• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.419-429
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• 1999

Identifying the boundary of the effective receiving power of waves is one of the most important factors for cell optimization. In this paper, we introduce a propagation loss prediction model which yields highly accurate prediction in very complex areas as Seoul where a mixture of many large buildings, small buildings, broad streets, narrow alleys, rivers and forests co-exist in an irregular arrangement. This prediction model is based on neural networks trained on field measurement data collected in the past. Using these data along with 3-D digital elevation maps and vector data for building structures, we extract the parameter values which mainly affect the amount of propagation loss. These parameter values are then used as the inputs to the neural network. Trained neural network becomes the approximated function of the propagation loss model which generalizes very well and can predict accurately in the regions not included in training the neural network. The experimental results show a superior performance over the other models in the cells operating in the city of Seoul.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10355-10361
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• 2015

Background: MicroRNAs (miRNAs) are small non-coding RNA molecules found in multicellular eukaryotes which are implicated in development of cancer, including cutaneous squamous cell carcinoma (cSCC). Expression is controlled by transcription factors (TFs) that bind to specific DNA sequences, thereby controlling the flow (or transcription) of genetic information from DNA to messenger RNA. Interactions result in biological signal control networks. Materials and Methods: Molecular components involved in cSCC were here assembled at abnormally expressed, related and global levels. Networks at these three levels were constructed with corresponding biological factors in term of interactions between miRNAs and target genes, TFs and miRNAs, and host genes and miRNAs. Up/down regulation or mutation of the factors were considered in the context of the regulation and significant patterns were extracted. Results: Participants of the networks were evaluated based on their expression and regulation of other factors. Sub-networks with two core TFs, TP53 and EIF2C2, as the centers are identified. These share self-adapt feedback regulation in which a mutual restraint exists. Up or down regulation of certain genes and miRNAs are discussed. Some, for example the expression of MMP13, were in line with expectation while others, including FGFR3, need further investigation of their unexpected behavior. Conclusions: The present research suggests that dozens of components, miRNAs, TFs, target genes and host genes included, unite as networks through their regulation to function systematically in human cSCC. Networks built under the currently available sources provide critical signal controlling pathways and frequent patterns. Inappropriate controlling signal flow from abnormal expression of key TFs may push the system into an incontrollable situation and therefore contributes to cSCC development.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.1
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• pp.41-49
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• 1990

The author observed the changes of vasculature of pre-and post-irradiation on DMBA induced rat tongue cancer. The study was performed by using vascular corrosion resin casting, and scanning electron microscopy. The results were as follows. 1. The capillaries runned parallely and formed bundles and, sometimes, plexus. The endothelial cells were arranged regularly and small pores were observed. 2. In irradiated normal tongue the capillaries were curved slightly and formed plexus on initial day of post-irradiation. On third day the capillaries and capillary pores were dilated and the endothelial cell arrangement was irregular. The effects of irradiation were gradually increased from initial to the 3rd day, though it was decreased after 7th day. 3. The vasculature of DMBA induced tongue cancer group were very irregular, and large avascular lesions were formed according to the cancer necrosis or tumor cell nest and the vasculature was narrowed and paralleled around the avascular lesion by compression of cancer cell nest. The vascular wall was roughened and dilated, forming club shaped or varix. 4. The vessels were curved and formed reticular network in irradiated DMBA induced tongue carinoma group. The free end of newly formed capillaries had regular width, and also irregular club shaped or aneurysmal dilatation were observed. The vascular structures were destroyed and vessels were fused in tumor necrosis lesion. The radiation effects were marked on the first and third day of irradiation and the effects were decreased after seventh day and showed capillary regeneration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9B
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• pp.774-782
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• 2003

Generally, in the Mobile IP technologies, the use of RSVP(Resource ReSerVation Protocol) is recommended in order to provide a mobile node real-time service. However, the handoff of a mobile node increases the registration delay, RSVP reservation delay and signalling overhead in the Mobile IP and RSVP interworking. Specially, the resource reservation on the path between a mobile node and a correspondent node is the duplicated reservation and then causes unnecessary creation of the signalling overhead and waste of the resource, since the majority of the path before handoff and after handoff is same. If the radius of a cell providing a wireless interface to a mobile node is small, the number of handoff will increase and also signalling overhead and duplicated resource reservation will increase. In this paper, we proposed the integration model of Cellular IP and RSVP with RSVP proxy scheme. Here, Cellular IP protocol minimizes registration delay, transfer delay, and loss by handoff in micro cell network, the RS VP proxy that minimizes the duplication of resource reservation prevents the path for RSVP session from change using the address for reservation of a mobile node. Proposed scheme was evaluated in comparison with the existing Mobile IP and RSVP interworking scheme using the probability of resource reservation fail to the radius of a cell and the handoff rate.

