• Journal of information and communication convergence engineering
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• v.12 no.2
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• pp.104-108
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• 2014

The field of body sensor networks has attracted interest of many researchers due to its potential to revolutionize medicine. These sensors are usually implanted inside the human body and communicate among themselves. In the process of receiving, processing, or transmitting data, these devices produce heat. This heat damages the tissues surrounding the devices in the case of prolonged exposure. In this paper, to reduce this damages, we have improved and evaluated two protocols-the least temperature routing protocol and adaptive least temperature routing protocol-by implementing clustering as well as a leadership rotation algorithm. We used Castalia to simulate a basic body area network cluster composed of 6 nodes. A throughput application was used to simulate all the nodes sending data to one sink node. Simulations results shows that improved communication protocol with leadership rotation algorithm significantly reduce the energy consumption as compared to a scheme without leadership rotation algorithm.

• Journal of Sensor Science and Technology
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• v.33 no.1
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• pp.12-17
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• 2024

Floating inverter amplifiers (FIAs) have recently garnered considerable attention owing to their high energy efficiency and inherent resilience to input common-mode voltages and process-voltage-temperature variations. Since the voltage gain of a simple FIA is low, it is typically cascaded or cascoded to achieve a higher voltage gain. However, cascading poses stability concerns in closed-loop applications, while cascoding limits the output swing. This study introduces a gain-enhanced FIA that features cross-coupled body biasing. Through simulations, it is demonstrated that the proposed FIA designed using a 28-nm complementary metal-oxide-semiconductor technology with a 1-V power supply can achieve a high voltage gain (> 90 dB) suitable for dynamic open-loop applications. The proposed FIA can also be used as a closed-loop amplifier by adjusting the amount of positive feedback due to the cross-coupled body biasing. The capability of achieving a high gain with minimum-length devices makes the proposed FIA a promising candidate for low-power, high-speed sensor interface systems.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.446-451
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• 2015

Recently, researches on sensor-based U-health applications that provide personal health information such as blood pressure, body temperature, and glucose, have actively been studied. The health information obtained via sensors, however, may have accuracy problems so that they can not be used unprocessed. This paper proposes a sensor abstraction layer for enhancing the accuracy of sensor readings from biomedical sensors that interact with smart phones. This layer recognizes sensor types and converts sensor readings into a form as specified in ISO/IEEE 11073 Personal Health Standard. When necessary, not only a filtering method that eliminates outlier values from sensor readings but also a summarization method that transforms them into more suitable forms, can also be applied. An android-based development board is used for the evaluation of proposed sensor abstraction layer. The results obtained by applying filtering and summarization show improved accuracy over unprocessed sensor readings of the body temperature and heartbeat sensors.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.109-116
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• 2016

Sensing module of standing and moving human body using shutter method was developed. The module consists of Fresnel lens, pyroelectric infrared (PIR) sensor, interface circuit of the PIR, micro control unit(MCU), and alarm light emitting diode(LED). The principle for standing human body is chopping the thermal of human body using camera shutter. The human sensing signal in MCU by algorithm of interrupt function is detected. By unifying an apparatus and print circuit board(PCB), the developed module can be replaced as commercial moving human body detector. Experiment results show that sensing distance is about 7.0m and sensing angles is about $110^{\circ}$ at room temperature. In these condition, sending ratio was 100% and the power dissipation of the module was 100mW.

• Journal of Sensor Science and Technology
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• v.26 no.6
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• pp.391-396
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• 2017

Human body motion detection is important in several industry sectors, such as entertainment, healthcare, rehabilitation, and so on. In this paper, we first discuss commercial human motion detection technologies (optical markers, MEMS acceleration sensors, infrared imaging, etc.) and then explain recent advances in the development of flexible and stretchable strain sensors for human motion detection. In particular, flexible and stretchable strain sensors that are fabricated using carbon nanotubes, silver nanowires, graphene, and other materials are reviewed.

