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To accurately predict and monitor an individual’s health, accurate information on the changing patterns of the individual’s physiological signals is required. In this study, obesity parameters were analyzed using regression analysis based on the physiological signals of individuals who performed continuous exercise. To this end, three healthy adult subjects participated in the experiment, and their health management was analyzed by monitoring changes in health information parameters while they performed continuous exercise with daily activities over a long period of time. Subjects’ exercise parameters included heart rate were collected through smart watches, and their specified obesity parameters were measured using a smart scale. The analysis results showed that weight and body fat decreased and muscle composition increased in conjunction with the amount of exercise for two subjects who performed continuous exercise while conducting daily activities. For one subject who did not perform any specific exercise, however, the weight and body muscle rate tended to increase slightly and the body fat rate tended to decrease slightly. It was found that continuous exercise improved the subjects’ ability to adapt to exercise, thereby increasing Max BPM and reducing weight. Performing continuous exercise while conducting daily activities appears to improve physical measures of health, as it decreases weight and body fat rate and increases body muscle rate. Health management analysis based on the physiological data collected from smart devices is expected to play a role in keeping the human body healthy.

In this study, a multi-sensor data fusion system using a load cell and vision sensor was considered in the development of a flatfish classifier for systematic fish management in aquaculture. In the single-sensor measurement method, each sensor has disadvantages. A load cell shows high performance in the measurement of adult fish, but the measurement of fry is affected significantly due to water weight (water weight disturbance). A vision sensor shows high performance in the measurement of fry, but the movement of fish (movement disturbance) affects the accurate measurement of adult fish. Therefore, in this study, these disturbances were compensated for using a datafusion algorithm, of which the performance was evaluated by a comparison between single sensor measurements and multi-sensor data fusion results.

This paper proposes the use of a gyrostabilizer to improve the response performance of an unmanned underwater vehicle navigated by a quadrant detector (QD) in shallow water docking operations under the influence of ocean disturbances. Reference tracking and disturbance attenuation were investigated with and without delayed response from the gyroscope. The control methodologies examined are combinations of forward Riccati and passive control, forward Riccati and proportional-derivative (PD) control, and forward Riccati and penalty function control. Forward Riccati control is applied to the yaw-pitch dynamics for command tracking, while gyro-dynamics control for disturbance attenuation is achieved using passive, PD, and penalty function controls. Overall, the forward Riccati and penalty function control method showed desired performance because the gyro-precession workspace was maintained within actuation limits while operating within a region of dominant precession spin or control.

The body weight support (BWS) system that allows a patient to support his or her body weight in step-wise fashion, depending on their physical condition, is an important intervention that assists individuals with gait disabilities in their gait rehabilitation. In this paper, we measured human body signals in order to verify a rehabilitation system using active harness that we developed for gait and balance training based on ceiling-rail platform. 20 healthy participants were performed to conduct daily activities related to lower limbs. They did a kind of motions related to daily life (Normal Walking, Stand-to-Sit, and Stair Walking Down) according to variation of body weight support rates (0%, 30%, 50% of subject’s body weight). The effectiveness of the weight supporting on healthy people is analyzed by the muscular activities and foot pressure distribution. In normal walking, the decrease of fore-foot pressure, lateral soleus muscle and biceps femoris muscle were remarkable. The result of stand-to-sit results motion indicated that the rearfoot pressure and tibialis anterior muscle activities exceptionally decreased according to body weight support. The stair walking down results indicate the marked drop of fore-foot pressure and rectus femoris muscle activities. Based on these results, a function of weight supporting is very helpful to improve the gait ability of people with gait disorder.

This study was to provide independent exercise loads in rowing exercise machine, on the improvement of muscle strength imbalance. We recruited twenty four subjects who exhibited one side's muscle strength is bigger in more of greater than 20% than other on one side. One group was dominant left side and the other group was dominant right side. Subjects performed the rowing exercise in electric load deviation rowing machine (Robo.gym, Humonic Co., Ltd, Daegu, Korea). The exercise was progressed to four sets a day including twenty five repetitions per set, and three days a week, for a total of eight weeks. Measurements consist of evaluation of muscular activity, joint torque in the elbow, shoulder. Exercise load deviation adapted that difference value of muscle strength between left and right side arms multiply 1RM% and its plus 1-RM 75% in each side. The result showed that the level of muscle imbalance significantly decreased in shoulder and elbow joint by adapting exercise load deviation. We found out that exercise load deviation provided to the positive effect both muscle strength and endurance at the same time. As a result of this study, rowing exercise using the exercise load deviation is effective in improving muscle strength imbalance.

