• Journal of Digital Convergence
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• v.13 no.12
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• pp.381-390
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• 2015

One of the fundamental requirements of entertainment applications is interactivity with users. The mobile device such as the smartphone, however, does not guarantee it due to the limit of the application processor's computing power, memory size and available electric power of the battery. This paper proposes a methodology to boost responsiveness of interactive applications by taking advantage of the parallel architecture of mobile devices which, for instance, have dual-core, quad-core or octa-core. To harness the multi-core architecture, it exploits the POSIX thread, a platform-independent thread library to be able to be used in various mobile platforms such as Android, iOS, etc. As a useful application example of the methodology, a heavy matrix calculation function was transformed to a parallelized version which showed around 2.5 ~ 3 times faster than the original version in a real-world usage environment.

• The KIPS Transactions:PartC
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• v.17C no.5
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• pp.433-440
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• 2010

Energy efficiency, low latency and scalability for wireless sensor networks are important requirements, especially, the wireless sensor network consist of a large number of sensor nodes should be minimized energy consumption of each node to extend network lifetime with limited battery power. An efficient algorithm and energy management technology for minimizing the energy consumption at each sensor node is also required to improve transfer rate. Thus, this paper propose no-overlap multi-pass protocol provides for sensor data transmission in the wireless sensor network environment. The proposed scheme should minimize network overhead through reduced a sensor data translation use to searched multi-path and added the multi-path in routing table. Proposed routing protocol may minimize the energy consumption at each node, thus prolong the lifetime of the sensor network regardless of where the sink node is located outside or inside the received signal strength range. To verify propriety proposed scheme constructs sensor networks adapt to current model using the real data and evaluate consumption of total energy.

• The Journal of Korean Physical Therapy
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• v.26 no.5
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• pp.358-364
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• 2014

Purpose: Flexed posture commonly increases with age in older women and is characterized by an excessive curvature in the thoracic spine (kyphosis), forward head posture, and decline in height. This study was conducted in order to determine the relationship between flexed posture, physical performance, and psychosocial factors in community dwelling elderly women in Korea. Methods: Fifty-two subjects with thoracic kyphosis of $40^{\circ}C$ or greater participated in this study. Flexed posture was measured using kyphosis angle (KA), forward head posture (FHP), and round shoulder (RS), and physical performance was evaluated using the short physical performance battery (SPPB), grip strength, and static and dynamic balance. Psychosocial factors were measured using depression and the quality of life (QOL). All data were analyzed using SPSS 18.0 software for windows. Results: KA showed significant correlation with SPPB score (r=-0.447) and dynamic balance (r=0.426) (p<0.05) depression (r=0.405) and QOL (r=-0.464) but not with grip strength and static balance in elderly individuals. FHP and RS showed significant correlation with SPPB score (r=0.002, r=-0341) and dynamic balance (r=-0.278, r=0.346) (p<0.05) but not with psychosocial factors. Conclusion: These findings suggest that flexed posture provides meaningful information about physical performance and psychosocial factors in elderly women. Our data suggest that the flexed posture may need to be addressed as part of the health management process for elderly women.

• Journal of Trauma and Injury
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• v.30 no.2
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• pp.33-40
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• 2017

Purpose: The role for minimally invasive surgery in chest trauma is vague, one that recently is more frequently performed, and one attractive option to be considered. Thoracoscopic surgery may improve morbidity, mortality, hasten recovery and shorten hospital stay. Methods: A total of 31 patients underwent video assisted thoracoscopic surgery for the treatment of blunt and penetrating chest trauma from June 9th, 2013 to March 21st, 2016 in Jeju, South Korea. Results: Twenty-three patients were males and eight patients were females. Their ages ranged from 23 to 81 years. The cause of injury was due to traffic accident in 17 patients, fall down in 5 patients, bicycle accident in 2 patients, battery in 2 patients, crushing injury in 2 patients, and slip down, kicked by horse, and stab wound in one patient each. Video assisted thoracoscopic exploration was performed in the 18 patients with flail chest or greater than 3 displaced ribs. The thoracoscopic procedures done were hematoma evacuation in 13 patients, partial rib fragment excision in 9 patients, lung suture in 5 patients, bleeding control (ligation or electrocautery) in 3 patients with massive hemothorax, diaphragmatic repair in two patients, wedge resection in two patients and decortication in 1 patient. There was only one patient with conversion to open thoracotomy. Conclusion: There is a broad range of procedures that can be done by thoracoscopic surgery and a painful thoracotomy incision can be avoided. Thoracoscopic surgery can be done safely and swiftly in the trauma patient.

• Journal of Korea Multimedia Society
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• v.22 no.11
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• pp.1324-1337
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• 2019

This study set out to investigate an energy harvesting device to ensure stable energy supply to batteries and data collection devices and a monitoring system for acer pictum sap to check collected data. Acer pictum sap farmers have written down weather information and yield of acer pictum sap manually for data storage. Since the job is done manually, there are many missing values in their data. In addition, it is not easy to manage batteries due to the characteristics of the areas where acer pictum sap is collected. The present study thus decided to build an energy harvesting device based on new renewable energy to ensure stable energy supply by taking into consideration power load, daily power consumption, and number of days with no sunshine for various devices. For a monitoring system, the investigator proposed a JSP-based web page to monitor temperature, humidity, volume of collected water, and battery state in real time. The proposed energy harvesting device was applied to reduce missing values in data. It promoted stable energy supply to the batteries and data collection devices, reducing the percentage of missing values in data from 30.55% to 0%.

