• Journal of Korean Academy of Nursing Administration
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• v.19 no.2
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• pp.315-327
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• 2013

Purpose: The purpose of this study was to investigate the patient safety culture in Korean nursing homes using the Nursing Home Survey Patient Safety Culture (NHS-PC), a valid tool, provided by the Agency for Healthcare Research and Quality (AHRQ) and to compare the results with AHRQ data. Methods: Administrators and staff (N=151) of six nursing homes in Seoul, Busan, Kyeonggi Province and Gyeongsangnam Province completed the survey in July, 2010. The data were analyzed using descriptive statistics, positive response rate, t-test, ANOVA, DUNCAN, Cronbach's ${\alpha}$. Results: The total mean (SD) positive response rate for patient safety culture was not significantly different from the AHRQ data. For composite levels, the results of 'handoffs' were significantly higher, and the results of 'feedback and communication about incidents' and 'nonpunitive responses to mistakes' were significantly lower than the AHRQ data. Conclusion: More effective strategies related to nonpunitive responses to mistakes and management activities for patient safety are needed to improve patient safety culture in nursing homes.

• Journal of information and communication convergence engineering
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• v.6 no.1
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• pp.19-23
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• 2008

The AQM (Active Queue Management) starts dropping packets earlier to notify traffic sources about the incipient stage of congestion. The AQM improves fairness between response flow (like TCP) and non-response flow (like UDP), and it can provide high throughput and link efficiency. In this paper, we suggest the QVARED (Queue Variation Adaptive RED) algorithm to respond to bursty traffic more actively. It is possible to provide more smoothness of average queue length and the maximum packet drop probability compared to RED and ARED (Adaptive RED). Therefore, it is highly adaptable to new congestion condition. Our simulation results show that the drop rate of QVARED is decreased by 80% and 40% compare to those of RED and ARED, respectively. This results in shorter end-to-end delay by decreasing the number of retransmitted packets. Also, the QVARED reduces a bias effect over 18% than that of drop-tail method; therefore packets are transmitted stably in the bursty traffic condition.

• Journal of Information Processing Systems
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• v.19 no.6
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• pp.817-829
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• 2023

Variable wireless channel is a big challenge for real-time video applications, and the rate adaptation of realtime video streaming becomes a hot topic. Intra-video coding is important for high-quality video communication and industrial video applications. In this paper, we proposed a novel adaptive scheme for real-time video transmission with intra-only coding over a wireless network. The key idea of this scheme is to estimate the instantaneous remaining capacity of the network to adjust the quality of the next several video frames, which not only can keep low queuing delay and ensure video quality, but also can respond to bandwidth changes quickly. We compare our scheme with three different schemes in the video transmission system. The experimental results show that our scheme has higher bandwidth utilization and faster bandwidth change response, while maintaining low queuing delay.

• Journal of Sensor Science and Technology
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• v.25 no.2
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• pp.131-137
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• 2016

In this study, a multilevel visible light communication (VLC) system based on resistor ladder circuit is designed to transmit medical data. VLC technology is being considered as an alternative wireless communication due to various advantages such as ubiquity, license free operation, low energy consumption, and no radio frequency (RF) radiation characteristics. With VLC even in places where traditional RF communication (e.g., Wi-Fi) is forbidden, significant bio-medical signal including the electrocardiography (ECG) and photoplethysmography (PPG) data can be transmitted. More lives could be saved anywhere by this potential advantage of VLC with a fast emergency response time. A multilevel transmission scheme is adopted to improve the data capacity with keeping simplicity, where data transmission rate can increase by log2m times (m is the number of voltage levels) than that of conventional VLC transmission based on on/off keying. In order to generate multi-amplitudes, resistor ladder circuit, which is a basic principle of digital to analog convertor, is employed, and information is transferred through LED (Light-Emitting Diode) with different voltage level. In the receiver side, multilevel signal is detected by optical receiver including a photo diode. Then, the collected data are analyzed to serve the necessary medical care to the concerned patient.

• Proceedings of the IEEK Conference
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• summer
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• pp.199-203
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• 2004

In this paper, we only describe the digital block of two-channel 18-bit analog-to-digital (A/D) converter employing sigma-delta method and xl28 decimation. The device contains two fourth comb filters with 1-bit input from sigma­delta modulator. each followed by a digital half band FIR(Finite Impulse Response) filters. The external analog sigma-delta modulators are sampled at 6.144MHz and the digital words are output at 48kHz. The fourth-order comb filter has designed 3 types of ways for optimal power consumption and signal-to-noise ratio. The following 3 digital filters are designed with 12tap, 22tap and 116tap to meet the specification. These filters eliminate images of the base band audio signal that exist at multiples of the input sample rate. We also designed these filters with 8bit and 16bit filter coefficient to analysis signal-to-noise ratio and hardware complexity. It also included digital output interface block for I2S serial data protocol, test circuit and internal input vector generator. It is fabricated with 0.35um HYNIX standard CMOS cell library with 3.3V supply voltage and the chip size is 2000um by 2000um. The function and the performance have been verified using Verilog XL logic simulator and Matlab tool.

