Multiple Fingerprinting Localization by an Artificial Neural Network.

Fingerprinting localization is a promising indoor positioning methods thanks to its advantage of using preinstalled infrastructure. For example, WiFi signal strength can be measured by pre-existing WiFi routers. In the offline phase, the fingerprinting localization method first stores of position and RSSI measurement pairs in a dataset. Second, it predicts a target's location by comparing the stored fingerprint database to the current measurement. The database size is normally huge, and data patterns are complicated; thus, an artificial neural network is used to model the relationship of fingerprints and locations. The existing fingerprinting locations, however, have been developed to predict only single locations. In practice, many users may require positioning services, and as such, the core algorithm should be capable of multiple localizations, which is the main contribution of this paper. In this paper, multiple fingerprinting localization is developed based on an artificial neural network and an analysis of the number of targets that can be estimated without loss of accuracy is conducted by experiments.

Influence of Isometric Exercise Combined With Electromyostimulation on Inflammatory Cytokine Levels, Muscle Strength, and Knee Joint Function in Elderly Women With Early Knee Osteoarthritis.

Background and Objectives: Muscle strengthening exercise is suggested to beneficial for patients with knee osteoarthritis (OA) and electrical muscular stimulation is reported to be effective in improvement of muscle strength. This study examined whether isometric exercise combined with whole body-electromyostimulation (WB-EMS) can improve serum cytokine levels, muscle strength, and knee function in elderly women with early knee OA. Materials and Methods: This randomized controlled study included 75 participants assigned into three groups: the control group (CON), isometric exercise group (ISOM), and isometric exercise and electromyostimulation group (ISOM + EMS). The two exercise groups performed their respective programs for 8 weeks, 3 days a week, 30 min a day. The main exercises for both groups were performed continuously during the 20 min in an alternation of a 6-s contraction with a 4-s break. At pre- and post-intervention, anthropometric variables, muscle strength, Knee Injury and Osteoarthritis Outcome Score (KOOS), and blood sampling for biomarkers including interleukin-6, tumor necrosis factor-α, C-reactive protein, and resistin were performed. Results: All variables at pre-intervention showed no significant differences among the three groups. However, there were significant differences between groups for body composition, muscle strength, KOOS subscale scores, and biomarkers. ISOM + EMS group resulted in a significant reduction in body weight, fat mass, fat percentage, inflammatory cytokine levels, and increased muscle strength. An ISOM + EMS group had the best KOOS score among all groups. Conclusion: Isometric exercise combined with WB-EMS resulted in the best overall improvements in knee function and alleviating the pain and symptoms of patients with early knee OA. Further, reduced levels of inflammatory cytokines were observed. These non-pharmacologic, non-invasive interventions should be considered by healthcare specialists for elderly patients with early knee OA.

Psychophysical condition of adolescents in coronavirus disease 2019.

This study investigated the prevalence of depression and levels of physical fitness in high school students during the coronavirus disease 2019 (COVID-19) pandemic. One hundred fifty participants were divided into four groups according to the number of days that they felt depressed due to the COVID-19 during the last 7 days: no-depression group (NDG, n=17), some-depression group (SDG, n=32), occasional-depression group (ODG, n=81), and most-depression group (MDG, n=20). Shuttle run for endurance capacity and standing long jump for muscle power were selected to estimate the states of type I and type II muscle fibers, respectively. This study found that the Center for Epidemiologic Studies Depression Scale score of MDG was significantly higher than those of other three groups. In addition, ODG and MDG showed the lowest interest in their school studies compared with other groups. Endurance capacity showed a significant difference among groups, whereas muscle power showed no significant difference among groups. In conclusion, this study suggests that higher levels of depression reflect a greater lack of interest in life and academics. Furthermore, lower endurance capacity appears to be associated with more severe levels of depression. This highlights the importance of maintaining type I muscle fibers through regular aerobic exercise.

Change in Denture Procedures after Implementation of National Health Insurance Coverage for the Elderly in Korea: A Nationwide Database.

BACKGROUND: Dental health is an important factor in daily life routines and is closely associated with maintaining a health-related quality of life. This study examined denture procedure changes after implementation of the National Health Insurance (NHI) Coverage of Dentures for the elderly. METHODS: We used the "Korean Community Health Survey (KCHS)" developed by the Korea Centers for Diseases Control and Prevention. We analyzed the association between policy implementation and dental health-related outcomes using difference-in-differences (DID) analysis to compare patients aged ≥75 with those 65-74 years before and after coverage. RESULTS: A comparison of age groups and coverage periods showed that patients aged ≥75 years had higher (OR: 1.038, 95% CI: 1.021-1.055) procedure rates after coverage. In particular, elderly patients on medical aid had significantly higher denture procedure rates, while those without oral health screening were more likely to have denture procedures. CONCLUSIONS: This study determined the impact of the NHI Coverage of Denture procedure policy for the elderly and found increased denture treatments in the elderly. This policy appeared to positively affect older patients by increasing denture procedures for low-income and medical aid beneficiaries. Hence, the government needs to increase oral health examination and dental health policies for the elderly.

