements the multicast functionality at end hosts rather than routers. This may require more overall bandwidth than IP multicast because duplicate packets travel the same physical links multiple times, but it provides an inexpensive, deployable method of providing point-to-multipoint group communication. In this paper we develop an efficient method applied greedy algorithm for solving two models of overlay multicast routing protocol that is aimed to construct MDST (Minimum Diameter Spanning Tree : minimum cost path from a source node to all its receivers) and MST (Minimum Spanning Tree : minimum total cost spanning all the members). We also simulate and analyze MDST and MST.

• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.273-280
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• 2008

In WSN(Wireless Sensor Network) many routing algorithms such as LEACH, PEGASIS and PEDEP consisting of sensor nodes with limited energy have been proposed to extend WSN lifetime. Under the assumption of perfect fusion, these algorithms used convergecast that periodically collects sensed data from all sensor nodes to a base station. But because these schemes studied less energy consumption for a convergecast as well as fairly energy consumption altogether, the minimum energy consumption for a convergecast was not focused enough nor how topology influences to energy consumption. This paper deals with routing topology and energy consumption for a single convergecast in the following ways. We chose major WSN topology as MSC(Minimum Spanning Chain)s, MSTs, PEGASIS chains and proposed LECSEN chains. We solved the MSC length by Linear Programming(LP) and propose the LECSEN chain to compete with MST and MSC. As a result of simulation by Monte Carlo method for calculation of the topology length and standard deviation of link length, we learned that LECSEN is competitive with MST in terms of total energy consumption and shows the best with the view of even energy consumption at the sensor nodes. Thus, we concluded LECSEN is a very useful routing topology in WSN.