The Catholic University of Pusan is situated in the southeastern South Korean port city of Busan. The current president is Son Sam-seok. The university is traditionally focused on nursing and health science, but in addition to these fields it includes schools of environmental science, business administration, computer information engineering, and social welfare. It enrolls about 1,200 students. Wikipedia.
Hwang S.,Catholic University of Pusan
International Journal of Software Engineering and its Applications | Year: 2015
The AIS is an automatic tracking system used on ships and by vessel traffic services for identifying and locating vessels through electronically exchanging data with other nearby ships and VTS stations. Defining new application specific message has augmented the functionalities and informational content of AIS. This paper proposes RF monitoring service using AIS application specific message. The vessel, which has an AIS RF monitoring device, measures and monitors the sensitivity of the AIS signal transmitted from other nearby ships, AtoN devices and base stations. It can facilitate maintenance of the AIS devices and can also determine the AIS signal strength. © 2015 SERSC.
Byun S.-S.,Catholic University of Pusan
Computer Networks | Year: 2016
Transmission control protocol (TCP) is the most popular transport layer protocol for applications that require reliable and ordered data delivery essentially. In this paper we consider the deployment of TCP to secondary users (SUs) in overlay cognitive radio networks (CRNs), and address its performance degradation; in CRNs, SU's transmissions are frequently disrupted by the detection of primary user's transmission, and which makes the SU experience consecutive retransmission-timeout and its exponential backoff. Subsequently, the TCP in SU does not proceed with the transmission even after the disruption is over or the SU hands over to other idle spectrum. To tackle this problem, we propose a cross-layer approach called TCP-Freeze-CR; lower layer protocols send the overlying TCP two different cross-layer signals, freeze on the detection of primary user's transmission, and unfreeze after handing over to an idle spectrum. Moreover we consider a practical situation where either secondary transmitter (ST) or secondary receiver (SR) detects primary user's transmission; therefore additional message exchanges are needed between ST and SR to retrieve and resynchronize to other idle spectrum, i.e., spectrum synchronization. This situation is more complex than the case where both ST and SR detect primary user's transmission. Hereby, we develop a spectrum synchronization procedure coupled with TCP-Freeze-CR into a finite state machine. All of our proposals are implemented and evaluated on a real CRN consisting of 6 software radio platforms. In the implementation, we deploy 802.15.4 implementation as a target physical layer protocol, and couple it with TCP-Freeze-CR using Unix Domain Socket. The experimental results illustrate that standard TCP suffers from significant performance degradation in CRNs, and show that TCP-Freeze-CR can greatly alleviate the degradation; e.g., for 1200 s, ST with TCP-Freeze-CR can send about 10 times more packets than ST with standard TCP. © 2016 Elsevier B.V. All rights reserved.
Jin H.,Chonbuk National University |
Park M.H.,Catholic University of Pusan |
Kim S.M.,Chonbuk National University
Oncology Reports | Year: 2015
Gastric cancer is the fourth most common cancer and is one of the leading causes of cancer-related mortality worldwide. Forkhead box M1 (FOXM1) is overexpressed in gastric cancer, suggesting that it is important in gastric cancer oncogenesis. However, no studies have investigated the role of 3,3'-diindolylmethane (DIM), a component of cruciferous vegetables, in the regulation of FOXM1 and its signaling pathway in gastric cancer. Here, we report for the first time that DIM effectively downregulated Akt/FOXM1 in gastric cancer cells. Combination treatment with DIM and paclitaxel significantly and dose-dependently inhibited the proliferation of SNU638 cells when compared to treatment with DIM or paclitaxel alone. Colony formation of SNU638 cells was significantly attenuated by treatment with DIM and paclitaxel, and DIM potentiated the inhibition of colony formation in SNU638 cells by paclitaxel when compared to treatment with a single agent. Treatment with DIM plus paclitaxel substantially increased apoptosis as indicated by increased levels of cleaved polyADP-ribose polymerase (PARP) and cleaved caspase-9 protein. DIM dose-dependently sensitized gastric cancer cells through downregulation of FOXM1 and potentiated the effects of paclitaxel. FOXM1 effector genes such as CDK4, p53 and cyclin D1 were downregulated in gastric cancer cells by combination treatment with DIM and paclitaxel. In addition, DIM significantly and dose-dependently inhibited phosphorylation of Akt and potentiated paclitaxel-induced inhibition of Akt function in gastric cancer cells. Therefore, our results indicate that DIM effectively potentiates the efficacy of chemotherapeutic agents such as paclitaxel by downregulation of the Akt/ FOXM1 signaling cascade in gastric cancer cells. Our findings suggest that DIM enhances the therapeutic efficacy of paclitaxel in gastric cancer and is a potential clinical anticancer agent for the prevention and/or treatment of gastric cancer.
Yu S.,Catholic University of Pusan
Advances in Information Sciences and Service Sciences | Year: 2012
In this study, we present an RFM model to establish a customer segmentation strategy at a Korean duty-free shop. In this shop, customers' visiting time and purchase amount are restricted by the government, so that a different purchase pattern from general retail distribution business is exhibited. At the shop, recency demonstrated normal distribution, but visiting frequency and purchase amounts showed a division between a small number of top-class customers and a multitude of bottom-class customers. Here, classes were identified through a normalization process involving the characteristics of visiting frequency and purchase amount among duty-free shop customers. Based on the result, an RFM model was developed, and RFM scores were allocated to customers who had bought goods at the duty-free shop in past five years. Through this process, a customer relationship management strategy was developed.
Park M.-J.,Catholic University of Pusan
Aging and Mental Health | Year: 2015
Objectives: This study examines the impact of social capital on depressive symptoms trajectories among Korean women aged 65 years or older. It also examines the difference in depressive symptoms and social capital by economic status (poverty group, non-poverty group) among community-dwelling older women in Korea. Method: This study used 2435 older women of the Korean Welfare Panel Study from 2006 (wave 1) to 2013 (wave 8) data using latent growth modeling. Social capital variables were cognitive (interpersonal trust, reciprocity) and structural (the size of family, the number of friends or neighbors, participation in leisure and volunteer activities). Results: The results showed both intra- and inter-individual variability in depressive symptoms over time. Interpersonal trust and reciprocity as cognitive social capital had an effect on the change of depressive symptoms in intercept and slope. The size of family, participation in leisure activities among structural social capital were associated with lower levels of depressive symptoms in intercept and slope. Conclusion: The results of this study suggest some practical implications for depression intervention and prevention and further research on late-life depression. © 2015 Taylor & Francis