Effects of equine riding on static and dynamic mechanical contraction of the thighs and trunk muscles in inactive women.

BACKGROUND AND OBJECTIVE: This study investigated whether equine riding affects static or dynamic mechanical contractions on the thighs and trunk muscles in inactive women. METHODS: Participants consisted of 30 women with a mean (SD) age of 21.06 (0.44) years. They were randomly allotted as follows: equine group (EQG, n= 15) and control group (CON, n= 15). Two types of muscle contraction properties in their thighs and trunk were measured through a tensiomyography (static muscle tester) and an isokinetic device (dynamic muscle tester), respectively. Using the body weights of EQG and CON as covariates, a 2-way between-groups multivariate analysis of covariance was used to investigate group differences in the mechanical quantification of the thighs and trunk. RESULTS: The effectiveness of 8 weeks of equine riding was hardly observed in a static muscle test, whereas in the dynamic muscle test, the dominant and non-dominant hip extensor/flexor, the dominant hip abductor/adductor, and trunk extensor in the EQG showed a significant increase, compared to no changes in the CON. CONCLUSIONS: This study did not find any particular differences in a static muscle test in inactive women, but showed improvements in the dynamic mechanical properties of the thighs and trunk, which are major muscle groups related to spinal alignment.

Effect of playing soccer on stress, sociality, and physical fitness in alienated youth: a retrospective study.

This study was to analyze bullying experiences, physical fitness, and stress and social support in young students who have taken part in a soccer program for approximately 3 years. Fifty-two participants who were divided into two groups: a control group that had not experienced alienation (NAG; n=45, 86.5%) and an experimental group that had ex-perienced alienation (AG; n=7, 13.5%). The frequency of alienation in AG was '1-2 times' or 'a few times' per week. NAG believed their in-volvement in the soccer program helped them improve their relation-ships with friends, cope with alienation, and overcome bullying. Muscle mass and basal metabolic rate of NAG showed higher levels than those of AG. Strength of NAG was significantly higher than that of AG. Stress levels of NAG were significantly lower than those of AG. Although so-cial support was not significantly different between groups, there was a higher tendency in NAG to have stronger social support compared to AG. In conclusion, this study suggests that physical fitness and stress levels can be improved by playing soccer. In particular, participating in a soccer program for an extended period of time can benefit individuals who are socially alienated.

Indoor Mapping Guidance Algorithm of Rotary-Wing UAV Including Dead-End Situations.

A mapping guidance algorithm of a quadrotor for unknown indoor environments is proposed. A sensor with limited sensing range is assumed to be mounted on the quadrotor to obtain object data points. With obtained data, the quadrotor computes velocity vector and yaw commands to move around the object while maintaining a safe distance. The magnitude of the velocity vector is also controlled to prevent a collision. The distance transform method is applied to establish dead-end situation logic as well as exploration completion logic. When a dead-end situation occurs, the guidance algorithm of the quadrotor is switched to a particular maneuver. The proposed maneuver enables the quadrotor not only to escape from the dead-end situation, but also to find undiscovered area to continue mapping. Various numerical simulations are performed to verify the performance of the proposed mapping guidance algorithm.

Time-Series Laplacian Semi-Supervised Learning for Indoor Localization †.

Machine learning-based indoor localization used to suffer from the collection, construction, and maintenance of labeled training databases for practical implementation. Semi-supervised learning methods have been developed as efficient indoor localization methods to reduce use of labeled training data. To boost the efficiency and the accuracy of indoor localization, this paper proposes a new time-series semi-supervised learning algorithm. The key aspect of the developed method, which distinguishes it from conventional semi-supervised algorithms, is the use of unlabeled data. The learning algorithm finds spatio-temporal relationships in the unlabeled data, and pseudolabels are generated to compensate for the lack of labeled training data. In the next step, another balancing-optimization learning algorithm learns a positioning model. The proposed method is evaluated for estimating the location of a smartphone user by using a Wi-Fi received signal strength indicator (RSSI) measurement. The experimental results show that the developed learning algorithm outperforms some existing semi-supervised algorithms according to the variation of the number of training data and access points. Also, the proposed method is discussed in terms of why it gives better performance, by the analysis of the impact of the learning parameters. Moreover, the extended localization scheme in conjunction with a particle filter is executed to include additional information, such as a floor plan.