• Journal of Sensor Science and Technology
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• v.22 no.3
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• pp.219-222
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• 2013

The exhaled breath contains gases generated from human body. When disease occurs in the body, exhaled breath may include gas components released from disease metabolism. If we can find specific elements through analysis of the exhaled gases, this approach is an effective way to diagnose the disease. The lung function has a close relationship with exhalation. Exhaled gases from COPD (Chronic Obstructive Pulmonary Disease) patients can be analyzed by gas chromatography-mass spectroscopy (GC-MS) and a gas sensor system. The exhaled breath for healthy person and COPD patients had different components. Significantly more benzendicarboxylic acid was detected from COPD patients than in healthy persons. In addition, patients had a variety of decane. Phosphorous compounds with different isomers were detected from patients. The results obtained by gas sensor system were processed by PCA (Principal Component Analysis). The PCA results revealed distinct difference between the patients and healthy people.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.395-401
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• 2019

This paper proposes a method for estimating the location of a magnetized tip that is inside a non-transparent space or body by using arrayed giant magnetoresistance (GMR) sensors. In general, an object located in such an opaque space can be detected using X-rays, magnetic fields, ultra-sonic sensors, etc., depending on its characteristics. X-ray is mostly used for medical purposes but frequent exposure to it could cause harm to patients as well as doctors. In this study, how well a GMR sensor is applicable instead of an X-ray is investigated. The sensor's voltage output is experimentally fitted to distance with a relationship of 3rd degree polynomial. To detect a small magnetized tip with 900 Oe inside a human body, a 2×2 arrayed GMR sensor and a location estimation algorithm based on information acquired from four sensors is developed. Evaluation tests show that the suggested method is applicable to limited cases with a distance less than 33-55 mm, and the location of a magnet tip is estimated relatively well with an error less than 1.5 mm.

• Smart Media Journal
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• v.4 no.1
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• pp.25-32
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• 2015

Powering wireless sensors with energy harvested from the environment is coming of age due to the increasing power densities of both storage and harvesting devices and the electronics performing energy efficient energy conversion. In order to maximize the functionality of the wireless sensor network, minimize missing packets, minimize latency and prevent the waste of energy, problems like congestion and inefficient energy usage must be addressed. Many sleep-awake protocols and efficient message priority techniques have been developed to properly manage the energy of the nodes and to minimize congestion. For a WSN that is operating in a strictly energy constrained environment, an energy-efficient transmission strategy is necessary. In this paper, we present a novel transmission priority decision scheme for a heterogeneous body sensor network composed of normal nodes and an energy harvesting node that acts as a cluster head. The energy harvesting node's decision whether or not to clear a normal node for sending is based on a set of metrics which includes the energy harvesting node's remaining energy, the total harvested energy, the type of message in a normal node's queue and finally, the implementation context of the wireless sensor network.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.981-990
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• 2021

Corona 19 quarantine is often not implemented at degraded bus stops. We conducted this study to improve these problems. The inside and outside of the shelter can be sterilized with UV photocatalyst coating to maintain a hygienic and clean shelter, and passengers can breathe smoothly by reducing carbon dioxide in the shelter using CO₂ sensors and fans. It is also expected that the body temperature can be measured using a body temperature sensor to prevent more than 20% of the spread of the coronavirus in the shelter by isolating suspected coronavirus patients in the first place. When the temperature measurement distance was less than 10cm, the accuracy of the temperature measurement was 98.9%. You can communicate your intention to ride safely and clearly without contacting the bus driver by using a ride bell that uses wireless communication inside the shelter.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.3
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• pp.187-192
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• 2017

This paper presents an ongoing study to develop a novel pressure sensor by means of a Nano Carbon Piezoresistive Composite (NCPC). The sensor was fabricated using the 3D printing process. We designed a miniaturized cantilever-type sensor electrode to improve the pressure sensing performance and utilized a 3D printer to build a small-sized body. The sensor electrode was made of 2 wt％ MWCNT/epoxy piezoresistive nano-composite, and the sensor body was encapsulated with a pipe plug cap for easy installation to any pressure system. The piezoresistivity responses of the sensor were converted into stable voltage outputs by using a signal processing system, which is similar to a conventional foil strain gauge. We evaluated the pressure-sensing performances using a pressure calibrator in the lab environment. The 3D-printed cantilever electrode pressure sensor showed linear voltage outputs of up to 16,500 KPa, which is a 200％ improvement in the pressure sensing range when compared with the bulk-type electrode used in our previous work.