The objective of the study was to investigate the effect of 3-D stabilization exercise using a whole body tilt device. A musculoskeletal (MS) model of the whole body was developed, and used to calculate the forces in the spine, assisted by EMG measurement. The inverse dynamics was solved using the MS model of the whole body with the input data of the eight different directions of the tilt: anterior (A), posterior (P), anterior right (AR), posterior right (PR), anterior left (AL), posterior left (PL), right (R), and left (L), replicating the tilting directions of the whole body device. The anterior and posterior directions of tilt mainly induced superficial back and front muscle activations, respectively. However, deep muscles, such as the semispinalis and mulifidi, were activated in all directions of tilt. The joint resultant forces in the right and left direction of tilt were the least; but some higher activations and more diverse recruitments of muscles were demanded. In the present investigation, 3-D stabilization exercise can provide considerable muscle activation and exercise effect, with the minimum perturbation of structure. Therefore, the proposed direction of tilt can be used to strengthen the targeted muscles, depending on the patient’s muscle conditions.

This study intended to identify the effect of the long time whole body vibration exercise on the muscle function and postural balance. The twenties subjects in young people were recruited, and they were classified into WBV and Non-WBV groups. The vibration exercise was conducted 30 minutes a day for 4 days a week for a total 8 weeks, and the vibration protocol were 25Hz frequency and 5mm amplitude. To verify the muscle function according to the long time vibration exercise, the isokinetic muscle function of the knee joint torque was evaluated, while the total work of maximal peak torque to evaluate the enhancement effect of muscular strength, as well as the average power, angle to peak torque, and acceleration time to evaluate the muscular reaction, was analyzed. Also, changes in COP were measured and analyzed to research the functional change of the postural balance. As a result of the experiment, the Non-WBV group did not show changes in the muscular function and postural balance function, while the WBV group showed increased muscular function by 29.11%(maximal peak torque: 17.91%, total work: 26.78%, average power: 39.11%, angle to peak torque: 25.21%, acceleration time: 36.51%), and increased postural balance function by 64.76%.

This paper deals with the problem of accurately tracking a single target, which has various trajectories, moving through the environment of underwater wireless sensor networks (UWSNs). This paper addresses the issues of estimating the states of the target, improving energy efficiency by using a distributed architecture. Each underwater wireless sensor node composing the UWSNs is battery-powered, so the energy conservation problem is a critical issue. This paper provides algorithms increasing the energy efficiency of each sensor node by using the proposed Wake-Up/Sleep (WUS) scheme. An interacting multiple model (IMM) filter is applied to the proposed distributed architecture in order to cope with a target maneuver. Simulation results illustrate the performance of the proposed tracking filter according to the various target maneuver patterns.

This paper presented the 8-weeks training effects of training system based on an unstable platform and a visual interactive system for improving the ability of postural control. To confirm the effects of the training, fifteen elderly volunteers took part in a series of balance training using this system. Fifteen elderly volunteers as the control group compared with the training group. To evaluate the effects of the training, the relevant parameters such as the time of timed up and go (TUG) test, the transfer limits of the different directions, the sway path of center of pressure (COP), and the root mean square (RMS) of COP in anteroposterior (AP) direction and mediolateral (ML) direction, concentric isokinetic strength of ankle and knee joints were measured from pre-training to post-training. The results showed that the training system could successfully assess the gradual improvement of the postural control capability of the volunteers in the system and showed a possibility of improving balance capability of the volunteers. Moreover, the significant improvement in the postural capability of the elderly suggested that the elderly could benefit more from the training using the system for the improvement of the ability of postural control.