• Korean Security Journal
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• no.6
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• pp.147-165
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• 2003

Since Electronic Security System is introduced in Korea in 1981 by foreign technology, Security market has been increasing considerably during short period, and It performs it's security roles well in place of security guards. As electronic and communication technology is highly developed, Electronic Security System and security market structure is changing naturally. Especially high-tech mobile communication technology will change the method of Electronic Security business. Also the pattens of residence and life style, such as the trend toward nuclear family and single life could effect security market. In recent year, new business models that apply the mobile phone and internet is appeared. Although Electronic Security System is changed by the changes of technology, It is very difficult to change the basic elements, such as sensing, alarm signal transfering, and response. The rate of increase of Electronic Security market is expected to matain it's increase pace for the time being. But the development of new system for new protectes such as childeren, old person, vehicle rather than immovable facility is necessary to prepare for the continuous competition.

• ETRI Journal
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• v.33 no.6
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• pp.985-988
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• 2011

A novel application of a dual-transmission line is proposed to design a lowpass filter (LPF). The proposed structure uses only transmission line elements to produce an equiripple LPF response with sharp roll-off. Design equations are derived using a lossless transmission line model. Controlling the electrical lengths, three transmission-zeros are realized in the stopband to obtain a sharp roll-off rate and wide stopband bandwidth. A single unit microstrip LPF with a 3-dB cut-off frequency at 1.0 GHz having a roll-off of 135 dB/GHz along with a stopband bandwidth of 69.5% is designed for validation.

• Journal of information and communication convergence engineering
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• v.11 no.3
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• pp.173-178
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• 2013

To discover objects of interest in unstructured peer-to-peer networks, the peers rely on flooding query messages which create incredible network traffic. This article evaluates the performance of an unstructured Gnutella-like protocol over mobile ad-hoc networks and proposes modifications to improve its performance. This paper offers an enhanced mechanism for an unstructured Gnutella-like network with improved peer features to better meet the mobility requirement of ad-hoc networks. The proposed system introduces a novel caching optimization technique and enhanced ultrapeer selection scheme to make communication more efficient between peers and ultrapeers. The paper also describes an enhanced query mechanism for efficient searching by applying multiple walker random walks with a jump and replication technique. According to the simulation results, the proposed system yields better performance than Gnutella, XL-Gnutella, and random walk in terms of the query success rate, query response time, network load, and overhead.

• Journal of information and communication convergence engineering
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• v.7 no.1
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• pp.7-12
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• 2009

The advanced computer network and Internet technology enables connectivity of computers through an open network environment. Despite the growing numbers of security threats to networks, most intrusion detection identifies security attacks mainly by detecting misuse using a set of rules based on past hacking patterns. This pattern matching has a high rate of false positives and can not detect new hacking patterns, making it vulnerable to previously unidentified attack patterns and variations in attack and increasing false negatives. Intrusion detection and prevention technologies are thus required. We proposed a network based hybrid Probe Intrusion Detection model using Fuzzy cognitive maps (PIDuF) that detects intrusion by DoS (DDoS and PDoS) attack detection using packet analysis. A DoS attack typically appears as a probe and SYN flooding attack. SYN flooding using FCM model captures and analyzes packet information to detect SYN flooding attacks. Using the result of decision module analysis, which used FCM, the decision module measures the degree of danger of the DoS and trains the response module to deal with attacks. For the performance evaluation, the "IDS Evaluation Data Set" created by MIT was used. From the simulation we obtained the max-average true positive rate of 97.064% and the max-average false negative rate of 2.936%. The true positive error rate of the PIDuF is similar to that of Bernhard's true positive error rate.

• The Journal of the Acoustical Society of Korea
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• v.32 no.2
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• pp.124-130
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• 2013

The performance of underwater acoustic communication system is sensitive to the ISI(Inter-Symbol Interference) due to delay spread develop of multipath signal propagation. The equalizer is used to combat the ISI. In this paper, the performances of underwater acoustic communication with turbo equalizer were evaluated by real data collected in Korean littoral sea. As a result, when one iterative decoding using turbo equalizer is applied, the performance was improved 1.5 dB than the case of the non-iterative equalizer at BER $10^{-4}$. In the case of two or three iterations the performance was enhanced about 3.5 dB, but the performance wasn't improved any more in the case of more than three times.