• Journal of KIISE:Information Networking
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• v.35 no.1
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• pp.76-90
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• 2008

Wireless sensor networks are expected to play a vital role in the upcoming age of ubiquitous computing such as home environmental, industrial, and military applications. Compared with the vivid utilization of the sensor networks, however, security and privacy issues of the sensor networks are still in their infancy because unique challenges of the sensor networks make it difficult to adopt conventional security policies. Especially, node compromise is a critical threat because a compromised node can drain out the finite amount of energy resources in battery-powered sensor networks by launching various insider attacks such as a false data injection. Even cryptographic authentication mechanisms and key management schemes cannot suggest solutions for the real root of the insider attack from a compromised node. In this paper, we propose a novel trust-based secure aggregation scheme which identifies trustworthiness of sensor nodes and filters out false data of compromised nodes to make resilient sensor networks. The proposed scheme suggests a defensible approach against the insider attack beyond conventional cryptographic solutions. The analysis and simulation results show that our aggregation scheme using trust evaluation is more resilient alternative to median.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.542-549
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• 2016

This paper presents a SoC (System-on-a-Chip) dedicated for a single-chip smart capsule which can be used to continuously monitor human alimentary canal pH and temperature values. The SoC is composed of the pH and temperature sensor interface circuit, a wireless transceiver, the power management circuit and the flow control logic. Fabricated in $0.18{\mu}m$ standard CMOS technology, the SoC occupies a die area of ${\sim}9 mm^2$. The SoC consumes 6.15 mW from a 3 V power supply, guaranteeing the smart capsule battery life is no less than 24 hours when using 50 mAh coin batteries. The experimental results show that measurement accuracy of the smart capsule is ${\pm}0.1$ pH and ${\pm}0.2^{\circ}C$ for pH and temperature sensing, respectively, which meets the requirement of in-body pH and temperature monitoring in clinical practice.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.774-784
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• 2009

A wireless sensor network consisting of a large number of nodes with limited battery power should minimize energy consumption at each node to prolong the network lifetime. To improve the sensitivity of wireless sensor networks, an efficient scheduling algorithm and energy management technology for minimizing the energy consumption at each node is desired. ill this paper, we propose energy-aware routing mechanism for maximum lifetime and to optimize the solution quality for sensor network maintenance and to relay node from its adjacent cluster heads according to the node"s residual energy and its distance to the base station. Proposed protocol may minimize the energy consumption at each node, thus prolong the lifetime of the system regardless of where the sink is located outside or inside the cluster. Simulation results of proposed scheme show that our mechanism balances the energy consumption well among all sensor nodes and achieves an obvious improvement on the network lifetime. To verify propriety using NS-2, proposed scheme constructs sensor networks adapt to current model and evaluate consumption of total energy, energy consumption of cluster head, average energy dissipation over varying network areas with HEED and LEACH-C.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.5
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• pp.479-484
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• 2016

In this paper, a design of DC level shifter transmitting and receiving control and data signal which have various DC level through daisy chain interface between master IC and slave is introduced in the cell voltage monitoring (CVM). Circuit designed with a latch structure have a function to operate in high speed and for output of variable DC level through transmission gate. As a result of the simulation and the measurement, it was confirmed that control and data signal could be transferred according to the change of DC level from 0V to 30V. Delay time was measured about 170ns. but, it was considered as a negligible tolerance due to a parasitic capacitance of measuring probe and test board.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.943-961
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• 2020

With the advent of IoT technology and Big Data computing, the importance of WSNs (Wireless Sensor Networks) has been on the rise. For energy-efficient and collection-efficient delivery of any sensed data, lots of novel wireless medium access control (MAC) protocols have been proposed and these MAC schemes are the basis of many IoT systems that leads the upcoming fourth industrial revolution. WSNs play a very important role in collecting Big Data from various IoT sensors. Also, due to the limited amount of battery driving the sensors, energy-saving MAC technologies have been recently studied. In addition, as new IoT technologies for Big Data computing emerge to meet different needs, both sensors and sinks need to be mobile. To guarantee stability of WSNs with dynamic topologies as well as frequent physical changes, the existing MAC schemes must be tuned for better adapting to the new WSN environment which includes energy-efficiency and collection-efficiency of sensors, coverage of WSNs and data collecting methods of sinks. To address these issues, in this paper, a self-organization scheme for mobile sensor networks with mobile multiple sinks has been proposed and verified to adapt both mobile sensors and multiple sinks to 3-dimensional group management MAC protocol. Performance evaluations show that the proposed scheme outperforms the previous schemes in terms of the various usage cases. Therefore, the proposed self-organization scheme might be adaptable for various computing and networking environments with big data.