In this paper, we are interested in the characteristics of a knee joint when the knee extension motion was assisted by a powered knee orthosis using a muscular stiffness force feedback. For this purpose, we developed the powered knee orthosis with an artificial pneumatic actuator, which is intended for the assistance and the enhancement of muscular activities of lower limbs. The objective of this study was to confirm the effectiveness of the powered knee orthosis that generated a knee extension torque in the motion related to a knee joint. Twenty healthy subjects participated in this study and their lower limb muscular activities were measured to identify the effectiveness of the powered knee orthosis during sit-to-stand (STS) and squat motion. The muscular activities between with and without assistance of knee extension motion were compared and analyzed for the assistance characteristics of the powered knee orthosis. To generate the knee extension torque, the knee orthosis was controlled using muscular stiffness force (MSF) feedback that is controlled by muscular activities of the vastus intermedius muscle that mainly related to the knee extension motion. For analysis of muscular activities, the surface electromyography of the muscles related to the knee extension motion, i.e., RF, vastus lateralis, vastus medialis and vastus intermedius muscles in lower limbs of the right side were recorded and biodex dynamometer was used to measure the maximal concentric isokinetic strength of the knee extensors. The experimental result showed that muscular activities in lower limbs with the assistance of the powered knee orthosis was reduced by 25.62% in rectus femoris muscle and 29.82% in biceps femoris muscle, respectively and knee extension torque of an knee joint wearing knee orthosis was increased by 17.68% in averaged peak torque. Based on the effectiveness of the powered knee orthosis, weaken elder people may have benefited from the knee extension motion augmented by the powered knee orthosis during activity of daily living, e.g., stair ascent.

The purpose of this study was to investigate the effect of indoor horse riding exercise equipment on the young people in their twenties. We classified the effects into flexibility, muscle strengthening, and muscular reaction. Subjects performed horse riding exercise using SRider (Neipplus Co. & Chonbuk National Univ, Korea) that we developed. Twenty male and twenty female subjects were included and they had no experience with horse riding as an exercise and no medical history of falling. Exercise was performed for 45 min a day and 3 days a week during 8 weeks in a constant temperature and humidity environment. Once a week, we conducted the bodyeffect measurements. We measured forward trunk flexion and backward trunk extension to verify the improvement of flexibility. We also measured lumbar joint torque using the BIODEX System3 to verify the improvement of muscle strength and reaction. Our results of flexibility showed that values of forward trunk flexion and backward trunk extension after the exercise were higher than those before the exercise. It also presented that the stimulated three-dimensional movement of the horse riding exercise activated joints and muscles not usually used. Besides, the continuous movement of horse riding can reduce muscle tonus and relax stiff muscles. The muscle strengthening and muscular reaction results showed that peak lumbar joint torque after the exercise was higher than that before the exercise. We found that the horse riding exercise using indoor equipment improved flexibility, muscle strength, and muscular reaction. Moreover, we hope that this work will help us understand the exercise characteristic of this equipment.

It is necessary to develop a rehabilitation robot for the assistance of movement of the ankle joint and the enhancement of ankle muscular activities during walking for the elderly. A powered ankle exoskeleton with an artificial pneumatic muscle has been designed to provide powered assistance in the plantarflexion motion of the ankle joint. The objective of this study was to confirm the effectiveness of the powered ankle exoskeleton for the plantarflexion torque of the ankle joint. Fifteen healthy and fifteen elderly people used a wearable ankle exoskeleton during the plantarflexion motion of the ankle joint. Participants were assessed with three parameters to confirm the effectiveness of the system: a) maximal voluntary isokinetic plantarflexion torque using a Biodexdynamometer, b) muscular activities of the lower limbs, c) correlation of the agonist muscle and plantar torque during plantarflexion motion of the ankle joint. The assistance of the plantarflexion motion of the ankle joint is determined by the plantarflexion torque of the artificial pneumatic muscle of the powered ankle exoskeleton, and the assistant timing was decided the detection of subject’s movement intention that they did plantarflexion motion of the ankle joint. We developed a muscular stiffness force sensor to detect the activation of the soleus muscle for feed-forward control of the ankle exoskeleton. The experimental results show that the muscular stiffness force of the soleus muscle with feed-forward control was decreased, and the plantarflexion torque of the ankle joint while only wearing the ankle exoskeleton was decreased, but the plantarflexion torque with feed-forward control was increased. The amount of increasing with feed-forward control is higher than that of decreasing only wearing the exoskeleton. Based on the effectiveness of the system with the healthy participants, the elderly may have benefited from the plantarflexion motion augmented by the powered ankle exoskeleton.

The initial step of the soldering process may consist of dissolution of metal substrate and the subsequent counterdiffusion between substrate atoms and solder elements. The counterdiffusion gives rise to the formation of the various interphases (phases at the interfacial region). A close investigation of the interphases formed at the very early stage of soldering will provide the root understanding to the soldering process. No in situ observation at the liquid/solid interaction was possible thus far. A number of studies attempted to adopt rapid quench of the soldered specimen at the very early stage of interaction, around 10 s or less after solder melts, so as to freeze the occurrences. The current article provides a review of the achievements of these studies, although not many, and the interphases formed during the very early stage of the soldering process for various solder systems.

