• Journal of Sensor Science and Technology
• /
• v.16 no.5
• /
• pp.361-368
• /
• 2007

Small size real-time ECG signal analysis function by QRS-complex detection was put into sensor nodes. Wireless sensor nodes attached on the patient’s body transmit ECG data continuously in normal u-healthcare system. So there are heavy communication traffics between sensor nodes and gateways. New developed platform for real-time analysis of ECG signals on sensor node can be used as an advanced diagnosis and alarming system for healthcare. Sensor node does not need to transmit ECG data all the time in wireless sensor network and to server PC via gateway. When sensor node detects suspicion or abnormality in ECG, then the ECG data in the network was transmitted to the server PC for further powerful analysis. This system can reduce data packet overload and save some power in wireless sensor network. It can also increase the server performance.

• Journal of Digital Contents Society
• /
• v.10 no.3
• /
• pp.395-400
• /
• 2009

The wide spread of the Internet service has brought in web GIS development. But, there are problems of the user access latencies, the network traffic, and the server overload in Internet Geographic Information System because spatial data are transferred in large volumes. In this paper, I propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.

• ETRI Journal
• /
• v.28 no.3
• /
• pp.282-290
• /
• 2006

In vertically overlaid cellular systems, a temporary traffic concentration can occur in a hot-spot area, and this adversely affects overall system capacity. In this paper, we develop an adaptive hot-spot operating scheme (AHOS) to mitigate the negative effects from the nonuniform distribution of user location and the variation in the mixture of QoS requirements in orthogonal frequency division multiple access downlink systems. Here, the base station in a macrocell can control the operation of picocells within the cell, and turns them on or off according to the system overload estimation function. In order to determine whether the set of picocells is turned on or off, we define an AHOS gain index that describes the number of subcarriers saved to the macrocell by turning a specific picocell on. For initiating the picocell OFF procedure, we utilize the changes in traffic concentration and co-channel interference to the neighboring cells. According to computer simulation, the AHOS has been proved to have maximize system throughput while maintaining a very low QoS outage probability under various system scenarios in both a single-cell and multi-cell environments.

• The KIPS Transactions:PartD
• /
• v.8D no.6
• /
• pp.637-644
• /
• 2001

EJB, providing specification for development and deployment of component based application, permits distributed development as central element of J2EE environment that manages automatically transaction management, persistence, concurrency control that are the most complicated work in enterprise environment. In this paper, we wish to resolve DAO's transaction logic complexity and performance reduction of system in the EJB based legacy system. Therefore, this paper describes the design and implementation of IDAO that applies Iterator pattern. IDAO gets effect that reduces complexity of transaction logic, system overload by database connection, and reduction of performance through container managed transaction.

• The KIPS Transactions:PartB
• /
• v.12B no.2 s.98
• /
• pp.167-172
• /
• 2005

A rapid growth in the number of Internet users and in massive media contents tends to cause server overload and high network traffic. As a consequence, it can be safely assumed that the quality of service is on the brink of deterioration. A solution of this problem is the development of the Content Distribution Network. Therefore, in this paper, we propose a transmission model using CDN. This model uses regional media server which closes to client, and uses MDC coding and multi-channel to reduce packet loss and delay. In conclusion, this study improved performance of multimedia service by reducing packet loss and delay.

• The KIPS Transactions:PartD
• /
• v.15D no.5
• /
• pp.699-704
• /
• 2008

By the dependence on Web from popularization of internet and increasing number of users, web services capability and security problem of communication is becoming a great issue. Existing web services technology decrease the capability of web application server by limiting the number of synchronous client, decreasing the processing load and increasing average response time. The encryption process to secure communication and the early expense of handshake decrease transmission speed and server capability by increasing the calculation time for connecting. Accordingly, this paper executes an encryption procedure by elliptical encryption algorithm to satisfy secure demands, improve the overload of server for web services and get reliability and security of web server architecture and proposes an improved mobile web sever which provides better ability and the techniques for deferred processing.