Effect of initial placement level and wall thickness on maintenance of the marginal bone level in implants with a conical implant-abutment interface: a 5-year retrospective study.

PURPOSE: Implant wall thickness and the height of the implant-abutment interface are known as factors that affect the distribution of stress on the marginal bone around the implant. The goal of this study was to evaluate the long-term effects of supracrestal implant placement and implant wall thickness on maintenance of the marginal bone level. METHODS: In this retrospective study, 101 patients with a single implant were divided into the following 4 groups according to the thickness of the implant wall and the initial implant placement level immediately after surgery: 0.75 mm wall thickness, epicrestal position; 0.95 mm wall thickness, epicrestal position; 0.75 mm wall thickness, supracrestal position; 0.95 mm wall thickness, supracrestal position. The marginal bone level change was assessed 1 day after implant placement, immediately after functional loading, and 1 to 5 years after prosthesis delivery. To compare the marginal bone level change, repeated-measures analysis of variance was used to evaluate the statistical significance of differences within groups and between groups over time. Pearson correlation coefficients were also calculated to analyze the correlation between implant placement level and bone loss. RESULTS: Statistically significant differences in bone loss among the 4 groups (P<0.01) and within each group over time (P<0.01) were observed. There was no significant difference between the groups with a wall thickness of 0.75 mm and 0.95 mm. In a multiple comparison, the groups with a supracrestal placement level showed greater bone loss than the epicrestal placement groups. In addition, a significant correlation between implant placement level and marginal bone loss was observed. CONCLUSIONS: The degree of bone resorption was significantly higher for implants with a supracrestal placement compared to those with an epicrestal placement.

Effects of winter skiing on stress, heart rate, apprehension, and enjoyment in collegiate students: a single randomized controlled trial.

This study investigated the effect of winter skiing on stress levels in collegiate students and also observed psychological factors related to heart rate, apprehension, and enjoyment. Two hundred thirty-eight male students were randomly classified into the control group (n=117) or the ski group (n=121). The control group received lectures on skiing; however, the ski group received practical ski training. Psychological measures included stress, apprehension, and enjoyment; physical measures included heart rate at pre- and postday. There were significant correlations between stress and apprehension (r=0.366) and stress and enjoyment (r=-0.441). Specifically, apprehension negatively correlated with enjoyment (r=-0.599). Between both groups, a significant interaction effect was found among stress, apprehension, and enjoyment. Moreover, compared with the control group, the ski group's stress and apprehension were significantly reduced, whereas the enjoyment was significantly enhanced. This study suggests that winter skiing is a suitable sport for reducing stress and providing a high level of enjoyment for collegiate students.

The effect of warm-ups with stretching on the isokinetic moments of collegiate men.

Performing warm-ups increases muscle temperature and blood flow, which contributes to improved exercise performance and reduced risk of injuries to muscles and tendons. Stretching increases the range of motion of the joints and is effective for the maintenance and enhancement of exercise performance and flexibility, as well as for injury prevention. However, stretching as a warm-up activity may temporarily decrease muscle strength, muscle power, and exercise performance. This study aimed to clarify the effect of stretching during warm-ups on muscle strength, muscle power, and muscle endurance in a nonathletic population. The subjects of this study consisted of 13 physically active male collegiate students with no medical conditions. A self-assessment questionnaire regarding how well the subjects felt about their physical abilities was administered to measure psychological readiness before and after the warm-up. Subjects performed a non-warm-up, warm-up, or warm-up regimen with stretching prior to the assessment of the isokinetic moments of knee joints. After the measurements, the respective variables were analyzed using nonparametric tests. First, no statistically significant intergroup differences were found in the flexor and extensor peak torques of the knee joints at 60°/sec, which were assessed to measure muscle strength. Second, no statistically significant intergroup differences were found in the flexor and extensor peak torques of the knee joints at 180°/sec, which were assessed to measure muscle power. Third, the total work of the knee joints at 240°/sec, intended to measure muscle endurance, was highest in the aerobic-stretch-warm-ups (ASW) group, but no statistically significant differences were found among the groups. Finally, the psychological readiness for physical activity according to the type of warm-up was significantly higher in ASW. Simple stretching during warm-ups appears to have no effect on variables of exercise physiology in nonathletes who participate in routine recreational sport activities. However, they seem to have a meaningful effect on exercise performance by affording psychological stability, preparation, and confidence in exercise performance.