The rupture of an aneurysm can lead to a subarachnoid hemorrhage, which can be fatal in a large percentage of cases. In treating aneurysms, intravascular stenting is thought as a better option compared with clipping treatment. The treatment of cerebral aneurysm with a porous stent also has recently been proposed as a minimally invasive way to prevent rupture and favor coagulation mechanism inside the aneurysm. Flow characteristics in a box-typed straight rigid silicone with a sphere attached to the center of a baseline straight tube have been investigated using particle image velocimetry (PIV) at Reynolds number of 300. A 20 mm long mesh-work of rhombus shape stent was tested in the present investigation. Four stent porosities of 100%, 80%, 74%, and 64% were examined. Reduced velocity, smaller average vorticity magnitude and different flow patterns inside the aneurysm are observed when the three different proposed stents are used. The lower porosity stent (Porosity = 64%) decreases the magnitude of the velocity by 98% and changes the flow pattern in the aneurysm. Our results show that not only the role of the porosity but also the stent shape affects the flow. Moreover, we hope that this work will help us understand the characteristic of stent designs.

A modified variable structure interacting multiple model (M-VSIMM) estimator for complex hybrid maneuver target tracking is presented. The M-VSIMM could potentially be applied to fire control systems (FCS) used on warships. Target model groups were designed using 3D dimensional dynamic target models. Optimal model group selection logic was proposed, contrary to the activation and termination logic in the original VSIMM. The system will respond faster with optimal model group selection logic. After performing simulations, the tracking performances of the Kalman, α-β(-γ), VDIE, IMM and M-VSIMM filters were compared under various maneuvering conditions.

This paper presents a study involving prediction of a complicated maneuvering target, with the aim of improving the tracking performance of a fire control system (FCS). In this study, we predict the position of a complicated maneuvering target 5 s in advance using the information up to the current time. Because of the large error caused by the complicated maneuvers and the long prediction time interval, the mechanical system of the fire control system will take a heavy load. In order to cope with this problem, several approaches to decreasing the prediction error have been proposed including the prediction algorithms based on the multiple model(MM) filter, interacting multiple model (IMM) filter, and variable dimension with input estimation (VDIE) filter. Finally, comparative simulation results are presented to verify the performance of the filters.

The soldering reaction and interfacial microstructure formed between liquid Sn–Zn–Ag solder and Cu at the early stage of soldering at 250 °C for 15 s were studied primarily with the aid of transmission electron microscope (TEM). To achieve the early stage reaction information, the soldered specimens, 5 mm × 5 mm × 500 μm solder on 10 mm × 10 mm × 20 μm Cu, were rapidly quenched in liquid nitrogen after soldering. The results of TEM interfacial analysis show that a Cu–Zn reaction zone, consisting of β′–CuZn and γ–Cu5Zn8, formed near Cu while a Ag–Zn zone, consisting of γ–Ag5Zn8 and ϵ–AgZn3, formed near solder. The innermost layer adjacent to the Cu substrate is an amorphous Cu-Zn diffusion region that contains dispersed β′–CuZn nanocrystalline cells. The β′–CuZn also precipitates in the γ–Ag5Zn8 and ϵ–AgZn3 layer due to the supersaturation of Cu.

The early dissolution behavior of Cu in a molten Sn–Zn–Ag solder was studied at 250 °C by fast quenching the dissolving specimen in liquid nitrogen. The atomic level dissolution behavior of Cu in the molten solder was revealed by high-resolution transmission electron microscopy. The dissolution of Cu occurs through channel dissolution and thermal vibrational dissolution. The dissolution channel has a dimension of less than 0.5 nm. The formation of channels, and thus the channel zone, is initiated by preferential removal of Cu atoms from the surface vacant site of Cu lattice. Relict strips of lattice between channels subsequently dissolve into the molten solder with the aid of thermal vibration and the interaction with liquid Zn atoms. The dissolved atoms form an atomic cluster zone. These clusters are the intermediate state of the dissolution of Cu from the channel zone into the molten Sn–Zn–Ag solder. The clusters convert into an amorphous structure prior to further formation of compound.