• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1329-1338
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• 2011

This paper proposes an algorithm and hardware architecture for a broadcast communication which has the worst bottleneck among multiprocessor using distributed memory architectures. In conventional systems, collective communication is converted into point-to-point communications by MPI library cell without considering the state of communication port of each processing node which represents the processing node is in busy state or free state. If conflicting point-to-point communication occurs during broadcast communication, the transmitting speed for broadcast communication is decreased. Thus, this paper proposed an algorithm which determines the order of point-to-point communications for broadcast communication according to the state of each processing node. According to the state of each processing node, the proposed algorithm decreases total broadcast communication time by transmitting message preferentially to the processing node with communication port in free state. The proposed MPI unit for broadcast communication is evaluated by modeling it with systemC. In addition, it achieved a highly improved performance for broadcast communication up to 78% with 16 nodes. This result shows the proposed algorithm is useful to improving total performance of MPSoC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.10
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• pp.841-849
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• 2012

This paper proposes an low-complexity soft-output multiple-input multiple-output (soft-MIMO) detection algorithm for achieving soft-output maximum-likelihood (soft-ML) performance under max-log approximation. The proposed algorithm is based on a parallel tree-search (PTS) applying a channel ordering by a sorted-QR decomposition (SQRD) with altered sort order. The empty-set problem that can occur in calculation of log-likelihood ratio (LLR) for each bit is solved by inserting additional nodes at each search level. Since only the closest node is inserted among nodes with opposite bit value to a selected node, the proposed node insertion scheme is very efficient in the perspective of computational complexity. The computational complexity of the proposed algorithm is approximately 37-74% of that of existing algorithms, and from simulation results for a $4{\times}4$ system, the proposed algorithm shows a performance degradation of less than 0.1dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.10
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• pp.708-714
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• 2014

Wireless sensor networks (WSNs) generally consist of densely deployed sensor nodes that depend on batteries for energy. Having a large number of densely deployed sensor nodes causes energy waste and high redundancy in sensor data transmissions. The problems of power limitation and high redundancy in sensing coverage can be solved by appropriate scheduling of node activity among sensor nodes. In this paper, we propose a cellular automata based node scheduling algorithm for prolonging network lifetime with a balance of energy savings among nodes while achieving high coverage quality. Based on a cellular automata framework, we propose a new mathematical model for the node scheduling algorithm. The proposed algorithm uses local interaction based on environmental state signaling for making scheduling decisions. We analyze the system behavior and derive steady states of the proposed system. Simulation results show that the proposed algorithm outperforms existing protocols by providing energy balance with significant energy savings while maintaining sensing coverage quality.

• Spatial Information Research
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• v.19 no.6
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• pp.111-121
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• 2011

In this paper, we proposes a sensor node positioning algorithm that utilizes the geo-spatial elements and considers the factors to represent the propagation loss generated by the various obstacles in the urban wireless environments. First, we measures the propagation loss about the radio frequencies in major road of the urban, and defines the correlation between the measured loss and the environment information for the road and its surrounding get from Urban GIS. Secondly, through the utilization of the loss-environment correlation, we describes the detailed instruction for requiring the radio coverage decision and deploy system implementation for the wireless sensor node in urban. By the consideration of interference factor by the building and the linear structure of road, we can evaluate the path loss below 5dB RMS error. And, we proposes the way to revise the sensor node deployment based on the corelation and the measured path loss.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.3
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• pp.143-150
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• 2014

In this paper, we propose an energy efficient and delay guaranteed node scheduling scheme inspired by biological systems, which have gained considerable attention as a computing and problem solving technique. With the identification of analogies between cellular signaling systems and WSN systems, we formulate a new mathematical model that considers the networking challenges of WSNs. The proposed bio-inspired algorithm determines the state of the sensor node, as required by each application and as determined by the local environmental conditions and the states of the adjacent nodes. A control analysis shows that the proposed bio-inspired scheme guarantees the system stability by controlling the parameters of each node. Simulation results also indicate that the proposed scheme provides significant energy savings, as well as reliable delay guarantees by controlling the states of the sensor nodes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.728-737
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• 2011

For the real time monitoring and tracking of shipping container which is one of the core objects for global logistics, Wireless Ad-Hoc Network technology might be needed in stacking environments such as ports, yards and ships. In this paper, we propose a container network routing protocol suitable for port or yard stacking environments which include some constraints such as shadow area problem from metal material, frequent movement of container, etc. With this protocol in which a mesh network algorithm is applied, every container data packet can be delivered to the sink node reliably even with frequent join/leave of container nodes. As soon as a node on path gets malfunction, alternative backup path is supported with notice to neighbor node, which makes constant total optimal path. We also verified that the performance of proposed protocol is better than AODV, one of previous major MANet(Mobile Ad-Hoc Network) protocol with a function for alternative path, which says the proposed protocol is better for frequent join/leave and variable link quality.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.753-757
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• 2013