Relative appendicular skeletal muscle mass is associated with isokinetic muscle strength and balance in healthy collegiate men.

There are few studies on the relationship between skeletal muscle mass and balance in the young ages. We investigated the relationship between appendicular skeletal muscle mass, isokinetic muscle strength of lower extremity, and balance among healthy young men using relative skeletal muscle index. Thirty men were grouped according to relative appendicular skeletal muscle mass index: higher skeletal muscle group (n = 15) and lower skeletal muscle group (n = 15). Static and dynamic balance abilities were measured using the following: a test where participants stood on one leg with eyes closed, a modified Clinical Test of Sensory Interaction on Balance (mCTSIB) with eyes open and eyes closed, a stability test, and limits of stability test. The muscle strength of lower extremities was measured with an isokinetic analyser in hip, knee, and ankle joints. Participants with higher appendicular skeletal muscle mass were significantly more stable in maintaining dynamic balance than those with lower appendicular skeletal muscle mass. Moreover, appendicular skeletal muscle mass index was positively correlated with dynamic balance ability. Participants with higher appendicular skeletal muscle mass had stronger strength in the lower extremity, and there were significant differences in the isokinetic torque ratios between groups. From these results, it can be inferred that higher appendicular skeletal muscle mass relates to muscle strength and the alteration in the peak torque ratio of the lower extremity, contributing to the maintenance of balance.

Comparison of isokinetic muscle strength and muscle power by types of warm-up.

[Purpose] The purpose of this study was to clarify the influence of static stretching at warm-up on the isokinetic muscle torque (at 60°/sec) and muscle power (at 180°/sec) of the flexor muscle and extensor muscle of the knee joint. [Subjects and Methods] The subjects of this study were 10 healthy students with no medically specific findings. The warm-up group and warm-up with stretching group performed their respective warm-up prior to the isokinetic muscle torque evaluation of the knee joint. One-way ANOVA was performed by randomized block design for each variable. [Results] The results were as follows: First, the flexor peak torque and extensor peak torque of the knee joint tended to decrease at 60°/sec in the warm-up with stretching group compared with the control group and warm-up group, but without statistical significance. Second, extensor power at 180°/sec was also not statistically significant. However, it was found that flexor power increased significantly in the warm-up with stretching group at 180°/sec compared with the control group and warm-up group in which stretching was not performed. [Conclusion] Therefore, it is considered that in healthy adults, warm-up including two sets of stretching for 20 seconds per muscle group does not decrease muscle strength and muscle power.

Target localization in wireless sensor networks using online semi-supervised support vector regression.

Machine learning has been successfully used for target localization in wireless sensor networks (WSNs) due to its accurate and robust estimation against highly nonlinear and noisy sensor measurement. For efficient and adaptive learning, this paper introduces online semi-supervised support vector regression (OSS-SVR). The first advantage of the proposed algorithm is that, based on semi-supervised learning framework, it can reduce the requirement on the amount of the labeled training data, maintaining accurate estimation. Second, with an extension to online learning, the proposed OSS-SVR automatically tracks changes of the system to be learned, such as varied noise characteristics. We compare the proposed algorithm with semi-supervised manifold learning, an online Gaussian process and online semi-supervised colocalization. The algorithms are evaluated for estimating the unknown location of a mobile robot in a WSN. The experimental results show that the proposed algorithm is more accurate under the smaller amount of labeled training data and is robust to varying noise. Moreover, the suggested algorithm performs fast computation, maintaining the best localization performance in comparison with the other methods.

Proper exercise decreases plasma carcinoembryonic antigen levels with the improvement of body condition in elderly women.

Aging increases the risk of chronic diseases including cancers. Physical exercise has the beneficial effects for the elderly susceptible to the development of cancers, through maintaining a healthy body condition and improving the immune system. However, excessive or insufficient exercise might increase the risk for cancer. In the present study, we investigated what exercise frequency improves cancer-related biomarkers, such as carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), red blood cell (RBC), and white blood cell (WBC), and the body composition of elderly women. Fifty-four females, aged 70 to 77 years, were divided into 4 groups: control, 1-day exercise (1E), 2-3-day exercise (2-3E), and 5-day exercise (5E) groups. The control group did not participate in any physical activity, while the subjects in the exercise groups underwent the exercise program for 12 weeks. As results, CEA was significantly decreased in the exercise groups, with the lowest values in 2-3E group. In contrast, AFP, RBC and WBC were not significantly changed. CEA is an oncofetal glycoprotein that is overexpressed in adenocarcinomas. Although the function of CEA has not been fully understood, CEA has been suggested to be involved in the release of pro-inflammatory cytokines via stimulating monocytes and macrophages. Moreover, body weight and body mass index were improved in the exercise groups, with the lowest levels in 5E group. Thus, we suggest that exercise for 2-3 days per week decreases the expression of CEA and improves body condition, without loading fatigue or stress, which may contribute to preventing cancer in the elderly women.