• IMMUNE NETWORK
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• v.20 no.6
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• pp.48.1-48.11
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• 2020

Hyperprogressive disease (HPD) is a distinct pattern of progression characterized by acceleration of tumor growth after treatment with anti-PD-1/PD-L1 Abs. However, the immunological characteristics have not been fully elucidated in patients with HPD. We prospectively recruited patients with metastatic non-small cell lung cancer treated with anti-PD-1/PD-L1 Abs between April 2015 and April 2018, and collected peripheral blood before treatment and 7-days post-treatment. HPD was defined as ≥2-fold increase in both tumor growth kinetics and tumor growth rate between pre-treatment and post-treatment. Peripheral blood mononuclear cells were analyzed by multi-color flow cytometry to phenotype the immune cells. Of 115 patients, 19 (16.5%) developed HPD, 52 experienced durable clinical benefit (DCB; partial response or stable disease ≥6 months), and 44 experienced non-hyperprogressive progression (NHPD). Patients with HPD had significantly lower progression-free survival (p<0.001) and overall survival (p<0.001). When peripheral blood immune cells were examined, the pre-treatment frequency of CD39⁺ cells among CD8⁺ T cells was significantly higher in patients with HPD compared to those with NHPD, although it showed borderline significance to predict HPD. Other parameters regarding regulatory T cells or myeloid derived suppressor cells did not significantly differ among patient groups. Our findings suggest high pre-treatment frequency of CD39⁺CD8⁺ T cells might be a characteristic of HPD. Further investigations in a larger cohort are needed to confirm our results and better delineate the immune landscape of HPD.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.101-123
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• 2013

Recently due to the advancements of science and information technology, the socio-economic business areas are changing from the industrial economy to a knowledge economy. Furthermore, companies need to do creation of new value through continuous innovation, development of core competencies and technologies, and technological convergence. Therefore, the identification of major trends in technology research and the interdisciplinary knowledge-based prediction of integrated technologies and promising techniques are required for firms to gain and sustain competitive advantage and future growth engines. The aim of this paper is to understand the recent research trend in management of technology (MOT) and to foresee promising technologies with deep knowledge for both technology and business. Furthermore, this study intends to give a clear way to find new technical value for constant innovation and to capture core technology and technology convergence. Bibliometrics is a metrical analysis to understand literature's characteristics. Traditional bibliometrics has its limitation not to understand relationship between trend in technology management and technology itself, since it focuses on quantitative indices such as quotation frequency. To overcome this issue, the network focused bibliometrics has been used instead of traditional one. The network focused bibliometrics mainly uses "Co-citation" and "Co-word" analysis. In this study, a keywords network analysis, one of social network analysis, is performed to analyze recent research trend in MOT. For the analysis, we collected keywords from research papers published in international journals related MOT between 2002 and 2011, constructed a keyword network, and then conducted the keywords network analysis. Over the past 40 years, the studies in social network have attempted to understand the social interactions through the network structure represented by connection patterns. In other words, social network analysis has been used to explain the structures and behaviors of various social formations such as teams, organizations, and industries. In general, the social network analysis uses data as a form of matrix. In our context, the matrix depicts the relations between rows as papers and columns as keywords, where the relations are represented as binary. Even though there are no direct relations between papers who have been published, the relations between papers can be derived artificially as in the paper-keyword matrix, in which each cell has 1 for including or 0 for not including. For example, a keywords network can be configured in a way to connect the papers which have included one or more same keywords. After constructing a keywords network, we analyzed frequency of keywords, structural characteristics of keywords network, preferential attachment and growth of new keywords, component, and centrality. The results of this study are as follows. First, a paper has 4.574 keywords on the average. 90% of keywords were used three or less times for past 10 years and about 75% of keywords appeared only one time. Second, the keyword network in MOT is a small world network and a scale free network in which a small number of keywords have a tendency to become a monopoly. Third, the gap between the rich (with more edges) and the poor (with fewer edges) in the network is getting bigger as time goes on. Fourth, most of newly entering keywords become poor nodes within about 2~3 years. Finally, keywords with high degree centrality, betweenness centrality, and closeness centrality are "Innovation," "R&D," "Patent," "Forecast," "Technology transfer," "Technology," and "SME". The results of analysis will help researchers identify major trends in MOT research and then seek a new research topic. We hope that the result of the analysis will help researchers of MOT identify major trends in technology research, and utilize as useful reference information when they seek consilience with other fields of study and select a new research topic.