Objective: To evaluate the relationships between lymph node ratio (LNR, the ratio of positive lymph nodes in excised axillary lymph nodes) and disease-free survival (DFS) by comparing with traditional absolute positive lymph node number (pN classification) for prediction of breast cancer (BC) progrnosis. Methods and Patients: We retrospectively reviewed patients who received comprehensive therapy in Department of Breast Surgery, Hubei Cancer Hospital, China from Jan 2002 to Dec 2006 (Group A), and Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, China from Jun 2008 to May 2012 (Group B). Patients were allocated to low-risk (${\leq}0.20$), intermediate-risk (> 0.20 but ${\leq}0.65$), high-risk (>0.65) groups by LNR. The primary endpoint was 5-DFS. Results: A total of 294 patients were included in our study. LNR was verified as a negative prognostic factor for DFS (P=0.002 in Group A, P<0.0001 in Group B). Then we found the effects of pN and LNR delamination on disease-free survival (DFS) had statistical significance (P=0.012 for pN and P=0.031 for LNR stratification in Group A, both of them P<0.001 in Group B). Compared to pN staging, LNR staging displayed superior performance in prognosis, the adjusted hazard ratio of recurrence being 2.07 (95%CI, 1.07 to 4.0) for intermediate risk group (P=0.030) and 2.44 (95%CI, 1.21 to 4.92) for high risk group (P=0.013) in Group A. Conclusions: LNR stratification proved an adverse prognostic factor of DFS in lymph nodes positive invasive BC using cut-off values 0.20 and 0.65, and was more predictive than traditional pN classification for 5-DFS.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.139-143
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• 2013

Patients at the same pathological stage of esophageal cancer (EC) that received the same surgical therapy by the same surgeon may have distinct prognoses. The current study aimed to explore the possibility of differentially-expressed microRNAs (miRNAs) underlying this phenomenon. Samples were collected from EC patients at the same tumor node metastasis (TNM) stage but with different prognoses. Paracancerous normal tissues were taken as controls. The specimens were histopathologically analyzed. Differentially-expressed miRNAs were analyzed using real-time quantitative reverse transcription polymerase chain reaction. Compared with patients with poor prognosis, those with good prognosis exhibited 88 two-fold or more than two-fold increased miRNA fragments and 4 half-decreased miRNAs. The most noticeably up-regulated miRNAs included hsa-miR-31, hsa-miR-196b, hsa-miR-652, hsa-miR-125a-5p, hsa-miR-146b, hsa-miR-200c, hsa-miR-23b, hsa-miR-29a, hsa-miR-186, hsa-miR-205, hsa-miR-376a, hsa-miR-410, hsa-miR-532-3p, and hsa-miR-598, whereas the most significantly-downregulated miRNAs were hsa-let-7e, hsa-miR-130b, and hsa-miR-103. EC patients at same TNM stage but with different prognoses show differentially-expressed miRNAs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.199-206
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• 2008

In this paper, we propose a novel Route_Reconf message as the RSVP message to maintain an RSVP session for hard handoff and consider path-comparing route (PCR) a PCR algorithm to find an intermediate node in the charge of downlink re-establishment. And, we consider information form each mode for the PCR algorithm, which also reduces the frequency and amount of exchanged RSVP message to minimize packet loss and delay between an intermediate node and a receiver. According to the proposed algorithm, a new support node (NSN) and an existing support node (ESN) along the RSVP path can be found; the former is a supporting RSVP session node newly searched and the latter is the last supporting node holding the previous session after handoff. On receiving the Route_Reconf message at the ESN, a new allocated route from a NSN to the MN waiting for the handoff via a new AR is configured by the ESN.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5B
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• pp.480-488
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• 2009

A mobile ad-hoc network is an autonomous collection of wireless mobile nodes that organizes a temporary network without any network infrastructure. Due to node mobility, it is a challenging task to maintain the network topology. In this paper, we propose a stable clustering algorithm that uses node mobility for cluster formation. In the proposed algorithm, the node mobility is measured by counting the number of nodes entering into/leaving from its transmission range. The node having the lowest mobility is selected as a cluster head. For topology maintenance with reduced control overhead, the cluster head adaptively controls the broadcasting period of hello message to the measured node mobility. Through computer simulations, it is verified that the proposed algorithm outperforms previous clustering algorithms in terms of control overhead, the rate of node mobility changes and the number of cluster head changes.