The effect of a complex training program on skating abilities in ice hockey players.

[Purpose] Little data exist on systemic training programs to improve skating abilities in ice hockey players. The purpose of this study was to evaluate the effectiveness of a complex training program on skating abilities in ice hockey players. [Methods] Ten male ice hockey players (training group) that engaged in 12 weeks of complex training and skating training and ten male players (control group) that only participated in 12 weeks of skating training completed on-ice skating tests including a 5 time 18 meters shuttle, t-test, Rink dash 5 times, and line drill before, during, and the training. [Results] Significant group-by-time interactions were found in all skating ability tests. [Conclusion] The complex training program intervention for 12 weeks improved their skating abilities of the ice hockey players.

Target tracking and classification from labeled and unlabeled data in wireless sensor networks.

Tracking the locations and identities of moving targets in the surveillance area of wireless sensor networks is studied. In order to not rely on high-cost sensors that have been used in previous researches, we propose the integrated localization and classification based on semi-supervised learning, which uses both labeled and unlabeled data obtained from low-cost distributed sensor network. In our setting, labeled data are obtained by seismic and PIR sensors that contain information about the types of the targets. Unlabeled data are generated from the RF signal strength by applying Gaussian process, which represents the probability of predicted target locations. Finally, by using classified unlabeled data produced by semi-supervised learning, identities and locations of multiple targets are estimated. In addition, we consider a case when the labeled data are absent, which can happen due to fault or lack of the deployed sensor nodes and communication failure. We overcome this situation by defining artificial labeled data utilizing characteristics of support vector machine, which provides information on the importance of each training data point. Experimental results demonstrate the accuracy of the proposed tracking algorithm and its robustness to the absence of the labeled data thanks to the artificial labeled data.

Target Localization Using Ensemble Support Vector Regression in Wireless Sensor Networks.

Target localization, whose goal is to estimate the location of an unknown target, is one of the key issues in applications of wireless sensor networks (WSNs). With recent advances in fabrication technology, deployments of large-scale WSNs have become economically feasible. However, there exist issues such as limited communication and the curse of dimensionality in applying machine-learning algorithms such as support vector regression (SVR) on large-scale WSNs. Here, in order to overcome such issues, we propose an ensemble implementation of SVR for the problem of target localization. The convergence property of the localization algorithm using the ensemble SVR is verified, and the robustness of the proposed scheme against measurement noise is analyzed. Furthermore, experimental results confirm that the estimation performance of the proposed method is more accurate and robust to measurement noise than the conventional SVR predictor.

The influence of maternal treadmill running during pregnancy on short-term memory and hippocampal cell survival in rat pups.

Maternal exercise during pregnancy has been suggested to exert the beneficial effects on the brain functions of offspring. In the present study, we attempted to determine the effects of maternal treadmill running during pregnancy on short-term memory ability, hippocampal cell survival, and the expression of brain-derived neurotrophic factor (BDNF) mRNA in rat pups. After confirming pregnancy, the pregnant rats were divided into two groups: the control group and the running group (n = 6 in each group). Beginning on the 15th day of pregnancy, the pregnant rats in the running group were forced to run on a treadmill for 30 min at a mild-intensity, once a day until delivery. After all the pregnant rats had given birth, there were rat pups available for use in this study in each group (n = 15 in each group). The latency of the step-down avoidance task was used in order to evaluate the short-term memory ability of the rat pups on the 28 days after birth. Immunohistochemistry for 5-bromo-2'-deoxyuridine (BrdU) and reverse transcription-polymerase chain reaction (RT-PCR) for BDNF mRNA were performed to determine hippocampal neurogenesis and hippocampal BDNF mRNA expression of the rat pups on the 29 days after birth, respectively. Our results revealed that maternal running during pregnancy resulted in significant increase in the expression of BDNF mRNA, enhanced hippocampal cell survival, and improved the short-term memory capability of rat pups, as compared to those measured in the control group. The findings of our study provide evidence that maternal running during gestational period may enhance the brain functions of offspring.