• IMMUNE NETWORK
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• v.1 no.1
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• pp.1-6
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• 2001

The identification of tumor-specific antigens has represented a critical milestone in cancer diagnosis and therapy. Clinical research in this area for leukemia has also been driven over the past few decades by the hope that surface antigens with restricted tissue expression would be identified. Disappointingly, only a small number of the leukemic antigens identified to date, meet sufficient criteria to be considered viable immunophenotypic markers. In this paper, we nominate anti-JL1 monoclonal antibody as an immunodiagnostic and immunotherapeutic candidate for leukemia. The JL1 molecule appears to be a novel cell surface antigen, which is strictly confined to a subpopulation of limited stages during the hematopoietic differentiation process. Despite the restricted distribution of the JL1 antigen in normal tissues and cells, anti-JL1 monoclonal antibody specifically recognizes various types of leukemia, irrespective of immunophenotypes. On the basis of these findings, we propose JL1 antigen as a tumor-specific marker, which shows promise as a candidate molecule for diagnosis and immunotherapy in leukemia, and one that spares normal bone marrow stem cells.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.465-474
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• 2001

In the network with small cell radius, a mobile terminal which has large mobility should perform frequent handover. This requires that handover mechanism must be done fastly. The currently existing method for handover uses an algorithm in which the bandwidth corresponding to the adjacent cells is supposed to be allocated. However, this method leads to the problem of requiring bandwidth allocation for many-unknown cells, due to the lack of information toward moving direction in mobile terminal. In this paper, we propose an efficient dynamic bandwidth allocation algorithm for solving those problem above, based on both path rerouting handover and soft handover mechanism with wireless ATM. As for the QoS, it has been shown that proposed algorithm shows better performance than that with static bandwidth allocation algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3054-3067
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• 2015

The phenomena of higher channel cross polarization discrimination (XPD) is mainly observed for future wireless technologies such as small cell network and massive multiple-input multiple-output (MIMO) system. Therefore, utilization of high XPD is very important and space-polarization division multiple access (SPDMA) with dual-polarized MIMO system could be a suitable solution to high-speed transmission in high XPD environment as well as reduction of array size at base station (BS). By SPDMA with dual-polarized MIMO system, two parallel data signals can be transmitted by both vertically and horizontally polarized antennas to serve different mobile stations (MSs) simultaneously compare to conventional space division multiple access (SDMA) with single-polarized MIMO system. This paper analyzes the performance of SPDMA for maximum ratio transmission (MRT) in time division duplexing (TDD) system by proposed dual-polarized MIMO spatial channel model (SCM) compare to conventional SDMA. Simulation results indicate that how SPDMA utilizes the high XPD as the number of MS increases and SPDMA performs very close to conventional SDMA for same number of antenna elements but half size of the array at BS.

• IMMUNE NETWORK
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• v.13 no.6
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• pp.289-294
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• 2013

Lipocalin-2 (LCN2) is an acute-phase protein induced by injury, infection, or other inflammatory stimuli. LCN2 binds small hydrophobic ligands and interacts with cell surface receptor to regulate diverse cellular processes. The role of LCN2 as a chemokine inducer in the central nervous system (CNS) has been previously reported. Based on the previous participation of LCN2 in neuroinflammation, we investigated the role of LCN2 in formalin-induced nociception and pathological pain. Formalin-induced nociceptive behaviors (licking/biting) and spinal microglial activation were significantly reduced in the second or late phase of the formalin test in Lcn2 knockout mice. Likewise, antibody-mediated neutralization of spinal LCN2 attenuated the mechanical hypersensitivity induced by peripheral nerve injury in mice. Taken together, our results suggest that LCN2 can be therapeutically targeted, presumably for both prevention and reversal of acute inflammatory pain as well as pathological pain.