• Safety and Health at Work
• /
• v.13 no.3
• /
• pp.350-356
• /
• 2022

Background: Although sick leave is a complex phenomenon, it is believed that there is potential for prevention at the workplace. However, little is known about this potential and what specific measures should be implemented. The purpose of the study was to identify perceived reasons to take work-related sick leave and to suggest preventive measures. The study was completed before the COVID-19 pandemic emerged, and the risk factors identified may have been amplified during the pandemic. Methods: An in-depth cross-sectional survey was conducted across a randomly selected sample of hospital nurses in Norway. The national sample comprised 1,297 nurses who participated in a survey about their sick leave during the previous 6 months. An open-ended question about perceived reasons for work-related sick leave was included to gather qualitative information. Results: Among hospital nurses, 27% of the last occurring sick leave incidents were perceived to be work-related. The most common reasons were high physical workload, high work pace, sleep problems, catching a viral or bacterial infection from patients or colleagues, and low staffing. Conclusions: Over a quarter of the last occurring sick leave incidents among Norwegian hospital nurses are potentially preventable. To retain and optimize scarce hospital nursing resources, strategies to reduce work-related sick leave may provide human and financial benefits. Preventive measures may include careful monitoring of nurses' workload and pace, optimizing work schedules to reduce the risk of sleep problems, and increasing staffing to prevent stress and work overload.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.5
• /
• pp.98-107
• /
• 1995

The in-process detection of drill wear and breakage is one of the most importnat technical problems in unmaned machining system. In this paper, the monitoring system is developed to monitor abnormal drilling states such as drill breakage, drill wear and unstable cutting using motor current. Drill breakage is detected by level monitoring. Tool wear is classified by fuzzy pattern recognition. The key feature for classification of tool wear is the estimated flank wear which is calculated by the proposed flank wear model. The characteristic of the model is not sensitive to the variation of cutting conditions but is sensitive to drill wear state. Unstable cutting states due to the unsmooth chip disposal and the overload are monitored by the variance/mean ratio of spindle motor current. Variance/mean ratio also includes the information about the prediction of drill wear and drill breakage. The evaluation experiments have shown that the developed system works very well.

• Journal of the Korea Safety Management & Science
• /
• v.26 no.1
• /
• pp.1-8
• /
• 2024

This study explores the impact of technostress on the intention to use telemedicine applications (apps) in the post-COVID19 era, a period marked by the rapid popularization of such apps to mitigate COVID19 infection risks. Utilizing the Technology Acceptance Model (TAM), the study identifies variables and proposes a research model. A questionnaire survey involving 364 adults is analyzed through Partial Least Squares-Structural Equation Modeling. Results indicate positive significance for variables linked to the TAM (perceived usefulness, perceived ease of use, attitude, and intention to use). Notably, techno-complexity negatively affects perceived ease of use, while techno-unreliability negatively impacts perceived usefulness and ease of use. Surprisingly, techno-uncertainty has a positive effect on both perceived usefulness and ease of use. Techno-overload, although negatively impacting perceived usefulness and ease of use, does not reach statistical significance. The study underscores the need to consider both positive and negative aspects, including technostress, when evaluating telemedicine app usage. Additionally, recognizing the varying impact of technostress based on users' ICT(Information and Communication Technology) confidence levels is crucial. Overall, these findings contribute academically to telemedicine app adoption literature and hold industrial significance by providing a user perspective on these apps.

• International Journal of Internet, Broadcasting and Communication
• /
• v.9 no.2
• /
• pp.64-69
• /
• 2017

The abstract should summarize the contents of the paper and written below the author information. Use th In Wide-area Wireless Sensor Networks, network lifetime is short due to energy consumption due to transmission distance. To improve this, we divide the sensor field into layers and reduce transmission distance through multi-hop transmission. However, there is a problem in that the transmission rate drops because there is no Cluster Head in the layer, or the transmission distance increases due to the layer, and energy is wasted. There are DL-LEACH and EDL-LEACH as Protocols to improve this. DL-LEACH uses either single-hop transmission or multi-hop transmission depending on the situation. As a result, the transmission distance is optimized, thereby reducing energy consumption. In case of EDL-LEACH, it is proposed to improve the data rate in DL-LEACH. It is the same as DL-LEACH, but the Cluster Head is mandatory for all layers to improve the transmission rate. Although there is no Cluster Head for each layer, the transmission rate is improved, but the network life is shortened. In this paper, we try to improve the network lifetime while maintaining the EDL-LEACH transmission rate. The shortened network lifetime is due to Cluster Head overload near the base station. To improve this, the Cluster Head distribution method is improved and the network lifetime is improved.